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161.
Raoul E. Benveniste LaRene Kuller Stanford T. Roodman Shiu-Lok Hu William R. Morton 《Journal of medical primatology》1993,22(2-3):74-79
Recombinant vaccinia virus expressing the envelope proteins of type D retrovirus-Washington (SRV-2/W) was used to immunize macaques against SRV-2 infection. Four immunized macaques which had resisted a prior low-dose challenge were rechallenged with a high dose (10” infectious particles) of SRV-2 two years after being immunized. All four non-immunized control macaques became infected, but the four vaccinated animals resisted this intravenous challenge, as determined by the inability to detect SRV-2 in peripheral blood mononuclear cells and by the lack of seroconversion to new viral antigens. 相似文献
162.
A balanced reciprocal translocation, t(15;21) (q262;q21) was observed in the mother and maternal grandfather of two patients. The propositus, who received the abnormal chromosome 15 from his mother, is trisomic for the distal part of chromosome 21, and his phenotype is that of classical trisomy 21. His sister, who is trisomic for the proximal part of 21q, is slightly retarded but developmentally normal otherwise. 相似文献
163.
Summary
The South wind in North Basque country is a foehnlike wind. Many patients hold it responsible for the temporary aggravation of their allergic symptoms, especially for the respiratory ones (rhinitis or asthma for example). Here, the oceanic climate, mild and temperate, favours the development of an abundant vegetation of trees and grass lands. The South wind plays an important role in releasing pollen grains, as it appears on the graphs drawn up during a study aiming at estimating its responsibility. 相似文献
164.
Leonne M. van der Leede-Plegt Bernadette C. E. van de Ven Raoul J. Bino Theo P. M. van der Salm Arjen J. van Tunen 《Plant cell reports》1992,11(1):20-24
Summary As part of our research to develop an alternative system for the transformation of recalcitrant plant species we investigated the use of the male gametophyte as a transformation vector. Therefore the activity of four different promoters (CaMV 35S, LAT52, chiA PA2 and TR2') was analyzed in pollen of a dicot (Nicotiana glutinosa) and a monocot (Lilium longiflorum) plant species. Gene constructs in which the ß-glucuronidase (GUS) gene was placed under the control of these promoters were introduced in pollen using a particle delivery system. No activity of the Cauliflower Mosaic Virus (CaMV) 35S promoter was detected in pollen of both N. glutinosa and L. longiflorum. The promoter of the tomato flower-specific LAT52 gene was highly active in N. glutinosa pollen but remained silent in L. longiflorum pollen. A similar expression pattern was observed for the pollen-specific Chalcone Flavanone Isomerase chiA PA2 promoter originally isolated from petunia. The TR2 mannopine synthase promoter of Agrobacterium tumefaciens, however, was active in pollen from Solanaceous species and also in pollen from the monocot L. longiflorum. This suggests that the TR2' promoter is active in vegetative and sporogenous tissues of dicot and monocot plant species.Abbreviations
ADH1
Alcohol Dehydrogenase 1
-
A. tumefaciens
Agrobacterium tumefaciens
-
CaMV
Cauliflower Mosaic Virus
-
ChiA
Chalcone Flavanone Isomerase A
-
L. longiflorum
Lilium longiflorum
- N. glutinosa
Nicotiana glutinosa
- Nos
Nopaline Synthase
- N. tabacum
Nicotiana tabacum 相似文献
165.
Karan J. Odom Kristal E. Cain Michelle L. Hall Naomi E. Langmore Raoul A. Mulder Sonia Kleindorfer Jordan Karubian Lyanne Brouwer Erik D. Enbody John Anthony Jones Jenlle L. Dowling Ana V. Leito Emma I. Greig Christine Evans Allison E. Johnson Kimberley K.A. Meyers Marcelo ArayaSalas Michael S. Webster 《Ecology and evolution》2021,11(24):17901
Historically, bird song complexity was thought to evolve primarily through sexual selection on males; yet, in many species, both sexes sing and selection pressure on both sexes may be broader. Previous research suggests competition for mates and resources during short, synchronous breeding seasons leads to more elaborate male songs at high, temperate latitudes. Furthermore, we expect male–female song structure and elaboration to be more similar at lower, tropical latitudes, where longer breeding seasons and year‐round territoriality yield similar social selection pressures in both sexes. However, studies seldom take both types of selective pressures and sexes into account. We examined song in both sexes in 15 populations of nine‐fairy‐wren species (Maluridae), a Southern Hemisphere clade with female song. We compared song elaboration (in both sexes) and sexual song dimorphism to latitude and life‐history variables tied to sexual and social selection pressures and sex roles. Our results suggest that song elaboration evolved in part due to sexual competition in males: male songs were longer than female songs in populations with low male survival and less male provisioning. Also, female songs evolved independently of male songs: female songs were slower paced than male songs, although only in less synchronously breeding populations. We also found male and female songs were more similar when parental care was more equal and when male survival was high, which provides strong evidence that sex role similarity correlates with male–female song similarity. Contrary to Northern Hemisphere latitudinal patterns, male and female songs were more similar at higher, temperate latitudes. These results suggest that selection on song can be sex specific, with male song elaboration favored in contexts with stronger sexual selection. At the same time, selection pressures associated with sex role similarity appear to favor sex role similarity in song structure. 相似文献
166.
