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Sample records for mis vib kujuneda

  1. Radicicol-Mediated Inhibition of Topoisomerase VIB-VIA Activity of the Human Malaria Parasite Plasmodium falciparum

    PubMed Central

    Chalapareddy, Sureshkumar; Chakrabarty, Swati; Bhattacharyya, Mrinal Kanti

    2016-01-01

    ABSTRACT Plasmodium falciparum topoisomerase VIB (TopoVIB)-TopoVIA (TopoVIB-VIA) complex can be potentially exploited as a drug target against malaria due to its absence from the human genome. Previous work in our laboratory has suggested that P. falciparum TopoVIB (PfTopoVIB) might be a target of radicicol since treatment of parasite cultures with this antibiotic is associated with upregulation of Plasmodium TopoVIB at the transcript level as well as at the protein level. Further studies demonstrated that radicicol treatment impaired mitochondrial replication of human malaria parasite P. falciparum. However, the technical challenge associated with the expression of the above protein complex hampered its functional characterization. Using Saccharomyces cerevisiae as a heterologous system, we expressed PfTopoVIB (Myc-tagged) and PfTopoVIA (Flag-tagged) (PfTopoVIB-VIA) proteins. Yeast two-hybrid analysis showed the formation of PfTopoVIB homodimers and PfTopoVIB/PfTopoVIA heteromers. Our study demonstrated that PfTopoVIB and PfTopoVIA together can rescue the lethal phenotype of yeast ΔtopoII mutants, whereas Plasmodium topoisomerase VIB alone cannot. Using yeast cell-free extracts harboring the PfTopoVIB-VIA protein complex, we have performed a decatenation assay and observed that PfTopoVIB-VIA can decatenate DNA in an ATP- and Mg2+-dependent manner. The specificity of this enzyme is established by abrogation of its activity in the presence of PfTopoVIB-specific antibody. Our study results show that radicicol and etoposide can specifically inhibit PfTopoVIB-VIA decatenation activity whereas the gyrase inhibitor novobiocin cannot. Such a yeast-based assay system can be employed in screening specific inhibitors against Plasmodium VIB-VIA. IMPORTANCE In this study we characterize topoisomerase VI from Plasmodium falciparum using genetic and biochemical approaches. We use various inhibitors and identify radicicol as a specific inhibitor of its decatenation activity. We

  2. Photoelectric MIS devices

    NASA Astrophysics Data System (ADS)

    Zuev, V. A.; Popov, V. G.

    The physical principles underlying the operation of MIS photoreceivers are examined, and the main characteristics of MIS structures are briefly discussed. Various types of MIS phototransducers are then discussed in detail. These include photoresistors, photodiodes, photovaractors, and phototransistors. Attention is also given to phototransducers and photoreceivers based on metal-silicon nitride-silicon oxide-semiconductor structures and related systems used for data recording. The prospects for the use of MIS devices in optoelectronic and photovoltaic applications are outlined.

  3. Life Sciences MIS

    NASA Technical Reports Server (NTRS)

    Dittman, R. A.; Marks, V.

    1983-01-01

    Management Information System, MIS, provides Life Sciences Projects Division at Johnson Space Center with automated system for project managment. MIS utilizes Tektronix 4027 color graphics display terminal and form-fillout capability. User interface with MIS data base is through series of forms.

  4. Expression and secretion of functional recombinant μO-conotoxin MrVIB-His-tag in Escherichia coli.

    PubMed

    Gao, Bingmiao; Zhangsun, Dongting; Hu, Yuanyan; Wu, Yong; Sheng, Lizi; Fang, Licong; Wu, Xiaosa; Yu, Jinpeng; Luo, Sulan

    2013-09-01

    μO-conotoxin MrVIB is a 31-amino acid peptide containing three disulfide bonds isolated from the venom of Conus marmoreus, which is a selective antagonist of voltage-gated sodium channel (VGSC) Nav1.8 and has a long-lasting analgesic activity. Drug development of MrVIB has long been hindered over 15 years by difficult chemical synthesis and oxidative folding. Herein we describe a different approach based on the recombinant expression of gene MrVIB in Escherichia coli. A secretion vector pET22b(+)-MrVIB fused with pelB leader signal peptide and His-tag was constructed, which was transformed into BL21 (DE3) strain of E. coli. The recombinant conotoxin MrVIB-His-tag (rMrVIB-His) was successfully expressed and secreted into the periplasmic space of BL21 (DE3) cells. The pelB leader signal peptide was properly cleaved and three disulfide bonds were also formed properly to yield biological active rMrVIB-His. Folded rMrVIB-His in the periplasmic fraction was isolated with a Ni-NTA affinity column, which was further purified using reverse-phase high-performance liquid chromatography (RP-HPLC) and identified by liquid chromatography/mass spectrometry-ion trap-time of flight mass spectrometry (LC/MS-IT-TOF). Biological activity assay of rMrVIB-His showed it had good analgesic effects in three pain models. PMID:23811388

  5. Declining MIS Enrollment: The Death of the MIS Degree?

    ERIC Educational Resources Information Center

    Saunders, Gary; Lockridge, T. Maurice

    2011-01-01

    There is little doubt that enrollments in MIS degree programs have been declining since the recession in the technical industry in 2001. Reagan's research (2008) indicates that enrollments in MIS degree programs is only about 25% of the 2001 level. Many MIS (IS) programs have been abandoned or combined with other related programs. While many…

  6. ALPHA MIS: Reference manual

    SciTech Connect

    Lovin, J.K.; Haese, R.L.; Heatherly, R.D.; Hughes, S.E.; Ishee, J.S.; Pratt, S.M.; Smith, D.W.

    1992-02-01

    ALPHA is a powerful and versatile management information system (MIS) initiated and sponsored and by the Finance and Business Management Division of Oak Ridge National Laboratory, who maintain and develop it in concert with the Business Systems Division for its Information Center. A general-purpose MIS, ALPHA allows users to access System 1022 and System 1032 databases to obtain and manage information. From a personal computer or a data terminal, Energy Systems employees can use ALPHA to control their own report reprocessing. Using four general commands (Database, Select, Sort, and Report) they can (1) choose a mainframe database, (2) define subsets within it, (3) sequentially order a subset by one or more variables, and (4) generate a report with their own or a canned format.

  7. Photocapacitive MIS infrared detectors

    NASA Technical Reports Server (NTRS)

    Sher, A.; Lu, S. S.-M.; Moriarty, J. A.; Crouch, R. K.; Miller, W. E.

    1978-01-01

    A new class of room-temperature infrared detectors has been developed through use of metal-insulator-semiconductor (MIS) or metal-insulator-semiconductor-insulator-metal (MISIM) slabs. The detectors, which have been fabricated from Si, Ge and GaAs, rely for operation on the electrical capacitance variations induced by modulated incident radiation. The peak detectivity for a 1000-A Si MISIM detector is comparable to that of a conventional Si detector functioning in the photovoltaic mode. Optimization of the photocapacitive-mode detection sensitivity is discussed.

  8. Re-evaluation of the 1962 Mark VI-B dynamic tests regarding reactivity coefficients

    SciTech Connect

    Burnett, T.

    1991-06-01

    The 1962 Mark VI-B rod tests have been re-evaluated. A significantly lower (more negative) coolant coefficient is now ascribed to that test, {minus}1 pcm/Deg-C vs the previously reported +2 pcm/Deg-C. The change from the previous value is because of revisions to delayed neutron constants and accounting for spatial effects. The new value is in reasonable agreement with the currently calculated value of {minus}2 pcm/Deg-C, considering measurement and calculational uncertainties. Therefore, the authors conclude that the current analytic models for physics and transient analysis methodology (GLASS, GRIMHX & TRIMHX, AND MARY) are fully consistent with 1962 test observations, and that there is no basis for assigning a calculational bias or increasing uncertainty allowances.

  9. The MIS Pipeline Toolkit

    NASA Astrophysics Data System (ADS)

    Teuben, Peter J.; Pound, M. W.; Storm, S.; Mundy, L. G.; Salter, D. M.; Lee, K.; Kwon, W.; Fernandez Lopez, M.; Plunkett, A.

    2013-01-01

    A pipeline toolkit was developed to help organizing, reducing and analyzing a large number of near-identical datasets. This is a very general problem, for which many different solutions have been implemented. In this poster we present one such solution that lends itself to users of the Unix command line, using the Unix "make" utility, and adapts itself easily to observational as well as theoretical projects. Two examples are given, one from the CARMA CLASSy survey, and another from a simulated kinematic survey of early galaxy forming disks. The CLASSy survey (discussed in more detail in three accompanying posters) consists of 5 different star forming regions, observed with CARMA, each containing roughly 10-20 datasets in continuum and 3 different molecular lines, that need to be combined in final data cubes and maps. The strength of such a pipeline toolkit shows itself as new data are accumulated, the data reduction steps are improved and easily re-applied to previously taken data. For this we employed a master script that was run nightly, and collaborators submitted improved script and/or pipeline parameters that control these scripts. MIS is freely available for download.

  10. Carbide-forming groups IVB-VIB metals: a new territory in the periodic table for CVD growth of graphene.

    PubMed

    Zou, Zhiyu; Fu, Lei; Song, Xiuju; Zhang, Yanfeng; Liu, Zhongfan

    2014-07-01

    Early transition metals, especially groups IVB-VIB metals, can form stable carbides, which are known to exhibit excellent "noble-metal-like" catalytic activities. We demonstrate herein the applications of groups IVB-VIB metals in graphene growth using atmospheric pressure chemical vapor deposition technique. Similar to the extensively studied Cu, Ni, and noble metals, these transition-metal foils facilitate the catalytic growth of single- to few-layer graphene. The most attractive advantage over the existing catalysts is their perfect control of layer thickness and uniformity with highly flexible experimental conditions by in situ converting the dissolved carbons into stable carbides to fully suppress the upward segregation/precipitation effect. The growth performance of graphene on these transition metals can be well explained by the periodic physicochemical properties of elements. Our work has disclosed a new territory of catalysts in the periodic table for graphene growth and is expected to trigger more interest in graphene research. PMID:24873697

  11. Probing Intra- versus Interchain Kinetic Preferences of L-Thr Acylation on Dimeric VibF with Mass Spectrometry

    PubMed Central

    Hicks, Leslie M.; Balibar, Carl J.; Walsh, Christopher T.; Kelleher, Neil L.; Hillson, Nathan J.

    2006-01-01

    We present a method to probe intra- and interchain activities within dimeric nonribosomal peptide synthetases. Utilizing domain inactivation and analytical mass mutants in conjunction with rapid-quench, mass spectrometry, and a probabilistic kinetic model, we have elucidated the pre-steady-state intra- and interchain rates and the corresponding flux of the acylation of L-Thr onto VibF. Although the intra rate is significantly faster than the inter rate, the data are most consistent with an even flux of covalent substrate loading where neither pathway dominates. These pre-steady-state results confirm previous steady-state in vitro mutant complementation studies of VibF. Extension of this methodology to other dimeric nonribosomal peptide synthetases, and to the related fatty acid and polyketide synthases, will further our biophysical understanding of their acyl-intermediate-processing pathways. PMID:16815901

  12. The TopoVIB-Like protein family is required for meiotic DNA double-strand break formation.

    PubMed

    Robert, T; Nore, A; Brun, C; Maffre, C; Crimi, B; Bourbon, H-M; de Massy, B

    2016-02-26

    Meiotic recombination is induced by the formation of DNA double-strand breaks (DSBs) catalyzed by SPO11, the ortholog of subunit A of TopoVI DNA topoisomerase (TopoVIA). TopoVI activity requires the interaction between A and B subunits. We identified a conserved family of plant and animal proteins [the TOPOVIB-Like (TOPOVIBL) family] that share strong structural similarity to the TopoVIB subunit of TopoVI DNA topoisomerase. We further characterize the meiotic recombination proteins Rec102 (Saccharomyces cerevisiae), Rec6 (Schizosaccharomyces pombe), and MEI-P22 (Drosophila melanogaster) as homologs to the transducer domain of TopoVIB. We demonstrate that the mouse TOPOVIBL protein interacts and forms a complex with SPO11 and is required for meiotic DSB formation. We conclude that meiotic DSBs are catalyzed by a complex involving SPO11 and TOPOVIBL. PMID:26917764

  13. Three-band tight-binding model for monolayers of group-VIB transition metal dichalcogenides

    SciTech Connect

    Liu, G. B.; Shan, Wen-Yu; Yao, Yugui; Yao, Wang; Xiao, Di

    2013-01-01

    We present a three-band tight-binding (TB) model for describing the low-energy physics in monolayers of group-VIB transition metal dichalcogenides MX2 (M = Mo, W; X = S, Se, Te). As the conduction- and valence-band edges are predominantly contributed by the dz2 , dxy, and dx2 y2 orbitals of M atoms, the TB model is constructed using these three orbitals based on the symmetries of the monolayers. Parameters of the TB model are fitted from the first-principles energy bands for all MX2 monolayers. The TB model involving only the nearest-neighbor M-M hoppings is sufficient to capture the band-edge properties in the K valleys, including the energy dispersions as well as the Berry curvatures. The TB model involving up to the third-nearest-neighbor M-M hoppings can well reproduce the energy bands in the entire Brillouin zone. Spin-orbit coupling in valence bands is well accounted for by including the on-site spin-orbit interactions ofM atoms. The conduction band also exhibits a small valley-dependent spin splitting which has an overall sign difference between MoX2 and WX2. We discuss the origins of these corrections to the three-band model. The three-band TB model developed here is efficient to account for low-energy physics in MX2 monolayers, and its simplicity can be particularly useful in the study of many-body physics and physics of edge states.

  14. [Project PEACH: A Prescriptive Educational Approach for Children with Handicaps. E.S.E.A. - Title VI-B. 1976-1977, and Appendix]. Report #77154.

    ERIC Educational Resources Information Center

    Scheiner, Louis

    The School District of Philadelphia, through its Prescriptive Educational Approach to Children with Handicaps (PEACH) Project, funded under E.S.E.A. Title VI-B, provided diagnostic, referral, and prescriptive educational services for preschool children (between 3 and 4.7 years). Priority was given to those children most severely handicapped and…

  15. MIS silicon solar cells: potential advantages

    SciTech Connect

    Cheek, G.; Mertens, R.

    1981-05-01

    Recent progress with silicon solar cells based on the MIS or SIS structure is reviewed. To be competitive with pn junction technology in the near term, these cells must be much cheaper or have a higher efficiency in a production environment. Apparently, the minority carrier MIS cells have the greatest potential for large-scale applications. The data currently indicate that all types of MIS/SIS cells have some inherent instability problems.

  16. VibA, a Homologue of a Transcription Factor for Fungal Heterokaryon Incompatibility, Is Involved in Antifungal Compound Production in the Plant-Symbiotic Fungus Epichloë festucae

    PubMed Central

    Niones, Jennifer T.

    2014-01-01

    Symbiotic association of epichloae endophytes (Epichloë/Neotyphodium species) with cool-season grasses of the subfamily Pooideae confers bioprotective benefits to the host plants against abiotic and biotic stresses. While the production of fungal bioprotective metabolites is a well-studied mechanism of host protection from insect herbivory, little is known about the antibiosis mechanism against grass pathogens by the mutualistic endophyte. In this study, an Epichloë festucae mutant defective in antimicrobial substance production was isolated by a mutagenesis approach. In an isolated mutant that had lost antifungal activity, the exogenous DNA fragment was integrated into the promoter region of the vibA gene, encoding a homologue of the transcription factor VIB-1. VIB-1 in Neurospora crassa is a regulator of genes essential in vegetative incompatibility and promotion of cell death. Here we show that deletion of the vibA gene severely affected the antifungal activity of the mutant against the test pathogen Drechslera erythrospila. Further analyses showed that overexpressing vibA enhanced the antifungal activity of the wild-type isolate against test pathogens. Transformants overexpressing vibA showed an inhibitory activity on test pathogens that the wild-type isolate could not. Moreover, overexpressing vibA in a nonantifungal E. festucae wild-type Fl1 isolate enabled the transformant to inhibit the mycelial and spore germination of D. erythrospila. These results demonstrate that enhanced expression of vibA is sufficient for a nonantifungal isolate to obtain antifungal activity, implicating the critical role of VibA in antifungal compound production by epichloae endophytes. PMID:24906411

  17. Schizosaccharomyces pombe centromere protein Mis19 links Mis16 and Mis18 to recruit CENP-A through interacting with NMD factors and the SWI/SNF complex.

    PubMed

    Hayashi, Takeshi; Ebe, Masahiro; Nagao, Koji; Kokubu, Aya; Sajiki, Kenichi; Yanagida, Mitsuhiro

    2014-07-01

    CENP-A is a centromere-specific variant of histone H3 that is required for accurate chromosome segregation. The fission yeast Schizosaccharomyces pombe and mammalian Mis16 and Mis18 form a complex essential for CENP-A recruitment to centromeres. It is unclear, however, how the Mis16-Mis18 complex achieves this function. Here, we identified, by mass spectrometry, novel fission yeast centromere proteins Mis19 and Mis20 that directly interact with Mis16 and Mis18. Like Mis18, Mis19 and Mis20 are localized at the centromeres during interphase, but not in mitosis. Inactivation of Mis19 in a newly isolated temperature-sensitive mutant resulted in CENP-A delocalization and massive chromosome missegregation, whereas Mis20 was dispensable for proper chromosome segregation. Mis19 might be a bridge component for Mis16 and Mis18. We isolated extragenic suppressor mutants for temperature-sensitive mis18 and mis19 mutants and used whole-genome sequencing to determine the mutated sites. We identified two groups of loss-of-function suppressor mutations in non-sense-mediated mRNA decay factors (upf2 and ebs1), and in SWI/SNF chromatin-remodeling components (snf5, snf22 and sol1). Our results suggest that the Mis16-Mis18-Mis19-Mis20 CENP-A-recruiting complex, which is functional in the G1-S phase, may be counteracted by the SWI/SNF chromatin-remodeling complex and non-sense-mediated mRNA decay, which may prevent CENP-A deposition at the centromere. PMID:24774534

  18. Licensing of Centromeric Chromatin Assembly through the Mis18α-Mis18β Heterotetramer.

    PubMed

    Nardi, Isaac K; Zasadzińska, Ewelina; Stellfox, Madison E; Knippler, Christina M; Foltz, Daniel R

    2016-03-01

    Centromeres are specialized chromatin domains specified by the centromere-specific CENP-A nucleosome. The stable inheritance of vertebrate centromeres is an epigenetic process requiring deposition of new CENP-A nucleosomes by HJURP. We show HJURP is recruited to centromeres through a direct interaction between the HJURP centromere targeting domain and the Mis18α-β C-terminal coiled-coil domains. We demonstrate Mis18α and Mis18β form a heterotetramer through their C-terminal coiled-coil domains. Mis18α-β heterotetramer formation is required for Mis18BP1 binding and centromere recognition. S. pombe contains a single Mis18 isoform that forms a homotetramer, showing tetrameric Mis18 is conserved from fission yeast to humans. HJURP binding disrupts the Mis18α-β heterotetramer and removes Mis18α from centromeres. We propose stable binding of Mis18 to centromeres in telophase licenses them for CENP-A deposition. Binding of HJURP deposits CENP-A at centromeres and facilitates the removal of Mis18, restricting CENP-A deposition to a single event per cell cycle. PMID:26942680

  19. Acetate kinase Activity and Kinetic Properties of the Enzyme in Desulfovibrio piger Vib-7 and Desulfomicrobium sp. Rod-9 Intestinal Bacterial Strains

    PubMed Central

    Kushkevych, Ivan V

    2014-01-01

    Activity of acetate kinase in cell-free extracts and individual fractions and the kinetic properties of the enzyme obtained from the Desulfovibrio piger Vib-7 and Desulfomicrobium sp. Rod-9 intestinal bacterial strains were presented at the first time. The highest activity of the enzyme was measured in the cell-free extracts (1.52 ± 0.163 and 0.46 ± 0.044 U × mg-1 protein for D. piger Vib-7 and Desulfomicrobium sp. Rod-9, respectively) compared to other fractions. The specific activity of acetate kinase in the extracts of both bacterial strains was determined at different temperature and pH. Analysis of the kinetic properties of the purified acetate kinase was carried out. The acetate kinase activity, initial (instantaneous) reaction rate (V0) and maximum rate of the acetate kinase reaction (Vmax) in D. piger Vib-7 and Desulfomicrobium sp. Rod-9 intestinal bacterial strains were defined. Michaelis constants (KmAcetyl phosphate and KmADP) of the enzyme reaction (2.54 ± 0.26 and 2.39 ± 0.24 mM for D. piger Vib-7 as well as 2.68 ± 0.25 and 2.47 ± 0.27 mM for Desulfomicrobium sp. Rod-9, respectively) were calculated. The described results of acetate kinase, an important enzyme in the process of organic compounds oxidation and dissimilatory sulfate reduction would be perspective and useful for clarification of the etiological role of these bacteria in the development of inflammatory bowel diseases in humans and animals. PMID:25598851

  20. Mis16 and Mis18 are required for CENP-A loading and histone deacetylation at centromeres.

    PubMed

    Hayashi, Takeshi; Fujita, Yohta; Iwasaki, Osamu; Adachi, Yoh; Takahashi, Kohta; Yanagida, Mitsuhiro

    2004-09-17

    Centromeres contain specialized chromatin that includes the centromere-specific histone H3 variant, spCENP-A/Cnp1. Here we report identification of five fission yeast centromere proteins, Mis14-18. Mis14 is recruited to kinetochores independently of CENP-A, and, conversely, CENP-A does not require Mis14 to associate with centromeres. In contrast, Mis15, Mis16 (strong similarity with human RbAp48 and RbAp46), Mis17, and Mis18 are all part of the CENP-A recruitment pathway. Mis15 and Mis17 form an evolutionarily conserved complex that also includes Mis6. Mis16 and Mis18 form a complex and maintain the deacetylated state of histones specifically in the central core of centromeres. Mis16 and Mis18 are the most upstream factors in kinetochore assembly as they can associate with kinetochores in all kinetochore mutants except for mis18 and mis16, respectively. RNAi knockdown in human cells shows that Mis16 function is conserved as RbAp48 and RbAp46 are both required for localization of human CENP-A. PMID:15369671

  1. Developing a Management Information Systems (MIS) Curriculum: Perspectives from MIS Practitioners.

    ERIC Educational Resources Information Center

    Ehie, Ike C.

    2002-01-01

    A management information systems (MIS) curriculum was developed through review of existing programs and feedback from 24 MIS practitioners. Key aspects of the role of the information systems professional were identified: knowledge of integrated business processes, programming skills, and technical skills in niche areas. (Contains 17 references.)…

  2. Chemical vapour deposition of group-VIB metal dichalcogenide monolayers: engineered substrates from amorphous to single crystalline.

    PubMed

    Ji, Qingqing; Zhang, Yu; Zhang, Yanfeng; Liu, Zhongfan

    2015-05-01

    As structural analogues of graphene but with a sizeable band gap, monolayers of group-VIB transition metal dichalcogenides (MX2, M = Mo, W; X = S, Se, Te, etc.) have emerged as the ideal two dimensional prototype for exploring fundamental issues in physics such as valley polarization, and for engineering a wide range of nanoelectronic, optoelectronic and photocatalytic applications. Recently, chemical vapour deposition (CVD) was introduced as a more efficient preparation method than traditional chemical or physical exfoliation options, and has allowed for the successful synthesis of large-area MX2 monolayers possessing a large domain size, high thickness uniformity and continuity, and satisfactory crystal quality. This tutorial review therefore focuses on introducing the more recent advances in the CVD growth of MX2 (MoS2, WS2, MoS2(1-x)Se2xetc.) monolayers via the sulphurisation/decomposition of pre-deposited metal-based precursors, or the one-step reaction and deposition of gaseous metal and chalcogen feedstocks. Differences in growth behaviour caused by commonly used amorphous SiO2/Si, and newly adopted insulating single crystal substrates such as sapphire, mica and SrTiO3, are also comparatively presented. Also discussed are the essential parameters that influence the growth of MX2, such as the temperature, the source-substrate distance and the composition of the carrier gas (Ar/H2). Finally, an assessment is provided for viable future pathways for fine-tuning of the domain size and orientation, thickness uniformity, and the bandgap of MX2 and its alloys. PMID:25256261

  3. Climate changes in south western Iberia and Mediterranean Outflow variations during two contrasting cycles of the last 1 Myrs: MIS 31-MIS 30 and MIS 12-MIS 11

    NASA Astrophysics Data System (ADS)

    Sánchez Goñi, M. F.; Llave, E.; Oliveira, D.; Naughton, F.; Desprat, S.; Ducassou, E.; Hodell, D. A.; Hernández-Molina, F. J.

    2016-01-01

    Grain size analysis and physical properties of Sites U1388, U1389 and U1390 collected in the Contourite Depositional System of the Gulf of Cádiz during the Integrated Ocean Drilling Program (IODP) Expedition 339 "Mediterranean Outflow" reveal relative changes in bottom current strength, a tracer of the dynamics of the Mediterranean Outflow Water (MOW), before and after the Middle Pleistocene Transition (MPT). The comparison of MOW behavior with climate changes identified by the pollen analysis and δ18O benthic foraminifera measurements of Site U1385, the Shackleton Site, collected in the south western Iberian margin shows that the interval MIS 31-MIS 30, ~ 1.1-1.05 million years ago (Ma), before the MPT, was marked by wetter climate and weaker bottom current than the interval MIS 12-MIS 11 (0.47-0.39 Ma), after the MPT. Similarly, the increase in fine particles from these glacials to interglacials and in coarse fraction from interglacials to glacials was coeval with forest and semi-desert expansions, respectively, indicating the lowering/enhancement of MOW strength during periods of regional increase/decrease of moisture. While these findings may not necessarily apply to all glacial/interglacial cycles, they nonetheless serve as excellent supporting examples of the hypothesis that aridification can serve as a good tracer for MOW intensity. The strongest regional aridity during MIS 12 coincides with a remarkable increase of coarse grain size deposition and distribution that we interpret as a maximum in MOW strength. This MOW intensification may have pre-conditioned the North Atlantic by increasing salinity, thereby triggering the strong resumption of the Meridional Overturning Circulation that could contribute to the great warmth that characterizes the MIS 11c super-interglacial.

  4. Model-based Characterization of the Parameters of Dissimilatory Sulfate Reduction Under the Effect of Different Initial Density of Desulfovibrio piger Vib-7 Bacterial Cells.

    PubMed

    Kushkevych, Ivan; Bolis, Marco; Bartos, Milan

    2015-01-01

    The objective of this study was to design a model of dissimilatory sulfate reduction process using the Verhulst function, with a particular focus on the kinetics of bacterial growth, sulfate and lactate consumption, and accumulation of hydrogen sulfide and acetate. The effect of the initial density (0.12±0.011, 0.25±0.024, 0.5±0.048 and 1.0±0.096 mg cells/ml of medium) of the sulfate-reducing bacteria Desulfovibrio piger Vib-7 on the growth and dissimilatory sulfate reduction was studied. The exponential growth phase of the D. piger Vib-7 was observed for 72 hours of cultivation at the (0.12 and 0.25 mg/ml) initial concentration of bacterial cells. Sulfate and lactate were consumed incompletely during this time. The increase in the initial concentration of cells to 0.5 and 1 mg/ml led to a shortening of the exponential bacterial growth phase and a shift to the stationary phase of the growth. In the case of 0.5 mg/ml seeding, the stationary growth phase was observed in the 36(th) hour of cultivation. The increase in the initial concentration of cells to 1 mg/ml led to the beginning of the stationary growth phase in 24th hours of cultivation. Under these conditions, sulfate and lactate were consumed completely in the 48th hour of cultivation. The kinetic analysis of the curves of bacterial growth and the process of dissimilatory sulfate reduction by D. piger Vib-7 was carried out. PMID:26668663

  5. NaVβ Subunits Modulate the Inhibition of NaV1.8 by the Analgesic Gating Modifier μO-Conotoxin MrVIB

    PubMed Central

    Wilson, Michael J.; Zhang, Min-Min; Azam, Layla; Olivera, Baldomero M.; Bulaj, Grzegorz

    2011-01-01

    Voltage-gated sodium channels (VGSCs) consist of a pore-forming α-subunit and regulatory β-subunits. Several families of neuroactive peptides of Conus snails target VGSCs, including μO-conotoxins and μ-conotoxins. Unlike μ-conotoxins and the guanidinium alkaloid saxitoxin (STX), which are pore blockers, μO-conotoxins MrVIA and MrVIB inhibit VGSCs by modifying channel gating. μO-MrVIA/B can block NaV1.8 (a tetrodotoxin-resistant isoform of VGSCs) and have analgesic properties. The effect of NaVβ-subunit coexpression on susceptibility to block by μO-MrVIA/B and STX has, until now, not been reported. Here, we show that β1-, β2-, β3-, and β4-subunits, when individually coexpressed with NaV1.8 in Xenopus laevis oocytes, increased the kon of the block produced by μO-MrVIB (by 3-, 32-, 2-, and 7-fold, respectively) and modestly decreased the apparent koff. Strong depolarizing prepulses markedly accelerated MrVIB washout with rates dependent on β-subunit coexpression. Thus, coexpression of β-subunits with NaV1.8 can strongly influence the affinity of the conopeptide for the channel. This observation is of particular interest because β-subunit expression can be dynamic, e.g., β2-expression is up-regulated after nerve injury (J Neurosci, 25:10970–10980, 2005); therefore, the effectiveness of a μO-conotoxin as a channel blocker could be enhanced by the conditions that may call for its use therapeutically. In contrast to MrVIB's action, the STX-induced block of NaV1.8 was only marginally, if at all, affected by coexpression of any of the β-subunits. Our results raise the possibility that μO-conotoxins and perhaps other gating modifiers may provide a means to functionally assess the β-subunit composition of VGSC complexes in neurons. PMID:21586605

  6. Differential Binding Partners of the Mis18α/β YIPPEE Domains Regulate Mis18 Complex Recruitment to Centromeres.

    PubMed

    Stellfox, Madison E; Nardi, Isaac K; Knippler, Christina M; Foltz, Daniel R

    2016-06-01

    The Mis18 complex specifies the site of new CENP-A nucleosome assembly by recruiting the CENP-A-specific assembly factor HJURP (Holliday junction recognition protein). The human Mis18 complex consists of Mis18α, Mis18β, and Mis18 binding protein 1 (Mis18BP1/hsKNL2). Although Mis18α and Mis18β are highly homologous proteins, we find that their conserved YIPPEE domains mediate distinct interactions that are essential to link new CENP-A deposition to existing centromeres. We find that Mis18α directly interacts with the N terminus of Mis18BP1, whereas Mis18β directly interacts with CENP-C during G1 phase, revealing that these proteins have evolved to serve distinct functions in centromeres of higher eukaryotes. The N terminus of Mis18BP1, containing both the Mis18α and CENP-C binding domains, is necessary and sufficient for centromeric localization. Therefore, the Mis18 complex contains dual CENP-C recognition motifs that are combinatorially required to generate robust centromeric localization that leads to CENP-A deposition. PMID:27239045

  7. Differential binding partners of the Mis18α/β YIPPEE domains regulates the Mis18 complex recruitment to centromeres

    PubMed Central

    Knippler, Christina M.; Foltz, Daniel R.

    2016-01-01

    The Mis18 complex specifies the site of new CENP-A nucleosome assembly by recruiting the CENP-A specific assembly factor HJURP (Holliday junction recognition protein). The human Mis18 complex consists of Mis18α, Mis18β and Mis18 binding protein 1 (Mis18BP1/hsKNL2). Although Mis18α and Mis18β are highly homologous proteins, we find that their conserved YIPPEE domains mediate distinct interactions that are essential to link new CENP-A deposition to existing centromeres. We find that Mis18α directly interacts with the N-terminus of Mis18BP1; whereas, Mis18β directly interacts with CENP-C during G1 phase, revealing that these proteins have evolved to serve distinct functions in centromeres of higher eukaryotes. The N-terminus of Mis18BP1, containing both the Mis18α and CENP-C binding domains, is necessary and sufficient for centromeric localization. Therefore, the Mis18 complex contains dual CENP-C recognition motifs that are combinatorially required to generate robust centromeric localization that leads to CENP-A deposition. PMID:27239045

  8. Language, Violence, and Indian Mis-education.

    ERIC Educational Resources Information Center

    Russell, Caskey

    2002-01-01

    Traces the history of institutionalized violence--both physical and symbolic--within American Indian education; the legacy of shame and guilt from the boarding school era, when oppression was internalized; and the relationship of such "mis-education" to the decline of Tlingit language and culture in southwestern Alaska. Discusses prospects for…

  9. Improved insulator layer for MIS devices

    NASA Technical Reports Server (NTRS)

    Miller, W. E.

    1980-01-01

    Insulating layer of supersonic conductor such as LaF sub 3 has been shown able to impart improved electrical properties to photoconductive detectors and promises to improve other metal/insulator/semiconductor (MIS) devices, e.g., MOSFET and integrated circuits.

  10. An Examination of the Introductory MIS Course

    ERIC Educational Resources Information Center

    Wang, Shouhong

    2007-01-01

    The introductory management information systems (MIS) course is a core course for all business majors at almost every business school. It is common for this course to have multiple sections taught by a mixed group of instructors each semester. Hence, consistent pedagogy and assessment are needed for multiple sections of this course. This paper…

  11. Incorporating Virtual Teamwork Training into MIS Curricula

    ERIC Educational Resources Information Center

    Chen, Fang; Sager, James; Corbitt, Gail; Gardiner, Stanley C.

    2008-01-01

    Due to increasing industry demand for personnel who work effectively in virtual/distributed teams, MIS students should undergo training to improve their awareness of and competence in virtual teamwork. This paper proposes a model for virtual teamwork training and describes the implementation of the model in a class where students were located in…

  12. Effects of MIS retorting on groundwater

    SciTech Connect

    Hester, N.E.

    1983-04-01

    Occidental Petroleum Corporation has conducted field tests on the modified-in-situ (MIS) oil shale retorting technology for a number of years at its Logan Wash site near De Beque, Colorado. A total of 8 major retorts have been burned, the last three of which were commercial sized. Concurrent with process development research, a significant program was undertaken to study the effects of the MIS technology on the environment. Groundwater was examined before, during and after the major retorting experiments by means of an extensive monitoring network. This network was comprised of monitoring wells at various distances from the retorting operation. Both alluvial wells and deep bedrock wells were examined. Water quality in local seeps and springs was also monitored. Almost eighty chemical and physical parameters of the water samples have been examined. Analyses of these data have shown no contamination of the groundwaters by the MIS retorts. The quality of water exiting MIS retorts during and after the retorting period has also been followed. Data from Retorts 1 through 6 show that the species mobilized by retorting are rapidly removed, and concentrations of chemicals in ''leachate'' from the retorts quickly approach the same range of values as seen in natural groundwaters. Statistical analyses have been made of both the retort waters and the groundwaters. Based on the results of these analyses a list of key variables has been identified whose measurement is most likely to identify contamination problems.

  13. Communicating MIS Research: A Citation Study of Journal Influence.

    ERIC Educational Resources Information Center

    Cooper, Randolph B.; And Others

    1993-01-01

    Examines journal influence in communicating management information systems (MIS) research over a nine-year period using citation analyses, researcher perceptions, and publishing patterns of MIS research universities. A core group of MIS journals is identified, and ranking according to journal influence is discussed. (37 references) (LRW)

  14. ALPHA MIS: Reference manual. Revision 2

    SciTech Connect

    Lovin, J.K.; Haese, R.L.; Heatherly, R.D.; Hughes, S.E.; Ishee, J.S.; Pratt, S.M.; Smith, D.W.

    1992-02-01

    ALPHA is a powerful and versatile management information system (MIS) initiated and sponsored and by the Finance and Business Management Division of Oak Ridge National Laboratory, who maintain and develop it in concert with the Business Systems Division for its Information Center. A general-purpose MIS, ALPHA allows users to access System 1022 and System 1032 databases to obtain and manage information. From a personal computer or a data terminal, Energy Systems employees can use ALPHA to control their own report reprocessing. Using four general commands (Database, Select, Sort, and Report) they can (1) choose a mainframe database, (2) define subsets within it, (3) sequentially order a subset by one or more variables, and (4) generate a report with their own or a canned format.

  15. Eic1 links Mis18 with the CCAN/Mis6/Ctf19 complex to promote CENP-A assembly.

    PubMed

    Subramanian, Lakxmi; Toda, Nicholas R T; Rappsilber, Juri; Allshire, Robin C

    2014-01-01

    CENP-A chromatin forms the foundation for kinetochore assembly. Replication-independent incorporation of CENP-A at centromeres depends on its chaperone HJURP(Scm3), and Mis18 in vertebrates and fission yeast. The recruitment of Mis18 and HJURP(Scm3) to centromeres is cell cycle regulated. Vertebrate Mis18 associates with Mis18BP1(KNL2), which is critical for the recruitment of Mis18 and HJURP(Scm3). We identify two novel fission yeast Mis18-interacting proteins (Eic1 and Eic2), components of the Mis18 complex. Eic1 is essential to maintain Cnp1(CENP-A) at centromeres and is crucial for kinetochore integrity; Eic2 is dispensable. Eic1 also associates with Fta7(CENP-Q/Okp1), Cnl2(Nkp2) and Mal2(CENP-O/Mcm21), components of the constitutive CCAN/Mis6/Ctf19 complex. No Mis18BP1(KNL2) orthologue has been identified in fission yeast, consequently it remains unknown how the key Cnp1(CENP-A) loading factor Mis18 is recruited. Our findings suggest that Eic1 serves a function analogous to that of Mis18BP1(KNL2), thus representing the functional counterpart of Mis18BP1(KNL2) in fission yeast that connects with a module within the CCAN/Mis6/Ctf19 complex to allow the temporally regulated recruitment of the Mis18/Scm3(HJURP) Cnp1(CENP-A) loading factors. The novel interactions identified between CENP-A loading factors and the CCAN/Mis6/Ctf19 complex are likely to also contribute to CENP-A maintenance in other organisms. PMID:24789708

  16. Eic1 links Mis18 with the CCAN/Mis6/Ctf19 complex to promote CENP-A assembly

    PubMed Central

    Subramanian, Lakxmi; Toda, Nicholas R. T.; Rappsilber, Juri; Allshire, Robin C.

    2014-01-01

    CENP-A chromatin forms the foundation for kinetochore assembly. Replication-independent incorporation of CENP-A at centromeres depends on its chaperone HJURPScm3, and Mis18 in vertebrates and fission yeast. The recruitment of Mis18 and HJURPScm3 to centromeres is cell cycle regulated. Vertebrate Mis18 associates with Mis18BP1KNL2, which is critical for the recruitment of Mis18 and HJURPScm3. We identify two novel fission yeast Mis18-interacting proteins (Eic1 and Eic2), components of the Mis18 complex. Eic1 is essential to maintain Cnp1CENP-A at centromeres and is crucial for kinetochore integrity; Eic2 is dispensable. Eic1 also associates with Fta7CENP-Q/Okp1, Cnl2Nkp2 and Mal2CENP-O/Mcm21, components of the constitutive CCAN/Mis6/Ctf19 complex. No Mis18BP1KNL2 orthologue has been identified in fission yeast, consequently it remains unknown how the key Cnp1CENP-A loading factor Mis18 is recruited. Our findings suggest that Eic1 serves a function analogous to that of Mis18BP1KNL2, thus representing the functional counterpart of Mis18BP1KNL2 in fission yeast that connects with a module within the CCAN/Mis6/Ctf19 complex to allow the temporally regulated recruitment of the Mis18/Scm3HJURP Cnp1CENP-A loading factors. The novel interactions identified between CENP-A loading factors and the CCAN/Mis6/Ctf19 complex are likely to also contribute to CENP-A maintenance in other organisms. PMID:24789708

  17. Atmospheric methane isotope records during MIS 4

    NASA Astrophysics Data System (ADS)

    Sowers, Todd; Bock, Michael; Mitchell, Hailey

    2014-05-01

    The long-term δ13CH4record has led to a new paradigm in our thinking of the biogeochemistry of atmospheric CH4 (Möller et al. 2013). Throughout the last glacial period, abrupt D/O CH4changes appear to be decoupled from δ13CH4, while for δDCH4 we are still missing the big picture. The lack of a clear long-term relationship between loading changes and the isotopic composition of atmospheric CH4suggests multiple sources/sinks were responsible for the observed changes and/or that the characteristic isotope value for some of these sources may have changed over time. During the early part of MIS 4, we observed a ~4o increase in δ13CH4during a period when CH4changes were less than 50 ppb. We measured 12 ice core samples from the NEEM core for δDCH4 covering DO 8 and the MIS 5-4 transition. These new δDCH4 data compliment previously published δDCH4 data from EDML covering the same period (Möller et al. 2013). Replicate analyses of NEEM ice from DO 8 agreed with previously measured samples from NGRIP (Bock et al., 2010). External precision of the analyses based on replicate air standards run throughout each analytical day were ±1.8‰These data were overlain on previously measured δ13CH4data from the Vostok and EDML ice cores from the same periods. The δ13CH4data for the MIS4 start at ~ -48o around 75ka and increase to -44o at 65ka and then decrease to -46o by 59ka. In contrast, NEEM δDCH4 values start at -90o at 70ka and decrease to -97o at 64ka before increasing to -92o by 59ka. These two records appear to be roughly in phase with one another but opposite in the sign of their changes. Comparison between NEEM and EDML δDCH4 data for MIS4 suggest the interpolar δDCH4 difference increases somewhat during the δ13CH4transition. We plan to discuss these records in terms of constraints on the biogeochemistry of atmospheric methane during MIS 4. Bock, M., J. Schmitt, L. Möller, R. Spahni, T. Blunier and H. Fischer (2010). "Hydrogen Isotopes Preclude Marine

  18. Perceived Requirements of MIS Curriculum Implementation in Bilingual Developing Countries

    ERIC Educational Resources Information Center

    Kabeil, Magdy M.

    2005-01-01

    This paper addresses additional requirements associated with implementing a standard curriculum of Management Information Systems (MIS) in bilingual developing countries where both students and workplace users speak English as a second language. In such countries, MIS graduates are required to develop bilingual computer applications and to…

  19. Centromere licensing: Mis18 is required to Polo-ver.

    PubMed

    Barnhart-Dailey, Meghan C; Foltz, Daniel R

    2014-09-01

    The Mis18 complex is a critical player in determining when and where centromeres are built. A new study identifies Polo-like kinase (Plk1) as a positive regulator required for the localization of Mis18 to centromeres. This is a critical step that is essential for proper centromere function and maintaining the integrity of the genome. PMID:25202874

  20. Integrating Intellectual Property Concepts into MIS Education: An Empirical Assessment

    ERIC Educational Resources Information Center

    Mykytyn, Peter P., Jr.; Mykytyn, Kathleen; Harrison, David A.

    2005-01-01

    The evolving legal environment surrounding intellectual property (IP) and its impact on information systems, especially involving electronic commerce, and the type of education and training provided by management information systems (MIS) faculty to MIS students is a relationship that has not been investigated. Although organizations are…

  1. Development and evaluation of the modular inclined screen (MIS)

    SciTech Connect

    Taft, E.P.; Winchell, F.C.; Plizga, A.W.

    1995-12-31

    The Electric Power Research Institute (EPRI) has developed and biologically evaluated a new type of fish diversion screen known as the Modular Inclined Screen (MIS). The MIS is designed to operate at any type of water intake with water velocities approaching the screen of up to 3.1 ms{sup -1}. The biological evaluation of the MIS was conducted in the laboratory with juveniles of eleven species. Fish passage was evaluated at five module velocities ranging from 0.6 to 3.1 ms{sup -1}. Net passage survival with a clean screen typically exceeded 99% at velocities up to 1.8 ms{sup -1} for most species, and exceeded 99% overall (all velocities combined) for channel catfish, coho salmon, brown trout, and Atlantic salmon. Fish passage tests with debris accumulation demonstrated that increases in screen head loss up to 12 cm did not reduce the ability of the MIS to safely and effectively divert fish, depending on species and module velocity. On the basis of these results, EPRI, Niagara Mohawk Power Corporation (NMPC) and other contributors have constructed a prototype MIS at NMPC`s Green Island Hydroelectric Project on the Hudson River. Field evaluations of this first MIS will be conducted in the fall of 1995. In addition to the MIS, the effectiveness of a strobe light system will be studied to determine its ability to divert blueback herring from the river to the MIS.

  2. MIS Development in Higher Education: A Framework for Systems Planning.

    ERIC Educational Resources Information Center

    St. John, Edward P.

    An institutional management systems development study examined the Management Information Systems (MIS) needs of 23 public institutions of higher education in Missouri. The result was a model framework for other institutions to develop MIS appropriate to their needs. One of five distinct structural development phases could be related to all…

  3. MIS: A Miriad Interferometry Singledish Toolkit

    NASA Astrophysics Data System (ADS)

    Pound, Marc; Teuben, Peter

    2011-10-01

    MIS is a pipeline toolkit using the package MIRIAD to combine Interferometric and Single Dish data. This was prompted by our observations made with the Combined Array For Research in Millimeter-wave Astronomy (CARMA) interferometer of the star-forming region NGC 1333, a large survey highlighting the new 23-element and singledish observing modes. The project consists of 20 CARMA datasets each containing interferometric as well as simultaneously obtained single dish data, for 3 molecular spectral lines and continuum, in 527 different pointings, covering an area of about 8 by 11 arcminutes. A small group of collaborators then shared this toolkit and their parameters via CVS, and scripts were developed to ensure uniform data reduction across the group. The pipeline was run end-to-end each night that new observations were obtained, producing maps that contained all the data to date. This approach could serve as a model for repeated calibration and mapping of large mixed-mode correlation datasets from ALMA.

  4. MIS: A MIRIAD Interferometry Singledish Toolkit

    NASA Astrophysics Data System (ADS)

    Pound, M. W.; Teuben, P.

    2012-09-01

    Building on the “drPACS” contribution at ADASS XX of a simple Unix pipeline infrastructure, we implemented a pipeline toolkit using the package MIRIAD to combine Interferometric and Single Dish data (MIS). This was prompted by our observations made with the Combined Array For Research in Millimeter-wave Astronomy (CARMA) interferometer of the star-forming region NGC 1333, a large survey highlighting the new 23-element and singledish observing modes. The project consists of 20 CARMA datasets each containing interferometric as well as simultaneously obtained single dish data, for 3 molecular spectral lines and continuum, in 527 different pointings, covering an area of about 8 by 11 arcminutes. A small group of collaborators then shared this toolkit and their parameters via CVS, and scripts were developed to ensure uniform data reduction across the group. The pipeline was run end-to-end each night as new observations were obtained, producing maps that contained all the data to date. We will show examples of the scripts and data products. This approach could serve as a model for repeated calibration and mapping of large mixed-mode correlation datasets from ALMA.

  5. Kinetic Properties of Pyruvate Ferredoxin Oxidoreductase of Intestinal Sulfate-Reducing Bacteria Desulfovibrio piger Vib-7 and Desulfomicrobium sp. Rod-9.

    PubMed

    Kushkevych, Ivan V

    2015-01-01

    Intestinal sulfate-reducing bacteria reduce sulfate ions to hydrogen sulfide causing inflammatory bowel diseases of humans and animals. The bacteria consume lactate as electron donor which is oxidized to acetate via pyruvate in process of the dissimilatory sulfate reduction. Pyruvate-ferredoxin oxidoreductase activity and the kinetic properties of the enzyme from intestinal sulfate-reducing bacteria Desulfovibrio piger and Desulfomicrobium sp. have never been well-characterized and have not been yet studied. In this paper we present for the first time the specific activity of pyruvate-ferredoxin oxidoreductase and the kinetic properties of the enzyme in cell-free extracts of both D. piger Vib-7 and Desulfomicrobium sp. Rod-9 intestinal bacterial strains. Microbiological, biochemical, biophysical and statistical methods were used in this work. The optimal temperature (+35°C) and pH 8.5 for enzyme reaction were determined. The spectral analysis of the puri- fied pyruvate-ferredoxin oxidoreductase from the cell-free extracts was demonstrated. Analysis of the kinetic properties of the studied enzyme was carried out. Initial (instantaneous) reaction velocity (V0), maximum amount of the product of reaction (Pmax), the reaction time (half saturation period) and maximum velocity of the pyruvate-ferredoxin oxidoreductase reaction (V ) were defined. Michaelis constants (Km) of the enzyme reaction were calculated for both intestinal bacterial strains. The studies of the kinetic enzyme properties in the intestinal sulfate-reducing bacteria strains in detail can be prospects for clarifying the etiological role of these bacteria in the development of inflammatory bowel diseases. PMID:26373169

  6. Evolution of electronic structure as a function of layer thickness in group-VIB transition metal dichalcogenides: emergence of localization prototypes.

    PubMed

    Zhang, Lijun; Zunger, Alex

    2015-02-11

    Layered group-VIB transition metal dichalcogenides (with the formula of MX2) are known to show a transition from an indirect band gap in the thick n-monolayer stack (MX2)n to a direct band gap at the n = 1 monolayer limit, thus converting the system into an optically active material suitable for a variety of optoelectronic applications. The origin of this transition has been attributed predominantly to quantum confinement effect at reduced n. Our analysis of the evolution of band-edge energies and wave functions as a function of n using ab initio density functional calculations including the long-range dispersion interaction reveals (i) the indirect-to-direct band gap transformation is triggered not only by (kinetic-energy controlled) quantum confinement but also by (potential-energy controlled) band repulsion and localization. On its own, neither of the two effects can explain by itself the energy evolution of the band-edge states relevant to the transformation; (ii) when n decreased, there emerge distinct regimes with characteristic localization prototypes of band-edge states deciding the optical response of the system. They are distinguished by the real-space direct/indirect in combination with momentum-space direct/indirect nature of electron and hole states and give rise to distinct types of charge distribution of the photoexcited carriers that control excitonic behaviors; (iii) the various regimes associated with different localization prototypes are predicted to change with modification of cations and anions in the complete MX2 (M = Cr, Mo, W and X = S, Se, Te) series. These results offer new insight into understanding the excitonic properties (e.g., binding energy, lifetime etc.) of multiple layered MX2 and their heterostructures. PMID:25562378

  7. Persistent climatic and oceanographic oscillations in the subpolar North Atlantic during the MIS 6 glaciation and MIS 5 interglacial

    NASA Astrophysics Data System (ADS)

    Mokeddem, Zohra; McManus, Jerry F.

    2016-06-01

    Rapidly accumulating sediments from the Björn drift deposit south of Iceland are studied for comparison of glacial/interglacial climate changes related to millennial variability of the subpolar surface and deep ocean circulation in the North Atlantic. High-resolution faunal, isotopic, and sedimentary analyses reveal a strong multimillennial climatic variability interpreted as oscillations in heat transport westward south of Iceland during marine isotope stage 6 (MIS 6), possibly related to the strength of the subpolar gyre (SPG). The oscillations persisted from MIS 6 through the following interglacial (MIS 5), although with diminished magnitude, and were respectively characterized by repeated advances of the polar front south of Iceland during MIS 6 and southward migrations of the Arctic front due to cold surface outflow through the East Greenland and East Iceland Currents during MIS 5. Incursions of cold, fresh surface waters, and drifting ice affected the dynamics of the SPG, episodically causing it to weaken and contract to the northwest. During these intervals of diminished SPG, the northward transport of subtropical heat and salt was strengthened and preferentially conveyed to the northeast past Iceland, enhancing deep-water formation in the Nordic Seas. By contrast, when the SPG was strong, more subtropical water and its associated heat were entrained within the relatively warm Irminger Current flowing westward south of Iceland. These oceanographic oscillations were associated with repeated multimillennial cooling and warming episodes during the glacial stage MIS 6, equivalent to the Dansgaard-Oeschger cycles of the last glaciation.

  8. MIS capacitor studies on silicon carbide single crystals

    NASA Technical Reports Server (NTRS)

    Kopanski, J. J.

    1990-01-01

    Cubic SIC metal-insulator-semiconductor (MIS) capacitors with thermally grown or chemical-vapor-deposited (CVD) insulators were characterized by capacitance-voltage (C-V), conductance-voltage (G-V), and current-voltage (I-V) measurements. The purpose of these measurements was to determine the four charge densities commonly present in an MIS capacitor (oxide fixed charge, N(f); interface trap level density, D(it); oxide trapped charge, N(ot); and mobile ionic charge, N(m)) and to determine the stability of the device properties with electric-field stress and temperature. The section headings in the report include the following: Capacitance-voltage and conductance-voltage measurements; Current-voltage measurements; Deep-level transient spectroscopy; and Conclusions (Electrical characteristics of SiC MIS capacitors).

  9. Further study of inversion layer MIS solar cells

    NASA Technical Reports Server (NTRS)

    Ho, Fat Duen

    1992-01-01

    Many inversion layer metal-insulator-semiconductor (IL/MIS) solar cells have been fabricated. As of today, the best cell fabricated by us has a 9.138 percent AMO efficiency, with FF = 0.641, V(sub OC) = 0.557 V, and I(sub SC) = 26.9 micro A. Efforts made for fabricating an IL/MOS solar cell with reasonable efficiencies are reported. The more accurate control of the thickness of the thin layer of oxide between aluminum and silicon of the MIS contacts has been achieved by using two different process methods. Comparison of these two different thin oxide processings is reported. The effects of annealing time of the sample are discussed. The range of the resistivity of the substrates used in the IL cell fabrication is experimentally estimated. Theoretical study of the MIS contacts under dark conditions is addressed.

  10. Precision stabilization system for MIS-structure rf capacitance

    SciTech Connect

    Antonenko, V.I.; Zhdan, A.G.

    1987-02-01

    A relatively simple resonant small-signal system is described for stabilization of the rf capacitance of MIS structures in the frequency range of 1-30 MHz that is based on a VM560 Q-meter. The relative sensitivity to capacitance variation ..delta..C/C is 2 x 10/sup -6/ at a level of C approx. 500 pF, the absolute sensitivity ..delta..C approx. 1 fF, and the response time is approx. 0.1 sec. The system is designed for relaxation spectroscopy of boundary states in MIS structures in the constant-capacitance mode by methods of unsteady capacitance and thermostimulated discharge of an MIS capacitor.

  11. 40Ar/39Ar dated climatic and hydrological variability between MIS20 and MIS18 at Sulmona Basin (central Italy)

    NASA Astrophysics Data System (ADS)

    Zanchetta, Giovanni; Giaccio, Biagio; Eleonora, Reagattieri; Nomade, Sebastien; Renne, Paul R.; Sprain, Courtney J.; Drysdale, Russell N.; Tzedakis, Polychronis C.; Messina, Paolo; Scardia, Giancarlo; Sposato, Andrea

    2015-04-01

    Understanding spatial-temporal variability, magnitude and different expressions of Quaternary millennial-scale palaeoclimatic changes is one of the frontier challenges of modern palaeoclimatology. Addressing this issue requires the acquisition of regionally representative, and ideally independently-dated, records of climatic variability. Multiproxy record (stable isotopes, XRF, MS, %CaCO3) from lacustrine succession of Sulmona basin (central Italy), highlights climatic and hydrological variability at orbital to millennial scales between MIS20 and MIS18. The record highlights the presence of interesting millennial scale variability within MIS19, considered to be the best orbital analogue of the current interglacial. The presence of several tephra layers precisely dated by 40Ar/39Ar technique, allow placement of the record within a robust time frame. Assembling a high-resolution paleoclimatic record for MIS19 anchored to a high-precision 40Ar/39Ar chronology, it is possible to show that the MIS 19c interglacial started shortly before the boreal summer insolation and obliquity maximum/precession minimum at 790-788 ka, and ended 11.6 ± 2.3 kyr later, when orbital parameters assumed a configuration similar to the present one.

  12. MIS and SIS solar cells on polycrystalline silicon

    SciTech Connect

    Cheek, G.; Mertens, R.

    1980-02-01

    MIS and SIS structured solar cells are receiving much attention in the photovoltaic community. Seemingly, these cells could be a viable alternative to thermally diffused p-n junctions for use on thin-film polycrystalline silicon substrates. This review describes MIS/SIS structured solar cells and the possible advantages of these structures for use with thin-film polycrystalline silicon. The results of efficiency calculations are presented. Also addressed are lifetime stability and fabrication techniques amenable to large scale production. Finally, the relative advantages and disadvantages of these cells and the results obtained are presented.

  13. A high-resolution mid-Pleistocene temperature record from Arctic Lake El'gygytgyn: a 50 kyr super interglacial from MIS 33 to MIS 31?

    NASA Astrophysics Data System (ADS)

    de Wet, Gregory A.; Castañeda, Isla S.; DeConto, Robert M.; Brigham-Grette, Julie

    2016-02-01

    Previous periods of extreme warmth in Earth's history are of great interest in light of current and predicted anthropogenic warming. Numerous so called "super interglacial" intervals, with summer temperatures significantly warmer than today, have been identified in the 3.6 million year (Ma) sediment record from Lake El'gygytgyn, northeast Russia. To date, however, a high-resolution paleotemperature reconstruction from any of these super interglacials is lacking. Here we present a paleotemperature reconstruction based on branched glycerol dialkyl glycerol tetraethers (brGDGTs) from Marine Isotope Stages (MIS) 35 to MIS 29, including super interglacial MIS 31. To investigate this period in detail, samples were analyzed with an unprecedented average sample resolution of 500 yrs from MIS 33 to MIS 30. Our results suggest the entire period currently defined as MIS 33-31 (∼1114-1062 kyr BP) was characterized by generally warm and highly variable conditions at the lake, at times out of phase with Northern Hemisphere summer insolation, and that cold "glacial" conditions during MIS 32 lasted only a few thousand years. Close similarities are seen with coeval records from high southern latitudes, supporting the suggestion that the interval from MIS 33 to MIS 31 was an exceptionally long interglacial (Teitler et al., 2015). Based on brGDGT temperatures from Lake El'gygytgyn (this study and unpublished results), warming in the western Arctic during MIS 31 was matched only by MIS 11 during the Pleistocene.

  14. Si and GaAs photocapacitive MIS infrared detectors

    NASA Technical Reports Server (NTRS)

    Sher, A.; Tsuo, Y. H.; Moriarty, J. A.; Miller, W. E.; Crouch, R. K.

    1980-01-01

    Improvement of the previously reported photocapacitive MIS infrared detectors has led to the development of exceptional room-temperature devices. Unoptimized peak detectivities on the order of 10 to the 13th cm sq rt Hz/W, a value which exceeds the best obtainable from existing solid-state detectors, have now been consistently obtained in Si and GaAs devices using high-capacitance LaF3 or composite LaF3/native-oxide insulating layers. The measured spectral response of representative samples is presented and discussed in detail together with a simple theory which accounts for the observed behavior. The response of an ideal MIS photocapacitor is also contrasted with that of both a conventional photoconductor and a p-i-n photodiode, and reasons for the superior performance of the MIS detectors are given. Finally, fundamental studies on the electrical, optical, and noise characteristics of the MIS structures are analyzed and discussed in the context of infrared-detector applications.

  15. Organizing for Effective Training Support in an MIS Environment.

    ERIC Educational Resources Information Center

    Hoffman, Stanford E.

    1994-01-01

    Describes how a management information system (MIS) at NASA (National Aeronautics and Space Administration) was adapted to ensure adequate training to accompany the development of computer applications. Highlights include semantic differences; user needs; time and budget constraints; and problems between users and programmers, including examples.…

  16. Assessing Students' Learning in MIS Using Concept Mapping

    ERIC Educational Resources Information Center

    Gregoriades, Andreas; Pampaka, Maria; Michail, Harris

    2009-01-01

    The work described here draws on the emerging need to internationalize the curriculum in higher education. The focus of the study is on the evaluation of a Management Information Systems (MIS) Module, and the specification of appropriate course of action that would support its internationalization. To realize this goal it is essential to identify…

  17. Key Information Systems Issues: An Analysis of MIS Publications.

    ERIC Educational Resources Information Center

    Palvia, Prashant C.; And Others

    1996-01-01

    Presents results of a content analysis of journal articles discussing management information systems (MIS) that was conducted to identify, classify, and prioritize the key issues; to perform a trend analysis; and to compare results with previous studies. Twenty-six key issues are ranked according to frequency of occurrence. Contains 52 references.…

  18. The Graduate MIS Security Course: Objectives and Challenges

    ERIC Educational Resources Information Center

    Jensen, Bradley K.; Guynes, Carl S.; Nyaboga, Andrew

    2009-01-01

    Given the magnitude of real and potential losses, both private and public employers increasingly expect graduates of management information systems (MIS) programs to understand information security concepts. The infrastructure requirements for the course includes setting up a secure laboratory environment to accommodate the development of viruses…

  19. A Perspective on a Management Information Systems (MIS) Program Review

    ERIC Educational Resources Information Center

    Yew, Bee K.

    2008-01-01

    This paper highlights relevant curriculum issues that were identified in a Management Information Systems (MIS) program review undertaken by a group of business faculty in a small regional university. The program review was initiated to improve job marketability of graduates and student enrollment. The review process is described as a collective…

  20. Lake level fluctuations and catchment dynamics at Lake Ohrid (Macedonia, Albania) during MIS6 and MIS5

    NASA Astrophysics Data System (ADS)

    Francke, Alexander; Wagner, Bernd; Just, Janna; Sadori, Laura; Masi, Alessia; Vogel, Hendrik; Lindhorst, Katja; Krastel, Sebastian; Dosseto, Anthony; Rothacker, Leo; Leicher, Niklas; Gromig, Raphael

    2016-04-01

    Lake Ohrid, presumably the oldest lake of Europe located at the border of Macedonia and Albania, is about 30 km long, 15 km wide, and up to 290 m deep. In 2013, an ICDP deep drilling campaign was carried out under the umbrella of the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project. At the main drill site (DEEP) in the central part of Lake Ohrid, the uppermost 568 m from a total sediment fill of ca. 700 m were recovered. Initial data from core catcher material indicate that the sediment sequence covers more than 1.2 million years. An age model, which is based on 11 tephrostratigragphic tie points and on tuning of biogeochemical proxy data versus orbital parameters reveals that that the upper 247 m of the DEEP site sequence cover the time period between 637 ka (MIS16) and the present. Inhere, we present sedimentological, (bio-)geochemical, environmental magnetic, and pollen data for the time period between MIS6 (191 ka) and MIS5 (71 ka). The data imply that MIS6 was one of the most severe glacial periods, while MIS5 was likely one of the more pronounced interglacial during the past 637 kyrs. The repercussions of these high amplitude climatic and environmental variations during this period are recorded in the sedimentological archive of Lake Ohrid. Previous studies based on hydro-acoustic and sediment core data from the northeastern part of the lake basin have shown that the lake level of Lake Ohrid was likely 60 m lower during MIS6. The ˜60 m lower lake level at Lake Ohrid during MIS6 can at least partly be explained by the ongoing subsidence, which persists in the basin until today. However, in the DEEP site sediments, the MIS6/MIS5 transition occurs at ca. 50 m sediment depth. This implies that climate-induced lake level fluctuation at Lake Ohrid are less severe compared for example to Lake Van (Turkey), were a 260 m lower lake level has been reported for the Younger Dryas. The imprint of the environmental variations between

  1. Planktic δ18O records in the northern South China Sea: MIS 5.5 vs MIS 1

    NASA Astrophysics Data System (ADS)

    Sarnthein, M.; Sadatzki, H.

    2012-04-01

    Benthic δ18O records show peak and average levels for Marine Isotope Stage (MIS) 5.5, which are 0.1-0.2 ‰ lighter than during MIS 1, a shift that largely results from changes in global ice volume. In planktic δ18O records of the northern South China Sea this trend may grow by 0.1-0.2 ‰ due to both a rise in sea surface temperatures (SST) during MIS 5.5 and enhanced freshwater input. On the other hand, dominant sources of atmospheric humidity may alter from the far distant equatorial Indian (18O depleted) to the nearby West Pacific Ocean (18O enriched), thus significantly influencing the δ18O value of the monsoon-controlled freshwater discharge to the South China Sea (Pausata et al., 2011), and accordingly, the local planktic δ18O signal of surface waters. We tested the role of these possibly opposed factors by means of planktic δ18O records with centennial-scale resolution at ODP Site 1144 (2040 m w.d.; Bühring et al., 2004) and MD05-2904 (2070 m w.d.; Ge et al., 2010). In contrast to an expected 18O depletion for MIS 5.5 of 0.3 ‰, the pertinent core sections were 18O enriched by 0.4 ‰ as compared to MIS 1. This positive shift may either suggest a major and dominant switch in atmosph¬eric water supply from Indian to nearby West Pacific sources or exhibit a loss of the sediment section crucial for MIS 5.5, that is a distinct stratigraphic gap. Highly resolved δ18O records obtained for comparison from three sediment cores retrieved nearby at much greater water depths (ODP Sites 1145, 1146; Core 17924) clearly show for MIS-5.5 the expected δ18O level that is slightly lighter than that of MIS 1, in harmony with increased SST (He et al., 2008), and thus support the hiatus model. It is also corroborated by large fields of (modern) erosional furrows which are generated by a vigorous inflow of Upper Pacific Deepwater passing along the continental slope off Hong Kong near 2350 m w.d. During interglacial MIS 5.5, this current had probably moved upslope by

  2. 48 CFR 226.370-8 - Goals and incentives for subcontracting with HBCU/MIs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... subcontracting with HBCU/MIs. 226.370-8 Section 226.370-8 Federal Acquisition Regulations System DEFENSE... subcontracting with HBCU/MIs. (a) In reviewing subcontracting plans submitted under the clause at FAR 52.219-9... included anticipated awards to HBCU/MIs in the small disadvantaged business goal; and (2) Consider...

  3. 48 CFR 226.370-8 - Goals and incentives for subcontracting with HBCU/MIs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... subcontracting with HBCU/MIs. 226.370-8 Section 226.370-8 Federal Acquisition Regulations System DEFENSE... subcontracting with HBCU/MIs. (a) In reviewing subcontracting plans submitted under the clause at FAR 52.219-9... included anticipated awards to HBCU/MIs in the small disadvantaged business goal; and (2) Consider...

  4. 48 CFR 226.370-8 - Goals and incentives for subcontracting with HBCU/MIs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... subcontracting with HBCU/MIs. 226.370-8 Section 226.370-8 Federal Acquisition Regulations System DEFENSE... subcontracting with HBCU/MIs. (a) In reviewing subcontracting plans submitted under the clause at FAR 52.219-9... included anticipated awards to HBCU/MIs in the small disadvantaged business goal; and (2) Consider...

  5. 48 CFR 226.370-8 - Goals and incentives for subcontracting with HBCU/MIs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... subcontracting with HBCU/MIs. 226.370-8 Section 226.370-8 Federal Acquisition Regulations System DEFENSE... subcontracting with HBCU/MIs. (a) In reviewing subcontracting plans submitted under the clause at FAR 52.219-9... included anticipated awards to HBCU/MIs in the small disadvantaged business goal; and (2) Consider...

  6. 32 CFR 22.325 - Historically Black colleges and universities (HBCUs) and other minority institutions (MIs).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... other minority institutions (MIs). Increasing the ability of HBCUs and MIs to participate in federally funded, university programs is an objective of Executive Order 12876 (3 CFR, 1993 Comp., p. 671) and 10 U... (HBCUs) and other minority institutions (MIs). 22.325 Section 22.325 National Defense Department...

  7. 32 CFR 22.325 - Historically Black colleges and universities (HBCUs) and other minority institutions (MIs).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... other minority institutions (MIs). Increasing the ability of HBCUs and MIs to participate in federally funded, university programs is an objective of Executive Order 12876 (3 CFR, 1993 Comp., p. 671) and 10 U... (HBCUs) and other minority institutions (MIs). 22.325 Section 22.325 National Defense Department...

  8. 32 CFR 22.325 - Historically Black colleges and universities (HBCUs) and other minority institutions (MIs).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... other minority institutions (MIs). Increasing the ability of HBCUs and MIs to participate in federally funded, university programs is an objective of Executive Order 12876 (3 CFR, 1993 Comp., p. 671) and 10 U... (HBCUs) and other minority institutions (MIs). 22.325 Section 22.325 National Defense Department...

  9. 32 CFR 22.325 - Historically Black colleges and universities (HBCUs) and other minority institutions (MIs).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... other minority institutions (MIs). Increasing the ability of HBCUs and MIs to participate in federally funded, university programs is an objective of Executive Order 12876 (3 CFR, 1993 Comp., p. 671) and 10 U... (HBCUs) and other minority institutions (MIs). 22.325 Section 22.325 National Defense Department...

  10. 32 CFR 22.325 - Historically Black colleges and universities (HBCUs) and other minority institutions (MIs).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... other minority institutions (MIs). Increasing the ability of HBCUs and MIs to participate in federally funded, university programs is an objective of Executive Order 12876 (3 CFR, 1993 Comp., p. 671) and 10 U... (HBCUs) and other minority institutions (MIs). 22.325 Section 22.325 National Defense Department...

  11. The Changing Role of the MIS Professional: From Project Leader to Project Coordinator.

    ERIC Educational Resources Information Center

    Paxton, David J.; Lieberman, Norman J.

    1980-01-01

    Shifts in the content and context of the MIS professional's role at Hahnemann Medical College and Hospital, and the resulting impact on system projects are explored. Benefits include user responsibility and increased participation, MIS as a key to user learning system capabilities and limitations, and formation of a MIS-user team. (MLW)

  12. M-I-S solar cell - Theory and experimental results

    NASA Technical Reports Server (NTRS)

    Childs, R.; Fortuna, J.; Geneczko, J.; Fonash, S. J.

    1976-01-01

    The paper presents an operating-mode analysis of an MIS solar cell and discusses the advantages which can arise as a result of the use of transport control, field shaping (increased n factor), and zero bias barrier height modification. It is noted that for an n-type semiconductor, it is relatively easy to obtain an enhanced n factor using acceptor-like states without an increase in diode saturation current, the converse being true for p-type semiconductors. Several MIS configurations are examined: an acceptor-like, localized state configuration producing field shaping and no change in diode saturation current, and acceptor-like localized configurations producing field shaping, with a decrease of diode saturation current, in one case, and an increase in the other.

  13. LaF3 insulators for MIS structures

    NASA Technical Reports Server (NTRS)

    Sher, A.; Tsuo, Y. H.; Moriarty, J. A.; Miller, W. E.; Crouch, R. K.; Seiber, B. A.

    1979-01-01

    Thin films of LaF3 deposited on Si or GaAs substrates have been observed to form blocking contacts with very high capacitances. This results in comparatively hysteresis-free and sharp C-V (capacitance-voltage) characteristics for MIS structures. Such structures have been used to study the interface states of GaAs with increased resolution and to construct improved photocapacitive infrared detectors.

  14. Fission yeast minichromosome loss mutants mis cause lethal aneuploidy and replication abnormality.

    PubMed Central

    Takahashi, K; Yamada, H; Yanagida, M

    1994-01-01

    Precise chromosome transmission in cell division cycle is maintained by a number of genes. The attempt made in the present study was to isolate temperature-sensitive (ts) fission yeast mutants that display high loss rates of minichromosomes at permissive or semipermissive temperature (designated mis). By colony color assay of 539 ts strains that contain a minichromosome, we have identified 12 genetic loci (mis1-mis12) and determined their phenotypes at restrictive temperature. Seven of them are related to cell cycle block phenotype at restrictive temperature, three of them in mitosis. Unequal distribution of regular chromosomes in the daughters is extensive in mis6 and mis12. Cells become inviable after rounds of cell division due to missegregation. The phenotype of mis5 is DNA replication defect and hypersensitivity to UV ray and hydroxyurea. mis5+ encodes a novel member of the ubiquitous MCM family required for the onset of replication. The mis5+ gene is essential for viability and functionally distinct from other previously identified members in fission yeast, cdc21+, nda1+, and nda4+. The mis11 mutant phenotype was the cell division block with reduced cell size. Progression of the G1 and G2 phases is blocked in mis11. The cloned mis11+ gene is identical to prp2+, which is essential for RNA splicing and similar to a mammalian splicing factor U2AF65. Images PMID:7865880

  15. Cueva Antón: A multi-proxy MIS 3 to MIS 5a paleoenvironmental record for SE Iberia

    NASA Astrophysics Data System (ADS)

    Zilhão, João; Ajas, Aurélie; Badal, Ernestina; Burow, Christoph; Kehl, Martin; López-Sáez, José Antonio; Pimenta, Carlos; Preece, Richard C.; Sanchis, Alfred; Sanz, Montserrat; Weniger, Gerd-Christian; White, Dustin; Wood, Rachel; Angelucci, Diego E.; Villaverde, Valentín; Zapata, Josefina

    2016-08-01

    Overlying a palustrine deposit of unknown age (complex FP), and protected from weathering and erosion inside a large cave/rock-shelter cavity, the sedimentary fill of Cueva Antón, a Middle Paleolithic site in SE Spain, corresponds in most part (sub-complexes AS2-to-AS5) to a ca.3 m-thick Upper Pleistocene terrace of the River Mula. Coupled with the constraints derived from the deposit's paleoclimatic proxies, OSL dating places the accumulation of this terrace in MIS 5a, and radiocarbon dates from the overlying breccia cum alluvium (sub-complex AS1) fall in the middle part of MIS 3; the intervening hiatus relates to valley incision and attendant erosion. The two intervals represented remain largely unknown in Iberia, where the archeology of the early-to-middle Upper Pleistocene is almost entirely derived from karst sites; Cueva Antón shows that this dearth of data, often interpreted in demographic terms, has depositional underpinnings ultimately determined by past climate variation. In early MIS 5a, the paleobotanical evidence indicates climate conditions similar to present, albeit wetter, followed by progressive cooling, reflected in the replacement of Aleppo pine by black pine and, at the very end, juniper-dominated landscapes - the latter characterizing also mid-MIS 3 times. The variation in sedimentary facies and composition of the mollusk assemblages reflects the changing position of the river channel relative to the back wall of the cave. Such changes represented the major constraint for the occupation of the site - most of the time inaccessible to terrestrial mammals, it was used throughout by the eagle-owl, explaining the abundance of rabbit bones. Human occupation occurred during a few, short windows of availability, and is reflected in well-preserved living floors defined by hearths, artefact scatters, and the remains of hunted herbivores. The stone tool assemblages are Middle Paleolithic, which, in Europe, implies a Neandertal identity for their makers

  16. Photic zone changes in the North West Pacific Ocean from MIS 4-5e

    NASA Astrophysics Data System (ADS)

    Swann, G. E. A.; Snelling, A. M.

    2014-08-01

    In comparison to other sectors of the marine system, the palaeoceanography of the subarctic North Pacific Ocean is poorly constrained. New diatom isotope records of δ13C, δ18O, δ30Si (δ13Cdiatom, δ18Odiatom, δ30Sidiatom), are presented alongside existing geochemical and isotope records to document changes in photic zone conditions, including nutrient supply and the efficiency of the soft-tissue biological pump, between Marine Isotope Stage (MIS) 4 and MIS 5e. Peaks in opal productivity in MIS 5b/c and MIS 5e are both associated with the breakdown of the regional halocline stratification and increased nutrient supply to the photic zone. Whereas the MIS 5e peak is associated with low rates of nutrient utilisation, the MIS 5b/c peak is associated with significantly higher rates of nutrient utilisation. Both peaks, together with other smaller increases in productivity in MIS 4 and 5a culminate with a~significant increase in freshwater input which strengthens/re-establishes the halocline and limits further upwelling of sub-surface waters to the photic zone. Whilst δ30Sidiatom and previously published records of diatom δ15N (δ15Ndiatom) (Brunelle et al., 2007, 2010) show similar trends until the latter half of MIS 5a, the records become anti-correlated after this juncture and into MIS 4, suggesting a possible change in photic zone state such as may occur with a shift to iron or silicon limitation.

  17. Photic zone changes in the north-west Pacific Ocean from MIS 4-5e

    NASA Astrophysics Data System (ADS)

    Swann, G. E. A.; Snelling, A. M.

    2015-01-01

    In comparison to other sectors of the marine system, the palaeoceanography of the subarctic North Pacific Ocean is poorly constrained. New diatom isotope records of δ13C, δ18O, δ30Si (δ13Cdiatom, δ18Odiatom, and δ30Sidiatom) are presented alongside existing geochemical and isotope records to document changes in photic zone conditions, including nutrient supply and the efficiency of the soft-tissue biological pump, between Marine Isotope Stage (MIS) 4 and MIS 5e. Peaks in opal productivity in MIS 5b/c and MIS 5e are both associated with the breakdown of the regional halocline stratification and increased nutrient supply to the photic zone. Whereas the MIS 5e peak is associated with low rates of nutrient utilisation, the MIS 5b/c peak is associated with significantly higher rates of nutrient utilisation. Both peaks, together with other smaller increases in productivity in MIS 4 and 5a, culminate with a significant increase in freshwater input which strengthens/re-establishes the halocline and limits further upwelling of sub-surface waters to the photic zone. Whilst δ30Sidiatom and previously published records of diatom δ15N (δ15Ndiatom) (Brunelle et al., 2007, 2010) show similar trends until the latter half of MIS 5a, the records become anti-correlated after this juncture and into MIS 4, suggesting a possible change in photic zone state such as may occur with a shift to iron or silicon limitation.

  18. MIS diode structure in As/+/ implanted CdS

    NASA Technical Reports Server (NTRS)

    Hutchby, J. A.

    1977-01-01

    Structure made by As implantation of carefully prepared high-conductivity CdS surfaces followed by Pt deposition and 450 C anneal display rectifying, although substantially different, I-V characteristics in the dark and during illumination with subband-gap light. Structures prepared in the same way on an unimplanted portion of the substrate have similar I-V characteristics, except that the forward turnover voltage for an illuminated unimplanted diode is much smaller than that for an implanted diode. It is suggested that the charge conduction in both structures is dominated by hole and/or electron tunneling through a metal-semiconductor potential barrier. The tunneling processes appear to be quite sensitive to subband-gap illumination, which causes the dramatic decreases of turnover voltages and apparent series resistances. The difference in turnover voltage appears to be caused by interface states between the Pt electrode and the implanted layer, which suggests a MIS model.

