31 research outputs found
Insektsinvasion i klimatförÀndringens spÄr
Under evolutionens gÄng har insekter erövrat större delen av jordklotet. De finns i nÀstan alla klimatzoner och biotoper och kan förhÄllandevis snabbt anpassa sig till Àndrade klimatförhÄllanden
Farming practices in Sweden related to feeding milk and colostrum from cows treated with antimicrobials to dairy calves
BACKGROUND: Milk produced by cows in receipt of antimicrobial therapy may contain antimicrobial residues. Such antimicrobial-containing waste milk must be withdrawn from human consumption and is therefore sometimes used as calf feed. Unfortunately, this approach might promote selection of antimicrobial resistant bacteria in the calvesâ intestinal microbiota. The objectives of this study were therefore to obtain an overview of waste milk feeding practices on Swedish dairy farms and to investigate if these practices were associated with certain farm characteristics. A representative group of 457 Swedish dairy farmers participated in a web-based survey with questions about the use of colostrum and milk from cows treated with antimicrobials at dry off or during lactation, respectively, as calf feed. RESULTS: Colostrum (milk from the first milking after calving) and transition milk (milk from the second milking to the fourth day after calving) from cows treated with antimicrobials at dry off was fed to calves on 89% and 85% of the farms in the study, respectively. When antimicrobial therapy was given to cows during lactation, 56% of the farms fed milk that was produced during the course of treatment to calves, whereas milk that was produced during the subsequent withdrawal period was fed to calves on 79% of the farms. Surveyed farmers were less prone to feed such milk if the antimicrobial therapy was due to mastitis than other infections. In Sweden, a majority of antimicrobial treatments during lactation are systemic administration of benzylpenicillin and thus, the bulk of waste milk in Sweden is likely to contain residues of this drug. Feeding waste milk to calves was more common on non-organic farms, and on farms located in Southern Sweden, and was less common on farms with cows housed in cold free stalls barns. CONCLUSIONS: Waste milk that may contain antimicrobial residues is, at least occasionally, used as feed for calves on a majority of surveyed Swedish dairy farms. Future work should focus on the effect of waste milk feeding on the occurrence of antimicrobial resistant bacteria in the calvesâ intestinal microbiota
Etiology and antimicrobial susceptibility of udder pathogens from cases of subclinical mastitis in dairy cows in Sweden
<p>Abstract</p> <p>Background</p> <p>A nationwide survey on the microbial etiology of cases of subclinical mastitis in dairy cows was carried out on dairy farms in Sweden. The aim was to investigate the microbial panorama and the occurrence of antimicrobial resistance. Moreover, differences between newly infected cows and chronically infected cows were investigated.</p> <p>Methods</p> <p>In total, 583 quarter milk samples were collected from 583 dairy cows at 226 dairy farms from February 2008 to February 2009. The quarter milk samples were bacteriological investigated and scored using the California Mastitis Test. Staphylococci were tested for betalactamase production and presence of resistance was evaluated in all specific udder pathogens. Differences between newly infected cows and chronically infected cows were statistically investigated using logistic regression analysis.</p> <p>Results</p> <p>The most common isolates of 590 bacteriological diagnoses were <it>Staphylococcus (S) aureus </it>(19%) and coagulase-negative staphylococci (CNS; 16%) followed by <it>Streptococcus (Str) dysgalactiae </it>(9%), <it>Str. uberis </it>(8%), <it>Escherichia (E.) coli </it>(2.9%), and <it>Streptococcus </it>spp. (1.9%). Samples with no growth or contamination constituted 22% and 18% of the diagnoses, respectively. The distribution of the most commonly isolated bacteria considering only bacteriological positive samples were: <it>S. aureus </it>- 31%, CNS - 27%, <it>Str. dysgalactiae </it>- 15%, <it>Str. uberis </it>- 14%, <it>E. coli </it>- 4.8%, and <it>Streptococcus </it>spp. - 3.1%. There was an increased risk of finding <it>S. aureus, Str. uberis </it>or <it>Str. dysgalactiae </it>in milk samples from chronically infected cows compared to findings in milk samples from newly infected cows. Four percent of the <it>S. aureus </it>isolates and 35% of the CNS isolates were resistant to penicillin G. Overall, resistance to other antimicrobials than penicillin G was uncommon.