Raoul Henry 《International Review of Hydrobiology》1993,78(4):501-511
Thermal regime and stability in Jurumirim Reservoir (São Paulo, Brazil) were studied for a year. Isothermy and thermal stratification were observed from June to September and from October to March, respectively. The annual heat budget was 14.0 Kcal · cm−2 and average heat gain per day was 67.2 cal · cm−2 · day−1. Maximum stability and wind work reached 324.2 and 3,037.5 g · cm · cm−2, respectively. According to thermal structure and heat content, Jurumirim Reservoir was classified as a warm tropical monomictic lake. 相似文献
167.
No trade-off between sprinting and climbing in two populations of the Lizard Podarcis hispanica (Reptilia: Lacertidae). 总被引:2,自引:0,他引:2
Raoul Van Damme Peter Aerts Bieke Vanhooydonck 《Biological journal of the Linnean Society. Linnean Society of London》1997,60(4):493-503
Biomechanical reflections suggest that lizards that have specialized in running should differ in parts of their morphological design from lizards that have specialized in climbing. Moreover, adaptation in one direction may conflict with performance in the other. We tested this assumed trade-off by measuring climbing and running performance in two subspecies of the Mediterranean lizard Poaarcis hispanica. One subspecies, P. h. atrata , inhabits a number of small islets near the Spanish coast. It is mainly ground dwelling. The other subspecies, P. h. hispanica , was sampled on the mainland of Spain. It frequendy occupies vertical elements within its habitat. Our data do not support the notion of a trade-off between both types of locomotion. Individuals of P. h. hispanica both run and climb faster than those of P. h. atrata. There is no difference between subspecies in ability to cling onto tilted substrates. Predictions on the morphology of both subspecies, inspired by biomechanical arguments, are not supported by our measurements. 相似文献
168.
169.
Nitric oxide synthesis enhances human immunodeficiency virus replication in primary human macrophages 下载免费PDF全文
Macrophages are suspected to play a major role in human immunodeficiency virus (HIV) infection pathogenesis, not only by their contribution to virus dissemination and persistence in the host but also through the dysregulation of immune functions. The production of NO, a highly reactive free radical, is thought to act as an important component of the host immune response in several viral infections. The aim of this study was to evaluate the effects of HIV type 1 (HIV-1) Ba-L replication on inducible nitric oxide synthase (iNOS) mRNA expression in primary cultures of human monocyte-derived macrophages (MDM) and then examine the effects of NO production on the level of HIV-1 replication. Significant induction of the iNOS gene was observed in cultured MDM concomitantly with the peak of virus replication. However, this induction was not accompanied by a measurable production of NO, suggesting a weak synthesis of NO. Surprisingly, exposure to low concentrations of a NO-generating compound (sodium nitroprusside) and L-arginine, the natural substrate of iNOS, results in a significant increase in HIV replication. Accordingly, reduction of L-arginine bioavailability after addition of arginase to the medium significantly reduced HIV replication. The specific involvement of NO was further demonstrated by a dose-dependent inhibition of viral replication that was observed in infected macrophages exposed to N(G)-monomethyl L-arginine and N(G)-nitro-L-arginine methyl ester (L-NAME), two inhibitors of the iNOS. Moreover, an excess of L-arginine reversed the addition of L-NAME, confirming that an arginine-dependent mechanism is involved. Finally, inhibitory effects of hemoglobin which can trap free NO in culture supernatants and in biological fluids in vivo confirmed that endogenously produced NO could interfere with HIV replication in human macrophages. 相似文献
170.