Does resemblance really matter? : A commentary on Gerard O'Brien

In this commentary on Gerard O’Brien’s “How does mind matter? —Solving the content causation problem”, I will investigate the notion of representational content presented in the latter. With this notion, O’Brien aims at giving an explanation of how mind matters in physicalist terms. His argumentation is motivated by, and supposedly directed towards, a problem he calls the content causation problem. Regarding this, I am most interested in reconstructing how his account relates to the presuppositions that make this problem so pressing in philosophical enquiry. O’Brien provides a very interesting answer to the question of “why mental content matters”, as motivated by the content causation problem. In particular, I will try to show that by making use of the notion of dispositions, it provides an interesting way of avoiding the presupposition that understanding content causation always requires the reduction of individual relational properties to individual intrinsic properties —probably because it is presupposed that such a reduction is impossible

Urate Lowering Therapy with Febuxostat in Daily Practice—A Multicentre, Open-Label, Prospective Observational Study

Introduction. Febuxostat, a novel xanthine oxidase inhibitor for the treatment of symptomatic hyperuricemia, showed superiority over allopurinol in the reduction of serum uric acid levels in pivotal studies. Whether this holds true the FORTE (febuxostat in the oral urate lowering treatment: effectiveness and safety) study was conducted to evaluate treatment with febuxostat under daily practice conditions. Materials/Methods. The multicentre, open-label, and prospective observational study was conducted in 1,690 German medical practices from 9/2010 to 5/2011. Safety and efficacy data were assessed at baseline and week 4. Results. Data from 5,592 gout patients (72.6% male, mean age 63.7 years) were collected. Under urate lowering treatment with febuxostat mean serum uric acid levels decreased significantly from 8.9±1.9 mg/dL (534.0±114.6 μmol/L) at baseline to 6.2±2.5 mg/dL (372.0±150.0 μmol/L) at week 4. 67% which reached the mean uric acid target (6.1±1.0 mg/dL [366.0±59.4 μmol/L]). Only 43.1% of patients received concomitant flare prophylaxis. A total of 178 adverse events (mostly gout flares) were reported in 152 patients (2.6%). Conclusion. Febuxostat lowers serum uric acid levels effectively in routine clinical practice. Overall, treatment with febuxostat in both available dosages (80 mg/120 mg) was safe and well tolerated

Berufliche Stabilitäts- und Flexibilitätsorientierungen in Ostdeutschland: Ergebnisse eines Forschungspraktikums

Das im folgenden vorgestellte Projekt Stabilitäts- und Flexibilitätsorientierungen in ostdeutschen Lebensverläufen wurde am Institut für Soziologie der Universität Leipzig im Rahmen eines Lehrpraktikums durchgeführt. In dem Projekt wurden berufliche Stabilitäts- und Flexibilitätsorientierungen ostdeutscher Beschäftigter vor dem Hintergrund individueller Ressourcen und Gelegenheitsstrukturen untersucht. Anhand von 68 biographischen Interviews älterer und jüngerer Kohorten sollte gezeigt werden, in welchem Maße individuelle Merkmale sowie familiäre, arbeitsmarktliche, sozialpolitische und betriebliche Gelegenheitsstrukturen die individuellen Handlungsorientierungen beeinflussen. Vor dem Hintergrund der \"Entstandardisierung\" von Lebenslaufmustern und der \"Flexibilisierung\" von Erwerbsverläufen wurde dabei nach den Ursachen und Veränderungen kohortenspezifischer Unterscheidungen berufsbiographischer Entwürfe gefragt.:Vorbemerkung; Stabilität und Flexibilität im Lebensverlauf; Analytisches Modell und methodisches Vorgehen; Ergebnisse; Bewältigungsstrategien – Eine Zusammenfassung; Literatur, Anhan

Information and Discriminability as Measures of Reliability of Sensory Coding

Response variability is a fundamental issue in neural coding because it limits all information processing. The reliability of neuronal coding is quantified by various approaches in different studies. In most cases it is largely unclear to what extent the conclusions depend on the applied reliability measure, making a comparison across studies almost impossible. We demonstrate that different reliability measures can lead to very different conclusions even if applied to the same set of data: in particular, we applied information theoretical measures (Shannon information capacity and Kullback-Leibler divergence) as well as a discrimination measure derived from signal-detection theory to the responses of blowfly photoreceptors which represent a well established model system for sensory information processing. We stimulated the photoreceptors with white noise modulated light intensity fluctuations of different contrasts. Surprisingly, the signal-detection approach leads to a safe discrimination of the photoreceptor response even when the response signal-to-noise ratio (SNR) is well below unity whereas Shannon information capacity and also Kullback-Leibler divergence indicate a very low performance. Applying different measures, can, therefore, lead to very different interpretations concerning the system's coding performance. As a consequence of the lower sensitivity compared to the signal-detection approach, the information theoretical measures overestimate internal noise sources and underestimate the importance of photon shot noise. We stress that none of the used measures and, most likely no other measure alone, allows for an unbiased estimation of a neuron's coding properties. Therefore the applied measure needs to be selected with respect to the scientific question and the analyzed neuron's functional context

Gene Regulation of Intestinal Porcine Epithelial Cells IPEC-J2 Is Dependent on the Site of Deoxynivalenol Toxicological Action

