1,667 research outputs found

    Proximate and ultimate factors in evolutionary thinking on art

    Get PDF
    Art is often described as an evolutionary adaptation, but not enough thought has been given to arguments in support of this claim. This can lead to a variety of explanatory issues, such as unjustly describing artmaking as an adaptation, not recognizing its complex nature, and its potentially even more complex evolutionary trajectory. This paper addresses one subject in particular, which is the conceptual distinction between ultimate and proximate levels of explanation. More specifically, this brief analysis investigates to what extent functional, adaptive explanations and proximate mechanisms might be confused, leading to strong adaptationist claims that may not be in accordance with the available evidence. In this paper, two hypotheses are discussed from this perspective, and it is argued that both of them, upon closer and more extensive analysis, might not stand the adaptationist test

    Over wetenschap en andere duivels

    Get PDF

    Temporal patterns of physical activity and sedentary behavior in 10-14 year-old children on weekdays

    Get PDF
    Background: An important but often ignored aspect of physical activity (PA) and sedentary behavior (SB) is the chronological succession of activities, or temporal pattern. The main purposes of this study were (1) to investigate when certain types of PA and SB compete against each other during the course of the day and (2) compare intensity-and domain-specific activity levels during different day-segments. Methods: The study sample consists of 211 children aged 10-14, recruited from 15 primary and 15 secondary schools. PA was assessed combining the SenseWear Mini Armband (SWM) with an electronic activity diary. The intensity-and domain-specific temporal patterns were plotted and PA differences between different day-segments (i.e., morning, school, early evening and late evening) were examined using repeated-measures ANCOVA models. Results: Physical activity level (PAL) was highest during the early evening (2.51 METSWM) and school hours (2.49 METSWM); the late evening segment was significantly less active (2.21 METSWM) and showed the highest proportion of sedentary time (54 % of total time-use). Throughout the different day-segments, several domains of PA and SB competed with each other. During the critical early-evening segment, screentime (12 % of time-use) and homework (10 %) were dominant compared to activity domains of sports (4 %) and active leisure (3 %). The domain of active travel competed directly with motor travel during the morning (5 % and 6 % respectively) and early-evening segment (both 8 %). Conclusions: Throughout the day, different aspects of PA and SB go in competition with each other, especially during the time period immediately after school. Detailed information on the temporal patterns of PA and SB of children could help health professionals to develop more effective PA interventions and promotion strategies. By making adaptations to the typical day schedule of children (e.g., through the introduction of extra-curricular PA after school hours), their daily activity levels might improve

    Using image-based modelling (SfM-MVS) to produce a 1935 ortho-mosaic of the Ethiopian highlands

    Get PDF
    Approximately 34,000 aerial photographs covering large parts of Ethiopia and dating back to 1935-1941 have been recently recovered. These allow investigating environmental dynamics for a past period that until now is only accessible from terrestrial photographs or narratives. As the archive consists of both oblique and vertical aerial photographs that cover rather small areas, methods of image-based modelling were used to orthorectify the images. In this study, 9 vertical and 18 low oblique aerial photographs were processed as an ortho-mosaic, covering an area of 25 km(2), west of Wukro town in northern Ethiopia. Using 15 control points (derived from Google Earth), a Root Means Square Error of 28.5 m in X 35.4 m in Y were achieved. These values can be viewed as optimal, given the relatively low resolution and poor quality of the imagery, the lack of metadata, the geometric quality of the Google Earth imagery and the recording characteristics. Land use remained largely similar since 1936, with large parts of the land being used as cropland or extensive grazing areas. Most remarkable changes are the strong expansion of the settlements as well as land management improvements. In a larger effort, ortho-mosaics covering large parts of Ethiopia in 1935-1941 will be produced

    Equal access to community interpreting in Flanders: a matter of self-reflective decision making?

    Get PDF
    The central issue tackled by this article revolves around decision-making by public service institutions in respect of the uses and perceived effects of community interpreting and translation in Flanders (Belgium) and/or other resources of language support (such as the use of a lingua franca, soliciting the help of a multilingual co-worker, etc.). The aim of the study was to obtain a clear understanding of processes and participant frameworks of decision-making with regard to language support within these institutions. Consequently, a qualitative survey was set up focusing on three selected geographic regions and, within these regions, on four domains of public service (health, education, public administration and employment assistance). Respondents were both institutional end users and immigrants. The results reveal a lack of national and local organizational policy and explicit procedures in the allocation of language support resources. This lack contributes to inequality in foreign language users’ access to the services of public institutions. It is recommended that a self-reflective framework be introduced for regulating access to a more systematic use of community interpreting alongside other instruments or strategies for bridging language barriers. Such a framework should be tailored to the needs of the institution’s clients and to domain-specific and local needs of the institution. It should also include the relative availability of other adequate instruments for bridging language barriers

    CERTIFICATION REPORT: The certification of the mass fractions of cadmium copper, manganese and nickel in dark chocolate: ERM BD512

