5,537 research outputs found

    Finnish Education in the 21st Century: Paradoxes and Visions

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    Since the publication of the 2000 PISA results highlighting Finland’s school children ranking #1 in the world for reading, and #3 for mathematics and science, fascination with Finland’s educational system has piqued the interest of educational researchers worldwide. Researchers have been captivated by the paradoxes of the Finnish education system: teach less, learn more; test less, learn more; and educational equity through growing diversity (Sahlberg, 2015). Starting with the 2012 PISA results and continuing with the 2015 scores, Finnish educators are now concerned about the downward trend in the data, with their students losing ground in reading, math and science and scores hovering around ranking 10th in the world. In this article, I report on the new Finnish vision of education, the newly revised national curriculum, as well as the newly emerging gender gap in their student achievement, as Finnish educators endeavor to maintain their previous track record of educational equity and attainment for all students

    Biochemical and Molecular Characterization of Proteoglycans in the Chick Nervous System

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    The nervous system contains hundreds of different cell-types which arise in a precise temporal and spatial developmental pattern. The complex pattern of neural development is characterized by a distinct series of events, which include cell proliferation, migration, differentiation, neurite extension, and synaptagenesis (Jacobson, 1978). Proteoglycans have been implicated in being involved in many of these processes, but have been poorly characterized in the developing vertebrate nervous system (Margolis and Margolis, 1989a; 1989b; 1993; Herndon and Lander, 1989). The studies outlined in this thesis have focussed on the identification, biochemical characterization, and developmental regulation of the major proteoglycan species in the developing chick nervous system. This analysis has provided insight into the different functions mediated by nervous system HSPGs and CSPGs\KSPGs, and have enabled us to produce specific proteoglycan antisera that can be used to elucidate specific proteoglycan functions. We have also described the molecular cloning, sequence analysis, and in situ mRNA localization, of a nervous system keratan sulfate proteoglycan, claustrin. These analyses have determined that claustrin is highly homologous to the mouse MAP1B protein, and furthermore, suggest that MAP1B itself may be a keratan sulfate proteoglycan. In situ localization of claustrin mRNA during chick development has reinforced previous studies (Cole and McCabe, 1991; McCabe and Cole, 1992; McCabe et al, 1991) suggesting that claustrin may be an inhibitory growth molecule localized to many of the proposed glial barrier structures in the developing chick CNS

    Lateral Auxin Transport in Stems and Roots

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    Emission spectra of luminous bacteria

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    The relation between the rate of photosynthesis and the pigment content was studied in seedlings of Avena sativa var. Victory. Etiolated seedlings were illuminated during different periods. Next, the rate of photosynthesis as well as the pigment concentrations were determined in the primary leaves. The saturation rate of photosynthesis proved to increase with increasing pigment concentrations until the ratio chlorophyl b / chlorophyll a approached its “normal” value. Although the amounts of both pigments still keep on increasing, the saturation rate of photosynthesis remains the same. In agreement with other authors we could observe that the formation of chlorophyll a starts immediately upon illumination, while b is formed only after a lapse of time. Xanthophylls are present in etiolated seedlings in relatively large amounts; their formation is not influenced by light. Other carotenoids are also present in non-illuminated plants, though in small amounts. Light, however, accelerates their development. As far as it was studied the quotient chlorophyll a / carotenes remains constant except for very low pigment concentrations

    The dynamics of z~1 clusters of galaxies from the GCLASS survey

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    We constrain the internal dynamics of a stack of 10 clusters from the GCLASS survey at 0.87<z<1.34. We determine the stack cluster mass profile M(r) using the MAMPOSSt algorithm of Mamon et al., the velocity anisotropy profile beta(r) from the inversion of the Jeans equation, and the pseudo-phase-space density profiles Q(r) and Qr(r), obtained from the ratio between the mass density profile and the third power of the (total and, respectively, radial) velocity dispersion profiles of cluster galaxies. Several M(r) models are statistically acceptable for the stack cluster (Burkert, Einasto, Hernquist, NFW). The total mass distribution has a concentration c=r200/r-2=4.0-0.6+1.0, in agreement with theoretical expectations, and is less concentrated than the cluster stellar-mass distribution. The stack cluster beta(r) is similar for passive and star-forming galaxies and indicates isotropic galaxy orbits near the cluster center and increasingly radially elongated with increasing cluster-centric distance. Q(r) and Qr(r) are almost power-law relations with slopes similar to those predicted from numerical simulations of dark matter halos. Combined with results obtained for lower-z clusters we determine the dynamical evolution of galaxy clusters, and compare it with theoretical predictions. We discuss possible physical mechanisms responsible for the differential evolution of total and stellar mass concentrations, and of passive and star-forming galaxy orbits [abridged].Comment: 12 pages, 7 figures. Version accepted for publication in A&A after minor modification

