Promises and potential pitfalls of a ‘cognitive neuroscience of mathematics learning'

The present commentary discusses the papers of the special issue on ‘cognitive neuroscience and mathematics learning' with respect to methodological and theoretical constraints of using neuroscientific methods to study educationally relevant processes associated with mathematics learning. A special focus is laid on the relevance of subject populations, methodological limitations of current neuroimaging methods and theoretical questions concerning the relationship between the well-studied neural correlates of numerical magnitude processing and the less-investigated neural processes underlying higher level mathematical skills, such as algebraic reasonin

Maturity and Decline in Press Markets of Small Countries. The Case of Austria

Digitalisation, changes in consumer behaviour and the repercussions of the Great Recession seriously threaten the traditional business models of print media. The paper at hand contributes a small state perspective on these issues by analysing the daily newspaper market in Austria in its maturity and decline. We provide a comprehensive overview of the developments and current state of the newspaper industry for the period 2000-2016, with a special emphasis on the move to digital. Thus we examine trends in circulation, online reach and revenue structures. In addition, ownership structures are explored, followed by an analysis of media concentration. We address how media policy, including subsidy schemes, have contributed to the status quo of the Austrian media landscape and evaluate how proposed policy changes take digital transition into account. Finally, core company strategies employed by newspaper enterprises are identified.Digitalisation, changes in consumer behaviour and the repercussions of the Great Recession seriously threaten the traditional business models of print media. The paper at hand contributes a small state perspective on these issues by analysing the daily newspaper market in Austria in its maturity and decline. We provide a comprehensive overview of the developments and current state of the newspaper industry for the period 2000-2016, with a special emphasis on the move to digital. Thus we examine trends in circulation, online reach and revenue structures. In addition, ownership structures are explored, followed by an analysis of media concentration. We address how media policy, including subsidy schemes, have contributed to the status quo of the Austrian media landscape and evaluate how proposed policy changes take digital transition into account. Finally, core company strategies employed by newspaper enterprises are identified

Promises and potential pitfalls of a \u27cognitive neuroscience of mathematics learning\u27

The present commentary discusses the papers of the special issue on \u27cognitive neuroscience and mathematics learning\u27 with respect to methodological and theoretical constraints of using neuroscientific methods to study educationally relevant processes associated with mathematics learning. A special focus is laid on the relevance of subject populations, methodological limitations of current neuroimaging methods and theoretical questions concerning the relationship between the well-studied neural correlates of numerical magnitude processing and the less-investigated neural processes underlying higher level mathematical skills, such as algebraic reasoning. © FIZ Karlsruhe 2010

Investigations on life-cycle and host specificity of the Malacosporea (Myxozoa)

