1,372 research outputs found

    Leadership for Culturally and Linguistically Responsive Schools (Book Review)

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    Review of Leadership for Culturally and Linguistically Responsive Schools

    Mathematical optimisation of drainage and economic land use for target water and salt yields

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    Land managers in upper catchments are being asked to make expensive changes in land use, such as by planting trees, to attain environmental service targets, including reduced salt loads in rivers, to meet needs of downstream towns, farms and natural habitats. End-of-valley targets for salt loads have sometimes been set without a quantitative model of cause and effect regarding impacts on water yields, economic efficiency or distribution of costs and benefits among stakeholders. This paper presents a method for calculating a ā€˜menuā€™ of technically feasible options for changes from current to future mean water yields and salt loads from upstream catchments having local groundwater flow systems, and the land-use changes to attain each of these options at minimum cost. It sets the economic stage for upstream landholders to negotiate with downstream parties future water-yield and salt-load targets, on the basis of what it will cost to supply these ecosystem services.discounting, landuse, NPV, opportunity-cost, salinity, Resource /Energy Economics and Policy,

    Chemistry by Mobile Phone (or how to justify more time at the bar)

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    By combining automatic environment monitoring with Java smartphones a system has been produced for the real-time monitoring of experiments whilst away from the lab. Changes in the laboratory environment are encapsulated as simple XML messages, which are published using an MQTT compliant broker. Clients subscribe to the MQTT stream, and produce a user display. An MQTT client written for the Java MIDP platform, can be run on a smartphone with a GPRS Internet connection, freeing us from the constraints of the lab. We present an overview of the technologies used, and how these are helping chemists make the best use of their time

    Parent Engagement at a Cristo Rey High School: Building Home-School Partnerships in a Multicultural Immigrant Community

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    Catholic social teaching affirms the primary role of parents in their childrenā€™s education, as well as the importance of a home-school partnership. The purposes of this article are to review the results of a mixed methods study of parent engagement at Cristo Rey Boston High School, and how the results of this study led to specific efforts to include parents more closely in the life of the school. Results suggest that parents in multicultural communities perceive their engagement to be an important part of their childrenā€™s education. Yet, this engagement may take different forms that may go unrecognized by school staff. Based on study findings, school administrators began integrating parent engagement efforts through a coordinated system of student advising. From the perspective of Catholic social teaching, recognizing and responding to these multicultural differences are a means of praxis that affirms human dignity and reduces barriers to education for the marginalized

    Accretion onto the Supermassive Black Hole in M87

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    Chandra X-ray observations of the giant elliptical galaxy M87 resolve the thermal state of the hot interstellar medium into the accretion (Bondi) radius of its central 3 10^9 Msun black hole. We measure the X-ray gas temperature and density profiles and calculate the Bondi accretion rate, Mdot_Bondi \sim 0.1 Msun/yr. The X-ray luminosity of the active nucleus of M87 observed with Chandra is L_{x, 0.5-7 \keV} \sim 7 \times 10^{40}erg/s. This value is much less than the predicted nuclear luminosity, L_{Bondi} \sim 5 \times 10^{44} erg/s, for accretion at the Bondi rate with a canonical accretion radiative efficiency of 10%. If the black hole in M87 accretes at this rate it must do so at a much lower radiative efficiency than the canonical value. The multiwavelength spectrum of the nucleus is consistent with that predicted by an advection-dominated flow. However, as is likely, the X-ray nucleus is dominated by jet emission then the properties of flow must be modified, possibly by outflows. We show that the overall energetics of the system are just consistent with the predicted Bondi nuclear power. This suggests that either most of the accretion energy is released in the relativistic jet or that the central engine of M87 undergoes on-off activity cycles. We show that, at present, the energy dumped into the ISM by the jet may reduce the accretion rate onto the black hole by a factor \propto (v_j/c_s)^{-2}, where v_j is the jet velocity and c_s the ISM sound speed, and that this is sufficient to account for the low nuclear luminosity.Comment: emulateapj.sty, revised version, accepted by Ap