  19. Centromere localization and function of Mis18 requires Yippee-like domain-mediated oligomerization.

    PubMed

    Subramanian, Lakxmi; Medina-Pritchard, Bethan; Barton, Rachael; Spiller, Frances; Kulasegaran-Shylini, Raghavendran; Radaviciute, Guoda; Allshire, Robin C; Arockia Jeyaprakash, A

    2016-04-01

    Mis18 is a key regulator responsible for the centromere localization of the CENP-A chaperone Scm3 in Schizosaccharomyces pombe and HJURP in humans, which establishes CENP-A chromatin that defines centromeres. The molecular and structural determinants of Mis18 centromere targeting remain elusive. Here, by combining structural, biochemical, and yeast genetic studies, we show that the oligomerization of S. pombe Mis18, mediated via its conserved N-terminal Yippee-like domain, is crucial for its centromere localization and function. The crystal structure of the N-terminal Yippee-like domain reveals a fold containing a cradle-shaped pocket that is implicated in protein/nucleic acid binding, which we show is required for Mis18 function. While the N-terminal Yippee-like domain forms a homodimer in vitro and in vivo, full-length Mis18, including the C-terminal α-helical domain, forms a homotetramer in vitro We also show that the Yippee-like domains of human Mis18α/Mis18β interact to form a heterodimer, implying a conserved structural theme for Mis18 regulation. PMID:26921242

  20. Roles of Mis18α in epigenetic regulation of centromeric chromatin and CENP-A loading.

    PubMed

    Kim, Ik Soo; Lee, Minkyoung; Park, Koog Chan; Jeon, Yoon; Park, Joo Hyeon; Hwang, Eun Ju; Jeon, Tae Im; Ko, Seoyoung; Lee, Ho; Baek, Sung Hee; Kim, Keun Il

    2012-05-11

    The Mis18 complex has been identified as a critical factor for the centromeric localization of a histone H3 variant, centromeric protein A (CENP-A), which is responsible for the specification of centromere identity in the chromosome. However, the functional role of Mis18 complex is largely unknown. Here, we generated Mis18α conditional knockout mice and found that Mis18α deficiency resulted in lethality at early embryonic stage with severe defects in chromosome segregation caused by mislocalization of CENP-A. Further, we demonstrate Mis18α's crucial role for epigenetic regulation of centromeric chromatin by reinforcing centromeric localization of DNMT3A/3B. Mis18α interacts with DNMT3A/3B, and this interaction is critical for maintaining DNA methylation and hence regulating epigenetic states of centromeric chromatin. Mis18α deficiency led to reduced DNA methylation, altered histone modifications, and uncontrolled noncoding transcripts in centromere region by decreased DNMT3A/3B enrichment. Together, our findings uncover the functional mechanism of Mis18α and its pivotal role in mammalian cell cycle. PMID:22516971

  1. Space Station Furnace Facility Management Information System (SSFF-MIS) Development

    NASA Technical Reports Server (NTRS)

    Mead, Robert M.

    1996-01-01

    Thios report summarizes the chronology, results, and lessons learned from the development of the SSFF-MIS. This system has been nearly two years in development and has yielded some valuable insights into specialized MIS development. Attachment A contains additions, corrections, and deletions by the COTR.

  2. An Empirical Study about the Critical Factors Affecting MIS Students' Job Opportunities

    ERIC Educational Resources Information Center

    Fang, Xiang; Lee, Sooun

    2005-01-01

    For the first time in many years, Management Information Systems (MIS) students and faculty are seeking ways to improve full-time job placement for program graduates. Due to sharp IT budget cuts, the slowing economy, and outsourcing, job opportunities for MIS graduates have become scarcer than ever before. In addition to achieving good academic…

  3. Tropically-driven climate shifts in southwestern Europe during MIS 19, a low eccentricity interglacial

    NASA Astrophysics Data System (ADS)

    Sánchez Goñi, M. F.; Rodrigues, T.; Hodell, D. A.; Polanco-Martínez, J. M.; Alonso-García, M.; Hernández-Almeida, I.; Desprat, S.; Ferretti, P.

    2016-08-01

    The relative roles of high- versus low-latitude forcing of millennial-scale climate variability are still not well understood. Here we present terrestrial-marine climate profiles from the southwestern Iberian margin, a region particularly affected by precession, that show millennial climate oscillations related to a nonlinear response to the Earth's precession cycle during Marine Isotope Stage (MIS) 19. MIS 19 has been considered the best analogue to our present interglacial from an astronomical point of view due to the reduced eccentricity centred at 785 ka. In our records, seven millennial-scale forest contractions punctuated MIS 19 superimposed to two orbitally-driven Mediterranean forest expansions. In contrast to our present interglacial, we evidence for the first time low latitude-driven 5000-yr cycles of drying and cooling in the western Mediterranean region, along with warmth in the subtropical gyre related to the fourth harmonic of precession. These cycles indicate repeated intensification of North Atlantic meridional moisture transport that along with decrease in boreal summer insolation triggered ice growth and may have contributed to the glacial inception, at ∼774 ka. The freshwater fluxes during MIS 19ab amplified the cooling events in the North Atlantic promoting further cooling and leading to MIS 18 glaciation. The discrepancy between the dominant cyclicity observed during MIS 1, 2500-yr, and that of MIS 19, 5000-yr, challenges the similar duration of the Holocene and MIS 19c interglacials under natural boundary conditions.

  4. Reaction dynamics of Al + O₂ → AlO + O studied by a crossed-beam velocity map imaging technique: vib-rotational state selected angular-kinetic energy distribution.

    PubMed

    Honma, Kenji; Miyashita, Kazuki; Matsumoto, Yoshiteru

    2014-06-01

    Oxidation reaction of a gas-phase aluminum atom by a molecular oxygen was studied by a crossed-beam condition at 12.4 kJ/mol of collision energy. A (1+1) resonance-enhanced multiphoton ionization (REMPI) via the D(2)Σ(+)-X(2)Σ(+) transition of AlO was applied to ionize the product. The REMPI spectrum was analyzed to determine rotational state distributions for v = 0-2 of AlO. For several vib-rotational states of AlO, state selected angular and kinetic energy distributions were determined by a time-sliced ion imaging technique for the first time. Kinetic energy distributions were well represented by that taken into account initial energy spreads of collision energy and the population of the spin-orbit levels of the counter product O((3)P(J)) determined previously. All angular distributions showed forward and backward peaks, and the forward peaks were more pronounced than the backward one for the states of low internal energy. The backward peak intensity became comparable to the forward one for the states of high internal energy. These results and the rotational state distributions suggested that the reaction proceeds via an intermediate which has a lifetime comparable to or shorter than its rotational period. PMID:24908005

  5. Reaction dynamics of Al + O2 → AlO + O studied by a crossed-beam velocity map imaging technique: Vib-rotational state selected angular-kinetic energy distribution

    NASA Astrophysics Data System (ADS)

    Honma, Kenji; Miyashita, Kazuki; Matsumoto, Yoshiteru

    2014-06-01

    Oxidation reaction of a gas-phase aluminum atom by a molecular oxygen was studied by a crossed-beam condition at 12.4 kJ/mol of collision energy. A (1+1) resonance-enhanced multiphoton ionization (REMPI) via the D2Σ+-X2Σ+ transition of AlO was applied to ionize the product. The REMPI spectrum was analyzed to determine rotational state distributions for v = 0-2 of AlO. For several vib-rotational states of AlO, state selected angular and kinetic energy distributions were determined by a time-sliced ion imaging technique for the first time. Kinetic energy distributions were well represented by that taken into account initial energy spreads of collision energy and the population of the spin-orbit levels of the counter product O(3PJ) determined previously. All angular distributions showed forward and backward peaks, and the forward peaks were more pronounced than the backward one for the states of low internal energy. The backward peak intensity became comparable to the forward one for the states of high internal energy. These results and the rotational state distributions suggested that the reaction proceeds via an intermediate which has a lifetime comparable to or shorter than its rotational period.

  6. Evaluation of the modular inclined screen (MIS) at the Green Island Hydroelectric Project: 1995 test results

    SciTech Connect

    Shiers, P.F.; Downing, J.K.; Plizga, A.W.; Taft, E.P.; Amaral, S.V.; Cook, T.C.; Marks, R.A.; Winchell, F.C.

    1996-05-01

    The Electric Power Research Institute (EPRI) developed a fish diversion screen, known as the Modular Inclined Screen (MIS), to prevent fish mortality at water intakes. hydraulic model testing and successful biological evaluation of the MIS had been completed in the laboratory. Following discussions with various federal and state agencies, the Green Island hydroelectric Project was selected as the field test location. This project is located on the Hudson River, just north of Albany, in Green Island, New York. The MIS test facility was operated and tested in the fall of 1995. In addition to the MIS, the effectiveness of a strobe light system was studied to determine its ability to divert blueblack herring form the river to the MIS.

  7. βTrCP-mediated ubiquitylation regulates protein stability of Mis18β in a cell cycle-dependent manner.

    PubMed

    Kim, Ik Soo; Lee, Minkyoung; Park, Joo Hyeon; Jeon, Raok; Baek, Sung Hee; Kim, Keun Il

    2014-01-01

    Ubiquitin E3 ligases including SCF complex are key regulators of cell cycle. Here, we show that Mis18β, a component of Mis18 complex governing CENP-A localization, is a new substrate of βTrCP-containing SCF complex. βTrCP interacted with Mis18β exclusively during interphase but not during mitosis and mediated proteasomal degradation of Mis18β leading to the inactivation of Mis18 complex during interphase. In addition, uncontrolled stabilization of Mis18β caused cell death. Together, we propose that βTrCP-mediated regulation of Mis18β stability is a mechanism to restrict centromere function of Mis18 complex from late mitosis to early G1 phase. PMID:24269809

  8. 49 CFR Appendix H to Part 40 - DOT Drug and Alcohol Testing Management Information System (MIS) Data Collection Form

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Information System (MIS) Data Collection Form H Appendix H to Part 40 Transportation Office of the Secretary..., App. H Appendix H to Part 40—DOT Drug and Alcohol Testing Management Information System (MIS) Data Collection Form The following form is the MIS Data Collection form required for use beginning in 2011...

  9. Correcting amplitude, time, and phase mis-ties in seismic data

    SciTech Connect

    Bishop, T.N. ); Nunns, A.G. )

    1994-06-01

    Seismic lines from different vintages frequently mis-tie where they intersect. The mis-ties may stem from different amplitudes, a shift in time, or different wave-let character. The authors can correct these mis-ties to a great extent by applying a scale factor, a static time shift, and a phase rotation to one of the lines. The authors describe algorithms to compute the amplitude, time, and phase differences at each intersection among a series of 2-D seismic lines. They can then use an iterative least-squares technique to derive optimal mis-tie corrections for each line. They include a necessary modification of the least-squares technique for the nonlinear phase data. The various algorithms are stable, fast, and accurate. They have used them in conjunction with an interactive workstation seismic interpretation program for five years. The scalar mis-tie corrections greatly enhance the consistency of the seismic data. The authors show the results of the mis-tie package applied to a 20-line survey consisting of five vintages of seismic data. The resulting mis-tie corrections significantly improve the fit between the 20 lines.

  10. MIS-behavior: practical heuristics for precise pediatric minimally invasive surgery.

    PubMed

    Blinman, Thane A

    2015-02-01

    Minimally invasive surgery (MIS) has changed pediatric urology and general surgery, offering less morbidity and new surgical options for many procedures. This promise goes unrealized when technical methods lag. Application of MIS in children is uneven after more than 2 decades of application. Principles of versatile and proficient technique may remain unstated and implicit in surgical training, often leaving surgical training an exercise in inference and imitation. This article describes some essential practical principles of precision MIS applied to patients of any size. PMID:25455179

  11. Dielectrics for GaN based MIS-diodes

    SciTech Connect

    Ren, F.; Abernathy, C.R.; MacKenzie, J.D.

    1998-02-01

    GaN MIS diodes were demonstrated utilizing AlN and Ga{sub 2}O{sub 3}(Gd{sub 2}O{sub 3}) as insulators. A 345 {angstrom} of AlN was grown on the MOCVD grown n-GaN in a MOMBE system using trimethylamine alane as Al precursor and nitrogen generated from a wavemat ECR N2 plasma. For the Ga{sub 2}O{sub 3}(Gd{sub 2}O{sub 3}) growth, a multi MBE chamber was used and a 195 {angstrom} oxide is E-beam evaporated from a single crystal source of Ga{sub 5}Gd{sub 3}O{sub 12}. The forward breakdown voltage of AlN and Ga{sub 2}O{sub 3}(Gd{sub 2}O{sub 3}) diodes are 5V and 6V, respectively, which are significantly improved from {approximately} 1.2 V of schottky contact. From the C-V measurements, both kinds of diodes showed good charge modulation from accumulation to depletion at different frequencies. The insulator GaN interface roughness and the thickness of the insulator were measured with x-ray reflectivity.

  12. El Nino Activity During MIS 5e in Peru

    NASA Astrophysics Data System (ADS)

    Rein, B.; Sirocko, F.

    2004-12-01

    Oceanography and climate along the coast of Peru is fundamentally linked to ENSO variability with stronger lithic flux into the sea and reduced marine bioproductivity during El Nino events. A 19 m long piston core with laminated marine sediments has been recovered on the edge of the Peruvian shelf (12 03'S, 77 40W, 184 m waterdepth) during cruise Sonne-147 in 2000. We present the lower 6 meters of this core that cover the time between 100 to 130 kyr before the present (BP). SST has been estimated from alkenone analysis with a mean temporal resolution of 300 years. Color logging along the core at 2 mm intervals revealed high resolution proxy data (3 to 30 a) for the precipitation on the continent (fine-grained lithics) and marine bioproduction (photosynthesis pigments: chlorines, carotenoids). Proxy data show that a major change occurred around 123 kyr BP. Mean sedimentation rate which is largely controlled by lithics dropped from 40-70 cm/kyr to 18 cm/kyr after 123 kyr BP. Contemporaneously SST start to decline towards the early Glacial level that is reached between 118 to 116 ka during the time of glacial inception. We conclude that stronger El Nino floods occurred before 123 kyr BP and El Ninos were weaker during the second half of MIS 5e. The change to weaker ENSO activity in Peru is therewith roughly contemporaneous with the beginning cooling in Greenland.

  13. Do Null Subjects (mis-)Trigger Pro-drop Grammars?

    PubMed

    Frazier, Lyn

    2015-12-01

    Native speakers of English regularly hear sentences without overt subjects. Nevertheless, they maintain a [−pro] grammar that requires sentences to have an overt subject. It is proposed that listeners of English recognize that speakers reduce predictable material and thus attribute null subjects to this process, rather than changing their grammars to a [−pro] setting. Mack et al. (J Memory Lang 67(1):211-223, 2012) showed that sentences with noise covering the subject are analyzed as having null subjects more often with a first person pronoun and with a present tense--properties correlated with more predictable referents--compared to a third person pronoun and past tense. However, those results might in principle have been due to reporting null subjects for verbs that often occur with null subjects. An experiment is reported here in which comparable results are found for sentences containing nonsense verbs. Participants preferred a null subject more often for first person present tense sentences than for third person past tense sentences. The results are as expected if participants are responding to predictability, the likelihood of reduction, rather than to lexical statistics. The results are argued to be important in removing a class of mis-triggering examples from the language acquisition problem. PMID:25086703

  14. Bounded Empathy: Neural Responses to Outgroup Targets’ (Mis)fortunes

    PubMed Central

    Cikara, Mina; Fiske, Susan T.

    2013-01-01

    The current study investigates whether mere stereotypes are sufficient to modulate empathic responses to other people’s (mis)fortunes, how these modulations manifest in the brain, and whether affective and neural responses relate to endorsing harm against different outgroup targets. Participants feel least bad when misfortunes befall envied targets, and worst when misfortunes befall pitied targets, as compared to ingroup targets. Participants are also least willing to endorse harming pitied targets, despite pitied targets being outgroup members. However, those participants who exhibit increased activation in functionally-defined insula/MFG when viewing pity targets experience positive events not only report feeling worse about those events, but also more willing to harm pity targets in a tradeoff scenario. Similarly, increased activation in anatomically-defined bilateral anterior insula, in response to positive events, predicts increased willingness to harm envy targets, but decreased willingness to harm ingroup targets, above and beyond self-reported affect in response to the events. Stereotypes’ specific content, and not just outgroup membership, modulates empathic responses and related behavioral consequences including harm. PMID:21671744

  15. Carter G. Woodson's Mis-Education of the Negro: A Re-Visit

    ERIC Educational Resources Information Center

    Hay, Samuel A.

    1975-01-01

    Discusses the thesis of C. G. Woodson's book, "Mis-Education of the Negro" (1933), and argues that the liberation of the Black in America depends to a large measure on the quality of his education: the change of their lot demands that the mis-educated re-educate himself and that the panorama of great Black achievers be ever before the student.…

  16. INVESTIGATION OF MIS ITEM 011589A AND 3013 CONTAINERS HAVING SIMILAR CHARACTERISTICS

    SciTech Connect

    Friday, G

    2006-08-23

    Recent testing has identified the presence of hydrogen and oxygen in MIS Item 011589A. This isolated observation has effectuated concern regarding the potential for flammable gas mixtures in containers in the storage inventory. This study examines the known physicochemical characteristics of MIS Item 011589A and queries the ISP Database for items that are most similar or potentially similar. Items identified as most similar are believed to have the highest probability of being chemically and structurally identical to MIS Item 011589A. Items identified as potentially like MIS Item 011589A have some attributes in common, have the potential to generate gases, but have a lower probability of having similar gas generating characteristics. MIS Item 011589A is an oxide that was generated prior to 1990 at Rocky Flats in Building 707. It was associated with foundry processing and had an actinide assay of approximately 77%. Prompt gamma analysis of MIS Item 011589A indicated the presence of chloride, fluorine, magnesium, sodium, and aluminum. Queries based on MIS representation classification and process of origin were applied to the ISP Database. Evaluation criteria included binning classification (i.e., innocuous, pressure, or pressure and corrosion), availability of prompt gamma analyses, presence of chlorine and magnesium, percentage of chlorine by weight, peak ratios (i.e., Na:Cl and Mg:Na), moisture, and percent assay. These queries identified 15 items that were most similar and 106 items that were potentially like MIS Item 011589A. Although these queries identified containers that could potentially generate flammable gases, verification and confirmation can only be accomplished by destructive evaluation and testing of containers from the storage inventory.

  17. Electrical characteristics of insulating aluminum nitride MIS nanostructures

    NASA Astrophysics Data System (ADS)

    Abdallah, Bassam; Al-Khawaja, Sameer; Alkhawwam, Anas

    2011-10-01

    Capacitance-voltage measurements of high quality PECVD and MBE grown aluminum nitride (AlN) thin films have been performed. The prepared films have shown polycrystalline (0 0 2)-preferential orientation, and were deposited on p-type Si (1 0 0) substrates with Pt forming the metal gate in a metal-insulator-semiconductor (MIS) configuration. The structure, crystallinity, texture and insulating properties have been found to depend on film thickness and were substantially influenced by the increase of the thickness. C- V measurements of the epitaxial and PECVD films were carried out and their insulating characteristics with increasing thickness (200-1000 nm) were investigated. The epitaxial films exhibited no hysteresis in capacitance behaviour, owing to better crystalline quality over the PECVD grown ones. Capacitance curves versus bias voltage have also been acquired at different temperatures; 10 K, 30 K and 50 K for deposited polycrystalline AlN films of (0 0 2) orientation. We have found that the defects trapped in the Pt/AlN/Si structure played a key role in dominating the overall behaviour of the C- V measurement curves. The trapped charges at the interface between the AlN insulating film and Si substrate caused the capacitance characteristics to shift to negative voltages, and the estimated charge density was of the order of 10 10 and 10 8 cm -2 eV -1 for the PECVD and epitaxial samples respectively. The I- V measurements referred to space-charge conduction mechanism, and the deduced leakage current was found to be of the order of 10 -9 A at 200 nm film thickness.

  18. Environmental interpretation of fossil insect assemblages from MIS 5 at Ziegler Reservoir, Snowmass Village, Colorado

    NASA Astrophysics Data System (ADS)

    Elias, Scott A.

    2014-11-01

    Organic-rich lake sediments from a trench exposed at the Ziegler Reservoir fossil site near Snowmass Village, Colorado yielded a sequence of 27 insect fossil assemblages, spanning the time interval from about 125 to 77 ka. The assemblages appear to represent MIS 5e, 5c, 5b, and 5a. A total of 99 taxa were identified, mostly beetles. The fossils represent the oldest known Pleistocene insect faunas from high elevation in the Rocky Mountains, and document a series of climatic oscillations from full interglacial to stadial and interstadial environments, accompanied by changes in regional biological communities. The MIS 5e fauna indicates summer temperatures similar to modern values, with winter temperatures 5-7 °C cooler than today. Regional climates cooled somewhat by MIS 5c, and during MIS 5b summer temperatures were 5-6 °C colder than modern values. Summer temperatures recovered to near-modern levels during early MIS 5a, and cooled by 1-2 °C at its end, although winter temperatures were apparently above modern levels. The indication of milder but wetter winters, strengthened by the inclusion of species found today only in the Pacific Northwest region, suggests conditions that may have led to increased snowpack at high elevations in this part of the Rocky Mountains, linked with the onset of MIS 4 glaciation.

  19. Mis17 Is a Regulatory Module of the Mis6-Mal2-Sim4 Centromere Complex That Is Required for the Recruitment of CenH3/CENP-A in Fission Yeast

    PubMed Central

    Shiroiwa, Yoshiharu; Hayashi, Takeshi; Fujita, Yohta; Villar-Briones, Alejandro; Ikai, Nobuyasu; Takeda, Kojiro; Ebe, Masahiro; Yanagida, Mitsuhiro

    2011-01-01

    Background The centromere is the chromosome domain on which the mitotic kinetochore forms for proper segregation. Deposition of the centromeric histone H3 (CenH3, CENP-A) is vital for the formation of centromere-specific chromatin. The Mis6-Mal2-Sim4 complex of the fission yeast S. pombe is required for the recruitment of CenH3 (Cnp1), but its function remains obscure. Methodology/Principal Findings Mass spectrometry was performed on the proteins precipitated with Mis6- and Mis17-FLAG. The results together with the previously identified Sim4- and Mal2-TAP precipitated proteins indicated that the complex contains 12 subunits, Mis6, Sim4, Mal2, Mis15, Mis17, Cnl2, Fta1-4, Fta6-7, nine of which have human centromeric protein (CENP) counterparts. Domain dissection indicated that the carboxy-half of Mis17 is functional, while its amino-half is regulatory. Overproduction of the amino-half caused strong negative dominance, which led to massive chromosome missegregation and hypersensitivity to the histone deacetylase inhibitor TSA. Mis17 was hyperphosphorylated and overproduction-induced negative dominance was abolished in six kinase-deletion mutants, ssp2 (AMPK), ppk9 (AMPK), ppk15 (Yak1), ppk30 (Ark1), wis4 (Ssk2), and lsk1 (P-TEFb). Conclusions Mis17 may be a regulatory module of the Mis6 complex. Negative dominance of the Mis17 fragment is exerted while the complex and CenH3 remain at the centromere, a result that differs from the mislocalization seen in the mis17-362 mutant. The known functions of the kinases suggest an unexpected link between Mis17 and control of the cortex actin, nutrition, and signal/transcription. Possible interpretations are discussed. PMID:21445296

  20. Soil Moisture Performance Prediction for the NPOESS Microwave Imager/Sounder (MIS)

    NASA Astrophysics Data System (ADS)

    Li, L.; McWilliams, G.

    2009-12-01

    Soil moisture is a key environmental variable in the global water, energy and carbon cycles and in environmental assessment and prediction. It greatly affects a broad range of scientific and operational applications in hydrology, climate studies and agriculture. Soil moisture is also a desired input parameter to Numerical Weather Prediction (NWP) models since it controls the land-atmosphere interaction, such as dust emission and heating/moistening of the lower atmosphere. It is also a critical battlespace environment variable affecting military operations. The soil moisture content is critically related to trafficability as well as being a vital determinant of thermal and electromagnetic signatures that are vital to the operational ground mission in C4ISR (command, control, communications, computers, intelligence, surveillance, and reconnaissance). The National Polar-orbiting Operational Environmental Satellite System’s (NPOESS) Microwave Imager/Sounder (MIS) instrument is in development, with soil moisture sensing depth as one of the two Key Performance Parameters (KPPs). The other one is ocean surface wind speed precision. Based on the current design, the MIS sensor shares many channel configurations similar to the WindSat instrument, which provides an opportunity to predict MIS soil moisture performance using WindSat data. The WindSat land surface algorithm is a physically-based algorithm used to retrieve simultaneously the soil moisture, land surface temperature and vegetation water content for a range of surface types except for snow, frozen, rainy and flood surfaces. The algorithm has been rigorously validated against global in-situ data and has demonstrated great science potential in study of soil moisture response to precipitation, ITCZ (Intertropical Convergence Zone) propagation, drought detection, and heat wave evolution. The evaluation results suggest that the WindSat data products meet IORD II threshold soil moisture requirements. To approximate MIS

  1. Speleothem record of the last 180 ka in Villars cave (SW France): Investigation of a large δ18O shift between MIS6 and MIS5

    NASA Astrophysics Data System (ADS)

    Wainer, K.; Genty, D.; Blamart, D.; Daëron, M.; Bar-Matthews, M.; Vonhof, H.; Dublyansky, Y.; Pons-Branchu, E.; Thomas, L.; van Calsteren, P.; Quinif, Yves; Caillon, N.

    2011-01-01

    The Vil-car-1 flowstone core from Villars cave (SW France) provides one of the first European speleothem records extending back to 180 ka, based on U-Th TIMS and MC-ICP-MS measurements. The core offers a continuous record of Termination II and the Last Interglacial. The penultimate deglaciation is characterized by a prominent 5‰ depletion in calcite δ18O. Determining which specific environmental factors controlled such a large oxygen isotopic shift offers the opportunity to assess the impact of various factors influencing δ18O variations in speleothem calcite. Oxygen isotope analyses of fluid inclusions indicate that drip water δ18O remained within a very narrow range of ±1‰ from Late MIS6 to the MIS5 δ18O optimum. The possibility of such a stable behaviour is supported by simple calculations of various effects influencing seepage water δ18O. Although this could suggest that the isotopic shift in calcite is mainly driven by temperature increase, attempts to quantify the temperature shift from Late MIS6 to the MIS5 δ18O optimum by assuming an equilibrium relationship between calcite and fluid inclusion δ18O yield unreasonably high estimates of ˜20 °C warming and Late MIS6 cave temperatures below 0 °C; this suggests that the flowstone calcite precipitated out of thermodynamic equilibrium at this site. Using a method proposed by Guo et al. (submitted for publication) combining clumped isotope measurements, fluid inclusion and modern calcite δ18O analyses, it is possible to quantitatively correct for isotopic disequilibrium and estimate absolute paleotemperatures. Although the precision of these absolute temperature reconstructions is limited by analytical uncertainties, the temperature rise between Late MIS6 and the MIS5 optimum can be robustly constrained between 13.2 ± 2.6 and 14.6 ± 2.6 °C (1σ), consistent with existing estimates from Western Europe pollen and sea-surface temperature records.

  2. Similar millennial climate variability on the Iberian margin during two early Pleistocene glacials and MIS 3

    NASA Astrophysics Data System (ADS)

    Birner, B.; Hodell, D. A.; Tzedakis, P. C.; Skinner, L. C.

    2016-01-01

    Although millennial-scale climate variability (<10 ka) has been well studied during the last glacial cycles, little is known about this important aspect of climate in the early Pleistocene, prior to the Middle Pleistocene Transition. Here we present an early Pleistocene climate record at centennial resolution for two representative glacials (marine isotope stages (MIS) 37-41 from approximately 1235 to 1320 ka) during the "41 ka world" at Integrated Ocean Drilling Program Site U1385 (the "Shackleton Site") on the southwest Iberian margin. Millennial-scale climate variability was suppressed during interglacial periods (MIS 37, MIS 39, and MIS 41) and activated during glacial inceptions when benthic δ18O exceeded 3.2‰. Millennial variability during glacials MIS 38 and MIS 40 closely resembled Dansgaard-Oeschger events from the last glacial (MIS 3) in amplitude, shape, and pacing. The phasing of oxygen and carbon isotope variability is consistent with an active oceanic thermal bipolar see-saw between the Northern and Southern Hemispheres during most of the prominent stadials. Surface cooling was associated with systematic decreases in benthic carbon isotopes, indicating concomitant changes in the meridional overturning circulation. A comparison to other North Atlantic records of ice rafting during the early Pleistocene suggests that freshwater forcing, as proposed for the late Pleistocene, was involved in triggering or amplifying perturbations of the North Atlantic circulation that elicited a bipolar see-saw response. Our findings support similarities in the operation of the climate system occurring on millennial time scales before and after the Middle Pleistocene Transition despite the increases in global ice volume and duration of the glacial cycles.

  3. New evidence for complex climate change in MIS 11 from Hoxne, Suffolk, UK

    PubMed Central

    Ashton, Nick; Lewis, Simon G.; Parfitt, Simon A.; Penkman, Kirsty E.H.; Russell Coope, G.

    2008-01-01

    The climatic signal of Marine Isotope Stage (MIS) 11 is well-documented in marine and ice-sheet isotopic records and is known to comprise at least two major warm episodes with an intervening cool phase. Terrestrial records of MIS 11, though of high resolution, are often fragmentary and their chronology is poorly constrained. However, some notable exceptions include sequences from the maar lakes in France and Tenaghi Philippon in Greece. In the UK, the Hoxnian Interglacial has been considered to correlate with MIS 11. New investigations at Hoxne (Suffolk) provide an opportunity to re-evaluate the terrestrial record of MIS 11. At Hoxne, the type Hoxnian Interglacial sediments are overlain by a post-Hoxnian cold-temperate sequence. The interglacial sediments and the later temperate phase are separated by the so-called ‘Arctic Bed’ from which cold-climate macroscopic plant and beetle remains have been recovered. The later temperate phase was deposited during an episode of boreal woodland and is associated with the artefacts, a diverse vertebrate fauna and molluscs. New amino acid geochronological data and biostratigraphical considerations suggest that the post-Hoxnian sequence correlates with late substages of MIS 11. The paper further investigates the correlation of the sequence at Hoxne with the palynological sequences found elsewhere in Europe and adjacent offshore areas. PMID:19777138

  4. A multi-proxy record of MIS 11-12 deglaciation and glacial MIS 12 instability from the Sulmona basin (central Italy)

    NASA Astrophysics Data System (ADS)

    Regattieri, Eleonora; Giaccio, Biagio; Galli, Paolo; Nomade, Sebastien; Peronace, Edoardo; Messina, Paolo; Sposato, Andrea; Boschi, Chiara; Gemelli, Maurizio

    2016-01-01

    A multi-proxy record (lithology, XRF, CaCO3 content, carbonate δ18O and δ13C) was acquired from a sediment core drilled in the intermountain Sulmona basin (central Italy). Tephrostratigraphic analyses of three volcanic ash layers ascribe the investigated succession to the MIS 12-MIS 11 period, spanning the interval ca. 500-410 ka. Litho-pedo facies assemblage indicates predominant lacustrine deposition, interrupted by a minor sub-aerial and lake low stand episode. Variations in major and minor elements concentrations are related to changes in the clastic input to the lake. The oxygen isotopic composition of carbonate (δ18Oc) intervals is interpreted mainly as a proxy for the amount of precipitation in the high-altitude catchment of the karst recharge system. The record shows pronounced hydrological variability at orbital and millennial time-scales, which appears closely related to the Northern Hemisphere summer insolation pattern and replicates North Atlantic and west Mediterranean Sea Surface Temperature (SST) fluctuations. The MIS 12 glacial inception is marked by an abrupt reduction of precipitation, lowering of the lake level and enhanced catchment erosion. A well-defined and isotopically prominent interstadial with increased precipitation maybe related to insolation maxima-precession minima at ca. 465 ka. This interstadial ends abruptly at ca. 457 ka and it is followed by a phase of strong short-term instability. Drastic lake-level lowering and enhanced clastic flux characterized the MIS 12 glacial maximum. Lacustrine deposition restarted about 440 ka ago. The MIS 12-MIS 11 transition is characterized by a rapid increase in the precipitation, lake-level rise and reduction in the clastic input, interrupted by a short and abrupt return to drier conditions. Comparison with marine records from the Iberian margin and western Mediterranean suggests that major events of ice rafted debris deposition, related to southward migrations of the polar front, match the

  5. Stable Isotope and Trace Element Records of Parts of MIS 5 and MIS 6 from Stalagmites from Lehman Cave, Nevada, USA

    NASA Astrophysics Data System (ADS)

    Cross, M.; McGee, D.; Broecker, W. S.; Quade, J.; Cheng, H.; Edwards, R. L.

    2014-12-01

    Recent years have seen the advent of high-resolution speleothem paleoclimate records from the Great Basin, adding to and refining our knowledge of the timing, duration, and nature of glacial/interglacial periods and transitions in Western North America from lake records and other archives of paleoclimatic change. Here we present a record of isotopic and geochemical change in stalagmites from Lehman Cave, (39.01°N, 114.22°W), a well-decorated cave on the western edge of the Bonneville Basin. These slow-growth stalagmites are 230Th dated to portions of Marine Isotope Stages 5 and 6. They replicate, at least in part, an orbitally-consistent Termination II (T-II) at 131 + 2 ka, first demonstrated in Great Basin speleothems by Shakun et al. (2011). T-II is expressed in our record as a +5.5‰ (from -7.5 to -2 ‰) and nearly +4‰ (from -14.4 to -10.5‰, when corrected for sea level) shift in δ13C and δ18O, respectively. There are notable similarities and differences among our record and other Great Basin records, Devils Hole (Winograd et al. 1992) and the recent speleothem records by Lachniet et al. (2014) and Denniston et al. (2007). Our record, for example, does not agree with the early timing of T-II in Devils Hole. However, during the latter portion of MIS 5, our record exhibits oxygen isotope values (-13 to -14‰ VPDB) significantly lighter than those in MIS 5e (-10.5 to -11‰ VPDB), similar to Devils Hole and Goshute Cave. In contrast, correlative values in Leviathan Cave (Lachniet et al., 2014) during the latter part of MIS5 are up to 3‰ heavier: -10.5‰ VPDB, matching MIS 5e values. Additionally, the lowest MIS 6 oxygen isotopic values in our record are reached at approximately 137.5 ± 2 ka, about 4 ka earlier than in the Lehman Cave sample presented in the Lachniet et al. record. We evaluate several potential explanations for these offsets in the MIS 5 samples, for example, variable degrees of isotopic enrichment. As a step towards reconciling these

  6. A Microscopic Information System (MIS) to assist in petrographic analysis

    NASA Astrophysics Data System (ADS)

    Tarquini, S.; Favalli, M.

    2009-04-01

    Rock texture results from all the petrological processes that have affected the rock system. The interpretation of a rock texture relies on the analysis of the morphometric parameters of the constituting components (e.g. crystals or grains). A consistent and statistically sound quantification of components size and shape is crucial to adequately unravel the petrology of a rock, but the gathering of these measurements may be time-consuming or difficult to achieve using low-cost facilities. The basic technique for texture analysis of rocks is the observation of thin sections in transmitted light by using a petrographic microscope. To automate and speed-up textural measurements from thin section in transmitted light, several image processing procedures have been published in the last two decades. Nevertheless, the complexity of the optical properties of crystals hampered the determination of a method that is completely satisfactory, especially for complex polymineralic plutonic rocks. This work provides a contribution to solve this problem. We present a novel composite procedure based on four approaches: i) the use of a slide scanner to acquire the input imagery in transmitted light from thin sections without using the petrographic microscope; ii) the storage of the resulting images in a GIS-like database structure that is extremely useful to retrieve, browse and analyze a large archive of images from a high number of thin sections; iii) the application of a custom image analysis procedure based on two region growing functions; iv) the refinement of the regions after raster to vector conversion using GIS software. We call the obtained analysis system a Microscopic Information System (MIS), because it relies on GIS software but it is not a geographic system. In this study we apply this technique to analyze 137 thin sections obtained from 49 samples of 8 different granitoid rocks that are commonly used in the decorative stone industry. For each thin section 5 collimated

  7. Studies of Large-Area Inversion-Layer Metal-Insulator-Semiconductor (IL/MIS) Solar Cells and Arrays

    NASA Technical Reports Server (NTRS)

    Ho, Fat Duen

    1996-01-01

    Many inversion-layer metal-insulator-semiconductor (IL/MIS) solar cells have been fabricated. There are around eighteen 1 cm(exp 2) IL/MIS solar cells which have efficiencies greater than 7%. There are only about three 19 cm(exp 2) IL/MIS cells which have efficiencies greater than 4%. The more accurate control of the thickness of the thin layer of oxide between aluminum and silicon of the MIS contacts has been achieved. A lot of effort and progress have been made in this area. A comprehensive model for MIS contacts under dark conditions has been developed that covers a wide range of parameters. It has been applied to MIS solar cells. One of the main advantages of these models is the prediction of the range of the thin oxide thickness versus the maximum efficiencies of the MIS solar cells. This is particularly important when the thickness is increased to 25 A. This study is very useful for our investigation of the IL/MIS solar cells. The two-dimensional numerical model for the IL/MIS solar cells has been tried to develop and the results are presented in this report.

  8. MIS and PN junction solar cells on thin-film polycrystalline silicon

    SciTech Connect

    Ariotedjo, A.; Emery, K.; Cheek, G.; Pierce, P.; Surek, T.

    1981-05-01

    The Photovoltaic Advanced Silicon (PVAS) Branch at the Solar Energy Research Institute (SERI) has initiated a comparative study to assess the potential of MIS-type solar cells for low-cost terrestrial photovoltaic systems in terms of performance, stability, and cost-effectiveness. Several types of MIS and SIS solar cells are included in the matrix study currently underway. This approach compares the results of MIS and p/n junction solar cells on essentially identical thin-film polycrystalline silicon materials. All cell measurements and characterizations are performed using uniform testing procedures developed in the Photovoltaic Measurements and Evaluation (PV M and E) Laboratory at SERI. Some preliminary data on the different cell structures on thin-film epitaxial silicon on metallurgical-grade substrates are presented here.

  9. Late quaternary sea level changes of Gabes coastal plain and shelf: Identification of the MIS 5c and MIS 5a onshore highstands, southern Mediterranean

    NASA Astrophysics Data System (ADS)

    Gzam, Maher; Mejdoub, Noureddine El; Jedoui, Younes

    2016-02-01

    The continental shelf of the Gulf of Gabes is outlined, during the MIS 5c and MIS 5a onshore highstands, by the genesis of forced regressive beach ridges situated respectively at -19 m b.s.l/100 ka and -8 m b.s.l/80 ka. This area, considered as a stable domain since at least the last 130 ka (Bouaziz et al. 2003), is a particular zone for the reconstruction of the late quaternary sea-level changes in the region. Shuttle Radar Topography Mission (SRTM) data and field observations are highlighted to deduce interaction between hydrodynamic factors and antecedent topography. Variations in geomorphology were attributed to geological inheritance. Petrography and sedimentary facies of the submerged coastal ridges reveal that the palaeocoastal morphology was more agitated than today and the fluvial discharges are consistent. Actual morphologic trend deduced from different environment coasts (sandy coasts, sea cliffs and tidal flat) is marked by accumulation of marine sands and progradation.

  10. The response of SST to insolation and ice sheet variability from MIS 3 to MIS 11 in the northwestern Mediterranean Sea (Gulf of Lions)

    NASA Astrophysics Data System (ADS)

    Cortina, Aleix; Sierro, Francisco Javier; Flores, José Abel; Martrat, Belen; Grimalt, Joan O.

    2015-12-01

    Here we present a sea surface temperature (SST) record based on the Uk'37 index from the PRGL1 borehole (Promess1) drilled on the upper slope of the Gulf of Lions (GL). This is the first continuous and high-resolution record in the northwestern Mediterranean Sea from marine oxygen isotope stage 3 (MIS) 3 to MIS 11. Due the location of the GL, the SST proxy can be considered to be a reliable tool to study the climate link between high latitude and midlatitude. During glacial inceptions, the northern ice sheet signal via cold northwesterly winds was first recorded in our study area in comparison with southern locations, highlighting the strong sensitivity of this location to high-latitude dynamics. Moreover, the amplitude of the millennial-scale variability in the western Mediterranean basin seems to be the result of both ice sheet and insolation variability.

  11. An Auto-management Thesis Program WebMIS Based on Workflow

    NASA Astrophysics Data System (ADS)

    Chang, Li; Jie, Shi; Weibo, Zhong

    An auto-management WebMIS based on workflow for bachelor thesis program is given in this paper. A module used for workflow dispatching is designed and realized using MySQL and J2EE according to the work principle of workflow engine. The module can automatively dispatch the workflow according to the date of system, login information and the work status of the user. The WebMIS changes the management from handwork to computer-work which not only standardizes the thesis program but also keeps the data and documents clean and consistent.

  12. Coccolithophore variability from the Shackleton Site (IODP Site U1385) through MIS 16-10

    NASA Astrophysics Data System (ADS)

    Maiorano, P.; Marino, M.; Balestra, B.; Flores, J.-A.; Hodell, D. A.; Rodrigues, T.

    2015-10-01

    Coccolithophore assemblages have been investigated at Integrated Ocean Drilling Program Site U1385, on the western Iberian margin, through Marine Isotope Stage (MIS) 16 to 10, between the end of the Mid-Pleistocene Transition and the Mid-Brunhes interval, with the aim to reconstruct orbital and millennial-scale surface water modifications. Assemblage variations are interpreted in terms of paleoclimate and paleoproductivity proxies. The pattern of C37 alkenones is also presented as an additional indicator of primary paleoproductivity. The overall proxies are compared with the available benthic and planktonic δ18O records and Ca/Ti profile. A new benthic and planktonic δ13C dataset is also shown. The coccolithophore abundance mirrors the Ca/Ti pattern indicating that coccolith-derived carbonate is the dominant contributor to carbonate production in the studied interval. The distinct increase in the coccolithophore abundance, as well as in the accumulation rate, occurring at the MIS 14/13 transition, reflects the beginning of the worldwide-scale mid-Brunhes blooming of Gephyrocapsa caribbeanica and triggers the increase in carbonate production imprinted on the Ca/Ti profile. Interglacials are marked by enhanced abundances of the coccolithophore warm water group (wwt group) that also displays high frequency variability related to precessional/insolation forcing. Warmest surface water conditions are recorded during MIS 15, suggesting an intensified contribution of the subtropical AzC, essentially during MIS 15.5 and 15.1. Reduced productivity in these intervals is in agreement with a major influence of nutrient-poor and less ventilated subtropical waters. On the other hand, productive and mixed surface water conditions can be inferred during MIS 13 in agreement with other North Atlantic records. A long lasting period of warm, stratified and oligotrophic waters is inferred during MIS 11.3, indicating a continuous and more persistent influence of subtropical waters at

  13. Differentiation of MIS 9 and MIS 11 in the continental record: vegetational, faunal, aminostratigraphic and sea-level evidence from coastal sites in Essex, UK

    NASA Astrophysics Data System (ADS)

    Roe, Helen M.; Coope, G. Russell; Devoy, Robert J. N.; Harrison, Colin J. O.; Penkman, Kirsty E. H.; Preece, Richard C.; Schreve, Danielle C.

    2009-11-01

    Multidisciplinary investigations of the vegetational, faunal and sea-level history inferred from the infills of buried channels on the coast of eastern Essex have a direct bearing on the differentiation of MIS 11 and MIS 9 in continental records. New data are presented from Cudmore Grove, an important site on Mersea Island that can be linked to the terrace sequence of the River Thames. The vegetational history has been reconstructed from a pollen sequence covering much of the interglacial represented. The temperate nature of the climate is apparent from a range of fossil groups, including plant remains, vertebrates (especially the rich herpetofauna), molluscs and beetles, which all have strong thermophilous components. The beetle data have been used to derive a Mutual Climatic Range reconstruction, suggesting that mean July temperatures were about 2 °C warmer than modern values for southeast England, whereas mean January temperatures may have been slightly colder. The sea-level history has been reconstructed from the molluscs, ostracods and especially the diatoms, which indicate that the marine transgression occurred considerably earlier in the interglacial cycle than at the neighbouring Hoxnian site at Clacton. There are a number of palynological similarities between the sequence at Cudmore Grove and Clacton, especially the presence of Abies and the occurrence of Azolla filiculoides megaspores. Moreover, both sites have yielded Palaeolithic archaeology, indeed the latter is the type site of the Clactonian (flake-and-core) industry. However, the sites can be differentiated on the basis of mammalian biostratigraphy, new aminostratigraphic data, as well as the differences in the sea-level history. The combined evidence suggests that the infill of the channel at Cudmore Grove accumulated during MIS 9, whereas the deposits at Clacton formed during MIS 11. The infill of a much later channel, yielding non-marine molluscs and vertebrates including Hippopotamus, appears

  14. Differentiation of MIS 9 and MIS 11 in the continental record: vegetational, faunal, aminostratigraphic and sea-level evidence from coastal sites in Essex, UK.

    PubMed

    Roe, Helen M; Coope, G Russell; Devoy, Robert J N; Harrison, Colin J O; Penkman, Kirsty E H; Preece, Richard C; Schreve, Danielle C

    2009-11-01

    Multidisciplinary investigations of the vegetational, faunal and sea-level history inferred from the infills of buried channels on the coast of eastern Essex have a direct bearing on the differentiation of MIS 11 and MIS 9 in continental records. New data are presented from Cudmore Grove, an important site on Mersea Island that can be linked to the terrace sequence of the River Thames. The vegetational history has been reconstructed from a pollen sequence covering much of the interglacial represented. The temperate nature of the climate is apparent from a range of fossil groups, including plant remains, vertebrates (especially the rich herpetofauna), molluscs and beetles, which all have strong thermophilous components. The beetle data have been used to derive a Mutual Climatic Range reconstruction, suggesting that mean July temperatures were about 2 degrees C warmer than modern values for southeast England, whereas mean January temperatures may have been slightly colder. The sea-level history has been reconstructed from the molluscs, ostracods and especially the diatoms, which indicate that the marine transgression occurred considerably earlier in the interglacial cycle than at the neighbouring Hoxnian site at Clacton. There are a number of palynological similarities between the sequence at Cudmore Grove and Clacton, especially the presence of Abies and the occurrence of Azolla filiculoides megaspores. Moreover, both sites have yielded Palaeolithic archaeology, indeed the latter is the type site of the Clactonian (flake-and-core) industry. However, the sites can be differentiated on the basis of mammalian biostratigraphy, new aminostratigraphic data, as well as the differences in the sea-level history. The combined evidence suggests that the infill of the channel at Cudmore Grove accumulated during MIS 9, whereas the deposits at Clacton formed during MIS 11. The infill of a much later channel, yielding non-marine molluscs and vertebrates including Hippopotamus

  15. Differentiation of MIS 9 and MIS 11 in the continental record: vegetational, faunal, aminostratigraphic and sea-level evidence from coastal sites in Essex, UK

    PubMed Central

    Roe, Helen M.; Coope, G. Russell; Devoy, Robert J.N.; Harrison, Colin J.O.; Penkman, Kirsty E.H.; Preece, Richard C.; Schreve, Danielle C.

    2009-01-01

    Multidisciplinary investigations of the vegetational, faunal and sea-level history inferred from the infills of buried channels on the coast of eastern Essex have a direct bearing on the differentiation of MIS 11 and MIS 9 in continental records. New data are presented from Cudmore Grove, an important site on Mersea Island that can be linked to the terrace sequence of the River Thames. The vegetational history has been reconstructed from a pollen sequence covering much of the interglacial represented. The temperate nature of the climate is apparent from a range of fossil groups, including plant remains, vertebrates (especially the rich herpetofauna), molluscs and beetles, which all have strong thermophilous components. The beetle data have been used to derive a Mutual Climatic Range reconstruction, suggesting that mean July temperatures were about 2 °C warmer than modern values for southeast England, whereas mean January temperatures may have been slightly colder. The sea-level history has been reconstructed from the molluscs, ostracods and especially the diatoms, which indicate that the marine transgression occurred considerably earlier in the interglacial cycle than at the neighbouring Hoxnian site at Clacton. There are a number of palynological similarities between the sequence at Cudmore Grove and Clacton, especially the presence of Abies and the occurrence of Azolla filiculoides megaspores. Moreover, both sites have yielded Palaeolithic archaeology, indeed the latter is the type site of the Clactonian (flake-and-core) industry. However, the sites can be differentiated on the basis of mammalian biostratigraphy, new aminostratigraphic data, as well as the differences in the sea-level history. The combined evidence suggests that the infill of the channel at Cudmore Grove accumulated during MIS 9, whereas the deposits at Clacton formed during MIS 11. The infill of a much later channel, yielding non-marine molluscs and vertebrates including Hippopotamus, appears

  16. Mapping the MIS Curriculum Based on Critical Skills of New Graduates: An Empirical Examination of IT Professionals

    ERIC Educational Resources Information Center

    Downey, James P.; McMurtrey, Mark E.; Zeltmann, Steven M.

    2008-01-01

    MIS curricula research almost always focuses on either curriculum issues or the critical skills required of new MIS graduates, rarely both. This study examines both by determining the critical skills required of new graduates, from the perspective of IT professionals in the field, then uniquely mapping those skills into a comprehensive yet…

  17. Inner centromere formation requires hMis14, a trident kinetochore protein that specifically recruits HP1 to human chromosomes

    PubMed Central

    Kiyomitsu, Tomomi; Iwasaki, Osamu; Obuse, Chikashi

    2010-01-01

    Centromeric DNA forms two structures on the mitotic chromosome: the kinetochore, which interacts with kinetochore microtubules, and the inner centromere, which connects sister kinetochores. The assembly of the inner centromere is poorly understood. In this study, we show that the human Mis14 (hMis14; also called hNsl1 and DC8) subunit of the heterotetrameric hMis12 complex is involved in inner centromere architecture through a direct interaction with HP1 (heterochromatin protein 1), mediated via a PXVXL motif and a chromoshadow domain. We present evidence that the mitotic function of hMis14 and HP1 requires their functional association at interphase. Alterations in the hMis14 interaction with HP1 disrupt the inner centromere, characterized by the absence of hSgo1 (Shugoshin-like 1) and aurora B. The assembly of HP1 in the inner centromere and the localization of hMis14 at the kinetochore are mutually dependent in human chromosomes. hMis14, which contains a tripartite-binding domain for HP1 and two other kinetochore proteins, hMis13 and blinkin, is a cornerstone for the assembly of the inner centromere and kinetochore. PMID:20231385

  18. 49 CFR Appendix H to Part 40 - DOT Drug and Alcohol Testing Management Information System (MIS) Data Collection Form

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false DOT Drug and Alcohol Testing Management Information System (MIS) Data Collection Form H Appendix H to Part 40 Transportation Office of the Secretary..., App. H Appendix H to Part 40—DOT Drug and Alcohol Testing Management Information System (MIS)...

  19. 49 CFR Appendix H to Part 40 - DOT Drug and Alcohol Testing Management Information System (MIS) Data Collection Form

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 1 2013-10-01 2013-10-01 false DOT Drug and Alcohol Testing Management Information System (MIS) Data Collection Form H Appendix H to Part 40 Transportation Office of the Secretary..., App. H Appendix H to Part 40—DOT Drug and Alcohol Testing Management Information System (MIS)...

  20. 49 CFR Appendix H to Part 40 - DOT Drug and Alcohol Testing Management Information System (MIS) Data Collection Form

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false DOT Drug and Alcohol Testing Management Information System (MIS) Data Collection Form H Appendix H to Part 40 Transportation Office of the Secretary..., App. H Appendix H to Part 40—DOT Drug and Alcohol Testing Management Information System (MIS)...

  1. Design of a Model Management Information System (MIS) for California's Regional Occupational Centers and Programs. Final Report.

    ERIC Educational Resources Information Center

    Dick, James C.; And Others

    The management information system (MIS) development project for California's Regional Occupational Centers and Programs (ROC/Ps) was conducted in 3 phases over a 12-month period. Phase I involved a literature review and field study to match MIS design features and development strategy with existing conditions in ROC/Ps. A decision support system…

  2. 49 CFR Appendix H to Part 40 - DOT Drug and Alcohol Testing Management Information System (MIS) Data Collection Form

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false DOT Drug and Alcohol Testing Management Information System (MIS) Data Collection Form H Appendix H to Part 40 Transportation Office of the Secretary..., App. H Appendix H to Part 40—DOT Drug and Alcohol Testing Management Information System (MIS)...

  3. Millennial-scale climate instabilities in the subtropical Atlantic during MIS 6 and 7

    NASA Astrophysics Data System (ADS)

    Scheinwald, A.; Billups, K.

    2012-12-01

    We have constructed a high resolution (~200 year) planktonic foraminiferal stable isotope record spanning Marine Isotope Stages (MIS) 6 and 7 in the subtropical Atlantic (ODP Site 1059). The record fills a gap in a ~1 million year long time series of millennial-scale surface ocean hydrography in this region. Our ultimate goal is to test the hypothesis that millennial-scale climate signals in the northwestern subtropical Atlantic are linked to external driving factors such as the harmonics of precession. Results show that longer-term trends in the oxygen isotope data spanning MIS 6-7 closely follow precessional forcing allowing us to refine the original age model of Grützner et al. (2002). High frequency variations are superimposed on the long-term trend during both the glacial MIS 6 and the interglacial MIS 7. Spectral analyses indicate high concentration of power at millennial-scale periodicities of 10.9 kyr, 5.2 kyr, and 2.8 kyr. These periodicities are close to those expected from harmonics of precessional forcing during this interval of time (11.5 kyr, 5.8 kyr, 2.8 kyr). We will show the evolution of the millennial-scale periodicities in this region over the past 1 million years by splicing the record into published ones and unifying the age model.

  4. Student Motivational Profiles in an Introductory MIS Course: An Exploratory Cluster Analysis

    ERIC Educational Resources Information Center

    Nelson, Klara

    2014-01-01

    This study profiles students in an introductory MIS course according to a variety of variables associated with choice of academic major. The data were collected through a survey administered to 12 sections of the course. A two-step cluster analysis was performed with gender as a categorical variable and students' perceptions of task value…

  5. The Inchworm and the Nightingale: On the (Mis)use of Data in Music Teacher Evaluation

    ERIC Educational Resources Information Center

    Robinson, Mitchell

    2015-01-01

    The music education profession is faced with two serious problems regarding the (mis)use of data in music teacher evaluation. The first has to do with the quality and kinds of data that music teachers have been forced to use; the second is concerned with how these data are being used in the music teacher evaluation process. The evidence I will use…

  6. Present state of the Mini-Invasive Surgery (MIS) in esophageal and gastric cancer.

    PubMed

    Azagra, J S; Goergen, M; Lens, V; Ibáñez-Aguirre, J F; Schiltz, M; Siciliano, I

    2006-03-01

    The purpose of this review is to stress the role of the Mini-Invasive Surgery (MIS) in the treatment of the esophagogastric malignant illnesses, supporting ourselves on the most relevant publications of the literature as well as on our own experience in this subject. In short, although no randomised prospective study has proven the MIS advantages in relation to the traditional surgery in the esophagectomy due to cancer, some authors preferently indicate this approach to selected and informed enough patients, who present the following: - High grade dysplasia, preferently choosing from laparoscopic transhiatal esophagectomy (LTE). - Carcinoma in situ, preferently choosing the LTE vs thoracoscopy. - Esophageal tumour locally advanced, in resectable patients with contraindication for a thoracotomy or, in initially non-resectable patients with tumoral reduction after neo-adjuvant chemo-radiotherapy. The arguments given by the authors are the postoperative spectacular improvement in relation to the comfort and quality of life and, the absence of oncological negative effects in the long-term followup. Concerning gastric cancer, the MIS, as exeresis surgical tool in the so-called gastric forms, is such a definite and oncological approach as the traditional approach, and superior to this as far as quality of life is concerned. When the MIS is used for treating locally advanced forms of gastric cancer, it is as safe as the laparotomic way and it seems to obtain the same oncological outcomes in the long-term. PMID:16648116

  7. First physical evidence for forested environment in the Arctic during MIS 3

    NASA Astrophysics Data System (ADS)

    Sarala, Pertti; Väliranta, Minna; Eskola, Tiina; Vaikutiené, Giedré

    2016-07-01

    Old sedimentological and geochronological records can be preserved underneath the central parts of the continental ice sheets under non-erosive, cold-based subglacial conditions. Organic deposits that predate the last deglaciation are of particular value for the information held on glacial-time climate and environmental conditions. In this study, we present multiproxy data derived from a well-preserved MIS 3 interstadial (55–25 ka ago) organic layer from inside the Arctic Circle in the Finnish Lapland. Biological proxy evidence, namely coming from aquatic plant species, indicates July temperatures as high as 14.4 °C, i.e. higher than those of today for the study site. Macrofossil evidence demonstrates for the first time the presence of pines accompanied by tree birch during the MIS 3 interstadial in northern Fennoscandia. These results concur with contemporary insolation model outcomes but contradict with the previous proxy-based view of open tundra conditions during the MIS 3. The data suggest that there are highly dynamic interstadial continental ice-sheet dynamics following changes in orbital forcing. Warm climate enabled the establishment of forests on exposed landscape. Moreover, we suggest that in the light of these new data, previous MIS 3 pollen data could be re-interpreted.

  8. First physical evidence for forested environment in the Arctic during MIS 3

    PubMed Central

    Sarala, Pertti; Väliranta, Minna; Eskola, Tiina; Vaikutiené, Giedré

    2016-01-01

    Old sedimentological and geochronological records can be preserved underneath the central parts of the continental ice sheets under non-erosive, cold-based subglacial conditions. Organic deposits that predate the last deglaciation are of particular value for the information held on glacial-time climate and environmental conditions. In this study, we present multiproxy data derived from a well-preserved MIS 3 interstadial (55–25 ka ago) organic layer from inside the Arctic Circle in the Finnish Lapland. Biological proxy evidence, namely coming from aquatic plant species, indicates July temperatures as high as 14.4 °C, i.e. higher than those of today for the study site. Macrofossil evidence demonstrates for the first time the presence of pines accompanied by tree birch during the MIS 3 interstadial in northern Fennoscandia. These results concur with contemporary insolation model outcomes but contradict with the previous proxy-based view of open tundra conditions during the MIS 3. The data suggest that there are highly dynamic interstadial continental ice-sheet dynamics following changes in orbital forcing. Warm climate enabled the establishment of forests on exposed landscape. Moreover, we suggest that in the light of these new data, previous MIS 3 pollen data could be re-interpreted. PMID:27363905

  9. The Interactive, Virtual Management Information Systems (MIS) Classroom: Creating an Active Learning Environment on the Internet.

    ERIC Educational Resources Information Center

    Abraham, Thomas

    This paper describes the creation of an active learning environment within an Internet-based course in the School of Business, Government and Technology at Kean University (New Jersey). The introductory Management Information Systems (MIS) course is an elective that has become increasingly popular with junior and senior business majors. The main…

  10. First physical evidence for forested environment in the Arctic during MIS 3.

    PubMed

    Sarala, Pertti; Väliranta, Minna; Eskola, Tiina; Vaikutiené, Giedré

    2016-01-01

    Old sedimentological and geochronological records can be preserved underneath the central parts of the continental ice sheets under non-erosive, cold-based subglacial conditions. Organic deposits that predate the last deglaciation are of particular value for the information held on glacial-time climate and environmental conditions. In this study, we present multiproxy data derived from a well-preserved MIS 3 interstadial (55-25 ka ago) organic layer from inside the Arctic Circle in the Finnish Lapland. Biological proxy evidence, namely coming from aquatic plant species, indicates July temperatures as high as 14.4 °C, i.e. higher than those of today for the study site. Macrofossil evidence demonstrates for the first time the presence of pines accompanied by tree birch during the MIS 3 interstadial in northern Fennoscandia. These results concur with contemporary insolation model outcomes but contradict with the previous proxy-based view of open tundra conditions during the MIS 3. The data suggest that there are highly dynamic interstadial continental ice-sheet dynamics following changes in orbital forcing. Warm climate enabled the establishment of forests on exposed landscape. Moreover, we suggest that in the light of these new data, previous MIS 3 pollen data could be re-interpreted. PMID:27363905

  11. Childhood (Mis)Fortune, Educational Attainment, and Adult Health: Contingent Benefits of a College Degree?

    ERIC Educational Resources Information Center

    Schafer, Markus H.; Wilkinson, Lindsay R.; Ferraro, Kenneth F.

    2013-01-01

    College-educated adults are healthier than other people in the United States, but selection bias complicates our understanding of how education influences health. This article focuses on the possibility that the health benefits of college may vary according to childhood (mis)fortune and people's propensity to attain a college degree in the first…

  12. An Empirical Examination of the Composition of Vocational Interest in Business Colleges: MIS vs. Other Majors

    ERIC Educational Resources Information Center

    Downey, James

    2011-01-01

    Given the diminishing number of Management Information Systems (MIS) majors, an understanding of the factors which influence student choice of major is crucial. It has been noted in many previous studies that interest in a major and career significantly influences the student's choice of college major; indeed, in most studies, it is the strongest…

  13. The Use of Facebook in an Introductory MIS Course: Social Constructivist Learning Environment

    ERIC Educational Resources Information Center

    Ractham, Peter; Kaewkitipong, Laddawan; Firpo, Daniel

    2012-01-01

    The major objective of this article is to evaluate via a Design Science Research Methodology (DSRM) the implementation of a Social Constructivist learning framework for an introductory Management Information System (MIS) course. Facebook was used as a learning artifact to build and foster a learning environment, and a series of features and…

  14. An Alumni Assessment of MIS Related Job Skill Importance and Skill Gaps

    ERIC Educational Resources Information Center

    Wilkerson, Jerod W.

    2012-01-01

    This paper presents the results of a job skill survey of Management Information Systems (MIS) alumni from a Northeastern U.S. university. The study assesses job skill importance and skill gaps associated with 104 technical and non-technical skill items. Survey items were grouped into 6 categories based on prior research. Skill importance and skill…

  15. An Activity Theory Approach to Analyze Barriers to a Virtual Management Information Systems (MIS) Curriculum

    ERIC Educational Resources Information Center

    Jaradat, Suhair; Qablan, Ahmad; Barham, Areej

    2011-01-01

    This paper explains how the activity theory is used as a framework to analyze the barriers to a virtual Management Information Stream (MIS) Curriculum in Jordanian schools, from both the sociocultural and pedagogical perspectives. Taking the activity system as a unit of analysis, this study documents the processes by which activities shape and are…

  16. Transmission line relay mis-operation detection based on time-synchronized field data

    SciTech Connect

    Esmaeilian, Ahad; Popovic, Tomo; Kezunovic, Mladen

    2015-05-04

    In this paper, a real-time tool to detect transmission line relay mis-operation is implemented. The tool uses time-synchronized measurements obtained from both ends of the line during disturbances. The proposed fault analysis tool comes into the picture only after the protective device has operated and tripped the line. The proposed methodology is able not only to detect, classify, and locate transmission line faults, but also to accurately confirm whether the line was tripped due to a mis-operation of protective relays. The analysis report includes either detailed description of the fault type and location or detection of relay mis-operation. As such, it can be a source of very useful information to support the system restoration. The focus of the paper is on the implementation requirements that allow practical application of the methodology, which is illustrated using the field data obtained the real power system. Testing and validation is done using the field data recorded by digital fault recorders and protective relays. The test data included several hundreds of event records corresponding to both relay mis-operations and actual faults. The discussion of results addresses various challenges encountered during the implementation and validation of the presented methodology.

  17. MIS versus Computer Science: An Empirical Comparison of the Influences on the Students' Choice of Major

    ERIC Educational Resources Information Center

    Downey, James P.; McGaughey, Ronnie; Roach, David

    2009-01-01

    A history of declining enrollments in university Management Information Systems (MIS) and computer science (CS) departments in the U.S. considerably impacts both college departments and business organizations that hire graduates. In order to reverse the enrollment trend, an understanding of the important similarities and differences that shape a…

  18. Gaze-Contingent Motor Channelling, haptic constraints and associated cognitive demand for robotic MIS.

    PubMed

    Mylonas, George P; Kwok, Ka-Wai; James, David R C; Leff, Daniel; Orihuela-Espina, Felipe; Darzi, Ara; Yang, Guang-Zhong

    2012-04-01

    The success of MIS is coupled with an increasing demand on surgeons' manual dexterity and visuomotor coordination due to the complexity of instrument manipulations. The use of master-slave surgical robots has avoided many of the drawbacks of MIS, but at the same time, has increased the physical separation between the surgeon and the patient. Tissue deformation combined with restricted workspace and visibility of an already cluttered environment can raise critical issues related to surgical precision and safety. Reconnecting the essential visuomotor sensory feedback is important for the safe practice of robot-assisted MIS procedures. This paper introduces a novel gaze-contingent framework for real-time haptic feedback and virtual fixtures by transforming visual sensory information into physical constraints that can interact with the motor sensory channel. We demonstrate how motor tracking of deforming tissue can be made more effective and accurate through the concept of Gaze-Contingent Motor Channelling. The method is also extended to 3D by introducing the concept of Gaze-Contingent Haptic Constraints where eye gaze is used to dynamically prescribe and update safety boundaries during robot-assisted MIS without prior knowledge of the soft-tissue morphology. Initial validation results on both simulated and robot assisted phantom procedures demonstrate the potential clinical value of the technique. In order to assess the associated cognitive demand of the proposed concepts, functional Near-Infrared Spectroscopy is used and preliminary results are discussed. PMID:20889367

  19. Transmission line relay mis-operation detection based on time-synchronized field data

    DOE PAGESBeta

    Esmaeilian, Ahad; Popovic, Tomo; Kezunovic, Mladen

    2015-05-04

    In this paper, a real-time tool to detect transmission line relay mis-operation is implemented. The tool uses time-synchronized measurements obtained from both ends of the line during disturbances. The proposed fault analysis tool comes into the picture only after the protective device has operated and tripped the line. The proposed methodology is able not only to detect, classify, and locate transmission line faults, but also to accurately confirm whether the line was tripped due to a mis-operation of protective relays. The analysis report includes either detailed description of the fault type and location or detection of relay mis-operation. As such,more » it can be a source of very useful information to support the system restoration. The focus of the paper is on the implementation requirements that allow practical application of the methodology, which is illustrated using the field data obtained the real power system. Testing and validation is done using the field data recorded by digital fault recorders and protective relays. The test data included several hundreds of event records corresponding to both relay mis-operations and actual faults. The discussion of results addresses various challenges encountered during the implementation and validation of the presented methodology.« less

  20. Minimally Invasive Direct Thoracic Interbody Fusion (MIS-DTIF): Technical Notes of a Single Surgeon Study

    PubMed Central

    Abbasi, Hamid

    2016-01-01

    Background Minimally invasive direct thoracic interbody fusion (MIS-DTIF) is a new single surgeon procedure for fusion of the thoracic vertebrae below the scapula (T6/7) to the thoracolumbar junction. In this proof of concept study, we describe the surgical technique for MIS-DTIF and report our experience and the perioperative outcomes of the first four patients who underwent this procedure. Study design/setting In this study we attempt to establish the safety and efficacy of MIS-DTIF. We have performed MIS-DTIF on six spinal levels in four patients with degenerative disk disease or disk herniation. We recorded surgery time, blood loss, fluoroscopy time, complications, and patient-reported pain. Methods Throughout the MIS-DTIF procedure, the surgeon is aided by biplanar fluoroscopic imaging and electrophysiological monitoring. The surgeon approaches the spine with a series of gentle tissue dilations and inserts a working tube that establishes a direct connection from the outside of the skin to the disk space. Through this working tube, the surgeon performs a discectomy and inserts an interbody graft or cage. The procedure is completed with minimally invasive (MI) posterior pedicle screw fixation. Results For the single level patients the mean blood loss was 90 ml, surgery time 43 minutes, fluoroscopy time 293 seconds, and hospital stay two days. For the two-level surgeries, the mean blood loss was 27 ml, surgery time 61 minutes, fluoroscopy time 321 seconds, and hospital stay three days. We did not encounter any clinically significant complications. Thirty days post-surgery, the patients reported a statistically significant reduction of 5.3 points on a 10-point sliding pain scale. Conclusions MIS-DTIF with pedicle screw fixation is a safe and clinically effective procedure for fusions of the thoracic spine. The procedure is technically straightforward and overcomes many of the limitations of the current minimally invasive (MI) approaches to the thoracic spine. MIS

  1. Investigating annually-resovled natural climate variability during MIS 11 using lacustrine records

    NASA Astrophysics Data System (ADS)

    Tye, G. J.; Palmer, A. P.; Candy, I.; Coxon, P.; Hardiman, M.

    2012-04-01

    Marine isotope stage 11 (MIS 11, ca 410,000 yrs BP) is considered to be one of the best analogues for current and future climate change due to the similarity of orbital forcing patterns during these two interglacials. Marine and ice-core records suggest that MIS 11 was a particularly long interglacial, characterised by stable climates. The investigation of high-resolution climate records from MIS 11 can, therefore, allow us to understand how the climate of a Holocene-like interglacial might evolve in the absence of anthropogenic modification. MIS 11 sediments preserved in the palaeolake basin at Marks Tey, eastern England, offer the potential for such a study as they are considered to be annually-laminated (varved) throughout a large part of the interglacial (Turner, 1970, 1975). The lamination sets appear to be comprised, primarily, of three regularly occurring laminae types; 1) authigenic carbonate, 2) diatom blooms, and 3) organic detritus, although there appears to be some variability in the microfacies of these laminations. The carbonate laminations are the key to the study of climate variability during MIS 11, as they represent authigenic carbonate precipitation, consistent with temperature/biologically driven changes in lake chemistry during the summer months. Oxygen isotopic analysis of the carbonate therefore gives a proxy for summer temperature. A period of key interest in the MIS 11 sequence at Marks Tey occurs during the early part of the interglacial, where there is a short-lived increase in grass pollen relative to tree pollen, termed the Non-Arboreal Pollen Zone (NAPZ). The cause of this shift in pollen has been subject to debate, with natural wildfire (Turner, 1970) or climatic deterioration (e.g. Kelly, 1964) being suggested as possible forcing mechanisms. In this study, as well as discussing the main characteristics of the MIS 11 sequence at Marks Tey, we will focus on the sedimentary, micromorphological and geochemical record of the NAPZ. In

  2. Mis16 Independently Recognizes Histone H4 and the CENP-ACnp1-Specific Chaperone Scm3sp.

    PubMed

    An, Sojin; Kim, Hanseong; Cho, Uhn-Soo

    2015-10-01

    CENP-A is a centromere-specific histone H3 variant that is required for kinetochore assembly and accurate chromosome segregation. For it to function properly, CENP-A must be specifically localized to centromeres. In fission yeast, Scm3sp and the Mis18 complex, composed of Mis16, Eic1, and Mis18, function as a CENP-A(Cnp1)-specific chaperone and a recruiting factor, respectively, and together ensure accurate delivery of CENP-A(Cnp1) to centromeres. Although how Scm3sp specifically recognizes CENP-A(Cnp1) has been revealed recently, the recruiting mechanism of CENP-A(Cnp1) via the Mis18 complex remains unknown. In this study, we have determined crystal structures of Schizosaccharomyces japonicus Mis16 alone and in complex with the helix 1 of histone H4 (H4α1). Crystal structures followed by mutant analysis and affinity pull-downs have revealed that Mis16 recognizes both H4α1 and Scm3sp independently within the CENP-A(Cnp1)/H4:Scm3sp complex. This observation suggests that Mis16 gains CENP-A(Cnp1) specificity by recognizing both Scm3sp and histone H4. Our studies provide insights into the molecular mechanisms underlying specific recruitment of CENP-A(Cnp1)/H4:Scm3sp into centromeres. PMID:26343758

  3. Mitotic regulator Mis18β interacts with and specifies the centromeric assembly of molecular chaperone holliday junction recognition protein (HJURP).

    PubMed

    Wang, Jianyu; Liu, Xing; Dou, Zhen; Chen, Liang; Jiang, Hao; Fu, Chuanhai; Fu, Guosheng; Liu, Dan; Zhang, Jiancun; Zhu, Tongge; Fang, Jingwen; Zang, Jianye; Cheng, Jinke; Teng, Maikun; Ding, Xia; Yao, Xuebiao

    2014-03-21

    The centromere is essential for precise and equal segregation of the parental genome into two daughter cells during mitosis. CENP-A is a unique histone H3 variant conserved in eukaryotic centromeres. The assembly of CENP-A to the centromere is mediated by Holliday junction recognition protein (HJURP) in early G1 phase. However, it remains elusive how HJURP governs CENP-A incorporation into the centromere. Here we show that human HJURP directly binds to Mis18β, a component of the Mis18 complex conserved in the eukaryotic kingdom. A minimal region of HJURP for Mis18β binding was mapped to residues 437-460. Depletion of Mis18β by RNA interference dramatically impaired HJURP recruitment to the centromere, indicating the importance of Mis18β in HJURP loading. Interestingly, phosphorylation of HJURP by CDK1 weakens its interaction with Mis18β, consistent with the notion that assembly of CENP-A to the centromere is achieved after mitosis. Taken together, these data define a novel molecular mechanism underlying the temporal regulation of CENP-A incorporation into the centromere by accurate Mis18β-HJURP interaction. PMID:24519934

  4. Mitotic Regulator Mis18β Interacts with and Specifies the Centromeric Assembly of Molecular Chaperone Holliday Junction Recognition Protein (HJURP)*

    PubMed Central

    Wang, Jianyu; Liu, Xing; Dou, Zhen; Chen, Liang; Jiang, Hao; Fu, Chuanhai; Fu, Guosheng; Liu, Dan; Zhang, Jiancun; Zhu, Tongge; Fang, Jingwen; Zang, Jianye; Cheng, Jinke; Teng, Maikun; Ding, Xia; Yao, Xuebiao

    2014-01-01

    The centromere is essential for precise and equal segregation of the parental genome into two daughter cells during mitosis. CENP-A is a unique histone H3 variant conserved in eukaryotic centromeres. The assembly of CENP-A to the centromere is mediated by Holliday junction recognition protein (HJURP) in early G1 phase. However, it remains elusive how HJURP governs CENP-A incorporation into the centromere. Here we show that human HJURP directly binds to Mis18β, a component of the Mis18 complex conserved in the eukaryotic kingdom. A minimal region of HJURP for Mis18β binding was mapped to residues 437–460. Depletion of Mis18β by RNA interference dramatically impaired HJURP recruitment to the centromere, indicating the importance of Mis18β in HJURP loading. Interestingly, phosphorylation of HJURP by CDK1 weakens its interaction with Mis18β, consistent with the notion that assembly of CENP-A to the centromere is achieved after mitosis. Taken together, these data define a novel molecular mechanism underlying the temporal regulation of CENP-A incorporation into the centromere by accurate Mis18β-HJURP interaction. PMID:24519934

  5. Electrical characteristics of TMAH-surface treated Ni/Au/Al2O3/GaN MIS Schottky structures

    NASA Astrophysics Data System (ADS)

    Reddy, M. Siva Pratap; Lee, Jung-Hee; Jang, Ja-Soon

    2014-03-01

    The electrical characteristics and reverse leakage mechanisms of tetramethylammonium hydroxide (TMAH) surface-treated Ni/Au/Al2O3/GaN metal-insulator-semiconductor (MIS) diodes were investigated by using the current-voltage ( I-V) and capacitance-voltage ( C-V) characteristics. The MIS diode was formed on n-GaN after etching the AlGaN in the AlGaN/GaN heterostructures. The TMAH-treated MIS diode showed better Schottky characteristics with a lower ideality factor, higher barrier height and lower reverse leakage current compared to the TMAH-free MIS diode. In addition, the TMAH-free MIS diodes exhibited a transition from Poole-Frenkel emission at low voltages to Schottky emission at high voltages, whereas the TMAH-treated MIS diodes showed Schottky emission over the entire voltage range. Reasonable mechanisms for the improved device-performance characteristics in the TMAH-treated MIS diode are discussed in terms of the decreased interface state density or traps associated with an oxide material and the reduced tunneling probability.

  6. How chromosome mis-segregation leads to cancer: lessons from BubR1 mouse models.

    PubMed

    Lee, Hyunsook

    2014-10-31

    Alteration in chromosome numbers and structures instigate and foster massive genetic instability. As Boveri has seen a hundred years ago (Boveri, 1914; 2008), aneuploidy is hallmark of many cancers. However, whether aneuploidy is the cause or the result of cancer is still at debate. The molecular mechanism behind aneuploidy includes the chromo-some mis-segregation in mitosis by the compromise of spindle assembly checkpoint (SAC). SAC is an elaborate network of proteins, which monitor that all chromosomes are bipolarly attached with the spindles. Therefore, the weakening of the SAC is the major reason for chromosome number instability, while complete compromise of SAC results in detrimental death, exemplified in natural abortion in embryonic stage. Here, I will review on the recent progress on the understanding of chromosome mis-segregation and cancer, based on the comparison of different mouse models of BubR1, the core component of SAC. PMID:25256220

  7. Fracture toughness testing of bi-material joints with high strength mis-match

    SciTech Connect

    Kocak, M.; Hornet, P.; Cornec, A.; Schwalbe, K.H.