Es ist bekannt, dass Parasiten der Klasse Malacosporea (Myxozoa) sowohl Fische als auch Süßwasserbryozoen infizieren, allerdings wurden die meisten Malacosporea bisher nur im Wirbellosenwirt beschrieben. Kenntnisse über Wirtsspektrum, Übertragungsmechanismen und innerartliche Unterschiede in der Empfänglichkeit gegenüber Malacosporea-Erregern sind bislang rar. Daher war es das Ziel dieser Dissertation Biologie und Lebenszyklen einiger Malacosporea-Parasiten intensiver zu untersuchen. Die Übertragung von T. brysalmonae auf Bryozoen war bisher nur mittels infizierter Bachforellen (Salmo trutta) erfolgreich. Daher wurde untersucht, ob neben Bachforellen möglicherweise andere Fischarten geeignete Wirte für T. bryosalmonae darstellen. Es konnte nachgewiesen werden, dass auch Bachsaiblinge (Salvelinus fontinalis) den Parasiten auf Bryozoen übertragen können. Im Gegensatz dazu lösten infizierte Regenbogenforellen (Oncorhynchus mykiss) und Äschen (Thymallus thymallus) keine Infektion bei Letzteren aus. Hechte konnten in diesen Versuchen nicht infiziert werden. Über die Anheftung und die Penetration von Sporen der Malacosporea bei Kontakt mit dem Fischwirt sind nur wenige Details bekannt. Offensichtlich dringen die Sporoplasmen dieser Sporen in die Epithelien des Wirts mittels amöboider Bewegungen ein. Zudem deuten die ultrasturkturellen Untersuchungen darauf hin, dass die Kiemen die Haupteintrittspforte für diesen Parasiten sind. Die Variabilität der Empfänglichkeit von vier Regenbogenforellenstämme und Bachforellen gegenüber T. bryosalmonae wurde mittels quantitativer real-time PCR untersucht. Dabei erwiesen sich Bachforellen als empfänglicher als Regenbogenforellen. In der Anfangsphase des Experiments wiesen zwei der Regenbogenforellenstämme eine geringere Parasitenlast auf als alle anderen Gruppen, allerdings vermehrten sich bei diesen beiden Stämmen die Parasiten schneller, was am letzten Entnahmezeitpunkt letztlich zur Angleichung der relativen Infektionsrate bei allen Stämmen führte. Mittels Immunhistochemie konnten Stadien von T. bryosalmonae in histologischen Schnitten detektiert werden, jedoch war ihre Anzahl gering. Im Gegensatz zu T. bryosalmonae sind die Kenntnisse zu den Lebenszyklen von Buddenbrockia spp. unvollständig und alle bekannten Arten dieser Gattung sind lediglich als Stadien im Bryozoenwirt beschrieben. In der vorliegenden Arbeit konnten bisher unbekannte Infektionen in den Nieren von Karpfen (Cyprinus carpio) und Elritzen (Phoxinus phoxinus) nachgewiesen werden. Der Elritzenparasit konnte als Buddenbrockia plumatellae identifiziert werden, wohingegen es sich bei dem Karpfenparasiten höchst wahrscheinlich um eine unbeschriebene Art handelt. Die Kohabitation von im Labor gezüchteten Bryozoen mit infizierten Karpfen führte nicht zu einem offenen Ausbruch der Infektion. Die Ergebnisse der vorliegenden Arbeit haben in entscheidendem Maße die Kenntnisse über das Wirtsspektrum und die Lebenszyklen von verschiedenen, auch mutmaßlich neuen, Malacosporea-Arten erweitert. Ebenso ergaben sich Hinweise auf Resistenzunterschiede verschiedener Regenbogenforellenstämme gegenüber T. bryosalmonae. Untersuchungen zu Aspekten der Invasion von T. bryosalmonae in den Fisch trugen entscheidend zur weiteren Aufklärung der frühen Infektionsprozesse der Malacosporea bei.The class Malacosporea is the most enigmatic, and probably the basal group of the unique metazoan phylum Myxozoa. They are known to parasitize fish and freshwater bryozoans, but still, most malacosporeans were only described from the invertebrate host. A complete life-cycle is merely known for Tetracapsuloides bryosalmonae, the parasite causing proliferative kidney disease in salmonid fish. Knowledge about host range, transmission mechanisms and intraspecific differences in resistance against malacosporean pathogens remains scarce hitherto. Therefore, the aim of the present thesis was to investigate the biology and the life-cycles of some malacosporean parasites in more detail. Firstly, the necessary culture of freshwater bryozoans to keep the life-cycle of these parasites in the laboratory could be established in the course of this study. Spores obtained from cultured bryozoans infected with malacosporeans thus enabled laboratory transmission experiments. It is well known that most salmonid species are susceptible to T. bryosalmonae-infection, but even in Northern pike (Esox lucius) developmental stages similar to this parasite were described previously. Nevertheless, transmission of this parasite to bryozoans was only achieved with infected brown trout (Salmo trutta). To find out whether other teleosts besides brown trout may also be suitable hosts for T. bryosalmonae, infection experiments with different fish species were conducted in the present study. By cohabitation of T. bryosalmonae-infected fish and laboratory raised bryozoans it was demonstrated that also brook trout (Salvelinus fontinalis) transmitted the disease to bryozoans. In contrast, infected rainbow trout (Oncorhynchus mykiss) and grayling (Thymallus thymallus) did not cause infection of the latter. Peculiarly, pike did not become infected at all in this experiment. For infection of such a wide range of fish species, a general mode of host invasion is necessary. Virtually no details about attachment and penetration of malacosporean spores encountering the fish host were known. To characterize these life-cycle stages ultra-structurally, infection trials and in vitro experiments with T. bryosalmonae actinospores were conducted. In vitro activation experiments, light microscopy and scanning electron microscopy (SEM) showed that sporoplasms of these spores penetrate host epithelia by means of amoeboid movement. Additionally, ultrastructural examinations indicated that the gills are main entry site for this parasite. Upon contact, the spores seemed to impair the gill epithelium to allow the entry of the sporoplasm at these sites. After penetration, the parasite is exposed to the immune system of the host, so the number of stages that enter and the intensity of the host response against the parasite will influence its development and multiplication. This variability in susceptibility was addressed in the present study, as reliable data about intra-specific differences in the response of fish to malacosporean infections was lacking up to this point. Four rainbow trout strains and brown trout were infected with T. bryosalmonae and infection intensity was monitored. According to results from quantitative real-time-PCR analysis, brown trout were more susceptible than rainbow trout. Two rainbow trout strains showed lower relative parasite load than all other groups early during the experiment, but parasites multiplied faster in these strains, resulting in an equal level of relative infection rate for all strains upon final sampling. T. bryosalmonae-stages were found stained by immuno-histochemistry in histological sections although their number was low, unfortunately impeding quantitative evaluation of parasite load. In contrast to T. bryosalmonae, knowledge of life-cycles of Buddenbrockia spp. was incomplete and all known species of this genus were described as stages in bryozoan hosts. In this study, cohabitation challenges with bryozoans containing the peculiar worm-like malaco-sporean stages and fish resulted in novel infections detected in kidneys of common carp (Cyprinus carpio) and minnow (Phoxinus phoxinus). Sequence comparison of 18S rDNA identified the parasite in minnows as Buddenbrockia plumatellae, while the carp infecting malacosporean is very likely a new species. Light and electron-microscopy of kidney samples of infected minnows and carp revealed parasite stages in the kidney tubules. Only single parasite cells were observed in minnow, while in carp, multicellular sporogonic stages were found in sections of kidney tubules. Cohabitation of laboratory raised bryozoans with infected carp did not yield in overt infection. Therefore, the complete life-cycle of this parasite has yet to be established. Phylogenetic analysis of the Buddenbrockia spp. known to date sub-stantiated the split of the B. plumatellae-clade into two lineages, but could not fully clarify the placement of the carp-infecting malacosporean. The results of this thesis fundamentally increased the knowledge on the range of compatible hosts and life-cycles of different, even putatively new, malacosporean species. Also, indi-cations for differential resistance of rainbow trout strains to T. bryosalmonae were found. Investigations on aspects of invasion of fish by T. bryosalmonae spores further clarified the early infection process of malacosporeans

