516 research outputs found

    Determinates of Success in an ALC Classroom

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    Students who attend an Alternative Learning Center (ALC) do so for a variety of reasons- They may arrive due to a deficit in credit, teen parent status, at-risk of dropping out, or behavioral issues. Once at the ALC many students comment that they are more successful, than they were in their main public high school. This study is an effort to understand what factors take place in my classroom at the ALC that increases the level of success felt by the students. Through open ended interviewing ten students shared their experiences in my classroom regarding the practices that I, as their teacher, engage in helps them to feel successful. Four key themes emerged from the student interviews concerning what I do in my classroom to help students feel successful. Recommendations based on the findings include ways that I can and should modify my classroom practices to increase student success

    Changes in hemlock looper [Lepidoptera: Geometridae] pupal distribution through a 3-year outbreak cycle

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    La distribution des chrysalides de l’arpenteuse de la pruche, Lambdina fiscellaria, a Ă©tĂ© Ă©tudiĂ©e au cours d’un cycle Ă©pidĂ©mique d’une durĂ©e de trois ans prĂšs du Lac Princeton sur l’üle d’Anticosti au QuĂ©bec. Au total, 10 sapins ont Ă©tĂ© coupĂ©s et toutes les chrysalides ont Ă©tĂ© comptĂ©es sur le tronc et les branches (partie non-foliĂ©e vs foliĂ©e) de la cime infĂ©rieure, mĂ©diane et supĂ©rieure, ainsi que sur le tronc sous la cime. En condition prĂ©Ă©pidĂ©mique, les chrysalides ont principalement Ă©tĂ© trouvĂ©es sur les branches des cimes mĂ©dianes et supĂ©rieures. Durant l’épidĂ©mie, la densitĂ© des chrysalides n’a pas augmentĂ© dans ces sites de pupaison et les larves se sont surtout transformĂ©es en chrysalides sur le tronc, Ă  partir du sol jusque dans la cime mĂ©diane, ainsi que sur les branches de la cime infĂ©rieure. Peu de chrysalides ont Ă©tĂ© trouvĂ©es sur la partie foliĂ©e des branches en pĂ©riode post-Ă©pidĂ©mique, la plupart Ă©tant trouvĂ©es sur la partie basale non-foliĂ©e qui apparaĂźt comme un endroit prĂ©fĂ©rentiel pour la pupaison de l'arpenteuse de la pruche. De façon Ă  optimiser la dĂ©tection des augmentations de populations dans les rĂ©seaux de surveillance, des piĂšges Ă  chrysalides devraient ĂȘtre placĂ©s Ă  hauteur de poitrine sur le tronc de sapins baumiers.The hemlock looper, Lambdina fiscellaria, pupal distribution was studied through a 3-year outbreak cycle near Lac Princeton on Anticosti Island in Quebec. Over the 3 years, 10 balsam fir trees were cut and all pupae were counted on the stem and branches (non-foliated vs foliated parts) of the lower, middle and upper crowns and on the stem below crown. In pre-outbreak conditions, pupae were mostly found on branches of the middle and upper crowns. During the outbreak, pupal density did not increase on these parts of the trees, since pupae were mostly found on the stem, from the ground to the middle crown, and on branches of the lower crown. Few pupae were found on the foliated portion of branches in post-outbreak conditions but most were found on the basal non-foliated part of branches, which appears to be a preferred location for hemlock looper pupation. In order to optimize detection of population increases in monitoring networks, we suggest using pupal traps at breast height on balsam fir trees

    Experimental Demonstration of Squeezed State Quantum Averaging

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    We propose and experimentally demonstrate a universal quantum averaging process implementing the harmonic mean of quadrature variances. The harmonic mean protocol can be used to efficiently stabilize a set of fragile squeezed light sources with statistically fluctuating noise levels. The averaged variances are prepared probabilistically by means of linear optical interference and measurement induced conditioning. We verify that the implemented harmonic mean outperforms the standard arithmetic mean strategy. The effect of quantum averaging is experimentally tested both for uncorrelated and partially correlated noise sources with sub-Poissonian shot noise or super-Poissonian shot noise characteristics.Comment: 4 pages, 5 figure