    1995-12-31

    This paper deals with the influence of strength mis-match on CTOD ({delta}{sub 5}) R-curves obtained from homogeneous and electron beam (EB) welded bimaterial CT and SENB specimens of two aluminum alloys. The R-curves of metal-metal bimaterial specimens are compared with the R-curves of each alloy to determine the effect of strength mismatch on the locally measured CTOD ({delta}{sub 5}) fracture toughness properties. The homogeneous specimens of two different aluminum alloys, namely 2024-FC and 2024-T351 with yield strengths of 80 and 360 MPa respectively, as well as EB welded bi-material 5 mm thick CT and SENB specimens (a/W = 0.15 and 0.5) have been tested at room temperature. The local CTOD ({delta}{sub 5}) fracture toughness measurements on such composite specimen configurations produced generally strength mis-match and geometry independent R-curves.

  8. Effects of ultrathin oxides in conducting MIS structures on GaAs

    NASA Technical Reports Server (NTRS)

    Childs, R. B.; Ruths, J. M.; Sullivan, T. E.; Fonash, S. J.

    1978-01-01

    Schottky barrier-type GaAs baseline devices (semiconductor surface etched and then immediately metalized) and GaAs conducting metal oxide-semiconductor devices are fabricated and characterized. The baseline surfaces (no purposeful oxide) are prepared by a basic or an acidic etch, while the surface for the MIS devices are prepared by oxidizing after the etch step. The metallizations used are thin-film Au, Ag, Pd, and Al. It is shown that the introduction of purposeful oxide into these Schottky barrier-type structures examined on n-type GaAs modifies the barrier formation, and that thin interfacial layers can modify barrier formation through trapping and perhaps chemical reactions. For Au- and Pd-devices, enhanced photovoltaic performance of the MIS configuration is due to increased barrier height.

  9. Modelling and extraction procedure for gate insulator and fringing gate capacitance components of an MIS structure

    NASA Astrophysics Data System (ADS)

    Tinoco, J. C.; Martinez-Lopez, A. G.; Lezama, G.; Mendoza-Barrera, C.; Cerdeira, A.; Estrada, M.

    2016-07-01

    CMOS technology has been guided by the continuous reduction of MOS transistors used to fabricate integrated circuits. Additionally, the use of high-k dielectrics as well as a metal gate electrode have promoted the development of nanometric MOS transistors. Under this scenario, the proper modelling of the gate capacitance, with the aim of adequately evaluating the dielectric film thickness, becomes challenging for nanometric metal-insulator-semiconductor (MIS) structures due to the presence of extrinsic fringing capacitance components which affect the total gate capacitance. In this contribution, a complete intrinsic–extrinsic model for gate capacitance under accumulation of an MIS structure, together with an extraction procedure in order to independently determine the different capacitance components, is presented. ATLAS finite element simulation has been used to validate the proposed methodology.

  10. Design, development and characterization of a modular end effector for MIS procedures.

    PubMed

    Izzo, A; Tortora, G; Dario, P; Menciassi, A

    2015-08-01

    The Minimally Invasive Surgery (MIS) paradigm is well established in modern surgical procedures. Although MIS is successful from the patient's viewpoint, the use of rigid instruments inserted through small skin incisions leads to dexterity constraints and loss of degree of motion. Robotics has been introduced as support for augmenting dexterity during interventions, restoring hand-eye coordination and providing tools with enhanced degrees of motion. However, surgical robots have high costs and large footprint, pushing the research towards the development of modular robots to be used in Naturally Orifice Trans-luminal Endoscopic Surgery (NOTES) procedures. The main need of having simple and cheap tools able to be interchanged during the surgical procedure became crucial. In this paper an innovative modular end-effector based on a compliant soft actuation system able to provide up to 5.78 N gripping forces is presented. PMID:26737874

  11. Automated software development tools in the MIS (Management Information Systems) environment

    SciTech Connect

    Arrowood, L.F.; Emrich, M.L.

    1987-09-11

    Quantitative and qualitative benefits can be obtained through the use of automated software development tools. Such tools are best utilized when they complement existing procedures and standards. They can assist systems analysts and programmers with project specification, design, implementation, testing, and documentation. Commercial products have been evaluated to determine their efficacy. User comments have been included to illustrate actual benefits derived from introducing these tools into MIS organizations.

  12. Basic mechanisms study for MIS solar cell structures on GaAs

    NASA Technical Reports Server (NTRS)

    Fonash, S. J.

    1978-01-01

    The solar cell structure examined is the MIS configuration on (n) GaAs. The metal room temperature oxide/(n) GaAs materials system was studied. Metals with electronegativities varying from 2.4 (Au) to 1.5 (Al) were used as the upper electrode. The thinnest metallization that did not interfere with the measurement techniques (by introducing essentially transmission line series resistance problems across a device) was used. Photovoltaic response was not optimized.

  13. Extensive MIS 3 glaciation in southernmost Patagonia revealed by cosmogenic nuclide dating of outwash sediments

    NASA Astrophysics Data System (ADS)

    Darvill, Christopher M.; Bentley, Michael J.; Stokes, Chris R.; Hein, Andrew S.; Rodés, Ángel

    2015-11-01

    The timing and extent of former glacial advances can demonstrate leads and lags during periods of climatic change and their forcing, but this requires robust glacial chronologies. In parts of southernmost Patagonia, dating pre-global Last Glacial Maximum (gLGM) ice limits has proven difficult due to post-deposition processes affecting the build-up of cosmogenic nuclides in moraine boulders. Here we provide ages for the Río Cullen and San Sebastián glacial limits of the former Bahía Inútil-San Sebastián (BI-SSb) ice lobe on Tierra del Fuego (53-54°S), previously hypothesised to represent advances during Marine Isotope Stages (MIS) 12 and 10, respectively. Our approach uses cosmogenic 10Be and 26Al exposure dating, but targets glacial outwash associated with these limits and uses depth-profiles and surface cobble samples, thereby accounting for surface deflation and inheritance. The data reveal that the limits formed more recently than previously thought, giving ages of 45.6 ka (+139.9/-14.3) for the Río Cullen, and 30.1 ka (+45.6/-23.1) for the San Sebastián limits. These dates indicate extensive glaciation in southern Patagonia during MIS 3, prior to the well-constrained, but much less extensive MIS 2 (gLGM) limit. This suggests the pattern of ice advances in the region was different to northern Patagonia, with the terrestrial limits relating to the last glacial cycle, rather than progressively less extensive glaciations over hundreds of thousands of years. However, the dates are consistent with MIS 3 glaciation elsewhere in the southern mid-latitudes, and the combination of cooler summers and warmer winters with increased precipitation, may have caused extensive glaciation prior to the gLGM.

  14. Pathological impact of SMN2 mis-splicing in adult SMA mice

    PubMed Central

    Sahashi, Kentaro; Ling, Karen K Y; Hua, Yimin; Wilkinson, John Erby; Nomakuchi, Tomoki; Rigo, Frank; Hung, Gene; Xu, David; Jiang, Ya-Ping; Lin, Richard Z; Ko, Chien-Ping; Bennett, C Frank; Krainer, Adrian R

    2013-01-01

    Loss-of-function mutations in SMN1 cause spinal muscular atrophy (SMA), a leading genetic cause of infant mortality. The related SMN2 gene expresses suboptimal levels of functional SMN protein, due to a splicing defect. Many SMA patients reach adulthood, and there is also adult-onset (type IV) SMA. There is currently no animal model for adult-onset SMA, and the tissue-specific pathogenesis of post-developmental SMN deficiency remains elusive. Here, we use an antisense oligonucleotide (ASO) to exacerbate SMN2 mis-splicing. Intracerebroventricular ASO injection in adult SMN2-transgenic mice phenocopies key aspects of adult-onset SMA, including delayed-onset motor dysfunction and relevant histopathological features. SMN2 mis-splicing increases during late-stage disease, likely accelerating disease progression. Systemic ASO injection in adult mice causes peripheral SMN2 mis-splicing and affects prognosis, eliciting marked liver and heart pathologies, with decreased IGF1 levels. ASO dose–response and time-course studies suggest that only moderate SMN levels are required in the adult central nervous system, and treatment with a splicing-correcting ASO shows a broad therapeutic time window. We describe distinctive pathological features of adult-onset and early-onset SMA. PMID:24014320

  15. Chromosome mis-segregation and cytokinesis failure in trisomic human cells

    PubMed Central

    Nicholson, Joshua M; Macedo, Joana C; Mattingly, Aaron J; Wangsa, Darawalee; Camps, Jordi; Lima, Vera; Gomes, Ana M; Dória, Sofia; Ried, Thomas; Logarinho, Elsa; Cimini, Daniela

    2015-01-01

    Cancer cells display aneuploid karyotypes and typically mis-segregate chromosomes at high rates, a phenotype referred to as chromosomal instability (CIN). To test the effects of aneuploidy on chromosome segregation and other mitotic phenotypes we used the colorectal cancer cell line DLD1 (2n = 46) and two variants with trisomy 7 or 13 (DLD1+7 and DLD1+13), as well as euploid and trisomy 13 amniocytes (AF and AF+13). We found that trisomic cells displayed higher rates of chromosome mis-segregation compared to their euploid counterparts. Furthermore, cells with trisomy 13 displayed a distinctive cytokinesis failure phenotype. We showed that up-regulation of SPG20 expression, brought about by trisomy 13 in DLD1+13 and AF+13 cells, is sufficient for the cytokinesis failure phenotype. Overall, our study shows that aneuploidy can induce chromosome mis-segregation. Moreover, we identified a trisomy 13-specific mitotic phenotype that is driven by up-regulation of a gene encoded on the aneuploid chromosome. DOI: http://dx.doi.org/10.7554/eLife.05068.001 PMID:25942454

  16. Novel large-area MIS-type x-ray image sensor for digital radiography

    NASA Astrophysics Data System (ADS)

    Kameshima, Toshio; Kaifu, Noriyuki; Takami, Eiichi; Morishita, Masakazu; Yamazaki, Tatsuya

    1998-07-01

    We have developed a brand new, large-area X-ray image sensor for Digital Radiography System (DRS). The sensor utilizes a thin film transistor (TFT)/metal insulator semiconductor (MIS)-type photoelectric converter array made from hydrogenated amorphous silicon (a-Si:H). The sensor has 2688 X 2688 pixels at a pitch of 160 micrometer. The active area is 17 inch X 17 inch. The sensor utilizes scintillator coupled to the array. The light generated by X-rays is detected by the MIS-type photoelectric converters, and the resultant signals are scanned out by switching the TFTs. The a-Si TFT/MIS-type photoelectric converter array is characterized by high signal to noise ratio (SNR) and simple fabrication process. We will describe the principle and the performance of the sensor. In addition, we will present some X-ray images of a human subject obtained with this sensor. Dynamic range of the sensor covers most of the exposure range for radiography. SNR is limited almost only by the X-ray photon noise. MTF is sufficient for digital chest radiography. X-ray images have good contrast. The experimental results and obtained images show that the brand new sensor has great advantages for replacing X-ray film. The simple fabrication process of the sensor promises high productivity and low cost of DRS.

  17. Bridging Small Molecules to Modified Bacterial Microparticles Using a Disulphide Linkage: MIS416 as a Cargo Delivery System

    PubMed Central

    Mainini, Francesco; Larsen, David S.; Webster, Gill A.; Young, Sarah L.; Eccles, Michael R.

    2015-01-01

    MIS416 is an intact minimal cell wall skeleton derived from Proprionibacterium acnes that is phagocytosed by antigen presenting cells, including dendritic cells (DCs). This property allows MIS416 to be exploited as a vehicle for the delivery of peptide antigens or other molecules (for example, nucleic acids) to DCs. We previously showed that covalent (non-cleavable) conjugation of OVA, a model antigen derived from ovalbumin, to MIS416 enhanced immune responses in DCs in vivo, compared to unconjugated MIS416 and OVA. Intracellular trafficking promotes the lysosomal degradation of MIS416, leading to the destruction of MIS416 plus the associated cargos conjugated to MIS416. However, lysosomal degradation of cargo may not be desired for some MIS416 conjugates. Here we have investigated whether a cleavable linkage could facilitate release of the cargo in the cytoplasm of DCs to avoid lysosomal degradation. DCs were treated in vitro with disulfide-containing conjugates, and as hypothesised faster release of SIINFEKL peptide in the cytoplasm of DCs was observed with the inclusion of a disulfide bond between MIS416 and cargo. The inclusion of a cleavable disulfide bond in the conjugates did not significantly alter the amount of SIINFEKL antigens presented on MHC I molecules on DCs as compared with conjugates without a disulfide bond. However, the conjugates containing disulfide-linkages performed either slightly better (p<0.05) than, or the same as conjugates without a disulfide bond with respect to in vitro OT-1 T-cell proliferation induced by the presentation of SIINFEKL antigens on DCs, or DC activation studies, respectively. However, disulfide-containing conjugates were less effective than conjugates without a disulfide bond in in vivo cytotoxicity assays. In conclusion, inclusion of a disulfide bond in MIS416-peptide conjugates was associated with efficient release of peptides in the cytoplasm of DCs, an important consideration for MIS416-mediated delivery of

  18. The MisR Response Regulator Is Necessary for Intrinsic Cationic Antimicrobial Peptide and Aminoglycoside Resistance in Neisseria gonorrhoeae.

    PubMed

    Kandler, Justin L; Holley, Concerta L; Reimche, Jennifer L; Dhulipala, Vijaya; Balthazar, Jacqueline T; Muszyński, Artur; Carlson, Russell W; Shafer, William M

    2016-08-01

    During infection, the sexually transmitted pathogen Neisseria gonorrhoeae (the gonococcus) encounters numerous host-derived antimicrobials, including cationic antimicrobial peptides (CAMPs) produced by epithelial and phagocytic cells. CAMPs have both direct and indirect killing mechanisms and help link the innate and adaptive immune responses during infection. Gonococcal CAMP resistance is likely important for avoidance of host nonoxidative killing systems expressed by polymorphonuclear granulocytes (e.g., neutrophils) and intracellular survival. Previously studied gonococcal CAMP resistance mechanisms include modification of lipid A with phosphoethanolamine by LptA and export of CAMPs by the MtrCDE efflux pump. In the related pathogen Neisseria meningitidis, a two-component regulatory system (2CRS) termed MisR-MisS has been shown to contribute to the capacity of the meningococcus to resist CAMP killing. We report that the gonococcal MisR response regulator but not the MisS sensor kinase is involved in constitutive and inducible CAMP resistance and is also required for intrinsic low-level resistance to aminoglycosides. The 4- to 8-fold increased susceptibility of misR-deficient gonococci to CAMPs and aminoglycosides was independent of phosphoethanolamine decoration of lipid A and the levels of the MtrCDE efflux pump and seemed to correlate with a general increase in membrane permeability. Transcriptional profiling and biochemical studies confirmed that expression of lptA and mtrCDE was not impacted by the loss of MisR. However, several genes encoding proteins involved in membrane integrity and redox control gave evidence of being MisR regulated. We propose that MisR modulates the levels of gonococcal susceptibility to antimicrobials by influencing the expression of genes involved in determining membrane integrity. PMID:27216061

  19. Proteasomal Inhibition Restores Biological Function of Mis-sense Mutated Dysferlin in Patient-derived Muscle Cells*

    PubMed Central

    Azakir, Bilal A.; Di Fulvio, Sabrina; Kinter, Jochen; Sinnreich, Michael

    2012-01-01

    Dysferlin is a transmembrane protein implicated in surface membrane repair of muscle cells. Mutations in dysferlin cause the progressive muscular dystrophies Miyoshi myopathy, limb girdle muscular dystrophy 2B, and distal anterior compartment myopathy. Dysferlinopathies are inherited in an autosomal recessive manner, and many patients with this disease harbor mis-sense mutations in at least one of their two pathogenic DYSF alleles. These patients have significantly reduced or absent dysferlin levels in skeletal muscle, suggesting that dysferlin encoded by mis-sense alleles is rapidly degraded by the cellular quality control system. We reasoned that mis-sense mutated dysferlin, if salvaged from degradation, might be biologically functional. We used a dysferlin-deficient human myoblast culture harboring the common R555W mis-sense allele and a DYSF-null allele, as well as control human myoblast cultures harboring either two wild-type or two null alleles. We measured dysferlin protein and mRNA levels, resealing kinetics of laser-induced plasmalemmal wounds, myotube formation, and cellular viability after treatment of the human myoblast cultures with the proteasome inhibitors lactacystin or bortezomib (Velcade). We show that endogenous R555W mis-sense mutated dysferlin is degraded by the proteasomal system. Inhibition of the proteasome by lactacystin or Velcade increases the levels of R555W mis-sense mutated dysferlin. This salvaged protein is functional as it restores plasma membrane resealing in patient-derived myoblasts and reverses their deficit in myotube formation. Bortezomib and lactacystin did not cause cellular toxicity at the regimen used. Our results raise the possibility that inhibition of the degradation pathway of mis-sense mutated dysferlin could be used as a therapeutic strategy for patients harboring certain dysferlin mis-sense mutations. PMID:22318734

  20. Last Interglacial (MIS5e) hydrographic shifts linked to meltwater discharges from the East Greenland margin

    NASA Astrophysics Data System (ADS)

    Zhuravleva, Anastasia; Bauch, Henning A.; Van Nieuwenhove, Nicolas

    2016-04-01

    The East Greenland Current (EGC) plays a key role in transporting polar water from the Arctic to convectional sites of the Iceland and Labrador seas. Ongoing melting of the Greenland Ice Sheet (GIS) as well as the Arctic sea ice prompts freshening of the EGC and accumulation of low-density water in the subpolar North Atlantic, thus affecting the stabilities of water mass overturning and subsequent northward heat transfer. To assess natural eastern GIS dynamics and possible freshwater-induced regional oceanic reorganizations we analyzed several sediment sequences from the poorly investigated area along the eastern Greenland margin and the western Nordic Seas. Records span the last interglacial (LIG, MIS5e) cycle, including deglacial Termination 2 and the LIG climatic optimum. On a global scale, the latter is believed to have been warmer than present, with a higher sea level, and may, therefore, serve as a promising analogue for future hydrographic changes. Based on various proxy data (stable isotopes, planktic foraminiferal assemblages, ice-rafted debris) our reconstructions support the notion of a "two-step development" of Termination 2 which underwent severe surface freshening in the subpolar North Atlantic. This is shown in extremely light oxygen isotopic values registered all along the eastern Greenland margin during early MIS5e, which are indicative for pronounced eastern/central GIS retreat and a further propagation of the resulting meltwater southward via the EGC. In addition, we find compelling evidence for at least two separate meltwater episodes in proximity of the eastern GIS during early MIS5e. The climatic episode in between is correlated with an early LIG warm peak, which may be linked to enhanced presence of Atlantic water in the central Nordic Seas (Bauch et al., 2012) and further downstream along southern Greenland (Hillaire-Marcel et al., 1994, Irvali et al., 2012). Our data, therefore, reveal a complex and variable dynamic of the EGC during MIS5e

  1. Human centromere chromatin protein hMis12, essential for equal segregation, is independent of CENP-A loading pathway.

    PubMed

    Goshima, Gohta; Kiyomitsu, Tomomi; Yoda, Kinya; Yanagida, Mitsuhiro

    2003-01-01

    Kinetochores are the chromosomal sites for spindle interaction and play a vital role for chromosome segregation. The composition of kinetochore proteins and their cellular roles are, however, poorly understood in higher eukaryotes. We identified a novel kinetochore protein family conserved from yeast to human that is essential for equal chromosome segregation. The human homologue hMis12 of yeast spMis12/scMtw1 retains conserved sequence features and locates at the kinetochore region indistinguishable from CENP-A, a centromeric histone variant. RNA interference (RNAi) analysis of HeLa cells shows that the reduced hMis12 results in misaligned metaphase chromosomes, lagging anaphase chromosomes, and interphase micronuclei without mitotic delay, while CENP-A is located at kinetochores. Further, the metaphase spindle length is abnormally extended. Spindle checkpoint protein hMad2 temporally localizes at kinetochores at early mitotic stages after RNAi. The RNAi deficiency of CENP-A leads to a similar mitotic phenotype, but the kinetochore signals of other kinetochore proteins, hMis6 and CENP-C, are greatly diminished. RNAi for hMis6, like that of a kinetochore kinesin CENP-E, induces mitotic arrest. Kinetochore localization of hMis12 is unaffected by CENP-A RNAi, demonstrating an independent pathway of CENP-A in human kinetochores. PMID:12515822

  2. Two different deglaciation processes in the subtropical Pacific at MIS 5/6 and 1/2

    NASA Astrophysics Data System (ADS)

    Ujiie, Y.; Asahi, H.

    2011-12-01

    Deglaciation process is one of the results that the tropical climate forcing impact on the global changes by its large heat capacity. However, the deglacial fluctuation has poorly been explored in the tropical Pacific area due to less resolution records from the marine deposits. The Okinawa region is available to represent the high-resolution paleocenographic records of the tropical-subtropical Pacific during the late Quaternary, because of the oscillation between the Kuroshio Current continuing from the North Equatorial Current and central water of the subtropical gyre in this region. Two IMAGES cores were collected from the Okinawa Trough (under the Kuroshio Current) and Ryukyu Trench (under the central water of the subtropical gyre), respectively. Both cores MD982196 (Okinawa Trough) and MD012398 (Ryukyu Trench) covered over the records until Marine Isotope Stage (MIS) 7. Here, we aim to demonstrate the deglacial fluctuations of the surface and intermediate waters during two glacial-interglacial shifts, MIS 6 to 5 and MIS 2 to 1, based on the comprehensive analyses of the oxygen isotopes, Mg/Ca ratios of two planktic foraminiferal faunas (surface and upper intermediate species), and faunal assemblages of planktic foraminifera. The glacial-interglacial cycles were clearly confirmed in whole of the Okinawa region by the planktic δ18O curves. Surface Mg/Ca paleo-temperature showed a same trend as the δ18O curve. However, the paleo-temperature of the upper intermediate water showed unique fluctuation: temperature increased from late MIS 6 to 5e, whereas decreased from MIS 2 to Holocene. Moreover, the temperature difference (dT) between the surface and intermediate layers defined these phenomena. Fast warming of intermediate layer proitor to the deglaciation MIS 5/6 delayed a stratification of water column, while cooling of this layer make a large dT during MIS 1/2. Intriguingly, the faunal compositions of planktic foraminifera changed through the shifts of the

  3. Outcome Measures of an Intracanal, Endoscopic Transforaminal Decompression Technique: Initial Findings from the MIS Prospective Registry

    PubMed Central

    Sclafani, Joseph A.; Raiszadeh, Kamshad; Laich, Dan; Shen, Jian; Bennett, Matthew; Blok, Robert; Liang, Kevin

    2015-01-01

    Background Minimally invasive transforaminal endoscopic procedures can achieve spinal decompression through either direct or indirect techniques. Subtle variations in trajectory of the surgical corridor can dictate access to the pathologic tissue. Two general strategies exist: the intradiscal “inside-out” technique and the extradiscal, intracanal (IC) technique. The IC technique utilizes a more lateral transforaminal approach than the intradiscal technique, which allows for a more direct decompression of the spinal canal. Objective This study is an assessment of IC patient outcome data obtained through analysis of a previously validated MIS Prospective Registry. Methods Post-hoc analysis was performed on the MIS Prospective Registry database containing 1032 patients. A subgroup of patients treated with the endoscopic IC technique was identified. Patient outcome measures after treatment of symptomatic disk herniation and neuroforaminal stenosis were evaluated. Results A total of 86 IC patients were analyzed. Overall, there was significant improvement in employment and walking tolerance as soon as 6 weeks post-op as well as significant one year VAS and ODI score improvement. Subanalysis of IC patients with two distinct primary diagnoses was performed. Group IC-1 (disc herniation) showed improvement in ODI and VAS back and leg outcomes at 1 year post-op. Group IC-2 (foraminal stenosis) showed VAS back and leg score improvement at one year post-op but did not demonstrate significant improvement in overall ODI outcome at any time point. The one year re-operation rate was 2% (1/40) for group IC-1 and 28% (5/18) for group IC-2. Conclusions The initial results of the MIS Registry IC subgroup show a significant clinical improvement when the technique is employed to treat patients with lumbar disc herniation. The treatment of foraminal stenosis can lead to improved short-term clinical outcome but is associated with a high re-operation rate at 1 year post-op. PMID

  4. Th-230 Dates of MIS 5e Coral Terraces in Kisar Island, Eastern Indonesia

    NASA Astrophysics Data System (ADS)

    Chiang, H. W.; Harris, R. A.; Prasetyadi, C.; Shen, C. C.; Chiu, T. C.; Cox, N. L.; Chen, Y. G.

    2010-05-01

    2004 Sumatra earthquakes caused a devastating tsunami and cost the lives of nearly 260,000 people in the South Asian region. These earthquakes and associated tsunami are sourced from convergence of the Indo-Australian and Asian Plates. In the eastern part of this plate boundary the Australian continent is colliding with Asia. The first turbiditic sand in Timor island was around 5 Ma and the collision propagated to the southwestern until ~2 Ma. But the activities of the neighborhood of the Timor island in the Quaternary or the Holocene is unknown. This study provides the new 230Th dates from the raised coral terraces at Kisar Island, eastern Indonesia. Eight fossil corals were measured by MC-ICP-MS at the National Taiwan University with permil-level precision. Two out of the eight samples having ~1.5 % calcite and acceptable δ234Uinitial showed robust ages of 123-121 ka. Another three open-system model ages were from 125-119 ka by Thompson et al.'s method (2003). These different elevated fossil corals with ages of 125-119 ka favored the two-peak sea-level curve in MIS 5e explained by Chappell and Veeh (1978). New age results relocated the second peak should be about three thousand years earlier than their proposed 119 ka. A minimum uplift rate of 0.1 m/kyrs is derived from the highest-position fossil corals. The 230Th-dated fossils in the north coast of Timor-Leste suggest the MIS 5e terraces could reach 55 m high, hence a referable uplift rate of ~0.4 m/kyrs could be a maximum estimate. The uplift rate of 0.1-0.4 m/ka since late Pleistocene is well consistent with published values from Atauro Island and Timor-Leste in eastern Indonesia. Based on the uplift rate, the terraces in eastern Kisar, with elevation lower than 100 m, expectedly located at MIS 7, 9, or 11; while the higher western terraces ranged from MIS 9-15. Besides, no remanet of Holocene fringe reefs around Kisar Island also suggests a relatively low activity of tectonics, in agreement with the modern

  5. High lake levels at Siling Co, central Tibet, during MIS 5e - 6

    NASA Astrophysics Data System (ADS)

    Shi, X.; Kirby, E.; Furlong, K. P.; Meng, K.; Marrero, S.; Wang, E.; Asmerom, Y.; Robinson, R. A.; Polyak, V. J.; Phillips, F. M.

    2013-12-01

    Flights of well-preserved paleoshorelines around lakes atop the Tibetan plateau reflect paleoclimatic conditions in this highest region in the world and provide important constraints on the history of hydrologic change. Regionally, previous studies have shown that many Tibetan lakes achieved highstand levels during the Late Pleistocene - Early Holocene transition. Whether similar extents were reached in the geologic past, however, remains uncertain due to sparse dating of ancient shoreline features. Here we focus on exposures of relict, high shorelines around Siling Co, in central Tibet. Previous study of a well-preserved sequence of shorelines suggest that lake levels during the Late Pleistocene - Early Holocene reached ~ 64 m above present lake level (referenced to 1976). We determined ages of even higher shorelines (up to ~76 m above present lake level) using a combination of U-series dating of tufa deposits, 36Cl depth profiles of beach ridges, and optically stimulated luminescence (OSL) of beach sand. We obtained a 36Cl depth profile age of 113 ka from a tombolo in central peninsula of Siling Co, 66 m above present level; an OSL age from this deposit, however, yielded an age of ~ 43 ka and probably reflects saturation of the OSL signal. U-Th ages of tufa deposits range from 145 - 159 ka and place minimum constraints on lake levels during MIS 6 of 65 - 76 m above present level. Finally, an even older 36Cl age of 178 ka was obtained from a high spit shoreline (~ 62 m above present level). Collectively, our results provide evidence that lake levels at Siling Co reached or exceeded the Early Holocene highstand during the MIS 5e (Eemian) interglacial, suggesting that paleohydrologic conditions were similar during these time periods. Moreover, the preservation of higher shorelines developed during MIS 6 suggest the presence of an even larger lake during the penultimate glacial stage. Comparison of our results with available δ18O records of an ice core in northern

  6. Space Station Furnace Facility Management Information System (SSFF-MIS) Development

    NASA Technical Reports Server (NTRS)

    Meade, Robert M.

    1996-01-01

    This report summarizes the chronology, results, and lessons learned from the development of the SSFF-MIS. This system has been nearly two years in development and has yielded some valuable insights into specialized MIS development. General: In December of 1994, the Camber Corporation and Science Applications International Corporation (SAIC) were contracted to design, develop, and implement a MIS for Marshall Space Flight Center's Space Station Furnace Facility Project. The system was to be accessible from both EBM-Compatible PC and Macintosh platforms. The system was required to contain data manually entered into the MIS as well as data imported from other MSFC sources. Electronic interfaces were established for each data source and retrieval was to be performed at prescribed time intervals. The SOW requirement that predominantly drove the development software selection was the dual-platform (IBM-PC and Macintosh) requirement. The requirement that the system would be maintained by Government personnel influenced the selection of Commercial Off-the-shelf software because of its inherent stability and readily available documentation and support. Microsoft FoxPro Professional 2.6 for Windows and Macintosh was selected as the development tool. This is a software development tool that has been in use for many years. It is stable and powerful. Microsoft has since released the replacement for this product, Microsoft Visual FoxPro, but at the time of this development, it was only available on the Windows platform. The initial contract included included the requirement for capabilities relating to the Work- and Organizational Breakdown Structures, cost (plan and actuals), workforce (plan and actuals), critical path scheduling, trend analysis, procurements and contracts, interface to manufacturing, Safety and Mission Assurance, risk analysis, and technical performance indicators. It also required full documentation of the system and training of users. During the course of

  7. Paleohydrological and paleoclimatic oscillations during MIS3 revealed by multi-proxies from Balikun Lake, NW China

    NASA Astrophysics Data System (ADS)

    An, Chengbang; Zhao, Yongtao

    2016-04-01

    Multi-disciplinary analyses (sedimental, geochemical) of a sedimental core (BLK11A) recovered from the centre of the Balikun Lake, eastern Tienshan Mts., provide evidence of paleohydrology and its climatic indications in the arid western China during MIS3. The results suggested fairly high-frequency MIS3 interstadial oscillations and alternate change patterns among nearly fresh water and brackish water and hypersaline water during the ~30 ka. We also found that: 1) the evolutional process of the lake responds indicatively and quickly to the climate change on sub-orbital and millennial timescales, the onset of MIS3 interstadial is featured by abrupt increases in both bioproductivity and chemical weathering; 2) the appearance of the halite lithofacies indicates gradually cooling and drying trends during the middle to late MIS3, this deteriorated environment shrunk the lake area and weakened the vegetation cover as well as watershed chemical weathering; 3) Our new interpretations differ from the assumption that highest lake level and wettest conditions occurred during the late MIS3 from Tibetan Plateau and Inner Mongolia, while suggest that the climate in the Balikun region, even most of arid western China areas would have undergone a progressive aridification. The evolution of the paleohydrology and climate change of Balikun Basin may have a strong correlation with the high latitude summer insolation and the climate in North Atlantic.

  8. Coping with unobservable and mis-classified states in capture-recapture studies

    USGS Publications Warehouse

    Kendall, W.L.

    2004-01-01

    Multistate mark-recapture methods provide an excellent conceptual framework for considering estimation in studies of marked animals. Traditional methods include the assumptions that (1) each state an animal occupies is observable, and (2) state is assigned correctly at each point in time. Failure of either of these assumptions can lead to biased estimates of demographic parameters. I review design and analysis options for minimizing or eliminating these biases. Unobservable states can be adjusted for by including them in the state space of the statistical model, with zero capture probability, and incorporating the robust design, or observing animals in the unobservable state through telemetry, tag recoveries, or incidental observations. Mis-classification can be adjusted for by auxiliary data or incorporating the robust design, in order to estimate the probability of detecting the state an animal occupies. For both unobservable and mis-classified states, the key feature of the robust design is the assumption that the state of the animal is static for at least two sampling occasions.

  9. Regional differences in interglacial climate expression: A revisit to MIS 5e

    NASA Astrophysics Data System (ADS)

    Bauch, H. A.

    2015-12-01

    Reconstructions of air and surface ocean temperatures of the Eemian interglacial (MIS5e) often infer higher values than those of the Holocene, with a recently estimated global sea level 6-9m meters above the present highstand. Many a study also have reported on Eemian climate instability with respect to both variability in temperatures and sea level. These variabilities are often explained by AMOC changes and by invoking massive bi-polar ice sheet losses. In spite of recent sea-level compilation studies on such fluctuations during the last interglacial using coral evidence, the questions remain how, where, and, notably, when could a rapid ice growth have occurred during the otherwise so warm but relatively short Eemian full-interglacial period? Ocean field data now indicate a relatively cool polar North Atlantic for a substantial part of the post-deglacial (T2) interval, whereas in the subpolar region ocean temperature peaked directly after T2 together with high insolation. Thus, based on circumstantial evidence significant glacier ice must have remained at sea-level along the polar periphery for rather long. In addition with other proxy data the overall sequence of events would therefore dictate a late global sea-level highstand during MIS5e.

  10. Climatic variability in the northern sector of the American tropics since the latest MIS 3

    NASA Astrophysics Data System (ADS)

    Lozano-García, Socorro; Ortega, Beatriz; Roy, Priyadarsi D.; Beramendi-Orosco, Laura; Caballero, Margarita

    2015-09-01

    We inferred millennial-scale climate variations and paleohydrological conditions in the northern sector of the American tropics for 30.3-5.5 cal ka BP using geochemical characteristics of sediments from Lake Chalco in central Mexico. The sediment sequence is chronologically constrained with three tephra and nine radiocarbon dates. Temporal variations in titanium, total inorganic carbon, total organic carbon/titanium ratio, carbon/nitrogen ratio, and silica/titanium ratio indicate changes in runoff, salinity, productivity, and sources. Higher concentrations of Ti indicate more runoff during latest Marine Isotope Stage (MIS) 3 (30.3-28.6 cal ka BP). Runoff was lower during the last glacial maximum (LGM; 23-19 cal ka BP) than during the Heinrich 2 event (26-24 cal ka BP). The interval of reduced runoff continued up to 17.5 cal ka BP but increased during the Bølling/Allerød. Trends of decreasing runoff and increasing salinity are observed throughout MIS 1. Lake Chalco received less runoff during the LGM compared to deglaciation, opposite the trend of other North American tropical records. Different amounts of rainfall at different sites are possibly due to shifts in the position of the Intertropical Convergence Zone, changes in the size of the Altlantic warm pool, and varying sea-surface temperatures of the Atlantic and Pacific oceans.

  11. Sea-level highstands during the Last interglacial (MIS 5e) in Mallorca

    NASA Astrophysics Data System (ADS)

    Lorscheid, T.; Stocchi, P.; Rovere, A.; Gómez-Pujol, L.; Mann, T.; Fornos, J. J.

    2015-12-01

    Last Intergalcial in the island of Mallorca (NW Mediterranean) have been the subject of research since the early 60's (Butzer & Cuerda 1960). Despite both the location and stratigraphy of MIS 5e outcrops in the island are well known, the elevation of relative sea level (RSL) markers around the island has never been measured with high-accuracy topographic techniques (e.g. DGPS) and the interpretation of the paleo RSL has never been carried out using standardized definition of the indicative meaning of each RSL marker. In this study we present the results of two field trips aimed at measuring last interglacial deposits in Mallorca with high-accuracy GPS and at establishing, surveying modern shorelines as analogs, indicative ranges and reference water level values for RSL markers across the island. Using an earth-ice coupled GIA-model we performed several model-runs for investigating isostatic adjustment since MIS 5e in the island. These results are compared with the elevation of our deposits in the field and discussed in terms of tectonics and eustasy.

  12. Metabolism and mis-metabolism of the neuropathological signature protein TDP-43.

    PubMed

    Huang, Chi-Chen; Bose, Jayarama Krishnan; Majumder, Pritha; Lee, Kuen-Haur; Huang, Jen-Tse Joseph; Huang, Jeffrey K; Shen, Che-Kun James

    2014-07-15

    TDP-43 (also known as TARDBP) is a pathological signature protein of neurodegenerative diseases, with TDP-43 proteinopathies including frontotemporal lobar degeneration (FTLD)-TDP and amyotrophic lateral sclerosis (ALS)-TDP. These TDP-43 proteinopathies are characterized by cytoplasmic insoluble TDP-43-positive aggregates in the diseased cells, the formation of which requires the seeding of TDP-25 fragment generated by caspase cleavage of TDP-43. We have investigated the metabolism and mis-metabolism of TDP-43 in cultured cells and found that endogenous and exogenously overexpressed TDP-43 is degraded not only by the ubiquitin proteasome system (UPS) and macroautophagy, but also by the chaperone-mediated autophagy (CMA) mediated through an interaction between Hsc70 (also known as HSPA8) and ubiquitylated TDP-43. Furthermore, proteolytic cleavage of TDP-43 by caspase(s) is a necessary intermediate step for degradation of the majority of the TDP-43 protein, with the TDP-25 and TDP-35 fragments being the main substrates. Finally, we have determined the threshold level of the TDP-25 fragment that is necessary for formation of the cytosolic TDP-43-positive aggregates in cells containing the full-length TDP-43 at an elevated level close to that found in patients with TDP-43 proteinopathies. A comprehensive model of the metabolism and mis-metabolism of TDP-43 in relation to these findings is presented. PMID:24860144

  13. Control of haptic master - slave robot system for minimally invasive surgery (MIS)

    NASA Astrophysics Data System (ADS)

    Oh, J. S.; Shin, W. K.; Uhm, C. H.; Lee, S. R.; Han, Y. M.; Choi, S. B.

    2013-02-01

    In this work, 4 degrees-of-freedom (DOF) haptic master featuring electrorheological (ER) fluid is proposed and integrated with a slave. Using an ER fluid, the haptic master is devised which can generate a repulsive force/torque with the 4-DOF motion and provide stimulus information to operator. For realization of master-slave MIS system, an encoder is installed with the ER haptic master to establish the MIS master system. The motion command of the haptic master is realized by slave surgery robot. In order to follow the motion of the haptic master, the mechanism of slave surgery robot is devised. Accordingly, the haptic master-slave system is established by incorporating the slave robot with the haptic master device in which the repulsive force/torque and desired position are transferred to each other. In order to obtain the desired torque trajectories, a sliding mode controller (SMC) is designed and implemented. It has been demonstrated that the desired effective torque tracking control performance is well achieved using the proposed master-slave system.

  14. Were the MIS 11 and MIS 5e warmer and/or wetter than the Holocene? Test comparison of Interglacial intensities using stable isotope data from Northern France tufa deposits.

    NASA Astrophysics Data System (ADS)

    Dabkowski, J.; Limondin-Lozouet, N.; Antoine, P.; Marca-Bell, A.; Andrews, J.

    2012-04-01

    Many recent palaeoclimatic studies have focused on MIS 5 (Eemian) and 11 as they are supposed to be the best analogues for our modern interglacial. As they are characteristic of temperate periods and result of calcite precipitation from meteogene water, tufas are key-deposits for palaeoclimatic reconstructions of these interglacials. Calcite oxygen and carbon stable isotopes (δ18O and δ13C) are known since the 80s to be important palaeoclimatic proxies for the Holocene and we recently have shown their suitability in Pleistocene tufas. At decadal-scale sampling resolution, δ18O of tufa records variations in δ18O of regional rainfall, and in this way reflects source or amount effects (particularly continentality), and temperature depending on locality. δ13C of tufa indicates moisture availability (linked to biomass type/abundance) and rainfall intensity. Using our new results from the tufa of Saint-Germain-le-Vasson (Normandy) dated to the first half of the Holocene, and those from Caours (Somme) and La-Celle-sur-Seine (Seine-et-Marne) respectively assigned to MIS 5e and MIS 11, we investigate similarities or differences between these Pleistocene interglacials and the modern one. Comparison between the sites is relevant as these tufas developed in a similar geological area (the Paris Basin) and are nowadays in the same humid and temperate climatic area. The Caours tufa presents carbon and oxygen isotopic compositions similar to the Saint-Germain sequence. Comparable temperature and humidity conditions are thus recorded during the Eemian and the Holocene. However, δ13C for the MIS 5e optimum are more negative than those for the Atlantic optimum (Holocene), which may indicate wetter conditions. In La Celle, slightly warmer conditions appear to be recorded for MIS 11 compared to the Holocene by higher δ18O values than in Saint-Germain. Moreover, two very humid episodes are observed in the La Celle δ13C profile whereas such wet conditions are not observed during

  15. Increasing the efficiency of a silicon tunnel MIS injector of hot electrons by using high-K oxides

    NASA Astrophysics Data System (ADS)

    Vexler, M. I.

    2015-09-01

    It is demonstrated theoretically that replacing silicon dioxide in a metal-insulator-semiconductor (MIS) structure with a double-layer insulator HfO2(ZrO2)/SiO2 must lead to a decrease in the relative contribution of electrons with comparatively low energies to the total tunneling current. As a consequence, a suppression of the current component associated with the charge transport into the valence band of Si or from it is predicted for many regimes, especially of the low-energy part of this component. This effect can improve the efficiency of injection devices, such as a transistor with a tunnel MIS emitter or a resonant-tunneling diode based on a heavily doped MIS structure.

  16. Surface photoelectromotive Force in MIS structures based on Pb /SUB 1-x/ Sn /SUB x/ Te epitaxial layers

    SciTech Connect

    Antonov, V.V.; Kazak, E.P.; Matveenko, A.V.; Medvedev, Y.V.; Olesk, A.O.; Voitsekhouskii, A.V.

    1985-12-01

    This paper studies the surface properties of the narrow-band material Pb /SUB 1-x/ Sn /SUB x/ Te, using MIS structures in which either the anodic-oxide film (AOF) or an LiF layer served as the dielectric. The kinetics of the formation of AOF on Pb /SUB 1-x/ Sn /SUB x/ Te is illustrated. The MIS structures Ni (anodic-oxide-film) (LiF) Pb /SUB 1-x/ Sn /SUB x/ Te are characterized by the presence of a fixed positive charge in the dielectric, a mobile change in the anodic oxide, as well as the injection and capture of carriers in traps in the dielectric during optical excitation of MIS structures.

  17. ENSO variability during MIS 11 (424-374 ka) from Tridacna gigas at Huon Peninsula, Papua New Guinea

    NASA Astrophysics Data System (ADS)

    Ayling, Bridget F.; Chappell, John; Gagan, Michael K.; McCulloch, Malcolm T.

    2015-12-01

    Marine Isotope Stage 11 (MIS 11) from ∼424,000 to 374,000 yrs ago included one of the longest and warmest interglacials of the last 800,000 yrs, and is a potential analogue for the Holocene due to the similarity of Earth's orbital configuration at this time. The question of how the El Niño-Southern Oscillation (ENSO) responds to warmer background climates remains unanswered and is critical to understand how the ENSO system will evolve under the influence of anthropogenic warming. In this study, we present a 35 yr-long, high-resolution record of MIS 11 climate variability in the Western Pacific Warm Pool (WPWP) based on coupled measurements of skeletal Mg/Ca and δ18O in giant Tridacna gigas clams from Huon Peninsula, Papua New Guinea. The δ18O of modern T. gigas from Huon Peninsula faithfully records sea surface temperature, salinity/rainfall and regional ENSO variability. The geochemical integrity of the MIS 11 T. gigas for recording paleo-ENSO events was established through trace element screening, detailed petrography and SEM analysis. The fossil T. gigas δ18O record indicates that ENSO was operating during a 35-yr window in MIS 11, but with fewer events of shorter duration compared to those experienced during the last 100 yrs. The suppressed ENSO variability in the MIS 11 T. gigas record corresponds with a reduction in the amplitude of the average annual cycle in δ18O values. Distinctive changes in local insolation seasonality, and T. gigas δ18O, brought about by changes in Earth's orbit, provide an additional geochronological constraint on the timing of reef growth at Huon Peninsula to around 402 ka during the MIS 11.3 sub-stage (∼424-395 ka).

  18. Contrasted ocean conditions in the northwest North Atlantic during marine isotope stages (MIS) 11, 5e and 1

    NASA Astrophysics Data System (ADS)

    de Vernal, Anne; Fréchette, Bianca; Hillaire-Marcel, Claude

    2014-05-01

    Cores raised during the IODP Expedition 303 in the north Atlantic were analysed to document paleoceanographical conditions during recent interglacials (cf. Hillaire-Marcel et al., Marine Geol. 2011). Two key sites illustrate conditions in the inner vs outer Labrador Sea, respectively at the southwest Greenland margin (Eirik Ridge Site 1305; 57° N-48° W) and the southern Labrador rise (Orphan Knoll Site 1302/1303; 50° N-45° W). Special attention was paid to marine isotope stages (MIS) 11 (ca. 424-324 ka), 5e (ca. 128-117 ka) and the Holocene (last 11,000 years). The microfossil content of sediments (dinocyst notably) and the isotopic composition of foraminifers indicate significant differences in the conditions that prevailed during these 3 interglacial stages. Optimal conditions with regard to sea-surface temperatures (SSTs) prevailed during MIS 5e (anomalies of about + 5° C) at both sites. However, occurrence of ice rafted debris (IRD) and variations in salinity suggest meltwater discharge along the Greenland and Labrador margins during the last interglacial. On the contrary, during MIS 11, SSTs were similar to modern off Greenland or slightly lower at Orphan Knoll, but salinity was higher at both sites and IRD close to nil, whereas both sites are presently under iceberg routes. Stable oxygen isotope values in the mesopelagic Neogloboquadrina pachyderma left coiled (Npl), are generally not unlike values observed during MIS 9 or 7, i.e., slightly higher than those which characterized MIS 5e and the present interglacial, particularly in the outer Labrador Sea. This points to either a higher salinity and or a lower temperature in the subsurface water layer occupied by Npl. Low IRD, high salinity together with relatively high 18O values in foraminifers suggest limited influence of meltwater from ice cap and sea ice during MIS 11, especially the first part of the interglacial.

  19. Deposition, fabrication and analysis of polycrystalline silicon MIS solar cells. Final Report, January 1-December 31, 1979

    SciTech Connect

    Anderson, W.A.

    1980-03-01

    Discussion of MIS cell fabrication techniques, protovoltaic response data, I-V-T analysis to reveal conduction mechanisms, a detailed computer model, optimum MIS solar cell design, surface state effects, Auger studies, reliability studies and e-beam deposition of thin silicon films are included. The most important features of the work during 1979 include the one pump-down fabrication process, establishing a consistent fabrication sequence, achieving 13% efficiency of 2 cm/sup 2/ area, an evaluation of conduction mechanisms, establishing a detailed computer model and setting up an improved e-beam system to deposit thin silicon films. Details are reported. (WHK)

  20. Electrical Conduction Along Dislocations in Silicon and its Effect on Mis Solar Cells.

    NASA Astrophysics Data System (ADS)

    Divigalpitiya, Weerawanni Mudiyanselage Ranjith

    1987-09-01

    The current-voltage (J-V) characteristics were measured for a series of metal-insulator-semiconductor (MIS) cells of Al-SiO_{rm x} -pSi structure with dislocation loops penetrating different depths into the semiconductor surface. All cell parameters except reverse saturation photocurrent were observed to be degraded with increasing dislocation length. The reverse saturation photocurrent is independent of the extent of damage in the samples. The experimental results are explained in terms of a mathematical model based on conduction of captured carriers along dislocations. The specific conductance of the dislocations studied was found to be in the order of 10^{rm -15} cm ohm^{rm -1}. To the first approximation, the bias dependence of the current along a dislocation was shown to be exp (qV_ {rm 0}/2kT) contrary to the general expectation that such a current is linear in the voltage V_{rm 0}. To our knowledge, this is the first time that conduction along dislocations has been observed at room temperature. The photoelectrochemical studies done elsewhere on the same sample lend strong support to the hypothesis of conduction along dislocations. The effect of atomic hydrogen passivation of dislocations was also studied. Upon passivation, all the solar cell characteristics improve in general. Occasionally, however, anomalous J-V characteristics were observed indicating the possibility of acceptor neutralization. This complicates the interpretation of the experimental results in terms of the dislocation conductivity model. The temperature dependence of the solar cell characteristics in the range of 100 to 300 K was studied. Temperature coefficients of open circuit voltage, short circuit current, fill factor and efficiency of the MIS structure closely resemble those of n^{rm +} p silicon solar cells indicating the electronic equivalence of Al-SiO_{rm x} -pSi structure to an abrupt one sided n ^{rm +}p junction. The MIS solar cell characteristics were found to be sensitive to

  1. The effect of Be and Cr electrode deposition rate on the performance of MIS solar cells

    NASA Astrophysics Data System (ADS)

    Moharram, A. H.; Panayotatos, P.; Yeh, J. L.; Lalevic, B.

    1985-07-01

    An experimental study has been performed on MIS solar cells with Be, Cr and layered Cr-Be electrodes on single crystal Si, Wacker and Monsanto poly-Si substrates. Electrical characterization in the dark and under illumination was correlated to X-ray and Auger spectroscopy results. It was found that the electrode deposition rate directly affects the oxygen content of the electrodes for all metal-substrate configurations. This oxygen is believed to originate from the deposition ambient as well as from the SiO2 layer. In the case of cells with Cr and layered Cr-Be electrodes oxygen acts to reduce the electrode work function (thus increasing the open-circuit voltage) in direct proportion to the relative content of oxygen to chromium.

  2. Admittance Investigation of MIS Structures with HgTe-Based Single Quantum Wells

    NASA Astrophysics Data System (ADS)

    Izhnin, Ihor I.; Nesmelov, Sergey N.; Dzyadukh, Stanislav M.; Voitsekhovskii, Alexander V.; Gorn, Dmitry I.; Dvoretsky, Sergey A.; Mikhailov, Nikolaj N.

    2016-02-01

    This work presents results of the investigation of admittance of metal-insulator-semiconductor structure based on Hg1 - x Cd x Te grown by molecular beam epitaxy. The structure contains a single quantum well Hg0.35Cd0.65Te/HgTe/Hg0.35Cd0.65Te with thickness of 5.6 nm in the sub-surface layer of the semiconductor. Both the conductance-voltage and capacitance-voltage characteristics show strong oscillations when the metal-insulator-semiconductor (MIS) structure with a single quantum well based on HgTe is biased into the strong inversion mode. Also, oscillations on the voltage dependencies of differential resistance of the space charge region were observed. These oscillations were related to the recharging of quantum levels in HgTe.

  3. Bifacial MIS inversion layer solar cells based on low temperature silicon surface passivation

    NASA Astrophysics Data System (ADS)

    Jaeger, K.; Hezel, R.

    A novel bifacial silicon solar cell fabricated by a simple low-temperature process is introduced. The front side is characterized by an MIS contact grid and a charged plasma silicon nitride layer. The rear side is made up of ohmic grid lines in combination with silicon nitride for surface passivation. This appears to be the first bifacial solar cell without any highly doped region and completely processed at temperatures below 500 C. An AM1 efficiency of 15 and 13.2 percent was achieved for front and back illumination, respectively. The dependence of the solar cell data on cell thickness was experimentally investigated in the range from 80 microns to 330 microns. This thickness dependence was confirmed by theoretical one-dimensional calculations.

  4. Studies on evaporated cesium incorporation in MIS inversion layer solar cells

    NASA Astrophysics Data System (ADS)

    Guo, L.; Hezel, R.

    1994-09-01

    For MIS inversion layer solar cells with plasma silicon nitride both as antireflection coating and charged dielectric, cesium was incorporated into the nitride film by thermal evaporation. Compared to the presently used technique of dipping the silicon wafer into an alcoholic solution of CsCl, cesium evaporation yields higher fixed interface charge densities resulting in a lower inversion layer sheet resistance. As a very important result, even for intense and very energetic u.v. light ( λ ⩽ 180 nm) not present in the solar spectrum, no negative effect on the cell properties could be observed. This makes it possible to fully utilize the high response of the inversion layer solar cell in the ultraviolet range.

  5. Reconstruction of MIS 5 climate in the central Levant using a stalagmite from Kanaan Cave, Lebanon

    NASA Astrophysics Data System (ADS)

    Nehme, C.; Verheyden, S.; Noble, S. R.; Farrant, A. R.; Sahy, D.; Hellstrom, J.; Delannoy, J. J.; Claeys, P.

    2015-12-01

    Lying at the transition between the temperate Mediterranean domain and subtropical deserts, the Levant is a key area to study the palaeoclimatic response over glacial-interglacial cycles. This paper presents a precisely dated last interglacial (MIS 5) stalagmite (129-84 ka) from the Kanaan Cave, Lebanon. Variations in growth rate and isotopic records indicate a warm humid phase at the onset of the last interglacial at ~ 129 ka that lasted until ~ 125 ka. A gradual shift in speleothem isotopic composition (125-122 ka) is driven mainly by the δ18O source effect of the eastern Mediterranean surface waters during sapropel 5 (S5). The onset of glacial inception began after ~ 122 ka, interrupted by a short wet pulse during the sapropel 4 (S4) event. Low growth rates and enriched oxygen and carbon values until ~ 84 ka indicate a transition to drier conditions during Northern Hemisphere glaciation.

  6. Admittance Investigation of MIS Structures with HgTe-Based Single Quantum Wells.

    PubMed

    Izhnin, Ihor I; Nesmelov, Sergey N; Dzyadukh, Stanislav M; Voitsekhovskii, Alexander V; Gorn, Dmitry I; Dvoretsky, Sergey A; Mikhailov, Nikolaj N

    2016-12-01

    This work presents results of the investigation of admittance of metal-insulator-semiconductor structure based on Hg1 - x Cd x Te grown by molecular beam epitaxy. The structure contains a single quantum well Hg0.35Cd0.65Te/HgTe/Hg0.35Cd0.65Te with thickness of 5.6 nm in the sub-surface layer of the semiconductor. Both the conductance-voltage and capacitance-voltage characteristics show strong oscillations when the metal-insulator-semiconductor (MIS) structure with a single quantum well based on HgTe is biased into the strong inversion mode. Also, oscillations on the voltage dependencies of differential resistance of the space charge region were observed. These oscillations were related to the recharging of quantum levels in HgTe. PMID:26831691

  7. Metal-Insulator-Semiconductor (MIS) Structure with AlN Dielectric

    SciTech Connect

    Mahyuddin, A.; Hassan, Z.; Cheong, K. Y.

    2009-06-01

    In this paper, we present the study of the structural and electrical properties of AlN/GaN thin films grown on Si (111) substrates by plasma-assisted molecular beam epitaxy (RF-MBE) with AlN buffer layer. The performance of aluminum nitride (AlN) as insulator and aluminum (Al) contacts is presented. The thickness of GaN film and AlN insulating film as seen from SEM cross section are about 357.3 nm and 63.38 nm respectively. The presence of Ga, Al and N are confirmed by energy dispersive X-ray (EDX) measurement. The X-ray diffraction (XRD) measurement reveals that the samples are all wurtzite hexagonal AlN and GaN structure. The fabricated metal-insulator-semiconductor (MIS) structure was characterized using capacitance-voltage (C-V) measurements.

  8. New Spectral Method for Halo Particle Definition in Intense Mis-matched Beams

    SciTech Connect

    Dorf, Mikhail A.; Davidson, Ronald C.; Startsev, Edward A.

    2011-04-27

    An advanced spectral analysis of a mis-matched charged particle beam propagating through a periodic focusing transport lattice is utilized in particle-in-cell (PIC) simulations. It is found that the betatron frequency distribution function of a mismatched space-charge-dominated beam has a bump-on-tail structure attributed to the beam halo particles. Based on this observation, a new spectral method for halo particle definition is proposed that provides the opportunity to carry out a quantitative analysis of halo particle production by a beam mismatch. In addition, it is shown that the spectral analysis of the mismatch relaxation process provides important insights into the emittance growth attributed to the halo formation and the core relaxation processes. Finally, the spectral method is applied to the problem of space-charge transport limits.

  9. Electro-physical characteristics of MIS structures with HgTe- based single quantum wells

    NASA Astrophysics Data System (ADS)

    Dzyadukh, S.; Nesmelov, S.; Voitsekhovskii, A.; Gorn, D.

    2015-12-01

    The paper presents brief research results of the admittance of metal-insulator- semiconductor (MIS) structures based on Hg1-xCdxTe grown by molecular-beam epitaxy (MBE) method including single HgCdTe/HgTe/HgCdTe quantum wells (QW) in the surface layer. The thickness of a quantum well was 5.6 nm, and the composition of barrier layers with the thickness of 35 nm was close to 0.65. Measurements were conducted in the range of temperatures from 8 to 200 K. It is shown that for structure with quantum well based on HgTe capacitance and conductance oscillations in the strong inversion are observed. Also it is assumed these oscillations are related with the recharging of quantum levels in HgTe.

  10. High capacitance density MIS capacitor using Si nanowires by MACE and ALD alumina dielectric

    NASA Astrophysics Data System (ADS)

    Leontis, I.; Botzakaki, M. A.; Georga, S. N.; G. Nassiopoulou, A.

    2016-06-01

    High capacitance density three-dimensional (3D) metal-insulator-semiconductor (MIS) capacitors using Si nanowires (SiNWs) by metal-assisted chemical etching and atomic-layer-deposited alumina dielectric film were fabricated and electrically characterized. A chemical treatment was used to remove structural defects from the nanowire surface, in order to reduce the density of interface traps at the Al2O3/SiNW interface. SiNWs with two different lengths, namely, 1.3 μm and 2.4 μm, were studied. A four-fold capacitance density increase compared to a planar reference capacitor was achieved with the 1.3 μm SiNWs. In the case of the 2.4 μm SiNWs this increase was ×7, reaching a value of 4.1 μF/cm2. Capacitance-voltage (C-V) measurements revealed that, following a two-cycle chemical treatment, frequency dispersion at accumulation regime and flat-band voltage shift disappeared in the case of the 1.3 μm SiNWs, which is indicative of effective removal of structural defects at the SiNW surface. In the case of the 2.4 μm SiNWs, frequency dispersion at accumulation persisted even after the two-step chemical treatment. This is attributed to a porous Si layer at the SiNW tops, which is not effectively removed by the chemical treatment. The electrical losses of MIS capacitors in both cases of SiNW lengths were studied and will be discussed.

  11. Similar response in δD(CH4) during Holocene, Eem, MIS 11 and antecedent terminations

    NASA Astrophysics Data System (ADS)

    Bock, M.; Schmitt, J.; Fischer, H.

    2012-04-01

    Methane (CH4) is the third most important greenhouse gas after water vapour and carbon dioxide (CO2). Since the industrial revolution the mixing ratio of CH4 in the atmosphere rose to ~1800 ppb, a value never reached within the last 800 000 years. Nowadays, CH4 contributes ~20% to the total radiative forcing from all of the long-lived greenhouse gases. This CH4 increase can only be assessed compared to its natural changes in the past. Firn air and air enclosures in polar ice cores represent the only direct paleoatmospheric archive. The latter show that atmospheric CH4 concentrations changed in concert with northern hemisphere temperature during both glacial/interglacial transitions as well as rapid climate changes (Dansgaard-Oeschger events). Since the different sources of atmospheric methane exhibit distinct carbon and hydrogen isotopic composition (δ13CH4 and δD(CH4)) reconstructions of these parameters on ice cores allow to constrain individual CH4 source/sink changes. δD(CH4) also reflects water cycle changes as hydrogen of precipitation is traced into methane produced from wetland/thermokarst/permafrost systems (Bock et al. 2010, Science). Using an improved technique (GC/P/irmMS) for analysis of δD(CH4) based on earlier developments (Bock et al. 2010, RCM) we produced high precision records for the penultimate termination and interglacial (marine isotope stages (MIS) 6 to 5) from the EDML (European Project for Ice Coring in Antarctica, Dronning Maud Land) ice core and for MIS 11 from the EDC ice core (European Project for Ice Coring in Antarctica, Dome Concordia). We compare our data sets with the last termination and the Holocene by means of own measurements and published records (Sowers 2006, 2010). The principle response of δD(CH4) is similar for the three investigated time periods which allows to identify main natural drivers.

  12. Study on the low leakage current of an MIS structure fabricated by ICP-CVD

    NASA Astrophysics Data System (ADS)

    Tsai, S.-Y.; Lu, Y.-M.; Hon, M.-H.

    2008-03-01

    As the dimensions of electric devices continue to shrink, it is becoming increasingly important to understand how to obtain good quality gate oxide film materials wilth higher carrier mobility, lower leakage current and greater reliability. All of them have become major concerns in the fabrication of thin film oxide transistors. A novel film deposition method called Inductively Coupled Plasma-Chemical Vapor Deposition (ICP-CVD) has received attraction in the semiconductor industry, because it can be capable of generating high density plasmas at extremely low temperature, resulting in less ion bombardment of the material surface. In this work, we present the results of crystallized silicon dioxide films deposited by inductively coupled plasma chemical vapor deposition technique at an extremely low temperature of 90°C. The value of the refractive index of the crystallized ICP-CVD SiO2 film depends on the r.f. power of the ICP system, and approximates to be 1.46. This value is comparable to that of SiO2 films prepared by thermal oxidation. As the r.f. power of ICP applied more than 1250 Watts, still only the (111) diffraction peak is observed by XRD, which implies a very strong preferred orientation or single crystal structure. Too low or too high r.f. power both produces amorphous SiO2 films. From the I-V curve, the MIS device with a SiO2 dielectric film has a lower leakage current density of 6.8×10-8A/cm2 at 1V as the film prepared at 1750 watts. The highest breakdown field in this study is 15.8 MV/cm. From the FTIR analysis, it was found that more hydrogen atoms incorporate into films and form Si-OH bonds as the r.f. power increases. The existence of Si-OH bonds leads to a poor reliability of the MIS device.

  13. High-elevation paleoenvironmental change during MIS 6-4 in the central Rockies of Colorado as determined from pollen analysis

    NASA Astrophysics Data System (ADS)

    Anderson, R. Scott; Jiménez-Moreno, Gonzalo; Ager, Thomas; Porinchu, David F.

    2014-11-01

    Paleoecological studies from Rocky Mountain (USA) high elevations encompassing the previous interglacial (MIS 5e) are rare. The ~ 10-m composite profile from the Ziegler Reservoir fossil site (2705 m asl) of central Colorado allows us to determine paleoenvironments from Marine Oxygen Isotope Stages (MIS) 6- 4 using pollen zones that are approximately equivalent to marine oxygen isotope stages. During Pollen Zone (PZ) 6 time, pollen assemblages dominated by Artemisia (sagebrush) suggest that alpine tundra or steppe occurred nearby. The transition to PZ 5e was characterized by a rapid increase in tree pollen, initially Picea (spruce) and Pinus (pine) but also Quercus (oak) and Pseudotsuga menziesii (Douglas-fir). Non-arboreal pollen (NAP) types increased during PZ 5d, while Abies (fir) and Juniperus (juniper) increased during PZ 5c. Pollen evidence suggests that temperatures during PZ 5b were as cold as during PZ 6, with the site again surrounded by alpine tundra. Picea dominated during PZ 5a before the onset of cooler conditions during PZ 4. The MIS 6-MIS 5e transition here was similar to the MIS 2-MIS 1 transition at other Rocky Mountain sites. However, the Ziegler Reservoir pollen record contains evidence suggesting unexpected climatic trends at this site, including a warmer-than-expected MIS 5d and cooler-than-expected MIS 5b.

  14. A high-elevation MIS 5 hydrologic record using mollusks and ostracodes from Snowmass Village, Colorado, USA

    NASA Astrophysics Data System (ADS)

    Sharpe, Saxon E.; Bright, Jordon

    2014-11-01

    Sediments containing terrestrial and aquatic mollusks and ostracodes from the Ziegler Reservoir fossil site (2705 m elevation) near Snowmass Village, Colorado, span ~ 130-87 ka (MIS 5e through 5b). The southeastern area of the site where taxa were recovered was a relatively fresh, shallow, well-vegetated wetland during MIS 5e through 5c time, approximately 2 m deep, with a total dissolved solids value of ~ 200-1000 mg L- 1. The wetland was seasonally or annually variable and groundwater discharged along the margins of the bounding moraine. Groundwater likely contributed solutes to the system and may have contributed 18O-enriched water. Based on stable isotopes from ostracode calcite (δ18OOST and δ13COST), seasonal evaporation occurred and the dissolved inorganic carbon pool was unexpectedly enriched in 13C. The mollusk and ostracode faunas changed little across the MIS 5e/5d/5c boundaries, whereas a distinct change in the ostracode fauna occurred between the deposition of Unit 11 and Unit 13, which corresponds in time to the MIS 5c/5b boundary, indicating some combination of increased surface and/or groundwater flow, a decrease in water temperature, and a freshening and a possible deepening of the wetland.

  15. Enhancing Student Learning across Disciplines: A Case Example Using a Systems Analysis and Design Course for MIS and ACS Majors

    ERIC Educational Resources Information Center

    Surendran, Ken; Ehie, Ike C.; Somarajan, Chellappan

    2005-01-01

    This paper illustrates an approach used to enhance student learning outcomes in a combined cross-listed Systems Analysis and Design (SA&D) course and examines benefits perceived by students through analysis of assessment and students feedback. The SA&D course is a required course in both the Management Information Systems (MIS) major and the…

  16. WindSat Soil Moisture and Vegetation Validation and Performance Prediction for the NPOESS Microwave Imager/Sounder (MIS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The National Polar-orbiting Operational Environmental Satellite System’s (NPOESS) Microwave Imager/Sounder (MIS) instrument is in development, with soil moisture sensing depth as one of the two Key Performance Parameters (KPPs). The other one is ocean surface wind speed precision. Based on the curre...

  17. The Use of Management Information Systems (MIS) in Decision Making in the South-West Nigerian Universities

    ERIC Educational Resources Information Center

    Ajayi, I. A.; Omirin, Fadekemi F.

    2007-01-01

    This study investigated the use of Management Information Systems (MIS) in decision-making on long-term planning, short-term planning and budgeting in the South-West Nigerian Universities. The study used the descriptive research design of the survey type. Data were collected from a sample of 600 subjects consisting of 400 academic staff holding…

  18. 77 FR 72905 - Pipeline Safety: Random Drug Testing Rate; Contractor MIS Reporting; and Obtaining DAMIS Sign-In...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-06

    ... mail the user name and password for the Drug and Alcohol Management Information System (DAMIS) to... operators' annual submissions of Management Information System (MIS) reports required by Sec. 199.119(a). If... January 19, 2010, PHMSA published an Advisory Bulletin (75 FR 2926) implementing the annual collection...

  19. Paleoproductivity vs. influx of terrestrial biomarker in sediment from the Korean Plateau, East Sea (Japan Sea) since the MIS 11

    NASA Astrophysics Data System (ADS)

    Hyun, Sangmin; Suh, Yean Jee; Ikehara, Miroru

    2015-04-01

    A piston core collected from the Korean Plateau, East Sea (Japan Sea) of Korea was conducted in terms of variations in paleoproductivity and influx of terrestrial biomarker. The distribution of terrestrial n-alkanes signatures is characterized by the occurrence of high odd number frequency with a minor contribution of specific compound (nC27 only). Average Chain Length (ACL) and Carbon Preferences Index (CPI), both of which are derived from n-alkane combination, show similar shifting between glacial and interglacial periods. Previous studies of SST variation have shown that glacial-interglacial scale changes were quite variable with the maximum range of 26oC in MIS 7, and the minimum range of 12oC during MIS 2 and 6. Therefore, paleovegetation communities had been changed in responding to paleoclimatological variations, and the input amount of terrestrial compound was strongly linked with paleoclimatologic changes. The isotopic composition of δ13C and δ15N of organic matter, which showed extreme temporal variation since MIS 11, indicates the influx of large amount of terrestrial organic matter from the neighboring terrestrial environments during MIS 2, 8 and 10. In particular, depleted values of δ13Corg during MIS 2, 8 and 10 were coincident with lower nitrogen isotope values indicating local paleoceanographic effects such as paleoproductivity changes. Decoupling between δ13Corg and δ15Norg during MIS 1, 3, 5, 7 and coupling of the two during MIS 8 and 11 can be observed, which appear to be interpreted as local productivity changes. In particular, high abundance of cholesterol and C21 n-alkanes, which were derived from diatom, increased during interglacial periods. Therefore, alkenones, SST and n-alkanes signatures coincide with δ13Corg and δ15Norg variations during glacial-interglacial cycles and further strongly associated with cholesterol abundance suggesting that the paleoenvironmental conditions in East Sea during glacial-interglacial periods were

  20. New chronology for Pleistocene shoreline deposits on the central US Atlantic Coast: implication for relative sea level during MIS 5 and 7

    NASA Astrophysics Data System (ADS)

    Shen, Z.; Wright, E. E.; Mauz, B.

    2015-12-01

    Emerged shoreline deposits are the most important records for studying relative sea level (RSL) of previous interglacial and understanding glacial/hydro isostasy. The Lower Atlantic Coastal Plain in the U.S. is characterized by coast-parallel barrier beaches and back-barrier deposits formed during maximum Pleistocene marine transgressions. Thus, they offer an opportunity to investigate RSL changes of multiple Pleistocene interglacials. However, the chronology of these deposits has been controversial due to the lack of reliable numerical ages, especially in South Carolina. Here we present stratigraphy and OSL dating results for both the late Pleistocene barrier and the back-barrier deposits between Georgetown and Myrtle Beach, South Carolina and discuss their sea-level implications. The barrier ridge near Georgetown is covered by about 1 m aeolian deposits dated to ~20 ka. The aeolian deposits overlie humic sand and laminated beach sand that is dated to ~80 ka, corresponding to Marine Isotope Stage (MIS) 5a. Stratigraphy of back-barrier deposits exposed along the Intracoastal Waterway near Myrtle Beach reveals a unit of back-barrier deposits separated from underlying shallow marine deposits by a paleosol. The back-barrier deposits are dated to MIS 5a while the lower shallow marine deposits yielded OSL ages corresponding to MIS 7 (~200 ka). The beach sand near Georgetown and the back-barrier deposits near Myrtle Beach together suggest that MIS 5a RSL was up to about 5 m above present sea level while the shallow marine deposits near Myrtle Beach indicate a MIS 7 RSL at or above present sea level along the northeastern South Carolina coast. The MIS 5a and MIS 7 RSL are in agreement with previous studies along other U.S. Atlantic coast. However, the missing of MIS 5e deposits between MIS 5a and MIS 7 deposits at the exposure near Myrtle Beach needs be confirmed with additional work.

  1. Continental and sea surface temperature variability in southeast Africa (Zambezi River region) since MIS 3

    NASA Astrophysics Data System (ADS)

    Castañeda, I. S.; Tjallingii, R.; Wang, Y. V.; Mets, A.; van der Lubbe, J.; Brummer, G.; Sinninghe Damste, J. S.; Schneider, R. R.; Schouten, S.

    2010-12-01

    At present, few paleoclimate records exist from the region of southeast Africa. The continental climate history of southeast Africa is of much interest since this region falls under the influence of both the Intertropical Convergence Zone (ITCZ) and Congo Air Boundary (CAB) and likely experienced considerably different hydrological conditions when glacial conditions prevailed. Likewise, the paleoceanographic history of the Mozambique Channel of the coast of southeast Africa is of much interest since mesoscale eddies (Agulhas rings) formed in this region transport and release warm and saline Indian Ocean waters into the South Atlantic influencing the buoyancy of Atlantic thermocline waters, deep-water formation, and Atlantic Meridional Overturning Circulation. Sea surface temperatures (SST) of the southern Indian Ocean are additionally important for modulating precipitation in southeast Africa. Here, we utilize multiple organic (TEX86, BIT Index, MBT, CBT) and inorganic (XRF core scanning) geochemical proxies on a sediment core collected from near the Zambezi River (core 64PE304-80; -18.24 °S, 37.87 °E) to examine continental conditions within the Zambezi River catchment as well as the SST history of the Mozambique Channel. Throughout the ~38 kyr record of 64PE304-80, variations in the BIT Index, a proxy for marine vs. soil organic matter input, closely track changes in the log (Ca/Ti) ratio, a proxy for marine vs. lithogenic input. These records indicate increased lithogenic/soil OM contributions in the Late Pleistocene portion of the record whereas the Holocene is characterized by increased marine contributions. This pattern likely reflects closer proximity of the Zambezi river mouth and transport of terrestrial material to the coring site during the last glacial sea-level lowstand. A particularly interesting feature of these records is pronounced millennial-scale fluctuations occurring within Marine Isotope Stages (MIS) 2 and 3, which posses a similar structure

  2. The Last Interglacial-Glacial cycle (MIS 5-2) re-examined based on long proxy records from central and northern Europe

    NASA Astrophysics Data System (ADS)

    Helmens, Karin F.

    2014-02-01

    Current multi-proxy studies on a long sediment sequence preserved at Sokli (N Finland), i.e. in the central area of Fennoscandian glaciations, are drastically changing classic ideas of glaciations, vegetation and climate in northern Europe during the Late Pleistocene. The sediments in the Sokli basin have escaped major glacial erosion due to non-typical bedrock conditions. In this review, the Sokli record is compared in great detail with other long proxy records from central, temperate and northern, boreal Europe. These comprise the classic records of La Grande Pile (E France) and Oerel (N Germany) and more recently obtained records from Horoszki Duże (E Poland) and Lake Yamozero (NW Russia). The focus of the review is on pollen, lithology and macrofossil- and insect-based temperature inferences. The long records are further compared with recent proxy data from nearby terrestrial sites as well as with the rapidly accumulating high-resolution proxy data from the ocean realm. The comparison allows a re-examination of the environmental history and climate evolution of the Last Interglacial-Glacial (LI-G) cycle (MIS 5-2). It shows that environmental and climate conditions during MIS 5 (ca 130-70 ka BP) were distinctly different from those during MIS 4-2 (ca 70-15 ka BP). MIS 5 is characterized by three long forested intervals (broadly corresponding to MIS 5e, 5c, 5a), both in temperate and northern boreal Europe. These mild periods were interrupted by two short, relatively cold and dry intervals (MIS 5d and 5b) with mountain-centered glaciation in Fennoscandia. Millennial scale climate events were superimposed upon these longer lasting climate fluctuations. The time interval encompassing MIS 4-2 shows open vegetation. It is characterized by two glacial maxima (MIS 4 and 2) with sub-continental scale glaciation over northern Europe and dry conditions in strongly continental eastern European settings. High amplitude climate oscillations of millennial duration

  3. Tracking millennial-scale climate variability through the Marine Isotope Stage (MIS) 12 using terrigenous biomarkers in lacustrine sediments from Valles Caldera, New Mexico, USA

    NASA Astrophysics Data System (ADS)

    Contreras, S.; Werne, J. P.; Brown, E. T.; Anderson, R. S.; Fawcett, P. J.

    2012-12-01

    The Quaternary is characterized by cyclic intervals of warm interglacial and cold glacial stages with the MIS 12 highlighted as one of the most severe glacial stages. Recent studies reported abrupt climatic episodes at millennial scale during MIS 12 and the transition to MIS 11 similar to Dansgaard-Oeschger [D/O] and Heinrich events but weaker in amplitude than the dramatic oscillations observed in the last glacial period. The climate variability of MIS 12 is well documented in marine and ice-sheet isotopic records but terrestrial records are scarce and often fragmented. We will present a high-resolution paleoclimate reconstruction through the MIS 12, including MIS 13-12 and MIS 12-11 transitions, from paleo-lake sediments taken in Valles Caldera, New Mexico. Measurements including scanning X-ray fluorescence, pollen, terrigenous biomarkers and bulk and compound-specific stable isotopes that usually serve as paleoclimatic proxies of precipitation and vegetation will be contrasted. Terrigenous lipid biomarkers confirm that vegetation responds rapidly to millennial-scale climate variability and provide knowledge of how these millennial oscillations impacted western North America.

  4. The MIS 5 palaeoenvironmental record in the SE Mediterranean coast of the Iberian Peninsula (Río Antas, Almería, Spain)

    NASA Astrophysics Data System (ADS)

    Torres, T.; Ortiz, J. E.; Blázquez, A. M.; Ruiz Zapata, B.; Gil, M. J.; Martín, T.; Sánchez-Palencia, Y.

    2015-08-01

    Landwards of a MIS5 bar, a borehole core (SRA) was analyzed to establish the relationship between the lagoonal record and the raised beach deposits in the surroundings of the Antas river mouth and to reconstruct the Pleistocene palaeoenvironmental evolution of the southern Mediterranean coast of the Iberian Peninsula. 63 samples were recovered for amino acid racemization dating, 86 samples for sedimentological and paleontological determination, 37 samples for pollen identification and 54 for biomarker analysis. AAR revealed that the borehole record contains MIS11, MIS6 and MIS5 deposits, the latter extensively represented. During the end of MIS6 and MIS5, a sand barrier developed and created a shallow lagoon with alternating terrestrial inputs this process being common in other Mediterranean realms. Litho- and biofacies allowed the identification of distinct paleoenvironments through time, with the presence of a lagoonal environment alternating with alluvial fan progradation. Biomarkers indicated constant input from terrestrial plants, together with variable development of aquatic macrophytes. The palynological content allowed the reconstruction of the paleoclimatological conditions during MIS6 and 5, with evidence of seven scenarios characterized by alternating arid and relatively humid conditions.

  5. Climate and vegetation since the Last Interglacial (MIS 5e) in a putative glacial refugium, northern Idaho, USA

    NASA Astrophysics Data System (ADS)

    Herring, Erin M.; Gavin, Daniel G.

