706 research outputs found
Desingularization in Computational Applications and Experiments
After briefly recalling some computational aspects of blowing up and of
representation of resolution data common to a wide range of desingularization
algorithms (in the general case as well as in special cases like surfaces or
binomial varieties), we shall proceed to computational applications of
resolution of singularities in singularity theory and algebraic geometry, also
touching on relations to algebraic statistics and machine learning. Namely, we
explain how to compute the intersection form and dual graph of resolution for
surfaces, how to determine discrepancies, the log-canoncial threshold and the
topological Zeta-function on the basis of desingularization data. We shall also
briefly see how resolution data comes into play for Bernstein-Sato polynomials,
and we mention some settings in which desingularization algorithms can be used
for computational experiments. The latter is simply an invitation to the
readers to think themselves about experiments using existing software, whenever
it seems suitable for their own work.Comment: notes of a summer school talk; 16 pages; 1 figur
Quantification 2.0? Bibliometric Infrastructures in Academic Evaluation
Due to developments recently termed as ‘audit,’ ‘evaluation,’ or ‘metric society,’ universities have become subject to ratings and rankings and researchers are evaluated according to standardized quantitative indicators such as their publication output and their personal citation scores. Yet, this development is not only based on the rise of new public management and ideas on ‘the return on public or private investment.’ It has also profited from ongoing technological developments. Due to a massive increase in digital publishing corresponding with the growing availability of related data bibliometric infrastructures for evaluating science are continuously becoming more differentiated and elaborate. They allow for new ways of using bibliometric data through various easily applicable tools. Furthermore, they also produce new quantities of data due to new possibilities in following the digital traces of scientific publications. In this article, I discuss this development as quantification 2.0. The rise of digital infrastructures for publishing, indexing, and managing scientific publications has not only made bibliometric data become a valuable source for performance assessment. It has triggered an unprecedented growth in bibliometric data production turning freely accessible data about scientific work into edited databases and producing competition for its users. The production of bibliometric data has thus become decoupled from their application. Bibliometric data have turned into a self-serving end while their providers are constantly seeking for new tools to make use of them.Peer Reviewe
Theoretical Contributions to a sociology of (e)valuation
Valuation and evaluation processes are currently a much discussed topic, in particular, in the sociology of science, in science and technology studies and in economic sociology. Phenomena such as university rankings or credit ratings are addressed in research on classification, categorization, commensuration, standardization, and quantification. However, beyond such discussions about ratings and rankings, the paper argues that valuation and evaluation processes should be furthermore understood as a substantial feature of the social. Valuation as the construction of classificatory systems through the attribution of value to objects, people and practices and evaluation as the enactment of such value-charged classificatory systems fundamentally contribute to the institutionalization of a commonly shared understanding of social reality. Focusing on conflicts about the attribution of value and the appropriateness of evaluation frameworks within everyday situations of decision-making might then help to address questions such as on institutional change
Theories of Valuation - Building Blocks for Conceptualizing Valuation between Practice and Structure
Phenomena of attributing value to objects, practices, and people, and of assessing their value have become a popular subject in sociological research. Classification, among other valuation practices, represents a central topic in these studies. Thus, the sociology of valuation is emerging as a new field that, however, lacks common ground in theorizing about its subject even though preoccupation with valuation has a long-standing history in sociology. Authors such as Durkheim, Simmel, and Dewey have interpreted valuation as more than a specific localizable phenomenon, in that valuation is a constitutive element of the fundament of the social. Discussing classical approaches to valuation and relating them to current sociological work, we identify key concepts within different theoretical approaches that need to be taken into account when theorizing valuation. We suggest five building blocks - valuation practices, value structures, valuation infrastructure, valuation situations, and reflexivity of valuation - theories of valuation need to consider for coming to terms with the multi-faceted empirical studies in the sociology of valuation
