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81.
82.
In order to understand the physiological functions of reactive oxygen species (ROS) generated in leaves, their direct measurement in vivo is of special importance. Here we report experiments with two dansyl-based ROS sensors, the singlet oxygen specific DanePy and HO-1889NH, which is reactive to both singlet oxygen and superoxide radicals. Here we report in vivo detection of (1)O(2) and O(2)(-*) by fluorescence quenching of two dansyl-based ROS sensors, the (1)O(2) specific DanePy and HO-1889NH, which was reactive with both (1)O(2) and O(2)(-*). The ROS sensors were administered to spinach leaves through a pinhole, and then the leaves were exposed to either excess photosynthetically active radiation or UV (280-360 nm) radiation. Microlocalization of the sensors' fluorescence and its ROS-induced quenching was followed with confocal laser scanning microscopy and with fluorescence imaging. These sensors were specifically localized in chloroplasts. Quenching analysis indicated that the leaves exposed to strong light produced (1)O(2), but hardly any O(2)(-*). On the other hand, the dominant ROS in UV-irradiated leaves was O(2)(-*), while (1)O(2) was minor. 相似文献
83.
Levels of extra‐pair paternity are associated with parental care in penduline tits (Remizidae) 下载免费PDF全文
Alex D. Ball René E. van Dijk Penn Lloyd Ákos Pogány Deborah A. Dawson Steve Dorus Rauri C. K. Bowie Terry Burke Tamás Székely 《Ibis》2017,159(2):449-455
In most passerine birds, individuals attempt to maximize their fitness by providing parental care while also mating outside their pair bond. A sex‐specific trade‐off between these two behaviours is predicted to occur, as the fitness benefits of extra‐pair mating differ between the sexes. We use nest observations and parentage analysis to reveal a negative association between male care and the incidence of extra‐pair paternity across three species of penduline tit (Remizidae). This provides evidence of a trade‐off between these two behaviours, possibly due to the devaluing of paternal care by extra‐pair offspring. 相似文献
84.
Soo K O'Rourke MP Khoo PL Steiner KA Wong N Behringer RR Tam PP 《Developmental biology》2002,247(2):251-270
Loss of Twist function in the cranial mesenchyme of the mouse embryo causes failure of closure of the cephalic neural tube and malformation of the branchial arches. In the Twist(-/-) embryo, the expression of molecular markers that signify dorsal forebrain tissues is either absent or reduced, but those associated with ventral tissues display expanded domains of expression. Dorsoventral organization of the mid- and hindbrain and the anterior-posterior pattern of the neural tube are not affected. In the Twist(-/-) embryo, neural crest cells stray from the subectodermal migratory path and the late-migrating subpopulation invades the cell-free zone separating streams of cells going to the first and second branchial arches. Cell transplantation studies reveal that Twist activity is required in the cranial mesenchyme for directing the migration of the neural crest cells, as well as in the neural crest cells within the first branchial arch to achieve correct localization. Twist is also required for the proper differentiation of the first arch tissues into bone, muscle, and teeth. 相似文献
85.
Adarichev VA Bárdos T Christodoulou S T Phillips M Mikecz K Glant TT 《Immunogenetics》2002,54(3):184-192
Collagen-induced arthritis (CIA) in DBA/1 and proteoglycan-induced arthritis (PGIA) in BALB/c mice are the most frequently used mouse models for studying clinical, immunological and genetic factors contributing to rheumatoid arthritis. DBA/1 ( H2(q)) mice are susceptible to CIA but resistant to PGIA, whereas BALB/c mice ( H2 (d)) are susceptible to PGIA and resistant to CIA. To gain insight into the mechanisms of how the major clinical (disease susceptibility, severity and onset of arthritis) and immunological traits (antigen-specific T- and B-cell responses) are influenced by the major histocompatibility complex (MHC), we have generated a unique intercross of BALB/c and DBA/1 parent strains, and the F1 and F2 hybrids were immunized for either CIA or PGIA. The major clinical and immunological traits were identified as either binary (qualitative) or quantitative traits on Chromosome 17 with a peak at MHC when the entire population was analyzed. In contrast, when only arthritic (susceptible) mice were selected and analyzed, the major clinical traits (severity and onset) 'lost' the linkage to MHC. Thus, MHC dictates disease susceptibility, but not the severity of arthritis. This was even more evident in the case of the H2(q) allele, which was clearly responsible for the dominant inheritance of arthritis in F2 hybrids (either CIA or PGIA). In conclusion, while certain MHC alleles strongly affect disease susceptibility and determine the mode of inheritance of a polygenic autoimmune disease, neither the type of inheritance (dominant vs recessive) nor other MHC components have evident effects upon the clinical symptoms of arthritis. 相似文献
86.
