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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. DU-AGG pilot plant design study

    SciTech Connect

    Lessing, P.A.; Gillman, H.

    1996-07-01

    The Idaho National Engineering Laboratory (INEL) is developing new methods to produce high-density aggregate (artificial rock) primarily consisting of depleted uranium oxide. The objective is to develop a low-cost method whereby uranium oxide powder (UO[sub 2], U[sub 3]O[sub ]8, or UO[sub 3]) can be processed to produce high-density aggregate pieces (DU-AGG) having physical properties suitable for disposal in low-level radioactive disposal facilities or for use as a component of high-density concrete used as shielding for radioactive materials. A commercial company, G-M Systems, conducted a design study for a manufacturing pilot plant to process DU-AGG. The results of that study are included and summarized in this report. Also explained are design considerations, equipment capacities, the equipment list, system operation, layout of equipment in the plant, cost estimates, and the proposed plan and schedule.

  3. 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…

  4. 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

  5. Distribution of AGG interruption patterns within nine world populations.

    PubMed

    Yrigollen, Carolyn M; Sweha, Stefan; Durbin-Johnson, Blythe; Zhou, Lili; Berry-Kravis, Elizabeth; Fernandez-Carvajal, Isabel; Faradz, Sultana Mh; Amiri, Khaled; Shaheen, Huda; Polli, Roberta; Murillo-Bonilla, Luis; Silva Arevalo, Gabriel de Jesus; Cogram, Patricia; Murgia, Alessandra; Tassone, Flora

    2014-11-01

    The CGG trinucleotide repeat within the FMR1 gene is associated with multiple clinical disorders, including fragile X-associated tremor/ataxia syndrome, fragile X-associated primary ovarian insufficiency, and fragile X syndrome. Differences in the distribution and prevalence of CGG repeat length and of AGG interruption patterns have been reported among different populations and ethnicities. In this study we characterized the AGG interruption patterns within 3,065 normal CGG repeat alleles from nine world populations including Australia, Chile, United Arab Emirates, Guatemala, Indonesia, Italy, Mexico, Spain, and United States. Additionally, we compared these populations with those previously reported, and summarized the similarities and differences. We observed significant differences in AGG interruption patterns. Frequencies of longer alleles, longer uninterrupted CGG repeat segments and alleles with greater than 2 AGG interruptions varied between cohorts. The prevalence of fragile X syndrome and FMR1 associated disorders in various populations is thought to be affected by the total length of the CGG repeat and may also be influenced by the AGG distribution pattern. Thus, the results of this study may be important in considering the risk of fragile X-related conditions in various populations.

  6. Distribution of AGG interruption patterns within nine world populations

    PubMed Central

    Yrigollen, Carolyn M.; Sweha, Stefan; Durbin-Johnson, Blythe; Zhou, Lili; Berry-Kravis, Elizabeth; Fernandez-Carvajal, Isabel; Faradz, Sultana MH; Amiri, Khaled; Shaheen, Huda; Polli, Roberta; Murillo-Bonilla, Luis; Silva Arevalo, Gabriel de Jesus; Cogram, Patricia; Murgia, Alessandra; Tassone, Flora

    2014-01-01

    Summary The CGG trinucleotide repeat within the FMR1 gene is associated with multiple clinical disorders, including fragile X-associated tremor/ataxia syndrome, fragile X-associated primary ovarian insufficiency, and fragile X syndrome. Differences in the distribution and prevalence of CGG repeat length and of AGG interruption patterns have been reported among different populations and ethnicities. In this study we characterized the AGG interruption patterns within 3,065 normal CGG repeat alleles from nine world populations including Australia, Chile, United Arab Emirates, Guatemala, Indonesia, Italy, Mexico, Spain, and United States. Additionally, we compared these populations with those previously reported, and summarized the similarities and differences. We observed significant differences in AGG interruption patterns. Frequencies of longer alleles, longer uninterrupted CGG repeat segments and alleles with greater than 2 AGG interruptions varied between cohorts. The prevalence of fragile X syndrome and FMR1 associated disorders in various populations is thought to be affected by the total length of the CGG repeat and may also be influenced by the AGG distribution pattern. Thus, the results of this study may be important in considering the risk of fragile X-related conditions in various populations. PMID:25606365

  7. Distribution of AGG interruption patterns within nine world populations.

    PubMed

    Yrigollen, Carolyn M; Sweha, Stefan; Durbin-Johnson, Blythe; Zhou, Lili; Berry-Kravis, Elizabeth; Fernandez-Carvajal, Isabel; Faradz, Sultana Mh; Amiri, Khaled; Shaheen, Huda; Polli, Roberta; Murillo-Bonilla, Luis; Silva Arevalo, Gabriel de Jesus; Cogram, Patricia; Murgia, Alessandra; Tassone, Flora

    2014-11-01

    The CGG trinucleotide repeat within the FMR1 gene is associated with multiple clinical disorders, including fragile X-associated tremor/ataxia syndrome, fragile X-associated primary ovarian insufficiency, and fragile X syndrome. Differences in the distribution and prevalence of CGG repeat length and of AGG interruption patterns have been reported among different populations and ethnicities. In this study we characterized the AGG interruption patterns within 3,065 normal CGG repeat alleles from nine world populations including Australia, Chile, United Arab Emirates, Guatemala, Indonesia, Italy, Mexico, Spain, and United States. Additionally, we compared these populations with those previously reported, and summarized the similarities and differences. We observed significant differences in AGG interruption patterns. Frequencies of longer alleles, longer uninterrupted CGG repeat segments and alleles with greater than 2 AGG interruptions varied between cohorts. The prevalence of fragile X syndrome and FMR1 associated disorders in various populations is thought to be affected by the total length of the CGG repeat and may also be influenced by the AGG distribution pattern. Thus, the results of this study may be important in considering the risk of fragile X-related conditions in various populations. PMID:25606365

  8. 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…

  9. Higher pollinator effectiveness by specialist than generalist flower-visitors of unspecialized Knautia arvensis (Dipsacaceae).

    PubMed

    Larsson, Magnus

    2005-12-01

    A critical issue in pollination ecology is the evolution of generalist pollination systems, and under which conditions floral specializations evolve from these. The gynodioecious herb Knautia arvensis (Dipsacaceae) exhibits a generalized pollination system, but is visited by both generalist and specialist flower-visitors. The present study tested pollinator effectiveness and pollinator importance of the pollen specialist solitary bee Andrena hattorfiana (Andrenidae) vs. the generalist flower-visitors to K. arvensis on the island of Oland, SE Sweden. Females of the specialist bee removed more pollen per inflorescence-visit than the major groups of generalist visitors such as bumblebees and flies. They also deposited more pollen per inflorescence-visit than any of the generalist visitor groups. The females have a preference for pollen-presenting vs. stigma-presenting inflorescences, a pattern shared with most of the generalist flower-visitors. Females of the specialist exert such a strong preference that they, despite their great pollinator effectiveness, make modest contribution to pollen transfer in K. arvensis. The females of A. hattorfiana accounted for 14.2% of the overall visits and 5.8% of the total pollination, the rest being performed by generalist visitors and males of A. hattorfiana. This study shows that pollinator effectiveness of a specialist can be superior while generalist flower-visitors select floral characters towards generalization through their greater contribution to overall pollen flow.

  10. 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,…

  11. 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

  12. 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)

  13. 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)

  14. The plant-specific G protein γ subunit AGG3 influences organ size and shape in Arabidopsis thaliana.

    PubMed

    Li, Shengjun; Liu, Yaju; Zheng, Leiying; Chen, Liangliang; Li, Na; Corke, Fiona; Lu, Yaru; Fu, Xiangdong; Zhu, Zhengge; Bevan, Michael W; Li, Yunhai

    2012-05-01

    • Control of organ size and shape by cell proliferation and cell expansion is a fundamental developmental process, but the mechanisms that set the size and shape of determinate organs are largely unknown in plants. • Molecular, genetic, cytological and biochemical approaches were used to characterize the roles of the Arabidopsis thaliana G protein γ subunit (AGG3) gene in organ growth. • Here, we describe A. thaliana AGG3, which promotes petal growth by increasing the period of cell proliferation. Both the N-terminal region and the C-terminal domains of AGG3 are necessary for the function of AGG3. By contrast, analysis of a series of AGG3 derivatives with deletions in specific domains showed that the deletion of any of these domains cannot completely abolish the function of AGG3. The GFP-AGG3 fusion protein is localized to the plasma membrane. The predicted transmembrane domain plays an important role in the plasma membrane localization of AGG3. Genetic analyses revealed that AGG3 action requires a functional G protein α subunit (GPA1) and G protein β subunit (AGB1). • Our findings demonstrate that AGG3, GPA1 and AGB1 act in the same genetic pathway to influence organ size and shape in A. thaliana.

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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)

  20. 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…

  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. Normal Birth Crossword Puzzle

    PubMed Central

    Hotelling, Barbara A.

    2006-01-01

    In this column, readers are introduced to Dawn Kersula and a crossword puzzle she designed to refresh and empower Lamaze childbirth education class participants with normal-birth information. The column's author goes on to demonstrate several ways crossword puzzles can be used in Lamaze classes. PMID:17322944

  3. 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)

  4. 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.

  5. 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)

  6. 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

  7. 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.

  8. 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.

  9. Musical Traditions. Puzzle Corner.

    ERIC Educational Resources Information Center

    Andrews, Ian A.

    1999-01-01

    Discusses the changes in musical experiences, such as live versus recorded music, as society has developed technologically. Presents a crossword puzzle that focuses on the traditions and musicians of baroque, classical, and romantic music each originating in Europe. Includes the clues and word list. (CMK)

  10. 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)

  11. 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

  12. 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.

  13. 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…

  14. 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

  15. 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)

  16. Darwin's puzzling Expression.

    PubMed

    Radick, Gregory

    2010-02-01

    Charles Darwin's The Expression of the Emotions in Man and Animals (1872) is a very different kind of work from On the Origin of Species (1859). This "otherness" is most extreme in the character of the explanations that Darwin offers in the Expression. Far from promoting his theory of natural selection, the Expression barely mentions that theory, instead drawing on explanatory principles which recall less Darwinian than Lamarckian and structuralist biological theorizing. Over the years, historians have offered a range of solutions to the puzzle of why the Expression is so "non-Darwinian". Close examination shows that none of these meets the case. However, recent research on Darwin's lifelong engagement with the controversies in his day over the unity of the human races makes possible a promising new solution. For Darwin, emotional expression served the cause of defending human unity precisely to the extent that natural selection theory did not apply. PMID:20338535

  17. Darwin's puzzling Expression.

    PubMed

    Radick, Gregory

    2010-02-01

    Charles Darwin's The Expression of the Emotions in Man and Animals (1872) is a very different kind of work from On the Origin of Species (1859). This "otherness" is most extreme in the character of the explanations that Darwin offers in the Expression. Far from promoting his theory of natural selection, the Expression barely mentions that theory, instead drawing on explanatory principles which recall less Darwinian than Lamarckian and structuralist biological theorizing. Over the years, historians have offered a range of solutions to the puzzle of why the Expression is so "non-Darwinian". Close examination shows that none of these meets the case. However, recent research on Darwin's lifelong engagement with the controversies in his day over the unity of the human races makes possible a promising new solution. For Darwin, emotional expression served the cause of defending human unity precisely to the extent that natural selection theory did not apply.

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. 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.

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

    PubMed Central

    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

    2015-01-01

    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

  4. 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.

  5. 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.

  6. Puzzles: A Pathetically Neglected, Commonly Available Resource.

    ERIC Educational Resources Information Center

    Maldonado, Nancy S.

    1996-01-01

    States that puzzles are an important tool in helping children engage in the problem-solving process. Claims that children are interested in puzzles because they can be active as observers, problem solvers, and learners, with little or no assistance from adults and others. Defines nine characteristics of good puzzle-making situations. (MOK)

  7. 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…

  8. 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)

  9. 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.)

  10. Shortening of the Lactobacillus paracasei subsp. paracasei BGNJ1-64 AggLb Protein Switches Its Activity from Auto-aggregation to Biofilm Formation.

    PubMed

    Miljkovic, Marija; Bertani, Iris; Fira, Djordje; Jovcic, Branko; Novovic, Katarina; Venturi, Vittorio; Kojic, Milan

    2016-01-01

    AggLb is the largest (318.6 kDa) aggregation-promoting protein of Lactobacillus paracasei subsp. paracasei BGNJ1-64 responsible for forming large cell aggregates, which causes auto-aggregation, collagen binding and pathogen exclusion in vitro. It contains an N-terminus leader peptide, followed by six successive collagen binding domains, 20 successive repeats (CnaB-like domains) and an LPXTG sorting signal at the C-terminus for cell wall anchoring. Experimental information about the roles of the domains of AggLb is currently unknown. To define the domain that confers cell aggregation and the key domains for interactions of specific affinity between AggLb and components of the extracellular matrix, we constructed a series of variants of the aggLb gene and expressed them in Lactococcus lactis subsp. lactis BGKP1-20 using a lactococcal promoter. All of the variants contained a leader peptide, an inter collagen binding-CnaB domain region (used to raise an anti-AggLb antibody), an anchor domain and a different number of collagen binding and CnaB-like domains. The role of the collagen binding repeats of the N-terminus in auto-aggregation and binding to collagen and fibronectin was confirmed. Deletion of the collagen binding repeats II, III, and IV resulted in a loss of the strong auto-aggregation, collagen and fibronectin binding abilities whereas the biofilm formation capability was increased. The strong auto-aggregation, collagen and fibronectin binding abilities of AggLb were negatively correlated to biofilm formation. PMID:27660628

  11. Shortening of the Lactobacillus paracasei subsp. paracasei BGNJ1-64 AggLb Protein Switches Its Activity from Auto-aggregation to Biofilm Formation

    PubMed Central

    Miljkovic, Marija; Bertani, Iris; Fira, Djordje; Jovcic, Branko; Novovic, Katarina; Venturi, Vittorio; Kojic, Milan

    2016-01-01

    AggLb is the largest (318.6 kDa) aggregation-promoting protein of Lactobacillus paracasei subsp. paracasei BGNJ1-64 responsible for forming large cell aggregates, which causes auto-aggregation, collagen binding and pathogen exclusion in vitro. It contains an N-terminus leader peptide, followed by six successive collagen binding domains, 20 successive repeats (CnaB-like domains) and an LPXTG sorting signal at the C-terminus for cell wall anchoring. Experimental information about the roles of the domains of AggLb is currently unknown. To define the domain that confers cell aggregation and the key domains for interactions of specific affinity between AggLb and components of the extracellular matrix, we constructed a series of variants of the aggLb gene and expressed them in Lactococcus lactis subsp. lactis BGKP1-20 using a lactococcal promoter. All of the variants contained a leader peptide, an inter collagen binding-CnaB domain region (used to raise an anti-AggLb antibody), an anchor domain and a different number of collagen binding and CnaB-like domains. The role of the collagen binding repeats of the N-terminus in auto-aggregation and binding to collagen and fibronectin was confirmed. Deletion of the collagen binding repeats II, III, and IV resulted in a loss of the strong auto-aggregation, collagen and fibronectin binding abilities whereas the biofilm formation capability was increased. The strong auto-aggregation, collagen and fibronectin binding abilities of AggLb were negatively correlated to biofilm formation. PMID:27660628

  12. Shortening of the Lactobacillus paracasei subsp. paracasei BGNJ1-64 AggLb Protein Switches Its Activity from Auto-aggregation to Biofilm Formation

    PubMed Central

    Miljkovic, Marija; Bertani, Iris; Fira, Djordje; Jovcic, Branko; Novovic, Katarina; Venturi, Vittorio; Kojic, Milan

    2016-01-01

    AggLb is the largest (318.6 kDa) aggregation-promoting protein of Lactobacillus paracasei subsp. paracasei BGNJ1-64 responsible for forming large cell aggregates, which causes auto-aggregation, collagen binding and pathogen exclusion in vitro. It contains an N-terminus leader peptide, followed by six successive collagen binding domains, 20 successive repeats (CnaB-like domains) and an LPXTG sorting signal at the C-terminus for cell wall anchoring. Experimental information about the roles of the domains of AggLb is currently unknown. To define the domain that confers cell aggregation and the key domains for interactions of specific affinity between AggLb and components of the extracellular matrix, we constructed a series of variants of the aggLb gene and expressed them in Lactococcus lactis subsp. lactis BGKP1-20 using a lactococcal promoter. All of the variants contained a leader peptide, an inter collagen binding-CnaB domain region (used to raise an anti-AggLb antibody), an anchor domain and a different number of collagen binding and CnaB-like domains. The role of the collagen binding repeats of the N-terminus in auto-aggregation and binding to collagen and fibronectin was confirmed. Deletion of the collagen binding repeats II, III, and IV resulted in a loss of the strong auto-aggregation, collagen and fibronectin binding abilities whereas the biofilm formation capability was increased. The strong auto-aggregation, collagen and fibronectin binding abilities of AggLb were negatively correlated to biofilm formation.

  13. Distribution of Pathogenic Genes aatA, aap, aggR, among Uropathogenic Escherichia coli (UPEC) and Their Linkage with StbA Gene.

    PubMed

    Nazemi, A; Mirinargasi, M; Merikhi, N; Sharifi, S H

    2011-07-01

    Urinary tract infection (UTI) with E. coli (UPEC) is one of the most common bacterial infections among human beings. In addition to the host predisposing factors, genes are also proposed to have an important role in the occurrence of UTIs. This study investigated the distribution of three pathogenic genes including aggR, aap and aatA among UPEC infected samples and their linkage with stbA, the essential gene for maintaining of pAA plasmid. A total of 244 samples were collected from patients with UTIs through clinical laboratories located in western side of Tehran (Iran) during years 2008-2009. E. coli isolation was performed according to standard laboratory methods. DNAs were extracted from samples using Boiling method, and the presence of aap, aggR, aatA and stbA genes were investigated by PCR. No pathogenic genes (aap, aggR, aatA) were found in 104 out of 244 UPEC samples, while 14 of them were carrying stbA gene. Out of 140 UPEC samples with pathogenic genes, 94 (46.6%) were carrying aap gene, 52 (23%) aggR gene, and 80 (35.4%) aatA gene. A total of 18 samples were also carrying all pathogenic genes together. Moreover, 44 out of 144 samples were carrying stbA gene. The results obtained by this study showed that the aggR, aap and aatA pathogenic genes have different existence patterns in different E. coli strains that infect different organs. Our study also showed that these three plasmid genes in EAEC strains are able to transpose in the genome and change their level of linkage with pAA plasmid essential gene stbA. Meanwhile, this study confirmed that aggR, aap and aatA genes are not specific to only EAEC strains.

  14. (Anti)hypertriton lifetime puzzle

    NASA Astrophysics Data System (ADS)

    Ma, Yu-Gang

    2016-05-01

    Most calculations on the lifetime of (anti)hypertriton gave a similar lifetime which is close to the lifetime of free Λ decays. However, recent measurements on (anti)hypertriton lifetime demonstrate a much short lifetime. All results for (anti)hypertriton lifetime by two-body decay channel of 3He + π for Au+Au collision at RHIC, Pb+Pb collision at LHC and Li + C collisions at GSI show a significant short lifetime in comparison with lifetime of free Λ decays. However, theoretical interpretation remains puzzle.

  15. 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

  16. 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.

  17. 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…

  18. Have a Book? Make a Puzzle.

    ERIC Educational Resources Information Center

    Texas Child Care, 1994

    1994-01-01

    Notes that puzzles, the cornerstone of table-top or manipulative learning areas in early childhood programs, are structured materials, self-correcting toys that help children in a variety of developmental areas. Suggests that handmade puzzles are less expensive and can be tailored for specific concepts, themes, or skill levels. Provides…

  19. 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.

  20. The RPA Atomization Energy Puzzle.

    PubMed

    Ruzsinszky, Adrienn; Perdew, John P; Csonka, Gábor I

    2010-01-12

    There is current interest in the random phase approximation (RPA), a "fifth-rung" density functional for the exchange-correlation energy. RPA has full exact exchange and constructs the correlation with the help of the unoccupied Kohn-Sham orbitals. In many cases (uniform electron gas, jellium surface, and free atom), the correction to RPA is a short-ranged effect that is captured by a local spin density approximation (LSDA) or a generalized gradient approximation (GGA). Nonempirical density functionals for the correction to RPA were constructed earlier at the LSDA and GGA levels (RPA+), but they are constructed here at the fully nonlocal level (RPA++), using the van der Waals density functional (vdW-DF) of Langreth, Lundqvist, and collaborators. While they make important and helpful corrections to RPA total and ionization energies of free atoms, they correct the RPA atomization energies of molecules by only about 1 kcal/mol. Thus, it is puzzling that RPA atomization energies are, on average, about 10 kcal/mol lower than those of accurate values from experiment. We find here that a hybrid of 50% Perdew-Burke-Ernzerhof GGA with 50% RPA+ yields atomization energies much more accurate than either one does alone. This suggests a solution to the puzzle: While the proper correction to RPA is short-ranged in some systems, its contribution to the correlation hole can spread out in a molecule with multiple atomic centers, canceling part of the spread of the exact exchange hole (more so than in RPA or RPA+), making the true exchange-correlation hole more localized than in RPA or RPA+. This effect is not captured even by the vdW-DF nonlocality, but it requires the different kind of full nonlocality present in a hybrid functional.

