Identifying the presence of neonicotinoidresistant peach-potato aphid (Myzus persicae) in the peach-growing regions of southern France and northern Spain     

Slater R  Paul VL  Andrews M  Garbay M  Camblin P 《Pest management science》2012,68(4):634-638

BACKGROUND: The neonicotinoid class of insecticides is a key component of pest management strategies used by stone fruit producers in Europe. Neonicotinoids are currently one of the most important tools for control of the peach‐potato aphid (Myzus persicae). Overreliance on neonicotinoids has led to the development of resistance through a combination of metabolic and target‐site resistance mechanisms in individual aphids. A resistance monitoring project was conducted by Syngenta in 2010 to determine the resistance status of M. persicae populations collected from France and Spain, and to determine the frequency of the target‐site mutation in those populations. RESULTS: Resistance monitoring suggests that resistance to neonicotinoids is relatively widespread in populations of M. persicae collected from peach orchards in the Languedoc‐Roussillon, Provence‐Alpes‐Cote d'Azur and Rhone‐Alpes regions of France, and resistance can be associated with the frequency of the target‐site mutation (R81T). The R81T mutation in its heterozygous form is also present in Spanish populations and is associated with neonicotinoid resistance. CONCLUSION: The widespread nature of neonicotinoid resistance in southern France and the potential for resistance development in northern Spain highlight the need for a coordinated management strategy employing insecticides with different modes of action to reduce the selection pressure with neonicotinoids. Copyright © 2011 Society of Chemical Industry  相似文献   

Mapping the origins and expansion of the Indo-European language family     

R Bouckaert  P Lemey  M Dunn  SJ Greenhill  AV Alekseyenko  AJ Drummond  RD Gray  MA Suchard  QD Atkinson 《Science (New York, N.Y.)》2012,337(6097):957-960

There are two competing hypotheses for the origin of the Indo-European language family. The conventional view places the homeland in the Pontic steppes about 6000 years ago. An alternative hypothesis claims that the languages spread from Anatolia with the expansion of farming 8000 to 9500 years ago. We used Bayesian phylogeographic approaches, together with basic vocabulary data from 103 ancient and contemporary Indo-European languages, to explicitly model the expansion of the family and test these hypotheses. We found decisive support for an Anatolian origin over a steppe origin. Both the inferred timing and root location of the Indo-European language trees fit with an agricultural expansion from Anatolia beginning 8000 to 9500 years ago. These results highlight the critical role that phylogeographic inference can play in resolving debates about human prehistory.  相似文献   

Physics. Room for just one photon     

Grangier P 《Science (New York, N.Y.)》2012,336(6083):812-813

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Mechanical control of morphogenesis by Fat/Dachsous/Four-jointed planar cell polarity pathway     

Bosveld F  Bonnet I  Guirao B  Tlili S  Wang Z  Petitalot A  Marchand R  Bardet PL  Marcq P  Graner F  Bellaïche Y 《Science (New York, N.Y.)》2012,336(6082):724-727

During animal development, several planar cell polarity (PCP) pathways control tissue shape by coordinating collective cell behavior. Here, we characterize by means of multiscale imaging epithelium morphogenesis in the Drosophila dorsal thorax and show how the Fat/Dachsous/Four-jointed PCP pathway controls morphogenesis. We found that the proto-cadherin Dachsous is polarized within a domain of its tissue-wide expression gradient. Furthermore, Dachsous polarizes the myosin Dachs, which in turn promotes anisotropy of junction tension. By combining physical modeling with quantitative image analyses, we determined that this tension anisotropy defines the pattern of local tissue contraction that contributes to shaping the epithelium mainly via oriented cell rearrangements. Our results establish how tissue planar polarization coordinates the local changes of cell mechanical properties to control tissue morphogenesis.  相似文献   

Interferometric identification of a pre-brown dwarf     

P André  D Ward-Thompson  J Greaves 《Science (New York, N.Y.)》2012,337(6090):69-72

It is not known whether brown dwarfs [stellar-like objects with masses less than the hydrogen-burning limit, 0.075 solar mass (M)[symbol:see text]] are formed in the same way as solar-type stars or by some other process. Here we report the clear-cut identification of a self-gravitating condensation of gas and dust with a mass in the brown-dwarf regime, made through millimeter interferometric observations. The level of thermal millimeter continuum emission detected from this object indicates a mass ~0.02 to 0.03 M[symbol:see text], whereas the small radius, <460 astronomical units, and narrow spectral lines imply a dynamical mass of 0.015 to 0.02 M[symbol:see text]. The identification of such a pre-brown dwarf core supports models according to which brown dwarfs are formed in the same manner as hydrogen-burning stars.  相似文献   

