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Sample records for agg dipsacaceae puzzle

  1. Towards resolving the Knautia arvensis agg. (Dipsacaceae) puzzle: primary and secondary contact zones and ploidy segregation at landscape and microgeographic scales

    PubMed Central

    Kolář, Filip; Štech, Milan; Trávníček, Pavel; Rauchová, Jana; Urfus, Tomáš; Vít, Petr; Kubešová, Magdalena; Suda, Jan

    2009-01-01

    Background and Aims Detailed knowledge of variations in ploidy levels and their geographic distributions is one of the key tasks faced in polyploid research in natural systems. Flow cytometry has greatly facilitated the field of cytogeography by allowing characterization of ploidy levels at both the regional and population scale, and at multiple stages of the life cycle. In the present study, flow cytometry was employed to investigate the patterns and dynamics of ploidy variation in the taxonomically challenging complex Knautia arvensis (Dipsacaceae) and some of its allies (K. dipsacifolia, K. slovaca) in Central Europe. Methods DNA ploidy levels were estimated by DAPI flow cytometry in 5205 adult plants, 228 seedlings and 400 seeds collected from 292 Knautia populations in seven European countries. The flow cytometric data were supplemented with conventional chromosome counts. A subset of 79 accessions was subjected to estimation of the absolute genome size using propidium iodide flow cytometry. Key Results and Conclusions Five different ploidy levels (from 2x to 6x) were found, with triploids of K. arvensis being recorded for the first time. The species also exhibited variation in the monoploid genome size, corresponding to the types of habitats occupied (grassland diploid populations had larger genome sizes than relict and subalpine diploid populations). Disregarding relict populations, the distribution of 2x and 4x cytotypes was largely parapatric, with a diffuse secondary contact zone running along the north-west margin of the Pannonian basin. Spatial segregation of the cytotypes was also observed on regional and microgeographic scales. The newly detected sympatric growth of diploids and tetraploids in isolated relict habitats most likely represents the primary zone of cytotype contact. Ploidy level was found to be a major determinant of the strength of inter-cytotype reproductive barriers. While mixed 2x + 4x populations virtually lacked the intermediate

  2. Puzzling Mechanisms

    ERIC Educational Resources Information Center

    van Deventer, M. Oskar

    2009-01-01

    The basis of a good mechanical puzzle is often a puzzling mechanism. This article will introduce some new puzzling mechanisms, like two knots that engage like gears, a chain whose links can be interchanged, and flat gears that do not come apart. It illustrates how puzzling mechanisms can be transformed into real mechanical puzzles, e.g., by…

  3. Puzzle Corner.

    ERIC Educational Resources Information Center

    Andrews, Ian A.

    1992-01-01

    Presents a crossword puzzle and a word find puzzle. Offers clues dealing with member nations in the British Commonwealth. Includes an answer key for the crossword puzzle. Suggests sources of information on the Commonwealth. (DK)

  4. Anatomical Injuries Induced by Leipotrix dipsacivagus Petanovic & Rector on Cut-leaf Teasel, Dipsacus laciniatus L. (Dipsacaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study highlighted some conspicuous structural malformations of the native Eurasian plant Dipsacus laciniatus L. (cutleaf teasel, Dipsacaceae) provoked by infestation by recently described eriophyid mite, Leipothrix dipsacivagus Petanovic & Rector. The most striking structural changes induced by...

  5. Signaling specificity provided by the Arabidopsis thaliana heterotrimeric G-protein γ subunits AGG1 and AGG2 is partially but not exclusively provided through transcriptional regulation.

    PubMed

    Thung, Leena; Chakravorty, David; Trusov, Yuri; Jones, Alan M; Botella, José Ramón

    2013-01-01

    The heterotrimeric G-protein complex in Arabidopsis thaliana consists of one α, one ß and three γ subunits. While two of the γ subunits, AGG1 and AGG2 have been shown to provide functional selectivity to the Gßγ dimer in Arabidopsis, it is unclear if such selectivity is embedded in their molecular structures or conferred by the different expression patterns observed in both subunits. In order to study the molecular basis for such selectivity we tested genetic complementation of AGG1- and AGG2 driven by the respectively swapped gene promoters. When expressed in the same tissues as AGG1, AGG2 rescues some agg1 mutant phenotypes such as the hypersensitivity to Fusarium oxysporum and D-mannitol as well as the altered levels of lateral roots, but does not rescue the early flowering phenotype. Similarly, AGG1 when expressed in the same tissues as AGG2 rescues the osmotic stress and lateral-root phenotypes observed in agg2 mutants but failed to rescue the heat-stress induction of flowering. The fact that AGG1 and AGG2 are functionally interchangeable in some pathways implies that, at least for those pathways, signaling specificity resides in the distinctive spatiotemporal expression patterns exhibited by each γ subunit. On the other hand, the lack of complementation for some phenotypes indicates that there are pathways in which signaling specificity is provided by differences in the primary AGG1 and AGG2 amino acid sequences. PMID:23520518

  6. Puzzles & Problems.

    ERIC Educational Resources Information Center

    Murphy, Pat, Ed.

    1993-01-01

    "Exploring" is a magazine of science, art, and human perception, produced by Exploratorium in collaboration with other participating museums. This issue focuses on puzzles and problem solving. Brain teasers, puzzles, and the strategies for solving them are included. Features include: (1) "Homework Assignment #3" (Paul Doherty); (2) "The Case of…

  7. Lockean Puzzles

    ERIC Educational Resources Information Center

    Milligan, Tony

    2007-01-01

    In analytic moral philosophy it is standard to use unrealistic puzzles to set up moral dilemmas of a sort that I will call Lockean Puzzles. This paper will try to pinpoint just what is and what is not problematic about their use as a teaching tool or component part of philosophical arguments. I will try to flesh out the claim that what may be lost…

  8. Deductive Puzzling

    ERIC Educational Resources Information Center

    Wanko, Jeffrey J.

    2010-01-01

    To help fifth- through eighth-grade students develop their deductive reasoning skills, the author used a ten-week supplementary curriculum so that students could answer logic questions. The curriculum, a series of lessons built around language-independent logic puzzles, has been used in classrooms of fifth through eighth grades. In most cases,…

  9. Incomplete Puzzle

    NASA Technical Reports Server (NTRS)

    2006-01-01

    15 April 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a mid-summer view of a portion of the south polar residual cap of Mars. The large, relatively flat-lying, puzzle-like pieces in this scene are mesas composed largely of solid carbon dioxide.

    Location near: 85.5oS, 76.8oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

  10. A new species of Aculops (Acari: Prostigmata: Eriophyidae) from Serbia on Dipsacus laciniatus L. (Dipsacaceae), a weed target of classical biological control in the United States of America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The new eriophyid mite species Aculops dipsaci n. sp. (Acari: Prostigmata: Eriophyidae) collected from Dipsacus laciniatus L. (Dipsacaceae) in northern Serbia is described and illustrated. Differential diagnosis is provided in comparison with Aculops salixis Xue, Song and Hong. This is the first e...

  11. Fully and partially Li-stuffed diamond polytypes with Ag-Ge structures: Li2AgGe and Li2.53AgGe2.

    PubMed

    Henze, Alexander; Hlukhyy, Viktor; Fässler, Thomas F

    2015-02-01

    In view of the search for and understanding of new materials for energy storage, the Li-Ag-Ge phase diagram has been investigated. High-temperature syntheses of Li with reguli of premelted Ag and Ge led to the two new compounds Li(2)AgGe and Li(2.80-x)AgGe(2) (x = 0.27). The compounds were characterized by single-crystal X-ray diffraction. Both compounds show diamond-polytype-like polyanionic substructures with tetrahedrally coordinated Ag and Ge atoms. The Li ions are located in the channels provided by the network. The compound Li(2)AgGe crystallizes in the space group R3̅m (No. 166) with lattice parameters of a = 4.4424(6) Å and c = 42.7104(6) Å. All atomic positions are fully occupied and ordered. Li(2.80-x)AgGe(2) crystallizes in the space group I4(1)/a (No. 88) with lattice parameters of a = 9.7606(2) Å and c = 18.4399(8) Å. The Ge substructure consists of unique (1)(∞)[Ge(10)] chains that are interconnected by Ag atoms to build a three-dimensional network. In the channels of this diamond-like network, not all of the possible positions are occupied by Li ions. Li atoms in the neighborhood of the vacancies show considerably enlarged displacement vectors. The occurrence of the vacancy is traced back to short Li-Li distances in the case of the occupation of the vacancy with Li. Both compounds are not electron-precise Zintl phases. The density of states, band structure, and crystal orbital Hamilton population analyses of Li(2.80-x)AgGe(2 )reveal metallic properties, whereas a full occupation of all Li sites leads to an electron-precise Zintl compound within a rigid-band model. Li(2)AgGe reveals metallic character in the ab plane and is a semiconductor with a small band gap along the c direction. PMID:25521213

  12. Puzzles, Pastimes, Problems.

    ERIC Educational Resources Information Center

    Eperson, D. B.

    1985-01-01

    Presents six mathematical problems (with answers) which focus on: (1) chess moves; (2) patterned numbers; (3) quadratics with rational roots; (4) number puzzles; (5) Euclidean geometry; and (6) Carrollian word puzzles. (JN)

  13. Benjamin Banneker's Mathematical Puzzles.

    ERIC Educational Resources Information Center

    Mahoney, John F.

    2003-01-01

    Benjamin Banneker, a self-taught African American mathematician, kept a journal containing a number of mathematical puzzles. Explores four of these puzzles, 200 years later, with the aid of 21st century technology. (Author/NB)

  14. The Proton Radius Puzzle

    NASA Astrophysics Data System (ADS)

    Downie, E. J.

    2016-03-01

    The proton radius puzzle is the difference between the proton radius as measured with electron scattering and in the excitation spectrum of atomic hydrogen, and that measured with muonic hydrogen spectroscopy. Since the inception of the proton radius puzzle in 2010 by the measurement of Pohl et al.[1], many possible resolutions to the puzzle have been postulated, but, to date, none has been generally accepted. New data are therefore necessary to resolve the issue. We briefly review the puzzle, the proposed solutions, and the new electron scattering and spectroscopy experiments planned and underway. We then introduce the MUSE experiment, which seeks to resolve the puzzle by simultaneously measuring elastic electron and muon scattering on the proton, in both charge states, thereby providing new information to the puzzle. MUSE addresses issues of two-photon effects, lepton universality and, possibly, new physics, while providing simultaneous form factor, and therefore radius, measurements with both muons and electrons.

  15. Puzzling Ways to Learn

    ERIC Educational Resources Information Center

    School Shop, 1975

    1975-01-01

    Four authors present crossword and wordfind puzzles developed for students in the areas of electricity, principles of hydraulics, finishing, construction, thermoplastic materials, patternmaking, wood, occupations, and drafting. (BP)

  16. [The Swedish ambulance services 1935-1936 of Gunnar Agge].

    PubMed

    Gustavsson, Pär; Nilsson, Peter M

    2006-01-01

    The fact that Sweden has been spared from war on its soil for almost 200 years, has not stopped Swedish citizens from participating in conflicts worldwide during this period. This has been described, especially from the soldiers perspective. The contribution of Swedish physicians has not been written about to the same extent. When Mussolini's Italy in October 1935 invaded the poor and underdeveloped country of Ethiopia (former Abyssinia) an ambulance was immediately organized by the Swedish Red Cross. To lead such an expedition, a great knowledge of Ethiopian culture och maybe most importantly, of the weather and geographical conditions, was undoubtedly demanded. Therefore, the Swedish Red Cross turned to two Ethiopian veterans. Doctor Fride Hylander, a missionary-son who had been working on a hospital project in the Ethiopian province of Harrar and his friend since school years, doctor Gunnar Agge, were assigned the leadership of the ambulance. Dr Agge had also participated in improving the Ethiopian health care both in Harrar and later as civilian and military doctor in the province of Ogaden, where he was medically responsible for the more than 9 000 men strong army that the Ethiopian emperor had stationed there after Italian provocations. Most of the other members of the ambulance were handpicked by these two leaders and many of them had, just like themselves, a stong religious belief. A money-raise was immediately initiated and in less than six weeks 700 000 Swedish crowns had been collected, more then twice the sum the ambulance was calculated to cost. In early november 1935 the ambulance was clear to go. Their primary objective was to travel through British Somaliland and establish a field-hospital in the province of Harrar. However, the Ethiopian emperor had other things in mind. He wanted to reorganize the ambulance and divide it in two and place it closer to the front line. The ambulance decided to go along with his wish. Both groups started eventually

  17. The Anatomy Puzzle Book.

    ERIC Educational Resources Information Center

    Jacob, Willis H.; Carter, Robert, III

    This document features review questions, crossword puzzles, and word search puzzles on human anatomy. Topics include: (1) Anatomical Terminology; (2) The Skeletal System and Joints; (3) The Muscular System; (4) The Nervous System; (5) The Eye and Ear; (6) The Circulatory System and Blood; (7) The Respiratory System; (8) The Urinary System; (9) The…

  18. The Puzzle Design Activity.

    ERIC Educational Resources Information Center

    Meyer, Marc E.

    1983-01-01

    A sampling of puzzles and games produced by students at North Rockland High School (New York) are presented as an example of a way student-designed activities can be used to cover a specific unit within the health education curriculum. Produced by 9th and 10th graders, the unit on alcohol consists of puzzles and word games using related vocabulary…

  19. The Textual Puzzle Technique.

    ERIC Educational Resources Information Center

    Lanier, Dorothy C.

    Textual puzzles may be used in freshman composition or introduction to writing courses to emphasize word order and subject-predicate agreement. These sentence puzzles demonstrate that the English language depends primarily upon word order to convey meaning, and assist students to avoid blending statement and question word order in their sentences…

  20. Puzzles and Hunts.

    ERIC Educational Resources Information Center

    Weissblum, Aaron

    2000-01-01

    A company designs and delivers treasure and scavenger hunts for corporate and institutional clients. Groups are divided into teams that must solve puzzles for directions or clues. The hunts build creativity, teamwork, communication skills, and an appreciation of others' strengths. An insert includes a four-puzzle mini-treasure hunt. (TD)

  1. Tangrams: Puzzles of Art

    ERIC Educational Resources Information Center

    Fee, Brenda

    2009-01-01

    Challenging one's brain is the beginning of making great art. Tangrams are a great way to keep students thinking about their latest art project long after leaving the classroom. A tangram is a Chinese puzzle. The earliest known reference to tangrams appears in a Chinese book dated 1813, but the puzzles existed long before that date. The puzzle…

  2. A Disciplined Chemical Puzzle

    ERIC Educational Resources Information Center

    Peris, Miguel

    2007-01-01

    A puzzle was developed as a resource for teaching intermediate chemistry students where they need to use general intelligence and logic skills. The puzzle involves identification of name, age, subdiscipline of chemistry and position of 6 students around the table by using certain data provided to them.

  3. Blood Type Puzzle.

    ERIC Educational Resources Information Center

    Kelly, Janet

    1997-01-01

    Presents a blood type puzzle that provides a visual, hands-on mechanism by which students can examine blood group reactions. Offers students an opportunity to construct their own knowledge about blood types. (JRH)

  4. Structure of amorphous Ag/Ge/S alloys: experimentally constrained density functional study.

    PubMed

    Akola, J; Beuneu, B; Jones, R O; Jóvári, P; Kaban, I; Kolář, J; Voleská, I; Wágner, T

    2015-12-01

    Density functional/molecular dynamics simulations have been performed to determine structural and other properties of amorphous Ag/Ge/S and Ge/S alloys. In the former, the calculations have been combined with experimental data (x-ray and neutron diffraction, extended x-ray absorption fine structure). Ag/Ge/As alloys have high ionic conductivity and are among the most promising candidates for future memristor technology. We find excellent agreement between the experimental results and large-scale (500 atoms) simulations in Ag/Ge/S, and we compare and contrast the structures of Ge/S and Ag/Ge/S. The calculated electronic structures, vibrational densities of states, ionic mobilities, and cavity distributions of the amorphous materials are discussed and compared with data on crystalline phases where available. The high mobility of Ag in solid state electrolyte applications is related to the presence of cavities and can occur via jumps to a neighbouring vacant site. PMID:26569035

  5. Structure of amorphous Ag/Ge/S alloys: experimentally constrained density functional study

    NASA Astrophysics Data System (ADS)

    Akola, J.; Beuneu, B.; Jones, R. O.; Jóvári, P.; Kaban, I.; Kolář, J.; Voleská, I.; Wágner, T.

    2015-12-01

    Density functional/molecular dynamics simulations have been performed to determine structural and other properties of amorphous Ag/Ge/S and Ge/S alloys. In the former, the calculations have been combined with experimental data (x-ray and neutron diffraction, extended x-ray absorption fine structure). Ag/Ge/As alloys have high ionic conductivity and are among the most promising candidates for future memristor technology. We find excellent agreement between the experimental results and large-scale (500 atoms) simulations in Ag/Ge/S, and we compare and contrast the structures of Ge/S and Ag/Ge/S. The calculated electronic structures, vibrational densities of states, ionic mobilities, and cavity distributions of the amorphous materials are discussed and compared with data on crystalline phases where available. The high mobility of Ag in solid state electrolyte applications is related to the presence of cavities and can occur via jumps to a neighbouring vacant site.

  6. FamAgg: an R package to evaluate familial aggregation of traits in large pedigrees

    PubMed Central

    Rainer, Johannes; Taliun, Daniel; D’Elia, Yuri; Pattaro, Cristian; Domingues, Francisco S.; Weichenberger, Christian X.

    2016-01-01

    Summary: Familial aggregation analysis is the first fundamental step to perform when assessing the extent of genetic background of a disease. However, there is a lack of software to analyze the familial clustering of complex phenotypes in very large pedigrees. Such pedigrees can be utilized to calculate measures that express trait aggregation on both the family and individual level, providing valuable directions in choosing families for detailed follow-up studies. We developed FamAgg, an open source R package that contains both established and novel methods to investigate familial aggregation of traits in large pedigrees. We demonstrate its use and interpretation by analyzing a publicly available cancer dataset with more than 20 000 participants distributed across approximately 400 families. Availability and implementation: The FamAgg package is freely available at the Bioconductor repository, http://www.bioconductor.org/packages/FamAgg. Contact: Christian.Weichenberger@eurac.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:26803158

  7. Bringing Together Evolution on Serpentine and Polyploidy: Spatiotemporal History of the Diploid-Tetraploid Complex of Knautia arvensis (Dipsacaceae)

    PubMed Central

    Kolář, Filip; Fér, Tomáš; Štech, Milan; Trávníček, Pavel; Dušková, Eva; Schönswetter, Peter; Suda, Jan

    2012-01-01

    Polyploidization is one of the leading forces in the evolution of land plants, providing opportunities for instant speciation and rapid gain of evolutionary novelties. Highly selective conditions of serpentine environments act as an important evolutionary trigger that can be involved in various speciation processes. Whereas the significance of both edaphic speciation on serpentine and polyploidy is widely acknowledged in plant evolution, the links between polyploid evolution and serpentine differentiation have not yet been examined. To fill this gap, we investigated the evolutionary history of the perennial herb Knautia arvensis (Dipsacaceae), a diploid-tetraploid complex that exhibits an intriguing pattern of eco-geographic differentiation. Using plastid DNA sequencing and AFLP genotyping of 336 previously cytotyped individuals from 40 populations from central Europe, we unravelled the patterns of genetic variation among the cytotypes and the edaphic types. Diploids showed the highest levels of genetic differentiation, likely as a result of long term persistence of several lineages in ecologically distinct refugia and/or independent immigration. Recurrent polyploidization, recorded in one serpentine island, seems to have opened new possibilities for the local serpentine genotype. Unlike diploids, the serpentine tetraploids were able to escape from the serpentine refugium and spread further; this was also attributable to hybridization with the neighbouring non-serpentine tetraploid lineages. The spatiotemporal history of K. arvensis allows tracing the interplay of polyploid evolution and ecological divergence on serpentine, resulting in a complex evolutionary pattern. Isolated serpentine outcrops can act as evolutionary capacitors, preserving distinct karyological and genetic diversity. The serpentine lineages, however, may not represent evolutionary ‘dead-ends’ but rather dynamic systems with a potential to further influence the surrounding populations, e

  8. Bringing together evolution on serpentine and polyploidy: spatiotemporal history of the diploid-tetraploid complex of Knautia arvensis (Dipsacaceae).

    PubMed

    Kolář, Filip; Fér, Tomáš; Štech, Milan; Trávníček, Pavel; Dušková, Eva; Schönswetter, Peter; Suda, Jan

    2012-01-01

    Polyploidization is one of the leading forces in the evolution of land plants, providing opportunities for instant speciation and rapid gain of evolutionary novelties. Highly selective conditions of serpentine environments act as an important evolutionary trigger that can be involved in various speciation processes. Whereas the significance of both edaphic speciation on serpentine and polyploidy is widely acknowledged in plant evolution, the links between polyploid evolution and serpentine differentiation have not yet been examined. To fill this gap, we investigated the evolutionary history of the perennial herb Knautia arvensis (Dipsacaceae), a diploid-tetraploid complex that exhibits an intriguing pattern of eco-geographic differentiation. Using plastid DNA sequencing and AFLP genotyping of 336 previously cytotyped individuals from 40 populations from central Europe, we unravelled the patterns of genetic variation among the cytotypes and the edaphic types. Diploids showed the highest levels of genetic differentiation, likely as a result of long term persistence of several lineages in ecologically distinct refugia and/or independent immigration. Recurrent polyploidization, recorded in one serpentine island, seems to have opened new possibilities for the local serpentine genotype. Unlike diploids, the serpentine tetraploids were able to escape from the serpentine refugium and spread further; this was also attributable to hybridization with the neighbouring non-serpentine tetraploid lineages. The spatiotemporal history of K. arvensis allows tracing the interplay of polyploid evolution and ecological divergence on serpentine, resulting in a complex evolutionary pattern. Isolated serpentine outcrops can act as evolutionary capacitors, preserving distinct karyological and genetic diversity. The serpentine lineages, however, may not represent evolutionary 'dead-ends' but rather dynamic systems with a potential to further influence the surrounding populations, e.g., via

  9. Micro-morphological alterations in young rosette leaves of Dipsacus laciniatus L. (Dipsacaceae) caused by infestation of the eriophyid mite Leipotrix dipsacivagus Petanovic et Rector (Acari: Eriophyoidea) under laboratory con

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The present study describes micro-morphological and hystological changes to the native Eurasian plant species Dipsacus laciniatus (Dipsacaceae) provoked by infestation of the eriophyid mite, Leipothrix dipsacivagus Petanovic et Rector. Conspicuous injuries to the leaf tissue were induced by mites f...

  10. Boggle Logic Puzzles: Minimal Solutions

    ERIC Educational Resources Information Center

    Needleman, Jonathan

    2013-01-01

    Boggle logic puzzles are based on the popular word game Boggle played backwards. Given a list of words, the problem is to recreate the board. We explore these puzzles on a 3 x 3 board and find the minimum number of three-letter words needed to create a puzzle with a unique solution. We conclude with a series of open questions.

  11. More Pebble Puzzles.

    ERIC Educational Resources Information Center

    Gibbs, William M.

    This booklet is a collection of puzzles, investigations, and games. They are designed to be used with large objects such as tins or stones and diagrams marked on the ground. The children are to be encouraged to use an experimental, trial-and-error approach at first, and then develop methods of solution. (MNS)

  12. La Francophonie. Puzzle Corner.

    ERIC Educational Resources Information Center

    Andrews, Ian A.

    2000-01-01

    Discusses the organization La Francophonie, which is an international community of people who speak French and convene to address issues. Presents a crossword puzzle that introduces readers to some of the nations involved in La Francophonie. Provides the across and down clues, a word list, and answer key. (CMK)

  13. AggModel: A soil organic matter model with measurable pools for use in incubation studies

    SciTech Connect

    Segoli, Moran; De Gryze, S.; Dou, Fugen; Lee, J.; Post, Wilfred M; Denef, K.; Six, Johan W U A

    2013-01-01

    Current soil organic matter (SOM) models are empirical in nature by employing few conceptual SOM pools that have a specific turnover time, but that are not measurable and have no direct relationship with soil structural properties. Most soil particles are held together in aggregates and the number, size and stability of these aggregates significantly affect the size and amount of organic matter contained in these aggregates, and its susceptibility to decomposition. While it has been shown that soil aggregates and their dynamics can be measured directly in the laboratory and in the field, the impact of soil aggregate dynamics on SOM decomposition has not been explicitly incorporated in ecosystem models. Here, we present AggModel, a conceptual and simulation model that integrates soil aggregate and SOM dynamics. In AggModel, we consider unaggregated and microaggregated soil that can exist within or external to macroaggregated soil. Each of the four aggregate size classes contains particulate organic matter and mineral-associated organic matter fractions. We used published data from laboratory incubations to calibrate and validate the biological and environmental effects on the rate of formation and breakdown of macroaggregates and microaggregates, and the organic matter dynamics within these different aggregate fractions. After calibration, AggModel explained more than 70% of the variation in aggregate masses and over 90% of the variation in aggregate-associated carbon. The model estimated the turnover time of macroaggregates as 32 days and 166 days for microaggregates. Sensitivity analysis of AggModel parameterization supported the notion that macroaggregate turnover rate has a strong control over microaggregate masses and, hence, carbon sequestration. In addition to AggModel being a proof-of-concept, the advantage of a model that is based on measurable SOM fractions is that its internal structure and dynamics can be directly calibrated and validated by using

  14. Nature's Greatest Puzzles

    SciTech Connect

    Quigg, Chris; /Fermilab

    2005-02-01

    It is a pleasure to be part of the SLAC Summer Institute again, not simply because it is one of the great traditions in our field, but because this is a moment of great promise for particle physics. I look forward to exploring many opportunities with you over the course of our two weeks together. My first task in talking about Nature's Greatest Puzzles, the title of this year's Summer Institute, is to deconstruct the premise a little bit.

  15. A DOUBLE NEUTRON STAR MERGER ORIGIN FOR THE COSMOLOGICAL RELATIVISTIC FADING SOURCE PTF11agg?

    SciTech Connect

    Wu, Xue-Feng; Gao, He; Ding, Xuan; Zhang, Bing; Dai, Zi-Gao; Wei, Jian-Yan

    2014-01-20

    The Palomar Transient Factory (PTF) team recently reported the discovery of a rapidly fading optical transient source, PTF11agg. A long-lived scintillating radio counterpart was identified, but the search for a high-energy counterpart showed negative results. The PTF team speculated that PTF11agg may represent a new class of relativistic outbursts. Here we suggest that a neutron star (NS)-NS merger system with a supra-massive magnetar central engine could be a possible source to power such a transient, if our line of sight is not on the jet axis direction of the system. These systems are also top candidates for gravitational wave sources to be detected in the advanced LIGO/Virgo era. We find that the PTF11agg data could be explained well with such a model, suggesting that at least some gravitational wave bursts due to NS-NS mergers may be associated with such a bright electromagnetic counterpart without a γ-ray trigger.

  16. A Microscale Oxidation Puzzle

    NASA Astrophysics Data System (ADS)

    Pelter, Michael W.; Macudzinski, Rebecca M.; Passarelli, Mary Ellen

    2000-11-01

    We have adapted oxidation of an alcohol with sodium hypochlorite solution to a "puzzle" approach by using a diol as the substrate for oxidation. The diols under investigation have both a primary and a secondary hydroxyl group. There are three possible outcomes to the reaction: (i) only the primary alcohol is oxidized to the aldehyde (or carboxylic acid); (ii) only the secondary alcohol is oxidized to the ketone; or (iii) both alcohols are oxidized. The assignment is to perform the reaction and determine the structure of the product through interpretation of the IR spectrum. Examples using two commercially available diols are shown.

  17. Pebble Puzzles. A Source Book of Simple Puzzles and Problems.

    ERIC Educational Resources Information Center

    Gibbs, William M.

    This booklet is a collection of puzzles, games, and investigations. All that children need are some stones or shells, on some of which they must write numerals. For playing with the whole class, the game or puzzles may be marked out on the floor or in sand; in that case, larger objects such as small rocks and empty tins may be used. Children are…

  18. Three Puzzles for Organic Laboratory.

    ERIC Educational Resources Information Center

    Todd, David; Pickering, Miles

    1988-01-01

    Notes that laboratory work should be more oriented towards puzzle solving rather than technique or illustration. Offers three organic laboratory puzzles which can be solved by melting point alone. Involves lab work at the 100-200-mg scale but still uses conventional glassware. (MVL)

  19. Comparative Mitogenomics of Plant Bugs (Hemiptera: Miridae): Identifying the AGG Codon Reassignments between Serine and Lysine

    PubMed Central

    Wang, Pei; Song, Fan; Cai, Wanzhi

    2014-01-01

    Insect mitochondrial genomes are very important to understand the molecular evolution as well as for phylogenetic and phylogeographic studies of the insects. The Miridae are the largest family of Heteroptera encompassing more than 11,000 described species and of great economic importance. For better understanding the diversity and the evolution of plant bugs, we sequence five new mitochondrial genomes and present the first comparative analysis of nine mitochondrial genomes of mirids available to date. Our result showed that gene content, gene arrangement, base composition and sequences of mitochondrial transcription termination factor were conserved in plant bugs. Intra-genus species shared more conserved genomic characteristics, such as nucleotide and amino acid composition of protein-coding genes, secondary structure and anticodon mutations of tRNAs, and non-coding sequences. Control region possessed several distinct characteristics, including: variable size, abundant tandem repetitions, and intra-genus conservation; and was useful in evolutionary and population genetic studies. The AGG codon reassignments were investigated between serine and lysine in the genera Adelphocoris and other cimicomorphans. Our analysis revealed correlated evolution between reassignments of the AGG codon and specific point mutations at the antidocons of tRNALys and tRNASer(AGN). Phylogenetic analysis indicated that mitochondrial genome sequences were useful in resolving family level relationship of Cimicomorpha. Comparative evolutionary analysis of plant bug mitochondrial genomes allowed the identification of previously neglected coding genes or non-coding regions as potential molecular markers. The finding of the AGG codon reassignments between serine and lysine indicated the parallel evolution of the genetic code in Hemiptera mitochondrial genomes. PMID:24988409

  20. Puzzle geometry and rigidity

    NASA Astrophysics Data System (ADS)

    Smania, Daniel

    2007-07-01

    We describe a new and robust method to prove rigidity results in complex dynamics. The new ingredient is the geometry of the critical puzzle pieces: under control of geometry and ``complex bounds'', two generalized polynomial-like maps which admit a topological conjugacy, quasiconformal outside the filled-in Julia set, are indeed quasiconformally conjugate. The proof uses a new abstract removability-type result for quasiconformal maps, following ideas of Heinonen and Koskela and of Kallunki and Koskela, optimized for applications in complex dynamics. We prove, as the first application of this new method, that, for even criticalities distinct from two, the period two cycle of the Fibonacci renormalization operator is hyperbolic with 1 -dimensional unstable manifold.

  1. The Puzzling Ophiuchus Stream

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    Dwarf galaxies or globular clusters orbiting the Milky Way can be pulled apart by tidal forces, leaving behind a trail of stars known as a stellar stream. One such trail, the Ophiuchus stream, has posed a serious dynamical puzzle since its discovery. But a recent study has identified four stars that might help resolve this streams mystery.Conflicting TimescalesThe stellar stream Ophiuchus was discovered around our galaxy in 2014. Based on its length, which appears to be 1.6 kpc, we can calculate the time that has passed since its progenitor was disrupted and the stream was created: ~250 Myr. But the stars within it are ~12 Gyr old, and the stream orbits the galaxy with a period of ~350 Myr.Given these numbers, we can assume that Ophiuchuss progenitor completed many orbits of the Milky Way in its lifetime. So why would it only have been disrupted 250 million years ago?Fanning StreamLed by Branimir Sesar (Max Planck Institute for Astronomy), a team of scientists has proposed an idea that might help solve this puzzle. If the Ophiuchus stellar stream is on a chaotic orbit common in triaxial potentials, which the Milky Ways may be then the stream ends can fan out, with stars spreading in position and velocity.The fanned part of the stream, however, would be difficult to detect because of its low surface brightness. As a result, the Ophiuchus stellar stream could actually be longer than originally measured, implying that it was disrupted longer ago than was believed.Search for Fan StarsTo test this idea, Sesar and collaborators performed a search around the ends of the stream, looking for stars thatare of the right type to match the stream,are at the predicted distance of the stream,are located near the stream ends, andhave velocities that match the stream and dont match the background halo stars.Histogram of the heliocentric velocities of the 43 target stars. Six stars have velocities matching the stream velocity. Two of these are located in the main stream; the other

  2. Sleep for Kids: Games and Puzzles

    MedlinePlus

    Games and Puzzles These games and puzzles can help you learn more about sleep! Learn about sleep with this fun crossword puzzle! Test your memory ... can't sleep? • dreams • • bring out the stars • games and puzzles • pj bear booklet • • home • about us • ...

  3. [The Parkinson puzzle].

    PubMed

    Guseo, András

    2012-12-30

    Parkinson's disease is one of the most frequent progressive degenerative disorders with unknown origin of the nervous system. The commutation of the disease on Guam led to the discovery of a neurotoxin which was also found in other continents. This neurotoxin was identified in the common cyanobacteria (blue-green algae). Early clinical observations suggested some loose correlations with gastric and duodenal ulcer and Parkinson's disease, while recent studies revealed a toxin, almost identical to that found in cyanobacteria in one strain of Helicobacter pylori, which proved to cause Parkinson like symptoms in animals. Therefore, it cannot be ruled out that there is a slowly progressive poisoning in Parkinson's disease. The disease specific alpha-sinuclein inclusions can be found in nerve cells of the intestinal mucosa far before the appearance of clinical symptoms indicating that the disease may start in the intestines. These results are strengthened by the results of Borody's fecal transplants, after which in Parkinson patients showed a symptomatic improvement. Based on these observations the Parkinson puzzle is getting complete. Although these observations are not evidence based, they may indicate a new way for basic clinical research, as well as a new way of thinking for clinicians. These new observations in psycho-neuro-immunology strengthen the fact that immunological factors may also play a critical factor facilitating local cell necrosis which may be influenced easily. PMID:23261994

  4. AggLb Is the Largest Cell-Aggregation Factor from Lactobacillus paracasei Subsp. paracasei BGNJ1-64, Functions in Collagen Adhesion, and Pathogen Exclusion In Vitro

    PubMed Central

    Miljkovic, Marija; Strahinic, Ivana; Tolinacki, Maja; Zivkovic, Milica; Kojic, Snezana; Golic, Natasa; Kojic, Milan

    2015-01-01

    Eleven Lactobacillus strains with strong aggregation abilities were selected from a laboratory collection. In two of the strains, genes associated with aggregation capability were plasmid located and found to strongly correlate with collagen binding. The gene encoding the auto-aggregation-promoting protein (AggLb) of Lactobacillus paracasei subsp. paracasei BGNJ1-64 was cloned using a novel, wide-range-host shuttle cloning vector, pAZILSJ. The clone pALb35, containing a 11377-bp DNA fragment, was selected from the SacI plasmid library for its ability to provide carriers with the aggregation phenotype. The complete fragment was sequenced and four potential ORFs were detected, including the aggLb gene and three surrounding transposase genes. AggLb is the largest known cell-surface protein in lactobacilli, consisting of 2998 aa (318,611 Da). AggLb belongs to the collagen-binding superfamily and its C-terminal region contains 20 successive repeats that are identical even at the nucleotide level. Deletion of aggLb causes a loss of the capacity to form cell aggregates, whereas overexpression increases cellular aggregation, hydrophobicity and collagen-binding potential. PCR screening performed with three sets of primers based on the aggLb gene of BGNJ1-64 enabled detection of the same type of aggLb gene in five of eleven selected aggregation-positive Lactobacillus strains. Heterologous expression of aggLb confirmed the crucial role of the AggLb protein in cell aggregation and specific collagen binding, indicating that AggLb has a useful probiotic function in effective colonization of host tissue and prevention of pathogen colonization. PMID:25955159

  5. Expression of terrain and surface geology in high-resolution helicopter-borne gravity gradient (AGG) data: examples from Great Sand Dunes National Park, Rio Grande Rift, Colorado

    USGS Publications Warehouse

    Drenth, Benjamin J.

    2013-01-01

    Airborne gravity gradient (AGG) data are rapidly becoming standard components of geophysical mapping programs, due to their advantages in cost, access, and resolution advantages over measurements of the gravity field on the ground. Unlike conventional techniques that measure the gravity field, AGG methods measure derivatives of the gravity field. This means that effects of terrain and near-surface geology are amplified in AGG data, and that proper terrain corrections are critically important for AGG data processing. However, terrain corrections require reasonable estimates of density for the rocks and sediments that make up the terrain. A recommended philosophical approach is to use the terrain and surface geology, with their strong expression in AGG data, to the interpreter’s advantage. An example of such an approach is presented here for an area with very difficult ground access and little ground gravity data. Nettleton-style profiling is used with AGG data to estimate the densities of the sand dunefield and adjacent Precambrian rocks from the area of Great Sand Dunes National Park in southern Colorado. Processing of the AGG data using the density estimate for the dunefield allows buried structures, including a hypothesized buried basement bench, to be mapped beneath the sand dunes.

  6. The STAT3 HIES mutation is a gain-of-function mutation that activates genes via AGG-element carrying promoters.

    PubMed

    Xu, Li; Ji, Jin-Jun; Le, Wangping; Xu, Yan S; Dou, Dandan; Pan, Jieli; Jiao, Yifeng; Zhong, Tianfei; Wu, Dehong; Wang, Yumei; Wen, Chengping; Xie, Guan-Qun; Yao, Feng; Zhao, Heng; Fan, Yong-Sheng; Chin, Y Eugene

    2015-10-15

    Cytokine or growth factor activated STAT3 undergoes multiple post-translational modifications, dimerization and translocation into nuclei, where it binds to serum-inducible element (SIE, 'TTC(N3)GAA')-bearing promoters to activate transcription. The STAT3 DNA binding domain (DBD, 320-494) mutation in hyper immunoglobulin E syndrome (HIES), called the HIES mutation (R382Q, R382W or V463Δ), which elevates IgE synthesis, inhibits SIE binding activity and sensitizes genes such as TNF-α for expression. However, the mechanism by which the HIES mutation sensitizes STAT3 in gene induction remains elusive. Here, we report that STAT3 binds directly to the AGG-element with the consensus sequence 'AGG(N3)AGG'. Surprisingly, the helical N-terminal region (1-355), rather than the canonical STAT3 DBD, is responsible for AGG-element binding. The HIES mutation markedly enhances STAT3 AGG-element binding and AGG-promoter activation activity. Thus, STAT3 is a dual specificity transcription factor that promotes gene expression not only via SIE- but also AGG-promoter activity. PMID:26384563

  7. Multichanneled puzzle-like encryption

    NASA Astrophysics Data System (ADS)

    Amaya, Dafne; Tebaldi, Myrian; Torroba, Roberto; Bolognini, Néstor

    2008-07-01

    In order to increase data security transmission we propose a multichanneled puzzle-like encryption method. The basic principle relies on the input information decomposition, in the same way as the pieces of a puzzle. Each decomposed part of the input object is encrypted separately in a 4 f double random phase mask architecture, by setting the optical parameters in a determined status. Each parameter set defines a channel. In order to retrieve the whole information it is necessary to properly decrypt and compose all channels. Computer simulations that confirm our proposal are presented.

  8. Chemistry of Art and Color Sudoku Puzzles

    ERIC Educational Resources Information Center

    Welsh, Michael J.

    2007-01-01

    Sudoku puzzle format was used to teach light science and chemistry terms to students of Chemistry of Art and Color. The puzzles were used to motivate and encourage students to learn chemistry in an easier and in friendly fashion.

  9. Package Them in Puzzles: Vocabulary, Culture, Conjugations.

    ERIC Educational Resources Information Center

    McElroy, Mary E.; Samaniego, Fabian A.

    1981-01-01

    Presents a method of using traditional puzzles and crosswords in foreign language instruction. Instead of merely providing amusement, the puzzles are designed to assist in the learning of various language skills. This article gives directions for developing puzzles specifically designed to teach grammar, vocabulary, and culture. (Author/PJM)

  10. Sudoku Puzzles as Chemistry Learning Tools

    ERIC Educational Resources Information Center

    Crute, Thomas D.; Myers, Stephanie A.

    2007-01-01

    A sudoku puzzle was designed that incorporated lists of chemistry terms like polyatomic ions, organic functional groups or strong nucleophiles that students need to learn. It was found that students enjoyed solving such puzzles and also such puzzles made the boring tasks of memorizing basic chemical terms an exciting one.

  11. Canadian Open Tennis. Puzzle Corner.

    ERIC Educational Resources Information Center

    Andrews, Ian A.

    2000-01-01

    Describes the du Maurier Open, a women's tennis tournament. Explains that tennis becomes an elite sport at the level of the du Maurier Open. Presents a crossword puzzle that focuses on many of the female tennis stars and provides the across and down clues, a word list, and the answer key. (CMK)

  12. On a Perplexing Polynomial Puzzle

    ERIC Educational Resources Information Center

    Richmond, Bettina

    2010-01-01

    It seems rather surprising that any given polynomial p(x) with nonnegative integer coefficients can be determined by just the two values p(1) and p(a), where a is any integer greater than p(1). This result has become known as the "perplexing polynomial puzzle." Here, we address the natural question of what might be required to determine a…

  13. Japanese Logic Puzzles and Proof

    ERIC Educational Resources Information Center

    Wanko, Jeffrey J.

    2009-01-01

    An understanding of proof does not start in a high school geometry course. Rather, attention to logical reasoning throughout a student's school experience can help the development of proof readiness. In the spirit of problem solving, the author has begun to use some Japanese logic puzzles other than sudoku to help students develop additional…

  14. STM study of azobenzene self-assembly on Ag/Ge(1 1 1)-( √{3}×√{3})R30°

    NASA Astrophysics Data System (ADS)

    Wu, H.-C.; Chou, L.-W.; Lee, Y.-R.; Su, C.; Lin, J.-C.

    2009-10-01

    The adsorption and self-organization of trans-azobenzene (TAB) on Ag/Ge(1 1 1)-( √{3}×√{3})R30° (Ag/Ge(1 1 1)- √{3}) were studied by low temperature scanning tunneling microscopy (LT-STM) in ultrahigh vacuum (UHV). High-resolution STM images allow the observation of individual TAB molecules and the commensurate TAB chain domains formed via the hydrogen bond enhanced intermolecular interaction and molecule-substrate interaction on Ag/Ge(1 1 1)- √{3}. From in situ observation of the substrate lattice, the TAB monolayers were found to form a (2 × 1) structure. Some coexisting cis-azobenzene (CAB) molecules were observed on the domain boundary of TAB overlayer. The structural model and the molecule registry corresponding to STM images for the monolayer of TAB on Ag/Ge(1 1 1)- √{3} are proposed and discussed.

  15. PTF11agg as the First Evidence for Reverse Shock Emission from a Post-merger Millisecond Magnetar

    NASA Astrophysics Data System (ADS)

    Wang, Ling-Jun; Dai, Zi-Gao

    2013-09-01

    Based on the stiff equations of state of neutron stars (NS) and the discovery of high-mass NSs, it is highly probable that a NS-NS merger will result in a rapidly rotating massive magnetar. The central magnetar will dissipate its rotational energy to the outflow by injecting Poynting flux, which will become lepton-dominated so that a long-lasting reverse shock (RS) develops. We calculate the emission of the RS as well as the emission of forward shock (FS) and find that, in most cases, the RS emission is stronger than FS emission. It is found that the recently discovered transient, PTF11agg, can be neatly accounted for by the RS emission powered by a millisecond magnetar. Other alternative models have been considered and cannot explain the observed light curves well. We therefore suggest that PTF11agg is the first evidence for RS emission from a post-merger millisecond magnetar.

  16. Quantitative Proteomics Analysis of Camelina sativa Seeds Overexpressing the AGG3 Gene to Identify the Proteomic Basis of Increased Yield and Stress Tolerance.

    PubMed

    Alvarez, Sophie; Roy Choudhury, Swarup; Sivagnanam, Kumaran; Hicks, Leslie M; Pandey, Sona

    2015-06-01

    Camelina sativa, a close relative of Arabidopsis, is an oilseed plant that is emerging as an important biofuel resource. The genome and transcriptome maps of Camelina have become available recently, but its proteome composition remained unexplored. A labeling LC-based quantitative proteomics approach was applied to decipher the Camelina seed proteome, which led to the identification of 1532 proteins. In addition, the effect of overexpression of the Arabidopsis G-protein γ subunit 3 (AGG3) on the Camelina seed proteome was elucidated to identify the proteomic basis of its increased seed size and improved stress tolerance. The comparative analysis showed a significantly higher expression of proteins involved in primary and secondary metabolism, nucleic acid and protein metabolism, and abscisic acid related responses, corroborating the physiological effects of AGG3 overexpression. More importantly, the proteomic data suggested involvement of the AGG3 protein in the regulation of oxidative stress and heavy metal stress tolerance. These observations were confirmed by the physiological and biochemical characterization of AGG3-overexpressing seeds, which exhibit a higher tolerance to exogenous cadmium in a glutathione-dependent manner. The activity of multiple redox-regulating enzymes is higher in seeds expressing enhanced levels of AGG3. Overall, these data provide critical evidence for the role of redox regulation by the AGG3 protein in mediating important seed-related traits. PMID:25944359

  17. Evidence for an unusual transmembrane configuration of AGG3, a Class C Gγ Subunit, of Arabidopsis

    PubMed Central

    Wolfenstetter, Susanne; Chakravorty, David; Kula, Ryan; Urano, Daisuke; Trusov, Yuri; McCurdy, David W.; Assmann, Sarah M.; Jones, Alan M.; Botella, Jose R.

    2015-01-01

    SUMMARY Heterotrimeric G proteins are crucial for the perception of external signals and subsequent signal transduction in animal and plant cells. In both model systems, the complex is comprised of one Gα, one Gβ and one Gγ subunit. However, in addition to the canonical Gγ subunits (Class A), plants also possess two unusual, plant-specific classes of Gγ subunits (Classes B and C) not yet found in animals. These include Gγ subunits lacking the C-terminal CaaX motif (Class B) which is important for membrane anchoring of the protein, and thus give rise to a flexible subpopulation of Gβ/γ heterodimers that is not necessarily restricted to the plasma membrane. Even more interesting, plants also contain Class C Gγ subunits which are twice the size of canonical Gγs, with a predicted transmembrane domain, and a large cysteine-rich, extracellular C-terminus. However, neither the presence of the transmembrane domain nor the membrane topology has been unequivocally demonstrated. Here, we provide compelling evidence that AGG3, a Class C Ggamma subunit of Arabidopsis, contains a functional transmembrane domain, which is sufficient but not essential for plasma membrane localization, and that the cysteine-rich C-terminus is extracellular. PMID:25430066

  18. AggNet: Deep Learning From Crowds for Mitosis Detection in Breast Cancer Histology Images.

    PubMed

    Albarqouni, Shadi; Baur, Christoph; Achilles, Felix; Belagiannis, Vasileios; Demirci, Stefanie; Navab, Nassir

    2016-05-01

    The lack of publicly available ground-truth data has been identified as the major challenge for transferring recent developments in deep learning to the biomedical imaging domain. Though crowdsourcing has enabled annotation of large scale databases for real world images, its application for biomedical purposes requires a deeper understanding and hence, more precise definition of the actual annotation task. The fact that expert tasks are being outsourced to non-expert users may lead to noisy annotations introducing disagreement between users. Despite being a valuable resource for learning annotation models from crowdsourcing, conventional machine-learning methods may have difficulties dealing with noisy annotations during training. In this manuscript, we present a new concept for learning from crowds that handle data aggregation directly as part of the learning process of the convolutional neural network (CNN) via additional crowdsourcing layer (AggNet). Besides, we present an experimental study on learning from crowds designed to answer the following questions. 1) Can deep CNN be trained with data collected from crowdsourcing? 2) How to adapt the CNN to train on multiple types of annotation datasets (ground truth and crowd-based)? 3) How does the choice of annotation and aggregation affect the accuracy? Our experimental setup involved Annot8, a self-implemented web-platform based on Crowdflower API realizing image annotation tasks for a publicly available biomedical image database. Our results give valuable insights into the functionality of deep CNN learning from crowd annotations and prove the necessity of data aggregation integration. PMID:26891484

  19. Current puzzles and future possibilities

    SciTech Connect

    Nagamiya, S.

    1982-02-01

    Four current puzzles and several future experimental possibilities in high-energy nuclear collision research are discussed. These puzzles are (1) entropy, (2) hydrodynamic flow, (3) anomalon, and (4) particle emission at backward angles in proton-nucleus collisions. The last one seems not to be directly related to the subject of the present school. But it is, because particle emission into the region far beyond the nucleon-nucleon kinematical limit is an interesting subject common for both proton-nucleus and nucleus-nucleus collisions, and the basic mechanism involved is strongly related in these two cases. Future experimental possibilities are described which include: (1) possibilities of studying multibaryonic excited states, (2) applications of neutron-rich isotopes, and (3) other needed experimental tasks. 72 references.

  20. Construction-Paper Puzzle Masterpieces

    ERIC Educational Resources Information Center

    Vance, Shelly

    2010-01-01

    Creating an appreciation of art history in her junior-high students has always been one of the author's greatest challenges as an art teacher. In this article, the author describes how her eighth-grade students re-created a famous work of art--piece by piece, like a puzzle or a stained-glass window--out of construction paper. (Contains 1 resource.)

  1. Transmission of the FRAXA haplotype from three nonpenetrant brothers to their affected grandsons: an update with AGG interspersion analysis.

    PubMed

    Mogk, R L; Carson, N L; Chudley, A E; Dawson, A J

    1998-01-01

    Recently, we reported on a family showing transmission of the FRAXA gene by three nonpenetrant, normally intelligent, full and half brothers to their affected grandsons [Kirkilionis et al., 1992]. We have reanalyzed this family for CGG repeat size by polymerase chain reaction (PCR) amplification/Southern blot and FMR1 methylation status using EcoRI/BssHII double digests with pE5-1 as the hybridization probe. The half brother was found to have a premutation allele size of 59 CGG repeats. MnlI digestion of PCR products showed the absence of intervening AGG sequences. All of his obligate carrier daughters had CGG alleles ranging from 65 to 90 repeats, with a final expansion of more than 200 repeats in his FRAXA-affected grandson and 131 repeats in his carrier granddaughter. Two full brothers were shown to have inherited a 47-CGG repeat premutation allele. Analysis of one brother showed that he stably transmitted the 47-repeat allele to his daughter. Analysis of the second brother, his daughter, and his granddaughter showed that this allele was meiotically unstable, with the allele size increasing from 47, to 48, to 49 from the father, to the daughter to the granddaughter, respectively. MnlI digestion and DNA sequencing of PCR products showed the absence of intervening AGG sequences. This is the first case in which the lack of AGG interspersions has been associated with instability of a gray zone allele resulting in a one-repeat increase in two successive generations. PMID:9450853

  2. Economics - A Puzzle: The People Power Solution.

    ERIC Educational Resources Information Center

    Bartlett, Glenda; Price, Marlene H.

    A third-grade class and fifth-grade remedial reading students gained a positive attitude toward contemporary economic problems by studying economics as a puzzle in this award-winning project. The following concepts were each approached as pieces of the puzzle to be solved: money, wants and needs, income, goods and services, scarcity, consumption…

  3. Guerrilla Puzzling: A Model for Research

    ERIC Educational Resources Information Center

    Zimmer, Marc

    2007-01-01

    There are two main settings for puzzle solving in higher education: graduate programs, with professors and both graduate and postdoctoral students; and predominantly undergraduate institutions, with professors and students. Research programs at large universities are well-oiled puzzle-solving machines. Graduate students there work long, hard hours…

  4. Advocacy: AASL Puts the Puzzle Together

    ERIC Educational Resources Information Center

    Johns, Sara Kelly

    2007-01-01

    School librarians work with people of all ages, abilities, and personalities; those people are the puzzle pieces that make advocacy for libraries effective. School librarians contribute to and use the resources of their state and national organizations' advocacy efforts. The completed picture of the puzzle is an excellent program with…

  5. Project-A-Puzzle. Second Edition.

    ERIC Educational Resources Information Center

    Porter, Richard D.

    This set of transparency masters of mathematical puzzles has as its intent the development of logical and perceptual skills. The puzzles include patterns, magic squares, and counting problems. Solutions and follow-up suggestions are provided on the back of each page. (MP)

  6. An extra tRNAGly(U*CU) found in ascidian mitochondria responsible for decoding non-universal codons AGA/AGG as glycine.

    PubMed

    Kondow, A; Suzuki, T; Yokobori, S; Ueda, T; Watanabe, K

    1999-06-15

    Amino acid assignments of metazoan mitochondrial codons AGA/AGG are known to vary among animal species; arginine in Cnidaria, serine in invertebrates and stop in vertebrates. We recently found that in the mitochondria of the ascidian Halocynthia roretzi these codons are exceptionally used for glycine, and postulated that they are probably decoded by a tRNA(UCU). In order to verify this notion unambig-uously, we determined the complete RNA sequence of the mitochondrial tRNA(UCU) presumed to decode codons AGA/AGG in the ascidian mitochondria, and found it to have an unidentified U derivative at the anticodon first position. We then identified the amino acids attached to the tRNA(U*CU), as well as to the conventional tRNAGly(UCC) with an unmodified U34, in vivo. The results clearly demonstrated that glycine was attached to both tRNAs. Since no other tRNA capable of decoding codons AGA/AGG has been found in the mitochondrial genome, it is most probable that this tRNA(U*CU) does actually translate codons AGA/AGG as glycine in vivo. Sequencing of tRNASer(GCU), which is thought to recognize only codons AGU/AGC, revealed that it has an unmodified guanosine at position 34, as is the case with vertebrate mitochondrial tRNASer(GCU) for codons AGA/AGG. It was thus concluded that in the ascidian, codons AGU/AGC are read as serine by tRNASer(GCU), whereas AGA/AGG are read as glycine by an extra tRNAGly(U*CU). The possible origin of this unorthodox genetic code is discussed. PMID:10352185

  7. Solving the BM Camelopardalis puzzle

    NASA Technical Reports Server (NTRS)

    Teke, Mathias; Busby, Michael R.; Hall, Douglas S.

    1989-01-01

    BM Camelopardalis (=12 Cam) is a chromospherically active binary star with a relatively large orbital eccentricity. Systems with large eccentricities usually rotate pseudosynchronously. However, BM Cam has been a puzzle since its observed rotation rate is virtually equal to its orbital period indicating synchronization. All available photometry data for BM Cam have been collected and analyzed. Two models of modulated ellipticity effect are proposed, one based on equilibrium tidal deformation of the primary star and the other on a dynamical tidal effect. When the starspot variability is removed from the data, the dynamical tidal model was the better approximation to the real physical situation. The analysis indicates that BM Cam is not rotating pseudosynchronously but rotating in virtual synchronism after all.

  8. Solving combinatorial problems: the 15-puzzle.

    PubMed

    Pizlo, Zygmunt; Li, Zheng

    2005-09-01

    We present a series of experiments in which human subjects were tested with a well-known combinatorial problem called the 15-puzzle and in different-sized variants of this puzzle. Subjects can solve these puzzles reliably by systematically building a solution path, without performing much search and without using distances among the states of the problem. The computational complexity of the underlying mental mechanisms is very low. We formulated a computational model of the underlying cognitive processes on the basis of our results. This model applied a pyramid algorithm to individual stages of each problem. The model's performance proved to be quite similar to the subjects' performance. PMID:16496727

  9. Unique AGG Interruption in the CGG Repeats of the FMR1 Gene Exclusively Found in Asians Linked to a Specific SNP Haplotype

    PubMed Central

    Limprasert, Pornprot; Thanakitgosate, Janpen; Jaruthamsophon, Kanoot; Sripo, Thanya

    2016-01-01

    Fragile X syndrome (FXS) is the most common inherited intellectual disability. It is caused by the occurrence of more than 200 pure CGG repeats in the FMR1 gene. Normal individuals have 6–54 CGG repeats with two or more stabilizing AGG interruptions occurring once every 9- or 10-CGG-repeat blocks in various populations. However, the unique (CGG)6AGG pattern, designated as 6A, has been exclusively reported in Asians. To examine the genetic background of AGG interruptions in the CGG repeats of the FMR1 gene, we studied 8 SNPs near the CGG repeats in 176 unrelated Thai males with 19–56 CGG repeats. Of these 176 samples, we identified AGG interruption patterns from 95 samples using direct DNA sequencing. We found that the common CGG repeat groups (29, 30, and 36) were associated with 3 common haplotypes, GCGGATAA (Hap A), TTCATCGC (Hap C), and GCCGTTAA (Hap B), respectively. The configurations of 9A9A9, 10A9A9, and 9A9A6A9 were commonly found in chromosomes with 29, 30, and 36 CGG repeats, respectively. Almost all chromosomes with Hap B (22/23) carried at least one 6A pattern, suggesting that the 6A pattern is linked to Hap B and may have originally occurred in the ancestors of Asian populations. PMID:27042357

  10. Polarization puzzles for the upper elementary grades

    NASA Astrophysics Data System (ADS)

    Chandrasekhar, Meera; Rainwater, David L.; Litherland, Rebecca Q.; Swope, Rodney A.; VanNest, Ann

    1995-10-01

    The concept of polarization and its most basic consequence, Malus' Law, is usually not taught in the elementary or middle grades because of conceptual difficulties. We introduce the concept of polarization using sunglasses to understand the consequences of parallel and crossed polarizers. We then expand the concept with four puzzles. The puzzles are cut out of sheets of linear polarizers and are viewed through a (hand held) spinning polarizer. The first puzzle is constructed out of wedge shaped pieces of linear polarizer so that the wheel appears to rotate when viewed through the spinning polarizer. The second puzzle consists of concentric circles that appear to radiate outward. The third and fourth puzzles are four- and twelve piece wedges that are manipulated to produce different symmetric designs. We have tested these activities on fifth and sixth graders, and find that they enjoy the manipulative as well as the problem solving aspects of the puzzles. They are also able to understand that when light is polarized, 'whatever it is that waves' (the electric field) is oriented in one direction. The materials are inexpensive and can be easily made by teachers for classroom learning.

