1,019 research outputs found

    Lily Perennializing in Ithaca, Louisiana and Holland

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    In May 2006, we published a newsletter (number 10) where we first reported on our experiences with multi-year flowering of a variety of “cut flower” hybrid lilies at Cornell’s outdoor trialing site, Bluegrass Lane, in Ithaca NY. In 2002-2003, we planted a range of LA, Asiatic and Oriental hybrid lilies to investigate perennialization. While not a formal trial, the 2006 newsletter showed that a range of hybrids, primarily bred for cut flower use, performed very well in outdoor garden situations in upstate New Yor

    Observing the Earth as an exoplanet with LOUPE, the Lunar Observatory for Unresolved Polarimetry of Earth

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    The detections of small, rocky exoplanets have surged in recent years and will likely continue to do so. To know whether a rocky exoplanet is habitable, we have to characterise its atmosphere and surface. A promising characterisation method for rocky exoplanets is direct detection using spectropolarimetry. This method will be based on single pixel signals, because spatially resolving exoplanets is impossible with current and near-future instruments. Well-tested retrieval algorithms are essential to interpret these single pixel signals in terms of atmospheric composition, cloud and surface coverage. Observations of Earth itself provide the obvious benchmark data for testing such algorithms. The observations should provide signals that are integrated over the Earth's disk, that capture day and night variations, and all phase angles. The Moon is a unique platform from where the Earth can be observed as an exoplanet, undisturbed, all of the time. Here, we present LOUPE, the Lunar Observatory for Unresolved Polarimetry of Earth, a small and robust spectropolarimeter to observe our Earth as an exoplanet.Comment: 14 pages, 3 figures, submitted in special Issue of Planetary and Space Science on Scientific Preparations for Lunar Exploratio

    The use of an e-learning constructivist solution in workplace learning

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    We wished to investigate whether an e-learning approach which uses constructivist principles can be successfully applied to train employees in a highly specialised skill thought to require expert individuals and extensive prolonged training. The approach involved the development of an e-learning package which included simulations and interactivity, then experimental testing in a case study workplace environment with the collection of both quantitative and qualitative data to assess the effectiveness of the package. Our study shows that this e-learning strategy improved the skills of the inexperienced operator significantly. We therefore propose that such programmes could be used as a work based training aid and used as a model system for the training of employees in complex skilled tasks in the workplace. This research demonstrates that the e-learning can be applied outside the traditional learning environment to train unskilled employees to undertake complex practical tasks which traditionally would involve prohibitively expensive instruction. This work also illustrates that simulations and interactivity are powerful tools in the design of successful e-learning packages in preparing learners for real world practical situations. Finally this study shows that workplace learners can be better served by elearning environments rather than conventional training as they allow asynchronous learning and private study which are valued by employees who have other demands on their time and are more comfortable receiving tuition privately Relevance to industry: E-learning using constructivist principles, and incorporating simulations and interactivity can be used successfully in the training of highly specialised and skilled tasks required in the modern workplace

    How spiking neurons give rise to a temporal-feature map

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    A temporal-feature map is a topographic neuronal representation of temporal attributes of phenomena or objects that occur in the outside world. We explain the evolution of such maps by means of a spike-based Hebbian learning rule in conjunction with a presynaptically unspecific contribution in that, if a synapse changes, then all other synapses connected to the same axon change by a small fraction as well. The learning equation is solved for the case of an array of Poisson neurons. We discuss the evolution of a temporal-feature map and the synchronization of the single cells’ synaptic structures, in dependence upon the strength of presynaptic unspecific learning. We also give an upper bound for the magnitude of the presynaptic interaction by estimating its impact on the noise level of synaptic growth. Finally, we compare the results with those obtained from a learning equation for nonlinear neurons and show that synaptic structure formation may profit from the nonlinearity

    Constitutively Enhanced Lymphatic Pumping in the Upper Limbs of Women Who Later Develop Breast Cancer-Related Lymphedema.

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    BACKGROUND: It has previously been shown that the lymph drainage rate in both upper limbs is greater in women destined to develop breast cancer-related lymphedema (BCRL) than in those who do not develop BCRL, indicating a constitutive predisposition. We explored constitutive differences further by measuring the maximum lymphatic pump pressure (Ppump) and the rate of (99m)Tc-Nanocoll transport generated by the contractile upper limb lymphatics before and after breast cancer surgery in a group of women who were followed for 2 years to determine their eventual BCRL or non-BCRL status. METHODS AND RESULTS: Ppump and tracer transport rate were measured by lymphatic congestion lymphoscintigraphy in the ipsilateral upper limb in 26 women pre- and post-breast cancer surgery. BCRL occurred in 10/26 (38.5%) cases. Ppump in the women who later developed BCRL (40.0 ± 8.2 mmHg) was 1.7-fold higher than in those who did not develop BCRL (23.1 ± 10.8 mmHg, p = 0.001). Moreover, the rate of lymph tracer transport into the forearm was 2.2-fold greater in the women who later developed BCRL (p = 0.052). Surgery did not significantly reduce Ppump measured 21 weeks postsurgery, but impaired forearm tracer transport in pre-BCRL women by 58% (p = 0.047), although not in those who did not develop BCRL. CONCLUSIONS: Women destined to develop BCRL have higher pumping pressures and lymph transport, indicating harder-working lymphatics before cancer treatment. Axillary lymphatic damage from surgery appears to compromise lymph drainage in those women constitutively predisposed to higher lymphatic pressures and lymph transport
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