Testverfahren zur Wirksamkeitsprüfung von Fraßgiftködern, Repellentien und Monitoringverfahren gegen Schaben, Ameisen und Bettwanzen
The aim of this study was the development and comparison of different testing systems for the efficacy evaluation of insecticides against ants and cockroaches, repellents against ants and bed bugs, and also monitoring systems for the detection of an infestation with cockroaches. Efficacy trials were performed with the bed bug, Cimex lectularius, three different species of cockroaches and two different species of ants. The results obtained will be relevant for the standardisation of testing for the authorisation of biocides as well as for the registration of products according to § 18 of the German Infection Protection Act (Infektionsschutzgesetz). This standardisation shall enable an improved assessment of these products. Bait choice trials were conducted with the cockroach species B. germanica and P. americana with two different formulations containing boric acid. Neither the size of the arena nor the distance between bait and harbourage influenced the outcome of the trials in a significant way. However, the composition of the insect population did have an impact on the trial, as the mortality of 50 % was reached earlier in mixed aged populations (juveniles and adults) than in homogenously juvenile populations for both species, differences between three (B. germanica) and eleven (P. americana) days occurred in choice trials. For B. germanica, mixed populations reached the mortality of 95 % about four days later than juvenile populations. For P. americana, the mortality of 95 % was also reached up to 14 days earlier with mixed populations than with juvenile populations. The efficacy of sticky traps for monitoring purposes as well as a camera system to detect the presence of cockroaches were tested in a simulated-use trial. The different types of sticky traps yielded varying efficacy rates: one of the sticky traps did not catch one single B. germanica, P. americana or B. orientalis cockroach, whereas a different sticky trap caught at least one individual of each species. The sticky traps caught most reliably B. orientalis, with two different trap types reaching capturing rates of 50 % and 90 %. However, for the other two species, capturing rates were lower, and a maximum of only 30 % was reached for B. germanica, for P. americana the capturing rate was lower than 10 %. A comparison of the camera system and the sticky traps showed that the camera system detected even small infestations (testing was performed with three individuals of each species) with a higher reliability than the sticky traps. Results of the bait choice trials with ants (T. melanocephalum and M. pharaonis) showed that one-chamber-systems should be used instead of multi-chamber-systems because of their mobile nesting behaviour. Variations in the distance between bait and nest do not influence significantly the course or outcome of the trial. However, the efficacy of the bait products yielded significantly different results for the time needed to achieve eradication. One of the baits reached an eradication of both ant species, the other did not. The use of multi-chamber-systems with rubber hose connections resulted as not suitable for T. melanocephalum, as this species exhibits a very mobile nesting behaviour and will build nests in any available structure. Trial set-ups taking into account the distance between bait and nest are therefore very difficult to replicate. A novel simulated-use trial for efficacy testing of repellents against ants was developed. The system showed different repellency rates of the tested substances for T. melanocephalum and M. pharaonis in the trial period of 48 h. Its results were compared to the results of a forced-choice test, and differences of the rates of repelled ants caused by the test design were detectable. Furthermore, differences in the repellency rates were found, which could be attributed to the two different ant species. For bed bugs, two systems for testing the efficacy of repellents were compared. One simulated the human host and the other the situation of searching for a hiding place. Results indicated that repelling bed bugs from areas or objects is more easily feasible than repelling them from a human host. The substances DEET and cinnamon oil were found to be suitable as repellents against bed bugs and ants. Traditionally used substances such as baking powder, in contrast, showed little or no repellent effect, depending on the ant species.Es wurden im Rahmen dieser Arbeit verschiedene Testverfahren zur Wirksamkeitsprüfung entwickelt und verglichen. Die Ergebnisse dieser Arbeit können genutzt werden, um in behördlichen Vorgaben, wie z. B. in der Biozidzulassung oder dem IfSG-Listungsverfahren, einheitlichere Standards zu verankern und so eine bessere Bewertung der Produkte zu ermöglichen.