  11. Does Cold Plasma Affect Breaking Dormancy and Seed Germination? A Study on Seeds of Lamb's Quarters (Chenopodium album agg.)

    NASA Astrophysics Data System (ADS)

    Božena, Šerá; Michal, Šerý; Vitězslav, Štrañák; Petr, Špatenka; Milan, tichý

    2009-12-01

    Low-pressure discharge is applied for stimulation of germination of two seed lots of Lamb's Quarters (Chenopodium album agg.) with different starting germinations (17%, 8%) and in different stages of dormancy. Different exposition durations with cold plasma treatment were applied. The variable of the ratio cumulative germination was calculated. The Richards' equation was used for curve-fitting and simulation of the growth curves. Population parameters, namely Vi - viability, Me - time, Qu - dispersion, and Sk - skewness, counted from the curves described the germination rate well. Significant differences among Qu confirmed the erratic dormancy and gradual germination of Lamb's Quarters. No difference in the Me parameter was found between two tested seed lots, and no interspecies characteristics were changed using low-pressure discharge. The results suggested that plasma treatment changed seed germination in Lamb's Quarters seeds.

  12. Tornillos: Pieces of a Puzzle

    NASA Astrophysics Data System (ADS)

    Hellweg, M.; Seidl, D.

    2001-12-01

    In the past decade several of the ash eruptions at Galeras volcano (Colombia) have been preceded by tornillos. These unusual seismic events of unknown origin have screw-like profiles on seismograms and can last up to several minutes. Since 1997, a joint project between the Bundesanstalt für Geowissenschaften und Rohstoffe (BGR) and the Instituto de Investigación e Información Geocientífica, Minero-Ambiental y Nuclear (INGEOMINAS) has supplemented the shortperiod network of the Observatorio Vulcanológico de Pasto with four broadband, three-component seismometer stations, continuous fumarole gas chemistry measurments, electromagnetic sensors, an infrasound sensor and weather observations in the hopes to learn more about the physical or chemical process which generates tornillos and their significance in the sequence leading to ash explosions. The events of a suite of tornillos which occurred at Galeras Volcano between 08 December 1999 and 11 February 2000 were recorded well at the crater rim broadband stations, ANG and ACH. They appear to be more complex than many of the tornillos recorded previously. They are multichromatic, having narrow spectral peaks at up to 9 frequencies. Some peaks last throughout the entire tornillo, others only contribute to the turn-on transient. We compare polarization, frequency, amplitudes and decay measured from this suite of tornillos in each frequency band at the stations ANG and ACH. They indicate a single source location for all these tornillos. While other parameters correlate well at both stations, the amplitude of the 1.9 Hz peak is nearly twice as large at ACH than at ANG. This may indicate a distinct radiation pattern at this frequency. While none of these observations gives us a clear picture of the source process of tornillos, they provide additional puzzle pieces we can add those collected from other measurements.

  13. Constitutive or seed-specific overexpression of Arabidopsis G-protein γ subunit 3 (AGG3) results in increased seed and oil production and improved stress tolerance in Camelina sativa.

    PubMed

    Roy Choudhury, Swarup; Riesselman, Adam J; Pandey, Sona

    2014-01-01

    Heterotrimeric G-proteins consisting of Gα, Gβ and Gγ subunits play an integral role in mediating multiple signalling pathways in plants. A novel, recently identified plant-specific Gγ protein, AGG3, has been proposed to be an important regulator of organ size and mediator of stress responses in Arabidopsis, whereas its potential homologs in rice are major quantitative trait loci for seed size and panicle branching. To evaluate the role of AGG3 towards seed and oil yield improvement, the gene was overexpressed in Camelina sativa, an oilseed crop of the Brassicaceae family. Analysis of multiple homozygous T4 transgenic Camelina lines showed that constitutive overexpression of AGG3 resulted in faster vegetative as well as reproductive growth accompanied by an increase in photosynthetic efficiency. Moreover, when expressed constitutively or specifically in seed tissue, AGG3 was found to increase seed size, seed mass and seed number per plant by 15%-40%, effectively resulting in significantly higher oil yield per plant. AGG3 overexpressing Camelina plants also exhibited improved stress tolerance. These observations draw a strong link between the roles of AGG3 in regulating two critical yield parameters, seed traits and plant stress responses, and reveal an effective biotechnological tool to dramatically increase yield in agricultural crops. PMID:24102738

  14. Layered Seed-Growth of AgGe Football-like Microspheres via Precursor-Free Picosecond Laser Synthesis in Water

    NASA Astrophysics Data System (ADS)

    Zhang, Dongshi; Gökce, Bilal; Notthoff, Christian; Barcikowski, Stephan

    2015-09-01

    Hybrid particles are of great significance in terms of their adjustable optical, electronic, magnetic, thermal and mechanical properties. As a novel technique, laser ablation in liquids (LAL) is famous for its precursor-free, “clean” synthesis of hybrid particles with various materials. Till now, almost all the LAL-generated particles originate from the nucleation-growth mechanism. Seed-growth of particles similar to chemical methods seems difficult to be achieved by LAL. Here, we not only present novel patch-joint football-like AgGe microspheres with a diameter in the range of 1 ~ 7 μm achievable by laser ablation in distilled water but also find direct evidences of their layered seed growth mechanism. Many critical factors contribute to the formation of AgGe microspheres: fast laser-generated plasma process provide an excellent condition for generating large amount of Ge and Ag ions/atoms, their initial nucleation and galvanic replacement reaction, while cavitation bubble confinement plays an important role for the increase of AgGe nuclei and subsequent layered growth in water after bubble collapse. Driven by work function difference, Ge acts as nucleation agent for silver during alloy formation. This new seed-growth mechanism for LAL technique opens new opportunities to develop a large variety of novel hybrid materials with controllable properties.

  15. Layered Seed-Growth of AgGe Football-like Microspheres via Precursor-Free Picosecond Laser Synthesis in Water

    PubMed Central

    Zhang, Dongshi; Gökce, Bilal; Notthoff, Christian; Barcikowski, Stephan

    2015-01-01

    Hybrid particles are of great significance in terms of their adjustable optical, electronic, magnetic, thermal and mechanical properties. As a novel technique, laser ablation in liquids (LAL) is famous for its precursor-free, “clean” synthesis of hybrid particles with various materials. Till now, almost all the LAL-generated particles originate from the nucleation-growth mechanism. Seed-growth of particles similar to chemical methods seems difficult to be achieved by LAL. Here, we not only present novel patch-joint football-like AgGe microspheres with a diameter in the range of 1 ~ 7 μm achievable by laser ablation in distilled water but also find direct evidences of their layered seed growth mechanism. Many critical factors contribute to the formation of AgGe microspheres: fast laser-generated plasma process provide an excellent condition for generating large amount of Ge and Ag ions/atoms, their initial nucleation and galvanic replacement reaction, while cavitation bubble confinement plays an important role for the increase of AgGe nuclei and subsequent layered growth in water after bubble collapse. Driven by work function difference, Ge acts as nucleation agent for silver during alloy formation. This new seed-growth mechanism for LAL technique opens new opportunities to develop a large variety of novel hybrid materials with controllable properties. PMID:26334136

  16. Bullet-Block Science Video Puzzle

    ERIC Educational Resources Information Center

    Shakur, Asif

    2015-01-01

    A science video blog, which has gone viral, shows a wooden block shot by a vertically aimed rifle. The video shows that the block hit dead center goes exactly as high as the one shot off-center. (Fig. 1). The puzzle is that the block shot off-center carries rotational kinetic energy in addition to the gravitational potential energy. This leads a…

  17. Ramanujan's Continued Fraction for a Puzzle

    ERIC Educational Resources Information Center

    Park, Poo-Sung

    2005-01-01

    This article describes a method of solution that Ramanujan may have used in solving the following puzzle: The number of a house is both the sum of the house numbers below it on the street and the sum of those above it. (The houses on a street are numbered consecutively, starting with 1.)

  18. Insights and Puzzles in Particle Physics

    NASA Astrophysics Data System (ADS)

    Leutwyler, H.

    2015-03-01

    I briefly review the conceptual developments that led to the Standard Model and discuss some of its remarkable qualitative features. On the way, I draw attention to several puzzling aspects that are beyond the reach of our present understanding of the basic laws of physics.

  19. Insights and puzzles in particle physics

    NASA Astrophysics Data System (ADS)

    Leutwyler, H.

    2015-01-01

    I briefly review the conceptual developments that led to the Standard Model and discuss some of its remarkable qualitative features. On the way, I draw attention to several puzzling aspects that are beyond the reach of our present understanding of the basic laws of physics.

  20. Exploring Organic Mechanistic Puzzles with Molecular Modeling

    ERIC Educational Resources Information Center

    Horowitz, Gail; Schwartz, Gary

    2004-01-01

    The molecular modeling was used to reinforce more general skills such as deducing and drawing reaction mechanisms, analyzing reaction kinetics and thermodynamics and drawing reaction coordinate energy diagrams. This modeling was done through the design of mechanistic puzzles, involving reactions not familiar to the students.

  1. Reinforcing Geometric Properties with Shapedoku Puzzles

    ERIC Educational Resources Information Center

    Wanko, Jeffrey J.; Nickell, Jennifer V.

    2013-01-01

    Shapedoku is a new type of puzzle that combines logic and spatial reasoning with understanding of basic geometric concepts such as slope, parallelism, perpendicularity, and properties of shapes. Shapedoku can be solved by individuals and, as demonstrated here, can form the basis of a review for geometry students as they create their own. In this…

  2. Mathematical History: Activities, Puzzles, Stories, and Games.

    ERIC Educational Resources Information Center

    Mitchell, Merle

    Based on the history of mathematics, these materials have been planned to enrich the teaching of mathematics in grades four, five, and six. Puzzles and games are based on stories about topics such as famous mathematicians, numerals of ancient peoples, and numerology. The sheets are arranged by grade level and are designed for easy duplication.…

  3. Identification, quantification, spatiotemporal distribution and genetic variation of major latex secondary metabolites in the common dandelion (Taraxacum officinale agg.).

    PubMed

    Huber, Meret; Triebwasser-Freese, Daniella; Reichelt, Michael; Heiling, Sven; Paetz, Christian; Chandran, Jima N; Bartram, Stefan; Schneider, Bernd; Gershenzon, Jonathan; Erb, Matthias

    2015-07-01

    The secondary metabolites in the roots, leaves and flowers of the common dandelion (Taraxacum officinale agg.) have been studied in detail. However, little is known about the specific constituents of the plant's highly specialized laticifer cells. Using a combination of liquid and gas chromatography, mass spectrometry and nuclear magnetic resonance spectrometry, we identified and quantified the major secondary metabolites in the latex of different organs across different growth stages in three genotypes, and tested the activity of the metabolites against the generalist root herbivore Diabrotica balteata. We found that common dandelion latex is dominated by three classes of secondary metabolites: phenolic inositol esters (PIEs), triterpene acetates (TritAc) and the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G). Purification and absolute quantification revealed concentrations in the upper mgg(-1) range for all compound classes with up to 6% PIEs, 5% TritAc and 7% TA-G per gram latex fresh weight. Contrary to typical secondary metabolite patterns, concentrations of all three classes increased with plant age. The highest concentrations were measured in the main root. PIE profiles differed both quantitatively and qualitatively between plant genotypes, whereas TritAc and TA-G differed only quantitatively. Metabolite concentrations were positively correlated within and between the different compound classes, indicating tight biosynthetic co-regulation. Latex metabolite extracts strongly repelled D. balteata larvae, suggesting that the latex constituents are biologically active. PMID:25682510

  4. Weird Stellar Pair Puzzles Scientists

    NASA Astrophysics Data System (ADS)

    2008-05-01

    Astronomers have discovered a speedy spinning pulsar in an elongated orbit around an apparent Sun-like star, a combination never seen before, and one that has them puzzled about how the strange system developed. Orbital Comparison Comparing Orbits of Pulsar and Its Companion to our Solar System. CREDIT: Bill Saxton, NRAO/AUI/NSF Click on image for full caption information and available graphics. "Our ideas about how the fastest-spinning pulsars are produced do not predict either the kind of orbit or the type of companion star this one has," said David Champion of the Australia Telescope National Facility. "We have to come up with some new scenarios to explain this weird pair," he added. Astronomers first detected the pulsar, called J1903+0327, as part of a long-term survey using the National Science Foundation's Arecibo radio telescope in Puerto Rico. They made the discovery in 2006 doing data analysis at McGill University, where Champion worked at the time. They followed up the discovery with detailed studies using the Arecibo telescope, the NSF's Robert C. Byrd Green Bank Telescope (GBT) in West Virginia, the Westerbork radio telescope in the Netherlands, and the Gemini North optical telescope in Hawaii. The pulsar, a city-sized superdense stellar corpse left over after a massive star exploded as a supernova, is spinning on its axis 465 times every second. Nearly 21,000 light-years from Earth, it is in a highly-elongated orbit that takes it around its companion star once every 95 days. An infrared image made with the Gemini North telescope in Hawaii shows a Sun-like star at the pulsar's position. If this is an orbital companion to the pulsar, it is unlike any companions of other rapidly rotating pulsars. The pulsar, a neutron star, also is unusually massive for its type. "This combination of properties is unprecedented. Not only does it require us to figure out how this system was produced, but the large mass may help us understand how matter behaves at extremely

  5. Puzzles in hyperon, charm and beauty physics.

    SciTech Connect

    Lipkin, H. J.

    2002-10-21

    Puzzles awaiting better experiments and better theory include: (1) the contradiction between good and bad SU(3) baryon wave functions in fitting Cabibbo theory for hyperon decays, strangeness suppression in the sea and the violation of the Gottfried Sum rule--no model fits all; (2) Anomalously enhanced Cabibbo-suppressed D{sup +} {yields} K*{sup +} (s{bar d}) decays; (3) anomalously enhanced and suppressed B {yields} {eta}{prime} X decays; (4) the OZI rule in weak decays; (5) Vector dominance (W {yields} {pi}, {rho}, a{sub 1}, D{sub s}, D*{sub s}) in weak decays; (6) puzzles in doubly-cabibbo-suppressed charm decays; and (7) problems in obtaining {Lambda} spin structure from polarization measurements of produced {Lambda}'s.

  6. Study of electric properties of amorphous AgGe1+xAs1-xS3 with content of carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Melnikova, Nina; Kurochka, Kirill; Volkova, Yana

    2013-06-01

    Multicomponent copper and silver chalcogenides have been known as promising materials for scientific and applied purposes. These materials are also under intense investigation for application in a phase-change random access memory. In order to obtain materials with a high ionic conductivity component, glassy silver chalcogenides AgGe1+xAs1-xS3 with the addition of nanotubes were synthesized. In this work the study of electrical properties of the amorphous chalcogenide AgGe1.4As0.6S3 (x = 0.4) with carbon nanotube content at a frequency of the alternating-current electric field varying from 1 Hz to 5 MHz and on direct current at ambient pressure and at pressure up to 30 GPa are presented. The ion transport was confirmed by means DC measurements in cells with blocking ion component of conductivity electrodes. An evaluation of the proportion of ionic conductivity can make a preliminary conclusion that the ionic component of the conductivity of at least 98%. Analyze of the baric dependences of AC properties have shown that the dielectric loss tangent and the real part of an admittance of the AgGe1.4As0.6S3 with carbon nanotube content compound exponentially increase with a pressure increase from 1 up to 30 GPa. The study was supported in part by the Ural Federal University development program with the financial support of young scientists; and by the Russian Foundation for Basic Research, project No. 12-02-31607.

  7. Early puzzle play: a predictor of preschoolers' spatial transformation skill.

    PubMed

    Levine, Susan C; Ratliff, Kristin R; Huttenlocher, Janellen; Cannon, Joanna

    2012-03-01

    Individual differences in spatial skill emerge prior to kindergarten entry. However, little is known about the early experiences that may contribute to these differences. The current study examined the relation between children's early puzzle play and their spatial skill. Children and parents (n = 53) were observed at home for 90 min every 4 months (6 times) between 2 and 4 years of age (26 to 46 months). When children were 4 years 6 months old, they completed a spatial task involving mental transformations of 2-dimensional shapes. Children who were observed playing with puzzles performed better on this task than those who did not, controlling for parent education, income, and overall parent word types. Moreover, among those children who played with puzzles, frequency of puzzle play predicted performance on the spatial transformation task. Although the frequency of puzzle play did not differ for boys and girls, the quality of puzzle play (a composite of puzzle difficulty, parent engagement, and parent spatial language) was higher for boys than for girls. In addition, variation in puzzle play quality predicted performance on the spatial transformation task for girls but not for boys. Implications of these findings as well as future directions for research on the role of puzzle play in the development of spatial skill are discussed. PMID:22040312

  8. Early Puzzle Play: A predictor of preschoolers’ spatial transformation skill

    PubMed Central

    Levine, S.C.; Ratliff, K.R.; Huttenlocher, J.; Cannon, J.

    2011-01-01

    Individual differences in spatial skill emerge prior to kindergarten entry. However, little is known about the early experiences that may contribute to these differences. The current study examines the relation between children’s early puzzle play and their spatial skill. Children and parents (n = 53) were observed at home for 90 minutes every four months (six times) between 2 and 4 years of age (26 to 46 months). When children were 4 years 6 months old, they completed a spatial task involving mental transformations of 2D shapes. Children who were observed playing with puzzles performed better on this task than those who did not, controlling for parent education, income, and overall parent word types. Moreover, among those children who played with puzzles, frequency of puzzle play predicted performance on the spatial transformation task. Although the frequency of puzzle play did not differ for boys and girls, the quality of puzzle play (a composite of puzzle difficulty, parent engagement, and parent spatial language) was higher for boys than girls. In addition, variation in puzzle play quality predicted performance on the spatial transformation task for girls but not boys. Implications of these findings as well as future directions for research on the role of the role of puzzle play in the development of spatial skill are discussed. PMID:22040312

  9. Modified Sigmund sputtering theory: isotopic puzzle

    NASA Astrophysics Data System (ADS)

    Zhang, Z. L.; Zhang, L.

    2005-05-01

    The theory of anisotropic sputtering proposed by Zhang [Z.L. Zhang, Phys. Rev. B 71 026101 (2005).] and [Z.L. Zhang and L. Zhang, Radiat. Eff. Defects Solids 159(5) 301 (2004).] has been generalized to sputtering of isotopic mixtures. The present theory (modified Sigmund theory) has been shown to fit numerous simulations and experimental measurements, including energy and angular distribution of sputtered atoms. In particular, the theory has successfully solved the isotope puzzle of sputtering induced by low energy and heavy ion bombardment.

  10. TOPICAL REVIEW The cosmological constant puzzle

    NASA Astrophysics Data System (ADS)

    Bass, Steven D.

    2011-04-01

    The accelerating expansion of the Universe points to a small positive vacuum energy density and negative vacuum pressure. A strong candidate is the cosmological constant in Einstein's equations of general relativity. Possible contributions are zero-point energies and the condensates associated with spontaneous symmetry breaking. The vacuum energy density extracted from astrophysics is 1056 times smaller than the value expected from quantum fields and standard model particle physics. Is the vacuum energy density time dependent? We give an introduction to the cosmological constant puzzle and ideas how to solve it.

  11. Predisposition to the fragile X syndrome in Jews of Tunisian descent is due to the absence of AGG interruptions on a rare Mediterranean haplotype.

    PubMed Central

    Falik-Zaccai, T C; Shachak, E; Yalon, M; Lis, Z; Borochowitz, Z; Macpherson, J N; Nelson, D L; Eichler, E E

    1997-01-01

    We have studied the ethnic distribution of the fragile X syndrome in Israel and have found that 36/136 (26.5%) of apparently unrelated pedigrees were of Tunisian Jewish descent. The Tunisian Jews, however, constitute only 2%-3% of the general Israeli population, identifying the first ethnic group significantly (P < .001) predisposed to the development of this disease. Associated with this increase in disease prevalence, we have found an unusually high incidence of FMR1 CGG repeats devoid of AGG interruptions among the normal Tunisian Jewish population (30/150, or 20.0%). Furthermore, the proportion of these alleles beyond the FMR1 CGG repeat instability threshold (>35 repeats) (8/150, or 5.3%) was significantly greater (P < .04) than that proportion found among non-Tunisian Jewish controls in Israel (1/136). Haplotype analysis has indicated that these large uninterrupted CGG repeat alleles are present on a previously unreported (DXS548-FRAXAC1-FRAXAC2) haplotype that accounts for all observed cases of disease among Tunisian Jewish X chromosomes. The high prevalence of disease among Tunisian Jews, we suggest, is due to a founder effect of this rare haplotype, which is completely devoid of AGG interruptions in the Jewish population of Tunisia. PMID:8981953

  12. 3D puzzle reconstruction for archeological fragments

    NASA Astrophysics Data System (ADS)

    Jampy, F.; Hostein, A.; Fauvet, E.; Laligant, O.; Truchetet, F.

    2015-03-01

    The reconstruction of broken artifacts is a common task in archeology domain; it can be supported now by 3D data acquisition device and computer processing. Many works have been dedicated in the past to reconstructing 2D puzzles but very few propose a true 3D approach. We present here a complete solution including a dedicated transportable 3D acquisition set-up and a virtual tool with a graphic interface allowing the archeologists to manipulate the fragments and to, interactively, reconstruct the puzzle. The whole lateral part is acquired by rotating the fragment around an axis chosen within a light sheet thanks to a step-motor synchronized with the camera frame clock. Another camera provides a top view of the fragment under scanning. A scanning accuracy of 100μm is attained. The iterative automatic processing algorithm is based on segmentation into facets of the lateral part of the fragments followed by a 3D matching providing the user with a ranked short list of possible assemblies. The device has been applied to the reconstruction of a set of 1200 fragments from broken tablets supporting a Latin inscription dating from the first century AD.

  13. Magic star puzzle for educational mathematics

    NASA Astrophysics Data System (ADS)

    Gan, Yee Siang; Fong, Wan Heng; Sarmin, Nor Haniza

    2013-04-01

    One of the interesting fields in recreational mathematics is the magic number arrangement. There are different kinds of arrays in the arrangement for a group of numbers. In particular, one of the arrays in magic number arrangement is called magic star. In fact, magic star involves combinatorics that contributes to geometrical analysis and number theory. Hence, magic star is suitable to be introduced as educational mathematics to cultivate interest in different area of mathematics. To obtain the solutions of normal magic stars of order six, the possible sets of numbers for every line in a magic star have been considered. Previously, the calculation for obtaining the solutions has been done manually which is time-consuming. Therefore, a programming code to generate all the fundamental solutions for normal magic star of order six without including the properties of rotation and reflection has been done. In this puzzle, a magic star puzzle is created by using Matlab software, which enables a user to verify the entries for the cells of magic star of order six. Moreover, it is also user-friendly as it provides interactive commands on the inputs given by the user, which enables the user to detect the incorrect inputs. In addition, user can also choose to view all the fundamental solutions as generated by the programming code.

  14. Accelerating Student Learning of Technology Terms: "The Crossword Puzzle Exercise"

    ERIC Educational Resources Information Center

    Whisenand, Thomas G.; Dunphy, Steven M.

    2010-01-01

    The authors suggest using an alternative teaching methodology to impart knowledge regarding information systems phraseology and vocabulary. Specifically, a series of crossword puzzles or scrabbles are used to present information system (IS) terminology to students in an introductory business information systems course. The puzzle terms and answers…

  15. Sudoku Puzzles for First-Year Organic Chemistry Students

    ERIC Educational Resources Information Center

    Perez, Alice L.; Lamoureux, G.

    2007-01-01

    Sudoku puzzle was designed to teach about amino acids and functional groups to the students of undergraduate organic chemistry students. The puzzles focus on helping the student learn the name, 3-letter code and 1-letter code of common amino acids and functional groups.

  16. Crossword Puzzles as Learning Tools in Introductory Soil Science

    ERIC Educational Resources Information Center

    Barbarick, K. A.

    2010-01-01

    Students in introductory courses generally respond favorably to novel approaches to learning. To this end, I developed and used three crossword puzzles in spring and fall 2009 semesters in Introductory Soil Science Laboratory at Colorado State University. The first hypothesis was that crossword puzzles would improve introductory soil science…

  17. Decoding Codewords: Statistical Analysis of a Newspaper Puzzle

    ERIC Educational Resources Information Center

    Meacock, Susan; Meacock, Geoff

    2012-01-01

    In recent years English newspapers have started featuring a number of puzzles other than the ubiquitous crossword. Many of the puzzles are of Japanese origin such as Sudoku, Kakuro or Hidato. However, one recent one is very English and is called variously Cross-code, Alphapuzzle or some other name. In this article, it will be known as Codeword.…

  18. Enumerating Small Sudoku Puzzles in a First Abstract Algebra Course

    ERIC Educational Resources Information Center

    Lorch, Crystal; Lorch, John

    2008-01-01

    Two methods are presented for counting small "essentially different" sudoku puzzles using elementary group theory: one method (due to Jarvis and Russell) uses Burnside's counting formula, while the other employs an invariant property of sudoku puzzles. Ideas are included for incorporating this material into an introductory abstract algebra course.…

  19. Sharing Skills: Reach for a Book; Book Week Puzzle Packet.

    ERIC Educational Resources Information Center

    Bauer, Caroline Feller

    1986-01-01

    Reach for a Book is the theme for Children's Book Week 1986, and book presentations, activities, and exhibits to emphasize the joy of reading are listed. A Book Week Puzzle Packet provides two puzzles designed to reinforce the idea of using the card catalog to find materials on specific subjects. (EM)

  20. A Puzzle Used to Teach the Cardiac Cycle

    ERIC Educational Resources Information Center

    Marcondes, Fernanda K.; Moura, Maria J. C. S.; Sanches, Andrea; Costa, Rafaela; Oliveira de Lima, Patricia; Groppo, Francisco Carlos; Amaral, Maria E. C.; Zeni, Paula; Gaviao, Kelly Cristina; Montrezor, Luís H.

    2015-01-01

    The aim of the present article is to describe a puzzle developed for use in teaching cardiac physiology classes. The puzzle presents figures of phases of the cardiac cycle and a table with five columns: phases of cardiac cycle, atrial state, ventricular state, state of atrioventricular valves, and pulmonary and aortic valves. Chips are provided…

  1. Jigsaw Puzzles. Australian Early Childhood Resource Booklets, No. 3.

    ERIC Educational Resources Information Center

    Fleer, Marilyn

    This booklet examines the educational value of jigsaw puzzles and gives practical suggestions on how to select and make them for use by children ages 1 through 8. It asserts that jigsaw puzzles provide children with the opportunity to develop problem-solving strategies, and discusses a theory of adult-child interaction that encourages the…

  2. Categorization Competence by Youth in Non-School Material (Puzzles)

    ERIC Educational Resources Information Center

    Buell, Robert R.; And Others

    1970-01-01

    Presents the procedures, results, and conclusions of a study to investigate the effects of (1) sex, (2) intelligence, and (3) prior experience in puzzle solving on the categorization skills of youth. A two-dimensional type puzzle involving 4 sorting variables was given to 110 ninth graders. 22 subjects, age from 7 to 18 were given a 3-dimensional…

  3. The Puzzle of HD 104994 (WR 46)

    NASA Astrophysics Data System (ADS)

    Marchenko, Sergey V.; Arias, Julia; Barbá, Rodolfo; Balona, Luis; Moffat, Anthony F. J.; Niemela, Virpi S.; Shara, Michael M.; Sterken, Christiaan

    2000-10-01

    Intense coordinated spectroscopic and photometric monitoring of the suspected Wolf-Rayet binary WR 46 in 1999 reveals clear periodic variations, P=0.329+/-0.013 days, in the radial velocities of the emission lines of highest ionization potential, O VI and N V, found deepest in the Wolf-Rayet wind and thus least likely to be perturbed by a companion. These are accompanied by coherent variability in the profiles of lines with lower ionization/excitation potential and in the continuum flux. Most probably originating from orbital motion of the Wolf-Rayet component of the binary, this periodic radial velocity signal disappears from time to time, thus creating a puzzle yet to be solved. We show that the entangled patterns of the line profile variability are mainly governed by transitions between high and low states of the system's continuum flux. Based in part on observations obtained at the European Southern Observatory, La Silla, Chile (ESO program 62.H-0110).

  4. The electron screening puzzle and nuclear clustering

    DOE PAGESBeta

    Spitaleri, C.; Bertulani, C. A.; Fortunato, L.; Vitturi, A.

    2016-02-12

    Accurate measurements of nuclear reactions of astrophysical interest within, or close to, the Gamow peak show evidence of an unexpected effect attributed to the presence of atomic electrons in the target. The experiments need to include an effective "screening" potential to explain the enhancement of the cross sections at the lowest measurable energies. Despite various theoretical studies conducted over the past 20 years and numerous experimental measurements, a theory has not yet been found that can explain the cause of the exceedingly high values of the screening potential needed to explain the data. Furthermore, in this letter we show thatmore » instead of an atomic physics solution of the "electron screening puzzle", the reason for the large screening potential values is in fact due to clusterization effects in nuclear reactions, in particular for reaction involving light nuclei.« less

  5. The puzzle of TRPV4 channelopathies

    PubMed Central

    Nilius, Bernd; Voets, Thomas

    2013-01-01

    Hereditary channelopathies, that is, mutations in channel genes that alter channel function and are causal for the pathogenesis of the disease, have been described for several members of the transient receptor potential channel family. Mutations in the TRPV4 gene, encoding a polymodal Ca2+ permeable channel, are causative for several human diseases, which affect the skeletal system and the peripheral nervous system, with highly variable phenotypes. In this review, we describe the phenotypes of TRPV4 channelopathies and overlapping symptoms. Putative mechanisms to explain the puzzle, and how mutations in the same region of the channel cause different diseases, are discussed and experimental approaches to tackle this surprising problem are suggested. PMID:23306656

  6. A PUZZLE INVOLVING GALACTIC BULGE MICROLENSING EVENTS

    SciTech Connect

    Cohen, Judith G.; Gould, Andrew; Johnson, Jennifer A.; Thompson, Ian B.; Feltzing, Sofia; Bensby, Thomas; Huang Wenjin; Melendez, Jorge; Lucatello, Sara; Asplund, Martin E-mail: gould@astronomy.ohio-state.edu E-mail: ian@obs.carnegiescience.edu E-mail: tbensby@eso.org E-mail: jorge@astro.up.pt E-mail: asplund@MPA-Garching.MPG.DE

    2010-03-01

    We study a sample of 16 microlensed Galactic bulge main-sequence turnoff region stars for which high-dispersion spectra have been obtained with detailed abundance analyses. We demonstrate that there is a very strong and highly statistically significant correlation between the maximum magnification of the microlensed bulge star and the value of the [Fe/H] deduced from the high resolution spectrum of each object. Physics demands that this correlation, assuming it to be real, be the result of some sample bias. We suggest several possible explanations, but are forced to reject them all, and are left puzzled. To obtain a reliable metallicity distribution in the Galactic bulge based on microlensed dwarf stars, it will be necessary to resolve this issue through the course of additional observations.

  7. Solving the Puzzle of Subhalo Spins

    NASA Astrophysics Data System (ADS)

    Wang, Yang; Lin, Weipeng; Pearce, Frazer R.; Lux, Hanni; Muldrew, Stuart I.; Onions, Julian

    2015-03-01

    Investigating the spin parameter distribution of subhalos in two high-resolution isolated halo simulations, recent work by Onions et al. suggested that typical subhalo spins are consistently lower than the spin distribution found for field halos. To further examine this puzzle, we have analyzed simulations of a cosmological volume with sufficient resolution to resolve a significant subhalo population. We confirm the result of Onions et al. and show that the typical spin of a subhalo decreases with decreasing mass and increasing proximity to the host halo center. We interpret this as the growing influence of tidal stripping in removing the outer layers, and hence the higher angular momentum particles, of the subhalos as they move within the host potential. Investigating the redshift dependence of this effect, we find that the typical subhalo spin is smaller with decreasing redshift. This indicates a temporal evolution, as expected in the tidal stripping scenario.

  8. Bullet-Block Science Video Puzzle

    NASA Astrophysics Data System (ADS)

    Shakur, Asif

    2015-01-01

    A science video blog,1 which has gone viral, shows a wooden block shot by a vertically aimed rifle. The video2 shows that the block hit dead center goes exactly as high as the one shot off-center. (Fig. 1). The puzzle is that the block shot off-center carries rotational kinetic energy in addition to the gravitational potential energy. This leads a majority of the bloggers to claim that the block shot off-center should not go as high as the one shot dead center. Others have claimed that the energy tied up as rotational energy is insignificant and the two blocks should rise to the same height within experimental error.

  9. The electron screening puzzle and nuclear clustering

    NASA Astrophysics Data System (ADS)

    Spitaleri, C.; Bertulani, C. A.; Fortunato, L.; Vitturi, A.

    2016-04-01

    Accurate measurements of nuclear reactions of astrophysical interest within, or close to, the Gamow peak show evidence of an unexpected effect attributed to the presence of atomic electrons in the target. The experiments need to include an effective "screening" potential to explain the enhancement of the cross sections at the lowest measurable energies. Despite various theoretical studies conducted over the past 20 years and numerous experimental measurements, a theory has not yet been found that can explain the cause of the exceedingly high values of the screening potential needed to explain the data. In this letter we show that instead of an atomic physics solution of the "electron screening puzzle", the reason for the large screening potential values is in fact due to clusterization effects in nuclear reactions, in particular for reaction involving light nuclei.

  10. A puzzle used to teach the cardiac cycle.

    PubMed

    Marcondes, Fernanda K; Moura, Maria J C S; Sanches, Andrea; Costa, Rafaela; de Lima, Patricia Oliveira; Groppo, Francisco Carlos; Amaral, Maria E C; Zeni, Paula; Gaviao, Kelly Cristina; Montrezor, Luís H

    2015-03-01

    The aim of the present article is to describe a puzzle developed for use in teaching cardiac physiology classes. The puzzle presents figures of phases of the cardiac cycle and a table with five columns: phases of cardiac cycle, atrial state, ventricular state, state of atrioventricular valves, and pulmonary and aortic valves. Chips are provided for use to complete the table. Students are requested to discuss which is the correct sequence of figures indicating the phases of cardiac cycle. Afterward, they should complete the table with the chips. Students of biology, dentistry, medicine, pharmacy, and nursing graduation courses from seven institutions performed the puzzle evaluation. They were invited to indicate whether the puzzle had been useful for learning about the subject by filling one of four alternatives. Of the students, 4.6% answered that it was not necessary but helped them to confirm what they had learned, 64.5% reported that although they had previously understood the cardiac cycle, the puzzle helped them to solve doubts and promoted a better understanding of it, and 30.9% said that they needed the puzzle to understand the cardiac cycle, without differences among courses, institutions, and course semesters. The results of the present study suggest that a simple and inexpensive puzzle may be useful as an active learning methodology applied after the theoretical lecture, as a complementary tool for studying cardiac cycle physiology. PMID:25727466

  11. Atomic structures of Ag/Ge(1 1 1) √39 × √39 and 6 × 6 surfaces studied by STM: observations of bias dependent reconstruction transformations

    NASA Astrophysics Data System (ADS)

    Zhang, H. M.; Uhrberg, R. I. G.

    2003-05-01

    The 6×6 and √39×√39 phases on Ag/Ge(1 1 1) have been studied by scanning tunneling microscopy (STM). Four types of 6×6 configurations are found which all consist of a √3×√3 layer with six extra Ag adatoms per 6×6 unit cell. These reconstructions show either mirrored or complementary relations. We observe interesting transitions between the different 6×6 reconstructions. The √39×√39 surface appears to have five extra Ag atoms per unit cell. By using various tip biases, we show that the √39×√39 domain orientation can be changed. Surface structure models of the √39×√39 and 6×6 phases are proposed based on the HCT structure of the underlying √3×√3 surface.

  12. Solar System Puzzle Kit: An Activity for Earth and Space Science.

    ERIC Educational Resources Information Center

    Vogt, Gregory L.; Rosenberg, Carla B.

    This Solar System Puzzle Kit for grades 5-8, allows students to create an eight-cube paper puzzle of the solar system and may be duplicated for classroom use or used as a take home activity for children and parents. By assembling the puzzle, hand-coloring the bodies of the solar system, and viewing the puzzle's 12 sides, students can reinforce…

  13. Puzzling through General Chemistry: A Light-Hearted Approach to Engaging Students with Chemistry Content

    ERIC Educational Resources Information Center

    Boyd, Susan L.

    2007-01-01

    Several puzzles are designed to be used by chemistry students as learning tools and teach them basic chemical concepts. The topics of the puzzles are based on the chapters from Chemistry, The Central Science used in general chemistry course and the puzzles are in various forms like crosswords, word searches, number searches, puzzles based on…

  14. Teaching the Blue-Eyed Islanders Puzzle in a Liberal Arts Mathematics Course

    ERIC Educational Resources Information Center

    Shea, Stephen

    2012-01-01

    The blue-eyed islanders puzzle is an old and challenging logic puzzle. This is a narrative of an experience introducing a variation of this puzzle on the first day of classes in a liberal arts mathematics course for non-majors. I describe an exercise that was used to facilitate the class's understanding of the puzzle.

  15. Latest Zika Puzzle: How U.S. Patient Infected Caregiver

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_159925.html Latest Zika Puzzle: How U.S. Patient Infected Caregiver Officials say ... MONDAY, July 18, 2016 (HealthDay News) -- The mysterious Zika virus continues to surprise health scientists. On Monday, ...

  16. Peripartum cardiomyopathy: A puzzle closer to solution

    PubMed Central

    Fett, James D

    2014-01-01

    Peripartum cardiomyopathy (PPCM) represents new heart failure in a previously heart-healthy peripartum patient. It is necessary to rule out all other known causes of heart failure before accepting a diagnosis of PPCM. The modern era for PPCM in the United States and beyond began with the report of the National Institutes of Health PPCM Workshop in 2000, clarifying all then-currently known aspects of the disease. Since then, hundreds of publications have appeared, an indication of how devastating this disease can be to young mothers and their families and the urgent desire to find solutions for its cause and better treatment. The purpose of this review is to highlight the important advances that have brought us nearer to the solution of this puzzle, focusing on what we have learned about PPCM since 2000; and what still remains unanswered. Despite many improvements in outcome, we still do not know the actual triggers that initiate the pathological process; but realize that cardiac angiogenic imbalances resulting from complex pregnancy-related immune system and hormonal changes play a key role. PMID:24669290

  17. Solving the puzzle of autoimmunity: critical questions

    PubMed Central

    Smilek, Dawn E.

    2015-01-01

    Despite recent advances in delineating the pathogenic mechanisms of autoimmune disease, the puzzle that reveals the true picture of these diverse immunological disorders is yet to be solved. We know that the human leukocyte antigen (HLA) loci as well as many different genetic susceptibility loci with relatively small effect sizes predispose to various autoimmune diseases and that environmental factors are involved in triggering disease. Models for mechanisms of disease become increasingly complex as relationships between components of both the adaptive and innate immune systems are untangled at the molecular level. In this article, we pose some of the important questions about autoimmunity where the answers will advance our understanding of disease pathogenesis and improve the rational design of novel therapies. How is autoimmunity triggered, and what components of the immune response drive the clinical manifestations of disease? What determines whether a genetically predisposed individual will develop an autoimmune disease? Is restoring immune tolerance the secret to finding cures for autoimmune disease? Current research efforts seek answers to these big questions. PMID:25750735

  18. Hepatitis B virus: the genotype E puzzle.

    PubMed

    Andernach, Iris E; Hübschen, Judith M; Muller, Claude P

    2009-07-01

    Hepatitis B virus (HBV) is highly endemic throughout sub-Saharan Africa. One of the two genotypes A and E dominates in most countries. With several subgenotypes and variants, genotype A is more diverse in Africa (4.00%) than in the rest of the world (2.96%), suggesting an African origin and a long history on the continent. Despite the African slave trade, genotype E has only sporadically been found within the Americas, indicating that this genotype was introduced only during the past 200 years into the general African population. A short history for this genotype in Africa is also supported by its conspicuously low genetic diversity (1.75%), which contrasts, however, with its excessively high HBsAg prevalence and its extensive spread throughout the vast West-African genotype E crescent. We discuss the spread and routes of transmission of genotype E and suggest that the distribution and current high prevalence levels of HBV (genotype E) in Africa are the result of the extensive use of unsafe needles, potentially solving the current African genotype E puzzle and shedding new light on the high HBV prevalence in Africa. PMID:19475565

  19. Climate Change: Geophysical Puzzles and Some Answers

    NASA Astrophysics Data System (ADS)

    Singer, S. F.

    2009-04-01

    Climate change is a complex subject, involving many disciplines of geophysics - from geodynamics and meteorology to solar-terrestrial relationships and solar-planetary dynamics. We will discuss a number of scientific puzzles, many still unanswered: · How much of climate change of the past century is anthropogenic and how much is caused by Nature? · How reliable are temperature data of the atmosphere and of the surface, including sea surface? · How reliable are climate models used to calculate future temperatures? · How good is the evidence for solar forcing of climate? · On a decadal time scale, is natural forcing mainly solar or due to internal oscillations? · Can the 1500-year cycle discovered in ice cores explain the Medieval Warming and Little Ice Age? · Why does sea level rise show no acceleration - and how to account for its observed magnitude? -------------------------------------------------------------------- Much of the presentation is based on the NIPCC report "Nature - Not Human Activity - Rules the Climate" http://www.sepp.org/publications/NIPCC_final.pdf

  20. Heavy quarkonium: progress, puzzles, and opportunities

    SciTech Connect

    Brambilla, N; Heltsley, B K; Vogt, R; Bodwin, G T; Eichten, E; Frawley, A D; Meyer, A B; Mitchell, R E; Papdimitriou, V; Petreczky, P; Petrov, A A; Robbe, P; Vairo, A; Andronic, A; Arnaldi, R; Artoisenet, P; Bali, G; Bertolin, A; Bettoni, D; Brodzicka, J; Bruno, G E; Caldwell, A; Catmore, J; Chang, C -H; Chao, K -T; Chudakov, E; Cortese, P; Crochet, P; Drutskoy, A; Ellwanger, U; Faccioli, P; Gabareen Mokhtar, A; Garcia i Tormo, X; Hanhart, C; Harris, F A; Kaplan, D M; Klein, S R; Kowalski, H; Lansberg, J -P; Levichev, E; Lombardo, V; Loureno, C; Maltoni, F; Mocsy, A; Mussa, R; Navarra, F S; Negrini, M; Nielsen, M; Olsen, S L; Pakhlov, P; Pakhlova, G; Peters, K; Polosa, A D; Qian, W; Qiu, J -W; Rong, G; Sanchis-Lozano, M A; Scomparin, E; Senger, P; Simon, F; Stracka, S; Sumino, Y; Voloshin, M; Weiss, C; Wohri, H K; Yuan, C -Z

    2011-02-01

    A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA, JLab, and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\\bar{c}, b\\bar{b}, and b\\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.

  1. Heavy quarkonium: progress, puzzles, and opportunities

    SciTech Connect

    Petreczky, P.; Brambilla, N.; Eidelman,S; B.K. Heltsley; Vogt, R.; Bodwiny, G.T.; Eichteny, E., et. al.

    2011-02-08

    A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c{bar c}, b{bar b}, and b{bar c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.

  2. Extensive frameshift at all AGG and CCC codons in the mitochondrial cytochrome c oxidase subunit 1 gene of Perkinsus marinus (Alveolata; Dinoflagellata)

    PubMed Central

    Masuda, Isao; Matsuzaki, Motomichi; Kita, Kiyoshi

    2010-01-01

    Diverse mitochondrial (mt) genetic systems have evolved independently of the more uniform nuclear system and often employ modified genetic codes. The organization and genetic system of dinoflagellate mt genomes are particularly unusual and remain an evolutionary enigma. We determined the sequence of full-length cytochrome c oxidase subunit 1 (cox1) mRNA of the earliest diverging dinoflagellate Perkinsus and show that this gene resides in the mt genome. Apparently, this mRNA is not translated in a single reading frame with standard codon usage. Our examination of the nucleotide sequence and three-frame translation of the mRNA suggest that the reading frame must be shifted 10 times, at every AGG and CCC codon, to yield a consensus COX1 protein. We suggest two possible mechanisms for these translational frameshifts: a ribosomal frameshift in which stalled ribosomes skip the first bases of these codons or specialized tRNAs recognizing non-triplet codons, AGGY and CCCCU. Regardless of the mechanism, active and efficient machinery would be required to tolerate the frameshifts predicted in Perkinsus mitochondria. To our knowledge, this is the first evidence of translational frameshifts in protist mitochondria and, by far, is the most extensive case in mitochondria. PMID:20507907

  3. International trade network: fractal properties and globalization puzzle.

    PubMed

    Karpiarz, Mariusz; Fronczak, Piotr; Fronczak, Agata

    2014-12-12

    Globalization is one of the central concepts of our age. The common perception of the process is that, due to declining communication and transport costs, distance becomes less and less important. However, the distance coefficient in the gravity model of trade, which grows in time, indicates that the role of distance increases rather than decreases. This, in essence, captures the notion of the globalization puzzle. Here, we show that the fractality of the international trade system (ITS) provides a simple solution for the puzzle. We argue that the distance coefficient corresponds to the fractal dimension of ITS. We provide two independent methods, the box counting method and spatial choice model, which confirm this statement. Our results allow us to conclude that the previous approaches to solving the puzzle misinterpreted the meaning of the distance coefficient in the gravity model of trade. PMID:25541810

  4. The Puzzle of Science; Making Sense of Incomplete Information

    NASA Astrophysics Data System (ADS)

    Shorey, B. U.

    2015-12-01

    There are many topics within Earth science including evolution, historical geology, and climate change, which have gained the status of theory becuse they have overwhelming evidence, yet there is still fragmentary information which can frustrate a student from coming to solid conclusions. Using a jigsaw puzzle whose image has been hidden, and the pieces only given out sparingly, students go though the process of getting more information. How does one get more puzzle pieces and what is the interpretive process? Experience with this exercise demonstrates how students can sketch out an incredibly accurate conception of the "big picture", despite not having all the puzzle pieces. The goal of this talk is to give a complete tool kit to perform as a comprehensive lesson plan. Guiding questions and copies of lesson plans and materials are supplied for this exercise.

  5. International Trade Network: Fractal Properties and Globalization Puzzle

    NASA Astrophysics Data System (ADS)

    Karpiarz, Mariusz; Fronczak, Piotr; Fronczak, Agata

    2014-12-01

    Globalization is one of the central concepts of our age. The common perception of the process is that, due to declining communication and transport costs, distance becomes less and less important. However, the distance coefficient in the gravity model of trade, which grows in time, indicates that the role of distance increases rather than decreases. This, in essence, captures the notion of the globalization puzzle. Here, we show that the fractality of the international trade system (ITS) provides a simple solution for the puzzle. We argue that the distance coefficient corresponds to the fractal dimension of ITS. We provide two independent methods, the box counting method and spatial choice model, which confirm this statement. Our results allow us to conclude that the previous approaches to solving the puzzle misinterpreted the meaning of the distance coefficient in the gravity model of trade.

  6. The Computational Complexity of the Kakuro Puzzle, Revisited

    NASA Astrophysics Data System (ADS)

    Ruepp, Oliver; Holzer, Markus

    We present a new proof of NP-completeness for the problem of solving instances of the Japanese pencil puzzle Kakuro (also known as Cross-Sum). While the NP-completeness of Kakuro puzzles has been shown before [T. Seta. The complexity of CROSS SUM. IPSJ SIG Notes, AL-84:51-58, 2002], there are still two interesting aspects to our proof: we show NP-completeness for a new variant of Kakuro that has not been investigated before and thus improves the aforementioned result. Moreover some parts of the proof have been generated automatically, using an interesting technique involving SAT solvers.

  7. The PRad experiment and the proton radius puzzle

    SciTech Connect

    Gasparian, Ashot H.

    2014-06-01

    New results from the recent muonic hydrogen experiments seriously questioned our knowledge of the proton charge radius, r_p. The new value, with its unprecedented less than sub-percent precision, is currently up to eight standard deviation smaller than the average value from all previous experiments, triggering the well-known "proton charge radius puzzle" in nuclear and atomic physics. The PRad collaboration is currently preparing a novel, magnetic-spectrometer-free ep scattering experiment in Hall B at JLab for a new independent r_p measurement to address this growing "puzzle" in physics.

  8. Finding optimal solutions to the twenty-four puzzle

    SciTech Connect

    Korf, R.E.; Taylor, L.A.

    1996-12-31

    We have found the first optimal solutions to random instances of the Twenty-Four Puzzle, the 5 x 5 version of the well-known sliding-tile puzzles. Our new contribution to this problem is a more powerful admissible heuristic function. We present a general theory for the automatic discovery of such heuristics, which is based on considering multiple subgoals simultaneously. In addition, we apply a technique for pruning duplicate nodes in depth-first search using a finite-state machine. Finally, we observe that as heuristic search problems are scaled up, more powerful heuristic functions become both necessary and cost-effective.

  9. Heavy quarkonium : progress, puzzles, and opportunities.

    SciTech Connect

    Brambilla, N.; Eidelman, S.; Heltsley, B. K.; Vogt, R.; Bodwin, G. T.; Quarkonium Working Group; High Energy Physics; Technische Univ. Munchen; Budker Inst. of Nuclear Physics; Cornell Univ.; LLNL; Univ. of California at Davis

    2011-01-01

    A golden age for heavy-quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the B-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations at BESIII, the LHC, RHIC, FAIR, the Super Flavor and/or Tau-Charm factories, JLab, the ILC, and beyond. The list of newly found conventional states expanded to include h{sub c}(1P), {chi}{sub c2} (2P), B{sub c}{sup +}, and {eta}{sub b} (1S). In addition, the unexpected and still-fascinating X(3872) has been joined by more than a dozen other charmonium- and bottomonium-like 'XYZ' states that appear to lie outside the quark model. Many of these still need experimental confirmation. The plethora of new states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c{bar c}, b{bar b}, and b{bar c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. Lattice QCD has grown from a tool with computational possibilities to an

  10. An Analysis of Instructor-Created Crossword Puzzles for Student Review

    ERIC Educational Resources Information Center

    Weisskirch, Robert S.

    2006-01-01

    This article evaluates the use of instructor-created crossword puzzles as a means of reviewing course material. Students completed one crossword puzzle in class to prepare for an exam, and then they had the opportunity to complete a second crossword puzzle outside of class to prepare for the second exam. Students generally rated the crossword…

  11. Teaching Proofs and Algorithms in Discrete Mathematics with Online Visual Logic Puzzles

    ERIC Educational Resources Information Center

    Cigas, John; Hsin, Wen-Jung

    2005-01-01

    Visual logic puzzles provide a fertile environment for teaching multiple topics in discrete mathematics. Many puzzles can be solved by the repeated application of a small, finite set of strategies. Explicitly reasoning from a strategy to a new puzzle state illustrates theorems, proofs, and logic principles. These provide valuable, concrete…

  12. On the puzzling distribution of cholesterol in the plasma membrane.

    PubMed

    Giang, H; Schick, M

    2016-09-01

    The distribution of cholesterol between the two leaves of the plasma membrane in mammalian cells presents a conundrum; given cholesterol's known affinity for sphingomyelin, which resides predominantly in the exoplasmic leaf, why is it that experiment finds a majority of the cholesterol in the cytoplasmic leaf? This article reviews a recently proposed solution to this puzzle. PMID:26724709

  13. A Jigsaw Puzzle Approach To Learning History in Introductory Psychology.

    ERIC Educational Resources Information Center

    Krauss, Judith

    1999-01-01

    Believes that it may be daunting for some students to learn about the history of psychology. Describes a teaching strategy that uses jigsaw puzzles to teach about the historical terms of structuralism, functionalism, and gestalt psychology. Finds that students performed better on test questions related to these three concepts after using this…

  14. Puzzle Them First! Motivating Adolescent Readers with Question-Finding

    ERIC Educational Resources Information Center

    Ciardiello, A. Vincent

    2007-01-01

    In this book, the author suggests that to truly learn, students should be puzzled about new knowledge. Question-finding, the unique strategy described in the book, fosters this learning by leading adolescent students to probe the multiple meanings of text and ask challenging, open-ended questions. Focus units illustrate how teachers can use…

  15. Generating Sudoku Puzzles and Its Applications in Teaching Mathematics

    ERIC Educational Resources Information Center

    Evans, Ryan; Lindner, Brett; Shi, Yixun

    2011-01-01

    This article presents a few methods for generating Sudoku puzzles. These methods are developed based on the concepts of matrix, permutation, and modular functions, and therefore can be used to form application examples or student projects when teaching various mathematics courses. Mathematical properties of these methods are studied, connections…

  16. Crossword Puzzles as a Learning Tool for Vocabulary Development

    ERIC Educational Resources Information Center

    Orawiwatnakul, Wiwat

    2013-01-01

    Introduction: Since vocabulary is a key basis on which reading achievement depends, various vocabulary acquisition techniques have become pivotal. Among the many teaching approaches, traditional or otherwise, the use of crossword puzzles seems to offer potential and a solution for the problem of learning vocabulary. Method: This study was…

  17. Unraveling "Braid": Puzzle Games and Storytelling in the Imperative Mood

    ERIC Educational Resources Information Center

    Arnott, Luke

    2012-01-01

    "Unraveling Braid" analyzes how unconventional, non-linear narrative fiction can help explain the ways in which video games signify. Specifically, this essay looks at the links between the semiotic features of Jonathan Blow's 2008 puzzle-platform video game Braid and similar elements in Georges Perec's 1978 novel "Life A User's Manual," as well as…

  18. To Txt or Not to Txt: That's the Puzzle

    ERIC Educational Resources Information Center

    Goh, Tiong-Thye; Hooper, Val

    2007-01-01

    This paper describes the potential use of a mobile phone Short Message Service (SMS) crossword puzzle system to promote interaction through learning activities in a large classroom environment. While personal response systems (PRS) have been used in the classroom environment to foster interaction, it is not an ideal tool with respect to cost and…

  19. Using Building-Block Puzzles to Practice Drawing Organic Mechanisms

    ERIC Educational Resources Information Center

    Erdik, Ender

    2005-01-01

    A study uses a thought-provoking, pencil-and-paper activity to aid students in writing organic reaction mechanisms. Organic and functional groups that constitute the formulas of organic and inorganic reactants, ionic intermediates, and products are presented as building blocks, which must be placed correctly in a given puzzle so that they bind…

  20. Is there really a W →τ ν puzzle?

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Bhubanjyoti; London, David; Datta, Alakabha

    2016-05-01

    According to the Particle Data Group, the measurements of B (W+→τ+ντ) and B (W+→ℓ+νℓ)(ℓ=e , μ ) disagree with one another at the 2.3 σ level. In this paper, we search for a new-physics (NP) explanation of this W →τ ν puzzle. We consider two NP scenarios: (i) the W mixes with a W ' boson that couples preferentially to the third generation, (ii) τ L ,R and ντ L mix with isospin-triplet leptons. Unfortunately, once other experimental constraints are taken into account, neither scenario can explain the above experimental result. Our conclusion is that the W →τ ν puzzle is almost certainly just a statistical fluctuation.

  1. Laser Spectroscopy of Muonic Hydrogen and the Puzzling Proton

    NASA Astrophysics Data System (ADS)

    Pohl, Randolf

    2016-09-01

    Laser spectroscopy of muonic hydrogen atoms, μp, has revealed a proton root-mean-square (rms) charge radius rE that is an order of magnitude more accurate than the CODATA world average from elastic electron-proton scattering and precision spectroscopy of regular (electronic) hydrogen. Interestingly, though, the value of rE from μp is 4%, or 7 combined standard deviations smaller than the CODATA value of rE. This discrepancy has been coined "proton radius puzzle". We summarize the experiment and give a brief overview of the theory in muonic hydrogen. Finally we discuss some possible scenarios for the resolution of the "proton radius puzzle".

  2. Validation of Italian rebus puzzles and compound remote associate problems.

    PubMed

    Salvi, Carola; Costantini, Giulio; Bricolo, Emanuela; Perugini, Marco; Beeman, Mark

    2016-06-01

    Rebus puzzles and compound remote associate problems have been successfully used to study problem solving. These problems are physically compact, often can be solved within short time limits, and have unambiguous solutions, and English versions have been normed for solving rates and levels of difficulty. Many studies on problem solving with sudden insight have taken advantage of these features in paradigms that require many quick solutions (e.g., solution priming, visual hemifield presentations, electroencephalography, fMRI, and eyetracking). In order to promote this vein of research in Italy, as well, we created and tested Italian versions of both of these tests. The data collected across three studies yielded a pool of 88 rebus puzzles and 122 compound remote associate problems within a moderate range of difficulty. This article provides both sets of problems with their normative data, for use in future research. PMID:26148823

  3. On the explanation of Peele`s Pertinent Puzzle

    SciTech Connect

    Gai, E.V.

    1994-12-31

    Investigation of Peele`s Pertinent Puzzle (PPP) by analytical and numerical simulation shows that if covariations of experimental data are determined within frames of rigorous maximum likelihood method (MLM), then least-squares method (LSM) gives for PPP correct but unusually looking results. It is shown also that some restrictions and corrections outside rigorous MLM frame bring to incorrect results instead of improved ones.

