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81.
82.
A novel approach to the design of sensitive fluorescent probes for nucleic acids detection is proposed. Suitable modifications of tri- and pentamethine cyanine dyes in the polymethine chain and/or in the heterocyclic residues can result in a significant decrease in unbound dye fluorescence intensity and an increase in dye emission intensity in the presence of DNA compared to the unsubstituted dye. The sharp enhancement in the fluorescence intensity upon dye interaction with double-stranded DNA permits the application of the modified tri- and pentamethine dyes as fluorescent probes in double-stranded DNA detection in homogeneous assays. 相似文献
83.
SM Jeyakumar M Raja Gopal Reddy C Garlapati S Desi Reddy A Vajreswari 《Biochemistry and Biophysics Reports》2020
The role of sexual dimorphic adipose tissue fat accumulation in the development of insulin resistance is well known. However, whether vitamin A status and/or its metabolic pathway display any sex- or depot (visceral/subcutaneous)-specific pattern and have a role in sexual dimorphic adipose tissue development and insulin resistance are not completely understood. Therefore, to assess this, 5 weeks old Wistar male and female rats of eight from each sex were provided either control or diabetogenic (high fat, high sucrose) diet for 26 weeks. At the end, consumption of diabetogenic diet increased the visceral fat depots (p < 0.001) in the males and subcutaneous depot (p < 0.05) in the female rats, compared to their sex-matched controls. On the other hand, it caused adipocyte hypertrophy (p < 0.05) of visceral depot (retroperitoneal) in the females and subcutaneous depot of the male rats. Although vitamin A levels displayed sex- and depot-specific increase due to the consumption of diabetogenic diet, the expression of most of its metabolic pathway genes in adipose depots remained unaltered. However, the mRNA levels of some of lipid droplet proteins (perilipins) and adipose tissue secretory proteins (interleukins, lipocalin-2) did display sexual dimorphism. Nonetheless, the long-term feeding of diabetogenic diet impaired the insulin sensitivity, thus affected glucose clearance rate and muscle glucose-uptake in both the sexes of rats. In conclusion, the chronic consumption of diabetogenic diet caused insulin resistance in the male and female rats, but did not corroborate with sexual dimorphic adipose tissue fat accumulation or its vitamin A status. 相似文献
84.
Current definitions of habitat are closely allied to the concept of patch and matrix. This concept is, for instance, central to the prevailing metapopulation models of population dynamics. But, butterfly population
dynamics, mobility and spatial structure can only properly be understood in the context of a resource-based definition of
habitats. In criticising current definitions of habitat, we illustrate how habitat is best understood in terms of resource
distributions. These transcend vegetation-based definitions of habitat and lie at the root of life history strategies, the
vulnerability of butterflies to environmental changes and extinction, and govern conservation status. We emphasise the need
for a resource-use database and demonstrate the shortcomings of current data for conserving butterflies; patch based definitions
of habitats are inappropriate for some species and for others do not provide a universal panacea, inadequately explaining
spatial occurrence when scaled over space and time. A resource-based habitat definition challenges the bipolar, patch vs. matrix view of landscape; the alternative is to view landscape as a continuum of overlapping resource distributions. We urge greater
attention to the details of butterfly behaviour and resource use as the keys to understanding how landscape is exploited and
therefore to successful conservation at the landscape scale. 相似文献
85.
AE Clarke S Bernatsky KH Costenbader MB Urowitz DD Gladman PR Fortin M Petri S Manzi DA Isenberg A Rahman D Wallace C Gordon C Peschken MA Dooley EM Ginzler C Aranow SM Edworthy O Nived S Jacobsen G Ruiz-Irastorza E Yelin SG Barr L Criswell G Sturfelt L Dreyer I Blanco L Gottesman CH Feldman R Ramsey-Goldman 《Arthritis research & therapy》2012,14(Z3):A16
86.
Jayne E Rattray Marc Strous Huub JM Op den Camp Stefan Schouten Mike SM Jetten Jaap S Sinninghe Damsté 《Biology direct》2009,4(1):8-16
Background
The fatty acids of anaerobic ammonium oxidizing (anammox) bacteria contain linearly concatenated cyclobutane moieties, so far unique to biology. These moieties are under high ring strain and are synthesised by a presently unknown biosynthetic pathway. 相似文献87.