  1. Oriental Puzzle Gives Students Graphics Practice.

    ERIC Educational Resources Information Center

    Reddick, David B.; Johnson, Terri

    1985-01-01

    Describes a class assignment in which graphics students use an ancient Chinese puzzle called a tangram. Students arrange the five triangles, one square, and one rhomboid into an animate and an inanimate object. (HTH)

  2. 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

  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.

  4. 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

  5. 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.

  6. The effect of dielectric constants on noble metal/semiconductor SERS enhancement: FDTD simulation and experiment validation of Ag/Ge and Ag/Si substrates.

    PubMed

    Wang, Tao; Zhang, Zhaoshun; Liao, Fan; Cai, Qian; Li, Yanqing; Lee, Shuit-Tong; Shao, Mingwang

    2014-02-11

    The finite-difference time-domain (FDTD) method was employed to simulate the electric field distribution for noble metal (Au or Ag)/semiconductor (Ge or Si) substrates. The simulation showed that noble metal/Ge had stronger SERS enhancement than noble metal/Si, which was mainly attributed to the different dielectric constants of semiconductors. In order to verify the simulation, Ag nanoparticles with the diameter of ca. 40 nm were grown on Ge or Si wafer (Ag/Ge or Ag/Si) and employed as surface-enhanced Raman scattering substrates to detect analytes in solution. The experiment demonstrated that both the two substrates exhibited excellent performance in the low concentration detection of Rhodamine 6G. Besides, the enhancement factor (1.3 × 10(9)) and relative standard deviation values (less than 11%) of Ag/Ge substrate were both better than those of Ag/Si (2.9 × 10(7) and less than 15%, respectively), which was consistent with the FDTD simulation. Moreover, Ag nanoparticles were grown in-situ on Ge substrate, which kept the nanoparticles from aggregation in the detection. To data, Ag/Ge substrates showed the best performance for their sensitivity and uniformity among the noble metal/semiconductor ones.

  7. 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

  8. 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.

  9. Isolation, characterization, sequencing and crystal structure of charybdin, a type 1 ribosome-inactivating protein from Charybdis maritima agg.

    PubMed

    Touloupakis, Eleftherios; Gessmann, Renate; Kavelaki, Kalliopi; Christofakis, Emmanuil; Petratos, Kyriacos; Ghanotakis, Demetrios F

    2006-06-01

    A novel, type 1 ribosome-inactivating protein designated charybdin was isolated from bulbs of Charybdis maritima agg. The protein, consisting of a single polypeptide chain with a molecular mass of 29 kDa, inhibited translation in rabbit reticulocytes with an IC50 of 27.2 nm. Plant genomic DNA extracted from the bulb was amplified by PCR between primers based on the N-terminal and C-terminal sequence of the protein from dissolved crystals. The complete mature protein sequence was derived by partial DNA sequencing and terminal protein sequencing, and was confirmed by high-resolution crystal structure analysis. The protein contains Val at position 79 instead of the conserved Tyr residue of the ribosome-inactivating proteins known to date. To our knowledge, this is the first observation of a natural substitution of a catalytic residue at the active site of a natural ribosome-inactivating protein. This substitution in the active site may be responsible for the relatively low in vitro translation inhibitory effect compared with other ribosome-inactivating proteins. Single crystals were grown in the cold room from PEG6000 solutions. Diffraction data collected to 1.6 A resolution were used to determine the protein structure by the molecular replacement method. The fold of the protein comprises two structural domains: an alpha + beta N-terminal domain (residues 4-190) and a mainly alpha-helical C-terminal domain (residues 191-257). The active site is located in the interface between the two domains and comprises residues Val79, Tyr117, Glu167 and Arg170.

  10. 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.

  11. 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…

  12. 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.

  13. 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…

  14. 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.)

  15. 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

  16. 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

  17. 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

  18. Cold climate BMPs: solving the management puzzle.

    PubMed

    Oberts, G L

    2003-01-01

    Snowmelt runoff and rain-on-snow events present some of the highest pollutant loading and most difficult management challenges in the course of a year in regions with cold climate. Frozen conduits, thick ice layers, low biological activity, altered chemistry, and saturated or frozen ground conditions all work against effective treatment of melt runoff. Understanding the source, evolution and transition that occurs within a melt event, and defining the management objectives for specific receiving waters will help focus the search for effective management techniques. Solving the management puzzle means putting together a strategy for both soluble and solids-associated water pollutants.

  19. 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.

  20. Electrophobic Scalar Boson and Muonic Puzzles

    NASA Astrophysics Data System (ADS)

    Liu, Yu-Sheng; McKeen, David; Miller, Gerald A.

    2016-09-01

    A new scalar boson which couples to the muon and proton can simultaneously solve the proton radius puzzle and the muon anomalous magnetic moment discrepancy. Using a variety of measurements, we constrain the mass of this scalar and its couplings to the electron, muon, neutron, and proton. Making no assumptions about the underlying model, these constraints and the requirement that it solve both problems limit the mass of the scalar to between about 100 keV and 100 MeV. We identify two unexplored regions in the coupling constant-mass plane. Potential future experiments and their implications for theories with mass-weighted lepton couplings are discussed.

  1. 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.

  2. 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.

  3. 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…

  4. 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…

  5. 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…

  6. 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…

  7. 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…

  8. The Crossword Puzzle as a Teaching Examination Tool.

    ERIC Educational Resources Information Center

    Borcher, Glenda; And Others

    1994-01-01

    Animal science students (n=107) answered questions in both crossword puzzle and fill-in-the-blank format; 41 students in another study received either format as weekly review/quizzes. Students answered more questions correctly with crossword puzzles and enjoyed the challenge, although they appeared more willing to attempt answers with the fill-in…

  9. 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.

  10. 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.…

  11. 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.…

  12. 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

  13. Electrophobic Scalar Boson and Muonic Puzzles.

    PubMed

    Liu, Yu-Sheng; McKeen, David; Miller, Gerald A

    2016-09-01

    A new scalar boson which couples to the muon and proton can simultaneously solve the proton radius puzzle and the muon anomalous magnetic moment discrepancy. Using a variety of measurements, we constrain the mass of this scalar and its couplings to the electron, muon, neutron, and proton. Making no assumptions about the underlying model, these constraints and the requirement that it solve both problems limit the mass of the scalar to between about 100 keV and 100 MeV. We identify two unexplored regions in the coupling constant-mass plane. Potential future experiments and their implications for theories with mass-weighted lepton couplings are discussed. PMID:27636468

  14. 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.

  15. 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.

  16. 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.

  17. Reconstructed structures of nanosized co islands on Ag/Ge(111) mean square root of 3 x mean square root of 3 surfaces.

    PubMed

    Fu, Tsu-Yi; Tsay, Sung-Lin; Lin, Chun-Liang

    2008-02-01

    Structural evolution of Co/Ag/Ge(111) at high temperatures was studied by using scanning tunneling microscopy and low energy electron diffraction. The mean square root of 3 x mean square root of 3-Ag layer between the substrate Ge( 11) and Co adatoms can avoid the formation of Co-Ge compounds below 800 K. The Co atoms nucleate to form islands where mean square root of 13 x mean square root of 13 or 2 x 2 reconstructions were observed after annealing between 373 K and 737 K. The mean square root of 13 x mean square root of 13 structure with mirror symmetry relative to [-211], [11-2], and [1-21] axes was observed for 1-2 layer Co islands. Co islands with over 2 layers appear 2 x 2 structure. All reconstruction structures of the nano-sized Co islands and substrate Ag/Ge(111) mean square root of 3 x mean square root of 3 surface were analyzed using the atomic hard sphere model. The bright protrusions of these reconstructions all sit in the centers of Ag or Ge trimers, which were predicted to have maximum binding energy.

  18. 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…

  19. 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.

  20. 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…

  1. The Meibomian Puzzle: Combining Pieces Together

    PubMed Central

    Butovich, Igor A.

    2009-01-01

    The purpose of this review was to summarize the available information on lipidomic analysis of human meibum and tear film, and critically evaluate the pertinent past and present analytical procedures and results obtained in various laboratories. Human meibum was shown to be a very complex mixture of lipids of various classes. For decades, their exact structures have remained elusive. Because of the limitations of the then-current techniques, most of the complex lipids that constitute meibum could not be analyzed as whole molecules and required prior hydrolysis and/or transesterification of the entire lipid pool. These procedures effectively made it very difficult, and often impossible, to reconstruct the complete structures of the original intact compounds, which prompted us to call this The Meibomian Puzzle. Modern techniques such as high-performance liquid chromatography in combination with mass spectrometry help in solving this puzzle by allowing a researcher to detect and analyze intact molecules of complex lipid compounds, even if present in extremely low concentrations. This current de-facto standard procedure in lipidomic analysis of natural lipids and their mixtures is compared with other experimental techniques such as nuclear magnetic resonance spectroscopy, infrared spectroscopy, gas chromatography, and thin layer chromatography, among the others. The results obtained by older techniques, and their limitations and deficiencies are discussed. It appears that some of the earlier findings did not withstand a scrupulous re-evaluation and need to be modified and/or corrected. The most intriguing development is the virtual absence in meibum of typical phospholipids – an important group of amphiphilic compounds whose role in the human tear film was thought to be to stabilize the entire tear film structure. Instead, another group of previously unidentified compounds, very long chain (O-acyl)-omega-hydroxy fatty acids, appears to be a stabilizing factor which

  2. 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, ...

  3. Experiments towards resolving the proton charge radius puzzle

    NASA Astrophysics Data System (ADS)

    Antognini, A.; Schuhmann, K.; Amaro, F. D.; Amaro, P.; Abdou-Ahmed, M.; Biraben, F.; Chen, T.-L.; Covita, D. S.; Dax, A. J.; Diepold, M.; Fernandes, L. M. P.; Franke, B.; Galtier, S.; Gouvea, A. L.; Götzfried, J.; Graf, T.; Hänsch, T. W.; Hildebrandt, M.; Indelicato, P.; Julien, L.; Kirch, K.; Knecht, A.; Kottmann, F.; Krauth, J. J.; Liu, Y.-W.; Machado, J.; Monteiro, C. M. B.; Mulhauser, F.; Nez, F.; Santos, J. P.; dos Santos, J. M. F.; Szabo, C. I.; Taqqu, D.; Veloso, J. F. C. A.; Voss, A.; Weichelt, B.; Pohl, R.

    2016-03-01

    We review the status of the proton charge radius puzzle. Emphasis is given to the various experiments initiated to resolve the conflict between the muonic hydrogen results and the results from scattering and regular hydrogen spectroscopy.

  4. Formative Assessment Probes: Mountaintop Fossil: A Puzzling Phenomenon

    ERIC Educational Resources Information Center

    Keeley, Page

    2015-01-01

    This column focuses on promoting learning through assessment. This month's issue describes using formative assessment probes to uncover several ways of thinking about the puzzling discovery of a marine fossil on top of a mountain.

  5. 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.

  6. 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.

  7. Local associations and the barium puzzle

    NASA Astrophysics Data System (ADS)

    Reddy, Arumalla B. S.; Lambert, David L.

    2015-12-01

    We have observed high-dispersion echelle spectra of main-sequence stars in five nearby young associations - Argus, Carina-Near, Hercules-Lyra, Orion and Subgroup B4 - and derived abundances for elements ranging from Na to Eu. These are the first chemical abundance measurements for two of the five associations, while the remaining three associations are analysed more extensively in our study. Our results support the presence of chemical homogeneity among association members with a typical star-to-star abundance scatter of about 0.06 dex or less over many elements. The five associations show log ɛ(Li) consistent with their age and share a solar chemical composition for all elements with the exception of Ba. We find that all the heavy elements (Y, Zr, La, Ce, Nd, Sm and Eu) exhibit solar ratios, i.e. [X/Fe] ≃ 0, while Ba is overabundant by about 0.2-0.3 dex. The origin of the overabundance of Ba is a puzzle. Within the formulation of the s-process, it is difficult to create a higher Ba abundance without a similar increase in the s-process contributions to other heavy elements (La-Sm). Given that Ba is represented by strong lines of Ba II and La-Sm are represented by rather weak ionized lines, the suggestion, as previously made by other studies, is that the Ba abundance may be systematically overestimated by standard methods of abundance analysis perhaps because the upper reaches of the stellar atmospheres are poorly represented by standard model atmospheres. A novel attempt to analyse the Ba I line at 5535 Å gives a solar Ba abundance for stars with effective temperatures hotter than about 5800 K but increasingly subsolar Ba abundances for cooler stars with apparent Ba deficiencies of 0.5 dex at 5100 K. This trend with temperature may signal a serious non-local thermodynamical equilibrium effect on the Ba I line.

  8. Three Modes of Hydrogeophysical Investigation: Puzzles, Mysteries, and Conundrums

    NASA Astrophysics Data System (ADS)

    Ferre, P. A.

    2011-12-01

    In an article in the New Yorker in 2007, Malcolm Gladwell discussed the distinction that national security expert Gregory Treverton has made between puzzles and mysteries. Specifically, puzzles are problems that we understand and that will eventually be solved when we amass enough information. (Think crossword puzzles.) Mysteries are problems for which we have the necessary information, but it is often overwhelmed by irrelevant or misleading input. To solve a mystery, we require improved analysis. (Think find-a-word.) Gladwell goes on to explain that, in the national security realm, the Cold War was a puzzle while the current national security condition is a mystery. I will discuss the past, current, and future trajectories of hydrogeophysics in terms of puzzles and mysteries. I will also add a third class of problem: conundrums - those for which we lack sufficient information about their structure to know how to solve them. A conundrum is a mystery with an unexpected twist. I hope to make the case that the future growth of hydrogeophysics lies in our ability to address this more challenging and more interesting class of problem.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  19. Tangram Puzzles: Focus on Search Terms, Descriptors, and Subject Headings.

    ERIC Educational Resources Information Center

    School Library Media Activities Monthly, 1993

    1993-01-01

    Describes the history of tangrams and their use as mathematical puzzles and explains how they can be adapted for library media specialists to use for developing subject headings on a particular topic. An example is given; and 28 resources on tangrams are listed, including books, nonprint materials, and addresses. (LRW)

  20. 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…

  1. 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…

  2. Update On the Puzzling Boyajian's Star

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-09-01

    Photometric time series for a neighboring star thats 25 NNW of Boyajians Star. No significant long-term dimming is seen which constrains the size of potential material obscuring Boyajians Star. [Wright et al. 2016/Benjamin Montet]Whats causing the mysterious light-curve dips of the so-called alien megastructure star, Boyajians Star? A recent study analyzes a variety of possible explanations to determine which ones are the most plausible.An Unusual Light CurveEarlier this year, astronomer Tabetha Boyajian reported on the unusual light curve of the star KIC 8462852. This star, now nicknamed Tabbys Star or Boyajians Star, showsunusual dips on day-long timescales that are too large to be explained by planet transits or similar phenomena.In addition to these short dips in luminosity, recent observations have also indicated that the star has faded by roughly 20% over the past hundred years. What could be causing both the short-term dips in the stars light and the long-term dimming over a century?Could the dimming be caused by an alien megastructure built by an extraterrestrial civilization? The authors find that a spherical structure is very unlikely. [Danielle Futselaar/SETI International]Alien Megastructures? Or Another Explanation?Boyajians Star was vaulted into the media spotlight when astronomer Jason Wright (Pennsylvania State University and University of California, Berkeley) proposed that its unusual light curve could potentially be explained by a surrounding megastructure built by an extraterrestrial civilization.Now Wright is back with co-author Steinn Sigurdsson (Pennsylvania State University). In a new study, Wright and Sigurdsson analyze an extensive list of explanations for the puzzling apparent behavior of Boyajians Star, based on our latest knowledge about this strange object.The Realm of PossibilitiesHere are just a few possible causes of Boyajians Stars dimming, as well as the authors assessment of their plausibility. For the full list, see the authors

  3. 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".

  4. 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.

  5. 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

  6. Particle Filter with State Permutations for Solving Image Jigsaw Puzzles

    PubMed Central

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

    2016-01-01

    We deal with an image jigsaw puzzle problem, which is defined as reconstructing an image from a set of square and non-overlapping image patches. It is known that a general instance of this problem is NP-complete, and it is also challenging for humans, since in the considered setting the original image is not given. Recently a graphical model has been proposed to solve this and related problems. The target label probability function is then maximized using loopy belief propagation. We also formulate the problem as maximizing a label probability function and use exactly the same pairwise potentials. Our main contribution is a novel inference approach in the sampling framework of Particle Filter (PF). Usually in the PF framework it is assumed that the observations arrive sequentially, e.g., the observations are naturally ordered by their time stamps in the tracking scenario. Based on this assumption, the posterior density over the corresponding hidden states is estimated. In the jigsaw puzzle problem all observations (puzzle pieces) are given at once without any particular order. Therefore, we relax the assumption of having ordered observations and extend the PF framework to estimate the posterior density by exploring different orders of observations and selecting the most informative permutations of observations. This significantly broadens the scope of applications of the PF inference. Our experimental results demonstrate that the proposed inference framework significantly outperforms the loopy belief propagation in solving the image jigsaw puzzle problem. In particular, the extended PF inference triples the accuracy of the label assignment compared to that using loopy belief propagation.

  7. 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.

  8. 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

  9. Crossword Puzzles as a Tool to Enhance Learning About Anti-Ulcer Agents

    PubMed Central

    Lynch, Launa M. J.; Macias-Moriarity, Lilia Z.

    2010-01-01

    Objective To design, implement, and evaluate the use of crossword puzzles as a low-stakes educational tool for enhancing learning about anti-ulcer agents. Design Crossword puzzles were created using a free Internet resource and administered to students during 3 consecutive lectures covering the pharmacology and medicinal chemistry of anti-ulcer agents. Student perceptions of the crossword puzzle were examined using an 8-item survey instrument. Assessment Over 90% of students indicated that crossword puzzles enhanced their learning, oriented them to the important topics, and served as good reviews of the lecture material. Conclusion Students perceived that crossword puzzles enhanced their learning of anti-ulcer agents. Use of crossword puzzles provides a simple and creative way to incorporate active learning into pharmacy classroom instruction. PMID:21088722

  10. Explaining the proton radius puzzle with disformal scalars

    NASA Astrophysics Data System (ADS)

    Brax, Philippe; Burrage, Clare

    2015-02-01

    We analyze the consequences of a disformal interaction between a massless scalar and matter particles in the context of atomic physics. We focus on the displacement of the atomic energy levels that it induces, and in particular the change in the Lamb shift between the 2s and 2p states. We find that the correction to the Lamb shift depends on the mass of the fermion orbiting around the nucleus, implying a larger effect for muonic atoms. Taking the cutoff scale describing the effective scalar field theory close to the QCD scale, we find that the disformal interaction can account for the observed difference in the proton radius of muonic versus electronic hydrogen. Explaining the proton radius puzzle is only possible when the scalar field is embedded in nonlinear theories which alleviate constraints from collider and stellar physics. Short distance properties of the Galileon where nonperturbative effects in vacuum are present ensure that unitarity is preserved in high-energy particle collisions. In matter, the chameleon mechanism alleviates the constraints on disformal interactions coming from the burning rates for stellar objects. We show how to combine these two properties in a single model which renders the proposed explanation of the proton radius puzzle viable.

  11. 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

  12. Tiny bubbles challenge giant turbines: Three Gorges puzzle

    PubMed Central

    Li, Shengcai

    2015-01-01

    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

  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. 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…

  15. 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…

  16. Using the Tower of Hanoi Puzzle to Infuse Your Mathematics Classroom with Computer Science Concepts

    ERIC Educational Resources Information Center

    Marzocchi, Alison S.

    2016-01-01

    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…

  17. 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…

  18. 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.

  19. 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…

  20. 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…

  1. 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…

  2. 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.…

  3. The puzzle-feeder as feeding enrichment for common marmosets (Callithrix jacchus): a pilot study.

    PubMed

    de Rosa, C; Vitale, A; Puopolo, M

    2003-04-01

    The use of a puzzle-feeder, as feeding enrichment, was investigated in three families of captive common marmosets (Callithrix jacchus). The study was carried out as a simultaneous choice test between two cages: one contained the puzzle-feeder, the other contained the usual food dishes, but otherwise both were arranged similarly. The monkeys were allowed to choose whether to feed from the usual dishes, or from the puzzle-feeder which required more effort. They were observed for two sessions in which they were differently motivated to feed. The enriched cage was always visited first, the marmosets managed to extract food from the puzzle-feeder, and spent more time eating from the puzzle-feeder when less hungry. These data contribute to a wider understanding on the use, and the effects, of feeding enrichments with different captive non-human primates. PMID:12689420

  4. 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…

  5. 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.