  4. Radial flow afterburner for event generators and the baryon puzzle

    NASA Astrophysics Data System (ADS)

    Cuautle, E.; Paic, G.

    2008-07-01

    A simple afterburner to add radial flow to the randomized transverse momentum obtained from event generators, PYTHIA and HIJING, has been implemented to calculate the p/π ratios and compare them with available data. A coherent trend of qualitative agreement has been obtained in pp and Au+Au collisions for various centralities. These results indicate that the radial flow does play an important role in the so-called baryon puzzle anomaly.

  5. Puzzles about 1/8 magic doping in cuprate

    NASA Astrophysics Data System (ADS)

    Feng, D. L.; Shen, Z.-X.; Zhou, X. J.; Shen, K. M.; Lu, D. H.; Marel, D. V. D.

    2006-01-01

    We discuss the puzzles surrounding the interpretation of the 1/8 anomaly in cuprates, highlighting the tension between the real and reciprocal space ways to look at the problem. This issue is relevant to the current discussion on the nature of charge ordering in the form of ‘stripe’ and ‘checker-board’ as derived from neutron and STM experiments. A resolution of this tension is important to fully understand the electronic structure.

  6. Lorentz violation in the gravity sector: The t puzzle

    NASA Astrophysics Data System (ADS)

    Bonder, Yuri

    2015-06-01

    Lorentz violation is a candidate quantum-gravity signal, and the Standard-Model Extension (SME) is a widely used parametrization of such a violation. In the gravitational SME sector, there is an elusive coefficient for which no effects have been found. This is known as the t puzzle and, to date, it has no compelling explanation. This paper analyzes whether there is a fundamental explanation for the t puzzle. To tackle this question, several approaches are followed. Mainly, redefinitions of the dynamical fields are studied, showing that other SME coefficients can be moved to nongravitational sectors. It is also found that the gravity SME sector can be consistently treated à la Palatini, and that, in the presence of spacetime boundaries, it is possible to correct its action to get the desired equations of motion. Moreover, through a reformulation as a Lanczos-type tensor, some problematic features of the t term, which should arise at the phenomenological level, are revealed. The most important conclusion of the paper is that there is no evidence of a fundamental explanation for the t puzzle, suggesting that it may be linked to the approximations taken at the phenomenological level.

  7. Strategies and correlates of jigsaw puzzle and visuospatial performance by persons with Prader-Willi syndrome.

    PubMed

    Verdine, Brian N; Troseth, Georgene L; Hodapp, Robert M; Dykens, Elisabeth M

    2008-09-01

    Some individuals with Prader-Willi syndrome exhibit strengths in solving jigsaw puzzles. We compared visuospatial ability and jigsaw puzzle performance and strategies of 26 persons with Prader-Willi syndrome and 26 MA-matched typically developing controls. Individuals with Prader-Willi syndrome relied on piece shape. Those in the control group used a different, picture-focused strategy. Individuals with Prader-Willi syndrome performed better than did the control group on an achromatic interlocking puzzle, whereas scores on puzzles with pictures (interlocking or noninterlocking) did not differ. Visuospatial scores related to performance on all puzzles in the control group and on the noninterlocking puzzle in the Prader-Willi syndrome group. The most proficient jigsaw puzzlers with Prader-Willi syndrome tended to be older and have shape-based strategies. PMID:18702555

  8. High-energy cosmic neutrino puzzle: a review.

    PubMed

    Ahlers, Markus; Halzen, Francis

    2015-12-01

    We appraise the status of high-energy neutrino astronomy and summarize the observations that define the 'IceCube puzzle.' The observations are closing in on the source candidates that may contribute to the observation. We highlight the potential of multi-messenger analysis to assist in the identification of the sources. We also give a brief overview of future search strategies that include the realistic possibility of constructing a next-generation detector larger by one order of magnitude in volume. PMID:26510451

  9. ysteries, Puzzles, and Paradoxes in Quantum Mechanics. Proceedings

    SciTech Connect

    Rodolfo, B.

    1999-02-01

    These proceedings represent papers presented at the Mysteries, Puzzles, and Paradoxes in Quantum Mechanics Workshop held in Italy, in August 1998. The Workshop was devoted to recent experimental and theoretical advances such as new interference, effects, the quantum eraser, non{minus}disturbing and Schroedinger{minus}cat{minus}like states, experiments, EPR correlations, teleportation, superluminal effects, quantum information and computing, locality and causality, decoherence and measurement theory. Tachyonic information transfer was also discussed. There were 45 papers presented at the conference,out of which 2 have been abstracted for the Energy,Science and Technology database.(AIP)

  10. Mixed heavy quark hybrid mesons, decay puzzles, and RHIC

    SciTech Connect

    Kisslinger, Leonard S.

    2009-06-01

    We estimate the energy of the lowest charmonium and upsilon states with hybrid admixtures using the method of QCD sum rules. Our results show that the {psi}{sup '}(2S) and {upsilon}(3S) states both have about a 50% admixture of hybrid and meson components. From this we find explanations of both the famous {rho}-{pi} puzzle for charmonium and the unusual pattern of {sigma} decays that have been found in {upsilon} decays. Moreover, this picture can be used for predictions of heavy quark production with the octet model for RHIC.

  11. Tetsuo Nozoe's Autograph Books: poems, puzzles and playfulness.

    PubMed

    Seeman, Jeffrey I

    2015-02-01

    The Nozoe Autograph Books contain entries from, literally, around the world of organic chemistry. Many of the inscriptions showed the poetic or even musical side of their signees. This Essay presents a diverse selection of the poetic entries of the autograph books, starting with a musical puzzle. This Essay and the interactive website that accompanies the Nozoe Autograph Book project are available free-access for at least a three-year period at http://www.tcr.wiley-vch.de/nozoe. PMID:25690991

  12. May heavy neutrinos solve underground and cosmic-ray puzzles?

    SciTech Connect

    Belotsky, K. M. Fargion, D. Khlopov, M. Yu. Konoplich, R. V.

    2008-01-15

    Primordial heavy neutrinos of the fourth generation might explain different astrophysical puzzles. The simplest fourth-neutrino scenario is consistent with known fourth-neutrino physics, cosmic ray antimatter, cosmic gamma fluxes, and positive signals in underground detectors for a very narrow neutrino mass window (46-47 GeV). However, accounting for the constraint of underground experiment CDMS prohibits solution of cosmic-ray puzzles in this scenario. We have analyzed extended heavy-neutrino models related to the clumpiness of neutrino density, new interactions in heavy-neutrino annihilation, neutrino asymmetry, and neutrino decay. We found that, in these models, the cosmic-ray imprint may fit the positive underground signals in DAMA/Nal experiment in the entire mass range 46-70 GeV allowed from uncertainties of electroweak parameters, while satisfaction of the CDMS constraint reduces the mass range to around 50 GeV, where all data can come to consent in the framework of the considered hypothesis.

  13. Yet another possible explanation of the solar-neutrino puzzle

    SciTech Connect

    Kolb, E.W.; Turner, M.S.; Walker, T.P.

    1986-04-01

    Mikheyev and Smirnov have shown that the interactions of neutrinos with matter can result in the conversion of electron neutrinos produced in the center of the sun to muon neutrinos. Bethe has exploited this and has pointed out that the solar-neutrino puzzle can be resolved if the mass difference squared of the two neutrinos is m/sub 2//sup 2/ - m /sub 1//sup 2/ approx. = 6 x 10/sup -5/ eV/sup 2/, and the mixing angle satisfies sin theta/sub v/ > 0.0065. We discuss a qualitatively different solution to the solar-neutrino puzzle which requires 1.0 x 10/sup -8/ < (m/sub 2//sup 2/ - m/sub 1//sup 2/) (sin/sup 2/ 2theta/sub v//cos 2theta/sub v/) < 6.1 x 10/sup -8/ eV/sup 2/. Our solutions result in a much smaller flux of neutrinos from the p - p process than predicted by standard solar models, while Bethe's solution results in a flux of neutrinos from the p - process that is about the same as standard solar models.

  14. Simultaneous explanation of the RK and R (D (*)) puzzles

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Bhubanjyoti; Datta, Alakabha; London, David; Shivashankara, Shanmuka

    2015-03-01

    At present, there are several hints of lepton flavor non-universality. The LHCb Collaboration has measured RK ≡ B (B+ →K+μ+μ-) / B (B+ →K+e+e-), and the BaBar Collaboration has measured R (D (*)) ≡ B (B bar →D (*) +τ-νbarτ) / B (B bar →D (*) +ℓ-νbarℓ) (ℓ = e , μ). In all cases, the experimental results differ from the standard model predictions by 2- 3 σ. Recently, an explanation of the RK puzzle was proposed in which new physics (NP) generates a neutral-current operator involving only third-generation particles. Now, assuming the scale of NP is much larger than the weak scale, this NP operator must be made invariant under the full SU (3)C × SU (2)L × U(1)Y gauge group. In this Letter, we note that, when this is done, a new charged-current operator can appear, and this can explain the R (D (*)) puzzle. A more precise measurement of the double ratio R (D) / R (D*) can rule out this model.

  15. Tiny bubbles challenge giant turbines: Three Gorges puzzle.

    PubMed

    Li, Shengcai

    2015-10-01

    Since the birth of the first prototype of the modern reaction turbine, cavitation as conjectured by Euler in 1754 always presents as a challenge. Following his theory, the evolution of modern reaction (Francis and Kaplan) turbines has been completed by adding the final piece of the element 'draft-tube' that enables turbines to explore water energy at efficiencies of almost 100%. However, during the last two and a half centuries, with increasing unit capacity and specific speed, the problem of cavitation has been manifested and complicated by the draft-tube surges rather than being solved. Particularly, during the last 20 years, the fierce competition in the international market for extremely large turbines with compact design has encouraged the development of giant Francis turbines of 700-1000 MW. The first group (24 units) of such giant turbines of 700 MW each was installed in the Three Gorges project. Immediately after commission, a strange erosion phenomenon appeared on the guide vane of the machines that has puzzled professionals. From a multi-disciplinary analysis, this Three Gorges puzzle could reflect an unknown type of cavitation inception presumably triggered by turbulence production from the boundary-layer streak transitional process. It thus presents a fresh challenge not only to this old turbine industry, but also to the fundamental sciences. PMID:26442144

  16. The puzzling unsolved mysteries of liquid water: Some recent progress

    NASA Astrophysics Data System (ADS)

    Stanley, H. E.; Kumar, P.; Xu, L.; Yan, Z.; Mazza, M. G.; Buldyrev, S. V.; Chen, S.-H.; Mallamace, F.

    2007-12-01

    Water is perhaps the most ubiquitous, and the most essential, of any molecule on earth. Indeed, it defies the imagination of even the most creative science fiction writer to picture what life would be like without water. Despite decades of research, however, water's puzzling properties are not understood and 63 anomalies that distinguish water from other liquids remain unsolved. We introduce some of these unsolved mysteries, and demonstrate recent progress in solving them. We present evidence from experiments and computer simulations supporting the hypothesis that water displays a special transition point (which is not unlike the “tipping point” immortalized by Malcolm Gladwell). The general idea is that when the liquid is near this “tipping point,” it suddenly separates into two distinct liquid phases. This concept of a new critical point is finding application to other liquids as well as water, such as silicon and silica. We also discuss related puzzles, such as the mysterious behavior of water near a protein.

  17. Studying the proton 'radius' puzzle with μp elastic scattering

    SciTech Connect

    Gilman, R.

    2013-11-07

    The disagreement between the proton radius determined from muonic hydrogen and from electronic measurements is called the proton radius puzzle. The resolution of the puzzle remains unclear and appears to require new experimental results. An experiment to measure muon-proton elastic scattering is presented here.

  18. Strategies and Correlates of Jigsaw Puzzle and Visuospatial Performance by Persons with Prader-Willi Syndrome

    ERIC Educational Resources Information Center

    Verdine, Brian N.; Troseth, Georgene L.; Hodapp, Robert M.; Dykens, Elisabeth M.

    2008-01-01

    Some individuals with Prader-Willi syndrome exhibit strengths in solving jigsaw puzzles. We compared visuospatial ability and jigsaw puzzle performance and strategies of 26 persons with Prader-Willi syndrome and 26 MA-matched typically developing controls. Individuals with Prader-Willi syndrome relied on piece shape. Those in the control group…

  19. What Puzzles Teachers in Rio de janeiro, and What Keeps Them Going?

    ERIC Educational Resources Information Center

    Lyra, Isolina; Fish, Solange; Braga, Walewska Gomes

    2003-01-01

    Focuses on the key mechanism of "puzzling" in Exploratory Practice (EP), a form of practitioner research, and the critical issue of sustainability in the context of volunteer teacher development work in Rio de Janeiro, Brazil. Investigated puzzles (concerns) of language teachers and grouped them into six categories; motivation, anxiety, teaching,…

  20. A Teacher's Ready-to-Use Packet of General Business Subjects Crossword Puzzles.

    ERIC Educational Resources Information Center

    Yacyk, Peter

    Eleven crossword puzzles, designed to give the student practice with the correct spelling and usage of those words needed to indicate his mastery of the concepts and understandings taught in business courses, are contained, with answer keys, in a teacher's packet. Any puzzle can be reproduced by ditto or by transparency for classroom use. There is…

  1. The King and Prisoner Puzzle: A Way of Introducing the Components of Logical Structures

    ERIC Educational Resources Information Center

    Roh, Kyeong Hah; Lee, Yong Hah; Tanner, Austin

    2016-01-01

    The purpose of this paper is to provide issues related to student understanding of logical components that arise when solving word problems. We designed a logic problem called the King and Prisoner Puzzle--a linguistically simple, yet logically challenging problem. In this paper, we describe various student solutions to the puzzle and discuss the…

  2. An Alternative Evaluation: Online Puzzle as a Course-End Activity

    ERIC Educational Resources Information Center

    Genç, Zülfü; Aydemir, Emrah

    2015-01-01

    Purpose: The purpose of this study is to determine whether the use of online puzzles in the instructional process has an effect on student achievement and learning retention. This study examined students ' perception and experiences on use of puzzle as an alternative evaluation tool. To achieve this aim, the following hypotheses were tested: using…

  3. Crossword Puzzle Makes It Fun: Introduce Green Manufacturing in Wood Technology Courses

    ERIC Educational Resources Information Center

    Iley, John L.; Hague, Doug

    2012-01-01

    Sustainable, or "green," manufacturing and its practices are becoming more and more a part of today's industry, including wood product manufacturing. This article provides introductory information on green manufacturing in wood technology and a crossword puzzle based on green manufacturing terms. The authors use the puzzle at the college level to…

  4. Three- and Four-Year-Olds Completing 150-Piece Puzzles? Impossible!

    ERIC Educational Resources Information Center

    Barron, Marlene

    1999-01-01

    Documented strategies preschool children used in completing complex, multipiece puzzles, which included focus on color, design, or shape. Found that all children could benefit and enjoy working on larger puzzles in the classroom and that the activity encouraged social literacy, completing a long-term project, scaffolding, and child development.…

  5. Two-Dimensional Parson's Puzzles: The Concept, Tools, and First Observations

    ERIC Educational Resources Information Center

    Ihantola, Petri; Karavirta, Ville

    2011-01-01

    Parson's programming puzzles are a family of code construction assignments where lines of code are given, and the task is to form the solution by sorting and possibly selecting the correct code lines. We introduce a novel family of Parson's puzzles where the lines of code need to be sorted in two dimensions. The vertical dimension is used to order…

  6. Making Peer-Assisted Content Distribution Robust to Collusion Using Bandwidth Puzzles

    NASA Astrophysics Data System (ADS)

    Reiter, Michael K.; Sekar, Vyas; Spensky, Chad; Zhang, Zhenghao

    Many peer-assisted content-distribution systems reward a peer based on the amount of data that this peer serves to others. However, validating that a peer did so is, to our knowledge, an open problem; e.g., a group of colluding attackers can earn rewards by claiming to have served content to one another, when they have not. We propose a puzzle mechanism to make contribution-aware peer-assisted content distribution robust to such collusion. Our construction ties solving the puzzle to possession of specific content and, by issuing puzzle challenges simultaneously to all parties claiming to have that content, our mechanism prevents one content-holder from solving many others' puzzles. We prove (in the random oracle model) the security of our scheme, describe our integration of bandwidth puzzles into a media streaming system, and demonstrate the resulting attack resilience via simulations.

  7. An Empirical Evaluation of Puzzle-Based Learning as an Interest Approach for Teaching Introductory Computer Science

    ERIC Educational Resources Information Center

    Merrick, K. E.

    2010-01-01

    This correspondence describes an adaptation of puzzle-based learning to teaching an introductory computer programming course. Students from two offerings of the course--with and without the puzzle-based learning--were surveyed over a two-year period. Empirical results show that the synthesis of puzzle-based learning concepts with existing course…

  8. Probabilistic Interpretation of Peelle's Pertinent Puzzle and its Resolution

    SciTech Connect

    Hanson, Kenneth M.; Kawano, Toshihiko; Talou, Patrick

    2005-05-24

    Peelle's Pertinent Puzzle (PPP) states a seemingly plausible set of measurements with their covariance matrix, which produce an implausible answer. To answer the PPP question, we describe a reasonable experimental situation that is consistent with the PPP solution. The confusion surrounding the PPP arises in part because of its imprecise statement, which permits to a variety of interpretations and resulting answers, some of which seem implausible. We emphasize the importance of basing the analysis on an unambiguous probabilistic model that reflects the experimental situation. We present several different models of how the measurements quoted in the PPP problem could be obtained, and interpret their solution in terms of a detailed probabilistic analysis. We suggest a probabilistic approach to handling uncertainties about which model to use.

  9. Probabilistic interpretation of Peelle's pertinent puzzle and its resolution

    SciTech Connect

    Hanson, Kenneth M.; Kawano, T.; Talou, P.

    2004-01-01

    Peelle's Pertinent Puzzle (PPP) states a seemingly plausible set of measurements with their covariance matrix, which produce an implausible answer. To answer the PPP question, we describe a reasonable experimental situation that is consistent with the PPP solution. The confusion surrounding the PPP arises in part because of its imprecise statement, which permits to a variety of interpretations and resulting answers, some of which seem implausible. We emphasize the importance of basing the analysis on an unambiguous probabilistic model that reflects the experimental situation. We present several different models of how the measurements quoted in the PPP problem could be obtained, and interpret their solution in terms of a detailed probabilistic analysis. We suggest a probabilistic approach to handling uncertainties about which model to use.

  10. Peelle's pertinent puzzle using the Monte Carlo technique

    SciTech Connect

    Kawano, Toshihiko; Talou, Patrick; Burr, Thomas; Pan, Feng

    2009-01-01

    We try to understand the long-standing problem of the Peelle's Pertinent Puzzle (PPP) using the Monte Carlo technique. We allow the probability density functions to be any kind of form to assume the impact of distribution, and obtain the least-squares solution directly from numerical simulations. We found that the standard least squares method gives the correct answer if a weighting function is properly provided. Results from numerical simulations show that the correct answer of PPP is 1.1 {+-} 0.25 if the common error is multiplicative. The thought-provoking answer of 0.88 is also correct, if the common error is additive, and if the error is proportional to the measured values. The least squares method correctly gives us the most probable case, where the additive component has a negative value. Finally, the standard method fails for PPP due to a distorted (non Gaussian) joint distribution.

  11. Four Small Puzzles That Rosetta Doesn't Solve

    PubMed Central

    Das, Rhiju

    2011-01-01

    A complete macromolecule modeling package must be able to solve the simplest structure prediction problems. Despite recent successes in high resolution structure modeling and design, the Rosetta software suite fares poorly on small protein and RNA puzzles, some as small as four residues. To illustrate these problems, this manuscript presents Rosetta results for four well-defined test cases: the 20-residue mini-protein Trp cage, an even smaller disulfide-stabilized conotoxin, the reactive loop of a serine protease inhibitor, and a UUCG RNA tetraloop. In contrast to previous Rosetta studies, several lines of evidence indicate that conformational sampling is not the major bottleneck in modeling these small systems. Instead, approximations and omissions in the Rosetta all-atom energy function currently preclude discriminating experimentally observed conformations from de novo models at atomic resolution. These molecular “puzzles” should serve as useful model systems for developers wishing to make foundational improvements to this powerful modeling suite. PMID:21625446

  12. Precision Spectroscopy of Atomic Hydrogen and the Proton Size Puzzle

    NASA Astrophysics Data System (ADS)

    Udem, Thomas

    2016-05-01

    Precise determination of transition frequencies of simple atomic systems are required for a number of fundamental applications such as tests of quantum electrodynamics (QED), the determination of fundamental constants and nuclear charge radii. The sharpest transition in atomic hydrogen occurs between the metastable 2S state and the 1S ground state. Its transition frequency has now been measured with almost 15 digits accuracy using an optical frequency comb and a cesium atomic clock as a reference. A recent measurement of the Lamb shift in muonic hydrogen is in significant contradiction to the hydrogen data if QED calculations are assumed to be correct. We hope to contribute to the resolution of this so called `proton size puzzle' by providing additional experimental input from the hydrogen side.

  13. The puzzle of Muslim advantage in child survival in India.

    PubMed

    Bhalotra, Sonia; Valente, Christine; van Soest, Arthur

    2010-03-01

    The socioeconomic status of Indian Muslims is, on average, considerably lower than that of upper-caste Hindus. Muslims nevertheless exhibit substantially higher child survival rates, and have done for decades. This paper analyses this seeming puzzle. A decomposition of the survival differential confirms that some compositional effects favour Muslims but that, overall, differences in characteristics and especially the Muslim deficit in parental education predict a Muslim disadvantage. The results of this study contribute to a recent literature that debates the importance of socioeconomic status (SES) in determining health and survival. They augment a growing literature on the role of religion or culture as encapsulating important unobservable behaviours or endowments that influence health, indeed, enough to reverse the SES gradient that is commonly observed. PMID:19969383

  14. Possible resolution of the strange quark polarization puzzle?

    NASA Astrophysics Data System (ADS)

    Leader, Elliot; Sidorov, Alexander V.; Stamenov, Dimiter B.

    2011-07-01

    The strange quark polarization puzzle, i.e. the contradiction between the negative polarized strange quark density obtained from analyses of inclusive deep inelastic scattering data and the positive values obtained from combined analyses of inclusive and semi-inclusive deep inelastic scattering data using de Florian, Sassot, Stratmann fragmentation functions, is discussed. To this end the results of a new combined next-to-leading order QCD analysis of the polarized inclusive and semi-inclusive deep inelastic scattering data, using the Hirai, Kumano, Nagai, Sudoh (HKNS) fragmentation functions, are presented. It is demonstrated that the polarized strange quark density is very sensitive to the kaon fragmentation functions, and if the set of HKNS fragmentation functions is used, the polarized strange quark density obtained from the combined analysis turns out to be negative and well consistent with values obtained from the pure deep inelastic scattering analyses.

  15. The puzzling reliability of the Force Concept Inventory

    NASA Astrophysics Data System (ADS)

    Lasry, Nathaniel; Rosenfield, Steven; Dedic, Helena; Dahan, Ariel; Reshef, Orad

    2011-09-01

    The Force Concept Inventory (FCI) has influenced the development of many research-based pedagogies. However, no data exists on the FCI's internal consistency or test-retest reliability. The FCI was administered twice to one hundred students during the first week of classes in an electricity and magnetism course with no review of mechanics between test administrations. High Kuder-Richardson reliability coefficient values, which estimate the average correlation of scores obtained on all possible halves of the test, suggest strong internal consistency. However, 31% of the responses changed from test to retest, suggesting weak reliability for individual questions. A chi-square analysis shows that change in responses was neither consistent nor completely random. The puzzling conclusion is that although individual FCI responses are not reliable, the FCI total score is highly reliable.

  16. A Jigsaw Puzzle Layer Cake of Spatial Data

    NASA Astrophysics Data System (ADS)

    Ma, Xiaogang; Fox, Peter

    2014-05-01

    The Infrastructure for Spatial Information in Europe (INSPIRE; http://inspire.jrc.ec.europa.eu) is a European Union (EU) directive that aims to provide a legal framework to share environmental spatial data among public sector organizations across Europe and to facilitate public access to data. To meet these goals, INSPIRE's organization is analogous to a layer cake in which each layer is composed of interlocking pieces of a jigsaw puzzle. The metaphor, although mixed, is apt (see additional supporting information in the online version of this article), and as researchers outside the program, we offer our perspective on how INSPIRE may address challenges raised by the variety of data themes and the wide coverage of collaborators.

  17. Strangeness in neutron star matter: a challenging puzzle

    NASA Astrophysics Data System (ADS)

    Lonardoni, Diego; Lovato, Alessandro; Gandolfi, Stefano; Pederiva, Francesco

    2014-09-01

    The onset of strange baryons in the core of neutron stars and the consequent softening of the equation of state have been questioned for a long time. Controversial theoretical predictions about the predicted maximum mass and the recent astrophysical observations are the grounds of the so called hyperon puzzle. We attempt to give our contribution to the discussion by studying the general problem of the hyperon-nucleon interaction by means of Auxiliary Field Diffusion Monte Carlo calculations. We employ a phenomenological approach showing that a three-body hyperon-nucleon force provides the strong repulsive contribution needed to correctly describe the systematics of medium-light Λ hypernuclei. The same potential has been used to determine the equation of state and the mass-radius relation of an infinite systems of neutrons and Λ particles. We find that the three-body hyperon-nucleon force has a dramatic effect on the equation of state and the predicted maximum mass. Our results suggest that more constraints on the nature of hyperon-neutron forces are needed before drawing any conclusion on the role played by hyperons in neutron stars. The onset of strange baryons in the core of neutron stars and the consequent softening of the equation of state have been questioned for a long time. Controversial theoretical predictions about the predicted maximum mass and the recent astrophysical observations are the grounds of the so called hyperon puzzle. We attempt to give our contribution to the discussion by studying the general problem of the hyperon-nucleon interaction by means of Auxiliary Field Diffusion Monte Carlo calculations. We employ a phenomenological approach showing that a three-body hyperon-nucleon force provides the strong repulsive contribution needed to correctly describe the systematics of medium-light Λ hypernuclei. The same potential has been used to determine the equation of state and the mass-radius relation of an infinite systems of neutrons and

  18. A Play on Words: Using Cognitive Computing as a Basis for AI Solvers in Word Puzzles

    NASA Astrophysics Data System (ADS)

    Manzini, Thomas; Ellis, Simon; Hendler, James

    2015-12-01

    In this paper we offer a model, drawing inspiration from human cognition and based upon the pipeline developed for IBM's Watson, which solves clues in a type of word puzzle called syllacrostics. We briefly discuss its situation with respect to the greater field of artificial general intelligence (AGI) and how this process and model might be applied to other types of word puzzles. We present an overview of a system that has been developed to solve syllacrostics.

  19. The puzzling origin of the Martian Northern Lowlands.

    NASA Astrophysics Data System (ADS)

    Altieri, F.; Carrozzo, G.; Carli, C.; Geminale, A.; Bellucci, G.

    Surface studies of the northern lowlands of Mars have shown that this region has undergone a complex history including volcanism, sedimentary deposition and secondary modification by climate change. Despite these analyses, the origin and the evolution of this region are still debated. No clear and definitive evidences have been found so far to conclude whether these plains were formed by a giant impact, were once covered by an ocean or were filled by a large quantity of lavas. In the visible and infrared spectral range, the northern lowlands differ from southern terrains in the NIR negative slope while they exhibit VNIR spectra similar to the southern pyroxene-rich areas (Carrozzo et al., 2012). These observations, combined with both recent detection of mafic minerals at higher spatial resolution by CRISM (Salvatore et al., 2010) and recent results of Horgan and Bell (2012), supports that their mineralogy is linked to weathered basalts with a glassy component. In addition to this, the spectral similarity of Acidalia area with the northern circumpolar sand dunes, apart from the hydration features, suggests that the weathering processes that took place there could be related to past glacial activity, in agreement with superficial morphology showing glacial structures. Aim of this work is to combine the OMEGA mineralogical maps with morphological features (Tanaka et al., 2011) and investigate possible terrestrial analogues in order to give some constrains on the composition and origin of these puzzling Martian terrains.

  20. Hyperon puzzle of neutron stars with Skyrme force models

    NASA Astrophysics Data System (ADS)

    Lim, Yeunhwan; Hyun, Chang Ho; Kwak, Kyujin; Lee, Chang-Hwan

    2015-12-01

    We consider the so-called hyperon puzzle of neutron star (NS). We employ Skyrme force models for the description of in-medium nucleon-nucleon (NN), nucleon-Lambda hyperon (NΛ) and Lambda-Lambda (ΛΛ) interactions. A phenomenological finite-range force (FRF) for the ΛΛ interaction is considered as well. Equation of state (EoS) of NS matter is obtained in the framework of density functional theory, and Tolman-Oppenheimer-Volkoff (TOV) equations are solved to obtain the mass-radius relations of NSs. It has been generally known that the existence of hyperons in the NS matter is not well supported by the recent discovery of large-mass NSs (M ≃ 2M⊙) since hyperons make the EoS softer than the one without them. For the selected interaction models, NΛ interactions reduce the maximum mass of NS by about 30%, while ΛΛ interactions can give about 10% enhancement. Consequently, we find that some Skyrme force models predict the maximum mass of NS consistent with the observation of 2M⊙ NSs, and at the same time satisfy observationally constrained mass-radius relations.

  1. Is the proton radius puzzle evidence of extra dimensions?

    NASA Astrophysics Data System (ADS)

    Dahia, F.; Lemos, A. S.

    2016-08-01

    The proton charge radius inferred from muonic hydrogen spectroscopy is not compatible with the previous value given by CODATA-2010, which, on its turn, essentially relies on measurements of the electron-proton interaction. The proton's new size was extracted from the 2S-2P Lamb shift in the muonic hydrogen, which showed an energy excess of 0.3 meV in comparison to the theoretical prediction, evaluated with the CODATA radius. Higher-dimensional gravity is a candidate to explain this discrepancy, since the muon-proton gravitational interaction is stronger than the electron-proton interaction and, in the context of braneworld models, the gravitational potential can be hugely amplified in short distances when compared to the Newtonian potential. Motivated by these ideas, we study a muonic hydrogen confined in a thick brane. We show that the muon-proton gravitational interaction modified by extra dimensions can provide the additional separation of 0.3 meV between the 2S and 2P states. In this scenario, the gravitational energy depends on the higher-dimensional Planck mass and indirectly on the brane thickness. Studying the behavior of the gravitational energy with respect to the brane thickness in a realistic range, we find constraints for the fundamental Planck mass that solve the proton radius puzzle and are consistent with previous experimental bounds.

  2. Fanconi anemia proteins and their interacting partners: a molecular puzzle.

    PubMed

    Kaddar, Tagrid; Carreau, Madeleine

    2012-01-01

    In recent years, Fanconi anemia (FA) has been the subject of intense investigations, primarily in the DNA repair research field. Many discoveries have led to the notion of a canonical pathway, termed the FA pathway, where all FA proteins function sequentially in different protein complexes to repair DNA cross-link damages. Although a detailed architecture of this DNA cross-link repair pathway is emerging, the question of how a defective DNA cross-link repair process translates into the disease phenotype is unresolved. Other areas of research including oxidative metabolism, cell cycle progression, apoptosis, and transcriptional regulation have been studied in the context of FA, and some of these areas were investigated before the fervent enthusiasm in the DNA repair field. These other molecular mechanisms may also play an important role in the pathogenesis of this disease. In addition, several FA-interacting proteins have been identified with roles in these "other" nonrepair molecular functions. Thus, the goal of this paper is to revisit old ideas and to discuss protein-protein interactions related to other FA-related molecular functions to try to give the reader a wider perspective of the FA molecular puzzle. PMID:22737580

  3. Hyperon Puzzle: Hints from Quantum Monte Carlo Calculations

    NASA Astrophysics Data System (ADS)

    Lonardoni, Diego; Lovato, Alessandro; Gandolfi, Stefano; Pederiva, Francesco

    2015-03-01

    The onset of hyperons in the core of neutron stars and the consequent softening of the equation of state have been questioned for a long time. Controversial theoretical predictions and recent astrophysical observations of neutron stars are the grounds for the so-called hyperon puzzle. We calculate the equation of state and the neutron star mass-radius relation of an infinite systems of neutrons and Λ particles by using the auxiliary field diffusion Monte Carlo algorithm. We find that the three-body hyperon-nucleon interaction plays a fundamental role in the softening of the equation of state and for the consequent reduction of the predicted maximum mass. We have considered two different models of three-body force that successfully describe the binding energy of medium mass hypernuclei. Our results indicate that they give dramatically different results on the maximum mass of neutron stars, not necessarily incompatible with the recent observation of very massive neutron stars. We conclude that stronger constraints on the hyperon-neutron force are necessary in order to properly assess the role of hyperons in neutron stars.

  4. Hyperon puzzle: hints from quantum Monte Carlo calculations.

    PubMed

    Lonardoni, Diego; Lovato, Alessandro; Gandolfi, Stefano; Pederiva, Francesco

    2015-03-01

    The onset of hyperons in the core of neutron stars and the consequent softening of the equation of state have been questioned for a long time. Controversial theoretical predictions and recent astrophysical observations of neutron stars are the grounds for the so-called hyperon puzzle. We calculate the equation of state and the neutron star mass-radius relation of an infinite systems of neutrons and Λ particles by using the auxiliary field diffusion Monte Carlo algorithm. We find that the three-body hyperon-nucleon interaction plays a fundamental role in the softening of the equation of state and for the consequent reduction of the predicted maximum mass. We have considered two different models of three-body force that successfully describe the binding energy of medium mass hypernuclei. Our results indicate that they give dramatically different results on the maximum mass of neutron stars, not necessarily incompatible with the recent observation of very massive neutron stars. We conclude that stronger constraints on the hyperon-neutron force are necessary in order to properly assess the role of hyperons in neutron stars. PMID:25793808

  5. The Puzzling Case of Hyperexcitability in Amyotrophic Lateral Sclerosis

    PubMed Central

    Bae, Jong Seok; Simon, Neil G.; Menon, Parvathi; Vucic, Steve

    2013-01-01

    The development of hyperexcitability in amyotrophic lateral sclerosis (ALS) is a well-known phenomenon. Despite controversy as to the underlying mechanisms, cortical hyperexcitability appears to be closely related to the interplay between excitatory corticomotoneurons and inhibitory interneurons. Hyperexcitability is not a static phenomenon but rather shows a pattern of progression in a spatiotemporal aspect. Cortical hyperexcitability may serve as a trigger to the development of anterior horn cell degeneration through a 'dying forward' process. Hyperexcitability appears to develop during the early disease stages and gradually disappears in the advanced stages of the disease, linked to the destruction of corticomotorneuronal pathways. As such, a more precise interpretation of these unique processes may provide new insight regarding the pathophysiology of ALS and its clinical features. Recently developed technologies such as threshold tracking transcranial magnetic stimulation and automated nerve excitability tests have provided some clues about underlying pathophysiological processes linked to hyperexcitability. Additionally, these novel techniques have enabled clinicians to use the specific finding of hyperexcitability as a useful diagnostic biomarker, enabling clarification of various ALS-mimic syndromes, and the prediction of disease development in pre-symptomatic carriers of familial ALS. In terms of nerve excitability tests for peripheral nerves, an increase in persistent Na+ conductances has been identified as a major determinant of peripheral hyperexcitability in ALS, inversely correlated with the survival in ALS. As such, the present Review will focus primarily on the puzzling theory of hyperexcitability in ALS and summarize clinical and pathophysiological implications for current and future ALS research. PMID:23626643

  6. Effect of a puzzle on the process of students' learning about cardiac physiology.

    PubMed

    Cardozo, Lais Tono; Miranda, Aline Soares; Moura, Maria José Costa Sampaio; Marcondes, Fernanda Klein

    2016-09-01

    The aim of the present study was to evaluate the effects of using a puzzle to learn about cardiac physiology. Students were divided into control and game groups. In class 1, the control group had a 2-h theoretical class about cardiac physiology, including a detailed description of the phases of the cardiac cycle, whereas the game group had a 50-min theoretical class without the description of the cardiac cycle. In class 2, the control group did an assessment exercise before an activity with the cardiac puzzle and the game group answered questions after the above-mentioned activity. While solving the puzzle, the students had to describe the cardiac cycle by relating the concepts of heart morphology and physiology. To evaluate short-term learning, the number of wrong answers and grades in the assessment exercise were compared between the control and game groups. To evaluate medium-term learning, we compared the grades obtained by students of the control and game groups in questions about cardiac physiology that formed part of the academic exam. In the assessment exercise, the game group presented a lower number of errors and higher score compared with the control group. In the academic exam, applied after both groups had used the puzzle, there was no difference in the scores obtained by the control and game groups in questions about cardiac physiology. These results showed a positive effect of the puzzle on students' learning about cardiac physiology compared with those not using the puzzle. PMID:27516391

  7. Electronic and atomic structures of a Sn induced 3√{ 3} × 3√{ 3} superstructure on the Ag/Ge(111) √{ 3} ×√{ 3} surface

    NASA Astrophysics Data System (ADS)

    Sohail, Hafiz M.; Uhrberg, R. I. G.

    2016-02-01

    We have investigated sub-monolayer coverages of Sn on the Ag/Ge(111) √{ 3} ×√{ 3} surface. It was found that ≈ 0.45 monolayer (ML) resulted in a new, well-defined, reconstruction with a 3√{ 3} × 3√{ 3} periodicity. The periodic structure of the surface atoms was verified by low-energy electron diffraction and scanning tunneling microscopy. The electronic structure was studied in detail using angle-resolved photoelectron spectroscopy and core level spectroscopy at a temperature of 100 K. Several surface bands were identified and their dispersions are presented along the Γbar -Mbar -Γbar and Γbar -Kbar -Mbar high symmetry lines of the 3√{ 3} × 3√{ 3} surface Brillouin zone (SBZ). The 3√{ 3} × 3√{ 3} surface has a metallic character since there is a strong surface band crossing the Fermi level near Γbar points coinciding with Kbar points of the 1 × 1 SBZ. The Fermi contour of the metallic band showed a hexagonal shape in contrast to the circular shaped Fermi contour of the initial √{ 3} ×√{ 3} surface. Both empty and filled state STM images showed a hexagonal arrangement of protrusions with a local √{ 3} ×√{ 3} periodicity and a superimposed modulation of the apparent heights resulting in a 3√{ 3} × 3√{ 3} periodicity.

  8. ON THE PUZZLE OF SPACE WEATHERING ALTERATION OF BASALTIC ASTEROIDS

    SciTech Connect

    Marchi, S.; Lazzarin, M.; Magrin, S.; De Sanctis, M. C. E-mail: monica.lazzarin@unipd.i E-mail: mariacristina.desanctis@iasf-roma.inaf.i

    2010-10-01

    The majority of basaltic asteroids are found in the inner main belt, although a few have also been observed in the outer main belt and near-Earth space. These asteroids-referred to as V-types-have surface compositions that resemble that of the 530 km sized asteroid Vesta. Besides the compositional similarity, dynamical evidence also links many V-type asteroids to Vesta. Moreover, Vesta is one of the few asteroids to have been identified as source of specific classes of meteorites, the howardite, eucrite, and diogenite achondrites (HEDs). Despite the general consensus on the outlined scenario, several questions remain unresolved. In particular, it is not clear if the observed spectral diversity among Vesta, V-types, and HEDs is due to space weathering, as is thought to be the case for S-type asteroids. In this Letter, SDSS photometry is used to address the question of whether the spectral diversity among candidate V-types and HEDs can be explained by space weathering. We show that visible spectral slopes of V-types are systematically redder with respect to HEDs, in a similar way to what is found for ordinary chondrite meteorites and S-types. On the assumption that space weathering is responsible for the slope mismatch, we estimated an upper limit for the reddening timescale of about 0.5 Ga. Nevertheless, the observed slope mismatch between HEDs and V-types poses several puzzles to understanding its origin. The implication of our findings is also discussed in light of the Dawn mission to Vesta.

  9. The puzzle of immune phenotypes of childhood asthma.

    PubMed

    Landgraf-Rauf, Katja; Anselm, Bettina; Schaub, Bianca

    2016-12-01

    new immunological molecules, the complex puzzle of childhood asthma is still far from being completed. Addressing the current challenges of distinct clinical asthma and wheeze phenotypes, including their stability and underlying endotypes, involves addressing the interplay of innate and adaptive immune regulatory mechanisms in large, interdisciplinary cohorts. PMID:27468754

  10. Hyperon puzzle, hadron-quark crossover and massive neutron stars

    NASA Astrophysics Data System (ADS)

    Masuda, Kota; Hatsuda, Tetsuo; Takatsuka, Tatsuyuki

    2016-03-01

    Bulk properties of cold and hot neutron stars are studied on the basis of the hadron-quark crossover picture where a smooth transition from the hadronic phase to the quark phase takes place at finite baryon density. By using a phenomenological equation of state (EOS) "CRover", which interpolates the two phases at around 3 times the nuclear matter density (ρ0, it is found that the cold NSs with the gravitational mass larger than 2M_{odot} can be sustained. This is in sharp contrast to the case of the first-order hadron-quark transition. The radii of the cold NSs with the CRover EOS are in the narrow range (12.5 ± 0.5) km which is insensitive to the NS masses. Due to the stiffening of the EOS induced by the hadron-quark crossover, the central density of the NSs is at most 4 ρ0 and the hyperon-mixing barely occurs inside the NS core. This constitutes a solution of the long-standing hyperon puzzle. The effect of color superconductivity (CSC) on the NS structures is also examined with the hadron-quark crossover. For the typical strength of the diquark attraction, a slight softening of the EOS due to two-flavor CSC (2SC) takes place and the maximum mass is reduced by about 0.2M_{odot}. The CRover EOS is generalized to the supernova matter at finite temperature to describe the hot NSs at birth. The hadron-quark crossover is found to decrease the central temperature of the hot NSs under isentropic condition. The gravitational energy release and the spin-up rate during the contraction from the hot NS to the cold NS are also estimated.

  11. Puzzle Imaging: Using Large-Scale Dimensionality Reduction Algorithms for Localization

    PubMed Central

    Glaser, Joshua I.; Zamft, Bradley M.; Church, George M.; Kording, Konrad P.

    2015-01-01

    Current high-resolution imaging techniques require an intact sample that preserves spatial relationships. We here present a novel approach, “puzzle imaging,” that allows imaging a spatially scrambled sample. This technique takes many spatially disordered samples, and then pieces them back together using local properties embedded within the sample. We show that puzzle imaging can efficiently produce high-resolution images using dimensionality reduction algorithms. We demonstrate the theoretical capabilities of puzzle imaging in three biological scenarios, showing that (1) relatively precise 3-dimensional brain imaging is possible; (2) the physical structure of a neural network can often be recovered based only on the neural connectivity matrix; and (3) a chemical map could be reproduced using bacteria with chemosensitive DNA and conjugative transfer. The ability to reconstruct scrambled images promises to enable imaging based on DNA sequencing of homogenized tissue samples. PMID:26192446

  12. The role of inhibitory control in children's cooperative behaviors during a structured puzzle task.

    PubMed

    Giannotta, Fabrizia; Burk, William J; Ciairano, Silvia

    2011-11-01

    This study examined the role of inhibitory control (measured by Stroop interference) in children's cooperative behaviors during a structured puzzle task. The sample consisted of 250 8-, 10-, and 12-year-olds (117 girls and 133 boys) attending classrooms in three primary schools in Northern Italy. Children individually completed an elaborated Stroop task, were paired with classmates into 125 dyads, and were observed during a 10-min puzzle task. Results confirmed that interaction partners exhibited similar levels of cooperative behaviors, and the cooperative behaviors of children predicted changes in the cooperative behaviors of their partners throughout the puzzle task. Cooperative behaviors of each interaction partner were predicted by the child's own inhibitory control as well as the inhibitory control of the partner. Findings are discussed within a developmental contextual framework. PMID:21645907

  13. Using the Tower of Hanoi puzzle to infuse your mathematics classroom with computer science concepts

    NASA Astrophysics Data System (ADS)

    Marzocchi, Alison S.

    2016-07-01

    This article suggests that logic puzzles, such as the well-known Tower of Hanoi puzzle, can be used to introduce computer science concepts to mathematics students of all ages. Mathematics teachers introduce their students to computer science concepts that are enacted spontaneously and subconsciously throughout the solution to the Tower of Hanoi puzzle. These concepts include, but are not limited to, conditionals, iteration, and recursion. Lessons, such as the one proposed in this article, are easily implementable in mathematics classrooms and extracurricular programmes as they are good candidates for 'drop in' lessons that do not need to fit into any particular place in the typical curriculum sequence. As an example for readers, the author describes how she used the puzzle in her own Number Sense and Logic course during the federally funded Upward Bound Math/Science summer programme for college-intending low-income high school students. The article explains each computer science term with real-life and mathematical examples, applies each term to the Tower of Hanoi puzzle solution, and describes how students connected the terms to their own solutions of the puzzle. It is timely and important to expose mathematics students to computer science concepts. Given the rate at which technology is currently advancing, and our increased dependence on technology in our daily lives, it has become more important than ever for children to be exposed to computer science. Yet, despite the importance of exposing today's children to computer science, many children are not given adequate opportunity to learn computer science in schools. In the United States, for example, most students finish high school without ever taking a computing course. Mathematics lessons, such as the one described in this article, can help to make computer science more accessible to students who may have otherwise had little opportunity to be introduced to these increasingly important concepts.

  14. Heavy quark dynamics in the QGP: Towards a solution of the RAA and ν2 puzzle

    NASA Astrophysics Data System (ADS)

    Scardina, F.; Das, S. K.; Plumari, S.; Greco, V.

    2016-05-01

    The two key observables related to heavy quarks that have been measured in experiments are the nuclear suppression factor RAA and the elliptic flow ν2. The simultaneous reproduction of these two observables is a puzzle which have challenged all the existing models. We discuss two ingredients responsible for addressing a large part of such a puzzle: the temperature dependence of the energy loss and the full solution of the Boltzmann collision integral for the scattering between the heavy quarks and the particle of the bulk.

  15. Jigsaw puzzle metasurface for multiple functions: polarization conversion, anomalous reflection and diffusion.

    PubMed

    Zhao, Yi; Cao, Xiangyu; Gao, Jun; Liu, Xiao; Li, Sijia

    2016-05-16

    We demonstrate a simple reconfigurable metasurface with multiple functions. Anisotropic tiles are investigated and manufactured as fundamental elements. Then, the tiles are combined in a certain sequence to construct a metasurface. Each of the tiles can be adjusted independently which is like a jigsaw puzzle and the whole metasurface can achieve diverse functions by different layouts. For demonstration purposes, we realize polarization conversion, anomalous reflection and diffusion by a jigsaw puzzle metasurface with 6 × 6 pieces of anisotropic tile. Simulated and measured results prove that our method offers a simple and effective strategy for metasurface design. PMID:27409942

  16. The Brain Explorer: Puzzles, Riddles, Illusions, and Other Mental Adventures. An Exploratorium Science-at-Home Book.

    ERIC Educational Resources Information Center

    Murphy, Pat; Klages, Ellen; Tesler, Pearl; Shore, Linda

    This book contains puzzles, riddles, illusions, experiments, and games for children ages 9-12. The experiments and activities teach students about the inner workings of their brain. Contents include: (1) "Caverns of Memory"; (2) "Forests of Hidden Treasure"; and (3) "The Puzzle House." (CCM)

  17. An Easy & Fun Way to Teach about How Science "Works": Popularizing Haack's Crossword-Puzzle Analogy

    ERIC Educational Resources Information Center

    Pavlova, Iglika V.; Lewis, Kayla C.

    2013-01-01

    Science is a complex process, and we must not teach our students overly simplified versions of "the" scientific method. We propose that students can uncover the complex realities of scientific thinking by exploring the similarities and differences between solving the familiar crossword puzzles and scientific "puzzles."…

  18. Utility of Self-Made Crossword Puzzles as an Active Learning Method to Study Biochemistry in Undergraduate Education

    ERIC Educational Resources Information Center

    Coticone, Sulekha Rao

    2013-01-01

    To incorporate an active learning component in a one-semester biochemistry course, students were asked to create crossword puzzles using key concepts. Student observations on the use of self-made crossword puzzles as an active-learning instructional tool were collected using a 5-point Likert survey at the end of the semester. A majority of the…

  19. Having Fun and Accepting Challenges Are Natural Instincts: Jigsaw Puzzles to Challenge Students and Test Their Abilities While Having Fun!

    ERIC Educational Resources Information Center

    Rodenbaugh, Hanna R.; Lujan, Heidi L.; Rodenbaugh, David W.; DiCarlo, Stephen E.

    2014-01-01

    Because jigsaw puzzles are fun, and challenging, students will endure and discover that persistence and grit are rewarded. Importantly, play and fun have a biological place just like sleep and dreams. Students also feel a sense of accomplishment when they have completed a puzzle. Importantly, the reward of mastering a challenge builds confidence…

  20. Jigsaw Puzzles and River Banks: Two Ways of Picturing Our Future

    ERIC Educational Resources Information Center

    Kretchmar, R. Scott

    2005-01-01

    The papers presented at the 2004 Academy meetings can be thought of as pieces from jigsaw puzzles. While the employment of this metaphor over the years has been useful, we may be ready for a new image, one that is both more accurate and inspiring. We can picture ourselves working at different locations along a river bank. Some of us work upstream,…

  1. Schooling, Cognitive Skills, and the Latin American Growth Puzzle. NBER Working Paper No. 15066

    ERIC Educational Resources Information Center

    Hanushek, Eric A.; Woessmann, Ludger

    2009-01-01

    Economic development in Latin America has trailed most other world regions over the past four decades despite its relatively high initial development and school attainment levels. This puzzle can be resolved by considering the actual learning as expressed in tests of cognitive skills, on which Latin American countries consistently perform at the…

  2. A Public-Key Based Authentication and Key Establishment Protocol Coupled with a Client Puzzle.

    ERIC Educational Resources Information Center

    Lee, M. C.; Fung, Chun-Kan

    2003-01-01

    Discusses network denial-of-service attacks which have become a security threat to the Internet community and suggests the need for reliable authentication protocols in client-server applications. Presents a public-key based authentication and key establishment protocol coupled with a client puzzle protocol and validates it through formal logic…

  3. Engaging Students in a Large Lecture: An Experiment Using Sudoku Puzzles

    ERIC Educational Resources Information Center

    Brophy, Caroline; Hahn, Lukas

    2014-01-01

    In this paper, we describe an in-class experiment that is easy to implement with large groups of students. The experiment takes approximately 15-20 minutes to run and involves each student completing one of four types of Sudoku puzzles and recording the time it takes to completion. The resulting data set can be used as a teaching tool at an…

  4. Parents' Attributions of Their Child's Jigsaw-Puzzle Performance: Comparing Two Genetic Syndromes

    ERIC Educational Resources Information Center

    Ly, Tran M.; Hodapp, Robert M.

    2005-01-01

    Parents' attributions of the jigsaw-puzzle performance of their child with Prader-Willi syndrome (n = 20) or Williams syndrome (n = 21) were examined. Parents in both groups placed more importance on internal versus external attributions. Parents of children with Prader-Willi syndrome exhibited a hedonic bias by attributing their child's success…

  5. The Quark Puzzle: A Novel Approach to Visualizing the Color Symmetries of Quarks

    ERIC Educational Resources Information Center

    Gettrust, Eric

    2010-01-01

    This paper describes a simple hands-on and visual-method designed to introduce physics students of many age groups to the topic of quarks and their role in forming composite particles (baryons and mesons). A set of puzzle pieces representing individual quarks that fit together in ways consistent with known restrictions of flavor, color, and charge…

  6. New Light on Autism and Other Puzzling Disorders of Childhood. Science Reports.

    ERIC Educational Resources Information Center

    Yahraes, Herbert

    The pamphlet discusses several puzzling disorders of childhood, including autism, atypical personality development (childhood psychosis), psychosocial dwarfism, and Tourette's syndrome. Psychosocial dwarfism is said to be characterized by a marked reduction in physical development and by immaturity in behavior, while Tourette's syndrome involves…

  7. Purim Puzzles and Laughs: A Project for Mixed-Ability Classes.

    ERIC Educational Resources Information Center

    Adler, Harry

    1996-01-01

    Discusses the use of puzzles and jokes to encourage student interest in an English-as-a-Second-Language class. The object of this project was to relate to a more human context, the playfulness that pushes aside arbitrary school time each spring when Purim comes. (CK)

  8. High-mass twins & resolution of the reconfinement, masquerade and hyperon puzzles of compact star interiors

    NASA Astrophysics Data System (ADS)

    Blaschke, David; Alvarez-Castillo, David E.

    2016-01-01

    We aim at contributing to the resolution of three of the fundamental puzzles related to the still unsolved problem of the structure of the dense core of compact stars (CS): (i) the hyperon puzzle: how to reconcile pulsar masses of 2 M⊙ with the hyperon softening of the equation of state (EoS); (ii) the masquerade problem: modern EoS for cold, high density hadronic and quark matter are almost identical; and (iii) the reconfinement puzzle: what to do when after a deconfinement transition the hadronic EoS becomes favorable again? We show that taking into account the compositeness of baryons (by excluded volume and/or quark Pauli blocking) on the hadronic side and confining and stiffening effects on the quark matter side results in an early phase transition to quark matter with sufficient stiffening at high densities which removes all three present-day puzzles of CS interiors. Moreover, in this new class of EoS for hybrid CS falls the interesting case of a strong first order phase transition which results in the observable high mass twin star phenomenon, an astrophysical observation of a critical endpoint in the QCD phase diagram.

  9. Puzzling Moments, Teachable Moments: Practicing Teacher Research in Urban Classrooms. Practitioners Inquiry Series

    ERIC Educational Resources Information Center

    Ballenger, Cynthia

    2009-01-01

    In her new book, bestselling author Cynthia Ballenger explores the intellectual strengths of students that teachers find "puzzling"--poor, urban, immigrant, or bilingual children who do not traditionally excel in school. Ballenger challenges the assumption that these children--whose families in many cases have less formal education, read fewer…

  10. (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…

  11. The Role of Inhibitory Control in Children's Cooperative Behaviors during a Structured Puzzle Task

    ERIC Educational Resources Information Center

    Giannotta, Fabrizia; Burk, William J.; Ciairano, Silvia

    2011-01-01

    This study examined the role of inhibitory control (measured by Stroop interference) in children's cooperative behaviors during a structured puzzle task. The sample consisted of 250 8-, 10-, and 12-year-olds (117 girls and 133 boys) attending classrooms in three primary schools in Northern Italy. Children individually completed an elaborated…

  12. Enhancing the Understanding of Government and Nonprofit Accounting with THE PUZZLE GAME: A Pilot Study

    ERIC Educational Resources Information Center

    Elson, Raymond J.; Ostapski, S. Andrew; O'Callaghan, Susanne; Walker, John P.

    2012-01-01

    Nontraditional teaching aids such as crossword puzzles have been successfully used in the classroom to enhance student learning. Government and nonprofit accounting is a confusing course for students since it has strange terminologies and contradicts the accounting concepts learned in other courses. As such, it is an ideal course for a…

  13. Gardner's Two Children Problems and Variations: Puzzles with Conditional Probability and Sample Spaces

    ERIC Educational Resources Information Center

    Taylor, Wendy; Stacey, Kaye

    2014-01-01

    This article presents "The Two Children Problem," published by Martin Gardner, who wrote a famous and widely-read math puzzle column in the magazine "Scientific American," and a problem presented by puzzler Gary Foshee. This paper explains the paradox of Problems 2 and 3 and many other variations of the theme. Then the authors…

  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. Understanding the proton radius puzzle: Nuclear structure effects in light muonic atoms

    NASA Astrophysics Data System (ADS)

    Ji, Chen; Hernandez, Oscar Javier; Nevo Dinur, Nir; Bacca, Sonia; Barnea, Nir

    2016-03-01

    We present calculations of nuclear structure effects to the Lamb shift in light muonic atoms. We adopt a modern ab-initio approach by combining state-of-the-art nuclear potentials with the hyperspherical harmonics method. Our calculations are instrumental to the determination of nuclear charge radii in the Lamb shift measurements, which will shed light on the proton radius puzzle.

  16. The Retention Puzzle Reconsidered: Second Year Student Attitudes and Experiences with Advising

    ERIC Educational Resources Information Center

    Walsh, Michael Edward

    2013-01-01

    College student retention has been described as a puzzle because retention rates have stagnated, and in some cases declined, despite over seventy years of research into the problem. The magnitude of the problem is that 50 percent of college students will leave their institution before obtaining a degree (Braxton, Hirschy, & McClendon, 2011).…

  17. Instructional Media Production for Early Childhood Education: A. B. C. Jig-Saw Puzzle, a Model

    ERIC Educational Resources Information Center

    Yusuf, Mudashiru Olalere; Olanrewaju, Olatayo Solomon; Soetan, Aderonke K.