    Perfect quantum error correction coding in 24 laser pulses

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    An efficient coding circuit is given for the perfect quantum error correction of a single qubit against arbitrary 1-qubit errors within a 5 qubit code. The circuit presented employs a double `classical' code, i.e., one for bit flips and one for phase shifts. An implementation of this coding circuit on an ion-trap quantum computer is described that requires 26 laser pulses. A further circuit is presented requiring only 24 laser pulses, making it an efficient protection scheme against arbitrary 1-qubit errors. In addition, the performance of two error correction schemes, one based on the quantum Zeno effect and the other using standard methods, is compared. The quantum Zeno error correction scheme is found to fail completely for a model of noise based on phase-diffusion.Comment: Replacement paper: Lost two laser pulses gained one author; added appendix with circuits easily implementable on an ion-trap compute

    “These Trees Have Stories to Tell”: Linking DĂ«nesÇ«ÌĆ‚Ä±nĂ© Oral History of Caribou Use with Trample Scar Frequency on Black Spruce Roots at Ɂedacho KuĂ©

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    For thousands of years Ɂedacho KuĂ© (Artillery Lake, Northwest Territories) has been a key water crossing site for barren-ground caribou (Rangifer tarandus groenlandicus). Human disturbance of barren-ground caribou habitat in northern Canada has emerged as an important focus of study in the last decade; particularly in the Bathurst range of the Northwest Territories where caribou populations have declined by more than 95% since the 1980s. Guided by local Indigenous leaders and Elders, a collaborative research project was developed with the DĂ«nesÇ«ÌĆ‚Ä±nĂ© people of ƁutsĂ«l K’e DĂ«ne First Nation (2012 – 14). This paper describes linkages between knowledge derived from DĂ«nesÇ«ÌĆ‚Ä±nĂ© oral history and quantitative dendroecological analysis of trample scars on black spruce (Picea mariana) root samples collected at Ɂedacho KuĂ© to provide a better understanding of caribou use at this location. Findings from oral histories and dendroecology analysis were consistent with one another and with previous dendroecology study in the region, although some discrepancies were detected in data from 1995 – 2006 that require further study to elucidate. Key findings include relatively low caribou use at Ɂedacho KuĂ© during the 1930s and late 1960s, with use increasing into the 1970s and peaking in the late 1980s, as well as Elder and hunter reports of no caribou in some years between 2005 and 2012. This work addresses a gap in scientific data about barren-ground caribou movements at Ɂedacho KuĂ© prior to satellite collar use in 1996 and corroborates previously documented oral histories about the enduring value of Ɂedacho KuĂ© as critical habitat to barren-ground caribou. Given the drastic decline of the Bathurst caribou over the last two decades, more research is needed to understand movements and their relationship to population dynamics. In this context, the research approach described in this paper could be used as an example of how to meaningfully bring together place-based Indigenous knowledge and science in addressing an urgent issue of Arctic sustainability.    Depuis des milliers d’annĂ©es, Ɂedacho KuĂ© (lac Artillery, Territoires du Nord-Ouest) sert d’important point de franchissement de cours d’eau pour le caribou de la toundra (Rangifer tarandus groenlandicus). La perturbation anthropique de l’habitat du caribou de la toundra dans le Nord canadien a fait l’objet d’études importantes ces dix derniĂšres annĂ©es, plus particuliĂšrement dans l’aire de rĂ©partition de Bathurst, dans les Territoires du Nord-Ouest, oĂč les populations de caribous ont chutĂ© de plus de 95 % depuis les annĂ©es 1980. Un projet de recherche collaborative guidĂ© par des chefs et des aĂźnĂ©s autochtones locaux a Ă©tĂ© conçu en consultation avec le peuple DĂ«nesÇ«ÌĆ‚Ä±nĂ© de la PremiĂšre Nation ƁutsĂ«l K’e DĂ«ne (2012 – 2014). Cet article dĂ©crit les liens entre les connaissances dĂ©rivĂ©es de l’histoire orale des DĂ«nesÇ«ÌĆ‚Ä±nĂ©s et l’analyse dendroĂ©cologique quantitative des cicatrices de piĂ©tinement se trouvant sur les Ă©chantillons de racines d’épinettes noires (Picea mariana) prĂ©levĂ©s Ă  Ɂedacho KuĂ© afin de mieux comprendre l’utilisation de ce lieu par les caribous. Les constatations dĂ©coulant de l’histoire orale et de l’analyse dendroĂ©cologique concordaient ensemble ainsi qu’avec une Ă©tude dendroĂ©cologique antĂ©rieure de la rĂ©gion, bien que certains Ă©carts aient Ă©tĂ© dĂ©celĂ©s dans les donnĂ©es de 1995 Ă  2006, Ă©carts qui se doivent d’ĂȘtre Ă©tudiĂ©s afin d’ĂȘtre Ă©lucidĂ©s. Parmi les principales constatations, notons l’utilisation relativement faible de Ɂedacho KuĂ© par les caribous pendant les annĂ©es 1930 et la fin des annĂ©es 1960, une utilisation accrue dans les annĂ©es 1970 ayant atteint un sommet vers la fin des annĂ©es 1980, ainsi que le signalement de l’absence de caribous par les aĂźnĂ©s et les chasseurs au cours de certaines annĂ©es entre 2005 et 2012. Notre recherche comble un manque de donnĂ©es scientifiques relativement aux dĂ©placements du caribou de la toundra Ă  Ɂedacho KuĂ© avant que les colliers Ă©metteurs Ă  transmission par satellite ne commencent Ă  ĂȘtre employĂ©s en 1996. Elle corrobore l’histoire orale documentĂ©e prĂ©cĂ©demment au sujet de la valeur durable de ?edacho KuĂ© en tant qu’habitat critique du caribou de la toundra. En raison de la chute importante de la population du caribou de Bathurst ces deux derniĂšres dĂ©cennies, de plus amples recherches s’imposent afin de comprendre les dĂ©placements et leur lien avec la dynamique de la population. Dans ce contexte, la dĂ©marche de recherche dĂ©crite dans cet article pourrait servir d’exemple montrant comment concilier les connaissances autochtones d’un endroit avec la science pour faire face Ă  un enjeu urgent de durabilitĂ© de l’Arctique.