    2015-06-01

    There are very few terrestrial sediment records from North America that contain a nearly continuous sequence spanning from the Last Interglacial period to the present. We present stratigraphic records of pollen and several other proxies from a Carex-dominated wetland, Star Meadows, located 140 km south of the maximum extent of the Cordilleran Ice Sheet and near the current southern extent of interior mesic forests in northern Idaho. Many species in this region are disjunct by 160 km of arid steppe and dry forest from their more extensive distribution along the Pacific Northwest coast and may have survived in an interior refugium. The chronology for the upper 251 cm was determined by six radiocarbon dates and one tephra deposit, and the age of the remainder of the core (251-809 cm) was estimated by correlation with SPECMAP δ18O. Fluctuating water levels were inferred from alternating peat, biogenic silica, and aquatic pollen types. During MIS 5e the region was warmer and drier than today and was dominated by Pinus (likely Pinus contorta) mixed conifer forest surrounding a Carex meadow. A cool-moist climate (MIS 5b-5d) soon developed, and the site was inundated with deep water. Pollen indicated wetland vegetation (Betula glandulosa, Typhaceae, and Salix) developed around a lake with a Pseudotsuga/Larix and Picea forest on the surrounding slopes. During MIS 5a, a warmer climate supported a Pseudotsuga/Larix, Abies, and Picea forest on the surrounding hillsides and a Carex-dominated environment within a dry meadow. From MIS 4 to MIS 3, a cool and wet Pinus and Picea forest predominated. Water levels rose, enabling Nuphar to persist within a perennial lake while a sedge fen established along the lake margin. As climate transitioned into MIS 2, a cooler and drier climate supported a Pinus and Picea subalpine parkland, though water levels remained high enough to support Nuphar. During the Last Glacial Maximum the sediment was mainly silt and clay with high Artemisia and

  6. The role of an Arctic ice shelf in the climate of the MIS 6 glacial maximum (140 ka)

    NASA Astrophysics Data System (ADS)

    Colleoni, F.; Krinner, G.; Jakobsson, M.

    2010-12-01

    During the last decade, Arctic icebreaker and nuclear submarine expeditions have revealed large-scale Pleistocene glacial erosion on the Lomonosov Ridge, Chukchi Borderland and along the Northern Alaskan margin indicating that the glacial Arctic Ocean hosted large Antarctic-style ice shelves. Dating of sediment cores indicates that the most extensive and deepest ice grounding occurred during Marine Isotope Stage (MIS) 6. The precise extents of Pleistocene ice shelves in the Arctic Ocean are unknown but seem comparable to present existing Antarctic ice shelves. How would an Antarctic-style ice shelf in the MIS 6 Arctic Ocean influence the Northern Hemisphere climate? Could it have impacted on the surface mass balance (SMB) of the MIS 6 Eurasian ice sheet and contributed to its large southward extent? We use an Atmospheric General Circulation Model (AGCM) to investigate the climatic impacts of both a limited MIS 6 ice shelf covering portions of the Canada Basin and a fully ice shelf covered Arctic Ocean. The AGCM results show that both ice shelves cause a temperature cooling of about 3 °C over the Arctic Ocean mainly due to the combined effect of ice elevation and isolation from the underlying ocean heat fluxes stopping the snow cover from melting during summer. The calculated SMB of the ice shelves are positive. The ice front horizontal velocity of the Canada Basin ice shelf is estimated to ≈ 1 km yr -1 which is comparable to the recent measurements of the Ross ice shelf, Antarctica. The existence of a large continuous ice shelf covering the entire Arctic Ocean would imply a mean annual velocity of icebergs of ≈12 km yr -1 through the Fram Strait. Our modeling results show that both ice shelf configurations could be viable under the MIS 6 climatic conditions. However, the cooling caused by these ice shelves only affects the Arctic margins of the continental ice sheets and is not strong enough to significantly influence the surface mass balance of the entire MIS

  7. The role of ultra-thin SiO2 layers in metal-insulator-semiconductor (MIS) photoelectrochemical devices (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Esposito, Daniel V.

    2015-08-01

    Solid-state junctions based on a metal-insulator-semiconductor (MIS) architecture are of great interest for a number of optoelectronic applications such as photovoltaics, photoelectrochemical cells, and photodetection. One major advantage of the MIS junction compared to the closely related metal-semiconductor junction, or Schottky junction, is that the thin insulating layer (1-3 nm thick) that separates the metal and semiconductor can significantly reduce the density of undesirable interfacial mid-gap states. The reduction in mid-gap states helps "un-pin" the junction, allowing for significantly higher built-in-voltages to be achieved. A second major advantage of the MIS junction is that the thin insulating layer can also protect the underlying semiconductor from corrosion in an electrochemical environment, making the MIS architecture well-suited for application in (photo)electrochemical applications. In this presentation, discontinuous Si-based MIS junctions immersed in electrolyte are explored for use as i.) photoelectrodes for solar-water splitting in photoelectrochemical cells (PECs) and ii.) position-sensitive photodetectors. The development and optimization of MIS photoelectrodes for both of these applications relies heavily on understanding how processing of the thin SiO2 layer impacts the properties of nano- and micro-scale MIS junctions, as well as the interactions of the insulating layer with the electrolyte. In this work, we systematically explore the effects of insulator thickness, synthesis method, and chemical treatment on the photoelectrochemical and electrochemical properties of these MIS devices. It is shown that electrolyte-induced inversion plays a critical role in determining the charge carrier dynamics within the MIS photoelectrodes for both applications.

  8. Glacial-interglacial variations in sediment organic carbon accumulation and benthic foraminiferal assemblages on the Bermuda Rise (ODP Site 1063) during MIS 13 to 10

    NASA Astrophysics Data System (ADS)

    Poli, Maria Serena; Meyers, Philip A.; Thunell, Robert C.; Capodivacca, Marco

    2012-09-01

    We have determined organic carbon concentrations and isotopic compositions and benthic foraminiferal assemblages in sediments deposited between ˜500 and 340 ka at ODP Site 1063 on the northeastern flank of the Bermuda Rise. This time interval includes Marine Isotope Stage (MIS) 11, a particularly warm and long interglacial that was similar to today, and MIS 12, one of the most severe glacials of the last 600 kyr. During MIS 11.3, the peak of interglacial warming, organic carbon accumulation rates are low and benthic foraminiferal assemblages are dominated by Nuttallides umbonifera, a species indicative of oligotrophic environments. Higher accumulation rates during MIS 12 and 10 correspond with elevated sedimentation rates (33-36 cm/kyr). This pattern implies a combination of enhanced delivery and improved preservation of sediment organic matter during these glacial times. Organic δ13C values are less negative during MIS 12 and MIS 10 than during MIS 11, which is consistent with greater glacial-stage marine productivity. High relative abundances ofOridorsalis umbonatus during glacial intervals probably records a low but sustained flux of highly degraded organic material. Large, recurrent fluctuations in the abundance of Epistominella exiguaat the beginnings of the MIS 12 and MIS 10 glaciations suggest a marked increase in local phytoplankton blooms at these times and consequent delivery of phytodetritus to the seafloor. The most likely causes of these variations are changes in the position and strength of the Gulf Stream and its associated cold-ring eddies, combined with increased advection of terrigenous sediments from northerly locations during glacial lowstands.

  9. Photoelectrical characteristics of MIS structures on the basis of graded-band-gap n-HgCdTe ( x = 0.21 0.23)

    NASA Astrophysics Data System (ADS)

    Voitsekhovskii, A. V.; Nesmelov, S. N.; Dzyadukh, S. M.; Varavin, V. S.; Dvoretskii, S. A.; Mikhailov, N. N.; Sidorov, Yu. G.; Vasil'Ev, V. V.; Zakhar'yash, T. I.; Mashukov, Yu. P.

    2006-10-01

    Voltage, frequency, and temperature dependences of photo-emf are experimentally studied in the MIS HgCdTe/SiO 2 / Si 3 N 4 and HgCdTe/AOF structures. The MIS structures were produced on the basis of graded-bandgap Hg 1-x Cd x Te films grown by molecular-beam epitaxy on GaAs substrates. It is found that the subsurface graded-band-gap layers do affect the photoelectrical characteristics of MIS structures. The mechanisms limiting the differential resistance in the space-charge region at various temperatures are revealed.

  10. Aluminum-natural oxide-P type silicon /MIS/ solar cells

    NASA Astrophysics Data System (ADS)

    Badura, E.; Zdanowicz, W.

    1980-12-01

    MIS (metal-interfacial region-semiconductor) solar cells are attractive because of their relatively high conversion efficiency. Their performance, however, is strongly affected by device preparation. Two methods are described for preparing Al - natural SiO - p-type Si cells which exhibit high photovoltaic values. The first, involving a 'nonsintered oxide' process, entails etching the active silicon surfaces in HF acid and exposing them to air at room temperature for 48 hours. The second method differs from the first only in that it requires the additional step of sintering the oxidized surfaces in a vacuum at about 500 C. In both cases, a semitransparent Al film is then applied to the oxide, after which an Al grid electrode and 70-nm SiOx antireflection coatings are deposited on the device. Measured against both the nonsintered cell and the Schottky barrier cell, the sintered assembly shows the highest open-circuit voltage (0.46-0.492), the highest fill factor (0.66-0.73), and the most efficient dark parameters.

  11. Early regional LGM (MIS 3) reflected in Central European Loess-Paleosol Sequences?

    NASA Astrophysics Data System (ADS)

    Zoeller, Ludwig; Fuchs, Markus

    2014-05-01

    The age of the "Brandenburg Phase", representing the regional LGM in Northern Germany and Poland, has been under debate. Evidence was found recently by OSL dating that it occurred during late MIS 3. In a new loess profile in the famous quarry of Nußloch south of Heidelberg (Germany) an exceptionally thick (6 m) loess-paleosol sequence (LPS) starts with a boreal brown soil regionally known as "Lohne soil", which terminates the Middle Pleniglacial LPS, according to classical stratigraphies. This paleosol is overlain by loess beds interbedding with weakly developed tundra-gley soils of typically Upper Pleniglacial habitus. Mean OSL ages from quartz fine and middle grains range between ca. 29 ka and ca. 35 ka in this part of the section which is much thicker than in previously studied corresponding parts of the loess stratigraphy at the Nußloch site. Our surprising dating results are, however, supported by recently dated loess beds in the Central European corridor between the ice margin of the Brandenburg Phase and the Northern Alpine LGM terminal moraines. Paleoenvironmental reconstructions point to cold but rather humid climatic conditions favouring rapid ice advance. We, thus, hypothesize that the rapid advance of Scandinavian ice into northern Central Europe which may have occurred ca. 10 ka prior to the global LGM, is reflected in some well-preserved Central European loess sections covering the last glacial cycle.

  12. Using bones to shape stones: MIS 9 bone retouchers at both edges of the Mediterranean Sea.

    PubMed

    Blasco, Ruth; Rosell, Jordi; Cuartero, Felipe; Fernández Peris, Josep; Gopher, Avi; Barkai, Ran

    2013-01-01

    A significant challenge in Prehistory is to understand the mechanisms involved in the behavioural evolution of human groups. The degree of technological and cultural development of prehistoric groups is assessed mainly through stone tools. However, other elements can provide valuable information as well. This paper presents two bone retouchers dated to the Middle Pleistocene MIS 9 used for the shaping of lithic artefacts. Originating from Bolomor Cave (Spain) and Qesem Cave (Israel), these two bone retouchers are among the earliest of the Old World. Although the emergence of such tools might be found in the latest phases of the Acheulean, their widespread use seems to coincide with independently emergent post-Acheulean cultural complexes at both ends of the Mediterranean Sea: the post-Acheulean/pre-Mousterian of Western Europe and the Acheulo Yabrudian Cultural Complex of the Levant. Both entities seem to reflect convergent processes that may be viewed in a wider cultural context as reflecting new technology-related behavioural patterns as well as new perceptions in stone tool manufacturing. PMID:24146928

  13. Geochemical proxies and millennial-scale climate variability during MIS 3 at Lake Chalco, central Mexico

    NASA Astrophysics Data System (ADS)

    Torres, E.; Lozano, S.; Roy, P.; Ortega, B.; Caballero, M.

    2013-05-01

    The Basin of Mexico (20N, 99W; 2240 m.a.s.l.) is present at the northern limit of the American tropics and is surrounded by up to 5400 m high mountains. The Lake Chalco is situated at the southern part of the basin and spreads over 120 km2. The precipitation in the modern era is influenced by the seasonal displacement of the Intertropical Convergence Zone and the high-pressure belt located at about 35 N. Five cores were drilled (up to 122.5 m depth) in order to document climate variability in paleohydrological conditions during the late Quaternary. The age model includes several 14C dates and tephra layers present in the upper 25 m of the core. We documented millennial-scale events during MIS 3 based on geochemical data (total organic carbon (TOC), total inorganic carbon (TIC), C/N ratio) and abundance of charcoal particles. By temporal correlation with GISP2 core we founded that Greenland interstadials match with TOC percentages suggesting wet conditions while stadials match with high TIC percentages and high charcoal concentrations suggesting dry conditions. We compared our data with speleothem records (δ18O) from Fort Station Cave (New Mexico) and Terciopelo Cave (Costa Rica), our preliminary results indicate that Chalco record has a similar climatic signal as Terciopelo Cave, both presented wet interstadials and dry stadials which appear to have been regulated by the seasonal migration of the ITCZ.

  14. Modeling the Hemodynamic Response Function in fMRI: Efficiency, Bias and Mis-modeling

    PubMed Central

    Lindquist, Martin A.; Loh, Ji Meng; Atlas, Lauren Y.; Wager, Tor D.

    2012-01-01

    Most brain research to date has focused on studying the amplitude of evoked fMRI responses, though there has recently been an increased interest in measuring onset, peak latency and duration of the responses as well. A number of modeling procedures provide measures of the latency and duration of fMRI responses. In this work we compare several techniques that vary in their assumptions, model complexity, and interpretation. For each method, we introduce methods for estimating amplitude, peak latency, and duration and for performing inference in a multi-subject fMRI setting. We then assess the techniques’ relative sensitivity and their propensity for mis-attributing task effects on one parameter (e.g., duration) to another (e.g., amplitude). Finally, we introduce methods for quantifying model misspecification and assessing bias and power-loss related to the choice of model. Overall, the results show that it is surprisingly difficult to accurately recover true task-evoked changes in BOLD signal and that there are substantial differences among models in terms of power, bias and parameter confusability. Because virtually all fMRI studies in cognitive and affective neuroscience employ these models, the results bear on the interpretation of hemodynamic response estimates across a wide variety of psychological and neuroscientific studies. PMID:19084070

  15. Northern Borneo stalagmite records reveal West Pacific hydroclimate across MIS 5 and 6

    NASA Astrophysics Data System (ADS)

    Carolin, Stacy A.; Cobb, Kim M.; Lynch-Stieglitz, Jean; Moerman, Jessica W.; Partin, Judson W.; Lejau, Syria; Malang, Jenny; Clark, Brian; Tuen, Andrew A.; Adkins, Jess F.

    2016-04-01

    Over the past decades, tropical stalagmite δ18O records have provided valuable insight on glacial and interglacial hydrological variability and its relationship to a variety of natural climate forcings. The transition out of the penultimate glaciation (MIS 6) represents an important target for tropical hydroclimate reconstructions, yet relatively few such reconstructions resolve this transition. Particularly, comparisons between Termination 1 and 2 provide critical insight on the extent and influence of proposed climate mechanisms determined from paleorecords and model experiments spanning the recent deglaciation. Here we present a new compilation of western tropical Pacific hydrology spanning 0-160 ky BP, constructed from eleven different U/Th-dated stalagmite δ18O records from Gunung Mulu National Park in northern Borneo. The reconstruction exhibits significant precessional power in phase with boreal fall insolation strength over the 0-160 ky BP period, identifying precessional insolation forcing as the dominant driver of hydroclimate variability in northern Borneo on orbital timescales. A comparison with a network of paleoclimate records from the circum-Pacific suggests the insolation sensitivity may arise from changes in the Walker circulation system. Distinct millennial-scale increases in stalagmite δ18O, indicative of reduced regional convection, occur within glacial terminations and may reflect a response to shifts in inter-hemispheric temperature gradients. Our results imply that hydroclimate in this region is sensitive to external forcing, with a response dominated by large-scale temperature gradients.

  16. HiT&MIS: Instrumentation for Auroral and Ionospheric Airglow Studies

    NASA Astrophysics Data System (ADS)

    Hewawasam, K.; Maguire, R.; Chakrabarti, S.; Cook, T.; Baumgardner, J. L.

    2014-12-01

    We have developed a high-throughput imaging spectrograph that uses an echelle grating operating at a high dispersion order to observe extended sources such as atmospheric airglow and auroral emissions at high spectral resolution. Instead of the conventional single slit this instrument uses four with appropriate foreoptics to image a long, narrow field of view of approximately 0.1 × 50 deg. By using interference filters for order sorting, this instrument can simultaneously observe multiple spectral features located anywhere in the visible band (approximately 300 to 1000 nm) at high resolution. The current implementation images the scene at 6 wavelengths (427.8, 486.1, 557.7, 630.0, 656.3 and 777.4 nm), but the flexibility of the design of the instrument allows varying the wavelengths of interest with minimal modifications. We have constructed two spectrographs to be located at different geomagnetic locations. This will enable tomography of atmospheric phenomena for full 3-D rendering of the volume emission. We will combine HiT&MIS data with data from LITES, GROUP-C (on ISS) and other ground based sources such as GIRO, HiTIES, HIRISE and CHIMES along with the 13 all-sky imagers operated by Boston University to form a more complete picture of the ionosphere.This work is supported by the NSF grant AGS1315354

  17. Mis-splicing of the ABCC2 gene linked with Bt toxin resistance in Helicoverpa armigera

    PubMed Central

    Xiao, Yutao; Zhang, Tao; Liu, Chenxi; Heckel, David G.; Li, Xianchun; Tabashnik, Bruce E.; Wu, Kongming

    2014-01-01

    Toxins from the bacterium Bacillus thuringiensis (Bt) are used widely for insect control in sprays and transgenic plants, but their efficacy is reduced when pests evolve resistance. Previous work showed that mutations in a gene encoding the transporter protein ABCC2 are linked with resistance to Bt toxins Cry1Ab, Cry1Ac or both in four species of Lepidoptera. Here we compared the ABCC2 gene of Helicoverpa armigera (HaABCC2) between susceptible strains and a laboratory-selected strain with >1,000-fold resistance to Cry1Ac relative its susceptible parent strain. We discovered a 73-base pair (bp) insertion in the cDNA of the resistant strain that generates a premature stop codon expected to yield a truncated ABCC2 protein. Sequencing of genomic DNA revealed that this insertion is an intron that is not spliced out because of a 6-bp deletion at its splicing site. Analysis of progeny from crosses revealed tight genetic linkage between HaABCC2 and resistance to Cry1Ac. These results provide the first evidence that mis-splicing of a gene encoding an ABCC2 protein confers resistance to a Bt toxin. PMID:25154974

  18. Autophagy and Mis-targeting of Therapeutic Enzyme in Skeletal Muscle in Pompe Disease

    PubMed Central

    Fukuda, Tokiko; Ahearn, Meghan; Roberts, Ashley; Mattaliano, Robert J.; Zaal, Kristien; Ralston, Evelyn; Plotz, Paul H.; Raben, Nina

    2009-01-01

    Enzyme replacement therapy (ERT) became a reality for patients with Pompe disease, a fatal cardiomyopathy and skeletal muscle myopathy caused by a deficiency of glycogen-degrading lysosomal enzyme acid alpha-glucosidase (GAA). The therapy, which relies on receptor-mediated endocytosis of recombinant human GAA (rhGAA), appears to be effective in cardiac muscle, but less so in skeletal muscle. We have previously shown a profound disturbance of the lysosomal degradative pathway (autophagy) in therapy-resistant muscle of GAA knockout mice (KO). Our findings here demonstrate a progressive age-dependent autophagic build-up in addition to enlargement of glycogen-filled lysosomes in multiple muscle groups in the KO. Trafficking and processing of the therapeutic enzyme along the endocytic pathway appear to be affected by the autophagy. Confocal microscopy of live single muscle fibers exposed to fluorescently labeled rhGAA indicates that a significant portion of the endocytosed enzyme in the KO was trapped as a partially processed form in the autophagic areas instead of reaching its target – the lysosomes. A fluid-phase endocytic marker was similarly mis-targeted and accumulated in vesicular structures within the autophagic areas. These findings may explain why ERT often falls short of reversing the disease process, and point to new avenues for the development of pharmacological intervention. PMID:17008131

  19. Using Bones to Shape Stones: MIS 9 Bone Retouchers at Both Edges of the Mediterranean Sea

    PubMed Central

    Blasco, Ruth; Rosell, Jordi; Cuartero, Felipe; Fernández Peris, Josep; Gopher, Avi; Barkai, Ran

    2013-01-01

    A significant challenge in Prehistory is to understand the mechanisms involved in the behavioural evolution of human groups. The degree of technological and cultural development of prehistoric groups is assessed mainly through stone tools. However, other elements can provide valuable information as well. This paper presents two bone retouchers dated to the Middle Pleistocene MIS 9 used for the shaping of lithic artefacts. Originating from Bolomor Cave (Spain) and Qesem Cave (Israel), these two bone retouchers are among the earliest of the Old World. Although the emergence of such tools might be found in the latest phases of the Acheulean, their widespread use seems to coincide with independently emergent post-Acheulean cultural complexes at both ends of the Mediterranean Sea: the post-Acheulean/pre-Mousterian of Western Europe and the Acheulo Yabrudian Cultural Complex of the Levant. Both entities seem to reflect convergent processes that may be viewed in a wider cultural context as reflecting new technology-related behavioural patterns as well as new perceptions in stone tool manufacturing. PMID:24146928

  20. Requirement of Mis6 centromere connector for localizing a CENP-A-like protein in fission yeast.

    PubMed

    Takahashi, K; Chen, E S; Yanagida, M

    2000-06-23

    Mammalian kinetochores contain the centromere-specific histone H3 variant CENP-A, whose incorporation into limited chromosomal regions may be important for centromere function and chromosome segregation during mitosis. However, regulation of CENP-A localization and its role have not been clear. Here we report that the fission yeast homolog SpCENP-A is essential for establishing centromere chromatin associated with equal chromosome segregation. SpCENP-A binding to the nonrepetitious inner centromeres depended on Mis6, an essential centromere connector protein acting during G1-S phase of the cell cycle. Mis6 is likely required for recruiting SpCENP-A to form proper connection of sister centromeres. PMID:10864871

  1. The interfacial properties of AOF/ZnS and LWIR bulk HgCdTe materials by MIS structures

    NASA Astrophysics Data System (ADS)

    Wang, Nili; Liu, Shijia; Lan, Tianyi; Zhao, Shuiping; Jiang, Peilu; Li, Xiangyang

    2012-10-01

    The semiconductor-passivating layer interface, as well as the dielectric properties of the passivants, plays an important role in HgCdTe based photoelectric detectors. Anodization is a commonly uses surface passivation for HgCdTe. ZnS is deposited on the AOF (anodic-oxide film) as antireflecting layer. The interfacial properties of the metal insulator semiconductor (MIS) structures were determined by capacitance-voltage (C-V) measurements in the frequency range 10 KHz-10 MHz. The results showed that the MIS detector could not reach the high frequency level even at frequencies up to 10 MHz. The interfacial state densities were 3.4×1011 cm-2q-1V-1 and the fixed charges were 1.1×1012 cm-2. The surface recombination velocity was 700 cm/s.

  2. Multi-proxy insights into last interglacial (MIS 5e) conditions in the southern Labrador Sea: Consistencies and inconsistencies

    NASA Astrophysics Data System (ADS)

    Van Nieuwenhove, Nicolas; Retailleau, Sophie; de Vernal, Anne; Hillaire-Marcel, Claude

    2013-04-01

    Last interglacial (Marine Isotopic Stage or MIS 5e) sediments from the Gloria Drift in the southernmost Labrador Sea (Core HU91-045-91; 53.33N 45.26W) were studied for their dinoflagellate cyst (dinocyst) content and their planktic foraminiferal assemblages and isotopic compositions. While both microfossil groups clearly reveal the occurrence of typical interglacial conditions in the area, they also reflect a slightly different evolution of the MIS 5e surface water conditions. The dinocyst assemblages are dominated by the cold-temperate species Nematosphaeropsis labyrinthus, with the secondary assemblages being composed by temperate oceanic Impagidinium species and the cosmopolitan species Operculodinium centrocarpum. The latter species shows a steady increase during the first half of MIS 5e, mirrored by a gradual decline of the polar planktic foraminifer Neogloboquadrina pachyderma (s). Still, reconstructed temperatures from the application of the modern analogue technique for this interval are fairly stable, albeit that those reconstructed from the dinocyst assemblages (~10 and 17 °C for winter and summer, respectively) exceed those reconstructed from the planktic foraminiferal assemblages (~5.5 and 9.5 °C) as well as modern values (~5.5 and 10.6 °C) by several degrees. This apparent inconsistency might be partly explained by distinct conditions within the respective water depth habitats of these micro-organisms, but other factors likely intervened, such as an offset in their respective seasonal production time and/or mixing of the fossil assemblages through advection from slightly distinct production areas. The early MIS 5e trend ended abruptly with a marked event characterized by a peak of Turborotalita quinqueloba, the quasi-disappearance of dinocysts, and a divergent shift of the stable oxygen isotope values in the polar and subpolar foraminifer species. This might hint towards a possible meltwater-related perturbation of the prevailing upper ocean

  3. High-elevation late Pleistocene (MIS 6-5) vertebrate faunas from the Ziegler Reservoir fossil site, Snowmass Village, Colorado

    NASA Astrophysics Data System (ADS)

    Sertich, Joseph J. W.; Stucky, Richard K.; McDonald, H. Gregory; Newton, Cody; Fisher, Daniel C.; Scott, Eric; Demboski, John R.; Lucking, Carol; McHorse, Brianna K.; Davis, Edward B.

    2014-11-01

    The vertebrate record at the Ziegler Reservoir fossil site (ZRFS) near Snowmass Village, Colorado ranges from ~ 140 to 77 ka, spanning all of Marine Oxygen Isotope Stage (MIS) 5. The site contains at least 52 taxa of macro- and microvertebrates, including one fish, three amphibian, four reptile, ten bird, and 34 mammal taxa. The most common vertebrate is Ambystoma tigrinum (tiger salamander), which is represented by > 22,000 elements representing the entire life cycle. The mastodon, Mammut americanum, is the most common mammal, and is documented by > 1800 skeletal elements making the ZRFS one of the largest accumulations of proboscidean remains in North America. Faunas at the ZRFS can be divided into two groups, a lake-margin group dating to ~ 140-100 ka that is dominated by woodland taxa, and a lake-center group dating to ~ 87-77 ka characterized by taxa favoring more open conditions. The change in faunal assemblages occurred between MIS 5c and 5a (vertebrates were absent from MIS 5b deposits), which were times of significant environmental change at the ZRFS. Furthermore, the ZRFS provides a well-dated occurrence of the extinct Bison latifrons, which has implications for the timing of the Rancholabrean Mammal Age in the region.

  4. Transconductance sensitivity enhancement in gated-MIS(p) tunnel diode by self-protective effective local thinning mechanism

    NASA Astrophysics Data System (ADS)

    Kao, Wei-Chih; Chen, Jun-Yao; Hwu, Jenn-Gwo

    2016-08-01

    Gated-MIS tunnel diode with ultrathin oxide has been proposed as a transconductance device. The on/off current ratio of a device is sensitive to oxide thickness. For thicker oxide, the on/off current ratio and transconductance sensitivity are inferior due to the lower oxide tunneling rate. In this work, a technique of utilizing the effective local thinning effect created by positive voltage stress (PVS), which only occurs with the oxide thickness larger than about 3 nm, is demonstrated to improve the on/off current ratio and transconductance sensitivity. After PVS, the on/off current ratio and transconductance sensitivity are strongly enhanced by the creation of an effective local thinning at the edge of the MIS(p) tunnel diode. A transconductance of 8.5 × 10-7 S was found in gated-MIS(p) tunnel diode operated at VTD = 0.5 V and VG ≅ -0.12 V after PVS treatment in contract to that of 1.8 × 10-10 S before PVS.

  5. Large shifts in vegetation and climate during the Early Weichselian (MIS 5d-c) inferred from multi-proxy evidence at Sokli (northern Finland)

    NASA Astrophysics Data System (ADS)

    Helmens, Karin F.; Väliranta, Minna; Engels, Stefan; Shala, Shyhrete

    2012-05-01

    For decades, detailed studies on Early Weichselian deposits have been made in central Europe. In contrast, these studies are rare in Fennoscandia in northern Europe. We here integrate an extensive multi-proxy data set obtained on sediments of MIS 5d-c age that form part of a long sediment record preserved at Sokli in northern Finland. We make a detailed interpretation of the vegetation and depositional history for MIS 5d-c using pollen, macrofossils, diatoms and other siliceous microfossils, insect remains, and sediment characteristics, and combine these data with recently published estimates on July temperatures based on chironomids and selected plant indicator species in order to make inferences of paleo-climate regimes. The fossil record obtained on the seven meter thick MIS 5d-c deposit at Sokli is exceptionally rich in species due to the large variety of habitats associated with an overall fluvial depositional environment. A braided river system flanked by steppe-tundra vegetation is inferred for MIS 5d. Mean July temperatures of at least 12-14 °C are indicated by chironomids and plant indicator species and are in agreement with the presence of conifers and birch trees as recorded by macrofossils. The reconstructed environmental conditions suggest strong continental climate conditions at Sokli during MIS 5d. The gradual infilling of an oxbow lake and subsequent return to stream channel deposition is traced in great detail in the overlying gyttja and gravelly sediment of MIS 5c age. The terrestrial pollen and plant macrofossil record from the gyttja shows the establishment of birch forest followed by the spread of pine and then spruce. Rich plant indicator species assemblages indicate that the boreal environment at Sokli during MIS 5c experienced July temperatures several degrees higher than the present-day value of 13 °C. The high summer temperatures and presence of larch suggest more continental conditions. More open vegetation returned at Sokli during late

  6. Changes in Organic Carbon Accumulation and Benthic Foraminiferal Assemblages in Sediments Deposited on the Bermuda Rise (odp Site 1063)DURING Mis 13 TO 10

    NASA Astrophysics Data System (ADS)

    Poli, M.; Meyers, P. A.; Thunell, R.; Capodivacca, M.

    2011-12-01

    We determined organic carbon concentrations, organic matter carbon and nitrogen isotopic compositions, and benthic foraminiferal assemblages in sediments deposited between ~500-340 ka at ODP Site 1063 on the northeastern flank of the Bermuda Rise to identify the nature of glacial-interglacial changes in this part of the North Atlantic. This time interval includes Marine Isotope Stage (MIS) 11, a particularly warm and long interglacial that was similar to today, and MIS 12, one of the most severe glacials of the last 600 ky. Higher organic carbon accumulation rates occurred during MIS 12 and 10 (up to 3.7 g m-2 yr-1), in correspondence with the highest sedimentation rates (33-36 cm/ky). This pattern suggests a combination of enhanced production and improved preservation of organic matter at these glacial times. Organic δ13C values are larger during MIS 12 and MIS 10 (~-22.5%) than during MIS 11.3 (~-25%), which is consistent with greater glacial-stage marine productivity. At the same time, smaller glacial-stage δ15N values (~3.5%) indicate diminished denitrification, which suggests better oceanic mixing at this location. Benthic foraminiferal assemblages are dominated by Nuttallides umbonifera during MIS 11.3, a species adapted to oligotrophic environments, and by Oridorsalis umbonatus during glacial intervals, a cosmopolitan taxon that dwells under a wide range of environmental conditions and probably prefers a low but sustained flux of highly degraded organic material. The beginnings of the MIS 10 and MIS 12 glaciations are characterized by large and rapid fluctuations in the abundance of Epistominella exigua, a species that inhabits seasonally deposited aggregates of phytodetritus produced during spring plankton blooms, thus suggesting a marked increase in local primary productivity at these times. We conclude that two kinds of glacial-interglacial changes affected delivery of organic matter to the sediments of Site 1063 - a southward shift of the Gulf Stream

  7. Terrestrial environments during MIS 11: evidence from the Palaeolithic site at West Stow, Suffolk, UK

    NASA Astrophysics Data System (ADS)

    Preece, R. C.; Parfitt, S. A.; Bridgland, D. R.; Lewis, S. G.; Rowe, P. J.; Atkinson, T. C.; Candy, I.; Debenham, N. C.; Penkman, K. E. H.; Rhodes, E. J.; Schwenninger, J.-L.; Griffiths, H. I.; Whittaker, J. E.; Gleed-Owen, C.

    2007-05-01

    , although there is clear faunal evidence for climatic deterioration. Both the molluscan and vertebrate faunas suggest correlation of the interglacial sediments with the Hoxnian. Uranium series dates from the tufa (˜455 ka BP), TL dates from burnt flints (414±30 ka BP) and a range of amino acid racemization data all support correlation of this interglacial with MIS 11. However, four OSL dates from sand beneath the interglacial sequence yield a mean age of 261±31 ka BP, far younger than all other age determinations and far younger than implied by the biostratigraphy. Archaeologically the site is unusual in showing prolonged human occupation within closed deciduous forest and evidence for controlled use of fire in a Lower Palaeolithic context. Biostratigraphical correlations with other Lower Palaeolithic sites support the suggestion that Acheulian and Clactonian industries both occurred in southern Britain during the same substage of the Hoxnian, although not necessarily at precisely the same time. The characteristics of the MIS 11 interglacial in Britain are discussed in the light of evidence from Beeches Pit and elsewhere.

  8. Coupled Warming and Drought in the American Southwest During Long mid-Pleistocene Interglacials (MIS 11 and 13)

    NASA Astrophysics Data System (ADS)

    Fawcett, P. J.; Werne, J.; Anderson, R.; Heikoop, J.; Brown, E.; Hurley, L.; Smith, S.; Berke, M.; Soltow, H.; Goff, F.; Geissman, J.; Woldegabriel, G.; Fessenden, J.; Cisneros-Dozal, M.; Allen, C. D.

    2008-12-01

    An 82-m deep lacustrine sediment core from the Valles Caldera, northern New Mexico reveals details of climate change over two glacial cycles in the middle Pleistocene. Core VC-3, taken from the Valle Grande, has a basal 40Ar/39Ar date of 552 kyr from a tephra associated with the eruption of the South Mountain rhyolite which formed the lake. A variety of proxies including core sedimentology, organic carbon and carbon isotopic ratios, pollen, scanning XRF analysis and a new paleotemperature proxy, MBT (methylated branched tetraether) content of soil bacteria reveal two major warm periods above the basal tephra which we correlate with interglacials MIS 13 and MIS 11. This chronology is corroborated by the identification of two geomagnetic field "events" which are correlated with globally recognized events (14α and 11α). The lacustrine record terminates at ~350 ka when the lake filled its available accommodation space behind the dam of rhyolite lava. MBT temperature estimates show average glacial temperatures in core VC-3 of ~ -4°C, and average interglacial temperatures of ~ +4°C, and the general trends are well corroborated by multiple proxies including pollen and lacustrine organic productivity estimates. A temperature increase of ~9°C occurs during Termination V, the largest glacial termination in the Pleistocene. Multiple proxies from VC-3 show significant structure during the two interglacials present in the core (MIS 13 and 11). Three warm substages (~ 2°C warmer) are recognized within MIS 11 based on organic productivity (Corg, Si/Ti ratios), pollen taxa, elevated charcoal from fires, and the MBT temperature estimates. These warm substages appear to be a strong response to precessional forcing in the SW continental interior even though the amplitude of eccentricity-modulated precession was at a minimum during MIS 11. These results suggest that future climate change in the SW may be characterized by similar natural temperature variability on precessional

  9. Variations of the paleo-productivity in benthic foraminifera records in MIS 3 from western South China Sea

    NASA Astrophysics Data System (ADS)

    Niu, Y.; Du, J.; Huang, B.; Chen, M.

    2010-12-01

    Understanding climate change of last glacial age as the background information of climate forecasting is particularly important in climate research. Marine Isotope Stage 3 (MIS 3, 61-24 ka B.P.) is a relative warm and unstable period in the last glacial. Millennium scale abrupt climate changes, such as Heinrich events and Dansgaard-Oeschger (D-O) cycles, are identified in this period. Research topic on the variations of monsoon during the glacial cycles, especially in MIS 3, is critical for understanding low latitude climatic change and the global paleo-environment as a whole. Fortunately, high resolution sedimentary records in western South China Sea provide us valuable materials to uncover how East Asia Summer Monsoon (EASM) system acts in a highly fluctuating climate ambient like MIS 3. Core 17954 is located in the modern summer upwelling area off the Vietnam coast in western South China Sea (SCS), its sediments record the variations of upwelling generated by EASM. In this work, we carry out paleo-ecological analyses on planktonic ( Neogloboquadrina dutertrei, Globigerina bulloides) and benthic foraminifera (Bulimina aculeate, Uvigerina peregrina, Cibicidoides wuellerstorfi, ect.) sampled from Core 17954 to investigate paleo-productivity and nutrition change of western SCS and its relation to EASM. The results show that benthic and planktonic foraminifera have similar responses to nutrition change. Various indicators of productivity on the basis of benthic foraminiferal analyses reflect an overall three stage change trend: productivity gradually increases from the beginning of MIS 3 (60-40 ka) to its maximum during 35-30 ka, and finally declines after 30 ka. There is also another important discovery, if we observe the climate change in MIS 3 as a whole, we can also find western SCS and Northern Hemisphere High latitude have strong correspondences in such changes: Heinrich events coincided with high productivity events in the western SCS. Further, the result of

  10. MIS5 hydrological variability from continental carbonates from the Sulmona Basin (central Italy)

    NASA Astrophysics Data System (ADS)

    Regattieri, Eleonora; Giaccio, Biagio; Zanchetta, Giovanni; Drysdale, Russell; Galli, Paolo; Nomade, Sebastien; Peronace, Edoardo; Wulf, Sabine

    2015-04-01

    There are few highly resolved, chronologically well-anchored continental records documenting the MIS5 climatic instability over Mediterranean area, particularly for montane sites. Understanding rapid climate changes in high-altitude areas is of particular relevance because water availability in the Mediterranean basin is generally scarce and unevenly distributed, and mostly dependent on runoff from mountain areas. Here we present a multiproxy record (δ18O, δ13C and CaCO3 content) from a lacustrine succession in the Sulmona basin (Abruzzo, central Italy) which spans the period ca. 90 to 120 ka. The succession is chronologically anchored by means on tephrochronology (40Ar/39Ar dating) and tephras correlations. The observed millennial variability is interpreted in terms of hydrological changes (i.e. amount and seasonality of the precipitation) and it is consistent with coeval well dated speleothem isotope record from central Italy, testifying the regional significance of δ18O variations and the accuracy of the proposed age model. The observed features correlate well also with Greenland stadials/interstadials from GI25 to GI22 and with North Atlantic cold events from C25 to C22, which are expressed as period of reduced precipitation. The correlations with high latitudes records indicate a strong Mediterranean-North Atlantic climate teleconnection during this period. The record also show different amplitude and expression of the wetter period interspersed among the Greenland stadials/North Atlantic C events. Correlations with pollen records allow to disentangle the seasonality pattern of the precipitation and potentially to unravel the modulation of the hydrological signal exerted by low-latitudes teleconnections on Mediterranean climate, especially during periods of enhanced monsoon activity.

  11. Northern Cordilleran Ice Sheet Dynamics in Coastal Alaska from MIS 3 to the Present: Initial Results

    NASA Astrophysics Data System (ADS)

    Penkrot, M. L.; Jaeger, J. M.; LeVay, L.; St-Onge, G.; Mix, A. C.; Bahlburg, H.; Davies-Walczak, M.; Gulick, S. P. S.

    2014-12-01

    Establishing the timing of northwestern Cordilleran ice sheet (NCIS) advance-retreat cycles in southern Alaska allows for investigation of global synchronicity in glacial-age climate forcing. Integrated Ocean Drilling Program Expedition 341 targeted the glacial dynamics of the NCIS in the coastal St. Elias range. Sediment cores from Site U1419 encompass times of global ice advance and retreat from MIS 3 to the present, based on a preliminary age model with 5-kya resolution developed using oxygen isotopes from benthic and planktonic foraminifera and stratigraphic correlation with a previously C-14 dated site survey core (Davies et al., 2011; doi:10.1029/2010PA002051). CT images of cores were used to identify sedimentary facies and relative ice sheet proximity. Six sedimentary facies were identified in the images; massive mud with and without lonestones, laminations with and without lonestones, massive and stratified diamict (>1 clast/cm). Elemental scanning XRF data were used to delineate possible downcore changes in sediment provenance using provenance-sensitive transition metals. Diamict and gravelly mud are the most common facies, indicative of persistent glacial input interpreted as marine-terminating glacial systems. Stratified diamicts are interpreted as periods of maximum ice extent (~18-20 ka), whereas massive mud (~14 ka-present) suggests terminus retreat. Intervals of laminated mud with and without lonestones are interpreted as periods of reduced ice cover, with the most recent (~14.5 kya) coinciding with the Bølling Interstade of northern Europe/Greenland (Davies et al., 2011). Downcore changes in Al-normalized metal XRF counts vary along with sedimentary lithoficies, suggesting changes in sediment provenance that may be related to the quantity of glacigenic sediment delivery to this location.

  12. U1 snRNA mis-binding: a new cause of CMT1B.

    PubMed

    Crehalet, Hervé; Latour, Philippe; Bonnet, Véronique; Attarian, Shahram; Labauge, Pierre; Bonello, Nathalie; Bernard, Rafaelle; Millat, Gilles; Rousson, Robert; Bozon, Dominique

    2010-02-01

    We report the molecular characterization of two splice mutations in two different French families affected with a late onset form of Charcot-Marie-Tooth disease type 1B (CMT1B), an autosomal dominant inherited disorder caused by mutations in the myelin protein zero gene. The first substitution, c.306G>A, located in exon 3, does not change the codon p.Val102Val but is co-transmitted with the disease in the first family. The second substitution, c.675+3dup, is an insertion of a T at position +3 of intron 5. To identify the functional impact of these nucleotide changes on splicing and because no RNA sample was available, we used in silico prediction and in vitro splicing assay. Mutation c.306G>A increases the strength of a preexisting cryptic donor site at position c.304 which becomes stronger than the normal donor site of intron 3. This variation creates a sequence that better matches the U1 small nuclear RNA (snRNA) binding consensus, and HeLa cells, transfected with the mutant minigene, produce a truncated exon 3 messenger RNA (mRNA). Mutation c.675+3dup was predicted to abolish the donor site of intron 5, and, indeed, HeLa cells transfected with the mutant minigene completely skip exon 5 from the transcript. The mutated sequence abolishes U1 snRNA binding and co-transfection of a mutated complementary U1 snRNA restored exon 5 inclusion in the mRNA. This work provides valuable information regarding the molecular basis of two forms of late onset of CMT1B, U1 snRNA mis-binding, and provides more evidence that a "silent" polymorphism may be a disease causing mutation. PMID:19475438

  13. The Bermuda Rise Record of MIS 11-12: Inferences from Organic Carbon Fluxes, Organic Matter Isotopic Composition and Benthic Foraminifera

    NASA Astrophysics Data System (ADS)

    Poli, M.; Meyers, P. A.; Thunell, R. C.; Capodivacca, M.

    2005-12-01

    We examined organic carbon content, organic matter carbon and nitrogen isotopic composition and benthic foraminiferal assemblages in sediments deposited between 500-390 ka on the northeastern flank of the Bermuda Rise (ODP Site 1063, 4584m water depth). This time interval includes Marine Isotope Stage 11 (MIS 11, ca 423 to 362 ka), a particularly warm and long interglacial characterized by a configuration of the Earth's orbit similar to today, and MIS 12, one of the most severe glacials of the last 600 ky. Sedimentation rates at Site 1063 are high due to advection of clay and silt into the region by deep recirculating gyres. In the study interval, we reconstructed values ranging between 7 cm/ky during MIS 11 and up to 50 cm/ky during MIS 10 and 12. Our organic carbon data show higher percentages and accumulation rates during MIS 10 and 12, in correspondence with the highest sedimentation rates (30-50 cm/ky). This pattern suggests a combination of enhanced organic matter production and preservation at these times. Del 13C and 15N values are lower during the MIS 10 and 12 than during MIS 11; a similar pattern is recorded at ODP Site 1058 (Blake Ridge) and may be the result of glacial-interglacial changes in the organic matter recycling in the western North Atlantic, possibly linked to sea level changes and consequent shifts in the area where nutrient recycling occurs. Benthic foraminiferal assemblages are dominated by N. umbonifer during MIS 11, a species adapted to oligotrophic environments, and by O. umbonatus during glacial intervals, a taxon that is more common below zones of seasonally high surface production in water deeper than 2km, and probably prefers low but sustained flux of highly degraded organic material. The beginnings of the MIS 10 and MIS 12 glaciations are characterized by large, rapid increases in the abundance of E. exigua, a species that inhabits seasonally deposited aggregates of phytodetritus produced during spring plankton blooms, thus

  14. The kinetochore protein Kis1/Eic1/Mis19 ensures the integrity of mitotic spindles through maintenance of kinetochore factors Mis6/CENP-I and CENP-A.

    PubMed

    Hirai, Hayato; Arai, Kunio; Kariyazono, Ryo; Yamamoto, Masayuki; Sato, Masamitsu

    2014-01-01

    Microtubules play multiple roles in a wide range of cellular phenomena, including cell polarity establishment and chromosome segregation. A number of microtubule regulators have been identified, including microtubule-associated proteins and kinases, and knowledge of these factors has contributed to our molecular understanding of microtubule regulation of each relevant cellular process. The known regulators, however, are insufficient to explain how those processes are linked to one another, underscoring the need to identify additional regulators. To find such novel mechanisms and microtubule regulators, we performed a screen that combined genetics and microscopy for fission yeast mutants defective in microtubule organization. We isolated approximately 900 mutants showing defects in either microtubule organization or the nuclear envelope, and these mutants were classified into 12 categories. We particularly focused on one mutant, kis1, which displayed spindle defects in early mitosis. The kis1 mutant frequently failed to assemble a normal bipolar spindle. The responsible gene encoded a kinetochore protein, Mis19 (also known as Eic1), which localized to the interface of kinetochores and spindle poles. We also found that the inner kinetochore proteins Mis6/CENP-I and Cnp1/CENP-A were delocalized from kinetochores in the kis1 cells and that kinetochore-microtubule attachment was defective. Another mutant, mis6, also displayed similar spindle defects. We conclude that Kis1 is required for inner kinetochore organization, through which Kis1 ensures kinetochore-microtubule attachment and spindle integrity. Thus, we propose an unexpected relationship between inner kinetochore organization and spindle integrity. PMID:25375240

  15. The Kinetochore Protein Kis1/Eic1/Mis19 Ensures the Integrity of Mitotic Spindles through Maintenance of Kinetochore Factors Mis6/CENP-I and CENP-A

    PubMed Central

    Hirai, Hayato; Arai, Kunio; Kariyazono, Ryo; Yamamoto, Masayuki; Sato, Masamitsu

    2014-01-01

    Microtubules play multiple roles in a wide range of cellular phenomena, including cell polarity establishment and chromosome segregation. A number of microtubule regulators have been identified, including microtubule-associated proteins and kinases, and knowledge of these factors has contributed to our molecular understanding of microtubule regulation of each relevant cellular process. The known regulators, however, are insufficient to explain how those processes are linked to one another, underscoring the need to identify additional regulators. To find such novel mechanisms and microtubule regulators, we performed a screen that combined genetics and microscopy for fission yeast mutants defective in microtubule organization. We isolated approximately 900 mutants showing defects in either microtubule organization or the nuclear envelope, and these mutants were classified into 12 categories. We particularly focused on one mutant, kis1, which displayed spindle defects in early mitosis. The kis1 mutant frequently failed to assemble a normal bipolar spindle. The responsible gene encoded a kinetochore protein, Mis19 (also known as Eic1), which localized to the interface of kinetochores and spindle poles. We also found that the inner kinetochore proteins Mis6/CENP-I and Cnp1/CENP-A were delocalized from kinetochores in the kis1 cells and that kinetochore-microtubule attachment was defective. Another mutant, mis6, also displayed similar spindle defects. We conclude that Kis1 is required for inner kinetochore organization, through which Kis1 ensures kinetochore-microtubule attachment and spindle integrity. Thus, we propose an unexpected relationship between inner kinetochore organization and spindle integrity. PMID:25375240

  16. Geochronologic evidence for a possible MIS-11 emergent barrier/beach-ridge in southeastern Georgia, USA

    NASA Astrophysics Data System (ADS)

    Markewich, H. W.; Pavich, M. J.; Schultz, A. P.; Mahan, S. A.; Aleman-Gonzalez, W. B.; Bierman, P. R.

    2013-01-01

    ˜450 ka to >1 Ma. The age and geomorphic data for Georgia and South Carolina possibly suggest the presence of MIS-11 (˜420-360 ka) shoreline deposits between 15 m and 28 m above present sea level in the Southeastern Atlantic Coastal Plain.

  17. MIS 3 Climate Variability Revealed by Two Stalagmites from Northern and South-Western Romania

    NASA Astrophysics Data System (ADS)

    Dragusin, V.; Hoffmann, D.; Onac, B. P.; Isverceanu, E.

    2011-12-01

    We present two stable isotope records of climate variability from stalagmites in northern (#1152 from Pestera Izvorul Tausoarelor, Rodna Mountains) and south-western (#POM1 from Pestera Ascunsa, Mehedinti Mountains) Romania. Both cave entrances are located at over 1000 m asl in areas covered by mature beech forests, in continental temperate climate. Superimposed on the present-day climatic conditions are two different climate influences: Atlantic in the north and sub-mediterranean in the south-west. Both stalagmites were dated by means of uranium series on a Thermo Neptune MC-ICP-MS at Centro Nacional de Investigacion sobre la Evolucion Humana (Burgos, Spain) and samples for stable O and C stable isotopes were analysed on a Thermo Delta V IRMS at the Stable Isotope Laboratory, University of South Florida. For the stable isotopes profile, stalagmite 1152 was sampled at an average interval of 100 years , whereas POM1 was sampled at a 30 years interval. The two stalagmites reveal differences in isotopic signature response to climatic variability. When the POM1 δ18O profile is compared to the NGRIP δ18O, a lower variability of its values is evident. Even so, we are still able to distinguish structures similar to Greenland Interstadials (GIs) 7 and 8, the latter being composed of two distinct units. The stalagmite 1152 δ18O profile shows less variability although some of the peaks in the values could be correlated to GIs 4 through 12. The absolute values of these two records vary around an average of -7.5%, very close to the typical Holocene values from this part of Europe. This may point to an enhanced Mediterranean circulation towards the north during MIS 3. In return, the δ13C values of the two stalagmites are very different and point to large differences in the activity of plants and soil organisms. POM1 values, averaging -5 to -6%, indicate a C4 type vegetation in the area above the cave, that could belong to alpine meadows. This may document a lowering of the

  18. Geochronologic evidence for a possible MIS-11 emergent barrier/beach-ridge in southeastern Georgia, USA

    USGS Publications Warehouse

    Markewich, H.W.; Pavich, M.J.; Schultz, A.P.; Mahan, S.A.; Aleman-Gonzalez, W. B.; Bierman, P.R.

    2013-01-01

    ~450 ka to >1 Ma. The age and geomorphic data for Georgia and South Carolina possibly suggest the presence of MIS-11 (~420−360 ka) shoreline deposits between 15 m and 28 m above present sea level in the Southeastern Atlantic Coastal Plain.

  19. High-resolution vegetation dynamics reconstitution in the Zaire/Congo watershed since MIS 6

    NASA Astrophysics Data System (ADS)

    Dalibard, Mathieu; Popescu, Speranta-Maria; Maley, Jean; Pittet, Bernard; Marsset, Tania; Baudin, François; Dennielou, Bernard; Sionneau, Thomas; Escarguel, Gilles; Droz, Laurence

    2010-05-01

    contemporaneously with a significant presence of afromontane forest in MIS 6 may be correlated with rainfall increase probably related to changes in the monsoon activity. The information in term of humidity obtained from some other proxies (clay mineralogy, organic carbon, and elemental ratio measured by XRF, such as Br, etc.) shows a similar trend with the pollen record. A spectral analysis has been performed and reveals that the reconstructed climatic parameters from the Zaire/Congo watershed correlated with Milankovitch cycles, including semi-precession cycles (10 kyrs) characteristic of the Equatorial zone.

  20. Paleoclimate variability during the Blake geomagnetic excursion (MIS 5d) deduced from a speleothem record

    NASA Astrophysics Data System (ADS)

    Rossi, Carlos; Mertz-Kraus, Regina; Osete, María-Luisa

    2014-10-01

    To evaluate possible connections between climate and the Earth's magnetic field, we examine paleoclimate proxies in a stalagmite (PA-8) recording the Blake excursion (˜112-˜116.4 ka) from Cobre cave (N Spain). Trace element, δ13C, δ18O, δ234U, fluorescent lamination, growth rate, and paleomagnetic records were synchronized using a floating lamina-counted chronology constrained by U-Th dates, providing a high-resolution multi-proxy paleoclimate record for MIS 5d. The alpine cave setting and the combination of proxies contributed to improve the confidence of the paleoclimatic interpretation. Periods of relatively warm and humid climate likely favored forest development and resulted in high speleothem growth rates, arguably annual fluorescent laminae, low δ13C and [Mg], and increased [Sr] and [Ba]. Colder periods limited soil activity and drip water availability, leading to reduced speleothem growth, poor development of fluorescent lamination, enhanced water-rock interaction leading to increased [Mg], δ13C, and δ234U, and episodic flooding. In the coldest and driest period recorded, evaporation caused simultaneous 18O and 13C enrichments and perturbed the trace element patterns. The Blake took place in a relatively warm interestadial at the inception of the Last Glacial period, but during a global cooling trend recorded in PA-8 by an overall decrease of δ18O and growth rate and increasing [Mg]. That trend culminated in the cessation of growth between ˜112 and ˜101 ka likely due to the onset of local glaciation correlated with Greenland stadial 25. That trend is consistent with a link between low geomagnetic intensity and climate cooling, but it does not prove it. Shorter term changes in relative paleointensity (RPI) relate to climate changes recorded in PA-8, particularly a prominent RPI low from ˜114.5 to ˜113 ka coincident with a significant cooling indicated by all proxy records, suggesting a link between geomagnetic intensity and climate at millennial

  1. A review of the MIS 5e highstand deposits from Santa Maria Island (Azores, NE Atlantic): palaeobiodiversity, palaeoecology and palaeobiogeography

    NASA Astrophysics Data System (ADS)

    Ávila, Sérgio P.; Melo, Carlos; Silva, Luís; Ramalho, Ricardo S.; Quartau, Rui; Hipólito, Ana; Cordeiro, Ricardo; Rebelo, Ana Cristina; Madeira, Patrícia; Rovere, Alessio; Hearty, Paul J.; Henriques, Diamantino; Silva, Carlos Marques da; Martins, António M. de Frias; Zazo, Caridad

    2015-04-01

    The privileged location of Santa Maria Island (Azores archipelago) in the middle of the North Atlantic makes the fossiliferous outcrops on this island of utmost importance to gain a better understanding of how coeval living communities relate to the broader evolutionary and biogeographic history of the Atlantic basin during the late Neogene and the Quaternary. Here we focus on this island's MIS 5e fossil record, offering a comprehensive review on the palaeobiodiversity, palaeoecology and palaeobiogeography of the biota living in the mid North Atlantic during this interglacial. Several studies in oceanic islands stress the huge impact of sea level changes on insular communities. Pleistocene sea-level changes occur during the short-time events known as "Terminations" (associated to glacial/interglacial shifts) as well as with the onset of glaciations (associated to interglacial/glacial shifts). Both are responsible for extinctions and local disappearance of species, bottleneck effects and formation of new species, resulting in community structure changes. This work increases the number of fossil marine taxa reported from the Last Interglacial deposits of Santa Maria to 143 species. All the 19 new records are molluscs (13 gastropods and 6 bivalves), thus increasing the number of fossil molluscs to 136 species. Although thermophilic members of the "Senegalese" tropical fauna were found in these deposits, many of the most emblematic species (e.g., Persististrombus latus (=Strombus bubonius), Cymbula safiana, Harpa doris, Cardita senegalensis, Barbatia plicata, Ctena eburnea or Hyotissa hyotis) are absent, suggesting that they did not reach the Azores. Our results indicate that the main differences between the species composition of the MIS 5e and the present-day shallow-water Azorean communities are probably due to the dropping of sea surface temperature associated with the onset of the last glaciation, which had both direct and indirect effects on species ecology. A

  2. Human occupation of the Arabian Empty Quarter during MIS 5: evidence from Mundafan Al-Buhayrah, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Groucutt, Huw S.; White, Tom S.; Clark-Balzan, Laine; Parton, Ash; Crassard, Rémy; Shipton, Ceri; Jennings, Richard P.; Parker, Adrian G.; Breeze, Paul S.; Scerri, Eleanor M. L.; Alsharekh, Abdullah; Petraglia, Michael D.

    2015-07-01

    The Empty Quarter (or Rub' al Khali) of the Arabian Peninsula is the largest continuous sandy desert in the world. It has been known for several decades that Late Pleistocene and Holocene deposits, representing phases of wetter climate, are preserved there. These sequences have yielded palaeontological evidence in the form of a variety of vertebrate and invertebrate fossils and have been dated using various radiometric techniques. However, evidence for human presence during these wetter phases has until now been ephemeral. Here, we report on the first stratified and dated archaeology from the Empty Quarter, recovered from the site of Mundafan Al-Buhayrah (MDF-61). Human occupation at the site, represented by stone tools, has been dated to the later part of Marine Isotope Stage (MIS) 5 using multiple luminescence dating techniques (multigrain and single grain OSL, TT-OSL). The sequence consists primarily of lacustrine and palustrine sediments, from which evidence for changing local environmental conditions has been obtained through analysis of fossil assemblages (phytoliths and non-marine molluscs and ostracods). The discovery of securely-dated archaeological material at ˜100 to 80 ka in the Empty Quarter has important implications for hypotheses concerning the timing and routes of dispersal of Homo sapiens out of Africa, which have been much debated. Consequently, the data presented here fill a crucial gap in palaeoenvironmental and archaeological understanding of the southern Arabian interior. Fossils of H. sapiens in the Levant, also dated to MIS 5, together with Middle Palaeolithic archaeological sites in Arabia and India are thought to represent the earliest dispersal of our species out of Africa. We suggest that the widespread occurrence of similar lithic technologies across southern Asia, coupled with a growing body of evidence for environmental amelioration across the Saharo-Arabian belt, indicates that occupation of the Levant by H. sapiens during MIS 5

  3. Human occupation of the Arabian Empty Quarter during MIS 5: evidence from Mundafan Al-Buhayrah, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Groucutt, Huw S.; White, Tom S.; Clark-Balzan, Laine; Parton, Ash; Crassard, Rémy; Shipton, Ceri; Jennings, Richard P.; Parker, Adrian G.; Breeze, Paul S.; Scerri, Eleanor M. L.; Alsharekh, Abdullah; Petraglia, Michael D.

    2015-07-01

    The Empty Quarter (or Rub' al Khali) of the Arabian Peninsula is the largest continuous sandy desert in the world. It has been known for several decades that Late Pleistocene and Holocene deposits, representing phases of wetter climate, are preserved there. These sequences have yielded palaeontological evidence in the form of a variety of vertebrate and invertebrate fossils and have been dated using various radiometric techniques. However, evidence for human presence during these wetter phases has until now been ephemeral. Here, we report on the first stratified and dated archaeology from the Empty Quarter, recovered from the site of Mundafan Al-Buhayrah (MDF-61). Human occupation at the site, represented by stone tools, has been dated to the later part of Marine Isotope Stage (MIS) 5 using multiple luminescence dating techniques (multigrain and single grain OSL, TT-OSL). The sequence consists primarily of lacustrine and palustrine sediments, from which evidence for changing local environmental conditions has been obtained through analysis of fossil assemblages (phytoliths and non-marine molluscs and ostracods). The discovery of securely-dated archaeological material at ∼100 to 80 ka in the Empty Quarter has important implications for hypotheses concerning the timing and routes of dispersal of Homo sapiens out of Africa, which have been much debated. Consequently, the data presented here fill a crucial gap in palaeoenvironmental and archaeological understanding of the southern Arabian interior. Fossils of H. sapiens in the Levant, also dated to MIS 5, together with Middle Palaeolithic archaeological sites in Arabia and India are thought to represent the earliest dispersal of our species out of Africa. We suggest that the widespread occurrence of similar lithic technologies across southern Asia, coupled with a growing body of evidence for environmental amelioration across the Saharo-Arabian belt, indicates that occupation of the Levant by H. sapiens during MIS 5

  4. Sub-orbital sea-level change in early MIS 5e: New evidence from the Gulf of Corinth, Greece

    NASA Astrophysics Data System (ADS)

    Andrews, Julian E.; Portman, Clive; Rowe, Peter J.; Leeder, Michael R.; Kramers, Jan D.

    2007-07-01

    New evidence from uplifted marine isotope stage (MIS) 5e carbonate deposits in the Gulf of Corinth demonstrate two rapid, sub-orbitally forced, sea-level oscillations in the early part of MIS 5e. Microbial bioherms with inter-grown marine coralline algae are interpreted as early highstand deposits. Presence of thin vadose flowstone (speleothem) coating inter-bioherm surfaces mark a short-lived regression of > 10 m, followed by sea-level recovery and re-establishment of the highstand, marked by coralline algae coating inter-bioherm cavity surfaces. These marine algae are then coated by a younger vadose flowstone, thick enough to provide an uncontaminated U/Th date of 134.8 ± 2.0 ka. The dated flowstone is itself encrusted by marine fauna and the entire sequence overlain by highstand marine sediments and marine aragonite cements dated to 114-118 ka, part of the sustained MIS 5e highstand. The age of the younger flowstone demonstrates that the early highstand occurred before 134.8 ± 2.0 ka, and uplift arguments suggest that the bioherms are unlikely to be older than ˜ 136 ka. These data are consistent with the notion that most of termination II (TII) sea-level rise had occurred before 135 ka; indeed they suggest sea-level at this time reached about 2-4 (± 4) m below present sea-level, 6-18 (± 4) m higher than previous estimates. This early highstand was itself punctuated by a rapid sea-level oscillation of > 10 m (as yet undated), and this oscillation, supported by new TII sea-level data from the Red Sea [Siddall, M., Bard, E., Rohling, E.J., Hemleben, C., 2006, Sea-level reversal during termination II, Geology, 34, 817-820.], probably occurred in about 1000 yr. The flowstone dated at 134.8 ± 2.0 ka is interpreted to record the early part of the 'Aladdin's Cave' regressive event from Papua New Guinea, although in Greece only the first 16 m of the event is recorded. The new data presented here support a recently published Red Sea TII sea-level curve: they also

  5. An Investigation into the Admittance of MIS-Structures Based on MBE HgCdTe with Quantum Wells

    NASA Astrophysics Data System (ADS)

    Dzyadukh, S. M.; Voitsekhovskii, A. V.; Nesmelov, S. N.; Dvoretskii, S. A.; N. Mikhailov, N.; Gorn, D. I.

    2013-12-01

    The results of investigations into the complex admittance of the MIS-structures based on heteroepitaxial MBE Hg1- x Cd x Te with quantum wells (QW) in the test-signal frequency range 1 kHz - 2 МHz at temperatures 8-300 K are reported. The thickness of single HgTe QWs was 5.6 and 7.1 nm, the content in the 35-nm thick barrier layers - 0.65 and 0.62, respectively.

  6. Last interglacial (MIS5e) sea-levels and uplift along the north-east Gulf of Aqaba

    NASA Astrophysics Data System (ADS)

    BAR (KOHN), N.; Stein, M.; Agnon, A.; Yehudai, M.; Lazar, B.; Shaked, Y.

    2014-12-01

    An uplifted flight of coral reef terraces, extending along the north-east margin of the Gulf of Aqaba (GOA), provides evidence for uplift rates and sea level high stands. GOA fills a narrow and deep tectonic depression lying along the southern sector of the Dead Sea Transform where it meets the Red Sea. This special configuration of the GOA and its latitude turn it into a dependable paleo-sea level monitor, sensitive only to global eustatic changes and local tectonic movements. A sequence of five uplifted coral reef terraces were mapped and characterized on basis of morphology and reef-facies, and their elevation above the present sea level was determined. The fossil reefs studied comprise fringing reefs, some with clear reef-structure that includes a reef flat and a shallow back lagoon. Most outcrops in the study area represent a transgressive sequence in which, during its highest stand, formed fringing reef terraces. We use U-Th ages of fossil corals samples found in growth position at various terraces. Corals from three uplifted reef terraces, R1, R2, and R3 were dated to the last interglacial period particularly to marine isotope stage (MIS) 5e. These ages were achieved from mainly calcitic corals (recrystallized in a freshwater phreatic environment). A few ages were derived from aragonite corals. The three terraces represent three sub-stages within MIS5e: R3 formed during a short standstill at ~130 ka BP; R2 formed during a long and steady standstill between ~128 to ~121 ka BP; and R1 represents a short standstill at ~117 ka BP. Assuming that terrace reef flats represent past sea level high stands, we calculated the coast average uplift rate and constrained the original terraces elevations. The reconstructed eustatic sea level variation during MIS 5e at GOA resembles observations from reef terraces in other locations. Combined, all indicate a significant sea-level rise from the MIS 6 low stand at ~134-130 ka and followed by a long and stable sea level high

  7. A global perspective on the timing and nature of sub-orbital sea level oscillations during MIS 5e

    NASA Astrophysics Data System (ADS)

    Dutton, A.; Webster, J.

    2015-12-01

    Although multiple, sub-orbital peaks in sea level during Marine Isotope Stage (MIS) 5e have a long history in the literature, there is still debate regarding the number, timing, and magnitude of sea-level peaks. A wide range of competing scenarios have been proposed based on observations from individual field sites including: (i) a stable sea level, (ii) a stable sea level punctuated by an ephemeral drop in sea level (2 peaks), (iii) a stable sea level followed by a rapid rise (2 peaks), or (iv) several (3-4) peaks in sea level that define an oscillating trend during the highstand. While some field sites appear to have conflicting evidence regarding the timing and nature of relative sea-level changes that cannot be reconciled through glacial isostatic processes alone, clearly there must be one global mean sea level (GMSL) reconstruction that gave rise to the evidence that is presently observed in the geologic record. We take a holistic approach to understanding the evolution of sea level during the MIS 5e highstand by integrating sedimentary, floral, faunal, and geochemical evidence from coral reef sites around the globe. Our aim is to develop a scenario for sea-level change during the MIS 5e highstand that satisfies the global observational dataset. Several conclusions emerge from this analysis: (1) there are many sites that preserve clear sedimentary evidence for two distinct sub-orbital peaks in sea level, and fewer that have possible evidence for more than two peaks; (2) there is conflicting evidence as to whether these two peaks are separated by an ephemeral sea-level fall, or whether they are defined by a stable sea level followed by a rapid rise; (3) multiple sites demonstrate significantly different geochemical signatures associated with distinct generations of reef growth as defined by their U-series geochemistry, indicating different post-depositional histories that may be related to differences in post-depositional marine submergence and exposure

  8. A climate model study of an intense Asian Monsoon in a La Niña-like climate of MIS-13

    NASA Astrophysics Data System (ADS)

    Karami, M. P.; Berger, A.; Herold, N.; Yin, Q. Z.

    2012-04-01

    Studying the paleo-monsoon during past interglacials is a valuable approach to improve our understanding of the monsoon system in present-day and future climates. We focus on Marine Isotopic stage 13 (MIS-13; ~0.5 Ma) which was a relatively cool interglacial, but with a paradoxically intense monsoonal precipitation over eastern and southern Asia. Our main goal is to understand the physics-based mechanism driving the intense monsoon, specifically the East Asian Summer Monsoon (EASM), during MIS-13. We applied both an intermediate complexity model (LOVECLIM) as well as fully coupled general circulation models (HadCM3 and CCSM3) to simulate pre-industrial and MIS-13 climates. The boundary conditions for MIS-13 were chosen for 506 ka with Northern-Hemisphere (NH) summer at perihelion and a CO2 concentration of 240 ppm. For pre-industrial, NH-winter occurring at perihelion and a CO2 concentration of 280 ppm were prescribed. Preliminary analysis of the model results shows different atmospheric and oceanic features in MIS-13 compared to the pre-industrial which could affect the EASM. The Northern Pacific Subtropical High (NPSH), which is an important factor in controlling the EASM, strengthened and extended to the northwest in MIS-13 partially due to cooling of the central Pacific Ocean. This in turn brought more moisture from the Central Pacific to the EASM-region and caused a northwestward shift and bending of the low-level jet along East Asia. The change in the low-level jet subsequently increased the meridional wind velocity at 850 mbar in the EASM-region providing more moisture from the tropical Pacific and Indian Oceans. In addition, higher sea-surface temperature in the Indian Ocean during MIS-13 further increased the source of moisture for the EASM. The Asian low, which is another component of the EASM-system, also shifted eastward moving the rain band northward. Moreover, it was found that MIS-13 had a dominant La Niña condition in the tropical Pacific. La Ni

  9. Insights into MIS 3 and 4 climate in the Alps from the Baumkirchen paleo-lake site: Results of pollen analysis

    NASA Astrophysics Data System (ADS)

    Barrett, Samuel; Drescher-Schneider, Ruth; Starnberger, Reinhard; Spötl, Christoph

    2016-04-01

    The well-known Baumkirchen site of western Austria has recently been the focus of a renewed research effort. New drilling has greatly extended the length of the known lacustrine sequence to over 250 m. Luminescence dating has corroborated the late MIS 3 radiocarbon dates for the upper part of the sequence and revealed two lake phases: the upper extending from late MIS 3 back to mid MIS 3, and the lower covering late MIS 4 or early MIS 3 back possibly as far as MIS 5a. X-ray fluorescence core scanning analysis confirmed the presence of two phases which have different geochemical signals, and provided a chemistry-based stratigraphy in the visually monotonous sediments. In these uniform sediments, the only clear indication of climatic conditions from the sediments themselves is a short sequence of ice-rafted debris corresponding to the end of MIS 4. However, given their age and location within the Alps, these sediments provide an important archive of Alpine climate in the last glacial cycle. We present new results from pollen analysis and discuss them in the context of previously reported findings. Due to high sedimentation rates, pollen counts were very low. However, two stadials and two interstadials were identified. The entire lower lake phase corresponding to MIS 4 was identified as a stadial, being characterised by a very low total pollen concentrations, a dominance of herb over tree pollen and significant reworking of pre-Quaternary forms and wood fragments. The upper lake phase contains two interstadials split by an intervening stadial. The interstadials are characterised by higher total pollen concentrations and proportion of woody species including the sporadic presence of relatively warm climate species with the upper of the two appearing better developed with these indicators more strongly expressed. This upper interstadial corresponds to the location of well dated plant remains putting its age around 35 ka cal BP, strongly suggesting a correlation to

  10. Climate and hydrology of the last interglaciation (MIS 5) in Owens Basin, California: Isotopic and geochemical evidence from core OL-92

    USGS Publications Warehouse

    Li, H.-C.; Bischoff, J.L.; Ku, T.-L.; Zhu, Z.-Y.

    2004-01-01

    ??18O, ??13C, total organic carbon, total inorganic carbon, and acid-leachable Li, Mg and Sr concentrations on 443 samples from 32 to 83 m depth in Owens Lake core OL-92 were analyzed to study the climatic and hydrological conditions between 60 and 155 ka with a resolution of ???200 a. The multi-proxy data show that Owens Lake overflowed during wet/cold conditions of marine isotope stages (MIS) 4, 5b and 6, and was closed during the dry/warm conditions of MIS 5a, c and e. The lake partially overflowed during MIS 5d. Our age model places the MIS 4/5 boundary at ca 72.5 ka and the MIS 5/6 boundary (Termination II) at ca 140 ka, agreeing with the Devils Hole chronology. The diametrical precipitation intensities between the Great Basin (cold/wet) and eastern China (cold/dry) on Milankovitch time scales imply a climatic teleconnection across the Pacific. It also probably reflects the effect of high-latitude ice sheets on the southward shifts of both the summer monsoon frontal zone in eastern Asia and the polar jet stream in western North America during glacial periods. ?? 2003 Elsevier Ltd. All rights reserved.

  11. Submillennial palynology and palaeoecology of the last glaciation at Taiquemó (˜50,000 cal yr, MIS 2 4) in southern Chile

    NASA Astrophysics Data System (ADS)

    Heusser, C. J.; Heusser, L. E.

    2006-03-01

    Stratigraphic palynology of core HE94-2B from a mire at Taiquemó (42.17°S, 73.60°W) on Isla Grande de Chiloé is one of the most closely sampled, continuous Pleistocene records in southern South America. Chronology of the 655-cm core that extends from Marine Isotope Stage (MIS) 4 through the Lateglacial is controlled by 27 finite radiocarbon dates. Sampled at 1-cm intervals, the high temporal resolution (mean ˜85 yr cm -1) captures short-term palaeoecological changes and successional restabilization of plant communities. Preponderance of Gramineae (grass) with Nothofagus dombeyi type (southern beech) characterizing Subantarctic Parkland under a cold climate in MIS 4 was followed by a conspicuously milder interval that lasted for some ten millennia in MIS 3. Of greater frequency and diversity at this time were more thermophilic taxa associated with North Patagonian Evergreen Forest ( Podocarpus, Pilgerodendron type , Pseudopanax, Myrtaceae). Subsequently with increasing cold and hyperhumidity, N. dombeyi type-Gramineae assemblages that included Subantarctic Parkland indicator taxa ( Lepidothamnus, Astelia, Gaimardia) increased stepwise in MIS 2-3. Parkland maxima in MIS 2 during the Last Glacial Maximum (LGM) date to glacial advances between ˜17,800 and 33,400 cal yr BP. On deglaciation, Lateglacial North Patagonian Evergreen Forest was subject to short-term stadial and interstadial climatic fluctuations. The high-resolution Taiquemó pollen record details and supports previous conclusions of interhemispheric synchrony of climatic and glacial events.

  12. Fluctuations of Mediterranean Outflow Water circulation in the Gulf of Cadiz during MIS 5 to 7: Evidence from benthic foraminiferal assemblage and stable isotope records

    NASA Astrophysics Data System (ADS)

    Singh, A. D.; Rai, A. K.; Tiwari, M.; Naidu, P. D.; Verma, K.; Chaturvedi, M.; Niyogi, A.; Pandey, D.

    2015-10-01

    We studied variations in benthic foraminiferal assemblages and δ13C for the last 225 kyr at IODP site U1387 which is currently bathed by upper core of the Mediterranean Outflow Water (MOW). The MOW paleocirculation and sea-floor environment (oxygen level, trophic condition, bottom current strength) have been inferred from faunal composition; species diversity, abundances of selected index species/groups, microhabitat preferences combined with δ13C record of the epifaunal Cibicidoides pachyderma. The faunal and isotope records indicate relatively better ventilation at sea-floor and low trophic condition during MIS 1, 5 and 7 possibly due to increased influence of upper MOW in the Gulf of Cadiz. Our multi-proxy record reflects significant and rapid changes during cold (stadial) and warm (interstadial) phases within the interglacials MIS 5 and 7 and at Termination II. The faunal and isotope records reveal strong MOW flow and better ventilated, oligotrophic bottom-water conditions during stadials MIS 5b, 5d, 7b and 7d. The study further demonstrates weakened MOW intensity associated with poor ventilation and increased trophic level at sea-floor during interstadials MIS 5a, 5e, 7a and 7c. MOW flow was relatively sluggish at Termination II, followed by its strengthening at the end of MIS 5e. The chronology of these events suggests that periods of weakened MOW correlate with sapropel layers of the Mediterranean Sea, implying strong coupling between glacial-interglacial climate and MOW circulation in the Gulf of Cadiz.

  13. MIS M2 initiation and termination link to the shallow CAS open and close?

    NASA Astrophysics Data System (ADS)

    Tan, Ning; Ramstein, Gilles; Dumas, Christophe; Contoux, Camille

    2016-04-01

    The Marine Isotope Stage M2 (3.264 -3.312 Ma) occurred just prior to the well documented warm mid-Pliocene (mPWP). With a 0.5‰ benthic foraminiferal δ180 shift (Lisiecki and Raymo, 2005), MIS M2 is thought to be a glacial comparable period associated with huge but uncertain sea-level records of 20-60m below present levels (Naish et al. 2009; Miller et al. 2012; Dwyer et al. 2009). However, the mechanism of M2 initiation and termination are still an enigma, since CO2 records were relatively higher than the Quaternary glaciation period and the minima summer insolation during M2 was stronger than other glacial periods. By inferring from data records, De Schepper (2013) proposed that the shallow open Central American Seaway (CAS) observed during M2 could play as a trigger in M2 initiation, then the closure of this shallow CAS resulted from M2 large ice sheet build-up terminates this glacial period. But this assumption has not been test by the model. In this study, we apply IPSL-CM5A Atmosphere-Ocean coupled General Circulation Model (AOGCM) and GRISLI ice sheet model to investigate mechanisms of M2 initiation and termination. We firstly investigate the role of "shallow open CAS" (De Schepper et al. 2013) on M2 initiation. In the mean time we also take into account the main forcing during M2, which includes astronomical parameters, Greenhouse gases and vegetation. Our results show that shallow open CAS plays an important role in reducing northward heat transport in Atlantic low latitudes by 0.05 - 0.1 PW, but it is not a key factor in NH ice sheet build-up; Astronomical parameters and CO2 concentration are essential to create a basic global cooling environment for M2 (cooling by ~3.65 K than mPWP); Cold vegetation replacement amplifies the cooling in north high latitudes by ~ 8 K, which finally allows large ice sheet building up in Northern Hemisphere (12.25 m sea level drop is simulated with considering ice sheet feedback on the climate). The simulated ice sheet

  14. Cep57 is a Mis12-interacting kinetochore protein involved in kinetochore targeting of Mad1-Mad2.

    PubMed

    Zhou, Haining; Wang, Tianning; Zheng, Tao; Teng, Junlin; Chen, Jianguo

    2016-01-01

    The spindle assembly checkpoint (SAC) arrests cells in mitosis by sensing unattached kinetochores, until all chromosomes are bi-oriented by spindle microtubules. Kinetochore accumulation of the SAC component Mad1-Mad2 is crucial for SAC activation. However, the mechanism by which Mad1-Mad2 accumulation at kinetochores is regulated is not clear. Here we find that Cep57 is localized to kinetochores in human cells, and binds to Mis12, a KMN (KNL1/Mis12 complex/Ndc80 complex) network component. Cep57 also interacts with Mad1, and depletion of Cep57 results in decreased kinetochore localization of Mad1-Mad2, reduced SAC signalling and increased chromosome segregation errors. We also show that the microtubule-binding activity of Cep57 is involved in the timely removal of Mad1 from kinetochores. Thus, these findings reveal that the KMN network-binding protein Cep57 is a mitotic kinetochore component, and demonstrate the functional connection between the KMN network and the SAC. PMID:26743940

  15. "Generality of mis-fit"? The real-life difficulty of matching scales in an interconnected world.

