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Experimental warming increases herbivory by leaf‐chewing insects in an alpine plant community 下载免费PDF全文
Tone Birkemoe Saskia Bergmann Toril E. Hasle Kari Klanderud 《Ecology and evolution》2016,6(19):6955-6962
Climate warming is predicted to affect species and trophic interactions worldwide, and alpine ecosystems are expected to be especially sensitive to changes. In this study, we used two ongoing climate warming (open‐top chambers) experiments at Finse, southern Norway, to examine whether warming had an effect on herbivory by leaf‐chewing insects in an alpine Dryas heath community. We recorded feeding marks on the most common vascular plant species in warmed and control plots at two experimental sites at different elevations and carried out a brief inventory of insect herbivores. Experimental warming increased herbivory on Dryas octopetala and Bistorta vivipara. Dryas octopetala also experienced increased herbivory at the lower and warmer site, indicating an overall positive effect of warming, whereas B. vivipara experienced an increased herbivory at the colder and higher site indicating a mixed effect of warming. The Lepidoptera Zygaena exulans and Sympistis nigrita were the two most common leaf‐chewing insects in the Dryas heath. Based on the observed patterns of herbivory, the insects life cycles and feeding preferences, we argue that Z. exulans is the most important herbivore on B. vivipara, and S. nigrita the most important herbivore on D. octopetala. We conclude that if the degree of insect herbivory increases in a warmer world, as suggested by this study and others, complex interactions between plants, insects, and site‐specific conditions make it hard to predict overall effects on plant communities. 相似文献
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Gunnar Hasle Gunnar A Bjune Dan Christensson Knut H Røed Anne C Whist Hans P Leinaas 《Acta veterinaria Scandinavica》2010,52(1):55
Background
The incidence of bovine babesiosis, caused by Babesia divergens (Apicomplexa: Piroplasmida) has decreased markedly since the 1930 s, but may re-emerge as a consequence of climate change and changes in legislation and pasturing practices. This is a potentially serious disease, with both economical and animal welfare consequences. Therefore, there is a need to survey the distribution of B. divergens. 相似文献3.
Grethe Rytter Hasle 《Nordic Journal of Botany》1983,3(5):593-608
Examination of type material showed that 8 taxa must be reduced to synonomy with Thalassiosira punctigera (Castr.) comb, nov., an extremely variable species as to size and valve structure. Preliminary experiments indicated a certain relationship between the areola size and the temperature at which clonal cultures had been grown. While previously known from the North Pacific and the South Atlantic Oceans in addition to a single record from the Caribbean Sea it has since 1979 been recorded regularly in the Skagerrak (between Denmark and Norway). 相似文献
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Self-reported height and childhood conditions among 1711 Danish male general workers born between 1923 and 1940 were analysed. No significant associations were found between adult height and father's occupation, growing up with both parents, paternal unemployment, sickness among the parents, parents receiving disability pension, economical problems in childhood, area of residence in childhood, and years at school. The study therefore provides no support for the hypothesis that poor childhood conditions are the cause of low adult height in this socially very homogeneous sample. 相似文献
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Grethe R. Hasle 《欧洲藻类学杂志》2013,48(3):475-480
The diatom Navicula endophytica sp. nov., first observed by Baardseth (1966) in the intercellular substance of receptacles of Ascophyllum nodosum, is described. The species has been encountered neither as an epiphyte on this seaweed nor as a planktonic form. 相似文献
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Examination of original material from the Ehrenberg collection plus clonal cultures from the Gulf of Mexico and net hauls from widely separated stations in the world's oceans confirms that Coscinodiscus eccentricus is correctly placed as Thalassiosira eccentrica (Ehrenb.) Cleve. A closely related species, T. symmetrica, is described, with, the main differences being found in the value processes and distribution patterns. The former species is more abundant in inshore waters; the latter has been found in oceanic waters. Comparisons are drawn between these 2 species, T. mendiolana and Planktoniella sol. 相似文献
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Savitha Kalidas Igor Cestari Severine Monnerat Qiong Li Sandesh Regmi Nicholas Hasle Mehdi Labaied Marilyn Parsons Kenneth Stuart Margaret A. Phillips 《Eukaryotic cell》2014,13(4):504-516
Human African trypanosomiasis (HAT) is an important public health threat in sub-Saharan Africa. Current drugs are unsatisfactory, and new drugs are being sought. Few validated enzyme targets are available to support drug discovery efforts, so our goal was to obtain essentiality data on genes with proven utility as drug targets. Aminoacyl-tRNA synthetases (aaRSs) are known drug targets for bacterial and fungal pathogens and are required for protein synthesis. Here we survey the essentiality of eight Trypanosoma brucei aaRSs by RNA interference (RNAi) gene expression knockdown, covering an enzyme from each major aaRS class: valyl-tRNA synthetase (ValRS) (class Ia), tryptophanyl-tRNA synthetase (TrpRS-1) (class Ib), arginyl-tRNA synthetase (ArgRS) (class Ic), glutamyl-tRNA synthetase (GluRS) (class 1c), threonyl-tRNA synthetase (ThrRS) (class IIa), asparaginyl-tRNA synthetase (AsnRS) (class IIb), and phenylalanyl-tRNA synthetase (α and β) (PheRS) (class IIc). Knockdown of mRNA encoding these enzymes in T. brucei mammalian stage parasites showed that all were essential for parasite growth and survival in vitro. The reduced expression resulted in growth, morphological, cell cycle, and DNA content abnormalities. ThrRS was characterized in greater detail, showing that the purified recombinant enzyme displayed ThrRS activity and that the protein localized to both the cytosol and mitochondrion. Borrelidin, a known inhibitor of ThrRS, was an inhibitor of T. brucei ThrRS and showed antitrypanosomal activity. The data show that aaRSs are essential for T. brucei survival and are likely to be excellent targets for drug discovery efforts. 相似文献
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E Paniagua-Crespo D P Hasle I Humphery-Smith C Bellon A M Simitzis 《Comptes rendus de l'Académie des sciences. Série III, Sciences de la vie》1989,309(11):499-503
The intracorneal inoculation of nude mice with Acanthamoeba hatchetti amoebae induced a keratitis with disruption of corneal fibres, inflammatory response, secondary vascularization and amoebic trophozoites. 相似文献
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