‘Warrant’ revisited: Integrating mathematics teachers’ pedagogical and epistemological considerations into Toulmin’s model for argumentation

In this paper, we propose an approach to analysing teacher arguments that takes into account field dependence—namely, in Toulmin’s sense, the dependence of warrants deployed in an argument on the field of activity to which the argument relates. Freeman, to circumvent issues that emerge when we attempt to determine the field(s) that an argument relates to, proposed a classification of warrants (a priori, empirical, institutional and evaluative). Our approach to analysing teacher arguments proposes an adaptation of Freeman’s classification that distinguishes between: epistemological and pedagogical a priori warrants, professional and personal empirical warrants, epistemological and curricular institutional warrants, and evaluative warrants. Our proposition emerged from analyses conducted in the course of a written response and interview study that engages secondary mathematics teachers with classroom scenarios from the mathematical areas of analysis and algebra. The scenarios are hypothetical, grounded on seminal learning and teaching issues, and likely to occur in actual practice. To illustrate our proposed approach to analysing teacher arguments here, we draw on the data we collected through the use of one such scenario, the Tangent Task. We demonstrate how teacher arguments, not analysed for their mathematical accuracy only, can be reconsidered, arguably more productively, in the light of other teacher considerations and priorities: pedagogical, curricular, professional and personal

Recent publications from the Alzheimer's Disease Neuroimaging Initiative: Reviewing progress toward improved AD clinical trials

INTRODUCTION: The Alzheimer's Disease Neuroimaging Initiative (ADNI) has continued development and standardization of methodologies for biomarkers and has provided an increased depth and breadth of data available to qualified researchers. This review summarizes the over 400 publications using ADNI data during 2014 and 2015. METHODS: We used standard searches to find publications using ADNI data. RESULTS: (1) Structural and functional changes, including subtle changes to hippocampal shape and texture, atrophy in areas outside of hippocampus, and disruption to functional networks, are detectable in presymptomatic subjects before hippocampal atrophy; (2) In subjects with abnormal β-amyloid deposition (Aβ+), biomarkers become abnormal in the order predicted by the amyloid cascade hypothesis; (3) Cognitive decline is more closely linked to tau than Aβ deposition; (4) Cerebrovascular risk factors may interact with Aβ to increase white-matter (WM) abnormalities which may accelerate Alzheimer's disease (AD) progression in conjunction with tau abnormalities; (5) Different patterns of atrophy are associated with impairment of memory and executive function and may underlie psychiatric symptoms; (6) Structural, functional, and metabolic network connectivities are disrupted as AD progresses. Models of prion-like spreading of Aβ pathology along WM tracts predict known patterns of cortical Aβ deposition and declines in glucose metabolism; (7) New AD risk and protective gene loci have been identified using biologically informed approaches; (8) Cognitively normal and mild cognitive impairment (MCI) subjects are heterogeneous and include groups typified not only by "classic" AD pathology but also by normal biomarkers, accelerated decline, and suspected non-Alzheimer's pathology; (9) Selection of subjects at risk of imminent decline on the basis of one or more pathologies improves the power of clinical trials; (10) Sensitivity of cognitive outcome measures to early changes in cognition has been improved and surrogate outcome measures using longitudinal structural magnetic resonance imaging may further reduce clinical trial cost and duration; (11) Advances in machine learning techniques such as neural networks have improved diagnostic and prognostic accuracy especially in challenges involving MCI subjects; and (12) Network connectivity measures and genetic variants show promise in multimodal classification and some classifiers using single modalities are rivaling multimodal classifiers. DISCUSSION: Taken together, these studies fundamentally deepen our understanding of AD progression and its underlying genetic basis, which in turn informs and improves clinical trial desig

Climate change and freshwater zooplankton: what does it boil down to?

Recently, major advances in the climate–zooplankton interface have been made some of which appeared to receive much attention in a broader audience of ecologists as well. In contrast to the marine realm, however, we still lack a more holistic summary of recent knowledge in freshwater. We discuss climate change-related variation in physical and biological attributes of lakes and running waters, high-order ecological functions, and subsequent alteration in zooplankton abundance, phenology, distribution, body size, community structure, life history parameters, and behavior by focusing on community level responses. The adequacy of large-scale climatic indices in ecology has received considerable support and provided a framework for the interpretation of community and species level responses in freshwater zooplankton. Modeling perspectives deserve particular consideration, since this promising stream of ecology is of particular applicability in climate change research owing to the inherently predictive nature of this field. In the future, ecologists should expand their research on species beyond daphnids, should address questions as to how different intrinsic and extrinsic drivers interact, should move beyond correlative approaches toward more mechanistic explanations, and last but not least, should facilitate transfer of biological data both across space and time

Social network analysis resolves temporal dynamics of male dominance relationships