    PubMed

    Keskitalo, E Carina H; Horstkotte, Tim; Kivinen, Sonja; Forbes, Bruce; Käyhkö, Jukka

    2016-10-01

    A clear understanding of processes at multiple scales and levels is of special significance when conceiving strategies for human-environment interactions. However, understanding and application of the scale concept often differ between administrative-political and ecological disciplines. These mirror major differences in potential solutions whether and how scales can, at all, be made congruent. As a result, opportunities of seeking "goodness-of-fit" between different concepts of governance should perhaps be reconsidered in the light of a potential "generality of mis-fit." This article reviews the interdisciplinary considerations inherent in the concept of scale in its ecological, as well as administrative-political, significance and argues that issues of how to manage "mis-fit" should be awarded more emphasis in social-ecological research and management practices. These considerations are exemplified by the case of reindeer husbandry in Fennoscandia. Whilst an indigenous small-scale practice, reindeer husbandry involves multi-level ecological and administrative-political complexities-complexities that we argue may arise in any multi-level system. PMID:26939924

  16. The use of a virtual reality simulator to explore and understand the impact of Linac mis-calibrations

    NASA Astrophysics Data System (ADS)

    Beavis, Andrew W.; Ward, James W.

    2014-03-01

    Purpose: In recent years there has been interest in using Computer Simulation within Medical training. The VERT (Virtual Environment for Radiotherapy Training) system is a Flight Simulator for Radiation Oncology professionals, wherein fundamental concepts, techniques and problematic scenarios can be safely investigated. Methods: The system provides detailed simulations of several Linacs and the ability to display DICOM treatment plans. Patients can be mis-positioned with 'set-up errors' which can be explored visually, dosimetrically and using IGRT. Similarly, a variety of Linac calibration and configuration parameters can be altered manually or randomly via controlled errors in the simulated 3D Linac and its component parts. The implication of these can be investigated by following through a treatment scenario or using QC devices available within a Physics software module. Results: One resultant exercise is a systematic mis-calibration of 'lateral laser height' by 2mm. The offset in patient alignment is easily identified using IGRT and once corrected by reference to the 'in-room monitor'. The dosimetric implication is demonstrated to be 0.4% by setting a dosimetry phantom by the lasers (and ignoring TSD information). Finally, the need for recalibration can be shown by the Laser Alignment Phantom or by reference to the front pointer. Conclusions: The VERT system provides a realistic environment for training and enhancing understanding of radiotherapy concepts and techniques. Linac error conditions can be explored in this context and valuable experience gained in a controlled manner in a compressed period of time.

  17. Early Wisconsinan (MIS 4) Arctic ground squirrel middens and a squirrel-eye-view of the mammoth-steppe

    NASA Astrophysics Data System (ADS)

    Zazula, Grant D.; Froese, Duane G.; Elias, Scott A.; Kuzmina, Svetlana; Mathewes, Rolf W.

    2011-08-01

    Fossil arctic ground squirrel ( Spermophilus parryii) middens were recovered from ice-rich loess sediments in association with Sheep Creek-Klondike and Dominion Creek tephras (ca 80 ka) exposed in west-central Yukon. These middens provide plant and insect macrofossil evidence for a steppe-tundra ecosystem during the Early Wisconsinan (MIS 4) glacial interval. Midden plant and insect macrofossil data are compared with those previously published for Late Wisconsinan middens dating to ˜25-29 14C ka BP (MIS 3/2) from the region. Although multivariate statistical comparisons suggest differences between the relative abundances of plant macrofossils, the co-occurrence of steppe-tundra plants and insects (e.g., Elymus trachycaulus, Kobresia myosuroides, Artemisia frigida, Phlox hoodii, Connatichela artemisiae) provides evidence for successive reestablishment of the zonal steppe-tundra habitats during cold stages of the Late Pleistocene. Arctic ground squirrels were well adapted to the cold, arid climates, steppe-tundra vegetation and well-drained loessal soils that characterize cold stages of Late Pleistocene Beringia. These glacial conditions enabled arctic ground squirrel populations to expand their range to the interior regions of Alaska and Yukon, including the Klondike, where they are absent today. Arctic ground squirrels have endured numerous Quaternary climate oscillations by retracting populations to disjunct "interglacial refugia" during warm interglacial periods (e.g., south-facing steppe slopes, well-drained arctic and alpine tundra areas) and expanding their distribution across the mammoth-steppe biome during cold, arid glacial intervals.

  18. Cep57 is a Mis12-interacting kinetochore protein involved in kinetochore targeting of Mad1–Mad2

    PubMed Central

    Zhou, Haining; Wang, Tianning; Zheng, Tao; Teng, Junlin; Chen, Jianguo

    2016-01-01

    The spindle assembly checkpoint (SAC) arrests cells in mitosis by sensing unattached kinetochores, until all chromosomes are bi-oriented by spindle microtubules. Kinetochore accumulation of the SAC component Mad1–Mad2 is crucial for SAC activation. However, the mechanism by which Mad1–Mad2 accumulation at kinetochores is regulated is not clear. Here we find that Cep57 is localized to kinetochores in human cells, and binds to Mis12, a KMN (KNL1/Mis12 complex/Ndc80 complex) network component. Cep57 also interacts with Mad1, and depletion of Cep57 results in decreased kinetochore localization of Mad1–Mad2, reduced SAC signalling and increased chromosome segregation errors. We also show that the microtubule-binding activity of Cep57 is involved in the timely removal of Mad1 from kinetochores. Thus, these findings reveal that the KMN network-binding protein Cep57 is a mitotic kinetochore component, and demonstrate the functional connection between the KMN network and the SAC. PMID:26743940

  19. Response of macrobenthic and foraminifer communities to changes in deep-sea environmental conditions from Marine Isotope Stage (MIS) 12 to 11 at the "Shackleton Site"

    NASA Astrophysics Data System (ADS)

    Rodríguez-Tovar, Francisco J.; Dorador, Javier; Martin-Garcia, Gloria M.; Sierro, Francisco J.; Flores, José A.; Hodell, David A.

    2015-10-01

    Integrative research including facies characterization, ichnological composition and foraminifer analysis has been conducted on cores from Site U1385 of the IODP Expedition 339 to evaluate the incidence of Marine Isotope Stage (MIS) 12 and MIS 11 on deep-sea environmental changes. Four color facies groups have been differentiated, showing variable transitions between them (bioturbated, gradual and sharp contacts). Trace fossil assemblage, assigned to the Zoophycos ichnofacies, consists of light and dark filled structures, with Alcyonidiopsis, Chondrites, Nereites, Planolites, Spirophyton, Thalassinoides, Thalassinoides-like structures, and Zoophycos. A deep-sea multi-tiered trace fossil community is interpreted, revealing predominance of well-oxygenated bottom and pore-waters, as well as abundance of food in the sediment for macrobenthic tracemaker community. Changes in environmental parameters are interpreted to be associated with significant variations in trace fossil distribution according to the differentiated intervals (A to M). Benthic foraminifer concentration in the sediments and variations of the planktonic foraminifer assemblages suggest significant changes in surface productivity and food supply to the sea floor since the ending of MIS 13 to the end of MIS 11 that could be correlated with the registered changes in facies and trace fossil assemblages. At the end of MIS 13 values of annual export productivity were very low, that together with the presence of light-color sediments and the continuous presence of light Planolites and Thalassinoides, reveal lower organic carbon flux to the bottom and high oxygen conditions (interval A). Afterwards the organic matter supply increased rapidly and remained very high until Termination V, determining an eutrophic environment, expressed by high benthic foraminifer accumulation rates, and reduced availability of oxygen, that correlate with the record of Spirophyton and Zoophycos, and the presence of Chondrites

  20. Extreme drying event in the Dead Sea basin during MIS5 from the ICDP Dead Sea Deep Drill Core

    NASA Astrophysics Data System (ADS)

    Goldstein, S. L.; Stein, M.; Ben-Avraham, Z.; Agnon, A.; Ariztegui, D.; Brauer, A.; Haug, G. H.; Ito, E.; Kitagawa, H.; Torfstein, A.; Yasuda, Y.; The Icdp-Dsddp Scientific Party

    2011-12-01

    The ICDP funded Dead Sea Deep Drilling Project (DSDDP) recovered the longest and most complete paleo-environmental record in the Middle East, drilling holes of ~450 and ~350 meters in length in deep (~300 m below the lake level) and shallow sites (~3 mbll) respectively. The Dead Sea expands during the glacials and contracts during interglacials, and the sediments comprise a geological archive of the evolving environmental conditions (e.g. rains, floods, dust-storms, droughts). Dead Sea sediments include inorganic aragonite, allowing for dating by U-series (e.g. Haase-Schramm et al. GCA 2004). The deep site cores were opened and described in June 2011. The cores are composed mainly of alternating intervals of marl (aragonite, gypsum and detritus) during glacials, and salts and marls during interglacials. From this stratigraphy we estimate that the deep site core spans ~200 kyr (to the boundary of MIS 6 and 7). A dramatic discovery is a ~40 cm thick interval of partly rounded pebbles at ~235 m below the lake floor. This is the only clean pebbly unit in the entire core. It appears to be a beach layer, near the deepest part of the Dead Sea, lying above ~35 meters of mainly salt. If it is a beach layer, it implies an almost complete dry-down of the paleo-Dead Sea. The pebble layer lies within the last interglacial interval. Our initial attempt to more precisely estimate the age of the possible dry down shows an intriguing correlation between the salt-mud stratigraphy of the Dead Sea core and the oxygen isotope record of Soreq Cave, whereby excursions to light oxygen in the speleothems correspond to periods of salt deposition. Through this comparison, we estimate that the possible dry down occurred during MIS 5e. The occurrence of ~35 meters of mainly salt along with the pebble layer demonstrates a severe dry interval during MIS 5. This observation has implications for the Middle East today, where the Dead Sea level is dropping as all the countries in the area use the

  1. Enhancement mode operation in AlInN/GaN (MIS)HEMTs on Si substrates using a fluorine implant

    NASA Astrophysics Data System (ADS)

    Zaidi, Z. H.; Lee, K. B.; Guiney, I.; Qian, H.; Jiang, S.; Wallis, D. J.; Humphreys, C. J.; Houston, P. A.

    2015-10-01

    We have demonstrated enhancement mode operation of AlInN/GaN (MIS)HEMTs on Si substrates using the fluorine treatment technique. The plasma RF power and treatment time was optimized to prevent the penetration of the fluorine into the channel region to maintain high channel conductivity and transconductance. An analysis of the threshold voltage was carried out which defined the requirement for the fluorine sheet concentration to exceed the charge at the dielectric/AlInN interface to achieve an increase in the positive threshold voltage after deposition of the dielectric. This illustrates the importance of control of both the plasma conditions and the interfacial charge for a reproducible threshold voltage. A positive threshold voltage of +3 V was achieved with a maximum drain current of 367 mA mm-1 at a forward gate bias of 10 V.

  2. From Lake Malawi Drilling: East African Climate May Have Caused Major Evolutionary Turnover in Mammalian Species During MIS 14

    NASA Astrophysics Data System (ADS)

    Johnson, Thomas; Werne, Josef

    2016-04-01

    Hominin evolution underwent important changes in the last 1.3 million years, including the extinction of Paranthropus at about 1.2 Ma, leaving Homo as the sole hominin genus. Our genus experienced a major increase in cranial capacity at about 500 ka, and our species, H. sapiens, first appeared at ~200 ka. There was a major turnover in mammalian species in East Africa between 540 and 400 ka, favoring descendants of smaller size and less specialized diet. An understanding of what drove evolution in these directions is fundamental to understanding the development of modern H. sapiens. Climate certainly played a role, for it is the principal factor that influences the distribution of vegetation and habitability on the landscape. We present a 1.3 million year record of temperature and hydroclimate in the basin of Lake Malawi, the second deepest lake in Africa, derived from a 380 m sediment sequence taken from a water depth of 590 m by the Lake Malawi Drilling Project. Seismic reflection profiles used to select the site portray an undisturbed sedimentary section that was not impacted by erosion, turbidity currents or mass wasting events. Sediment samples were analyzed to produce records of temperature (TEX86) and aridity (Ca content and leaf wax δ13C). The temperature record displays progressively larger amplitude glacial-interglacial variations from MIS 13 (~500 ka) to MIS 5 (~125 ka). Intervals of low Ca abundance, which reflect lake high stands, correlate with times of depleted δ13Cwax and relatively warm temperatures. The Malawi basin experienced warm, wet interglacials and cooler (by about 2 - 4°C), dry glacial periods, with roughly a 100 ky periodicity since the Mid-Pleistocene Transition (MPT), about 900 ka. The paleoclimate record from Lake Malawi sediments portrays a transition from a highly variable and predominantly arid climate prior to 900 ka to a progressively more humid environment after the MPT dominated by 100 ky cycles consisting of warm, wet

  3. Analysis of off-state leakage mechanisms in GaN-based MIS-HEMTs: Experimental data and numerical simulation

    NASA Astrophysics Data System (ADS)

    Marino, F. A.; Bisi, D.; Meneghini, M.; Verzellesi, G.; Zanoni, E.; Van Hove, M.; You, S.; Decoutere, S.; Marcon, D.; Stoffels, S.; Ronchi, N.; Meneghesso, G.

    2015-11-01

    This paper presents an extensive analysis of the off-state conduction mechanisms in AlGaN/GaN Meta-Insulator-Semiconductor (MIS) transistors. Based on combined bi-dimensional numerical simulation and experimental measurements, we demonstrate the following relevant results: (i) under off-state bias conditions, the drain current can show a significant increase when the drain bias is swept up to 600 V; (ii) several mechanisms can be responsible for off-state current conduction, including band-to-band tunneling and impact ionization; (iii) two-dimensional numerical simulations indicate that band-to-band tunneling plays a major role, while impact ionization does not significantly contribute to the overall leakage. Temperature-dependent I-V measurements were also carried out to identify the origin of the vertical drain-bulk leakage.

  4. An association-adjusted consensus deleterious scheme to classify homozygous Mis-sense mutations for personal genome interpretation

    PubMed Central

    2013-01-01

    Background Personal genome analysis is now being considered for evaluation of disease risk in healthy individuals, utilizing both rare and common variants. Multiple scores have been developed to predict the deleteriousness of amino acid substitutions, using information on the allele frequencies, level of evolutionary conservation, and averaged structural evidence. However, agreement among these scores is limited and they likely over-estimate the fraction of the genome that is deleterious. Method This study proposes an integrative approach to identify a subset of homozygous non-synonymous single nucleotide polymorphisms (nsSNPs). An 8-level classification scheme is constructed from the presence/absence of deleterious predictions combined with evidence of association with disease or complex traits. Detailed literature searches and structural validations are then performed for a subset of homozygous 826 mis-sense mutations in 575 proteins found in the genomes of 12 healthy adults. Results Implementation of the Association-Adjusted Consensus Deleterious Scheme (AACDS) classifies 11% of all predicted highly deleterious homozygous variants as most likely to influence disease risk. The number of such variants per genome ranges from 0 to 8 with no significant difference between African and Caucasian Americans. Detailed analysis of mutations affecting the APOE, MTMR2, THSB1, CHIA, αMyHC, and AMY2A proteins shows how the protein structure is likely to be disrupted, even though the associated phenotypes have not been documented in the corresponding individuals. Conclusions The classification system for homozygous nsSNPs provides an opportunity to systematically rank nsSNPs based on suggestive evidence from annotations and sequence-based predictions. The ranking scheme, in-depth literature searches, and structural validations of highly prioritized mis-sense mutations compliment traditional sequence-based approaches and should have particular utility for the development of

  5. A sustained +21 m sea-level highstand during MIS 11 (400 ka): direct fossil and sedimentary evidence from Bermuda

    NASA Astrophysics Data System (ADS)

    Olson, Storrs L.; Hearty, Paul J.

    2009-02-01

    A small, protected karstic feature exposed in a limestone quarry in Bermuda preserved abundant sedimentary and biogenic materials documenting a transgressive phase, still-stand, and regressive phase of a sea-level in excess of 21.3 m above present during Marine Isotope Stage (MIS) 11 (400 ka) as determined by U/Th dating and amino acid racemization. Cobbles and marine sediments deposited during the high-energy transgressive phase exhibit rim cements indicating a subsequent phreatic environment. This was succeeded stratigraphically by a still-stand deposition of fine calcareous lagoonal sediments containing bioclasts of red algae and benthic and planktonic foraminifera that was intensely burrowed by marine invertebrates, probably upogebiid shrimp, that could not be produced under any condition other than sustained marine submergence. Overlying this were pure carbonate beach sands of a low-energy regressive phase containing abundant remains of terrestrial and marine vertebrates and invertebrates. The considerable diversity of this fauna along with taphonomic evidence from seabird remains indicates deposition by high run-up waves over a minimum duration of months, if not years. The maximum duration has yet to be determined but probably did not exceed one or two thousand years. The most abundant snails in this fauna are two species indicative of brackish water and high-tide line showing that a Ghyben-Herzberg lens must have existed at > + 20 m. The nature of these sediments and fossil accumulation is incompatible with tsunami deposition and, given the absence of evidence for tectonic uplift of the Bermuda pedestal or platform, provide proof that sea-level during MIS 11 exceeded +20 m, a fact that has widespread ramifications for geologists, biogeographers, and human demographics along the world's coastlines.

  6. Late Pleistocene (MIS5-3) environmental reconstruction from north-eastern Iberia through microvertebrate and palaeobotanical records

    NASA Astrophysics Data System (ADS)

    Allue, Ethel; Bennàssar, Maria; Biltekin, Demet; Blain, Hugues-Alexandre; Burjachs, Francesc; Euba, Itxaso; Expósito, Isabel; Fernández-García, Mónica; López-García, Juan Manuel

    2014-05-01

    The aim of this work is to analyze the environmental changes during the Late Pleistocene on the basis of a multi-approach study based on natural and archaeological deposits from NE Iberian Peninsula. The focussed area, although having a small extension (some 32.000 square kilometres), covers a large range of ecosystems and bioclimatic conditions from the Mediterranean seashore to the summit of the Pyrenean mountain ranges (up to 2000 masl). This synthetical approach includes materials from various contexts including 10 archaeological deposits and a single natural deposit. In this work, plant (pollen and charcoals) and animal (small mammals, amphibians and reptiles) records are being analysed and compared in order to present an overview of the environmental changes occurred from the MIS5 to MIS3. On the first hand, we are using the small-vertebrate records recovered from archaeological deposits. These proxies are mainly the product of pellets from birds of prey and are key ecological markers. On the second hand, palaeobotanical evidences, pollen and charcoal, have different formation processes. Charcoal remains are mostly from archaeological deposits and are due to human activities related to fire showing evidences of the local vegetation. Pollen evidences from archaeological and natural contexts are deposited through natural processes (wind, insects, etc.) and show regional scale vegetation record. Results indicate the presence of temperate elements during all these periods (especially at the seashore area), with a more important representation and extension southwards or changes in altitude from taxa with eurosiberian affinities during coldest periods. Forest coverage, plant and vertebrate distribution along the territory point out a mosaic landscape formed by open areas and forests. These landscapes have probably a more or less Mediterranean or Eurosiberian character depending on the climatic moment and their location with variations along the sequence.

  7. Late persistence of the Acheulian in southern Britain in an MIS 8 interstadial: evidence from Harnham, Wiltshire

    NASA Astrophysics Data System (ADS)

    Bates, M. R.; Wenban-Smith, F. F.; Bello, S. M.; Bridgland, D. R.; Buck, L. T.; Collins, M. J.; Keen, D. H.; Leary, J.; Parfitt, S. A.; Penkman, K.; Rhodes, E.; Ryssaert, C.; Whittaker, J. E.

    2014-10-01

    This paper presents evidence of the discovery of a new Middle Pleistocene site in central southern England, with undisturbed evidence of hominin occupation well-dated to an interstadial towards the end of Marine Isotope Stage 8, c. 250,000 BP. The site consists of a preserved remnant of a river terrace and its alluvial floodplain overlain by chalk-rich bankside deposits, all abutting a Chalk bedrock riverbank. It preserves an area of occupation with activity focused on the riverbank, complemented by occasional activity on a palaeo-landsurface developed on the surface of the alluvial floodplain. Lithic technology at the site consists almost entirely of handaxe manufacture, allowing attribution to an Acheulian industrial tradition. Mammalian and other palaeo-environmental remains are present and associated with the occupation horizons, including large mammal bones showing signs of hominin interference. Dating was based on OSL determinations on the sediments and amino acid racemisation of molluscan remains, supported by biostratigraphic indications. Besides being a rare instance of an undisturbed Palaeolithic palaeo-landscape covering several hectares, the site contributes to wider Quaternary research concerns over the ability of Middle Pleistocene hominins to tolerate colder climatic episodes in higher latitudes, and over settlement history and changing lithic industrial traditions of northwest Europe in relation to climate change and British peninsularity. It is suggested that the Harnham evidence may represent an insular population that had persisted in southern Britain since MIS 10/9, which became locally extinct during the glacial maximum 8.2 marking the end of MIS 8.

  8. OSL ages in central Norway support a MIS 2 interstadial (25-20 ka) and a dynamic Scandinavian ice sheet

    NASA Astrophysics Data System (ADS)

    Johnsen, Timothy F.; Olsen, Lars; Murray, Andrew

    2012-06-01

    Recent work has suggested that the Scandinavian ice sheet was much more dynamic than previously believed, and its western marine-based margin can provide an analogue to the rapid-paced fluctuations and deglaciation observed at the margins of the Antarctic and Greenland ice sheets. In this study we used a complimentary dating technique, OSL (Optically Stimulated Luminescence dating), to support the existence of the Trofors interstadial in central Norway; an ice-free period that existed from ˜25 to 20 ka recorded at multiple sites throughout Norway (cf. Andøya interstadial) and that divides the Last Glacial Maximum (LGM) into two stadials. OSL signal component analysis was used to optimize data analysis, and internal (methodological) tests show the results to be of good quality. Both large and small aliquots gave consistent OSL ages (22.3 ± 1.7 ka, n = 7) for sub-till glaciofluvial/fluvial sediments at the Langsmoen stratigraphic site, and an apparent old age (˜100 ka) for a poorly-bleached sample of glaciolacustrine sediment at the nearby stratigraphically-related Flora site. Eight radiocarbon ages of sediment from the Flora site gave consistent ages (20.9 ± 1.6 cal ka BP) that overlap within 1σ with OSL ages from the nearby Langsmoen site. The similarity in age within and between these stratigraphically-related sites and using different geochronological techniques strongly suggests that this area was ice-free around ˜21 or 22 ka. The existence of the Trofors interstadial along with other interstadials during the Middle and Late Weichselian (MIS 3 and MIS 2) indicates that not only the western margin, but the whole western part of the Scandinavian ice sheet, from the ice divide to the ice margin was very dynamic. These large changes in the ice margin and accompanying drawdown of the ice surface would have affected the eastern part of the ice sheet as well.

  9. Abrupt sand-dune accumulation at the northeastern margin of the Tibetan Plateau challenges the wet MIS3a inferred from numerous lake-highstands

    PubMed Central

    Long, Hao; Fuchs, Markus; Yang, Linhai; Cheng, Hongyi

    2016-01-01

    Over the Tibetan Plateau and adjacent regions, numerous 14C-based lake records revealed a ubiquitous wet climatic period during 40–25 ka (late MIS 3), which is in contradiction with the global pattern of generally cold and dry climates. This paper focuses on OSL dating results of a large set of sand dunes and alluvial sediments (50 OSL ages) from the Qinwangchuan (QWC) Basin at the northeast edge of the Tibetan Plateau, with the aim to test the validity of the anomalous wet condition for the late MIS 3 interval, evidenced by numerous lake highstands. The abrupt sand dune accumulation as indication of increased aridity in the study area was OSL dated to ~40–13 ka. This dry climatic inference of the sand dune system from QWC apparently shows no wet MIS 3a event. Thus, the anomalous wet conditions revealed by high lake levels for the late MIS 3 phase may not be a universal phenomena across entire western China. PMID:27172907

  10. Paul Goodman, 30 Years Later: "Growing Up Absurd"; "Compulsory Mis-Education, and The Community of Scholars"; and "The New Reformation"--A Retrospective

    ERIC Educational Resources Information Center

    Kaminsky, James S.

    2006-01-01

    This article is a retrospective account of the legacy of Paul Goodman's major educational works: "Growing Up Absurd"; "Compulsory Mis-education, and The Community of Scholars"; and "The New Reformation." It is argued here that what remains of interest in Goodman's work is to be found in the tropes and the anarchic Zeitgeist of his work. The legacy…

  11. 49 CFR 40.26 - What form must an employer use to report Management Information System (MIS) data to a DOT agency?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false What form must an employer use to report Management Information System (MIS) data to a DOT agency? 40.26 Section 40.26 Transportation Office of the... Employer Responsibilities § 40.26 What form must an employer use to report Management Information...

  12. Extra-long interglacial in Northern Hemisphere during MISs 15-13 arising from limited extent of Arctic ice sheets in glacial MIS 14.

    PubMed

    Hao, Qingzhen; Wang, Luo; Oldfield, Frank; Guo, Zhengtang

    2015-01-01

    Knowledge of the behavior of Northern Hemisphere (NH) ice sheets over the past million years is crucial for understanding the role of orbitally driven insolation changes on glacial/interglacial cycles. Here, based on the demonstrable link between changes in Chinese loess grain-size and NH ice-sheet extent, we use loess grain-size records to confirm that northern ice-sheets were restricted during marine oxygen isotope stage (MIS) 14. Thus, an unusually long NH interglacial climate of over 100 kyr persisted during MISs 15-13, much longer than expected from marine oxygen isotope records. Taking a global view of the paleoclimate records, MIS 14 inception seems to be a response to changes in Antarctic ice-sheets rather than to NH cooling. Orbital configuration in the two Polar regions shows that the onset of MIS 14 was forced by austral insolation changes, rather than by boreal summer insolation, as Milankovitch theory proposes. Our analysis of MIS 14 raises the possibility that southern insolation forcing may have played an important role in the inception of several other glacials. We suggest that the extra-long NH interglacial climate during MISs 15-13 provided favorable conditions for the second major dispersal episode of African hominins into Eurasia. PMID:26159304

  13. Extra-long interglacial in Northern Hemisphere during MISs 15-13 arising from limited extent of Arctic ice sheets in glacial MIS 14

    PubMed Central

    Hao, Qingzhen; Wang, Luo; Oldfield, Frank; Guo, Zhengtang

    2015-01-01

    Knowledge of the behavior of Northern Hemisphere (NH) ice sheets over the past million years is crucial for understanding the role of orbitally driven insolation changes on glacial/interglacial cycles. Here, based on the demonstrable link between changes in Chinese loess grain-size and NH ice-sheet extent, we use loess grain-size records to confirm that northern ice-sheets were restricted during marine oxygen isotope stage (MIS) 14. Thus, an unusually long NH interglacial climate of over 100 kyr persisted during MISs 15−13, much longer than expected from marine oxygen isotope records. Taking a global view of the paleoclimate records, MIS 14 inception seems to be a response to changes in Antarctic ice-sheets rather than to NH cooling. Orbital configuration in the two Polar regions shows that the onset of MIS 14 was forced by austral insolation changes, rather than by boreal summer insolation, as Milankovitch theory proposes. Our analysis of MIS 14 raises the possibility that southern insolation forcing may have played an important role in the inception of several other glacials. We suggest that the extra-long NH interglacial climate during MISs 15−13 provided favorable conditions for the second major dispersal episode of African hominins into Eurasia. PMID:26159304

  14. Abrupt sand-dune accumulation at the northeastern margin of the Tibetan Plateau challenges the wet MIS3a inferred from numerous lake-highstands.

    PubMed

    Long, Hao; Fuchs, Markus; Yang, Linhai; Cheng, Hongyi

    2016-01-01

    Over the Tibetan Plateau and adjacent regions, numerous (14)C-based lake records revealed a ubiquitous wet climatic period during 40-25 ka (late MIS 3), which is in contradiction with the global pattern of generally cold and dry climates. This paper focuses on OSL dating results of a large set of sand dunes and alluvial sediments (50 OSL ages) from the Qinwangchuan (QWC) Basin at the northeast edge of the Tibetan Plateau, with the aim to test the validity of the anomalous wet condition for the late MIS 3 interval, evidenced by numerous lake highstands. The abrupt sand dune accumulation as indication of increased aridity in the study area was OSL dated to ~40-13 ka. This dry climatic inference of the sand dune system from QWC apparently shows no wet MIS 3a event. Thus, the anomalous wet conditions revealed by high lake levels for the late MIS 3 phase may not be a universal phenomena across entire western China. PMID:27172907

  15. Abrupt sand-dune accumulation at the northeastern margin of the Tibetan Plateau challenges the wet MIS3a inferred from numerous lake-highstands

    NASA Astrophysics Data System (ADS)

    Long, Hao; Fuchs, Markus; Yang, Linhai; Cheng, Hongyi

    2016-05-01

    Over the Tibetan Plateau and adjacent regions, numerous 14C-based lake records revealed a ubiquitous wet climatic period during 40–25 ka (late MIS 3), which is in contradiction with the global pattern of generally cold and dry climates. This paper focuses on OSL dating results of a large set of sand dunes and alluvial sediments (50 OSL ages) from the Qinwangchuan (QWC) Basin at the northeast edge of the Tibetan Plateau, with the aim to test the validity of the anomalous wet condition for the late MIS 3 interval, evidenced by numerous lake highstands. The abrupt sand dune accumulation as indication of increased aridity in the study area was OSL dated to ~40–13 ka. This dry climatic inference of the sand dune system from QWC apparently shows no wet MIS 3a event. Thus, the anomalous wet conditions revealed by high lake levels for the late MIS 3 phase may not be a universal phenomena across entire western China.

  16. Temperature-Dependent Electrical Properties and Carrier Transport Mechanisms of TMAH-Treated Ni/Au/Al2O3/GaN MIS Diode

    NASA Astrophysics Data System (ADS)

    Reddy, M. Siva Pratap; Puneetha, Peddathimula; Reddy, V. Rajagopal; Lee, Jung-Hee; Jeong, Seong-Hoon; Park, Chinho

    2016-08-01

    The temperature-dependent electrical properties and carrier transport mechanisms of tetramethylammonium hydroxide (TMAH)-treated Ni/Au/Al2O3/GaN metal-insulator-semiconductor (MIS) diodes have been investigated by current-voltage (I-V) and capacitance-voltage (C-V) measurements. The experimental results reveal that the barrier height (I-V) increases whereas the ideality factor decreases with increasing temperature. The TMAH-treated Ni/Au/Al2O3/GaN MIS diode showed nonideal behaviors which indicate the presence of a nonuniform distribution of interface states (N SS) and effect of series resistance (R S). The obtained R S and N SS were found to decrease with increasing temperature. Furthermore, it was found that different transport mechanisms dominated in the TMAH-treated Ni/Au/Al2O3/GaN MIS diode. At 150 K to 250 K, Poole-Frenkel emission (PFE) was found to be responsible for the reverse leakage, while Schottky emission (SE) was the dominant mechanism at high electric fields in the temperature range from 300 K to 400 K. Feasible energy band diagrams and possible carrier transport mechanisms for the TMAH-treated Ni/Au/Al2O3/GaN MIS diode are discussed based on PFE and SE.

  17. Sea surface temperature and salinity patterns in the northern North Atlantic and the Arctic during interglacial MIS 11c: Implications for oceanic circulation reconstruction

    NASA Astrophysics Data System (ADS)

    Kandiano, E.; van der Meer, M.; Schouten, S.; Fahl, K.; Polyak, L. V.; Cronin, T. M.; Bauch, H. A.; Sinninghe Damste, J. S.

    2013-12-01

    Sea surface temperature (SST) patterns in the northern North Atlantic, the Nordic seas, and the western Arctic Ocean (AO) were reconstructed across the MIS 11c interglacial, a potential future climate analogue, using planktic foraminiferal abundances, alkenone-based Uk'37 and glycerol dialkyl glycerol tetraether (GDGT)-based TEX86 analyses. Foraminiferal SST reconstructions were supported by foraminiferal counts of small-sized fractions and rare foraminiferal species, stable oxygen isotope measurements on benthic and planktic foraminifers, and ice rafted debris records. Additionally, the hydrogen isotopic (δD) compositions of long chain alkenones were determined to assess variations in paleo sea surface salinity in the North Atlantic. In the North Atlantic our newly produced TEX86 -based SSTs range between 14 and 19 °C in agreement with summer foraminiferal SST (13 and 18 °C) and alkenone SSTs (13 and 16 °C). However, the former showed higher fluctuations than SSTs based on foraminiferal abundances. In concordance with δ18O records TEX86 SSTs demonstrate notable variability in the middle of MIS 11c, between 400 and 410 ka, which is consistent with the intra-MIS 11c cold event in the Arctic indicated by planktic foraminifers. This pattern implies that the interglacial MIC 11c climate was probably not as stable as it widely believed. The preliminary alkenone δD data show that during MIS 11c salinity values in the North Atlantic were similar to Holocene values. Foraminiferal SST records imply that during MIS 11c at least parts of the AO experienced unusually warm and probably ice free conditions, whereas the Nordic seas remained rather cold, especially during the early phase of this period, as it is inferred from foraminiferal and alkenone SSTs. At the same time all our SST records show that the North Atlantic was 1-2°C warmer than present during MIS 11c. This pattern suggests that during MIS 11c the North Atlantic Current was deflected to the west, which

  18. Terrestrial biomarkers in the sediment of the East Sea (Japan Sea) since the MIS 11: implications for paleoproductivity and paleoclimatic changes

    NASA Astrophysics Data System (ADS)

    Hyun, S.; Suh, Y. J.; Woo, K. S.; Ikehara, M.

    2014-12-01

    Terrestrial biomarkers such as n-alkanes and cholesterol were analyzed to infer the variations of paleoproductivity and the corresponding paleoclimatologic information from the sediment of the Korean Plateau, East Sea (Japan Sea) since the Marine Isotope Stage (MIS) 11 (ca. 400 ka). Previous studies of SST variation have shown that glacial-interglacial scale changes were quite variable with the maximum range of 26oC in MIS 7, and the minimum range of 12oC during MIS 2 and 6. The distribution of terrestrial n-alkanes signatures is characterized by the occurrence of high odd number frequency with a minor contribution of specific compound (nC27 only). Average Chain Length (ACL) and Carbon Preferences Index (CPI), both of which are derived from n-alkane combination, show similar shifting between glacial and interglacial periods. This suggests that paleovegetation communities had been changed in responding to paleoclimatological variations, and the input amount of terrestrial compound was strongly linked with paleoclimatologic changes. In particular, depleted values of δ13Corg during MIS 2, 8 and 10 were coincident with lower nitrogen isotope values indicating local paleoceanographic effects such as paleoproductivity changes. Decoupling between δ13Corg and δ15Norg during MIS 1, 3, 5, 7 and coupling of the two during MIS 8 and 11 can be observed, which appear to be interpreted as local productivity changes. In particular, high abundance of cholesterol and C21 n-alkanes, which were derived from diatom, increased during interglacial periods. Therefore, alkenones, SST and n-alkanes signatures coincide with δ13Corg and δ15Norg variations during glacial-interglacial cycles and further strongly associated with cholesterol abundance suggesting that the paleoenvironmental conditions in East Sea during glacial-interglacial periods were sensitive not only to global climate changes but also to local paleceanographic variations. Surface water circulation around the Korea

  19. From a hiatus of 10 ka to loess of 6 m thickness - the MIS3/2 transition in the Central European loess belt

    NASA Astrophysics Data System (ADS)

    Zoeller, Ludwig

    2015-04-01

    Periglacial loess is not only suited as a high-resolution terrestrial archive of palaeoenvironmental conditions but also as a record of geomorphodynamic phases charactererized by the alternation of sedimentation and repeated unconformities through erosion, visible as both, parallel unconformity (often hard to detect by untrained bare eyes) and relief unconformity. The synopsis of complete refined stratigraphy and unconformities is, thus, essential for "Deriving palaeoenvironmental information from non-continuous sedimentary archives". The Central European Loess Belt is well-suited to monitor this approach, at least in its northern part. The onset of periglacial conditions following a pedocomplex of interstadial soils (attributed to the Denekamp Complex) dates from late MIS 3. Periglacial conditions continue through MIS 2. The interaction of sedimentation and erosion during the MIS 3/2 transition is studied in a transect from Alsace (Eastern France) via Germany to Silesia (Poland). At Achenheim (Alsace) this transition is represented by a ca. 10 ka lasting hiatus. At Nussloch (near Heidelberg, Germany) 6 m thick loess intercalating with tundra-gleys is dated into late MIS 3 and is covered by up to ca. 9 m of MIS 2 loess. In Ostrau (Saxony, Germany) this transition occured in ca. 1 m thick loess derivates including three tundra-soils, a weak brown soil, solifluction and cryoturbation features, and ice wedging. Age control of Silesian loess (Poland) is still ambiguous, but from own IRSL test measurements it is obvious that late MIS 3-loess deposited rather close to the Weichselian ice margin was also affected by gelifluction and cryoturbation. At Dolní Věstonice (Southern Moravia, Czech Republic) the MIS 3/2 transition can be assumed in an up to 40 cm thick tundra gley layer developed under the influence of gelifluction. The thickness of loess deposited in the time window under debate appears to depend on sediment availability from nearby sources, e.g. from large

  20. Paired microfossil evidence for a delayed development of fully marine surface water conditions in the Nordic seas during the Last interglacial (MIS 5e)

    NASA Astrophysics Data System (ADS)

    van Nieuwenhove, N.; Bauch, H. A.; Kandiano, E. S.

    2010-12-01

    Dinoflagellate cyst (dinocyst) and foraminiferal records of sediment cores from The Vøring and Iceland Plateau and south of the Fram Strait were used to reconstruct the evolution of the surface circulation in the Nordic seas during the last interglacial (Marine Isotopic Stage or MIS 5e). The location of the cores, under the modern pathway of the warm Norwegian Atlantic Current (NwAC) and within the mixing zone of the NwAC and the cold East Greenland Current (EGC), allows to reconstruct the spreading of inflowing North Atlantic surface waters across the Nordic seas during the climate progression of MIS 5e. The microfossil records, supported by stable isotope and IRD data, reveal that during the first ~6000 years of MIS 5e a more pronounced stratification and seasonality existed in the eastern Nordic seas, presumably as a result of long-lasting deglacial effects. Thus, the northward heat flux was reduced during this time in this area. It was only during late MIS 5e, and when IRD-input into the eastern Nordic seas had come to a halt, that the northward flow of warm Atlantic water masses intensified so that interglacial conditions became also eminent in the surface waters south of the Fram Strait. Our data further suggest that the stronger NwAC of late MIS 5e entailed an intensification of the EGC. While this brought comparatively colder conditions towards the Iceland Plateau it was also the only time when proper, that is fully marine, warm interglacial surface conditions co-existed in the eastern Nordic seas.

  1. Vegetation and climate history in arid western China during MIS2: New insights from pollen and grain-size data of the Balikun Lake, eastern Tien Shan

    NASA Astrophysics Data System (ADS)

    Zhao, Yongtao; An, Cheng-Bang; Mao, Limi; Zhao, Jiaju; Tang, Lingyu; Zhou, Aifeng; Li, Hu; Dong, Weimiao; Duan, Futao; Chen, Fahu

    2015-10-01

    Marine Isotope Stage (MIS) 2 is mostly a cold period encompassing the Last Glacial Maximum (LGM), but the regional expression of MIS2 in arid areas of China is not well known. In this paper, we use high-resolution lacustrine pollen and grain-size records from Balikun Lake to infer vegetation, lake evolution, and climate in arid western China during MIS2. Our results suggest that: 1) the regional vegetation around Balikun was mainly dominated by desert and/or desert-steppe, and Balikun Lake was relatively shallow and experienced high aeolian input during MIS2; 2) distinctive runoff from mountain glacial meltwater in the eastern parts of the Balikun basin caused a high relative abundance of Artemisia pollen during the LGM (26.5-19.2 cal kyr BP), while simultaneously the desert areas expanded as indicated by the high abundance of desert shrubs (e.g., Elaeagnaceae, Rhamnaceae, Hippophae). This cold and dry LGM climate triggered a substantial lowering of lake level; 3) an extremely cold and dry climate prevailing from 17.0 to 15.2 cal kyr BP, correlated with Heinrich event 1 (H1), would explain the low vegetation cover found then; and 4) the warm and humid Bølling/Allerød interstadial (BA: ca. 15-ca. 13 cal kyr BP) is clearly recorded in the Balikun region by the development of wetland herb communities (e.g., Poaceae, Cyperaceae, Typha), and the lake level rose due to increased runoff. Our results challenge the traditional view of cold and wet climatic conditions and high lake levels in arid western China during the LGM, and we propose that changes in local temperature modulated by July insolation was an indispensable factor in triggering vegetation evolution in the Balikun region during MIS2.

  2. Last interglacial reef limestones, northeastern St. Croix, US Virgin Islands—evidence of tectonic tilting and subsidence since MIS 5.5

    NASA Astrophysics Data System (ADS)

    Toscano, M. A.; MacIntyre, I. G.; Lundberg, J.

    2012-03-01

    Most last interglacial (MIS 5.5) coral reef deposits in the Caribbean are emergent. However, in St. Croix, these are found mainly at depth, underneath Holocene material and confirmed by TIMS U-Th dated corals from eight cores through Holocene reefs. The only emergent MIS 5.5 marine deposit peaks at +1.5 m MSL at the northwestern end of the island. The Late Pleistocene surface decreases at least 9.25 m (based on reef crest elevations) in elevation over 15 km along a 0.62 m/km eastward (alongshore) slope. Neither differential erosion nor a naturally sloping deposit is likely, thus the directional elevation decrease requires the influence of tectonic processes. Platform tilting or differential subsidence increasing in rate to the east probably operated both during and since the last interglacial and created progressively greater accommodation space for increasingly thicker overlying Holocene reefs in an eastward direction. Rates of subsidence since MIS 5.5 increase from west to east, from 0.02 mm/year to 0.1 mm/year, assuming a MIS 5.5 +6-m sea level and +4 m initial reef elevation. St. Croix's association with extensional shelf faulting from the northern part of the Virgin Islands Basin, the Anegada Fault to the east and the Puerto Rico Trench to the north may be significant in terms of identifying mechanisms for, or past events resulting in, directional tilting. Identification of differential elevations of MIS 5.5 reefs adds substantially to the information on Late Quaternary tectonism of the area.

  3. Tsunami deposits at MIS Stages 5e and 9 on Oahu, Hawaii: implications for sea level at interglacial stages

    NASA Astrophysics Data System (ADS)

    McMurtry, G. M.; Campbell, J. F.; Fryer, G. J.; Tappin, D. R.; Fietzke, J.

    2010-12-01

    Sandy, basalt-coral conglomerates associated with both beachrock and coral reefs are found at high elevations on Oahu, Hawaii. They have been attributed to either brief, sea level high-stands or storms. The Kahe Point conglomerates are at 12.5 m elevation, whereas the main stage MIS-5e reef at this location has a maximum elevation of 8.2 m. They are loosely consolidated and poorly cemented, graded, poorly sorted, and with varying amounts of basalt and coral clasts ranging from cobble to boulder size. Coral in these deposits has been U-series dated by us at between 120-125 ka (n=5). Four distinct beds, with a gently seaward tilt, are recognized in a road cut section, with each bed composed of a few cm-thick topset bed of fine-grained, shelly, calcareous sand to silt. Similar high elevation conglomerates and 5e reefs are also described at Mokapu and Kaena Points on Oahu, indicating an island-wide deposit. Older coral clasts, dated at 130 to 142 ka (n=6; oldest by alpha spectrometry) found in association with the stage 5e corals suggest reworking and incorporation of older low-stand reef material. The coarse grain size of the conglomerates indicates deposition from a high-energy event; thus a high-stand source is ruled out. We also consider that the overall lithology and up to 0.5 m bed thickness not to be the result of storms; a series of high frequency storm events is considered unlikely. The weight of the evidence in our opinion clearly indicates deposition by a series of tsunami waves. If correct, this has implications for “probabilistic” models of sea level peaks at least 6.6 m higher than present at stage 5e that use such data in their models (e. g., Kopp et al., 2009), at least for Oahu. Within about 2 km of the Kahe deposit, in a road cut at Ko Olina, there is another markedly similar high-energy, sandy basalt-bearing coral conglomerate sequence at 21 to 25 m elevation. There are at least two distinct beds about one meter in thickness, both gently seaward

  4. Development of a high-resolution record of Great Basin climate change during MIS 5, 6, and 7

    NASA Astrophysics Data System (ADS)

    Cross, M.; McGee, D.; Broecker, W. S.; Quade, J.; Cheng, H.; Edwards, R.

    2013-12-01

    As evinced by the cycles of the large paleolakes Lahontan and Bonneville, the currently semi-arid to arid Great Basin region of the United States has experienced significant changes in climate and water balance in the past. Although there has been substantial research concerning these changes for times around and since the last glacial maximum, relatively little is known about the region's previous climate and water balance history. There is a clear need for a long-term record for earlier glacial and interglacial periods. Here, we present some of our initial results from Lehman Cave (39.01°N, 114.22°W), a well-decorated, active cave located on the edge of the Bonneville Basin in the Great Basin National Park, for times correlating with large portions of Marine Oxygen Isotope Stages (MIS) 5, 6, and 7. We initially surveyed a suite of speleothems to obtain times and durations of growth phases to aid in choosing samples appropriate for more extensive analysis. Approximately eighty 2 to 10 mg samples with a mean 238U of 400 ppb, representing most of the major growth phases of this suite of 20 speleothems, were analyzed for preliminary uranium-thorium dates. A subset of eight of these stalagmites grew collectively over large portions of MIS 5 and 6 (an interval that includes the Little Valley lake cycle of the Bonneville Basin) as well as a substantial portion of MIS 7. This record includes several significant periods of contemporaneous growth, including: 81.5 to 103 ka, which corresponds to the interval between Dansgaard-Oeschger events 21 and 23; 204 to 207 ka; and 118 to 132 ka, an interval including the beginning of the last interglacial period and the end of Termination II and Heinrich Stadial 11. We have yet to identify growth phases between 103 to 118 ka, 134 to 137 ka, and 164 to 169 ka. Initial stable isotope results indicate a shift of approximately +3‰ δ18O and +5‰ δ13C around 131 × 2.5 ka, which agrees within error with the findings of Shakun et al

  5. An interdisciplinary approach to reconstructing hydrologically controlled terrestrial habitat dynamics during MIS 5 from sediments of Lake Ohrid (Albania, Macedonia)

    NASA Astrophysics Data System (ADS)

    Holtvoeth, Jens; Vogel, Hendrik; Rushworth, Danielle; Copsey, Harriet; Imeri, Alma; Valsecchi, Verushka; Cara, Magdalena; Schouten, Stefan; Wagner, Bernd; Wolff, George A.; Pancost, Richard D.

    2016-04-01

    We investigated sediments from a piston core (site Co1202) in the northeastern part of Lake Ohrid (Macedonia, Albania) that cover the period from 136 to 97 ka, i.e. most of marine isotope stage (MIS) 5 including Termination II and the peak warm period of MIS 5e (Eemian). The aim of the study was to reconstruct climatically controlled changes in the terrestrial habitat by combining data from elemental, lipid biomarker (alkyl lipids, glycerol dialkyl glycerol tetraethers/GDGTs) and compound-specific carbon isotope analyses with pollen data. Comparison of biomarker data from sediments and modern materials shows a close similarity between the average biomarker composition of sediments and soils. This is confirmed by statistical analyses, implying that a dominant proportion of the sedimentary alkyl lipids derives from soils while aquatic sources (macrophytes, phytoplankton) can be ruled out as a major source. The carbonate record of the Co1202 sediments and the GDGT-based proxy for lake surface water temperature (TEX86) closely follow climatic trends as they are known from the North Atlantic realm, including marine isotope sub-stage 5d and short-term climate events such as cold events C25, C24 and C23. By contrast, proxies based on alkyl lipid composition reveal an entirely different pattern. Episodes of slow, continuous change are disrupted by abrupt shifts. This suggests a threshold-controlled system, with supply of organic matter from specific sources being increased or suppressed by a sudden change of supply pathways. Such a mechanism is provided by lake level change that includes rapid flooding or exposure of extensive tectonic terraces in the vicinity of site Co1202 as documented by geophysical surveys. Both flooding and exposure change the areas that certain habitats occupy in the catchment of the site, e.g., the proportions of vegetation and soils on the surrounding mountain slopes relative to that on low-lying terrace surfaces. Several such abrupt changes can

  6. Coral Reef Response to Marine Isotope Stage (MIS) 5e Sea Level Changes in the Granitic Seychelles

    NASA Astrophysics Data System (ADS)

    Vyverberg, K.; Dechnik, B.; Dutton, A.; Webster, J.; Zwartz, D.

    2015-12-01

    Sea-level position has a direct control on coral reef morphology and composition. Examining changes in these parameters in fossil reefs can inform reconstructions of past sea-level behavior and, indirectly, ice sheet dynamics. Here we provide a detailed examination of fossil reefs from Marine Isotope Stage (MIS) 5e. These fossil reefs are located in the granitic Seychelles, which is tectonically stable site and far-field from the former margins of Northern Hemisphere ice sheets. To reconstruct relative sea level (RSL), we combine RTK and Total Station elevation surveys with sedimentary and taxonomic evaluations of eight fossil reef sites. Carbonate coralgal reef buildups of the shallowest portion of the reef are preserved in limestone outcrops that are protected by granite boulder overhangs. Two primary outcrop morphologies were observed at these sites: plastering and massive. Plastering outcrops manifest as thin (~ 1 m height x 1 m width x 0.5 m depth) vertical successions of reef framework and detritus, while massive outcrops are larger (~ 2-6 m height x 2-6 m width x 1-2 m depth). The base of these limestone outcrops consistently record a period of reef growth, characterized by corals or coralline algae colonizing the surface or face of a granite boulder and building upwards. This lower reefal unit is capped by a disconformity that is commonly overlain by coral rubble or a ~10 cm thick layer of micrite. Rubble units contain coarse fragments of the coralgal reef buildups while micrite layers consist of a relatively homogeneous fine-grained carbonate, bearing coral-dwelling, Pyrgomatid barnacles. In many of the outcrops, this succession is repeated upsection with another unit of coralgal reef framework capped by a disconformity that is recognized by the sharp transition to coral rubble or micrite with barnacles. We identified four distinct fossil coralgal assemblages in the limestone outcrops. These assemblages are consistent with modern assemblages which

  7. Environmental changes of the Mazovian (Holsteinian /~MIS 11) palaeolake near Szymanowo (eastern Poland) in the light of malacological analysis

    NASA Astrophysics Data System (ADS)

    Szymanek, Marcin

    2014-06-01

    The malacofauna of the palaeolake deposits at Szymanowo (eastern Poland) was investigated. It represents the younger part of the climatic optimum of the Mazovian (Holsteinian) Interglacial (~MIS 11) and possibly the postoptimal period. The mollusc assemblage is composed of both standing and running water species, mostly connected with temperate climate. The presence of biostratigraphical indicators of the Mazovian, Viviparus diluvianus (Kunth, 1865), Lithoglyphus jahni Urbański, 1975 and Pisidium clessini Neumayr, 1875, is noteworthy. Variability in the structure and composition of the assemblage enables palaeoecological reconstruction. Changes in the water-level, vegetation and energy conditions are inferred from the malacological succession. Three stages of the lake development were distinguished. The first one is connected with deeper conditions and predominance of V. diluvianus and L. jahni. The second one, dominated by Bithynia tentaculata (Linnaeus, 1758), records a fall of the water-level and the growth of aquatic plants, evidenced by high frequencies of Valvata cristata Muller, 1774 and Acroloxus lacustris (Linnaeus, 1758). The third stage corresponds to another rise of the water-level and an increase in V. diluvianus, L. jahni, Valvata piscinalis Muller, 1774 and Pisidium henslowanum (Sheppard, 1823), which evidence some higher energy conditions.

  8. Subsurface North Atlantic warming as a trigger of rapid cooling events: evidence from the early Pleistocene (MIS 31-19)

    NASA Astrophysics Data System (ADS)

    Hernández-Almeida, I.; Sierro, F.-J.; Cacho, I.; Flores, J.-A.

    2015-04-01

    Subsurface water column dynamics in the subpolar North Atlantic were reconstructed in order to improve the understanding of the cause of abrupt ice-rafted detritus (IRD) events during cold periods of the early Pleistocene. We used paired Mg / Ca and δ18O measurements of Neogloboquadrina pachyderma (sinistral - sin.), deep-dwelling planktonic foraminifera, to estimate the subsurface temperatures and seawater δ18O from a sediment core from Gardar Drift, in the subpolar North Atlantic. Carbon isotopes of benthic and planktonic foraminifera from the same site provide information about the ventilation and water column nutrient gradient. Mg / Ca-based temperatures and seawater δ18O suggest increased subsurface temperatures and salinities during ice-rafting, likely due to northward subsurface transport of subtropical waters during periods of weaker Atlantic Meridional Overturning Circulation (AMOC). Planktonic carbon isotopes support this suggestion, showing coincident increased subsurface ventilation during deposition of IRD. Subsurface accumulation of warm waters would have resulted in basal warming and break-up of ice-shelves, leading to massive iceberg discharges in the North Atlantic. The release of heat stored at the subsurface to the atmosphere would have helped to restart the AMOC. This mechanism is in agreement with modelling and proxy studies that observe a subsurface warming in the North Atlantic in response to AMOC slowdown during Marine Isotope Stage (MIS) 3.

  9. Subsurface North Atlantic warming as a trigger of rapid cooling events: evidences from the Early Pleistocene (MIS 31-19)

    NASA Astrophysics Data System (ADS)

    Hernández-Almeida, I.; Sierro, F.-J.; Cacho, I.; Flores, J.-A.

    2014-10-01

    Subsurface water column dynamics in the subpolar North Atlantic were reconstructed in order to improve the understanding of the cause of abrupt IRD events during cold periods of the Early Pleistocene. We used Mg / Ca-based temperatures of deep-dwelling (Neogloboquadrina pachyderma sinistral) planktonic foraminifera and paired Mg / Ca-δ18O measurements to estimate the subsurface temperatures and δ18O of seawater at Site U1314. Carbon isotopes on benthic and planktonic foraminifera from the same site provide information about the ventilation and water column nutrient gradient. Mg / Ca-based temperatures and δ18O of seawater suggest increased temperatures and salinities during ice-rafting, likely due to enhanced northward subsurface transport of subtropical waters during periods of AMOC reduction. Planktonic carbon isotopes support this suggestion, showing coincident increased subsurface ventilation during deposition of ice-rafted detritus (IRD). Warm waters accumulated at subsurface would result in basal warming and break-up of ice-shelves, leading to massive iceberg discharges in the North Atlantic. Release of heat and salt stored at subsurface would help to restart the AMOC. This mechanism is in agreement with modelling and proxy studies that observe a subsurface warming in the North Atlantic in response to AMOC slowdown during the MIS3.

  10. Simulating the impact of freshwater inputs and deep-draft icebergs formed during a MIS 6 Barents Ice Sheet collapse

    NASA Astrophysics Data System (ADS)

    Green, Clare L.; Green, J. A. Mattias; Bigg, Grant R.

    2011-06-01

    An intermediate complexity climate model is used to simulate the collapse of the Barents Ice Sheet during Marine Isotope Stage 6 (MIS 6; 140 ka B.P) with the purpose of investigating whether a mass input of freshwater from the collapse could have affected the convection and deep water formation in the North Atlantic Ocean. Further experiments used a coupled dynamic and thermodynamic iceberg model to determine the effects of deep-draft icebergs, rather than freshwater alone, on the ocean circulation. The results predict that the collapse of the Barents Ice Sheet had a significant impact on the meridional overturning circulation in both the Atlantic and Pacific oceans. Freshwater fluxes have more of an impact on the Atlantic overturning circulation during the actual release period compared to icebergs, but the bergs induce effects over longer time scales even after the pulse is removed. Freshwater fluxes of 0.15 sverdrup (Sv) and iceberg surges of 0.1 Sv trigger significant changes in the global patterns, particularly in the North Pacific where there is strengthening of the overturning circulation at the expense of that in the North Atlantic, and associated increases in Pacific sea surface temperatures. These results highlight the importance of simulating not only the correct flux but also the form of the freshwater input from ice sheet collapses appropriately.

  11. Sea surface temperatures did not control the first occurrence of Hudson Strait Heinrich Events during MIS 16

    NASA Astrophysics Data System (ADS)

    Naafs, B. David A.; Hefter, Jens; Ferretti, Patrizia; Stein, Ruediger; Haug, Gerald H.

    2011-12-01

    Hudson Strait (HS) Heinrich Events, ice-rafting events in the North Atlantic originating from the Laurentide ice sheet (LIS), are among the most dramatic examples of millennial-scale climate variability and have a large influence on global climate. However, it is debated as to whether the occurrence of HS Heinrich Events in the (eastern) North Atlantic in the geological record depends on greater ice discharge, or simply from the longer survival of icebergs in cold waters. Using sediments from Integrated Ocean Drilling Program (IODP) Site U1313 in the North Atlantic spanning the period between 960 and 320 ka, we show that sea surface temperatures (SSTs) did not control the first occurrence of HS Heinrich(-like) Events in the sedimentary record. Using mineralogy and organic geochemistry to determine the characteristics of ice-rafting debris (IRD), we detect the first HS Heinrich(-like) Event in our record around 643 ka (Marine Isotope Stage (MIS) 16), which is similar as previously reported for Site U1308. However, the accompanying high-resolution alkenone-based SST record demonstrates that the first HS Heinrich(-like) Event did not coincide with low SSTs. Thus, the HS Heinrich(-like) Events do indicate enhanced ice discharge from the LIS at the end of the Mid-Pleistocene Transition, not simply the survivability of icebergs due to cold conditions in the North Atlantic.

  12. Schizosaccharomyces pombe Hat1 (Kat1) Is Associated with Mis16 and Is Required for Telomeric Silencing

    PubMed Central

    Tong, Kevin; Keller, Thomas; Hoffman, Charles S.

    2012-01-01

    The Hat1 histone acetyltransferase has been implicated in the acetylation of histone H4 during chromatin assembly. In this study, we have characterized the Hat1 complex from the fission yeast Schizosaccharomyces pombe and have examined its role in telomeric silencing. Hat1 is found associated with the RbAp46 homologue Mis16, an essential protein. The Hat1 complex acetylates lysines 5 and 12 of histone H4, the sites that are acetylated in newly synthesized H4 in a wide range of eukaryotes. Deletion of hat1 in S. pombe is itself sufficient to cause the loss of silencing at telomeres. This is in contrast to results obtained with an S. cerevisiae hat1Δ strain, which must also carry mutations of specific acetylatable lysines in the H3 tail domain for loss of telomeric silencing to occur. Notably, deletion of hat1 from S. pombe resulted in an increase of acetylation of histone H4 in subtelomeric chromatin, concomitant with derepression of this region. A similar loss of telomeric silencing was also observed after growing cells in the presence of the deacetylase inhibitor trichostatin A. However, deleting hat1 did not cause loss of silencing at centromeres or the silent mating type locus. These results point to a direct link between Hat1, H4 acetylation, and the establishment of repressed telomeric chromatin in fission yeast. PMID:22771823

  13. Schizosaccharomyces pombe Hat1 (Kat1) is associated with Mis16 and is required for telomeric silencing.

    PubMed

    Tong, Kevin; Keller, Thomas; Hoffman, Charles S; Annunziato, Anthony T

    2012-09-01

    The Hat1 histone acetyltransferase has been implicated in the acetylation of histone H4 during chromatin assembly. In this study, we have characterized the Hat1 complex from the fission yeast Schizosaccharomyces pombe and have examined its role in telomeric silencing. Hat1 is found associated with the RbAp46 homologue Mis16, an essential protein. The Hat1 complex acetylates lysines 5 and 12 of histone H4, the sites that are acetylated in newly synthesized H4 in a wide range of eukaryotes. Deletion of hat1 in S. pombe is itself sufficient to cause the loss of silencing at telomeres. This is in contrast to results obtained with an S. cerevisiae hat1Δ strain, which must also carry mutations of specific acetylatable lysines in the H3 tail domain for loss of telomeric silencing to occur. Notably, deletion of hat1 from S. pombe resulted in an increase of acetylation of histone H4 in subtelomeric chromatin, concomitant with derepression of this region. A similar loss of telomeric silencing was also observed after growing cells in the presence of the deacetylase inhibitor trichostatin A. However, deleting hat1 did not cause loss of silencing at centromeres or the silent mating type locus. These results point to a direct link between Hat1, H4 acetylation, and the establishment of repressed telomeric chromatin in fission yeast. PMID:22771823

  14. Aligning MIS5 proxy records from Lake Ohrid (FYROM) with independently dated Mediterranean archives: implications for core chronology

    NASA Astrophysics Data System (ADS)

    Zanchetta, G.; Regattieri, E.; Giaccio, B.; Wagner, B.; Sulpizio, R.; Francke, A.; Vogel, L. H.; Sadori, L.; Masi, A.; Sinopoli, G.; Lacey, J. H.; Leng, M. L.; Leicher, N.

    2015-10-01

    The DEEP site sediment sequence obtained during the ICDP SCOPSCO project at Lake Ohrid was dated using tephrostratigraphic information, cyclostratigraphy, and orbital tuning through marine isotope record. Although this approach is suitable for the generation of a general chronological framework of the long succession, it is insufficient to resolve more detailed paleoclimatological questions, such as leads and lags of climate events between marine and terrestrial records or between different regions. In this paper, we demonstrate how the use of different tie points can affect cyclostratigraphy and orbital tuning for the period between ca. 140 and 70 ka and how the results can be correlated with directly/indirectly radiometrically-dated Mediterranean marine and continental proxy records. The alternative age model obtained shows consistent differences with that proposed by Francke et al. (2015) for the same interval, in particular at the level of the MIS6-5e transition. According to this age model, different proxies from the DEEP site sediment record support an increase of temperatures between glacial to interglacial conditions, which is almost synchronous with a rapid increase in sea surface temperature observed in the western Mediterranean. The results show how important a detailed study of independent chronological tie points is for synchronizing different records and to highlight asynchronisms of climate events.

  15. Mis-regulation of Mammalian Target of Rapamycin (mTOR) Complexes Induced by Albuminuria in Proximal Tubules*

    PubMed Central

    Peruchetti, Diogo B.; Cheng, Jie; Caruso-Neves, Celso; Guggino, William B.

    2014-01-01

    High albumin concentrations in the proximal tubule of the kidney causes tubulointerstitial injury, but how this process occurs is not completely known. To address the signal transduction pathways mis-regulated in renal injury, we studied the modulation of mammalian target of rapamycin (mTOR) complexes by physiologic and pathophysiologic albumin concentrations in proximal tubule cells. Physiologic albumin concentrations activated the PI3K/mTORC2/PKB/mTORC1/S6 kinase (S6K) pathway, but pathophysiologically high albumin concentrations overactivated mTORC1 and inhibited mTORC2 activity. This control process involved the activation of ERK1/2, which promoted the inhibition of TSC2 and activation of S6K. Furthermore, S6K was crucial to promoting the over activation of mTORC1 and inhibition of mTORC2. Megalin expression at the luminal membrane is reduced by high concentrations of albumin. In addition, knockdown of megalin mimicked all the effects of pathophysiologic albumin concentrations, which disrupt normal signal transduction pathways and lead to an overactivation of mTORC1 and inhibition of mTORC2. These data provide new perspectives for understanding the molecular mechanisms behind the effects of albumin on the progression of renal disease. PMID:24790108

  16. Multiproxy record of the last interglacial (MIS 5e) off central and northern California, U.S.A., from Ocean Drilling Program sites 1018 and 1020

    USGS Publications Warehouse

    Poore, Richard Z.; Dowsett, H.J.; Barron, J.A.; Heusser, L.; Ravelo, A.C.; Mix, A.

    2000-01-01

    Environmental and climatic conditions during the last interglacial (about 125,000 years ago) along the Central and Northern California coastal region are interpreted from study of marine cores recovered by the Ocean Drilling Program at sites 1018 and 1020. Marine microfossil and pollen assemblages, oxygen isotopes in benthic foraminifers, physical properties, and calcium carbonate contents of cored sediments are proxies indicating strong links between the marine and terrestrial environments during marine isotope stage 5 (MIS 5). At the beginning of the last interglacial (MIS 5e), reduction in global ice volume, increase in surface temperature, and warming of air temperature along the Central and Northern California coast were synchronous within the resolution of our sampling record.

  17. Techno-Cultural Characterization of the MIS 5 (c. 105 – 90 Ka) Lithic Industries at Blombos Cave, Southern Cape, South Africa

    PubMed Central

    Douze, Katja; Wurz, Sarah; Henshilwood, Christopher Stuart

    2015-01-01

    Blombos Cave is well known as an important site for understanding the evolution of symbolically mediated behaviours among Homo sapiens during the Middle Stone Age, and during the Still Bay in particular. The lower part of the archaeological sequence (M3 phase) contains 12 layers dating to MIS 5 with ages ranging from 105 to 90 ka ago (MIS 5c to 5b) that provide new perspectives on the technological behaviour of these early humans. The new data obtained from our extensive technological analysis of the lithic material enriches our currently limited knowledge of this time period in the Cape region. By comparing our results with previously described lithic assemblages from sites south of the Orange River, we draw new insights on the extent of the techno-cultural ties between these sites and the M3 phase at Blombos Cave and highlight the importance of this phase within the Middle Stone Age cultural stratigraphy. PMID:26580219

  18. Techno-Cultural Characterization of the MIS 5 (c. 105 - 90 Ka) Lithic Industries at Blombos Cave, Southern Cape, South Africa.

    PubMed

    Douze, Katja; Wurz, Sarah; Henshilwood, Christopher Stuart

    2015-01-01

    Blombos Cave is well known as an important site for understanding the evolution of symbolically mediated behaviours among Homo sapiens during the Middle Stone Age, and during the Still Bay in particular. The lower part of the archaeological sequence (M3 phase) contains 12 layers dating to MIS 5 with ages ranging from 105 to 90 ka ago (MIS 5c to 5b) that provide new perspectives on the technological behaviour of these early humans. The new data obtained from our extensive technological analysis of the lithic material enriches our currently limited knowledge of this time period in the Cape region. By comparing our results with previously described lithic assemblages from sites south of the Orange River, we draw new insights on the extent of the techno-cultural ties between these sites and the M3 phase at Blombos Cave and highlight the importance of this phase within the Middle Stone Age cultural stratigraphy. PMID:26580219

  19. Expression of the Plasmodium falciparum Immunodominant Epitope (NANP)4 on the Surface of Salmonella enterica Using the Autotransporter MisL

    PubMed Central

    Ruiz-Pérez, Fernando; León-Kempis, Rocío; Santiago-Machuca, Araceli; Ortega-Pierres, Guadalupe; Barry, Eileen; Levine, Myron; González-Bonilla, César

    2002-01-01

    Gram-negative bacterial proteins which are exported from the cytosol to the external environment by the type V secretion system are also known as autotransporters. Once translocated to the periplasmic compartment by the sec-dependent general secretory pathway, their C-terminal domain forms a pore through which the N-terminal domain travels to the outer membrane without the need of other accessory proteins. MisL (protein of membrane insertion and secretion) is a protein of unknown function located in the pathogenicity island SPI-3 of Salmonella enterica and classified as an autotransporter due to its high homology to Escherichia coli AIDA-I. In the present work, the MisL C-terminal translocator domain was used to display the immunodominant B-cell epitope of the circumsporozoite protein (CSP) from Plasmodium falciparum on the surface of Salmonella enterica serovar Typhimurium (serovar Typhimurium SL3261) and serovar Typhi (serovar Typhi CVD 908). The MisL β domain was predicted by alignment with AIDA-I, amplified from serovar Typhimurium SL3261, cloned in a plasmid fused to four repeats of the tetrapeptide NANP behind the Escherichia coli heat-labile enterotoxin B subunit signal peptide to ensure periplasmic traffic, and expressed under the control of the anaerobically inducible nirB promoter. The fusion protein was translocated to the outer membrane of both bacterial strains, although the foreign epitope was displayed more efficiently in serovar Typhimurium SL3261, which elicited a better specific antibody response in BALB/c mice. More importantly, antibodies were able to recognize the native CSP in P. falciparum sporozoites. These results confirm that MisL is indeed an autotransporter and that it can be used to express foreign immunogenic epitopes on the surface of gram-negative bacteria. PMID:12065502

  20. The sea-level highstand correlated to marine isotope stage (MIS) 7 in the coastal plain of the state of Rio Grande do Sul, Brazil.

    PubMed

    Lopes, Renato P; Dillenburg, Sergio R; Schultz, Cesar L; Ferigolo, Jorge; Ribeiro, Ana Maria; Pereira, Jamil C; Holanda, Elizete C; Pitana, Vanessa G; Kerber, Leonardo

    2014-12-01

    The coastal plain of the state of Rio Grande do Sul, in southern Brazil, includes four barrier-lagoon depositional systems formed by successive Quaternary sea-level highstands that were correlated to marine isotope stages (MIS) 11, 9, 5 and 1, despite the scarcity of absolute ages. This study describes a sea-level highstand older than MIS 5, based on the stratigraphy, ages and fossils of the shallow marine facies found in coastal barrier (Barrier II). This facies outcrops along the banks of Chuí Creek, it is composed of fine, well-sorted quartz sand and contains ichnofossils Ophiomorpha nodosa and Rosselia sp., and molluscan shells. The sedimentary record indicates coastal aggradation followed by sea-level fall and progradation of the coastline. Thermoluminescence (TL) and electron spin resonance (ESR) ages from sediments and fossil shells point to an age of ∼220 ka for the end of this marine transgression, thus correlating it to MIS 7 (substage 7e). Altimetric data point to a maximum amplitude of about 10 meters above present-day mean sea-level, but tectonic processes may be involved. Paleoceanographic conditions at the time of the highstand and correlations with other deposits in the Brazilian coasts are also discussed. PMID:25493694

  1. Dansgaard-Oeschger forcing of sea surface temperature variability in the midlatitude North Atlantic between 500 and 400 ka (MIS 12)

    NASA Astrophysics Data System (ADS)

    Naafs, B. D. A.; Hefter, J.; Stein, R.

    2014-11-01

    Using a high-resolution record of alkenone-based sea surface temperatures (SSTs) from the midlatitude North Atlantic covering the period between 500 and 400 ka here we show that during Marine Isotope Stage (MIS) 12, SSTs in this region were characterized by numerous abrupt jumps in the order of 3-6°C, spaced every 3-4 ka. We argue that these abrupt warming events in the midlatitude North Atlantic reflect Dansgaard-Oeschger (D/O) events, which are corroborated by the correlation to the synthetic record of Greenland climate for this time period. These results demonstrate that during MIS 12 the direct influence of high-latitude climate was far larger than during the last glacial and reached all the way into the midlatitude North Atlantic. In addition the consistent temporal lag between surface water cooling and appearance of ice-rafted debris demonstrates that icebergs were not the cause for cooling in the North Atlantic at this time. We hypothesize that the extreme impact of D/O events during MIS 12 as recorded in our record must have had an imprint on global climate and will therefore be important to evaluate future high-resolution climate records or model efforts that cover this time period.

  2. A high-elevation, multi-proxy biotic and environmental record of MIS 6-4 from the Ziegler Reservoir fossil site, Snowmass Village, Colorado, USA

    USGS Publications Warehouse

    Miller, Ian M.; Pigati, Jeffrey S.; Anderson, R. Scott; Johnson, Kirk R.; Mahan, Shannon; Ager, Thomas A.; Baker, Richard G.; Blaauw, Maarten; Bright, Jordon; Brown, Peter M.; Bryant, Bruce; Calamari, Zachary T.; Carrara, Paul E.; Michael D., Cherney; Demboski, John R.; Elias, Scott A.; Fisher, Daniel C.; Gray, Harrison J.; Haskett, Danielle R.; Honke, Jeffrey S.; Jackson, Stephen T.; Jiménez-Moreno, Gonzalo; Kline, Douglas; Leonard, Eric M.; Lifton, Nathaniel A.; Lucking, Carol; McDonald, H. Gregory; Miller, Dane M.; Muhs, Daniel R.; Nash, Stephen E.; Newton, Cody; Paces, James B.; Petrie, Lesley; Plummer, Mitchell A.; Porinchu, David F.; Rountrey, Adam N.; Scott, Eric; Sertich, Joseph J. W.; Sharpe, Saxon E.; Skipp, Gary L.; Strickland, Laura E.; Stucky, Richard K.; Thompson, Robert S.; Wilson, Jim

    2014-01-01

    In North America, terrestrial records of biodiversity and climate change that span Marine Oxygen Isotope Stage (MIS) 5 are rare. Where found, they provide insight into how the coupling of the ocean–atmosphere system is manifested in biotic and environmental records and how the biosphere responds to climate change. In 2010–2011, construction at Ziegler Reservoir near Snowmass Village, Colorado (USA) revealed a nearly continuous, lacustrine/wetland sedimentary sequence that preserved evidence of past plant communities between ~ 140 and 55 ka, including all of MIS 5. At an elevation of 2705 m, the Ziegler Reservoir fossil site also contained thousands of well-preserved bones of late Pleistocene megafauna, including mastodons, mammoths, ground sloths, horses, camels, deer, bison, black bear, coyotes, and bighorn sheep. In addition, the site contained more than 26,000 bones from at least 30 species of small animals including salamanders, otters, muskrats, minks, rabbits, beavers, frogs, lizards, snakes, fish, and birds. The combination of macro- and micro-vertebrates, invertebrates, terrestrial and aquatic plant macrofossils, a detailed pollen record, and a robust, directly dated stratigraphic framework shows that high-elevation ecosystems in the Rocky Mountains of Colorado are climatically sensitive and varied dramatically throughout MIS 5.

  3. Human choices and environmental constraints: deciphering the variability of large game procurement from Mousterian to Aurignacian times (MIS 5-3) in southwestern France

    NASA Astrophysics Data System (ADS)

    Discamps, Emmanuel; Jaubert, Jacques; Bachellerie, François

    2011-09-01

    The evolution in the selection of prey made by past humans, especially the Neandertals and the first anatomically modern humans, has been widely debated. Between Marine Isotope Stages (MIS) 5 and 3, the accuracy of absolute dating is still insufficient to precisely correlate paleoclimatic and archaeological data. It is often difficult, therefore, to estimate to what extent changes in species procurement are correlated with either climate fluctuations or deliberate cultural choices in terms of subsistence behavior. Here, the full development of archeostratigraphy and Bayesian statistical analysis of absolute dates allows the archeological and paleoclimatic chronologies to be compared. The variability in hunted fauna is investigated using multivariate statistical analysis of quantitative faunal lists of 148 assemblages from 39 archeological sequences from MIS 5 through MIS 3. Despite significant intra-technocomplex variability, it is possible to identify major shifts in the human diet during these stages. The integration of archeological data, paleoclimatic proxies and the ecological characteristics of the different species of prey shows that the shifts in large game hunting can be explained by an adaptation of the human groups to climatic fluctuations. However, even if Middle and Early Upper Paleolithic men adapted to changes in their environment and to contrasting landscapes, they ultimately belonged to the ecosystems of the past and were limited by environmental constraints.

  4. A high-elevation, multi-proxy biotic and environmental record of MIS 6–4 from the Ziegler Reservoir fossil site, Snowmass Village, Colorado, USA

    SciTech Connect

    Ian M. Miller; Mitchell A. Plummer; Various Others

    2014-10-01

    In North America, terrestrial records of biodiversity and climate change that span Marine Oxygen Isotope Stage (MIS) 5 are rare. Where found, they provide insight into how the coupling of the ocean–atmosphere system is manifested in biotic and environmental records and how the biosphere responds to climate change. In 2010–2011, construction at Ziegler Reservoir near Snowmass Village, Colorado (USA) revealed a nearly continuous, lacustrine/wetland sedimentary sequence that preserved evidence of past plant communities between ~140 and 55 ka, including all of MIS 5. At an elevation of 2705 m, the Ziegler Reservoir fossil site also contained thousands of well-preserved bones of late Pleistocene megafauna, including mastodons, mammoths, ground sloths, horses, camels, deer, bison, black bear, coyotes, and bighorn sheep. In addition, the site contained more than 26,000 bones from at least 30 species of small animals including salamanders, otters, muskrats, minks, rabbits, beavers, frogs, lizards, snakes, fish, and birds. The combination of macro- and micro-vertebrates, invertebrates, terrestrial and aquatic plant macrofossils, a detailed pollen record, and a robust, directly dated stratigraphic framework shows that high-elevation ecosystems in the Rocky Mountains of Colorado are climatically sensitive and varied dramatically throughout MIS 5

  5. Spatial Asian Monsoon variability at MIS 6.2 inferred from oxygen isotope records of stalagmites from Yangkou Cave, Chongqing, China

    NASA Astrophysics Data System (ADS)

    Huang, L.; Li, T.; Yang, X.; Shen, C.

