M & L Jaargang 13/2

GeneriekGeert Van der Linden Kasseiwegen in de Vlaamse Ardennen, zeldzaam edelgesteente. [Cobbled roads in the Flemish Ardennes, a precious stone.]Rik Vanwalleghem De aantrekkelijkheid van het schaarse. [The attractivity of rare things (annex to: Cobbled roads in the Flemish Ardennes).Winterse toestanden durven wel eens onder de allesverhullende asfaltbekledingen aan hun bestaan herinneren. In de Vlaamse Ardennen behoren kasseiwegen dank zij recente beschermingsmaatregelen daarentegen tot de dagelijkse realiteit, tot grote vreugde overigens van wielersportfanaten.Hoe kinderkoppen en fietsbanden zich intussen tot elkaar verhouden, vertellen ons uit onverdachte hoek landschapsdeskundige Geert Van der Linden en sportredacteur Rik Vanwalleghem.Christina Ceulemans, Daniel De Jonghe en Vera Vereecken Textielvondsten in Limburg. [Discoveries of textile fabrics in Limburg.]Wetenschappelijk onderzoek van Maaslandse reliek-collecties leidden de jongste jaren tot de ontdekking van onvermoede historische textielfragmenten.Bijzonder suggestief zijn hierbij de rijkelijk gestoffeerde reliekschedels uit Tongeren, Sint-Truiden en Herkenrode. De gecoördineerde aanpak door Christina Ceulemans, Daniël De Jonghe en Vera Vereecken opent meteen veelbelovende perspectieven.Marc Mees - Den schoonen constighen eyseren boom. De smeedijzeren boom van Sint-Gummarus uit de Kluizekerk te Lier. [The wrought-iron tree of Saint-Gummarus at the Kluizekerk in Lier.]Toegepast op bomen lijkt het materiaal allesbehalve evident, zelfs in Lier waar Lodewijk Van Boeckel ooit nog de smeedkunst tot zeldzame hoogten tilde.Naar aanleiding van diens restauratie door Aimé Stroobants, wist Marc Mees de Boom van Sint-Gummarus alvast in een vernieuwd daglicht te plaatsen (of is \u27kaarslicht\u27 hier méér op zijn plaats?).Elie Degrande m.m.v. Miek Goossens Gewelfbouw. [Vaulted construction.]Slechts uitzonderlijk kijkt M&L over de landsgrenzen heen. De eenmalige heropbouw van éen volledig kerkgewelf in het Nederlandse Ubbingen, stelde het Brugse Vrij Technisch Instituut nochtans in staat een uitzonderlijke ervaring op te doen.Aan de hand van eigen werkdocumenten, maakt Elie Degrande ons hiervan deelgenoot.SummaryM&L Binnenkran

The mirror crack'd: both pigment and structure contribute to the glossy blue appearance of the mirror orchid, Ophrys speculum.

The Mediterranean orchid genus Ophrys is remarkable for its pseudocopulatory pollination mechanism; naïve male pollinators are attracted to the flowers by olfactory, visual and tactile cues. The most striking visual cue is a highly reflective, blue speculum region at the centre of the labellum, which mimics the corresponding female insect and reaches its strongest development in the mirror orchid, O. speculum. We explored the structure and properties of the much-discussed speculum by scanning and transmission electron microscopic examination of its ultrastructure, visible and ultraviolet (UV) angle-resolved spectrophotometry of the intact tissue, and mass spectrometry of extracted pigments. The speculum contrasts with the surrounding labellar epidermis in being flat-celled with a thick, smooth cuticle. The speculum is extremely glossy, reflecting intense white light in a specular direction, but at more oblique angles it predominantly reflects blue and UV light. Pigments in the speculum, dominantly the cyanidin 3-(3''-malonylglucoside), are less diverse than in the surrounding regions of the labellar epidermis and lack quercetin copigments. Several physical and biochemical processes interact to produce the striking and much-discussed optical effects in these flowers, but the blue colour is not produced by structural means and is not iridescent

Risk factors for childhood overweight: a 30-month longitudinal study of 3- to 6-year-old children

OBJECTIVE: The increasing prevalence of childhood overweight is an important health issue. There is a need for longitudinal research among children in order to identify risk factors for childhood overweight. The objective of the present research was to identify potential sociodemographic and behavioural risk factors for development of childhood overweight among 3- to 6-year-old children. DESIGN: Longitudinal study. SETTING: Sixteen pre-primary and primary schools. SUBJECTS: BMI Z-scores at baseline and two follow-up measurements were calculated for 568 children. Sociodemographic, parental adiposity, familial composition, child's diet, physical activity and sedentary behavioural data were collected through questionnaires. RESULTS: Several risk factors for the development of childhood overweight were found. Being an only child, lower maternal educational level, maternal and paternal overweight, more than 1 h screen time on weekdays and high soft drinks consumption were shown to be positively associated with the development of childhood overweight. CONCLUSIONS: Although behavioural factors are important, our findings support the thesis that interventions on the prevention of childhood overweight should focus on high-risk groups, i.e. children from low socio-economic background or with high parental BMI. Interventions should address the whole family and take into account their lifestyle and structure

Effects of a 2-year healthy eating and physical activity intervention for 3-6-year-olds in communities of high and low socio-economic status: the POP (Prevention of Overweight among Pre-school and school children) project