    2015-01-01

    In this paper, a. b. c. jig-saw puzzle was produced for early childhood education using local materials. This study was a production based type of research, to serve as a supplemental or total learning resource. Its production followed four phases of development referred to as information, design, production and evaluation. The storyboard cards,…

  18. A Guide to Puzzles and Games in Second Language Pedagogy. Language and Literacy Series.

    ERIC Educational Resources Information Center

    Danesi, Marcel

    This guide presents, discusses and describes a selection of games and puzzles for school second language instruction. The first chapter discusses the value of these activities in language teaching, including the psychology of problem-solving, the process of motivating and involving students, three key questions to ask about games in the classroom…

  19. Sequential Monte Carlo for Maximum Weight Subgraphs with Application to Solving Image Jigsaw Puzzles

    PubMed Central

    Adluru, Nagesh; Yang, Xingwei; Latecki, Longin Jan

    2015-01-01

    We consider a problem of finding maximum weight subgraphs (MWS) that satisfy hard constraints in a weighted graph. The constraints specify the graph nodes that must belong to the solution as well as mutual exclusions of graph nodes, i.e., pairs of nodes that cannot belong to the same solution. Our main contribution is a novel inference approach for solving this problem in a sequential monte carlo (SMC) sampling framework. Usually in an SMC framework there is a natural ordering of the states of the samples. The order typically depends on observations about the states or on the annealing setup used. In many applications (e.g., image jigsaw puzzle problems), all observations (e.g., puzzle pieces) are given at once and it is hard to define a natural ordering. Therefore, we relax the assumption of having ordered observations about states and propose a novel SMC algorithm for obtaining maximum a posteriori estimate of a high-dimensional posterior distribution. This is achieved by exploring different orders of states and selecting the most informative permutations in each step of the sampling. Our experimental results demonstrate that the proposed inference framework significantly outperforms loopy belief propagation in solving the image jigsaw puzzle problem. In particular, our inference quadruples the accuracy of the puzzle assembly compared to that of loopy belief propagation. PMID:26052182

  20. Geoscience Data Puzzles: Developing Students' Ability to Make Meaning from Data

    NASA Astrophysics Data System (ADS)

    Kastens, K. A.; Turrin, M.

    2010-12-01

    One of the most fundamental aspects of geoscience expertise is the ability to extract insights from observational earth data. Where an expert might see trends, patterns, processes, and candidate causal relationships, a novice could look at the same data representation and see dots, wiggles and blotches of color. The problem is compounded when the student was not personally involved in collecting the data or samples and thus has no experiential knowledge of the Earth setting that the data represent. In other words, the problem is especially severe when students tap into the vast archives of professionally-collected data that the geoscience community has worked so hard to make available for instructional use over the internet. Moreover, most high school and middle school teachers did not themselves learn Earth Science through analyzing data, and they may lack skills and/or confidence needed to scaffold students through the process of learning to interpret realistically-complex data sets. We have developed “Geoscience Data Puzzles” with the paired goals of (a) helping students learn about the earth from data, and (b) helping teachers learn to teach with data. Geoscience Data Puzzles are data-using activities that purposefully present a low barrier-to-entry for teachers and a high ratio of insight-to-effort for students. Each Puzzle uses authentic geoscience data, but the data are carefully pre-selected in order to illuminate a fundamental Earth process within tractable snippets of data. Every Puzzle offers "Aha" moments, when the connection between data and process comes clear in a rewarding burst of insight. Every Puzzle is accompanied by a Pedagogical Content Knowledge (PCK) guide, which explicates the chain of reasoning by which the puzzle-solver can use the evidence provided by the data to construct scientific claims. Four types of reasoning are stressed: spatial reasoning, in which students make inferences from observations about location, orientation, shape

  1. Puzzling electron behavior analogous to the Braess paradox in a mesoscopic networ

    NASA Astrophysics Data System (ADS)

    Toussaint, Sébastien; Faniel, Sébastien; Martins, Frederico; Pala, Marco; Desplanque, Ludovic; Wallart, Xavier; Huant, Serge; Sellier, Hermann; Bayot, Vincent; Hackens, Benoit

    A counterintuitive behavior analogous to the Braess paradox is encountered in a two-terminal mesoscopic network patterned in a two-dimensional electron system (2DES). Decreasing locally the electron density of one channel in the network paradoxically leads to an increased network conductance. Our scanning gate microscopy experiments reveals this puzzling conductance variation, thanks to tip-induced localized modifications of electron flow throughout the network's channels at low temperature, in the ballistic and coherent regime of transport. We compare the amplitude of the measured anomalous conductance variation with conductance changes induced by other mechanisms at play in the mesoscopic network, such as interference phenomena between different paths, and Coulomb blockade due to disorder-induced localized states. The robustness of this puzzling behavior is inspected by varying the global 2DES density, magnetic field and temperature S.T. acknowledges support from the Belgian FRS-FNRS (FRIA).

  2. Puzzling electron behavior analogous to the Braess paradox in a mesoscopic network

    NASA Astrophysics Data System (ADS)

    Toussaint, Sébastien; Faniel, Sébastien; Martins, Frederico; Pala, Marco; Desplanque, Ludovic; Wallart, Xavier; Huant, Serge; Sellier, Hermann; Bayot, Vincent; Hackens, Benoit

    A counterintuitive behavior analogous to the Braess paradox is encountered in a two-terminal mesoscopic network patterned in a two-dimensional electron system (2DES). Decreasing locally the electron density of one channel in the network paradoxically leads to an increased network conductance. Our scanning gate microscopy experiments reveals this puzzling conductance variation, thanks to tip-induced localized modifications of electron flow throughout the network's channels at low temperature, in the ballistic and coherent regime of transport. We compare the amplitude of the measured anomalous conductance variation with conductance changes induced by other mechanisms at play in the mesoscopic network, such as interference phenomena between different paths, and Coulomb blockade due to disorder-induced localized states. The robustness of this puzzling behavior is inspected by varying the global 2DES density, magnetic field and temperature. S.T. acknowledges support from the Belgian FRS-FNRS (FRIA).

  3. Applicability, Indispensability, and Underdetermination: Puzzling Over Wigner's `Unreasonable Effectiveness of Mathematics'

    NASA Astrophysics Data System (ADS)

    Gelfert, Axel

    2014-05-01

    In his influential 1960 paper `The Unreasonable Effectiveness of Mathematics in the Natural Sciences', Eugene P. Wigner raises the question of why something that was developed without concern for empirical facts—mathematics—should turn out to be so powerful in explaining facts about the natural world. Recent philosophy of science has developed `Wigner's puzzle' in two different directions: First, in relation to the supposed indispensability of mathematical facts to particular scientific explanations and, secondly, in connection with the idea that aesthetic criteria track theoretical desiderata such as empirical success. An important aspect of Wigner's article has, however, been overlooked in these debates: his worries about the underdetermination of physical theories by mathematical frameworks. The present paper argues that, by restoring this aspect of Wigner's argument to its proper place, Wigner's puzzle may become an instructive case study for the teaching of core issues in the philosophy of science and its history.

  4. (Mis)Perception of Sleep in Insomnia: A puzzle and a resolution

    PubMed Central

    Harvey, Allison G.; Tang, Nicole

    2011-01-01

    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 universal). Resolving this puzzle has clinical, theoretical, and public health importance. There are implications for assessment, definition, and treatment. Moreover, solving the puzzle creates an opportunity for "real world" applications of theories from clinical, perceptual, and social psychology as well as neuroscience. Herein we evaluate thirteen possible resolutions to the puzzle. Specifically, we consider the possible contribution, to misperception, of: (1) features inherent to the context of sleep (e.g., darkness); (2) the definition of sleep onset which may lack sensitivity for insomnia patients; (3) insomnia being an exaggerated sleep complaint; (4) psychological distress causing magnification; (5) a deficit in time estimation ability; (6) sleep being misperceived as wake; (7) worry and selective attention toward sleep-related threats; (8) a memory bias influenced by current symptoms and emotions, a confirmation bias/belief bias or a recall bias linked to the intensity/recency of symptoms; (9) heightened physiological arousal; (10) elevated cortical arousal; (11) the presence of brief awakenings; (12) a fault in neuronal circuitry; and (13) there being two insomnia subtypes (one with and one without misperception). The best supported resolutions were misperception of sleep as wake, worry, and brief awakenings. A deficit in time estimation ability was not supported. We conclude by proposing several integrative solutions. PMID:21967449

  5. An Interactive 3D Virtual Anatomy Puzzle for Learning and Simulation - Initial Demonstration and Evaluation.

    PubMed

    Messier, Erik; Wilcox, Jascha; Dawson-Elli, Alexander; Diaz, Gabriel; Linte, Cristian A

    2016-01-01

    To inspire young students (grades 6-12) to become medical practitioners and biomedical engineers, it is necessary to expose them to key concepts of the field in a way that is both exciting and informative. Recent advances in medical image acquisition, manipulation, processing, visualization, and display have revolutionized the approach in which the human body and internal anatomy can be seen and studied. It is now possible to collect 3D, 4D, and 5D medical images of patient specific data, and display that data to the end user using consumer level 3D stereoscopic display technology. Despite such advancements, traditional 2D modes of content presentation such as textbooks and slides are still the standard didactic equipment used to teach young students anatomy. More sophisticated methods of display can help to elucidate the complex 3D relationships between structures that are so often missed when viewing only 2D media, and can instill in students an appreciation for the interconnection between medicine and technology. Here we describe the design, implementation, and preliminary evaluation of a 3D virtual anatomy puzzle dedicated to helping users learn the anatomy of various organs and systems by manipulating 3D virtual data. The puzzle currently comprises several components of the human anatomy and can be easily extended to include additional organs and systems. The 3D virtual anatomy puzzle game was implemented and piloted using three display paradigms - a traditional 2D monitor, a 3D TV with active shutter glass, and the DK2 version Oculus Rift, as well as two different user interaction devices - a space mouse and traditional keyboard controls. PMID:27046584

  6. A 17 keV neutrino and large magnetic moment solution of the solar neutrino puzzle

    NASA Astrophysics Data System (ADS)

    Akhmedov, E. Kh.; Senjanovic, G.; Tao, Zhijian; Berezhiani, Z. G.

    1992-08-01

    Zee-type models with Majorons naturally incorporate the 17 keV neutrino but in their minimal version fail to simultaneously solve the solar neutrino puzzle. If there is a sterile neutrino state, a particularly simple solution is found to the solar neutrino problem, which besides nu(sub 17) predicts a light Zeldovich-Konopinski-Mahmoud neutrino nu(sub light) = nu(sub e) + nu(sub mu)(sup c) with a magnetic moment being easily as large as 10(exp -11)(mu)(sub B) through the Barr-Freire-Zee mechanism.

  7. 17 keV neutrino and large magnetic moment solution of the solar neutrino puzzle

    NASA Astrophysics Data System (ADS)

    Akhmedov, Eugeni Kh.; Berezhiani, Zurab G.; Senjanović, Goran; Tao, Zhijian

    1993-01-01

    Zee-type models with majorons naturally incorporate the 17 keV neutrino but in their minimal version fail to simultaneously solve the solar neutrino puzzle. If there is a sterile neutrino state, we find a particularly simple solution to the solar neutrino problem, which besides ν17 predicts a light Zeldovich-Konopinski-Mahmoud neutrino νlight = νe + νcμ with a magnetic moment being easily as large as 10 -11μB through the Barr-Freire-Zee mechanism.

  8. Sirtuin Activation: A Role for Plasma Membrane in the Cell Growth Puzzle

    PubMed Central

    2013-01-01

    For more than 20 years, the observation that impermeable oxidants can stimulate cell growth has not been satisfactorily explained. The discovery of sirtuins provides a logical answer to the puzzle. The NADH-dependent transplasma membrane electron transport system, which is stimulated by growth factors and interventions such as calorie restriction, can transfer electrons to external acceptors and protect against stress-induced apoptosis. We hypothesize that the activation of plasma membrane electron transport contributes to the cytosolic NAD+ pool required for sirtuin to activate transcription factors necessary for cell growth and survival. PMID:23033342

  9. The puzzle of the steady-state rotation of a reverse sprinkler

    NASA Astrophysics Data System (ADS)

    Rueckner, Wolfgang

    2015-04-01

    The continuous rotation of the reverse sprinkler has been a puzzle for over two decades. This article presents a series of experiments that demonstrate that a properly designed reverse sprinkler experiences no steady-state torque and does not rotate. Ignoring transients when the flow starts and stops, if any sustained rotation of the reverse sprinkler occurs, it is because a force couple produces a torque accompanied by vortex flow inside the body of the sprinkler. No steady-state rotation occurs if the vortex is suppressed or prevented from forming in the first place. Demonstrative proof is given that an ideal reverse sprinkler does not rotate.

  10. Goal anticipation during action observation is influenced by synonymous action capabilities, a puzzling developmental study.

    PubMed

    Gredebäck, Gustaf; Kochukhova, Olga

    2010-04-01

    Eighteen- and 25-month-old human toddlers' ability to manually solve a puzzle and their ability to anticipate the goal during observation of similar actions were investigated. Results demonstrate that goal anticipation during action observation is dependent on manual ability, both on a group level (only 25-month-olds solved the manual task and anticipated the goal during observation) and individually within the older age group (r (xy) = 0.53). These findings suggests a connection between manual ability and the ability to anticipate the goal of others' actions in toddlers, in accordance with the direct matching hypothesis. PMID:20041233

  11. The resolution of an entropy puzzle for 4D non-BPS black holes

    NASA Astrophysics Data System (ADS)

    Banerjee, Nabamita; Bansal, Sukruti; Lodato, Ivano

    2016-05-01

    We show the equality between macroscopic and microscopic (statistical) black hole entropy for a class of four dimensional non-supersymmetric black holes in mathcal{N} = 2 supergravity theory, up to the first subleading order in their charges. This solves a long standing entropy puzzle for this class of black holes. The macroscopic entropy has been computed in the presence of a newly derived higher-derivative supersymmetric invariant of [1], connected to the five dimensional supersymmetric Weyl squared Lagrangian. Microscopically, the crucial role in obtaining the equivalence is played by the anomalous gauge gravitational Chern-Simons term.

  12. A Hybrid alldifferent-Tabu Search Algorithm for Solving Sudoku Puzzles.

    PubMed

    Soto, Ricardo; Crawford, Broderick; Galleguillos, Cristian; Paredes, Fernando; Norero, Enrique

    2015-01-01

    The Sudoku problem is a well-known logic-based puzzle of combinatorial number-placement. It consists in filling a n(2) × n(2) grid, composed of n columns, n rows, and n subgrids, each one containing distinct integers from 1 to n(2). Such a puzzle belongs to the NP-complete collection of problems, to which there exist diverse exact and approximate methods able to solve it. In this paper, we propose a new hybrid algorithm that smartly combines a classic tabu search procedure with the alldifferent global constraint from the constraint programming world. The alldifferent constraint is known to be efficient for domain filtering in the presence of constraints that must be pairwise different, which are exactly the kind of constraints that Sudokus own. This ability clearly alleviates the work of the tabu search, resulting in a faster and more robust approach for solving Sudokus. We illustrate interesting experimental results where our proposed algorithm outperforms the best results previously reported by hybrids and approximate methods. PMID:26078751

  13. Heavy flavor puzzle at LHC: a serendipitous interplay of jet suppression and fragmentation.

    PubMed

    Djordjevic, Magdalena

    2014-01-31

    Both charged hadrons and D mesons are considered to be excellent probes of QCD matter created in ultrarelativistic heavy ion collisions. Surprisingly, recent experimental observations at LHC show the same jet suppression for these two probes, which--contrary to pQCD expectations--may suggest similar energy losses for light quarks and gluons in the QCD medium. We here use our recently developed energy loss formalism in a finite-size dynamical QCD medium to analyze this phenomenon that we denote as the "heavy flavor puzzle at LHC." We show that this puzzle is a consequence of an unusual combination of the suppression and fragmentation patterns and, in fact, does not require invoking the same energy loss for light partons. Furthermore, we show that this combination leads to a simple relationship between the suppressions of charged hadrons and D mesons and the corresponding bare quark suppressions. Consequently, a coincidental matching of jet suppression and fragmentation allows considerably simplifying the interpretation of the corresponding experimental data. PMID:24580442

  14. Eta Carinae: A Box of Puzzles...Some Solved, Others Await

    NASA Technical Reports Server (NTRS)

    Gull, Theodore

    2010-01-01

    In the l840's, Eta Carinae brightened to rival Sirius, then faded. Today we see a marginally naked-eye binary with an expanding, very dusty bipolar Homunculus. The energetics of the ejected mass (>l2 to 40 solar masses at 500-700 km/s plus outer bullets/strings up to 3000 km/s} approach that of a supernova. Extragalactic SN surveys detect near-supernovae thought to be like the Great Eruption of the 1840's. Eta Carinae presents an abundance of puzzles: rich in N, but 1/100th the solar C and O abundances; Ti, V, Sr, Sc persist in atomic states.... yet an abundance of molecules and dust exists in the Homunculus. How did molecules and dust form with low C and O? A near supernova occurred in the l840m, yet both binary companions, with total mass > 120 solar masses, survive in a very eccentric orbit. What is the near future of this system: a GRB? a SN? or just two WR stars that ultimately become two SNs? These and other puzzles will be presented

  15. A Hybrid alldifferent-Tabu Search Algorithm for Solving Sudoku Puzzles

    PubMed Central

    Crawford, Broderick; Paredes, Fernando; Norero, Enrique

    2015-01-01

    The Sudoku problem is a well-known logic-based puzzle of combinatorial number-placement. It consists in filling a n2 × n2 grid, composed of n columns, n rows, and n subgrids, each one containing distinct integers from 1 to n2. Such a puzzle belongs to the NP-complete collection of problems, to which there exist diverse exact and approximate methods able to solve it. In this paper, we propose a new hybrid algorithm that smartly combines a classic tabu search procedure with the alldifferent global constraint from the constraint programming world. The alldifferent constraint is known to be efficient for domain filtering in the presence of constraints that must be pairwise different, which are exactly the kind of constraints that Sudokus own. This ability clearly alleviates the work of the tabu search, resulting in a faster and more robust approach for solving Sudokus. We illustrate interesting experimental results where our proposed algorithm outperforms the best results previously reported by hybrids and approximate methods. PMID:26078751

  16. A puzzle form of a non-verbal intelligence test gives significantly higher performance measures in children with severe intellectual disability

    PubMed Central

    Bello, Katrina D; Goharpey, Nahal; Crewther, Sheila G; Crewther, David P

    2008-01-01

    Background Assessment of 'potential intellectual ability' of children with severe intellectual disability (ID) is limited, as current tests designed for normal children do not maintain their interest. Thus a manual puzzle version of the Raven's Coloured Progressive Matrices (RCPM) was devised to appeal to the attentional and sensory preferences and language limitations of children with ID. It was hypothesized that performance on the book and manual puzzle forms would not differ for typically developing children but that children with ID would perform better on the puzzle form. Methods The first study assessed the validity of this puzzle form of the RCPM for 76 typically developing children in a test-retest crossover design, with a 3 week interval between tests. A second study tested performance and completion rate for the puzzle form compared to the book form in a sample of 164 children with ID. Results In the first study, no significant difference was found between performance on the puzzle and book forms in typically developing children, irrespective of the order of completion. The second study demonstrated a significantly higher performance and completion rate for the puzzle form compared to the book form in the ID population. Conclusion Similar performance on book and puzzle forms of the RCPM by typically developing children suggests that both forms measure the same construct. These findings suggest that the puzzle form does not require greater cognitive ability but demands sensory-motor attention and limits distraction in children with severe ID. Thus, we suggest the puzzle form of the RCPM is a more reliable measure of the non-verbal mentation of children with severe ID than the book form. PMID:18671882

  17. KnowledgePuzzle: A Browsing Tool to Adapt the Web Navigation Process to the Learner's Mental Model

    ERIC Educational Resources Information Center

    AlAgha, Iyad

    2012-01-01

    This article presents KnowledgePuzzle, a browsing tool for knowledge construction from the web. It aims to adapt the structure of web content to the learner's information needs regardless of how the web content is originally delivered. Learners are provided with a meta-cognitive space (e.g., a concept mapping tool) that enables them to plan…

  18. Pieces of the Puzzle: Factors in the Improvement of Urban School Districts on the National Assessment of Educational Progress. Abstract

    ERIC Educational Resources Information Center

    Casserly, Michael; Price-Baugh, Ricki; Corcoran, Amanda; Lewis, Sharon; Uzzell, Renata; Simon, Candace; Heppen, Jessica; Leinwand, Steve; Salinger, Terry; de Mello, Victor Bandeira; Dogan, Enis; Novotny, Laura

    2011-01-01

    This is an abridged, summary report of selected findings from "Pieces of the Puzzle: Factors in the Improvement of Urban School Districts on the National Assessment of Educational Progress"--a comprehensive study prepared by the Council of the Great City Schools in collaboration with the American Institutes for Research (AIR) and with funding from…

  19. Tracking the Footprints Puzzle: The Problematic Persistence of Science-as-Process in Teaching the Nature and Culture of Science

    ERIC Educational Resources Information Center

    Ault, Charles R., Jr.; Dodick, Jeff

    2010-01-01

    For many decades, science educators have asked, "In what ways should learning the content of traditional subjects serve as the means to more general ends, such as understanding the nature of science or the processes of scientific inquiry?" Acceptance of these ends reduces the role of disciplinary context; the "Footprints Puzzle" and Oregon's…

  20. An Effective Method of Introducing the Periodic Table as a Crossword Puzzle at the High School Level

    ERIC Educational Resources Information Center

    Joag, Sushama D.

    2014-01-01

    A simple method to introduce the modern periodic table of elements at the high school level as a game of solving a crossword puzzle is presented here. A survey to test the effectiveness of this new method relative to the conventional method, involving use of a wall-mounted chart of the periodic table, was conducted on a convenience sample. This…

  1. The triplet puzzle theory indicates extensive formation of heteromers between opioid and chemokine receptor subtypes.

    PubMed

    Tarakanov, Alexander O; Fuxe, Kjell

    2015-11-01

    Biochemical studies had previously demonstrated examples of heteromerization between opioid and chemokine receptors. Based on the triplet puzzle theory, it has been discovered that opioid receptors are structurally more closely related to chemokine receptors than to other class A G-protein-coupled receptors. Their similarity is established in terms of the number of triplet homologies Asn-Leu-Ala, Thr-Leu-Pro, and Tyr-Ala-Phe in the amino acid code of extensive numbers of members of these two receptor groups. Such widespread similarities probably mean that many opioid and chemokine receptor subtypes utilize some of these mutual triplets to form heteromers. The findings underline that heteromerization among these two receptor groups can represent a major general mechanism for significant interactions between opioid peptides and chemokines in pain and neuroinflammation within the neural-glial networks of the CNS including immune cells. PMID:26133164

  2. OLD PUZZLE, NEW INSIGHTS: A LITHIUM-RICH GIANT QUIETLY BURNING HELIUM IN ITS CORE

    SciTech Connect

    Aguirre, V. Silva; Christensen-Dalsgaard, J.; Jessen-Hansen, J.; Ruchti, G. R.; Hekker, S.; Cassisi, S.; Datta, A.; Jendreieck, A.; Mazumdar, A.; Mosser, B.; Stello, D.; Beck, P. G.; De Ridder, J.

    2014-03-20

    About 1% of giant stars have been shown to have large surface Li abundances, which is unexpected according to standard stellar evolution models. Several scenarios for lithium production have been proposed, but it is still unclear why these Li-rich giants exist. A missing piece in this puzzle is the knowledge of the exact stage of evolution of these stars. Using low- and-high-resolution spectroscopic observations, we have undertaken a survey of lithium-rich giants in the Kepler field. In this Letter, we report the finding of the first confirmed Li-rich core-helium-burning giant, as revealed by asteroseismic analysis. The evolutionary timescales constrained by its mass suggest that Li production most likely took place through non-canonical mixing at the RGB tip, possibly during the helium flash.

  3. {open_quotes}Super{close_quotes} Japanese site gears up to sole neutrino puzzle

    SciTech Connect

    Normile, D.

    1995-11-03

    Ever since Wolfgang Pauli proposed the existence of neutrinos in 1930 to explain some puzzling features of the radioactive decay of certain atoms, expermentalists have labored hard to detect enough of the elusive particles to determine their properties. It took 26 years to prove that Pauli`s particle even exits-a feat for which Frederick Reines of the University of California (UC), Irvine, won the Nobel Prize last month. Soon, however, physicists will be capturing neutrinos in unprecedented numbers in a 50,000-metric-ton tank that will fill with water starting next month. Researchers hope that this colossal waterbath will yield an answer to one of the most pressing questions is cosmology and high-energy physics: Do neutrinos have mass?The $100 million experiment, called Super-Kamiokande, in located in a lead mine west of Tokyo. This article describes the work to be conducted.

  4. Standard model and supersymmetric flavor puzzles at the CERN Large Hadron Collider

    SciTech Connect

    Feng, Jonathan L.; Lester, Christopher G.; Nir, Yosef; Shadmi, Yael

    2008-04-01

    Can the Large Hadron Collider explain the masses and mixings of the known fermions? A promising possibility is that these masses and mixings are determined by flavor symmetries that also govern new particles that will appear at the LHC. We consider well-motivated examples in supersymmetry with both gravity and gauge mediation. Contrary to spreading belief, new physics need not be minimally flavor violating. We build nonminimally flavor violating models that successfully explain all known lepton masses and mixings, but span a wide range in their predictions for slepton flavor violation. In natural and favorable cases, these models have metastable sleptons and are characterized by fully reconstructible events. We outline many flavor measurements that are then possible and describe their prospects for resolving both the standard model and new physics flavor puzzles at the Large Hadron Collider.

  5. Mycobacterium avium ss paratuberculosis-associated diseases: piecing the Crohn's puzzle together.

    PubMed

    Gitlin, Laura; Borody, Thomas Julius; Chamberlin, William; Campbell, Jordana

    2012-09-01

    The relation of Mycobacterium avium ss paratuberculosis (MAP) to Crohn's Disease (CD) and other MAP-associated conditions remains controversial. New data, coupled with the analogous Helicobacter pylori (H. pylori) story, has permitted us to piece together the MAP puzzle and move forward with a more scientific way of treating inflammatory bowel disease, particularly CD. As infection moves centre stage in inflammatory bowel disease, the dated "aberrant reaction" etiology has lost scientific credibility. Now, our growing understanding of MAP-associated diseases demands review and articulation. We focus here on (1) the concept of MAP-associated diseases; (2) causality, Johne Disease, the "aberrant reaction" hypothesis; and (3) responses to published misconceptions questioning MAP as a pathogen in CD. PMID:22858515

  6. A Theoretical Model of Jigsaw-Puzzle Pattern Formation by Plant Leaf Epidermal Cells.

    PubMed

    Higaki, Takumi; Kutsuna, Natsumaro; Akita, Kae; Takigawa-Imamura, Hisako; Yoshimura, Kenji; Miura, Takashi

    2016-04-01

    Plant leaf epidermal cells exhibit a jigsaw puzzle-like pattern that is generated by interdigitation of the cell wall during leaf development. The contribution of two ROP GTPases, ROP2 and ROP6, to the cytoskeletal dynamics that regulate epidermal cell wall interdigitation has already been examined; however, how interactions between these molecules result in pattern formation remains to be elucidated. Here, we propose a simple interface equation model that incorporates both the cell wall remodeling activity of ROP GTPases and the diffusible signaling molecules by which they are regulated. This model successfully reproduces pattern formation observed in vivo, and explains the counterintuitive experimental results of decreased cellulose production and increased thickness. Our model also reproduces the dynamics of three-way cell wall junctions. Therefore, this model provides a possible mechanism for cell wall interdigitation formation in vivo. PMID:27054467

  7. The puzzling Venusian polar atmospheric structure reproduced by a general circulation model

    PubMed Central

    Ando, Hiroki; Sugimoto, Norihiko; Takagi, Masahiro; Kashimura, Hiroki; Imamura, Takeshi; Matsuda, Yoshihisa

    2016-01-01

    Unlike the polar vortices observed in the Earth, Mars and Titan atmospheres, the observed Venus polar vortex is warmer than the midlatitudes at cloud-top levels (∼65 km). This warm polar vortex is zonally surrounded by a cold latitude band located at ∼60° latitude, which is a unique feature called ‘cold collar' in the Venus atmosphere. Although these structures have been observed in numerous previous observations, the formation mechanism is still unknown. Here we perform numerical simulations of the Venus atmospheric circulation using a general circulation model, and succeed in reproducing these puzzling features in close agreement with the observations. The cold collar and warm polar region are attributed to the residual mean meridional circulation enhanced by the thermal tide. The present results strongly suggest that the thermal tide is crucial for the structure of the Venus upper polar atmosphere at and above cloud levels. PMID:26832195

  8. The puzzling Venusian polar atmospheric structure reproduced by a general circulation model.

    PubMed

    Ando, Hiroki; Sugimoto, Norihiko; Takagi, Masahiro; Kashimura, Hiroki; Imamura, Takeshi; Matsuda, Yoshihisa

    2016-01-01

    Unlike the polar vortices observed in the Earth, Mars and Titan atmospheres, the observed Venus polar vortex is warmer than the midlatitudes at cloud-top levels (∼65 km). This warm polar vortex is zonally surrounded by a cold latitude band located at ∼60° latitude, which is a unique feature called 'cold collar' in the Venus atmosphere. Although these structures have been observed in numerous previous observations, the formation mechanism is still unknown. Here we perform numerical simulations of the Venus atmospheric circulation using a general circulation model, and succeed in reproducing these puzzling features in close agreement with the observations. The cold collar and warm polar region are attributed to the residual mean meridional circulation enhanced by the thermal tide. The present results strongly suggest that the thermal tide is crucial for the structure of the Venus upper polar atmosphere at and above cloud levels. PMID:26832195

  9. Gold-nanoparticle-mediated jigsaw-puzzle-like assembly of supersized plasmonic DNA origami.

    PubMed

    Yao, Guangbao; Li, Jiang; Chao, Jie; Pei, Hao; Liu, Huajie; Zhao, Yun; Shi, Jiye; Huang, Qing; Wang, Lianhui; Huang, Wei; Fan, Chunhai

    2015-03-01

    DNA origami has rapidly emerged as a powerful and programmable method to construct functional nanostructures. However, the size limitation of approximately 100 nm in classic DNA origami hampers its plasmonic applications. Herein, we report a jigsaw-puzzle-like assembly strategy mediated by gold nanoparticles (AuNPs) to break the size limitation of DNA origami. We demonstrated that oligonucleotide-functionalized AuNPs function as universal joint units for the one-pot assembly of parent DNA origami of triangular shape to form sub-microscale super-origami nanostructures. AuNPs anchored at predefined positions of the super-origami exhibited strong interparticle plasmonic coupling. This AuNP-mediated strategy offers new opportunities to drive macroscopic self-assembly and to fabricate well-defined nanophotonic materials and devices. PMID:25612825

  10. Height of female Americans in the 19th century and the antebellum puzzle.

    PubMed

    Carson, Scott Alan

    2011-03-01

    Using 19th century state prison records, this study contrasts the biological standard of living of comparable US African-American and white females during a period of relatively rapid economic development. White females were consistently taller than black females by about 1.5 cm (0.6 in.). Whites from Great Lakes and Plains states and black Southwestern females were the tallest. US females were tall compared to their European counterparts. The height of females began to decline in the antebellum period, possibly before that of males. The recovery of physical stature was also earlier among females than among males. This implies that the biological standard of lower-class men and women did not move in parallel during the onset of modern economic growth. It also implies that the antebellum puzzle was most likely rooted in the endogenous forces of socio-economic change rather than the exogenous changes in the disease environment. PMID:21276759

  11. The role of genetics in estrogen responses: a critical piece of an intricate puzzle

    PubMed Central

    Wall, Emma H.; Hewitt, Sylvia C.; Case, Laure K.; Lin, Chin-Yo; Korach, Kenneth S.; Teuscher, Cory

    2014-01-01

    The estrogens are female sex hormones that are involved in a variety of physiological processes, including reproductive development and function, wound healing, and bone growth. They are mainly known for their roles in reproductive tissues—specifically, 17β-estradiol (E2), the primary estrogen, which is secreted by the ovaries and induces cellular proliferation and growth of the uterus and mammary glands. In addition to the role of estrogens in promoting tissue growth and development during normal physiological states, they have a well-established role in determining susceptibility to disease, particularly cancer, in reproductive tissues. The responsiveness of various tissues to estrogen is genetically controlled, with marked quantitative variation observed across multiple species, including humans. This variation presents both researchers and clinicians with a veritable physiological puzzle, the pieces of which—many of them unknown—are complex and difficult to fit together. Although genetics is known to play a major role in determining sensitivity to estrogens, there are other factors, including parent of origin and the maternal environment, that are intimately linked to heritable phenotypes but do not represent genotype, per se. The objectives of this review article were to summarize the current knowledge of the role of genotype, and uterine and neonatal environments, in phenotypic variation in the response to estrogens; to discuss recent findings and the potential mechanisms involved; and to highlight exciting research opportunities for the future.—Wall, E. H., Hewitt, S. C., Case, L. K, Lin, C.-Y., Korach, K. S., Teuscher, C. The role of genetics in estrogen responses: a critical piece of an intricate puzzle. PMID:25212221

  12. Biophysical Puzzles Concerning Magnetite-Based Magnetoreception in the Common Nematode, Caenorhabditis elegans.

    NASA Astrophysics Data System (ADS)

    Kirschvink, J. L.; Kobayashi, A. K.

    2015-12-01

    A recent report demonstrating magnetotactic behavior in the nematode worm, C. elegans, presents two intriguing biophysical puzzles. Vidal-Gadea et al. (2015, DOI: 10.7554/eLife.07493) show that wild-type, well-fed populations from both Hemispheres migrate upwards when their soil environment is moist and wet, and downward when starved. Their data show that inverting the vertical component of the magnetic field reverses the migration direction, indicating that it is a magnetically polar (not axial) response. Also, the angle of magnetic migration varies with the inclination angle of the local geomagnetic field at the native site, minimizing travel time. This ancestral magnetic migration direction persists even when strains are taken to different areas. We note that only a single-domain ferromagnetic magnetoreceptor (e.g, magnetite) is capable of producing a polar magnetotactic response, and in support there is one report of magnetosomes in C. elegans (Cranfield et al., 2004;DOI 10.1098/rsbl.2004.0209). However, the polarity of a magnetosome is determined at the time it grows across the SPM/SD threshold, and the magnetic orientation will lock-in randomly unless biased by the strong field of adjacent magnetosomes. Hence, the persistence of a North or South seeking direction preference within these populations demands that stable magnetosome chains of fixed polarity must be transmitted from parents, to the eggs, to the larvae, and then to the new adults. This is similar to the non-genetic inheritance process by which populations of magnetotactic bacteria can maintain North- or South-seeking swimming preference. Furthermore, for a magnetotactic organism to maintain a consistent angle from the magnetic axis is not enough to make it go vertical; it would go in a cone. For them to go vertical as reported (or to deviate at their natal magnetic inclination) demands that they must have a separate gravity sensor with which to measure the inclination angle relative to the

  13. Set selection dynamical system neural networks with partial memories, with applications to Sudoku and KenKen puzzles.

    PubMed

    Boreland, B; Clement, G; Kunze, H

    2015-08-01

    After reviewing set selection and memory model dynamical system neural networks, we introduce a neural network model that combines set selection with partial memories (stored memories on subsets of states in the network). We establish that feasible equilibria with all states equal to ± 1 correspond to answers to a particular set theoretic problem. We show that KenKen puzzles can be formulated as a particular case of this set theoretic problem and use the neural network model to solve them; in addition, we use a similar approach to solve Sudoku. We illustrate the approach in examples. As a heuristic experiment, we use online or print resources to identify the difficulty of the puzzles and compare these difficulties to the number of iterations used by the appropriate neural network solver, finding a strong relationship. PMID:25984696

  14. Genetic variation in the vulnerable and endemic Monkey Puzzle tree, detected using RAPDs.

    PubMed

    Bekessy, Sarah A; Allnutt, T R; Premoli, A C; Lara, A; Ennos, R A; Burgman, M A; Cortes, M; Newton, A C

    2002-04-01

    Araucaria araucana (Monkey Puzzle), a southern South American tree species of exceptional cultural and economic importance, is of conservation concern owing to extensive historical clearance and current human pressures. Random amplified polymorphic DNA (RAPD) markers were used to characterise genetic heterogeneity within and among 13 populations of this species from throughout its natural range. Extensive genetic variability was detected and partitioned by analysis of molecular variance, with the majority of variation existing within populations (87.2%), but significant differentiation was recorded among populations (12.8%). Estimates of Shannon's genetic diversity and percent polymorphism were relatively high for all populations and provide no evidence for a major reduction in genetic diversity from historical events, such as glaciation. All pairwise genetic distance values derived from analysis of molecular variance (Phi(ST)) were significant when individual pairs of populations were compared. Although populations are geographically divided into Chilean Coastal, Chilean Andes and Argentinean regions, this grouping explained only 1.77% of the total variation. Within Andean groups there was evidence of a trend of genetic distance with increasing latitude, and clustering of populations across the Andes, suggesting postglacial migration routes from multiple refugia. Implications of these results for the conservation and use of the genetic resource of this species are discussed. PMID:11920130

  15. Remarks on the "Non-canonicity Puzzle": Lagrangian Symmetries of the Einstein-Hilbert Action

    NASA Astrophysics Data System (ADS)

    Kiriushcheva, N.; Komorowski, P. G.; Kuzmin, S. V.

    2012-07-01

    Given the non-canonical relationship between variables used in the Hamiltonian formulations of the Einstein-Hilbert action (due to Pirani, Schild, Skinner (PSS) and Dirac) and the Arnowitt-Deser-Misner (ADM) action, and the consequent difference in the gauge transformations generated by the first-class constraints of these two formulations, the assumption that the Lagrangians from which they were derived are equivalent leads to an apparent contradiction that has been called "the non-canonicity puzzle". In this work we shall investigate the group properties of two symmetries derived for the Einstein-Hilbert action: diffeomorphism, which follows from the PSS and Dirac formulations, and the one that arises from the ADM formulation. We demonstrate that unlike the diffeomorphism transformations, the ADM transformations (as well as others, which can be constructed for the Einstein-Hilbert Lagrangian using Noether's identities) do not form a group. This makes diffeomorphism transformations unique (the term "canonical" symmetry might be suggested). If the two Lagrangians are to be called equivalent, canonical symmetry must be preserved. The interplay between general covariance and the canonicity of the variables used is discussed.

  16. Learning and Memory Processes Following Cochlear Implantation: The Missing Piece of the Puzzle.

    PubMed

    Pisoni, David B; Kronenberger, William G; Chandramouli, Suyog H; Conway, Christopher M

    2016-01-01

    At the present time, there is no question that cochlear implants (CIs) work and often work very well in quiet listening conditions for many profoundly deaf children and adults. The speech and language outcomes data published over the last two decades document quite extensively the clinically significant benefits of CIs. Although there now is a large body of evidence supporting the "efficacy" of CIs as a medical intervention for profound hearing loss in both children and adults, there still remain a number of challenging unresolved clinical and theoretical issues that deal with the "effectiveness" of CIs in individual patients that have not yet been successfully resolved. In this paper, we review recent findings on learning and memory, two central topics in the field of cognition that have been seriously neglected in research on CIs. Our research findings on sequence learning, memory and organization processes, and retrieval strategies used in verbal learning and memory of categorized word lists suggests that basic domain-general learning abilities may be the missing piece of the puzzle in terms of understanding the cognitive factors that underlie the enormous individual differences and variability routinely observed in speech and language outcomes following cochlear implantation. PMID:27092098

  17. Theory of mind: a new perspective on the puzzle of belief ascription

    PubMed Central

    Airenti, Gabriella

    2015-01-01

    The concept of theory of mind (ToM) has considerably changed since its first proposal. The aim of first human studies was to understand how young children acquire the representation of others’ mental states, in particular beliefs, and how they distinguish them from their own and from reality. The False Belief Task was designed to prove the acquisition of this capacity. According to children’s performance in this test the acquisition of ToM has been attested at around 4 years of age. In last years it has been shown that using spontaneous response tasks also 15-month-old-children could attribute to an agent a false belief about the location of an object. These results have generated the puzzle of belief-ascription: Why do 3-year-old children fail the classical false belief tasks whereas much younger children show the correct expectation in the spontaneous response tasks? In this paper I shall argue that (i) infants and young children, when confronted with the two forms of false belief tasks do not face the same problem and (ii) behind the two testing situations there are different ways to understand theory of mind. I shall propose that what appears in infants is the natural human disposition to intersubjectivity. PMID:26321995

  18. Orbital Wall Reconstruction with Two-Piece Puzzle 3D Printed Implants: Technical Note.

    PubMed

    Mommaerts, Maurice Y; Büttner, Michael; Vercruysse, Herman; Wauters, Lauri; Beerens, Maikel

    2016-03-01

    The purpose of this article is to describe a technique for secondary reconstruction of traumatic orbital wall defects using titanium implants that act as three-dimensional (3D) puzzle pieces. We present three cases of large defect reconstruction using implants produced by Xilloc Medical B.V. (Maastricht, the Netherlands) with a 3D printer manufactured by LayerWise (3D Systems; Heverlee, Belgium), and designed using the biomedical engineering software programs ProPlan and 3-Matic (Materialise, Heverlee, Belgium). The smaller size of the implants allowed sequential implantation for the reconstruction of extensive two-wall defects via a limited transconjunctival incision. The precise fit of the implants with regard to the surrounding ledges and each other was confirmed by intraoperative 3D imaging (Mobile C-arm Systems B.V. Pulsera, Philips Medical Systems, Eindhoven, the Netherlands). The patients showed near-complete restoration of orbital volume and ocular motility. However, challenges remain, including traumatic fat atrophy and fibrosis. PMID:26889349

  19. Micro and regular saccades across the lifespan during a visual search of "Where's Waldo" puzzles.

    PubMed

    Port, Nicholas L; Trimberger, Jane; Hitzeman, Steve; Redick, Bryan; Beckerman, Stephen

    2016-01-01

    Despite the fact that different aspects of visual-motor control mature at different rates and aging is associated with declines in both sensory and motor function, little is known about the relationship between microsaccades and either development or aging. Using a sample of 343 individuals ranging in age from 4 to 66 and a task that has been shown to elicit a high frequency of microsaccades (solving Where's Waldo puzzles), we explored microsaccade frequency and kinematics (main sequence curves) as a function of age. Taking advantage of the large size of our dataset (183,893 saccades), we also address (a) the saccade amplitude limit at which video eye trackers are able to accurately measure microsaccades and (b) the degree and consistency of saccade kinematics at varying amplitudes and directions. Using a modification of the Engbert-Mergenthaler saccade detector, we found that even the smallest amplitude movements (0.25-0.5°) demonstrate basic saccade kinematics. With regard to development and aging, both microsaccade and regular saccade frequency exhibited a very small increase across the life span. Visual search ability, as per many other aspects of visual performance, exhibited a U-shaped function over the lifespan. Finally, both large horizontal and moderate vertical directional biases were detected for all saccade sizes. PMID:26049037

  20. Puzzle of the {sup 6}Li Quadrupole Moment: Steps toward Solving It

    SciTech Connect

    Blokhintsev, L.D.; Kukulin, V.I.; Pomerantsev, V.N.

    2005-07-01

    The problem of the origin of the quadrupole deformation in the {sup 6}Li ground state is investigated with allowance for the three-deuteron component of the {sup 6}Li wave function. Two long-standing puzzles related to the tensor interaction in the {sup 6}Li nucleus are known: that of an anomalous smallness of the {sup 6}Li quadrupole moment (being negative, it is smaller in magnitude than the {sup 7}Li quadrupole moment by a factor of 5) and that of an anomalous behavior of the tensor analyzing power T{sub 2q} in the scattering of polarized {sup 6}Li nuclei on various targets. It is shown that a large (in magnitude) negative exchange contribution to the {sup 6}Li quadrupole moment from the three-deuteron configuration cancels almost completely the 'direct' positive contribution due to the {alpha}d folding potential. As a result, the total quadrupole moment proves to be close to zero and highly sensitive to fine details of the tensor nucleon-nucleon interaction in the {sup 4}He nucleus and of its wave function.

  1. Possible resolution of the B{yields}{pi}{pi}, {pi}K puzzles

    SciTech Connect

    Li Hsiangnan; Mishima, Satoshi

    2011-02-01

    We show that there exist uncanceled soft divergences in the k{sub T} factorization for nonfactorizable amplitudes of two-body nonleptonic B meson decays, similar to those identified in hadron hadroproduction. These divergences can be grouped into a soft factor using the eikonal approximation, which is then treated as an additional nonperturbative input in the perturbative QCD formalism. Viewing the special role of the pion as a qq bound state and as a pseudo Nambu-Goldstone boson, we postulate that the soft effect associated with it is significant. This soft factor enhances the nonfactorizable color-suppressed tree amplitudes, such that the branching ratios B({pi}{sup 0}{pi}{sup 0}) and B({pi}{sup 0}{rho}{sup 0}) are increased under the constraint of the B({rho}{sup 0}{rho}{sup 0}) data, the difference between the direct CP asymmetries A{sub CP}({pi}{sup {+-}}K{sup {+-}}) and A{sub CP}({pi}{sup 0}K{sup {+-}}) is enlarged, and the mixing-induced CP asymmetry S{sub {pi}}{sup 0}{sub K{sub S}} is reduced. Namely, the known {pi}{pi} and {pi}K puzzles can be resolved simultaneously.

  2. Physics and financial economics (1776-2014): puzzles, Ising and agent-based models.

    PubMed

    Sornette, Didier

    2014-06-01

    This short review presents a selected history of the mutual fertilization between physics and economics--from Isaac Newton and Adam Smith to the present. The fundamentally different perspectives embraced in theories developed in financial economics compared with physics are dissected with the examples of the volatility smile and of the excess volatility puzzle. The role of the Ising model of phase transitions to model social and financial systems is reviewed, with the concepts of random utilities and the logit model as the analog of the Boltzmann factor in statistical physics. Recent extensions in terms of quantum decision theory are also covered. A wealth of models are discussed briefly that build on the Ising model and generalize it to account for the many stylized facts of financial markets. A summary of the relevance of the Ising model and its extensions is provided to account for financial bubbles and crashes. The review would be incomplete if it did not cover the dynamical field of agent-based models (ABMs), also known as computational economic models, of which the Ising-type models are just special ABM implementations. We formulate the 'Emerging Intelligence Market Hypothesis' to reconcile the pervasive presence of 'noise traders' with the near efficiency of financial markets. Finally, we note that evolutionary biology, more than physics, is now playing a growing role to inspire models of financial markets. PMID:24875470

  3. Physics and financial economics (1776-2014): puzzles, Ising and agent-based models

    NASA Astrophysics Data System (ADS)

    Sornette, Didier

    2014-06-01

    This short review presents a selected history of the mutual fertilization between physics and economics—from Isaac Newton and Adam Smith to the present. The fundamentally different perspectives embraced in theories developed in financial economics compared with physics are dissected with the examples of the volatility smile and of the excess volatility puzzle. The role of the Ising model of phase transitions to model social and financial systems is reviewed, with the concepts of random utilities and the logit model as the analog of the Boltzmann factor in statistical physics. Recent extensions in terms of quantum decision theory are also covered. A wealth of models are discussed briefly that build on the Ising model and generalize it to account for the many stylized facts of financial markets. A summary of the relevance of the Ising model and its extensions is provided to account for financial bubbles and crashes. The review would be incomplete if it did not cover the dynamical field of agent-based models (ABMs), also known as computational economic models, of which the Ising-type models are just special ABM implementations. We formulate the ‘Emerging Intelligence Market Hypothesis’ to reconcile the pervasive presence of ‘noise traders’ with the near efficiency of financial markets. Finally, we note that evolutionary biology, more than physics, is now playing a growing role to inspire models of financial markets.

  4. FIRST MODERN PHOTOMETRIC INVESTIGATION OF THE PUZZLING W UMa TYPE CLOSE BINARY SYSTEM OF TZ BOOTIS

    SciTech Connect

    Christopoulou, P.-E.; Parageorgiou, A.; Chrysopoulos, I.

    2011-10-15

    New CCD photometric BVRI observations of the puzzling W UMa type binary star, TZ Bootis, are presented from our observations in 2010. By using the updated version of the Wilson-Devinney code, the first modern photometric solution is deduced from new photometric observations and published spectroscopic data. This low mass ratio binary turns out to be a deep overcontact system with f = 52% of A-subtype. A spot model has been applied to fit the particular features of light curves. Based on our seven new light minimum times and all others compiled from the literature over 70 yr, we studied the orbital period from the O-C curve. It is found that a 31.2 yr cyclic variation exists with an amplitude of 0.033 days, overlaying a secular decrease at a rate of dP/dt = -2.1 x 10{sup -8} days yr{sup -1}. The cyclic period change may indicate that TZ Boo is a triple or a quadruple system as confirmed from the published spectroscopic data. The long-term orbital period decrease is interpreted by mass transfer from the more to the less massive component and/or angular momentum loss by the magnetic breaking which would cause the overcontact degree to increase and finally the binary will evolve into a single rapidly rotating star.

  5. The Variance of Solar Wind Magnetic Fluctuations: Solutions and Further Puzzles

    NASA Technical Reports Server (NTRS)

    Roberts, D. A.; Goldstein, M. L.

    2006-01-01

    We study the dependence of the variance directions of the magnetic field in the solar wind as a function of scale, radial distance, and Alfvenicity. The study resolves the question of why different studies have arrived at widely differing values for the maximum to minimum power (approximately equal to 3:1 up to approximately equal to 20:1). This is due to the decreasing anisotropy with increasing time interval chosen for the variance, and is a direct result of the "spherical polarization" of the waves which follows from the near constancy of |B|. The reason for the magnitude preserving evolution is still unresolved. Moreover, while the long-known tendency for the minimum variance to lie along the mean field also follows from this view (as shown by Barnes many years ago), there is no theory for why the minimum variance follows the field direction as the Parker angle changes. We show that this turning is quite generally true in Alfvenic regions over a wide range of heliocentric distances. The fact that nonAlfvenic regions, while still showing strong power anisotropies, tend to have a much broader range of angles between the minimum variance and the mean field makes it unlikely that the cause of the variance turning is to be found in a turbulence mechanism. There are no obvious alternative mechanisms, leaving us with another intriguing puzzle.

  6. The High-Density Lipoprotein Puzzle: Why Classic Epidemiology, Genetic Epidemiology, and Clinical Trials Conflict?

    PubMed

    Rosenson, Robert S

    2016-05-01

    Classical epidemiology has established the incremental contribution of the high-density lipoprotein (HDL) cholesterol measure in the assessment of atherosclerotic cardiovascular disease risk; yet, genetic epidemiology does not support a causal relationship between HDL cholesterol and the future risk of myocardial infarction. Therapeutic interventions directed toward cholesterol loading of the HDL particle have been based on epidemiological studies that have established HDL cholesterol as a biomarker of atherosclerotic cardiovascular risk. However, therapeutic interventions such as niacin, cholesteryl ester transfer protein inhibitors increase HDL cholesterol in patients treated with statins, but have repeatedly failed to reduce cardiovascular events. Statin therapy interferes with ATP-binding cassette transporter-mediated macrophage cholesterol efflux via miR33 and thus may diminish certain HDL functional properties. Unraveling the HDL puzzle will require continued technical advances in the characterization and quantification of multiple HDL subclasses and their functional properties. Key mechanistic criteria for clinical outcomes trials with HDL-based therapies include formation of HDL subclasses that improve the efficiency of macrophage cholesterol efflux and compositional changes in the proteome and lipidome of the HDL particle that are associated with improved antioxidant and anti-inflammatory properties. These measures require validation in genetic studies and clinical trials of HDL-based therapies on the background of statins. PMID:26966281

  7. Learning and Memory Processes Following Cochlear Implantation: The Missing Piece of the Puzzle

    PubMed Central

    Pisoni, David B.; Kronenberger, William G.; Chandramouli, Suyog H.; Conway, Christopher M.

    2016-01-01

    At the present time, there is no question that cochlear implants (CIs) work and often work very well in quiet listening conditions for many profoundly deaf children and adults. The speech and language outcomes data published over the last two decades document quite extensively the clinically significant benefits of CIs. Although there now is a large body of evidence supporting the “efficacy” of CIs as a medical intervention for profound hearing loss in both children and adults, there still remain a number of challenging unresolved clinical and theoretical issues that deal with the “effectiveness” of CIs in individual patients that have not yet been successfully resolved. In this paper, we review recent findings on learning and memory, two central topics in the field of cognition that have been seriously neglected in research on CIs. Our research findings on sequence learning, memory and organization processes, and retrieval strategies used in verbal learning and memory of categorized word lists suggests that basic domain-general learning abilities may be the missing piece of the puzzle in terms of understanding the cognitive factors that underlie the enormous individual differences and variability routinely observed in speech and language outcomes following cochlear implantation. PMID:27092098

  8. MSSM anatomy of the polarization puzzle in B{yields}{phi}K* decays

    SciTech Connect

    Huang Chaoshang; Ko, Pyungwon; Wu Xiaohong; Yang Yadong

    2006-02-01

    We analyze the B{yields}{phi}K* polarization puzzle in the minimal supersymmetric standard model (MSSM) including the neutral Higgs boson (NHB) contributions. To calculate the nonfactorizable contributions to the hadronic matrix elements of operators, we have used the QCD factorization framework to the {alpha}{sub s} order. It is shown that the recent experimental results of the polarization fractions in B{yields}{phi}K* decays, which are difficult to be explained in SM, could be explained in MSSM if there are flavor nondiagonal squark mass matrix elements of 2nd and 3rd generations, which also satisfy all relevant constraints from known experiments (B{yields}X{sub s}{gamma},B{sub s}{yields}{mu}{sup +}{mu}{sup -},B{yields}X{sub s}{mu}{sup +}{mu}{sup -},B{yields}X{sub s}g,{delta}M{sub s}= , etc.). We have shown in detail that the experimental results can be accommodated with the flavor nondiagonal mass insertion of chirality RL, RL+LR, RR, or LL+RR when the NHB contributions as well as O({alpha}{sub s}) corrections of hadronic matrix elements of operators are included. However, the branching ratios for the decay are smaller than the experimental measurements.

  9. From polarisation to practice: puzzles and insights on integrated approaches from public health professionals.

    PubMed

    Buffardi, Anne L

    2014-01-01

    Much of the debate in the global health literature about vertical and horizontal programmatic approaches, between narrowly targeted interventions and those providing broader system-wide support, has taken place at the global level. Based on a comparative case study of international donors in the health sector in Peru that varied in their vertical-horizontal orientation, this article examines the extent to which health care practitioners and national policy-makers perceive and attempt to reconcile the tension between these approaches. Informants readily identified advantages and disadvantages of both approaches, but did not perceive a marked vertical-horizontal division, suggesting that tensions appear to be less pronounced in practice than academic debates suggest. A clear consensus did not emerge, and although more people spoke of a mixed approached, they too puzzled over how best to balance trade-offs. In practice, there were examples of more integrated approaches, targeted aspects of horizontal programmes and system-strengthening elements of vertical programmes; however, they were not explicitly identified as such. Practitioner perspectives reinforced the diverse and dynamic nature of disease, both epidemics and country profiles, and suggest that focusing on periods of transition and points of integration may be a fruitful path forward. PMID:24992263

  10. V2487 Oph 1998: a puzzling recurrent nova observed with XMM-Newton

    NASA Astrophysics Data System (ADS)

    Hernanz, M.; Sala, G.; Ospina, N.

    2014-07-01

    V2487 Oph exploded as a classical nova in 1998. Several years later it was identified as a recurrent nova, with a previous eruption in 1900. Most recurrent novae host massive white dwarfs (WDs), which could increase in mass after each eruption, finally reaching the Chandrasekar mass and exploding as type Ia supernovae, if CO WDs. We observed V2487 Oph with XMM-Newton between 2 and 9 years after its explosion, to study its post-outburst behavior, and the WD and companion star properties. The emission revealed restablished accretion onto a magnetic WD in a cataclysmic variable of the intermediate polar (IP) type. Interestingly, V2487 Oph was also detected in hard X-rays with INTEGRAL/IBIS, and was again tentatively classified as IP. There's not yet a confirmation of P_{spin}(WD) < P_{orbit}, the defining property of IPs. V2487 Oph is not the first nova exploding in a magnetic CV, but it is indeed challenging to reach explosive conditions without genuine accretion disks. Also, the type of binary system should be reconciled with the fact of being recurrent (where larger accretion rates than in CVs are required). It will be discussed how XMM-Newton observations (EPIC and RGS) provide insight into such a puzzling object.

  11. Interactive Puzzles for the mean climate dyanmics and climate change with the Monash Simple Climate Model

    NASA Astrophysics Data System (ADS)

    Dommenget, D.

    2014-12-01

    The Monash university interactive simple climate model is a web-based interface that allows students and the general public to explore the physical simulation of the climate system with a real global climate model. It is based on the Globally Resolved Energy Balance (GREB) model that simulates most of the main physical processes in the climate system in a very simplistic way and therefore allows very fast and simple climate model simulations. Despite its simplicity the model simulates the mean climate and its response to external forcings, such as doubling of the CO2 concentrations very realistically.The Monash simple climate model web-interface allows you to do some entertaining and educational puzzles about the interaction of climate dynamics. By turning switches OFF and ON you control physical processes in the climate system, but you do not know what these processes. By testing a number of experiments you learn about the interactions in the climate system and thereby figure out which switch controls what process in the climate system. The presentation will illustrate how this web-base tool works and what are the possibilities in teaching students with this tool are.