The intestinal epithelial cell layer represents the border between the luminal and systemic side of the gut. The decision between absorption and exclusion of substances is the quintessential function of the gut and varies along the gut axis. Consequently, potentially toxic substances may reach the basolateral domain of the epithelial cell layer via blood stream. The mycotoxin deoxynivalenol (DON) is a Fusarium derived secondary metabolite known to enter the blood stream and displaying a striking toxicity on the basolateral side of polarised epithelial cell layers in vitro. Here we analysed potential mechanisms of apical and basolateral DON toxicity reflected in the gene expression. We used the jejunum-derived, polarised intestinal porcine epithelial cell line IPEC-J2 as an in vitro cell culture model. Luminal and systemic DON challenge of the epithelial cell layer was mimicked by a DON application from the apical or basolateral compartment of membrane inserts for 72 h. We compared the genome-wide gene expression of untreated and DON-treated IPEC-J2 cells with the GeneChip® Porcine Genome Array of Affymetrix. Low basolateral DON (200 ng/mL) application triggered 10 times more gene transcripts in comparison to the corresponding apical application (2539 versus 267) despite the intactness of the challenged cell layer as measured by transepithelial electrical resistance. Analysis of the regulated genes by bioinformatic resource DAVID identified several groups of biochemical pathways modulated by concentration and orientation of DON application. Selected genes representing pathways of the cellular metabolism, information processing and structural design were analysed in detail by quantitative PCR. Our findings clearly show that apical and basolateral challenge of epithelial cell layers trigger different gene response profiles paralleled with a higher susceptibility towards basolateral challenge. The evaluation of toxicological potentials of mycotoxins should take this difference in gene regulation dependent on route of application into account

Does the perception of fairness and standard of care in the health system depend on the field of study? Results of an empirical analysis

Background: The main challenge in the context of health care reforms and priority setting is the establishment and/or maintenance of fairness and standard of care. For the political process and interdisciplinary discussion, the subjective perception of the health care system might even be as important as potential objective criteria. Of special interest are the perceptions of academic disciplines, whose representatives act as decision makers in the health care sector. The aim of this study is to explore and compare the subjective perception of fairness and standard of care in the German health care system among students of medicine, law, economics, philosophy, and religion. Methods: Between October 2011 and January 2012, we asked freshmen and advanced students of the fields mentioned above to participate in a paper and pencil survey. Prior to this, we formulated hypotheses. The data were analysed by micro econometric regression techniques. Results: Data from 1,088 students were included in the study. Medical students, freshmen, and advanced students perceive the standard of care significantly as being better than non-medical students. Differences in the perception of fairness are not significant between the freshmen of the academic disciplines; however, they increase with the number of study terms. Besides the field of study, further variables such as gender and health status have a significant impact on perceptions. Conclusions: Our results show that there are differences in the perception of fairness and standard of care between academic disciplines, which might influence the interdisciplinary discussion on health care reforms and priority setting.Leibniz University Hannover/Wege in die Forschung I

Monitoring the Morphology of M87* in 2009–2017 with the Event Horizon Telescope

The Event Horizon Telescope (EHT) has recently delivered the first resolved images of M87*, the supermassive black hole in the center of the M87 galaxy. These images were produced using 230 GHz observations performed in 2017 April. Additional observations are required to investigate the persistence of the primary image feature—a ring with azimuthal brightness asymmetry—and to quantify the image variability on event horizon scales. To address this need, we analyze M87* data collected with prototype EHT arrays in 2009, 2011, 2012, and 2013. While these observations do not contain enough information to produce images, they are sufficient to constrain simple geometric models. We develop a modeling approach based on the framework utilized for the 2017 EHT data analysis and validate our procedures using synthetic data. Applying the same approach to the observational data sets, we find the M87* morphology in 2009–2017 to be consistent with a persistent asymmetric ring of ~40 μas diameter. The position angle of the peak intensity varies in time. In particular, we find a significant difference between the position angle measured in 2013 and 2017. These variations are in broad agreement with predictions of a subset of general relativistic magnetohydrodynamic simulations. We show that quantifying the variability across multiple observational epochs has the potential to constrain the physical properties of the source, such as the accretion state or the black hole spin

First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole

We present measurements of the properties of the central radio source in M87 using Event Horizon Telescope data obtained during the 2017 campaign. We develop and fit geometric crescent models (asymmetric rings with interior brightness depressions) using two independent sampling algorithms that consider distinct representations of the visibility data. We show that the crescent family of models is statistically preferred over other comparably complex geometric models that we explore. We calibrate the geometric model parameters using general relativistic magnetohydrodynamic (GRMHD) models of the emission region and estimate physical properties of the source. We further fit images generated from GRMHD models directly to the data. We compare the derived emission region and black hole parameters from these analyses with those recovered from reconstructed images. There is a remarkable consistency among all methods and data sets. We find that >50% of the total flux at arcsecond scales comes from near the horizon, and that the emission is dramatically suppressed interior to this region by a factor >10, providing direct evidence of the predicted shadow of a black hole. Across all methods, we measure a crescent diameter of 42 +/- 3 mu as and constrain its fractional width to b

First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole

We present the first Event Horizon Telescope (EHT) images of M87, using observations from April 2017 at 1.3 mm wavelength. These images show a prominent ring with a diameter of similar to 40 mu as, consistent with the size and shape of the lensed photon orbit encircling the "shadow" of a supermassive black hole. The ring is persistent across four observing nights and shows enhanced brightness in the south. To assess the reliability of these results, we implemented a two-stage imaging procedure. In the first stage, four teams, each blind to the others' work, produced images of M87 using both an established method (CLEAN) and a newer technique (regularized maximum likelihood). This stage allowed us to avoid shared human bias and to assess common features among independent reconstructions. In the second stage, we reconstructed synthetic data from a large survey of imaging parameters and then compared the results with the corresponding ground truth images. This stage allowed us to select parameters objectively to use when reconstructing images of M87. Across all tests in both stages, the ring diameter and asymmetry remained stable, insensitive to the choice of imaging technique. We describe the EHT imaging procedures, the primary image features in M87, and the dependence of these features on imaging assumptions