Why do boys eat less fruit and vegetables than girls?     

Bere E  Brug J  Klepp KI 《Public health nutrition》2008,11(3):321-325

OBJECTIVE: To explore why boys eat less fruit and vegetables (F&V) than girls, using longitudinal data following pupils from the age of 12.5 to 15.5 years, including perceived accessibility, modelling, intention, preferences, self-efficacy and knowledge of recommendations as potential mediators. DESIGN/SETTING/SUBJECTS: A longitudinal study, based on data collected among the control schools within the intervention project 'Fruits and Vegetables Make the Marks'. This sample contains 896 6th and 7th graders from 20 randomly selected elementary schools within two Norwegian counties. Questionnaires were administered in May 2002 and May 2005 (when the participants were in 9th and 10th grade in 18 secondary elementary schools). RESULTS: In single mediation analyses all determinants mediated parts of the gender difference, but only preferences decreased the gender difference to a level below statistical significance. Preferences alone explained 81% of the gender difference. In the multiple mediation analyses, the six mediators together explained 91% of the gender difference, but only preferences and perceived accessibility contributed uniquely to the explanation, with 25% and 10% respectively. CONCLUSIONS: Preference appears as the strongest mediator of the difference in F&V intakes between boys and girls. Further research should explore why girls like F&V more than boys.  相似文献   

Identification of the volatile component(s) causing the characteristic foxy odor in various cultivars of Fritillaria imperialis L. (Liliaceae)     

Helsper JP  Bücking M  Muresan S  Blaas J  Wietsma WA 《Journal of agricultural and food chemistry》2006,54(14):5087-5091

To identify the component(s) causing the foxy odor, characteristic for some Fritillaria imperialis cultivars, the headspace of flower bulbs was analyzed using gas chromatography-olfactometry (GC-O) and GC-mass spectrometry (GC-MS). Six Fritillaria species and cultivars were selected as follows: F. imperialis cv. Premier (very strong foxy odor), F. imperialis cv. Lutea (strong foxy odor), F. imperialis ssp. Inodora (no odor), Fritillaria eduardii (weak mousy odor), Fritillaria raddeana (no odor), and an F1 of F. imperialis Lutea x Inodora (weak foxy odor). Volatiles from these flower bulbs were accumulated on Tenax and injected into the GC by thermodesorption. The majority of the volatiles consisted of low molecular weight aliphatic compounds. GC-O revealed that the foxy odor was caused by a single component, identified as 3-methyl-2-butene-1-thiol on the basis of smell in GC-O analyses (two GC columns), mass spectra, and retention times. Chemical identification was substantiated by GC-O and GC-MS of an authentic standard of 3-methyl-2-butene-1-thiol, prepared by organic synthesis.  相似文献   

Development of a buried bag technique to study biochars incorporated in a compost or composting medium     

Naser Khan  Ian Clark  Nanthi Bolan  Sebastian Meier  Christopher P. Saint  Miguel A. Sánchez-Monedero  Syd Shea  Johannes Lehmann  Rongliang Qiu 《Journal of Soils and Sediments》2017,17(3):656-664

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Biomechanical comparison between pins and polymethylmethacrylate and the SOP locking plate system to stabilize canine lumbosacral fracture‐luxation in flexion and extension          下载免费PDF全文

Johannes J. Nel BVSc  Cor‐Jacques Kat BEng  PhD 《Veterinary surgery : VS》2017,46(6):789-796

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Distribution of root-knot nematode species and their virulence on vegetables in northern temperate agro-ecosystems of the Pakistani-administered territories of Azad Jammu and Kashmir     

Tariq-Khan  Muhammad  Munir  Anjum  Mukhtar  Tariq  Hallmann  Johannes  Heuer  Holger 《植物病害和植物保护杂志》2017,124(3):201-212

Journal of Plant Diseases and Protection - Root-knot nematodes (RKN) are yield devastating plant pathogens. Objective of this study was to investigate the distribution of RKN and their threat to...  相似文献   

Effective monitoring of freshwater fish     

Johannes Radinger  J. Robert Britton  Stephanie M. Carlson  Anne E. Magurran  Juan Diego Alcaraz‐Hernndez  Ana Almodvar  Lluís Benejam  Carlos Fernndez‐Delgado  Graciela G. Nicola  Francisco J. Oliva‐Paterna  Mar Torralva  Emili García‐Berthou 《Fish and Fisheries》2019,20(4):729-747