  6. Resolution to the B{yields}{pi}K puzzle

    SciTech Connect

    Li Hsiangnan; Mishima, Satoshi; Sanda, A.I.

    2005-12-01

    We calculate the important next-to-leading-order contributions to the B{yields}{pi}K, {pi}{pi} decays from the vertex corrections, the quark loops, and the magnetic penguins in the perturbative QCD approach. It is found that the latter two reduce the leading-order penguin amplitudes by about 10% and modify only the B{yields}{pi}K branching ratios. The main effect of the vertex corrections is to increase the small color-suppressed tree amplitude by a factor of 3, which then resolves the large difference between the direct CP asymmetries of the B{sup 0}{yields}{pi}{sup {+-}}K{sup {+-}} and B{sup {+-}}{yields}{pi}{sup 0}K{sup {+-}} modes. The puzzle from the large B{sup 0}{yields}{pi}{sup 0}{pi}{sup 0} branching ratio still remains.

  7. 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.

  8. 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.

  9. 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.

  10. Fibromyalgia: A Puzzling and Painful Condition | NIH MedlinePlus the Magazine

    MedlinePlus

    ... of this page please turn JavaScript on. Feature: Fibromyalgia Fibromyalgia: A Puzzling and Painful Condition Past Issues / Spring ... or internal organs. Wise Choices: Feeling Better with Fibromyalgia Get enough sleep. Getting the right kind of ...

  11. Reading, Writing, and Language: Young Children Solving the Written Language Puzzle.

    ERIC Educational Resources Information Center

    Dyson, Anne Haas

    1982-01-01

    Reviews literature defining the characteristics of the complex puzzle children encounter moving from oral language to print. Illustrates that, by reading their own writing, children discover the precise connection between reading, writing, and language. (HTH)

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. Usefulness of Crossword Puzzles in Helping First-Year BVSc Students Learn Veterinary Terminology.

    PubMed

    Abuelo, Angel; Castillo, Cristina; May, Stephen A

    2016-01-01

    Appropriate terminology is essential for successful communication among health professionals. However, students have traditionally been encouraged to learn terminology by rote memorization and recall, strategies that students try to avoid. The use of crossword puzzles as a learning tool has been evaluated in other education disciplines, but not for terminology related to veterinary science. Hence, the objective of this study was to test whether crossword puzzles might be an effective aid to learning veterinary terminology. Forty-two first-year students enrolled in a Bachelor of Veterinary Science program were randomly divided into two groups and their previous knowledge of veterinary terms tested. One group received a list of 30 terms with their definitions. The other group received the same list plus six specially designed puzzles incorporating these 30 terms. After 50 minutes, both groups completed a post-intervention test and the results were compared statistically. The results showed that the students using the crossword puzzles performed better in the post-intervention test, correctly retaining more terms than the students using only rote learning. In addition, qualitative data, gathered through an electronic survey and focus group discussions, revealed a positive attitude among students toward the use of crossword puzzles.

  2. Usefulness of Crossword Puzzles in Helping First-Year BVSc Students Learn Veterinary Terminology.

    PubMed

    Abuelo, Angel; Castillo, Cristina; May, Stephen A

    2016-01-01

    Appropriate terminology is essential for successful communication among health professionals. However, students have traditionally been encouraged to learn terminology by rote memorization and recall, strategies that students try to avoid. The use of crossword puzzles as a learning tool has been evaluated in other education disciplines, but not for terminology related to veterinary science. Hence, the objective of this study was to test whether crossword puzzles might be an effective aid to learning veterinary terminology. Forty-two first-year students enrolled in a Bachelor of Veterinary Science program were randomly divided into two groups and their previous knowledge of veterinary terms tested. One group received a list of 30 terms with their definitions. The other group received the same list plus six specially designed puzzles incorporating these 30 terms. After 50 minutes, both groups completed a post-intervention test and the results were compared statistically. The results showed that the students using the crossword puzzles performed better in the post-intervention test, correctly retaining more terms than the students using only rote learning. In addition, qualitative data, gathered through an electronic survey and focus group discussions, revealed a positive attitude among students toward the use of crossword puzzles. PMID:27111003

  3. The DS86 neutron dosimetry enigma: Some missing pieces to the puzzle

    SciTech Connect

    Gold, R.

    1994-12-31

    International programs have been conducted over the last four decades to quantify the exposure of atom bomb survivors from Hiroshima and Nagasaki. Unfortunately, the quest for accurate gamma-ray and neutron exposure doses of atom bomb survivors has proven illusive. Efforts in the most recent of these programs, designated as Dosimetry System 1986 (DS86), have revealed a serious and persistent discrepancy between neutron transport calculations and thermal neutron activation measurements at the Hiroshima site, which will be called the DS86 neutron dosimetry enigma. It is established that this enigma is a complex puzzle that precludes simple solutions. This conclusion is deduced through the identification of a number of missing pieces to the puzzle. Implications and conclusions that can be inferred from these missing puzzle pieces are advanced.

  4. 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

  5. Parents' attributions of their child's jigsaw-puzzle performance: comparing two genetic syndromes.

    PubMed

    Ly, Tran M; Hodapp, Robert M

    2005-04-01

    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 to internal factors (particularly when the child was good at puzzles), downplayed the role of chance when their child had higher puzzle skills and higher cognitive functioning, and differentiated between internal and external attributions. In contrast, parents of children with Williams syndrome showed an inconsistent attributional pattern. These findings help identify how parents understand the intellectual performance of their child with disabilities and how interventions might be beneficial. PMID:15757368

  6. 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

  7. 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.

  8. 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

  9. 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…

  10. 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."…

  11. 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…

  12. Herschel unveils a puzzling uniformity of distant dusty galaxies

    NASA Astrophysics Data System (ADS)

    Elbaz, D.; Hwang, H. S.; Magnelli, B.; Daddi, E.; Aussel, H.; Altieri, B.; Amblard, A.; Andreani, P.; Arumugam, V.; Auld, R.; Babbedge, T.; Berta, S.; Blain, A.; Bock, J.; Bongiovanni, A.; Boselli, A.; Buat, V.; Burgarella, D.; Castro-Rodriguez, N.; Cava, A.; Cepa, J.; Chanial, P.; Chary, R.-R.; Cimatti, A.; Clements, D. L.; Conley, A.; Conversi, L.; Cooray, A.; Dickinson, M.; Dominguez, H.; Dowell, C. D.; Dunlop, J. S.; Dwek, E.; Eales, S.; Farrah, D.; Förster Schreiber, N.; Fox, M.; Franceschini, A.; Gear, W.; Genzel, R.; Glenn, J.; Griffin, M.; Gruppioni, C.; Halpern, M.; Hatziminaoglou, E.; Ibar, E.; Isaak, K.; Ivison, R. J.; Lagache, G.; Le Borgne, D.; Le Floc'h, E.; Levenson, L.; Lu, N.; Lutz, D.; Madden, S.; Maffei, B.; Magdis, G.; Mainetti, G.; Maiolino, R.; Marchetti, L.; Mortier, A. M. J.; Nguyen, H. T.; Nordon, R.; O'Halloran, B.; Okumura, K.; Oliver, S. J.; Omont, A.; Page, M. J.; Panuzzo, P.; Papageorgiou, A.; Pearson, C. P.; Perez Fournon, I.; Pérez García, A. M.; Poglitsch, A.; Pohlen, M.; Popesso, P.; Pozzi, F.; Rawlings, J. I.; Rigopoulou, D.; Riguccini, L.; Rizzo, D.; Rodighiero, G.; Roseboom, I. G.; Rowan-Robinson, M.; Saintonge, A.; Sanchez Portal, M.; Santini, P.; Sauvage, M.; Schulz, B.; Scott, D.; Seymour, N.; Shao, L.; Shupe, D. L.; Smith, A. J.; Stevens, J. A.; Sturm, E.; Symeonidis, M.; Tacconi, L.; Trichas, M.; Tugwell, K. E.; Vaccari, M.; Valtchanov, I.; Vieira, J.; Vigroux, L.; Wang, L.; Ward, R.; Wright, G.; Xu, C. K.; Zemcov, M.

    2010-07-01

    The Herschel Space Observatory enables us to accurately measure the bolometric output of starburst galaxies and active galactic nuclei (AGN) by directly sampling the peak of their far-infrared (IR) emission. Here we examine whether the spectral energy distribution (SED) and dust temperature of galaxies have strongly evolved over the last 80% of the age of the Universe. We discuss possible consequences for the determination of star-formation rates (SFR) and any evidence for a major change in their star-formation properties. We use Herschel deep extragalactic surveys from 100 to 500 μm to compute total IR luminosities in galaxies down to the faintest levels, using PACS and SPIRE in the GOODS-North field (PEP and HerMES key programs). An extension to fainter luminosities is done by stacking images on 24 μm prior positions. We show that measurements in the SPIRE bands can be used below the statistical confusion limit if information at higher spatial resolution is used, e.g. at 24 μm, to identify “isolated” galaxies whose flux is not boosted by bright neighbors. Below z 1.5, mid-IR extrapolations are correct for star-forming galaxies with a dispersion of only 40% (0.15 dex), therefore similar to z 0 galaxies, over three decades in luminosity below the regime of ultra-luminous IR galaxies (ULIRGs, LIR ≥ 1012 Lsun). This narrow distribution is puzzling when considering the range of physical processes that could have affected the SED of these galaxies. Extrapolations from only one of the 160 μm, 250 μm or 350 μm bands alone tend to overestimate the total IR luminosity. This may be explained by the lack of far-IR constraints around and above 150 μm (rest-frame) before Herschel on those templates. We also note that the dust temperature of luminous IR galaxies (LIRGs, LIR ≥ 1011 Lsun) around z 1 is mildly colder by 10-15% than their local analogs and up to 20% for ULIRGs at z 1.6 (using a single modified blackbody-fit to the peak far-IR emission with an

  13. 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…

  14. Games and Puzzles in the Second Language Classroom: A Second Look.

    ERIC Educational Resources Information Center

    Danesi, Marcel; Mollica, Anthony

    1994-01-01

    Revisits puzzleology (the study of puzzles and games in human cultures) in second language teaching to give the teacher an overview of the relevant facts "vis-a-vis" their incorporation into classroom instruction and to provide an elementary typology of puzzleological techniques for the teacher interested in incorporating them in language classes.…

  15. Children with Praderwilli Syndrome Vs. Williams Syndrome: Indirect Effects on Parents during a Jigsaw Puzzle Task

    ERIC Educational Resources Information Center

    Ly, T. M.; Hodapp, R. M.

    2005-01-01

    Background: Genetic disorders predispose individuals to exhibit characteristic behaviours, which in turn elicit particular behaviours from others. In response to the strength of Prader?Willi syndrome (PWS) and weakness of Williams syndrome (WS) in visual-spatial tasks such as jigsaw puzzles, parents' behaviours can be affected by their child's…

  16. 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…

  17. (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…

  18. 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).…

  19. 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…

  20. Random Tree-Puzzle leads to the Yule-Harding distribution.

    PubMed

    Vinh, Le Sy; Fuehrer, Andrea; von Haeseler, Arndt

    2011-02-01

    Approaches to reconstruct phylogenies abound and are widely used in the study of molecular evolution. Partially through extensive simulations, we are beginning to understand the potential pitfalls as well as the advantages of different methods. However, little work has been done on possible biases introduced by the methods if the input data are random and do not carry any phylogenetic signal. Although Tree-Puzzle (Strimmer K, von Haeseler A. 1996. Quartet puzzling: a quartet maximum-likelihood method for reconstructing tree topologies. Mol Biol Evol. 13:964-969; Schmidt HA, Strimmer K, Vingron M, von Haeseler A. 2002. Tree-Puzzle: maximum likelihood phylogenetic analysis using quartets and parallel computing. Bioinformatics 18:502-504) has become common in phylogenetics, the resulting distribution of labeled unrooted bifurcating trees when data do not carry any phylogenetic signal has not been investigated. Our note shows that the distribution converges to the well-known Yule-Harding distribution. However, the bias of the Yule-Harding distribution will be diminished by a tiny amount of phylogenetic information. maximum likelihood, phylogenetic reconstruction, Tree-Puzzle, tree distribution, Yule-Harding distribution.

  1. Booklists for the Teaching of Mathematics in Schools: Puzzles, Problems, Games and Mathematical Recreations (Ref: PGR).

    ERIC Educational Resources Information Center

    Mathematical Association, Leicester (England).

    Presented is a listing of books recommended by the Mathematical Association of the United Kingdom dealing with Puzzles, Problems, Games, and Mathematical Recreations. The following information on each book is provided: author; title; publisher; cost to the nearest pound; categories of use; and a code that indicates if the book in question is out…

  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. Spatial Puzzles and the Assessment of Children's Problem-Solving Performance.

    ERIC Educational Resources Information Center

    Hill, Douglas M.; Redden, Michael G.

    1984-01-01

    Seventy fifth-grade students in Australia were observed as each solved a jigsaw puzzle. Boys obtained higher scores on a measure of cognitive style and took less time to complete the jigsaw task; the two measures were significantly correlated. Uses of tangrams are also discussed. (MNS)

  4. Tangrams: An Ancient Chinese Puzzle. A Conceptual Skill Development Kit for All Grade Levels.

    ERIC Educational Resources Information Center

    Kubota, Carol

    A multi-subject approach to using tangram puzzles in the classroom is included along with a short history section and accompanying lessons. These lessons provide an introduction to tangrams; methods for teaching bilingual and English-dominant children concepts and skills through activities that do not require strong English skills; and activities…

  5. 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,…

  6. 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.

  7. 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.

  8. 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,…

  9. 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…

  10. 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…

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. 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

  16. Action and puzzle video games prime different speed/accuracy tradeoffs.

    PubMed

    Nelson, Rolf A; Strachan, Ian

    2009-01-01

    To understand the way in which video-game play affects subsequent perception and cognitive strategy, two experiments were performed in which participants played either a fast-action game or a puzzle-solving game. Before and after video-game play, participants performed a task in which both speed and accuracy were emphasized. In experiment 1 participants engaged in a location task in which they clicked a mouse on the spot where a target had appeared, and in experiment 2 they were asked to judge which of four shapes was most similar to a target shape. In both experiments, participants were much faster but less accurate after playing the action game, while they were slower but more accurate after playing the puzzle game. Results are discussed in terms of a taxonomy of video games by their cognitive and perceptual demands.

  17. [Analysis of the Puzzle between Acupuncture Community and Acupuncture Clinical Trials].

    PubMed

    Huo, Rui-li; Ma, Sheng-xing

    2016-03-01

    Recently a number of acupuncture clinical trial projects mainly conducted by conventional scientists have generated many negative results. A large meta-analysis of patient-level acupuncture data for the treatment of chronic pain conditions have demonstrated that the effects of verum acupuncture on pain improvement have statistically significant, but small, differences compared with sham-acupuncture procedures and no difference between acupuncture points and non-points. These conclusions have puzzled the acupuncture community and made confusion for acupuncture research and practices. The purpose of this paper was to compare differences between acupuncture clinical practices and the trial studies, which include "acupuncture technical principles", "acupuncture clinical trial design", and "acupuncture practice based on the theory of traditional Chinese medicine". These factors contribute to the puzzle between the acupuncture community/practice and acupuncture clinical trials, which can be improved in future studies. PMID:27236879

  18. Role of Nitric Oxide in Glioblastoma Therapy: Another Step to Resolve the Terrible Puzzle ?

    PubMed

    Altieri, R; Fontanella, M; Agnoletti, A; Panciani, P P; Spena, G; Crobeddu, E; Pilloni, G; Tardivo, V; Lanotte, M; Zenga, F; Ducati, A; Garbossa, D

    2015-01-01

    Glioblastoma Multiforme, the most common and aggressive primary brain tumor, remains incurable despite of the advent of modern surgical and medical treatments. This poor prognosis depends by the recurrence after surgery and intrinsic or acquired resistance to chemotherapy and radiotherapy. Nitric oxide is a small molecule that plays a key roles in glioma pathophysiology. Many researches showing that NO is involved in induction of apoptosis, radiosensitization and chemosensitization. Therefore, NO role, if clarified, may improve the knowledge about this unsolved puzzle called GBM.

  19. On the puzzling feature of the silence of precursory electromagnetic emissions

    NASA Astrophysics Data System (ADS)

    Eftaxias, K.; Potirakis, S. M.; Chelidze, T.

    2013-09-01

    It has been suggested that fracture-induced MHz-kHz electromagnetic emissions (EME), which emerge from a few days up to a few hours before the main seismic shock occurrence permit a real-time monitoring of the damage process during the last stages of earthquake preparation, as it happens at the laboratory scale. Despite fairly abundant evidence, electromagnetic (EM) precursors have not been adequately accepted as credible physical phenomena. These negative views are enhanced by the fact that certain "puzzling features" are repetitively observed in candidate fracture-induced pre-seismic EME. More precisely, EM silence in all frequency bands appears before the main seismic shock occurrence, as well as during the aftershock period. Actually, the view that "acceptance of "precursive" EM signals without convincing co-seismic signals should not be expected" seems to be reasonable. In this work we focus on this point. We examine whether the aforementioned features of EM silence are really puzzling ones or, instead, reflect well-documented characteristic features of the fracture process, in terms of universal structural patterns of the fracture process, recent laboratory experiments, numerical and theoretical studies of fracture dynamics, critical phenomena, percolation theory, and micromechanics of granular materials. Our analysis shows that these features should not be considered puzzling.

  20. A puzzle assembly strategy for fabrication of large engineered cartilage tissue constructs.

    PubMed

    Nover, Adam B; Jones, Brian K; Yu, William T; Donovan, Daniel S; Podolnick, Jeremy D; Cook, James L; Ateshian, Gerard A; Hung, Clark T

    2016-03-21

    Engineering of large articular cartilage tissue constructs remains a challenge as tissue growth is limited by nutrient diffusion. Here, a novel strategy is investigated, generating large constructs through the assembly of individually cultured, interlocking, smaller puzzle-shaped subunits. These constructs can be engineered consistently with more desirable mechanical and biochemical properties than larger constructs (~4-fold greater Young׳s modulus). A failure testing technique was developed to evaluate the physiologic functionality of constructs, which were cultured as individual subunits for 28 days, then assembled and cultured for an additional 21-35 days. Assembled puzzle constructs withstood large deformations (40-50% compressive strain) prior to failure. Their ability to withstand physiologic loads may be enhanced by increases in subunit strength and assembled culture time. A nude mouse model was utilized to show biocompatibility and fusion of assembled puzzle pieces in vivo. Overall, the technique offers a novel, effective approach to scaling up engineered tissues and may be combined with other techniques and/or applied to the engineering of other tissues. Future studies will aim to optimize this system in an effort to engineer and integrate robust subunits to fill large defects. PMID:26895780

  1. The puzzle of massive negative ions above the ionospheric D-region - Revisit, new insights, and suggestion of a puzzle solution

    NASA Astrophysics Data System (ADS)

    Arnold, Frank

    2015-04-01

    Inspired by new experimental possibilities, previous pioneering rocket borne ion-mass spectrometer measurements, made by our MPIK-Heidelberg research group in the lower ionosphere, are revisited and reanalyzed. The most puzzling observation made in two of our previous rocket missions is the detection of a layer of massive negative ions (about 100-400 atomic mass units), dominating the negative ion population present at heights between the top of the ionospheric D-region and about 90 km. The presence of these massive negative ions suggests that they are relatively stable against electron detachment by UV-photons and by free oxygen atoms. Loss of these ions should, at least, occur by recombination with positive ions. Since charge neutralization via negative ion-positive ion recombination is much slower than positive ion-electron recombination, negative ions should live much longer than positive ions and therefore may grow more efficiently. Previously, we have hypothesized that the formation of, at least, some of the massive negative ions may involve meteoric material. Interestingly, the massive negative ions may have potentially important direct and indirect roles. They may influence noctilucent cloud formation and their formation may significantly influence free electron loss. Furthermore the massive negative ions have an important indirect role as an analytical tool for highly sensitive detection of ultra-trace gases, particularly certain meteoric molecular gases, present in the lower ionosphere. However, the sparse previous rocket borne measurements of the massive negative ions suffered from limited sensitivity and relatively poor mass resolution. Therefore, unambiguous identification of their mass numbers and chemical nature was not possible. In the present contribution is suggested a powerful novel rocket borne ion mass spectrometer technique with greatly improved sensitivity and mass resolution, which should have the potential of contributing markedly to

  2. 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

  3. RNA-Puzzles: A CASP-like evaluation of RNA three-dimensional structure prediction

    PubMed Central

    Cruz, José Almeida; Blanchet, Marc-Frédérick; Boniecki, Michal; Bujnicki, Janusz M.; Chen, Shi-Jie; Cao, Song; Das, Rhiju; Ding, Feng; Dokholyan, Nikolay V.; Flores, Samuel Coulbourn; Huang, Lili; Lavender, Christopher A.; Lisi, Véronique; Major, François; Mikolajczak, Katarzyna; Patel, Dinshaw J.; Philips, Anna; Puton, Tomasz; Santalucia, John; Sijenyi, Fredrick; Hermann, Thomas; Rother, Kristian; Rother, Magdalena; Serganov, Alexander; Skorupski, Marcin; Soltysinski, Tomasz; Sripakdeevong, Parin; Tuszynska, Irina; Weeks, Kevin M.; Waldsich, Christina; Wildauer, Michael; Leontis, Neocles B.; Westhof, Eric

    2012-01-01

    We report the results of a first, collective, blind experiment in RNA three-dimensional (3D) structure prediction, encompassing three prediction puzzles. The goals are to assess the leading edge of RNA structure prediction techniques; compare existing methods and tools; and evaluate their relative strengths, weaknesses, and limitations in terms of sequence length and structural complexity. The results should give potential users insight into the suitability of available methods for different applications and facilitate efforts in the RNA structure prediction community in ongoing efforts to improve prediction tools. We also report the creation of an automated evaluation pipeline to facilitate the analysis of future RNA structure prediction exercises. PMID:22361291

  4. Does random tree puzzle produce Yule-Harding trees in the many-taxon limit?

    PubMed

    Zhu, Sha; Steel, Mike

    2013-05-01

    It has been suggested that a random tree puzzle (RTP) process leads to a Yule-Harding (YH) distribution, when the number of taxa becomes large. In this study, we formalize this conjecture, and we prove that the two tree distributions converge for two particular properties, which suggests that the conjecture may be true. However, we present statistical evidence that, while the two distributions are close, the RTP appears to converge on a different distribution than does the YH. By way of contrast, in the concluding section we show that the maximum parsimony method applied to random two-state data leads a very different (PDA, or uniform) distribution on trees.