    2011-12-01

    Using the oxygen isotope records of stalagmites collected from different caves in China, Asian Monsoon (AM) variation over past 380 ka has been reconstructed (e.g. Wang et al., 2001, Science, 294, 2345-2348; Yuan et al., 2004, Science, 304, 575-578; Wang et al., 2008, Nature, 451, 1090-1093; Cheng et al., 2009, Science, 326, 248-252; Zhao et al., 2010, EPSL, 298, 191-198). Chinese cave δ18O records show that summer AM intensity primarily follows Northern Hemisphere summer insolation on orbital timescales. However, an unusual stalagmite δ18O-inferred weakest summer AM at the marine isotope stage (MIS) 6.2 (129-136 ka) is recorded in Sanbao Cave (Hubei province; 31°40'N, 110°26'E) (Wang et al., 2008, Nature, 451, 1090-1093). To clarify that this weakest summer AM during the penultimate deglaciation in Hubei province is site-specific or dominant in the entire mainland, we have collected stalagmite samples with deposition time intervals of interest from Yangkou Cave (Chongqing city; 29°2'N, 107°11'E) located about 400 km southwest to Sanbao Cave. Using MC-ICP-MS techniques on these stalagmites with high uranium levels of 1-20 ppm, we can refine the durations and intensities of the summer AM events during the entire MIS 6 and also further understand the spatial variability and possible mechanism for the weakest summer AM at the MIS 6.2.

  6. The sea-level highstand correlated to marine isotope stage (MIS) 7 in the coastal plain of the state of Rio Grande do Sul, Brazil.

    PubMed

    Lopes, Renato P; Dillenburg, Sergio R; Schultz, Cesar L; Ferigolo, Jorge; Ribeiro, Ana Maria; Pereira, Jamil C; Holanda, Elizete C; Pitana, Vanessa G; Kerber, Leonardo

    2014-12-01

    The coastal plain of the state of Rio Grande do Sul, in southern Brazil, includes four barrier-lagoon depositional systems formed by successive Quaternary sea-level highstands that were correlated to marine isotope stages (MIS) 11, 9, 5 and 1, despite the scarcity of absolute ages. This study describes a sea-level highstand older than MIS 5, based on the stratigraphy, ages and fossils of the shallow marine facies found in coastal barrier (Barrier II). This facies outcrops along the banks of Chuí Creek, it is composed of fine, well-sorted quartz sand and contains ichnofossils Ophiomorpha nodosa and Rosselia sp., and molluscan shells. The sedimentary record indicates coastal aggradation followed by sea-level fall and progradation of the coastline. Thermoluminescence (TL) and electron spin resonance (ESR) ages from sediments and fossil shells point to an age of ∼220 ka for the end of this marine transgression, thus correlating it to MIS 7 (substage 7e). Altimetric data point to a maximum amplitude of about 10 meters above present-day mean sea-level, but tectonic processes may be involved. Paleoceanographic conditions at the time of the highstand and correlations with other deposits in the Brazilian coasts are also discussed. PMID:25590701

  7. Palaeoecology of well-preserved coral communities in a siliciclastic environment from the Late Pleistocene (MIS 7), Kish Island, Persian Gulf (Iran): the development of low-relief reef frameworks (biostromes) in increasingly restricted environments

    NASA Astrophysics Data System (ADS)

    Mossadegh, Zahra Karimi; Parker, Justin; Gischler, Eberhard; Oschmann, Wolfgang; Blakeway, David; Eisenhauer, Anton

    2013-03-01

    Major changes in community structure and depositional relief of high-latitude coral communities in the southern Persian Gulf between marine isotope stage (MIS) 7 and the present day suggest that the area has become increasingly restricted. Corals and bivalves from outcrops on Kish Island, Iran, were identified in order to interpret the Late Pleistocene palaeoenvironmental setting. U/Th disequilibrium dating was used to constrain the ages of the stratigraphic units. During MIS 7, two coral-bearing sequences were deposited on what is now Kish Island. The lower sequence is dated as MIS 7.5 and changes laterally from an assemblage dominated by Cyphastrea sp. and Platygyra daedalea in the west to one characterized by branching Montipora in the east. By contrast, the upper sequence, dated as MIS 7.1, transitions from an assemblage dominated by platy Montipora in the west to a diverse assemblage of Platygyra and other faviids in the east. The assemblages of both sequences are within a marl matrix and bounded by thin lithified mollusc-rich layers. Corals and bivalves indicate that the sequences were deposited on gentle slopes in sheltered environments less than 20 m deep. The MIS 7 deposits may be classified as coral carpets or biostromes that developed a low-relief framework. During MIS 5, coral communities were no longer framework building and are now limited to an Acropora-rich layer of coral rubble that covers large parts of the island, and two small incipient reefs with sparse faviids. Similarities between the MIS 5 and modern nearshore coral communities suggest that the environmental conditions during MIS 5 were comparable to those of today. The late Pleistocene coral carpets and non-framework coral communities of the southern Persian Gulf may serve as models for coral biostromes in the fossil record, which formed under restricted environmental conditions such as elevated terrigenous input, high turbidity, and strong seasonal changes in temperature and/or salinity.

  8. A coccolithophore based view on paleoenvironmental changes in the open ocean mid-latitude North Atlantic between 130 and 48 ka BP with special emphasis on MIS 5e

    NASA Astrophysics Data System (ADS)

    Schwab, C.; Kinkel, H.; Weinelt, M.; Repschläger, J.

    2013-12-01

    As oceanographic changes in the North Atlantic are known to modulate global climate, they are key to the understanding of past and future climate changes. Especially the mid-latitudes of the open ocean North Atlantic may be of interest, regarding the large area covered. We therefore reconstructed past changes in productivity and hydrography from a new sediment core (MD08-3179Cq) taken in the open ocean mid-latitude North Atlantic in the vicinity of the Azores Current System. Concomitant to the reorganizations of environmental conditions in the North Atlantic between 130 and 48 ka BP, changes in coccolithophore assemblages and changes in the abundance of siliceous plankton (diatoms) indicate a southward shift of the Azores Front (AzF), and hence a southward retreat of the North Atlantic subtropical gyre, as well as an increased productivity, during glacial Marine Isotope Stage (MIS) 4, Termination II and during cold substages of MIS 5. Furthermore we hypothesize that the ecological changes led to distinct evolutionary patterns of coccolithophores, resulting e.g. in a dominance of Gephyrocapsaornata between 76 and 105 ka BP. Additionally, high-resolution analysis of MIS 5e indicate a short reversal towards cool conditions during MIS 5e, corresponding to a basin-wide cooling event. Full interglacial conditions are reached only late in the Azores region. During MIS 5e an increased advection of Subantarctic Mode Water (SAMW), and/or the possibility to occupy new habitats after glacial conditions, result in a distinct coccolithophore productivity peak. As global temperature during MIS 5e are assumed to be similar to the expected future global climate change, MIS 5e serves as a possible scenario for future changes. Taking MIS 5e as a possible analogue for expected future climate change, our results indicate that an expected decrease in marine primary productivity, due to the expansion of the oligotrophic gyres, may be attenuated by increased coccolithophore productivity.

  9. Millennial-Scale Climate Variability During a mid-Pleistocene Glacial (MIS 12) from a Terrestrial Lacustrine Record in the Valles Caldera, New Mexico

    NASA Astrophysics Data System (ADS)

    Fawcett, P. J.; Brown, E. T.; Werne, J. P.; Contreras, S.; Anderson, R. S.; Dodd, J. P.; Sharp, Z. D.; Heikoop, J. M.; Allen, C. D.

    2011-12-01

    We present a high-resolution terrestrial climate record from the Valles Caldera, New Mexico which spans some 200,000 years from mid MIS 14 to early MIS 10. The glacial periods represented in the record exhibit millennial-scale Dansgaard-Oeschger like variability, especially in MIS 12, one of the coldest glacials in the Pleistocene. High resolution proxies from core VC-3 including scanning XRF data, sediment density, color, and magnetic susceptibility show approximately 23 millennial-scale oscillations in MIS 12 with an average duration of 2,300 years. Many of these oscillations are characterized by relatively slow coolings followed by abrupt warmings, similar to D-O events in the Greenland ice core record. MBT/CBT MAT estimates in the MIS 12 portion of the core show stadial to interstadial warmings of up to 6 °C. The VC-3 stadials correlate with high percentages of boreal taxa pollen ( Picea, Abies ) (up to 25%) while interstadials have lower boreal pollen percentages (~5%) and many correlate with local maxima in Juniperus> and Quercus> . Significant changes in the hydrologic cycle also occur at these millennial timescales. Oxygen isotope data from diatom silica record changes of up to 10 per mil from stadial to interstadial, probably reflecting a combination of changes in moisture source (Pacific vs. Gulf of Mexico), moisture transport pathway, and the seasonality of precipitation. Several interstadials correlate with increases in Cyperaceae (sedge) pollen suggesting a shallower lake with a broad marshy zone around its margin. This zone was minimized during stadials when the lake was deeper. Interstadial shallowing probably resulted from higher evaporation rates and/or a reduction in winter precipitation. This combination of proxies from the Valles Caldera suggests that glacial stage millennial-scale climate variability in the American southwest was strongly driven by changes in the strength and location of the winter polar jet, which in turn affected the local

  10. A new age within MIS 7 for the Homo neanderthalensis of Saccopastore in the glacio-eustatically forced sedimentary successions of the Aniene River Valley, Rome

    NASA Astrophysics Data System (ADS)

    Marra, Fabrizio; Ceruleo, Piero; Jicha, Brian; Pandolfi, Luca; Petronio, Carmelo; Salari, Leonardo

    2015-12-01

    Field observations as well as borehole, sedimentological and geochronologic data allow us to reconstruct the geologic setting of the Aniene River Valley in northern Rome, framing it within the recently recognized picture of temporally constrained, glacio-eustatically forced aggradational successions of this region. The sedimentary successions cropping out in this area include those described in the literature of the early 20th century in Saccopastore, where two skulls of Homo neanderthalensis were recovered. Based on the geometry, elevation and sedimentologic features of the investigated sedimentary deposits, the stratigraphic record of Saccopastore is correlated with the aggradational succession deposited in response to sea-level rise during glacial termination III at the onset of MIS 7 (i.e. ˜250 ka), corresponding to the local Vitinia Formation, as opposed to previous correlation with the MIS 5 interglacial and a locally defined "Tyrrhenian" stage (˜130 ka). This previous attribution was based on the interpretation of the sedimentary succession of Saccopastore, occurring between 15 and 21 m a.s.l., as a fluvial terrace formed around 130 ka during the Riss-Würm interglacial, ca. 6 m above the present-day alluvial plain of the Aniene River. In contrast to this interpretation, a 40Ar/39Ar age of 129 ± 2 ka determined for this study on a pyroclastic-flow deposit intercalated in a fluvial-lacustrine sequence forming a terrace ˜37 m a.s.l. near the coast of Rome constrains the aggradational succession in this area to MIS 5, precluding the occurrence of an equivalent fluvial terrace at lower elevation in the inland sector of Saccopastore. We therefore interpret the stratigraphic record of Saccopastore as the basal portion of the aggradational succession deposited in response to sea-level rise during MIS 7, whose equivalent fluvial terrace occurs around 55 m a.s.l. in this region. We also review the published paleontological and paleoethnological records recovered

  11. Mass accumulation rate changes in Chinese loess during MIS 2, and asynchrony with records from Greenland ice cores and North Pacific Ocean sediments during the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Kang, Shugang; Roberts, Helen M.; Wang, Xulong; An, Zhisheng; Wang, Min

    2015-12-01

    Sensitivity-corrected quartz optically stimulated luminescence (OSL) dating methods have been widely accepted as a promising tool for the construction of late Pleistocene chronology and mass or dust accumulation rates (MARs or DARs) on the Chinese Loess Plateau (CLP). Many quartz OSL ages covering marine isotope stage (MIS) 2 (equal to L1-1 in Chinese loess) have been determined for individual sites within the CLP in the past decade. However, there is still a lack of detailed MAR or DAR reconstruction during MIS 2 across the whole of the CLP. Here, we present detailed MARs determined for eight sites with closely-spaced quartz OSL ages covering ∼MIS 2, and relative MARs suggested by a probability density analysis of 159 quartz OSL ages ranging from ∼30 to 10 ka ago, from 15 sites on the CLP. The results show enhanced dust accumulation during the Last Glacial Maximum (LGM), with particularly rapid dust accumulation from ∼23 to 19 ka ago (the late LGM). In contrast, MARs determined for the last deglaciation (from ∼19 to 12 ka ago) are low. The MAR changes during MIS 2 in Chinese loess are mainly controlled by the East Asian winter monsoon (EAWM) intensity, which is forced by Northern Hemisphere ice volume. The MAR changes also indicate that dust accumulation during MIS 2 is generally continuous at millennial time scales on the CLP. Comparison of Asian-sourced aeolian dust MARs in Chinese loess with those preserved in Greenland ice cores and North Pacific Ocean sediments indicates that rapid dust accumulation occurred from ∼26 to 23 ka ago (the early LGM) in Greenland ice cores and North Pacific Ocean sediments, suggesting a several kilo-year difference in timing when compared with the rapid dust accumulation during the late LGM in Chinese loess. This asynchronous timing in enhanced dust accumulation is probably related to both changes in the EAWM intensity and changes in the mean position of zone axis of the Westerly jet, both of which are greatly influenced

  12. Millennial scale change in climate and iceberg calving on the Svalbard margin during MIS 2 and 3

    NASA Astrophysics Data System (ADS)

    Jessen, S. P.; Rasmussen, T. L.

    2009-04-01

    We present results on the millennial scale Dansgaard-Oescger events from the high Arctic (>76N), and the response of the Svalbard-Barents Sea Ice Sheet to rapid climate change. The study is based on the distribution of planktic δ18O values, magnetic susceptibility and the concentration and composition of ice rafted debris (IRD) in two different size fractions in two marine sediment cores from the west Svalbard margin at 1130 and 1880 meter water depth. Both cores cover the Marine Isotope Stages (MIS) 2 and 3 in high resolution. The magnetic susceptibility and the oxygen isotope records can be correlated in great detail to previously published records from the southern Norwegian Sea and northern North Atlantic and show a similar pattern of variation with high values during the warm interstadial periods and low values during cold stadial phases. In both cores we find higher IRD concentrations and fluxes during the warm interstadial phases than during the cold stadial phases. The composition of IRD also changes with the millennial scale shifts. In the interstadial phases, the IRD consists of characteristic dark coloured, metamorphic and sedimentary rocks (schists, slates, shales and sandstones) derived from local sources from Svalbard and the Barents Sea. In the stadial phases the IRD is composed predominantly of quartz derived from sources elsewhere. Our results demonstrate that outlet glaciers from the Svalbard-Barents Sea Ice Sheet responded to the interstadial-stadial climatic fluctuations, with highest calving rates during climatic warmth. This is in anti-phase with ice sheets from lower latitudes, i.e. the Icelandic, Scandinavian, and British ice sheets, which have all been reported to calve within the cold stadial phase. The response of the high Arctic ice sheet indicates that ocean and atmospheric heat was the trigger for the iceberg release.

  13. Detection of aeromagnetic anomaly change associated with volcanic activity: An application of the generalized mis-tie control method

    NASA Astrophysics Data System (ADS)

    Nakatsuka, Tadashi; Utsugi, Mitsuru; Okuma, Shigeo; Tanaka, Yoshikazu; Hashimoto, Takeshi

    2009-12-01

    Repeat aeromagnetic surveys may assist in mapping and monitoring long-term changes associated with volcanic activity. However, when dealing with repeat aeromagnetic survey data, the problem of how to extract the real change of magnetic anomalies from a limited set of observations arises, i.e. the problem of spatial aliasing. Recent development of the generalized mis-tie control method for aeromagnetic surveys flown at variable elevations enables us to statistically extract the errors from ambiguous noise sources. This technique can be applied to overcome the spatial alias effect when detecting magnetic anomaly changes between aeromagnetic surveys flown at different times. We successfully apply this technique to Asama Volcano, one of the active volcanoes in Japan, which erupted in 2004. Following the volcanic activity in 2005, we conducted a helicopter-borne aeromagnetic survey, which we compare here to the result from a previous survey flown in 1992. To discuss small changes in magnetic anomalies induced by volcanic activity, it is essential to estimate the accuracy of the reference and the repeat aeromagnetic measurements and the probable errors induced by data processing. In our case, the positioning inaccuracy of the 1992 reference survey was the most serious factor affecting the estimation of the magnetic anomaly change because GPS was still in an early stage at that time. However, our analysis revealed that the magnetic anomaly change over the Asama Volcano area from 1992 to 2005 exceeded the estimated error at three locations, one of which is interpreted as a loss of magnetization induced by volcanic activity. In this study, we suffered from the problem of positioning inaccuracy in the 1992 survey data, and it was important to evaluate its effect when deriving the magnetic anomaly change.

  14. Late Quaternary landscape development at the margin of the Pomeranian phase (MIS 2) near Lake Wygonin (Northern Poland)

    NASA Astrophysics Data System (ADS)

    Hirsch, Florian; Schneider, Anna; Nicolay, Alexander; Błaszkiewicz, Mirosław; Kordowski, Jarosław; Noryskiewicz, Agnieszka M.; Tyszkowski, Sebastian; Raab, Alexandra; Raab, Thomas

    2015-04-01

    , Florian Hirsch, Anna Schneider, Alexander Nicolay, Mirosław Błaszkiewicz, Jarosław Kordowski, Agnieszka M. Noryskiewicz, Sebastian Tyszkowski, Alexandra Raab, Thomas Raab, Late Quaternary landscape development at the margin of the Pomeranian phase (MIS 2) near Lake Wygonin (Northern Poland), Pages 28-44, 2015, with permission from Elsevier.

  15. Ice sheet dynamics on the Lofoten-Vesterålen shelf, north Norway, from Late MIS-3 to Heinrich Stadial 1

    NASA Astrophysics Data System (ADS)

    Brendryen, Jo; Haflidason, Haflidi; Rise, Leif; Chand, Shyam; Vanneste, Maarten; Longva, Oddvar; L'Heureux, Jean Sébastien; Forsberg, Carl Fredrik

    2015-07-01

    We present an account of the glacial dynamics from late Marine Isotope Stage (MIS) 3 to the Heinrich Stadial (HS) 1 on the Lofoten-Vesterålen margin, Northern Norway. This account is based on an analysis of the sedimentary stratigraphy on the upper slope close to the ice sheet grounding line at the continental shelf edge, and an analysis of the glacial morphology on the shelf areas. Our results point to a dynamic ice sheet that waxed and waned on the Lofoten-Vesterålen continental shelf from the late MIS-3, through the Last Glacial Maximum (LGM) and the HS 1. Glacigenic debris flows and deposition of laminated diamicts suggest that the ice sheet reached the shelf edge on several occasions. These are dated to ˜25.5 ka BP (HS3), between 21.1 and 21.7 ka BP, ˜19.5 ka BP, 15.6 ka BP and 14.4 ka BP (uncorrected 14C ages). A contouritic sorted sand sediment unit that formed in a relatively warm interval during Late MIS-3 suggests that a strong Norwegian Atlantic Slope Current also developed during glacial interstadials implying that the oceanic circulation in the eastern Norwegian Sea was similar as today. The general pattern is that the ice sheet advanced onto the shelf during cold period with little influx of Atlantic Water to the Norwegian Sea and that it retreated toward the coast during intervals with higher temperatures and higher influx of warm Atlantic Water. The last ice advance to the edge of the continental shelf occurred during HS 1.

  16. Investigation into MIS 11 in the U.S. Great Basin Using Trace Elements and Stable Isotopes from two Lehman Caves Stalagmites

    NASA Astrophysics Data System (ADS)

    Neary, A.; McGee, D.; Tal, I.; Shakun, J. D.

    2015-12-01

    Marine Isotope Stage 11 (MIS 11) represents a long interglacial period of high temperatures and muted orbital variability that occurred around 424-374 kya, and is referred to as a 'super-interglacial'. MIS 11 is marked by especially pronounced high latitude warming in the Northern Hemisphere from 410-400 ka and thus presents a natural experiment for investigating the response of Great Basin precipitation to high latitude temperatures.MIS 11 is recorded by stalagmites LC3 and BT1 from Lehman Caves in Great Basin National Park, Nevada. LC3 represents 378-413 ka, while BT1 has a bottom age of 410 ka. Ongoing U-Th dating will refine chronologies from these samples. We will present stable isotope (δ13C and δ18O) and trace element (Mg/Ca and Sr/Ca) data from these stalagmites to study changes in precipitation recorded in them. Previous studies have shown a relationship between Mg/Ca, Sr/Ca, δ13C and prior calcite precipitation, and thus infiltration rates, in the cave system (Cross et al., 2015; Steponaitis et al., 2015). Meanwhile, δ18O has been shown to reflect larger scale atmospheric circulation.We will compare the records to previously published trace element and stable isotope data from more recent interglacials (Lachniet et al., 2014; Cross et al., 2015; Steponaitis et al., 2015) to test whether extensive high-latitude warming during MIS 11 was marked by anomalous precipitation patterns in the Great Basin. As they are coeval, we will also test the reproducibility between the stalagmites.References cited:Cross M., et al. (2015) Great Basin hydrology, paleoclimate, and connections with the North Atlantic: A speleothem stable isotope and trace element record from Lehman Caves, NV. Quaternary Science Reviews, in press.Steponaitis E., et al. (2015) Mid-Holocene drying the U.S. Great Basin recorded in Nevada speleothems. Quaternary Science Reviews, in press.Lachniet M. S., et al. (2014) Orbital control of western North America atmospheric circulation and climate

  17. MIS 5e sea level: up to what point can we use literature reviews to answer the most pressing questions on the Last Interglacial ice sheets?

    NASA Astrophysics Data System (ADS)

    Rovere, A.; Raymo, M. E.

    2014-12-01

    During MIS 5e (between ~128 and 116 kyr BP) greenhouse gas concentrations were comparable to pre-industrial levels, summer insolation was higher by ~10% at high latitudes and polar temperatures in both hemispheres were about 3-5 °C warmer than today. Sea level (SL) at this time has been a subject of numerous studies (and some debate) with ~1000 sites with MIS 5e sea level markers recognized worldwide. Recently, Kopp et al. (Nature, 2009) and Dutton & Lambeck (Science, 2012) analyzed worldwide datasets of sea level markers pertaining to the last interglacial. After accounting for GIA, they reached similar conclusions that eustatic (i.e., globally averaged) sea level (ESL) was between +5 and +9.4 m above modern during MIS 5e. Furthermore, Kopp et al. (Nature, 2009; GJI, 2013) suggest that sea level was not uniform during the LIG, but instead underwent at least two rapid oscillations including a rapid late 5e rise first proposed by Hearty et al. (QSR, 2007) and later by O'Leary et al. (Nat. Geo., 2013). Investigating the temporal and geographic variability of MIS 5e sea level opens new lines of research, in particular the possibility to fingerprint (Hay et al., QSR, 2014) the source of the proposed rapid ice sheet collapse near the end of the Last Interglacial. In this presentation we ask: can we use a database of published sea level estimates for this purpose? To answer this question, we built a relative sea level (RSL) database using RSLcalc 2.0; this is a relational database specifically designed to review relative sea level data points while keeping all the relevant information contained in the original publications. RSlcalc allows to estimate the measurement error (on the actual elevation of the SL feature), the error on the indicative range (the elevation range occupied by a sea level indicator) as well as the reference water level (the relationship between the marker and the former sea level). We show that the majority of published data have an accuracy of few

  18. Orbital and Millennial-scale Variability Reflected on Continental-scale Vegetation Changes in the Southern Subtropics between MIS 6 and 3

    NASA Astrophysics Data System (ADS)

    Urrego, D. H.; Sanchez Goni, M.; Daniau, A.; Martinez, P.

    2011-12-01

    While our understanding of the effects of orbital and millennial-scale variability on the vegetation has grown during the past decades, empirical data from some climatically important periods and regions are still lacking. Scarce data exist for instance for deep-time glacial-interglacial cycles that could provide suitable analogs for current climate-change. Recent global-scale reconstructions of vegetation responses to rapid events during the last glacial cycle have been useful, however, these global compilations clearly show that some regions, namely the southern tropics and subtropics, remain understudied. Here we present results from one of the few available continental-scale vegetation records from southwestern Africa spanning the last glacial-interglacial cycle. We have conducted multiproxy analyses of marine core MD96 2098 (25°36'S, 12°38'E), retrieved from the Lüderitz slope off the coast of Namibia. Preservation of pollen and other terrestrial microfossils is facilitated at this site by the Benguela upwelling system and the proximity to the Orange River mouth. Chronological control has been derived from radiocarbon dates and marine isotope stratigraphy. We have used pollen analyses, benthic foraminifer d18O (1), X-ray Fluorescence, geochemistry (2), foraminifer assemblages and microcharcoal quantification (3) to reconstruct the terrestrial vegetation and climatic history of the southwestern part of Africa and offshore between 190 and 30 ka. We find that MIS 6 and 4 are characterized by expanding Semidesert and Fynbos vegetation, while expanding grasslands characterized MIS 5. The termination of MIS 5 is also punctuated by an expansion of humid forests. At millennial timescales, variations in grasslands are generally coupled with stadials and interstadials. The expansion of semidesert is associated with decreased continental humidity caused by the strengthening of the Benguela upwelling during MIS 6 and 4. The expansion of grasslands during the

  19. Microstructural Character and Stable Isotope Signatures of Calcite Veins in the Mis and SMS Sedimentary Rock Cores, Victoria Land Basin, Antarctica

    NASA Astrophysics Data System (ADS)

    Millan, C.; Wilson, T. J.; Paulsen, T. S.

    2010-12-01

    The two drilling projects in the ANDRILL portfolio, the McMurdo Ice Shelf (MIS) project and the Southern McMurdo Sound (SMS) project, successfully recovered 1285 and 1138 m respectively of Neogene sedimentary core from the Victoria Land rift basin in Antarctica. The MIS core contains 1475 faults, veins, and clastic dikes, with veins making nearly half of this population. Of the 1050 natural fractures logged in the SMS core, just over half of them were characterized as veins. This study combines microscopic study of textures and crosscutting relationships between veins, cements, and microstructures to determine the evolution of fluid sources relative to the deformation history during rifting. Isotopic analysis of carbonate fracture fills has been completed in order to discriminate whether fluids precipitated from the glacial melt-waters or from some other hydrological regime. Opening-mode fibrous veins, pressure shadows on clast margins and small and diffuse, anastomosing vein swarms are common. Most veins are filled by calcite, although zeolite and late-stage pyrite are also common. Many calcite veins are associated with discrete faults and have conjugate geometries, dip-slip slickenfibers, and calcite filled voids along pull-aparts, indicating veins formed during fault displacement. In the MIS core, fibrous opening-mode are commonly wavy to tightly folded, indicating the host sediment was cohesive enough to fracture but was not fully lithified, and accommodated vein buckling during compaction. Veins commonly exhibit multiple generations of calcite fill and many are strongly twinned. Cathodoluminescence microscopy shows minor changes in color and intensity and minimal zoning of calcite vein fill, suggesting relatively rapid crystallization of fluids of similar chemistry. However, stable isotope analyses reveal large variations in values: in the MIS core, oxygen values range from -5.35 to -11.97 (VPDB) and carbon values range from -7.15 to -21.91 (VPDB); the SMS

  20. Effectiveness of MIS technique as a treatment modality for open intra-articular calcaneal fractures: A prospective evaluation with matched closed fractures treated by conventional technique.

    PubMed

    Dhillon, Mandeep Singh; Gahlot, Nitesh; Satyaprakash, Sambit; Kanojia, Rajendra Kumar

    2015-09-01

    Twenty-five displaced intra-articular calcaneal fractures in 21 patients, aged 15-55 years were included in this study. Sanders' type I fractures, severe crushing or partial amputation, were excluded from the study. Patients were divided into group 1 (open fractures treated by MIS), and group 2 (closed fractures treated by ORIF). Group 1 had 16 and group 2 had 9 cases. Seven of 25 fractures (28%) developed wound related issues postoperatively. One patient (11.1%) in group 2 had wound margin necrosis, while 6 patients (37.5%) in group 1 developed pin tract and/or wound infection. At 1-year follow-up, the mean MFS for group 1 was 79 and mean MFS for group 2 was 84.4 (66.67% were good). The AOFAS score for group 1 was 77.37 and for group 2 was 86.1. The Bohlers' angle was restored in 81.16% cases in group 1 and 88.8% in group 2, while Gissane angle was restored in 68.75% of group 1 cases and 77.79% of group 2 cases. This study shows that acceptable fracture reduction can be obtained and maintained by MIS technique and it can be used as the primary definitive treatment option in open calcaneal fractures. PMID:26209469

  1. Revised 14C dating of ice wedge growth in interior Alaska (USA) to MIS 2 reveals cold paleoclimate and carbon recycling in ancient permafrost terrain

    NASA Astrophysics Data System (ADS)

    Lachniet, Matthew S.; Lawson, Daniel E.; Sloat, Alison R.

    2012-09-01

    Establishing firm radiocarbon chronologies for Quaternary permafrost sequences remains a challenge because of the persistence of old carbon in younger deposits. To investigate carbon dynamics and establish ice wedge formation ages in Interior Alaska, we dated a late Pleistocene ice wedge, formerly assigned to Marine Isotope Stage (MIS) 3, and host sediments near Fairbanks, Alaska, with 24 radiocarbon analyses on wood, particulate organic carbon (POC), air-bubble CO2, and dissolved organic carbon (DOC). Our new CO2 and DOC ages are up to 11,170 yr younger than ice wedge POC ages, indicating that POC is detrital in origin. We conclude an ice wedge formation age between 28 and 22 cal ka BP during cold stadial conditions of MIS 2 and solar insolation minimum, possibly associated with Heinrich event 2 or the last glacial maximum. A DOC age for an ice lens in a thaw unconformity above the ice wedge returned a maximum age of 21,470 ± 200 cal yr BP. Our variable 14C data indicate recycling of older carbon in ancient permafrost terrain, resulting in radiocarbon ages significantly older than the period of ice-wedge activity. Release of ancient carbon with climatic warming will therefore affect the global 14C budget.

  2. Groove-type channel enhancement-mode AlGaN/GaN MIS HEMT with combined polar and nonpolar AlGaN/GaN heterostructures

    NASA Astrophysics Data System (ADS)

    Duan, Xiao-Ling; Zhang, Jin-Cheng; Xiao, Ming; Zhao, Yi; Ning, Jing; Hao, Yue

    2016-08-01

    A novel groove-type channel enhancement-mode AlGaN/GaN MIS high electron mobility transistor (GTCE-HEMT) with a combined polar and nonpolar AlGaN/GaN heterostucture is presented. The device simulation shows a threshold voltage of 1.24 V, peak transconductance of 182 mS/mm, and subthreshold slope of 85 mV/dec, which are obtained by adjusting the device parameters. Interestingly, it is possible to control the threshold voltage accurately without precisely controlling the etching depth in fabrication by adopting this structure. Besides, the breakdown voltage (V B) is significantly increased by 78% in comparison with the value of the conventional MIS-HEMT. Moreover, the fabrication process of the novel device is entirely compatible with that of the conventional depletion-mode (D-mode) polar AlGaN/GaN HEMT. It presents a promising way to realize the switch application and the E/D-mode logic circuits. Project supported by the National Science and Technology Major Project, China (Grant No. 2013ZX02308-002) and the National Natural Science Foundation of China (Grant Nos. 11435010, 61474086, and 61404099).

  3. Electrical behavior of MIS devices based on Si nanoclusters embedded in SiOxNy and SiO2 films

    PubMed Central

    2011-01-01

    We examined and compared the electrical properties of silica (SiO2) and silicon oxynitride (SiOxNy) layers embedding silicon nanoclusters (Sinc) integrated in metal-insulator-semiconductor (MIS) devices. The technique used for the deposition of such layers is the reactive magnetron sputtering of a pure SiO2 target under a mixture of hydrogen/argon plasma in which nitrogen is incorporated in the case of SiOxNy layer. Al/SiOxNy-Sinc/p-Si and Al/SiO2-Sinc/p-Si devices were fabricated and electrically characterized. Results showed a high rectification ratio (>104) for the SiOxNy-based device and a resistive behavior when nitrogen was not incorporating (SiO2-based device). For rectifier devices, the ideality factor depends on the SiOxNy layer thickness. The conduction mechanisms of both MIS diode structures were studied by analyzing thermal and bias dependences of the carriers transport in relation with the nitrogen content. PMID:21711698

  4. Marine-to-lacustrine transition, mud volcanism, and slope instability in an active tectonic setting: the MIS 5 to 4 transition in the Sea of Marmara, Turkey

    NASA Astrophysics Data System (ADS)

    Grall, Céline; Henry, Pierre; Kendé, Julia; Namık Çaǧatay, M.; Kadir Eriş, K.; Paillès, Christine; Sorlien, Christopher; Shillington, Donna; McHugh, Cecilia; Steckler, Michael; Çifçi, Günay; Géli, Louis

    2016-04-01

    MTDs. At the transition from Marine Isotope Stage (MIS) 5 to 4, sea-level fell from 25 to 85 m below the modern sea-level resulting in the disconnection of the Sea of Marmara. Sapropels deposited on the shelf before the disconnection and are attributed to MIS-5 (Cagatay et al. 2009). Grall et al, (2014) proposed that MTDs found above the Red-H1 were deposited at the beginning of MIS-4 at ~70 ka and that MTD complexes found during earlier glacial cycles also accumulated after marine to lacustrine-disconnections, possibly in relation with hydrate dissociation and/or clay swelling. Buried mud volcanoes located within the NNAF damage zone pierce the Red-H1 reflector but not the reflector above, suggesting that the last main eruption may also happens at the beginning of MIS-4. We will present preliminary assessment of the paleoenvironmental changes across the MIS-5 to 4 transition from bio-indicators and geochemistry.

  5. Effect of Pulse Nanosecond Volume Discharge in Air at Atmospheric Pressure on Electrical Properties of Mis Structures Based on p-HgCdTe Grown by Molecular Beam Epitaxy

    NASA Astrophysics Data System (ADS)

    Voitsekhovskii, A. V.; Nesmelov, S. N.; Dzyadukh, S. M.; Grigor'ev, D. V.; Tarasenko, V. F.; Shulepov, M. A.

    2015-11-01

    The effect of the pulse nanosecond volume discharge in air at atmospheric pressure on the admittance of MIS structures based on MBE graded-gap p-Hg0.78Cd0.22Te is studied in a wide range of frequencies and temperatures. It is shown that the impact of the discharge leads to significant changes in electrical characteristics of MIS structures (the density of positive fixed charge increases), to the changes in the nature of the hysteresis of capacitance-voltage characteristics, and to an increase in the density of surface states. A possible reason for the changes in the characteristics of MIS structures after exposure to the discharge is substantial restructuring of the defect-impurity system of the semiconductor near the interface.

  6. Last glacial pollen record from Lanzhou (Northwestern China) and possible forcing mechanisms for the MIS 3 climate change in Middle to East Asia

    NASA Astrophysics Data System (ADS)

    Jiang, Hanchao; Mao, Xue; Xu, Hongyan; Thompson, Jessica; Wang, Ping; Ma, Xiaolin

    2011-03-01

    The vegetation on the northeastern margin of the Tibetan Plateau is highly sensitive to climatic changes and thus represents a potentially interesting environmental archive. Pollen samples from the Fanjiaping Loess section in Lanzhou on the western Chinese Loess Plateau (CLP) were analyzed in conjunction with OSL dating. The results indicate that pollen zone B (60.6-46.0 ka, correlative to the early MIS 3) had the greatest abundances of Cupressaceae, Tsuga, Gramineae and Cyperaceae of the entire section, suggesting a warm phase during the last glacial period. These pollen taxa decreased significantly in abundance in the zones C (46.0-39.0 ka) and D (39.0-27.0 ka), reflecting a substantial climate cooling from the middle MIS 3 to MIS 2. These results correlate with climate records from the South China Sea, the CLP, Baikal Lake, North America, North Atlantic Ocean and other regions, and probably correspond with the decline of northern high-latitude insolation and the increase of global ice volume from 50 to 20 ka. In particular, arboreal pollen, fern spore and algae abundances declined sharply since ˜40 ka, while shrub and herb pollen reached the highest abundances. Conifer pollen Picea and Abies abundance also rose markedly and increased up the section. This implies significant climate deterioration and likely corresponded with substantial growth of the polar ice sheets since ˜40 ka. The decreasing temperature caused by an insolation decline during the last glacial period probably reinforced the cooling effect in a 'snow/ice/albedo' feedback, which would result in less climate sensitivity to radiative forcing. Meanwhile, vegetation decline in the Northern Hemisphere during the last glacial period and tundra development at high latitudes possibly caused additional cooling, enhancing the growth of polar ice sheets since 40 ka. The development of polar ice sheets increased the polar-to-equator temperature and pressure gradients, strengthening the westerlies and

  7. Geological "Ground Truth" of Sea-level Highstand Events During Warm Interglaciations (MIS 11 and 5e): Taking the Punch out of Proxy Precision

    NASA Astrophysics Data System (ADS)

    Hearty, P. J.

    2005-12-01

    High-resolution sea-level records for marine isotope stages (MIS) 11 and 5e from coastal outcrops in Bahamas, Bermuda, Hawaii, and Western Australia provide physical confirmation of extreme ice-melting events during Pleistocene interglacials. Field evidence indicates MIS 11 sea level rose in a series of oscillations to c. +20 m, while that of MIS 5e reached its maximum of +6-10 m. Because these were brief events (100s yrs), their true magnitude is generally muted or obscured in deep-sea oxygen isotope records; generally averaged over thousands of years by the combined effects of sampling, bioturbation, and sedimentation rates. Further unresolvable variables such as temperature and salinity further cloud the isotope proxy record. Thus, the tangible rock record is of greatest importance in understanding the nature of these extreme events. Geomorphology, sedimentary structures, taphonomy of and dating of organisms, and petrology provide ground truth at field sites. Sea-level highstands preserve terraces and benches by erosion and subsequent deposition of sub- and intertidal sediments. Fenestral porosity is a measure of intertidal wetting and drying of sand, while decimetre-scale, high-angle cross beds of poorly-sorted sand and gravel indicate shallow subtidal conditions. In situ coral heads describe similar subtidal conditions. Delicate, sometimes partially articulated skeletons of birds and reptiles in sea caves reveal a protected shoreline. An early generation of isopachous, fibrous cement verifies the presence of marine phreatic water over a sustained period of time. These features, often misinterpreted (McMurtry, 2004, AGU Fall Meeting, OS21E-06), categorically exclude emplacement by tsunami waves. Oceanic isotope records cannot produce an equivalent level of resolution of short, extreme events via (in terms of age, duration, rates of sea-level and ice-volume changes), thus shifting the `burden of proof' to proxy methods to identify such events. In our quest to

  8. Burried MIS 5 abrasion platforms in the Bay of Koper (Gulf of Trieste, Northern Adriatic) confirm long-term subsidence of the Northern Adriatic region

    NASA Astrophysics Data System (ADS)

    Trobec, Ana; Šmuc, Andrej; Poglajen, Sašo; Vrabec, Marko

    2016-04-01

    The youngest seafloor sediments of the Gulf of Trieste (Northern Adriatic) are represented by an up to several 100 meters thick succession of Pliocene to Quaternary continental and shallow-marine deposits recording numerous transgressive-regressive cycles. These sediments are separated from older lithologies (mainly Eocene flysch) by an erosional unconformity. Previous geophysical campaigns conducted in the Italian part of the Gulf of Trieste revealed a complex undulating morphology of the unconformity characterised by numerous morphological steps in the flysch appearing between 40 and 200 m below sea level. From correlation with onshore well data from the Friuli and Veneto area it is assumed that the highest system of these unconformities located at approximately 40 mbsl represents a marine abrasion platform formed during the MIS 5 period sea-level highstand. We present the first observations of these abrasion platforms in the Bay of Koper in the southern (Slovenian) part of the Gulf of Trieste. A series of perpendicular sub-bottom sonar profiles with a spacing of 250-500 meters was acquired in the Bay of Koper between 2009 and 2012 with the Innomar parametric sediment echo sounder SES-2000. Along the northern coast of the bay several acoustic facies were resolved, including the top erosional unconformity surface of the flysch. On this surface we located platforms at 35 ms (platform A), 40 ms (platform B) and 50 ms (platform C) of two-way-travel time. The top of abrasion platform B coincides with the top of a sediment progradational wedge which overlies abrasion platform C. No progradational wedge is developed at the top of platform A. Due to signal attenuation and multiples sub-bottom profiles could not be interpreted below 53 ms TWT time. We used a sound velocity of 1650 m/s for the time to depth conversion, which places the platforms at the depth of 28, 33 and 41 mbsl, respectively. Assuming that the abrasion platforms are a remnant of the MIS 5 highstand, this

  9. A multiple-approach radiometric age estimate for the Rotoiti and Earthquake Flat eruptions, New Zealand, with implications for the MIS 4/3 boundary

    USGS Publications Warehouse

    Wilson, C.J.N.; Rhoades, D.A.; Lanphere, M.A.; Calvert, A.T.; Houghton, B.F.; Weaver, S.D.; Cole, J.W.

    2007-01-01

    Pyroclastic fall deposits of the paired Rotoiti and Earthquake Flat eruptions from the Taupo Volcanic Zone (New Zealand) combine to form a widespread isochronous horizon over much of northern New Zealand and the southwest Pacific. This horizon is important for correlating climatic and environmental changes during the Last Glacial period, but has been the subject of numerous disparate age estimates between 35.1??2.8 and 71??6 ka (all errors are 1 s.d.), obtained by a variety of techniques. A potassium-argon (K-Ar) age of 64??4 ka was previously determined on bracketing lavas at Mayor Island volcano, offshore from the Taupo Volcanic Zone. We present a new, more-precise 40Ar/39Ar age determination on a lava flow on Mayor Island, that shortly post-dates the Rotoiti/Earthquake Flat fall deposits, of 58.5??1.1 ka. This value, coupled with existing ages from underlying lavas, yield a new estimate for the age of the combined eruptions of 61.0??1.4 ka, which is consistent with U-Th disequilibrium model-age data for zircons from the Rotoiti deposits. Direct 40Ar/39Ar age determinations of plagioclase and biotite from the Rotoiti and Earthquake Flat eruption products yield variable values between 49.6??2.8 and 125.3??10.0 ka, with the scatter attributed to low radiogenic Ar yields, and/or alteration, and/or inheritance of xenocrystic material with inherited Ar. Rotoiti/Earthquake Flat fall deposits occur in New Zealand in association with palynological indicators of mild climate, attributed to Marine Isotope Stage (MIS) 3 and thus used to suggest an age that is post-59 ka. The natures of the criteria used to define the MIS 4/3 boundary in the Northern and Southern hemispheres, however, imply that the new 61 ka age for the Rotoiti/Earthquake Flat eruption deposits will provide the inverse, namely, a more accurate isochronous marker for correlating diverse changes across the MIS 4/3 boundary in the southwest Pacific. ?? 2007 Elsevier Ltd. All rights reserved.

  10. Application of ICP-SFMS, ICP-AES integrate method to the geochemical characterization of ANDRILL-MIS oceanic sediment samples

    NASA Astrophysics Data System (ADS)

    Rugi, F.; Castellano, E.; Marino, F.; Ghedini, C.; Severi, M.; Becagli, S.; Traversi, R.; Udisti, R.

    2009-12-01

    An integrated system for the determination of 39 major and trace (including Rare Earths Elements -REE) metals in soils and marine sediments was set up by using Inductively Coupled Plasma - Sector Field Mass Spectrometry (ICP-SFMS) and Inductively Coupled Plasma - Atomic Emission Spectrophotometry (ICP - AES) devices, in order to achieve an extensive geochemical characterization. Major elements, in particular silicon, are also quantified with PIXE technique. Method selectivity, accuracy and reproducibility was evaluated analyzing six certified materials: Basalt, Hawaiian Volcanic Observatory (BHVO-1); Japanese Andesite (JA-2); Montana Soil (NIST 2711); Antarctic Sediment (CRM-MURST-ISS-A1); Antarctic Sediment (GBW 073113) e Antarctic Sediment (NIST 2702); after mineralization with fluoridric, nitric and perchloric acids on hot plate. The choice of the isotope (ICP-SFMS) or wavelength (ICP-AES) was addressed obtaining the best compromise between high sensitivity and suitable selectivity for the metal determination. Particular care was paid in optimizing analytical quantification of each species, because of the huge difference in concentration of major and trace elements in geological samples. For ICP-SFMS, high resolution (10,000 m/Δm) was selected for all metals to avoid isobaric interferences. An accurate blank evaluation was carried out, especially for metals present at sub-ppb levels in the extract solutions (REE and other trace elements). The obtained operative blank values included sample manipulation and digestion, reagent content and analytical procedures. ICP-SFMS and ICP-AES methods were applied to the characterization of the geochemical composition of sample from the first 90 m of Mc Murdo Ice Shelf (MIS) marine core, in the framework of the ANDRILL (ANtarctic DRILLing) Project. This international project aims to study the role of the Antarctic Continent within the global climatic system, by the recovery and analysis of two deep sediment cores (named MIS

  11. Analysis of interface states of Al/TiO2/Si0.3Ge0.7 MIS structures using the conductance technique

    NASA Astrophysics Data System (ADS)

    Chakraborty, S.; Bera, M. K.; Bose, P. K.; Maiti, C. K.

    2006-03-01

    TiO2 films have been deposited at a low temperature (~150 °C) using titanium tetrakis isopropoxide (TTIP) as an organometallic precursor on Si0.3Ge0.7 heterolayers by a microwave plasma-enhanced chemical vapour deposition system. Interfacial properties of the as-deposited films have been characterized using capacitance-voltage and conductance-voltage techniques measured at different frequencies. The energy distribution of interface states and the relaxation time have been determined from Gp/ω versus ω analysis. A Dit level of Al/TiO2/SiGe MIS capacitors in the range of 2.87 × 1011 eV-1 cm-2 (in EC-0.446) eV to 5.04 × 1011 eV-1 cm-2 (in EC-0.696) eV has been observed from conductance measurements.

  12. Capacitance-voltage characteristics of (Al/Ti)/Al{sub 2}O{sub 3}/n-GaN MIS structures

    SciTech Connect

    Ivanov, P. A. Potapov, A. S.; Nikolaev, A. E.; Lundin, V. V.; Sakharov, A. V.; Tsatsulnikov, A. F.; Afanas’ev, A. V.; Romanov, A. A.; Osachev, E. V.

    2015-08-15

    The capacitance-voltage characteristics of (Al/Ti)/Al{sub 2}O{sub 3}/n-GaN metal—insulator-semiconductor (MIS) structures are measured and analyzed. n-Type GaN films are grown on sapphire (0001) substrates by the metal-organic chemical vapor deposition method. An aluminum-oxide layer with a thickness of 60 nm is deposited onto the surface of GaN by the method of atomic-layer deposition from the gas phase. Metallic contacts are deposited by the electron-beam evaporation of titanium and aluminum in vacuum. According to the measurement results, the breakdown-field strength of the oxide, its dielectric constant, and the integrated electron density of states at the oxide-semiconductor interface are 5 × 10{sup 6} V/cm, 7.5, and 3 × 10{sup 12} cm{sup −2}, respectively.

  13. 'We shed tears, but there is no one there to wipe them up for us': narratives of (mis)trust in a materially deprived community.

    PubMed

    Ward, Paul; Coates, Anna

    2006-07-01

    This article reports on a qualitative study in a materially deprived locality in northern England, which originally aimed to explore local residents' views of proposed changes to local health care provision. However, participants also quickly moved the research agenda onto widespread discussions of (mis)trust. Unlike much sociological literature that defines trust as operating on two levels (inter-personal and system-based), their narratives of trust were constructed on several inter-connected levels. We explore mistrust in local general practitioners (GPs) as a factor of mistrust of a number of local and national organizations and social systems, rather than solely related to the medical system. Widespread mistrust of 'authority' was narrated through a shared history of disinvestment and loss of services in the locality and 'broken promises' by a range of institutions, which precipitated feelings of social exclusion and disembeddedness. PMID:16775016

  14. Paleoclimate reconstruction in the Levant region from the petrography and the geochemistry of a MIS 5 stalagmite from the Kanaan Cave, Lebanon

    NASA Astrophysics Data System (ADS)

    Nehme, C.; Verheyden, S.; Noble, S. R.; Farrant, A. R.; Delannoy, J. J.; Claeys, P.

    2015-07-01

    Lying at the transition between the temperate Mediterranean domain and subtropical deserts, the Levant is a key area to study the palaeoclimatic response over glacial-interglacial cycles. This paper presents a precisely dated last interglacial (MIS 5) stalagmite (129-84 ka) from the Kanaan Cave, Lebanon. Variations in growth rate and isotopic records indicate a warm humid phase at the onst of the last interglacial at ~129 ka that lasted until ~125 ka. A gradual shift in speleothem isotopic composition (125-122 ka) is driven mainly by the δ18O source effect of the Eastern Mediterranean surface waters during Sapropel S5. The onset of glacial inception began after ~122 ka, interrupted by a short wet pulse during Sapropel S4. Low growth rates and enriched oxygen and carbon values until ~84 ka indicate a transition to drier conditions during Northern Hemisphere glaciation.

  15. Climate and sea-level variation during MIS 21 from a sediment core in Osaka Bay, Japan: a sign of termination of the Mid-Pleistocene Climate Transition

    NASA Astrophysics Data System (ADS)

    Kitaba, I.; Harada, M.; Hyodo, M.; Katoh, S.; Sato, H.; Matsushita, M.

    2010-12-01

    The Quaternary climate system is strongly dominated by changes in the Earth’s orbital elements. The dominant cyclicity changed from about 41 ka (obliquity cycle) to about 100 ka (eccentricity cycle) during the interval known as the Mid-Pleistocene climate transition (MPT), roughly 1.25-0.7 Ma. This study reports climate and sea-level variation for the marine oxygen isotope stage (MIS) 21, encompassing the end of the MPT, based on a pollen, diatom and sulfur record from a 50-m thick sequence in a core from Osaka Bay, western Japan. An extremely warm climate coincided with the sea-level highstand of substage 21.5, when the warm-temperate element Quercus (Cyclobalanopsis) exceeds 40% of total arboreal pollen. This was followed by a warm-temperate to temperate and humid climate that continued until the end of MIS 21. Climate was dominated by precessional cyclicity, with an inverse correlation between temperature and precipitation. The postglacial sea-level rise reached its highest peak in substage 21.5, when paleo-Osaka Bay reached its maximum extent including the Kyoto and Nara Basins. At this time pelagic diatoms were dominant in the central part of the bay. Sea level dropped below the Osaka Bay sill (about -60m at present) during substage 21.4, followed by a rise above the sill in substage 21.3, and a drop at 21.2. Sea level remained below the sill during substage 21.1. The thermal maximum and sea-level peak occurrence just after the rapid postglacial sea level rise, after which there was a gradual decline in temperature and sea-level accompanied by precession-related oscillations; these features are typical of the post-MPT interglacials dominated by 100-ka cyclicity. These features may be a sign of termination of the MPT.

  16. Constraining Seasonal and Vertical Distributions of Planktonic Foraminifera for Paleoclimate Reconstruction Since MIS3 at the Axial Seamount, Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Chen, S. L.; Ravelo, A. C.; Clague, D. A.

    2015-12-01

    The California Current is an upwelling region with dynamic interactions between circulation, biological productivity and ecology. A 77 cm piston push core was taken from the Juan de Fuca Ridge Axial Seamount using a Remotely Operated Vehicle (ROV) (2213m, 45.55º N, 130.08º W), an active submarine volcano ~480 km off Oregon's coast. Five radiocarbon dates indicate that the sediment ranges from 42.6 ka at 77 cm to 17.6 ka at 15 cm, with an average sediment accumulation rate of 2.47 cm/ka from 77-15 cm, and an average rate of 0.85 cm/ka during the postglacial period (<17.6 ka). Multiple species of planktic foraminifera from the core representing subtropical, subartic, and arctic fauna have been used to constrain changes in vertical and seasonal temperature since Marine Isotope Stage 3 (MIS3). Measurements of δ18O of the upwelling species Globigerina bulloides, the thermocline dwelling species Neogloboquadrina dutertrei, and the warm mixed-layer species Orbulina universa are offset from each other, reflecting vertical and seasonal variation among the planktonic foraminifera. Of the three species, G. bulloides shows the least variation in δ18O, possibly indicating that marked changes in temperature are masking changes in the δ18O of seawater due to global ice volume changes. G. bulloides and O. universa δ18O values are similar in MIS 3 and diverge with time, indicating the development of strong seasonal succession of species, since the last glacial maximum. Bulk nitrogen isotopes and nitrogen flux provide additional constraints on upwelling strength and insight into local biological productivity and nutrient dynamics. Obtaining Mg/Ca data will clarify the δ 18O interpretation except deep in the core where metal-bearing authigenic precipitates affect Mg concentrations. These climatic proxies together provide insight into how global climate change and local seamount volcanism impacts regional productivity in the California Current.

  17. Aligning and synchronization of MIS5 proxy records from Lake Ohrid (FYROM) with independently dated Mediterranean archives: implications for DEEP core chronology

    NASA Astrophysics Data System (ADS)

    Zanchetta, Giovanni; Regattieri, Eleonora; Giaccio, Biagio; Wagner, Bernd; Sulpizio, Roberto; Francke, Alex; Vogel, Hendrik; Sadori, Laura; Masi, Alessia; Sinopoli, Gaia; Lacey, Jack H.; Leng, Melanie J.; Leicher, Niklas

    2016-05-01

    The DEEP site sediment sequence obtained during the ICDP SCOPSCO project at Lake Ohrid was dated using tephrostratigraphic information, cyclostratigraphy, and orbital tuning through the marine isotope stages (MIS) 15-1. Although this approach is suitable for the generation of a general chronological framework of the long succession, it is insufficient to resolve more detailed palaeoclimatological questions, such as leads and lags of climate events between marine and terrestrial records or between different regions. Here, we demonstrate how the use of different tie points can affect cyclostratigraphy and orbital tuning for the period between ca. 140 and 70 ka and how the results can be correlated with directly/indirectly radiometrically dated Mediterranean marine and continental proxy records. The alternative age model presented here shows consistent differences with that initially proposed by Francke et al. (2015) for the same interval, in particular at the level of the MIS6-5e transition. According to this new age model, different proxies from the DEEP site sediment record support an increase of temperatures between glacial to interglacial conditions, which is almost synchronous with a rapid increase in sea surface temperature observed in the western Mediterranean. The results show how a detailed study of independent chronological tie points is important to align different records and to highlight asynchronisms of climate events. Moreover, Francke et al. (2016) have incorporated the new chronology proposed for tephra OH-DP-0499 in the final DEEP age model. This has reduced substantially the chronological discrepancies between the DEEP site age model and the model proposed here for the last glacial-interglacial transition.

  18. The Biomarker Inventory, Trace, and Source of Heinrich Events and Heinrich-type Layers (MIS 8-16) in the North Atlantic

    NASA Astrophysics Data System (ADS)

    Hefter, J.; Stein, R.; Sinninghe Damsté, J. S.

    2007-12-01

    Multiple cores from different locations in the North Atlantic were recovered during IODP Expeditions 303/306. We have investigated the biomarker distributions of identified Heinrich layers (HL) and ambient glacial/interglacial samples from Site U1305, located in the Labrador Sea in proximity to the former major iceberg discharge pathway derived via the Hudson Strait from the Laurentide-Ice-Shield (LIS).A unique association of a multitude of "petrogenic" compounds such as benzohopanes, D-ring monoaromatic 8,14-secohopanes, rearranged diasterenes, mono- and triaromatic steranes, isorenieratene-derivatives as well as characteristic pristane/n- C17 and pristane/phytane ratios ideally allows to distinguish organic matter from HL compared to adjacent samples. They therefore are regarded and can be used as organic-geochemical tracers not only for the occurrence of Heinrich Events of the last glacial cycle but also for older Heinrich-like events.We present a biomarker based high resolution record of such events during a time interval from about 320-460 kyr at Site U1313 (MIS 10-12) and an extended record (MIS 8-16) of Heinrich-type events from Site U1308, i.e. from positions near the Mid-Atlantic Ridge and distal to the LIS.In addition, the HL-specific biomarker association provides circumstantial evidence to derive from a relatively immature, Paleozoic marine rock deposited under occasional photic zone anoxic conditions, that is today located on the Laurentide/Canadian shield. Reinvestigation of available geologic and organic-geochemical data allowed narrowing down this assumed source to an Ordovician oil shale close to Hudson Strait, that indeed bears a striking resemblance in terms of biomarker distributions when compared to the specific association of compounds from samples of Heinrich Events.

  19. Characterization of a rapid climate shift at the MIS 8/7 transition in central Spain (Valdocarros II, Autonomous Region of Madrid) by means of the herpetological assemblages

    NASA Astrophysics Data System (ADS)

    Blain, Hugues-Alexandre; Panera, Joaquin; Uribelarrea, David; Rubio-Jara, Susana; Pérez-González, Alfredo

    2012-07-01

    Climate instability with high-amplitude and rapid shifts during the Middle Pleistocene is well known from pollen records and deep-ocean sediment cores. Although poorly correlatable with such long climate/environment records, the successive fossil amphibian and reptile assemblages from the Middle Pleistocene site of Valdocarros II (Autonomous Region of Madrid, central Spain) provide a unique opportunity to characterize the climatic and environmental features of such rapid (certainly less than 1000 years) shifts from cold to warm conditions in a terrestrial sequence. As the amphibians and reptiles do not differ at species level from the extant herpetofauna of the Iberian Peninsula, they can contribute to the reconstruction of the landscape and climate. In this paper, the mutual climatic range and habitat weighting methods are applied to the herpetofaunistic assemblages in order to estimate quantitative data. The difference in mean annual temperature between "cold" and "warm" periods is estimated at 3.2 °C, with a greater increase in temperature during winter (+3 °C) than during summer (+1 °C). During "cold" periods the climate was more Oceanic (although preserving some dryness during the summers), whereas during "warm" periods the climate became Mediterranean (with mild winters and a long period of dryness in the summer and early autumn). Though higher during cold periods, the continentality (or atmospheric temperature range) remained roughly similar, in accordance with the geographical location of the site in the centre of the Iberian Peninsula. A greater amount of open landscape occurred during "cold" periods, whereas during "warm" periods the wooded areas expanded from 20% to 40% of the landscape surface. Such climatic/environmental changes, together with the numeric datings of the site, suggest that this shift may correspond to the transition from MIS 8 to MIS 7, also called Termination III.

  20. Temperature dependent electrical characterisation of Pt/HfO{sub 2}/n-GaN metal-insulator-semiconductor (MIS) Schottky diodes

    SciTech Connect

    Shetty, Arjun Vinoy, K. J.; Roul, Basanta; Mukundan, Shruti; Mohan, Lokesh; Chandan, Greeshma; Krupanidhi, S. B.

    2015-09-15

    This paper reports an improvement in Pt/n-GaN metal-semiconductor (MS) Schottky diode characteristics by the introduction of a layer of HfO{sub 2} (5 nm) between the metal and semiconductor interface. The resulting Pt/HfO{sub 2}/n-GaN metal-insulator-semiconductor (MIS) Schottky diode showed an increase in rectification ratio from 35.9 to 98.9(@ 2V), increase in barrier height (0.52 eV to 0.63eV) and a reduction in ideality factor (2.1 to 1.3) as compared to the MS Schottky. Epitaxial n-type GaN films of thickness 300nm were grown using plasma assisted molecular beam epitaxy (PAMBE). The crystalline and optical qualities of the films were confirmed using high resolution X-ray diffraction and photoluminescence measurements. Metal-semiconductor (Pt/n-GaN) and metal-insulator-semiconductor (Pt/HfO{sub 2}/n-GaN) Schottky diodes were fabricated. To gain further understanding of the Pt/HfO{sub 2}/GaN interface, I-V characterisation was carried out on the MIS Schottky diode over a temperature range of 150 K to 370 K. The barrier height was found to increase (0.3 eV to 0.79 eV) and the ideality factor decreased (3.6 to 1.2) with increase in temperature from 150 K to 370 K. This temperature dependence was attributed to the inhomogeneous nature of the contact and the explanation was validated by fitting the experimental data into a Gaussian distribution of barrier heights.

  1. Gulf of Mexico Sea-Surface Temperatures and Laurentide Meltwater Input During MIS 3: Implications for High/Low Latitude Linkages

    NASA Astrophysics Data System (ADS)

    Hill, H. W.; Flower, B. P.; Hastings, D. W.; Hollander, D. J.; Lodico, J.; Quinn, T. M.

    2002-12-01

    A new sediment core from the Orca Basin, Gulf of Mexico, will be helpful in determining the role of low latitude ocean dynamics in rapid climate change. The 31.79-m core (MD02-2551; 26o56.78'N, 91o21.75'W), obtained in July 2002 aboard the R/V Marion Dufrense will provide, for the first time, an opportunity to study Gulf of Mexico sea-surface temperature (SST) and sea-surface salinity (SSS), as well as meltwater input from the Laurentide Ice Sheet (LIS) during the Dansgaard-Oeschger (D-O) cycles found in Marine Isotope Stage (MIS) 3, 24-57 ka. The anoxic Orca Basin, which sits 290 km south of the Mississippi Delta, is filled with a hypersaline brine resulting in undisturbed laminations and excellent preservation of planktonic foraminifera. A coarse resolution isotope stratigraphy of the core using Globigerinoides ruber (pink and white variety) with a size fraction from 250-355 microns and faunal abundances suggests the oldest sediments are from MIS 3, resulting in an average sedimentation rate of >50 cm/1000 years. A distinct negative isotope anomaly, reaching δ18O -4 ‰ based on pink G. ruber, occurs at 2625 cm, which is best explained by increased meltwater input from the LIS. More detailed work on the core, including AMS 14C age control, will demonstrate how SST and meltwater input relate to D-O events. Multi-proxy data, including δ18O, Mg/Ca and Uk'37, make it possible to deconvolve SST and SSS. Understanding the relationship between subtropical SST, Greenland air temperatures and high latitude SST, in addition to LIS meltwater input, will test the hypothesis that subtropical SST changes lead high-latitude climate change.

  2. Electrical properties and transport mechanisms of Au/Ba0.6Sr0.4TiO3/GaN metal-insulator-semiconductor (MIS) diode at high temperature range

    NASA Astrophysics Data System (ADS)

    Rajagopal Reddy, V.

    2016-05-01

    The electrical and transport mechanisms of a fabricated Au/Ba0.6Sr0.4TiO3 (BST)/GaN metal-insulator-semiconductor (MIS) diode have been studied in the temperature range of 280-430 K by current-voltage ( I- V) and capacitance-voltage ( C- V) measurements. The barrier heights (BHs) of the Au/BST/GaN MIS diode are found to be 0.85 eV ( I- V)/1.35 ( C- V) at 280 K and 1.14 eV ( I- V)/1.17 ( C- V) at 430 K. The series resistance ( R S) values determined by Cheung's functions are in good agreement with each other. The difference between BHs estimated by I- V and C- V methods are also discussed. Results show that the estimated interface state density ( N SS) of MIS diode decreases with an increase in temperature. Observations have indicated that the BH increases whereas ideality factor R S and N SS decreases with increasing temperature. Results have demonstrated that the reverse leakage current is dominated by Poole-Frenkel emission at temperatures of 280-340 K and by Schottky emission at temperatures of 370-430 K. It is also noted that there is a transition of the conduction mechanism in Au/BST/GaN MIS diode from Poole-Frenkel to Schottky emission at temperatures of 340-370 K.

  3. The ESA Mice in Space (MIS) habitat: effects of cage confinement on neuromusculoskeletal structure and function and stress/behavior using wild-type C57Bl/6JRj mice in a modular science reference model (MSRM) test on ground

    NASA Astrophysics Data System (ADS)

    Blottner, Dieter; Vico, Laurence; Jamon, D. Berckmansp L. Vicop Y. Liup R. Canceddap M.

    Background: Environmental conditions likely affect physiology and behaviour of mice used for Life Sciences Research on Earth and in Space. Thus, mice habitats with sufficient statistical numbers should be developed for adequate life support and care and that should meet all nesces-sary ethical and scientific requirements needed to successfully perform animal experimentation in Space. Aim of study: We here analysed the effects of cage confinement on the weightbear-ing musculoskeletal system, behaviour and stress of wild-type mice (C57BL/6JRj, 30 g b.wt., total n = 24) housed for 25 days in a prototypical ground-based MSRM (modular science ref-erence module) in the frame of breadboard activities for a fully automated life support habitat called "Mice in Space" (MIS) at the Leuven University, Belgium. Results: Compared with control housing (individually ventilated cages, IVC-mice) the MIS mice revealed no significant changes in soleus muscle size and myofiber distribution (type I vs. II) and quality of bone (3-D microarchitecture and mineralisation of calvaria, spine and femur) determined by confocal and micro-computed tomography. Corticosterone metabolism measured non-invasively (faeces) monitored elevated adrenocortical activity at only start of the MIS cage confinement (day 1). Behavioural tests (i.e., grip strength, rotarod, L/D box, elevated plus-maze, open field, ag-gressiveness) performed subsequently revealed only minor changes in motor performance (MIS vs. controls). Conclusions: The MIS habitat will not, on its own, produce major effects that could confound interpretation of data induced by microgravity exposure on orbit as planned for future biosatellite programmes. Sponsors: ESA-ESTEC, Noordwijk, NL

  4. Vegetation and climate change inferred from two marine pollen records in the low latitude west Pacific during the Marine Isotope Stage (MIS) 3

    NASA Astrophysics Data System (ADS)

    Bian, Y.; Li, J.; Jian, Z.; Chu, F.; Kuhnt, W.; Chu, Z.

    2013-12-01

    The climate change in the low latitude area since the last glacial is one of the most hotspot for Quaternary climate research, and the West Pacific Warm Pool (WPWP) is thought to play a key role in the propagation and amplification of climate changes through its influence on the global distribution of heat and water vapour. Meanwhile tropical vegetation is the most outstanding and obvious feature of South-East Asian landscapes, is expected to provide valuable information for the palaeoclmatic conditions. Pollen records from the tropical West Pacific indicate that the tropical vegetation is much sensitive to the environment and climate change, and their good correspondence with palaeocliamte change in glacial/interglacial timescales. Due to the low resolution of sediment cores, few of previous vegetation studies concerned on rapid climate change. In this study, pollen analysis from the sediment cores MD06-3075 retrieved from the Davao Gulf off Southern Philippine and MD98-2178 from western Sulawesi sea are used to reconstruct the vegetation and climate history of the tropical West Pacific and short timescale variation during the MIS 3. Based on AMS14C dating and plankton foraminifera oxygen isotope, the sedimentary records of the last 50,000 years at station MD06-3075 was obtained with a sample resolution of 400 years; records of almost the last 90,000 was included in sediments at station MD98-2178, where pollen analysis includes records of the last 77,000 years with a temporal resolution of 400-800 years. Pollen records from these two marine core show significant periodinal changes during MIS 3. The mangrove pollen content increase at 43-39 ka B.P. and 31-29 ka B.P., while the tropical mid-upper montane rainforest pollen decrease at that two periods from MD06-3075. The MD98-2178 record present that those two groups fluctuate during the 57-51 ka B.P., 48-44 ka B.P. and 38-28 ka B.P. Considering the oxygen isotope value and the SSTMg/Ca record , the temperature

  5. A Multi-proxy Approach to Distinguish Between Changes in SST and Meltwater Input in the Gulf of Mexico Back to MIS 3.

    NASA Astrophysics Data System (ADS)

    Lodico, J. M.; Hastings, D. W.; Flower, B. P.; Quinn, T. M.

    2002-12-01

    The Gulf of Mexico (GOM) is part of the Western Hemisphere Warm Pool providing a source of heat and moisture to the North American continent and Northern high latitudes. Paleoclimatic records from the GOM can test the hypothesis that the tropical climate system is an important driver of past global climate change. In July 2002, core MD02-2551 was taken by the French research vessel Marion Dufresne at 26°56.78 N 91°21.75 W and recovered 31.79 m of sediment from Orca Basin situated in the northern GOM 290 km south of the present Louisiana coast. The basin is advantageous for high-resolution paleoclimatology because of a brine layer overlying the sediment that preserves sedimentary laminations and high sedimentation rates estimated at greater than 50 cm/1000 yr. A multi-proxy approach using Mg/Ca and δ18O from foraminiferal calcite will isolate past sea surface temperature (SST) and δ18O of sea water (controlled by salinity, and ice volume). Separation of these parameters will help establish the relationship between changing GOM SSTs and meltwater input from the Laurentide Ice Sheet. The chronology of the core is being established using AMS C14 dating. Both white and pink species of the planktonic foraminifera Globigerinoides ruber were analyzed for δ18O and will be analyzed for Mg/Ca. Coarse resolution data from white G. ruber show a mean value of about -1.5 per mil during the Holocene (low variability of <0.5 per mil) and a mean value of about 0.0 per mil at the Last Glacial Maximum (low variability of <0.5 per mil). Marine Isotope Stage Three (MIS 3) indicates a mean value of about -0.75 per mil (high variability of >0.5 per mil). Sea surface temperature and sea surface salinity have distinctly higher variability during MIS 3 in comparison to the Holocene. Foraminiferal Mg data will add an additional constraint for SST. Phasing between GOM SSTs and high latitude temperatures will help assess the role of the tropical climate system on global climate change.

  6. Millennial scale precipitation changes over Easter Island (Southern Pacific) during MIS 3: Inter-hemispheric connections during North Atlantic abrupt cold events

    NASA Astrophysics Data System (ADS)

    Margalef, Olga; Cacho, Isabel; Pla-Rabes, Sergi; Cañellas-Boltà, Núria; Pueyo, Juan Jose; Sáez, Alberto; Valero-Garcés, Blas L.; Giralt, Santiago

    2013-04-01

    Marine Isotope Stage (MIS) 3 climate has been globally characterized by the occurrence of millennial-scale climate variations defined over North Atlantic as Dansgaard-Oeschger and Heinrich events. Despite climate variability has been broadly explored over North Atlantic records, the response of the tropical and subtropical latitudes, especially in the Southern Hemisphere, still remains as a matter of debate. Rano Aroi peat record (Easter Island, Chile, 27°S) provides a unique opportunity to understand Southern Pacific atmospheric and oceanic changes during these stadial-interstadial transitions because of its exceptional location on the interplay of the South Pacific Convergence Zone (SPCZ), the Intertropical Convergence Zone (ITCZ), the South Pacific Anticyclone (SPA) and the Southern Westerlies (SW). Rano Aroi record contains 8 main enhanced precipitation events between 70 and 40 kyr BP that can be correlated with the timing of Heinrich events 5, 5a and 6 as well as other cold stadials. These humid events are also present in other Southern Hemisphere continental sites and correspond to dry periods on Northern Hemisphere records. This opposite hydrologic trend has been explained by the latitudinal migration of ITCZ and has been supported by several climatic models. As Easter Island precipitation is mainly dependent on SPCZ storm track belt activity, we suggest that the southern migration of the ITCZ is associated to an expansion of SPCZ to the east. This process should be intimately related to a weakening of the Walker circulation, which is further supported by an estimation of d18Osw gradient along the equator for the same time period. Consequently, atmospheric and oceanic responses during these cold stadials and Heinrich events might lead to a configuration that resembles the warm ENSO state over Southern Pacific, as previously suggested by some global climatic models. Rano Aroi record clearly points out that shifts in hydrological cycle in tropical Southern

  7. The `Antarctic signal' in Northeast Atlantic benthic δ 18O during MIS 3 attributed primarily to deep-water temperature variations

    NASA Astrophysics Data System (ADS)

    Skinner, L. C.; Shackleton, N. J.

    2004-12-01

    A key, and unresolved though much theorised aspect of millennial climate variability during the last glacial period is the consistent asynchrony of planktonic and benthic foraminiferal δ 18O recorded in the Northeast Atlantic (Shackleton et al., Paleoceanography 15, 565, 2000), and in particular the apparent coupling of such variations with an identical asynchrony between Greenland and Antarctic temperatures (Blunier et al., Nature 394, 739, 1998). These relationships result in an apparent coupling of Antarctic temperature and benthic δ 18O variations throughout Marine Isotope Stage (MIS) 3. It was originally proposed that a climatic parameter with a long time-constant, such as global ice-volume, must account for the millennial benthic δ 18O signal. Based on reconstructions of Red Sea salinity and coral terrace facies variations (Chappell, QSR 21, 1229, 2002; Siddall et al., Nature 423, 853, 2003) it has since been suggested that benthic δ 18O has indeed responded to rapid glacioeustatic sea level fluctuations. Importantly, the sea level variations thus reconstructed could only account for approximately half of the observed amplitude of benthic δ 18O; or if invoked as a complete explanation for the benthic δ 18O signal would require a sensitivity of Atlantic deep-water δ 18O to ice-volume change that was two times larger than on glacial - interglacial time-scales. Here, we present preliminary measurements of Mg/Ca ratios in benthic foraminifera from core MD01-2444 (recovered from 2,656m on the Iberian Margin) that indicate that most of the `Antarctic' benthic δ 18O signal may be attributed to local deep-water temperature variations, and hence that sea-level fluctuations co-ordinated with Antarctic climate cannot account entirely for the benthic signal. Furthermore, it appears that sea-level change may not be in phase with the benthic δ 18O, and that the timing of sea-level high-stands should not be inferred from the benthic δ 18O record. The deep

  8. Radiometric dating (U/Th) of the lower marine terrace (MIS 5.5) west of Nice (French Riviera): Morphological and neotectonic quantitative implications

    NASA Astrophysics Data System (ADS)

    Dubar, Michel; Innocent, Christophe; Sivan, Olivier

    2008-11-01

    Measurements of U/Th disequilibrium by mass spectrometry with a plasma source were used for the dating of shells collected on the lower marine terrace to the west of Nice. The dates obtained (129 ± 30 ka) arranged with palaeoclimatic data indicate that this terrace corresponds to the MIS 5.5 (Tyrrhenian pro parte) and can be correlated with the level with Strombus bubonius located to the east of Nice. Thus, a profile of almost 70 km can be restored with precision from altimetric measurements of the deposits and from sedimentological indicators of the sea level. This profile passes from the tectonic foreland of Provence to the front of the Nice Alpine Range after skirting the Pliocene Var Basin. It thus crosses major structural limits. As expected, the deformation of the lower Tyrrhenian terrace consists of a west-to-east uplift with two boundaries: (1): the "Var Fault" located under the Pliocene Basin; and (2): the border fault of the Nice Range. On a regional scale, the uplift appears closely related to the Nice Range activity. It decreases to the east, in the Flyschs zone, then increases again up to the Apennines chain.

  9. Ctf3p, the Mis6 budding yeast homolog, interacts with Mcm22p and Mcm16p at the yeast outer kinetochore.

    PubMed

    Measday, Vivien; Hailey, Dale W; Pot, Isabelle; Givan, Scott A; Hyland, Katherine M; Cagney, Gerard; Fields, Stan; Davis, Trisha N; Hieter, Philip

    2002-01-01

    The budding yeast kinetochore is composed of an inner and outer protein complex, which binds to centromere (CEN) DNA and attaches to microtubules. We performed a genetic synthetic dosage lethality screen to identify novel kinetochore proteins in a collection of chromosome transmission fidelity mutants. Our screen identified several new kinetochore-related proteins including YLR381Wp/Ctf3p, which is a member of a conserved family of centromere-binding proteins. Ctf3p interacts with Mcm22p, Mcm16p, and the outer kinetochore protein Ctf19p. We used chromatin immunoprecipitation to demonstrate that Ctf3p, Mcm22p, and Mcm16p bind to CEN DNA in a Ctf19p-dependent manner. In addition, Ctf3p, Mcm22p, and Mcm16p have a localization pattern similar to other kinetochore proteins. The fission yeast Ctf3p homolog, Mis6, is required for loading of a CENP-A centromere specific histone, Cnp1, onto centromere DNA. We find however that Ctf3p is not required for loading of the budding yeast CENP-A homolog, Cse4p, onto CEN DNA. In contrast, Ctf3p and Ctf19p fail to bind properly to the centromere in a cse4-1 mutant strain. We conclude that the requirements for CENP-A loading onto centromere DNA differ in fission versus budding yeast. PMID:11782448

  10. Rapid and cyclic dust accumulation during MIS 2 in Central Asia inferred from loess OSL dating and grain-size analysis

    PubMed Central

    Li, Yun; Song, Yougui; Lai, Zhongping; Han, Li; An, Zhisheng

    2016-01-01

    Due to lack of reliable proxies from the Westerlies-dominant region, the strength change of Northern Hemisphere Westerlies remains poorly understood. The aim of this study is to provide a reliable paleoclimatic proxy about the Northern Hemisphere Westerlies change. Here we report a 30.7 m thick loess section from the Ili basin directly controlled by the Westerlies. Based on optically stimulated luminescence (OSL) and high resolution grain-size records, we reconstruct the change history of the Westerlies strength during the last glacial period (mainly Marine Isotope Stages 2, MIS2), being similar with the Westerlies index recorded in the Qinghai Lake sediments. Within error limits, all ages are in stratigraphic order. We further compare the climatic records among the Ili loess, Qinghai Lake and the NGRIP, their similarity shows a good climatic coupling relationship among the Central Asia, East Asia and the North Atlantic, and the Westerlies plays a critical influence in transporting the North Atlantic signal to Central and East Asia. PMID:27586593

  11. Modifications to toxic CUG RNAs induce structural stability, rescue mis-splicing in a myotonic dystrophy cell model and reduce toxicity in a myotonic dystrophy zebrafish model

    SciTech Connect

    deLorimier, Elaine; Coonrod, Leslie A.; Copperman, Jeremy; Taber, Alex; Reister, Emily E.; Sharma, Kush; Todd, Peter K.; Guenza, Marina G.; Berglund, J. Andrew

    2014-10-10

    In this study, CUG repeat expansions in the 3' UTR of dystrophia myotonica protein kinase (DMPK) cause myotonic dystrophy type 1 (DM1). As RNA, these repeats elicit toxicity by sequestering splicing proteins, such as MBNL1, into protein–RNA aggregates. Structural studies demonstrate that CUG repeats can form A-form helices, suggesting that repeat secondary structure could be important in pathogenicity. To evaluate this hypothesis, we utilized structure-stabilizing RNA modifications pseudouridine (Ψ) and 2'-O-methylation to determine if stabilization of CUG helical conformations affected toxicity. CUG repeats modified with Ψ or 2'-O-methyl groups exhibited enhanced structural stability and reduced affinity for MBNL1. Molecular dynamics and X-ray crystallography suggest a potential water-bridging mechanism for Ψ-mediated CUG repeat stabilization. Ψ modification of CUG repeats rescued mis-splicing in a DM1 cell model and prevented CUG repeat toxicity in zebrafish embryos. This study indicates that the structure of toxic RNAs has a significant role in controlling the onset of neuromuscular diseases.