  12. The puzzle of the ankle in the Ultrahigh Energy Cosmic Ray Spectrum, and composition indicators

    NASA Astrophysics Data System (ADS)

    Farrar, Glennys

    2015-08-01

    The sharp change in slope of the ultra-high energy cosmic ray spectrum around 10^18.6 eV (the ankle), combined with evidence of a light but extragalactic component near and below the ankle and intermediate composition above, has proved exceedingly challenging to understand theoretically. In this talk I discuss two possible solutions to the puzzle and how they can be (in)validated.First, I present a new mechanism whereby photo-disintegration of ultra-high energy nuclei in the region surrounding a UHECR accelerator naturally accounts for the observed spectrum and inferred composition (using LHC-tuned models extrapolated to UHE) at Earth. We discuss the conditions required to reproduce the spectrum above 10^17.5 eV and the composition, which -- in our model -- consists below the ankle of extragalactic protons and the high energy tail of Galactic Cosmic Rays, and above the ankle of surviving nuclei from the extended source. Predictions for the spectrum and flavors of neutrinos resulting from this process will be presented, and also implications for candidate sources.The other possible explanation is that in actuality UHECRs are entirely or almost entirely protons, and the cross-section for p-Air scattering increases more rapidly above center-of-mass energy of 70 TeV (10 times the current LHC cm energy) than predicted in conventional models. This gives an equally good fit to the depth-of-shower maximum behavior obverved by Auger, while being an intriguing sign of new state in QCD at extremely high energy density.

  13. Testing explanations of the B{yields}{phi}K* polarization puzzle

    SciTech Connect

    Datta, Alakabha; Gritsan, Andrei V.; London, David; Nagashima, Makiko; Szynkman, Alejandro

    2007-08-01

    B{yields}{phi}K* (b{yields}s) is three separate decays, one for each polarization of the final-state vector mesons (one longitudinal, two transverse). It is observed that the fraction of transverse decays, f{sub T}, and the fraction of longitudinal decays, f{sub L}, are roughly equal: f{sub T}/f{sub L}{approx_equal}1, in opposition to the naive expectation that f{sub T}<puzzles, two possibilities remain within the standard model: penguin annihilation and rescattering. In this paper we examine the predictions of these two explanations for f{sub T}/f{sub L} in b{yields}d decays. In B{yields}{rho}{rho} decays, only B{sub d}{sup 0}{yields}{rho}{sup 0}{rho}{sup 0} can possibly exhibit a large f{sub T}/f{sub L}. In B decays related by U-spin, we find two promising possibilities: (i) B{sup +}{yields}K*{sup 0}{rho}{sup +} (b{yields}s) and B{sup +}{yields}K*{sup 0}K*{sup +} (b{yields}d) and (ii) B{sub s}{yields}K*{sup 0}K*{sup 0} (b{yields}s) and B{sub d}{sup 0}{yields}K*{sup 0}K*{sup 0} (b{yields}d). The measurement of f{sub T}/f{sub L} in these pairs of decays will allow us to test penguin annihilation and rescattering. Finally, it is possible to distinguish penguin annihilation from rescattering by performing a time-dependent angular analysis of B{sub d}{sup 0}{yields}K*{sup 0}K*{sup 0}.

  14. Ogaden Basin subsidence history: Another key to the Red Sea-Gulf of Aden tectonic puzzle

    SciTech Connect

    Pigott, J.D.; Neese, D.; Carsten, G.

    1995-08-01

    Previous work has attempted to understand the tectonic evolution of the Red Sea-Gulf of Aden region through a focus upon plate kinematics and reconstruction of plate interactions in a two dimensional sense. A significant complement to the three dimensional puzzle can be derived from a critical examination of the vertical component, tectonic subsidence analysis. By removing the isostatic contributions of sediment loading and unloading, and fluctuations in sea level, the remaining thermal-mechanical contribution to a basin`s subsidence can be determined. Such an analysis of several Ogaden Basin wells reveals multiple pulses of tectonic subsidence and uplift which correspond to far-field tectonic activities in the Red Sea and Gulf of Aden. One of the more dramatic is a Jurassic tectonic pulse circa 145-130 m.a., and a later extensional event which correlates to a major subsidence event ubiquitous through-out the Gulf of Aden, related to Gondwana Land breakup activities. Tectonic uplift during the Tertiary coincides with early Red Sea rifting episodes. Such activities suggest the Ogaden Basin has been a relatively stable East African cratonic basin, but with heating-extension events related to nearby plate interactions. In terms of hydrocarbon generation, the use of steady state present day geothermal gradients, coupled with subsidence analysis shows that potential Paleozoic and Mesozoic source rocks initiated generation as early as the Jurassic. The generating potential of Paleozoic source rocks would only be exacerbated by later heating events. Furthermore, cooling and tectonic uplift during the Tertiary would tend to arrest on-going hydrocarbon generation for Jurassic source rocks in the Ogaden area.

  15. OT1_efalgaro_1: The Herschel/HIFI insight on the CH+ puzzle

    NASA Astrophysics Data System (ADS)

    Falgarone, E.

    2010-07-01

    Seventy years after its discovery in the diffuse interstellar medium, the origin of the CH+ cation is still elusive. Herschel/HIFI offers a unique opportunity to disclose the underlying gas dynamics at the origin of CH+ in the diffuse medium by allowing high sensitivity and high spectral resolution observations of the CH+ (J=1-0) transition, unreachable from the ground: it will be the leading and only instrument and the observations will bring a completely new look at this resilient puzzle. The abundant CH+ ion is not only a sensitive tracer of the most tenuous phases of the interstellar medium but it is likely a specific tracer of turbulent dissipation, because its formation route is highly endoenergic. We propose absorption spectroscopy observations of mainly the CH+ J=1-0 line, against 10 background dust continuum sources, bright enough to allow us to sample a broad variety of galactic environments. The lines-of-sight will probe the outskirts of star-forming regions, including one InfraRed Dark Cloud, where turbulent dissipation is most intense, and diffuse gas at high galactic latitude where turbulence is milder. The primarily goal of this project is the comparison of the CH+ abundances with model predictions of turbulent dissipation regions, in which dissipation proceeds either in low-velocity shocks or intense velocity-shears. Another goal is testing the possibility that CH+ forms at the turbulent interface between the two thermally stable phases of the interstellar medium. As HF, CH+ is a potential sensitive tracer of diffuse matter in the early universe. Understanding its origin and the dissipative processes that it traces will shed a new light on galaxy formation and evolution.

  16. Identifying sediment discontinuities and solving dating puzzles using monitoring and palaeolimnological records

    NASA Astrophysics Data System (ADS)

    Dong, Xuhui; Sayer, Carl D.; Bennion, Helen; Maberly, Stephen C.; Yang, Handong; Battarbee, Richard W.

    2016-05-01

    Palaeolimnological studies should ideally be based upon continuous, undisturbed sediment sequences with reliable chronologies. However for some lake cores, these conditions are not met and palaeolimnologists are often faced with dating puzzles caused by sediment disturbances in the past. This study chooses Esthwaite Water from England to illustrate how to identify sedimentation discontinuities in lake cores and how chronologies can be established for imperfect cores by correlation of key sediment signatures in parallel core records and with long-term monitoring data (1945-2003). Replicated short cores (ESTH1, ESTH7, and ESTH8) were collected and subjected to loss-on-ignition, radiometric dating (210Pb, 137Cs, and 14C), particle size, trace metal, and fossil diatom analysis. Both a slumping and a hiatus event were detected in ESTH7 based on comparisons made between the cores and the long-term diatom data. Ordination analysis suggested that the slumped material in ESTH7 originated from sediment deposited around 1805-1880 AD. Further, it was inferred that the hiatus resulted in a loss of sediment deposited from 1870 to 1970 AD. Given the existence of three superior 14C dates in ESTH7, ESTH1 and ESTH7 were temporally correlated by multiple palaeolimnological proxies for age-depth model development. High variability in sedimentation rates was evident, but good agreement across the various palaeolimnological proxies indicated coherence in sediment processes within the coring area. Differences in sedimentation rates most likely resulted from the natural morphology of the lake basin. Our study suggests that caution is required in selecting suitable coring sites for palaeolimnological studies of small, relatively deep lakes and that proximity to steep slopes should be avoided wherever possible. Nevertheless, in some cases, comparisons between a range of contemporary and palaeolimnological records can be employed to diagnose sediment disturbances and establish a chronology.

  17. OT1_dneufeld_2: The puzzle of water vapour in carbon-rich stars

    NASA Astrophysics Data System (ADS)

    Neufeld, D.

    2010-07-01

    Using the HIFI instrument, we will address the puzzling - but widespread - appearance of water vapour in carbon-rich stars. Following up on detections of water in ALL SIX carbon-rich AGB stars observed to date in a pilot study performed in the HIFISTARS Key Program, we will target additional water transitions in four stars already observed or expected to show the most luminous water emissions. The target stars are CIT6, IRAC 15194-5155, V Cygni, and S Cep, and the additional transitions are the 4(22)-3(31) and 3(12) - 2(21) transitions at 916 GHz and 1153 GHz. Combined with spectra already obtained for the low-lying water transitions, and interpreted in the context of water excitation models, the proposed observations will place strong constraints upon the location of the emitting water. We will therefore be able to distinguish between various hypotheses that have been proposed for the origin of the observed water: the vaporization of orbiting comets or dwarf planets; catalytic formation on dust grains; or chemical processes initiated by the photodissociation of CO. In addition, we will carry out deep integrations to observe the lowest 1(11) - 0(00) transition of para-water at 1113 GHz in two carbon-rich AGB stars: IRAS+40540 and V Hya; here, ortho-water has been securely detected but existing observations of the 1113 GHz para-water line yield weak detections that lack the signal-to-noise ratio needed to constrain the ortho-to-para ratio.

  18. Resolution of puzzles from the LSND, KARMEN, and MiniBooNE experiments

    SciTech Connect

    Gninenko, S. N.

    2011-01-01

    This work has attempted to reconcile puzzling neutrino oscillation results from the LSND, KARMEN, and MiniBooNE experiments. We show that the LSND evidence for {nu}{sub {mu}}{yields}{nu}e oscillations, its long-standing disagreement with the results from KARMEN, and the anomalous event excess observed by MiniBooNE in {nu}{sub {mu}} and {nu}{sub {mu}} data could all be explained by the existence of a heavy sterile neutrino ({nu}{sub h}). All these results are found to be consistent with each other, assuming that the {nu}{sub h} is created in {nu}{sub {mu}} neutral-current interactions and decays radiatively into a photon and a light neutrino. Assuming the {nu}{sub h} is produced through mixing with {nu}{sub {mu}}, the combined analysis of the LSND and MiniBooNe excess events suggests that the {nu}{sub h} mass is in the range from 40 to 80 MeV, the mixing strength is |U{sub {mu}h}|{sup 2{approx_equal}}10{sup -3}-10{sup -2}, and the lifetime is {tau}{sub {nu}{sub h}} < or approx. 10{sup -9} s. Surprisingly, this LSND-MiniBooNE parameter window is found to be unconstrained by the results from the most sensitive experiments. We set new limits on |U{sub {mu}h}|{sup 2} for the favorable mass region from the precision measurements of the Michel spectrum by the TWIST experiment. The results obtained provide a strong motivation for a sensitive search for the {nu}{sub h} in a near future K decay or neutrino experiments, which fit well in the existing and planned experimental programs at CERN or FNAL. The question of whether the heavy neutrino is a Dirac or Majorana particle is briefly discussed.

  19. Marriage à-la-MOND: Baryonic dark matter in galaxy clusters and the cooling flow puzzle

    NASA Astrophysics Data System (ADS)

    Milgrom, Mordehai

    2008-05-01

    I start with a brief introduction to MOND phenomenology and its possible roots in cosmology—a notion that may turn out to be the most far reaching aspect of MOND. Next I discuss the implications of MOND for the dark matter (DM) doctrine: MOND's successes imply that baryons determine everything. For DM this would mean that the puny tail of leftover baryons in galaxies wags the hefty DM dog. This has to occur in many intricate ways, and despite the haphazard construction history of galaxies—a very tall order. I then concentrate on galaxy clusters in light of MOND, which still requires some yet undetected cluster dark matter, presumably in some baryonic form (CBDM). This CBDM might contribute to the heating of the X-ray emitting gas and thus alleviate the cooling flow puzzle. MOND, qua theory of dynamics, does not directly enter the microphysics of the gas; however, it does force a new outlook on the role of DM in shaping the cluster gas dynamics: MOND tells us that the cluster DM is not cold dark matter, is not so abundant, and is not expected in galaxies; it is thus not subject to constraints on baryonic DM in galaxies. The mass in CBDM required in a whole cluster is, typically, similar to that in hot gas, but is rather more centrally concentrated, totally dominating the core. The CBDM contribution to the baryon budget in the universe is thus small. Its properties, deduced for isolated clusters, are consistent with the observations of the "bullet cluster". Its kinetic energy reservoir is much larger than that of the hot gas in the core, and would suffice to keep the gas hot for many cooling times. Heating can be effected in various ways depending on the exact nature of the CBDM, from very massive black holes to cool, compact gas clouds.

  20. Puzzle Feeders and Gum Feeders as Environmental Enrichment for Common Marmosets.

    PubMed

    Roberts, R. Lucille; Roytburd, Luba A.; Newman, John D.

    1999-09-01

    Common marmosets (Callithrix jacchus jacchus) are highly social New World monkeys that consume a principally gummivorous and insectivorous diet. We examined the efficacy of two types of foraging devices, Puzzle-Feeders(tm) and gum feeders, as environmental enrichment for marmosets housed singly (n = 16) or in sibling (n = 4) and heterosexual (n = 8) pairs. In experiment 1, marmosets were exposed to each of the two types of foraging devices for three hours, once per week for two weeks. Thirty-minute observations were conducted at the beginning and end of each exposure period. Marmosets in all housing conditions experienced significant reductions in the frequency of stereotyped pacing and significantly less time sitting still while exposed to the foraging devices. Marmosets experienced significantly lower levels of feeder use and significantly more time sitting still at the end of the three-hour exposure than at the beginning. Marmosets that were singly or sibling housed used the devices the most and had the largest reductions in time spent sitting still during enrichment. In experiment 2, singly housed marmosets were given two types of gum feeders, a wooden and a Gumabone(tm) gum feeder, each for a week-long period. Thirty-minute observations were conducted three times per week immediately after loading the feeders with fresh gum. The wooden gum feeders were heavily gouged during the week-long exposure, although significantly less use of both types of gum feeders was observed on the third and fifth days. These results indicated that marmosets in variable social housing conditions can benefit from environmental enrichment additional to social housing, and that foraging enrichment promotes increased non-stereotyped movement and decreased pacing in this species. PMID:12086412

  1. Plastid DNA sequencing and nuclear SNP genotyping help resolve the puzzle of central American Platanus

    PubMed Central

    De Castro, Olga; Di Maio, Antonietta; Lozada García, José Armando; Piacenti, Danilo; Vázquez-Torres, Mario; De Luca, Paolo

    2013-01-01

    Background and Aims Recent research on the history of Platanus reveals that hybridization phenomena occurred in the central American species. This study has two goals: to help resolve the evolutive puzzle of central American Platanus, and to test the potential of real-time polymerase chain reaction (PCR) for detecting ancient hybridization. Methods Sequencing of a uniparental plastid DNA marker [psbA-trnH(GUG) intergenic spacer] and qualitative and quantitative single nucleotide polymorphism (SNP) genotyping of biparental nuclear ribosomal DNA (nrDNA) markers [LEAFY intron 2 (LFY-i2) and internal transcribed spacer 2 (ITS2)] were used. Key Results Based on the SNP genotyping results, several Platanus accessions show the presence of hybridization/introgression, including some accessions of P. rzedowskii and of P. mexicana var. interior and one of P. mexicana var. mexicana from Oaxaca (= P. oaxacana). Based on haplotype analyses of the psbA-trnH spacer, five haplotypes were detected. The most common of these is present in taxa belonging to P. orientalis, P. racemosa sensu lato, some accessions of P. occidentalis sensu stricto (s.s.) from Texas, P. occidentalis var. palmeri, P. mexicana s.s. and P. rzedowskii. This is highly relevant to genetic relationships with the haplotypes present in P. occidentalis s.s. and P. mexicana var. interior. Conclusions Hybridization and introgression events between lineages ancestral to modern central and eastern North American Platanus species occurred. Plastid haplotypes and qualitative and quantitative SNP genotyping provide information critical for understanding the complex history of Mexican Platanus. Compared with the usual molecular techniques of sub-cloning, sequencing and genotyping, real-time PCR assay is a quick and sensitive technique for analysing complex evolutionary patterns. PMID:23798602

  2. The Formation of Galaxies and Supermassive Black Holes: Insights and Puzzles

    NASA Astrophysics Data System (ADS)

    Somerville, Rachel S.

    2014-01-01

    Galaxies exist at a nexus of physical scales, molded by physics ranging from the “small” scales of star formation and accretion onto nuclear black holes, up to the very large scales of the cosmic web. It is this special property that makes galaxies so fascinating and so challenging to study, both observationally and theoretically. The past two decades have seen enormous progress in our understanding of how galaxies form and evolve. We have surveyed slices of the sky at many wavelengths, and built sophisticated models and simulations that attempt to capture the complex array of physics that influences galaxy evolution. We are only now coming into possession of large samples of galaxies for which we can study the internal structure as well as the large scale environment in detail, from the epoch of ‘cosmic high noon’ ( 2) to the present. At the same time, numerical simulations set within a cosmological framework have only recently succeeded in building galaxies with realistic internal structures. It has been known for several years that galaxies are growing in mass and radius, experiencing morphological transformation, and ‘downsizing’ their star formation activity over cosmic time. Now, new observations are painting a picture in which the internal structure of galaxies (size and morphology) is intimately linked with their star formation activity and formation history. There are hints that the co-evolution of supermassive black holes with their host galaxies may be the driving force behind these correlations - but this remains controversial. While cosmological simulations set within the hierarchical formation scenario of Cold Dark Matter currently offer a plausible story for interpreting these observations, many puzzles remain. I will review recent insights gleaned from deep multi-wavelength surveys and state-of-the-art theoretical models and simulations, as well as highlight the open questions and challenges for the future.

  3. RNA-Puzzles Round II: assessment of RNA structure prediction programs applied to three large RNA structures.

    PubMed

    Miao, Zhichao; Adamiak, Ryszard W; Blanchet, Marc-Frédérick; Boniecki, Michal; Bujnicki, Janusz M; Chen, Shi-Jie; Cheng, Clarence; Chojnowski, Grzegorz; Chou, Fang-Chieh; Cordero, Pablo; Cruz, José Almeida; Ferré-D'Amaré, Adrian R; Das, Rhiju; Ding, Feng; Dokholyan, Nikolay V; Dunin-Horkawicz, Stanislaw; Kladwang, Wipapat; Krokhotin, Andrey; Lach, Grzegorz; Magnus, Marcin; Major, François; Mann, Thomas H; Masquida, Benoît; Matelska, Dorota; Meyer, Mélanie; Peselis, Alla; Popenda, Mariusz; Purzycka, Katarzyna J; Serganov, Alexander; Stasiewicz, Juliusz; Szachniuk, Marta; Tandon, Arpit; Tian, Siqi; Wang, Jian; Xiao, Yi; Xu, Xiaojun; Zhang, Jinwei; Zhao, Peinan; Zok, Tomasz; Westhof, Eric

    2015-06-01

    This paper is a report of a second round of RNA-Puzzles, a collective and blind experiment in three-dimensional (3D) RNA structure prediction. Three puzzles, Puzzles 5, 6, and 10, represented sequences of three large RNA structures with limited or no homology with previously solved RNA molecules. A lariat-capping ribozyme, as well as riboswitches complexed to adenosylcobalamin and tRNA, were predicted by seven groups using RNAComposer, ModeRNA/SimRNA, Vfold, Rosetta, DMD, MC-Fold, 3dRNA, and AMBER refinement. Some groups derived models using data from state-of-the-art chemical-mapping methods (SHAPE, DMS, CMCT, and mutate-and-map). The comparisons between the predictions and the three subsequently released crystallographic structures, solved at diffraction resolutions of 2.5-3.2 Å, were carried out automatically using various sets of quality indicators. The comparisons clearly demonstrate the state of present-day de novo prediction abilities as well as the limitations of these state-of-the-art methods. All of the best prediction models have similar topologies to the native structures, which suggests that computational methods for RNA structure prediction can already provide useful structural information for biological problems. However, the prediction accuracy for non-Watson-Crick interactions, key to proper folding of RNAs, is low and some predicted models had high Clash Scores. These two difficulties point to some of the continuing bottlenecks in RNA structure prediction. All submitted models are available for download at http://ahsoka.u-strasbg.fr/rnapuzzles/. PMID:25883046

  4. RNA-Puzzles Round II: assessment of RNA structure prediction programs applied to three large RNA structures

    PubMed Central

    Miao, Zhichao; Adamiak, Ryszard W.; Blanchet, Marc-Frédérick; Boniecki, Michal; Bujnicki, Janusz M.; Chen, Shi-Jie; Cheng, Clarence; Chojnowski, Grzegorz; Chou, Fang-Chieh; Cordero, Pablo; Cruz, José Almeida; Ferré-D'Amaré, Adrian R.; Das, Rhiju; Ding, Feng; Dokholyan, Nikolay V.; Dunin-Horkawicz, Stanislaw; Kladwang, Wipapat; Krokhotin, Andrey; Lach, Grzegorz; Magnus, Marcin; Major, François; Mann, Thomas H.; Masquida, Benoît; Matelska, Dorota; Meyer, Mélanie; Peselis, Alla; Popenda, Mariusz; Purzycka, Katarzyna J.; Serganov, Alexander; Stasiewicz, Juliusz; Szachniuk, Marta; Tandon, Arpit; Tian, Siqi; Wang, Jian; Xiao, Yi; Xu, Xiaojun; Zhang, Jinwei; Zhao, Peinan; Zok, Tomasz; Westhof, Eric

    2015-01-01

    This paper is a report of a second round of RNA-Puzzles, a collective and blind experiment in three-dimensional (3D) RNA structure prediction. Three puzzles, Puzzles 5, 6, and 10, represented sequences of three large RNA structures with limited or no homology with previously solved RNA molecules. A lariat-capping ribozyme, as well as riboswitches complexed to adenosylcobalamin and tRNA, were predicted by seven groups using RNAComposer, ModeRNA/SimRNA, Vfold, Rosetta, DMD, MC-Fold, 3dRNA, and AMBER refinement. Some groups derived models using data from state-of-the-art chemical-mapping methods (SHAPE, DMS, CMCT, and mutate-and-map). The comparisons between the predictions and the three subsequently released crystallographic structures, solved at diffraction resolutions of 2.5–3.2 Å, were carried out automatically using various sets of quality indicators. The comparisons clearly demonstrate the state of present-day de novo prediction abilities as well as the limitations of these state-of-the-art methods. All of the best prediction models have similar topologies to the native structures, which suggests that computational methods for RNA structure prediction can already provide useful structural information for biological problems. However, the prediction accuracy for non-Watson–Crick interactions, key to proper folding of RNAs, is low and some predicted models had high Clash Scores. These two difficulties point to some of the continuing bottlenecks in RNA structure prediction. All submitted models are available for download at http://ahsoka.u-strasbg.fr/rnapuzzles/. PMID:25883046

  5. Lower ionosphere large positive and negative ions are still puzzling: A potential role in ion induced aerosol formation

    NASA Astrophysics Data System (ADS)

    Arnold, Frank

    2016-04-01

    Inspired by greatly improved possibilities in future rocket borne high mass resolution ion mass spectrometry, previous pioneering rocket borne ion-mass spectrometer measurements, made by our MPIK-Heidelberg research group in the lower ionosphere, are revisited and reanalyzed. Here the focus is placed upon puzzling observations of lower ionosphere large positive and large negative ions. These have a role in lower ionosphere free electron removal. They also have a potential role in lower ionosphere aerosol and eventually even cloud formation. Measurements and model simulations are presented.

  6. Unresolved puzzles in the x-ray emission produced by charge exchange measured on electron beam ion traps

    SciTech Connect

    Beiersdorfer, P.; Brown, G. V.; Clementson, J.; Kilbourne, C. A.; Kelley, R. L.; Leutenegger, M. A.; Porter, F. S.; Schweikhard, L.

    2013-04-19

    Charge exchange recombination, the transfer of one or more electrons from an atomic or molecular system to a positive ion, is a common phenomenon affecting laboratory and astrophysical plasmas. Controlled studies of this process in electron beam ion traps during the past one and a half decades have produced multiple observations that are difficult to explain with available spectral models. Some of the most recent observations are so puzzling that they bring in doubt the existence of a coherent predictive capability for line formation by charge exchange, making investigations of charge exchange a fertile ground for continued measurements and theoretical development.

  7. A New Species of Aculops Keifer (Acari: Prostigmata: Eriophyidae) on Dipsacus laciniatus L. (Dipsacaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Investigations have been conducted in Europe in the last decade in order to find potential agents for biological control of invasive teasels in North America. During surveys conducted in Serbia in May 2007, the new eriophyid mite species Aculops dipsaci n. sp. (Acari: Prostigmata: Eriophyidae) was ...

  8. The puzzling deuteration of methanol in low- to high-mass protostars

    NASA Astrophysics Data System (ADS)

    Ratajczak, A.; Taquet, V.; Kahane, C.; Ceccarelli, C.; Faure, A.; Quirico, E.

    2011-04-01

    Context. The current theory of methanol deuteration on interstellar grains predicts that the abundance ratio of the singly deuterated isotopologues [CH2DOH]/[CH3OD] should always be ~3. In warm regions where grain mantles have sublimated, gaseous methanol is detectable via its rotational transitions. In previous observational studies, the gas-phase [CH2DOH]/[CH3OD] ratio was measured and found to be significantly larger than 3 in low-mass protostars and close to 1 in the Orion IRc2 massive hot core. Aims: We present new measurements of the gas-phase [CH2DOH]/[CH3OD] ratio in two additional high-mass protostars, as well as in two intermediate-mass protostars, to either confirm or exclude the dependence of this ratio on the mass of the protostar. Methods: The observations were carried out using the IRAM-30 m telescope. Several rotational lines of each isotopologue were detected toward the intermediate-mass protostars, while only CH3OD lines were detected in the massive hot cores. The ratio [CH2DOH]/[CH3OD] (or its upper limit) was computed from both the averaged column densities and directly from line flux ratios. Results: Our results confirm that the [CH2DOH]/[CH3OD] ratio is substantially lower in massive hot cores than in (low-mass) hot-corinos, by typically one order of magnitude. Furthermore, they suggest that intermediate-mass protostars have similar properties to low-mass protostars. Conclusions: The measured [CH2DOH]/[CH3OD] ratios are inconsistent with the current theory of methanol deuteration, independently of the mass of the source. While the large ratios measured in low- and intermediate-mass sources can be explained qualitatively by various selective depletion mechanisms, the small ratios (<2) measured toward massive hot cores are puzzling. A revision of the deuterium chemistry in hot cores is suggested. Table A.1 is only available in electronic form at http://www.aanda.org

  9. The Puzzle of HCN in Comets: Is it both a Product and a Primary Species?

    NASA Astrophysics Data System (ADS)

    Mumma, Michael J.; Bonev, Boncho P.; Charnley, Steven B.; Cordiner, Martin A.; DiSanti, Michael A.; Gibb, Erika L.; Magee-Sauer, Karen; Paganini, Lucas; Villanueva, Geronimo L.

    2014-11-01

    Hydrogen cyanide has long been regarded as a primary volatile in comets, stemming from its presence in dense molecular cloud cores and its supposed storage in the cometary nucleus. Here, we examine the observational evidence for and against that hypothesis, and argue that HCN may also result from near-nucleus chemical reactions in the coma. The distinction (product vs. primary species) is important for multiple reasons: 1. HCN is often used as a proxy for water when the dominant species (H2O) is not available for simultaneous measurement, as at radio wavelengths. 2. HCN is one of the few volatile carriers of nitrogen accessible to remote sensing. If HCN is mainly a product species, its precursor becomes the more important metric for compiling a taxonomic classification based on nitrogen chemistry. 3. The stereoisomer HNC is now confirmed as a product species. Could reaction of a primary precursor (X-CN) with a hydrocarbon co-produce both HNC and HCN? 4. The production rate for CN greatly exceeds that of HCN in some comets, demonstrating the presence of another (more important) precursor of CN. Several puzzling lines of evidence raise issues about the origin of HCN: a. The production rates of HCN measured through rotational (radio) and vibrational (infrared) spectroscopy agree in some comets - in others the infrared rate exceeds the radio rate substantially. b. With its strong dipole moment and H-bonding character, HCN should be linked more strongly in the nuclear ice to other molecules with similar properties (H2O, CH3OH), but instead its spatial release in some comets seems strongly coupled to volatiles that lack a dipole moment and thus do not form H-bonds (methane, ethane). c. The nucleus-centered rotational temperatures measured for H2O and other species (C2H6, CH3OH) usually agree within error, but those for HCN are often slightly smaller. d. In comet ISON, ALMA maps of HCN and the dust continuum show a slight displacement 80 km) in the centroids. We will

  10. William Wales and the 1769 transit of Venus: puzzle solving and the determination of the astronomical unit

    NASA Astrophysics Data System (ADS)

    Metz, Don

    2009-05-01

    According to Thomas Kuhn, a significant part of “normal science” is the fact gathering, empirical work which is intended to illustrate an existing paradigm. Some of this effort focuses on the determination of physical constants such as the astronomical unit (AU). For Kuhn, normal science is also what prepares students for membership in a particular scientific community and is embodied in some form in our science textbooks. However, neither Kuhn nor the textbook says much about the individuals who practice normal science, especially those who had been relegated to the “hack” duties of long and arduous measurement and calculation. In this paper, to provide a context for students of astronomy, I will outline the story of the determination of the AU and in particular the contribution of William Wales, an obscure British astronomer. Wales, toiling in the shadow of Halley (of Halley’s comet fame), Mason and Dixon (of Mason and Dixon line fame) and the infamous Captain Cook endured a brutal winter in northern Canada for a brief glimpse of the 1769 transit of Venus. In the end, Wales supplied one small piece of the puzzle in the determination of the AU and he exemplified the human spirit and persistence of a Kuhnian “puzzle solver”.

  11. Parent perspectives from a neonatal intensive care unit: a missing piece of the culturally congruent care puzzle.

    PubMed

    Wiebe, Adrienne; Young, Brenda

    2011-01-01

    The majority of existing theoretical models and tools of culturally competent and congruent care have been developed from the health care provider perspective. Recently, the Culturally Congruent Care Puzzle proposed a model in the form of a three-dimensional puzzle with a provider level and a client level that interact to create the outcome level, which is culturally congruent care. However, the constructs that comprise the client, or patient, level, have not yet been clearly articulated. This study explored parent (client/patient) perceptions of culturally congruent care within a tertiary neonatal intensive care unit based on interviews with culturally diverse families with hospitalized infants (n = 21). The findings identified four primary constructs in the client/patient level: (a) a provider-client relationship of caring and trust, (b) respectful and appropriate communication, (c) culturally responsive and accessible social and spiritual supports, and (d) a welcoming and flexible organizational environment. These four interconnecting pieces are infused with the sociopolitical history and dynamics of culture, ethnicity, immigration, and colonization that clients/patients bring to their experience of health and health care. These elements of the client/patient level also interact with the provider level in various ways. PMID:20592061

  12. Can Word Puzzles be Tailored to Improve Different Dimensions of Verbal Fluency? A Report of an Intervention Study.

    PubMed

    Murphy, Mike; Spillane, Katie; Cully, James; Navarro-Pardo, Esperanza; Moret-Tatay, Carmen

    2016-08-17

    Verbal fluency is commonly used as a proxy measure of executive functioning, as it involves cognitive flexibility, working memory, and inhibitory control. Previous research has demonstrated that crosswords can be a useful means of improving verbal fluency, results consistent with the cognitive reserve hypothesis; the form of verbal fluency affected has, however, differed across studies. The present study sought to assess the extent to which it was possible to target phonemic (PVF) and semantic verbal fluency (SVF) separately through word puzzles designed to focus on semantic/thematic and structural clues respectively. Fifty-three university students were randomly assigned to one of three groups: semantic/thematic, structural, or a daily diary control group. They were assessed on PVF and SVF at baseline, and immediately following a four-week intervention. Age, sex, and depression scores were controlled for. A 2 × 3 mixed ANCOVA showed that the structural group improved significantly more in PVF during the intervention period than did the semantic/thematic or control groups, with the improvement linked to improved switching performance. The effect size was large. No significant difference in improvement in SVF emerged, although the effect size was moderate. The findings support the notion that it is possible to improve specific forms of verbal fluency through tailored brief word-puzzle interventions. PMID:27224052

  13. Development of DU-AGG (Depleted Uranium Aggregate)

    SciTech Connect

    Lessing, P.A.

    1995-09-01

    Depleted uranium oxide (UO{sub 2} or U0{sub 3}) powder was mixed with fine mineral additives, pressed, and heated to about 1,250{degree}C. The additives were chemically constituted to result in an iron-enriched basalt (IEB). Melting and wetting of the IEB phase caused the urania powder compact to densify (sinter) via a liquid phase sintering mechanism. An inorganic lubricant was found to aid in green-forming of the body. Sintering was successful in oxidizing (air), inert (argon), or reducing (dry hydrogen containing) atmospheres. The use of ground U0{sub 3} powders (93 vol %) followed by sintering in a dry hydrogen-containing atmosphere significantly increased the density of samples (bulk density of 8.40 g/cm{sup 3} and apparent density of 9.48 g/cm{sup 3}, open porosity of 11.43%). An improvement in the microstructure (reduction in open porosity) was achieved when the vol % of U0{sub 3} was decreased to 80%. The bulk density increased to 8.59 g/cm{sup 3}, the apparent density decreased slightly to 8.82 g/cm{sup 3} (due to increase of low density IEB content), while the open porosity decreased to an excellent number of 2.78%. A representative sample derived from 80 vol % U0{sub 3} showed that most pores were closed pores and that, overall, the sample achieved the excellent relative density value of 94.1% of the estimated theoretical density (composite of U0{sub 2} and IEB). It is expected that ground powders of U0{sub 3} could be successfully used to mass produce lowcost aggregate using the green-forming technique of briquetting.

  14. A note on the puzzling spindown behavior of the Galactic center magnetar SGR J1745-2900

    NASA Astrophysics Data System (ADS)

    Tong, Hao

    2015-09-01

    SGR J1745-2900 is a magnetar near the Galactic center. X-ray observations of this source found a decreasing X-ray luminosity accompanied by an enhanced spindown rate. This negative correlation between X-ray luminosity and spindown rate is hard to understand. The wind braking model of magnetars is employed to explain this puzzling spindown behavior. During the release of magnetic energy of magnetars, a system of particles may be generated. Some of these particles remain trapped in the magnetosphere and may contribute to the X-ray luminosity. The rest of the particles can flow out and take away the rotational energy of the central neutron star. A smaller polar cap angle will cause the decrease of X-ray luminosity and enhanced spindown rate of SGR J1745-2900. This magnetar is shortly expected to have a maximum spindown rate.

  15. The puzzle of half-integral quanta in the application of the adiabatic hypothesis to rotational motion

    NASA Astrophysics Data System (ADS)

    Duncan, Anthony; Pérez, Enric

    2016-05-01

    We present and discuss an interesting and puzzling problem Ehrenfest found in his first application of the adiabatic hypothesis, in 1913. It arose when trying to extend Planck's quantization of the energy of harmonic oscillators to a rotating dipole within the frame of the old quantum theory. Such an extension seemed to lead unavoidably to half-integral values for the rotational angular momentum of a system (in units of ℏ). We present the problem in its original form along with the (few) responses we have found to Ehrenfest's treatment. After giving a brief account of the classical and quantum adiabatic theorem, we also describe how Quantum Mechanics provides an explanation for this difficulty.

  16. Early anisotropic hydrodynamics and thermalization and Hanbury-Brown-Twiss puzzles in the BNL Relativistic Heavy Ion Collider (RHIC)

    SciTech Connect

    Ryblewski, Radoslaw; Florkowski, Wojciech

    2010-08-15

    We address the problem of whether the early thermalization and Hanbury-Brown-Twiss (HBT) puzzles in relativistic heavy-ion collisions may be solved by the assumption that the early dynamics of the produced matter is locally anisotropic. The hybrid model describing the purely transverse hydrodynamic evolution followed by the perfect-fluid hydrodynamic stage is constructed. The transition from the transverse to perfect-fluid hydrodynamics is described by the Landau matching conditions applied at a fixed proper time {tau}{sub tr}. The global fit to the RHIC data reproduces the soft hadronic observables (the pion, kaon, and the proton spectra, the pion and kaon elliptic flow, and the pion HBT radii) with the accuracy of about 20%. These results indicate that the assumption of the very fast thermalization may be relaxed. In addition, the presented model suggests that a large part of the inconsistencies between the theoretical and experimental HBT results may be removed.

  17. `Consistent bosonization-debosonization': A resolution of the non-equilibrium transport puzzle blazes a new path forward

    NASA Astrophysics Data System (ADS)

    Shah, Nayana

    In this talk, we will critically reexamine the bosonization-debosonization procedure for systems including certain types of localized features (although more general scenarios are possible). By focusing on the case of a tunneling junction out of equilibrium, I will show that the conventional approach gives results that are not consistent with the exact solution of the problem even at the qualitative level and highlight the inconsistencies that can adversely affect the results of all types of calculations. I will subsequently report on a `Consistent bosonization-debosonization' procedure that we have developed to resolve the aforementioned non-equilibrium transport puzzle and argue that this framework should be widely applicable. I will touch upon its application for the two-lead Kondo problem that besides being a key theoretical prototype of a strongly correlated system is also of immediate experimental relevance in many ways (see also related talk by Bolech).

  18. Face puzzle-two new video-based tasks for measuring explicit and implicit aspects of facial emotion recognition.

    PubMed

    Kliemann, Dorit; Rosenblau, Gabriela; Bölte, Sven; Heekeren, Hauke R; Dziobek, Isabel

    2013-01-01

    Recognizing others' emotional states is crucial for effective social interaction. While most facial emotion recognition tasks use explicit prompts that trigger consciously controlled processing, emotional faces are almost exclusively processed implicitly in real life. Recent attempts in social cognition suggest a dual process perspective, whereby explicit and implicit processes largely operate independently. However, due to differences in methodology the direct comparison of implicit and explicit social cognition has remained a challenge. Here, we introduce a new tool to comparably measure implicit and explicit processing aspects comprising basic and complex emotions in facial expressions. We developed two video-based tasks with similar answer formats to assess performance in respective facial emotion recognition processes: Face Puzzle, implicit and explicit. To assess the tasks' sensitivity to atypical social cognition and to infer interrelationship patterns between explicit and implicit processes in typical and atypical development, we included healthy adults (NT, n = 24) and adults with autism spectrum disorder (ASD, n = 24). Item analyses yielded good reliability of the new tasks. Group-specific results indicated sensitivity to subtle social impairments in high-functioning ASD. Correlation analyses with established implicit and explicit socio-cognitive measures were further in favor of the tasks' external validity. Between group comparisons provide first hints of differential relations between implicit and explicit aspects of facial emotion recognition processes in healthy compared to ASD participants. In addition, an increased magnitude of between group differences in the implicit task was found for a speed-accuracy composite measure. The new Face Puzzle tool thus provides two new tasks to separately assess explicit and implicit social functioning, for instance, to measure subtle impairments as well as potential improvements due to social cognitive

  19. RED DWARF DYNAMO RAISES PUZZLE OVER INTERIORS OF LOWEST-MASS STARS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    -years away in the constellation Aquila. Gliese 752A is a red dwarf that is one-third the mass of the Sun and slightly more than half its diameter. By contrast, VB10 is physically smaller than the planet Jupiter and only about nine percent the mass of our Sun. This very faint star is near the threshold of the lowest possible mass for a true star (.08 solar masses), below which nuclear fusion processes cannot take place according to current models. A team led by Linsky used Hubble's Goddard High Resolution Spectrograph (GHRS) to make a one-hour long exposure of VB10 on October 12, 1994. No detectable ultraviolet emission was seen until the last five minutes, when bright emission was detected in a flare. Though the star's normal surface temperature is 4,500 degrees Fahrenheit, Hubble's GHRS detected a sudden burst of 270,000 degrees Fahrenheit in the star's outer atmosphere. Linsky attributes this rapid heating to the presence of an intense, but unstable, magnetic field. THE INTERIOR WORKINGS OF A STELLAR DYNAMO Before the Hubble observation, astronomers thought magnetic fields in stars required the same dynamo process which creates magnetic fields on the Sun. In the classic solar model, heat generated by nuclear fusion reactions at the star's center escapes through a radiative zone just outside the core. The heat travels from the radiative core to the star's surface through a convection zone. In this region, heat bubbles to the surface by motions similar to boiling in a pot of water. Dynamos, which accelerate electrons to create magnetic forces, operate when the interior of a star rotates faster than the surface. Recent studies of the Sun indicate its convective zone rotates at nearly the same rate at all depths. This means the solar dynamo must operate in the more rapidly rotating radiative core just below the convective zone. The puzzle is that stars below 20 percent the mass of our Sun do not have radiative cores, but instead transport heat from their core through

  20. ESA's Rosetta mission and the puzzles that Hale-Bopp left behind

    NASA Astrophysics Data System (ADS)

    1997-04-01

    kilometres with a set of remote-sensing instruments. As the spacecraft moves around the nucleus at a very leisurely walking pace, other onboard instruments will analyse the dust and vapours, which will emanate from Comet Wirtanen with ever-increasing vigour as the Sun's rays warm it. Rosetta will drop a lander on to the comet's surface, for close inspection of its physical condition and chemical composition. The lander is a venture led by Germany, France and Italy, with participation from Austria, Finland, Hungary, Poland and the UK. As a box packed with scientific instruments and standing on three legs, the lander will be capable of anchoring itself to one spot and drilling into the surface. It may also be able to hop like a flea to visit another part of the nucleus. A combination of solar energy and electric batteries will enable operations to last for several months. "The combination of Rosetta in orbit around the comet and the lander on its surface is very powerful from a scientific point of view," says Gerhard Schwehm, ESA's project scientist for Rosetta. "We shall watch Comet Wirtanen brewing up like a volcano as it feels the heat of the Sun. In place of hazy impressions of the nucleus of a comet half hidden by its dust clouds, we shall see all the details with unprecedented clarity." Unanswered questions During and after the 1986 appearance of Halley's Comet, comet science made great progress. More recent comets have revealed important secrets to ESA's Infrared Space Observatory and to other space telescopes examining them at wavelengths unobservable from the Earth. Yet basic questions about comets remain unanswered. Just as the Rosetta Stone was the key that unlocked the meaning of Egyptian hieroglyphs, so the Rosetta spacecraft is intended to decipher the meaning of comets and their role in the origin and history of the Solar System. Here are a few of the main puzzles. * What does a comet weigh? Guesses about the density of cometary material vary widely, and only an

  1. RED DWARF DYNAMO RAISES PUZZLE OVER INTERIORS OF LOWEST-MASS STARS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    -years away in the constellation Aquila. Gliese 752A is a red dwarf that is one-third the mass of the Sun and slightly more than half its diameter. By contrast, VB10 is physically smaller than the planet Jupiter and only about nine percent the mass of our Sun. This very faint star is near the threshold of the lowest possible mass for a true star (.08 solar masses), below which nuclear fusion processes cannot take place according to current models. A team led by Linsky used Hubble's Goddard High Resolution Spectrograph (GHRS) to make a one-hour long exposure of VB10 on October 12, 1994. No detectable ultraviolet emission was seen until the last five minutes, when bright emission was detected in a flare. Though the star's normal surface temperature is 4,500 degrees Fahrenheit, Hubble's GHRS detected a sudden burst of 270,000 degrees Fahrenheit in the star's outer atmosphere. Linsky attributes this rapid heating to the presence of an intense, but unstable, magnetic field. THE INTERIOR WORKINGS OF A STELLAR DYNAMO Before the Hubble observation, astronomers thought magnetic fields in stars required the same dynamo process which creates magnetic fields on the Sun. In the classic solar model, heat generated by nuclear fusion reactions at the star's center escapes through a radiative zone just outside the core. The heat travels from the radiative core to the star's surface through a convection zone. In this region, heat bubbles to the surface by motions similar to boiling in a pot of water. Dynamos, which accelerate electrons to create magnetic forces, operate when the interior of a star rotates faster than the surface. Recent studies of the Sun indicate its convective zone rotates at nearly the same rate at all depths. This means the solar dynamo must operate in the more rapidly rotating radiative core just below the convective zone. The puzzle is that stars below 20 percent the mass of our Sun do not have radiative cores, but instead transport heat from their core through

  2. ESA's Rosetta mission and the puzzles that Hale-Bopp left behind

    NASA Astrophysics Data System (ADS)

    1997-04-01

    kilometres with a set of remote-sensing instruments. As the spacecraft moves around the nucleus at a very leisurely walking pace, other onboard instruments will analyse the dust and vapours, which will emanate from Comet Wirtanen with ever-increasing vigour as the Sun's rays warm it. Rosetta will drop a lander on to the comet's surface, for close inspection of its physical condition and chemical composition. The lander is a venture led by Germany, France and Italy, with participation from Austria, Finland, Hungary, Poland and the UK. As a box packed with scientific instruments and standing on three legs, the lander will be capable of anchoring itself to one spot and drilling into the surface. It may also be able to hop like a flea to visit another part of the nucleus. A combination of solar energy and electric batteries will enable operations to last for several months. "The combination of Rosetta in orbit around the comet and the lander on its surface is very powerful from a scientific point of view," says Gerhard Schwehm, ESA's project scientist for Rosetta. "We shall watch Comet Wirtanen brewing up like a volcano as it feels the heat of the Sun. In place of hazy impressions of the nucleus of a comet half hidden by its dust clouds, we shall see all the details with unprecedented clarity." Unanswered questions During and after the 1986 appearance of Halley's Comet, comet science made great progress. More recent comets have revealed important secrets to ESA's Infrared Space Observatory and to other space telescopes examining them at wavelengths unobservable from the Earth. Yet basic questions about comets remain unanswered. Just as the Rosetta Stone was the key that unlocked the meaning of Egyptian hieroglyphs, so the Rosetta spacecraft is intended to decipher the meaning of comets and their role in the origin and history of the Solar System. Here are a few of the main puzzles. * What does a comet weigh? Guesses about the density of cometary material vary widely, and only an

  3. The puzzle of the 1996 Bárdarbunga, Iceland, earthquake: no volumetric component in the source mechanism

    USGS Publications Warehouse

    Tkalcic, Hrvoje; Dreger, Douglas S.; Foulger, Gillian R.; Julian, Bruce R.

    2009-01-01

    A volcanic earthquake with Mw 5.6 occurred beneath the Bárdarbunga caldera in Iceland on 29 September 1996. This earthquake is one of a decade-long sequence of  events at Bárdarbunga with non-double-couple mechanisms in the Global Centroid Moment Tensor catalog. Fortunately, it was recorded well by the regional-scale Iceland Hotspot Project seismic experiment. We investigated the event with a complete moment tensor inversion method using regional long-period seismic waveforms and a composite structural model. The moment tensor inversion using data from stations of the Iceland Hotspot Project yields a non-double-couple solution with a 67% vertically oriented compensated linear vector dipole component, a 32% double-couple component, and a statistically insignificant (2%) volumetric (isotropic) contraction. This indicates the absence of a net volumetric component, which is puzzling in the case of a large volcanic earthquake that apparently is not explained by shear slip on a planar fault. A possible volcanic mechanism that can produce an earthquake without a volumetric component involves two offset sources with similar but opposite volume changes. We show that although such a model cannot be ruled out, the circumstances under which it could happen are rare.

  4. Event-by-Event Hydrodynamics+Jet Energy Loss: A Solution to the R_{AA}⊗v_{2} Puzzle.

    PubMed

    Noronha-Hostler, Jacquelyn; Betz, Barbara; Noronha, Jorge; Gyulassy, Miklos

    2016-06-24

    High p_{T}>10  GeV elliptic flow, which is experimentally measured via the correlation between soft and hard hadrons, receives competing contributions from event-by-event fluctuations of the low-p_{T} elliptic flow and event-plane angle fluctuations in the soft sector. In this Letter, a proper account of these event-by-event fluctuations in the soft sector, modeled via viscous hydrodynamics, is combined with a jet-energy-loss model to reveal that the positive contribution from low-p_{T} v_{2} fluctuations overwhelms the negative contributions from event-plane fluctuations. This leads to an enhancement of high-p_{T}>10  GeV elliptic flow in comparison to previous calculations and provides a natural solution to the decade-long high-p_{T} R_{AA}⊗v_{2} puzzle. We also present the first theoretical calculation of high-p_{T} v_{3}, which is shown to be compatible with current LHC data. Furthermore, we discuss how short-wavelength jet-medium physics can be deconvoluted from the physics of soft, bulk event-by-event flow observables using event-shape engineering techniques. PMID:27391718

  5. The Puzzle of Italian Rice Origin and Evolution: Determining Genetic Divergence and Affinity of Rice Germplasm from Italy and Asia

    PubMed Central

    Jiang, Zhuxi; Basso, Barbara; Sala, Francesco; Spada, Alberto; Grassi, Fabrizio; Lu, Bao-Rong

    2013-01-01

    The characterization of genetic divergence and relationships of a set of germplasm is essential for its efficient applications in crop breeding and understanding of the origin/evolution of crop varieties from a given geographical region. As the largest rice producing country in Europe, Italy holds rice germplasm with abundant genetic diversity. Although Italian rice varieties and the traditional ones in particular have played important roles in rice production and breeding, knowledge concerning the origin and evolution of Italian traditional varieties is still limited. To solve the puzzle of Italian rice origin, we characterized genetic divergence and relationships of 348 rice varieties from Italy and Asia based on the polymorphisms of microsatellite fingerprints. We also included common wild rice O. rufipogon as a reference in the characterization. Results indicated relatively rich genetic diversity (He = 0.63-0.65) in Italian rice varieties. Further analyses revealed a close genetic relationship of the Italian traditional varieties with those from northern China, which provides strong genetic evidence for tracing the possible origin of early established rice varieties in Italy. These findings have significant implications for the rice breeding programs, in which appropriate germplasm can be selected from a given region and utilized for transferring unique genetic traits based on its genetic diversity and evolutionary relationships. PMID:24265814

  6. Event-by-Event Hydrodynamics +Jet Energy Loss: A Solution to the RA A⊗v2 Puzzle

    NASA Astrophysics Data System (ADS)

    Noronha-Hostler, Jacquelyn; Betz, Barbara; Noronha, Jorge; Gyulassy, Miklos

    2016-06-01

    High pT>10 GeV elliptic flow, which is experimentally measured via the correlation between soft and hard hadrons, receives competing contributions from event-by-event fluctuations of the low-pT elliptic flow and event-plane angle fluctuations in the soft sector. In this Letter, a proper account of these event-by-event fluctuations in the soft sector, modeled via viscous hydrodynamics, is combined with a jet-energy-loss model to reveal that the positive contribution from low-pT v2 fluctuations overwhelms the negative contributions from event-plane fluctuations. This leads to an enhancement of high-pT>10 GeV elliptic flow in comparison to previous calculations and provides a natural solution to the decade-long high-pT RA A⊗v2 puzzle. We also present the first theoretical calculation of high-pT v3, which is shown to be compatible with current LHC data. Furthermore, we discuss how short-wavelength jet-medium physics can be deconvoluted from the physics of soft, bulk event-by-event flow observables using event-shape engineering techniques.

  7. OT2_efalgaro_2: The Herschel/HIFI insight on the CH+ puzzle in the diffuse medium

    NASA Astrophysics Data System (ADS)

    Falgarone, E.

    2011-09-01

    Seventy years after its discovery in the diffuse interstellar medium, the origin of the CH+ cation is still elusive. Herschel/HIFI offers a unique opportunity to disclose the underlying gas dynamics at the origin of CH+ in the diffuse medium by allowing high sensitivity and high spectral resolution observations of the CH+(J=1-0) transition, unreachable from the ground: it is the only instrument, for the decades to come, able to bring a completely new look at this resilient puzzle. The abundant CH+ ion is not only a sensitive tracer of the most tenuous phases of the interstellar medium but it appears as a specific tracer of turbulent dissipation, because its formation route is highly endoenergic. We propose absorption spectroscopy observations of the CH+ J=1-0 line, against 7 background dust continuum sources, bright enough to allow the sample Galactic environments with highly different turbulent dissipation rates. We take advantage of the high opacity of the CH+(1-0) transition to search for CH+ in more diffuse components than previously observed: in the high-latitude diffuse medium, in gas out of the Galactic disk and in the outer Galaxy. The unknown H2 molecular fraction of these poorly explored parts of the diffuse Galactic component will be inferred from the CH absorption lines. The primarily goal of this project is the comparison of the CH+ abundances with model predictions, in which turbulent dissipation proceeds either in low-velocity shocks or intense velocity-shears. Another goal is testing the possibility that CH+ forms at the turbulent interface between the two thermally stable phases of the interstellar medium. Last, as HF, CH+ is a potential sensitive tracer of diffuse molecular matter in the early universe. Understanding its origin and the dissipative processes that it traces will shed a new light on galaxy formation and evolution.

  8. A compilation of electronic transitions in the CO molecule and the interpretation of some puzzling interstellar absorption features

    NASA Astrophysics Data System (ADS)

    Morton, Donald C.; Noreau, Louis

    1994-11-01

    This compilation lists wavenumbers, wavelengths, and oscillator strengths for 1589 electronic transitions of (12)C(16)O, (13)C(16)O, (12)C(18)O, and (13)C(18)O between 1000 and 1545 A. These are the transitions from J double prime = 0 to 6 and v double prime = 0 of the ground term which are most likely to appear as interstellar absorption lines in spectra observed with the Hubble Space Telescope and other instruments in space. We include a derivation of the formulae relating transition probabilities, lifetimes, line strengths, and oscillator strengths for individual rovibronic transitions and whole bands. The compilation contains all the known spin-permitted bands A1Pi - X1Sigma+, B1Sigma+ - X1Sigma+, C1Sigma+ - X1Sigma+, E1Pi - X1Sigma+, and F1Sigma+ - X1Sigma+, as well as the spin-forbidden a'3Sigma+ - X1Sigma+, d3delta - X1Sigma+ and e3Sigma- - X1Sigma+ bands which are enhanced by perturbations of A1Pi on certain of their upper levels. Oscillator strengths are quoted for each rovibronic transition, taking account of the mixing of the triplet states with A1 Pi, v' = 0 to 6. A separate finding list orders the stronger transitions with J double prime less than or equal to 3 by wavelength. Comparison of the compiled data with existing UV observations of HD 27778, zeta Oph, and 20 Aql shows how the a' - X, d - X, and e - X bands that borrow oscillator strength from A - X can account for several puzzling absorption features. Finally, we include some suggestions for further study with spectrographs in the laboratory and in space.

  9. Spectator scattering and annihilation contributions as a solution to the πK and ππ puzzles within QCD factorization approach

    NASA Astrophysics Data System (ADS)

    Chang, Qin; Sun, Junfeng; Yang, Yueling; Li, Xiaonan

    2014-09-01

    The large branching ratios for pure annihilation B ¯s0→π+π- and B ¯d0→K+K- decays reported by CDF and LHCb collaborations recently and the so-called πK and ππ puzzles indicate that spectator scattering and annihilation contributions are important to the penguin-dominated, color-suppressed tree dominated, and pure annihilation nonleptonic B decays. Combining the available experimental data for Bu ,d→ππ, πK and KK ¯ decays, we do a global fit on the spectator scattering and annihilation parameters XH(ρH,ϕH), XAi(ρAi,ϕAi) and XAf(ρAf,ϕAf), which are used to parametrize the end point singularity in amplitudes of spectator scattering, nonfactorizable and factorizable annihilation topologies within the QCD factorization framework, in three scenarios for different purpose. Numerically, in Scenario II, we get (ρAi,ϕAi[∘])=(2.88-1.30+1.52,-103-40+33) and (ρAf,ϕAf[∘])=(1.21-0.25+0.22,-40-8+12) at the 68% confidence level, which are mainly demanded by resolving the πK puzzle and confirm the presupposition that XAi≠XAf. In addition, correspondingly, the B-meson wave function parameter λB is also fitted to be 0.18-0.08+0.11 MeV, which plays an important role for resolving both πK and ππ puzzles. With the fitted parameters, the QCD factorization results for observables of Bu ,d→ππ, πK and KK ¯ decays are in good agreement with experimental measurements. Many more experimental and theoretical efforts are expected to understand the underlying QCD dynamics of spectator scattering and annihilation contributions.

  10. The Temperature Puzzle

    NASA Video Gallery

    All of the events of the past decade - all of our memories -- have something in common. They all took place during the hottest decade ever recorded since humans began keeping temperature records ab...

  11. The Malignant Protein Puzzle.

    PubMed

    Walker, Lary C; Jucker, Mathias

    2016-01-01

    When most people hear the words malignant and brain, cancer immediately comes to mind. But our authors argue that proteins can be malignant too, and can spread harmfully through the brain in neurodegenerative diseases that include Alzheimer's, Parkinson's, CTE, and ALS. Studying how proteins such as PrP, amyloid beta, tau, and others aggregate and spread, and kill brain cells, represents a crucial new frontier in neuroscience. PMID:27408676

  12. The puzzle of homeopathy.

    PubMed

    Reilly, D

    2001-01-01

    Homeopathy is a branch of Western medicine that has mostly been rejected by Western orthodoxy for the last 200 years because of conceptual and scientific clashes. Homeopathy uses microdoses of potential toxins to provoke defense and self-regulatory responses, rather than the more orthodox approach of blocking body reactions. This approach hints at its clinical scope: it can help, at times resolve, conditions that are intrinsically reversible rather than mechanical problems, deficiencies, or irreversible breakdowns in body functions where it is only palliative. In recent years, there has been a renaissance of interest. Public demand has soared, and with it professional interest. Approximately 20% of Scotland's general practitioners have completed basic training. This is partly occasioned by public interest in complementary medicine and a sympathy with the more mind-body approach of homeopathy, and partly by recent scientific evidence. Some homeopathic dilutions are so extreme they are dismissed by critics as only placebo. Yet trials and meta-analyses of controlled trials are pointing toward real effects, mechanism of action unknown. Clinical outcome studies suggest useful clinical impact and excellent safety. There seems to be a potential to enhance patient care by integrating the two systems. PMID:11822623

  13. The Birth Order Puzzle.

    ERIC Educational Resources Information Center

    Zajonc, R. B.; And Others

    1979-01-01

    Discusses the controversy of the relationship between birth order and intellectual performance through a detailed evaluation of the confluence model which assumes that the rate of intellectual growth is a function of the intellectual environment within the family and associated with the special circumstances of last children. (CM)

  14. Pentaquarks: Facts and Puzzles

    SciTech Connect

    Narodetskii, I.M.

