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971.
Sadeq Alzubik Belkair Christophe Mazzia Alain Pasquet 《Biocontrol Science and Technology》2018,28(9):823-836
It is well known that spiders are present in high numbers in orchards and may contribute to biocontrol. Some recent studies in central Europe further showed that some spiders are active year-round and consume pests even in winter. Using cardboard traps laid every two weeks, we carried out a survey to determine which spider and earwig species are active from September to May in an experimental, pesticide-free, apple orchard under a Mediterranean climate. We observed that spider activity was never completely absent. The structure of the spider communities showed a marked seasonality in three periods (so-called ‘autumn’, ‘winter’ and ‘spring’). Only two spider genera, Philodromus and Trachelas, were highly active in winter (percentage of catches during this season above 40%) and six others (Lathys, Clubiona, Gnaphosa, Theridion, Phrurolithus) had moderate activity (between 20 and 40%). The two earwig species had different patterns of winter activity with Forficula auricularia almost absent whereas F. pubescens was moderately active on trees. Spider community abundance, diversity and evenness significantly decreased between autumn and winter and remained low in the following spring probably because the attractiveness of the traps is much lower at this time of year due to mild temperatures and the presence of leaves on the trees. Winter-active spiders could contribute to pest biocontrol during the cold season and we advocate that the use of broad-spectrum pesticides at the end of winter, as classically applied in orchards, may be counter-productive for pest control. 相似文献
972.
In animals, it is known that age affects the abilities of the brain. In spiders, we showed that aging affects web characteristics due to behavioral alterations during web building. In this study, we investigated the effects of age on the associations between morphological changes to the spider brain and changes in web characteristics. The orb web spider Zygiella x-notata (Araneae, Araneidae) was used to test these relationships. Experiments were conducted on young (19 ± 2 days after adult molt, N = 13) and old (146 ± 32 days, N = 20) virgin females. The brain volume decreased with age (by 10%). Age also had an impact on the number of anomalies in the capture area generated during web building. The statistical relationships between the volume of the brain and web characteristics showed that there was an effect of age on both. Our results showed that in spiders, aging affects the brain volume and correlates with characteristics (anomalies) of the web. As web building is the result of complex behavioral processes, we suggest that aging affects spider behavior by causing some brain alterations. 相似文献
973.
The role of the CroR response regulator in resistance of Enterococcus faecalis to D‐cycloserine is defined using an inducible receiver domain
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Cécile Muller Sébastien Massier Yoann Le Breton Alain Rincé 《Molecular microbiology》2018,107(3):416-427
Enterococcus faecalis is an opportunistic multidrug‐resistant human pathogen causing severe nosocomial infections. Previous investigations revealed that the CroRS two‐component regulatory pathway likely displays a pleiotropic role in E. faecalis, involved in virulence, macrophage survival, oxidative stress response as well as antibiotic resistance. Therefore, CroRS represents an attractive potential new target for antibiotherapy. In this report, we further explored CroRS cellular functions by characterizing the CroR regulon: the ‘domain swapping’ method was applied and a CroR chimera protein was generated by fusing the receiver domain from NisR to the output domain from CroR. After demonstrating that the chimera CroR complements a croR gene deletion in E. faecalis (stress response, virulence), we conducted a global gene expression analysis using RNA‐Seq and identified 50 potential CroR targets involved in multiple cellular functions such as cell envelope homeostasis, substrate transport, cell metabolism, gene expression regulation, stress response, virulence and antibiotic resistance. For validation, CroR direct binding to several candidate targets was demonstrated by EMSA. Further, this work identified alr, the gene encoding the alanine racemase enzyme involved in E. faecalis resistance to D‐cycloserine, a promising antimicrobial drug to treat enterococcal infections, as a member of the CroR regulon. 相似文献
974.
Ok‐Ryul Song Christophe J Queval Raffaella Iantomasi Vincent Delorme Sabrina Marion Romain Veyron‐Churlet Elisabeth Werkmeister Michka Popoff Isabelle Ricard Samuel Jouny Nathalie Deboosere Frank Lafont Alain Baulard Laurent Marsollier Eik Hoffmann Priscille Brodin 《EMBO reports》2018,19(1):29-42
The interaction of Mycobacterium tuberculosis (Mtb) with pulmonary epithelial cells is critical for early stages of bacillus colonization and during the progression of tuberculosis. Entry of Mtb into epithelial cells has been shown to depend on F‐actin polymerization, though the molecular mechanisms are still unclear. Here, we demonstrate that mycobacterial uptake into epithelial cells requires rearrangements of the actin cytoskeleton, which are regulated by ADP‐ribosylation factor 1 (Arf1) and phospholipase D1 (PLD1), and is dependent on the M3 muscarinic receptor (M3R). We show that this pathway is controlled by Arf GTPase‐activating protein 1 (ArfGAP1), as its silencing has an impact on actin cytoskeleton reorganization leading to uncontrolled uptake and replication of Mtb. Furthermore, we provide evidence that this pathway is critical for mycobacterial entry, while the cellular infection with other pathogens, such as Shigella flexneri and Yersinia pseudotuberculosis, is not affected. Altogether, these results reveal how cortical actin plays the role of a barrier to prevent mycobacterial entry into epithelial cells and indicate a novel role for ArfGAP1 as a restriction factor of host–pathogen interactions. 相似文献
975.