  5. 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

  6. Exchange rate regimes, saving glut and the Feldstein Horioka puzzle: The East Asian experience

    NASA Astrophysics Data System (ADS)

    Kaya-Bahçe, Seçil; Özmen, Erdal

    2008-04-01

    This paper investigates whether the recent experience of the emerging East Asian countries with current account surpluses is consistent with the “saving glut” hypothesis and the Feldstein and Horioka puzzle. The evidence suggests that the saving retention coefficients declined substantially in most of the countries after an endogenous break date coinciding with a major exchange rate regime change with the 1997-1998 crisis. Exchange rate flexibility appears to be enhancing financial integration. The results are consistent with an “investment slump” explanation rather than the “saving glut” postulation.

  7. 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.

  8. 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.

  9. Role of Nitric Oxide in Glioblastoma Therapy: Another Step to Resolve the Terrible Puzzle ?

    PubMed Central

    Altieri, R.; Fontanella, M.; Agnoletti, A.; Panciani, P.P.; Spena, G.; Crobeddu, E.; Pilloni, G.; Tardivo, V.; Lanotte, M.; Zenga, F.; Ducati, A.; Garbossa, D.

    2015-01-01

    Glioblastoma Multiforme, the most common and aggressive primary brain tumor, remains incurable despite of the advent of modern surgical and medical treatments. This poor prognosis depends by the recurrence after surgery and intrinsic or acquired resistance to chemotherapy and radiotherapy. Nitric oxide is a small molecule that plays a key roles in glioma pathophysiology. Many researches showing that NO is involved in induction of apoptosis, radiosensitization and chemosensitization. Therefore, NO role, if clarified, may improve the knowledge about this unsolved puzzle called GBM. PMID:26535188

  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. 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

  12. 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.

  13. 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.

  14. 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

  15. 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

  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. 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…

  18. 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…

  19. 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…

  20. {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.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. Completing the nuclear reaction puzzle of the nucleosynthesis of 92Mo

    NASA Astrophysics Data System (ADS)

    Tveten, G. M.; Spyrou, A.; Schwengner, R.; Naqvi, F.; Larsen, A. C.; Eriksen, T. K.; Bello Garrote, F. L.; Bernstein, L. A.; Bleuel, D. L.; Crespo Campo, L.; Guttormsen, M.; Giacoppo, F.; Görgen, A.; Hagen, T. W.; Hadynska-Klek, K.; Klintefjord, M.; Meyer, B. S.; Nyhus, H. T.; Renstrøm, T.; Rose, S. J.; Sahin, E.; Siem, S.; Tornyi, T. G.

    2016-08-01

    One of the greatest questions for modern physics to address is how elements heavier than iron are created in extreme astrophysical environments. A particularly challenging part of that question is the creation of the so-called p -nuclei, which are believed to be mainly produced in some types of supernovae. The lack of needed nuclear data presents an obstacle in nailing down the precise site and astrophysical conditions. In this work, we present for the first time measurements on the nuclear level density and average γ strength function of 92Mo. State-of-the-art p -process calculations systematically underestimate the observed solar abundance of this isotope. Our data provide stringent constraints on the 91Nb(p ,γ )92Mo reaction rate, which is the last unmeasured reaction in the nucleosynthesis puzzle of 92Mo. Based on our results, we conclude that the 92Mo abundance anomaly is not due to the nuclear physics input to astrophysical model calculations.

  6. A possible hadronic excess in psi(2S) decay and the rho pi puzzle

    SciTech Connect

    Suzuki, Mahiko

    2000-11-09

    We study the so-called {rho}{pi} puzzle of the {psi}(2S) decay by incorporating two inputs; the relative phase between the one-photon and the gluonic decay amplitude, and a possible hadronic excess in the inclusive nonelectromagnetic decay rate of {psi}(2S). We look into the possibility that the hadronic excess in {psi}(2S) originates from a decay process of long-distance origin which is absent from the J/{upsilon} decay. We propose that the amplitude of this additional process happens to nearly cancel the short-distance gluonic amplitude in the exclusive decay {psi}(2S) {yields} 1{sup -}0{sup -} and turn the sum dominantly real in contrast to the J/{psi} decay. We present general consequences of this mechanism and survey two models which might possibly explain the source of this additional amplitude.

  7. 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.

  8. 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

  9. The solar neutrino puzzle and the vL --> vR conversion hypothesis

    NASA Astrophysics Data System (ADS)

    Barbieri, R.; Fiorentini, G.

    As a possible explanation of the solar neutrino puzzle, several authors have invoked a neutrino helicity rotation (vL --> vR) in the solar magnetic field, coupled to a neutrino magnetic moment. We discuss: (i) the effect on the vL --> vR conversion probability of the different coherent interaction with matter of the two neutrino helicity states; (ii) the azimuthal asymmetry in the elastic v-e scattering of solar neutrinos, due to the interference between the weak and the electromagnetic amplitude. We also briefly comment on the theoretical problem posed by a neutrino magnetic moment as large as 10-10μB. Dipartimento di Fisica, Università di Cagliari, Italy.

  10. 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

  11. 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

  12. 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.

  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. Ratio of hadronic decay rates of J/{psi} and {psi}(2S) and the {rho}{pi} puzzle

    SciTech Connect

    Gu, Y. F.; Li, X. H.

    2001-06-01

    The so-called {rho}{pi} puzzle of J/{psi} and {psi}(2S) decays is examined using the experimental data available to date. Two different approaches were taken to estimate the ratio of J/{psi} and {psi}(2S) hadronic decay rates. While one of the estimates could not yield the exact ratio of {psi}(2S) to J/{psi} inclusive hadronic decay rates, the other, based on a computation of the inclusive ggg decay rate for {psi}(2S)(J/{psi}) by subtracting other decay rates from the total decay rate, differs by two standard deviations from the naive prediction of perturbative QCD, even though its central value is nearly twice as large as what was naively expected. A comparison between this ratio, upon making corrections for specific exclusive two-body decay modes, and the corresponding experimental data confirms the puzzles in J/{psi} and {psi}(2S) decays. We find from our analysis that the exclusively reconstructed hadronic decays of the {psi}(2S) account for only a small fraction of its total decays, and a ratio exceeding the above estimate should be expected to occur for a considerable number of the remaining decay channels. We also show that the recent new results from the BES experiment provide crucial tests of various theoretical models proposed to explain the puzzle.

  15. Evolutionary contributions to solving the "matrilineal puzzle": a test of Holden, Sear, and Mace's model.

    PubMed

    Mattison, Siobhán M

    2011-07-01

    Matriliny has long been debated by anthropologists positing either its primitive or its puzzling nature. More recently, evolutionary anthropologists have attempted to recast matriliny as an adaptive solution to modern social and ecological environments, tying together much of what was known to be associated with matriliny. This paper briefly reviews the major anthropological currents in studies of matriliny and discusses the contribution of evolutionary anthropology to this body of literature. It discusses the utility of an evolutionary framework in the context of the first independent test of Holden et al.'s 2003 model of matriliny as daughter-biased investment. It finds that historical daughter-biased transmission of land among the Mosuo is consistent with the model, whereas current income transmission is not. In both cases, resources had equivalent impacts on male and female reproduction, a result which predicts daughter-biased resource transmission given any nonzero level of paternity uncertainty. However, whereas land was transmitted traditionally to daughters, income today is invested in both sexes. Possible reasons for this discrepancy are discussed. PMID:22388801

  16. The use of the puzzle box as a means of assessing the efficacy of environmental enrichment.

    PubMed

    O'Connor, Angela M; Burton, Thomas J; Leamey, Catherine A; Sawatari, Atomu

    2014-01-01

    Environmental enrichment can dramatically influence the development and function of neural circuits. Further, enrichment has been shown to successfully delay the onset of symptoms in models of Huntington's disease (1-4), suggesting environmental factors can evoke a neuroprotective effect against the progressive, cellular level damage observed in neurodegenerative disorders. The ways in which an animal can be environmentally enriched, however, can vary considerably. Further, there is no straightforward manner in which the effects of environmental enrichment can be assessed: most methods require either fairly complicated behavioral paradigms and/or postmortem anatomical/physiological analyses. This protocol describes the use of a simple and inexpensive behavioral assay, the Puzzle Box (5-7) as a robust means of determining the efficacy of increased social, sensory and motor stimulation on mice compared to cohorts raised in standard laboratory conditions. This simple problem solving task takes advantage of a rodent's innate desire to avoid open enclosures by seeking shelter. Cognitive ability is assessed by adding increasingly complex impediments to the shelter's entrance. The time a given subject takes to successfully remove the obstructions and enter the shelter serves as the primary metric for task performance. This method could provide a reliable means of rapidly assessing the efficacy of different enrichment protocols on cognitive function, thus paving the way for systematically determining the role specific environmental factors play in delaying the onset of neurodevelopmental and neurodegenerative disease. PMID:25590345

  17. [What type of welfare policy promotes health?: the puzzling interrelation of economic and health inequality].

    PubMed

    Hurrelmann, K; Richter, M; Rathmann, K

    2011-06-01

    In all highly developed countries, the overall health status of the population has significantly improved within the past 30 years. The most important reason for this is the increase in economic prosperity. Economic wealth, however, today is much more unequally distributed than it was 3 decades ago. Countries with relatively small disparities in the availability of material resources between socioeconomic groups, such as the Scandinavian countries, have better health outcomes on the population level. Health inequalities, however, have also reached a higher level than 30 years ago. As of today, we do not have convincing explanations for the interrelation of economic and health inequality. This paper gives an overview of existing research on a comparative basis. The research results are ambivalent. They show the puzzling result that the Scandinavian countries with their highly distributive welfare policy manage to achieve the comparatively highest level of economic, but not health, equity. Based on these results, we develop proposals for future research approaches. A central assumption is that in rich societies no longer only material, but more and more immaterial determinants are crucial for the formation of health inequality. The promotion of "salutogenic" self-management capabilities in socially disadvantaged groups is considered to be the central element in effective intervention strategies.

  18. 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

  19. The Sir David Cuthbertson Medal Lecture. Hunting for new pieces to the complex puzzle of obesity.

    PubMed

    Frühbeck, Gema

    2006-11-01

    Disentangling the neuroendocrine systems that regulate energy homeostasis and adiposity has been a long-standing challenge in pathophysiology, with obesity being an increasingly important public health problem. Adipose tissue is no longer considered a passive bystander in body-weight regulation. It actively secretes a large number of hormones, growth factors, enzymes, cytokines, complement factors and matrix proteins, at the same time as expressing receptors for most of these elements, which influence fuel storage, mobilisation and utilisation at both central and peripheral sites. Thus, an extensive cross talk at a local and systemic level in response to specific external stimuli or metabolic changes underpins the multifunctional characteristics of adipose tissue. In addition to the already-known adipokines, such as IL, TNFalpha, leptin, resistin and adiponectin, more recently attention has been devoted to 'newcomers' to the 'adipose tissue arena', which include aquaporin, caveolin, visfatin, serum amyloid A and vascular endothelial growth factor. While in vitro and in vivo experiments have provided extremely valuable information, the advances in genomics, proteomics and metabolomics are offering a level of information not previously attainable to help unlock the molecular basis of obesity. The potential and power of combining pathophysiological observations with the wealth of information provided by the human genome, knock-out models, transgenesis, DNA microarrays, RNA silencing and other emerging technologies offer a new and unprecedented view of a complex disease, conferring novel insights into old questions by identifying new pieces to the unfinished jigsaw puzzle of obesity.

  20. Alteration of time perception in young and elderly people during jigsaw puzzle tasks with different complexities.

    PubMed

    Iwamoto, Yuko; Hoshiyama, Minoru

    2011-12-01

    We investigated the relationship between time perception during tasks and subjective feelings in young and elderly people. Simple and complex jigsaw puzzles were given to healthy young and elderly subjects. The subjects were asked to estimate the time they had taken to complete the tasks after performing them. The ratio of the subjective to actual duration of time, the duration judgment ratio (DJR), and the relationship between the DJR and the subjective feelings during the tasks were analysed. The elderly group required a significantly longer time than the younger group for both tasks, and both elderly and young subjects estimated a longer time than the actual time to complete the tasks. The effect of the tasks on the DJR was significant, and the value was higher for the 24-piece than 54-piece task in both groups. The DJR was smaller in subjects with "much interest" than in those with "little interest" in the 24-piece task, but there was no difference in the 54-piece task. The results indicate that time perception was modulated by subjective feelings during the task, as well as by the age and task complexity. Because the goal and the result of the task may modulate time perception during it, time perception while actually performing the task may differ from that after completing it.

  1. The placebo puzzle: examining the discordant space between biomedical science and illness/healing.

    PubMed

    Pohlman, Shawn; Cibulka, Nancy J; Palmer, Janice L; Lorenz, Rebecca A; SmithBattle, Lee

    2013-03-01

    The placebo response presents an enigma to biomedical science: how can 'inert' or 'sham' procedures reduce symptoms and produce physiological changes that are comparable to prescribed treatments? In this study, we examine this puzzle by explicating the discordant space between the prevailing biomedical paradigm, which focuses on a technical understanding of diagnosis and treatment, and a broader understanding of illness and healing as relational and embodied. Although biomedical achievements are impressive, the knowledge resulting from this paradigm is limited by its ontological and epistemological assumptions. When the body and world are objectified, illness meanings, therapeutic relationships, and healing practices are dismissed or distorted. In spite of a robust critique of the tenets of biomedicine for guiding practice, the biomedical paradigm retains a tenacious hold on evidence-based medicine and nursing, downplaying our clinical understanding of the sentient body, patients' life-worlds, and illness and healing. In reality, skilled nurses rely on multiple forms of knowledge in providing high-quality care to particular patients. Clinically wise nurses integrate their experience and knowledge of patients' priorities, fears, and illness trajectories along with biomedical findings to make astute judgments and promote health and healing.

  2. Unraveling the puzzling intermediate states in the Biham-Middleton-Levine traffic model

    NASA Astrophysics Data System (ADS)

    Olmos, L. E.; Muñoz, J. D.

    2015-05-01

    The Biham-Middleton-Levine (BML) traffic model, a cellular automaton with eastbound and northbound cars moving by turns on a square lattice, has been an underpinning model in the study of collective behavior by cars, pedestrians, and even internet packages. Contrary to initial beliefs that the model exhibits a sharp phase transition from freely flowing to fully jammed, it has been reported that it shows intermediate stable phases, where jams and freely flowing traffic coexist, but there is no clear understanding of their origin. Here, we analyze the model as an anisotropic system with a preferred fluid direction (northeast) and find that it exhibits two differentiated phase transitions: the system is either longer in the flow direction (longitudinal) or perpendicular to it (transversal). The critical densities where these transitions occur enclose the density interval of intermediate states and can be approximated by mean-field analysis, all derived from the anisotropic exponent relating the longitudinal and transversal correlation lengths. Thus, we arrive at the interesting result that the puzzling intermediate states in the original model are just a superposition of these two different behaviors of the phase transition, solving by the way most mysteries behind the BML model, which turns out to be a paradigmatic example of such anisotropic critical systems.

  3. The use of the puzzle box as a means of assessing the efficacy of environmental enrichment.

    PubMed

    O'Connor, Angela M; Burton, Thomas J; Leamey, Catherine A; Sawatari, Atomu

    2014-12-29

    Environmental enrichment can dramatically influence the development and function of neural circuits. Further, enrichment has been shown to successfully delay the onset of symptoms in models of Huntington's disease (1-4), suggesting environmental factors can evoke a neuroprotective effect against the progressive, cellular level damage observed in neurodegenerative disorders. The ways in which an animal can be environmentally enriched, however, can vary considerably. Further, there is no straightforward manner in which the effects of environmental enrichment can be assessed: most methods require either fairly complicated behavioral paradigms and/or postmortem anatomical/physiological analyses. This protocol describes the use of a simple and inexpensive behavioral assay, the Puzzle Box (5-7) as a robust means of determining the efficacy of increased social, sensory and motor stimulation on mice compared to cohorts raised in standard laboratory conditions. This simple problem solving task takes advantage of a rodent's innate desire to avoid open enclosures by seeking shelter. Cognitive ability is assessed by adding increasingly complex impediments to the shelter's entrance. The time a given subject takes to successfully remove the obstructions and enter the shelter serves as the primary metric for task performance. This method could provide a reliable means of rapidly assessing the efficacy of different enrichment protocols on cognitive function, thus paving the way for systematically determining the role specific environmental factors play in delaying the onset of neurodevelopmental and neurodegenerative disease.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. Within-river phosphorus retention: accounting for a missing piece in the watershed phosphorus puzzle.

    PubMed

    Jarvie, Helen P; Sharpley, Andrew N; Scott, J Thad; Haggard, Brian E; Bowes, Michael J; Massey, Lesley B

    2012-12-18

    The prevailing "puzzle" in watershed phosphorus (P) management is how to account for the nonconservative behavior (retention and remobilization) of P along the land-freshwater continuum. This often hinders our attempts to directly link watershed P sources with their water quality impacts. Here, we examine aspects of within-river retention of wastewater effluent P and its remobilization under high flows. Most source apportionment methods attribute P loads mobilized under high flows (including retained and remobilized effluent P) as nonpoint agricultural sources. We present a new simple empirical method which uses chloride as a conservative tracer of wastewater effluent, to quantify within-river retention of effluent P, and its contribution to river P loads, when remobilized under high flows. We demonstrate that within-river P retention can effectively mask the presence of effluent P inputs in the water quality record. Moreover, we highlight that by not accounting for the contributions of retained and remobilized effluent P to river storm-flow P loads, existing source apportionment methods may significantly overestimate the nonpoint agricultural sources and underestimate wastewater sources in mixed land-use watersheds. This has important implications for developing effective watershed remediation strategies, where remediation needs to be equitably and accurately apportioned among point and nonpoint P contributors.

  13. 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.

  14. Genome puzzle master (GPM): an integrated pipeline for building and editing pseudomolecules from fragmented sequences

    PubMed Central

    Zhang, Jianwei; Kudrna, Dave; Mu, Ting; Li, Weiming; Copetti, Dario; Yu, Yeisoo; Goicoechea, Jose Luis; Lei, Yang; Wing, Rod A.

