22,376 research outputs found
Limnological study of Zealand Pond, White Mountains, New Hampshire
Zealand Pond, New Hampshire, was chosen as the site of a remote lake study. Data were collected between July 18 and August 29,1997. Zealand Pond had a relatively high pH (6.3-6.9) and alkalinity (2.3- 3.1 mg CaCO3 /liter), considering its small size and elevation (752 m). The lake was not thermally stratified, presumably due to its shallow depth and exposure to wind. Zealand Pond had a diverse zooplankton community, with two calanoid copepod species (Hesperodiaptomus wilsonae and Leptodiaptomus ashlandi), two cyclopoid copepods (Mesocyclops edax and Ectocyclops phaleratus), six cladoceran species (Daphnia ambigua, Daphnia pulex, Ceriodaphnia reticulata, Bosmina longirostris, Alona costata, and Polyphemus pediculus), and two rotifer species (Keratella taurocephala and Conochilus sp.). Densities of zooplankton ranged from 57.6 (Hesperodiaptomus) to 0.04 (Alona) animals per liter. Zooplankton species were documented with photographs and key identifying features. Low densities of fish were also present in the lake. Features of Zealand Pond are compared to other high altitude lakes
Computer program simplifies design of rotating components of turbomachinery
Digital computer program performs stress analysis and burst speed calculations on rotating axisymmetric turbomachinery components. The computer printout contains the displacement of each nodal point, the stress at the center of each element, the average tangential stress within the component, and the burst speed
Circumstellar shells, the formation of grains, and radiation transfer
Advances in infrared astronomy during the last decade have firmly established the presence of dust around a large number of cold giant and supergiant stars. To describe the properties of stars and to understand their evolution, it is necessary to know the nature of the giants and their influence on stellar radiation. Two questions are considered: the formation of grains around cold stars and the modification of stellar radiation by the stellar shell
The Tell-Tale “Heart”: Determining “Fair” Use of Unpublished Texts
Copyright laws require that courts consider at least four factors in determining whether a quotation or close paraphrase of another\u27s unpublished work without permission falls under fair use. Several cases involving fairuse are discussed
Cultural differences in complex addition: efficient Chinese versus adaptive Belgians and Canadians
In the present study, the authors tested the effects of working-memory load on math problem solving in 3 different cultures: Flemish-speaking Belgians, English-speaking Canadians, and Chinese-speaking Chinese currently living in Canada. Participants solved complex addition problems (e.g., 58 + 76) in no-load and working-memory load conditions, in which either the central executive or the phonological loop was loaded. The authors used the choice/no-choice method to obtain unbiased measures of strategy selection and strategy efficiency. The Chinese participants were faster than the Belgians, who were faster and more accurate than the Canadians. The Chinese also required fewer working-memory resources than did the Belgians and Canadians. However, the Chinese chose less adaptively from the available strategies than did the Belgians and Canadians. These cultural differences in math problem solving are likely the result of different instructional approaches during elementary school (practice and training in Asian countries vs. exploration and flexibility in non-Asian countries), differences in the number language, and informal cultural norms and standards. The relevance of being adaptive is discussed as well as the implications of the results in regards to the strategy choice and discovery simulation model of strategy selection (J. Shrager & R. S. Siegler, 1998)
Fruit over sunbed : carotenoid skin coloration is found more attractive than melanin coloration
Skin coloration appears to play a pivotal part in facial attractiveness. Skin yellowness contributes to an attractive appearance and is influenced both by dietary carotenoids and by melanin. While both increased carotenoid coloration and increased melanin coloration enhance apparent health in Caucasian faces by increasing skin yellowness, it remains unclear firstly, whether both pigments contribute to attractiveness judgements, secondly, whether one pigment is clearly preferred over the other, and thirdly, whether these effects depend on the sex of the face. Here, in three studies, we examine these questions using controlled facial stimuli transformed to be either high or low in (a) carotenoid coloration, or (b) melanin coloration. We show, firstly, that both increased carotenoid coloration and increased melanin coloration are found attractive compared to lower levels of these pigments. Secondly, we show that carotenoid coloration is consistently preferred over melanin coloration when levels of coloration are matched. In addition, we find an effect of the sex of stimuli with stronger preferences for carotenoids over melanin in female compared to male faces, irrespective of the sex of the observer. These results are interpreted as reflecting preferences for sex-typical skin coloration: men have darker skin than women and high melanisation in male faces may further enhance this masculine trait, thus carotenoid coloration is not less desirable, but melanin coloration is relatively more desirable in males compared to females. Taken together, our findings provide further support for a carotenoid-linked health-signalling system that is highly important in mate choice.PostprintPeer reviewe
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ASSIMILATION OF MARTIAN OZONE
Observations of atmospheric ozone on Mars can be used to develop the representation of trace gas transport, sources and sinks within global circulation models and constrain middle atmosphere wind speeds which are not observed directly. Ozone is also readily destroyed by OH which recycles CO2 to provide global stability of the atmosphere, a process still not fully understood.