The function of the left angular gyrus in mental arithmetic: Evidence from the associative confusion effect

While the left angular gyrus (lAG) has been repeatedly implicated in mental arithmetic, its precise functional role has not been established. On the one hand, it has been speculated that the lAG is involved in task-specific processes. On the other hand, the observation of relative deactivation during arithmetic has led to the contention that differential lAG activation reflects task-unrelated difficulty effects associated with the default mode network (DMN). Using functional magnetic resonance imaging, we investigated the neural correlates of the associative confusion effect that allowed us to dissociate effects of task difficulty and task-related arithmetic processes on lAG activation. The associative confusion effect is characterized by poorer performance while verifying addition and multiplication equations whose solutions are associated with the other operation (confusion equations: e.g., 9 × 6 = 15 ) compared with solutions unrelated to both operations (non-confusion equations: e.g., 9 × 6 = 52 ). Comparing these two conditions revealed higher activation of the anterior lAG (areas PGa, PFm, and PF) and the left dorsolateral prefrontal cortex for the confusion problems. This effect displayed only slight anatomical overlap with the well-established reverse problem-size effect (small minus large problems) and task-related deactivation in the parietal cortex. The finding of greater lAG activity (less deactivation) in the more difficult task condition is inconsistent with the hypothesis that lAG activation during mental arithmetic reflects task difficulty related modulations of the DMN. Instead, the present findings provide further support for the symbol-referent mapping hypothesis, suggesting that the lAG mediates the automatic mapping of arithmetic problems onto solutions stored in memory. © 2011 Wiley Periodicals, Inc

BU INC's Inktober Zine 2018

The BU Illustration Narrative Collaborative (BU INC), previously known as the Boston University Comic Arts (BUCA), is a student-run organization that brings together comic artists and illustrators of all backgrounds and skill levels. We meet twice weekly to share our work with each other, draw together, and learn together. Our goal is to provide learning and networking opportunities for our members as well as to introduce the world of comics to the Boston University community!This Inktober zine was produced by BU's very own Illustration Narrative Collaborative. The zine consists of over 50 pages of stunning black and white artwork from club members, novice and experienced alike