476 research outputs found
Sequoiadendron giganteum (Cupressaceae) at Lake Fulmor, Riverside County, California
A GPS census made on 19 June 2012 of the Lake Fulmor area, northwestern San Jacinto Mountains, Riverside County, California, revealed seven trees of the Sierra Nevada endemic Sequoiadendron giganteum (Cupressaceae). The trees occur in a 234-meter-long narrow strip along the northwestern side of the lake. The population appears to be naturalizing. The largest tree (45 cm DBH, about 20 m tall), planted in 1980, is reproductively mature. Its six offspring to the northeast and southwest are 3–5 m tall and do not presently bear cones
Naturalization of Sequoiadendron giganteum (Cupressaceae) in Montane Southern California
After the August 1974 fire in the upper Hall Canyon area on the southwestern flank of Black Mountain in the northwestern San Jacinto Mountains, Riverside County, California, the United States Forest Service revegetated the burn in the mixed-conifer forest with the Sierra Nevada endemic Sequoiadendron giganteum (Cupressaceae). On 1 May 2009 a GPS census starting at the head of Hall Canyon revealed both in the canyon and upslope beyond it at least 157 individuals in the vicinity of the Black Mountain Trail, plus an outlier 450 m distant near the summit. This species alien to southern California is regenerating prolifically on Black Mountain, as revealed by multiple age classes, from juveniles (seedlings and saplings) about 20–60 cm tall to young adult trees over 6 m tall, up to about 40 years old, and reproductively mature. The naturalized population (2009) also appears to be spreading from its initial \u27\u27small area\u27\u27 of introduction (1974). Analysis of published print and Internet literature suggests similar post-fire naturalizations of S. giganteum in the San Gabriel and San Bernardino Mountains of Los Angeles and San Bernardino Counties. State and regional floras and checklists for California should acknowledge the naturalization of this species in montane southern California in the San Jacintos and possibly elsewhere
Homogeneous Catalysis with Metal Complexes in a Pharmaceuticals' and Vitamins' Company: Why, What for, and Where to Go?
Homogeneous catalysis with metal complexes is considered a key methodology to become and remain competitive in the manufacture of biologically active molecules and fine chemicals. Opportunities for such methodology will be discussed. Examples of homogeneous catalytic processes developed
at Roche are presented, together with a survey of process R&D activities at Roche in this field with special emphasis on enantioselective hydrogenation reactions
A Resolution Of The Eugenia–Syzygium Controversy (Myrtaceae)
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141151/1/ajb210113.pd
Text Understanding with the Attention Sum Reader Network
Several large cloze-style context-question-answer datasets have been
introduced recently: the CNN and Daily Mail news data and the Children's Book
Test. Thanks to the size of these datasets, the associated text comprehension
task is well suited for deep-learning techniques that currently seem to
outperform all alternative approaches. We present a new, simple model that uses
attention to directly pick the answer from the context as opposed to computing
the answer using a blended representation of words in the document as is usual
in similar models. This makes the model particularly suitable for
question-answering problems where the answer is a single word from the
document. Ensemble of our models sets new state of the art on all evaluated
datasets.Comment: Presented at ACL 201
Variance Reduction in Monte Carlo Counterfactual Regret Minimization (VR-MCCFR) for Extensive Form Games using Baselines
Learning strategies for imperfect information games from samples of
interaction is a challenging problem. A common method for this setting, Monte
Carlo Counterfactual Regret Minimization (MCCFR), can have slow long-term
convergence rates due to high variance. In this paper, we introduce a variance
reduction technique (VR-MCCFR) that applies to any sampling variant of MCCFR.
Using this technique, per-iteration estimated values and updates are
reformulated as a function of sampled values and state-action baselines,
similar to their use in policy gradient reinforcement learning. The new
formulation allows estimates to be bootstrapped from other estimates within the
same episode, propagating the benefits of baselines along the sampled
trajectory; the estimates remain unbiased even when bootstrapping from other
estimates. Finally, we show that given a perfect baseline, the variance of the
value estimates can be reduced to zero. Experimental evaluation shows that
VR-MCCFR brings an order of magnitude speedup, while the empirical variance
decreases by three orders of magnitude. The decreased variance allows for the
first time CFR+ to be used with sampling, increasing the speedup to two orders
of magnitude
John Theodore Buchholz (1888-1951) Studying Conifers in California, Especially Sequoiadendron and Sequoia (Cupressaceae) in 1936
Biographical details are given for John Theodore Buchholz (1888–1951), including his interest in conifers of California and New Caledonia. Buchholz made detailed studies of the vegetative morphology, reproductive morphology, and embryology of Sequoiadendron giganteum and Sequoia sempervirens prior to his 1939 segregation of Sequoiadendron from Sequoia. Buchholz, a professor at the University of Illinois (1929–1951), spent spring and summer of his 1936 sabbatical in California. Description of Buchholz\u27s technique for morphological collections provides valuable information about his itineraries and his herbarium collections of S. giganteum in 1936. Buchholz also spent the summers of 1940, 1942, and 1944 in California collecting Sequoiadendron (1940) and cultivated material of Podocarpus (1942), as well as investigating Pinus (1942, 1944). Information sources included: obituaries and other biographical accounts of Buchholz and his students, labels of his herbarium collections, 55 letters archived at the California Academy of Sciences and the University of Illinois, and Buchholz\u27s extensive bibliography on gymnosperms (57 titles, including those of his student Netta Elizabeth Gray, 1913–1970). Publications with available PDFs allowed systematic searching of relevant dates and text strings
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