    2005-05-01

    On the occasion of the celebration of the 70th birthday of Prof. Yu.A. Simonov, we contribute a brief review of the status of exotic baryons, which are most likely pentaquark states. We summarize the experimental status of exotic baryons, discuss the baryon antidecuplet to which exotic baryons possibly belong, and review theoretical expectations for the masses and widths of recently discovered {theta} and {xi}{sub 3/2} baryons which have come from studies of QCD sum rules, lattice QCD, and quark models. We also pay special attention to the dynamical calculation of pentaquark masses in a framework of the QCD string approach originally elaborated by Simonov for baryons and using the Jaffe-Wilczek [ud]{sup 2}q-bar approximation for the pentaquark states.

  15. Das DNA-Puzzle

    NASA Astrophysics Data System (ADS)

    Kirchner, Stefan

    Im Jahre 1953 wurde von James Watson und Francis Crick erstmalig der strukturelle Aufbau der sogenannten DNA (Desoxyribonukleinsäure) beschrieben, welche das Erbgut jedes Lebewesens enthält. Der wesentliche Teil des Erbguts wird dabei durch eine sehr lange Folge der vier Basen Adenin (A), Cytosin (C), Guanin (G) und Thymin (T) codiert. Seit einigen Jahren ist es möglich, die Folge der vier Basen zu einer gegebenen DNA zu bestimmen. Biologen bezeichnen diesen Vorgang als Sequenzierung.

  16. Puzzles Pastimes Problems.

    ERIC Educational Resources Information Center

    Eperson, D. B.

    1991-01-01

    This section includes eight problems to which the journal invites readers to respond. Problem topics include angles in alternate segments, pentominoes, a new triangle of numbers, cricket scores, symmetrical pentagons, inequalities, a pythagorean dissection, and magic squares. (MDH)

  17. Amino Acid Crossword Puzzle

    ERIC Educational Resources Information Center

    Sims, Paul A.

    2011-01-01

    Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…

  18. Pebble Puzzle Solved

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Figure 1 In the quest to determine if a pebble was jamming the rock abrasion tool on NASA's Mars Exploration Rover Opportunity, scientists and engineers examined this up-close, approximate true-color image of the tool. The picture was taken by the rover's panoramic camera, using filters centered at 601, 535, and 482 nanometers, at 12:47 local solar time on sol 200 (August 16, 2004).

    Colored spots have been drawn on this image corresponding to regions where panoramic camera reflectance spectra were acquired (see chart in Figure 1). Those regions are: the grinding wheel heads (yellow); the rock abrasion tool magnets (green); the supposed pebble (red); a sunlit portion of the aluminum rock abrasion tool housing (purple); and a shadowed portion of the rock abrasion tool housing (brown). These spectra demonstrated that the composition of the supposed pebble was clearly different from that of the sunlit and shadowed portions of the rock abrasion tool, while similar to that of the dust-coated rock abrasion tool magnets and grinding heads. This led the team to conclude that the object disabling the rock abrasion tool was indeed a martian pebble.

  19. The Particle Puzzle

    NASA Video Gallery

    This video explores the complexity of atmospheric aerosols: how they impact climate and how researchers study them. Glory's Aerosol Polarimetry Sensor and Cloud Camera will provide an unprecedented...

  20. X-ray illumination of globular cluster puzzles. [globular cluster X ray sources as clues to Milky Way Galaxy age and evolution

    NASA Technical Reports Server (NTRS)

    Lightman, A. P.; Grindlay, J. E.

    1982-01-01

    Globular clusters are thought to be among the oldest objects in the Galaxy, and provide, in this connection, important clues for determining the age and process of formation of the Galaxy. The present investigation is concerned with puzzles relating to the X-ray emission of globular clusters, taking into account questions regarding the location of X-ray emitting clusters (XEGC) unusually near the galactic plane and/or galactic center. An adopted model is discussed for the nature, formation, and lifetime of X-ray sources in globular clusters. An analysis of the available data is conducted in connection with a search for correlations between binary formation time scales, central relaxation times, galactic locations, and X-ray emission. The positive correlation found between distance from galactic center and two-body binary formation time for globular clusters, explanations for this correlation, and the hypothesis that X-ray sources in globular clusters require binary star systems provide a possible explanation of the considered puzzles.

  1. Putting the Whole Grain Puzzle Together: Health Benefits Associated with Whole Grains—Summary of American Society for Nutrition 2010 Satellite Symposium123

    PubMed Central

    Jonnalagadda, Satya S.; Harnack, Lisa; Hai Liu, Rui; McKeown, Nicola; Seal, Chris; Liu, Simin; Fahey, George C.

    2011-01-01

    The symposium “Putting the Whole Grain Puzzle Together: Health Benefits Associated with Whole Grains” sponsored by the ASN brought together researchers to review the evidence regarding the health benefits associated with whole grains. Current scientific evidence indicates that whole grains play an important role in lowering the risk of chronic diseases, such as coronary heart disease, diabetes, and cancer, and also contribute to body weight management and gastrointestinal health. The essential macro- and micronutrients, along with the phytonutrients present in whole grains, synergistically contribute to their beneficial effects. Current evidence lends credence to the recommendations to incorporate whole grain foods into a healthy diet and lifestyle program. The symposium also highlighted the need for further research to examine the role of whole grain foods in disease prevention and management to gain a better understanding of their mechanisms of action. PMID:21451131

  2. Cross-linking of the extracellular matrix by the maillard reaction in aging and diabetes: an update on "a puzzle nearing resolution".

    PubMed

    Monnier, Vincent M; Mustata, Georgian T; Biemel, Klaus L; Reihl, Oliver; Lederer, Marcus O; Zhenyu, Dai; Sell, David R

    2005-06-01

    The aging extracellular matrix is characterized by an age-related increase in insolubilization, yellowing, and stiffening, all of which can be mimicked by the Maillard reaction in vitro. These phenomena are accelerated in metabolic diseases such as diabetes and end-stage renal disease, which have in common with physiological aging the accumulation of various glycation products and cross-links. Eight years ago we concluded that the evidence favored oxidative cross-linking in experimental diabetes [Monnier, V.M. et al. 1996. The mechanism of collagen cross-linking in diabetes: a puzzle nearing completion. Diabetes 45(Suppl. 3): 67-72] and proposed a major role for a putative non-UV active cross-link derived from glucose. Below, we provide an update of the field that leads to the conclusion that, while oxidation might be important for Maillard reaction-mediated cross-linking via Strecker degradation and allysine formation, the single most important collagen cross-link known to date in diabetes and aging is glucosepane, a lysyl-arginine cross-link that forms under nonoxidative conditions. PMID:16037276

  3. Multicomponent Molecular Puzzles for Photofunction Design: Emission Color Variation in Lewis Acid-Base Pair Crystals Coupled with Guest-to-Host Charge Transfer Excitation.

    PubMed

    Ono, Toshikazu; Sugimoto, Manabu; Hisaeda, Yoshio

    2015-08-01

    Simple yet ubiquitous multimolecular assembly systems with color-tunable emissions are realized by cooperative electron donor-acceptor interactions, such as the boron-nitrogen (B-N) dative bond as a Lewis acid-base pair and charge transfer (CT) interactions. These are ternary-component systems consisting of a naphthalenediimide derivative (NDI), tris(pentafluorophenyl)borane (TPFB), and aromatic molecules (guest) with an NDI:TPFB:guest ratio of 1:2:2. The crystal shows guest-dependent color-tunable emissions such as deep blue to orange when a guest molecule of benzene is replaced with other π-conjugated systems. A good correlation between the emission wavelength and ionization potential of the guest and electronic structure calculations indicated that the emission is due to the CT transition from the guest to the NDI. The present study suggests that a rational solution of multcomponent molecular puzzles would be useful for obtaining novel photofunctional solid-state systems. PMID:26211567

  4. Long term puzzles of the CH and CD energetics and related phenomena revisited; solutions sought through REMPI-photofragmentations of bromomethanes.

    PubMed

    Hafliðason, Arnar; Wang, Huasheng; Kvaran, Ágúst

    2016-01-21

    Ever since the pioneering work by Herzberg and Johns in 1969 (The Astrophysical Journal, 1969, 158, 399) the spectral assignment and the energetics of the fundamental molecular fragment CH, in the region of 63 000-65 000 cm(-1) (7.81-8.06 eV), have remained a puzzle to a large extent. The dissociation of bromoform and deuterated bromoform following two-photon resonance excitations to molecular Rydberg states forms the fragment species CH* and CD* in the excited state A(2)Δ(v' =0) as well as carbon and bromine atoms in the ground and first excited states, C/C* and Br/Br*. Further (1r + 1i)REMPI of CH* and CD* resonance excites the fragments to the energy region of concern, whereas the atom fragments were identified by further (2r + 1i)REMPI. Analysis based on spectral simulations, isotope shifts and comparison with other data allowed spectral identifications, assignments and partial characterization of four highly excited bound states for each of the molecular fragments (CH**/CD**); including the (3)(2)Π valence state and the (4)(2)Π Rydberg state, for the first time. Perturbations, shown as line-shifts, line-intensity and/or line-width alterations, due to the level-to-level state interactions between the bound states and predissociations by a repulsive state are recognized. Recording of C(+) signals in REMPI of several bromomethanes for a one-photon energy of about 40 333 cm(-1) allows the clarification of a mystery concerning a broad C(+) band frequently observed. This work, presented, demonstrates the usefulness of molecular REMPI for fragment analysis. PMID:26674135

  5. Unraveling a 146 Years Old Taxonomic Puzzle: Validation of Malabar Snakehead, Species-Status and Its Relevance for Channid Systematics and Evolution

    PubMed Central

    Anvar Ali, Palakkaparambil Hamsa; Sukumaran, Mithun; Tharian, Josin C.; Dahanukar, Neelesh; Baby, Fibin; Peter, Reynold; Devi, Karunakaran Rema; Radhakrishnan, Kizhakke Veetil; Haniffa, Mohamed AbdulKather; Britz, Ralf; Antunes, Agostinho

    2011-01-01

    Background The Malabar snakehead Channa diplogramma is one of the most enigmatic and least understood species within the family Channidae, which comprise one of the most important groups of freshwater food fish in tropical Asia. Since its description from peninsular India in 1865, it has remained a taxonomic puzzle with many researchers questioning its validity, based on its striking similarity with the South East Asian C. micropeltes. In this study, we assessed the identity of the Malabar snakehead, C. diplogramma, using morphological and molecular genetic analyses, and also evaluated its phylogenetic relationships and evolutionary biogeography. Methodology/Principal Findings The morphometric and meristic analysis provided conclusive evidence to separate C. diplogramma and C. micropeltes as two distinct species. Number of caudal fin rays, lateral line scales, scales below lateral line; total vertebrae, pre-anal length and body depth were the most prominent characters that can be used to differentiate both the species. Channa diplogramma also shows several ontogenic color phases during its life history, which is shared with C. micropeltes. Finally, the genetic distance between both species for the partial mitochondrial 16S rRNA and COI sequences is also well above the intra-specific genetic distances of any other channid species compared in this study. Conclusions/Significance The current distribution of C. diplogramma and C. micropeltes is best explained by vicariance. The significant variation in the key taxonomic characters and the results of the molecular marker analysis points towards an allopatric speciation event or vicariant divergence from a common ancestor, which molecular data suggests to have occurred as early as 21.76 million years ago. The resurrection of C. diplogramma from the synonymy of C. micropeltes has hence been confirmed 146 years after its initial description and 134 years after it was synonymised, establishing it is an endemic species of

  6. Slow Proton Transfer Coupled to Unfolding Explains the Puzzling Results of Single-Molecule Experiments on BBL, a Paradigmatic Downhill Folding Protein

    PubMed Central

    Cerminara, Michele; Campos, Luis A.; Ramanathan, Ravishankar; Muñoz, Victor

    2013-01-01

    A battery of thermodynamic, kinetic, and structural approaches has indicated that the small α-helical protein BBL folds-unfolds via the one-state downhill scenario. Yet, single-molecule fluorescence spectroscopy offers a more conflicting view. Single-molecule experiments at pH 6 show a unique half-unfolded conformational ensemble at mid denaturation, whereas other experiments performed at higher pH show a bimodal distribution, as expected for two-state folding. Here we use thermodynamic and laser T-jump kinetic experiments combined with theoretical modeling to investigate the pH dependence of BBL stability, folding kinetics and mechanism within the pH 6–11 range. We find that BBL unfolding is tightly coupled to the protonation of one of its residues with an apparent pKa of ∼7. Therefore, in chemical denaturation experiments around neutral pH BBL unfolds gradually, and also converts in binary fashion to the protonated species. Moreover, under the single-molecule experimental conditions (denaturant midpoint and 279 K), we observe that proton transfer is much slower than the ∼15 microseconds folding-unfolding kinetics of BBL. The relaxation kinetics is distinctly biphasic, and the overall relaxation time (i.e. 0.2–0.5 ms) becomes controlled by the proton transfer step. We then show that a simple theoretical model of protein folding coupled to proton transfer explains quantitatively all these results as well as the two sets of single-molecule experiments, including their more puzzling features. Interestingly, this analysis suggests that BBL unfolds following a one-state downhill folding mechanism at all conditions. Accordingly, the source of the bimodal distributions observed during denaturation at pH 7–8 is the splitting of the unique conformational ensemble of BBL onto two slowly inter-converting protonation species. Both, the unprotonated and protonated species unfold gradually (one-state downhill), but they exhibit different degree of unfolding at any

  7. Puzzling With Online Games (BAM-COG): Reliability, Validity, and Feasibility of an Online Self-Monitor for Cognitive Performance in Aging Adults

    PubMed Central

    Baars, Maria A E; Olde Rikkert, Marcel G M; Kessels, Roy P C

    2013-01-01

    Background Online interventions are aiming increasingly at cognitive outcome measures but so far no easy and fast self-monitors for cognition have been validated or proven reliable and feasible. Objective This study examines a new instrument called the Brain Aging Monitor–Cognitive Assessment Battery (BAM-COG) for its alternate forms reliability, face and content validity, and convergent and divergent validity. Also, reference values are provided. Methods The BAM-COG consists of four easily accessible, short, yet challenging puzzle games that have been developed to measure working memory (“Conveyer Belt”), visuospatial short-term memory (“Sunshine”), episodic recognition memory (“Viewpoint”), and planning (“Papyrinth”). A total of 641 participants were recruited for this study. Of these, 397 adults, 40 years and older (mean 54.9, SD 9.6), were eligible for analysis. Study participants played all games three times with 14 days in between sets. Face and content validity were based on expert opinion. Alternate forms reliability (AFR) was measured by comparing scores on different versions of the BAM-COG and expressed with an intraclass correlation (ICC: two-way mixed; consistency at 95%). Convergent validity (CV) was provided by comparing BAM-COG scores to gold-standard paper-and-pencil and computer-assisted cognitive assessment. Divergent validity (DV) was measured by comparing BAM-COG scores to the National Adult Reading Test IQ (NART-IQ) estimate. Both CV and DV are expressed as Spearman rho correlation coefficients. Results Three out of four games showed adequate results on AFR, CV, and DV measures. The games Conveyer Belt, Sunshine, and Papyrinth have AFR ICCs of .420, .426, and .645 respectively. Also, these games had good to very good CV correlations: rho=.577 (P=.001), rho=.669 (P<.001), and rho=.400 (P=.04), respectively. Last, as expected, DV correlations were low: rho=−.029 (P=.44), rho=−.029 (P=.45), and rho=−.134 (P=.28

  8. Structural comparison of Ag-Ge-S bulk glasses and thin films

    NASA Astrophysics Data System (ADS)

    Wang, Fei; Jain, Mukul; Dunn, Porter; de Leo, Carter; Boolchand, Punit

    2007-03-01

    Ternary glasses of composition (GeS3)1-xAgx (x=0.1 and 0.2) are studied in form of bulk and thin films. Bulk glasses are synthesized and examined in Raman scattering and SEM. Raman scattering results of bulk glasses show that with increasing x, an increasing fraction of the Ag additive enters the base glass as Ag^+ with S^-anions serving to form thiogermanate species with one, two and three non-bridging S^- species. SEM measurements of the bulk glass show the material is intrinsically phase separated. White colored islands are observed distributed in a dark base. The EDS measurements show islands are Ag rich and the base is relatively Ag deficient. The Ag rich islands are expected to be mainly glassy phase Ag2S. Thin films of same compositions are fabricated using thermal evaporation. Films are evaporated following two different procedures to prevent the material from spitting. One method was preheating outgas and the other method was using tungsten mesh wrapped boats. The stoichiometry and molecular structure of films under each procedure are analyzed by Raman scattering and SEM to be compared with bulk glasses.

  9. Materials Data on Ce3(AgGe)4 (SG:71) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  10. Acute toxicity, brine shrimp cytotoxicity, anthelmintic and relaxant potentials of fruits of Rubus fruticosus Agg

    PubMed Central

    2013-01-01

    Background Rubus fruticosus is used in tribal medicine as anthelmintic and an antispasmodic. In the current work, we investigated the anthelmintic and antispasmodic activities of crude methanol extract of fruits of R. fruticosus on scientific grounds. Acute toxicity and brine shrimp cytotoxicity activity of the extract were also performed. Methods Acute toxicity study of crude methanol extract of R. fruticosus was performed on mice. In vitro Brine shrimp cytotoxicity assay was performed on shrimps of Artemia salina. In vitro Anthelmintic activity was tested against Raillietina spiralis and Ascaridia galli. Relaxant activities were tested on spontaneous rabbits’ jejunal preparations. Calcium chloride curves were constructed to elucidate possible mode of action of the extract. Results LD 50 of the extract for acute toxicity studies was 887.75 ± 9.22 mg/ml. While CC 50 of the extract for Brine shrimps cytotoxicity assay was 13.28 ± 2.47 μg/ml. Test samples of crude methanolic extract of R. fruticosus (Rf.Cr) at concentration 20 mg/ml showed excellent anthelmintic activity against Raillietina spiralis. Anthelmintic activity was 1.37 times of albendazole against the Raillietina spiralis at concentration 40 mg/ml. At higher concentration (40 mg/ml), Rf.Cr has 89. 83% parasiticidal activity. The mean EC50 relaxation activity for spontaneous and KCl-induced contractions was 7.96 ± 0.1 and 6.45 ± 0.29 mg/ml, respectively. EC 50 (Log[Ca++]M) for control calcium chloride curves was −1.75 ± 0.01 vs. EC 50 −1.78 ± 0.06 in the presence of 3.0 mg/ml of Rf.Cr. Similarly, EC 50(Log[Ca++]M) in the absence and presence of verapamil (0.1 μM) were −2.46 ± 0.01 and −1.72 ± 0.02, respectively. Conclusions The anthelmintic and relaxant activities explained traditional uses of R. fruticosus on scientific grounds. Relaxant activity follows the inhibition of voltage gated channels. Although the plant extract has cytotoxic effects, yet it is evident from acute toxicity study that it is safe in concentration 100 mg/kg. Further work is required to isolate pharmacologically active compounds. PMID:23773797

  11. Telomere replication: poised but puzzling

    PubMed Central

    Sampathi, Shilpa; Chai, Weihang

    2011-01-01

    Abstract Faithful replication of chromosomes is essential for maintaining genome stability. Telomeres, the chromosomal termini, pose quite a challenge to replication machinery due to the complexity in their structures and sequences. Efficient and complete replication of chromosomes is critical to prevent aberrant telomeres as well as to avoid unnecessary loss of telomere DNA. Compelling evidence supports the emerging picture of synergistic actions between DNA replication proteins and telomere protective components in telomere synthesis. This review discusses the actions of various replication and telomere-specific binding proteins that ensure accurate telomere replication and their roles in telomere maintenance and protection. PMID:21122064

  12. The Middle East population puzzle.

    PubMed

    Omran, A R; Roudi, F

    1993-07-01

    An overview is provided of Middle Eastern countries on the following topics; population change, epidemiological transition theory and 4 patterns of transition in the middle East, transition in causes of death, infant mortality declines, war mortality, fertility, family planning, age and sex composition, ethnicity, educational status, urbanization, labor force, international labor migration, refugees, Jewish immigration, families, marriage patterns, and future growth. The Middle East is geographically defined as Bahrain, Egypt, Iraq, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, United Arab Emirates, Yemen, Gaza and the West Bank, Iran, Turkey, and Israel. The Middle East's population grew very little until 1990 when the population was 43 million. Population was about doubled in the mid-1950s at 80 million. Rapid growth occurred after 1950 with declines in mortality due to widespread disease control and sanitation efforts. Countries are grouped in the following ways: persistent high fertility and declining mortality with low to medium socioeconomic conditions (Jordan, Oman, Syria, Yemen, and the West Bank and Gaza), declining fertility and mortality in intermediate socioeconomic development (Egypt, Lebanon, Turkey, and Iran), high fertility and declining mortality in high socioeconomic conditions (Bahrain, Iraq, Kuwait, Qatar, Saudi Arabia, and the United Arab Emirates), and low fertility and mortality in average socioeconomic conditions (Israel). As birth and death rates decline, there is an accompanying shift from communicable diseases to degenerative diseases and increases in life expectancy; this pattern is reflected in the available data from Egypt, Kuwait, and Israel. High infant and child mortality tends to remain a problem throughout the Middle East, with the exception of Israel and the Gulf States. War casualties are undetermined, yet have not impeded the fastest growing population growth rate in the world. The average fertility is 5 births/woman by the age of 45. Muslim countries tend to have larger families. Contraceptive use is low in the region, with the exception of Turkey and Egypt and among urban and educated populations. More than 40% of the population is under 15 years of age. The region is about 50% Arabic (140 million). Educational status has increased, particularly for men; the lowest literacy rates for women are in Yemen and Egypt. The largest countries are Iran, Turkey, and Egypt. PMID:12318382

  13. Imaginary Continents: A Geologic Puzzle.

    ERIC Educational Resources Information Center

    Bartholomew, Rolland, B.; And Others

    1978-01-01

    Reproduces the contents of a CEEP instructional module on the concept of radioactive decay. Includes objectives, materials, procedure, and summary questions. Reproducable illustrations also included. (MA)

  14. The evolutionary puzzle of suicide.

    PubMed

    Aubin, Henri-Jean; Berlin, Ivan; Kornreich, Charles

    2013-12-01

    Mechanisms of self-destruction are difficult to reconcile with evolution's first rule of thumb: survive and reproduce. However, evolutionary success ultimately depends on inclusive fitness. The altruistic suicide hypothesis posits that the presence of low reproductive potential and burdensomeness toward kin can increase the inclusive fitness payoff of self-removal. The bargaining hypothesis assumes that suicide attempts could function as an honest signal of need. The payoff may be positive if the suicidal person has a low reproductive potential. The parasite manipulation hypothesis is founded on the rodent-Toxoplasma gondii host-parasite model, in which the parasite induces a "suicidal" feline attraction that allows the parasite to complete its life cycle. Interestingly, latent infection by T. gondii has been shown to cause behavioral alterations in humans, including increased suicide attempts. Finally, we discuss how suicide risk factors can be understood as nonadaptive byproducts of evolved mechanisms that malfunction. Although most of the mechanisms proposed in this article are largely speculative, the hypotheses that we raise accept self-destructive behavior within the framework of evolutionary theory. PMID:24351787

  15. The Gran Sasso muon puzzle

    SciTech Connect

    Fernandez-Martinez, Enrique; Mahbubani, Rakhi E-mail: rakhi@cern.ch

    2012-07-01

    We carry out a time-series analysis of the combined data from three experiments measuring the cosmic muon flux at the Gran Sasso laboratory, at a depth of 3800 m.w.e. These data, taken by the MACRO, LVD and Borexino experiments, span a period of over 20 years, and correspond to muons with a threshold energy, at sea level, of around 1.3 TeV. We compare the best-fit period and phase of the full muon data set with the combined DAMA/NaI and DAMA/LIBRA data, which spans the same time period, as a test of the hypothesis that the cosmic ray muon flux is responsible for the annual modulation detected by DAMA. We find in the muon data a large-amplitude fluctuation with a period of around one year, and a phase that is incompatible with that of the DAMA modulation at 5.2σ. Aside from this annual variation, the muon data also contains a further significant modulation with a period between 10 and 11 years and a power well above the 99.9% C.L threshold for noise, whose phase corresponds well with the solar cycle: a surprising observation for such high energy muons. We do not see this same period in the stratospheric temperature data.

  16. Paradoxes, puzzles and passing time.

    PubMed

    Rankin-Box, D

    1999-12-01

    Whilst technology and our understanding about the world has improved, I suspect that in many ways, the hopes, fears, worries, joy and love we feel are not so different from that of our ancestors of 500 or 700 years ago, though the social circumstances may have altered. We have beliefs and dreams and daily routines in our lives and many people hang onto age old superstitions without really knowing their origins, e.g. crossing our fingers for luck, touching wood, throwing salt over a shoulder or reading about star signs. The night sky also looks different to 1000 years ago. When we look up at the stars we see an image of the past in the present: the light we see set off from its origin long before the advent of antibiotics, the Russian Revolution or the first man on the moon. As we move forwards, the benefits of modern medicine and improvements in social and environmental issues (compared to just 100 years ago) have, paradoxically, provided us with a quality of life that allows us to live longer and gain a greater insight into the world around us. There is an opportunity to reflect and wonder at the healers of the early middle ages and of the way in which we wish medicine to develop. When reflecting about the past 1000 years, patterns begin to emerge of times past, epochs of healing and revolutions in the way we perceive myriad aspects of health and healing. I am sure there are ways of combining ancient ways with modern thinking, of blending art and science, of balancing logic and rationality with love, fun, humour and empathy. Of building on experience, so that caring is spiritually therapeutic, freeing our patients and ourselves as we move into the future and the new millennium. PMID:10887877

  17. The Puzzle of Septarian Concretions

    NASA Astrophysics Data System (ADS)

    John, C. M.; Dale, A.; Mozley, P.; Smalley, P. C.; Muggeridge, A. H.

    2014-12-01

    Carbonate concretions in clastic rocks and their septarian fracture fills act as 'time capsules', capturing the signatures of chemical and biological processes during diagenesis. However, many aspects of the formation of concretions and septarian fractures remain poorly understood, for although concretions occur in clastic rocks throughout the geological record, they are rarely documented in recent shallow-burial environments. Consequently, the depth and temperature at which concretion-forming processes occur are often poorly constrained. Carbonate clumped isotopes have recently been applied successfully to concretions and fracture fills that begin to unravel the conditions for the formation of concretions and septarian fractures. Here, we present carbonate clumped isotope results of fracture fills from eight different concretions from various locations, including multiple phases of fill in 4 concretions. Our results suggest that they precipitated over a range of temperatures (22°C - 85°C) from d18Oporewater values between -12‰ to 3‰ and within different d13Ccarbonate zones. The majority of fills precipitated at lower (<50°C) temperatures, although the fluids were not always meteoric. For 3 concretions containing fractures with multiple phases, the d18Oporewater becomes progressively heavier with each later phase and increasing temperature. The one exception to this is in the Barton Clay Formation (UK) where the fractures must have been continuously filled during exhumation as the latest cement phase is the coolest with a d18Oporewater more 18O-depleted than the earliest phase. Therefore, concretion growth must usually initiate early on (<~1 km burial), and subsequent fracturing is also usually early. However, the fracture infilling can occur over a range of depths and can record the diagenetic history of a formation. We gratefully acknowledge a BP and EPSRC Case Studentship for funding this project, and the Natural History Museum London for providing samples.

  18. Solving the Assistant Principal's Puzzle

    ERIC Educational Resources Information Center

    Hartley, Douglas

    2009-01-01

    How does an assistant principal complete the large number of managerial duties and, at the same time, serve as a credible instructional leader? This book provides practical recommendations for successfully filling the dual role as manager and instructional leader, building effective relationships, using power appropriately, and productively…

  19. Plant Puzzles, An Environmental Investigation.

    ERIC Educational Resources Information Center

    National Wildlife Federation, Washington, DC.

    This environmental unit is one of a series designed for integration within an existing curriculum. The unit is self-contained and requires minimal teacher preparation. The philosophy of the units is based on an experience-oriented process that encourages self-paced independent student work. The purpose of this unit is to familiarize students with…

  20. A Puzzle in Elementary Ballistics.

    ERIC Educational Resources Information Center

    Haugland, Ole Anton

    1983-01-01

    Provides an answer to the question of why it is easy to miss when shooting uphill or downhill. Experimental results indicate that when shooting uphill or downhill, sight should not be adjusted to actual distance but to distance multiplied by the cosine of the inclination angle. (JN)

  1. Puzzling Facts From Lunar Exploration

    ERIC Educational Resources Information Center

    Page, Thornton

    1973-01-01

    Inconsistencies have arisen between earth-bound observations and data collected from space probes. These inconsistencies center on the moon's structure, temperature, magnetization, composition, and origin. (DF)

  2. The puzzle of monogamous marriage

    PubMed Central

    Henrich, Joseph; Boyd, Robert; Richerson, Peter J.

    2012-01-01

    The anthropological record indicates that approximately 85 per cent of human societies have permitted men to have more than one wife (polygynous marriage), and both empirical and evolutionary considerations suggest that large absolute differences in wealth should favour more polygynous marriages. Yet, monogamous marriage has spread across Europe, and more recently across the globe, even as absolute wealth differences have expanded. Here, we develop and explore the hypothesis that the norms and institutions that compose the modern package of monogamous marriage have been favoured by cultural evolution because of their group-beneficial effects—promoting success in inter-group competition. In suppressing intrasexual competition and reducing the size of the pool of unmarried men, normative monogamy reduces crime rates, including rape, murder, assault, robbery and fraud, as well as decreasing personal abuses. By assuaging the competition for younger brides, normative monogamy decreases (i) the spousal age gap, (ii) fertility, and (iii) gender inequality. By shifting male efforts from seeking wives to paternal investment, normative monogamy increases savings, child investment and economic productivity. By increasing the relatedness within households, normative monogamy reduces intra-household conflict, leading to lower rates of child neglect, abuse, accidental death and homicide. These predictions are tested using converging lines of evidence from across the human sciences. PMID:22271782

  3. Reviewing the Puzzle of CLIL

    ERIC Educational Resources Information Center

    Ioannou Georgiou, Sophie

    2012-01-01

    Content and language integrated learning (CLIL) has become a well-known term for foreign language teachers and language researchers. A little more than a decade ago, it was a term unheard of in most staff rooms or professional conferences. This paper seeks to define CLIL and to look into the reasons that have propelled it to widespread adoption.…

  4. Oki-Doku: Number Puzzles

    ERIC Educational Resources Information Center

    Gomez, Cristina; Novak, Dani

    2014-01-01

    The Common Core State Standards for Mathematics (CCSSM) (CCSSI 2010) emphasize the Standards for Mathematical Practice (SMP) that describe processes and proficiencies included in the NCTM Process Standards (NCTM 2000) and in the Strands for Mathematical Proficiency (NRC 2001). The development of these mathematical practices should happen in…

  5. Community College a Research Puzzle

    ERIC Educational Resources Information Center

    Viadero, Debra

    2009-01-01

    When President Barack Obama unveiled his plans this summer for a $12 billion federal investment in the nation's community colleges, he said he wanted the initiative to yield an additional 5 million community college graduates by 2020. Research suggests that reaching that goal may be a tall order. Community colleges have abysmal graduation rates:…

  6. The Church/State Puzzle.

    ERIC Educational Resources Information Center

    Holmes, Cecile S.

    2002-01-01

    Describes appropriate school district policies and procedures in light of two U.S. Supreme Court religion-in-schools decisions: "Santa Fe Independent School District v. Doe" and "The Good News Club v. Milford Central School." (PKP)

  7. Superoxide dismutase: an evolutionary puzzle

    SciTech Connect

    Lee, Y.M.; Friedman, D.J.; Ayala, F.J.

    1985-02-01

    The authors have obtained the complete amino acid sequence of copper/zinc-containing superoxide dismutase (SOD, superoxide:superoxide oxidoreductase, EC 1.15.1.1) from Drosophila melanogaster. The sequence of this enzyme is also known for man, horse, cow, and the yeast Saccharomyces cerevisiae. The rate of evolution of this enzyme is far from constant. The number of amino acid substitutions per 100 residues per 100 million years is 30.9 when the three mammals are compared to each other, 10.6 when Drosophila is compared to the three mammals, and 5.8 when the yeast is compared to the four animals. The first value represents one of the fastest evolutionary rates for any protein, the second is similar to the globin rate, and the third is similar to some cytochromes and other slowly evolving proteins. Hence, SOD is not acceptable evolutionary clock. Another peculiarity of this enzyme is that a two-amino-acid deletion must have occurred independently in the lineages going to the cow and to Drosophila. The authors conclude that using the primary structure of a single gene or protein to time evolutionary events or to reconstruct phylogenetic relationships is potentially fraught with error.

  8. The toxin and antidote puzzle

    PubMed Central

    2011-01-01

    Insects carry out essential ecological functions, such as pollination, but also cause extensive damage to agricultural crops and transmit human diseases such as malaria and dengue fever. Advances in insect transgenesis are making it increasingly feasible to engineer genes conferring desirable phenotypes, and gene drive systems are required to spread these genes into wild populations. Medea provides one solution, being able to spread into a population from very low initial frequencies through the action of a maternally-expressed toxin linked to a zygotically-expressed antidote. Several other toxin-antidote combinations are imaginable that distort the offspring ratio in favor of a desired transgene, or drive the population towards an all-male crash. We explore two such systems—Semele, which is capable of spreading a desired transgene into an isolated population in a confined manner; and Merea, which is capable of inducing a local population crash when located on the Z chromosome of a Lepidopteron pest. PMID:21876382

  9. Puzzling Snowballs: Main Belt Comets

    NASA Astrophysics Data System (ADS)

    Yang, Bin; Meech, Karen

    2015-03-01

    Main belt comets (MBCs) are a class of newly discovered objects that exhibit comet-like appearances and yet are dynamically indistinguishable from ordinary main belt asteroids. The measured size and albedo of MBCs are similar to those of classical comets. At present, six MBCs have been discovered, namely 133P/Elst-Pizarro, 176P/LINEAR, 238P/Read, P/2008 R1, P/La Sagra and P/2006 VW139. The total number of active MBCs is estimated to be at the level of a few hundreds (Hsieh & Jewitt, 2006). Several explanations for the activity of MBCs have been suggested. These include impact ejection, sublimation and rotational instability. However, since renewed activity has been observed in 133P and 238P at successive perihelion passages, the most likely explanation may be a thermally-driven process - e.g sublimation of exposed surface ice. Although the proximity of MBCs to the Sun (r ~ 3 AU) makes the survival of surface ice improbable, thermal models have shown that water ice is thermally stable under a regolith layer a few meters thick. The study of MBCs has recently been complicated by the discoveries of two asteroid collisional events (P/2010 A2 (LINEAR) and (596) Scheila) in 2010, where comet-like dust coma/tail have been attributed to recent impacts. If MBCs are indeed icy, they represent the closest and the third established reservoir of comets (after the Oort cloud and the Kuiper belt). As such, they may have been an important source of water for the Earth's oceans. I will review the current state of MBC studies, present the latest observational results and discuss possible mechanisms that could produce the observed activity. I will also talk about current and future space missions that are dedicated or closely related to MBC studies.

  10. Solving the centriole disengagement puzzle.

    PubMed

    Fry, Andrew M

    2015-01-01

    The microcephaly protein, Cep215, contributes to the engagement of duplicated centrioles in interphase. Now two distinct pools of Cep215 at centrosomes are identified, one bound to Cep68 and the other to pericentrin. Plk1-mediated degradation of Cep68 and separase-mediated cleavage of pericentrin release both pools of Cep215, thereby promoting centriole disengagement. PMID:25679029

  11. Teaching Boys: A Relational Puzzle

    ERIC Educational Resources Information Center

    Raider-Roth, Miriam B.; Albert, Marta K.; Bircann-Barkey, Ingrid; Gidseg, Eric; Murray, Terry

    2008-01-01

    Focus of Study: This article investigates how teachers' relationships with boys can be central in bolstering boys' resilience and connection to their work in schools. Specifically, we examine how teachers understand the ways that their relationships with boys shape their teaching practice as well as their understandings of boys' learning in…

  12. Scientists Puzzle Over Acid Rain

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1975

    1975-01-01

    Reports on a growing concern over increased acidity in atmospheric percipitation. Explores possible causes of the increased acidity, identifies chemical components of precipitation in various parts of the world, and presents environmental changes that might be attributed to the acidity. (GS)

  13. Anorexia nervosa: an evolutionary puzzle.

    PubMed

    Gatward, Nicholas

    2007-01-01

    Anorexia nervosa (AN) has proven difficult to explain and is especially so from an evolutionary perspective. It is widespread, has probably existed for centuries and includes a genetic component but leads to starvation, infertility and sometimes death. An attempt to explain AN will be made using a synthesis of evolutionary ideas about responses to threat. Dietary restriction is described as a response to perceived threats of exclusion from the group, which would once have been dangerous. This can develop into AN only where the weight loss sets off an ancient adaptive response to the threat of famine. Eating again and weight gain would mean re-entering the competition for status and belonging and are therefore felt as threatening. This synthesis can explain the unusual mix of features found in AN that are otherwise resistant to explanation. PMID:17676667

  14. Morphological injury to cut-leaf teasel, Dipsacus laciniatus L. (Dipsacaceae) induced by the eriophyid mite Leipothrix dipsacivagus Petanovic et Rector (Acari: Eriophyoidea)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The eriophyid mite Leipothrix dipsacivagus Petanovic et Rector provokes severe malformations to its host plant, cut-leaf teasel (Dipsacus laciniatus L.), in the field. These injuries were examined at the morpho-anatomical level in infested plants collected in the field and experimentally infested p...

  15. Phenotypic Differences Among Leipothrix dipsacivagus Pet. et Rector and L. knautiae (Liro) (Acari: Prostigmata: Eriophyidae) Populations Inhabiting Dipsacus L. and Knautia L. (Dipsacaceae) Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Only three eriophyoid mite species of the genus Leipothrix Keifer are known to occur on dipsacaceous plants including hosts in the genera Knautia (L.) Succisa Haller, and Dipsacus L.. These three species are similar, but differ in few key characters. Description of eriophyoids includes over 250 char...

  16. Reviews Equipment: BioLite Camp Stove Game: Burnout Paradise Equipment: 850 Universal interface and Capstone software Equipment: xllogger Book: Science Magic Tricks and Puzzles Equipment: Spinthariscope Equipment: DC Power Supply HY5002 Web Watch

    NASA Astrophysics Data System (ADS)

    2013-05-01

    WE RECOMMEND BioLite CampStove Robust and multifaceted stove illuminates physics concepts 850 Universal interface and Capstone software Powerful data-acquisition system offers many options for student experiments and demonstrations xllogger Obtaining results is far from an uphill struggle with this easy-to-use datalogger Science Magic Tricks and Puzzles Small but perfectly formed and inexpensive book packed with 'magic-of-science' demonstrations Spinthariscope Kit for older students to have the memorable experience of 'seeing' radioactivity WORTH A LOOK DC Power Supply HY5002 Solid and effective, but noisy and lacks portability HANDLE WITH CARE Burnout Paradise Car computer game may be quick off the mark, but goes nowhere fast when it comes to lab use WEB WATCH 'Live' tube map and free apps would be a useful addition to school physics, but maths-questions website of no more use than a textbook

  17. A novel mutation, IVS2-2AgG, associated with acute intermittent porphyria in a Chinese family.

    PubMed

    Jiao, Huang; Xianfeng, Zhang; Hui, Han; Yuhong, Zhan; Chu, Zhang

    2015-08-01

    Porphyria is a group of disorders caused by the accumulation of porphyrin and porphyrin precursors due to the abnormalities in certain enzymes that normally participate in the production of haem. We report a case of a woman with severe menstruation-related abdominal pain, hyponatraemia, and psychiatric symptoms. Excessive porphobilinogen was found in her urine. A new mutation in intron 2 (IVS2-2Ag→G), which had never previously been reported in patients with porphyria or in healthy Chinese population, was identified in the heterozygous state in the patient and her mother. PMID:26228342

  18. Nursing education: current themes, puzzles and paradoxes.

    PubMed

    Tanner, Christine A

    2007-01-01

    It would be tempting to declare that transformation of nursing education in the current context of faculty shortages and other scarce resources as Mission Impossible. But I believe that the opposite is true. It is my sense that the rapid changes in healthcare, the shifting population needs and the acute nursing shortage have catalyzed fundamental change, perhaps the most profound in the 50 year history of WIN. The first steps of that transformation are becoming increasingly apparent as nursing faculty begin to challenge their long-standing, taken-for-granted assumptions; as they set aside differences and their internecine warfare of the entry-into-practice debates; as they begin stronger and deeper collaborations with their clinical partners. We won't see the evidence of these changes in the literature for a while, because they are just getting started. There's not a lot to report yet. Here are some examples of the changes afoot: The Oregon Consortium for Nursing Education has resulted from unprecedented collaboration between community college and university faculty, with an eye to develop a standard, competency-based curriculum to prepare the "new" nurse, and to improve access to a seamless baccalaureate curriculum. The first students were enrolled in nursing courses in fall, 2006 on 8 campuses--the four campuses of OHSU and 4 community colleges, with additional community college campuses admitting students in '07 and '08. In this curriculum, fundamentals of nursing have been redefined as evidence-based practice, culturally sensitive and relationship-centered care, leadership and clinical judgment, with these concepts and others introduced early and spiraled throughout the curriculum. Through a 2-year faculty development program, faculty leaders in the OCNE partner programs have taken to heart the many lessons about learning, intentionally attending to content selection that will help reduce the volume while focusing on the most prevalent. Instructional approaches have been tremendously changed, with an emphasis on case-based instruction, integrating distance delivery technologies, and using simulation, drawing on best practices in the development of these approaches (Billings, et al., 2001; Issenberg, et al .2005; Jeffries, 2005). OCNE leaders obtained funding from Kaiser Permanente Northwest to begin the long, collaborative, consensus building process to transform clinical education. Evaluation has and will continue to be an integral part of this work, with an eye to adding to our collective knowledge of best practices in nursing education. We see evidence of similar efforts, mostly state or regional, in order to build on prior alliances, acknowledge geographic particularities, and respond to local needs in many other parts of the country, from Hawaii to New Jersey, Texas to Montana. The nursing shortage has been a primary catalyst. It has captured the interest of potential funders, individual donors, foundations to the Federal government. The keys are collaboration and a collective voice for nursing, a willingness to work through long-standing and divisive issues, and most importantly, a moral commitment to the populations we serve. PMID:17900063

  19. The Schulhof Family: Solving the Age Puzzle

    NASA Astrophysics Data System (ADS)

    Vokrouhlický, David; Ďurech, Josef; Pravec, Petr; Kušnirák, Peter; Hornoch, Kamil; Vraštil, Jan; Krugly, Yurij N.; Inasaridze, Raguli Ya.; Ayvasian, Vova; Zhuzhunadze, Vasili; Molotov, Igor E.; Pray, Donald; Husárik, Marek; Pollock, Joseph T.; Nesvorný, David

    2016-03-01

    The Schulhof family, a tight cluster of small asteroids around the central main belt body (2384) Schulhof, belongs to a so far rare class of very young families (estimated ages less than 1 Myr). Characterization of these asteroid clusters may provide important insights into the physics of the catastrophic disruption of their parent body. The case of the Schulhof family has been up to now complicated by the existence of two proposed epochs of its origin. In this paper, we first use our own photometric observations, as well as archival data, to determine the rotation rate and spin axis orientation of the largest fragment (2384) Schulhof. Our data also allow us to better constrain the absolute magnitude of this asteroid, and thus also improve the determination of its geometric albedo. Next, using the up-to-date catalog of asteroid orbits, we perform a new search of smaller members in the Schulhof family, increasing their number by 50%. Finally, the available data are used to access Schulhof's family age anew. We now find that the younger of the previously proposed two ages of this family is not correct, resulting from a large orbital uncertainty of single-opposition members. Our new runs reveal a single age solution of about 800 kyr with a realistic uncertainty of 200 kyr.

  20. Solving the Kaonic-Helium Puzzle

    NASA Astrophysics Data System (ADS)

    Hayano, Ryugo S.; Beer, G.; Bhang, H.; Cargnelli, M.; Chiba, J.; Choi, S.; Curceanu, C.; Fukuda, Y.; Hanaki, T.; Iio, M.; Ishikawa, T.; Ishimoto, S.; Ishiwatari, T.; Itahashi, K.; Iwai, M.; Iwasaki, M.; Juhász, B.; Kienle, P.; Marton, J.; Matsuda, Y.; Ohnishi, H.; Okada, S.; Outa, H.; Sato, M.; Schmid, P.; Suzuki, S.; Suzuki, T.; Tatsuno, H.; Tomono, D.; Widmann, E.; Yamazaki, T.; Yim, H.; Zmeskal, J.

    We have measured the Balmer-series x-rays of kaonic 4He atoms using large-area silicon drift x-ray detectors (SDDs) in order to study the low-energy bar {K}-nucleus strong interaction. The energy of the 3d → 2p transition was determined to be 6467 ± 3(stat) ± 2(syst) eV. The resulting strong-interaction energy-level shift is in agreement with theoretical calculations, thus eliminating a long-standing discrepancy between theory and experiment.

  1. New Sellafield study poses a puzzle

    SciTech Connect

    Kingman, S.

    1993-10-29

    Three years ago, an epidemiological study rocked the nuclear industry by suggesting a link between exposure to radiation among men and leukemia in their children. The study, by the late British epidemiologist Martin Gardner, focused on workers at the Sellafield nuclear reprocessing plant in northwest England and had profound implications for the nuclear industry: If a causal link between exposure and cancer could be proven, occupational exposure limits to radiation would have to be tightened and British Nuclear Fuels, the operator of Sellafield, might be open to litigation from the affected children and their relatives. A new study by Britain's Health and Safety Executive (HSE) found only fragile evidence that long-term cumulative exposure to radiation by fathers before conception of their children was linked to an increased risk of the child developing leukemia and non-Hodgkins lymphoma. But in Seascale, 3 kilometers south of Sellafield, the rate of leukemia and non-Hodgkins lymphoma among children whose fathers worked in Sellafield and lived in Seascale when they were born was about 14 times the national average. The findings remain uncertain as to cause of the cancers.

  2. The puzzle of the triple repeats

    SciTech Connect

    Morell, V.

    1993-06-04

    Two years ago, when researchers discovered the gene that causes a hereditary form of mental retardation known as fragile-X syndrome, they also turned up a mutation so unexpected geneticists are still scratching their heads over it. The defect, which makes genes balloon in size by adding extra copies of a three base-pair repeated sequence of DNA, was the first of its kind. Despite decades of study, nothing like it had ever been seen in any of the species that laid the foundations for modern genetics: bacteria, the fruit fly Drosophila melanogaster, and the mouse. The mutations caused by these expanding trinucleotide repeats turned out be common causes of human disease. In the past 2 years, they have been fingered as the culprits in three hereditary disorders besides fragile-X syndrome: myotronic dystrophy, spinobullar muscular atrophy (also known as Kennedy's disease), and just this March-Huntington's disease. The FMR-1 gene, which is the one at fault in fragile-X syndrome, shows just how much the trinucleotide repeats can expand. The normal gene carries at most 50 copies of the CGG trinucleotide. But in children who inherit the gene from these carriers and actually develop mental retardation and the other fragile-X symptoms, the FMR-1 gene may have hundreds to thousands of CGG repeats. Huge expansions of another trinucleotide repeat (CTG) can also occur from one generation to the next in the gene that causes myotonic dystrophy (DM), while smaller, although no less devastating, expansions in the CAG trinucleotide repeat lead to Huntington's and Kennedy's diseases.

  3. Bequest Motives and the Annuity Puzzle

    PubMed Central

    Lockwood, Lee M.

    2011-01-01

    Few retirees annuitize any wealth, a fact that has so far defied explanation within the standard framework of forward-looking, expected utility-maximizing agents. Bequest motives seem a natural explanation. Yet the prevailing view is that people with plausible bequest motives should annuitize part of their wealth, and thus that bequest motives cannot explain why most people do not annuitize any wealth. I show, however, that people with plausible bequest motives are likely to be better off not annuitizing any wealth at available rates. The evidence suggests that bequest motives play a central role in limiting the demand for annuities. PMID:22822300

  4. ESA's Cluster solved an auroral puzzle

    NASA Astrophysics Data System (ADS)

    2003-05-01

    These aurorae - seen as bright spots in Earth’s atmosphere and called ‘dayside proton auroral spots’ - occur when fractures appear in the Earth’s magnetic field, allowing particles given out from the Sun to squirt through and collide with the molecules in our atmosphere. This is the first time that a precise and direct connection between the two events has been made. The Earth’s magnetic field acts like a shield, protecting Earth from the constant stream of tiny particles ejected by the Sun and known as the ‘solar wind’. The solar wind itself is made of hydrogen atoms, broken into their constituent pieces: protons and electrons. When electrons find routes into our atmosphere, they collide with and excite the atoms in the air. When these excited atoms release their energy, it is given out as light, creating the glowing ‘curtains’ we see as the aurora borealis (or the aurora australis in the southern hemisphere). Dayside proton auroral spots are caused by protons ‘stealing’ electrons from the atoms in our atmosphere. On 18 March last year, a jet of energetic solar protons collided with the Earth’s atmosphere and created a bright ‘spot’ seen by NASA’s IMAGE spacecraft, just as Cluster passed overhead and straight through the region where the proton jet was emanating. An extensive analysis of the Cluster results has now shown that the region was experiencing a turbulent event known as ‘magnetic reconnection’. Such a phenomenon takes place when the Earth’s usually impenetrable magnetic field fractures and has to find a new stable configuration. Until the field mends itself, solar protons leak through the gap and jet into Earth’s atmosphere creating the dayside proton aurora. Philippe Escoubet, ESA’s Cluster Project Scientist, comments, “Thanks to Cluster’s observations scientists can directly and firmly link for the first time a dayside proton auroral spot and a magnetic reconnection event.” Tai Phan, leading the investigation at the University of California, Berkeley, United States, now looks forward to a new way of studying the Earth’s protective shield. He says, “This result has opened up a new area of research. We can now watch dayside proton aurorae and use those observations to know where and how the cracks in the magnetic field are formed and how long the cracks remain open. That makes it a powerful tool to study the entry of the solar wind into the Earth’s magnetosphere.” The Earth’s interaction with the Sun is a current focus of scientific attention because of its importance in knowing how the Sun affects the Earth, most notably our climate. Also, while not immediately dangerous to us on Earth, it is also important for quantifying the danger to satellites, which can be damaged or destroyed by powerful solar flares. Note to Editors: Proton aurorae were globally imaged for the first time by NASA’s IMAGE spacecraft. The images revealed the presence of the ‘dayside proton auroral spots’. By a fortunate coincidence, IMAGE and Cluster both spotted the event on 18 March 2002. Combining with IMAGE’s observations, Cluster made it possible to establish the ground truth of the phenomenon. The paper on these results, Simultaneous Cluster and IMAGE Observations of Cusp Reconnection and Auroral Spot for Northward IMF by Tai Phan and 24 other authors will be published in Geophysical Research Letters, 21 May 2003, Vol. 30, No. 10. The principal investigators responsible for the instruments that made these results possible are: Henri Rème of CESR/Toulouse, France (Cluster Proton Detectors), Andre Balogh of Imperial College, London, United Kingdom (Cluster Magnetic Field Instrument) and Stephen Mende of University of California, Berkeley, United States (IMAGE/FUV). More about Cluster ESA’s Cluster is a collection of four spacecraft, launched on two Russian rockets during the summer of 2000. They are now flying in formation around the Earth, relaying the most detailed ever information about how the solar wind affects our planet in 3D. The solar wind is the perpetual str

  5. Solving flavor puzzles with quiver gauge theories

    NASA Astrophysics Data System (ADS)

    Antebi, Yaron E.; Nir, Yosef; Volansky, Tomer

    2006-04-01

    We consider a large class of models where the SU(5) gauge symmetry and a Froggatt-Nielsen (FN) Abelian flavor symmetry arise from a U(5)×U(5) quiver gauge theory. An intriguing feature of these models is a relation between the gauge representation and the horizontal charge, leading to a restricted set of possible FN charges. Requiring that quark masses are hierarchical, the lepton flavor structure is uniquely determined. In particular, neutrino mass anarchy is predicted.

  6. Astrochemistry: Fullerene solves an interstellar puzzle

    NASA Astrophysics Data System (ADS)

    Ehrenfreund, Pascale; Foing, Bernard

    2015-07-01

    Laboratory measurements confirm that a 'buckyball' ion is responsible for two near-infrared absorption features found in spectra of the interstellar medium, casting light on a century-old astrochemical mystery. See Letter p.322

  7. Child Exploitation: Some Pieces of the Puzzle.

    ERIC Educational Resources Information Center

    Rohlader, Dorothy

    The report addresses the status in North Carolina and in the nation of child exploitation. Legislative and judicial backgrounds of child pornography and child prostitution are reviewed, and difficulties in obtaining statistical data are noted. Law enforcement issues in pornography are cited, and suggestions for further legislation regarding child…

  8. The puzzle of {sup 32}Mg

    SciTech Connect

    Fortune, H. T.

    2011-08-15

    An analysis of results of the {sup 30}Mg(t,p) {sup 32}Mg reaction demonstrates that the ground state is the normal state and the excited 0{sup +} state is the intruder, contrary to popular belief. Additional experiments are suggested.

  9. Piecing Together the "Workplace Multilingualism" Jigsaw Puzzle

    ERIC Educational Resources Information Center

    Hua, Zhu

    2014-01-01

    Multilingualism in the workplace is different from multilingualism at home or in other domains of social life. It has more direct, yet entangled, economic and social implications and serves interactional purposes which can be at any point on the continuum of goal-orientation and relationship-building. Multilingualism in the workplace is both a…

  10. Piecing together the biggest puzzle of all.

    PubMed

    Rees, M J

    2000-12-01

    In this month's essay, the last in the Pathways of Discovery series, Martin J. Rees celebrates the way astronomers and cosmologists have systematically uncovered the biography of the universe. Rife with neutron stars, black holes, and multiple universes that emerge from quantum fluctuation, it's a story as grand as it is strange. PMID:17742057

  11. New pieces of the Trichinella puzzle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Contrary to our understanding of just a few decades ago, the genus Trichinella now consists of a complex assemblage of no less than 9 different species and 3 additional genotypes whose taxonomic status remains in flux. New data and methodologies have allowed advancements in detection and differentia...

  12. Solving the RNA polymerase I structural puzzle

    PubMed Central

    Moreno-Morcillo, María; Taylor, Nicholas M. I.; Gruene, Tim; Legrand, Pierre; Rashid, Umar J.; Ruiz, Federico M.; Steuerwald, Ulrich; Müller, Christoph W.; Fernández-Tornero, Carlos

    2014-01-01

    Knowing the structure of multi-subunit complexes is critical to understand basic cellular functions. However, when crystals of these complexes can be obtained they rarely diffract beyond 3 Å resolution, which complicates X-ray structure determination and refinement. The crystal structure of RNA polymerase I, an essential cellular machine that synthesizes the precursor of ribosomal RNA in the nucleolus of eukaryotic cells, has recently been solved. Here, the crucial steps that were undertaken to build the atomic model of this multi-subunit enzyme are reported, emphasizing how simple crystallographic experiments can be used to extract relevant biological information. In particular, this report discusses the combination of poor molecular replacement and experimental phases, the application of multi-crystal averaging and the use of anomalous scatterers as sequence markers to guide tracing and to locate the active site. The methods outlined here will likely serve as a reference for future structural determination of large complexes at low resolution. PMID:25286842

  13. Two puzzling aspects of protein crystal growth

    NASA Technical Reports Server (NTRS)

    Grant, M. L.; Saville, D. A.

    1988-01-01

    A study is presented of several mechanisms which may reduce crystal growth rates and or terminate crystal growth. It is found that salt gradients which change the local chemical potential of the protein are insufficient to account for the slow crystal growth rates which have been reported. Contaminants which adsorb protein from solution may reduce the effective protein concentration, but the impurity's concentration and its affinity for protein are unknown. Association of protein molecules in bulk solution can reduce the monomer concentration significantly, but extant theory and experiment are not sensitive enough to determine the actual concentration of aggregates in solution. For systems of interest, shear-induced effects were found to be too weak to interfere with normal binding of incoming protein molecules. Although we found that most crystal growth occurs in a regime where both interfacial kinetics and diffusion influence crystal growth, the role of mass transfer rates on the terminal size of crystals is unknown, primarily because no data exist which cover the size range of interest (0.1 mm to 1 mm in length).

  14. A common solution of two cosmic puzzles

    NASA Astrophysics Data System (ADS)

    Dado, Shlomo; Dar, Arnon

    2016-05-01

    We show that the properties of the background of astronomical neutrinos above 30 TeV, which was discovered with IceCube, are those expected from the all sky high-energy gamma-ray background radiation (GBR), which was measured below 2 TeV with Fermi-LAT, if both backgrounds were formed by the decay of mesons produced in hadronic collisions of the high energy cosmic rays (CRs) with diffuse matter in/near the CR sources.