Social organization is often studied through point estimates of individual association or interaction patterns, which does not account for temporal changes in the course of familiarization processes and the establishment of social dominance. Here, we present new insights on short-term temporal dynamics in social organization of mixed-sex groups that have the potential to affect sexual selection patterns. Using the live-bearing Atlantic molly (Poecilia mexicana), a species with pronounced male size polymorphism, we investigated social network dynamics of mixed sex experimental groups consisting of eight females and three different-sized males over a period of 5 days. Analyzing association-based social networks as well as direct measures of spatial proximity, we found that large males tended to monopolize most females, while excluding small- and medium-bodied males from access to females. This effect, however, emerged only gradually over time, and different-sized males had equal access to females on day 1 as well as day 2, though to a lesser extent. In this highly aggressive species with strong social dominance stratifications, the observed temporal dynamics in male-female association patterns may balance the presumed reproductive skew among differentially competitive male phenotypes when social structures are unstable (i.e., when individual turnover rates are moderate to high). Ultimately, our results point toward context-dependent sexual selection arising from temporal shifts in social organization. © 2014 Springer-Verlag Berlin Heidelberg

Practical guidelines for rigor and reproducibility in preclinical and clinical studies on cardioprotection

The potential for ischemic preconditioning to reduce infarct size was first recognized more than 30 years ago. Despite extension of the concept to ischemic postconditioning and remote ischemic conditioning and literally thousands of experimental studies in various species and models which identified a multitude of signaling steps, so far there is only a single and very recent study, which has unequivocally translated cardioprotection to improved clinical outcome as the primary endpoint in patients. Many potential reasons for this disappointing lack of clinical translation of cardioprotection have been proposed, including lack of rigor and reproducibility in preclinical studies, and poor design and conduct of clinical trials. There is, however, universal agreement that robust preclinical data are a mandatory prerequisite to initiate a meaningful clinical trial. In this context, it is disconcerting that the CAESAR consortium (Consortium for preclinicAl assESsment of cARdioprotective therapies) in a highly standardized multi-center approach of preclinical studies identified only ischemic preconditioning, but not nitrite or sildenafil, when given as adjunct to reperfusion, to reduce infarct size. However, ischemic preconditioning—due to its very nature—can only be used in elective interventions, and not in acute myocardial infarction. Therefore, better strategies to identify robust and reproducible strategies of cardioprotection, which can subsequently be tested in clinical trials must be developed. We refer to the recent guidelines for experimental models of myocardial ischemia and infarction, and aim to provide now practical guidelines to ensure rigor and reproducibility in preclinical and clinical studies on cardioprotection. In line with the above guideline, we define rigor as standardized state-of-the-art design, conduct and reporting of a study, which is then a prerequisite for reproducibility, i.e. replication of results by another laboratory when performing exactly the same experiment

Sustainable development appreciated? The development of a monitor on sustainability consciousness and behaviour

Uit verschillende recente onderzoeken blijkt dat de Nederlandse consument niet warm loopt voor duurzame producten of diensten. Daarnaast laat recent onderzoek zien dat de belangstelling voor duurzame producten of diensten verschilt tussen consumenten. Hoe is dit te verklaren? Om deze vraag te kunnen beantwoorden deden Telos en Motivaction in opdracht van het MNP-RIVM onderzoek naar het duurzaamheidbewustzijn en -gedrag van de Nederlandse bevolking. Er werden drie duurzaamheidsegmenten gevonden, op grond van de waardenpatronen van mensen. Laag duurzamen: zijn sterk gericht op leven in het hier en nu, houden erg van gemak, stellen het eigen belang centraal, zijn hedonistisch en materialistisch ingesteld, zijn niet bezorgd over het milieu. Middelhoog duurzamen: zijn bezorgd over het milieu, willen milieubewust leven, zijn gehecht aan maatschappelijke verantwoordelijkheid van bedrijven, zijn betrokken bij de buurt, voelen zich verantwoordelijk voor de maatschappij. Hoog duurzamen: hebben dezelfde mentaliteit als middelhoog duurzamen en willen daarnaast ook bewust milieuvriendelijk consumeren, meer betalen voor milieuvriendelijke en natuurlijk gefabriceerde producten en zijn tevens betrokken bij de wereldgemeenschap. De duurzaamheidsegmenten zijn vergeleken met de door Motivaction ontwikkelde 'sociale milieus'. Traditionele burgers enerzijds en kosmopolieten/ postmaterialisten anderzijds bleken het meest duurzaam. Bij de eerste gaat het vooral om zorg en behoud van de eigen omgeving, bij de tweede vooral om mondiale betrokkenheid. Men kan met andere woorden vanuit een totaal verschillende waardenorientatie tot duurzaamheid komen. Opvallend was verder dat generaties sterk blijken te verschillen in de mate van duurzaamheid. Jongere generaties vinden duurzame ontwikkeling een stuk minder belangrijk dan ouderen. Dit kan waarschijnlijk deels worden toegeschreven aan de levensfase waarin men zich bevindt, maar er zijn ook aanwijzingen dat duurzaamheid minder goed aansluit bij het waardenpatroon van jongere generaties.From several studies it follows that Dutch consumers are not really interested in buying sustainable products or services. But these studies also conclude that some consumers are more sustainable in their purchasing behaviour than others. In order to explain this difference the Dutch population was divided into three sustainability segments, on the basis of the values people hold. Low sustainable: The people in this segment are fixed upon here and now, appreciate comfort, centre on self-interest, are hedonistic and materialistic, don't worry about the environment. Medium sustainable: Worry about the environment, are trying to live eco-conscious, believe in the social responsibility of trade and industry, are involved in their neighbourhood, feel responsible for society. High sustainable: Hold the same mentality as the medium sustainable segment, but want to consciously consume eco-friendly, want to pay more for eco-friendly products and are involved in world affairs. The sustainability segments were compared to the so-called 'social milieus', developed by Motivaction. Two groups stood out. Traditional citizens on the one hand and cosmopolitans and post materialists on the other appeared to be most sustainable. This implies that individuals with totally different value patterns can be more or less equally sustainable. Traditional citizens are in particular concerned with the care and preservation of their own surroundings, whereas cosmopolitans and post materialists are more involved with global issues. Generations appeared to be remarkably different in their level of sustainability. Younger generations consider sustainable development to be far less important than older ones. Likely, this can be attributed to the phase of life, although some indications point to the fact that sustainability does not match the value pattern of younger generations well.RIV

