10,863 research outputs found

    Effects of Light and Nutrients on Tomato Plant Compensation for Herbivory by \u3ci\u3eManduca Sexta\u3c/i\u3e (Lepidoptera: Sphingidae)

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    This preliminary study examined how two resources (light and nutrients) influence the ability of tomato plants to show growth compensation for defoliation by the tobacco homworm (Manduca sexta). Growth rate and biomass of plants grown under high and low levels of light and nutrients, and exposed to 4 levels of defoliation by Manduca sexta were measured. Nutrients affected plant growth rate much more strongly than did light. Light and nutrients, however, each influenced how herbivory affected plant growth. Defoliation significantly decreased growth rate only under conditions of low light and high nutrients. Biomass, on the other hand. was low under all resource treatments except high levels of both light and nutrients, and defoliation significantly decreased biomass only under high levels of both resources. Thus, plants appeared to compensate for damage. in terms of biomass, only under conditions of either low light and/or low nutrients

    Feeding Patterns and Attachment Ability of \u3ci\u3eAltica Subplicata\u3c/i\u3e (Coleoptera: Chrysomelidae) on Sand-Dune Willow

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    To investigate feeding patterns of a specialist herbivore, Altica subplicata, larvae and adults were caged separately on host plants, Salix cordata, and leaf damage was estimated. Young, relatively more pubescent leaves near the tops of the shoots were consumed more than older leaves. Larvae clearly preferred the young, pubescent leaves and avoided the oldest leaves. Adults showed a stronger preference for the first five young leaves, but amount of consumption did not differ among the older leaves. Attachment ability on smooth and pubescent leaves was examined as a possible factor influencing feeding patterns. Scanning electron microscopy of tarsal adhesive structures and leaf surfaces was conducted to investigate how A. subplicata attaches to its host. Adhesive setae on the tarsi of adults may be effective for attachment on the older, smooth leaves and their tarsal claws are likely used to cling to trichomes of pubescent leaves. Larvae have fleshy adhesive pads for attachment. Laboratory experiments on attachment of larvae and adults to smooth and pubescent leaves under various wind conditions showed that wind caused difficulty in attachment and movement, but leaf pubescence did not affect the number of beetles that fell off leaves. However, larvae fell off more quickly when placed on pubescent leaves. Thus, other factors such as nutritional quality and microclimate provided by trichomes may be responsible for the preference for pubescent leaves exhibited by A. subplicata

    Network Lasso: Clustering and Optimization in Large Graphs

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    Convex optimization is an essential tool for modern data analysis, as it provides a framework to formulate and solve many problems in machine learning and data mining. However, general convex optimization solvers do not scale well, and scalable solvers are often specialized to only work on a narrow class of problems. Therefore, there is a need for simple, scalable algorithms that can solve many common optimization problems. In this paper, we introduce the \emph{network lasso}, a generalization of the group lasso to a network setting that allows for simultaneous clustering and optimization on graphs. We develop an algorithm based on the Alternating Direction Method of Multipliers (ADMM) to solve this problem in a distributed and scalable manner, which allows for guaranteed global convergence even on large graphs. We also examine a non-convex extension of this approach. We then demonstrate that many types of problems can be expressed in our framework. We focus on three in particular - binary classification, predicting housing prices, and event detection in time series data - comparing the network lasso to baseline approaches and showing that it is both a fast and accurate method of solving large optimization problems

    The Exclusionary Rule in the Public School Administrative Disciplinary Proceeding: Answering the Question after New Jersey v. T.L.O.

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    In New Jersey v. TL. 0. the Supreme Court confirmed the fourth amendment rights of students to be free from unreasonable searches and seizures in public schools but declined to address the propriety of any particular recourse for violations of these rights. This Note proposes that the exclusionary rule should apply in public school disciplinary proceedings in which the student\u27s misconduct is chargeable as a crime and the proposed sanction is removal from school f\u27r ten days or more. The Note argues that the Court\u27s recognition of students\u27 constitutional rights as well as the rule\u27s underlying rationales support its application in this context, and recommends guidelines for its implementation

    Sideslip-induced static pressure errors in flight-test measurements

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    During lateral flight-test maneuvers of a V/STOL research aircraft, large errors in static pressure were observed. An investigation of the data showed a strong correlation of the pressure record with variations in sideslip angle. The sensors for both measurements were located on a standard air-data nose boom. An algorithm based on potential flow over a cylinder that was developed to correct the pressure record for sideslip-induced errors is described. In order to properly apply the correction algorithm, it was necessary to estimate and correct the lag error in the pressure system. The method developed for estimating pressure lag is based on the coupling of sideslip activity into the static ports and can be used as a standard flight-test procedure. The estimation procedure is discussed and the corrected static-pressure record for a typical lateral maneuver is presented. It is shown that application of the correction algorithm effectively attenuates sideslip-induced errors

    Evidence for Antiferromagnetic Order in La2−x_{2-x}Cex_{x}CuO4_{4} from Angular Magnetoresistance Measurements

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    We investigated the in-plane angular magnetoresistivity (AMR) of T′% T^{^{\prime}}-phase La2−x_{2-x}Cex_{x}CuO4_{4} (LCCO) thin films (x=0.06−0.15% x=0.06-0.15) fabricated by a pulsed laser deposition technique. The in-plane AMR with H∥ab\mathbf{H}\parallel ab shows a twofold symmetry instead of the fourfold behavior found in other electron-doped cuprates such as Pr2−x% _{2-x}Cex_{x}CuO4_{4} and Nd2−x_{2-x}Cex_{x}CuO4_{4}. The twofold AMR disappears above a certain temperature, TDT_{D}. The TD(x)T_{D}(x) is well above Tc(x)T_{c}(x) for x=0.06x=0.06 (∼110\sim 110 K), and decreases with increasing doping, until it is no longer observed above Tc(x)T_{c}(x) at x=0.15x=0.15. This twofold AMR below TD(x)T_{D}(x) is suggested to originate from an antiferromagnetic or spin density wave order.Comment: to be published in Phys. Rev. B, Vol. 80 (2009

    Similarity Measure Development for Case-Based Reasoning- A Data-driven Approach

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    In this paper, we demonstrate a data-driven methodology for modelling the local similarity measures of various attributes in a dataset. We analyse the spread in the numerical attributes and estimate their distribution using polynomial function to showcase an approach for deriving strong initial value ranges of numerical attributes and use a non-overlapping distribution for categorical attributes such that the entire similarity range [0,1] is utilized. We use an open source dataset for demonstrating modelling and development of the similarity measures and will present a case-based reasoning (CBR) system that can be used to search for the most relevant similar cases
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