排序方式: 共有34条查询结果,搜索用时 15 毫秒
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Kathleen M. Maloney Jenny Ancca‐Juarez Renzo Salazar Katty Borrini‐Mayori Malwina Niemierko Joshua O. Yukich Cesar Naquira Joseph A. Keating Michael Z. Levy 《Journal of vector ecology》2013,38(1):6-11
The vector of Chagas disease, Triatoma infestans, is largely controlled by the household application of pyrethroid insecticides. Because effective, large‐scale insecticide application is costly and necessitates numerous trained personnel, alternative control techniques are badly needed. We compared the residual effect of organophosphate‐based insecticidal paint (Inesfly 5A IGR? (I5A)) to standard deltamethrin, and a negative control, against T. infestans in a simulated natural environment. We evaluated mortality, knockdown, and ability to take a blood meal among 5th instar nymphs. I5A paint caused significantly greater mortality at time points up to nine months compared to deltamethrin (Fisher's Exact Test, p < 0.01 in all instances). A year following application, mortality among nymphs in the I5A was similar to those in the deltamethrin (χ2 = 0.76, df=1, p < 0.76). At months 0 and 1 after application, fewer nymphs exposed to deltamethrin took a blood meal compared to insects exposed to paint (Fisher's Exact Tests, p < 0.01 and p < 0.01, respectively). Insecticidal paint may provide an easily‐applied means of protection against vectors of Chagas disease. 相似文献
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Pindon A Van Hecke G Josson K Van Gompel P Lesage A Leysen JE Jurzak M 《Bioscience reports》2004,24(3):215-223
The family of 5-HT4 receptors comprises 16 putative splice variants. We have previously shown that there are differences in signal transduction of the h5-HT4a and h5-HT4b receptors. In the present study, the internalization of these two splice variants following receptor stimulation was investigated with confocal microscopy on living cells. Chimeric receptors, h5-HT4a-GFP and h5-HT4b-GFP were generated by fusing the coding sequence of the 5-HT4 receptor with the coding sequence of the GFP. The agonist stimulation of fluorescent receptors resulted in a time-dependent internalization of the h5-HT4b-GFP receptor, but not of the h5-HT4a-GFP receptor. The h5-HT4b receptor displays a dual coupling to Gαi,o and Gαs proteins, in contrast to the h5-HT4a receptor, which couples to Gαs proteins only. We investigated whether the difference in internalization of the two splice variant receptors was related to their differential coupling. Therefore, we performed agonist-stimulation of the receptor following inhibition of the Gαi,o protein coupling using PTX. The h5-HT4b receptor internalization is PTX insensitive. We co-transfected the fluorescent chimeric receptors with other wild-type variants, which did not produce an alteration of the receptor trafficking. These findings provide the first evidence of differential internalization between the two splice variants, 5-HT4a and 5-HT4b receptors. 相似文献
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Ricardo Castillo-Neyra Corentin M. Barbu Renzo Salazar Katty Borrini Cesar Naquira Michael Z. Levy 《PLoS neglected tropical diseases》2015,9(1)
Chagas disease affects millions of people in Latin America. The control of this vector-borne disease focuses on halting transmission by reducing or eliminating insect vector populations. Most transmission of Trypanosoma cruzi, the causative agent of Chagas disease, involves insects living within or very close to households and feeding mostly on domestic animals. As animal hosts can be intermittently present it is important to understand how host availability can modify transmission risk to humans and to characterize the host-seeking dispersal of triatomine vectors on a very fine scale. We used a semi-field system with motion-detection cameras to characterize the dispersal of Triatoma infestans, and compare the behavior of vector populations in the constant presence of hosts (guinea pigs), and after the removal of the hosts. The emigration rate – net insect population decline in original refuge – following host removal was on average 19.7% of insects per 10 days compared to 10.2% in constant host populations (p = 0.029). However, dispersal of T. infestans occurred in both directions, towards and away from the