1,048 research outputs found

    Google Search and the Law on Dominance in the EU:An Assessment of the Compatibility of Current Methodology with Multi-Sided Platforms in Online Search

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    Business platforms that utilise, or are based upon, internet technology are omnipresent in consumers daily lives. Since the dawn of the World Wide Web, the amount of web content has increased greatly. Simultaneously, business interests have sparked, meeting the arisen demand for particular online services. As a consequence, economists have defined a novel market in these sectors, namely that of multi-sided platform markets. To an important extent, these markets experience network effects, which can strengthen a platform operator’s position in relation to competitors. In turn, competition authorities have witnessed various dominant undertakings emerging. The focus of this article is on one particular internet sector, to wit, that of World Wide Web Search, and on one firm in particular, Google Incorporated. It critically analyses how the Google Search algorithms are shaped from a technological perspective, how these are or can be categorised in accordance with the economic theory of multi-sided platform markets, and how these perform under current dominance law analysis in the European Union, more specifically Art. 102 TFEU. To that end, it will also take into account the recent Google Commitments procedure by the European Commission

    Google Search and the Law on Dominance in the EU:An Assessment of the Compatibility of Current Methodology with Multi-Sided Platforms in Online Search

    Get PDF
    Business platforms that utilise, or are based upon, internet technology are omnipresent in consumers daily lives. Since the dawn of the World Wide Web, the amount of web content has increased greatly. Simultaneously, business interests have sparked, meeting the arisen demand for particular online services. As a consequence, economists have defined a novel market in these sectors, namely that of multi-sided platform markets. To an important extent, these markets experience network effects, which can strengthen a platform operator’s position in relation to competitors. In turn, competition authorities have witnessed various dominant undertakings emerging. The focus of this article is on one particular internet sector, to wit, that of World Wide Web Search, and on one firm in particular, Google Incorporated. It critically analyses how the Google Search algorithms are shaped from a technological perspective, how these are or can be categorised in accordance with the economic theory of multi-sided platform markets, and how these perform under current dominance law analysis in the European Union, more specifically Art. 102 TFEU. To that end, it will also take into account the recent Google Commitments procedure by the European Commission

    Beginnings of the Cold War

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    Optimal Population Codes for Space: Grid Cells Outperform Place Cells

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    Rodents use two distinct neuronal coordinate systems to estimate their position: place fields in the hippocampus and grid fields in the entorhinal cortex. Whereas place cells spike at only one particular spatial location, grid cells fire at multiple sites that correspond to the points of an imaginary hexagonal lattice. We study how to best construct place and grid codes, taking the probabilistic nature of neural spiking into account. Which spatial encoding properties of individual neurons confer the highest resolution when decoding the animal’s position from the neuronal population response? A priori, estimating a spatial position from a grid code could be ambiguous, as regular periodic lattices possess translational symmetry. The solution to this problem requires lattices for grid cells with different spacings; the spatial resolution crucially depends on choosing the right ratios of these spacings across the population. We compute the expected error in estimating the position in both the asymptotic limit, using Fisher information, and for low spike counts, using maximum likelihood estimation. Achieving high spatial resolution and covering a large range of space in a grid code leads to a trade-off: the best grid code for spatial resolution is built of nested modules with different spatial periods, one inside the other, whereas maximizing the spatial range requires distinct spatial periods that are pairwisely incommensurate. Optimizing the spatial resolution predicts two grid cell properties that have been experimentally observed. First, short lattice spacings should outnumber long lattice spacings. Second, the grid code should be self-similar across different lattice spacings, so that the grid field always covers a fixed fraction of the lattice period. If these conditions are satisfied and the spatial “tuning curves” for each neuron span the same range of firing rates, then the resolution of the grid code easily exceeds that of the best possible place code with the same number of neurons

    Representation of acoustic communication signals by insect auditory receptor neurons

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    Despite their simple auditory systems, some insect species recognize certain temporal aspects of acoustic stimuli with an acuity equal to that of vertebrates; however, the underlying neural mechanisms and coding schemes are only partially understood. In this study, we analyze the response characteristics of the peripheral auditory system of grasshoppers with special emphasis on the representation of species-specific communication signals. We use both natural calling songs and artificial random stimuli designed to focus on two low-order statistical properties of the songs: their typical time scales and the distribution of their modulation amplitudes. Based on stimulus reconstruction techniques and quantified within an information-theoretic framework, our data show that artificial stimuli with typical time scales of >40 msec can be read from single spike trains with high accuracy. Faster stimulus variations can be reconstructed only for behaviorally relevant amplitude distributions. The highest rates of information transmission (180 bits/sec) and the highest coding efficiencies (40%) are obtained for stimuli that capture both the time scales and amplitude distributions of natural songs. Use of multiple spike trains significantly improves the reconstruction of stimuli that vary on time scales <40 msec or feature amplitude distributions as occur when several grasshopper songs overlap. Signal-to-noise ratios obtained from the reconstructions of natural songs do not exceed those obtained from artificial stimuli with the same low-order statistical properties. We conclude that auditory receptor neurons are optimized to extract both the time scales and the amplitude distribution of natural songs. They are not optimized, however, to extract higher-order statistical properties of the song-specific rhythmic patterns

    Resolution of Nested Neuronal Representations Can Be Exponential in the Number of Neurons

