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31.
Pimm SL Ayres M Balmford A Branch G Brandon K Brooks T Bustamante R Costanza R Cowling R Curran LM Dobson A Farber S da Fonseca GA Gascon C Kitching R McNeely J Lovejoy T Mittermeier RA Myers N Patz JA Raffle B Rapport D Raven P Roberts C Rodriguez JP Rylands AB Tucker C Safina C Samper C Stiassny ML Supriatna J Wall DH Wilcove D 《Science (New York, N.Y.)》2001,293(5538):2207-2208
32.
Rapid adaptive fixation of a new favorable mutation is expected to affect neighboring genes along the chromosome. Evolutionary theory predicts that the chromosomal region would show a reduced level of genetic variation and an excess of rare alleles. We have confirmed these predictions in a region of the X chromosome of Drosophila melanogaster that contains a newly evolved gene for a component of the sperm axoneme. In D. simulans, where the novel gene does not exist, the pattern of genetic variation is consistent with selection against recurrent deleterious mutations. These findings imply that the pattern of genetic variation along a chromosome may be useful for inferring its evolutionary history and for revealing regions in which recent adaptive fixations have taken place. 相似文献
33.
Andrea Pulfrich Colleen A. Parkins George M. Branch Rodrigo H. Bustamante Claudio R. Velsquez 《水产资源保护:海洋与淡水生态系统》2003,13(3):257-278
- 1. Extensive diamond mining occurs on land and in the sea on the west coasts of South Africa and Namibia, raising fears that diamond‐mining activities may impact commercial rock‐lobster fisheries and benthic communities. To explore this possibility, the effects of the diamond‐mining fines‐discharge on intertidal and subtidal rocky‐shore communities and on the population structure of the rock lobster Jasus lalandii were assessed at Elizabeth Bay.
- 2. Sampling over six years at sites covering a range of wave exposures compared impacted sites with comparable reference sites never exposed to the fines. Percentage cover and densities of benthic organisms were recorded on both intertidal and subtidal reefs. Rock‐lobster abundance was estimated from counts and catch‐per‐unit‐effort, and their length frequencies and sex ratios compared in impacted and reference areas.
- 3. The deposition of fines had no effect at wave‐exposed sites, but did impact intertidal and subtidal communities at sheltered localities where fines accumulated because wave action was insufficient to disperse them. Reductions of grazers, proliferation of algae and increased dominance by filter‐feeders were recorded at the impacted sites and persisted throughout the monitoring programme. Differences in community structure associated with different levels of wave exposure were, however, greater than those produced by depositing fines. The detected effects of fines‐deposits on the benthos were local and likely to be reversible after cessation of mining.
- 4. The fines‐deposit had no detectable effects on the sex‐ratio, size or abundance of rock lobsters, indicating that there is no conflict between the deposition of fines and the fishery for rock lobsters, although substantial inter‐site variability makes it difficult to regard the results as definitive.
34.
Irene Gavilanes-Terán Aurelia Pérez-Espinosa M. Ángeles Bustamante Luís Gálvez-Sola Janneth Jara-Samaniego 《Communications in Soil Science and Plant Analysis》2015,46(4):137-156
The increase of the agroindustrial sector in South America gives the opportunity to apply the most effective strategies for the disposal and treatment of generated organic wastes. Therefore, it is important to identify the variability in the composition of the agroindustrial wastes to carry out their adequate management. The Ecuadorian province of Chimborazo is located in the central area of the inter-Andean corridor. The main agroindustries in this province are related to the production of vegetables, meat, ornamental plants, flour from different cereals and wood. The management of the wastes from these agroindustries is not optimized with respect to the associated environmental consequences. Therefore, the aim of this work was to carry out a characterization of the different organic wastes from agroindustry to evaluate their potential use as soil amendments. Twenty-seven samples of different types of agroindustrial wastes from the vegetable and animal food-processing industry, wood industry, and ornamental plant production were evaluated for pH, electrical conductivity, water-soluble anions, organic matter, total organic carbon (Corg), total nitrogen (Nt), C/N ratio, water-soluble carbon (Cw), water-soluble polyphenols, macro- and micronutrients, potentially toxic elements, and germination index (GI). The results showed that, in general, the agroindustrial residues were characterized by acidic pH, low EC values, and high organic-matter contents. The macro- and micronutrients and heavy-metal concentrations were greater in the animal agroindustrial wastes than in those from vegetable sources. Most of the materials showed high C/N ratio, low GI values, and high Cw contents, which indicated a lack of organic-matter stability, due to the high content of easily degradable and phytotoxic compounds. 相似文献
35.
Caio V. Z. Cipro Paco Bustamante Rosalinda C. Montone 《Water, air, and soil pollution》2017,228(5):188
The use of low-polarity organic solvents is widespread in cleanup/extraction processes in order to carry compounds of interest, remove interferences and separate phases, among other uses. A large number of studies have used delipidation to remove excess of lipids to analyse carbon stable isotopes in biological tissues for trophic and behavioural ecology investigations. In this context, the primary aim of this study is to assess the influence of one delipidation process on the results of total mercury (Hg) analyses and the possible use of delipidated samples from previous analyses, such as for stable isotopes, in Hg level determination. Samples of vegetation (angiosperm, lichens and mosses), invertebrates (krill and limpets), fish (marbled and black rockcod), bird liver and eggs (Antarctic, Gentoo and Adélie penguins, kelp gull, Antarctic tern, cape petrel and giant southern petrel) and pinniped tissues (Weddell seal, crabeater seal, southern elephant seal and Antarctic fur seal) were analysed for Hg before and after delipidation by cyclohexane. The difference between the two measurements ranged individually from ?63 to 136% (in the moss Sanionia uncinata) and the averages ranged from ?60 to 66% (in pinniped tissues). The proportion of organic Hg, which presents considerable lipophilicity, but also high affinity for sulfhydryl groups in proteins, might be responsible for such variability. Given the limitations of our study, we think it is safe to say that delipidated samples could not be used to infer total Hg values in non-delipidated ones. 相似文献
36.
