226 research outputs found
Comparative evaluation of insecticide efficacy tests against Drosophila suzukii on grape berries in laboratory, semi-field and field trials
As the period for field trials on grapevine is limited, we designed a laboratory test system to evaluate the effectiveness of selected insecticides against spotted-wing Drosophila (SWD), Drosophila suzukii, on different types of grape berries all year round. Tests were undertaken during winter and early spring with table grapes of different purchased varieties according to their seasonal availability and with wine grapes from experimental field plots in autumn. In preliminary experiments, we defined parameters for a standard laboratory test system for screening the effectiveness of several formulated insecticides in two different experimental set-ups: i) application before confining adults with berries and ii) application after confining adult D. suzukii with berries. These approaches allowed us to determine the contact activity of the products on adult D. suzukii or the impact on the larval development until the emergence of adult flies. The developed test system is suitable for screening substances with diverse types of activity on different grape types. In a second step, we combined laboratory bioassays with field applications in a semi-field persistence study and lastly we installed a randomized field plot in order to compare the effectiveness of selected insecticides in the laboratory and under field conditions. In all cases, the products Karate Zeon and SpinTor proved most efficacious in their contact mortality or as oviposition deterrents, while Mospilan SG and Coragen exhibited a good larvicidal activity. However, important disagreements occurred for the efficacy of currently authorized insecticides among laboratory, semi-field and practical field applications. The transferability of laboratory results into the field is discussed
On the String Consensus Problem and the Manhattan Sequence Consensus Problem
In the Manhattan Sequence Consensus problem (MSC problem) we are given
integer sequences, each of length , and we are to find an integer sequence
of length (called a consensus sequence), such that the maximum
Manhattan distance of from each of the input sequences is minimized. For
binary sequences Manhattan distance coincides with Hamming distance, hence in
this case the string consensus problem (also called string center problem or
closest string problem) is a special case of MSC. Our main result is a
practically efficient -time algorithm solving MSC for sequences.
Practicality of our algorithms has been verified experimentally. It improves
upon the quadratic algorithm by Amir et al.\ (SPIRE 2012) for string consensus
problem for binary strings. Similarly as in Amir's algorithm we use a
column-based framework. We replace the implied general integer linear
programming by its easy special cases, due to combinatorial properties of the
MSC for . We also show that for a general parameter any instance
can be reduced in linear time to a kernel of size , so the problem is
fixed-parameter tractable. Nevertheless, for this is still too large
for any naive solution to be feasible in practice.Comment: accepted to SPIRE 201
Fast branching algorithm for Cluster Vertex Deletion
In the family of clustering problems, we are given a set of objects (vertices
of the graph), together with some observed pairwise similarities (edges). The
goal is to identify clusters of similar objects by slightly modifying the graph
to obtain a cluster graph (disjoint union of cliques). Hueffner et al. [Theory
Comput. Syst. 2010] initiated the parameterized study of Cluster Vertex
Deletion, where the allowed modification is vertex deletion, and presented an
elegant O(2^k * k^9 + n * m)-time fixed-parameter algorithm, parameterized by
the solution size. In our work, we pick up this line of research and present an
O(1.9102^k * (n + m))-time branching algorithm
Parameterizing by the Number of Numbers
The usefulness of parameterized algorithmics has often depended on what
Niedermeier has called, "the art of problem parameterization". In this paper we
introduce and explore a novel but general form of parameterization: the number
of numbers. Several classic numerical problems, such as Subset Sum, Partition,
3-Partition, Numerical 3-Dimensional Matching, and Numerical Matching with
Target Sums, have multisets of integers as input. We initiate the study of
parameterizing these problems by the number of distinct integers in the input.
We rely on an FPT result for ILPF to show that all the above-mentioned problems
are fixed-parameter tractable when parameterized in this way. In various
applied settings, problem inputs often consist in part of multisets of integers
or multisets of weighted objects (such as edges in a graph, or jobs to be
scheduled). Such number-of-numbers parameterized problems often reduce to
subproblems about transition systems of various kinds, parameterized by the
size of the system description. We consider several core problems of this kind
relevant to number-of-numbers parameterization. Our main hardness result
considers the problem: given a non-deterministic Mealy machine M (a finite
state automaton outputting a letter on each transition), an input word x, and a
census requirement c for the output word specifying how many times each letter
of the output alphabet should be written, decide whether there exists a
computation of M reading x that outputs a word y that meets the requirement c.
