Optimal Pacing for Running 400 m and 800 m Track Races

Physicists seeking to understand complex biological systems often find it rewarding to create simple "toy models" that reproduce system behavior. Here a toy model is used to understand a puzzling phenomenon from the sport of track and field. Races are almost always won, and records set, in 400 m and 800 m running events by people who run the first half of the race faster than the second half, which is not true of shorter races, nor of longer. There is general agreement that performance in the 400 m and 800 m is limited somehow by the amount of anaerobic metabolism that can be tolerated in the working muscles in the legs. A toy model of anaerobic metabolism is presented, from which an optimal pacing strategy is analytically calculated via the Euler-Lagrange equation. This optimal strategy is then modified to account for the fact that the runner starts the race from rest; this modification is shown to result in the best possible outcome by use of an elementary variational technique that supplements what is found in undergraduate textbooks. The toy model reproduces the pacing strategies of elite 400 m and 800 m runners better than existing models do. The toy model also gives some insight into training strategies that improve performance.Comment: 14 pages, 4 figures, submitted to the American Journal of Physic

New biocide active substances:needs and challenges in the EU as viewed by industry

Emerging regulatory initiatives in the EU are driving towards more environmentally safe chemicals, used as such or in a wide range of products and applications. The aim of the regulations is also to foster and support the emergence of new or safer alternatives and to drive innovations thereof. Biocides are chemicals, which are used in a vast and steadily growing number of applications in order to preserve product safety and quality, however, the number of the Active Substances (AS) used in biocides is decreasing in the EU concurrent with the implementation of the Biocidal Product Directive (BPD). Accordingly, the present study attempts to elucidate views of representatives of the biocide industry in order to identify some of the present drivers and challenges of new AS development in the different biocide application areas, with emphasis on the economic feasibility of safer biocide development in the future. Notably, the costs of vertebrate testing are a major factor in development of new AS. Therefore, an evaluation of the costs of such tests and their total proportion of total AS development costs is also discussed. Industry expectations for the implementation of the BPD and impacts thereof are presented.<br

Exploring the Renewal of IT-enabled Resources from a Structural Perspective

Organizations are exposed to ever-increasing dynamic environments, making sustaining the derivation of IT benefits critical. However, researchers have observed that IT benefits are short-lived and have called for studies on how organizations can sustain the derivation of IT benefits, especially in dynamic environments. Research shows that the integration of IT assets and other organizational resources needed to form IT-enabled resources from which organizations derive IT benefits can also constrain the renewal of IT-enabled resources to sustain the derivation of IT benefits. In this study, we draw on relevant theories, published empirical cases, and a primary case study to explore, from a structural perspective, the renewal of IT-enabled resources to sustain the derivation of IT benefits. We find that certain structural properties (i.e., component flexibility, component centrality, and component coupling) emerge during the formation and modification of IT-enabled resources and influence the renewal of IT-enabled resources. We extend Nevo and Wade’s model on the formation of IT-enabled resources with the structural properties and offer eight propositions on how the structural properties and organizational capabilities influence the renewal of IT-enabled resources. We discuss the theoretical and managerial implications and identify areas for future research

Verkostonalyysiä soveltamalla voidaan tutkia kuinka opettajaopiskelijat näkevät yhteydet opetttajantiedon osa-alueiden välillä

In this article we present a new approach to investigating teacher knowledge. The essay data related to Finnish future teachers' (N = 18) perceptions of the "knowledge required for teaching mathematics" were transformed into a network. We classified the knowledge topics using the Mathematical Knowledge for Teaching (MKT) framework and examined the relationships between the issues raised with the aid of network analysis. According to the results, the future teachers see the six MKT domains in a hierarchical sequence. As it is not subject specific, this approach is also applicable in the investigation of teacher knowledge of other subjects. (C) 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Teachers and their Educators - Views on Contents and their Development Needs in Mathematics Teacher Education