    2016-01-01

    Motivation: Next generation sequencing technologies have revolutionized our ability to rapidly and affordably generate vast quantities of sequence data. Once generated, raw sequences are assembled into contigs or scaffolds. However, these assemblies are mostly fragmented and inaccurate at the whole genome scale, largely due to the inability to integrate additional informative datasets (e.g. physical, optical and genetic maps). To address this problem, we developed a semi-automated software tool—Genome Puzzle Master (GPM)—that enables the integration of additional genomic signposts to edit and build ‘new-gen-assemblies’ that result in high-quality ‘annotation-ready’ pseudomolecules. Results: With GPM, loaded datasets can be connected to each other via their logical relationships which accomplishes tasks to ‘group,’ ‘merge,’ ‘order and orient’ sequences in a draft assembly. Manual editing can also be performed with a user-friendly graphical interface. Final pseudomolecules reflect a user’s total data package and are available for long-term project management. GPM is a web-based pipeline and an important part of a Laboratory Information Management System (LIMS) which can be easily deployed on local servers for any genome research laboratory. Availability and Implementation: The GPM (with LIMS) package is available at https://github.com/Jianwei-Zhang/LIMS Contacts: jzhang@mail.hzau.edu.cn or rwing@mail.arizona.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27318200

  15. 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.

  16. 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

  17. 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.

  18. Solving the 56Ni Puzzle of Magnetar-powered Broad-lined Type IC Supernovae

    NASA Astrophysics Data System (ADS)

    Wang, Ling-Jun; Han, Yan-Hui; Xu, Dong; Wang, Shan-Qin; Dai, Zi-Gao; Wu, Xue-Feng; Wei, Jian-Yan

    2016-11-01

    Broad-lined Type Ic supernovae (SNe Ic-BL) are of great importance because their association with long-duration gamma-ray bursts (LGRBs) holds the key to deciphering the central engine of LGRBs, which refrains from being unveiled despite decades of investigation. Among the two popularly hypothesized types of central engine, i.e., black holes and strongly magnetized neutron stars (magnetars), there is mounting evidence that the central engine of GRB-associated SNe (GRB-SNe) is rapidly rotating magnetars. Theoretical analysis also suggests that magnetars could be the central engine of SNe Ic-BL. What puzzled the researchers is the fact that light-curve modeling indicates that as much as 0.2{--}0.5 {M}ȯ of 56Ni was synthesized during the explosion of the SNe Ic-BL, which is unfortunately in direct conflict with current state-of-the-art understanding of magnetar-powered 56Ni synthesis. Here we propose a dynamic model of magnetar-powered SNe to take into account the acceleration of the ejecta by the magnetar, as well as the thermalization of the injected energy. Assuming that the SN kinetic energy comes exclusively from the magnetar acceleration, we find that although a major fraction of the rotational energy of the magnetar is to accelerate the SN ejecta, a tiny fraction of this energy deposited as thermal energy of the ejecta is enough to reduce the needed 56Ni to 0.06 M ⊙ for both SN 1997ef and SN 2007ru. We therefore suggest that magnetars could power SNe Ic-BL in aspects both of energetics and of 56Ni synthesis.

  19. Steps towards a solution of the FS Aurigae puzzle - II. Confirmation of the intermediate polar status

    NASA Astrophysics Data System (ADS)

    Neustroev, V. V.; Tovmassian, G. H.; Zharikov, S. V.; Sjoberg, George

    2013-07-01

    FS Aur is famous for a variety of uncommon and puzzling periodic photometric and spectroscopic variabilities. It was previously proposed that the precession of a fast-rotating magnetically accreting white dwarf can successfully explain these phenomena. We present a study of FS Aur based on two extensive sets of optical photometric observations and three X-ray data sets in which we intended to verify whether the observational properties of the long-period modulations observed in FS Aur and V455 And are similar in appearance to the spin modulation in ordinary intermediate polars (IPs). These new optical observations have revealed, for the first time in photometric data, the variability with the presumed precession period of the white dwarf, previously seen only spectroscopically. We also found that the modulations with the precession and orbital periods are evident in X-ray data. We show that the observed properties of FS Aur closely resemble those of other IPs, thus confirming this cataclysmic variable as a member of the class. Our analysis of multicolour observations of IPs has shown that a time series analysis of colour indices appears to be a powerful technique for revealing hidden variabilities and shedding light on their nature. We have found that the (B - I) power spectrum of V1223 Sgr indicates the presence in the data of the spin pulsation which is not seen in the optical light curve at all. Also, the analysis of the colour indices of V455 And revealed the presence of the photometric variations which, similarly to FS Aur, was previously observed only spectroscopically.

  20. 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.

  1. 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.

  2. 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.

  3. 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}.

  4. The Puzzling Li-rich Red Giant Associated with NGC 6819

    NASA Astrophysics Data System (ADS)

    Carlberg, Joleen K.; Smith, Verne V.; Cunha, Katia; Majewski, Steven R.; Mészáros, Szabolcs; Shetrone, Matthew; Allende Prieto, Carlos; Bizyaev, Dmitry; Stassun, Keivan G.; Fleming, Scott W.; Zasowski, Gail; Hearty, Fred; Nidever, David L.; Schneider, Donald P.; Holtzman, Jon A.; Frinchaboy, Peter M.

    2015-03-01

    A Li-rich red giant (RG) star (2M19411367+4003382) recently discovered in the direction of NGC 6819 belongs to the rare subset of Li-rich stars that have not yet evolved to the luminosity bump, an evolutionary stage where models predict Li can be replenished. The currently favored model to explain Li enhancement in first-ascent RGs like 2M19411367+4003382 requires deep mixing into the stellar interior. Testing this model requires a measurement of 12C/13C, which is possible to obtain from Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra. However, the Li-rich star also has abnormal asteroseismic properties that call into question its membership in the cluster, even though its radial velocity and location on color-magnitude diagrams are consistent with membership. To address these puzzles, we have measured a wide array of abundances in the Li-rich star and three comparison stars using spectra taken as part of the APOGEE survey to determine the degree of stellar mixing, address the question of membership, and measure the surface gravity. We confirm that the Li-rich star is a RG with the same overall chemistry as the other cluster giants. However, its log g is significantly lower, consistent with the asteroseismology results and suggestive of a very low mass if the star is indeed a cluster member. Regardless of the cluster membership, the 12C/13C and C/N ratios of the Li-rich star are consistent with standard first dredge-up, indicating that Li dilution has already occurred, and inconsistent with internal Li enrichment scenarios that require deep mixing.

  5. 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

  6. Does the diffusion dark matter-dark energy interaction model solve cosmological puzzles?

    NASA Astrophysics Data System (ADS)

    Szydłowski, Marek; Stachowski, Aleksander

    2016-08-01

    We study dynamics of cosmological models with diffusion effects modeling dark matter and dark energy interactions. We show the simple model with diffusion between the cosmological constant sector and dark matter, where the canonical scaling law of dark matter (ρd m ,0a-3(t )) is modified by an additive ɛ (t )=γ t a-3(t ) to the form ρd m=ρd m ,0a-3(t )+ɛ (t ). We reduced this model to the autonomous dynamical system and investigate it using dynamical system methods. This system possesses a two-dimensional invariant submanifold on which the dark matter-dark energy (DM-DE) interaction can be analyzed on the phase plane. The state variables are density parameter for matter (dark and visible) and parameter δ characterizing the rate of growth of energy transfer between the dark sectors. A corresponding dynamical system belongs to a general class of jungle type of cosmologies represented by coupled cosmological models in a Lotka-Volterra framework. We demonstrate that the de Sitter solution is a global attractor for all trajectories in the phase space and there are two repellers: the Einstein-de Sitter universe and the de Sitter universe state dominating by the diffusion effects. We distinguish in the phase space trajectories, which become in good agreement with the data. They should intersect a rectangle with sides of Ωm ,0∈[0.2724 ,0.3624 ] , δ ∈[0.0000 ,0.0364 ] at the 95% CL. Our model could solve some of the puzzles of the Λ CDM model, such as the coincidence and fine-tuning problems. In the context of the coincidence problem, our model can explain the present ratio of ρm to ρd e, which is equal 0.457 6-0.0831+0.1109 at a 2 σ confidence level.

  7. New data and an old puzzle: the negative association between schizophrenia and rheumatoid arthritis

    PubMed Central

    Lee, S Hong; Byrne, Enda M; Hultman, Christina M; Kähler, Anna; Vinkhuyzen, Anna AE; Ripke, Stephan; Andreassen, Ole A; Frisell, Thomas; Gusev, Alexander; Hu, Xinli; Karlsson, Robert; Mantzioris, Vasilis X; McGrath, John J; Mehta, Divya; Stahl, Eli A; Zhao, Qiongyi; Kendler, Kenneth S; Sullivan, Patrick F; Price, Alkes L; O’Donovan, Michael; Okada, Yukinori; Mowry, Bryan J; Raychaudhuri, Soumya; Wray, Naomi R; Byerley, William; Cahn, Wiepke; Cantor, Rita M; Cichon, Sven; Cormican, Paul; Curtis, David; Djurovic, Srdjan; Escott-Price, Valentina; Gejman, Pablo V; Georgieva, Lyudmila; Giegling, Ina; Hansen, Thomas F; Ingason, Andrés; Kim, Yunjung; Konte, Bettina; Lee, Phil H; McIntosh, Andrew; McQuillin, Andrew; Morris, Derek W; Nöthen, Markus M; O’Dushlaine, Colm; Olincy, Ann; Olsen, Line; Pato, Carlos N; Pato, Michele T; Pickard, Benjamin S; Posthuma, Danielle; Rasmussen, Henrik B; Rietschel, Marcella; Rujescu, Dan; Schulze, Thomas G; Silverman, Jeremy M; Thirumalai, Srinivasa; Werge, Thomas; Agartz, Ingrid; Amin, Farooq; Azevedo, Maria H; Bass, Nicholas; Black, Donald W; Blackwood, Douglas H R; Bruggeman, Richard; Buccola, Nancy G; Choudhury, Khalid; Cloninger, Robert C; Corvin, Aiden; Craddock, Nicholas; Daly, Mark J; Datta, Susmita; Donohoe, Gary J; Duan, Jubao; Dudbridge, Frank; Fanous, Ayman; Freedman, Robert; Freimer, Nelson B; Friedl, Marion; Gill, Michael; Gurling, Hugh; De Haan, Lieuwe; Hamshere, Marian L; Hartmann, Annette M; Holmans, Peter A; Kahn, René S; Keller, Matthew C; Kenny, Elaine; Kirov, George K; Krabbendam, Lydia; Krasucki, Robert; Lawrence, Jacob; Lencz, Todd; Levinson, Douglas F; Lieberman, Jeffrey A; Lin, Dan-Yu; Linszen, Don H; Magnusson, Patrik KE; Maier, Wolfgang; Malhotra, Anil K; Mattheisen, Manuel; Mattingsdal, Morten; McCarroll, Steven A; Medeiros, Helena; Melle, Ingrid; Milanova, Vihra; Myin-Germeys, Inez; Neale, Benjamin M; Ophoff, Roel A; Owen, Michael J; Pimm, Jonathan; Purcell, Shaun M; Puri, Vinay; Quested, Digby J; Rossin, Lizzy; Ruderfer, Douglas; Sanders, Alan R; Shi, Jianxin; Sklar, Pamela; St. Clair, David; Stroup, T Scott; Van Os, Jim; Visscher, Peter M; Wiersma, Durk; Zammit, Stanley; Bridges, S Louis; Choi, Hyon K; Coenen, Marieke JH; de Vries, Niek; Dieud, Philippe; Greenberg, Jeffrey D; Huizinga, Tom WJ; Padyukov, Leonid; Siminovitch, Katherine A; Tak, Paul P; Worthington, Jane; De Jager, Philip L; Denny, Joshua C; Gregersen, Peter K; Klareskog, Lars; Mariette, Xavier; Plenge, Robert M; van Laar, Mart; van Riel, Piet

    2015-01-01

    Background: A long-standing epidemiological puzzle is the reduced rate of rheumatoid arthritis (RA) in those with schizophrenia (SZ) and vice versa. Traditional epidemiological approaches to determine if this negative association is underpinned by genetic factors would test for reduced rates of one disorder in relatives of the other, but sufficiently powered data sets are difficult to achieve. The genomics era presents an alternative paradigm for investigating the genetic relationship between two uncommon disorders. Methods: We use genome-wide common single nucleotide polymorphism (SNP) data from independently collected SZ and RA case-control cohorts to estimate the SNP correlation between the disorders. We test a genotype X environment (GxE) hypothesis for SZ with environment defined as winter- vs summer-born. Results: We estimate a small but significant negative SNP-genetic correlation between SZ and RA (−0.046, s.e. 0.026, P = 0.036). The negative correlation was stronger for the SNP set attributed to coding or regulatory regions (−0.174, s.e. 0.071, P = 0.0075). Our analyses led us to hypothesize a gene-environment interaction for SZ in the form of immune challenge. We used month of birth as a proxy for environmental immune challenge and estimated the genetic correlation between winter-born and non-winter born SZ to be significantly less than 1 for coding/regulatory region SNPs (0.56, s.e. 0.14, P  = 0.00090). Conclusions: Our results are consistent with epidemiological observations of a negative relationship between SZ and RA reflecting, at least in part, genetic factors. Results of the month of birth analysis are consistent with pleiotropic effects of genetic variants dependent on environmental context. PMID:26286434

  8. 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.

  9. 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

  10. 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.

  11. 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/.

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. The missing piece of the puzzle: low-luminosity AGN in the Unified Model

    NASA Astrophysics Data System (ADS)

    Mezcua, Mar; Prieto, Almudena; Fernandez Ontiveros, Juan Antonio

    One of the puzzling questions in AGN studies is whether the Unified Model for AGN also holds for the most numerous class among them: low-luminosity AGN (LLAGN; Lbol<=10(42) erg/s). LLAGN outstand from the Unified Model as lacking the big blue bump in the optical-UV, footprint of the accretion disk, and being radiatively inefficient. A possible explanation is that the overall energy output in these faint nuclei is dominated by a jet. This scenario is supported by the finding that: (1) the high-spatial-resolution spectral energy distribution (SED) of some LLAGN is well described by non-thermal synchrotron jet emission from radio to the UV; and (2) 67% LLAGN in the Palomar Sample observed at sub-arcsec resolution present extended or marginally resolved radio cores, most of them with a flat or slightly inverted radio spectrum and non-thermal brightness temperatures above 10(5) K footprint of a relativistic jet. In this work we also present the detection of extended jet-like radio structures in NGC 1097 and NGC 2911 and the first resolved parsec-scale jet in the nucleus of the Sombrero galaxy, based on the analysis of sub-arcsec resolution radio data of a sample of nearby LLAGN for which high-spatial-resolution SED of their core emission is available. This allows us to investigate their energetic balance without drawing on (most) of the ad-hoc assumptions usually considered in large statistical surveys. We find that most of the LLAGN in the sample show a kinematic jet luminosity larger than the radiated bolometric luminosity, in agreement with previous statistical studies, which indicates that the jet kinematic output dominates the nuclear energetics of LLAGN. However, our individualized study reveals that the total bolometric luminosity is larger than the jet power in those sources without detected large-scale (> 100 parsec) jet radio emission. Finally, we find that the Eddington ratios are highly sub-Eddington (<10(-4) ) even when adding the jet power to the total

  17. A possible solution to the B → ππ puzzle using the principle of maximum conformality

    NASA Astrophysics Data System (ADS)

    Qiao, Cong-Feng; Zhu, Rui-Lin; Wu, Xing-Gang; Brodsky, Stanley J.

    2015-09-01

    The measured Bd →π0π0 branching fraction deviates significantly from conventional QCD predictions, a puzzle which has persisted for more than 10 years. This may be a hint of new physics beyond the Standard Model; however, as we shall show in this paper, the pQCD prediction is highly sensitive to the choice of the renormalization scales which enter the decay amplitude. In the present paper, we show that the renormalization scale uncertainties for B → ππ can be greatly reduced by applying the Principle of Maximum Conformality (PMC), and more precise predictions for CP-averaged branching ratios B (B → ππ) can be achieved. Combining the errors in quadrature, we obtain B (Bd →π0π0)|PMC = (0.98-0.31+0.44) ×10-6 by using the light-front holographic low-energy model for the running coupling. All of the CP-averaged B → ππ branching fractions predicted by the PMC are consistent with the Particle Data Group average values and the recent Belle data. Thus, the PMC provides a possible solution for the Bd →π0π0 puzzle.

  18. 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”.

  19. 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

  20. 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.

  1. 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.

  2. BOUNDS ON LEPTON FLAVOR CHANGING CURRENTS AND THE SOLAR NEUTRINO PUZZLE:. Bounds on Lepton Flavor Changing Currents

    NASA Astrophysics Data System (ADS)

    degl'Innocenti, Scilla; Ricci, Barbara

    We present a phenomenological analysis of a lepton flavor changing current, considering the case of interactions among leptons which change the neutrino flavor and are diagonal in the charged lepton sector. In the case of νe↔νµ transition, we derive a bound on the vector coupling constant GV≤0.16 GF from experimental data on νµ-e scattering. For a transition νe↔νx, from (anti) νe-e scattering experiments and from the analysis of advanced stellar evolutionary phases, we find GV≤0.55 GF. We discuss the compatibility of these data with a possible explanation of the solar neutrino puzzle. We also analyze how the present bounds can be improved in future long baseline neutrino experiments and atmospheric neutrino detectors.

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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.

  8. The puzzle of Italian rice origin and evolution: determining genetic divergence and affinity of rice germplasm from Italy and Asia.

    PubMed

    Cai, Xingxing; Fan, Jing; 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 (H(e) = 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.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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)

  15. 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...

  16. 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;…

  17. China: moral puzzles.

    PubMed

    Xu, T M

    1990-01-01

    This is the first of a set of three articles concerned with "bioethics on the Pacific Rim." The author, vice president of Beijing Medical University and vice chairman of the Beijing Academic Association for Morality, identifies population control, euthanasia, and the allocation of health care resources as bioethical issues of current interest in his country. Population policy in China is grounded in public welfare arguments. The idea of a right to choose one's death is found in Chinese philosophy, although Chinese legal experts believe that euthanasia is not compatible with present criminal, civil, or family law. Allocation of health resources remains a problem in China, even throughout the free medical service that serves a small portion, largely composed of government employees, of the country's population of 1.08 billion.

  18. 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...

  19. 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

  20. 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)

  1. 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.

  2. China: moral puzzles.

    PubMed

    Xu, T M

    1990-01-01

    This is the first of a set of three articles concerned with "bioethics on the Pacific Rim." The author, vice president of Beijing Medical University and vice chairman of the Beijing Academic Association for Morality, identifies population control, euthanasia, and the allocation of health care resources as bioethical issues of current interest in his country. Population policy in China is grounded in public welfare arguments. The idea of a right to choose one's death is found in Chinese philosophy, although Chinese legal experts believe that euthanasia is not compatible with present criminal, civil, or family law. Allocation of health resources remains a problem in China, even throughout the free medical service that serves a small portion, largely composed of government employees, of the country's population of 1.08 billion. PMID:2318623

  3. 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.

  4. 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.

  5. 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

  6. bar{B}_{d,s} → D^{*}_{d,s} V and bar{B}_{d,s}^* → D_{d,s} V decays in QCD factorization and possible puzzles

    NASA Astrophysics Data System (ADS)

    Chang, Qin; Chen, Ling-Xin; Zhang, Yun-Yun; Sun, Jun-Feng; Yang, Yue-Ling

    2016-10-01

    Motivated by the rapid development of heavy-flavor experiments, phenomenological studies of nonleptonic bar{B}_{d,s} → D^{*}_{d,s} V and bar{B}_{d,s}^* → D_{d,s} V (V=ρ ,K^*) decays are performed within the framework of QCD factorization. Relative to the previous work, the QCD corrections to the transverse amplitudes are evaluated at next-to-leading order. The theoretical predictions of the observables are updated. For the measured bar{B}_{d,s} → D^{*}_{d,s} V decays, the tensions between theoretical results and experimental measurements, i.e. the "R_{ds}V puzzle" and "D^{*} V (or R_{V/ℓ bar{ν }_ℓ }) puzzle", are presented after detailed analyses. For the bar{B}_{d,s}^* → D_{d,s} V decays, they have relatively large branching fractions of the order ≳ O(10^{-9}) and are in the scope of Belle-II and LHCb experiments. Moreover, they also provide a way to crosscheck the possible puzzles mentioned above through the similar ratios R_{ds}^' V} and R_{V/ℓ bar{ν }_ℓ }^' }. More refined experimental measurements and theoretical efforts are required to confirm or refute such two anomalies.

  7. Emerging biomarkers for evaluating cardiovascular risk in the chronic kidney disease patient: how do new pieces fit into the uremic puzzle?