We show that this problem is hard for W[1]. If the question is whether there
exists an input word x such that a computation of M on x outputs a word that
meets c, the problem becomes fixed-parameter tractable
Neues aus dem Versuchswesen im ökologischen Obst- und Weinbau
Der Sachbereich Ökologischer Anbau des Versuchszentrums Laimburg und die Unità Sperimentazione Agraria e Agricoltura Sostenibile des Agrarinstituts in San Michele all’Adige, Fondazione Edmund Mach, organisierten im August 2012 eine öffentliche Versuchsvorstellung. Dadurch boten wir einmal mehr die Möglichkeit, einem breiten Publikum Einblicke in die aktuellsten Versuchsaktivitäten und -ergebnisse zu geben
Tunable few electron quantum dots in InAs nanowires
Quantum dots realized in InAs are versatile systems to study the effect of
spin-orbit interaction on the spin coherence, as well as the possibility to
manipulate single spins using an electric field. We present transport
measurements on quantum dots realized in InAs nanowires. Lithographically
defined top-gates are used to locally deplete the nanowire and to form
tunneling barriers. By using three gates, we can form either single quantum
dots, or two quantum dots in series along the nanowire. Measurements of the
stability diagrams for both cases show that this method is suitable for
producing high quality quantum dots in InAs.Comment: 8 pages, 4 figure
Axonal excitability does not differ between painful and painless diabetic or chemotherapy-induced distal symmetrical polyneuropathy in a multi-centre observational study
OBJECTIVE: Axonal excitability reflects ion channel function and it is proposed that this may be a biomarker in painful (versus painless) polyneuropathy. Our objective was to investigate the relationship between axonal excitability parameters and chronic neuropathic pain in deeply phenotyped cohorts with diabetic or chemotherapy induced distal symmetrical polyneuropathy. METHODS: 239 participants with diabetic polyneuropathy were recruited from sites in the UK and Denmark, and 39 participants that developed chemotherapy-induced polyneuropathy were recruited from Denmark. Participants were separated into those with probable or definite neuropathic pain and those without neuropathic pain. Axonal excitability of large myelinated fibres was measured with the threshold tracking technique. The stimulus site was the median nerve and the recording sites were the index finger (sensory studies) and abductor pollicis brevis muscle (motor studies). RESULTS: Participants with painless and painful polyneuropathy were well matched across clinical variables. Sensory and motor axonal excitability measures, including recovery cycle, threshold electrotonus, strength duration time constant, and current-threshold relationship, did not show differences between participants with painful and painless diabetic polyneuropathy, while there were only minor changes for chemotherapy-induced polyneuropathy. INTERPRETATION: Axonal excitability did not significantly differ between painful and painless diabetic or chemotherapy induced polyneuropathy in a multi-centre observational study. Threshold tracking assesses the excitability of myelinated axons; the majority of nociceptors are unmyelinated and although there is some overlap of the 'channelome' between these axonal populations, our results suggest that alternative measures such as microneurography are required to understand the relationship between sensory neuron excitability and neuropathic pain. This article is protected by copyright. All rights reserved
Swiftly Computing Center Strings
Hufsky F, Kuchenbecker L, Jahn K, Stoye J, Böcker S. Swiftly Computing Center Strings. BMC Bioinformatics. 2011;12(1): 106
More Than Forty Prominent Economists Urge Supreme Court to Allow EPA to Consider Costs and Consequences of Clean Air Regulations
More than forty prominent economists filed a Friend of the Court brief with the Supreme Court, asking the justices to overturn a lower court ruling that the Environmental Protection Agency (EPA) may not take into account the costs of regulations when setting standards under the Clean Air Act. Calling the lower court ruling "economically unsound," the economists argued that the EPA "should be allowed to consider explicitly the full consequences" of regulatory decisions, including costs, benefits, and any other relevant facts. In their Amici Curiae brief, the economists contended that the "plain aim" of the Clean Air Act "is protecting the public health&quo.t; That aim, they said, "is unlikely to be achieved without, at least, an implicit balancing of benefits and costs." The Supreme Court filing was organized by the American Enterprise Institute-Brookings Joint Center for Regulatory Studies. The bipartisan group of economists signing the brief included three Nobel laureates, seven former chairmen of the President's Council of Economic Advisers, and two former directors of the White House Office of Management and Budget. The case, American Trucking Association v. Carol M. Browner, Administrator of the Environmental Protection Agency , was appealed to the Supreme Court after a Federal Court in Washington D.C. ruled that the EPA was not permitted to consider costs in setting regulatory standards for enforcing the Clean Air Act. "We believe it would be imprudent for the EPA to ignore costs totally, particularly given their magnitude in this case," the economists stated in the brief. "The EPA estimates that those [clean air] standards could cost on the order of $50 billion annually." The brief argued, "Not considering costs makes it difficult to set a defensible standard, especially when there is no threshold below which health risks disappear." Ignoring costs, the economists said, "could lead to a decision to set the standard at zero pollution," which would threaten "the very economic prosperity on which public health primarily depends." The economists declared: "The importance of this issue cannot be overstated. Both direct benefits and costs of environmental, health, and safety regulations are substantial, estimated to be several hundred billion dollars annually." If the Supreme Court overturns the lower court ruling and allows the EPA to consider costs in establishing clear air regulations, the brief argued, it would be "a historic moment in the making of regulatory policy."Environment, Other Topics
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