</p> <p>Conclusions</p> <p><it>Staphylococcus aureus </it>and CNS were the most frequently isolated pathogens and resistance to antimicrobials was rare.</p
Field Attractants for Pachnoda interrupta Selected by Means of GC-EAD and Single Sensillum Screening
The sorghum chafer, Pachnoda interrupta Olivier (Coleoptera: Scarabaeidae: Cetoniinae), is a key pest on sorghum, Sorghum bicolor (L.) Moench (Poaceae), in Ethiopia. At present there is a lack of efficient control methods. Trapping shows promise for reduction of the pest population, but would benefit from the development of attractive lures. To find attractants that could be used for control of P. interrupta, either by mass trapping or by monitoring as part of integrated pest management, we screened headspace collections of sorghum and the highly attractive weed Abutilon figarianum Webb (Malvaceae) for antennal activity using gas chromatograph-coupled electroantennographic detection (GC-EAD). Compounds active in GC-EAD were identified by combined gas chromatography and mass spectrometry (GC-MS). Field trapping suggested that attraction is governed by a few influential compounds, rather than specific odor blends. Synthetic sorghum and abutilon odor blends were attractive, but neither blend outperformed the previously tested attractants eugenol and methyl salicylate, of which the latter also was part of the abutilon blend. The strong influence of single compounds led us to search for novel attractive compounds, and to investigate the role of individual olfactory receptor neurons (ORNs) in the perception of kairomones. We screened the response characteristics of ORNs to 82 putative kairomones in single sensillum recordings (SSR), and found a number of key ligand candidates for specific classes of ORNs. Out of these key ligand candidates, six previously untested compounds were selected for field trapping trials: anethole, benzaldehyde, racemic 2,3-butanediol, isoamyl alcohol, methyl benzoate and methyl octanoate. The compounds were selected on the basis that they activated different classes of ORNs, thus allowing us to test potential kairomones that activate large non-overlapping populations of the peripheral olfactory system, while avoiding redundant multiple activations of the same ORN type. Field trapping results revealed that racemic 2,3-butanediol is a powerful novel attractant for P. interrupta
"Det brÀnns i hjÀrnan" : om elevers upplevelser av att ha befunnit sig i matematiksvÄrigheter under sin grundskoletid
I denna kvalitativa studie har vi genomfört fokusgruppssintervjuer med elever pÄ gymnasieskolans introduktionsprogram (IM) som Ànnu inte nÄtt kunskapskraven för matematik i Är 9. Syftet med studien Àr att fÄ en förstÄelse av hur elever kan uppleva situationen att befinna sig i matematiksvÄrigheter samt deras syn pÄ grundskolans matematikundervisning. Eftersom matematik Àr det Àmne som störst mÀngd elever inte nÄr mÄlen i anser vi att det Àr vÀsentligt att se problematiken ur ett elevperspektiv för att kunna sÀtta in lÀmpliga ÄtgÀrder. Resultaten har analyserats utifrÄn Brosseaus teorier om den didaktiska triangeln och Bronfenbrenners utvecklingsekologiska systemteori. De visar att elevernas negativa uppfattning om matematik till stor del beror pÄ otydliga förklaringar och brist pÄ hjÀlp. Lektionerna upplevdes som enformiga och lÄngtrÄkiga och matematiken som alltför uppdelad i olika fristÄende omrÄden. Dessutom upplevs Àmnet som irrelevant. Resultaten visar pÄ brister som rör den didaktiska triangelns samtliga sidor samt att problem handlar om faktorer pÄ samtliga nivÄer utifrÄn Bronfenbrenners systemteori.