    Get PDF
    This report describes the production of ERM-BD512, which is a matrix material certified for the mass fraction of cadmium, copper, manganese and nickel. This material was produced following ISO Guide 34:2009 and is certified in accordance with ISO Guide 35:2006. The CRM was produced from commercially available dark chocolate produced in Peru. About 15 kg of chocolate bars were melted, the melt was homogenised and cast into moulds to produce pellets of about 0.5 g. Between unit-homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006 [ ]. Within-unit homogeneity was quantified to determine the minimum sample intake. The certified mass fraction of Cd was obtained by measurement, using the technique of isotope dilution ICP MS. The mass fractions of Cu, Mn and Ni were obtained by an interlaboratory comparison of laboratories of demonstrated competence and adhering to ISO/IEC 17025:2005. Technically invalid results were removed but no outliers were eliminated on statistical grounds only. Uncertainties of the certified values were calculated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties related to possible inhomogeneity, instability and characterisation. The material is intended for quality control and assessment of method performance. As with any reference material, it can be used for establishing control charts or validation studies. The CRM is available in packages of 6 glass vials, each containing a single pellet of about 0.5 g, which were sealed under an atmosphere of argon. The minimum amount of sample to be used is 250 mg. The CRM was accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium.JRC.F.6-Reference Material

    EURL-FA Control Proficiency test report: Determination of authorised coccidiostats in compound feed

    Get PDF
    The European Union Reference Laboratory for Feed Additives (EURL-FA), hosted by the Joint Research Centre (JRC), a Directorate General of the European Commission, has been mandated by the Directorate General for Health and Food Safety (DG SANTE) to organise a proficiency test (PT) among appointed National Reference Laboratories (NRLs) in the frame of its control activities (according to the Regulation (EC) No 882/2004 [1]). The aim of this PT was to assess the capacity of the NRLs to correctly determine selected authorised coccidiostats added to feed matrices at realistic authorised levels and at cross-contamination levels. Thirty-six European National and Official Control laboratories were invited and twenty-nine laboratories registered to the 2017 PT exercise. Twenty-five of the registered laboratories reported results for the analyses. The test items used in this exercise were produced by the JRC. Purchased commercial poultry compound feed, tested by the EURL-FA Control as being blank for the target analytes, was milled and ground and then spiked with the required coccidiostat standard solution or with the relevant authorised feed additive. The first item was spiked with a standard solution containing monensin, narasin and diclazuril, at cross-contamination level (MAT 1). The second test item (MAT 2) was spiked with an authorised feed additive Maxiban®, containing narasin (narasin AL) and nicarbazin, at additive level. MAT 1 and MAT 2 were subsequently homogenised and distributed in glass bottles. All bottles were labelled ensuring a random number encoding and dispatched to all registered participants on 27 June 2017. Laboratories were informed of the composition of the test material regarding the composition in coccidiostats for MAT 2 and had therefore only to quantify the content. For MAT 1 the laboratories had to screen for the presence of all 11 authorised coccidiostats and to quantify the detected ones. The assigned values (xpt) for the mass content of monensin, diclazuril and narasin in MAT 1 were calculated from the formulation as recommended by the IUPAC harmonized protocol [2]. The uncertainties for the assigned values (u(xpt)) were calculated according to the ISO Guide for the Expression of Uncertainty in Measurement (GUM) [3]. For narasin and nicarbazin in MAT 2, no assigned value was set since the criterion for sufficient homogeneity could not be met. Participants were invited to report their measurement uncertainties. This was done by twenty-three out of twenty-five reporting participants for monensin and narasin, seventeen for diclazuril, and twenty for narasin AL and nicarbazin. Laboratory results were rated using z and ζ (zeta) scores in accordance with ISO 13528:2015 [4]. The relative standard deviation for proficiency assessment (σpt) for each assigned value was calculated using the relevant Horwitz [5] or modified Horwitz equation [6]. The z scores obtained were considered satisfactory if their absolute values were equal to or below 2. The outcome of this PT exercise is mixed; the percentage of satisfactory results reported by the laboratories for MAT 1 is 88%, 80% and 57% for monensin, narasin and diclazuril respectively. For narasin AL and nicarbazin in MAT 2, no scoring was computed but the data reported by the laboratories were examined. In general, there was good agreement among the values of mass content of narasin and nicarbazin reported results. The laboratories also reported qualitative results as regards the presence of one or more of the other authorised coccidiostats. On the whole, the rate of false positive results was of 4% for robenidine, lasalocid, salinomycin and maduramicin; 5% for nicarbazin; 8% for decoquinate; and 0% for all the others. Two laboratories did not quantify diclazuril in MAT 1 while stating a limit of quantification of the method used lower than the assigned value, leading to a false negative rate of 9% for this analyte. One laboratory could not quantify diclazuril in MAT 1 due to the lack of sensitivity of the method used.JRC.F.5-Food and Feed Complianc
    corecore