Freshwater ecosystems constitute only a small fraction of the planet's water resources, yet support much of its diversity, with freshwater fish accounting for more species than birds, mammals, amphibians or reptiles. Fresh waters are, however, particularly vulnerable to anthropogenic impacts, including habitat loss, climate and land use change, pollution and biological invasions. This environmental degradation, combined with unprecedented rates of biodiversity change, highlights the importance of robust and replicable programmes to monitor freshwater fish. Such monitoring programmes can have diverse aims, including confirming the presence of a single species (e.g., early detection of alien species), tracking changes in the abundance of threatened species, or documenting long‐term temporal changes in entire communities. Irrespective of their motivation, monitoring programmes are only fit for purpose if they have clearly articulated aims and collect data that can meet those aims. This review, therefore, highlights the importance of identifying the key aims in monitoring programmes and outlines the different methods of sampling freshwater fish that can be used to meet these aims. We emphasize that investigators must address issues around sampling design, statistical power, species’ detectability, taxonomy and ethics in their monitoring programmes. Additionally, programmes must ensure that high‐quality monitoring data are properly curated and deposited in repositories that will endure. Through fostering improved practice in freshwater fish monitoring, this review aims to help programmes improve understanding of the processes that shape the Earth's freshwater ecosystems and help protect these systems in face of rapid environmental change.  相似文献   

Institutional context and place-based policy: The case of Coventry & Warwickshire     

Johannes Glückler 《Growth and change》2020,51(1):234-255

A key problem of downscaling or transferring policies across regions is embedding these policies into a place for them to unleash the full potential of regional economies. This paper elaborates on the analytical framework of “institutional context” to bridge the gap between rich theorizations and poor empirical capture of institutions in studies of regional development. The institutional context is constituted by three pillars—regulations, organizations, and institutions—as well as by the interrelations between these pillars. Applied to the British region of Coventry and Warwickshire, a qualitative analysis of expert interviews finds institutional patterns of short-termism, moderate levels of social capital and an embryonic relational infrastructure to constrain the place-based strategy for industrial diversification. This regional case illustrates the more general challenge for regional policy in the UK of devising place-based strategies under conditions of continuous rescaling of regional governance and the implementation of a new National Industrial Strategy. In conclusion, the analysis suggests a shift from “nodal” to “linking” policies that support cross-network connections and help grow a regional field for collective action to cross-fertilize knowledge and foster innovation and entrepreneurship in emerging industries.  相似文献   

Investigation of serum survivin in dogs suffering from cancer: a multicenter study     

Annkathrin Estaller  Martin Kessler  Axel Wehrend  Frank Gessler  Johannes Hirschberger  Stephan Neumann 《Journal of veterinary science (Suw?n-si, Korea)》2021,22(6)

BackgroundIn contrast to human medicine, only a small number of serum tumor markers are established in veterinary medicine even though they are a non-invasive diagnostic tool.ObjectivesThis study examined whether survivin could be suitable as a potential canine serum tumor marker.MethodsThis study measured the serum survivin concentrations of dogs with mammary tumors (n = 33), squamous cell carcinoma (n = 9), soft-tissue sarcoma (n = 18) and multicentric lymphoma (n = 22), using a commercially available, competitive immunoassay kit (BlueGene). The serum survivin concentrations were compared with those of a healthy control group (n = 20) and a control group of dogs with non-neoplastic diseases (n = 17).ResultsDogs with malignant tumors had serum survivin concentrations between 15 and 5,906 pg/mL (median, 72 pg/mL), those in the healthy group ranged from 7 to 99 pg/mL (median, 21 pg/mL) and those in the group of dogs suffering from non-neoplastic diseases from 15 to 93 pg/mL (median, 42 pg/mL). The differences in the survivin concentrations between the healthy dogs and dogs with malignant tumors and between the dogs with non-neoplastic diseases and those with malignant tumors were significant (p < 0.001 and p = 0.006, respectively).ConclusionsThe serum survivin concentrations in dogs with malignant tumors, with some exceptions, are higher than in dogs with benign tumors and dogs that do not suffer from a malignancy. Therefore, survivin can provide information on the presence of malignant tumors and be used as a tumor marker in dogs.  相似文献   

    

Johannes Papajoannou 《Forstwissenschaftliches Centralblatt》1936,58(6):194-205

Ohne Zusammenfassung  相似文献   

Temperature and soil moisture change microbial allocation of pesticide-derived carbon     

Johannes Wirsching  Luciana Chavez Rodriguez  Franziska Ditterich  Holger Pagel  Rushan He  Marie Uksa  Christian Zwiener  Ellen Kandeler  Christian Poll 《European Journal of Soil Science》2023,74(5):e13417

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