Antibody response to vaccines for rhinotracheitis, caliciviral disease, panleukopenia, feline leukemia, and rabies in tigers (Panthera tigris) and lions (Panthera leo)     

Risi E  Agoulon A  Allaire F  Le Dréan-Quénec'hdu S  Martin V  Mahl P 《Journal of zoo and wildlife medicine》2012,43(2):248-255

This article presents the results of a study of captive tigers (Panthera tigris) and lions (Panthera leo) vaccinated with a recombinant vaccine against feline leukemia virus; an inactivated adjuvanted vaccine against rabies virus; and a multivalent modified live vaccine against feline herpesvirus, calicivirus, and panleukopenia virus. The aim of the study was to assess the immune response and safety of the vaccines and to compare the effects of the administration of single (1 ml) and double (2 ml) doses. The animals were separated into two groups and received either single or double doses of vaccines, followed by blood collection for serologic response for 400 days. No serious adverse event was observed, with the exception of abortion in one lioness, potentially caused by the incorrect use of the feline panleukopenia virus modified live vaccine. There was no significant difference between single and double doses for all vaccines. The recombinant vaccine against feline leukemia virus did not induce any serologic response. The vaccines against rabies and feline herpesvirus induced a significant immune response in the tigers and lions. The vaccine against calicivirus did not induce a significant increase in antibody titers in either tigers or lions. The vaccine against feline panleukopenia virus induced a significant immune response in tigers but not in lions. This report demonstrates the value of antibody titer determination after vaccination of nondomestic felids.  相似文献   

Connecting an architectural plant model to a forest stand dynamics model—application to Austrian black pine stand visualization     

Lu?FengEmail author  Philippe?de?Reffye  Philippe?Dreyfus  Daniel?Auclair 《Annals of Forest Science》2012,69(2):245-255

• Context  

Forest stand dynamics models simulate the growth of trees in stands; based on field measurements and system knowledge, they provide a relatively precise representation of forest growth and are well adapted for forest management purposes. Architectural models describe the structure of plants according to ontogenetic development processes; as a support of biomass production and partitioning at organ scale, they simulate individual tree development.  相似文献   

Rickettsiae in arthropods collected from the North African Hedgehog (Atelerix algirus) and the desert hedgehog (Paraechinus aethiopicus) in Algeria     

Khaldi M  Socolovschi C  Benyettou M  Barech G  Biche M  Kernif T  Raoult D  Parola P 《Comparative immunology, microbiology and infectious diseases》2012,35(2):117-122

Hedgehogs have become a popular pet despite their potential role in zoonotic disease transmission. We conducted an entomological study in a mountainous region of northeast Algeria in which we collected 387 fleas (Archeopsylla erinacei) and 342 ticks (Rhipicephalus sanguineus and Haemaphysalis erinacei) from Paraechinus aethiopicus and Atelerix algirus hedgehogs. Of the hedgehogs sampled, 77.7% and 91% were infested with fleas and ticks, respectively. Significantly more ticks and fleas were collected from A. algirus than from P. aethiopicus. Rickettsia felis was detected in 95.5% of fleas and R. massiliae was detected in 6.25% of Rh. sanguineus ticks by molecular tools. A new Rickettsia species of the spotted fever group was detected in 11.25% of Rh. sanguineus and in 77% of H. erinacei ticks. Overall, we show that hedgehogs can act as hosts for ectoparasites infected with several rickettsial agents. These data justify a more detailed investigation of animal reservoirs for Rickettsiae.  相似文献   

cDNA-AFLP analysis of gene expression changes in apple trees induced by phytoplasma infection during compatible interaction     

Majid Aldaghi  Assunta Bertaccini  Philippe Lepoivre 《European journal of plant pathology / European Foundation for Plant Pathology》2012,134(1):117-130

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A new protolimonoid from Capuronianthus mahafalensis     

Fossen T  Rasoanaivo P  Manjovelo CS  Raharinjato FH  Yahorava S  Yahorau A  Wikberg JE 《Fitoterapia》2012,83(5):901-906

From stem barks of Capuronianthus mahafalensis (Meliaceae) endemic to Madagascar, a new protolimonoid named capulin containing a four membered ring in its side chain was isolated by repeated silica gel column chromatography. Its structure was determined by 1D and 2D NMR spectroscopy and high-resolution MS. To the best of our knowledge, this is the first time that a four-membered ring occurs in the side chain of protolimonoids.  相似文献