Es konnte mit B. germanica und P. americana und zwei unterschiedlich formulierten Borsäureködern festgestellt werden, dass in Fraßköderprüfungen die Größe der Testarena und zugleich der Abstand zwischen Köder und Versteck keinen signifikanten Unterschied auf den Verlauf und die Ergebnisse der Prüfungen hatte. Die Zusammensetzung der Testpopulation dagegen hatte einen Einfluss auf den Versuchsverlauf. Eine Mortalität von 50 % der Versuchstiere wurde bei beiden Arten in den gemischten Populationen (Juvenile und Adulte) schneller erreicht als in juvenilen Testpopulationen, die Unterschiede lagen zwischen drei (B. germanica) und elf (P. americana) Tagen in den Wahlversuchen. In den Versuchen mit B. germanica erreichten allerdings juvenile Testpopulationen eine Mortalität von 95 % bis zu vier Tage schneller als gemischte Populationen. In Versuchen mit P. americana dagegen erreichten gemischte Testpopulationen eine Mortalität von 95 % bis zu 14 Tage schneller als juvenile Testpopulationen.
In einem simulated use-Test zur Prüfung der Effizienz von Monitoringsystemen für Schaben konnte gezeigt werden, dass verschiedene Klebefallenmodelle unterschiedlich effektiv waren. So gab es eine Klebefalle, die keines der eingesetzten Tiere von B. germanica, P. americana und B. orientalis fing, bei einem anderen Modell wurde von jeder der drei getesteten Schabenarten mindestens ein Tier gefangen. Die Klebefallen detektierten am zuverlässigsten B. orientalis, bei zwei Modellen wurden 50 % und bis über 90 % der eingesetzten Tiere gefangen. Für die beiden anderen Arten dagegen waren sie weniger effektiv, die Fangraten lagen bei B. germanica bei maximal 30 %, von P. americana wurden weniger als 10 % der Tiere gefangen.
Ein Vergleich zwischen dem Kamerasystem zur Schabendetektion und den Klebefallen zeigte, dass das Kamerasystem auch bei kleinen Befällen (im Test drei Tiere einer Schabenart) eine zuverlässige Detektion aller drei Schabenarten ermöglichte.
Für T. melanocephalum und M. pharaonis konnte gezeigt werden, dass für die Durchführung von Wirksamkeitsprüfungen von Fraßködern 1-Kammersysteme gegenüber Mehrkammersystemen zu bevorzugen sind auf Grund des mobilen Nistverhaltens der Ameisen. Die Distanz zwischen Nest und Köder kann in diesen 1-Kammersystemen variieren, ohne dass sich signifikante Unterschiede in der Dauer bis zur Tilgung in der Prüfung ergeben.
Die Wirkung der Köder, die in den Versuchen angewendet wurden, ergab signifikante Unterschiede in der Dauer bis zur Tilgung für beide Arten. Mit einem Köder konnten alle Tiere in den Versuchen getilgt werden, mit dem anderen Köder war dies nicht der Fall.
Ein im Rahmen dieser Arbeit entwickelter simulated use-Test für die Wirksamkeitsprüfung von Repellentien gegen Ameisen zeigte die unterschiedliche Wirkung der verschiedenen Substanzen auf die Ameisenarten innerhalb der Expositionszeit von 48 h. Ein Vergleich des Anteils der repellierten Ameisen mit denen aus einem forced choice-Test zeigte teilweise Unterschiede auf Grund des Testdesigns. Außerdem gab es artspezifische Unterschiede der Wirkung der Substanzen auf T. melanocephalum und M. pharaonis.
Für Bettwanzen wurden zwei Testsysteme zur Wirksamkeitsprüfung von Repellentien miteinander verglichen, dies waren die Simulation eines Wirts sowie die Suche nach einem Versteck. Es zeigte sich, dass die Abwehr von Bettwanzen von Bereichen oder Gegenständen eine realisierbarere Situation darstellt als die Abwehr vor Bettwanzenstichen.
DEET ebenso wie Zimtöl zeigten sich gegen Ameisen und Bettwanzen als stark repellierende Mittel. Hausmittel wie Backpulver gegen Ameisen hatten dagegen je nach Ameisenart nur eine geringe bis gar keine repellierende Wirkung
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