  12. Modifications to toxic CUG RNAs induce structural stability, rescue mis-splicing in a myotonic dystrophy cell model and reduce toxicity in a myotonic dystrophy zebrafish model

    DOE PAGESBeta

    deLorimier, Elaine; Coonrod, Leslie A.; Copperman, Jeremy; Taber, Alex; Reister, Emily E.; Sharma, Kush; Todd, Peter K.; Guenza, Marina G.; Berglund, J. Andrew

    2014-10-10

    In this study, CUG repeat expansions in the 3' UTR of dystrophia myotonica protein kinase (DMPK) cause myotonic dystrophy type 1 (DM1). As RNA, these repeats elicit toxicity by sequestering splicing proteins, such as MBNL1, into protein–RNA aggregates. Structural studies demonstrate that CUG repeats can form A-form helices, suggesting that repeat secondary structure could be important in pathogenicity. To evaluate this hypothesis, we utilized structure-stabilizing RNA modifications pseudouridine (Ψ) and 2'-O-methylation to determine if stabilization of CUG helical conformations affected toxicity. CUG repeats modified with Ψ or 2'-O-methyl groups exhibited enhanced structural stability and reduced affinity for MBNL1. Molecular dynamicsmore » and X-ray crystallography suggest a potential water-bridging mechanism for Ψ-mediated CUG repeat stabilization. Ψ modification of CUG repeats rescued mis-splicing in a DM1 cell model and prevented CUG repeat toxicity in zebrafish embryos. This study indicates that the structure of toxic RNAs has a significant role in controlling the onset of neuromuscular diseases.« less

  13. Modifications to toxic CUG RNAs induce structural stability, rescue mis-splicing in a myotonic dystrophy cell model and reduce toxicity in a myotonic dystrophy zebrafish model.

    PubMed

    deLorimier, Elaine; Coonrod, Leslie A; Copperman, Jeremy; Taber, Alex; Reister, Emily E; Sharma, Kush; Todd, Peter K; Guenza, Marina G; Berglund, J Andrew

    2014-11-10

    CUG repeat expansions in the 3' UTR of dystrophia myotonica protein kinase (DMPK) cause myotonic dystrophy type 1 (DM1). As RNA, these repeats elicit toxicity by sequestering splicing proteins, such as MBNL1, into protein-RNA aggregates. Structural studies demonstrate that CUG repeats can form A-form helices, suggesting that repeat secondary structure could be important in pathogenicity. To evaluate this hypothesis, we utilized structure-stabilizing RNA modifications pseudouridine (Ψ) and 2'-O-methylation to determine if stabilization of CUG helical conformations affected toxicity. CUG repeats modified with Ψ or 2'-O-methyl groups exhibited enhanced structural stability and reduced affinity for MBNL1. Molecular dynamics and X-ray crystallography suggest a potential water-bridging mechanism for Ψ-mediated CUG repeat stabilization. Ψ modification of CUG repeats rescued mis-splicing in a DM1 cell model and prevented CUG repeat toxicity in zebrafish embryos. This study indicates that the structure of toxic RNAs has a significant role in controlling the onset of neuromuscular diseases. PMID:25303993

  14. Rapid and cyclic dust accumulation during MIS 2 in Central Asia inferred from loess OSL dating and grain-size analysis.

    PubMed

    Li, Yun; Song, Yougui; Lai, Zhongping; Han, Li; An, Zhisheng

    2016-01-01

    Due to lack of reliable proxies from the Westerlies-dominant region, the strength change of Northern Hemisphere Westerlies remains poorly understood. The aim of this study is to provide a reliable paleoclimatic proxy about the Northern Hemisphere Westerlies change. Here we report a 30.7 m thick loess section from the Ili basin directly controlled by the Westerlies. Based on optically stimulated luminescence (OSL) and high resolution grain-size records, we reconstruct the change history of the Westerlies strength during the last glacial period (mainly Marine Isotope Stages 2, MIS2), being similar with the Westerlies index recorded in the Qinghai Lake sediments. Within error limits, all ages are in stratigraphic order. We further compare the climatic records among the Ili loess, Qinghai Lake and the NGRIP, their similarity shows a good climatic coupling relationship among the Central Asia, East Asia and the North Atlantic, and the Westerlies plays a critical influence in transporting the North Atlantic signal to Central and East Asia. PMID:27586593

  15. Late-Pleistocene (MIS 3-2) palaeoenvironments as recorded by sediments, palaeosols, and ground-squirrel nests at Duvanny Yar, Kolyma lowland, northeast Siberia

    NASA Astrophysics Data System (ADS)

    Zanina, O. G.; Gubin, S. V.; Kuzmina, S. A.; Maximovich, S. V.; Lopatina, D. A.

    2011-08-01

    A detailed study of the Duvanny Yar section in the Kolyma Lowland (Yakutia) provides the most extensive knowledge to date about late-Pleistocene soil formation processes and environments in the North-East Siberian Arctic. Late-Quaternary palaeoenvironmental changes were reconstructed using paleopedological data and a range of palaeoecological bio-indicators (palynomorphs, plant macrofossils and insects). The frozen sediments representing marine isotope stage 3 (MIS-3), which encompasses the Karginsky interstadial, include profiles of four palaeosols of different ages. The oldest palaeosol is early Karginskian, and three overlying soil horizons represent a late-Karginskian pedocomplex. Palaeopedological data indicate a change of from synlithogenic soil formation processes to epigenic ones during these intervals. The intervening periods of synlithogenic pedogenesis were accompanied by active accumulation of eolian deposits. The Earlier Karginskian period of pedogenesis occurred in the absence of eolian sedimentation and when summer conditions were warm. The wide spectrum of peaty and peaty-gley soils observed in the late-Karginskian deposits developed under conditions of progressive cooling. The structure and content of fossil rodent burrows dated to approximately 30 000 yr BP from frozen late-Pleistocene deposits at Duvanny Yar indicate an arid and severe climate, a depth of active layer of 60-80 cm, and a wide distribution of disturbed habitats with pioneer and steppe vegetation.

  16. Wet oxidation of Al{sub x}GA{sub 1-x}As: arsenic barriers on the road to mis

    SciTech Connect

    Ashby, C.I.H.; Sullivan, J.P.; Newcomer, P.P.; Missert, N.A.; Hou, H.Q.; Hammons, B.E.; Baca, A.G.

    1997-02-01

    Three characteristic regimes were identified during wet thermal oxidation of AlxGa(1-x)As (x=1 to 0.90) on GaAs: oxidation of Al and Ga in the alloy to form to an amorphous oxide layer, formation and elimination of elemental As and of amorphous As2O3, and crystallization of the oxide film. Residual As can produce up to a 100fold increase in leakage current and a 30% increase in bulk dielectric constant. Very low As levels produce partial Fermi-level pinning at the oxidized AlxGa(1-x)As/GaAs interface. Local Schottky- barrier pinning of the Fermi level at As precipitates at the oxide/GaAs interface may be the source of the apparent high interface state density. The presence of thermodynamically favored interfacial As may impose a fundamental limit on the application of AlGaAs wet oxidation for achieving MIS devices without post-oxidation processing to remove the residual As from the interface.

  17. Constraints on Neogene deformation in the southern Terror Rift from calcite twinning analyses of veins within the ANDRILL MIS core, Victoria Land Basin, Antarctica

    NASA Astrophysics Data System (ADS)

    Paulsen, T. S.; Demosthenous, C.; Wilson, T. J.; Millan, C.

    2009-12-01

    The ANDRILL MIS (McMurdo Ice Shelf) Drilling Project obtained over 1200 meters of Neogene sedimentary and volcanic rocks in 2006/2007. Systematic fracture logging of the AND-1B core identified 1,475 natural fractures, i.e. pre-existing fractures in the rock intersected by coring. The most abundant natural fractures are normal faults and calcite veins; reverse faults, brecciated zones, and sedimentary intrusions are also present. In order to better understand Neogene deformation patterns within the southern Terror Rift, we have been conducting strain analyses on mechanically twinned calcite within healed fractures in the drill core. Twinning strains using all of the data from each sample studied to date range from 2% to 10%. The cleaned data (20% of the largest magnitude deviations removed) typically show ≤30% negative expected values, consistent with a single deformation episode or multiple ~coaxial deformation episodes. The majority of the samples record horizontal extension, similar to strain patterns expected in a normal fault regime and/or vertical sedimentary compaction in a continental rift system. The morphology, width, and intensity of twins in the samples suggest that twinning typically occurred at temperatures <170° C. Twinning intensities suggest differential stress magnitudes that caused the twinning ranged from 216 to 295 MPa.

  18. Modifications to toxic CUG RNAs induce structural stability, rescue mis-splicing in a myotonic dystrophy cell model and reduce toxicity in a myotonic dystrophy zebrafish model

    PubMed Central

    deLorimier, Elaine; Coonrod, Leslie A.; Copperman, Jeremy; Taber, Alex; Reister, Emily E.; Sharma, Kush; Todd, Peter K.; Guenza, Marina G.; Berglund, J. Andrew

    2014-01-01

    CUG repeat expansions in the 3′ UTR of dystrophia myotonica protein kinase (DMPK) cause myotonic dystrophy type 1 (DM1). As RNA, these repeats elicit toxicity by sequestering splicing proteins, such as MBNL1, into protein–RNA aggregates. Structural studies demonstrate that CUG repeats can form A-form helices, suggesting that repeat secondary structure could be important in pathogenicity. To evaluate this hypothesis, we utilized structure-stabilizing RNA modifications pseudouridine (Ψ) and 2′-O-methylation to determine if stabilization of CUG helical conformations affected toxicity. CUG repeats modified with Ψ or 2′-O-methyl groups exhibited enhanced structural stability and reduced affinity for MBNL1. Molecular dynamics and X-ray crystallography suggest a potential water-bridging mechanism for Ψ-mediated CUG repeat stabilization. Ψ modification of CUG repeats rescued mis-splicing in a DM1 cell model and prevented CUG repeat toxicity in zebrafish embryos. This study indicates that the structure of toxic RNAs has a significant role in controlling the onset of neuromuscular diseases. PMID:25303993

  19. Special Features of Admittance in Mis Structures Based on Graded-Gap MBE n-Hg1- x Cd x Te ( x = 0.31-0.32) in a Temperature Range OF 8-300 K

    NASA Astrophysics Data System (ADS)

    Voitsekhovskii, A. V.; Nesmelov, S. N.; Dzyadukh, S. M.; Vasil'ev, V. V.; Varavin, V. S.; Dvoretskii, S. A.; Mikhailov, N. N.; Kuz'min, V. D.; Remesnik, V. G.

    2014-09-01

    Admittance of MIS structures based on graded-gap n-Hg1- х Cd х Te ( x = 0.31-0.32) grown by molecular beam epitaxy (MBE) is investigated in a wide temperature range (8-300 K). It is shown that the temperature and frequency dependences of the differential resistance of space charge region for structures with a graded-gap layer are qualitatively similar to those for structures without a graded-gap layer. It is found that for MIS structures based on MBE n-Hg1- х Cd х Te ( x = 0.31-0.32), regardless of the presence of a graded-gap layer, the differential resistance of space charge region is limited by the processes of Shockley-Read generation in the temperature range of 25-100 K.

  20. Summary of the Snowmastodon Project Special Volume. A high-elevation, multi-proxy biotic and environmental record of MIS 6-4 from the Ziegler Reservoir fossil site, Snowmass Village, Colorado, USA

    NASA Astrophysics Data System (ADS)

    Miller, Ian M.; Pigati, Jeffrey S.; Scott Anderson, R.; Johnson, Kirk R.; Mahan, Shannon A.; Ager, Thomas A.; Baker, Richard G.; Blaauw, Maarten; Bright, Jordon; Brown, Peter M.; Bryant, Bruce; Calamari, Zachary T.; Carrara, Paul E.; Cherney, Michael D.; Demboski, John R.; Elias, Scott A.; Fisher, Daniel C.; Gray, Harrison J.; Haskett, Danielle R.; Honke, Jeffrey S.; Jackson, Stephen T.; Jiménez-Moreno, Gonzalo; Kline, Douglas; Leonard, Eric M.; Lifton, Nathaniel A.; Lucking, Carol; Gregory McDonald, H.; Miller, Dane M.; Muhs, Daniel R.; Nash, Stephen E.; Newton, Cody; Paces, James B.; Petrie, Lesley; Plummer, Mitchell A.; Porinchu, David F.; Rountrey, Adam N.; Scott, Eric; Sertich, Joseph J. W.; Sharpe, Saxon E.; Skipp, Gary L.; Strickland, Laura E.; Stucky, Richard K.; Thompson, Robert S.; Wilson, Jim

    2014-11-01

    In North America, terrestrial records of biodiversity and climate change that span Marine Oxygen Isotope Stage (MIS) 5 are rare. Where found, they provide insight into how the coupling of the ocean-atmosphere system is manifested in biotic and environmental records and how the biosphere responds to climate change. In 2010-2011, construction at Ziegler Reservoir near Snowmass Village, Colorado (USA) revealed a nearly continuous, lacustrine/wetland sedimentary sequence that preserved evidence of past plant communities between ~ 140 and 55 ka, including all of MIS 5. At an elevation of 2705 m, the Ziegler Reservoir fossil site also contained thousands of well-preserved bones of late Pleistocene megafauna, including mastodons, mammoths, ground sloths, horses, camels, deer, bison, black bear, coyotes, and bighorn sheep. In addition, the site contained more than 26,000 bones from at least 30 species of small animals including salamanders, otters, muskrats, minks, rabbits, beavers, frogs, lizards, snakes, fish, and birds. The combination of macro- and micro-vertebrates, invertebrates, terrestrial and aquatic plant macrofossils, a detailed pollen record, and a robust, directly dated stratigraphic framework shows that high-elevation ecosystems in the Rocky Mountains of Colorado are climatically sensitive and varied dramatically throughout MIS 5.

  1. Peculiarities of Determining the Dopant Concentration in the Near-Surface Layer of a Semiconductor by Measuring the Admittance of MIS Structures Based on P-Hg0.78Cd0.22Te Grown by Molecular Beam Epitaxy

    NASA Astrophysics Data System (ADS)

    Voitsekhovskii, A. V.; Nesmelov, S. N.; Dzyadukh, S. M.

    2016-06-01

    Peculiarities of determining the concentration and distribution profile of dopant in the near-surface layer of a semiconductor by measuring the admittance of MIS structures based on p-Hg0.78Cd0.22Te grown by molecular beam epitaxy are studied. A technique is proposed for the determining the concentration of dopant based on the measurement of the admittance of MIS structures in the frequency range of 50 kHz - 1 MHz. It is shown that in this frequency range, the capacitance-voltage characteristics of MIS structures based on p-Hg0.78Cd0.22Te with a near-surface graded-gap layer have a high- frequency behavior with respect to the recharge time of surface states located near the Fermi level of intrinsic semiconductor. The distribution profile of dopant in the nearsurface layer of the semiconductor is calculated. It is shown that in p-Hg0.78Cd0.22Te with a near-surface graded-gap layer, the dopant concentration has the lowest value near the interface with the insulator.

  2. Awakening to Opportunities in International Business: A Title VI-B Grant and Partnership Approach

    ERIC Educational Resources Information Center

    Haynes, Joan; Rutz, Rebecca

    2007-01-01

    Subsequent to hurricane Katrina, Mississippi Gulf Coast businesses are rebuilding and rewriting rules. This catastrophic event has offered the coast a tremendous opportunity to write new rules furthering the redevelopment and expansion of international trade through the ports of Gulfport and Pascagoula and the expansion of the tourism industry.

  3. Effects of Music Therapy on Handicapped Students: A Title VI-B Project.

    ERIC Educational Resources Information Center

    McCarthy, Robert E.; Bakaitis, Patricia

    Evaluated were the effects of music therapy sessions on the behavior of approximately 300 moderately retarded, physically handicapped and multiply handicapped students. Data on attentive behavior and disruptive behavior were recorded by 37 special education teachers, 25 instructional aides and one principal who were trained to observe and record…

  4. Climate and Antartic Intermediate Water Covariations on Centennial-Millennial Timescales during MIS 3—Constraining the Role of the "Oceanic Tunnel" in Abrupt Climate Change.

    NASA Astrophysics Data System (ADS)

    Kleiven, H. F.; Ninnemann, U.

    2014-12-01

    The equatorward ventilation of Southern Hemisphere extratropical water masses to the low latitude thermocline has been proposed as a window through which the high latitude ocean can modulate tropical climate on anything from decadal to orbital timescales. This hypothesis is founded largely on the observation that tropical thermocline waters originate mostly in the Southern Hemisphere and that computer simulations suggest property anomalies in these source regions can advect through the intermediate ocean, "the ocean tunnel" to influence tropical SST. However, few observational records of extratropical ocean changes are available to assess their impacts on multi-decadal and longer timescales. Here we add to the observational record using new decadally resolved planktonic and benthic foraminiferal isotopic records spanning MIS 3 (20-50 ka) from the Chilean slope ODP Site 1233 that is located on the northern margin of the Antarctic Circumpolar Current and its seafloor lies in the core of Antarctic Intermediate Water (AAIW). Thus the site is ideally situated to reconstruct both near surface and AAIW variability in the high southern latitudes. On centennial to millennial timescales, changes in intermediate water properties track those in the near surface albeit with a reduced amplitude—confirming the idea that changes in the extratropical ocean effect the oceanic tunnel on these timescales. The new benthic and plantic foraminiferal isotope results demonstrate that variations in intermediate ocean properties and climate of the southeast Pacific closely align with those recorded in the EPICA ice core from Dronning Maud Land. Such abrupt, synoptic scale changes in Antarctic climate and dynamics will have potentially widespread climatic and biogeochemical consequences along the downstream flowpath of AAIW. The broad coherence of the observed Antarctic signal supports the concept of hemispheric thermal asynchrony on millennial timescales, and the extension of this climate

  5. (Mis) Perceptions and Interactions of Sleep Specialists and Generalists: Obstacles to Referrals to Sleep Specialists and the Multidisciplinary Team Management of Sleep Disorders

    PubMed Central

    Hayes, Sean M.; Murray, Suzanne; Castriotta, Richard J.; Landrigan, Christopher P.; Malhotra, Atul

    2012-01-01

    Study Objectives: This study assessed generalists' perceptions and challenges in providing care to sleep disorders patients and the role of sleep specialists in improving gaps in care. Methods: A mixed-method approach included qualitative (semi-structured interviews, discussion groups) and quantitative (online surveys) data collection techniques regarding care of patients with obstructive sleep apnea (OSA) and shift work disorder (SWD). Results: Participants: OSA: generalists n = 165, specialists (internists, neurologists, psychiatrists, pulmonologists) n = 12; SWD: generalists n = 216, specialists n = 108. Generalists reported challenges in assessing sleep disorders and diagnosing patients with sleep complaints. Generalists lacked confidence (selected ≤ 3 on a 5-pt Likert scale) in managing polypharmacy and drug interactions (OSA: 54.2%; SWD: 62.6%), addiction (OSA: 61.8%), and continuous positive airway pressure (OSA: 66.5%). Generalists in both studies reported deficits in knowledge of monitoring sleep disorders (OSA: 57.7%; SWD: 78.7%), rather relying on patients' subjective reports; 23% of SWD generalists did not identify SWD as a medical condition. Challenges to generalist-specialist collaboration were reported, with 66% of generalists and 68% of specialists in the SWD study reporting lack of coordination as a barrier. Generalists reported lack of consistency in sleep medicine and a perceived lack of value in consulting with sleep specialists. Conclusions: Knowledge and attitudinal challenges were found in primary care of patients with sleep disorders. Sleep specialists need to clarify and educate practitioners regarding primary care's approach. Citation: Hayes SM; Murray S; Castriotta RJ; Landrigan CP; Malhotra A. (Mis) perceptions and interactions of sleep specialists and generalists: obstacles to referrals to sleep specialists and the multidisciplinary team management of sleep disorders. J Clin Sleep Med 2012;8(6):633-642. PMID:23243396

  6. Climate variability and volcanic history of the Eastern Romanian Carpathians since early MIS 3 recorded in sediments from Mohoş crater

    NASA Astrophysics Data System (ADS)

    Bormann, M.; Veres, D.; Wulf, S.; Papadopoulou, M.; Panagiotopoulos, K.; Schaebitz, F.

    2015-12-01

    We present a 30m long sediment record covering the last ca. 50,000 years from the in-filled Mohoş crater (46°05' N; 25°55' E) located on Ciomadul volcano (Romania) that was retrieved in 2014. The record consists of bog and lacustrine sediments that are inter-bedded with tephra deposits. Ciomadul volcano, hosting the superimposed craters of Mohoş and Sf. Ana, is the youngest volcanic edifice in the Carpathian-Balkan region. Thus, tephra-analysis on the Mohoş sediments gives valuable insights into the volcanic history of that region, mainly arising from the younger crater of Sf Ana and several secondary domes. For investigations into the past climate history, the Mohoş sediment sequence has been analysed using a multi-proxy approach including geophysical, geochemical and sedimentological parameters. Multi-Sensor core logging and ITRAX X-ray fluorescence scanning have been performed at high-resolution, whereas grain size analysis, TOC and C/N ratios supplement the geophysical and geochemical data. Chronological control is based on radiocarbon and luminescence dating. We also present first results of the tephra-analysis on the Mohoş sediment record and their correlation to medium-distal pyroclastic deposits originating in this volcanic field. We further discuss responses of this mid-altitude site (1050 m a.s.l.) to past climate oscillations since early MIS 3. To date, the Mohoş core record provides the longest time series from the Carpathian region. This study is part of the Collaborative Research Centre 806 "Our Way To Europe; Culture-Environment Interaction and Human Mobility in the Late Quaternary" (www.sfb806.de); subproject B2.

  7. Millennial-scale precipitation variability over Easter Island (South Pacific) during MIS 3: inter-hemispheric teleconnections with North Atlantic abrupt cold events

    NASA Astrophysics Data System (ADS)

    Margalef, O.; Cacho, I.; Pla-Rabes, S.; Cañellas-Boltà, N.; Pueyo, J. J.; Sáez, A.; Pena, L. D.; Valero-Garcés, B. L.; Rull, V.; Giralt, S.

    2015-04-01

    Marine Isotope Stage 3 (MIS 3, 59.4-27.8 kyr BP) is characterized by the occurrence of rapid millennial-scale climate oscillations known as Dansgaard-Oeschger cycles (DO) and by abrupt cooling events in the North Atlantic known as Heinrich events. Although both the timing and dynamics of these events have been broadly explored in North Atlantic records, the response of the tropical and subtropical latitudes to these rapid climatic excursions, particularly in the Southern Hemisphere, still remains unclear. The Rano Aroi peat record (Easter Island, 27° S) provides a unique opportunity to understand atmospheric and oceanic changes in the South Pacific during these DO cycles because of its singular location, which is influenced by the South Pacific Anticyclone (SPA), the Southern Westerlies (SW), and the Intertropical Convergence Zone (ITCZ) linked to the South Pacific Convergence Zone (SPCZ). The Rano Aroi sequence records 6 major events of enhanced precipitation between 38 and 65 kyr BP. These events are compared with other hydrological records from the tropical and subtropical band supporting a coherent regional picture, with the dominance of humid conditions in Southern Hemisphere tropical band during Heinrich Stadials (HS) 5, 5a and 6 and other Stadials while dry conditions prevailed in the Northern tropics. This antiphased hydrological pattern between hemispheres has been attributed to ITCZ migration, which in turn might be associated with an eastward expansion of the SPCZ storm track, leading to an increased intensity of cyclogenic storms reaching Easter Island. Low Pacific Sea Surface Temperature (SST) gradients across the Equator were coincident with the here-defined Rano Aroi humid events and consistent with a reorganization of Southern Pacific atmospheric and oceanic circulation also at higher latitudes during Heinrich and Dansgaard-Oeschger stadials.

  8. Severe cooling episodes at the onset of deglaciations on the Southwestern Iberian margin from MIS 21 to 13 (IODP site U1385)

    NASA Astrophysics Data System (ADS)

    Martin-Garcia, Gloria M.; Alonso-Garcia, Montserrat; Sierro, Francisco J.; Hodell, David A.; Flores, José A.

    2015-12-01

    Here we reconstruct past sea surface water conditions on the SW Iberian Margin by analyzing planktonic foraminifer assemblages from IODP Site U1385 sediments (37°34.285‧N, 10°7.562‧W; 2585 m depth). The data provide a continuous climate record from Marine Isotope Stages (MIS) 21 to 13, extending the existing paleoclimate record of the Iberian Margin back to the ninth climatic cycle (867 ka). Millennial-scale variability in Sea Surface Temperature (SST) occurred during interglacial and glacial periods, but with wider amplitude (> 5 °C) at glacial onsets and terminations. Pronounced stadial events were recorded at all deglaciations, during the middle Pleistocene. These events are recorded by large amplitude peaks in the percentage of Neogloboquadrina pachyderma sinistral coincident with heavy values of planktonic δ18O and low Ca/Ti ratios. This prominent cooling of surface waters along the Portuguese margin is the result of major reorganizations of North Atlantic surface and deep-water circulation in response to freshwater release to the North Atlantic when ice sheets collapse at the onset of deglaciations. In fact, most of these cooling events occurred at times of maximum or increasing northern Hemisphere summer insolation. The slowdown of deep North Atlantic deep-water formation reduced the northward flow of the warm subtropical North Atlantic Drift, which was recorded on the Iberian margin by enhanced advection of northern cold subpolar waters. Following each episode of severe cooling at the onset of deglaciations, surface water experienced abrupt warming that initiated the climatic optimum during the early phase of interglacials. Abrupt warming was recorded by a sudden increase of the subtropical assemblage that indicates enhanced northward transport of heat through the North Atlantic Drift. At the onset of glaciations, SST along the Portuguese margin remained relatively warm while the surface waters of the North Atlantic experienced cooling, generating a

  9. Cova del Rinoceront (Castelldefels, Barcelona): a terrestrial record for the Last Interglacial period (MIS 5) in the Mediterranean coast of the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Daura, J.; Sanz, M.; Julià, R.; García-Fernández, D.; Fornós, J. J.; Vaquero, M.; Allué, E.; López-García, J. M.; Blain, H. A.; Ortiz, J. E.; Torres, T.; Albert, R. M.; Rodríguez-Cintas, À.; Sánchez-Marco, A.; Cerdeño, E.; Skinner, A. R.; Asmeron, Y.; Polyak, V. J.; Garcés, M.; Arnold, L. J.; Demuro, M.; Pike, A. W. G.; Euba, I.; Rodríguez, R. F.; Yagüe, A. S.; Villaescusa, L.; Gómez, S.; Rubio, A.; Pedro, M.; Fullola, J. M.; Zilhão, J.

    2015-04-01

    The Cova del Rinoceront, a site in NE Iberia, contains a thick sedimentary fill preserving a faunal archive from the penultimate glacial and the the last interglacial periods. Layers I to III have been dated to between 74 and 147 ka, coinciding with MIS 5a to 5e, a period poorly represented in the Mediterranean terrestrial record. The results from Cova del Rinoceront are of broader interest for the reconstruction of ecological dynamics during warm stages and the understanding of the evolution and geographical variation of several taxa. The palaeoecological evidence suggests a landscape dominated by mixed wooded vegetation with mild climatic conditions, slightly more humid than today. Several vertebrate taxa, including Haploidoceros mediterraneus, Stephanorhinus hundsheimensis and Glis glis, are documented for the first time in the early Upper Pleistocene of Europe, showing that these species persisted across the region for longer than previously thought. In addition, the recovery of a small lithic assemblage indicates human presence in the surroundings of the site. The 11 m-thick stratigraphic section also provides an ideal setting in which to compare several geochronological methods. U-Th dating of the flowstones that cap the deposit, of speleothems formed along the cave walls, and of speleothems buried by the deposit at different elevations provides minimum and maximum ages of 74 and 175 ka, respectively, for the accumulation. The ages obtained by luminescence, electron spin resonance (ESR), amino acid racemisation (AAR), palaeomagnetism and U-series dating of bone are in good agreement with each other and are stratigraphically consistent. This well-dated faunal succession presents a unique opportunity to assess changes in the Pleistocene fauna of the Mediterranean coast over an interval of more than 100 ka.

  10. Ecosystem regimes and responses in a coupled ancient lake system from MIS 5b to present: the diatom record of lakes Ohrid and Prespa

    NASA Astrophysics Data System (ADS)

    Cvetkoska, Aleksandra; Jovanovska, Elena; Francke, Alexander; Tofilovska, Slavica; Vogel, Hendrik; Levkov, Zlatko; Donders, Timme H.; Wagner, Bernd; Wagner-Cremer, Friederike

    2016-05-01

    We reconstruct the aquatic ecosystem interactions since the last interglacial period in the oldest, most diverse, hydrologically connected European lake system, by using palaeolimnological diatom and selected geochemistry data from Lake Ohrid "DEEP site" core and equivalent data from Lake Prespa core, Co1215. Driven by climate forcing, the lakes experienced two adaptive cycles during the last 92 ka: "interglacial and interstadial" and "glacial" cycle. The short-term ecosystems reorganizations, e.g. regime shifts within these cycles substantially differ between the lakes, as evident from the inferred amplitudes of variation. The deeper Lake Ohrid shifted between ultra oligo- and oligotrophic regimes in contrast to the much shallower Lake Prespa, which shifted from a deeper, (oligo-) mesotrophic to a shallower, eutrophic lake and vice versa. Due to the high level of ecosystem stability (e.g. trophic state, lake level), Lake Ohrid appears relatively resistant to external forcing, such as climate and environmental change. Recovering in a relatively short time from major climate change, Lake Prespa is a resilient ecosystem. At the DEEP site, the decoupling between the lakes' response to climate change is marked in the prolonged and gradual changes during the MIS 5/4 and 2/1 transitions. These response differences and the lakes' different physical and chemical properties may limit the influence of Lake Prespa on Lake Ohrid. Regime shifts of Lake Ohrid due to potential hydrological change in Lake Prespa are not evident in the data presented here. Moreover, a complete collapse of the ecosystems functionality and loss of their diatom communities did not happen in either lake for the period presented in the study.

  11. Ecosystem regimes and responses in a coupled ancient lake system from MIS 5b to present: the diatom record of lakes Ohrid and Prespa

    NASA Astrophysics Data System (ADS)

    Cvetkoska, A.; Jovanovska, E.; Francke, A.; Tofilovska, S.; Vogel, H.; Levkov, Z.; Donders, T. H.; Wagner, B.; Wagner-Cremer, F.

    2015-09-01

    In order to understand the panarchy and interactions since the last interglacial period in the oldest, most diverse and hydrologically connected European lake system, we assess changes in the diatom record and selected geochemistry data from Lake Ohrid's "DEEP site" core and compare it with the diatom and multi-proxy data from Lake Prespa core Co1215. Driven by climate forcing, tephra impact and/or human influence, the lakes experienced two adaptive cycles during the last 92 ka: "interglacial and interstadial-regime" and "glacial-regime". The patterns of regime shifts appear synchronous in both lakes, while differences occur in the inferred amplitudes of the variations. The deeper Lake Ohrid shifted between ultraoligo- and oligotrophic regimes in contrast to the more shallow Lake Prespa, which shifts from (oligo-) mesotrophic to eutrophic conditions. In response to external forcing, Lake Ohrid exhibits a high capacity to buffer disturbances, whereas Lake Prespa is much more resilient and "recovers" in relatively short time. This decoupling of the response is evident during the MIS 5/4 and 2/1 transitions, when Lake Ohrid displays prolonged and gradual changes. The lakes' specific differences in the response and feedback mechanisms and their different physical and chemical properties, probably confine a direct influence of Lake Prespa's shallow/eutrophic regimes over the productivity regimes of Lake Ohrid. Regime shifts of Lake Ohrid due to the hydrological connectivity with Lake Prespa are not evident in the data presented here. Moreover, complete ecological collapse did not happened in both lakes for the period presented in the study.

  12. Shatter cones: (Mis)understood?

    PubMed

    Osinski, Gordon R; Ferrière, Ludovic

    2016-08-01

    Meteorite impact craters are one of the most common geological features in the solar system. An impact event is a near-instantaneous process that releases a huge amount of energy over a very small region on a planetary surface. This results in characteristic changes in the target rocks, from vaporization and melting to solid-state effects, such as fracturing and shock metamorphism. Shatter cones are distinctive striated conical fractures that are considered unequivocal evidence of impact events. They are one of the most used and trusted shock-metamorphic effects for the recognition of meteorite impact structures. Despite this, there is still considerable debate regarding their formation. We show that shatter cones are present in several stratigraphic settings within and around impact structures. Together with the occurrence of complete and "double" cones, our observations are most consistent with shatter cone formation due to tensional stresses generated by scattering of the shock wave due to heterogeneities in the rock. On the basis of field mapping, we derive the relationship D sc = 0.4 D a, where D sc is the maximum spatial extent of in situ shatter cones, and D a is the apparent crater diameter. This provides an important, new, more accurate method to estimate the apparent diameter of eroded complex craters on Earth. We have reestimated the diameter of eight well-known impact craters as part of this study. Finally, we suggest that shatter cones may reduce the strength of the target, thus aiding crater collapse, and that their distribution in central uplifts also records the obliquity of impact. PMID:27532050

  13. Shatter cones: (Mis)understood?

    PubMed Central

    Osinski, Gordon R.; Ferrière, Ludovic

    2016-01-01

    Meteorite impact craters are one of the most common geological features in the solar system. An impact event is a near-instantaneous process that releases a huge amount of energy over a very small region on a planetary surface. This results in characteristic changes in the target rocks, from vaporization and melting to solid-state effects, such as fracturing and shock metamorphism. Shatter cones are distinctive striated conical fractures that are considered unequivocal evidence of impact events. They are one of the most used and trusted shock-metamorphic effects for the recognition of meteorite impact structures. Despite this, there is still considerable debate regarding their formation. We show that shatter cones are present in several stratigraphic settings within and around impact structures. Together with the occurrence of complete and “double” cones, our observations are most consistent with shatter cone formation due to tensional stresses generated by scattering of the shock wave due to heterogeneities in the rock. On the basis of field mapping, we derive the relationship Dsc = 0.4 Da, where Dsc is the maximum spatial extent of in situ shatter cones, and Da is the apparent crater diameter. This provides an important, new, more accurate method to estimate the apparent diameter of eroded complex craters on Earth. We have reestimated the diameter of eight well-known impact craters as part of this study. Finally, we suggest that shatter cones may reduce the strength of the target, thus aiding crater collapse, and that their distribution in central uplifts also records the obliquity of impact. PMID:27532050

  14. Ge photocapacitive MIS infrared detectors

    NASA Technical Reports Server (NTRS)

    Binari, S. C.; Miller, W. E.; Tsuo, Y. H.; Miller, W. E.

    1979-01-01

    An undoped Ge photocapacitive detector is reported which has peak normalized detectivities at wavelengh 1.4 microns and chopping frequencies 13-1000 Hz of 9 x 10 to the 12th, 4 x 10 to the 9th cm Hz to the 1/2th/W operating respectively at temperatures 77, 195, and 295 K. The observed temperature, spectral, and frequency response of the signal and noise are explained in terms of the measured space charge and interface state properties of the device.

  15. MisReading LIS Education.

    ERIC Educational Resources Information Center

    Wiegand, Wayne

    1997-01-01

    Discusses the need to place a greater emphasis on the subject of reading in library and information science (LIS) education and research. Topics include literacy studies, print culture history, reader-response theory, ethnography of reading, genre fiction and cultural studies, information versus reading, and access to information versus content of…

  16. Manpower management information system /MIS/

    NASA Technical Reports Server (NTRS)

    Gravette, M. C.; King, W. L.

    1971-01-01

    System of programs capable of building and maintaining data bank provides all levels of management with regular manpower evaluation reports and data source for special management exercises on manpower.

  17. Land-Ocean Correlation of Orbital-Scale Climatic Changes in the Western Mediterranean during MIS 1/2 and 11/12

    NASA Astrophysics Data System (ADS)

    Hambach, B.; Huang, Y.; Rosell Mele, A.

    2010-12-01

    The interval between 405 and 340 thousand years before present has been argued to be the most recent astronomical analogue for the last glacial and current interglacial period. This similarity is mainly a function of orbital scale climatic changes (eccentricity, precession). To gain a better insight into the Iberian peninsular climate and its transitions during these periods, a marine sediment core from the Alboran Sea, Western Mediterranean, is used to reconstruct climate relevant variables related to surface ocean, atmospheric circulation and hydrology by applying a set of organic geochemical proxies (biomarkers). The location of the core, between the African continent and the Iberian Peninsula make it especially interesting for investigating regional climate changes and transitions in an area with significant hominid remains. Here we present millennial scale resolution data (2 ky) for the interval from 0 to 130 and 374-484 ky corresponding to MIS 1-6 and 11-12, respectively. The results of this multi-biomarker analysis give new insights into past ocean climate conditions as well as into the processes that occurred onshore during this period. The reconstruction of sea surface temperatures is done by the analysis of alkenones (UK37’-index). Chlorophyllic pigment concentration is used as proxy for paleoproductivity. Terrestrial eolian inputs and vegetation changes are determined by the analysis of n-alkyl compounds (long chain n-alkanes, n-alkenols and n-alkanoic acids) which are major components of leaf waxes from terrestrial higher plants. Like mineral aerosols, these compounds are wind-transported from terrestrial vegetation sources to adjacent oceans where the particles settle and are preserved in ocean sediments with very little diagenetic alteration. To assess hydrology related shifts in Iberian peninsular climate, the compound specific hydrogen isotope ratio in higher plant n-alkanes was used. These biomarkers offer a promising tool for reconstructing

  18. Minimizing ultraviolet noise due to mis-matches between detector flow cell and post column mobile phase temperatures in supercritical fluid chromatography: effect of flow cell design.

    PubMed

    Berger, Terry A

    2014-10-17

    A mis-match between the post-column mobile phase temperature and the UV detector flow cell temperature can cause significant UV noise in supercritical fluid chromatography (SFC). Deviations as little as 5 °C can increase noise as much as 5 times, making the detector unsuited for trace analysis. Two approaches were used to minimize this noise. When a flow cell was in direct thermal contact (metal on metal) with the detector optical bench, the mobile phase temperature was actively controlled to the measured flow cell temperature, by using one of the heat exchangers (HX) in the column compartment. However, with some older, but still widely used flow cell designs, this required repeated, hourly monitoring of the flow cell temperature and repeated manual adjustment of the heat exchanger temperature, due to thermal drift. Flow cell design had a strong influence on susceptibility to this thermally induced noise. Thermally insulating the flow cell from the optical bench made some cells much less susceptible to such thermally induced noise. Five different flow cells, some insulated, some un-insulated, were evaluated. Most had a truncated conical flow path, but one had a cylindrical flow path. Using either approach, the ASTM noise, with a 10mm, 13 μL conical flow cell, could be optimized to ≈0.007 mAU at 2.5 Hz, in SFC, which is very near the 0.006 mAU manufacturer's specification for HPLC. The insulated version of this flow cell required far less optimization, compared to the un-insulated version. At 150 bar, an experimental 3mm, 2 μL flow cell, with only one side insulated, yielded noise slightly too high (≈0.16-0.18 mAU) for trace analysis, at 80 Hz. However, at 200 bar, noise at 80 Hz was <0.06 mAU, which should allow quantification of a 1 mAU tall trace component with a signal to noise ratio (S/N) >10. Even partially un-insulated, this flow cell design was much less susceptible to thermally induced noise. Further insulating this flow cell design failed to improve

  19. Processus mis en jeu dans l'evolution morpho-dynamique de Roberts Bank (Delta du Fraser): Observation et modelisation hydrodynamiques et sedimentaires

    NASA Astrophysics Data System (ADS)

    Meule, Samuel

    Roberts Bank couvre le delta intertidal entre le bras principal du fleuve Fraser et la pointe du Cap Roberts en Colombie Britannique, Canada. Sous la pression du developpement urbain et la modification du regime sedimentaire, cette plage de sable fin est soumise a une erosion significative. L'identification des forces hydrodynamiques, leur importance et leur interaction permettent de determiner les zones de transport, et donc la stabilite de Roberts Bank. Deux periodes de mesures associees a des phases de modelisation de la houle et des courants ont ete effectuees lors de ce travail. La premiere periode de mesure, entre le 29 juin et le 8 juillet 2001, a permis l'identification de processus hydrodynamiques et sedimentaires associes aux forts courants de maree presents le long de Roberts Bank. La seconde phase de mesure, entre le 1er mars et le 26 mars 2002, a permis d'etudier les processus de remise en suspension associes a la houle. Des phases de modelisation ont ete menees a partir des connaissances acquises sur le terrain, afin d'affiner la comprehension des processus sedimentaires et notamment les interactions houle - courant - sediment. Les mecanismes, mis en evidence dans cette etude, participent au faconnage de Roberts Bank, contribuent a son erosion et a la mise en place de nouvelles structures sedimentaires. Les courants de flot de maree vont initier la creation de nuages de resuspension de sediment depuis le fond. En eau peu profonde, la composante " onshore" du courant de maree induit un transport a la cote, tandis qu'en eau plus profonde une faible composante " offshore" du courant peut favoriser un transport au large le long de la pente. Les chenaux, les dunes subaquatiques et les surfaces d'erosion affleurantes fournissent une rugosite de fond suffisante a la generation de turbulence et donc de nuages de sediment en suspension. Lors de la maree de jusant, les sediments resuspendus en eau peu profonde, sont transportes vers le large a partir d

  20. Palaeoclimate reconstruction in the Levant region from the petrographic and growth rate of a MIS 5 stalagmite from the Kanaan cave, Lebanon

    NASA Astrophysics Data System (ADS)

    Nehme, Carole; Verheyden, Sophie; Stephen, Noble; Delannoy, Jean-Jacques; Salem, Ghada; Gerard, Jocelyne; Farrant, Andrew

    2015-04-01

    Mount Lebanon consists mainly of carbonate rocks which contain numerous caves with an abundance of well-preserved speleothem deposits. A 23 cm long stalagmite (K1-2010) was obtained from Kanaan cave, situated just north of Beirut within the western flank of central Mount Lebanon at 100 m altitude. To develop an age model for the speleothem, a suite of uranium series (U-Th) dates was performed in the NERC Isotope Geosciences Laboratory at the British Geological Survey. The speleothem displays two main segments: The lower segment (segment 1) is 8.2 cm long and displays a general growth axis varying from 8.5 cm diameter in the lower part to 6 cm in its middle part. This segment grew from at least 129.7 ± 0.8 ka to 111.8 ± 0.7 ka. Several hiatuses are observed and are probably linked to detrital layers. The higher segment (segment 2) is 12.3 cm long and displays a thinner diameter varying from 6.5 to 4 cm at its topmost part. This segment grew continuously from 102.5 ± 0.96 to 85.3 ± 0.8 ka. The lower segment, deposited during S-5 event in the Eastern Mediterranean (128-117 ka) shows growth rates reaching 0.15 cm/100 yr coinciding with enhanced rainfall events in speleothem records from the Southern Levant during the S-5 event as suggested by Frumkin (1999) and Bar-Mathews (2003). Speleothem growth stopped between 103.5 and 109 ka and the growth axis rotated. The higher segment shows a more moderate growth rate (0.09 cm/100 yr) until 100 ka, corresponding to low δ18O values in speleothems from Peqiin and Soreq caves and thus to enhanced rainfall events. Very low growth rates (0.03 to 0.06 cm/100 yr) from 100 to 85 ka are associated with colder climates during the latter part of MIS5 subsequent to the S-5 event. This stalagmite demonstrates the palaeoclimatic potential of speleothem records in the northern Levant region.

  1. High-resolution OSL dating of a late Quaternary sequence from Xingkai Lake (NE Asia): Chronological challenge of the "MIS 3a Mega-paleolake" hypothesis in China

    NASA Astrophysics Data System (ADS)

    Long, Hao; Shen, Ji; Wang, Yong; Gao, Lei; Frechen, Manfred

    2015-10-01

    In this paper a combined OSL (49 samples) and 14C (14 samples) dating study was conducted on a sediment core from Xingkai Lake, NE Asia. A single-aliquot regenerative-dose protocol was used to determine the equivalent dose (De) of the extracted fine-grained (FG) quartz fraction; the suitability of the measurement procedure was confirmed by a set of luminescence tests (e.g., preheat plateau and dose recovery measurements). In addition, a post-IR infrared stimulated luminescence protocol at 290 °C (pIRIR290) was applied to the polymineral FG fraction of seven samples. Our results can be summarized as follows: (1) The uppermost sample was dated to ∼110 a, indicating that the OSL signal of FG quartz has been well bleached. This has been further confirmed by the consistency of OSL ages and pIRIR290 ages within <80 ka. The resulting OSL ages generally increased with depth, and the lowermost samples of core XK08 reached back to the last interglacial, although the pIRIR290 dating suggested that the quartz OSL ages likely begin to be underestimated beyond 80 ka; (2) The comparison of OSL and 14C ages suggested that the radiocarbon dating technique may significantly underestimate the age of sediments for samples older than 30 cal ka BP (corresponding to ∼25 14C ka BP), and thus it is necessary to pay attention when using such old 14C dates for paleoclimatic/archaeological interpretation; (3) This study challenges the radiocarbon-based chronology of the "MIS 3a Mega-paleolake" hypothesis, which had been reiterated for many years and extensively reported across northern and western China; and (4) The current high-resolution OSL dating record (one-age/5-10 cm) showed clear sedimentation rate changes down the core. The identified variations in the sedimentation processes at the orbital timescale may be related to regional/global climatic changes during the past 130 ka, and the high sedimentation rate during the last ∼0.4 ka has probably been caused by intensified human

  2. Surface exposure chronology of the Waimakariri glacial sequence in the Southern Alps of New Zealand: Implications for MIS-2 ice extent and LGM glacial mass balance

    NASA Astrophysics Data System (ADS)

    Rother, Henrik; Shulmeister, James; Fink, David; Alexander, David; Bell, David

    2015-11-01

    During the late Quaternary, the Southern Alps of New Zealand experienced multiple episodes of glaciation with large piedmont glaciers reaching the coastal plains in the west and expanding into the eastern alpine forelands. Here, we present a new 10Be exposure age chronology for a moraine sequence in the Waimakariri Valley (N-Canterbury), which has long been used as a reference record for correlating glacial events across New Zealand and the wider Southern Hemisphere. Our data indicate that the Waimakariri glacier reached its maximum last glaciation extent prior to ∼26 ka well before the global last glaciation maximum (LGM). This was followed by a gradual reduction in ice volume and the abandonment of the innermost LGM moraines at about 17.5 ka. Significantly, we find that during its maximum extent, the Waimakariri glacier overflowed the Avoca Plateau, previously believed to represent a mid-Pleistocene glacial surface (i.e. MIS 8). At the same time, the glacier extended to a position downstream of the Waimakariri Gorge, some 15 km beyond the previously mapped LGM ice limit. We use a simple steady-state mass balance model to test the sensitivity of past glacial accumulation to various climatic parameters, and to evaluate possible climate scenarios capable of generating the ice volume required to reach the full local-LGM extent. Model outcomes indicate that under New Zealand's oceanic setting, a cooling of 5 °C, assuming modern precipitation levels, or a cooling of 6.5 °C, assuming a one third reduction in precipitation, would suffice to drive the Waimakariri glacier to the eastern alpine forelands (Canterbury Plains). Our findings demonstrate that the scale of LGM glaciation in the Waimakariri Valley and adjacent major catchments, both in terms of ice volume and downvalley ice extent, has been significantly underestimated. Our observation that high-lying glacial surfaces, so far believed to represent much older glacial episodes, were glaciated during the LGM

  3. Mis-regulation of 3-deoxy-D-arabino-heptulosonate 7-phosphate synthetase does not account for growth inhibition by phenylalanine in Agmenellum quadruplicatum.

    PubMed

    Jensen, R A; Stenmark-Cox, S; Ingram, L O

    1974-12-01

    The growth of the blue-green bacterium, Agmenellum quadruplicatum, is inhibited in the presence of l-phenylalanine. This species has a single, constitutively synthesized 3-deoxy-d-arabino-heptulosonate 7-phosphate (DAHP) synthetase. l-Phenylalanine inhibits DAHP synthetase non-competitively with respect to both substrate reactants. Other aromatic amino acids do not inhibit the activity of DAHP synthetase. A common expectation for branch-point enzymes such as DAHP synthetase is a balanced pattern of feedback control by all of the ultimate end products. It seemed likely that growth inhibition might equate with defective regulation within the branched aromatic pathway. Accordingly, the possibility was examined that mis-regulation of DAHP synthetase by l-phenylalanine in wild-type cells causes starvation for precursors of the other aromatic end products. However, the molecular basis for growth inhibition cannot be attributed to l-phenylalanine inhibition of DAHP synthetase for the following reasons: (i) DAHP synthetase enzymes from l-phenylalanine-resistant mutants are more, rather than less, sensitive to feedback inhibition by l-phenylalanine. (ii) Shikimate not only fails to antagonize inhibition, but is itself inhibitory. (iii) Neither the sensitivity nor the completeness of l-phenylalanine inhibition of the wild-type enzyme in vitro appears sufficient to account for the potent inhibition of growth in vivo by l-phenylalanine. The dominating effect of l-phenylalanine in the control of DAHP synthetase appears to reflect a mechanism that prevents rather than causes growth inhibition by l-phenylalanine. The alteration of the control of DAHP synthetase in mutants selected for resistance to growth inhibition by l-phenylalanine did indicate that the cause for this metabolite vulnerability can be localized within the aromatic amino acid pathway. Apparently, an aromatic intermediate (between shikimate and the end products) accumulates in the presence of l

  4. An MIS 3 age organic deposit from Balglass Burn, central Scotland: palaeoenvironmental significance and implications for the timing of the onset of the LGM ice sheet in the vicinity of the British Isles

    NASA Astrophysics Data System (ADS)

    Brown, Eleanor J.; Rose, James; Coope, Russell G.; Lowe, John J.

    2007-03-01

    This paper reports the analysis of a glaciotectonised organic deposit located between a lower weathered till and an upper unweathered till at Balglass Burn, north of the Campsie Fells in central Scotland, UK, close to the centre of ice accumulation in Scotland. Sedimentology, pollen, macroscopic plant remains and Coleoptera indicate accumulation in a small pond, as part of an open, tundra landscape with low floral diversity. MCR palaeotemperature reconstructions for the Coleoptera give a mean temperature for the warmest and the coldest months of 8 to 10°C and -26 to -10°C respectively, indicating the presence of at least discontinuous permafrost. Six AMS dates on Carex fruit and Coleoptera fragments give ages between 34 480 and 28 050 14C yr BP (ca. 39.8 to ca. 32.8 cal. yr BP; Fairbanks et al. ([2005])). The upper till and the glaciotectonism are attributed to glaciation during the LGM. Glaciotectonic deformation means that the ages do not indicate sequential development and it is not possible to relate this palaeo-evidence to the fine resolution palaeoclimatic signature for MIS 3. However, the fact that this part of central Scotland was ice-free at this time means that some recent proposals suggesting that the British ice sheet began to accumulate around the middle of MIS 3 are unlikely to be correct. Copyright

  5. A Comparison of Paleomagnetic Secular Variation during MIS 7-10 between the Bering Sea (IODP Ex. 323) and North Atlantic Ocean (ODP Leg 172): Implications for the space/time pattern of field and environmental variability (Invited)

    NASA Astrophysics Data System (ADS)

    Lund, S.; Okada, M.; Acton, G.; Clement, B. M.; Stoner, J. S.; Platzman, E. S.

    2013-12-01

    Detailed records of Brunhes paleomagnetic secular variation (PSV) during Marine Isotope Stages (MIS) 7-10 have been recovered from four IODP Ex. 323 sites in the Bering Sea (U1339, U1343-U1345) and four ODP Leg 172 sites from the subtropical North Atlantic Ocean (1060-1063). Reproducible records of PSV (both directions and paleointensity) have been recovered from three or more holes at each site and correlated among the four independent sites in each region. These PSV records provide an unprecedented database for considering patterns of long-term secular variation and evidence for excursional field behavior on a larger than individual regional scale. We will present reproducible evidence for sustained long-term secular variation in each region and assess the extent to which they may be interrelated. We have identified the times of magnetic field excursions 7α, 7β, 8α, 9α, and 9β in the Atlantic records and correlated those times to the Bering Sea records. There are no true excursions in the Bering Sea at those times, but several of these intervals mark the most anomalous field behavior in the Bering Sea during MIS 7-10. In both regions, the PSV also serves as a high-resolution chronostratigraphic tool for regional correlation of environmental variability. Both regions show clear, reproducible evidence among the sites for synchronous millennial-scale environmental variability that has not been diagnosed previously.

  6. Combining 14C/U-Th Series Geochronology and Stable/Clumped Isotope Geochemistry of MIS 2 Lake Tufas of Lake Chewaucan, Oregon, USA to Reconstruct Deglacial Climate in the Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Hudson, A. M.; Quade, J.; Ali, G.; Boyle, D. P.; Bassett, S.; Huntington, K. W.

    2015-12-01

    Shoreline deposits surrounding closed-basin lake remnants in the Great Basin of North America have been critical to defining the timing and extent of lake highstands during Marine Isotope Stage 2, recording the wettest climate conditions during the last glacial cycle. We present 14C and U-Th series ages and stable and clumped isotope results from MIS 2 microbialite tufas of pluvial Lake Chewaucan, southern Oregon. At ~42.5°N latitude, the Chewaucan basin is the one of the northernmost lake systems in the Great Basin, a critical location for investigating regional climate. Dating of modern tufa and DIC indicates no 14C reservoir effect. Low lake depth is observed for peak LGM conditions (21.0 ka, +11 m above modern), consistent with regional records and climate model results. In contrast with other Great Basin lake reconstructions for deglacial MIS 2, Lake Chewaucan was deepest during the Bølling/Ållerod (B/A; 14.5-13.0 ka, +50 m) and early Holocene (10.9-9.5 ka +15 m) warm periods, with lowstands during Heinrich Event 1 (+0-1 m) and Younger Dryas cold periods (+0 m). This supports previous evidence for wet interstadials in the Pacific Northwest (PNW) during MIS 2-3, the opposite of the central/southern Great Basin, where stadials correlate with wet conditions. δ18O values of tufas (-0.9 to -4.4‰ PDB) reflect high evaporation relative to inflowing meteoric water (-13.6‰ SMOW), and lake water (-6.7 SMOW). δ13C values (+1.7 to +4.5‰ PDB) are consistent with equilibrium with lake DIC (+1.5‰ PDB) and atmospheric CO2, supporting atmospheric 14C equilibrium. Clumped isotope temperatures for modern tufa (20±7°C) are consistent with summer lake surface temperature for modern lake remnant, Abert Lake (17.7-22.0°C), supporting previous clumped isotope results for tufas as summer temperature indicators. Clumped temperatures for the B/A highstand are 19±4°C, indicating near modern lake temperatures during deepest lake conditions. 13±4°C is indicated for the

  7. Mis-sesnse mutations in Tafazzin (TAZ) that escort to mild clinical symptoms of Barth syndrome is owed to the minimal inhibitory effect of the mutations on the enzyme function: In-silico evidence.

    PubMed

    Debnath, Surajit; Addya, Soma

    2015-03-01

    Tafazzin (EC 2.3.1.23) is a Phospholipid Transacylase involved in Cardiolipin remodeling on mitochondrial membrane and coded by TAZ gene (Cytogenetic Location: Xq28) in human. Its mutations cause Barth syndrome (MIM ID: #302060)/3-Methyl Glutaconyl Aciduria Type II, an inborn error of metabolism often leading to foetal or infantile fatality. Nevertheless, some mis-sense mutations result in mild clinical symptoms. To evaluate the rationale of mild symptoms and for an insight of Tafazzin active site, sequence based and structure based ramifications of wild and mutant Tafazzins were compared in-silico. Sequence based domain predictions, surface accessibilities on substitution & conserved catalytic sites with statistical drifts, as well as thermal stability changes for the mutations and the interaction analysis of Tafazzin were performed. Crystal structure of Tafazzin is not yet resolved experimentally, therefore 3D coordinates of Tafazzin and its mutants were spawned through homology modeling. Energetically minimized and structurally validated models were used for comparative docking simulations. We analyzed active site geometry of the models in addition to calculating overall substrate binding efficiencies for each of the enzyme-ligand complex deduced from binding energies instead of comparing only the docking scores. Also, individual binding energies of catalytic residues on conserved HX4D motif of Acyltransferase superfamily present in Tafazzins were estimated. This work elucidates the basis of mild symptoms in patients with mis-sense mutations, identifies the most pathogenic mutant among others in the study and also divulges the critical role of HX4D domain towards successful transacylation by Taffazin. The in-silico observations are in complete agreement with clinical findings reported for the patients with mutations. PMID:25118650

  8. The Taimyr Peninsula and the Severnaya Zemlya archipelago, Arctic Russia: a synthesis of glacial history and palaeo-environmental change during the Last Glacial cycle (MIS 5e-2)

    NASA Astrophysics Data System (ADS)

    Möller, Per; Alexanderson, Helena; Funder, Svend; Hjort, Christian

    2015-01-01

    We here suggest a glacial and climate history of the Taimyr Peninsula and Severnaya Zemlya archipelago in arctic Siberia for the last about 150 000 years (ka). Primarily it is based on results from seven field seasons between 1996 and 2012, to a large extent already published in papers referred to in the text - and on data presented by Russian workers from the 1930s to our days and by German colleagues working there since the 1990s. Although glaciations even up here often started in the local mountains, their culminations in this region invariably seems to have centred on the shallow Kara Sea continental shelf - most likely due to expanding marine ice-shelves grounding there, as a combined effect of thickening ice and eustatically lowered sea-levels. The most extensive glaciation so far identified in this region (named the Taz glaciation) took place during Marine Isotope Stage 6 (MIS 6), i.e. being an equivalent to the late Saale/Illinoian glaciations. It reached c. 400 km southeast of the Kara Sea coast, across and well beyond the Byrranga Mountain range and ended c. 130 ka. It was followed by the MIS 5e (Karginsky/Eemian) interglacial, with an extensive marine transgression to 140 m above present sea level - facilitated by strong isostatic downloading during the preceding glaciation. During the latest (Zyryankan/Weichselian/Wisconsinan) glacial cycle followed a series of major glacial advances. The earliest and most extensive, culminating c. 110-100 ka (MIS 5d-5e), also reached south of the Byrranga mountains and its post-glacial marine limit there was c. 100 m a.s.l. The later glacial phases (around 70-60 ka and 20 ka) terminated at the North Taimyr Ice Marginal Zone (NTZ), along or some distance inland from the present northwest coast of Taimyr. They dammed glacial lakes, which caused the Taimyr River to flow southwards where to-day it flows northwards into the Kara Sea. The c. 20 ka glacial phase, contemporary with the maximum (LGM) glaciation in NW Europe

  9. High-temperature studies of multiple fluorinated traps within an Al2O3 gate dielectric for E-Mode AlGaN/GaN power MIS-HEMTs

    NASA Astrophysics Data System (ADS)

    Wang, Yun-Hsiang; Liang, Yung C.; Samudra, Ganesh S.; Chu, Po-Ju; Liao, Ya-Chu; Huang, Chih-Fang; Kuo, Wei-Hung; Lo, Guo-Qiang

    2016-02-01

    Normally-off AlGaN/GaN MIS-HEMT devices with multiple fluorinated ALD-Al2O3 layers as the gate dielectric have been reported to achieve a high threshold voltage for normally-off operations with satisfactory performance for both on and off states at room temperature. However, a large swing in gate threshold voltage is found when devices operate at elevated temperatures. Hence, further study of the gate dielectric on the distribution of fluorinated trap states in the energy band are required to assess the gate function at higher temperatures. Through the use of the charge analytical model and Poole-Frenkel trap emission theory, the gate voltage stressing measurement was carried out to accurately find the effective trap state distribution within the Al2O3 energy bandgap created by fluorinated treatments. For the samples fabricated and used in the investigation, we found that a higher population of fluorinated trap states located deeper than 1.1 eV corresponding to emission levels above 200 °C would allow more trapped charges to remain in the dielectric at high temperature for better threshold voltage retention. We also discovered that a higher fluorine treatment power on the gate dielectric could yield a higher trap state density at deeper levels, resulting in better temperature stability.

  10. Ferrocenylphenylphosphine and diferrocenylphosphine: new two-electron ligands in complexes of group VIB and VII transition metals

    SciTech Connect

    Losilkina, V.I.; Baranetskaya, N.K.; Tolkunova, V.S.; Krylova, A.I.; Vil'chevskaya, V.D.; Setkina, V.N.

    1987-10-10

    Previously unknown carbonyl complexes were synthesized: C/sub 6/H/sub 6/Cr(CO)/sub 2/PFcPhH, C/sub 6/H/sub 6/Cr(CO)/sub 2/PFc/sub 2/H, C/sub 5/H/sub 5/Mn(CO)/sub 2/PFcPhH, C/sub 5/H/sub 5/Mn(CO)/sub 2/PFc/sub 2/H, and M(CO)/sub 5/PFc/sub 2/H (M = Cr, Mo, W). The ligands PFcPhH and PFc/sub 2/H have weaker electron-donor properties than the ligand PFc/sub 3/ in analogous systems. Under the conditions of isotopic exchange of hydrogen in CF/sub 3/COOH there occurs the protonation of C/sub 6/H/sub 6/Cr(CO)/sub 2/PFcH on the chromium atom. For the complex C/sub 6/H/sub 6/Cr(CO)/sub 2/PFc/sub 2/H it was found that, in the reaction of the isotopic exchange of hydrogen, hydrogens of both the ..pi..-benzene ring and the ..pi..-cyclopentadienyl rings of the phosphine ligand take part, and, moreover, at equal rates. By the method of the isotopic exchange of hydrogen and by spectral methods (IR and PMR) it was shown that the nature of the central metal atom in the complexes M(CO)/sub 5/PFc/sub 2/H, in which M = Cr, Mo, W, has no substantial influence on the spectral characteristics and on the reactivities of these complexes.

  11. Corrigendum to "Revisiting a magneto-elastic strange attractor" [J. Sound Vib. 333 (6) (2014) 1767-1780

    NASA Astrophysics Data System (ADS)

    Tam, Jee Ian; Holmes, Philip

    2016-04-01

    It has come to our attention that certain numerical parameter values quoted in the above-referenced paper are incorrect. Corrected versions of the relevant passages appear below. We apologize for any inconvenience occasioned for readers by these errors, which were inadvertently introduced by the second author in preparing the manuscript.

  12. Multiple meteoroid impacts in Antarctica at 481,000ky: a possible cause for the mid-Brunhes Event/MIS 11 Stage via the disruption of the West Antarctic Ice Sheet?

    NASA Astrophysics Data System (ADS)

    Rice, A. R.; Weihaupt, J. G.; van der Hoeven, F.

    2010-12-01

    cores and of the same age. The indication is that this impact event affected an area of around 6 million square kilometers if not more. The date of 481,000 years for the impacts as implied by the Transantarctic Mountains ablation debris and the ice cores place them at the mid-Brunhes event, i.e., the onset of MIS 11, which is characterized by the replacement of a heavy glacial with an unusually long and warm interglacial interval and a major marine transgression (sea levels > 20m above present). The collapse of a major ice sheet has to be inferred in order to produce similar high sea-levels. As this deglaciation is not associated with an early CO2 peak nor does it seem attributable to Milankovitch mechanisms, it is tempting to suggest that the initiator of MIS11 is the disruption of the Antarctic Ice Sheets by major bolide impacts with attendant loss of the West Antarctic Ice Sheet. There may be possible analogs here that have relevance to mankind’s present environmental issues.

  13. MIS-based sensors with hydrogen selectivity

    DOEpatents

    Li; ,Dongmei; Medlin, J. William; McDaniel, Anthony H.; Bastasz, Robert J.

    2008-03-11

    The invention provides hydrogen selective metal-insulator-semiconductor sensors which include a layer of hydrogen selective material. The hydrogen selective material can be polyimide layer having a thickness between 200 and 800 nm. Suitable polyimide materials include reaction products of benzophenone tetracarboxylic dianhydride 4,4-oxydianiline m-phenylene diamine and other structurally similar materials.

  14. (Mis)Conceptions about Generalizability Theory.

    ERIC Educational Resources Information Center

    Brennan, Robert L.

    2000-01-01

    Reviews some of the more salient conceptual features of generalizability (G) theory. Provides a framework for considering some misconceptions about G theory. Focuses on particularly prevalent or serious misconceptions. G theory provides a rich conceptual framework and tools for working with a defined universe, but it does not tell an investigator…

  15. Teachers' (Mis)Understandings of Resilience

    ERIC Educational Resources Information Center

    Green, Deborah; Oswald, Murray; Spears, Barbara

    2007-01-01

    This study aimed to extend previous studies into resilience, by identifying the roles that teachers played in fostering resilience (N=57: females n=43; and males n=14). A quantitative scale was administered to teachers in South Australia's Catholic education sector to determine the extent to which they were involved in fostering resilience. A…

  16. Standardizing the MIS Course: Benefits and Pitfalls

    ERIC Educational Resources Information Center

    Foltz, C. Bryan; O'Hara, Margaret T.; Wise, Harold

    2004-01-01

    Although many universities require courses in management information systems for their business majors, little information exists as to what objectives should be included in the course, and the course topics vary greatly across institutions. Differences in course objectives even exist within schools if multiple sections of the course are taught by…

  17. The (Mis)Education of Generation M

    ERIC Educational Resources Information Center

    Ziegler, Susan G.

    2007-01-01

    The focus of this paper is on the potential problems and challenges presented by the content, quantity and quality of contemporary media influences (electronic, print and digital). Whereas most articles in this arena focus on one form of media influences (e.g., video games), this article looks at the cumulative scope of influence presented by…

  18. Assurance of Learning in the MIS Program

    ERIC Educational Resources Information Center

    Harper, Jeffrey S.; Harder, Joseph T.

    2009-01-01

    This article describes the development of a systematic and practical methodology for assessing program effectiveness and monitoring student development in undergraduate decision sciences programs. The model we present is based on a student's progression through learning stages associated with four key competencies: technical, analytical,…

  19. Corrigendum to "An equation decoupling approach to identify the equivalent foundation in rotating machinery using modal parameters" [J. Sound Vib. 365 (2016) 182-198

    NASA Astrophysics Data System (ADS)

    Yu, Minli; Feng, Ningsheng; Hahn, Eric J.

    2016-08-01

    The authors would like to apologise for the error made to the affiliation details of Dr Ningsheng Feng and Dr Eric J. Hahn in the original publication and who are both affiliated to The School of Mechanical and Manufacturing Engineering, The University of New South Wales, Sydney, NSW 2052, Australia

  20. Erratum to "Characterization of parallel misalignment in rotating machines by means of the modulated signal of incremental encoders" [J. Sound Vib. 333/21 (2014) 5229-5243

    NASA Astrophysics Data System (ADS)

    Meroño Pérez, P. A.; GómezdeLeón, F. C.; Zaghar, L.

    2016-08-01

    The publisher regrets the paper 'Characterization of parallel misalignment in rotating machines by means of the modulated signal of incremental encoders' was incorrectly published as a Review Article rather than a Research Article.

  1. Natural longitudinal frequencies of a uniform rod with a tip mass or a spring [J. Sound Vib. 77(1) (1981) 147-148

    NASA Astrophysics Data System (ADS)

    Kadıoğlu, Fethi; Tekin, Gülçin

    2016-06-01

    The aim of this communication is to correct the equation which gives the condition for eigenvalues and present the corrected numerical solutions that give the natural longitudinal frequencies for a rod with a spring at the tip in a published letter [1].

  2. Corrigendum to "Reflection and damping properties for semi-infinite string equations with non-classical boundary conditions" [J. Sound & Vibration Vib. 336 (2014) 179-190

    NASA Astrophysics Data System (ADS)

    Akkaya, Tugce; van Horssen, Wim T.

    2015-03-01

    The authors regret that the following mistakes in referencing for the article "Reflection and damping properties for semi-infinite string equations with non-classical boundary conditions" ran through to the production version of this paper and therefore wish to correct this mistake in this corrigendum.

  3. The making of Amerexico: (mis)handling illegal immigration.

    PubMed

    Andreas, P

    1994-01-01

    The border and social policies that the United States shares with Mexico have had only a modest impact on the level of illegal immigration. Alternative methods could reduce the social backlash against Mexican immigrants in US states of destination. Federal Relief Aid to states affected by new arrivals would ameliorate hostility. Although economic stagnation may depress the flow of immigrants or job opportunities, legal or illegal, economic recovery is dependent on the hard work of immigrants. The political solution has been to tighten border controls. Other options are possible. There should be pressure placed on multilateral institutions such as the World Bank and the International Monetary Fund to incorporate immigration issues in economic policy decisions. Many market reforms have contributed to greater emigration. The US has the option to use both supply and demand side options. Enforcement of workplace rules on minimum wages and health and safety standards would make it more difficult to exploit immigrant workers and would decrease the incentive to hire illegal workers. In a deregulated market stricter work standards were considered difficult to attain. A 1993 opinion poll revealed that 65% thought immigration was not beneficial. Border apprehension rates have increased dramatically over the past 30 years. The most recent policies aim to encourage the mobility of capital and trade through the NAFTA free trade agreement while trying to discourage human resource mobility. The push factors in Mexico are identified as high levels of poverty and unemployment, overpopulation, and economic stagnation. NAFTA and prior economic development efforts have not addressed the push factors. Disruption of traditional ways and changes toward greater industrialization spur emigration. The US program to develop border export industry encouraged migration from the interior of Mexico to border areas. Recent Mexican policies have changed the incentives for small farmers to stay on their lands, and Mexican urban areas are overpopulated. Experience has taught that migration flows are easier to start than stop. PMID:12319795

  4. Child Soldiers and Iconography: Portrayals and (Mis)Representations

    ERIC Educational Resources Information Center

    Denov, Myriam

    2012-01-01

    Over the past decade, child soldiers have inundated the popular media. Images of boys armed with AK47s appear ubiquitous, providing a cautionary tale of innocent childhood gone awry. While these representations turn commonly held assumptions of a protected and innocuous childhood on its head, what they conceal is as provocative as what they…

  5. Using Google AdWords in the MBA MIS Course

    ERIC Educational Resources Information Center

    Rosso, Mark A.; McClelland, Marilyn K.; Jansen, Bernard J.; Fleming, Sundar W.

    2009-01-01

    From February to June 2008, Google ran its first ever student competition in sponsored Web search, the 2008 Google Online Marketing Challenge (GOMC). The 2008 GOMC was based on registrations from 61 countries: 629 course sections from 468 universities participated, fielding over 4000 student teams of approximately 21,000 students. Working with a…

  6. (Mis-)Measuring the Relative Pay of Public School Teachers

    ERIC Educational Resources Information Center

    Podgursky, Michael; Tongrut, Ruttaya

    2006-01-01

    Statistics on the relative pay of public school teachers are routinely cited by plaintiffs in school finance ("adequacy") lawsuits. However, comparisons of pay and benefits for public school teachers to those of professional employees in other sectors are complicated by the fact that most teachers work under contracts that are nine or ten months…

  7. Adding XML to the MIS Curriculum: Lessons from the Classroom

    ERIC Educational Resources Information Center

    Wagner, William P.; Pant, Vik; Hilken, Ralph

    2008-01-01

    eXtensible Markup Language (XML) is a new technology that is currently being extolled by many industry experts and software vendors. Potentially it represents a platform independent language for sharing information over networks in a way that is much more seamless than with previous technologies. It is extensible in that XML serves as a "meta"…

  8. A Hollywood View of Christian Mis-Education

    ERIC Educational Resources Information Center

    Resnick, David

    2011-01-01

    "Saved!" is the first Hollywood movie to focus on private religious education and is therefore a significant milestone in popular culture. The movie is critical of the school along the very dimensions of concern to Brighouse (2006): undermining personal autonomy, fostering social divisiveness, and promoting anti-democratic values. This article is…

  9. High School Exit Exams and "Mis"measurement

    ERIC Educational Resources Information Center

    Tienken, Christopher H.

    2011-01-01

    Test score validity takes center stage in the debate over the use of high school exit exams. Scant literature addresses the amount of conditional standard error of measurement (CSEM) present in individual student results on high school exit exams. The purpose of this study is to fill a void in the literature and add a national review of the CSEM,…

  10. (Mis)regulation--the case of commercial surrogacy.

    PubMed

    Mahajan, Tarang

    2015-01-01

    In the most recent attempt to regulate commercial surrogacy, the Ministry of Home Affairs (MHA) has issued a notice altering the category of visa for foreign nationals entering into commercial surrogacy arrangements from "tourist" to "medical". Upon close scrutiny, it becomes clear that this measure is a far too hasty and unprincipled step. Given the varying laws across different countries, commercial surrogacy has been an area marked by a fair amount of legal ambiguity and conflict, for example, with respect to the citizenship status of the child and legally accepted parentage of commissioning parents. The MHA's step towards addressing some of the dilemmas is, however, grossly inadequate and discriminatory. In spite of its seeming advantages, of some administrative and legal oversight of the industry, the notice will impact the existing practices in questionable ways since its provisions remain to be vetted through the lens of medical ethics and social justice. The measures, which are supposed to ensure legality, disambiguation and some degree of security for the commercial surrogate, end up giving a clean chit to the industry for the time being. If the step taken by the MHA was meant to be urgent, one wonders at the lack of motivation to strengthen public debate and produce a piece of legislation that can address the various concerns and dilemmas generated by the assisted reproductive technologies (ARTs). This is especially with reference to legislation that ensures the health and democratic rights of those who are at a disadvantage due to the power imbalance in commercial surrogacy arrangements. PMID:25716437

  11. Developmental Patterning: Putting the Squeeze on Mis-specified Cells.

    PubMed

    Nakajima, Yu-Ichiro; Gibson, Matthew C

    2016-03-01

    Widely implicated in human disease, abnormal cellular cysts reflect dramatic defects in the maintenance of epithelial integrity. A new study reports that epithelial cysts may arise as a surprisingly general consequence of clonal defects in the specification of cell identity. PMID:26954441

  12. The (mis)reporting of statistical results in psychology journals.

    PubMed

    Bakker, Marjan; Wicherts, Jelte M

    2011-09-01

    In order to study the prevalence, nature (direction), and causes of reporting errors in psychology, we checked the consistency of reported test statistics, degrees of freedom, and p values in a random sample of high- and low-impact psychology journals. In a second study, we established the generality of reporting errors in a random sample of recent psychological articles. Our results, on the basis of 281 articles, indicate that around 18% of statistical results in the psychological literature are incorrectly reported. Inconsistencies were more common in low-impact journals than in high-impact journals. Moreover, around 15% of the articles contained at least one statistical conclusion that proved, upon recalculation, to be incorrect; that is, recalculation rendered the previously significant result insignificant, or vice versa. These errors were often in line with researchers' expectations. We classified the most common errors and contacted authors to shed light on the origins of the errors. PMID:21494917

  13. Do Null Subjects (Mis-)Trigger Pro-Drop Grammars?

    ERIC Educational Resources Information Center

    Frazier, Lyn

    2015-01-01

    Native speakers of English regularly hear sentences without overt subjects. Nevertheless, they maintain a [[superscript -]pro] grammar that requires sentences to have an overt subject. It is proposed that listeners of English recognize that speakers reduce predictable material and thus attribute null subjects to this process, rather than changing…

  14. Informed consent in the (mis)information age.

    PubMed

    Nelson, Erin L

    2004-01-01

    Recent studies suggest that large numbers of health-care consumers are turning to the Internet as a source of health information. This article considers the potential impact of on-line health information on women's health-care decisions, and the role of physicians relating to their patients' use of the Internet as an information source. In particular, the article examines the effect of on-line health information on the informed consent process. Physicians' disclosure obligations (their legal duty to provide information to patients) and the law of informed consent are briefly described. The article then considers the Internet as a source of health information, and instances and types of misinformation. Finally, the article suggests steps physicians may take to help their patients benefit from Internet health information and to become critical consumers who do not fall victim to inaccurate or misleading information. The article concludes by suggesting that physicians make a practice of asking their patients about alternate sources of information they may have accessed, in order to help ensure that patients' health-care decisions are based on current, accurate, and complete information. PMID:14715125

  15. An Alternative Method To Measure MIS Faculty Teaching Performance.

    ERIC Educational Resources Information Center

    Simon, Judith C.; Soliman, Khalid S.