    A new way of editing a flora

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    Modern electronic tools have become common tools of most scientists. Flora writers and other botanists producing large manuscripts with a certain fixed structure may go even further and use the so-called Mail Merge option in a word processor such as Microsoft Word™. This tool allows structuring a document strictly, especially for the contributions of invited authors, to pre-format the final layout, and to simplify correspondence with contributors. Contributors fill in a structured Microsoft Excel™ spreadsheet with fixed headings, without any requirements for layout or formatting. The file is then used as data source for a merge document in the word processor. For completion of an entire Flora, such as the Flore Analytique du Bénin (Akoègninou et al., 2006), this iteration was done with 45 authors, producing over 180 different manuscripts, viz. one for each family. Final editing includes a check on correct language, insertion of separately produced keys, figures, references, etc

    Evidence for strong evolution in galaxy environmental quenching efficiency between z = 1.6 and z = 0.9

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    Indexación: Web of Science; Scopus.We analyse the evolution of environmental quenching efficiency, the fraction of quenched cluster galaxies which would be star forming if they were in the field, as a function of redshift in 14 spectroscopically confirmed galaxy clusters with 0.87 < z < 1.63 from the Spitzer Adaptation of the Red-Sequence Cluster Survey. The clusters are the richest in the survey at each redshift. Passive fractions rise from 42-13 +10 per cent at z ~ 1.6 to 80-9 +12 per cent at z ~ 1.3 and 88-3 +4 per cent at z < 1.1, outpacing the change in passive fraction in the field. Environmental quenching efficiency rises dramatically from 16-19 +15 per cent at z ~ 1.6 to 62-15 +21 per cent at z~1.3 and 73-7 +8 per cent at z ≲ 1.1. This work is the first to show direct observational evidence for a rapid increase in the strength of environmental quenching in galaxy clusters at z ~ 1.5, where simulations show cluster-mass haloes undergo non-linear collapse and virialization.https://academic.oup.com/mnrasl/article/465/1/L104/241728

    Understanding and Finding Solutions to the Problem of Sedimentation in the National Wildlife Refuge System

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    The National Wildlife Refuge System (Refuge System) is a collection of public lands maintained by the U.S. Fish and Wildlife Service for migratory birds and other wildlife. Wetlands on individual National Wildlife Refuges (Refuges) may be at risk of increased sedimentation because of land use and water management practices. Increased sedimentation can reduce wetland habitat quality by altering hydrologic function, degrading water quality, and inhibiting growth of vegetation and invertebrates. On Refuges negatively affected by increased sedimentation, managers have to address complex questions about how to best remediate and mitigate the negative effects. The best way to account for these complexities is often not clear. On other Refuges, managers may not know whether sedimentation is a problem. Decision makers in the Refuge System may need to allocate resources to studying which Refuges could be at risk. Such analyses would help them understand where to direct support for managing increased sedimentation. In this paper, we summarize a case study demonstrating the use of decision-analytic tools in the development of a sedimentation management plan for Agassiz National Wildlife Refuge, Minnesota. Using what we learned from that process, we surveyed other Refuges in U.S. Fish and Wildlife Service Region 3 (an area encompassing the states of Illinois, Indiana, Iowa, Ohio, Michigan, Minnesota, Missouri, and Wisconsin) and Region 6 (an area encompassing the states of Colorado, Kansas, Montana, Nebraska, North Dakota, South Dakota, Utah, and Wyoming) about whether they experience sediment-related impacts to management. Our results show that cases of management being negatively affected by increased sedimentation are not isolated. We suggest that the Refuge System conduct a comprehensive and systematic assessment of increased sedimentation among Refuges to understand the importance of sedimentation in context with other management problems that Refuges face. The results of such an assessment could guide how the Refuge System allocates resources to studying and managing widespread stressors

    A skewer survey of the Galactic halo from deep CFHT and INT images

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    We study the density profile and shape of the Galactic halo using deep multicolour images from the MENeaCS and CCCP projects, over 33 fields selected to avoid overlap with the Galactic plane. Using multicolour selection and PSF homogenization techniques we obtain catalogues of F stars (near-main sequence turnoff stars) out to Galactocentric distances up to 60kpc. Grouping nearby lines of sight, we construct the stellar density profiles through the halo in eight different directions by means of photometric parallaxes. Smooth halo models are then fitted to these profiles. We find clear evidence for a steepening of the density profile power law index around R=20 kpc, from -2.50 +- 0.04 to -4.85 +- 0.04, and for a flattening of the halo towards the poles with best-fit axis ratio 0.63 +- 0.02. Furthermore, we cannot rule out a mild triaxiality (w>=0.8). We recover the signatures of well-known substructure and streams that intersect our lines of sight. These results are consistent with those derived from wider but shallower surveys, and augur well for upcoming, wide-field surveys of comparable depth to our pencil beam surveys.Comment: 14 pages, 8 figures, 6 table
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