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Ecological thresholds and large carnivores conservation: Implications for the Amur tiger and leopard in China
The ecological threshold concept describes how changes in one or more factors at thresholds can result in a large shift in the state of an ecosystem. This concept focuses attention on limiting factors that affect the tolerance of systems or organisms and changes in them. Accumulating empirical evidence for the existence of ecological thresholds has created favorable conditions for practical application to wildlife conservation. Applying the concept has the potential to enhance conservation of two large carnivores, Amur tiger and leopard, and the knowledge gained could guide the construction of a proposed national park. In this review, ecological thresholds that result from considering a paradigm of bottom-up control were evaluated for their potential to contribute to the conservation of Amur tiger and leopard. Our review highlights that large carnivores, as top predators, are potentially affected by ecological thresholds arising from changes in climate (or weather), habitat, vegetation, prey, competitors, and anthropogenic disturbances. What's more, interactions between factors and context dependence need to be considered in threshold research and conservation practice, because they may amplify the response of ecosystems or organisms to changes in specific drivers. Application of the threshold concept leads to a more thorough evaluation of conservation needs, and could be used to guide future Amur tiger and leopard research and conservation in China. Such application may inform the conservation of other large carnivores worldwide
Opportunities for weed manipulation using GMHT row crops
The herbicides and cultivation systems available in most non-GM crops allow farmers little flexibility as to when they control weeds. However, glyphosate and glufosinate-ammonium, as used in GM herbicide tolerant crops, offer the opportunity to control large weeds and weed control can be timed according to the agronomic and environmental aims of the user. This paper will use sugar beet as a model crop and report results where different approaches to weed control have been used and discuss their relevance in the wider agricultural and environmental contextNon peer reviewe
Box Drawings for Learning with Imbalanced Data
The vast majority of real world classification problems are imbalanced,
meaning there are far fewer data from the class of interest (the positive
class) than from other classes. We propose two machine learning algorithms to
handle highly imbalanced classification problems. The classifiers constructed
by both methods are created as unions of parallel axis rectangles around the
positive examples, and thus have the benefit of being interpretable. The first
algorithm uses mixed integer programming to optimize a weighted balance between
positive and negative class accuracies. Regularization is introduced to improve
generalization performance. The second method uses an approximation in order to
assist with scalability. Specifically, it follows a \textit{characterize then
discriminate} approach, where the positive class is characterized first by
boxes, and then each box boundary becomes a separate discriminative classifier.
This method has the computational advantages that it can be easily
parallelized, and considers only the relevant regions of feature space
Energy cycle and bound of Qi chaotic system
© 2017 The Qi chaotic system is transformed into a Kolmogorov-type system, thereby facilitating the analysis of energy exchange in its different forms. Regarding four forms of energy, the vector field of this chaotic system is decomposed into four forms of torque: inertial, internal, dissipative, and external. The rate of change of the Casimir function is equal to the exchange power between the dissipative energy and the supplied energy. The exchange power governs the orbital behavior and the cycling of energy. With the rate of change of Casimir function, a general bound and least upper bound of the Qi chaotic attractor are proposed. A detailed analysis with illustrations is conducted to uncover insights, in particular, cycling among the different types of energy for this chaotic attractor and key factors producing the different types of dynamic modes
Competition of different coupling schemes in atomic nuclei
Shell model calculations reveal that the ground and low-lying yrast states of
the nuclei Pd and Cd are mainly built upon isoscalar
spin-aligned neutron-proton pairs each carrying the maximum angular momentum
J=9 allowed by the shell which is dominant in this nuclear region.
This mode of excitation is unique in nuclei and indicates that the spin-aligned
pair has to be considered as an essential building block in nuclear structure
calculations. In this contribution we will discuss this neutron-proton pair
coupling scheme in detail. In particular, we will explore the competition
between the normal monopole pair coupling and the spin-aligned coupling
schemes. Such a coupling may be useful in elucidating the structure properties
of and neighboring nuclei.Comment: 10 pages, 7 figures, 1 table. Proceedings of the Conference on
Advanced Many-Body and Statistical Methods in Mesoscopic Systems, Constanta,
Romania, June 27th - July 2nd 2011. To appear in Journal of Physics:
Conference Serie
Fusing Data with Correlations
Many applications rely on Web data and extraction systems to accomplish
knowledge-driven tasks. Web information is not curated, so many sources provide
inaccurate, or conflicting information. Moreover, extraction systems introduce
additional noise to the data. We wish to automatically distinguish correct data
and erroneous data for creating a cleaner set of integrated data. Previous work
has shown that a na\"ive voting strategy that trusts data provided by the
majority or at least a certain number of sources may not work well in the
presence of copying between the sources. However, correlation between sources
can be much broader than copying: sources may provide data from complementary
domains (\emph{negative correlation}), extractors may focus on different types
of information (\emph{negative correlation}), and extractors may apply common
rules in extraction (\emph{positive correlation, without copying}). In this
paper we present novel techniques modeling correlations between sources and
applying it in truth finding.Comment: Sigmod'201
Transport properties and anisotropy in rare earth doped CaFe2As2 single crystals with Tc above 40 K
In this paper we report the superconductivity above 40 K in the electron
doping single crystal Ca1-xRexFe2As2 (Re = La, Ce, Pr). The x-ray diffraction
patterns indicate high crystalline quality and c-axis orientation. the
resistivity anomaly in the parent compound CaFe2As2 is completely suppressed by
partial replacement of Ca by rare earth and a superconducting transition
reaches as high as 43 K, which is higher than the value in electron doping
FeAs-122 compounds by substituting Fe ions with transition metal, even
surpasses the highest values observed in hole doping systems with a transition
temperature up to 38 K. The upper critical field has been determined with the
magnetic field along ab-plane and c-axis, yielding the anisotropy of 2~3.
Hall-effect measurements indicate that the conduction in this material is
dominated by electron like charge carriers. Our results explicitly demonstrate
the feasibility of inducing superconductivity in Ca122 compounds via electron
doping using aliovalent rare earth substitution into the alkaline earth site,
which should add more ingredients to the underlying physics of the iron-based
superconductors.Comment: 21 pages, 7 figure
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