    2003-01-01

    Developed a method of measuring a professor's performance using student evaluations in the field of information systems by measuring differences in student perceptions and knowledge. Findings for 328 students show the usefulness of this method in assessing teacher performance. (SLD)

  16. Black School White School: Racism and Educational (Mis) Leadership

    ERIC Educational Resources Information Center

    Brooks, Jeffrey S.

    2012-01-01

    How do race and race relations influence leadership practice and the education of students? In this timely and provocative book, the author identifies cultural and unstated norms and beliefs around race and race relations, and explores how these dynamics influence the kind of education students receive. Drawing on findings from extensive…

  17. Base pairing and base mis-pairing in nucleic acids

    NASA Technical Reports Server (NTRS)

    Wang, A. H. J.; Rich, A.

    1986-01-01

    In recent years we have learned that DNA is conformationally active. It can exist in a number of different stable conformations including both right-handed and left-handed forms. Using single crystal X-ray diffraction analysis we are able to discover not only additional conformations of the nucleic acids but also different types of hydrogen bonded base-base interactions. Although Watson-Crick base pairings are the predominant type of interaction in double helical DNA, they are not the only types. Recently, we have been able to examine mismatching of guanine-thymine base pairs in left-handed Z-DNA at atomic resolution (1A). A minimum amount of distortion of the sugar phosphate backbone is found in the G x T pairing in which the bases are held together by two hydrogen bonds in the wobble pairing interaction. Because of the high resolution of the analysis we can visualize water molecules which fill in to accommodate the other hydrogen bonding positions in the bases which are not used in the base-base interactions. Studies on other DNA oligomers have revealed that other types of non-Watson-Crick hydrogen bonding interactions can occur. In the structure of a DNA octamer with the sequence d(GCGTACGC) complexed to an antibiotic triostin A, it was found that the two central AT base pairs are held together by Hoogsteen rather than Watson-Crick base pairs. Similarly, the G x C base pairs at the ends are also Hoogsteen rather than Watson-Crick pairing. Hoogsteen base pairs make a modified helix which is distinct from the Watson-Crick double helix.

  18. Spatial (mis-)interpretation of pointing gestures to distal referents.

    PubMed

    Herbort, Oliver; Kunde, Wilfried

    2016-01-01

    Pointing gestures are a vital aspect of human communication. Nevertheless, observers consistently fail to determine the exact location to which another person points when that location lies in the distance. Here we explore the reasons for this misunderstanding. Humans usually point by extending the arm and finger. We show that observer's interpret these gestures by nonlinear extrapolation of the pointer's arm-finger line. The nonlinearity can be adequately described as the Bayesian-optimal integration of a linear extrapolation of the arm-finger line and observers' prior assumptions about likely referent positions. Surprisingly, the spatial rule describing the interpretation of pointing gestures differed from the rules describing the production of these gestures. In the latter case, the eye, index finger, and referent were aligned. We show that the differences in the production and interpretation of pointing gestures accounts for the systematic spatial misunderstanding of pointing gestures to distant referents. No evidence was found for the hypotheses that action-related processes are involved in the perception of pointing gestures. How participants interpreted pointing gestures was independent of how they produce these gestures and whether they had practiced pointing movements before. By contrast, both the production and interpretation seem to be primarily determined by salient visual cues. (PsycINFO Database Record PMID:26322693

  19. REPORT ON THE MODELING OF THE LARGE MIS CANS

    SciTech Connect

    E. MOODY; J. LYMAN; K. VEIRS

    2000-12-01

    Changes in gas composition and gas pressure for closed systems containing plutonium dioxide and water are studied using a model that incorporates both radiolysis and chemical reactions. The model is used to investigate the behavior of material stored in storage containers conforming to DOE-STD-3013-99 storage standard. Scaling of the container to allow use of smaller amounts of nuclear material in experiments designed to bound the behavior of all material destined for long-term storage is studied. It is found that the container volume must be scaled along with the amount of material to achieve applicable results.

  20. The University Revisioned: An Alternative to Corporate Mis-Education

    ERIC Educational Resources Information Center

    Lustig, Jeff

    2005-01-01

    Corporatization refers not only to the subordination of academic programs to outside business interest, but also to the more troubling intrusion of corporate forms of governance and market criteria of performance into the institution as a whole. In this paper, the author wants to show how this corporatization affects the substance, structure and…

  1. Rendering of virtual fixtures for MIS using generalized sigmoid functions.

    PubMed

    Ren, Jing; Patel, Rajni V; McIsaac, Kenneth A

    2006-01-01

    To avoid undesired collisions and improve the level of safety and precision, artificial potential field (APF) can be employed to generate virtual forces around protected tissue and to provide surgeons with real-time force refection through haptic feedback. In this paper, we propose a potential field-based force model using the generalized sigmoid function, and show that it can represent a large class of shapes. The proposed approach has several advantages such as computational efficiency, easily adjustable level of force reflection, and force continuity. PMID:16404096

  2. The ICCB MIS Facility Inventory & Utilization Users Handbook.

    ERIC Educational Resources Information Center

    Illinois Community Coll. Board, Springfield.

    This handbook is designed to assist community college administrators in using the various reports generated by the facility inventory and utilization subsystem of the Illinois Community College Board management information system. Among the reports generated by the subsystem are: room utilization report, campus classroom usage report, room use…

  3. Emanations and ``induced'' radioactivity: From mystery to (mis)use

    NASA Astrophysics Data System (ADS)

    Kolar, Z. I.

    1999-01-01

    Radon, Rn; atomic number Z=85; is a (gaseous) chemical element of which no stable but only radioactive isotopes exist. Three of them, namely actinon (219Rn), thoron (220Rn) and radon (222Rn) are the decay products of naturally occurring radioisotopes of radium:223Ra,224Ra and226Ra, respectively. The natural Rn isotopes were discovered within the period 1899-1902 and at that time referred to as emanations because they came out (emanated) of sources/materials containing actinium, thorium and radium, respectively. The (somewhat mysterious) emanations appeared to disintegrate into radioactive decay products which by depositing at solid surfaces gave rise to “induced” radioactivity i.e. radioactive substances with various half-lives. Following the discovery of the emanations the volume of the research involving them and their disintegration products grew steeply. The identity of a number of these radioactive products was soon established. Radium- emanation was soon used as a source of RaD (210Pb) to be applied as an “indicator” (radiotracer) for lead in a study on the solubility of lead sulphide and lead chromate. Moreover, radium and its emanation were introduced into the medical practice. Inhaling radon and drinking radon-containing water became an accepted medicinal use (or misuse?) of that gas. Shortly after the turn of the century, the healing (?) action of natural springs (spas) was attributed to their radium emanation i.e. radon. Bathing in radioactive spring water and drinking it became very popular. Even today, bathing in radon-containing water is still a common medical treatment in Jáchymov, Czech Republic.

  4. Marketing Feud: An Active Learning Game of (Mis)Perception

    ERIC Educational Resources Information Center

    Schee, Brian A. Vander

    2011-01-01

    This paper presents the results of implementing an active learning activity in the principles of marketing course adapted from the television show "Family Feud". The objectives of the Marketing Feud game include increasing awareness of marketing misperceptions, clarifying marketing misunderstandings, encouraging class participation, and building…

  5. The "Packaged" Approach to MIS: HEPS vs. NCHEMS.

    ERIC Educational Resources Information Center

    Gardner, Don E.

    The dissemination and use of software from the National Center for Higher Education Management Systems (NCHEMS) has had a definite impact on the development of management information systems in postsecondary education. In addition to the NCHEMS information system products, a computer software package called HEPS (Higher Education Planning System)…

  6. The readout system for the ArTeMis camera

    NASA Astrophysics Data System (ADS)

    Doumayrou, E.; Lortholary, M.; Dumaye, L.; Hamon, G.

    2014-07-01

    During ArTeMiS observations at the APEX telescope (Chajnantor, Chile), 5760 bolometric pixels from 20 arrays at 300mK, corresponding to 3 submillimeter focal planes at 450μm, 350μm and 200μm, have to be read out simultaneously at 40Hz. The read out system, made of electronics and software, is the full chain from the cryostat to the telescope. The readout electronics consists of cryogenic buffers at 4K (NABU), based on CMOS technology, and of warm electronic acquisition systems called BOLERO. The bolometric signal given by each pixel has to be amplified, sampled, converted, time stamped and formatted in data packets by the BOLERO electronics. The time stamping is obtained by the decoding of an IRIG-B signal given by APEX and is key to ensure the synchronization of the data with the telescope. Specifically developed for ArTeMiS, BOLERO is an assembly of analogue and digital FPGA boards connected directly on the top of the cryostat. Two detectors arrays (18*16 pixels), one NABU and one BOLERO interconnected by ribbon cables constitute the unit of the electronic architecture of ArTeMiS. In total, the 20 detectors for the tree focal planes are read by 10 BOLEROs. The software is working on a Linux operating system, it runs on 2 back-end computers (called BEAR) which are small and robust PCs with solid state disks. They gather the 10 BOLEROs data fluxes, and reconstruct the focal planes images. When the telescope scans the sky, the acquisitions are triggered thanks to a specific network protocol. This interface with APEX enables to synchronize the acquisition with the observations on sky: the time stamped data packets are sent during the scans to the APEX software that builds the observation FITS files. A graphical user interface enables the setting of the camera and the real time display of the focal plane images, which is essential in laboratory and commissioning phases. The software is a set of C++, Labview and Python, the qualities of which are respectively used for rapidity, powerful graphic interfacing and scripting. The commands to the camera can be sequenced in Python scripts. The paper describes the whole electronic and software readout chain designed to fulfill the specificities of ArTeMiS and its performances. The specific options used are explained, for example, the limited room in the Cassegrain cabin of APEX has led us to a quite compact design. This system was successfully used in summer 2013 for the commissioning and the first scientific observations with a preliminary set of 4 detectors at 350μm.

  7. Water mass exchange between the Nordic seas and the Arctic Ocean on millennial timescale during MIS 4-MIS 2

    NASA Astrophysics Data System (ADS)

    Rasmussen, Tine L.; Thomsen, Erik; Nielsen, Tove

    2014-03-01

    The climate of the last glaciation circa 65,000-25,000 years ago was interrupted by about 15 abrupt temperature fluctuations, the so-called Dansgaard-Oeschger events consisting of warm interstadials and cold stadials recorded in Greenland ice cores. The largest fluctuations occur in the North Atlantic region, but they have been registered over the most of the world. The events are linked to changes in deep water formation in the Nordic seas and North Atlantic, disrupting the thermohaline circulation. Yet, Dansgaard-Oeschger events have so far not been recorded north of the convection areas in the central Nordic seas, and it is not known if they affected the water exchange between the Nordic seas and the Arctic Ocean. In this study, we analyze core JM05-31GC from the northern Fram Strait at the very entrance to the Arctic Ocean. The core contains sediments from marine isotope stages (MISs) 4-2. The results show millennial timescale shifts in all the investigated proxies including the distribution of planktonic and benthic foraminifera, planktonic and benthic oxygen and carbon isotopes, and several sedimentological parameters. In JM05-31GC, the interstadials are characterized by relatively high surface and low bottom water temperatures, low content of ice-rafted debris, and well-ventilated bottom water. Stadials are characterized by the presence of icebergs and decreasing surface water and increasing bottom water temperatures due to increased inflow of Atlantic subsurface water. Ventilation decreased during Heinrich events and most stadials. The results show that the Dansgaard-Oeschger events strongly affected the water exchange between the Nordic seas and the Arctic Ocean.

  8. A Case of Telecommunications (Mis)Management; [and] A Case of Telecommunications (Mis)Management: Case Analysis.

    ERIC Educational Resources Information Center

    Fin, T. Andrew; Rogers, Priscilla S.; Taylor, James R.

    1999-01-01

    Presents a series of analyses of a case involving implementing a new voice-mail system, noting a newly appointed manager's failure to obtain feedback about the planned transition and evaluate user needs; successful introduction of any new technology is variable and suggests a degree of incrementalism; and four major issues arising in similar cases…

  9. Corrigendum to "Wavenumber prediction and measurement of axisymmetric waves in buried fluid-filled pipes: Inclusion of shear coupling at a lubricated pipe/soil interface" [J. Sound Vib. 332 (5) (2013) 1216-1230

    NASA Astrophysics Data System (ADS)

    Muggleton, J. M.; Yan, J.

    2014-03-01

    It is with regret that we have noticed an error in Figs. 4b and 5b, relating to the shell-dominated, s=2 wave, and consequently in the accompanying text in Section 4.2. The figures should be as follows:

  10. Corrigendum to "Free vibration analysis of a cracked shear deformable beam on a two-parameter elastic foundation using a lattice" [ J. Sound Vib. 333 (11) (2014) 2359-2377

    NASA Astrophysics Data System (ADS)

    Attar, M.; Karrech, A.; Regenauer-Lieb, K.

    2015-03-01

    The authors have recently noticed that there are two missing references in the introduction of the article which are substantial as they describe the original motivation for this work and properly reference academic guidance and support that underpin the early phases of this project. The first author would also like to include an acknowledgement from two scholars in the acknowledgements section of the article. The authors apologize for this oversight.

  11. Corrigendum to "Transition from progressive to quasi-standing waves behavior of the radiation force of acoustic waves-Example of a high-order Bessel beam on a rigid sphere" [J. Sound Vib. 329 (2010) 3319-3324

    NASA Astrophysics Data System (ADS)

    Mitri, F. G.

    2016-02-01

    Moreover, the corrected plots that should replace the dashed (blue) curves, corresponding to the results for a first-order Bessel vortex beam in Figs. 2 and 3 of [1], are provided. Note that the plots shown in the (black) solid and (red) dot-dashed lines are accurate, and are plotted here for convenience.

  12. Changes in planktic and benthic foraminifer assemblages in the Gulf of Lions, off south France: Response to climate and sea level change from MIS 6 to MIS 11

    NASA Astrophysics Data System (ADS)

    Cortina, Aleix; Sierro, Francisco Javier; Filippelli, Gabriel; Flores, José Abel; Berné, Serge

    2013-04-01

    A multidisciplinary study involving micropaleontological and geochemical tools was carried out in borehole PRGL1 (Promess 1), with the aim of reconstructing the impact of climate change and sea level variation between 133 ka and 406 ka in the upper slope of the Gulf of Lions. We used factor analysis to obtain three main benthic assemblages related to eutrophic, mesotrophic, and oxygenated environments; planktic foraminifers were grouped as warm-water and cold-turbulent species. These results were compared with records of CaCO3 and major and trace elements (Al, Ca, K, Sr) as well as the C/N ratio of organic matter. Power and cross-spectral analysis showed a straightforward relationship between precession minima and thermal stratification of the water column as well as the occurrence of eutrophic bottom conditions during lowstand periods and mesotrophic environments at times of highstand. These eutrophic-mesotrophic oscillations, usually driven by global eustatic change, also involved regional variations in CaCO3 source to this environment. During periods of precession maxima, enhancement of northwesterly winds increased primary productivity by mixing, enhancing the percentage of cold-turbulent species in the water column and the proportion of oxygenated benthic species on the bottom. During interglacial stages, these events were recorded by lower biogenic carbonate at the expense of higher silicate-related components most likely due to a higher supply from Pyrenees rivers. The record of oxygenated benthic species can be a good proxy to monitor past changes in Winter Intermediate Water dynamics driven by northwesterly winds.

  13. New optically stimulated luminescence ages provide evidence of MIS3 and MIS2 eolian activity on Black Mesa, northeastern Arizona, USA

    USGS Publications Warehouse

    Ellwein, A.L.; Mahan, S.A.; McFadden, L.D.

    2011-01-01

    Eolian deposition on the semiarid southern Colorado Plateau has been attributed to episodic aridity during the Quaternary Period. However, OSL ages from three topographically controlled (e.g. falling) dunes on Black Mesa in northeastern Arizona indicate that eolian sediments there were deposited in deep tributary valleys as early as 35-30. ka, with most sand deposited before 20. ka. In contrast, the oldest OSL ages for sand sheets fall within the Pleistocene-Holocene climatic transition (~. 12-8. ka). Thus most eolian sediment accumulated on Black Mesa under climatic conditions that were in general cooler, moister, and more variable than today, not more arid, pointing to a considerable increase in sediment supply. ?? 2010 University of Washington.

  14. Tephra correlations and climatic events between the MIS6/5 transition and the beginning of MIS3 in Theopetra Cave, central Greece

    NASA Astrophysics Data System (ADS)

    Karkanas, Panagiotis; White, Dustin; Lane, Christine S.; Stringer, Chris; Davies, William; Cullen, Victoria L.; Smith, Victoria C.; Ntinou, Maria; Tsartsidou, Georgia; Kyparissi-Apostolika, Nina

    2015-06-01

    Three cryptotephra layers associated with important periods of climatic change were identified in the Middle Palaeolithic sequence of Theopetra Cave, Greece. The lower cryptotephra layer, THP-TII5, is correlated with the P-11 Pantellerian eruption dated to ˜128-131 ka. This cryptotephra postdates a thick sequence of combustion layers that show a complex vegetation succession quite similar to that of the last deglaciation succession in the cave. Two other cryptotephras, THP-TII10 and THP-TII12, are correlated with the Nisyros Upper Pumice and the Pantellerian Y6/Green Tuff, dated to >50 ka and 45.7 ka, respectively. This sequence confirms the position of the Nisyros Upper tephra, below the Pantellerian Green Tuff, in the volcanic event stratigraphy of the Mediterranean. Moreover, these two upper cryptotephras bracket an extended combustion layer with interstadial vegetation characteristics that may be coincident with the complex Greenland Interstadial 13-14. On the basis of this new chronology it can be deduced that the intensity of occupation and presence or absence of humans in the cave were closely related to climatic changes. In addition, a remarkable similarity in the pattern of occupational intensity during the last two deglaciations can be suggested.

  15. Listening to "The Thick Bunch": (Mis)Understanding and (Mis)Representation of Young People in Jobs without Training in the South West of England

    ERIC Educational Resources Information Center

    Lawy, Robert; Quinn, Jocey; Diment, Kim

    2009-01-01

    Young people in jobs without training are ubiquitous but invisible, working in shops, cafes, and other low-waged, low-status occupations. Commonly elided with young people who are not in education, employment or training, they are positioned as the "thick bunch" with empty and meaningless working lives. The main purpose of the research was to…

  16. The power of (Mis)perception: Rethinking suicide contagion in youth friendship networks.

    PubMed

    Zimmerman, Gregory M; Rees, Carter; Posick, Chad; Zimmerman, Lori A

    2016-05-01

    Suicide is a leading cause of death among youth. In the wake of peer suicide, youth are vulnerable to suicide contagion. But, questions remain about the mechanisms through which suicide spreads and the accuracy of youths' estimates of friends' suicidal behaviors. This study addresses these questions within school-aged youths' friendship networks. Social network data were drawn from two schools in the National Longitudinal Study of Adolescent to Adult Health, from which 2180 youth in grades 7-12 nominated up to ten friends. A measure of "perceived" friends' attempted suicide was constructed based on respondents' reports of their friends' attempted suicide. This measure was broader than a "true" measure of friends' attempted suicide, constructed from self-reports of nominated friends who attended respondents' schools. Sociograms graphically represented the accuracy with which suicide attempters estimated friends' suicide attempts. Results from cross-tabulation with Chi-square analysis indicated that approximately 4% of youth (88/2180) attempted suicide, and these youth disproportionately misperceived (predominantly overestimated) friends' suicidal behaviors, compared to non-suicide-attempters. Penalized logistic regression models indicated that friends' self-reported attempted suicide was unrelated to respondent attempted suicide. But, the odds of respondent attempted suicide were 2.54 times higher (95% CI, 1.06-6.10) among youth who accurately perceived friends' attempted suicide, and 5.40 times higher (95% CI, 3.34-8.77) among youth who overestimated friends' attempted suicide. The results suggest that at-risk youth overestimate their friends' suicidal behaviors, which exacerbates their own risk of suicidal behavior. Methodologically, this suggests that a continued collaboration among network scientists, suicide researchers, and medical providers is necessary to further examine the mechanisms surrounding this phenomenon. Practically, it is important to screen at-risk youth for exposure to peer suicide and to use the social environment created by adolescent friendship networks to empower and support youth who are susceptible to suicidal thoughts and behaviors. PMID:27060539

  17. VizieR Online Data Catalog: Merging galaxies (mis)alignments (Barrera-Ballesteros+, 2015)

    NASA Astrophysics Data System (ADS)

    Barrera-Ballesteros, J. K.; Garcia-Lorenzo, B.; Falcon-Barroso, J.; van de Ven, G.; Lyubenova, M.; Wild, V.; Mendez-Abreu, J.; Sanchez, S. F.; Marquez, I.; Masegosa, J.; Monreal-Ibero, A.; Ziegler, B.; Del Olmo, A.; Verdes-Montenegro, L.; Garcia-Benito, R.; Husemann, B.; Mast, D.; Kehrig, C.; Iglesias-Paramo, J.; Marino, R. A.; Aguerri, J. A. L.; Walcher, C. J.; Vilchez, J. M.; Bomans, D. J.; Cortijo-Ferrero, C.; Gonzalez Delgado, R. M.; Bland-Hawthorn, J.; McIntosh, D. H.; Bekeraite, S.; CALIFA Collaboration

    2016-01-01

    The sample presented in this work was selected from 256 objects observed until March 20131. These galaxies are part of the CALIFA mother sample (hereafter CALIFA MS). We consider as objects in pairs those galaxies with companions within a projected distance of 160kpc, systemic velocity difference smaller than 300km/s, and a difference in r-band magnitude smaller than 2mag (relative distances, systemic velocities, and magnitudes were taken from NED3). Observations were carried out using the PPAK instrument at Calar Alto Observatory. Its main component consists of 331 fibers of 2.7" diameter each, concentrated in a single hexagon bundle covering a FoV of 74"x64", with a filling factor of ~60%. Three dithering pointings are taken for each object to reach a filling factor of 100% across the entire FoV (see details in Husemann et al. 2013). The final data cube consists of more than 4000 spectra at a sampling of 1"x1" per spaxel. (4 data files).

  18. (Mis)Understanding Human Beings: Theory, Value, and Progress in Education Research

    ERIC Educational Resources Information Center

    Hostetler, Karl

    2010-01-01

    There is renewed interest in what can be called an "experimentist" approach to education research. The claim is that if researchers would focus on experiments and "evidence-based" policies and practices, irreversible progress in education can be achieved. This experimentist approach cannot provide the understanding of knowledge and human beings…

  19. Electrical Characterization of Amorphous Silicon MIS-Based Structures for HIT Solar Cell Applications.

    PubMed

    García, Héctor; Castán, Helena; Dueñas, Salvador; Bailón, Luis; García-Hernansanz, Rodrigo; Olea, Javier; Del Prado, Álvaro; Mártil, Ignacio

    2016-12-01

    A complete electrical characterization of hydrogenated amorphous silicon layers (a-Si:H) deposited on crystalline silicon (c-Si) substrates by electron cyclotron resonance chemical vapor deposition (ECR-CVD) was carried out. These structures are of interest for photovoltaic applications. Different growth temperatures between 30 and 200 °C were used. A rapid thermal annealing in forming gas atmosphere at 200 °C during 10 min was applied after the metallization process. The evolution of interfacial state density with the deposition temperature indicates a better interface passivation at higher growth temperatures. However, in these cases, an important contribution of slow states is detected as well. Thus, using intermediate growth temperatures (100-150 °C) might be the best choice. PMID:27423876

  20. Impact of abrupt climate change in the tropical southeast Atlantic during Marine Isotope Stage (MIS) 3

    NASA Astrophysics Data System (ADS)

    Hessler, Ines; Steinke, Stephan; Groeneveld, Jeroen; Dupont, Lydie; Wefer, Gerold

    2011-12-01

    High resolution planktonic foraminifera Mg/Ca paleotemperatures and oxygen isotopes of seawater of Ocean Drilling Program (ODP) Site 1078 (off Angola) have been reconstructed and reveal insights into the seasonal thermal evolution of the Angola Current (AC), the Angola-Benguela Front (ABF), and the Benguela Current (BC) during the last glacial (50-23.5 ka BP). Special emphasis is put on time intervals possibly associated with the North Atlantic Heinrich Stadials (HS), which are thought to lead to an accumulation of heat in the South Atlantic due to a reduction of the Atlantic Meridional Overturning Circulation (AMOC). Within dating uncertainties, Globigerinoides ruber (pink) Mg/Ca-based sea surface temperature (SST) estimates that represent southern hemisphere summer surface conditions show several warming episodes that coincide with North Atlantic HS, thus supporting the concept of the bipolar thermal seesaw. In contrast, the Mg/Ca-based temperatures of Globigerina bulloides, representing the SST of the ABF/BC system during southern hemisphere winter, show no obvious response to the North Atlantic HS in the study area. We suggest that surface water cooling during the winter season is due to enhanced upwelling or upwelling of colder water masses which has most likely mitigated a warming of the ABF/BC system during HS. We further speculate that the seasonal asymmetry in our SST record results from seasonal differences in the dominance of atmospheric and oceanic teleconnections during periods of northern high latitude cooling.

  1. Potential (mis)match?: Marriage Markets amidst Socio-Demographic Change in India, 2005–2050

    PubMed Central

    Kashyap, Ridhi; Esteve, Albert; García-Román, Joan

    2015-01-01

    We explore the impact of socio-demographic change on marriage patterns in India by examining the hypothetical consequences of applying three sets of marriage pairing propensities – contemporary patterns by age, by age and education, and changing propensities that allow for greater educational homogamy and reduced educational asymmetries – to future population projections. Future population prospects for India indicate three trends that will impact marriage patterns: i) female-deficit in sex ratios at birth; ii) declining birth cohort size; iii) female educational expansion. Existing literature posits declining marriage rates for men arising from skewed sex ratios at birth (SRB) in India’s population. In addition to skewed SRBs, India’s population will experience female educational expansion in the coming decades. Female educational expansion and its impact on marriage patterns must be jointly considered with demographic changes, given educational differentials and asymmetries in union formation that exist in India, as across much of the world. We systematize contemporary pairing propensities using data from the 2005–2006 Indian National Family Health Survey and the 2004 Socio-Economic Survey and apply these and the third set of changing propensities to IIASA/VID multi-state population projections by educational attainment using an iterative longitudinal projection procedure. If today’s age patterns of marriage are viewed against age-sex population composition until 2050, men experience declining marriage prevalence. However, when education is included, women, particularly those with higher education experience a more salient rise in non-marriage. Significant changes in pairing patterns towards greater levels of educational homogamy and gender symmetry can counteract a marked rise in non-marriage. PMID:25604846

  2. On the (mis-) Behavior of Thunderstorms at the Grand Canyon, Arizona

    NASA Astrophysics Data System (ADS)

    Cummins, K. L.; Saba, M. M.; Schulz, W.; Noggle, C.; Quick, M. G.; Saraiva, A. C.; Krider, E. P.

    2009-12-01

    The area density of cloud-to-ground (CG) lightning strokes reported by the NLDN near the Grand Canyon, Arizona, show strong variations near the canyon rim. The average area density of strokes outside the canyon is about 8-times larger than within the canyon, and there is a clear increase in the frequency of lightning attachments near the top edge of the canyon rim. If the attachments are made at or near the top of the rim, this could imply a very large attractive radius and unusually long upward leaders, perhaps produced by enhanced electric fields at the canyon rim just prior to ground termination. If the attachments are made along the face of the canyon near the rim, another possible explanation of the existing data, then the high area density near the rim and the low density within the canyon might be explained by the random spatial development of downward branches in the lightning leader just prior to attachment, interacting with the slope and protrusions along the canyon walls. This geometrical development might cause attachment to occur to the canyon walls before the lower-altitude leader channels can attach to the canyon floor. Two other possible factors are (1) the attenuation or distortion of the electromagnetic fields produced by the lightning due to propagation from deep within the canyon to the surface and (2) a difficulty for lightning-producing storms to form over or propagate into the wider regions of the canyon. The effects of EM propagation will likely result in low-amplitude fields and/or produce waveforms that the NLDN will not classify as CG strokes. Storm-propagation effects will likely reduce the convection and the electrification of clouds over the wide portions of the canyon, and result in a lower area density of flashes. We will present limited results of some measurements that were obtained during July 2009 relating to each of the above factors, and we will outline our plans for additional measurements during July/August 2010 or 2011.

  3. Chomsky on MisEducation. Critical Perspectives Series: A Book Series Dedicated to Paulo Freire

    ERIC Educational Resources Information Center

    Chomsky, Noam

    2004-01-01

    Noam Chomsky's prolific writings have made him one of the most-quoted educators in history--the only living writer on a most-cited list that includes Plato, Shakespeare, and Freud. Yet until now, no book has systematically offered Chomsky's influential writings on education. In this book, Noam Chomsky encourages a larger understanding of…

  4. Fabrication and testing of MIS solar cells on a-Si:F:H

    NASA Astrophysics Data System (ADS)

    Han, M. K.; Anderson, W. A.

    1980-11-01

    Fabrication techniques and improved a-Si:H film processing were achieved to produce a short circuit current density of 7.5 mA sq/cm and open circuit voltage of 740 mV on large area a-Si cells by the deposition of an inexpensive semitransparent metal (Cr) as a top electrode on a N-I-P structure. This corresponds to a 2% efficiency using AMl illumination. A V(sub oc) of 830 mV and fill factor of 0.54 were also separately obtained. A relatively simple and inexpensive deposition technique using a one pumpdown vacuum system, Al grid, and thin metal film structure were applied to reduce the cost of a-Si:H cell fabrication. A SEM study of a-Si film quality shows the substrate texture to greatly influence the film morphology. This in turn serves to influence the uniformity of photovoltaic response on completed solar cells. The studies of optical transmittance of various thin metal films promote the utilization of Cr and Cu as a top electrode. Dark and illuminated I-V characteristics show that current conduction mechanisms and recombination phenomena are not the same under dark and illuminated conditions.

  5. The (Mis)Identification of Ineffective Classroom Teaching Practice: Critical Interrogations of Classroom Teacher Effectiveness Research

    ERIC Educational Resources Information Center

    Skourdoumbis, Andrew

    2013-01-01

    This paper critiques specific forms of classroom teacher effectiveness research. In doing so, the paper suggests that education policy-making deems and employs teacher effectiveness research as a promising and capable contrivance for the identification of ineffective classroom teaching practice. The paper engages with this policy debate by using a…

  6. MIS In-Service Session on The Dynamics of Small College Management. Volume II. Conference Proceedings.

    ERIC Educational Resources Information Center

    Bailey, Jan, Ed.

    This document presents the proceedings of an invitational conference, held in Washington, D.C., February 21-22, 1974 concerning the dynamics of small college management. Discussion topics encompassed management information systems packages for small colleges. Various presentations discussed the Plantran System, the resource requirements prediction…

  7. Measuring the Performance and Intelligence of Systems: Proceedings of the 2002 PerMIS Workshop

    NASA Astrophysics Data System (ADS)

    Messina, E. R.; Meystel, A. M.

    2002-09-01

    Contents include the following: Performance Metrics; Performance of Multiple Agents; Performance of Mobility Systems; Performance of Planning Systems; General Discussion Panel 1; Uncertainty of Representation I; Performance of Robots in Hazardous Domains; Modeling Intelligence; Modeling of Mind; Measuring Intelligence; Grouping: A Core Procedure of Intelligence; Uncertainty in Representation II; Towards Universal Planning/Control Systems.

  8. Directly dated MIS 3 lake-level record from Lake Manix, Mojave Desert, California, USA

    USGS Publications Warehouse

    Reheis, Marith; Miller, David M.; McGeehin, John P.; Redwine, Joanna R.; Oviatt, Charles G.; Bright, Jordon E.

    2015-01-01

    An outcrop-based lake-level curve, constrained by ~ 70 calibrated 14C ages on Anodonta shells, indicates at least 8 highstands between 45 and 25 cal ka BP within 10 m of the 543-m upper threshold of Lake Manix in the Mojave Desert of southern California. Correlations of Manix highstands with ice, marine, and speleothem records suggest that at least the youngest three highstands coincide with Dansgaard–Oeschger (D–O) stadials and Heinrich events 3 and 4. The lake-level record is consistent with results from speleothem studies in the Southwest that indicate cool wet conditions during D–O stadials. Notably, highstands between 43 and 25 ka apparently occurred at times of generally low levels of pluvial lakes farther north as interpreted from core-based proxies. Mojave lakes may have been supported by tropical moisture sources during oxygen-isotope stage 3, perhaps controlled by southerly deflection of Pacific storm tracks due to weakening of the sea-surface temperature gradient in response to North Atlantic climate perturbations.

  9. CIS/MIS Curriculums in AACSB-Accredited Colleges of Business.

    ERIC Educational Resources Information Center

    Maier, J. Lee; Gambill, Stan

    1996-01-01

    Of 108 business colleges with computer information systems/management information systems majors, 43 responded to a survey. Curricula appear slow to respond to current needs. COBOL programming is still very popular. Only one management-type course is offered. (SK)

  10. (Mis)understanding Safety Culture and Its Relationship to Safety Management.

    PubMed

    Guldenmund, Frank W

    2010-10-01

    Although the concept of safety culture was coined in relation to major accidents like Chernobyl and Piper Alpha, it has been embraced by the safety community at large as a cause for unsafe practice. In this article, three approaches to safety culture are discussed in terms of their underlying concepts of culture and organizational culture. Culture is an intangible, fuzzy concept encompassing acquired assumptions that is shared among the members of a group and that provides meaning to their perceptions and actions and those of others. The basic assumptions that form the essence of a culture are shared, yet tacit, convictions, which manifest themselves subtly in the visible world. As applied by safety researchers, the culture concept is deprived of much of its depth and subtlety, and is morphed into a grab bag of behavioral and other visible characteristics, without reference to the meaning these characteristics might actually have, and often infused with normative overtones. By combining the three approaches, we can resurrect the notion of safety culture and strengthen its analytical potential in understanding the development and implementation of safety management systems. PMID:20626685

  11. Radiogenic Nd isotope labeling of the northern NE Atlantic during MIS 2

    NASA Astrophysics Data System (ADS)

    Roberts, Natalie L.; Piotrowski, Alexander M.

    2015-08-01

    Paleoceanographic reconstructions rely on chemical proxies which are controlled by physical, chemical, and biological marine parameters. The accurate interpretation of proxy records relies on the integrity of proxy-environmental relationships through time, and under changing conditions. In this study we closely examine paleo controls on authigenic Nd isotope records from five cores in the northern NE Atlantic, approximating a depth-transect, allowing spatial and temporal relationships to be reconstructed. We compare our Nd isotope records with other paleocirculation proxies, and consider the sedimentalogical controls on Nd isotope signals, by comparing ice-rafted detritus lithology and counts, detrital sediment chemistry and redox sensitive element concentrations measured on foraminifera authigenic coatings. With this suite of geochemical and sedimentalogical data we show that Nd isotope records in the northern NE Atlantic were labeled by radiogenic sediments, however this modification did not occur in the pore-waters of each core, but instead likely reflects changes in the Nd isotopic composition of deep-waters caused by the input of ice-rafted sediment during Heinrich events and the last glacial maximum. This study has implications for understanding how localized changes in the Nd isotope signal can set a watermass end-member composition, decoupling chemical proxy-circulation relationships locally, but providing a signal which can be potentially traced along the deep-water flowpath. Such scenarios must be considered in future interpretations of glacial Nd isotope records taken from within the ice-rafted detritus belt and downstream along watermass flowpaths.

  12. The spiral of science (mis)education, Parker's ``multiple influences,'' and missed opportunities

    NASA Astrophysics Data System (ADS)

    Richardson Bruna, Katherine

    2014-06-01

    In this reflection on Carolyn Parker's article, I connect to my own professional work at the intersection of Latino education and science education as well as to my own personal interest in liberation theology. I use constructs central to liberation theology to indicate what a liberationist science might look like and push us, in doing so, to put learning, not teaching, at the center of our efforts.

  13. The Spiral of Science (Mis)Education, Parker's "Multiple Influences," and Missed Opportunities

    ERIC Educational Resources Information Center

    Richardson Bruna, Katherine

    2014-01-01

    In this reflection on Carolyn Parker's article, I connect to my own professional work at the intersection of Latino education and science education as well as to my own personal interest in liberation theology. I use constructs central to liberation theology to indicate what a liberationist science might look like and push us, in doing so, to…

  14. Mis-expression of a PISTILLATA-like MADS box gene prevents fruit development in grapevine.

    PubMed

    Fernandez, Lucie; Chaïb, Jamila; Martinez-Zapater, José-Miguel; Thomas, Mark R; Torregrosa, Laurent

    2013-03-01

    The FLESHLESS BERRY (Flb) somatic variant identified in the grapevine cultivar Ugni Blanc develops grape berries without flesh, suggesting a role for the altered gene in differentiation of flesh cells. Here we describe identification of the molecular defect responsible for this phenotype. Using a combination of genetic and transcriptomic approaches, we detected the insertion of a miniature inverted-repeat transposable element in the promoter region of the PISTILLATA-like (VvPI) gene, the grapevine homologue of Arabidopsis PISTILLATA. The transposon insertion causes specific ectopic expression of the corresponding VvPI allele during early fruit development, causing expression of genes specific for petal and stamen development within the fruit. A causal relationship between the insertion and the phenotype was demonstrated by phenotypic and molecular analyses of somatic revertants showing that ectopic expression and mutant phenotype were always linked to the presence of the transposon insertion. The various phenotypic effects of the flb mutation on ovary morphology, fruit set and fruit development, depending on the cell lineage affected, are presented for each phenotype, offering new insights into floral and fleshly fruit development. The results highlight the importance of VvPI repression after fertilization to achieve normal fleshy fruit development, and the complex genetic, genomic and cellular interactions required for the flower to fruit transition in grapevine. PMID:23181568

  15. Testing Report: Littleford-Day Dryer Operation: Dryer Operation Impacts of Proposed MIS Mitigation Changes

    SciTech Connect

    Shimskey, Rick W.; Buchmiller, William C.; Elmore, Monte R.

    2007-06-01

    Pacific Northwest National Laboratory performed a series of tests using the Littleford Day 22-liter dryer during investigations that evaluated changes in the melter-feed composition for the Demonstration Bulk Vitrification System. During testing, a new melter-feed formulation was developed that improved dryer performance while improving the retention of waste salts in the melter feed during vitrification.

  16. The Effects and Side-Effects of Statistics Education: Psychology Students' (Mis-)Conceptions of Probability

    ERIC Educational Resources Information Center

    Morsanyi, Kinga; Primi, Caterina; Chiesi, Francesca; Handley, Simon

    2009-01-01

    In three studies we looked at two typical misconceptions of probability: the representativeness heuristic, and the equiprobability bias. The literature on statistics education predicts that some typical errors and biases (e.g., the equiprobability bias) increase with education, whereas others decrease. This is in contrast with reasoning theorists'…

  17. Adolescent (Mis)Perceptions about Nicotine Addiction: Results from a Mixed-Methods Study

    ERIC Educational Resources Information Center

    Roditis, Maria; Lee, Joann; Halpern-Felsher, Bonnie L.

    2016-01-01

    Purpose: Despite evidence that adolescents become addicted to nicotine even after limited use, adolescents believe they can experiment with or smoke cigarettes for a few years and easily quit. The goal of this study was to examine adolescents' understanding of the definition and process of nicotine addiction using a mixed-methods approach. Method:…

  18. The (mis)Alignment of the Earth Science Literacy Principles to the National Science Education Standards

    NASA Astrophysics Data System (ADS)

    Ladue, N.; Clark, S.; Thompson, J.; Beckendorf, K.; Wysession, M. E.

    2009-12-01

    The initiative to develop the Earth Science Literacy Principles (ESLP) was an effort to encourage community consensus about the Big Ideas in the Earth Sciences, especially in the solid-earth and hydrologic geosciences. The Principles have been aligned to the National Science Education Standards (NSES) in order to make them more useable for curriculum developers, textbook writers and K-12 educators. The alignment demonstrates that much of the content that is highly valued in the NSES involving Earth and Space Science is not related to the fundamental concepts in the ESLP. Surprisingly, the greatest alignment of concepts in the ESLP is to standards related to Personal and Societal Perspectives in the NSES. Analysis of the alignment demonstrates the highly interdisciplinary nature of the Earth sciences in addressing standards related to Physical Science, Life Science, and Science and Technology in addition to those previously mentioned. An in-depth analysis will follow to examine content valued by the NSES that has been left out of the ESLP, as well as the converse.

  19. Primary Renal Hydatid Cyst: Mis-Interpretation as a Renal Malignancy

    PubMed Central

    Choi, Hoon; Park, Jae Young; Kim, Jae-Heon; Moon, Du Geon; Lee, Jeong-Gu

    2014-01-01

    Primary renal echinococcosis, a rare disease involving the kidney, accounts for 2-3% of human echinococcosis. A 64-year-old female patient from Uzbekistan presented with complaints of left flank pain. A CT scan revealed a cystic mass in the upper to midpole of the left kidney. We regarded this lesion as a renal malignancy and hand-assisted laparoscopic radical nephrectomy was performed to remove the renal mass. The mass consisted of a large unilocular cyst and multiple smaller cysts without any grossly visible renal tissue. The final pathologic diagnosis was a renal hydatid cyst. For patients from endemic areas, hydatid cyst should be included in the differential diagnosis. Here, we present a case of renal hydatid cyst in a female patient who relocated from Uzbekistan to Korea. PMID:25031471

  20. Changes in Academic Dishonesty among MIS Majors between 1999 and 2004

    ERIC Educational Resources Information Center

    Brown, Bob S.; Weible, Rick

    2006-01-01

    A questionnaire on academic dishonesty was administered to management information systems majors at an eastern state university in 1999 and 2004. The often-cited proposition that the level of student academic dishonesty among college and university students is increasing was unsupported. While the level of participation in one practice increased…

  1. RNA-binding protein mis-regulation in microsatellite expansion disorders

    PubMed Central

    Goodwin, Marianne; Swanson, Maurice S.

    2015-01-01

    RNA-binding proteins (RBPs) play pivotal roles in multiple cellular pathways from transcription to RNA turnover by interacting with RNA sequence and/or structural elements to form distinct RNA-protein complexes. Since these complexes are required for the normal regulation of gene expression, mutations that alter RBP functions may result in a cascade of deleterious events that lead to severe disease. Here, we focus on a group of hereditary disorders, the microsatellite expansion diseases, which alter RBP activities and result in abnormal neurological and neuromuscular phenotypes. While many of these diseases are classified as adult-onset disorders, mounting evidence indicates that disruption of normal RNA-protein interaction networks during embryogenesis modifies developmental pathways which ultimately leads to disease manifestations later in life. Efforts to understand the molecular basis of these disorders has already uncovered novel pathogenic mechanisms, including RNA toxicity and repeat-associated non-ATG (RAN) translation, and current studies suggest that additional surprising insights into cellular regulatory pathways will emerge in the future. PMID:25201111

  2. Use and mis-use of supplementary material in science publications.

    PubMed

    Pop, Mihai; Salzberg, Steven L

    2015-01-01

    Supplementary material is a ubiquitous feature of scientific articles, particularly in journals that limit the length of the articles. While the judicious use of supplementary material can improve the readability of scientific articles, its excessive use threatens the scientific review process and by extension the integrity of the scientific literature. In many cases supplementary material today is so extensive that it is reviewed superficially or not at all. Furthermore, citations buried within supplementary files rob other scientists of recognition of their contribution to the scientific record. These issues are exacerbated by the lack of guidance on the use of supplementary information from the journals to authors and reviewers. We propose that the removal of artificial length restrictions plus the use of interactive features made possible by modern electronic media can help to alleviate these problems. Many journals, in fact, have already removed article length limitations (as is the case for BMC Bioinformatics and other BioMed Central journals). We hope that the issues raised in our article will encourage publishers and scientists to work together towards a better use of supplementary information in scientific publishing. PMID:26525146

  3. Spin-orbit angle distribution and the origin of (mis)aligned hot Jupiters

    NASA Astrophysics Data System (ADS)

    Crida, A.; Batygin, K.

    2014-07-01

    Context. For 61 transiting hot Jupiters, the projection of the angle between the orbital plane and the stellar equator (called the spin-orbit angle) has been measured. For about half of them, a significant misalignment is detected, and retrograde planets have been observed. This challenges scenarios of the formation of hot Jupiters. Aims: In order to better constrain formation models, we relate the distribution of the real spin-orbit angle Ψ to the projected one β. Then, a comparison with the observations is relevant. Methods: We analyse the geometry of the problem to link analytically the projected angle β to the real spin-orbit angle Ψ. The distribution of Ψ expected in various models is taken from the literature, or derived with a simplified model and Monte Carlo simulations in the case of the disk-torquing mechanism. Results: An easy formula to compute the probability density function (PDF) of β knowing the PDF of Ψ is provided. All models tested here look compatible with the observed distribution beyond 40 degrees, which is so far poorly constrained by only 18 observations. But only the disk-torquing mechanism can account for the excess of aligned hot Jupiters, provided that the torquing is not always efficient. This is the case if the exciting binaries have semi-major axes as large as ~104 AU. Conclusions: Based on comparison with the set of observations available today, scattering models and the Kozai cycle with tidal friction models can not be solely responsible for the production of all hot Jupiters. Conversely, the presently observed distribution of the spin-orbit angles is compatible with most hot Jupiters having been transported by smooth migration inside a proto-planetary disk, itself possibly torqued by a companion.

  4. Spin-Orbit angle distribution and the origin of (mis)aligned hot Jupiters

    NASA Astrophysics Data System (ADS)

    Crida, A.; Batygin, K.

    2014-12-01

    The angle between the orbital plane and the stellar equator (called the spin-orbit angle) has been measured for about 60 hot Jupiters, half of them showing significant misalignment. This challenges scenarios of the formation of hot Jupiters. Recently, it has been proposed that misalignment could be a consequence of the torquing of the proto-planetary disk by a transcient binary companion of the host star Here, we analyse the geometry of the problem, and compare the probability density function (PDF) of the projected spin-orbit angle expected in various mechanisms, with the observed one. Scattering models and the Kozai cycle with tidal friction models can not be solely responsible for the production of all hot Jupiters. Conversely, the presently observed distribution of the spin-orbit angles is compatible with most hot Jupiters having been transported by smooth migration inside a proto-planetary disk, itself possibly torqued by a companion.

  5. Full device analysis of novel metamaterial coated PN and MIS solar cells using numerical methods

    NASA Astrophysics Data System (ADS)

    Mandel, Isroel; Gollub, Jonah N.; Sarantos, Chris; Pishbin, Nafiseh; Crouse, David T.

    2012-02-01

    In this work we describe how to model the efficiency of solar cells with novel metamaterial coatings optimized for light harvesting. Full device modeling is implemented using optical and electrical simulations. As a proof of concept, we simulate the operation of a metamaterial contact on a first generation monocrystalline silicon solar cell. We compare device characteristics and efficiencies to standard antireflective coatings applied to a grid contact cell. The effects of the metamaterial contact on silicon solar cell efficiencies is discussed for PN junction and metal-insulator-semiconductor cell structures. It is found that the metal-insulator-semiconductor solar cell designed performs better than the PN junction cell.

  6. Characterization of Defects in Scaled Mis Dielectrics with Variable Frequency Charge Pumping

    NASA Astrophysics Data System (ADS)

    Paulsen, Ronald Eugene

    1995-01-01

    Historically, the interface trap has been extensively investigated to determine the effects on device performance. Recently, much attention has been paid to trapping in near-interface oxide traps. Performance of high precision analog circuitry is affected by charge trapping in near-interface oxide traps which produces hysteresis, charge redistribution errors, and dielectric relaxation effects. In addition, the performance of low power digital circuitry, with reduced noise margins, may be drastically affected by the threshold voltage shifts associated with charge trapping in near -interface oxide traps. Since near-interface oxide traps may substantially alter the performance of devices, complete characterization of these defects is necessary. In this dissertation a new characterization technique, variable frequency charge pumping, is introduced which allows charge trapped at the interface to be distinguished from the charge trapped within the oxide. The new experimental technique is an extension of the charge pumping technique to low frequencies such that tunneling may occur from interface traps to near-interface oxide traps. A generalized charge pumping model, based on Shockley-Read-Hall statistics and trap-to-trap tunneling theory, has been developed which allows a more complete characterization of near-interface oxide traps. A pair of coupled differential equations governing the rate of change of occupied interface and near-interface oxide traps have been developed. Due to the experimental conditions in the charge pumping technique the equations may be decoupled, leading to an equation governing the rate of change of occupied interface traps and an equation governing the rate of change of occcupied near-interface oxide traps. Solving the interface trap equation and applying non-steady state charge dynamics leads to an interface trap component of the charge pumping current. In addition, solution to the near-interface oxide trap equation leads to an additional oxide trap component to the charge pumping current. Numerical simulations have been performed to support the analytical development of the generalized charge pumping model. By varying the frequency of the applied charge pumping waveform and monitoring the charge recombined per cycle, the contributions from interface traps may be separated from the contributions of the near-interface oxide traps. The generalized charge pumping model allows characterization of the density and spatial distribution of near-interface oxide traps from this variable frequency charge pumping technique. Characterization of interface and near-interface oxide trap generation has been performed on devices exposed to ionizing radiation, hot electron injection, and high -field/Fowler-Nordheim stressing. Finally, using SONOS nonvolatile memory devices, a framework has been established for experimentally determining not only the spatial distribution of near-interface oxide traps, but also the energetic distribution. An experimental approach, based on tri-level charge pumping, is discussed which allows the energetic distribution of near-interface oxide traps to be determined.

  7. Inconsistent treatment estimates from mis-specified logistic regression analyses of randomized trials.

    PubMed

    Matthews, J N S; Badi, N H

    2015-08-30

    When the difference between treatments in a clinical trial is estimated by a difference in means, then it is well known that randomization ensures unbiassed estimation, even if no account is taken of important baseline covariates. However, when the treatment effect is assessed by other summaries, for example by an odds ratio if the outcome is binary, then bias can arise if some covariates are omitted, regardless of the use of randomization for treatment allocation or the size of the trial. We present accurate closed-form approximations for this asymptotic bias when important normally distributed covariates are omitted from a logistic regression. We compare this approximation with ones in the literature and derive more convenient forms for some of these existing results. The expressions give insight into the form of the bias, which simulations show is usable for distributions other than the normal. The key result applies even when there are additional binary covariates in the model. PMID:25869059

  8. (Mis)Perceptions of Continuing Education: Insights from Knowledge Translation, Quality Improvement, and Patient Safety Leaders

    ERIC Educational Resources Information Center

    Kitto, Simon C.; Bell, Mary; Goldman, Joanne; Peller, Jennifer; Silver, Ivan; Sargeant, Joan; Reeves, Scott

    2013-01-01

    Introduction: Minimal attention has been given to the intersection and potential collaboration among the domains of continuing education (CE), knowledge translation (KT), quality improvement (QI), and patient safety (PS), despite their overlapping objectives. A study was undertaken to examine leaders' perspectives of these 4 domains and their…

  9. Re-Birthing the Monstrous: James Whale's (Mis)Reading of Mary Shelley's "Frankenstein."

    ERIC Educational Resources Information Center

    Picart, Caroline Joan S.

    1998-01-01

    Contributes to scholarship on film and feminism by showing how James Whale's film attempts to excise or severely delimit the disturbing critique of the Romantic politics of gender in Mary Shelley's novel "Frankenstein." Discusses parthenogenesis, showing how the novel critiques the Romantic rhetorical reconstructions of masculine divinity and…

  10. Measuring the Performance and Intelligence of Systems: Proceedings of the 2002 PerMIS Workshop

    NASA Technical Reports Server (NTRS)

    Messina, E. R.; Meystel, A. M.

    2002-01-01

    Contents include the following: Performance Metrics; Performance of Multiple Agents; Performance of Mobility Systems; Performance of Planning Systems; General Discussion Panel 1; Uncertainty of Representation I; Performance of Robots in Hazardous Domains; Modeling Intelligence; Modeling of Mind; Measuring Intelligence; Grouping: A Core Procedure of Intelligence; Uncertainty in Representation II; Towards Universal Planning/Control Systems.

  11. Effects of entertainment (mis) education: exposure to entertainment television programs and organ donation intention.

    PubMed

    Yoo, Jina H; Tian, Yan

    2011-03-01

    This study investigates antecedents and outcomes of entertainment television consumption in organ donation with the Orientation₁-Stimulus-Orientation₂-Response (O₁-S-O₂ -R) model. It reveals that organ donation knowledge seems significantly related to recall of entertainment television programs and attitudes toward organ donation. Meanwhile, recall of entertainment television programs significantly predicts people's perception of medical mistrust, which in turn negatively predicts attitudes toward organ donation, while attitudes toward organ donation significantly predict behavioral intention in signing a donor card. It also suggests significant mediation relationships among the pre-orientation variable, stimulus, post-orientation variable, and attitudinal and behavioral outcomes. This study provides an integrative theoretical framework to study media effects on organ donation and empirical evidence for "entertainment miseducation" (Morgan, Harrison, Chewning, Davis, & DiCorcia, 2007). PMID:21271421

  12. DNA damage response during mitosis induces whole chromosome mis-segregation

    PubMed Central

    Bakhoum, Samuel F.; Kabeche, Lilian; Murnane, John P.; Zaki, Bassem I.; Compton, Duane A.

    2014-01-01

    Many cancers display both structural (s-CIN) and numerical (w-CIN) chromosomal instabilities. Defective chromosome segregation during mitosis has been shown to cause DNA damage that induces structural rearrangements of chromosomes (s-CIN). In contrast, whether DNA damage can disrupt mitotic processes to generate whole chromosomal instability (w-CIN) is unknown. Here we show that activation of the DNA damage response (DDR) during mitosis selectively stabilizes kinetochore-microtubule (k-MT) attachments to chromosomes through Aurora-A and Plk1 kinases, thereby increasing the frequency of lagging chromosomes during anaphase. Inhibition of DDR proteins, ATM or Chk2, abolishes the effect of DNA damage on k-MTs and chromosome segregation, whereas activation of the DDR in the absence of DNA damage is sufficient to induce chromosome segregation errors. Finally, inhibiting the DDR during mitosis in cancer cells with persistent DNA damage suppresses inherent chromosome segregation defects. Thus, DDR during mitosis inappropriately stabilizes k-MTs creating a link between s-CIN and w-CIN. PMID:25107667

  13. MALDI-MIS INVESTIGATIONS OF DRINKING WATER PATHOGENS--GIARDIA AND CRYPTOSPORIDIUM

    EPA Science Inventory

    The protozoan parasites, Cryptosporidium parvum and Giardia lamblia, have been responsible for numerous waterborne outbreaks of gastrointestinal illness in the United States. The 1993 cryptosporidiosis outbreak in Milwaukee affected approximately 400,000 people and resulted in o...

  14. What is it that lingers? Garden-path (mis)interpretations in younger and older adults.

    PubMed

    Malyutina, Svetlana; den Ouden, Dirk-Bart

    2016-05-01

    Previous research has shown that comprehenders do not always conduct a full (re)analysis of temporarily ambiguous "garden-path" sentences. The present study used a sentence-picture matching task to investigate what kind of representations are formed when full reanalysis is not performed: Do comprehenders "blend" two incompatible representations as a result of shallow syntactic processing or do they erroneously maintain the initial incorrect parsing without incorporating new information, and does this vary with age? Twenty-five younger and 15 older adults performed a multiple-choice sentence-picture matching task with stimuli including early-closure garden-path sentences. The results suggest that the type of erroneous representation is affected by linguistic variables, such as sentence structure, verb type, and semantic plausibility, as well as by age. Older adults' response patterns indicate an increased reliance on inferencing based on lexical and semantic cues, with a lower bar for accepting an initial parse and with a weaker drive to reanalyse a syntactic representation. Among younger adults, there was a tendency to blend two representations into a single interpretation, even if this was not licensed by the syntax. PMID:25920901

  15. Language and Nutrition (Mis)Information: Food Labels, FDA Policies and Meaning

    ERIC Educational Resources Information Center

    Taylor, Christy Marie

    2013-01-01

    In this dissertation, I address the ways in which food manufacturers can exploit the often vague and ambiguous nature of FDA policies concerning language and images used on food labels. Employing qualitative analysis methods (Strauss, 1987; Denzin and Lincoln, 2003; Mackey and Gass, 2005) that drew upon critical discourse analysis (Fairclough,…

  16. Financial Aid: Who Needs It? MIS Research Profile, Volume One, Number 1, Mar. 1973.

    ERIC Educational Resources Information Center

    Jackson, Linda M.

    This report examines various aspects of financial aid including financial need as the basis for financial aid to students and the problem of inadequate funds. Recommendations suggest: (1) When forms are administered to the students, more guidance is needed to make them aware of the differences in the two systems presently serving the colleges and…

  17. Ethical Issues in the Introduction of New Technologies: From Mis to POEM.

    PubMed

    Ferreres, Alberto R; Patti, Marco

    2015-07-01

    The ethical debate regarding the introduction of new technologies in the surgical health care environment is discussed in this manuscript, with a special emphasis on minimally invasive and NOTES procedures for the treatment of esophageal achalasia. It offers an overview of the ethical principles and considerations about the implementation of new techniques and technologies. PMID:25894402

  18. Understanding public (mis)understanding of tDCS for enhancement

    PubMed Central

    Cabrera, Laura Y.; Reiner, Peter B.

    2015-01-01

    In order to gain insight into the public’s perspective on using the minimally invasive technique transcranial direct current stimulation (tDCS) as an enhancement tool, we analyzed and compared online comments in key popular press articles from two different periods (pre-commercialization and post-commercialization). The main conclusion drawn from this exploratory investigation is that public perception regarding tDCS has shifted from misunderstanding to cautionary realism. This change in attitude can be explained as moving from a focus on an emergent technology to a focus on its applications, benefits, and risks as the technology becomes more grounded within the public domain. Future governance of tDCS should include the concerns and enthusiasms of the public. PMID:25964748

  19. (Mis)reading Social Class in the Journey towards College: Youth Development in Urban America

    ERIC Educational Resources Information Center

    Bloom, Janice L.

    2007-01-01

    While college is perceived as a given for many middle- and upper-income students graduating from high school, the transition from secondary to higher education is a much more complicated one for low-income students, particularly poor and working-class students of color. This article focuses on the critical juncture--one that is under-explored in…

  20. The (Mis)use of the Finnish Teacher Education Model: "Policy-Based Evidence-Making"?

    ERIC Educational Resources Information Center

    Chung, Jennifer

    2016-01-01

    Background: International achievement studies such as the Programme for International Student Assessment (PISA) have an increasing influence on education policy worldwide. The use of such data can provide a basis for evidence-based policy-making to initiate educational reform. Finland, a high performer in PISA, is often cited as an example of both…

  1. Tree Trunks from MIS3 Revealed in Pacific Northwest Landslide Deposits

    NASA Astrophysics Data System (ADS)

    van de Water, P. K.; Leavitt, S. W.; Panyushkina, I. P.; Jull, A. T.; Testa, N. R.; Squire, J.

    2010-12-01

    Multiple large tree trunks have been discovered in landslide deposits dating to before the last full-glacial provide a new source for paleo-climatic reconstructions from the northwest coast of North America. Excavation during US Highway 20 realignment through the Oregon Coast Range uncovered organic deposits at depth that included the boles of twelve large trees. Radiocarbon dates on subsurface organic material from multiple landslide deposits range from 17,850 ± 100 to >46,400 (radiocarbon dates B.P.). A single cohort of twelve tree trunks, found emplaced nearly upright, date to >53,000 radiocarbon years B.P. The sedimentary deposits are interpreted as paleo-translational landslides involving the Tyee Formation. The trees are tentatively identified as Thuja plicata, Pseudotsuga menziesii, and Abies spp. Preservation of the wood material and associated macrofossils is excellent because of clay sediments that encased the material, halting decomposition. Preliminary analysis shows excellent preservation of late-wood rings but the early wood is composed primarily of ghost tracheids. Ring counts from a portion of the Thuja plicata bole, a four inch block of outer rings, contained between 120 to 130 rings of annual growth with good sensitivity for climate reconstruction. This makes the find particularly important for inferring high-resolution environmental variability, because it is one of only very few deposits of wood of this age worldwide. In addition to paleobotanical and paleoclimatic information, the large amount of wood will be used for radioisotope and stable isotope studies.

  2. Exploratory Factor Analysis as a Construct Validation Tool: (Mis)applications in Applied Linguistics Research

    ERIC Educational Resources Information Center

    Karami, Hossein

    2015-01-01

    Factor analysis has been frequently exploited in applied research to provide evidence about the underlying factors in various measurement instruments. A close inspection of a large number of studies published in leading applied linguistic journals shows that there is a misconception among applied linguists as to the relative merits of exploratory…

  3. Pursuing Justice for Refugee Students: Addressing Issues of Cultural (Mis)Recognition

    ERIC Educational Resources Information Center

    Keddie, Amanda

    2012-01-01

    In this paper Nancy Fraser's conceptual tools are drawn on to theorise issues of justice in a culturally diverse primary school in Australia where approximately 30% of the student population are immigrant/refugees. The paper examines justice issues of cultural recognition in relation to refugee student identity, behaviour and assessment. Drawing…

  4. Teaching Higher Order Thinking in the Introductory MIS Course: A Model-Directed Approach

    ERIC Educational Resources Information Center

    Wang, Shouhong; Wang, Hai

    2011-01-01

    One vision of education evolution is to change the modes of thinking of students. Critical thinking, design thinking, and system thinking are higher order thinking paradigms that are specifically pertinent to business education. A model-directed approach to teaching and learning higher order thinking is proposed. An example of application of the…

  5. Are phonological influences on lexical (mis)selection the result of a monitoring bias?

    PubMed Central

    Ratinckx, Elie; Ferreira, Victor S.; Hartsuiker, Robert J.

    2009-01-01

    A monitoring bias account is often used to explain speech error patterns that seem to be the result of an interactive language production system, like phonological influences on lexical selection errors. A biased monitor is suggested to detect and covertly correct certain errors more often than others. For instance, this account predicts that errors which are phonologically similar to intended words are harder to detect than ones that are phonologically dissimilar. To test this, we tried to elicit phonological errors under the same conditions that show other kinds of lexical selection errors. In five experiments, we presented participants with high cloze probability sentence fragments followed by a picture that was either semantically related, a homophone of a semantically related word, or phonologically related to the (implicit) last word of the sentence. All experiments elicited semantic completions or homophones of semantic completions, but none elicited phonological completions. This finding is hard to reconcile with a monitoring bias account and is better explained with an interactive production system. Additionally, this finding constrains the amount of bottom-up information flow in interactive models. PMID:18942035

  6. Isotopic variability of cave bears (δ15N, δ13C) across Europe during MIS 3

    NASA Astrophysics Data System (ADS)

    Krajcarz, Magdalena; Pacher, Martina; Krajcarz, Maciej T.; Laughlan, Lana; Rabeder, Gernot; Sabol, Martin; Wojtal, Piotr; Bocherens, Hervé

    2016-01-01

    Collagen, the organic fraction of bone, records the isotopic parameters of consumed food for carbon (δ13C) and nitrogen (δ15N). This relationship of isotopic signature between diet and tissue is an important tool for the study of dietary preferences of modern and fossil animal species. Since the first information on the isotopic signature of cave bear was reported, numerous data from Europe have become available. The goal of this work is to track the geographical variation of cave bear collagen isotopic values in Europe during Marine Isotopic Stage 3 (about 60,000-25,000 yr BP). In this study the results of new δ13C and δ15N isotopic analyses of cave bear collagen from four Central-Eastern European sites are presented, as well as a review of all published isotopic data for cave bears of the same period. The main conclusion is a lack of geographical East-West pattern in the variations of δ13C and δ15N values of cave bear collagen. Moreover, no relationship was found between cave bear taxonomy and isotopic composition. The cave bears from Central-Eastern Europe exhibit δ13C and δ15N values near the average of the range of Central, Western and Southern European cave bears. Despite the fact that most cave bear sites follow an altitudinal gradient, separate groups of sites exhibit shift in absolute values of δ13C, what disturbs an altitude-related isotopic pattern. The most distinct groups are: high Alpine sites situated over 1500 m a.s.l. - in terms of δ13C; and two Romanian sites Peştera cu Oase and Urşilor - in case of δ15N. Although the cave bear isotopic signature is driven by altitude, the altitudinal adjustment of isotopic data is not enough to explain the isotopic dissimilarity of these cave bears. The unusually high δ15N signature of mentioned Romanian sites is an isolated case in Europe. Cave bears from relatively closely situated Central-Eastern European sites and other Romanian sites are more similar to Western European than to Romanian populations in terms of isotopic composition, and probably ecology.

  7. Conceptual mis(understandings) of fractions: From area models to multiple embodiments

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaofen; Clements, M. A. (Ken); Ellerton, Nerida F.

    2015-06-01

    Area-model representations seem to have been dominant in the teaching and learning of fractions, especially in primary school mathematics curricula. In this study, we investigated 40 fifth grade children's understandings of the unit fractions, , and , represented through a variety of different models. Analyses of pre-teaching test and interview data revealed that although the participants were adept at partitioning regional models, they did not cope well with questions for which unit fractions were embodied in non-area-model scenarios. Analyses of post-teaching test and interview data indicated that after their participation in an instructional intervention designed according to Dienes' (1960) dynamic principle, the students' performances on tests improved significantly, and their conceptual understandings of unit fractions developed to the point where they could provide reasonable explanations of how they arrived at solutions. Analysis of retention data, gathered more than 3 months after the teaching intervention, showed that the students' newly found understandings had, in most cases, been retained.

  8. (Mis)perception of Sleep in Insomnia: A Puzzle and a Resolution

    ERIC Educational Resources Information Center

    Harvey, Allison G.; Tang, Nicole K. Y.

    2012-01-01

    Insomnia is prevalent, causing severe distress and impairment. This review focuses on illuminating the puzzling finding that many insomnia patients misperceive their sleep. They overestimate their sleep onset latency (SOL) and underestimate their total sleep time (TST), relative to objective measures. This tendency is ubiquitous (although not…

  9. The mis-measurement of extreme global poverty: A case study in the Pacific Islands

    PubMed Central

    Gubhaju, Bina

    2015-01-01

    Debate over the measurement of global poverty in low- and middle-income countries continues unabated. There is considerable controversy surrounding the ‘dollar a day’ measure used to monitor progress against the Millennium Development Goals. This article shines fresh light on the debate with new empirical analyses of poverty (including child poverty), inequality and deprivation levels in the Pacific island state of Vanuatu. The study focuses not only on economic and monetary metrics and measures, but also the measures of deprivation derived from sociology in relation to shelter, sanitation, water, information, nutrition, health and education. Until recently, there had been few, if any, attempts to study poverty and deprivation disparities among children in this part of the world. Different measures yield strikingly different estimates of poverty. The article, therefore, attempts to situate the study findings in the broader international context of poverty measurement and discusses their implications for future research and the post-2015 development agenda. PMID:26336359

  10. Potential (Mis)match? Marriage Markets Amidst Sociodemographic Change in India, 2005-2050.

    PubMed

    Kashyap, Ridhi; Esteve, Albert; García-Román, Joan

    2015-02-01

    We explore the impact of sociodemographic change on marriage patterns in India by examining the hypothetical consequences of applying three sets of marriage pairing propensities-contemporary patterns by age, contemporary patterns by age and education, and changing propensities that allow for greater educational homogamy and reduced educational asymmetries--to future population projections. Future population prospects for India indicate three trends that will impact marriage patterns: (1) female deficit in sex ratios at birth; (2) declining birth cohort size; (3) female educational expansion. Existing literature posits declining marriage rates for men arising from skewed sex ratios at birth (SRBs) in India's population. In addition to skewed SRBs, India's population will experience female educational expansion in the coming decades. Female educational expansion and its impact on marriage patterns must be jointly considered with demographic changes, given educational differences and asymmetries in union formation that exist in India, as across much of the world. We systematize contemporary pairing propensities using data from the 2005-2006 Indian National Family Health Survey and the 2004 Socio-Economic Survey and apply these and the third set of changing propensities to multistate population projections by educational attainment using an iterative longitudinal projection procedure. If today's age patterns of marriage are viewed against age/sex population composition until 2050, men experience declining marriage prevalence. However, when education is included, women--particularly those with higher education--experience a more salient rise in nonmarriage. Significant changes in pairing patterns toward greater levels of educational homogamy and gender symmetry can counteract a marked rise in nonmarriage. PMID:25604846

  11. All Recent Mars Landers Have Landed Downrange - Are Mars Atmosphere Models Mis-Predicting Density?

    NASA Technical Reports Server (NTRS)

    Desai, Prasun N.

    2008-01-01

    All recent Mars landers (Mars Pathfinder, the two Mars Exploration Rovers Spirit and Opportunity, and the Mars Phoenix Lander) have landed further downrange than their pre-entry predictions. Mars Pathfinder landed 27 km downrange of its prediction [1], Spirit and Opportunity landed 13.4 km and 14.9 km, respectively, downrange from their predictions [2], and Phoenix landed 21 km downrange from its prediction [3]. Reconstruction of their entries revealed a lower density profile than the best a priori atmospheric model predictions. Do these results suggest that there is a systemic issue in present Mars atmosphere models that predict a higher density than observed on landing day? Spirit Landing: The landing location for Spirit was 13.4 km downrange of the prediction as shown in Fig. 1. The navigation errors upon Mars arrival were very small [2]. As such, the entry interface conditions were not responsible for this downrange landing. Consequently, experiencing a lower density during the entry was the underlying cause. The reconstructed density profile that Spirit experienced is shown in Fig. 2, which is plotted as a fraction of the pre-entry baseline prediction that was used for all the entry, descent, and landing (EDL) design analyses. The reconstructed density is observed to be less dense throughout the descent reaching a maximum reduction of 15% at 21 km. This lower density corresponded to approximately a 1- low profile relative to the dispersions predicted. Nearly all the deceleration during the entry occurs within 10- 50 km. As such, prediction of density within this altitude band is most critical for entry flight dynamics analyses and design (e.g., aerodynamic and aerothermodynamic predictions, landing location, etc.).

  12. The Four Personae of Racism: Educators' (Mis)Understanding of Individual vs. Systemic Racism

    ERIC Educational Resources Information Center

    Young, Evelyn Y.

    2011-01-01

    This study used CRT to engage educators in critical discourse regarding the persistence of racism in urban schooling. A combined method of action research and critical case study was employed to raise a group of educators' race consciousness through antiracist training. Findings revealed conflicting views of racism as an individual pathology vs. a…

  13. The Use of Problem-Based Learning to Enhance MIS Education

    ERIC Educational Resources Information Center

    Mykytyn, Kathleen; Pearson, Ann; Paul, Souren; Mykytyn, Peter P., Jr.

    2008-01-01

    Many colleges of business require a course in computer applications concepts, often consisting of spreadsheet and database applications. Quite often, students resist taking the class because they do not see any worth to it, it duplicates what they already have taken, and they already know much of what is purported to be taught in the class.…

  14. (Mis)Aligned Ambitions? Parent Resources, Student Alignment, and Piecing Together the Hispanic College Puzzle

    ERIC Educational Resources Information Center

    Ryan, Sarah Margaret

    2012-01-01

    The fact that Latina/o students are losing ground to their non-Latino White peers in four-year college enrollment and bachelor's degree attainment even as Latino college enrollment and graduation rates are at an all time high constitutes a perplexing puzzle. In order to realize the potential "demographic dividend" embedded in the…

  15. The (mis)use of subjective process measures in software engineering

    NASA Technical Reports Server (NTRS)

    Valett, Jon D.; Condon, Steven E.

    1993-01-01

    A variety of measures are used in software engineering research to develop an understanding of the software process and product. These measures fall into three broad categories: quantitative, characteristics, and subjective. Quantitative measures are those to which a numerical value can be assigned, for example effort or lines of code (LOC). Characteristics describe the software process or product; they might include programming language or the type of application. While such factors do not provide a quantitative measurement of a process or product, they do help characterize them. Subjective measures (as defined in this study) are those that are based on the opinion or opinions of individuals; they are somewhat unique and difficult to quantify. Capturing of subjective measure data typically involves development of some type of scale. For example, 'team experience' is one of the subjective measures that were collected and studied by the Software Engineering Laboratory (SEL). Certainly, team experience could have an impact on the software process or product; actually measuring a team's experience, however, is not a strictly mathematical exercise. Simply adding up each team member's years of experience appears inadequate. In fact, most researchers would agree that 'years' do not directly translate into 'experience.' Team experience must be defined subjectively and then a scale must be developed e.g., high experience versus low experience; or high, medium, low experience; or a different or more granular scale. Using this type of scale, a particular team's overall experience can be compared with that of other teams in the development environment. Defining, collecting, and scaling subjective measures is difficult. First, precise definitions of the measures must be established. Next, choices must be made about whose opinions will be solicited to constitute the data. Finally, care must be given to defining the right scale and level of granularity for measurement.

  16. The Silence of Fear: Making Sense of Student (Mis)Behavior

    ERIC Educational Resources Information Center

    Peterek-Bonner, Emily

    2009-01-01

    The purpose of this personal narrative is to retrospectively analyze the actions and reactions of a young, female, white teacher who was faced with the reality of the dichotomy of race and power in a large school system. When an African American male student brings a gun to school, the teacher's personal assumptions come to the forefront, bringing…

  17. Syntectonic fluid flux during rift faulting: Record from the MIS core, Victoria Land Basin, Antarctica

    NASA Astrophysics Data System (ADS)

    Millan, C.; Wilson, T. J.; Paulsen, T. S.

    2009-12-01

    The McMurdo Ice Shelf project successfully recovered 1285 m of Neogene sedimentary core from the Victoria Land Basin, a large rift basin within the West Antarctic Rift System (WARS) of Antarctica. The core contains 1475 natural fractures that were logged as faults, veins and clastic dikes, associated with the southern extension of the Neogene-active? Terror Rift fault zone. Veins constitute about 625 of this population. Most veins are filled with calcite, although zeolites and minor chlorite are common towards the bottom of the core. In the lower ~300 m of the core, veins contain opening-mode fiber fills and are wavy to tightly folded due to vertical shortening. Folded, opening-mode folded veins are filled by calcite fibers that grew normal to vein walls, indicating the host sediment was cohesive enough to fracture but was not fully lithified and accommodated vein buckling during compaction. Fold hinges are fractured and wedging of vein segments is marked by overlapping tips separated by zones with strong chlorite and clay fabrics, suggesting shearing during further vertical contraction of the host rock. Calcite veins are commonly strongly twinned. Cathodoluminescence microscopy shows minor changes in color and intensity and minimal concentric or sectoral zoning, suggesting relatively rapid crystallization of fluids of similar chemistry. However, stable isotope analyses reveal large variations in values, with carbon values ranging from -21.91 to -7.15 (VPBD) and oxygen values ranging from -5.35 to -11.97 (VPBD). Further detailed investigation of the fracture fills using cathodoluminescence and electron microscopy combined with isotopic analysis of carbon and oxygen will document the generations of the filling material in more detail and will constrain the sources and evolution of the fluids. There has clearly been significant structural control on fluid pathways during lithification, compaction and diagenesis of strata deforming within the Terror Rift zone.

  18. (Mis)use of Prescribed Stimulants in the Medical Student Community: Motives and Behaviors

    PubMed Central

    Fond, Guillaume; Gavaret, Martine; Vidal, Christophe; Brunel, Lore; Riveline, Jean-Pierre; Micoulaud-Franchi, Jean-Arthur; Domenech, Philippe

    2016-01-01

    Abstract The aim of this study was to estimate the prevalence of psychostimulant use in the French medical community and their motives. A population-based cross-sectional study using a self-administered online survey was done. A total of 1718 French students and physicians (mean age, 26.84±7.19 years, 37.1% men) were included. Self-reported lifetime use, motives, socio-demographic and academic features for over the counter (OTC), medically prescribed (MPP), and illicit (IP) psychostimulant users were reported. Lifetime prevalence of psychostimulant use was 33% (29.7% for OTC, 6.7% for MPP, and 5.2% for IP). OTC consumption mainly aimed at increasing academic performance and wakefulness during competitive exams preparation. OTC consumption started early and was predictive of later MPP use. Corticoids were the most frequently consumed MPP (4.5%) before methylphenidate and modafinil. Motives for MPP consumption were increased academic performance, concentration, memory, and wakefulness. Psychostimulant use is common among French medical community. Our results suggest that restrictions on methylphenidate and modafinil prescriptions are effective at limiting their use. However, these restrictions may explain the observed rates of corticoids consumption, which raise a new public health problem, given that corticoids may have severe side effects. PMID:27100420

  19. Applied Derrida: (Mis)Reading the Work of Mourning in Educational Research

    ERIC Educational Resources Information Center

    Lather, Patti

    2003-01-01

    Whatever the meaning of the "post" these days, it is pervasive, elusive and marked by a proliferation of conflicting definitions that refuse to settle into meaning. Efforts to accommodate/incorporate the "post" in educational research have not been easy. In the pages of the "Educational Researcher" alone, McLaren and Farahmandpur (2000) warn…

  20. Off Our Lawns and out of Our Basements: How We (Mis)Understand the Millennial Generation

    ERIC Educational Resources Information Center

    Mechler, Heather

    2013-01-01

    In this article, the author explores the existing research on the characteristics of Millennials within historical, social, and economic contexts. While many researchers have made claims about Millennials, they fail to consider how parenting styles, economic factors, historical events, and shifts in educational priorities may have created the…