    Suzaku Observations of Local Ultraluminous Infrared Galaxies

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    We report the results from our analysis of {\it Suzaku} XIS (0.5-10 keV) and HXD/PIN (15-40 keV) observations of five well-known local ULIRGs: {\em IRAS} F05189-2524, {\em IRAS} F08572+3915, Mrk 273, PKS 1345+12, and Arp 220. The XIS observations of F05189-2524 and Mrk 273 reveal strong iron lines consistent with Fe KĪ±\alpha and changes in spectral shapes with respect to previous {\it Chandra} and {\it XMM-Newton} observations. Mrk 273 is also detected by the HXD/PIN at āˆ¼\sim1.8-Ļƒ\sigma. For F05189-2524, modeling of the data from the different epochs suggests that the change in spectral shape is likely due to the central source switching off, leaving behind a residual reflection spectrum, or an increase in the absorbing column. An increase in the covering fraction of the absorber can describe the spectral variations seen in Mrk 273, although a reduction in the intrinsic AGN luminosity cannot be formally ruled out. The {\it Suzaku} spectra of Mrk 273 are well fit by a ~94% covering fraction model with a column density of āˆ¼1024\sim10^{24} cmāˆ’2^{-2}. The absorption-corrected log[L2āˆ’10keVL_{\rm 2-10 keV} / LIRL_{\rm IR}] ratio is consistent with those found in PG Quasars. The 0.5-10 keV spectrum of PKS 1345+12 and Arp 220 seem unchanged from previous observations and their hard X-ray emission is not convincingly detected by the HXD/PIN. The large column density derived from CO observations and the large equivalent width of an ionized Fe line in Arp 220 can be reconciled by an ionized reflection model. F08572+3915 is undetected in both the XIS and HXD/PIN, but the analysis of unpublished {\em Chandra} data provides a new measurement at low energies.Comment: 37 pages including 4 tables and 10 figures. Accepted for publication in ApJ. It is tentatively scheduled to appear in the January 20, 2009 issue of Ap

    Interventions Supporting the Social Integration of Refugee Children and Youth in School Communities: A Review of the Literature

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    Schools function as a primary driver of integration and as a link to resources and assets that promote healthy development. Nevertheless, most research studies on school-based programs are conducted on mainstream students, and school professionals looking to deliver interventions serving refugee students are forced to choose between evidence-based programs designed for the mainstream and developing new programs in the cultural framework of their students. The purpose of this literature review is to provide a summary of recent research on successful, evidence-based programs as well as promising interventions and practice recommendations in five core practice areas in schools: school leadership and culture, teaching, mental health, after-school programming, and school-parent-community partnerships. These findings are presented drawing from theoretical frameworks of ecological systems, social capital, segmented assimilation, resilience, and trauma, and describe how such theories may be used to inform programs serving refugee children and youth. Additionally, this review describes the core components of successful programs across these practice areas to inform researchers and practitioners as they select and develop programs in their own school communities. Finally, this review concludes with a discussion of human rights in the education of refugee children and youth

    Revealing the Dusty Warm Absorber in MCG--6-30-15 with the Chandra HETG

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    We present detailed evidence for a warm absorber in the Seyfert 1 galaxy MCG--6-30-15 and dispute earlier claims for relativistic O line emission. The HETG spectra show numerous narrow, unresolved (FWHM < 200 km/s) absorption lines from a wide range of ionization states of N, O, Mg, Ne, Si, S, Ar, and Fe. The O VII edge and 1s^2--1snp resonance line series to n=9 are clearly detected at rest in the AGN frame. We attribute previous reports of an apparently highly redshifted O VII edge to the 1s^2--1snp (n > 5) O VII resonance lines, and a neutral Fe L absorption complex. The shape of the Fe L feature is nearly identical to that seen in the spectra of several X-ray binaries, and in laboratory data. The implied dust column density agrees with that obtained from reddening studies, and gives the first direct X-ray evidence for dust embedded in a warm absorber. The O VIII resonance lines and weak edge are also detected, and the spectral rollover below 2 keV is explained by the superposition of numerous absorption lines and edges. We identify, for the first time, a KLL resonance in the O VI photoabsorption cross section, giving a measure of the O VI column density. The O VII (f) emission detected at the systemic velocity implies a covering fraction of ~5% (depending on the observed vs. time-averaged ionizing flux). Our observations show that a dusty warm absorber model is not only adequate to explain all the spectral features > 0.48 keV (< 26 \AA) the data REQUIRE it. This contradicts the interpretation of Branduardi-Raymont et al. (2001) that this spectral region is dominated by highly relativistic line emission from the vicinity of the black hole.Comment: 4.5 pages, 1 color figure, accepted (April 2001) for publication in ApJL, not many changes from the initial submission - updated/added some measuements for the O VII resonance series, and added a discussion about FeO2 grain

    The Combechem MQTT LEGO microscope: a grid enabled scientific apparatus demonstrator

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    Grid computing impacts directly on the experimental scientific laboratory in the areas of monitoring and remote control of experiments, and the storage, processing and dissemination of the resulting data. We highlight some of the issues in extending the use of an MQ Telemetry Transport (MQTT) broker from facilitating the remote monitoring of an experiment and its environment to the remote control of an apparatus. To demonstrate these techniques, an Intel-Play QX3 microscope has been "grid-enabled" using a combination of software to control the microscope imaging, and sample handling hardware built from LEGO Mindstorms. The whole system is controlled remotely by passing messages using an IBM WebSphere Message Broker. <br/
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