    PubMed

    Stenvinkel, Peter; Carrero, Juan Jesús; Axelsson, Jonas; Lindholm, Bengt; Heimbürger, Olof; Massy, Ziad

    2008-03-01

    Premature cardiovascular disease (CVD), including stroke, peripheral vascular disease, sudden death, coronary artery disease, and congestive heart failure, is a notorious problem in patients with chronic kidney disease (CKD). Because the presence of CVD is independently associated with kidney function decline, it appears that the relationship between CKD and CVD is reciprocal or bidirectional, and that it is this association that leads to the vicious circle contributing to premature death. As randomized, placebo-controlled trials have so far been disappointing and unable to show a survival benefit of various treatment strategies, such a lipid-lowering, increased dialysis dose and normalization of hemoglobin, the risk factor profile seems to be different in CKD compared with the general population. Indeed, seemingly paradoxical associations between traditional risk factors and cardiovascular outcome in patients with advanced CKD have complicated our efforts to identify the real cardiovascular culprits. This review focuses on the many new pieces that need to be fit into the complicated puzzle of uremic vascular disease, including persistent inflammation, endothelial dysfunction, oxidative stress, and vascular ossification. Each of these is not only highly prevalent in CKD but also more strongly linked to CVD in these patients than in the general population. However, a causal relationship between these new markers and CVD in CKD patients remains to be established. Finally, two novel disciplines, proteomics and epigenetics, will be discussed, because these tools may be helpful in the understanding of the discussed vascular risk factors.

  8. 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

  9. Reversible migration of silver on memorized pathways in Ag-Ge40S60 films

    NASA Astrophysics Data System (ADS)

    Orava, J.; Kozicki, M. N.; Yannopoulos, S. N.; Greer, A. L.

    2015-07-01

    Reversible and reproducible formation and dissolution of silver conductive filaments are studied in Ag-photodoped thin-film Ge40S60 subjected to electric fields. A tip-planar geometry is employed, where a conductive-atomic-force microscopy tip is the tip electrode and a silver patch is the planar electrode. We highlight an inherent "memory" effect in the amorphous chalcogenide solid-state electrolyte, in which particular silver-ion migration pathways are preserved "memorized" during writing and erasing cycles. The "memorized" pathways reflect structural changes in the photodoped chalcogenide film. Structural changes due to silver photodoping, and electrically-induced structural changes arising from silver migration, are elucidated using Raman spectroscopy. Conductive filament formation, dissolution, and electron (reduction) efficiency in a lateral device geometry are related to operation of the nano-ionic Programmable Metallization Cell memory and to newly emerging chalcogenide-based lateral geometry MEMS technologies. The methods in this work can also be used for qualitative multi-parameter sampling of metal/amorphous-chalcogenide combinations, characterizing the growth/dissolution rates, retention and endurance of fractal conductive filaments, with the aim of optimizing devices.

  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. 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...

  12. 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...

  13. 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

  14. 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

  15. Pharmacoresistant epilepsy: unmet needs in solving the puzzle(s).

    PubMed

    Weaver, Donald F; Pohlmann-Eden, Bernd

    2013-05-01

    Pharmacoresistant epilepsy is a significant medical problem. The 2nd Halifax International Epilepsy Conference & Retreat identified crucial needs, which if successfully addressed, will aid in paving the way to improved lives for people with pharmacoresistant epilepsy. These are needs: (1) for an evidence-based and dynamic definition of pharmacoresistant epilepsy; (2) for a comprehensive description of the natural history of pharmacoresistant epilepsy; (3) for a comprehensive description of the complications and comorbidities of pharmacoresistant epilepsy; (4) for a rigorous delineation of the epidemiology and socioeconomic impact of pharmacoresistant epilepsy; (5) for clinically meaningful diagnostic and prognostic physiologically based electroencephalography (EEG) biomarkers; (6) for clinically meaningful diagnostic and prognostic anatomically based (MRI Imaging) biomarkers; (7) for biomolecular/biochemical mechanistic understanding of etiopathogenesis for pharmacoresistant epilepsy; (8) for representative animal models of pharmacoresistant epilepsy; (9) for new and effective drugs or other novel treatments for pharmacoresistant epilepsy; and (10) to promote continuing research and research funding targeting pharmacoresistant epilepsy.

  16. 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)

  17. The Evolutionary Puzzle of Suicide

    PubMed Central

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

    2013-01-01

    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

  18. 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.

  19. 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

  20. 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

  1. Horse trichinellosis, an unresolved puzzle.

    PubMed

    Pozio, E; Tamburrini, A; La Rosa, G

    2001-06-01

    In spite of routine controls to detect Trichinella larvae in horse-meat, human infections due to horse-meat consumption continue to occur in France and Italy. The epidemiology of horse trichinellosis since its discovery in 1975 is outlined, addressing the possible modes of natural transmission to horses, the need to develop more sensitive methods for detecting Trichinella larvae in horses, and the economic impact of horse trichinellosis. Investigations of human outbreaks due to horse-meat consumption have implicated single cases of inadequate veterinary controls on horses imported from non-European Union countries. In particular, most cases of human infection have been attributed to horses imported from Eastern Europe, where pig trichinellosis is re-emerging and the main source of infection in horses.

  2. The High School Dropout Puzzle.

    ERIC Educational Resources Information Center

    Finn, Chester E., Jr.

    1987-01-01

    Even as school standards rise, the on-time graduation rate remains generally stable and the proportion of the American population that has completed high school is the greatest in our history. Negative estimates are based on a lack of definitions and data discrepancies. Two strategies for increasing the graduate rate are discussed. (PS)

  3. 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.

  4. Solving the English Phonological Puzzle.

    ERIC Educational Resources Information Center

    Piper, Terry

    A research project was undertaken to investigate the acquisition of the English sound system by kindergarten children of various first language backgrounds. Sixteen children were selected from three kindergartens in Prince Rupert, British Columbia according to the following criteria: (1) no English was spoken by parents; (2) the child scored 3 or…

  5. 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.

  6. 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.

  7. 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

  8. 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)

  9. Natural-gas price puzzle

    SciTech Connect

    Russell, M.

    1983-02-01

    Rectifying natural-gas underpricing and distortions in production has benefited the overall economy, but transition costs are large, and problems and strains continue. The natural-gas price story began with the 1954 price controls that developed into a wasteful, inefficient, and unfair system of too-low gas prices that resulted in the 1978 Natural Gas Policy Act (NGPA). While meeting a number of goals, NGPA has also led to current large increases in gas prices, ironically at a time when producers complain of more gas than they can sell. This glut, however, may be a surplus of short-run deliverability rather than an increase in supply. Prices have not fallen even temporarily because long-term contracts common between pipelines and producers typically prevent downward adjustment of prices to meet demand fluctuations, and the economy (hence the consumer) cannot escape the costof sustaining capacity through up-and-down demand. Transportation and delivery costs that, while getting smaller in relation to wellhead prices, are rising, and inflation, higher interest rates, and costs of uncollectables add to the price. In addition, while a straightforward supply, demand, and cost explanation of the price picture is accurate enough on a national basis, the average cost of gas as it enters a particular pipeline is affected by such complexities as historical accident, location, timing, bargaining power, and management decisions.

  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.

  11. 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.…

  12. Addressing the Puzzle of Race

    ERIC Educational Resources Information Center

    Coleman, Samuel

    2011-01-01

    Although racial discrimination poses a devastating instrument of oppression, social work texts lack a clear and consistent definition of "race". The solution lies in according race the status of an "actor version" concept, while exploring the origins and variations of race ideas using "scientific observer version" explanations. This distinction…

  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. Pieces to the Motivation Puzzle.

    ERIC Educational Resources Information Center

    Powell, Lacey

    1984-01-01

    Students enter music classes for various reasons. Teachers must study the group in order to understand the attitudes and motivations of students. Advises the teacher to emphasize the intrinsic rewards of learning and to set individual strategies of positive reinforcement and negative punishment. (CS)

  15. 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…

  16. The evolutionary puzzle of suicide.

    PubMed

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

    2013-12-09

    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.

  17. 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)

  18. The puzzle of monogamous marriage.

    PubMed

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

    2012-03-01

    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.

  19. 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…

  20. 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

  1. 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

  2. Performance of Children With Developmental Dyslexia on Two Skill Learning Tasks-Serial Reaction Time and Tower of Hanoi Puzzle: A Test of the Specific Procedural Learning Difficulties Theory.

    PubMed

    Vakil, Eli; Lowe, Michal; Goldfus, Carol

    2015-01-01

    Among the various theories proposed to explain developmental dyslexia (DD), the theory of specific procedural learning difficulties has gained certain support and is the framework for the current research. This theory claims that an inability to achieve skill automaticity explains the difficulties experienced by individuals with DD. Previous research on automaticity and DD has exhibited methodological issues such as a failure to test a range of skills. The current study broadens previous findings by delineating various reading skills correlated with several aspects of skill acquisition. Furthermore, the study utilizes two nonverbal tasks that reflect distinct types of skills: Serial Reaction Time (SRT) and the Tower of Hanoi Puzzle (TOHP). A total of 53 children aged 11 to 13 participated in the study, of whom 23 were children with DD and 30 were controls. Participants completed a test battery that consisted of reading tests, the SRT, and the TOHP. Results show no differences in learning rate between individuals with or without DD, although individuals with DD performed both tasks at a slower rate. Correlations were identified between a number of reading measures and measures of skill acquisition, expressed primarily in individuals with DD. Implications are examined in the discussion. PMID:24153401

  3. How to Tackle the Credentials Puzzle

    ERIC Educational Resources Information Center

    Jenkins, Rob

    2008-01-01

    In this article, the author discusses the issue of credentials in reply to one of the correspondents who is confused about the credentials she needs to teach at a community college. Generally speaking, to teach in programs that award associate of arts or associate of science degrees--i.e., to teach at a community college--faculty members are…

  4. 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.

  5. Puzzles, promises and a cure for ageing

    PubMed Central

    Vijg, Jan; Campisi, Judith

    2009-01-01

    Recent discoveries in the science of ageing indicate that lifespan in model organisms such as yeast, nematodes, flies and mice is plastic and can be manipulated by genetic, nutritional or pharmacological intervention. A better understanding of the targets of such interventions, as well as the proximate causes of ageing-related degeneration and disease, is essential before we can evaluate if abrogation of human senescence is a realistic prospect. PMID:18756247

  6. 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.

  7. 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

  8. The puzzle of oceanic oxygen utilization

    NASA Astrophysics Data System (ADS)

    Koeve, Wolfgang; Kähler, Paul

    2014-05-01

    The biological carbon pump is an important component of the oceanic carbon cycle and expected to respond to the anthropogenic perturbation of climate and ocean chemistry. Yet, large uncertainties exist in the quantification of the strength of the biological carbon pump of today's ocean. The export of organic matter from the ocean's euphotic zone is a critical benchmark number of this strength. Local measurements of the export flux are highly uncertain, due f.e. to severe methodological issues and undersampling of the ocean. Uncertainties in the contribution of dissolved organic matter to export further add when it comes to a global assessment. The vertical integral of oxygen utilization in the interior of the ocean is considered an independent and save estimate of export production, which accounts for particles as well as dissolved export pathways. For that purpose regional oxygen utilization rates (OUR) have been computed from apparent oxygen utilization (AOU) and an estimate of the time elapsed since the last contact with the atmosphere. Surprisingly the assumptions underlying this concept have not been tested rigorously. Using global ocean biogeochemical models we compare OUR computed from AOU and an ideal age tracer with an independent and perfect estimate of ocean respiration available in the model. Consistently in three different global models, we find that OUR underestimates true respiration by a factor of about three. Most of the differences between respiration and OUR are observed in the upper 1000m of the ocean. In addition to this underestimate in bulk global numbers, we find also important qualitative differences between the two independent approaches. For example, the contribution of dissolved organic matter driving oxygen utilization is largely underestimated when based on bulk tracer concentrations (AOU, DOC), which is the usual approach applied to observations. Also, diagnosing the global importance of denitrification relative to oxic metabolism is found to be uncertain by a factor of three when based on analysis of bulk tracers.

  9. 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…

  10. 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 stream of subatomic particles given out by the Sun and it can damage communications satellites and power stations on the Earth. The Cluster mission is expected to continue until at least 2005. Cluster is part of the International Living with a Star programme (ILWS), in which space agencies worldwide get together to investigate how variations in the Sun affect the environment of Earth and the other planets. In particular, ILWS concentrate on those aspects of the Sun-Earth system that may affect mankind and society. ILWS is a collaborative initiative between Europe, the United States, Russia, Japan and Canada.

  11. 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.

  12. 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).

  13. 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

  14. 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.

  15. 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.

  16. Drinking in snakes: resolving a biomechanical puzzle.

    PubMed

    Cundall, David; Brainerd, Elizabeth L; Constantino, Joseph; Deufel, Alexandra; Grapski, Douglas; Kley, Nathan J

    2012-03-01

    Snakes have long been thought to drink with a two-phase buccal-pump mechanism, but observations that some snakes can drink without sealing the margins of their mouths suggest that buccal pumping may not be the only drinking mechanism used by snakes. Here, we report that some snakes appear to drink using sponge-like qualities of specific regions of the oropharyngeal and esophageal mucosa and sponge-compressing functions of certain muscles and bones of the head. The resulting mechanism allows them to transport water upward against the effects of gravity using movements much slower than those of many other vertebrates. To arrive at this model, drinking was examined in three snake species using synchronized ciné and electromyographic recordings of muscle activity and in a fourth species using synchronized video and pressure recordings. Functional data were correlated with a variety of anatomical features to test specific predictions of the buccal-pump model. The anatomical data suggest explanations for the lack of conformity between a buccal-pump model of drinking and the performance of the drinking apparatus in many species. Electromyographic data show that many muscles with major functions in feeding play minor roles in drinking and, conversely, some muscles with minor roles in feeding play major roles in drinking. Mouth sealing by either the tongue or mental scale, previously considered critical to drinking in snakes, is incidental to drinking performance in some species. The sponge mechanism of drinking may represent a macrostomatan exaptation of mucosal folds, the evolution of which was driven primarily by the demands of feeding.

  17. 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.

  18. 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...

  19. 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)

  20. 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.…

  1. 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.

  2. 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…

  3. 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.

  4. The Post-Communist Fertility Puzzle.

    PubMed

    Billingsley, Sunnee

    2010-04-01

    Fertility has unanimously declined across the entire post-communist region. This study explores the variation in fertility trends over time among these countries and assesses to what degree three explanations are applicable: second demographic transition (SDT), postponement transition (PPT) or reaction to the economic crisis. Moreover, on the basis of SDT and PPT theoretical tenets, as well as descriptive evidence, the economic context is hypothesized to be linked to two processes of fertility decline conversely. The results show that no one theoretical explanation is sufficient to explain the complex fertility declines across the entire post-communist region from 1990 to 2003. In some countries, a great part of the decline in fertility occurred before significant postponement of childbearing began, which indicates that the dramatic decline was due to stopping behavior or postponement of higher order births. Postponement of first births, either through PPT or SDT processes, greatly contributed to fertility decline in a small number of countries. Pooled cross-sectional time-series analyses of age-specific birthrates confirm that these two distinct processes are present and show that the economic crisis explanation has explanatory power for declining birth rates. In contrast, logistic regressions show that the likelihood of postponing childbirth increases with improved economic conditions. These results confirm the importance of taking the economic context into account when discussing explanations for fertility decline. More specifically, the results indicate that the severity and duration of economic crisis, or absence thereof, influenced the extent and manner in which fertility declined.

  5. 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.

  6. 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.

  7. Aleutian mink disease: puzzles and paradigms.

    PubMed

    Bloom, M E; Kanno, H; Mori, S; Wolfinbarger, J B

    1994-12-01

    Aleutian mink disease (AD) is a naturally occurring persistent virus infection of mink caused by the Aleutian mink disease parvovirus (ADV). The classical form of AD, which occurs in adult mink, is notable for high titers of antiviral antibodies, hypergammaglobulinemia, plasmacytosis, and immune complex disease. In addition, there is a progressive renal disease characterized by mesangial proliferative glomerulonephritis and severe interstitial nephritis. Development of AD depends on both host and viral factors, and mink of certain genotypes fail to develop progressive disease when inoculated with low-virulence strains of virus. In newborn mink kits, ADV causes a fatal, acute interstitial pneumonitis associated with permissive viral replication in alveolar type 2 cells, but treatment of newborn kits with anti-viral antibody aborts the acute disease and converts into one resembling the persistent infection observed in adults. In infected adult mink, ADV is sequestered as immune complexes in lymphoid organs, but actual viral replication is restricted at the level of the individual cell and can be detected in only a small population of macrophages and follicular dendritic cells. ADV infection of mink primary macrophages and the human macrophage cell line U937 is antibody dependent and leads to the production of the cytokine interleukin-6. Furthermore, levels of interleukin-6 are increased in lymph node culture supernatants from infected mink. Chronic production of interleukin-6 may promote development of the immune disorder characteristic of AD. PMID:7889316

  8. 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)

  9. Visual Neuroscience: The Puzzle of Perceptual Stability.

    PubMed

    Zimmermann, Eckart; Bremmer, Frank

    2016-03-01

    Our world appears stable, although our eyes constantly shift its image across the retina. What brain mechanisms allow for this perceptual stability? A recent study has brought us a step closer to answering this millennial question. PMID:26954439

  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. 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.

  12. 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

  13. 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…

  14. 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.

  15. 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.

  16. 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…

  17. 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

  18. Assembling pieces of the centromere epigenetics puzzle

    PubMed Central

    González-Barrios, Rodrigo; Soto-Reyes, Ernesto; Herrera, Luis A.

    2012-01-01

    The centromere is a key region for cell division where the kinetochore assembles, recognizes and attaches to microtubules so that each sister chromatid can segregate to each daughter cell. The centromeric chromatin is a unique rigid chromatin state promoted by the presence of the histone H3 variant CENP-A, in which epigenetic histone modifications of both heterochromatin or euchromatin states and associated protein elements are present. Although DNA sequence is not regarded as important for the establishment of centromere chromatin, it has become clear that this structure is formed as a result of a highly regulated epigenetic event that leads to the recruitment and stability of kinetochore proteins. We describe an integrative model for epigenetic processes that conform regional chromatin interactions indispensable for the recruitment and stability of kinetochore proteins. If alterations of these chromatin regions occur, chromosomal instability is promoted, although segregation may still take place. PMID:22207360

  19. 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.

  20. 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.

  1. Serotonin, Amygdala and Fear: Assembling the Puzzle.

    PubMed

    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.

  2. 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…

  3. 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.

  4. Solving the RAA ⊗ υ 2 puzzle

    NASA Astrophysics Data System (ADS)

    Noronha-Hostler, Jacquelyn

    2016-08-01

    For the past ten years RAA(p T ), the nuclear modification factor that encodes the suppression of high pT particles due to energy loss within the medium was fairly well described by many theoretical models. However, the same models systematically underpredicted the high pT elliptic flow, υ2, which is experimentally measured as the correlation between soft and hard hadrons. All previous calculations neglected the effect of event-by-event fluctuations of an expanding viscous hydrodynamical background as well as the soft-hard flow harmonic correlations in the experimentally measured υ2. In this talk I show how event-by-event viscous hydrodynamics (computed using the v-USPhydro code) coupled to an energy loss model (BBMG) is able to simultaneously describe soft physics observables as well as the high-pT RAA and υ2. Suggestions for future more differential calculations at the LHC run2 are made to explore soft-hard flow correlations.

  5. 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.

  6. 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

  7. Solve Your Scheduling Puzzle without a Computer.

    ERIC Educational Resources Information Center

    Toy, Steve

    1982-01-01

    The small Lone Star school district in Otis (Colorado) developed a year-long process for creating its master course schedule. The scheduling process includes a needs assessment, a curriculum scheduling committee of teachers and students, a trial run of the schedule, and board approval of the master schedule. (RW)

  8. 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.

  9. 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

  10. Presidents and Teacher Education: Solving the Puzzle.

    ERIC Educational Resources Information Center

    Broad, Molly Corbett

    2000-01-01

    Discusses the need for more and better trained teachers in the nation's public schools and urges closer collaboration between K-12 and institutions of higher education. Proposes six roles for colleges and universities, such as ensuring that teacher education programs have necessary technological resources, increasing education research, and…

  11. 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

  12. 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.

  13. 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.

  14. Completing the puzzle of blood circulation: the discovery of capillaries.

    PubMed

    Karamanou, Marianna; Androutsos, George

    2010-01-01

    Marcello Malpighi is considered to be the founder of microscopic anatomy. For almost 40 years he used the newly invented microscope to study and discover many structures of human body, animals and plants. One of his greatest contributions to science was the establishment by direct observation of an anatomical linkage between arteries and veins, the capillary network, a monumental work that completed Harvey's theory of blood circulation.

  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. Piecing together the puzzle of acetaldehyde as a neuroactive agent.

