64 research outputs found

    Constructive Quantum Shannon Decomposition from Cartan Involutions

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    The work presented here extends upon the best known universal quantum circuit, the Quantum Shannon Decomposition proposed in [Vivek V. Shende, Stephen S. Bullock and Igor Markov, Synthesis of Quantum Logic Circuits, IEEE Trans. Comput.-Aided Des. Integr. Circuits Syst. 25 (6): 1000-1010 (2006)]. We obtain the basis of the circuit's design in a pair of Cartan decompositions. This insight gives a simple constructive algorithm for obtaining the Quantum Shannon Decomposition of a given unitary matrix in terms of the corresponding Cartan involutions

    Mortality and Flowering of Great Basin Perennial Forbs After Experimental Burning: Implications for Wild Bees

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    The fates of native bee communities in the Great Basin sagebrush steppe are linked with the susceptibilities of their floral hosts to increasingly frequent wildfires. Postfire survival and subsequent flowering of six prevalent perennial wildflowers representing five families were quantified across a range of realistic fire severities created using a calibrated propane burn barrel. Five burn prescriptions of varying intensity and duration were applied to cultivated rows of basalt milkvetch (Astragalus filipes Torr. ex A. Gray), Blue Mountain prairie clover (Dalea ornata Eaton & J. Wright), sulphur-flower buckwheat (Eriogonum umbellatum Torr.), fernleaf biscuitroot (Lomatium dissectum Nutt.), blue penstemon (Penstemon cyaneus Pennell), and gooseberryleaf globemallow (Sphaeralcea grossularifolia Hook. & Arn.). Overall differences in their fire sensitivitieswere maximal at peak fire severity, ranging from 80% survival (L. dissectum) to complete mortality (E. umbellatum and P. cyaneus). Although A. filipes survived well (85%), half of the 95 burn survivors then failed to flower the year after burning. The postfire fate of plant-pollinator interactions is a function of the bees’ nesting habits, their floral host’s sensitivity to a given burn intensity (both in terms of survival and flowering), and the reproductive interdependence of bee and floral host (taxonomic specialists vs. generalists)

    BREEDING BIOLOGY AND BEE GUILD OF DOUGLAS’ DUSTYMAIDEN, \u3ci\u3eCHAENACTIS DOUGLASII\u3c/i\u3e (ASTERACEAE, HELENIEAE)

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    Douglas’ dustymaiden, Chaenactis douglasii (Hook.) Hook. & Arn., is a widespread, inconspicuous, short-lived perennial wildflower that blooms in early summer and is found in basin sagesteppe to upper montane areas throughout the U.S. Intermountain West. The species is proving practical to grow for seed and is expected to be used for western rangeland rehabilitation. Through manual pollination experiments, C. douglasii was found to be only weakly self-fertile; 15% of flowers from geitonogamy and autogamy treatments yielded filled achenes. In contrast, 57% of outcrossed flowers produced achenes filled with endosperm, with every capitulum yielding some fertile seeds. Freely visited flowers from a wild population produced 91% fertile achenes, indicating that seed production was not pollinator limited. Floral visitors to C. douglasii were sparse, consisting entirely of bees, most of them floral generalists. Museum specimens of bees taken at C. douglasii and 3 closely related congenerics comprise 175 species in 39 genera and all 6 North American bee families. A population of the manageable mesolectic cavity-nesting bee, Osmia californica, when released at one sagesteppe site, provisioned its cells primarily with pale, spiny pollen resembling that of the C. douglasii growing at La doncella de Douglas, Chaenactis douglasii (Hook). Hook. & Arn., es una flor silvestre ampliamente distribuida, no conspicua, de corta vida y perenne que florece a principios de verano desde las estepas de salvia hasta las áreas montañosas a lo largo del oeste de los Estados Unidos. Ha resultado práctico cultivarla por sus semillas y se espera que se las utilice para la rehabilitación de las tierras de pastoreo del oeste. Mediante experimentos manuales de polinización, se comprobó que esta especie es apenas auto-fértil; 15% de las flores provenientes de los tratamientos de geitonogamia y autogamia produjeron aquenios cubiertos. En contraste, el 57% de las flores desarrolladas por fecundación cruzada produjeron aquenios cubiertos con endospermo, con cada capítulo produciendo algunas semillas fértiles. Las flores de una población silvestre que fueron visitadas libremente produjeron un 91% de aquenios fértiles, lo que indica que la producción de semillas en ese lugar no estuvo limitada por la polinización. Los visitantes florales de C. douglasii fueron escasos, y consistieron totalmente de abejas, la mayoría de las cuales fueron generalistas. Especímenes de abejas de museo colectadas en C. douglasii y tres congenéricas estrechamente relacionadas comprenden 175 especies en 39 géneros y las seis familias de abejas de América del Norte. Una población de abejas manejables que anidan en cavidades, Osmia californica, cuando fue liberada en un sitio de estepa de salvia, provisionó a sus celdas principalmente con polen pálido y espinoso que se asemejaba al de C. douglasii que crecía en el sitio. Esta abeja y la abeja de miel parecen ser las más propicias para polinizar las plantas doncellas que se cultivan para semillas

    The effect of photobleaching on bee (Hymenoptera: Apoidea) setae color and its implications for studying aging and behavior

