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91.
92.
Manuel Liebeke Michael W. Bruford Robert K. Donnelly Timothy M. D. Ebbels Jie Hao Peter Kille Elma Lahive Rachael M. Madison A. John Morgan Gabriela A. Pinto-Juma David J. Spurgeon Claus Svendsen Jacob G. Bundy 《Biology letters》2014,10(9)
Molecular genetic methods can distinguish divergent evolutionary lineages in what previously appeared to be single species, but it is not always clear what functional differences exist between such cryptic species. We used a metabolomic approach to profile biochemical phenotype (metabotype) differences between two putative cryptic species of the earthworm Lumbricus rubellus. There were no straightforward metabolite biomarkers of lineage, i.e. no metabolites that were always at higher concentration in one lineage. Multivariate methods, however, identified a small number of metabolites that together helped distinguish the lineages, including uncommon metabolites such as Nε-trimethyllysine, which is not usually found at high concentrations. This approach could be useful for characterizing functional trait differences, especially as it is applicable to essentially any species group, irrespective of its genome sequencing status. 相似文献
93.
J. B. Donnelly J. J. Lynch M. E. D. Webster 《International journal of biometeorology》1974,18(3):233-247
Heart rates, respiratory rates, body temperatures, ad libitum ‘day’ and ‘night’ food consumption and body weight changes have been examined in 15 mature Merino wethers shorn in moderate environmental conditions. All sheep showed a depression in food consumption for two days after shearing. Sheep that gained weight during the next three weeks then increased their food consumption at night by approximately 30% although the average daily consumption was only increased by 5%. Sheep that lost weight showed a depressed food consumption throughout the three week period after shearing. Marked increases in the temperature difference between ear skin and air as well as thermal tachypnoea during the warmest period of the day were recorded in all sheep 14–16 days after shearing. This indicated that the critical temperature for all sheep had decreased by about 10°C. These signs of acclimatisation appeared at similar times in all sheep, suggesting that increased resistance to body cooling developed at similar rates in weight gain and weight loss sheep and independent of the origin of body heat production. The results of the investigations are discussed in relation to the concept that the initial response to cold stress includes a depression in food intake and that the duration of this depression is a function of the cold stimulus and the strain it induces in the sheep. 相似文献
94.
During the last decade increasing attention has been given to the role of free radicals in biological oxidations. The subject has been of increasing interest to both the food scientist and the physiologist. Free radical scavengers in the form of both indigenous and added antioxidants are necessary for the successful preservation of food; free radicals are increasingly being implicated in the onset of, among others, ischaemic heart disease and for protection against these diseases it is suggested that the dietary intake of the antioxidant vitamins should be increased especially for diets high in polyunsaturated fats. 1,2 Convenience and snack foods which absorb substantial amounts of frying oils are being increasingly consumed. Since poly-unsaturated fatty acids are particularly susceptible to oxidation by free radicals during the storage, cooking and frying of foods, the potential risk of exposure to lipid degradation products' is likely to have increased. In foods the non-enzymic and lipoxygenase catalysed oxidation of polyunsaturated fatty acids, β-carotene and vitamin A can result in the loss of essential nutrients and the development of off-flavours. 相似文献
95.
The rosette assay was used to study antigen-binding activity by cells in lymphoid tissues of rabbits immunized with sheep red blood cells and in unimmunized controls. Percentages of rosette-forming cells (RFC) observed were compared with those of cells which secreted antibody (plaque-forming cells, PFC) and cells which both bound antigen and secreted antibody. Rosette-forming cells and PFC were shown to be two distinct reactive cell populations. Thus, in the spleen less than 1% of RFC also formed plaques. Immediately following antigen stimulation, the number of RFC in the bone marrow decreased to below detectable limits. After an initial rise, the number of RFC in the appendix declined similarly. In contrast, RFC levels in the spleen rose steadily from the time of immunization. These patterns suggest that bone marrow and appendix may function as a reservoir of antigen-binding cells which are released to other sites following antigenic stimulation. Rosette-forming cells were rarely observed in the thymus. Rosette-inhibition studies using antisera specific for bone marrow-derived cells (anti-B) and thymus-derived cells (anti-T) revealed a markedly greater proportion of T-RFC in the appendix than in the spleen. 相似文献
96.
R Moriggi Jr HS Di Mauro SC Dias JM Matos MB Urtado NF Camar?o IV Sousa Neto DC Nascimento RA Tibana CO Assump??o J Prestes CB Urtado 《Biology of sport / Institute of Sport》2015,32(4):289-294
Low intensity resistance exercise (RE) with blood flow restriction (BFR) has gained attention in the literature due to the beneficial effects on functional and morphological variables, similar to those observed during traditional RE without BFR, while the effects of BFR on post-exercise hypotension remain unclear. The aim of the present study was to compare the blood pressure (BP) response of trained normotensive individuals to RE with and without BFR. In this cross-over randomized trial, eight male subjects (23.8 ± 4 years, 74 ± 3 kg, 174 ± 4 cm) completed two exercise protocols: traditional RE (3 x 10 repetitions at 70% one-repetition maximum [1-RM]) and low intensity RE (3 x 15 repetitions at 20% 1-RM) with BFR. Blood pressure measurements were performed after 15 min of seated rest (0), immediately after and 10 min, 20 min, 30 min, 40 min, 50 min and 60 min after the experimental sessions. Similar hypotensive effects for systolic BP (SBP) were observed for both protocols (P < 0.05) after exercise, with no differences between groups (P > 0.05) and no statistically significant difference for diastolic BP (P > 0.05). These results suggest that in normotensive trained individuals, both traditional RE and RE with BFR induce hypotension for SBP, which is important to prevent cardiovascular disturbances. 相似文献
97.