Serum samples of 113 dogs visiting "outpatient clinics", 52 dogs kept in shelters and 35 animals from a military dog training centre were examined for Toxoplasma gondii specific antibodies using a latex agglutination test. Significant differences in seroprevalences were found between dogs from the training centre (8.6% of positive results) and the other populations examined (40.7% of positive seroreagents in animals visiting outpatient clinics and 44.2% in the group from shelters, respectively). Among clinic patients, dogs fed raw meat were significantly more frequently seropositive (65.2%) than those eating only commercial dry feed or cooked meat (25.7%). No statistically significant differences were noted in males compared to females and in pure breed dogs compared to crossbreed dogs. The antibodies were usually found in low titres under 60 IU/ml (69.6% of positive results). High titres (120-480 IU/ml) were detected in 2 of 3 dogs with clinical toxoplasmosis. In these dogs IFAT T. gondii specific IgM were detected and a favourable response to antiprotozoal treatment was observed. All the dogs with medium and high titres were given raw meat. Age and the presence of cats did not seem to have any influence on T. gondii seroprevalence. Neospora caninum specific antibodies in low titres ranging from 1:20-1:320 were found in 7 (9.7%) of 72 T. gondii positive seroreagents. 相似文献
37.
Jackson PC Meinzer FC Bustamante M Goldstein G Franco A Rundel PW Caldas L Igler E Causin F 《Tree physiology》1999,19(11):717-724
Source water used by woody perennials in a Brazilian savanna (Cerrado) was determined by comparing the stable hydrogen isotope composition (deltaD) of xylem sap and soil water at different depths during two consecutive dry seasons (1995 and 1996). Plant water status and rates of water use were also determined and compared with xylem water deltaD values. Overall, soil water deltaD decreased with increasing depth in the soil profile. Mean deltaD values were -35 per thousand for the upper 170 cm of soil and -55 per thousand between 230 and 400 cm depth at the end of the 1995 dry season. Soil water content increased with depth, from 18% near the surface to about 28% at 400 cm. A similar pattern of decreasing soil water deltaD with increasing depth was observed at the end of the 1996 dry season. Patterns consistent with hydraulic lift were observed in soil profiles sampled in 1995 and 1997. Concurrent analyses of xylem and soil water deltaD values indicated a distinct partitioning of water resources among 10 representative woody species (five deciduous and five evergreen). Among these species, four evergreen and one deciduous species acquired water primarily in the upper soil layers (above 200 cm), whereas three deciduous and one evergreen species tapped deep sources of soil water (below 200 cm). One deciduous species exhibited intermediate behavior. Total daily sap flow was negatively correlated with xylem sap deltaD values indicating that species with higher rates of water use during the dry season tended to rely on deeper soil water sources. Among evergreen species, minimum leaf water potentials were also negatively correlated with xylem water deltaD values, suggesting that access to more readily available water at greater depth permitted maintenance of a more favorable plant water status. No significant relationship between xylem water deltaD and plant size was observed in two evergreen species, suggesting a strong selective pressure for small plants to rapidly develop a deep root system. The degree of variation in soil water partitioning, leaf phenology and leaf longevity was consistent with the high diversity of woody species in the Cerrado. 相似文献
38.
Rocío Bustamante María A. Daza Susana Canfrán Paloma García María Suárez Ignacio Trobo Ignacio A. Gómez de Segura 《Veterinary anaesthesia and analgesia》2018,45(4):545-556
Objective
To determine the noninferior postoperative analgesic efficacy of cimicoxib compared to buprenorphine following elective ovariohysterectomy in healthy bitches.Study design
Prospective, randomized, blinded, controlled clinical trial.Animals
A total of 63 healthy dogs.Methods
To provide perioperative analgesia, cimicoxib 2 mg kg?1 (orally), buprenorphine 0.02 mg kg?1 (two doses, intramuscularly), or both drugs combined, were administered. Dogs were sedated with acepromazine and anaesthetized with propofol and isoflurane. Pain was assessed with the short form of the Glasgow Composite Pain Scale (GCPS), a pain numerical rating scale (NRS) and mechanical nociceptive thresholds (MNT), preoperatively and at 1, 2, 4, 6, 20 and 23 hours after extubation. Sedation was also scored at the same time points. A noninferiority approach was employed to determine the efficacy of cimicoxib compared to buprenorphine. Treatment groups were compared with parametric [analysis of variance (anova), t test] and nonparametric test as appropriate (Kruskal–Wallis, chi-square).Results
The GCPS, pain NRS and MNT tests demonstrated noninferiority of cimicoxib compared to buprenorphine (rejection of inferiority: p < 0.001, all). Furthermore, cimicoxib provided better analgesia compared to buprenorphine alone according to the GCPS (p < 0.01) and NRS (p < 0.05), but not the MNT. Conversely, an increase in the analgesic effect when cimicoxib was combined with buprenorphine was only observed with the MNT (p < 0.01). There were no differences in rescue analgesia requirements both intra- and postoperatively between treatments. Gastrointestinal side effects were increased in dogs administered cimicoxib, whereas dogs treated with buprenorphine had higher sedation scores 1-hour postoperatively and required lower doses of propofol for the induction of anaesthesia.Conclusions and clinical relevance
Cimicoxib has noninferior postoperative analgesic efficacy compared to buprenorphine, and both drugs have comparable analgesic effects for the control of postoperative pain in bitches undergoing ovariohysterectomy. 相似文献39.
40.