Objectives
To estimate the annual cost to patients, the health service and society of infectious intestinal disease (IID) from Campylobacter, norovirus and rotavirus.Design
Secondary data analysis.Setting
The United Kingdom population, 2008–9.Main outcome measures
Cases and frequency of health services usage due to these three pathogens; associated healthcare costs; direct, out-of-pocket expenses; indirect costs to patients and caregivers.Results
The median estimated costs to patients and the health service at 2008–9 prices were: Campylobacter £50 million (95% CI: £33m–£75m), norovirus £81 million (95% CI: £63m–£106m), rotavirus £25m (95% CI: £18m–£35m). The costs per case were approximately £30 for norovirus and rotavirus, and £85 for Campylobacter. This was mostly borne by patients and caregivers through lost income or out-of-pocket expenditure. The cost of Campylobacter-related Guillain-Barré syndrome hospitalisation was £1.26 million (95% CI: £0.4m–£4.2m).Conclusions
Norovirus causes greater economic burden than Campylobacter and rotavirus combined. Efforts to control IID must prioritise norovirus. For Campylobacter, estimated costs should be considered in the context of expenditure to control this pathogen in agriculture, food production and retail. Our estimates, prior to routine rotavirus immunisation in the UK, provide a baseline vaccine cost-effectiveness analyses. 相似文献87.
The effect of Mn2+ and Ca2+ ions on the rate of trypsin autolysis was studied at pH 7.0 and at 34.4-60.2°C. For comparison, the kinetic constants of esterolytic activity of trypsin in the presence of the metal ion were determined at pH 7.4 and at 36° and 40°C. There was no significant difference in the rate of autolysis between Mn2+ and Ca2+ in the temperature range 34-47°C, but at 56.8° and 60.2° autolysis was slightly more rapid in the presence of Mn2+. The Mn2+ or Ca2+ ion bound to trypsin is supposed to control the conformation and thereby the stability and the activity of the enzyme. This indirect effect of Mn2+ and Ca2+ is discussed on a structural basis of the enzyme molecule. 相似文献
88.
Mode of Action of the Toxin from Pseudomonas phaseolicola: I. Toxin Specificity, Chlorosis, and Ornithine Accumulation 下载免费PDF全文
The specificity of the Pseudomonas phaseolicola toxin for enzyme inhibition and its relationship to toxin-induced chlorosis in bean leaves (Phaseolus vulgaris L.) was examined. The toxin showed no significant inhibitory activity against glutamine synthetase, glutamine transferase, carbamyl phosphate synthetase, aspartate carbamoyltransferase, or arginase at concentrations 100-fold higher than that needed to inhibit ornithine carbamoyltransferase by 50%. 相似文献
89.
90.
Parental cooperation in a changing climate: fluctuating environments predict shifts in care division 下载免费PDF全文
Orsolya Vincze András Kosztolányi Zoltán Barta Clemens Küpper Monif Alrashidi Juan A. Amat Araceli Argüelles Ticó Fiona Burns John Cavitt Warren C. Conway Medardo Cruz‐López Atahualpa Eduardo Desucre‐Medrano Natalie dos Remedios Jordi Figuerola Daniel Galindo‐Espinosa Gabriel E. García‐Peña Salvador Gómez Del Angel Cheri Gratto‐Trevor Paul Jönsson Penn Lloyd Tomás Montalvo Jorge Enrique Parra Raya Pruner Pinjia Que Yang Liu Sarah T. Saalfeld Rainer Schulz Lorenzo Serra James J. H. St Clair Lynne E. Stenzel Michael A. Weston Maï Yasué Sama Zefania Tamás Székely 《Global Ecology and Biogeography》2017,26(3):347-358