    PubMed

    Correa, Mercè; Salamone, John D; Segovia, Kristen N; Pardo, Marta; Longoni, Rosanna; Spina, Liliana; Peana, Alessandra T; Vinci, Stefania; Acquas, Elio

    2012-01-01

    Mainly known for its more famous parent compound, ethanol, acetaldehyde was first studied in the 1940s, but then research interest in this compound waned. However, in the last two decades, research on acetaldehyde has seen a revitalized and uninterrupted interest. Acetaldehyde, per se, and as a product of ethanol metabolism, is responsible for many pharmacological effects which are not clearly distinguishable from those of its parent compound, ethanol. Consequently, the most recent advances in acetaldehyde's psychopharmacology have been inspired by the experimental approach to test the hypothesis that some of the effects of ethanol are mediated by acetaldehyde and, in this regard, the characterization of metabolic pathways for ethanol and the localization within discrete brain regions of these effects have revitalized the interest on the role of acetaldehyde in ethanol's central effects. Here we present and discuss a wealth of experimental evidence that converges to suggest that acetaldehyde is an intrinsically active compound, is metabolically generated in the brain and, finally, mediates many of the psychopharmacological properties of ethanol.

  17. The effective molarity (EM) puzzle in proton transfer reactions.

    PubMed

    Karaman, Rafik

    2009-08-01

    The DFT and HF calculation results for the proton transfer reactions of three different systems reveal that the reaction mechanism (transfer of a proton to a nucleophile) is largely determined by the distance between the two reactive centers (r). Systems with relatively large r values tend to abstract a proton from a molecule of water, whereas, these with a relatively small r values prefer to be engaged intramolecularly and their interaction with water is only via hydrogen bonding. Further, the results indicate that the effective molarity (logEM) for an intramolecular process is strongly correlated with the distance between the two reacting centers (r) in accordance with Menger's "spatiotemporal hypothesis".

  18. Shedding Synchrotron Light on a Puzzle of Glasses

    SciTech Connect

    Chumakov, Aleksandr

    2007-12-05

    Vibrational dynamics of glasses remains a point of controversial discussions. In particular, the density of vibrational states (DOS) reveals an excess of states above the Debye model called "boson peak." Despite the fact that this universal feature for all glasses has been known for more than 35 years, the nature of the boson peak is still not understood. The application of nuclear inelastic scattering via synchrotron radiation perhaps provides a clearer, more consistent picture of the subject. The distinguishing features of nuclear inelastic scattering relative to, e.g., neutron inelastic scattering, are ideal momentum integration and exact scaling of the DOS in absolute units. This allows for reliable comparison to data from other techniques such as Brillouin light scattering. Another strong point is ideal isotope selectivity: the DOS is measured for a single isotope with a specific low-energy nuclear transition. This allows for special "design" of an experiment to study, for instance, the dynamics of only center-of-mass motions. Recently, we have investigated the transformation of the DOS as a function of several key parameters such as temperature, cooling rate, and density. In all cases the transformation of the DOS is sufficiently well described by a transformation of the continuous medium, in particular, by changes of the macroscopic density and the sound velocity. These results suggest a collective sound-like nature of vibrational dynamics in glasses and cast doubts on microscopic models of glass dynamics. Further insight can be obtained in combined studies of glass with nuclear inelastic and inelastic neutron scattering. Applying two techniques, we have measured the energy dependence of the characteristic correlation length of atomic motions. The data do not reveal localization of atomic vibrations at the energy of the boson peak. Once again, the results suggest that special features of glass dynamics are related to extended motions and not to local models.

  19. Piecing together the Curriculum Puzzle: Learning through Drama Education.

    ERIC Educational Resources Information Center

    Darell, Rachel

    Current research in primary school drama education provides a complex and challenging stage for playing out current theoretical debates in both education and within the specific field of drama. This paper discusses some of these controversies, in particular, the view that education has a modernist agenda, and the conflict this causes in what many…

  20. Corporate culture: the missing piece of the healthcare puzzle.

    PubMed

    Waldman, J Deane; Smith, Howard L; Hood, Jacqueline N

    2003-01-01

    The U.S. healthcare system requires radical, not incremental, change. Management issues in healthcare delivery are fundamentally different from those in the business world. Systems thinking forces a focus on corporate culture, about which there is little hard data. The use of cost/benefit analysis suffers from the lack of any accepted measure of long-term "benefit." The authors make four observations: (1) corporate culture is both part of the cause and part of the cure for healthcare; (2) long-term financial and functional measures are necessary to make evidence-based decisions; (3) valid, nationwide data must be developed regarding the corporate culture of medicine; and (4) direct (unmodified) application of management theory or practices will not achieve sustainable improvements.

  1. 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…

  2. 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

  3. Strangeness in nuclei and neutron stars: A challenging puzzle

    DOE PAGESBeta

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

    2016-03-25

    The prediction of neutron stars properties is strictly connected to the employed nuclear interactions. The appearance of hyperons in the inner core of the star is strongly dependent on the details of the underlying hypernuclear force. Here, we summarize our recent quantum Monte Carlo results on the development of realistic two- and threebody hyperon-nucleon interactions based on the available experimental data for light- and medium-heavy hypernuclei.

  4. A Puzzle-Based Seminar for Computer Engineering Freshmen

    ERIC Educational Resources Information Center

    Parhami, Behrooz

    2008-01-01

    We observe that recruitment efforts aimed at alleviating the shortage of skilled workforce in computer engineering must be augmented with strategies for retaining and motivating the students after they have enrolled in our educational programmes. At the University of California, Santa Barbara, we have taken a first step in this direction by…

  5. Muonium in Sulphur: μSR's Oldest Puzzle

    NASA Astrophysics Data System (ADS)

    Cox, S. F. J.; Lord, J. S.; McKenzie, I.; Adjizian, J.-J.; Jayasooriya, U. A.; Reid, I. D.

    New level-crossing resonance data shows the muonium defect centre in solid sulphur to have axial symmetry with hugedipolar anisotropyatlow cryogenic temperatures.Above100K,thetwo principalvaluesofthehyperfine tensor fall dramaticallyand pro rata, both apparently collapsingto zeroatthe melting point. Thefallis accompaniedby the onset of muon spin-lattice relaxation, visible on the microsecond timescale with low-field rates peaking around room temperature. In conjuction with old zero-field data, the low-T hyperfine parameters are determined accurately. New supercell density-functional calculations suggest their assignment to muonium at a bond-centre (BC) site in a closed-ringS8MuBC complex. The striking decrease of time-average parameters and the appearance of fluctuations causing relaxation are attributed to a dynamic equilibrium or chemical exchange with neutral configurations having muchlowerhyperfine coupling, accessedby smallcyclic displacements fromtheBC site.Time-average occupancy ofthissitefallswith temperatureandvanishesatthemeltingpoint.

  6. Pathophysiology of septic encephalopathy--an unsolved puzzle.

    PubMed

    Flierl, Michael A; Rittirsch, Daniel; Huber-Lang, Markus S; Stahel, Philip F

    2010-01-01

    The exact cellular and molecular mechanisms of sepsis-induced encephalopathy remain elusive. The breakdown of the blood-brain barrier (BBB) is considered a focal point in the development of sepsis-induced brain damage. Contributing factors for the compromise of the BBB include cytokines and chemokines, activation of the complement cascade, phagocyte-derived toxic mediators, and bacterial products. To date, we are far from fully understanding the neuropathology that develops as a secondary remote organ injury as a consequence of sepsis. However, recent studies suggest that bacterial proteins may readily cross the functional BBB and trigger an inflammatory response in the subarachnoid space, in absence of a bacterial invasion. A better understanding of the pathophysiological events leading to septic encephalopathy appears crucial to advance the clinical care for this vulnerable patient population.

  7. 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.

  8. 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…

  9. 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.

  10. The unresolved puzzle why alanine extensions cause disease.

    PubMed

    Winter, Reno; Liebold, Jens; Schwarz, Elisabeth

    2013-08-01

    The prospective increase in life expectancy will be accompanied by a rise in the number of elderly people who suffer from ill health caused by old age. Many diseases caused by aging are protein misfolding diseases. The molecular mechanisms underlying these disorders receive constant scientific interest. In addition to old age, mutations also cause congenital protein misfolding disorders. Chorea Huntington, one of the most well-known examples, is caused by triplet extensions that can lead to more than 100 glutamines in the N-terminal region of huntingtin, accompanied by huntingtin aggregation. So far, nine disease-associated triplet extensions have also been described for alanine codons. The extensions lead primarily to skeletal malformations. Eight of these proteins represent transcription factors, while the nuclear poly-adenylate binding protein 1, PABPN1, is an RNA binding protein. Additional alanines in PABPN1 lead to the disease oculopharyngeal muscular dystrophy (OPMD). The alanine extension affects the N-terminal domain of the protein, which has been shown to lack tertiary contacts. Biochemical analyses of the N-terminal domain revealed an alanine-dependent fibril formation. However, fibril formation of full-length protein did not recapitulate the findings of the N-terminal domain. Fibril formation of intact PABPN1 was independent of the alanine segment, and the fibrils displayed biochemical properties that were completely different from those of the N-terminal domain. Although intranuclear inclusions have been shown to represent the histochemical hallmark of OPMD, their role in pathogenesis is currently unclear. Several cell culture and animal models have been generated to study the molecular processes involved in OPMD. These studies revealed a number of promising future therapeutic strategies that could one day improve the quality of life for the patients.

  11. 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.

  12. 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…

  13. Republic of South Africa: unraveling the population puzzle. Country profile.

    PubMed

    Spain, D

    1984-06-01

    This discussion of the Republic of South Africa focuses on population growth, regions and cities, ethnicity and religion of the population, age distribution, housing and households, education, employment, income, and marketing and communication. South Africans, condemmed by the world community for their policy of racial discriminatioon, contend that outsiders fail to understand the system they legalized in 1948. Apartheid calls for developing different political institutions for blacks and whites in preparation for their eventual separation. According to this reasoning, black Africans are not considered permanent residents of South Africa, but rather of the "homelands" to which each tribal group has been assigned by the government. 4 homelands have been made independent, and if the remaining 6 become independent as scheduled, South Africa theoretically will no longer have any black citizens. Under this plan, nearly 90% of the current area of South Africa would go to whites, while the remaining 10% would be divided among the 10 homelands. The UN has condemmed the homelands policy, and no country has recognized their independence. By law South Africa has 4 distinct populations: Africans, whites, coloureds, and asians. Rhe combination of Afrikaners and British makes up the white population. Whites are in the minority and numbered only 4.7 million in 1983, or 15% of the total population. Since whites rule the country, their importance is far disproportionate to their numbers. There were 2.7 million coloureds in 1983, approximately 9% of all South Africans. Black africans, the single largest population group, numbered 22.7 million in 1983, or 73% of the total population. Blacks are divided in 10 subgroups corresponding to the 10 ethnicallyy based homelands. The largest groups are the Zulu (5.9 million in 1981) and the Xhosa (3.1 million). Population growth varies by race. The annual growth rate for the entire country was 2.4% in 1983, but for blacks it was 2.7% and for whites it was only 1.5%. The birthrate among whites in 1980 was 16.5 births/1000 whites compared with 40 births/1000 blacks. Immigration has played an important role in South Africa's white population growth. Net migration in 1981 was 33,000; 55% of new arrivals were from Europe and 40% were from other African countries. In 1980, just over half the population (53%) lived in urban areas. Approximately 90% of whites and Asians lived in urban areas, while 3/4 of coloureds and 38% of blacks were classified as urban. understanding South Africa's racial and ethnic divisions is the key to understanding the country. Political and social interaction across racial lines is forbidden. Economic relationships are strictly controlled by the passbrook system. The passbook, which must be carried by every black aged 16 and olfder, establishes a black's right to be in a particular area of the country. South Africa's population is fairly young due to a history of high fertility and high mortality among blacks, coloureds, and Asias. For the population as a whole, 38% were under age 15 in 1980 and 4% were aged 65 and older. Whites accounted for 22% and blacks 64% of the labor force in 1980. The government has tried to narrow the wage gap between white and black workers. In 1972 blacks earned only 15% of whites salaries; by 1981 black wages were 24% of white wages. PMID:12313172

  14. Lessons learned while playing with the Arctic plate tectonic puzzle

    NASA Astrophysics Data System (ADS)

    Skogseid, J.; Meisling, K. E.; Miller, E. L.; Nikishin, A. M.

    2013-12-01

    The plate tectonic evolution of the Amerasia Basin in the Arctic Ocean is controversial, and a number of models have been suggested in which the common denominator is that they are all poorly constrained. In general the Canada Basin and the Makarov-Podvodnikov Basin, are separated by the Alpha-Mendeleev Ridge, which has a bathymetric and geophysical signature indicating either over-thickened oceanic crust or magmatically overprinted continental fragments. Both interpretations imply that the ridge has a connection to the High Arctic Large Igneous Province probably associated with a mantle plume emplacement beneath the lithosphere, causing excess magmatism in the region starting at about 125 Ma. It is widely accepted that the ';windshield wiper' model of Lawver et al. (2002) is applicable for the Canada Basin proper, yet it is still debated whether the boundary transform is located close to the Lomonosov Ridge, beneath the Alpha-Mendeleev Ridge, or on the Alaskan side of the Chukchi Borderland and Northwind Ridge. It remains a major uncertainty where large offset regional shear zones required by some models could be hidden beneath the Arctic continental shelves and how they were linked into the South Anhui Paleo-Ocean. The approach taken in this study is to dissect the Chukotka terranes, formed by long-lived compressional tectonism associated with the Pacific subduction system, to explore different scenarios for South Anhui Ocean evolution and consider potential Paleo-Pacific driving mechanisms for Amerasia Basin opening. The Chukotka terranes represent a complex of magmatic and sedimentary units younging towards the subduction zone, thus allowing restoration by ';undocking' them one by one. The remaining elements of the Alaskan and Siberian shelves are subsequently linked to conjugate elements on the North American and Eurasian plates based on correlation of geochemical and stratigraphic ';tie-points'. The study utilizes available geological markers, crustal cross sections, gravity and magnetic data, and mantle tomography models, seeking to discover pros and cons for different plate tectonic scenarios, with the ultimate goal of a unified model.

  15. Screening for depression: only one piece of the puzzle.

    PubMed

    Novak, M; Mucsi, I; Mendelssohn, D C

    2013-06-01

    In this issue of NDT, van den Beukel et al. from the Netherlands suggest that a 5-item survey questionnaire might be used to replace the Beck Depression Index to screen patients with chronic kidney disease (CKD) for depression. The nephrology community is at a tipping point in terms of the assessment of outcomes, especially among patients on dialysis. Indeed, the entire healthcare community has begun to shift its focus to patient-reported outcomes (PROs), including quality of life, patient satisfaction and the psychosocial determinants of health. Beyond depression, there are a myriad of aspects of psychological distress that include anxiety, worrying, fear of progression of kidney disease and the fear of the future in general, death and dying, hopelessness, questions around the meaning of life and the experience of recurrent psychological and physical trauma through the CKD trajectory. We encourage the community and its researchers to embrace and research PROs, with the aim to create a holistic, patient-centered model of care for patients at all stages of CKD, including those on chronic dialysis and after transplantation, keeping the whole person-and their families-in mind.

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. 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.,…

  1. 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

  2. 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.

  3. 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.

  4. Hybrid Ameloblastoma of the Maxilla: A Puzzling Pathology.

    PubMed

    Lakshmi, Chintamaneni Raja; Bhavana, Sujana Mulk; Nallamilli, Sai Madhavi; Prabhat, Meka Poorna Venkata; Sarat, Gummadapu; Anuradha, Chennupati

    2016-07-01

    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

  5. 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

  6. Patchwork plagiarism--a jigsaw of stolen puzzle pieces.

    PubMed

    Supak Smolcić, Vesna; Bilić-Zulle, Lidija

    2013-01-01

    Plagiarism remains at the top in terms of interest to the scientific community. In its many vicious forms, patchwork plagiarism is characterized by numerous unresolved issues and often passes "below the radar" of editors and reviewers. The problem of detecting the complexity of misconduct has been partially resolved by plagiarism detection software. However, interpretation of relevant reports is not always obvious or easy. This article deals with plagiarism in general and patchwork plagiarism in particular, as well as related problems that editors must deal with to maintain the integrity of scientific journals.

  7. X-Ray Counterparts of Puzzling Gev-Tev Sources

    NASA Astrophysics Data System (ADS)

    Kargaltsev, Oleg

    2014-09-01

    We propose to look for X-ray counterparts of the extended TeV source HESS J1616-508 that may also have been detected with Fermi at GeV energies. The nature of the source and the connection between the TeV source and the nearby GeV sources are unknown. It has been suggested that it may be a relic plerion powered by the offset PSR J1617-5055, but a deep Chandra observation of this pulsar and its wind nebula has not confirmed this hypothesis. To understand the nature of this long-standing "dark accelerator", we propose to observe the GeV sources (which could be young pulsars) and another nearby young pulsar (J1614-5048) to check whether or not they could supply relativistic particles and power the TeV source. We will also explore the nature of the GeV sources.

  8. 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.

  9. Republic of South Africa: unraveling the population puzzle. Country profile.

    PubMed

    Spain, D

    1984-06-01

    This discussion of the Republic of South Africa focuses on population growth, regions and cities, ethnicity and religion of the population, age distribution, housing and households, education, employment, income, and marketing and communication. South Africans, condemmed by the world community for their policy of racial discriminatioon, contend that outsiders fail to understand the system they legalized in 1948. Apartheid calls for developing different political institutions for blacks and whites in preparation for their eventual separation. According to this reasoning, black Africans are not considered permanent residents of South Africa, but rather of the "homelands" to which each tribal group has been assigned by the government. 4 homelands have been made independent, and if the remaining 6 become independent as scheduled, South Africa theoretically will no longer have any black citizens. Under this plan, nearly 90% of the current area of South Africa would go to whites, while the remaining 10% would be divided among the 10 homelands. The UN has condemmed the homelands policy, and no country has recognized their independence. By law South Africa has 4 distinct populations: Africans, whites, coloureds, and asians. Rhe combination of Afrikaners and British makes up the white population. Whites are in the minority and numbered only 4.7 million in 1983, or 15% of the total population. Since whites rule the country, their importance is far disproportionate to their numbers. There were 2.7 million coloureds in 1983, approximately 9% of all South Africans. Black africans, the single largest population group, numbered 22.7 million in 1983, or 73% of the total population. Blacks are divided in 10 subgroups corresponding to the 10 ethnicallyy based homelands. The largest groups are the Zulu (5.9 million in 1981) and the Xhosa (3.1 million). Population growth varies by race. The annual growth rate for the entire country was 2.4% in 1983, but for blacks it was 2.7% and for whites it was only 1.5%. The birthrate among whites in 1980 was 16.5 births/1000 whites compared with 40 births/1000 blacks. Immigration has played an important role in South Africa's white population growth. Net migration in 1981 was 33,000; 55% of new arrivals were from Europe and 40% were from other African countries. In 1980, just over half the population (53%) lived in urban areas. Approximately 90% of whites and Asians lived in urban areas, while 3/4 of coloureds and 38% of blacks were classified as urban. understanding South Africa's racial and ethnic divisions is the key to understanding the country. Political and social interaction across racial lines is forbidden. Economic relationships are strictly controlled by the passbrook system. The passbook, which must be carried by every black aged 16 and olfder, establishes a black's right to be in a particular area of the country. South Africa's population is fairly young due to a history of high fertility and high mortality among blacks, coloureds, and Asias. For the population as a whole, 38% were under age 15 in 1980 and 4% were aged 65 and older. Whites accounted for 22% and blacks 64% of the labor force in 1980. The government has tried to narrow the wage gap between white and black workers. In 1972 blacks earned only 15% of whites salaries; by 1981 black wages were 24% of white wages.

  10. Revisiting the connectivity puzzle of the common coral Pocillopora damicornis.

    PubMed

    Torda, G; Lundgren, P; Willis, B L; van Oppen, M J H

    2013-12-01

    Understanding levels of connectivity among scleractinian coral populations over a range of temporal and spatial scales is vital for managing tropical coral reef ecosystems. Here, we use multilocus microsatellite genotypes to assess the spatial genetic structure of two molecular operational taxonomic units (MOTUs, types α and β) of the widespread coral Pocillopora damicornis on the Great Barrier Reef (GBR) and infer the extent of connectivity on spatial scales spanning from local habitat types to latitudinal sectors of the GBR. We found high genetic similarities over large spatial scales spanning > 1000 km from the northern to the southern GBR, but also strong genetic differentiation at local scales in both MOTUs. The presence of a considerable number of first-generation migrants within the populations sampled (12% and 27% for types α and β, respectively) suggests that genetic differentiation over small spatial scales is probably a consequence of stochastic recruitment from different genetic pools into recently opened up spaces on the reef, for example, following major disturbance events. We explain high genetic similarity among populations over hundreds of kilometres by long competency periods of brooded zooxanthellate larvae and multiple larval release events each year, combined with strong longshore currents typical along the GBR. The lack of genetic evidence for predominantly clonal reproduction in adult populations of P. damicornis, which broods predominantly asexually produced larvae, further undermines the paradigm that brooded larvae settle close to parent colonies shortly after the release.

