38 research outputs found

    Farmers’ management of functional biodiversity goes beyond pest management in organic European apple orchards

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    Supporting functional biodiversity (FB), which provides natural pest regulation, is an environmentally sound and promising approach to reduce pesticide use in perennial cultures such as apple, especially in organic farming. However, little is known about farmers’ practices and motivations to implement techniques that favor FB, especially whether or not they really expect anything from FB in terms of pest regulation. In fact, FB-supporting techniques (FB-techniques) are massively questioned by practitioners due to inadequate information about their effectiveness. An interview survey was performed in eight European countries(i) to describe farmers’ practices and identify promising FB-techniques: (ii) to better understand their perceptions of and values associated with FB; and (iii) to identify potential drivers of (non-)adoption. Fifty-five advisors and 125 orchard managers with various degrees of experience and convictions about FB were interviewed and a total of 24 different FB-techniques which can be assigned to three different categories (ecological infrastructures, farming practices and redesign techniques) were described. Some were well-established measures (e.g., hedges and bird houses), while others were more marginal and more recent (e.g., animal introduction and compost). On average, farmers combined more than four techniques that had been implemented over a period of 13 years, especially during their establishment or conversion period. In general, it was difficult for farmers to evaluate the effectiveness of individual FB-techniques on pest regulation. They considered FB-techniques as a whole, targeting multiple species, and valued multiple ecosystem services in addition to pest regulation. The techniques implemented and their associated values differed among farmers who adopted various approaches towards FB. Three different approaches were defined: passive, active and integrated. Their appraisal of FB is even more complex because it may change with time and experience. These findings provide empirical evidence that the practical implementation of promising techniques remains a challenge, considering the diversity of situations and evaluation criteria. Increased cooperation between researchers, farmers and advisors should more effectively target research, advisory support and communication to meet farmers’ needs and perceptions

    Norwegian patients and retail chicken meat share cephalosporin-resistant Escherichia coli and IncK/bla<sub>CMY-2</sub> resistance plasmids

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    Objectives In 2012 and 2014 the Norwegian monitoring programme for antimicrobial resistance in the veterinary and food production sectors (NORM-VET) showed that 124 of a total of 406 samples (31%) of Norwegian retail chicken meat were contaminated with extended-spectrum cephalosporin-resistant Escherichia coli. The aim of this study was to compare selected cephalosporin-resistant E. coli from humans and poultry to determine their genetic relatedness based on whole genome sequencing (WGS). Methods Escherichia coli representing three prevalent cephalosporin-resistant multi-locus sequence types (STs) isolated from poultry (n = 17) were selected from the NORM-VET strain collections. All strains carried an IncK plasmid with a blaCMY-2 gene. Clinical E. coli isolates (n = 284) with AmpC-mediated resistance were collected at Norwegian microbiology laboratories from 2010 to 2014. PCR screening showed that 29 of the clinical isolates harboured both IncK and blaCMY-2. All IncK/blaCMY-2-positive isolates were analysed with WGS-based bioinformatics tools. Results Analysis of single nucleotide polymorphisms (SNP) in 2.5 Mbp of shared genome sequences showed close relationship, with fewer than 15 SNP differences between five clinical isolates from urinary tract infections (UTIs) and the ST38 isolates from poultry. Furthermore, all of the 29 clinical isolates harboured IncK/blaCMY-2 plasmid variants highly similar to the IncK/blaCMY-2 plasmid present in the poultry isolates. Conclusions Our results provide support for the hypothesis that clonal transfer of cephalosporin-resistant E. coli from chicken meat to humans may occur, and may cause difficult-to-treat infections. Furthermore, these E. coli can be a source of AmpC-resistance plasmids for opportunistic pathogens in the human microbiota

    Prenatal testosterone does not explain sex differences in spatial ability

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    The most consistent sex differences in cognition are found for spatial ability, in which males, on average, outperform females. Utilizing a twin design, two studies have shown that females with male co-twins perform better than females with female co-twins on a mental rotation task. According to the Twin Testosterone Transfer hypothesis (TTT) this advantage is due to in-uterine transmission of testosterone from males to females. The present study tested the TTT across 14 different spatial ability measures, including mental rotation tasks, in a large sample of 19–21-year-old twins. Males performed significantly better than females on all spatial tasks, with effect sizes ranging from η2 = 0.02 to η2 = 0.16. Females with a male co-twin outperformed females with a female co-twin in two of the tasks. The effect sizes for both differences were negligible (η2 < 0.02). Contrary to the previous studies, our results gave no indication that prenatally transferred testosterone, from a male to a female twin, influences sex differences in spatial ability

    Implementace systémů pro řešení vědeckých úkolů

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    Import 08/08/2008Prezenční545 - Institut ekonomiky a systémů řízeníNeuveden

    Pollinator communities in strawberry crops – variation at multiple spatial scales

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    Predicting potential pollination services of wild bees in crops requires knowledge of their spatial distribution within fields. Field margins can serve as nesting and foraging habitats for wild bees and can be a source of pollinators. Regional differences in pollinator community composition may affect this spill-over of bees. We studied how regional and local differences affect the spatial distribution of wild bee species richness, activity-density and body size in crop fields. We sampled bees both from the field centre and at two different types of semi-natural field margins, grass strips and hedges, in 12 strawberry fields. The fields were distributed over four regions in Northern Europe, representing an almost 1100 km long north-south gradient. Even over this gradient, daytime temperatures during sampling did not differ significantly between regions and did therefore probably not impact bee activity. Bee species richness was higher in field margins compared with field centres independent of field size. However, there was no difference between centre and margin in body-size or activity-density. In contrast, bee activity-density increased towards the southern regions, whereas the mean body size increased towards the north. In conclusion, our study revealed a general pattern across European regions of bee diversity, but not activity-density, declining towards the field interior which suggests that the benefits of functional diversity of pollinators may be difficult to achieve through spill-over effects from margins to crop. We also identified dissimilar regional patterns in bee diversity and activity-density, which should be taken into account in conservation management
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