  15. Counselor Trainee Effectiveness: More Puzzle Pieces?

    ERIC Educational Resources Information Center

    Loesch, Larry C.; And Others

    1978-01-01

    This study continues the search for meaningful relationships between counselor trainee characteristics and effectiveness. Self-disclosure, dogmatism, locus of control, Machiavellianism, academic aptitude, and sex of counselor trainees were investigated for relationships to effectiveness during practicum or internship. (Author)

  16. Bicuspid Aortic Valve: Unlocking the Morphogenetic Puzzle.

    PubMed

    Longobardo, Luca; Jain, Renuka; Carerj, Scipione; Zito, Concetta; Khandheria, Bijoy K

    2016-08-01

    Although bicuspid aortic valve is the most common congenital abnormality, it is perhaps erroneous to consider this disease one clinical entity. Rather, it may be useful to consider it a cluster of diseases incorporating different phenotypes, etiologies, and pathogenesis. Discussion of bicuspid aortic valve can be difficult because there is no clear consensus on a phenotypic description among authors, and many classification schemes have been proposed. The literature suggests that different phenotypes have different associations and clinical manifestations. In addition, recent studies suggest a genetic basis for the disease, yet few genes have so far been described. Furthermore, recent scientific literature has been focusing on the increased risk of aortic aneurysms, but the pathogenesis of bicuspid aortic valve aortopathy is still unclear. The aim of this paper is to review the current evidence about the unsolved issues around bicuspid aortic valve. PMID:27059385

  17. Nanosprings, Another Piece of the Nanotechnology Puzzle

    NASA Astrophysics Data System (ADS)

    McIlroy, David

    2003-11-01

    Nanotechnology is being touted as the next significant advancement in science and technology. The proposed applications for nanotechnology range from biological sensors to nanorobotics, to name a few. In order to take nanotechnology from the realm of science fiction to reality we need determine what is possible, as dictated by the laws of physics, and what is not. Often times when approaching a new problem we have a tendency to over complicate the problem. Therefore, when developing nanomachines we should start simple. An excellent place to start is with toys. Toys are designed to perform complex functions using the simplest of designs. If we dictate that our toy performs a function or action then energy will be needed, as well as a means for storing energy. The simplest mechanism that satisfies these two requirements is a spring. In this presentation a summary of the efforts to develop nanosprings, springs that are on the order of tens of nanometers, will be presented.

  18. Whose Standards? (B) Reaching the Assessment Puzzle

    ERIC Educational Resources Information Center

    Polimeni, John M.; Iorgulescu, Raluca I.

    2009-01-01

    Love it or hate it, assessment has become the new reality on college and university campuses. Although measuring student achievement of course outcomes is not an easy task, assessment does not need to be a complex or painful experience. This paper describes the methods used to assess student achievement of the stated course outcomes in…

  19. Puzzles in practice: splenic vein thrombosis.

    PubMed

    McIntyre, Brittany; Marsh, Melanie; Walden, Jeffrey

    2016-06-01

    This report details a 58-year-old gentleman who presented to his outpatient primary care physician's clinic several times over four weeks for ongoing epigastric pain radiating into his left flank, dry heaving, and constipation. He was presumed to have gastritis at each visit and prescribed escalating doses of proton pump inhibitors. Due to the unrelenting pain, he eventually was admitted to the hospital and diagnosed with splenic vein thrombosis after computed tomography imaging of the abdomen. Our literature search revealed that pancreatic pathology is overwhelmingly the contributing factor to splenic vein thrombosis. Our patient had prominent collateral vasculature, suggesting that his splenic vein thrombosis was chronic in nature and likely the cause of his ongoing abdominal pain. Splenic vein thrombosis is an uncommon cause of abdominal pain, but one that should be included in the treating physician's differential diagnoses when abdominal pain is ongoing despite medical therapy. Although he had no evidence of initial findings on radiography, our patient was eventually diagnosed with biopsy-proven pancreatic cancer. Our case report demonstrates how patients presenting with persistent or worsening abdominal pain despite the use of proton pump inhibitors or other acid reducing agents and potential 'red flag' findings such as decreased appetite and weight loss should be worked up for other potential sources of abdominal pathology. PMID:27157637

  20. Solving flavor puzzles with quiver gauge theories

    SciTech Connect

    Antebi, Yaron E.; Nir, Yosef; Volansky, Tomer

    2006-04-01

    We consider a large class of models where the SU(5) gauge symmetry and a Froggatt-Nielsen (FN) Abelian flavor symmetry arise from a U(5)xU(5) quiver gauge theory. An intriguing feature of these models is a relation between the gauge representation and the horizontal charge, leading to a restricted set of possible FN charges. Requiring that quark masses are hierarchical, the lepton flavor structure is uniquely determined. In particular, neutrino mass anarchy is predicted.

  1. The puzzles of dark matter searches

    SciTech Connect

    Khlopov, Maxim Yu.

    2010-06-23

    Positive results of dark matter searches in DAMA/NaI and DAMA/LIBRA experiments, being put together with negative results of other groups, imply nontrivial particle physics solutions for cosmological dark matter. Stable particles with charge -2 bind with primordial helium in O-helium 'atoms' (OHe), representing a specific Warmer than Cold nuclear-interacting form of dark matter. Slowed down in the terrestrial matter, OHe is elusive for direct methods of underground Dark matter detection like those used in CDMS experiment, but its reactions with nuclei can lead to annual variations of energy release in the interval of energy 2-6 keV in DAMA/NaI and DAMA/LIBRA experiments. Schrodinger equation for system of nucleus and OHe is considered and reduced to an equation of relative motion in a spherically symmetrical potential well, formed by the Yukawa tail of nuclear scalar isoscalar attraction potential, acting on He beyond the nucleus, and dipole Coulomb repulsion between the nucleus and OHe at distances from the nuclear surface, smaller than the size of OHe. The values of coupling strength and mass of meson, mediating scalar isoscalar nuclear potential, are rather uncertain. Within these uncertainties we find a narrow window of these parameters, at which the sodium and/or iodine nuclei have a few keV binding energy with OHe. The concentration of OHe in the matter of underground detectors is adjusted to the incoming flux of cosmic O-helium at the timescale less than few minutes. Therefore the rate of radiative capture of Na and/or I by OHe should experience annual modulations. Transitions to more energetic levels of Na+OHe (I+OHe) system imply tunneling through dipole Coulomb barrier that leads to suppression of annual modulation of events with MeV-tens MeV energy release in the correspondence with the results of DAMA experiments. The proposed explanation inevitably leads to prediction of abundance of anomalous Na (and/or I) corresponding to the signal, observed by DAMA. At nuclear parameters, reproducing DAMA results, the energy release predicted for detectors with chemical content other than NaI differ in the most cases from the one in DAMA detector. In particular, it is shown that in the case of CDMS the energy of OHe-germanium bound state is beyond the range of 2-6 keV and its formation should not lead to ionization in the energy interval of DAMA signal.

  2. Magnetohydrodynamic puzzles in the protoplanetary nebula

    NASA Technical Reports Server (NTRS)

    Levy, Eugene H.

    1991-01-01

    The following subject areas are covered: (1) magnetization of meteorites; (2) the possible origin of a nebular magnetic field; (3) the possibility of magnetic flares; (4) external manifestations; (5) dynamical effects of the magnetic fields; and (6) the problem of ionization.

  3. Embedded Course Reserves: Piecing the Puzzle Together

    ERIC Educational Resources Information Center

    Clumpner, Krista E.; Burgmeier, Michael; Gillespie, Thomas J.

    2011-01-01

    Northern Michigan University (NMU) is a public 4-year undergraduate institution of higher education with an enrollment of approximately 9,500 students. The university's Division of Academic Information Services encompasses both the staff of the library, which includes authors Clumpner and Burgmeier, and the instructional technology areas, where…

  4. Solving the puzzle of "red" Sirius.

    NASA Astrophysics Data System (ADS)

    Ceragioli, R. C.

    The present paper is the second of two published in this journal concerning the problem of whether Sirius has changed its intrinsic colour from reddish to bluish white since Antiquity. The fundamental question to be answered is this: why did the ancients - and in particular Ptolemy - sometimes refer to Sirius as "reddish" when it cannot have been intrinsically different from its present bluish white colour? The author anticipates the answer by saying that ancient assessments of Sirius's reddishness depended on the varying appearances that the Dog-star shows near the horizon, where it sometimes appears reddish because of atmospheric scattering and the scintillation of its light. At higher altitudes in a calm sky, Sirius must have shown its intrinsic bluish white colour.

  5. Abortion in Vietnam: measurements, puzzles, and concerns.

    PubMed

    Goodkind, D

    1994-01-01

    This report summarizes current knowledge about abortion in Vietnam, drawing upon government statistics, survey data, and fieldwork undertaken by the author in Vietnam throughout 1993 and part of 1994. The official total abortion rate in Vietnam in 1992 was about 2.5 per woman, the highest in Asia and worrisome for a country with a still-high total fertility rate of 3.7 children per woman. Vietnamese provinces exhibited substantial variation in both the rate of abortion and the type of procedures performed. Among the hypotheses explored to explain Vietnam's high rate of abortion are the borrowing of family planning strategies from other poor socialist states where abortion is common; current antinatal population policies that interact with a lack of contraceptive alternatives; and a rise in pregnancies among young and unmarried women in the wake of recent free-market reforms. Because family-size preferences are still declining, abortion rates may continue to increase unless the incidence of unwanted pregnancy can be reduced, a goal that Vietnamese population specialists are seeking to achieve. PMID:7716799

  6. The CO/Pt(111) Puzzle

    SciTech Connect

    FEIBELMAN,PETER J.; HAMMER,B.; NORSHOV,J.K.; WAGNER,F.; SCHEFFLER,M.; STUMPF,R.; DUMESIC,J.; WATWE,R.

    2000-07-12

    Notwithstanding half a dozen theoretical publications, well-converged density-functional calculations, whether based on a local or generalized-gradient exchange-correlation potential, whether all-electron or employing pseudopotentials underestimate CO's preference for low-coordination binding sites on Pt(111) and vicinals to it. For example, they imply that CO should prefer hollow- to atop-site adsorption on Pt(111), in apparent contradiction to a host of low temperature experimental studies.

  7. A Web Based Puzzle for Energy Sources

    ERIC Educational Resources Information Center

    Secken, Nilgun

    2006-01-01

    At present many countries in the world consume too much fossil fuels such as petroleum, natural gas and coal to meet their energy needs. These fossil fuels are not renewable; their sources are limited and reducing gradually. More importantly they have been becoming more expensive day by day and their damage to the environment has been increasing.…

  8. Mercury concentration in coal - Unraveling the puzzle

    USGS Publications Warehouse

    Toole-O'Neil, B.; Tewalt, S.J.; Finkelman, R.B.; Akers, D.J.

    1999-01-01

    Based on data from the US Geological Survey's COALQUAL database, the mean concentration of mercury in coal is approximately 0.2 ??gg-1. Assuming the database reflects in-ground US coal resources, values for conterminous US coal areas range from 0.08 ??gg-1 for coal in the San Juan and Uinta regions to 0.22 ??gg-1 for the Gulf Coast lignites. Recalculating the COALQUAL data to an equal energy basis unadjusted for moisture differences, the Gulf Coast lignites have the highest values (36.4 lb of Hg/1012 Btu) and the Hams Fork region coal has the lowest value (4.8 lb of Hg/1012Btu). Strong indirect geochemical evidence indicates that a substantial proportion of the mercury in coal is associated with pyrite occurrence. This association of mercury and pyrite probably accounts for the removal of mercury with the pyrite by physical coal cleaning procedures. Data from the literature indicate that conventional coal cleaning removes approximately 37% of the mercury on an equal energy basis, with a range of 0% to 78%. When the average mercury reduction value is applied to in-ground mercury values from the COALQUAL database, the resulting 'cleaned' mercury values are very close to mercury in 'as-shipped' coal from the same coal bed in the same county. Applying the reduction fact or for coal cleaning to eastern US bituminous coal, reduces the mercury input load compared to lower-rank non-deaned western US coal. In the absence of analytical data on as-shipped coal, the mercury data in the COALQUAL database, adjusted for deanability where appropriate, may be used as an estimator of mercury contents of as-shipped coal. ?? 1998 Published by Elsevier Science Ltd. All rights reserved.

  9. Back pain: A puzzle in children.

    PubMed

    Nahle, Imad S; Hamam, Mohamed S; Masrouha, Karim Z; Afeiche, Nadim E; Abdelnoor, Johnny

    2016-08-01

    Back pain in children is underdiagnosed and increases incidence in adolescence. A systematic approach can diagnose the most common causes: trauma, structural deformities, inflammatory diseases, infection and malignancy. PMID:27535879

  10. Fitting aerodynamics and propulsion into the puzzle

    NASA Technical Reports Server (NTRS)

    Johnston, Patrick J.; Whitehead, Allen H., Jr.; Chapman, Gary T.

    1987-01-01

    The development of an airbreathing single-stage-to-orbit vehicle, in particular the problems of aerodynamics and propulsion integration, is examined. The boundary layer transition on constant pressure surfaces at hypersonic velocities, and the effects of noise on the transition are investigated. The importance of viscosity, real-gas effects, and drag at hypersonic speeds is discussed. A propulsion system with sufficient propulsive lift to enhance the performance of the vehicle is being developed. The difficulties of engine-airframe integration are analyzed.

  11. The Deuterium Puzzle in the Symmetric Universe

    NASA Technical Reports Server (NTRS)

    Leroy, B.; Nicolle, J. P.; Schatzman, E.

    1973-01-01

    The examination of the experimental data concerning the reaction antiproton + He-4 yields pions + nuclei shows that the low abundance of D 2 can be explained only by assuming a low He abundance at the beginning of the radiative era. This is a completely independant confirmation of the evasion of neutrons (and antineutrons) from the emulsion before the end of the epoch where nucleogenesis might have taken place, and leads to an estimate of the size of the emulsion when T = 1 MeV.

  12. The deuterium puzzle in the symmetric universe

    NASA Technical Reports Server (NTRS)

    Leroy, B.; Nicolle, J. P.; Schatzman, E.

    1973-01-01

    An attempt was made to use deuterium abundance in the symmetric universe to prove that no nucleosynthesis takes place during annihilation and therefore neutrons were loss before nucleosynthesis. Data cover nucleosynthesis during the radiative era, cross section estimates, maximum abundance of He-4 at the end of nucleosynthesis area, and loss rate.

  13. The puzzles of dark matter searches

    NASA Astrophysics Data System (ADS)

    Khlopov, Maxim Yu.

    2010-06-01

    Positive results of dark matter searches in DAMA/NaI and DAMA/LIBRA experiments, being put together with negative results of other groups, imply nontrivial particle physics solutions for cosmological dark matter. Stable particles with charge -2 bind with primordial helium in O-helium ``atoms'' (OHe), representing a specific Warmer than Cold nuclear-interacting form of dark matter. Slowed down in the terrestrial matter, OHe is elusive for direct methods of underground Dark matter detection like those used in CDMS experiment, but its reactions with nuclei can lead to annual variations of energy release in the interval of energy 2-6 keV in DAMA/NaI and DAMA/LIBRA experiments. Schrodinger equation for system of nucleus and OHe is considered and reduced to an equation of relative motion in a spherically symmetrical potential well, formed by the Yukawa tail of nuclear scalar isoscalar attraction potential, acting on He beyond the nucleus, and dipole Coulomb repulsion between the nucleus and OHe at distances from the nuclear surface, smaller than the size of OHe. The values of coupling strength and mass of meson, mediating scalar isoscalar nuclear potential, are rather uncertain. Within these uncertainties we find a narrow window of these parameters, at which the sodium and/or iodine nuclei have a few keV binding energy with OHe. The concentration of OHe in the matter of underground detectors is adjusted to the incoming flux of cosmic O-helium at the timescale less than few minutes. Therefore the rate of radiative capture of Na and/or I by OHe should experience annual modulations. Transitions to more energetic levels of Na+OHe (I+OHe) system imply tunneling through dipole Coulomb barrier that leads to suppression of annual modulation of events with MeV-tens MeV energy release in the correspondence with the results of DAMA experiments. The proposed explanation inevitably leads to prediction of abundance of anomalous Na (and/or I) corresponding to the signal, observed by DAMA. At nuclear parameters, reproducing DAMA results, the energy release predicted for detectors with chemical content other than NaI differ in the most cases from the one in DAMA detector. In particular, it is shown that in the case of CDMS the energy of OHe-germanium bound state is beyond the range of 2-6 keV and its formation should not lead to ionization in the energy interval of DAMA signal.

  14. QALYs, euthanasia and the puzzle of death.

    PubMed

    Barrie, Stephen

    2015-08-01

    This paper considers the problems that arise when death, which is a philosophically difficult concept, is incorporated into healthcare metrics, such as the quality-adjusted life year (QALY). These problems relate closely to the debate over euthanasia and assisted suicide because negative QALY scores can be taken to mean that patients would be 'better off dead'. There is confusion in the literature about the meaning of 0 QALY, which is supposed to act as an 'anchor' for the surveyed preferences on which QALYs are based. In the context of the debate over euthanasia, the QALY assumes an ability to make meaningful comparisons between life-states and death. Not only is this assumption questionable, but the ethical debate is much more broad than the question of whether death is preferable to a state of living. QALYs are derived from preferences about health states, so do not necessarily reflect preferences about events (eg, dying) or actions (eg, killing). This paper presents a new kind of problem for the QALY. As it stands, the QALY provides confused and unreliable information when it reports zero or negative values, and faces further problems when it appears to recommend death. This should preclude its use in the debate over euthanasia and assisted suicide. These problems only apply where the QALY involves or seems to involve a comparison between life-states and death, and are not relevant to the more general discussion of the use of QALYs as a tool for comparing the benefits derived from treatment options. PMID:25082901

  15. Oxidation of coal: a mechanistic puzzle

    SciTech Connect

    Chakrabartty, S.K.

    1981-03-29

    The mechanism of coal oxidation was investigated by two-phase oxidation of hvb and lvb coals. The oxidants used were commercial bleach, tetrabutylammonium fluoroborate and tetrabutylammonium permanganate. After extraction, the compounds were characterized by gas chromatography/mass spectroscopy. Coal-oxidation is much more complicated than would be expected from oxidations of standard organic compounds. It is reasonable to assume that aliphatic structures, particularly benzylic methyl, methylene or methine groups, or carbon adjacent to hetero-atoms are the most reactive, and are oxidized to ketones or carboxylic acids. In order to degrade coal to CO/sub 2/ and water-soluble low-molecular-weight compounds by mild oxidants, an abundance of these functional groups must be assumed. However, the stability of ethyl-polyvinylbenzene polymer towards hypochlorite oxidant indicates that activation of coal-carbon for oxidation results from features other than electronegativity of aromatic rings. The uniqueness of the coal-oxidation has to rest on a destabilizing factor which makes even aromatic sites vulnerable. One may speculate that mineral matter in coal is coordinated with aromatic structures, and that the resultant complexes are destabilized by electrophilic attack. If a coal is an entangled interpenetrating macromolecular mixture, the destabilizing effect would decrease with increasing compactness of the physical structure which accompanies increase in rank;higher rank coals would therefore be less reactive. However, if the oxidant can also, like mineral matter, intercalate, it would open the structure up, and produce destabilization. The success of wet oxidation would then depend less on the oxidation potential than on the ability of the oxidant to intercalate. The oxidation of lvb coal with assistance from phase-transfer catalysts in a two-phase system is consistent with this view.

  16. Solving the RNA polymerase I structural puzzle

    SciTech Connect

    Moreno-Morcillo, María; Taylor, Nicholas M. I.; Gruene, Tim; Legrand, Pierre; Rashid, Umar J.; Ruiz, Federico M.; Steuerwald, Ulrich; Müller, Christoph W.; Fernández-Tornero, Carlos

    2014-10-01

    Details of the RNA polymerase I crystal structure determination provide a framework for solution of the structures of other multi-subunit complexes. Simple crystallographic experiments are described to extract relevant biological information such as the location of the enzyme active site. Knowing the structure of multi-subunit complexes is critical to understand basic cellular functions. However, when crystals of these complexes can be obtained they rarely diffract beyond 3 Å resolution, which complicates X-ray structure determination and refinement. The crystal structure of RNA polymerase I, an essential cellular machine that synthesizes the precursor of ribosomal RNA in the nucleolus of eukaryotic cells, has recently been solved. Here, the crucial steps that were undertaken to build the atomic model of this multi-subunit enzyme are reported, emphasizing how simple crystallographic experiments can be used to extract relevant biological information. In particular, this report discusses the combination of poor molecular replacement and experimental phases, the application of multi-crystal averaging and the use of anomalous scatterers as sequence markers to guide tracing and to locate the active site. The methods outlined here will likely serve as a reference for future structural determination of large complexes at low resolution.

  17. A Palaeozoic Puzzle in Cenozoic Science.

    ERIC Educational Resources Information Center

    Mikkelsen, Tom

    1982-01-01

    The sword-tailed horseshoe crab (Limulus polyphemus) has developed its own defense against bacteria surrounding it. This defense system, under the name "Limulus test," now provides medicine and hygiene with a valuable means of detecting bacterial endotoxins at extremely low levels. (Author/JN)

  18. Serotonin, Amygdala and Fear: Assembling the Puzzle

    PubMed Central

    Bocchio, Marco; McHugh, Stephen B.; Bannerman, David M.; Sharp, Trevor; Capogna, Marco

    2016-01-01

    The fear circuitry orchestrates defense mechanisms in response to environmental threats. This circuitry is evolutionarily crucial for survival, but its dysregulation is thought to play a major role in the pathophysiology of psychiatric conditions in humans. The amygdala is a key player in the processing of fear. This brain area is prominently modulated by the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). The 5-HT input to the amygdala has drawn particular interest because genetic and pharmacological alterations of the 5-HT transporter (5-HTT) affect amygdala activation in response to emotional stimuli. Nonetheless, the impact of 5-HT on fear processing remains poorly understood.The aim of this review is to elucidate the physiological role of 5-HT in fear learning via its action on the neuronal circuits of the amygdala. Since 5-HT release increases in the basolateral amygdala (BLA) during both fear memory acquisition and expression, we examine whether and how 5-HT neurons encode aversive stimuli and aversive cues. Next, we describe pharmacological and genetic alterations of 5-HT neurotransmission that, in both rodents and humans, lead to altered fear learning. To explore the mechanisms through which 5-HT could modulate conditioned fear, we focus on the rodent BLA. We propose that a circuit-based approach taking into account the localization of specific 5-HT receptors on neurochemically-defined neurons in the BLA may be essential to decipher the role of 5-HT in emotional behavior. In keeping with a 5-HT control of fear learning, we review electrophysiological data suggesting that 5-HT regulates synaptic plasticity, spike synchrony and theta oscillations in the BLA via actions on different subcellular compartments of principal neurons and distinct GABAergic interneuron populations. Finally, we discuss how recently developed optogenetic tools combined with electrophysiological recordings and behavior could progress the knowledge of the mechanisms underlying 5-HT modulation of fear learning via action on amygdala circuits. Such advancement could pave the way for a deeper understanding of 5-HT in emotional behavior in both health and disease. PMID:27092057

  19. Aquaporins: another piece in the osmotic puzzle.

    PubMed

    Alleva, Karina; Chara, Osvaldo; Amodeo, Gabriela

    2012-09-21

    Osmolarity not only plays a key role in cellular homeostasis but also challenges cell survival. The molecular understanding of osmosis has not yet been completely achieved, and the discovery of aquaporins as molecular entities involved in water transport has caused osmosis to again become a focus of research. The main questions that need to be answered are the mechanism underlying the osmotic permeability coefficients and the extent to which aquaporins change our understanding of osmosis. Here, attempts to answer these questions are discussed. Critical aspects of the state of the state of knowledge on osmosis, a topic that has been studied since 19th century, are reviewed and integrated with the available information provided by in vivo, in vitro and in silico approaches. PMID:22728434

  20. Valentin Peschansky and the puzzles of magnetotransport

    NASA Astrophysics Data System (ADS)

    Pudalov, V. M.

    2011-10-01

    Since the 1950's, the Kharkov school of theoretical physics has been a world leader in the theory of metals. In particular, the research by V. G. Peschansky for many years has focused on the relationship between the magnetic field dependence of components of the resistivity and the electron energy spectrum. Peschansky developed an elegant theory of magnetoresistance that took surface scattering of electrons into account. The physics of bulk 3D metals was almost exhausted by the end of 1970's and Peschansky extended his research to low-dimensional electron systems. Throughout his scientific life, V. G. Peschansky has advocated the idea that magnetoresistance is a powerful tool for exploring the rich physics of electron systems. The many experimental and theoretical studies of magnetoresistance behavior in various systems, from simple to the most complex, have, by now, confirmed the fruitfulness of this idea.

  1. Puzzling Out the Cell's Power Plant.

    ERIC Educational Resources Information Center

    Miller, Julie Ann

    1979-01-01

    The biological research, of Gottfried Schatz at the University of Basel and Gunter Blobel at Rockefeller University, which explains a mechanism by which mitochondrial proteins are transported across membranes is described. Results indicate that the construction and heredity of mitochondria have surprising differences from other cell processes. (BT)

  2. The puzzle of Mt. Etna 2015 activity

    NASA Astrophysics Data System (ADS)

    Salerno, Giuseppe Giovanni; Caltabiano, Tommaso; Cannata, Andrea; Cannavo', Flavio; Currenti, Gilda; Di Grazia, Giuseppe; La Spina, Alessandro; Palano, Mimmo; Napoli, Rosalba; Sciotto, Mariangela; Spampinato, Letizia

    2016-04-01

    During 2015, Mt. Etna volcano activity consisted of a sequence of seismic and volcanic events indicative of a complex cause-effect relationship between volcanism and tectonics. Here we analyze in details all these events in order to figure out a possible and reliable causative mechanism able to explain the measured evidences by exploiting an extensive and multi-parametric dataset, including geochemical, volcanological, magnetic, seismic, and geodetic data. The integration of the different parameters allowed us to observe a long-lasting inflation episode abruptly interrupted by two vigorous short-term deflations and an intense dynamics of the northern sector of the volcano unstable flank. This last feature was characterized by two seismic swarms (Mmax = 3.6) occurring along the central sector of the Pernicana Fault and aseismic slip with intense deformation affecting the north-eastern edge of the unstable flank. This is not the first time in which the interaction between volcanism and tectonics has been observed at Mt. Etna although poorly constrained. In our case, the used multidisciplinary approach suggested us that in 2015 the eruptive activity was mainly triggered by the tectonic framework of the volcano unstable flank.

  3. World History Plays, Puzzles and Activities.

    ERIC Educational Resources Information Center

    Stevens, Lawrence

    This instructional resource, for grades 7-10, includes a collection of 10 plays with related learning activities. Units of study include: (1) "Alexander the Great and the Greeks"; (2) "The Black Death and the End of the Middle Ages"; (3) "Robert Clive and Imperialism"; (4) "Christopher Columbus and the Age of Exploration"; (5) "Fall of the…

  4. Initial Aid is Puzzle to Track

    ERIC Educational Resources Information Center

    McNeil, Michele

    2009-01-01

    States and federal agencies are off to a slow and uneven start in allowing the public to track the first allotments from up to $100 billion in new education funding under the federal economic-stimulus package, despite strong pledges of transparency for the program from the Obama administration. Although about $145 million in aid has been sent from…

  5. The missing puzzle piece: splicing mutations

    PubMed Central

    Lewandowska, Marzena A

    2013-01-01

    Proper gene splicing is highly dependent on the correct recognition of exons. Among the elements allowing this process are the “cis” (conserved sequences) and “trans” (snRNP, splicing factors) elements. Splicing mutations are related with a number of genetic disorders and usually induce exon skipping, form new exon/intron boundaries or activate new cryptic exons as a result of alterations at donor/acceptor sites. They constitute more than 9% of the currently published mutations, but this value is highly underestimated as many of the potential mutations are located in the “cis” elements and should be confirmed experimentally. The most commonly detected splicing mutations are located at donor (5’) and acceptor (3’) sites. Mutations at the branch point are rare (only over a dozen are known to date), and are mostly searched and detected when no alteration has been detected in the sequenced exons and UTRs. Polypyrimidine tract mutations are equally rare. High throughput technologies, as well as traditional Sanger sequencing, allow detection of many changes in intronic sequences and intron/exon boundaries. However, the assessment whether a mutation affects exon recognition and results in a genetic disorder has to be conducted using molecular biology methods: in vitro transcription of the sequence of interest cloned into a plasmid, with and without alterations, or mutation analysis via a hybrid minigene system. Even though microarrays and new generation sequencing methods pose difficulties in detecting novel branch point mutations, these tools seem appropriate to expand the mutation detection panel especially for diagnostic purposes. PMID:24294354

  6. Puzzles Produce Strangers: A Puzzling Result for Revelation-Effect Theories

    ERIC Educational Resources Information Center

    Assfalg, Andre; Bernstein, Daniel M.

    2012-01-01

    The revelation effect is a change in response behavior induced by a preceding problem-solving task. Previous studies have shown a revelation effect for faces when the problem-solving task includes attractiveness ratings of the faces. Immediately after this problem-solving task participants judged faces as more familiar than without the…

  7. Research on Aging: A Piece of the Puzzle.

    ERIC Educational Resources Information Center

    Cohen, Gene D.

    1979-01-01

    By following disorders over time, particularly into later life, and by studying changes that occur with the aging process, one sees new findings and clues emerging. These new leads can add to understanding mental illness and its treatment as well as human development in general. (Author)

  8. The APOSTLE simulations: solutions to the Local Group's cosmic puzzles

    NASA Astrophysics Data System (ADS)

    Sawala, Till; Frenk, Carlos S.; Fattahi, Azadeh; Navarro, Julio F.; Bower, Richard G.; Crain, Robert A.; Dalla Vecchia, Claudio; Furlong, Michelle; Helly, John. C.; Jenkins, Adrian; Oman, Kyle A.; Schaller, Matthieu; Schaye, Joop; Theuns, Tom; Trayford, James; White, Simon D. M.

    2016-04-01

    The Local Group galaxies offer some of the most discriminating tests of models of cosmic structure formation. For example, observations of the Milky Way (MW) and Andromeda satellite populations appear to be in disagreement with N-body simulations of the `lambda cold dark matter' (ΛCDM) model: there are far fewer satellite galaxies than substructures in CDM haloes (the `missing satellites' problem); dwarf galaxies seem to avoid the most massive substructures (the `too-big-to-fail' problem); and the brightest satellites appear to orbit their host galaxies on a thin plane (the `planes of satellites' problem). Here we present results from APOSTLE (A Project Of Simulating The Local Environment), a suite of cosmological hydrodynamic simulations of 12 volumes selected to match the kinematics of the Local Group (LG) members. Applying the EAGLE code to the LG environment, we find that our simulations match the observed abundance of LG galaxies, including the satellite galaxies of the MW and Andromeda. Due to changes to the structure of haloes and the evolution in the LG environment, the simulations reproduce the observed relation between stellar mass and velocity dispersion of individual dwarf spheroidal galaxies without necessitating the formation of cores in their dark matter profiles. Satellite systems form with a range of spatial anisotropies, including one similar to the MWs, confirming that such a configuration is not unexpected in ΛCDM. Finally, based on the observed velocity dispersion, size, and stellar mass, we provide estimates of the maximum circular velocity for the haloes of nine MW dwarf spheroidals.

  9. Thinking and Excellence in Education: Pieces of the Same Puzzle?

    ERIC Educational Resources Information Center

    Moses, Monte

    1985-01-01

    The article asserts that current educational practice must be redirected from an exclusive focus on content to one on human development, thinking, and then content. Implications for teaching thinking include opportunities for teaching students to accumulate meaningful concrete experiences, and the importance of classrooms becoming stimulus…

  10. IQ Wars Continue with Battles over New Puzzles

    ERIC Educational Resources Information Center

    Shea, Christopher

    2012-01-01

    James R. Flynn is an accidental IQ specialist. In the early 1980s, the American-born political scientist thought he might spend a few pages in a planned book on "how to defend humane ideals" grappling with the argument that the gap in IQ scores between blacks and whites was genetically rooted. It was not his first foray into that subject, but this…

  11. Internalized Racism: One More Piece of the Puzzle

    ERIC Educational Resources Information Center

    Speight, Suzette L.

    2007-01-01

    In this issue, Robert T. Carter has made an important contribution to the literature in clinical psychologists understanding of the psychological injury caused by experiences of racism. However, Carter's focus on specific encounters with racism might be narrow and limited. The author of this reaction contends that racial incidents (i.e.,…

  12. Critical study of the B{yields}K{pi} puzzle

    SciTech Connect

    Kim, C.S.; Oh, Sechul; Yu, Chaehyun

    2005-10-01

    In the light of new experimental results on B{yields}K{pi} decays, we critically study the decay processes B{yields}K{pi} in a phenomenological way. Using the quark diagram approach and the currently available data, we determine the allowed values of the relevant theoretical parameters, corresponding to the electroweak (EW) penguin, the color-suppressed tree contribution, etc. In order to find the most likely values of the parameters in a statistically reliable way, we use the {chi}{sup 2} minimization technique. Our result shows that the current data for B{yields}K{pi} decays strongly indicate (large) enhancements of both the EW penguin and the color-suppressed tree contributions. In particular, the color-suppressed tree effect needs to be enhanced by about an order of magnitude to fit the present data.

  13. Resolving B-CP puzzles in QCD factorization

    SciTech Connect

    Cheng, H.-Y.; Chua, C.-K.

    2009-10-01

    Within the framework of QCD factorization (QCDF), power corrections due to penguin annihilation can account for the observed rates of penguin-dominated two-body decays of B mesons and direct CP asymmetries A{sub CP}(K{sup -}{pi}{sup +}), A{sub CP}(K*{sup -}{pi}{sup +}), A{sub CP}(K{sup -}{rho}{sup 0}) and A{sub CP}({pi}{sup +}{pi}{sup -}). However, the predicted direct CP-violating effects in QCDF for B{sup -}{yields}K{sup -}{pi}{sup 0}, K{sup -}{eta}, {pi}{sup -}{eta} and B{sup 0}{yields}{pi}{sup 0}{pi}{sup 0} are wrong in signs when confronted with experiment. We show that subleading 1/m{sub b} power corrections to the color-suppressed tree amplitude due to spectator scattering or final-state interactions will yield correct signs for aforementioned CP asymmetries and accommodate the observed {pi}{sup 0}{pi}{sup 0} and {rho}{sup 0}{pi}{sup 0} rates simultaneously. Implications are discussed.

  14. Motor Learning: The FoxP2 Puzzle Piece

    PubMed Central

    Teramitsu, Ikuko; White, Stephanie A.

    2009-01-01

    Mutation of the DNA-binding region of the FOXP2 protein causes an inherited language disorder. A recent study provides the first data on mice with this mutation, which exhibit deficits in motor-skill learning and abnormal properties of neural circuits that contribute to these skills. PMID:18430631

  15. The CD-ROM Puzzle: Where Do the Pieces Fit?

    ERIC Educational Resources Information Center

    Moes, Robert J.

    1986-01-01

    Representing the point of view of Philips Subsystems and Peripherals on Compact Disc-Read Only Memory (CD-ROM) and Compact Disc-Interactive (CD-I) issues, this position paper attempts to point out differences and similarities between the basic CD-ROM standard and the CD-I standard proposed for interactive use of data. (Author/MBR)

  16. Connectives: Fitting Another Piece of the Vocabulary Instruction Puzzle

    ERIC Educational Resources Information Center

    Crosson, Amy C.; Lesaux, Nonie K.

    2013-01-01

    Connectives (e.g., although, consequently, in contrast) are often considered the "signposts" of texts. In this article we argue that connectives represent a special kind of vocabulary knowledge that students need to develop both in order to read challenging, academic texts with understanding and to produce academic writing. Yet tapping…

  17. Thermal Effects on the "Ice-Cube Puzzle"

    ERIC Educational Resources Information Center

    Lima, F. M. S.; Monteiro, F. F.

    2012-01-01

    When an ice cube floating on water in a container melts, it is said in some textbooks that the water level does not change. However, as pointed out by Lan in a recent work, when the buoyant force from a less dense fluid resting above the waterline is taken into account, one should expect a detectable "increase" in the volume of water. Here in this…

  18. Focusing on Fibromyalgia : A Puzzling and Painful Condition

    MedlinePlus

    ... on Fibromyalgia Health Capsules Infertility Treatments and Children’s Development Help for Rare and Undiagnosed Conditions Featured Website: NIH Office of Dietary Supplements Past Issues Most ...

  19. Applying Statistical Methods To The Proton Radius Puzzle

    NASA Astrophysics Data System (ADS)

    Higinbotham, Douglas

    2016-03-01

    In recent nuclear physics publications, one can find many examples where chi2 and reduced chi2 are the only tools used for the selection of models even though a chi2 difference test is only meaningful for nested models. With this in mind, we reanalyze electron scattering data, being careful to clearly define our selection criteria as well as using a co-variance matrix and confidence levels as per the statistics section of the particle data book. We will show that when applying such techniques to hydrogen elastic scattering data, the nested models often require fewer parameters than typically used and that non-nested models are often rejected inappropriately.

  20. The Puzzles Of the Prokineticin 2 Pathway in Human Reproduction

    PubMed Central

    Balasubramanian, Ravikumar; Plummer, Lacey; Sidis, Yisrael; Pitteloud, Nelly; Cecilia, Martin; Zhou, Qun-Yong; Crowley, William F.

    2011-01-01

    The Prokineticins, 1 (PROK1) and prokineticin 2 (PROK2), are two closely related proteins that were identified as the mammalian homologues of their two amphibian homologues, mamba intestinal toxin (MIT-1) and Bv8. MIT-1 was initially identified as a non-toxic constituent in the venom of the black mamba snake (Dendroaspis polylepis) (Joubert and Strydom 1980) while Bv8 was identified in the skin secretion of the toad, Bombina variegate (Mollay, Wechselberger et al. 1999). All three homologues stimulate gastrointestinal motility thus accounting for their family name “prokineticins” (Schweitz, Bidard et al. 1990; Schweitz, Pacaud et al. 1999). However, since its initial description, both PROK1 and PROK2 have been found to regulate a dazzling array of biological functions throughout the body. In particular, PROK1 acts as a potent angiogenic mitogen on endocrine vascular epithelium, thus earning its other name, Endocrine Gland-Vascular Endothelial Factor (EG-VEGF) (LeCouter, Lin et al. 2002). In contrast, the PROK2 signaling pathway is a critical regulator of olfactory bulb morphogenesis and sexual maturation in mamamals and this function is the focus of this review. PMID:21664414

  1. The Puzzle of Inheritance: Genetics and the Methods of Science.

    ERIC Educational Resources Information Center

    Cutter, Mary Ann G.; Drexler, Edward; Friedman, B. Ellen; McCullough, Laurence B.; McInerney, Joseph D.; Murray, Jeffrey C.; Rossiter, Belinda; Zola, John

    This instructional module contains a description of the Human Genome Project (HGP). A discussion of issues in the philosophy of science and some of the ethical, legal, and social implications of research in genetics, and a survey of fundamental genetics concepts and of new, nontraditional concepts of inheritance are also included. Six…

  2. PUZZLES OF THE INTERPLANETARY MAGNETIC FIELD IN THE INNER HELIOSPHERE

    SciTech Connect

    Khabarova, Olga; Obridko, Vladimir

    2012-12-20

    Deviations of the interplanetary magnetic field (IMF) from Parker's model are frequently observed in the heliosphere at different distances r from the Sun. Usually, it is supposed that the IMF behavior corresponds to Parker's model overall, but there is some turbulent component that impacts and disrupts the full picture of the IMF spatial and temporal distribution. However, the analysis of multi-spacecraft in-ecliptic IMF measurements from 0.29 AU to 5 AU shows that the IMF radial evolution is rather far from expected. The radial IMF component decreases with the adiabatic power index (|B{sub r} | {proportional_to} r {sup -5/3}), the tangential component |B{sub r}| {proportional_to} r {sup -1}, and the IMF strength B {proportional_to} r {sup -1.4}. This means that the IMF is not completely frozen in the solar wind. It is possible that turbulent processes in the inner heliosphere significantly influence the IMF expansion. This is confirmed by the analysis of the B{sub r} distribution's radial evolution. B{sub r} has a well-known bimodal histogram only at 0.7-2.0 AU. The bimodality effect gradually disappears from 1 AU to 4 AU, and B{sub r} becomes quasi-normally distributed at 3-4 AU (which is a sign of rapid vanishing of the stable sector structure with heliocentric distance). We consider a quasi-continuous magnetic reconnection, occurring both at the heliospheric current sheet and at local current sheets inside the IMF sectors, to be a key process responsible for the solar wind turbulization with heliocentric distance as well as for the breakdown of the ''frozen-in IMF'' law.

  3. Hungarian Verbal Puzzles and the Intensity of Language Contact.

    ERIC Educational Resources Information Center

    Kontra, Miklos

    2001-01-01

    Provides empirical support for two components of Thomason and Kaufman's intensity of language contact: the length of contact and the role of exposure to the source language. Tests the hypothesis that several hundred years of intimate contact and widespread bilingualism among borrowing-language speakers are needed for extensive structural changes…

  4. Intricate Puzzle of Oil and Gas Reserves Growth

    EIA Publications

    1997-01-01

    This article begins with a background discussion of the methods used to estimate proved oil and gas reserves and ultimate recovery, which is followed by a discussion of the factors that affect the ultimate recovery estimates of a field or reservoir.

  5. FERPA: Only a Piece of the Privacy Puzzle.

    ERIC Educational Resources Information Center

    O'Donnell, Margaret L.

    2003-01-01

    Discusses the history of the Family Educational Rights and Privacy Act (FERPA), the Falvo and Gonzaga U.S. Supreme Court cases, and how universities might rethink FERPA in light of digital records. A discussion of Professor Lawrence Lessig's book "Code and Other Laws of Cyberspace" is used as a framework for discussing institutional choices with…

  6. Brazil's scientists scramble to solve the Zika puzzle.

    PubMed

    Bispo, Ana

    2016-03-01

    The World Health Organization has declared the recent leap in the number of microcephaly cases and their suspected association with Zika virus a public health emergency of international concern. Ana Bispo tells Andréia Azevedo Soares why Brazil should have some scientific answers in coming months. PMID:26966326

  7. Timing the origin of human malarias: the lemur puzzle

    PubMed Central

    2011-01-01

    Background Timing the origin of human malarias has been a focus of great interest. Previous studies on the mitochondrial genome concluded that Plasmodium in primates, including those parasitic to humans, radiated relatively recently during a process where host switches were common. Those investigations, however, assumed constant rate of evolution and tightly bound (fixed) calibration points based on host fossils or host distribution. We investigate the effect of such assumptions using different molecular dating methods. We include parasites from Lemuroidea since their distribution provides an external validation to time estimates allowing us to disregard scenarios that cannot explain their introduction in Madagascar. Results We reject the assumption that the Plasmodium mitochondrial genome, as a unit or each gene separately, evolves at a constant rate. Our analyses show that Lemuroidea parasites are a monophyletic group that shares a common ancestor with all Catarrhini malarias except those related to P. falciparum. However, we found no evidence that this group of parasites branched with their hosts early in the evolution of primates. We applied relaxed clock methods and different calibrations points to explore the origin of primate malarias including those found in African apes. We showed that previous studies likely underestimated the origin of malarial parasites in primates. Conclusions The use of fossils from the host as absolute calibration and the assumption of a strict clock likely underestimate time when performing molecular dating analyses on malarial parasites. Indeed, by exploring different calibration points, we found that the time for the radiation of primate parasites may have taken place in the Eocene, a time consistent with the radiation of African anthropoids. The radiation of the four human parasite lineages was part of such events. The time frame estimated in this investigation, together with our phylogenetic analyses, made plausible a scenario where gorillas and humans acquired malaria from a Pan lineage. PMID:21992100

  8. Patient puzzle. Use systematic assessment to detect & correct patient conditions.

    PubMed

    Stoy, W A

    2001-01-01

    Medic 27 responds to a report of a fall victim at 27 West Pinnacle Lane. En route, the crew learns from dispatch that the patient fell approximately 25 feet from the roof of a three-story structure onto the roof of an adjacent garage. The caller reports the patient "going in and out of consciousness." The EMS crew requests the dispatch of a rescue unit and ladder company to assist on scene and the placement of a medical helicopter on standby. On scene, the patient's wife reports her husband accidentally disturbed a hornets' nest as he secured a weather vane to the top of the family home. She says the hornets stung her husband repeatedly. In his attempt to avoid the stings, his movements jarred the ladder, causing him to fall to the roof below. As you walk to the side of the patient's home, his wife adds that her husband has a cardiac condition and now complains of chest pain and trouble breathing. You wonder what you'll find when you reach the victim. Is he a medical patient with traumatic injuries or a trauma patient with medical complications? PMID:11213605

  9. Autism and the Social Brain: The First-Year Puzzle.

    PubMed

    Elsabbagh, Mayada; Johnson, Mark H

    2016-07-15

    The atypical features of social perception and cognition observed in individuals with a diagnosis of autism have been explained in two different ways. First, domain-specific accounts are based on the assumption that these end-state symptoms result from specific impairments within component structures of the social brain network. Second, domain-general accounts hypothesize that rather than being localized, atypical brain structure and function are widespread, or hypothesize that the apparent social brain differences are the consequence of adaptations to earlier occurring widespread changes in brain function. Critical evidence for resolving this basic issue comes from prospective longitudinal studies of infants at risk for later diagnosis. We highlight selected studies from the newly emerging literature on infants at familial risk for autism to shed light on this issue. Despite multiple reports of possible alterations in brain function in the first year of life, overt behavioral symptoms do not emerge until the second year. Our review reveals only mixed support, within this very early period, for localized deficits in social brain network systems and instead favors the view that atypical development involving perceptual, attentional, motor, and social systems precede the emerging autism phenotype. PMID:27113503

  10. Puzzles with Tachyon in SSFT and Cosmological Applications

    NASA Astrophysics Data System (ADS)

    Aref'eva, I.

    This work is my contribution to the proceedings of the conference``SFT2010 --- the Third International Conference on String Field Theory and Related Aspects''. We discuss properties of nonlocal tachyons and nonlocal SFT inspired cosmology.

  11. MOLECULAR DIAGNOSTICS - ANOTHER PIECE IN THE ENVIRONMENTAL PUZZLE

    EPA Science Inventory

    Molecular biology offers sensitive and expedient tools for the detection of exposure to environmental stressors. Molecular approaches provide the means for detection of the "first cellular event(s)" in response to environmental changes-specifically, immediate changes in gene expr...

  12. Plasmalemmal VDAC controversies and maxi-anion channel puzzle.

    PubMed

    Sabirov, Ravshan Z; Merzlyak, Petr G

    2012-06-01

    The maxi-anion channel has been observed in many cell types from the very beginning of the patch-clamp era. The channel is highly conductive for chloride and thus can modulate the resting membrane potential and play a role in fluid secretion/absorption and cell volume regulation. A wide nanoscopic pore of the maxi-anion channel permits passage of excitatory amino acids and nucleotides. The channel-mediated release of these signaling molecules is associated with kidney tubuloglomerular feedback, cardiac ischemia/hypoxia, as well as brain ischemia/hypoxia and excitotoxic neurodegeneration. Despite the ubiquitous expression and physiological/pathophysiological significance, the molecular identity of the maxi-anion channel is still obscure. VDAC is primarily a mitochondrial protein; however several groups detected it on the cellular surface. VDAC in lipid bilayers reproduced the most important biophysical properties of the maxi-anion channel, such as a wide nano-sized pore, closure in response to moderately high voltages, ATP-block and ATP-permeability. However, these similarities turned out to be superficial, and the hypothesis of plasmalemmal VDAC as the maxi-anion channel did not withstand the test by genetic manipulations of VDAC protein expression. VDAC on the cellular surface could also function as a ferricyanide reductase or a receptor for plasminogen kringle 5 and for neuroactive steroids. These ideas, as well as the very presence of VDAC on plasmalemma, remain to be scrutinized by genetic manipulations of the VDAC protein expression. This article is part of a Special Issue entitled: VDAC structure, function, and regulation of mitochondrial metabolism. PMID:21986486

  13. The puzzling case of asteroid 8 Flora solved

    NASA Technical Reports Server (NTRS)

    Di Martino, M.; Zappala, V.; Cellino, A.; Barucci, M. A.; Harris, A. W.; Young, J. W.

    1989-01-01

    This paper reports the results obtained in an international campaign devoted to the observations of the asteroid 8 Flora, a possible target of the Vesta mission. Using the lightcurves obtained during three oppositions (1980, 1983, 1984), a synodic rotational period of 12.87 hours was determined. This period, applied to the lightcurves of 8 Flora already published, satisfactorily explains these observations. Applying the AM-method described by Zappala et al. (1983), the pole position was calculated. The slope parameter G, determined during the 1969 and 1983 apparitions, differs by about 0.10. Considering that in those years the ecliptic longitudes of the asteroid were about 115 degrees apart, this fact probably indicates the presence of variations in the structure and chemical compositions of the surface.

  14. Implantation and the placenta: Key pieces of the development puzzle

    SciTech Connect

    Cross, J.C.; Werb, Z.; Fisher, S.J.

    1994-12-02

    The mammalian embryo cannot develop without the placenta. Its specialized cells (trophoblast, endoderm, and extraembryonic mesoderm) form early in development. They attach the embryo to the uterus (implantation) and form vascular connections necessary for nutrient transport. In addition, the placenta redirects maternal endocrine, immune, and metabolic functions to the embryo`s advantage. These complex activities are sensitive to disruption, as shown by the high incidence of early embryonic mortality and pregnancy diseases in humans, as well as the numerous peri-implantation lethal mutations in mice. Integration of molecular and developmental approaches has recently produced insights into the molecules that control these processes.

  15. Prove It! Putting Together the Evidence-Based Practice Puzzle

    ERIC Educational Resources Information Center

    Little, Hannah Byrd

    2015-01-01

    Why is it important to prove that school libraries add value to the school program? The National Center for Education Statistics reports that 20 percent of U.S. public schools lack a full or part-time certified librarian (NCES 2013). In California the ratio of certified school librarians to students is 1:7,374 (California Department of Education…

  16. Non-coeliac gluten sensitivity: piecing the puzzle together

    PubMed Central

    Iven, Julie

    2015-01-01

    The avoidance of wheat- and gluten-containing products is a worldwide phenomenon. While coeliac disease is well-established, much remains unknown about whether gluten can be a trigger of gastrointestinal and/or extra-intestinal symptoms in patients without coeliac disease. In this article, we discuss the latest scientific evidence and our current understanding for the possible mechanisms of this largely ambiguous group, termed ‘non-coeliac gluten sensitive’ (NCGS). We can conclude that NCGS should be regarded as an independent disease outside of coeliac disease and wheat allergy, and that the number of patients affected is likely to be limited. Many questions remain unanswered and it needs to be verified whether the elimination of dietary gluten alone is sufficient for the control of symptoms, and to understand the overlap with other components of wheat. PMID:25922675

  17. Ferroptosis: A missing puzzle piece in the p53 blueprint?

    PubMed Central

    Wang, Shang-Jui; Ou, Yang; Jiang, Le; Gu, Wei

    2016-01-01

    ABSTRACT Recent evidence indicates that canonical functions of p53 (i.e., apoptosis and growth arrest) are dispensable for p53-mediated tumor suppression. We have uncovered a novel function of p53 that contributes to tumor suppression through regulation of cystine metabolism, reactive oxygen species responses, and ferroptosis. The p53-mediated ferroptotic response via SLC7A11 denotes an extra layer of defense against tumorigenesis in conjunction with other p53 functions. PMID:27314071

  18. Genomic imprinting: A missing piece of the Multiple Sclerosis puzzle?

    PubMed

    Ruhrmann, Sabrina; Stridh, Pernilla; Kular, Lara; Jagodic, Maja

    2015-10-01

    Evidence for parent-of-origin effects in complex diseases such as Multiple Sclerosis (MS) strongly suggests a role for epigenetic mechanisms in their pathogenesis. In this review, we describe the importance of accounting for parent-of-origin when identifying new risk variants for complex diseases and discuss how genomic imprinting, one of the best-characterized epigenetic mechanisms causing parent-of-origin effects, may impact etiology of complex diseases. While the role of imprinted genes in growth and development is well established, the contribution and molecular mechanisms underlying the impact of genomic imprinting in immune functions and inflammatory diseases are still largely unknown. Here we discuss emerging roles of imprinted genes in the regulation of inflammatory responses with a particular focus on the Dlk1 cluster that has been implicated in etiology of experimental MS-like disease and Type 1 Diabetes. Moreover, we speculate on the potential wider impact of imprinting via the action of imprinted microRNAs, which are abundantly present in the Dlk1 locus and predicted to fine-tune important immune functions. Finally, we reflect on how unrelated imprinted genes or imprinted genes together with non-imprinted genes can interact in so-called imprinted gene networks (IGN) and suggest that IGNs could partly explain observed parent-of-origin effects in complex diseases. Unveiling the mechanisms of parent-of-origin effects is therefore likely to teach us not only about the etiology of complex diseases but also about the unknown roles of this fascinating phenomenon underlying uneven genetic contribution from our parents. This article is part of a Directed Issue entitled: Epigenetics dynamics in development and disease. PMID:26002250

  19. Solving the puzzles of cutin and suberin polymer biosynthesis.

    PubMed

    Beisson, Fred; Li-Beisson, Yonghua; Pollard, Mike

    2012-06-01

    Cutin and suberin are insoluble lipid polymers that provide critical barrier functions to the cell wall of certain plant tissues, including the epidermis, endodermis and periderm. Genes that are specific to the biosynthesis of cutins and/or aliphatic suberins have been identified, mainly in Arabidopsis thaliana. They notably encode acyltransferases, oxidases and transporters, which may have either well-defined or more debatable biochemical functions. However, despite these advances, important aspects of cutin and suberin synthesis remain obscure. Central questions include whether fatty acyl monomers or oligomers are exported, and the extent of extracellular assembly and attachment to the cell wall. These issues are reviewed. Greater emphasis on chemistry and biochemistry will be required to solve these unknowns and link structure with function. PMID:22465132

  20. Osteoprotegerin in Bone Metastases: Mathematical Solution to the Puzzle

    PubMed Central

    Ryser, Marc D.; Qu, Yiding; Komarova, Svetlana V.

    2012-01-01

    Bone is a common site for cancer metastasis. To create space for their growth, cancer cells stimulate bone resorbing osteoclasts. Cytokine RANKL is a key osteoclast activator, while osteoprotegerin (OPG) is a RANKL decoy receptor and an inhibitor of osteoclastogenesis. Consistently, systemic application of OPG decreases metastatic tumor burden in bone. However, OPG produced locally by cancer cells was shown to enhance osteolysis and tumor growth. We propose that OPG produced by cancer cells causes a local reduction in RANKL levels, inducing a steeper RANKL gradient away from the tumor and towards the bone tissue, resulting in faster resorption and tumor expansion. We tested this hypothesis using a mathematical model of nonlinear partial differential equations describing the spatial dynamics of OPG, RANKL, PTHrP, osteoclasts, tumor and bone mass. We demonstrate that at lower expression rates, tumor-derived OPG enhances the chemotactic RANKL gradient and osteolysis, whereas at higher expression rates OPG broadly inhibits RANKL and decreases osteolysis and tumor burden. Moreover, tumor expression of a soluble mediator inducing RANKL in the host tissue, such as PTHrP, is important for correct orientation of the RANKL gradient. A meta-analysis of OPG, RANKL and PTHrP expression in normal prostate, carcinoma and metastatic tissues demonstrated an increase in expression of OPG, but not RANKL, in metastatic prostate cancer, and positive correlation between OPG and PTHrP in metastatic prostate cancer. The proposed mechanism highlights the importance of the spatial distribution of receptors, decoys and ligands, and can be applied to other systems involving regulation of spatially anisotropic processes. PMID:23093918

  1. Hereditary breast cancer: ever more pieces to the polygenic puzzle.

    PubMed

    Bogdanova, Natalia; Helbig, Sonja; Dörk, Thilo

    2013-01-01

    Several susceptibility genes differentially impact on the lifetime risk for breast cancer. Technological advances over the past years have enabled the detection of genetic risk factors through high-throughput screening of large breast cancer case-control series. High- to intermediate penetrance alleles have now been identified in more than 20 genes involved in DNA damage signalling and repair, and more than 70 low-penetrance loci have been discovered through recent genome-wide association studies. In addition to classical germ-line mutation and single-nucleotide polymorphism, copy number variation and somatic mosaicism have been proposed as potential predisposing mechanisms. Many of the identified loci also appear to influence breast tumour characteristics such as estrogen receptor status. In this review, we briefly summarize present knowledge about breast cancer susceptibility genes and discuss their implications for risk prediction and clinical practice. PMID:24025454

  2. Organizational Culture and Student Persistence: Prospects and Puzzles.

    ERIC Educational Resources Information Center

    Kuh, George D.

    2002-01-01

    Examines five shibboleths (common ideas) about the relationship between campus culture and student persistence. Describes a six-step approach for using the peer group and classroom as key elements in cultivating a success-oriented institutional culture. (Author/EV)

  3. Tumor Suppressor Genes: A Key to the Cancer Puzzle?

    ERIC Educational Resources Information Center

    Oppenheimer, Steven B.