Rapid Construction of a Chloromethyl-Substituted Duocarmycin-like Prodrug
The construction of duocarmycin-like compounds is often associated with lengthy synthetic routes. Presented herein is the development of a short and convenient synthesis of a type of duocarmycin prodrug. The 1,2,3,6-tetrahydropyrrolo[3,2-e]indole-containing core is here constructed from commercially available Boc-5-bromoindole in four steps and 23% overall yield, utilizing a BuchwaldâHartwig amination followed by a sodium hydride-induced regioselective bromination. In addition, protocols for selective mono- and di-halogenations of positions 3 and 4 were also developed, which could be useful for further exploration of this scaffold
NÄgra lÀrares/speciallÀrares kunskap om Alternativ och kompletterande kommunikation (AKK) i grundsÀrskolan : hur anvÀnds AKK för inkludering i skolmiljön?
SammanfattningDenna studie behandlar omrÄdet kommunikation i grundsÀrskolan. Syftet med studien var att ta vara pÄ verksamma lÀrare/speciallÀrares kunskap om och nyttan av Alternativ och Kompletterande Kommunikation (AKK) i grundsÀrskolan samt att undersöka hur de genom anvÀndningen av AKK som verktyg skapar förutsÀttningar för elevers inkludering i skolmiljön. Studien Àr kvalitativ och intervjuer med lÀrare/ speciallÀrare har genomförts för att kunna ta del av deras syn och tankar kring AKK samt betydelsen av AKK för elevernas lÀrande och sociala samvaro. Data analyserades med stöd av Vygotskijs (1934) teorier om sprÄkets betydelse, Molanders (1996) teori om sprÄk och tyst kunskap samt Wetsos (2006) slutsatser om relationen mellan barn och vuxen relaterat till sprÄklig utveckling. Tidigare forskning, nationellt och internationellt, visar att AKK Àr viktigt för elever med kommunikationssvÄrigheter och att det saknas vuxna runt elever som kan modellera (visa vÀgen) och utbilda inom AKK. Studien visar pÄ ett liknande resultat och att det saknas vuxna runt elever som kan utbilda inom AKK. Mer kunskap och fortbildning inom AKK behövs. AKK ses vara ett oerhört viktigt verktyg för att ge elever möjlighet att lÀra och lÀrare att skapa förutsÀttningar för utbyte samt leda insatser för att nÄ inkludering av elever i skolmiljön
NÄgra lÀrares/speciallÀrares kunskap om Alternativ och kompletterande kommunikation (AKK) i grundsÀrskolan : hur anvÀnds AKK för inkludering i skolmiljön?
SammanfattningDenna studie behandlar omrÄdet kommunikation i grundsÀrskolan. Syftet med studien var att ta vara pÄ verksamma lÀrare/speciallÀrares kunskap om och nyttan av Alternativ och Kompletterande Kommunikation (AKK) i grundsÀrskolan samt att undersöka hur de genom anvÀndningen av AKK som verktyg skapar förutsÀttningar för elevers inkludering i skolmiljön. Studien Àr kvalitativ och intervjuer med lÀrare/ speciallÀrare har genomförts för att kunna ta del av deras syn och tankar kring AKK samt betydelsen av AKK för elevernas lÀrande och sociala samvaro. Data analyserades med stöd av Vygotskijs (1934) teorier om sprÄkets betydelse, Molanders (1996) teori om sprÄk och tyst kunskap samt Wetsos (2006) slutsatser om relationen mellan barn och vuxen relaterat till sprÄklig utveckling. Tidigare forskning, nationellt och internationellt, visar att AKK Àr viktigt för elever med kommunikationssvÄrigheter och att det saknas vuxna runt elever som kan modellera (visa vÀgen) och utbilda inom AKK. Studien visar pÄ ett liknande resultat och att det saknas vuxna runt elever som kan utbilda inom AKK. Mer kunskap och fortbildning inom AKK behövs. AKK ses vara ett oerhört viktigt verktyg för att ge elever möjlighet att lÀra och lÀrare att skapa förutsÀttningar för utbyte samt leda insatser för att nÄ inkludering av elever i skolmiljön