  11. 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…

  12. 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…

  13. The Tangram: It's More than an Ancient Puzzle.

    ERIC Educational Resources Information Center

    Kriegler, Shelley

    1991-01-01

    Presents a unit of study involving tangrams that integrates geometric relationships, scale drawings, graphing, patterns, and logical thinking. Provides worksheets for independent and cooperative activities to discover geometric shapes using a specified number of tangram pieces. (MDH)

  14. 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.

  15. LRRK2, a puzzling protein: insights into Parkinson's disease pathogenesis.

    PubMed

    Esteves, A Raquel; Swerdlow, Russell H; Cardoso, Sandra M

    2014-11-01

    Leucine-rich repeat kinase 2 (LRRK2) is a large, ubiquitous protein of unknown function. Mutations in the gene encoding LRRK2 have been linked to familial and sporadic Parkinson's disease (PD) cases. The LRRK2 protein is a single polypeptide that displays GTPase and kinase activity. Kinase and GTPase domains are involved in different cellular signaling pathways. Despite several experimental studies associating LRRK2 protein with various intracellular membranes and vesicular structures such as endosomal/lysosomal compartments, the mitochondrial outer membrane, lipid rafts, microtubule-associated vesicles, the golgi complex, and the endoplasmic reticulum its broader physiologic function(s) remain unidentified. Additionally, the cellular distribution of LRRK2 may indicate its role in several different pathways, such as the ubiquitin-proteasome system, the autophagic-lysosomal pathway, intracellular trafficking, and mitochondrial dysfunction. This review discusses potential mechanisms through which LRRK2 may mediate neurodegeneration and cause PD. PMID:24907399

  16. Braneworld puzzle about entropy bounds and a maximal temperature

    SciTech Connect

    Brustein, Ram; Eichler, David; Foffa, Stefano

    2005-06-15

    Entropy bounds applied to a system of N species of light quantum fields in thermal equilibrium at temperature T are saturated in four dimensions at a maximal temperature T{sub max}=M{sub Planck}/{radical}(N). We show that the correct setup for understanding the reason for the saturation is a cosmological one, and that a possible explanation is the copious production of black holes at this maximal temperature which prevents any further rise in temperature. The proposed explanation implies, if correct, that N light fields cannot be in thermal equilibrium in an ideal gas phase at temperatures T above T{sub max}. However, we have been unable to identify a concrete mechanism that is efficient and quick enough to prevent the universe from exceeding this limiting temperature. The same issues can be studied in the framework of AdS/CFT by using a brane moving in a five dimensional AdS-Schwarzschild space to model a radiation dominated universe. In this case we show that T{sub max} is the temperature at which the brane just reaches the horizon of the black hole, and that entropy bounds and the generalized second law of thermodynamics seem to be violated when the brane continues to fall into the black hole. We find, again, that the known physical mechanisms, including black hole production, are not efficient enough to prevent the brane from falling into the black hole. We propose several possible explanations for the apparent violation of entropy bounds, but none is a conclusive one.

  17. 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…

  18. Anaerobes: a piece in the puzzle for alternative biofuels.

    PubMed

    Lawson, Paul A; Allen, Toby D; Caldwell, Matthew E; Tanner, Ralph S

    2011-08-01

    Although much newsprint is devoted to the subject of reducing the United States and other major developed countries dependence on their respective foreign energy sources; the most challenging issues for society is to provide long-term, sustainable energy sources to accommodate the global population as a whole. The projected population of planet Earth for the year 2050 is estimated to be in excess of 9 billion. With hydrocarbon-based energy becoming limiting it is unlikely that one type of energy will alone replace our dependence on this source. So-called "green" technologies that include solar, wind and wave powers are now being explored to reduce on traditional hydrocarbon-based fuel sources. The diverse and functional properties of microbes, and in particular anaerobes, are now being utilized in the production of biofuels and may provide one piece of the jigsaw for future energy requirements. Here we present some results of a screening program to identify and characterize a number of carbon monoxide oxidizing, ethanol-producing acetogenic anaerobes phylogenetically located within the Clostridiales.

  19. 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.

  20. 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.

  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. 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.

  3. Shedding Synchrotron Light on a Puzzle of Glasses

    ScienceCinema

    Chumakov, Aleksandr [European Synchrotron Radiation Facility, Grenoble, France

    2016-07-12

    Vibrational dynamics of glasses remains a point of controversial discussions. In particular, the density of vibrational states (DOS) reveals an excess of states above the Debye model called "boson peak." Despite the fact that this universal feature for all glasses has been known for more than 35 years, the nature of the boson peak is still not understood. The application of nuclear inelastic scattering via synchrotron radiation perhaps provides a clearer, more consistent picture of the subject. The distinguishing features of nuclear inelastic scattering relative to, e.g., neutron inelastic scattering, are ideal momentum integration and exact scaling of the DOS in absolute units. This allows for reliable comparison to data from other techniques such as Brillouin light scattering. Another strong point is ideal isotope selectivity: the DOS is measured for a single isotope with a specific low-energy nuclear transition. This allows for special "design" of an experiment to study, for instance, the dynamics of only center-of-mass motions. Recently, we have investigated the transformation of the DOS as a function of several key parameters such as temperature, cooling rate, and density. In all cases the transformation of the DOS is sufficiently well described by a transformation of the continuous medium, in particular, by changes of the macroscopic density and the sound velocity. These results suggest a collective sound-like nature of vibrational dynamics in glasses and cast doubts on microscopic models of glass dynamics. Further insight can be obtained in combined studies of glass with nuclear inelastic and inelastic neutron scattering. Applying two techniques, we have measured the energy dependence of the characteristic correlation length of atomic motions. The data do not reveal localization of atomic vibrations at the energy of the boson peak. Once again, the results suggest that special features of glass dynamics are related to extended motions and not to local models.

  4. Where Does Conflict Management Fit in the System's Leadership Puzzle?

    ERIC Educational Resources Information Center

    Cook, Vickie S.; Johnston, Linda M.

    2008-01-01

    Superintendents are faced with conflicts every day. The conflicts arise around issues of personnel, community roles, funding, politics, and work/life balance. Good leadership involves an understanding of how to deal with conflict, whom to involve in the conflict resolution, how to set up structures and processes that ensure conflict doesn't…

  5. 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…

  6. 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.

  7. Learned Helplessness: A Piece of the Burnout Puzzle.

    ERIC Educational Resources Information Center

    Greer, John G.; Wethered, Chris E.

    1984-01-01

    The article uses learned helplessness as a model for better understanding burnout experienced by teachers of exceptional children. Comparisons are made between the treatment for learned helplessness and parallel strategies for preventing burnout, including helping educators to set realistic goals and recognize the control which they do have.…

  8. 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…

  9. 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.

  10. 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.

  11. Peroxin Puzzles and Folded Freight: Peroxisomal Protein Import in Review

    NASA Astrophysics Data System (ADS)

    Crookes, Wendy J.; Olsen, Laura J.

    Peroxisomes are organelles that perform a variety of functions, including the metabolism of hydrogen peroxide and the oxidation of fatty acids. Peroxisomes do not possess organellar DNA; all peroxisomal matrix proteins are posttranslationally translocated into the organelle. The mechanism of peroxisomal protein translocation has been the subject of vigorous research in the past decade. Many of the proteins (peroxins, abbreviated Pex) that play critical roles in peroxisome biogenesis have been identified through functional complementation of yeast strains and of Chinese hamster ovary cell lines that are defective in peroxisome biogenesis. Researchers are now turning towards biochemical and genetic analyses of these peroxins to define their roles in peroxisome biogenesis and to discover interacting protein partners. Evidence suggests that some of the interacting partners include molecular chaperones. Several current models for peroxisomal protein import are presented.

  12. Ernst Moerk and the Puzzle of Zero-Trial Learning

    ERIC Educational Resources Information Center

    Palmer, David C.

    2005-01-01

    In this article, the author shares an anecdote demonstrating one-trial learning which is commonplace in human behavior. The demonstration suggests that under some conditions, when people hear someone speak, their behavior changes, even in the absence of an apparent contingency of reinforcement, but only if they have in their repertoire verbal…

  13. 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).

  14. The Buzzword Puzzle: Finding the Right Technology for the Problem

    NASA Astrophysics Data System (ADS)

    King, T. A.; Walker, R. J.; Joy, S. P.

    2005-12-01

    What is the best way to move data from point A to point B? That all depends on what connects the two points and what kind of data you are trying to move. Selecting the right technology requires a careful consideration of the problem, an awareness of existing solutions and knowledge of appropriate standards. When moving a solution through the design, implementation and deployment stages there are a variety of development methods. Matching the development method to the scale of the task is important. Some of the technology challenges that the science community must address overlap with our commercial counterparts. However, there are some technology challenges which are unique to science and require new and innovative approaches. Based on our experience developing solutions for NASA's Planetary Data System (PDS), Dawn Science Center, and the Space Physics Archive Search and Extract (SPASE) project we have considerable experience in what does and does not work. We present an assessment of the adoption threshold of selected standards, technology and development methods. We will discuss how changing expectations and evolving requirements impact the effectiveness of chosen solutions.

  15. 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.

  16. 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 ...

  17. Professional Development. One State's Process in the Articulation Puzzle.

    ERIC Educational Resources Information Center

    Baptiste, Nancy; Cahill, Betsy

    1996-01-01

    Notes that many states are establishing educational and training systems to form a coordinated early care and education professional development system that allows professionals to access easily advanced levels of education without redundancy of content or expenditure of unnecessary time and money. Discusses New Mexico's establishment of core…

  18. Cost-effectiveness analysis and insurance coverage: solving a puzzle.

    PubMed

    Pauly, Mark

    2015-05-01

    The conventional model for the use of cost-effectiveness analysis for health programs involves determining whether the cost per unit of effectiveness of the program is lower than some socially determined maximum acceptable cost per unit of effectiveness. If a program is better by this criterion, the policy implication is that it should be implemented by full coverage of its cost by insurance; if not, the program should not be implemented. This paper examines the unanswered question of how cost-effectiveness analysis should be performed and interpreted when insurance coverage may involve cost sharing. It explores the question of how cost sharing should be related to the magnitude of a cost-effectiveness ratio. A common view that cost sharing should vary inversely with program cost-effectiveness is shown to be incorrect. A key issue in correct analysis is whether there is heterogeneity in marginal effectiveness of care that cannot be perceived by the social planner but is known by the demander. It is possible that some programs that would fail the social efficiency test at full coverage will be acceptable with positive cost sharing. Combining individual and social preferences affects both the choice of programs and the extent of cost sharing.

  19. 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.

  20. 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...

  1. 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

  2. The puzzle of kidney dysfunction in heart failure: an introduction.

    PubMed

    Metra, Marco; Voors, Adriaan A

    2012-03-01

    Heart failure and kidney disease often coexist, and each of the two conditions may lead to progression of the other. Kidney dysfunction is an independent prognostic factor in patients with either acute or chronic heart failure. Worsening renal function may be related with poorer outcomes as well. Multiple mechanisms are involved in the cardio-renal interaction, including hemodynamic abnormalities, neurohormonal and inflammatory activation, oxidative stress, anemia, and abnormalities in mineral and vitamin D metabolism. Serum creatinine has limitations for the assessment of kidney function in patients with heart failure as its short-term changes are dependent on hemodynamic changes and fluid status. New biomarkers of glomerular and tubular function might allow an earlier and more accurate detection of worsening renal function.

  3. A Nitration Reaction Puzzle for the Organic Chemistry Laboratory

    ERIC Educational Resources Information Center

    Wieder, Milton J.; Barrows, Russell

    2008-01-01

    Treatment of phenylacetic acid with 90% HNO[subscript 3] yields a product, I, whose observed melting point is 175-179 degrees C and whose equivalent weight is approximately 226 grams. Treatment of phenylacetic acid with 70% HNO[subscript 3] yields a product, II, whose observed melting point is 106-111 degrees C and whose equivalent weight is…

  4. 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…

  5. 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)

  6. 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…

  7. Penguin diagrams, charmless B decays, and the ``missing charm puzzle''

    NASA Astrophysics Data System (ADS)

    Lenz, Alexander; Nierste, Ulrich; Ostermaier, Gaby

    1997-12-01

    We calculate the contributions of penguin diagrams with internal u or c quarks to various inclusive charmless B-decay rates. Further we analyze the influence of the chromomagnetic dipole operator Q8 on these rates. We find that the rates corresponding to B¯-->Xuūs, B¯-->Xdd¯s, B¯-->Xss¯s, B¯-->Xss¯d, and B¯-->Xdd¯d are dominated by the new penguin contributions. The contributions of Q8 sizably diminish these rates. Despite an increase of the total charmless decay rate by 36%, the new contributions are not large enough to explain the charm deficit observed by ARGUS and CLEO. We predict nc=1.33+/-0.06 for the average number of charmed particles per B decay in the standard model. Then the hypothesis of an enhancement of the chromomagnetic dipole coefficient C8 by new physics contributions is analyzed. We perform a model-independent fit of C8 to the experimental data. If the CKM structure of the new physics contribution is the same as in the standard model, \\|C8(MW)\\| must be enhanced by a factor of 9 to 16 in order to explain the observed charm deficit.

  8. 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.

  9. 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

  10. NS1: A corner piece in the dengue pathogenesis puzzle?

    PubMed

    Thomas, Stephen J

    2015-09-01

    Soluble dengue virus NS1 protein induces proinflammatory immune responses via Toll-like receptor 4 and disrupts endothelial cell integrity, resulting in vascular leakage (Beatty et al. and Modhiran et al., this issue). PMID:26355028

  11. Monarch butterfly orientation: missing pieces of a magnificent puzzle

    PubMed

    Brower

    1996-01-01

    From late August to early September, millions of adult monarch butterflies of the eastern North American population cease reproducing, become highly gregarious and begin migrating southwards. By mid-October, they migrate through central Texas into Mexico where they follow the Sierra Madre Oriental across the Tropic of Cancer. They then shift direction westwards towards the Transverse Neovolcanic Belt of mountains where they overwinter without breeding. A rapid exodus northwards occurs at the spring equinox, and by early April both sexes reach the Gulf Coast states where the females lay eggs on the resurgent spring milkweed (Asclepias) flora and die. Adults of the new generation continue the migration to the northernmost breeding range, arriving by early June. Two or more short-lived breeding generations are produced over the summer, spread eastwards across the Appalachian Mountains and, by September, the autumn migration is again under way. This paper presents a new hypothesis that the orientation of adult monarchs undergoes a continual clockwise shifting throughout the 3-5 generations, rotating by 360 in the course of the year. This hypothesis is consistent with the timing of arrivals and the relative abundances of the successive generations of monarchs throughout eastern North America, with the directions of movement of their spring, summer and autumn generations, and with the timing of their arrival at the overwintering area in central Mexico.

  12. 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.

  13. Safety of gene therapy: new insights to a puzzling case.

    PubMed

    Rothe, Michael; Schambach, Axel; Biasco, Luca

    2014-01-01

    Over the last few years, the transfer of therapeutic genes via gammaretro- or lentiviral vector systems has proven its virtue as an alternative treatment for a series of genetic disorders. The number of approved phase I/II clinical trials, especially for rare diseases, is steadily increasing, but the overall hurdles to become a broadly acceptable therapy remain numerous. The efforts by clinicians and basic scientists have tremendously improved the knowledge available about feasibility and biosafety of gene therapy. Nonetheless, despite the generation of a plethora of clinical and preclinical safety data, we still lack sufficiently powerful assays to predictively assess the exact levels of toxicity that might be observed in any given clinical gene therapy. Insertional mutagenesis is one of the major concerns when using integrating vectors for permanent cell modification, and the occurrence of adverse events related to genotoxicity, in early gene therapy trials, has refrained the field of gene therapy from emerging further. In this review, we provided a comprehensive overview on the basic principles and potential co-factors concurring in the generation of adverse events reported in gene therapy clinical trials using integrating vectors. Additionally, we summarized the available systems to assess genotoxicity at the preclinical level and we shed light on the issues affecting the predictive value of these assays when translating their results into the clinical arena. In the last section of the review we briefly touched on the future trends and how they could increase the safety of gene therapy employing integrating vector technology to take it to the next level.

  14. 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.

  15. The olfactory system as a puzzle: playing with its pieces.

    PubMed

    Díaz, D; Gómez, C; Muñoz-Castañeda, R; Baltanás, F; Alonso, J R; Weruaga, E

    2013-09-01

    The mammalian olfactory bulb (OB) has all the features of a whole mammalian brain but in a more reduced space: neuronal lamination, sensory inputs, afferences, or efferences to other centers of the central nervous system, or a contribution of new neural elements. Therefore, it is widely considered as "a brain inside the brain." Although this rostral region has the same origin and general layering as the other cerebral cortices, some distinctive features make it very profitable in experimentation in neurobiology: the sensory inputs are driven directly on its surface, the main output can be accessed anatomically, and new elements appear in it throughout adult life. These three morphological characteristics have been manipulated to analyze further the response of the whole OB. The present review offers a general outlook into the consequences of such experimentation in the anatomy, connectivity and neurochemistry of the OB after (a) sensory deprivation, mainly by naris occlusion; (b) olfactory deinnervation by means of olfactory epithelium damage, olfactory nerve interruption, or even olfactory tract disruption; (c) the removal of the principal neurons of the OB; and (d) management of the arrival of newborn interneurons from the rostral migratory stream. These experiments were performed using surgical or chemical methods, but also by means of the analysis of genetic models, some of whose olfactory components are missing, colorless or mismatching within the wild-type scenario of odor processing.

  16. 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

  17. 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.

  18. Those Puzzling Pendulums: Engaging Students to Learn about Pendulum Properties

    ERIC Educational Resources Information Center

    Rosenblatt, Louis

    2004-01-01

    Inquiry labs in the science classroom help students make connections and discover scientific relationships for themselves. This article describes an inquiry laboratory in which students explore the properties of a pendulum. Since most students are familiar with pendulums before they get to high school, they have discovered that the period is…

  19. 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.

  20. 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.

  1. Hereditary breast cancer: ever more pieces to the polygenic puzzle

    PubMed Central

    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. 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.

  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. 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.

  5. 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.

  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. The flavor puzzle in multi-Higgs models

    NASA Astrophysics Data System (ADS)

    Blechman, Andrew E.; Petrov, Alexey A.; Yeghiyan, Gagik

    2010-11-01

    We reconsider the flavor problem in the models with two Higgs doublets. By studying two generation toy models, we look for flavor basis independent constraints on Yukawa couplings that will give us the mass hierarchy while keeping all Yukawa couplings of the same order. We then generalize our findings to the full three generation Standard Model. We find that we need two constraints on the Yukawa couplings to generate the observed mass hierarchy, and a slight tuning of Yukawa couplings of order 10%, much less than the Standard Model. We briefly study how these constraints can be realized, and show how flavor changing currents are under control for K - bar{K} mixing in the neardecoupling limit.

  8. Dolls, Blocks, and Puzzles: Playing with Mathematical Understandings

    ERIC Educational Resources Information Center

    Eisenhauer, Mary Jane; Feikes, David

    2009-01-01

    This article describes a learning experience designed for teachers of children in primary classrooms (K-3) who are taking graduate courses. The learning experience offers new insights into the different ways young children encounter math in their natural, playful environment. Through a hands-on workshop approach, the students engaged in firsthand…

  9. Puzzles and resolutions of information duplication in de Sitter space

    NASA Astrophysics Data System (ADS)

    Danielsson, Ulf H.; Domert, Daniel; Olsson, Martin E.

    2003-10-01

    In this paper we consider a scenario consisting of a de Sitter phase followed by a phase described by a scale factor a(t)˜tq, where 1/3

  10. 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

  11. Two puzzles for Marquis's conservative view on abortion.

    PubMed

    Card, Robert F

    2006-09-01

    Don Marquis argues that abortion is morally wrong in most cases since it deprives the fetus of the value of its future. I criticize Marquis's argument for the modified conservative view by adopting an argumentative strategy in which I work within his basic account: if it is granted that his fundamental idea is sound, what follows about the morality of abortion? I conclude that Marquis is faced with a dilemma: either his position must shift towards the extreme conservative view on which abortion is never morally permissible, or he must abandon any recognizably conservative view. This dilemma suggests that Marquis's view is either deeply implausible or that he cannot use this argument to successfully support his preferred position. PMID:17100010

  12. 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

  13. 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

  14. 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…

  15. 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

  16. 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

  17. 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…

  18. 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…

  19. 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

  20. 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…