    1991-01-01

    Author describes developments in understanding of tumor suppressor genes or antioncogenes that he feels is most important breakthrough in solving cancer problem. Describes 1969 starting work of Harris with mouse fibroblast genes and later work of Knudson with retinoblastoma cells. Provides evidence that deletion of chromosome that results in the…

  4. Puzzles in bonding and spectroscopy: the case of dicarbon.

    PubMed

    Macrae, Roderick M

    2016-01-01

    The unstable molecule C₂ has been of interest since its identification as the source of the "Swan band" features observable in the spectra offlames, carbon arcs, white dwarf stars, and comets, and it continues to serve as a focal point for experimental and theoretical discovery. Recent spectroscopic work has identified a quintet state of the molecule for the first time, while new insights into the bond order of C₂ in its ground state have been provided by sophisticated computational methods based on valence bond theory. This article gives a review of spectroscopic and computational work on C₂ including both historical background and the most recent discoveries. PMID:27120813

  5. Canonical Wnt signaling in the oligodendroglial lineage--puzzles remain.

    PubMed

    Guo, Fuzheng; Lang, Jordan; Sohn, Jiho; Hammond, Elizabeth; Chang, Marcello; Pleasure, David

    2015-10-01

    The straightforward concept that accentuated Wnt signaling via the Wnt-receptor-β-catenin-TCF/LEF cascade (also termed canonical Wnt signaling or Wnt/β-catenin signaling) delays or blocks oligodendrocyte differentiation is very appealing. According to this concept, canonical Wnt signaling is responsible for remyelination failure in multiple sclerosis and for persistent hypomyelination in periventricular leukomalacia. This has given rise to the hope that pharmacologically inhibiting this signaling will be of therapeutic potential in these disabling neurological disorders. But current studies suggest that Wnt/β-catenin signaling plays distinct roles in oligodendrogenesis, oligodendrocyte differentiation, and myelination in a context-dependent manner (central nervous system regions, developmental stages), and that Wnt/β-catenin signaling interplays with, and is subjected to regulation by, other central nervous system factors and signaling pathways. On this basis, we propose the more nuanced concept that endogenous Wnt/β-catenin activity is delicately and temporally regulated to ensure the seamless development of oligodendroglial lineage cells in different contexts. In this review, we discuss the role Wnt/β-catenin signaling in oligodendrocyte development, focusing on the interpretation of disparate results, and highlighting areas where important questions remain to be answered about oligodendroglial lineage Wnt/β-catenin signaling. PMID:25782433

  6. Epigenetic silencing of tumor suppressor genes: Paradigms, puzzles, and potential.

    PubMed

    Kazanets, Anna; Shorstova, Tatiana; Hilmi, Khalid; Marques, Maud; Witcher, Michael

    2016-04-01

    Cancer constitutes a set of diseases with heterogeneous molecular pathologies. However, there are a number of universal aberrations common to all cancers, one of these being the epigenetic silencing of tumor suppressor genes (TSGs). The silencing of TSGs is thought to be an early, driving event in the oncogenic process. With this in consideration, great efforts have been made to develop small molecules aimed at the restoration of TSGs in order to limit tumor cell proliferation and survival. However, the molecular forces that drive the broad epigenetic reprogramming and transcriptional repression of these genes remain ill-defined. Undoubtedly, understanding the molecular underpinnings of transcriptionally silenced TSGs will aid us in our ability to reactivate these key anti-cancer targets. Here, we describe what we consider to be the five most logical molecular mechanisms that may account for this widely observed phenomenon: 1) ablation of transcription factor binding, 2) overexpression of DNA methyltransferases, 3) disruption of CTCF binding, 4) elevation of EZH2 activity, 5) aberrant expression of long non-coding RNAs. The strengths and weaknesses of each proposed mechanism is highlighted, followed by an overview of clinical efforts to target these processes. PMID:27085853

  7. Some puzzles about logarithmic relaxations and a few possible resolutions

    SciTech Connect

    Pollak, M.

    2014-08-20

    Three subjects are examined in connection with the relaxation of an electron glass. 1. In most cases the experimental decay time τ is found to relate to a history of the system rather than to the time it takes to reach equilibrium. The reason is that in a non-ergodic system equilibrium cannot be reached in any experiment but the knowledge of an equilibrium property is essential in evaluating the time to reach it. 2. An alternative theory is proposed for the interpretation of aging experiments. The proposed theory is deemed to better represent the physics and is more in keeping with the relaxation theory. 3. A current relaxation theory for the electron glass fails to take into account a certain renewal process during the evolution of the relaxation, namely the possibility of fast transitions following a slow transition. Ramifications of such a neglect are explored.

  8. FTire and puzzling tyre physics: teacher, not student

    NASA Astrophysics Data System (ADS)

    Gipser, Michael

    2016-04-01

    By means of some instructive examples, the contribution shows how even complex phenomena and relations in tyre physics are better understood by using a physics-based tyre simulation model like FTire. In contrast to approximation-based phenomenological models, such an approach will give insight into, rather than requiring description of, the tyre's behaviour. Examples studied here comprise * predicted influence of wheel load, inflation pressure, camber angle, and slow rolling speed on parking torque, * predicted influence of inflation pressure on cornering stiffness and pneumatic trail, * relaxation length: ramping up and down slip angle and wheel load, * handling characteristic on very rough roads, * a strange phenomenon: cleats that 'attract' a tyre. Related to these studies, user-friendly simulation tools on the basis of FTire are introduced, which help in understanding the above-mentioned complex tyre properties. One of these tools, being valuable both in teaching and for vehicle/tyre dynamics experts in industry and research, allows the user to interactively modify, during a running simulation, tyre geometry, material data, and operating conditions. The impact of these variations both on tyre forces and moments as well as on internal tyre states can be directly seen in a running animation, and later analysed with a large variety of post-processing tools. Animations for all case studies are available for download on http://www.cosin.eu/animations. All registered trademarks used here are properties of their respective owners.

  9. The Puzzlingly Small Ca II Triplet Absorption in Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    Saglia, R. P.; Maraston, Claudia; Thomas, Daniel; Bender, Ralf; Colless, Matthew

    2002-11-01

    We measure the central values (within Re/8) of the Ca II triplet line indices CaT* and CaT and the Paschen index PaT at 8600 Å for a 93% complete sample of 75 nearby early-type galaxies with BT<12 mag and Vgal<2490 km s-1. We find that the values of CaT* are constant to within 5% over the range of central velocity dispersions 100 km s-1<=σ<=340 km s-1, while the PaT (and CaT) values are mildly anticorrelated with σ. Using simple and composite stellar population models, we show the following: (1) The measured CaT* and CaT are lower than expected from simple stellar population (SSP) models with Salpeter initial mass functions (IMFs) and with metallicities and ages derived from optical Lick (Fe, Mg, and Hβ) indices. Uncertainties in the calibration, the fitting functions, and the SSP modeling taken separately cannot explain the discrepancy. On average, the observed PaT values are within the range allowed by the models and the large uncertainties in the fitting functions. (2) The steepening of the IMF at low masses required to lower the CaT* and CaT indices to the observed values is incompatible with the measured FeH index at 9916 Å and the dynamical mass-to-light ratios of elliptical galaxies. (3) Composite stellar populations with a low-metallicity component reduce the disagreement, but rather artificial metallicity distributions are needed. Another explanation may be that calcium is indeed underabundant in elliptical galaxies.

  10. Success in health information exchange projects: solving the implementation puzzle.

    PubMed

    Sicotte, Claude; Paré, Guy

    2010-04-01

    Interest in health information exchange (HIE), defined as the use of information technology to support the electronic transfer of clinical information across health care organizations, continues to grow among those pursuing greater patient safety and health care accessibility and efficiency. In this paper, we present the results of a longitudinal multiple-case study of two large-scale HIE implementation projects carried out in real time over 3-year and 2-year periods in Québec, Canada. Data were primarily collected through semi-structured interviews (n=52) with key informants, namely implementation team members and targeted users. These were supplemented with non-participants observation of team meetings and by the analysis of organizational documents. The cross-case comparison was particularly relevant given that project circumstances led to contrasting outcomes: while one project failed, the other was a success. A risk management analysis was performed taking a process view in order to capture the complexity of project implementations as evolving phenomena that are affected by interdependent pre-existing and emergent risks that tend to change over time. The longitudinal case analysis clearly demonstrates that the risk factors were closely intertwined. Systematic ripple effects from one risk factor to another were observed. This risk interdependence evolved dynamically over time, with a snowball effect that rendered a change of path progressively more difficult as time passed. The results of the cross-case analysis demonstrate a direct relationship between the quality of an implementation strategy and project outcomes. PMID:20137847

  11. Gastrotricha: A Marine Sister for a Freshwater Puzzle

    PubMed Central

    Todaro, M. Antonio; Dal Zotto, Matteo; Jondelius, Ulf; Hochberg, Rick; Hummon, William D.; Kånneby, Tobias; Rocha, Carlos E. F.

    2012-01-01

    Background Within an evolutionary framework of Gastrotricha Marinellina flagellata and Redudasys fornerise bear special interest, as they are the only Macrodasyida that inhabit freshwater ecosystems. Notwithstanding, these rare animals are poorly known; found only once (Austria and Brazil), they are currently systematised as incertae sedis. Here we report on the rediscovery of Redudasys fornerise, provide an account on morphological novelties and present a hypothesis on its phylogenetic relationship based on molecular data. Methodology/Principal Findings Specimens were surveyed using DIC microscopy and SEM, and used to obtain the 18 S rRNA gene sequence; molecular data was analyzed cladistically in conjunction with data from 42 additional species belonging to the near complete Macrodasyida taxonomic spectrum. Morphological analysis, while providing new information on taxonomically relevant traits (adhesive tubes, protonephridia and sensorial bristles), failed to detect elements of the male system, thus stressing the parthenogenetic nature of the Brazilian species. Phylogenetic analysis, carried out with ML, MP and Bayesian approaches, yielded topologies with strong nodal support and highly congruent with each other. Among the supported groups is the previously undocumented clade showing the alliance between Redudasys fornerise and Dactylopodola agadasys; other strongly sustained clades include the densely sampled families Thaumastodermatidae and Turbanellidae and most genera. Conclusions/Significance A reconsideration of the morphological traits of Dactylopodola agadasys in light of the new information on Redudasys fornerise makes the alliance between these two taxa very likely. As a result, we create Anandrodasys gen. nov. to contain members of the previously described D. agadasys and erect Redudasyidae fam. nov. to reflect this novel relationship between Anandrodasys and Redudasys. From an ecological perspective, the derived position of Redudasys, which is deeply nested within the Macrodasyida clade, unequivocally demonstrates that invasion of freshwater by gastrotrichs has taken place at least twice, in contrast with the single event hypothesis recently put forward. PMID:22348127

  12. The missing piece in the acid-rain puzzle

    SciTech Connect

    Powicki, C.R.

    1989-09-01

    This article discusses the role of geology in acid precipitation research and water quality. Knowledge of the composition and reactivity of the soil and bedrock through which acid precipitation flows is necessary to predict its effects on a body of water. Acidification not only has direct impacts, through water quality changes in water bodies, but also indirect long-term effects attributable to weathering rates. Once the capacity of the soil to buffer acidic loading is exceeded, sudden changes in soil chemistry may occur with dramatic effects on dependent biota.

  13. Extreme ultraviolet lithography: A few more pieces of the puzzle

    SciTech Connect

    Anderson, Christopher N.

    2009-05-20

    The work described in this dissertation has improved three essential components of extreme ultraviolet (EUV) lithography: exposure tools, photoresist, and metrology. Exposure tools. A field-averaging illumination stage is presented that enables nonuniform, high-coherence sources to be used in applications where highly uniform illumination is required. In an EUV implementation, it is shown that the illuminator achieves a 6.5% peak-to-valley intensity variation across the entire design field of view. In addition, a design for a stand-alone EUV printing tool capable of delivering 15 nm half-pitch sinusoidal fringes with available sources, gratings and nano-positioning stages is presented. It is shown that the proposed design delivers a near zero line-edge-rougness (LER) aerial image, something extremely attractive for the application of resist testing. Photoresist. Two new methods of quantifying the deprotection blur of EUV photoresists are described and experimentally demonstrated. The deprotection blur, LER, and sensitivity parameters of several EUV photoresists are quantified simultaneously as base weight percent, photoacid generator (PAG) weight percent, and post-exposure bake (PEB) temperature are varied. Two surprising results are found: (1) changing base weight percent does not significantly affect the deprotection blur of EUV photoresist, and (2) increasing PAG weight percent can simultaneously reduce LER and E-size in EUV photoresist. The latter result motivates the development of an EUV exposure statistics model that includes the effects of photon shot noise, the PAG spatial distribution, and the changing of the PAG distribution during the exposure. In addition, a shot noise + deprotection blur model is used to show that as deprotection blur becomes large relative to the size of the printed feature, LER reduction from improved counting statistics becomes dominated by an increase in LER due to reduced deprotection contrast. Metrology. Finally, this dissertation describes MOSAIC, a new wavefront metrology that enables complete wavefront recovery from print or aerial image based measurements. This new technique, based on measuring the local focal length of the optic at sampled positions in the pupil, recovers the curvature of the aberration and uses the curvature to recover the aberration itself. In a modeled EUV implementation, MOSAIC is shown to recover the SEMATECH Berkeley MET wavefront with a 4.2% RMS error: a 4% improvement over the reported errors of the original lateral shearing interferometry wavefront measurement.

  14. Pull or Push? Octopuses Solve a Puzzle Problem.

    PubMed

    Richter, Jonas N; Hochner, Binyamin; Kuba, Michael J

    2016-01-01

    Octopuses have large brains and exhibit complex behaviors, but relatively little is known about their cognitive abilities. Here we present data from a five-level learning and problem-solving experiment. Seven octopuses (Octopus vulgaris) were first trained to open an L shaped container to retrieve food (level 0). After learning the initial task all animals followed the same experimental protocol, first they had to retrieve this L shaped container, presented at the same orientation, through a tight fitting hole in a clear Perspex partition (level 1). This required the octopuses to perform both pull and release or push actions. After reaching criterion the animals advanced to the next stage of the test, which would be a different consistent orientation of the object (level 2) at the start of the trial, an opaque barrier (level 3) or a random orientation of the object (level 4). All octopuses were successful in reaching criterion in all levels of the task. At the onset of each new level the performance of the animals dropped, shown as an increase in working times. However, they adapted quickly so that overall working times were not significantly different between levels. Our findings indicate that octopuses show behavioral flexibility by quickly adapting to a change in a task. This can be compared to tests in other species where subjects had to conduct actions comprised of a set of motor actions that cannot be understood by a simple learning rule alone. PMID:27003439

  15. Blacks and High Self-Esteem: A Puzzle

    ERIC Educational Resources Information Center

    Simmons, Roberta G.

    1978-01-01

    Changes in research findings related to the self-esteem of blacks may be due to the impact of ideology; or to methodological differences, such as the populations studied, the definitions and dimensions of self-image conceptualized, and the measures used. This article is a commentary on the previous Adam article (TM 503 243). (BW)

  16. PROMISES AND PUZZLES, THE PLIGHT OF THE INNER-CITY.

    ERIC Educational Resources Information Center

    GALLOWAY, CHARLES

    EMPHASIS ON THE PROBLEMS OF TEACHING CULTURALLY DISADVANTAGED PUPILS HAS ONLY MADE THE TASK OF THE INNER-CITY TEACHER MORE DIFFICULT, AND HAS CREATED CONFUSION IN THE SCHOOLS REGARDING THE MEANS AND ENDS OF EDUCATION. NEGATIVE IDENTIFICATION OF THE SCHOOL AS THE PRIMARY VEHICLE FOR OVERCOMING CULTURAL GAPS AND WEAKNESSES MAY BE PARTIALLY DUE TO…

  17. HD 96446: a puzzle for current models of magnetospheres?

    NASA Astrophysics Data System (ADS)

    Neiner, C.; Landstreet, J. D.; Alecian, E.; Owocki, S.; Kochukhov, O.; Bohlender, D.; MiMeS Collaboration

    2012-10-01

    Context. Oblique magnetic dipole fields have been detected in Bp stars for several decades, and more recently also in normal massive stars. In the past decade, it has been established that stellar magnetospheres form through the channelling and confinement of an outflowing stellar wind by the stellar magnetic field. This explains specific properties of magnetic massive stars, such as their rotationally modulated photometric light curve, Hα emission, UV spectra, and X-ray emission. Aims: In the framework of the MiMeS (Magnetism in Massive Stars) project, four HARPSpol observations of the magnetic Bp star HD 96446 have been obtained. HD 96446 is very similar to σ Ori E, the prototype of centrifugally supported rigidly rotating magnetospheres (CM) and is therefore a perfect target to study the validity of this model. Methods: We first updated the basic parameters of HD 96446 and studied its spectral variability. We then analysed the HARPSpol spectropolarimetric observations using the LSD (Least-Squares Deconvolution) technique to derive the longitudinal magnetic field and Zeeman signatures in various types of lines. With LTE spectrum modelling, we derived constraints on the field modulus, the rotational velocity, and the inclination angle, and measured non-solar abundances of several elements which we checked with NLTE modelling. Finally, we calculated the magnetic confinement and Alfvén and Kepler radii from the stellar magnetic field and rotation properties, and we examined the various types of magnetospheres that may be present around HD 96446. Results: We find radial velocity variations with a period around 2.23 h, that we attribute to β Cep-type p-mode pulsations. We detect clear direct magnetic Stokes V signatures with slightly varying values of the longitudinal magnetic field, typical of an oblique dipole rotator, and show that these signatures are not much perturbed by the radial velocity variations. The magnetic confinement parameter and Alfvén radius in the centrifugally supported, rigidly-rotating magnetosphere (CM) model points towards the presence of confined material in the magnetosphere. However, HD 96446 does not present signatures of the presence of such confined material, such as Hα emission. Conclusions: We conclude that, even though HD 96446 fulfills all criteria to host a CM with confined material, it does not. The rotation period must be significantly revised, or another model of magnetosphere with a leakage mechanism will need to be developed to explain the magnetic environment of this star. Based on observations obtained with the HARPSpol spectropolarimeter at ESO, Chile (Program ID 187.D-0917).

  18. Quantum Criticality and the (alpha)/(delta) Puzzle

    SciTech Connect

    Chapline, G

    2008-10-06

    In an overview of the elemental actinides Np and Pu stand out because of their anomalously low melting temperatures and the variety of complex phase transitions that occur in these elements and their alloys as a result of relatively modest changes in temperature and pressure. In this paper we suggest a novel explanation based on an analogy between the evolution of the actinide ground state as a function of spin orbit coupling and the behavior of thin film superconductors in a magnetic field. The key point is that in 'bad metals' spin orbit interactions give rise to low energy monopole-like solitons with quantized spin currents, which play much the same role as Abrikosov vortices in thin film superconductors. In Np and {alpha}-Pu these solitons form an ordered solid, while in impurity stabilized {delta}-Pu they form a pair condensate. This provides a simple explanation for the heretofore unexplained phenomenology of {alpha}/{delta} transition. Near room temperature {delta}-Pu represents a novel form of condensed matter: a 'Planckian metal' analogous to the quark-gluon plasma.

  19. USDA-VETNET: A MOLECULAR APPROACH TO EPIDEMIOLOGIC PUZZLES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    USDA - VetNet was established as a complimentary central database of PFGE fingerprints to CDC’s PulseNet. VetNet analyze PFGE fingerprints recovered from various animal sources including poultry, cattle (feed lot and dairy), and swine throughout the US. These isolates are presently being received ...

  20. Language Competence in a Puzzle of Modern Russian Vocational Education

    ERIC Educational Resources Information Center

    Vladislavovich, Serikov Vladislav; Alexandrovna, Loktyushina Elena; Konstantinovna, Pichugina Viktoria

    2014-01-01

    The article shows that foreign language skills influence the professional success in a globalized economy. Training experts who are able to use foreign languages at the level required for professional communications is highly urgent for today's Russia, however there is hardly any experience of training such experts in accordance with international…

  1. The Diffuse Interstellar Bands: an Elderly Astro-Puzzle Rejuvenated

    NASA Astrophysics Data System (ADS)

    Cox, Nick L. J.

    2011-12-01

    The interstellar medium constitutes a physically and chemically complex component of galaxies and is important in the cycle of matter and the evolution of stars. From various spectroscopic clues we now know that the interstellar medium is rich in organic compounds. However, identifying the exact nature of all these components remains a challenge. In particular the identification of the so-called diffuse band carriers has been alluding astronomers for almost a century. In recent decades, observational, experimental and theoretical advances have rapidly lead to renewed interest in the diffuse interstellar bands (DIBs). This has been instigated partly by their perceived relation to the infrared aromatic emission bands, the UV extinction bump and far-UV rise, and the growing number of (small) organic molecules identified in space. This chapter gives an overview of the observational properties and behaviour of the DIBs, and their presence throughout the Universe. I will highlight recent progress in identifying their carriers and discuss their potential as tracers and probes of (extra)-Galactic ISM conditions.

  2. Asthma in pregnancy: one more piece of the puzzle.

    PubMed

    Zanforlin, Alessandro; Corsico, Angelo G; DI Marco, Fabiano; Patella, Vincenzo; Scichilone, Nicola

    2016-02-01

    Asthma is the most commonly occurring respiratory complication during pregnancy, and is associated with a wide range of adverse maternal and perinatal outcomes. However, there is strong evidence that an adequate control of asthma can improve the health of both mothers and their babies. Despite the well-known risks of poorly-controlled asthma during pregnancy, a large proportion of women have sub-optimal asthma control, due to concerns surrounding risks related to pharmacological agents and uncertainties regarding the effectiveness and safety of different management strategies. A recent retrospective study showed that step-up therapy with low-dose inhaled corticosteroids / long-acting β2-agonist inhalers (ICS/LABA) or high-dose ICS presents the same risk profile in terms of major congenital malformations. These results are consistent with asthma management guidelines and provide scientific evidence to help physicians and mothers make evidence-based treatment decisions during pregnancy, particularly when stepping up to higher doses of ICS or addition of a LABA are required. These reassuring results should encourage women to continue their asthma medications when required to control their asthma during pregnancy and increase the likelihood of healthy pregnancies and newborns. This commentary focuses on some critical issues of this recent work and to the need of future study to evaluate the safety during pregnancy of novel molecules recently introduced for asthma treatment. PMID:27427392

  3. A New Look at Some Solar Wind Turbulence Puzzles

    NASA Technical Reports Server (NTRS)

    Roberts, Aaron

    2006-01-01

    Some aspects of solar wind turbulence have defied explanation. While it seems likely that the evolution of Alfvenicity and power spectra are largely explained by the shearing of an initial population of solar-generated Alfvenic fluctuations, the evolution of the anisotropies of the turbulence does not fit into the model so far. A two-component model, consisting of slab waves and quasi-two-dimensional fluctuations, offers some ideas, but does not account for the turning of both wave-vector-space power anisotropies and minimum variance directions in the fluctuating vectors as the Parker spiral turns. We will show observations that indicate that the minimum variance evolution is likely not due to traditional turbulence mechanisms, and offer arguments that the idea of two-component turbulence is at best a local approximation that is of little help in explaining the evolution of the fluctuations. Finally, time-permitting, we will discuss some observations that suggest that the low Alfvenicity of many regions of the solar wind in the inner heliosphere is not due to turbulent evolution, but rather to the existence of convected structures, including mini-clouds and other twisted flux tubes, that were formed with low Alfvenicity. There is still a role for turbulence in the above picture, but it is highly modified from the traditional views.

  4. Crossword Puzzles for Chemistry Education: Learning Goals beyond Vocabulary

    ERIC Educational Resources Information Center

    Yuriev, Elizabeth; Capuano, Ben; Short, Jennifer L.

    2016-01-01

    Chemistry is a technical scientific discipline strongly underpinned by its own complex and diverse language. To be successful in the problem-solving aspects of chemistry, students must master the language of chemistry, and in particular, the definition of terms and concepts. To assist students in this challenging task, a variety of instructional…

  5. Condensed matter physics of planets - Puzzles, progress and predictions

    NASA Technical Reports Server (NTRS)

    Stevenson, D. J.

    1984-01-01

    Attention is given to some of the major unresolved issues concerned with the physics of planetary interiors. The important advances in observations, and experimental and theoretical investigations are briefly reviewed, and some areas for further study are identified, including: the characteristics of atomic and electronic degrees of freedom at the high pressures and temperatures typical of a condensed planetary core; the behavior of water at megabar pressures; and the nature of the core-alloy in the earth and in the core mantle phase boundary. Consideration is also given to the behavior of carbon at high pressures and temperatures in the presence of oxygen and hydrogen; the behavior of the volatile ice assemblage in Titan at pressures of 2-40 kbar; and the electrical conductivities of matter under planetary core conditions.

  6. Ferroptosis: A missing puzzle piece in the p53 blueprint?

    PubMed

    Wang, Shang-Jui; Ou, Yang; Jiang, Le; Gu, Wei

    2016-05-01

    Recent evidence indicates that canonical functions of p53 (i.e., apoptosis and growth arrest) are dispensable for p53-mediated tumor suppression. We have uncovered a novel function of p53 that contributes to tumor suppression through regulation of cystine metabolism, reactive oxygen species responses, and ferroptosis. The p53-mediated ferroptotic response via SLC7A11 denotes an extra layer of defense against tumorigenesis in conjunction with other p53 functions. PMID:27314071

  7. Motivating Computer Engineering Freshmen through Mathematical and Logical Puzzles

    ERIC Educational Resources Information Center

    Parhami, B.

    2009-01-01

    As in many other fields of science and technology, college students in computer engineering do not come into full contact with the key ideas and challenges of their chosen discipline until the third year of their studies. This situation poses a problem in terms of keeping the students motivated as they labor through their foundational, basic…

  8. Resolving the Puzzle of MS1248-7+5706

    NASA Technical Reports Server (NTRS)

    Aldcroft, Thomas

    1999-01-01

    The X-ray source MS1248.7+5706 has been identified as a radio-quiet quasar at z=1.84, making it an ideal object for investigating the X-ray spectral evolution of radio-quiet quasars. However. spectral modeling of our ASCA observation of this X-ray source indicated that it might be confused by or misidentified with, a nearby K5V star. A high-resolution X-ray image has been obtained with the ROSAT HRI to enable us to interpret our ASCA spectra. An analysis of the new HRI observation shows that the X-ray source in the ASCA error circle most closely coincides with the position of the K5V star. It therefore appears that the identification of MS1248.7+5706 with a z=1.84 quasar is incorrect. Since MS1248.7+5706 is the second most luminous quasar in the Einstein Medium Sensitivity Survey, the bright end of the EMSS luminosity function will be impacted.

  9. EZ Pegasi - The last pieces of the puzzle

    NASA Technical Reports Server (NTRS)

    Howell, S. B.; Williams, W. M.; Barden, S. C.; Bopp, B. W.

    1986-01-01

    Based on UBV differential photometric observations carried out at the Braeside Observatory between October 19, 1984 and January 11, 1985, it is shown that EZ Peg is in synchronous rotation with a photometric period of 11.6626 days. The orbital solution of Griffin (1985) is in good agreement with the present results, and it is employed to analyze the emission properties of the Ca II and H-alpha emission in the system. It is suggested that the emission of the system is almost entirely associated with the primary component, and the two stars appear to be similar in size and luminosity.

  10. Possible explanation of the solar-neutrino puzzle

    NASA Technical Reports Server (NTRS)

    Bethe, H. A.

    1986-01-01

    A new derivation of the Mikheyev and Smirnov (1985) mechanism for the conversion of electron neutrinos into mu neutrinos when traversing the sun is presented, and various hypotheses set forth. It is assumed that this process is responsible for the detection of fewer solar neutrinos than expected, with neutrinos below a minimum energy, E(m), being undetectable. E(m) is found to be about 6 MeV, and the difference of the squares of the respective neutrino masses is calculated to be 6 X 10 to the - 5th sq eV. A restriction on the neutrino mixing angle is assumed such that the change of density near the crossing point is adiabatic. It is predicted that no resonance conversion of neutrinos will occur in the dense core of supernovae, but conversion of electron neutrinos to mu neutrinos will occur as they escape outward through a density region around 100.

  11. A Guide to Making the Autism Puzzle Fit

    ERIC Educational Resources Information Center

    Wagner, Sheila

    2011-01-01

    This fall in schools across the nation, students with autism spectrum disorder (ASD) will experience educational opportunities that, until recently, were denied to them. Because the No Child Left Behind Act and the Individuals with Disabilities Education Act ensure that students with ASD are included in the student body, principals must make…

  12. Pavlov's influence on American psychology: completing the puzzle.

    PubMed

    Ruiz, Gabriel; Sánchez, Natividad; Gonzalo De la Casa, Luis

    2005-01-01

    In this paper, a historical approach to the influence of Pavlov on American psychology is presented. After consider what we call the "received view": Pavlov's influence on American psychology is seen mainly, perhaps solely, as related to behaviorism, we present an alternative view in which the influence of the Russian is interpreted in relation to Florence Edna Mateer (1887-1961), William Horsley Gantt (1892-1980) and Howard Scott Liddell (1895-1962). PMID:19238772

  13. Neurocognitive impairments in schizophrenia: a piece of the epigenetic puzzle.

    PubMed

    Asarnow, R F

    1999-01-01

    This paper is a review of studies examining the neurobehavioral antecedents of schizophrenia which flesh out neurodevelopmental models of schizophrenia by detailing the time course of the ontogeney of neurobehavioral impairments in schizophrenia. A follow back design was used to identify precursors of psychotic symptoms in children with a schizophrenic disorder. The vast majority of children with a schizophrenic disorder had significant developmental delays beginning early in life. For example, gross deficits in early language development were found in almost 80% of the schizophrenic children. Somewhat later in development impairments in fine motor and bi-manual coordination are noted. Some of these early developmental delays are transitory. For example, basic language skills are among the best preserved neurocognitive functions in children and adults with schizophrenia. The results of our cross-sectional neurocognitive studies suggest that children with schizophrenia suffer from limitations in the ability to engage in effortful cognitive processing or impairments in working memory. The links between these elementary neurocognitive impairments and the development of formal thought disorder as well as discourse deficits in children with a schizophrenic disorder will be discussed. PMID:10546977

  14. Solving the Puzzle: Dual Language Learners with Challenging Behaviors

    ERIC Educational Resources Information Center

    Nemeth, Karen; Brillante, Pamela

    2011-01-01

    It can be difficult for any teacher to support a child whose behavior is disruptive, but a language barrier can certainly complicate the situation. Children who are new to English may not be able to tell teachers what's going on. This makes it even more important for teachers to learn specific strategies to interpret the child's actions and plan…

  15. Evaluating Programs in Real Time: Interpreting Puzzle Pieces.

    ERIC Educational Resources Information Center

    Innocenti, Mark S.

    2002-01-01

    In this commentary on a previous article that revealed modest and inconsistent results of the Parents as Teachers program, issues are highlighted that those involved in real-world evaluation need to consider. Study attrition, defining meaningful primary outcomes, and need to use a participatory approach to develop outcome-based interventions are…

  16. The Child's Lexical Representation: The "Puzzle-Puddle-Pickle" Evidence.

    ERIC Educational Resources Information Center

    Macken, Marlys A.

    Smith's 1973 model of articulatory phonological development between the ages of two and four is re-examined in an attempt to develop a model that includes the possibility of both perceptual and articulatory learning. Smith's data, regarding phonological transformations of words after rules established by his infant son's pronunciation of the words…

  17. The neurobiology of autism: new pieces of the puzzle.

    PubMed

    Acosta, Maria T; Pearl, Phillip L

    2003-03-01

    The neurobiologic basis of autism is reviewed, with discussion of evidence from genetic, magnetic resonance imaging, neuropathology, and functional neuroimaging studies. Although autism is a behaviorally valid syndrome, it is remarkably heterogeneous and involves multiple developmental domains as well as a wide range of cognitive, language, and socioemotional functioning. Although multiple etiologies are implicated, recent advances have identified common themes in pathophysiology. Genetic factors play a primary role, based on evidence from family studies, identification of putative genes using genome-wide linkage analyses, and comorbidities with known genetic mutations. The RELN gene, which codes for an extracellular protein guiding neuronal migration, has been implicated in autism. Numerous neuropathologic changes have been described, including macroencephaly, acceleration and then deceleration in brain growth, increased neuronal packing and decreased cell size in the limbic system, and decreased Purkinje cell number in the cerebellum. Abnormalities in organization of the cortical minicolumn, representing the fundamental subunit of vertical cortical organization, may underlie the pathology of autism and result in altered thalamocortical connections, cortical disinhibition, and dysfunction of the arousal-modulating system of the brain. The role of acquired factors is speculative, with insufficient evidence to link the measles-mumps-rubella (MMR) vaccine with autism or to change immunization practices. PMID:12583844

  18. The Kinematic Puzzle of the Gulf of California Rift system

    NASA Astrophysics Data System (ADS)

    Stock, J. M.

    2007-05-01

    Extensive recent studies of the Gulf of California greatly advanced our understanding of the kinematics of this Pacific-North America plate boundary rift and its crustal structure. However, some kinematic discrepancies that need to be resolved, particularly for the time interval 12-6 Ma, after subduction had stopped but possibly before major opening began in the northern Gulf basins. Correlation of pyroclastic flow deposits across the Upper Delfin Basin segment (Oskin et al., 2001 and subsequent papers) indicates that virtually all of the opening between the coastlines in this segment (from San Felipe/Puertecitos in Baja California to the W side of Tiburon Island) occurred since ~6.1 Ma producing ~250 km of opening of the marine basin. This implies that the crust in the basin should have been brought into the region since ca. 6 Ma, perhaps by production of new igneous crust or remobilization of continental crust to fill the ~250-km gap. The total amount of post-6 Ma opening in the rift, including the onland deformation, is consistent with expected Pacific-North America displacement determined from the global plate circuit since 6 Ma, and it is also consistent with the slip history of the southern San Andreas fault. A smaller amount of motion (tens of kms) can be identified geologically post-12.5 Ma and pre-6 Ma. However, this is not sufficient to match the plate circuit results, which seem to require several hundred more km of Pacific-North America plate motion at this latitude between 12 Ma and 6 Ma. This motion has to have been located elsewhere, not between the modern marine basin boundaries. The Pliocene basin history of the Gulf has varied from place to place, as the loci of extension moved around in the rift system Similar variations in late Miocene time could explain this discrepancy, with abandoned extensional or strike-slip fault systems elsewhere, perhaps in the Sonoran coastal plain. However, further geological and geophysical work is needed to characterize this area and see if such a model is feasible and whether faults can be found that will link kinematically northward to structures of the same age, east of the San Andreas fault. A related discrepancy comes from reports of middle Miocene microfossils in marine sediments within these young northern Gulf basins. If these microfossils are primary, then the 250 km of opening would have a longer history, but it would not change the fact that some slip is missing and must be found elsewhere. In addition, the extensive volcanism in the Puertecitos Volcanic Province and Delfin Basin region since 12.5 Ma should have left a record in the marine sediments. Ash and pumice from these eruptions have been found in the onland exposures of the Gulf marine deposits (Puertecitos Fm, San Felipe marine sequence). Similar evidence should be sought in any future drill holes into the marine section.

  19. Plausible explanation for the Δ5/2+(2000) puzzle

    NASA Astrophysics Data System (ADS)

    Xie, Ju-Jun; Martínez Torres, A.; Oset, E.; González, P.

    2011-05-01

    From a Faddeev calculation for the π-(Δρ)N5/2-(1675) system we show the plausible existence of three dynamically generated I(JP)=3/2(5/2+) baryon states below 2.3 GeV, whereas only two resonances, Δ5/2+(1905)(****) and Δ5/2+(2000)(**), are cataloged in the Particle Data Book Review. Our results give theoretical support to data analyses extracting two distinctive resonances, Δ5/2+(~1740) and Δ5/2+(~2200), from which the mass of Δ5/2+(2000)(**) is estimated. We propose that these two resonances should be cataloged instead of Δ5/2+(2000). This proposal gets further support from the possible assignment of the other baryon states found in the approach in the I=1/2,3/2 with JP=1/2+,3/2+,5/2+ sectors to known baryonic resonances. In particular, Δ1/2+(1750)(*) is naturally interpreted as a πN1/2-(1650) bound state.

  20. Neptune and Triton: Essential pieces of the Solar System puzzle

    NASA Astrophysics Data System (ADS)

    Masters, A.; Achilleos, N.; Agnor, C. B.; Campagnola, S.; Charnoz, S.; Christophe, B.; Coates, A. J.; Fletcher, L. N.; Jones, G. H.; Lamy, L.; Marzari, F.; Nettelmann, N.; Ruiz, J.; Ambrosi, R.; Andre, N.; Bhardwaj, A.; Fortney, J. J.; Hansen, C. J.; Helled, R.; Moragas-Klostermeyer, G.; Orton, G.; Ray, L.; Reynaud, S.; Sergis, N.; Srama, R.; Volwerk, M.

    2014-12-01

    The planet Neptune and its largest moon Triton hold the keys to major advances across multiple fields of Solar System science. The ice giant Neptune played a unique and important role in the process of Solar System formation, has the most meteorologically active atmosphere in the Solar System (despite its great distance from the Sun), and may be the best Solar System analogue of the dominant class of exoplanets detected to date. Neptune's moon Triton is very likely a captured Kuiper Belt object, holding the answers to questions about the icy dwarf planets that formed in the outer Solar System. Triton is geologically active, has a tenuous nitrogen atmosphere, and is predicted to have a subsurface ocean. However, our exploration of the Neptune system remains limited to a single spacecraft flyby, made by Voyager 2 in 1989. Here, we present the high-level science case for further exploration of this outermost planetary system, based on a white paper submitted to the European Space Agency (ESA) for the definition of the second and third large missions in the ESA Cosmic Vision Programme 2015-2025. We discuss all the major science themes that are relevant for further spacecraft exploration of the Neptune system, and identify key scientific questions in each area. We present an overview of the results of a European-led Neptune orbiter mission analysis. Such a mission has significant scope for international collaboration, and is essential to achieve our aim of understanding how the Solar System formed, and how it works today.

  1. Pull or Push? Octopuses Solve a Puzzle Problem

    PubMed Central

    Richter, Jonas N.; Hochner, Binyamin; Kuba, Michael J.

    2016-01-01

    Octopuses have large brains and exhibit complex behaviors, but relatively little is known about their cognitive abilities. Here we present data from a five-level learning and problem-solving experiment. Seven octopuses (Octopus vulgaris) were first trained to open an L shaped container to retrieve food (level 0). After learning the initial task all animals followed the same experimental protocol, first they had to retrieve this L shaped container, presented at the same orientation, through a tight fitting hole in a clear Perspex partition (level 1). This required the octopuses to perform both pull and release or push actions. After reaching criterion the animals advanced to the next stage of the test, which would be a different consistent orientation of the object (level 2) at the start of the trial, an opaque barrier (level 3) or a random orientation of the object (level 4). All octopuses were successful in reaching criterion in all levels of the task. At the onset of each new level the performance of the animals dropped, shown as an increase in working times. However, they adapted quickly so that overall working times were not significantly different between levels. Our findings indicate that octopuses show behavioral flexibility by quickly adapting to a change in a task. This can be compared to tests in other species where subjects had to conduct actions comprised of a set of motor actions that cannot be understood by a simple learning rule alone. PMID:27003439

  2. Paleomagnetism of the Wyoming Craton: A Pre-Laurentian Puzzle

    NASA Astrophysics Data System (ADS)

    Kilian, T.; Chamberlain, K.; Mitchell, R. N.; Evans, D. A.; Bleeker, W.; Lecheminant, A. N.

    2010-12-01

    The Archean Wyoming craton is mostly buried beneath Phanerozoic sediments in the Rocky Mountains of the west central United States. Exposures of the craton are entirely in thrust-bounded Laramide uplifts and contain numerous swarms of Neoarchean-Proterozoic mafic dikes. U-Pb ages from these dikes include ~2685 Ma from a dike in the Owl Creek Mountains (Frost et al., 2006) as well as another in the Bald Mountain region of the Bighorn Mountains (this study), ~2170 Ma from the Wind River Mountain quartz diorite (Harlan et al., 2003), ~2110 Ma from a dike in the Granite Mountains (Bowers and Chamberlain, 2006), ~2010 Ma from a Kennedy dike in the Laramie Range (Cox et al., 2000), and ~780 Ma for dikes in the Beartooth and Teton Mountains (Harlan et al., 1997). These possible age ranges of magmatic events will allow a detailed comparison with other cratons, especially Superior and Slave. Prior to the assembly of Laurentia, Wyoming may have been connected with Slave in supercraton Sclavia (Bleeker, 2003; Frost et al., 2007), or alternatively, Wyoming may have been attached to the present southern margin of Superior in the supercraton Superia, as judged by similarities of the thrice-glaciated Huronian and Snowy Pass sedimentary successions (Roscoe and Card, 1993). Paleomagnetic results will be presented from over 150 dikes in the Wyoming craton. All dikes were from the basement uplifts of the Beartooth Mountains, Bighorn Mountains, Owl Creek Mountains, Granite Mountains, Ferris Mountains and Laramie Range. Dikes range in widths from 1 to >100 meters, and trends vary across all orientations. Stable remanence is observed in majority of sites with at least 8 different directions from the various uplifts. Structural corrections are applied when necessary to restore shallowly dipping Cambrian strata to horizontal. The paleomagnetic study is being integrated with precise U-Pb geochronology of dikes that bear stable remanence directions. Results will eventually allow a comparison of results from both Slave and Superior cratons throughout the Archean and Proterozoic. The data will test the prior connections, or lack thereof, among the Archean cratons in Laurentia, and help assess whether there was a supercontinent during the Archean-Proterozoic transition.

  3. ADDing a piece to the puzzle of cognition in schizophrenia.

    PubMed

    Bosia, Marta; Pigoni, Alessandro; Zagato, Laura; Merlino, Lino; Casamassima, Nunzia; Lorenzi, Cristina; Pirovano, Adele; Smeraldi, Enrico; Manunta, Paolo; Cavallaro, Roberto

    2016-01-01

    The biological bases of cognitive impairment in schizophrenia are poorly understood and may lie in insults in neurodevelopment, leading to alterations in critical structures. Synapses proteins are claimed to have etiopathogenic roles and more direct effects on core cognitive functions. Adducins family proteins seem of great interest, as they are fundamental constituents of synapses, involved in actin cytoskeleton assembly-disassembly, responsible of synaptic plasticity. ADD2 is more prominently expressed in brain tissues and influences memory and learning, commonly impaired in schizophrenia. In the present study we tested 342 patients with schizophrenia for three common adducins genetic variants, ADD1 rs4961, ADD2 rs4984 and ADD3 rs3731566, reported to have significant effects on circulatory system in humans. Neuropsychological measures were evaluated with the Brief Assessment of Cognition in Schizophrenia (BACS), a broad battery evaluating core cognitive domains. The analysis showed significant effects of ADD2 genotype on almost every cognitive domain. Moreover, significant interactions between ADD1 and ADD3 were also observed on some BACS subtests, namely Symbol Coding and Verbal Memory. Our findings suggest that adducins are involved in cognitive impairment in schizophrenia. This effect may result both from a direct mechanism affecting synaptic building and plasticity and indirectly as a consequence of vascular insults. PMID:26723519

  4. Disentangling the Puzzle of Hydrogen Bonding in Vitamin C.

    PubMed

    Peña, Isabel; Daly, Adam M; Cabezas, Carlos; Mata, Santiago; Bermúdez, Celina; Niño, Amaya; López, Juan C; Grabow, Jens-Uwe; Alonso, José L

    2013-01-01

    Fast-passage Fourier transform microwave spectroscopy in combination with a laser ablation source has been successfully applied to probe vitamin C (l-ascorbic acid) in the gas phase. Its ethyldiol side chain and two hydroxyl groups around the γ-lactone ring provide five internal rotation axes, enabling vitamin C to assume a wide variety of nonplanar 3D cooperative hydrogen bond networks that can also include the keto and ether functions. The rotational constants extracted from the analysis of the spectrum unequivocally identify the existence of three dominant conformers stabilized by different intramolecular hydrogen bonding motifs forming five-, six-, or seven-membered rings. PMID:26291213

  5. The Puzzling Unidimensionality of DSM-5 Substance Use Disorder Diagnoses

    PubMed Central

    MacCoun, Robert J.

    2013-01-01

    There is a perennial expert debate about the criteria to be included or excluded for the DSM diagnoses of substance use dependence. Yet analysts routinely report evidence for the unidimensionality of the resulting checklist. If in fact the checklist is unidimensional, the experts are wrong that the criteria are distinct, so either the experts are mistaken or the reported unidimensionality is spurious. I argue for the latter position, and suggest that the traditional reflexive measurement model is inappropriate for the DSM; a formative measurement model would be a more accurate characterization of the institutional process by which the checklist is created, and a network or causal model would be a more appropriate foundation for a scientifically grounded diagnostic system. PMID:24324446

  6. Possible resolution of the black hole information puzzle

    SciTech Connect

    Polchinski, J. ); Strominger, A. )

    1994-12-15

    The problem of information loss is considered under the assumption that the process of black hole evaporation terminates in the decay of the black hole interior into a baby universe. We show that such theories can be decomposed into superselection sectors labeled by eigenvalues of the third-quantized baby universe field operator, and that scattering is unitary within each superselection sector. This result relies crucially on the quantum-mechanical variability of the decay time. It is further argued that the decay rate in the black hole rest frame is necessarily proportional to [ital e][sup [minus][ital S

  7. Youth with Aggressive and Violent Behaviors: Pieces of a Puzzle.

    ERIC Educational Resources Information Center

    Edmonson, Hank M.; Bullock, Lyndal M.

    1998-01-01

    A study investigated the perceptions of five male elementary students with behavior disorders regarding aggression and violence in schools. Students associated aggressive and violent behavior with drug use, stealing, destruction of property, fighting, and gangs. Participants suggested adding more police to schools and involving students in…

  8. Assembling the Puzzle: Pathways of Oxytocin Signaling in the Brain.

    PubMed

    Grinevich, Valery; Knobloch-Bollmann, H Sophie; Eliava, Marina; Busnelli, Marta; Chini, Bice

    2016-02-01

    Oxytocin (OT) is a neuropeptide, which can be seen to be one of the molecules of the decade due to its profound prosocial effects in nonvertebrate and vertebrate species, including humans. Although OT can be detected in various physiological fluids (blood, saliva, urine, cerebrospinal fluid) and brain tissue, it is unclear whether peripheral and central OT releases match and synergize. Moreover, the pathways of OT delivery to brain regions involved in specific behaviors are far from clear. Here, we discuss the evolutionarily and ontogenetically determined pathways of OT delivery and OT signaling, which orchestrate activity of the mesolimbic social decision-making network. Furthermore, we speculate that both the alteration in OT delivery and OT receptor expression may cause behavioral abnormalities in patients afflicted with psychosocial diseases. PMID:26001309

  9. Prions, amyloids, and RNA: Pieces of a puzzle.

    PubMed

    Nizhnikov, Anton A; Antonets, Kirill S; Bondarev, Stanislav A; Inge-Vechtomov, Sergey G; Derkatch, Irina L

    2016-05-01

    Amyloids are protein aggregates consisting of fibrils rich in β-sheets. Growth of amyloid fibrils occurs by the addition of protein molecules to the tip of an aggregate with a concurrent change of a conformation. Thus, amyloids are self-propagating protein conformations. In certain cases these conformations are transmissible / infectious; they are known as prions. Initially, amyloids were discovered as pathological extracellular deposits occurring in different tissues and organs. To date, amyloids and prions have been associated with over 30 incurable diseases in humans and animals. However, a number of recent studies demonstrate that amyloids are also functionally involved in a variety of biological processes, from biofilm formation by bacteria, to long-term memory in animals. Interestingly, amyloid-forming proteins are highly overrepresented among cellular factors engaged in all stages of mRNA life cycle: from transcription and translation, to storage and degradation. Here we review rapidly accumulating data on functional and pathogenic amyloids associated with mRNA processing, and discuss possible significance of prion and amyloid networks in the modulation of key cellular functions. PMID:27248002

  10. Reading the Pictures: A Missing Piece of the Literacy Puzzle

    ERIC Educational Resources Information Center

    Teachout, Chad; Bright, April

    2007-01-01

    The authors teach in an inner-city school where 74 percent of the students qualify for the free/reduced-price lunch program; 96 percent of the students are Hispanic, and 59 percent are learning English as their second language. Given that most of the children come from similar home environments, they set out to discover the difference between the…

  11. Aeronomical processes in cometary atmospheres - The carbon compounds' puzzle

    NASA Astrophysics Data System (ADS)

    Festou, M. C.

    Observational data on the abundances of C compounds in cometary nuclei and theoretical models of the physical processes involved in their visible and UV emissions are reviewed. The data are presented in tables and graphs, and the C/OH abundance ratio is found to vary from 0.005-0.06 in comets Bradfield, Encke, and Austin to about 0.5 in comets Kohoutek and West. The presence of a strong short-scale-length source of C (1D) atoms in the comets is held to rule out the possibility that CO is the parent species responsible for the C-compound emissions, and it is shown that the minor compounds, CN, C2, C3, CS, CH, and CS2 could account for the observed abundances of both C (1D) and C (3P). It is suggested that cometary nuclei are of inhomogeneous structure and undergo aging processes in the solar system.

  12. Hybrid Ameloblastoma of the Maxilla: A Puzzling Pathology

    PubMed Central

    Lakshmi, Chintamaneni Raja; Bhavana, Sujana Mulk; Nallamilli, Sai Madhavi; Prabhat, Meka Poorna Venkata; Sarat, Gummadapu; Anuradha, Chennupati

    2016-01-01

    Ameloblastomas are slow growing, locally invasive, benign odontogenic tumors of an epithelial origin, accounting for approximately 1% of all oral tumors. A 40-year-old man presented with a chief complaint of a swelling over the left side of his face of 4 years’ duration. On examination, gross facial asymmetry was detected, and a well-defined swelling was noted intraorally involving the left maxilla medially from the mid palatal raphe and obliterating the buccal vestibule laterally. The swelling was non-tender and exhibited dual consistencies: firm in the palate and cystic in the vestibular region. Computed tomography revealed a multilocular radiolucency, which involved the left maxilla, encroached into the left maxillary sinus and the nasal complex, and caused bony erosion. Early diagnosis and treatment are the key tools in managing ameloblastomas, failure of which may lead to a significant deterioration of the prognosis and an increased recurrence rate. Uncommon variants of ameloblastomas have been gaining interest recently. To date, 25 cases of hybrid ameloblastomas have been documented in the scientific literature. We present an extremely rare hybrid type of the ameloblastoma with combined follicular, cystic, acanthomatous, and desmoplastic variants, which render it the first of its kind to have ever been reported. PMID:27365557

  13. The puzzles of the prokineticin 2 pathway in human reproduction.

    PubMed

    Balasubramanian, Ravikumar; Plummer, Lacey; Sidis, Yisrael; Pitteloud, Nelly; Martin, Cecilia; Zhou, Qun-Yong; Crowley, William F

    2011-10-22

    Prokineticin, 1 (PROK1) and prokineticin 2 (PROK2), are two closely related proteins that were identified as the mammalian homologs of their two amphibian homologs, mamba intestinal toxin (MIT-1) and Bv8. MIT-1 was initially identified as a non-toxic constituent in the venom of the black mamba snake (Dendroaspis polylepis) (Joubert and Strydom, 1980) while Bv8 was identified in the skin secretion of the toad, Bombina variegate (Mollay et al., 1999). All three homologs stimulate gastrointestinal motility thus accounting for their family name "prokineticins" (Schweitz et al., 1990, 1999). However, since its initial description, both PROK1 and PROK2 have been found to regulate a dazzling array of biological functions throughout the body. In particular, PROK1 acts as a potent angiogenic mitogen on endocrine vascular epithelium, thus earning its other name, Endocrine gland-vascular endothelial factor (EG-VEGF) (LeCouter et al., 2002). In contrast, the PROK2 signaling pathway is a critical regulator of olfactory bulb morphogenesis and sexual maturation in mammals and this function is the focus of this review. PMID:21664414

  14. The assessment of WWTP performance: Towards a jigsaw puzzle evaluation?

    PubMed

    Papa, Matteo; Ceretti, Elisabetta; Viola, Gaia Claudia Viviana; Feretti, Donatella; Zerbini, Ilaria; Mazzoleni, Giovanna; Steimberg, Nathalie; Pedrazzani, Roberta; Bertanza, Giorgio

    2016-02-01

    A chemical and bio-analytical protocol is proposed as a holistic monitoring framework for the assessment of WWTPs (Wastewater Treatment Plants) performance. This combination of tests consists of: i) an analysis of emerging contaminants, to be added to the established physico-chemical parameters in order to understand the causes of (new) pollution phenomena and ii) some of the bio-analytical tools most widely applied in the field of wastewater research, which provide information on groups of chemicals with a common mode of toxic action (baseline toxicity, estrogenicity and mutagenicity/genotoxicity, selected as the most representative for human health). The negative effects of the discharge can thus be highlighted directly and used to assess the global environmental impact of WWTPs. As a validation, this multi-tiered approach was applied to a full-scale WWTP (150,000 p.e.), where different measurements were carried out: EDCs (Endocrine Disrupting Compounds) detection; algal growth inhibition, bioluminescence inhibition and acute toxicity test (for baseline toxicity); an E-Screen-like assay (for estrogenic activity); Ames, Allium cepa and Comet tests (for mutagenic/genotoxic activity). As a result, the WWTP showed good performance for all these issues, displaying its ability to enhance effluent quality, except for residual mutagenic behaviour, probably due to the by-products generated by the tertiary ozonation. PMID:26688267

  15. Systematics for low energy incomplete fusion: Still a puzzle?

    NASA Astrophysics Data System (ADS)

    Yadav, Abhishek; Shuaib, Mohd; Aggarwal, Abhay V.; Sharma, Vijay R.; Bala, Indu; Singh, D. P.; Singh, P. P.; Unnati; Sharma, M. K.; Kumar, R.; Singh, R. P.; Muralithar, S.; Singh, B. P.; Prasad, R.

    2016-05-01

    In order to have a better and clear picture of incomplete fusion reactions at energies ≈4-7MeV/nucleon, the excitation function measurements have been performed for 18O+159Tb system. The experimental data have been analyzed within the framework of compound nucleus decay. The cross-section for xn/pxn-channels are found to be well reproduced by PACE4 predictions, which suggest their production via complete fusion process. However, a significant enhancement in the excitation functions of α-emitting channels has been observed over the theoretical ones, which has been attributed due to the incomplete fusion processes. The incomplete fusion fractions have been deduced at each studied energy and compared with other nearby systems for better insight into the underlying dynamics. The incomplete fusion fraction has been found to be sensitive to the projectile's energy and α-Q-value.

  16. The Key Role of Emotions in the Schizophrenia Puzzle

    PubMed Central

    Ciompi, Luc

    2015-01-01

    The aim of this paper is to show that the dynamic effects of emotions in schizophrenia are underestimated and partly misunderstood. This may be related to an insufficient consideration for certain key properties of emotions, especially their energizing effects. After introductory remarks on current notions on emotions in schizophrenia, I present an alternative view based on my concept of affect-logic and discuss some of its therapeutic implications. PMID:25481397

  17. Missing Pieces in the Puzzle of Plant MicroRNAs.

    PubMed

    Reis, Rodrigo S; Eamens, Andrew L; Waterhouse, Peter M

    2015-11-01

    Plant microRNAs (miRNAs) are important regulatory switches. Recent advances have revealed many regulatory layers between the two essential processes, miRNA biogenesis and function. However, how these multilayered regulatory processes ultimately control miRNA gene regulation and connects miRNAs and plant responses with the surrounding environment is still largely unknown. In this opinion article, we propose that the miRNA pathway is highly dynamic and plastic. The apparent flexibility of the miRNA pathway in plants appears to be controlled by a number recently identified proteins and poorly characterized signaling cascades. We further propose that altered miRNA accumulation can be a direct consequence of the rewiring of interactions between proteins that function in the miRNA pathway, an avenue that remains largely unexplored. PMID:26442682

  18. Predicaments, Problems. Puzzles, and Paradoxes in Educational Research.

    ERIC Educational Resources Information Center

    Broudy, H. S.

    Educational research is designed to deal with problems. Some problems in American education cannot be understood outside their historical-philosophical contexts. This paper presents arguments concerning the limitations of standard empirical research in the field of education. This is accomplished by following developments in the culture that have…

  19. The Child's Lexical Representation: The "Puzzle-Puddle-Pickle" Evidence.

    ERIC Educational Resources Information Center

    Macken, Marlyn A.

    1980-01-01

    Presents two models of language acquisition: one postulating articulatory learning of underlying adult forms and the other both articulatory and perceptual learning. Reanalyzes the first model's data and concludes that two types of phonological rules are recognizable: perceptual-encoding rules and output (articulatory) rules. Identifies properties…

  20. On the puzzling deactivation mechanism of thymine after light irradiation

    SciTech Connect

    Gonzalez, Leticia; Gonzalez-Vazquez, Jesus; Samoylova, Elena; Schultz, Thomas

    2008-12-08

    The possible deactivation mechanisms of thymine after UV light irradiation are reviewed in the light of theoretical calculations. Recent experiments reveal that three transient species with lifetimes in the fs, ps, and ns regime are present in thymine. The possibility of ground or excited state tautomerization is explored and discarded. The role of {pi}{sigma}* states, as well as of the proposed minimum of the {pi}{pi}* excited state surface are assessed. In view of the obtained calculations and results available from the literature, the measured time scales can be tentatively attributed to a model involving different conical intersections between the {pi}{pi}*, n{pi}*, and the electronic ground state, as well as deactivation via the triplet states. Time-resolved photoelectron experiments supported by theoretical calculations are proposed to appraise the validity of this model.