    Fe limitation decreases transcriptional regulation over the diel cycle in the model diatom Thalassiosira pseudonana.

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    Iron (Fe) is an important growth factor for diatoms and its availability is further restricted by changes in the carbonate chemistry of seawater. We investigated the physiological attributes and transcriptional profiles of the diatom Thalassiosira pseudonana grown on a day: night cycle under different CO2/pH and iron concentrations, that in combination generated available iron (Fe\u27) concentrations of 1160, 233, 58 and 12 pM. We found the light-dark conditions to be the main driver of transcriptional patterns, followed by Fe\u27 concentration and CO2 availability, respectively. At the highest Fe\u27 (1160 pM), 55% of the transcribed genes were differentially expressed between day and night, whereas at the lowest Fe\u27 (12 pM), only 28% of the transcribed genes displayed comparable patterns. While Fe limitation disrupts the diel expression patterns for genes in most central metabolism pathways, the diel expression of light- signaling molecules and glycolytic genes was relatively robust in response to reduced Fe\u27. Moreover, we identified a non-canonical splicing of transcripts encoding triose-phosphate isomerase, a key-enzyme of glycolysis, generating transcript isoforms that would encode proteins with and without an active site. Transcripts that encoded an active enzyme maintained a diel expression at low Fe\u27, while transcripts that encoded the non-active enzyme lost the diel expression. This work illustrates the interplay between nutrient limitation and transcriptional regulation over the diel cycle. Considering that future ocean conditions will reduce the availability of Fe in many parts of the oceans, our work identifies some of the regulatory mechanisms that may shape future ecological communities
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