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    Historically, bee age has been estimated using measurements of wing wear and integument color change.  These measurements have been useful in studies of foraging ecology and plant-pollinator interactions.  Wing wear is speculated to be affected by the behaviors associated with foraging, nesting, and mating activities.  Setal color change may be an additional parameter used to measure bee age if it is affected by sun exposure during these same activities.  The objectives of this study were to experimentally assess the effect of direct sun exposure on setal color, unicellular hair-like processes of the integument, and determine whether wing wear and integument photobleaching are correlated.  To quantify photobleaching of setae, we measured changes in hue of lab-reared Bombus huntii Greene (Apidae) exposed to natural sunlight.  We found that sun exposure was a significant variable in determining setal bleaching.  To assess the relationship between wing wear and setal photobleaching, we scored wing wear and measured setal hue of B. huntii, Melecta pacifica fulvida Cresson (Apidae), and Osmia integra Cresson (Megachilidae) from museum specimens.  Wing wear and setal hue values were positively correlated for all three species; however, the strength of the relationship varies across bee species as indicated by correlation coefficient estimates.  Our results suggest that setal color change is affected by sun exposure, and is likely an accurate estimate of bee age.  We suggest that future investigations of bee aging consider a suite of morphometric characteristics due to differences in natural history and sociobiology that may be confounded by the use of a single characteristic

    Glioblastomas acquire myeloid-affiliated transcriptional programs via epigenetic immunoediting to elicit immune evasion

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    Glioblastoma multiforme (GBM) is an aggressive brain tumor for which current immunotherapy approaches have been unsuccessful. Here, we explore the mechanisms underlying immune evasion in GBM. By serially transplanting GBM stem cells (GSCs) into immunocompetent hosts, we uncover an acquired capability of GSCs to escape immune clearance by establishing an enhanced immunosuppressive tumor microenvironment. Mechanistically, this is not elicited via genetic selection of tumor subclones, but through an epigenetic immunoediting process wherein stable transcriptional and epigenetic changes in GSCs are enforced following immune attack. These changes launch a myeloid-affiliated transcriptional program, which leads to increased recruitment of tumor-associated macrophages. Furthermore, we identify similar epigenetic and transcriptional signatures in human mesenchymal subtype GSCs. We conclude that epigenetic immunoediting may drive an acquired immune evasion program in the most aggressive mesenchymal GBM subtype by reshaping the tumor immune microenvironment

    Action 3:30R: Process evaluation of a cluster randomised feasibility study of a revised teaching assistant-led extracurricular physical activity intervention for 8 to 10 year olds

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    Background: Numerous interventions to increase children's physical activity levels are published, yet, few studies report indicators of external validity. Process evaluations are critical for assessing intervention implementation, sustainability and effectiveness. A mixed-methods process evaluation, using the RE-AIM framework, was conducted to evaluate the internal and external validity of Action 3:30R, a revised teaching assistant-led after-school intervention which aimed to increase physical activity in children aged 8-10 years and was underpinned by Self-determination Theory (SDT). Methods: Data were collected and reported in line with the five components of RE-AIM (Reach, Effectiveness, Adoption, Implementation and Maintenance). Quantitative measures included logbooks, registers and self-reported teaching-efficacy, autonomy support, child enjoyment and perceived exertion questionnaires. Questionnaire data were collected at three points throughout the 15-week intervention. Observations by trained researchers were also conducted to assess fidelity to the intervention manual and its underpinning theory. Post-intervention focus groups with pupils and interviews with teaching assistants (TAs), school staff and external stakeholders explored the implementation and potential sustainability of Action 3:30R from stakeholders' perspectives. Results: Action 3:30R appealed to a broad range of pupils, including girls and less-active pupils. The Action 3:30R TA training was implemented as intended and was perceived as valuable professional development. Releasing staff for training was a barrier in two of the six intervention schools, which were unable to deliver the intervention as a result. Pupils enjoyed the intervention, and the Action 3:30R core principles underpinned by SDT were implemented with high fidelity, as was the intervention itself. Scheduling conflicts with other clubs and lack of parental support were perceived as the main barriers to recruitment and attendance. Lack of space and season were cited as the main barriers affecting the quality of delivery. The study shows evidence of maintenance, as one intervention school decided to continue Action 3:30R beyond the study. Funding and continued TA training were suggested as factors which may affect the maintenance of Action 3:30R. Conclusions: Action 3:30R is an enjoyable, autonomy-supportive after-school programme, which engages a range of pupils and offers TAs valuable training. RE-AIM provided helpful structure and is recommended for intervention evaluations. Trial registration: ISRCTN34001941. Prospectively registered 01/12/2016

    The Future of Precision Medicine : Potential Impacts for Health Technology Assessment

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    Objective Precision medicine allows health care interventions to be tailored to groups of patients based on their disease susceptibility, diagnostic or prognostic information or treatment response. We analyse what developments are expected in precision medicine over the next decade and consider the implications for health technology assessment (HTA) agencies. Methods We perform a pragmatic review of the literature on the health economic challenges of precision medicine, and conduct interviews with representatives from HTA agencies, research councils and researchers from a variety of fields, including digital health, health informatics, health economics and primary care research. Results Three types of precision medicine are highlighted as likely to emerge in clinical practice and impact upon HTA agencies: complex algorithms, digital health applications and ‘omics’-based tests. Defining the scope of an evaluation, identifying and synthesizing the evidence and developing decision analytic models will more difficult when assessing more complex and uncertain treatment pathways. Stratification of patients will result in smaller subgroups, higher standard errors and greater decision uncertainty. Equity concerns may present in instances where biomarkers correlate with characteristics such as ethnicity, whilst fast-paced innovation may reduce the shelf-life of guidance and necessitate more frequent reviewing. Discussion Innovation in precision medicine promises substantial benefits to patients, but will also change the way in which some health services are delivered and evaluated. As biomarker discovery accelerates and AI-based technologies emerge, the technical expertise and processes of HTA agencies will need to adapt if the objective of value for money is to be maintained

    Neurotropic virus infections as the cause of immediate and delayed neuropathology

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