To make optimal use of information, observations and model information are combined by the process of data assimilation. Although data assimilation is now commonplace on Earth, it is a fairly new concept for other planetary systems, with Mars the only other current candidate. The satellites currently orbiting Mars, combined with the future planned satellite missions, create a great opportunity for the development of trace gas data assimilation techniques for extraterrestrial planets.
For this project we use the LMD/UK Martian Global Circulation Model. The model uses a UK spectral dynamical core and transport scheme from a collaboration between the Open University and Oxford University along with physical parameterisations [6] primarily developed by the Laboratoire de Météorologie Dynamique and Instituto de Astrofísica de Andalucía. Combined with the LMD photochemical module and the UK Analysis Correction scheme tuned for Mars for assimilation of observations, we can investigate the evolution of ozone throughout a Martian year.
Preliminary results are discussed from investigation of the adjusted model ozone abundance while testing a method of assimilating artificial ozone data. Once refined, the technique will then be used for the assimilation of real observations from the SPICAM and MARCI instruments which provide total ozone column abundance
Combining multiple resolutions into hierarchical representations for kernel-based image classification
Geographic object-based image analysis (GEOBIA) framework has gained
increasing interest recently. Following this popular paradigm, we propose a
novel multiscale classification approach operating on a hierarchical image
representation built from two images at different resolutions. They capture the
same scene with different sensors and are naturally fused together through the
hierarchical representation, where coarser levels are built from a Low Spatial
Resolution (LSR) or Medium Spatial Resolution (MSR) image while finer levels
are generated from a High Spatial Resolution (HSR) or Very High Spatial
Resolution (VHSR) image. Such a representation allows one to benefit from the
context information thanks to the coarser levels, and subregions spatial
arrangement information thanks to the finer levels. Two dedicated structured
kernels are then used to perform machine learning directly on the constructed
hierarchical representation. This strategy overcomes the limits of conventional
GEOBIA classification procedures that can handle only one or very few
pre-selected scales. Experiments run on an urban classification task show that
the proposed approach can highly improve the classification accuracy w.r.t.
conventional approaches working on a single scale.Comment: International Conference on Geographic Object-Based Image Analysis
(GEOBIA 2016), University of Twente in Enschede, The Netherland
Status of the ILC Main Linac BPM R&D
An introduction and the status of R&D activities for a high-resolution,
"cold" beam position monitor (BPM) and the related read-out electronics are
discussed. Two different BPM detector concepts, to be attached to the SC
quadrupole and located inside the ILC cryomodule, are currently under
investigation: A resonant dipole-mode cavity-style BPM pickup, developed at
Fermilab, and a re-entrant resonant coaxial waveguide BPM, designed by
CEA-Saclay. While the 1.5 GHz dipole-mode cavity BPM is still in the R&D phase,
the re-entrant BPM has already passed first beam tests, including its read-out
system. Furthermore, the LAPP group is developing radiation tolerant digital
read-out systems, which are tested at the CLIC test facility (CTF).Comment: LCWS / ILC08 conference contribution, 6 pages, 6 figure
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