initial location of the hosts. The majority of insects that moved towards the original location of guinea pigs remained there for 4 weeks. Oviposition and mortality were observed and analyzed in the context of insect dispersal, but only mortality was higher in the group where animal hosts were removed (p-value <0.01). We discuss different survival strategies associated with the observed behavior and its implications for vector control. Removing domestic animals in infested areas increases vector dispersal from the first day of host removal. The implications of these patterns of vector dispersal in a field setting are not yet known but could result in movement towards human rooms. 相似文献
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K. E. Samocha J. E. Lim R. Cheng G. Sokoloff A. A. Palmer 《Genes, Brain & Behavior》2010,9(7):759-767
Prepulse inhibition (PPI) of the startle response is a measure of sensorimotor gating, a process that filters out extraneous sensory, motor and cognitive information. Humans with neurological and psychiatric disorders, including schizophrenia, obsessive‐compulsive disorder and Huntington's disease, exhibit a reduction in PPI. Habituation of the startle response is also disrupted in schizophrenic patients. In order to elucidate the genes involved in sensorimotor gating, we phenotyped 472 mice from an F2 cross between LG/J × SM/J for PPI and genotyped these mice genome‐wide using 162 single nucleotide polymorphism (SNP) markers. We used prepulse intensity levels that were 3, 6 and 12 dB above background (PPI3, PPI6 and PPI12, respectively). We identified a significant quantitative trait locus (QTL) on chromosome 12 for all three prepulse intensities as well as a significant QTL for both PPI6 and PPI12 on chromosome 11. We identified QTLs on chromosomes 7 and 17 for the startle response when sex was included as an interactive covariate and found a QTL for habituation of the startle response on chromosome 4. We also phenotyped 135 mice from an F34 advanced intercross line (AIL) between LG/J × SM/J for PPI and genotyped them at more than 3000 SNP markers. Inclusions of data from the AIL mice reduced the size of several of these QTLs to less than 5 cM. These results will be useful for identifying genes that influence sensorimotor gaiting and show the power of AIL for fine mapping of QTLs. 相似文献
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Global maximization of Jatropha oil production under semi‐arid conditions by balancing vegetative growth with reproductive capacity 下载免费PDF全文
Yiftach Vaknin Uri Yermiyahu Asher Bar‐Tal Yael Samocha 《Global Change Biology Bioenergy》2018,10(6):382-392
Jatropha curcas L. is a drought tolerant crop that is globally cultivated under semi‐arid conditions as a biodiesel feedstock. Despite its great potential, however, many projects failed to reach commercially viable seed and oil yields. The aim of the study was to provide globally applicable solutions for maximization of Jatropha oil production under semi‐arid conditions. Under extremely low irrigation (10% of potential evapotranspiration; ETp), fruit production was very low and a surprisingly significant portion of the fruits delayed their maturity up to six months post‐bloom. Increasing irrigation to mid‐level (60% ETp) significantly elevated fruit production and speeded up the ripening rate, whereas further increasing irrigation to a higher level (90% ETp) decreased seed and oil yields, probably due to the increased investment in vegetative growth. Nevertheless, maximal seed and oil yields at 60% ETp remained far below targeted yields. Coupling irrigation at 60% ETp, with induction of vegetative arrest, by soil application of a commercial gibberellin synthesis inhibitor, brought forward the second bloom period by two months, reduced vegetative growth, promoted floral production and significantly enhanced reproductive capacity by more than doubling oil production. The results show that under semi‐arid conditions, commercially viable seed and oil yields of Jatropha can be achieved by carefully balancing vegetative growth with reproductive capacity through the combined application of optimal irrigation regimes and induced vegetative arrest. 相似文献