J Prieto-Lloret D F Donnelly A J Rico R Moratalla C González R J Rigual 《Journal of applied physiology》2007,103(4):1269-1275
Hypoxia-induced dopamine (DA) release from carotid body (CB) glomus cells and activation of postsynaptic D(2) receptors have been proposed to play an important role in the neurotransmission process between the glomus cells and afferent nerve endings. To better resolve the role of D(2) receptors, we examined afferent nerve activity, catecholamine content and release, and ventilation of genetically engineered mice lacking D(2) receptors (D(2)(-/-) mice). Single-unit afferent nerve activities of D(2)(-/-) mice in vitro were significantly reduced by 45% and 25% compared with wild-type (WT) mice during superfusion with saline equilibrated with mild hypoxia (Po(2) approximately 50 Torr) or severe hypoxia (Po(2) approximately 20 Torr), respectively. Catecholamine release in D(2)(-/-) mice was enhanced by 125% in mild hypoxia and 75% in severe hypoxia compared with WT mice, and the rate of rise was increased in D(2)(-/-) mice. We conclude that CB transduction of hypoxia is still present in D(2)(-/-) mice, but the response magnitude is reduced. However, the ventilatory response to acute hypoxia is maintained, perhaps because of an enhanced processing of chemoreceptor input by brain stem respiratory nuclei. 相似文献
98.
Nicholas L. Silverman Brady W. Allred John Patrick Donnelly Teresa B. Chapman Jeremy D. Maestas Joseph M. Wheaton Jeff White David E. Naugle 《Restoration Ecology》2019,27(2):269-278
Restoration of riparian and wet meadow ecosystems in semiarid rangelands of the western United States is a high priority given their ecological and hydrological importance in the region. However, traditional restoration approaches are often intensive and costly, limiting the extent over which they can be applied. Practitioners are increasingly trying new restoration techniques that are more cost‐effective, less intensive, and can more practically scale up to the scope of degradation. Unfortunately, practitioners typically lack resources to undertake outcome‐based evaluations necessary to judge the efficacy of these techniques. In this study, we use freely available, satellite remote sensing to explore changes in vegetation productivity (normalized difference vegetation index) of three distinct, low‐tech, riparian and wet meadow restoration projects. Case studies are presented that range in geographic location (Colorado, Oregon, and Nevada), restoration practice (Zeedyk structures, beaver dam analogs, and grazing management), and time since implementation. Restoration practices resulted in increased vegetation productivity of up to 25% and increased annual persistence of productive vegetation. Improvements in productivity with time since restoration suggest that elevated resilience may further enhance wildlife habitat and increase forage production. Long‐term, documented outcomes of conservation are rare; we hope our findings empower practitioners to further monitor and explore the use of low‐tech methods for restoration of ecohydrologic processes at meaningful spatial scales. 相似文献
99.
Mzilahowa T Ball AJ Bass C Morgan JC Nyoni B Steen K Donnelly MJ Wilding CS 《Medical and veterinary entomology》2008,22(3):258-263
Abstract. Bioassays for insecticide resistance in adult mosquitoes were conducted on samples of Anopheles gambiae Giles s.l . (Diptera: Culicidae) species collected as larvae from breeding sites in the lower Shire Valley, Malawi. The results indicate full susceptibility to permethrin, deltamethrin and malathion, but reduced susceptibility to DDT in one sample from Thom (LT50 of 8.39 min for females and 25.09 min for males). Polymerase chain reaction-based species identification of the mosquitoes assayed revealed a mixture of Anopheles arabiensis Patton and Anopheles quadriannulatus (Theobold). The LT50 did not differ significantly between species. Genotyping of the L1014F and L1014S kdr alleles showed all mosquito specimens to be homozygous wild type; thus the reduced susceptibility detected is not attributable to target site insensitivity and instead is likely to be metabolic in nature. Anopheles quadriannulatus is characteristically zoophagic and exophilic. Indeed, of 82 Anopheles collected through knockdown collections within dwellings, only one was An. quadriannulatus and the rest were An. arabiensis . They are unlikely, therefore, to have been exposed to selection pressure arising from insecticide-treated net usage or to DDT indoor residual spraying. Therefore, it is suggested that this example of reduced susceptibility to DDT in An. quadriannulatus reflects selection in the larval stages. 相似文献
100.