Sustainable development appreciated? The development of a monitor on sustainability consciousness and behaviour

From several studies it follows that Dutch consumers are not really interested in buying sustainable products or services. But these studies also conclude that some consumers are more sustainable in their purchasing behaviour than others. In order to explain this difference the Dutch population was divided into three sustainability segments, on the basis of the values people hold. Low sustainable: The people in this segment are fixed upon here and now, appreciate comfort, centre on self-interest, are hedonistic and materialistic, don't worry about the environment. Medium sustainable: Worry about the environment, are trying to live eco-conscious, believe in the social responsibility of trade and industry, are involved in their neighbourhood, feel responsible for society. High sustainable: Hold the same mentality as the medium sustainable segment, but want to consciously consume eco-friendly, want to pay more for eco-friendly products and are involved in world affairs. The sustainability segments were compared to the so-called 'social milieus', developed by Motivaction. Two groups stood out. Traditional citizens on the one hand and cosmopolitans and post materialists on the other appeared to be most sustainable. This implies that individuals with totally different value patterns can be more or less equally sustainable. Traditional citizens are in particular concerned with the care and preservation of their own surroundings, whereas cosmopolitans and post materialists are more involved with global issues. Generations appeared to be remarkably different in their level of sustainability. Younger generations consider sustainable development to be far less important than older ones. Likely, this can be attributed to the phase of life, although some indications point to the fact that sustainability does not match the value pattern of younger generations well.Uit verschillende recente onderzoeken blijkt dat de Nederlandse consument niet warm loopt voor duurzame producten of diensten. Daarnaast laat recent onderzoek zien dat de belangstelling voor duurzame producten of diensten verschilt tussen consumenten. Hoe is dit te verklaren? Om deze vraag te kunnen beantwoorden deden Telos en Motivaction in opdracht van het MNP-RIVM onderzoek naar het duurzaamheidbewustzijn en -gedrag van de Nederlandse bevolking. Er werden drie duurzaamheidsegmenten gevonden, op grond van de waardenpatronen van mensen. Laag duurzamen: zijn sterk gericht op leven in het hier en nu, houden erg van gemak, stellen het eigen belang centraal, zijn hedonistisch en materialistisch ingesteld, zijn niet bezorgd over het milieu. Middelhoog duurzamen: zijn bezorgd over het milieu, willen milieubewust leven, zijn gehecht aan maatschappelijke verantwoordelijkheid van bedrijven, zijn betrokken bij de buurt, voelen zich verantwoordelijk voor de maatschappij. Hoog duurzamen: hebben dezelfde mentaliteit als middelhoog duurzamen en willen daarnaast ook bewust milieuvriendelijk consumeren, meer betalen voor milieuvriendelijke en natuurlijk gefabriceerde producten en zijn tevens betrokken bij de wereldgemeenschap. De duurzaamheidsegmenten zijn vergeleken met de door Motivaction ontwikkelde 'sociale milieus'. Traditionele burgers enerzijds en kosmopolieten/ postmaterialisten anderzijds bleken het meest duurzaam. Bij de eerste gaat het vooral om zorg en behoud van de eigen omgeving, bij de tweede vooral om mondiale betrokkenheid. Men kan met andere woorden vanuit een totaal verschillende waardenorientatie tot duurzaamheid komen. Opvallend was verder dat generaties sterk blijken te verschillen in de mate van duurzaamheid. Jongere generaties vinden duurzame ontwikkeling een stuk minder belangrijk dan ouderen. Dit kan waarschijnlijk deels worden toegeschreven aan de levensfase waarin men zich bevindt, maar er zijn ook aanwijzingen dat duurzaamheid minder goed aansluit bij het waardenpatroon van jongere generaties