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Dorit Samocha‐Bonet Dov Lichtenberg Aaron Tomer Varda Deutsch Tamar Mardi Yelena Goldin Subchi Abu‐Abeid Galina Shenkerman Hana Patshornik Itzhak Shapira Shlomo Berliner 《Obesity (Silver Spring, Md.)》2003,11(3):403-407
Objective: Previous studies have suggested that obesity enhances the inflammatory response, producing macromolecules involved in the induction and/or maintenance of increased erythrocyte aggregation. The objectives of this study were to evaluate the correlation between inflammation markers, erythrocyte adhesiveness/aggregation, and the degree of obesity and to assess phosphatidylserine expression on erythrocyte surface membrane of obese vs. nonobese individuals. Research Methods and Procedures: Erythrocyte adhesiveness/aggregation in the peripheral venous blood was evaluated by using a new biomarker, phosphatidylserine expression was assessed by means of flow cytometry, and markers of inflammation were measured in 65 subjects: 30 obese [body mass index (BMI) = 41 ± 7.7 kg/m2] and 35 nonobese (BMI = 24 ± 2.7 kg/m2) individuals. Pearson correlations and Student's t test were performed. Results: A highly significant difference was noted in the degree of erythrocyte adhesiveness/aggregation and markers of inflammation between the study groups. BMI correlated with erythrocyte adhesiveness/aggregation (r = 0.42, p = 0.001), erythrocyte sedimentation rate (r = 0.42, p = 0.001), high‐sensitive C‐reactive protein (r = 0.55, p < 10?4), fibrinogen (r = 0.37, p = 0.004), and white blood cell count (r = 0.45, p < 10?4). The degree of erythrocyte adhesiveness/aggregation correlated with erythrocyte sedimentation rate (r = 0.5, p < 10?4), high‐sensitive C‐reactive protein (r = 0.56, p < 10?4), fibrinogen (r = 0.54, p < 10?4), and white blood cell count (r = 0.32, p = 0.01). Discussion: Our results suggest that obesity‐related erythrocyte adhesiveness/aggregation is probably mediated through increased concentrations of adhesive macromolecules in the circulation and not necessarily through hyperlipidemia or phosphatidylserine exposure on erythrocyte's membrane. 相似文献
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Shahar Samra Yael Samocha Dan Eisikowitch Yiftach Vaknin 《Global Change Biology Bioenergy》2014,6(6):756-767
Jatropha curcas L. is the subject of many research and breeding programs concerned with its potential as an oil crop for biodiesel production. Despite an increasing amount of information regarding this relatively new crop, pollination requirements of this plant are largely neglected. The aim of the study was to evaluate the relative significance of ants and honeybees as potential pollinators of J. curcas grown under Mediterranean conditions. Jatropha curcas plants bloomed throughout the summer and fall, peaking twice, in early summer and late fall. During this period, the plants were visited by 70 species of insects representing 45 families from seven orders, with most species rarely being observed. Ants and Honeybees were the most common species, accounting for >95% of all flower visits. The foraging behavior of the honeybees followed the pattern of bloom phenology, especially during the summer, and mostly promoted cross‐pollination. Ants on the other hand, mostly promoted self pollination showing no such correlative behavior, reacting often too late to nectar availability, and were highly susceptible to climatic changes. Pollinator exclusion treatments revealed that during summer, fruit and seed sets, as well as seed size and oil and protein contents, were relatively similar for ant and bee‐pollinated flowers. During fall, however, reproductive success of bee‐pollinated flowers was relatively high (66%), while fruit set of ant‐pollinated flowers was significantly reduced from 71 to 11%. In conclusion, while both groups are equal in their pollination effectiveness in the summer, during the fall the honeybees are almost the sole pollinators of the plant. Based on bloom phenology and pollination activity data, the honeybees are responsible for the pollination of more than 80% of the annual reproductive potential of J. curcas, under Mediterranean conditions. 相似文献
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Orit Uziel Einat Beery Vladimir Dronichev Katty Samocha Sergei Gryaznov Lola Weiss Shimon Slavin Michal Kushnir Yardena Nordenberg Claudette Rabinowitz Baruch Rinkevich Tania Zehavi Meir Lahav 《PloS one》2010,5(2)