Finland has scored well in international assessments (e.g. PISA, TIMSS), and the pressure to attain excellent scores has activated a drive toward even more effective mathematics teacher education. This article presents the results of a qualitative assessment of the mathematics teacher education provided by the University of Eastern Finland. In this study, the views held by practicing teachers (N=101) and teacher educators (N=19) are compared so that the outstanding development needs of mathematics teacher education in terms of their contents can be revealed. The data was gathered via an electronic survey and was mainly analyzed using data-driven methods. In addition, framework provided by Mathematical Knowledge for Teaching (MKT) was used to categorize the respondents’ views regarding the contents of mathematics teacher education and to develop general guidelines for the reform of mathematics teacher education. The results indicate that mathematics teacher education should include pure mathematical content (Common Content Knowledge, CCK) and mathematical content that will have been designed only for future teachers (Specialized Content Knowledge, SCK). Teacher educators and practicing teachers both held the view that the relevance of CCK studies depend on the connections between university and school mathematics. Pedagogical studies should also be reformed because practicing teachers have realized that effective teaching (Knowledge of Content and Teaching, KCT) requires knowledge about learning mathematics (Knowledge of Content and Students, KCS) that is not offered in the current educational system on a sufficiently broad basis. In this study, suggestions for developing mathematics teacher education were mostly connected to four domains of MKT: (CCK, SCK, KCT and KCS). Interestingly those domains are the same domains which has been empirically tested and better conceptualized

ARGUMENTOINTIA PAINOTTAVA LUONNONTIETEEN KOULUOPETUS – KATSAUS TAVOITTEISIIN

Tässä artikkelissa tarkastellaan argumentointia painottavan luonnontieteen kouluopetuksen tavoitteita kansainvälisen tutkimuskirjallisuuden pohjalta. Tarkasteluun valittiin 14 luonnontieteen kouluopetuksen kansainvälistä tutkimusartikkelia, joissa esiintyvät kuvaukset argumentoinnin tavoitteista luokiteltiin niissä esiintyvien teemojen perusteella. Tavoitekuvauksista erottui kolme pääteemaa: koulussa opetettavien luonnontieteiden autenttisuuden lisääminen, oppilaiden ajattelu- ja vuorovaikutustaitojen kehittymisen tukeminen sekä sisältötiedon osaamisen ja luonnontieteellisen sivistyksen syventäminen. Autenttisen kuvan välittäminen luonnontieteistä oppilaille näyttäytyi edellytyksenä muiden oppimistavoitteiden saavuttamiselle. Tavoitteiden tunnistaminen edesauttaa argumentoinnin painottamista suomalaisessa luonnontieteen opetuksessa.Tässä artikkelissa tarkastellaan argumentointia painottavan luonnontieteen kouluopetuksen tavoitteita kansainvälisen tutkimuskirjallisuuden pohjalta. Tarkasteluun valittiin 14 luonnontieteen kouluopetuksen kansainvälistä tutkimusartikkelia, joissa esiintyvät kuvaukset argumentoinnin tavoitteista luokiteltiin niissä esiintyvien teemojen perusteella. Tavoitekuvauksista erottui kolme pääteemaa: koulussa opetettavien luonnontieteiden autenttisuuden lisääminen, oppilaiden ajattelu- ja vuorovaikutustaitojen kehittymisen tukeminen sekä sisältötiedon osaamisen ja luonnontieteellisen sivistyksen syventäminen. Autenttisen kuvan välittäminen luonnontieteistä oppilaille näyttäytyi edellytyksenä muiden oppimistavoitteiden saavuttamiselle. Tavoitteiden tunnistaminen edesauttaa argumentoinnin painottamista suomalaisessa luonnontieteen opetuksessa

Cannabinoid Receptor Type 1 in Parkinson's Disease : A Positron Emission Tomography Study with [F-18]FMPEP-d(2)

Background The endocannabinoid system is a widespread neuromodulatory system affecting several biological functions and processes. High densities of type 1 cannabinoid (CB1) receptors and endocannabinoids are found in basal ganglia, which makes them an interesting target group for drug development in basal ganglia disorders such as Parkinson's disease (PD). Objective The aim of this study was to investigate CB1 receptors in PD with [F-18]FMPEP-d(2) positron emission tomography (PET) and the effect of dopaminergic medication on the [F-18]FMPEP-d(2) binding. Methods The data consisted of 16 subjects with PD and 10 healthy control subjects (HCs). All participants underwent a [F-18]FMPEP-d(2) high-resolution research tomograph PET examination for the quantitative assessment of cerebral binding to CB1 receptors. To investigate the effect of dopaminergic medication on the [F-18]FMPEP-d(2) binding, 15 subjects with PD underwent [F-18]FMPEP-d(2) PET twice, both on and off antiparkinsonian medication. Results [F-18]FMPEP-d(2) distribution volume was significantly lower in the off scan compared with the on scan in basal ganglia, thalamus, hippocampus, and amygdala (P < 0.05). Distribution volume was lower in subjects with PD off than in HCs globally (P < 0.05), but not higher than in HCs in any brain region. Conclusions Subjects with PD have lower CB1 receptor availability compared with HCs. PD medication increases CB1 receptor toward normal levels. (c) 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder SocietyPeer reviewe