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    Collective computation is typically polynomial in the number of computational elements, such as transistors or neurons, whether one considers the storage capacity of a memory device or the number of floating-point operations per second of a CPU. However, we show here that the capacity of a computational network to resolve real-valued signals of arbitrary dimensions can be exponential in N, even if the individual elements are noisy and unreliable. Nested, modular codes that achieve such high resolutions mirror the properties of grid cells in vertebrates, which underlie spatial navigation

    A rapid method to monitor parasitoid infestations in Drosophila suzukii populations

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    Parasitoide Wespen tragen zur Kon­trol­le von Insektenpopulationen bei und sind daher ein wichtiger Baustein zur biologischen Bekämpfung invasiver Schädlinge. Während der Ausbreitung von invasiven Schädlingen in neue Gebiete folgen ihnen häufig Parasitoide aus ihren Heimatregionen nach. Die Überwachung der einheimischen und der adventiven Parasitoidpopulationen und die Auswertung ihres Erfolgs bei der Reduzierung von Schädlingspopulationen im Freiland ist aufwändig, und beruht meist auf langwierigen Parasitierungs- und Schlupfversuchen. Wir haben eine schnelle und kostengünstige Methode zum Nachweis von Parasitoiden bei der invasiven Kirschessigfliege, Drosophila suzukii, entwickelt. Sie basiert auf dem Amplifizieren der Hymenoptera-spezifischen 28S rRNA Sequenz von DNA oder RNA aus Fliegenpuppen, welche den Nachweis von Parasitoiden bis auf Artniveau ermöglicht.Parasitoid wasps are efficient natural enemies of other insects. They are in focus as an important biological pest management element to control invasive pest species. While spreading into new areas these invasive pests are often followed by their natural parasitoids from their home regions. The monitoring of native and adventive parasitoids, and their success in controlling the pest populations in the field, is cumbersome and relies mainly on hatching experiments. Here, we present a rapid method to detect parasitoid infestations in the invasive agricultural pest Drosophila suzukii. We specifically amplified a hymenopteran 28S rRNA sequence from DNA or RNA extracted from fly pupae. This allowed the determination of parasitoid infestations at the species level

    Control of non-autonomous cell survival and overgrowth and autonomous apoptosis by members of the ESCRT-II complex

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    Die Aufrechterhaltung der Integrität für die Signalübertragung zwischen Zellen ist eine notwendige Voraussetzung für die Homöostase im Organismus. Die Sortierung von Proteinen als Rezeptoren am frühen Endosom spielt dabei eine wichtige Rolle sowohl für die Übertragung des Signals als auch die Inaktivierung des Rezeptors. Regulatorische Veränderungen in diesem Prozess können unter anderem zur Entstehung von Krankheiten wie unter anderem auch der Krebsentwicklung beitragen. In einem genetischen Screen für Suppressoren des proapoptotischen Gens hid in Drosophila haben wir zwei Allele von vps25 identifiziert. Vps25 ist eine Komponente der ESCRT Maschinerie, die für die Sortierung von Proteinen am frühen Endosom benötigt wird. Paradoxerweise wurden vps25 Mosaike als Suppressoren von hid-induzierter Apoptose identifiziert obwohl Zellen, die mutant für vps25 sind, sterben. Wir zeigen jedoch, daß die nichtautonome Erhöhung von Diap1 Protein, einem Apoptoseinhibitor, für die Suppression von hid verantwortlich ist. Darüberhinaus lösen Klone die mutant fuer vps25 sind nichtautonome Proliferation durch eine Störung im Abbau des Notch Rezeptors aus, dessen ektopische Aktivierung zur Stimulation des mitogenen JAK/STAT Signalweges führt. Der apoptotische Phänotyp von mutantem vps25 Gewebe ist das Resultat autonomer Aktivierung von mindestens zwei Zelltod Signalwegen. Sowohl Hid als auch JNK tragen zur Apoptose von vps25 mutanten Zellen bei. Eine Inhibition von Zelltod in vps25 Klonen verursacht starke Überwachstumsphänotypen. Desweiteren ist die Signalübertragung durch den Hippo Signalweg in vps25 Klonen erhöht und hippo Mutanten blockieren Apoptose vollständig in vps25 Klonen. Wir führen auch eine Analyse der anderen ESCRT-II Komponenten vps22 und vps36 durch. Wie im Fall von vps25 zeichnen sich vps22 und vps36 Mutanten durch endosomale Defekte aus, die in erhöhter Notch und JAK/STAT Signalübertragung und automomem Zelltod resultieren. Überraschenderweise haben vps22 Mutanten keine Auswirkung auf nichtautonome apoptotische Resistenz, verursachen aber starkes nichtautonomes Überwachstum. vps36 Mutanten weisen hingegen einen reziproken Phänotyp auf, der sich durch eine Erhöhung der apoptotischen Resistenz auszeichnet, aber kaum nichtautonome Proliferation beeinflusst. Obwohl also vps22, vps25 und vps36 eine innige physikalische Verwandtschaft als ESCRT-II Komponenten teilen, haben sie verschiedenartige genetische Eigenschaften. Zusammenfassend lässt sich sagen, dass die phänotypische Analyse von vps22, vps25 und vps36 Mutanten die Notwendigkeit der Regulation von Rezeptoren durch Sortierung von Proteinen am frühen Endosom hervorhebt, um eine adaequate Gewebshomöostase zu gewährleisten und ein Modell zu einem besseren Verständnis der Mechanismen bereitstellt, die zur Krebsentstehung im Menschen beitragen
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