Objective: The purpose of the present study was to evaluate the effects of a school-based, 2-year, multi-component intervention on BMI, eating and physical activity behaviour in Flanders, Belgium, targeting children aged 3–6 years in communities of high and low socio-economic status (SES). Design: Cluster-randomized controlled trial. Setting: Thirty-one pre-primary and primary schools in three different intervention communities and three paired-matched (on SES profile) control communities in Flanders, Belgium. Subjects: BMI Z-scores at baseline and follow-up were calculated for 1102 children. Questionnaires with sociodemographic data and FFQ were available from 694 of these 1102 children. Results: No significant effects were found on BMI Z-scores for the total sample. However, there was a significant decrease in BMI Z-score of 0?11 in the low-SES intervention community compared with the low-SES control community, where the BMI Z-score increased by 0?04 (F56?26, P50?01). No significant intervention effects could be found for eating behaviour, physical activity or screen-time. There were no significant interaction effects of age and gender of the children on the outcome variables. Conclusions: Although no significant effects were found for BMI Z-scores in the total sample, this intervention had a promising effect in the low-SES community of reducing excess weight gain among young children

Chilean bee diversity: Contrasting patterns of species and phylogenetic turnover along a large‐scale ecological gradient

Abstract Chile's isolation and varied climates have driven the evolution of a unique biodiversity with a high degree of endemism. As a result, Chile encompasses diverse environments, including the Mediterranean‐type ecosystem, a global biodiversity hotspot. These environments are currently threatened by anthropogenic land use change impacting the integrity of local biomes and associated species. This area is the most intensively sampled in the country with high endemicity of native bee species. Characterizing habitat requirements of bees is a pressing priority to safeguard these insects and the ecosystem services they provide. We investigated broadscale patterns of bee (Hymenoptera: Apoidea: Anthophila) diversity using newly accessible expert‐validated datasets comprising digitized specimen records from Chilean and US collections, and novel expert‐validated‐type specimen data for the bees of Chile. We used a generalized dissimilarity modeling (GDM) approach to explore both compositional and phylogenetic β‐diversity patterns across latitudinal, altitudinal, climate, and habitat gradients in well‐sampled bee assemblages in Central Chile. Using the GDM measures of increasing compositional and environmental dissimilarity, we categorized and compared the most important drivers of these patterns and used them to classify “wild bee ecoregions” (WBEs) representing unique assemblages. Turnover of bee assemblages was explained primarily by latitudinal variation (proxy for climate) from south to north in Chile. However, temperature variations, precipitation, and the presence of bare soil also significantly explained turnover in bee assemblages. In comparison, we observed less turnover in phylogenetic biodiversity corresponding to spatial gradients. We identified six de novo ecoregions (WBEs), all with distinct taxa, endemic lineages, and representative species. The WBEs represent distinct spatial classifications but have similarities to existing biogeographical classifications, ecosystems, and bioclimatic zones. This approach establishes the baseline needed to prioritize bee species conservation efforts across this global biodiversity hotspot. We discuss the novelty of this classification considering previous biogeographical characterizations and their relevance in assessing conservation priorities for bee conservation. We argue that Chile's WBEs highlight areas in need of funding for bee species surveys and description, distribution mapping, and strengthening of conservation policies.info:eu-repo/semantics/publishe

Chilean bee diversity: Contrasting patterns of species and phylogenetic turnover along a large‐scale ecological gradient

Abstract Chile's isolation and varied climates have driven the evolution of a unique biodiversity with a high degree of endemism. As a result, Chile encompasses diverse environments, including the Mediterranean‐type ecosystem, a global biodiversity hotspot. These environments are currently threatened by anthropogenic land use change impacting the integrity of local biomes and associated species. This area is the most intensively sampled in the country with high endemicity of native bee species. Characterizing habitat requirements of bees is a pressing priority to safeguard these insects and the ecosystem services they provide. We investigated broadscale patterns of bee (Hymenoptera: Apoidea: Anthophila) diversity using newly accessible expert‐validated datasets comprising digitized specimen records from Chilean and US collections, and novel expert‐validated‐type specimen data for the bees of Chile. We used a generalized dissimilarity modeling (GDM) approach to explore both compositional and phylogenetic β‐diversity patterns across latitudinal, altitudinal, climate, and habitat gradients in well‐sampled bee assemblages in Central Chile. Using the GDM measures of increasing compositional and environmental dissimilarity, we categorized and compared the most important drivers of these patterns and used them to classify “wild bee ecoregions” (WBEs) representing unique assemblages. Turnover of bee assemblages was explained primarily by latitudinal variation (proxy for climate) from south to north in Chile. However, temperature variations, precipitation, and the presence of bare soil also significantly explained turnover in bee assemblages. In comparison, we observed less turnover in phylogenetic biodiversity corresponding to spatial gradients. We identified six de novo ecoregions (WBEs), all with distinct taxa, endemic lineages, and representative species. The WBEs represent distinct spatial classifications but have similarities to existing biogeographical classifications, ecosystems, and bioclimatic zones. This approach establishes the baseline needed to prioritize bee species conservation efforts across this global biodiversity hotspot. We discuss the novelty of this classification considering previous biogeographical characterizations and their relevance in assessing conservation priorities for bee conservation. We argue that Chile's WBEs highlight areas in need of funding for bee species surveys and description, distribution mapping, and strengthening of conservation policies