88.
Host plants and butterfly biology. Do host‐plant strategies drive butterfly status? 总被引:10,自引:1,他引:9
Roger L. H. Dennis John G. Hodgson Richard Grenyer Tim G. Shreeve David B. Roy 《Ecological Entomology》2004,29(1):12-26
Abstract. 1. To determine whether rarity and decline is linked to organism ecology, associations have been examined between butterfly larval host‐plant competitive, stress‐tolerant, ruderal (C‐S‐R) strategies and butterfly biology. 2. Associations have been sought between mean C‐S‐R scores for larval host plants with butterfly life history, morphology and physiology variables, resource use, population attributes, geography, and conservation status. Comparisons are carried out across species and controlled for phylogenetic patterning. 3. Butterfly biology is linked to host‐plant strategies. An increasing tendency of a butterfly's host plants to a particular strategy biases that butterfly species to functionally linked life‐history attributes and resource breadth and type. In turn, population attributes and geography are significantly and substantially affected by host choice and the strategies of these host plants. 4. The greatest contrast is between butterfly species whose host plants are labelled C and R strategists and those whose host plants are labelled S strategists. Increasingly high host‐plant C and R strategy scores bias butterflies to rapid development, short early stages, multivoltinism, long flight periods, early seasonal emergence, higher mobility, polyphagy, wide resource availability and biotope occupancy, open, areally expansive, patchy population structures, denser distributions, wider geographical ranges, resistance to range retractions as well as to increasing rarity in the face of environmental changes. Increasing host‐plant S strategy scores have reversed tendencies, biasing those butterfly species to extended development times, fewer broods, short flight periods, smaller wing expanse and lower mobility, monophagy, restricted resource exploitation and biotope occupancy, closed, areally limited populations with typical metapopulation structures, sparse distributions, and limited geographical ranges, range retractions, and increased rarity. 5. Species with S strategy host plants are species vulnerable to current environmental changes and species of conservation concern. 相似文献
89.
Multiple transect counts following Butterfly Monitoring Scheme (UKBMS) guidelines and Jolly–Seber estimates of population
size were used to monitor the abundance of second generation Lasiommata megera on a single site in southern England. The two methods resulted in different patterns of emergence being detected. The proportion
of the population (estimated by Jolly–Seber) recorded with transect counts depended on the time of day and weather with afternoon
transect counts best recording the trend in abundance over the flight period, but even then counts recorded a variable fraction
of the population (6.2–51.3%). Increasing the frequency with which transect counts are carried out per week reduced variation
and increased the fit of transect counts to Jolly–Seber generated population estimates. However, indices of abundance generated
from randomly selected transect counts for L. megera within sampling weeks varied 4-fold and indices for other butterfly species were also highly variable. For L. megera, transect count variability is attributed to non-representative placement of the transect route and changes in the behaviour
and spatial distribution in relation to population size and season. We suggest that transect counts need to be fully validated
before the data are used to monitor changes of butterfly populations at individual sites. 相似文献
90.
Shreeve SM Sreedharan SP Hacker MP Gannon DE Morgan MJ 《Biochemical and biophysical research communications》2000,272(3):922-928
We have characterized vasoactive intestinal peptide (VIP) receptor/G-protein coupling in rat alveolar macrophage (AM) membranes and find that pertussis toxin treatment and antisera against G(alphai3) and G(alphas) reduce high-affinity (125)I-VIP binding, indicating that both G(alphas) and G(alphai3) couple to the VIP-receptor. The predominant VIP-receptor subtype in AM is VPAC(1) and we examined the G-protein interactions of the human VPAC(1) that had been transfected into HEK293 cells. VPAC(1) has a molecular mass of 56 kDa; GTP analogs reduced (125)I-VIP binding to this protein demonstrating that high-affinity binding of VIP to the receptor requires coupling to G-protein. Functional VIP/VPAC(1)/G-protein complexes were captured by covalent cross-linking and analyzed by Western blotting. The transfected human VPAC(1) receptor in HEK293 was found to be coupled to G(alphas) but not G(alphai) or G(alphaq). Furthermore, pertussis toxin treatment had no effect on VPAC(1)/G-protein coupling in these cells. These observations suggest that the G-proteins activated by VPAC(1) may be dependent upon species and cell type. 相似文献