976.
Delcourt Alain Mathieu Gisèle Baji Halima Kimny Tan Flammang Michel Compagnon Paul-Louis 《Mycopathologia》1997,137(1):27-32
Six new polyazole derivatives from 2-(2,4-dichlorophenyl)-1,3-dioxolane were studied for their antifungal activity against pathogenic fungi for humans and animals. The antimycotic effect was largely restricted to the filamentous fungi with Aspergillus fumigatus and Scedosporium apiospermum being remarkably susceptible. Three compounds were as effective as the two references, ketoconazole and oxiconazole. The structure-activity relationships revealed that an oxime group combined with four chlorine atoms increased the antifungal properties of the chemical series.This revised version was published online in October 2005 with corrections to the Cover Date. 相似文献
977.
Intestinal-type fibroblasts selectively influence proliferation rate and peptide synthesis in the murine entero-endocrine cell line STC-1 总被引:1,自引:0,他引:1
978.
Improved Screening of cDNAs Generated by mRNA Differential Display Enables the Selection of True Positives and the Isolation of Weakly Expressed Messages 总被引:22,自引:1,他引:21
Zegzouti Hicham Marty Christel Jones Brian Bouquin Thomas Latché Alain Pech Jean Claude Bouzayen Mondher 《Plant Molecular Biology Reporter》1997,15(3):236-245
The high percentage of false positives generated by differential display (as high as 85%) has previously limited the potential of the method. This report describes an efficient methodology that enables false positives to be discarded prior to cloning, via reverse Northern analysis. This first step of the screening also allows the detection of putative low abundance differential clones. Following cloning, a second reverse Northern combined with partial DNA sequencing and RT-PCR detection allows isolation of all differential cDNAs including very low abundance clones. Use of the sequential screening procedure described here led to the isolation of novel tomato genes responding to the plant hormone ethylene while minimising labor and materials input. 相似文献
979.
With a view toward describing behavioral variability among individuals of the primitively eusocial speciesBelonogaster juncea juncea, we recorded the time-activity budget spent on five behavioral categories (foraging, building, feeding, inactivity, and reproduction)
by 52 individuals belonging to four postemergence colonies. A principal-components analysis coupled with a hierarchical cluster
analysis enabled us to discern four behavioral roles. The reproductive role is reserved to one individual (functional monogyny)
and the workers’ role is differentiated into foragers, builders, and guards. The foragers are females that spend the most
time (82.6% of their time) foraging, supplying the nest with prey load and liquid matter. The builders are individuals (with
41.5% of their time off the nest) that tend to bring pulp into the nest and then undertake building activities. The guards
are those females that spend the most time (79.7% of their time) being inactive on the nest. 相似文献
980.
Alain L. Bardou Pierre M. Auger Jean-Luc Chasse Renaud Seigneuric 《Acta biotheoretica》1997,45(3-4):227-236
Limitations of antiarrhythmic drugs on cardiac sudden death prevention appeared since the early 80's. The "Cardiac Arrhythmia
Suppression Trial"(CAST) showed more recently that mortality was significantly higher inpatients treated with some particular
antiarrhythmic drugs than in non-treated patients. In this field, our group recently demonstrated that a bolus of a Class
1B antiarrhythmic drug was able to trigger a ventricular fibrillation due to transient blocks induction.
The aim of the present work was to systematically study, by use of the van Capelle and Durrer (VCD) model which allows to
simulate ventricular activation wave propagation, the link between arrhythmogenic effects and the ability of transient blocks
to possibly degenerate in severe arrhythmias. A fragment of the ventricular wall is represented by an array of 16384elements
electrically coupled. Effects of induction of one or several transient blocks, as the effects of their size and duration on
possible induction of reentries have been studied. Results obtained show that various combinations between these different
parameters may trigger reentries, ventricular tachycardia and/or more complex patterns assimilable to ventricular fibrillation.
These results clearly evidence the fact that possible induction of transient blocks may directly be related to risk factor
associated to arrhythmogenic effects of antiarrhythmic drugs.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献