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161.
162.
FERNANDO ANDRADE-NARVAEZ SILVIA B. CANTO-LARA MARIA DEL ROSARIO GARCIA-MISS 《Developing world bioethics》2009,9(3):157-160
Occupational health remains neglected in developing countries because of competing social, economic and political challenges. Ethical issues in the workplace related to the hazards and risks of becoming infected by Leishmania (Leishmania) mexicana , through the bite of naturally infected sand flies, is another area of concern that has been neglected as well. We report here the results of reviewing two entomological field studies carried out in our research center from 2003 to 2006. Eight students from our School of Biology were invited to catch sand flies. A total of six of the eight (75%) developed a typical clinical picture of Localized Cutaneous Leishmaniasis (LCL) caused by L. (L.) mexicana . In this article we identify the ethical issues related to these kinds of studies and propose some guidelines for conducting them. 相似文献
163.
In modern malting barley breeding it is important to increase the level of -amylase activity level in barley. The aim of this study was to investigate if a PCR method for screening -amy1 alleles can be used as an indicator for -amylase activity level in barley. Activity was assayed from 24 cultivars, 7 lines, and a Hordeum spontaneum PI 296897 strain grown in the same field. The -amy1 alleles were identified by amplifying the intron III-specific region of the gene using PCR. No new alleles were detected in addition to the three alleles found earlier: cv Adorra-like, cv Haruna Nijo-like and PI 296897-like -amy1 allele. Samples were grouped according to the nature of their -amy1 locus and enzyme activities were compared between the groups. Cultivars carrying a cv Haruna Nijo-like -amy1 allele had 1.3 times and lines carrying a PI 296897-like -amy1 allele had 2.1 times higher -amylase activity than cultivars carrying a cv Adorra-like -amy1 allele. The mean activities are significantly different in the allele groups (Kruskal–Wallis: for protein H= 11.54, P< 0.01; for meal H= 12.74, P< 0.01). PCR fragments can be used as allele specific markers to predict the level of -amylase activity in breeding when such variation of the intron III is concerned. 相似文献
164.
GUSTAVO SEBASTIÁN CABANNE FABRÍCIO R. SANTOS CRISTINA YUMI MIYAKI 《Biological journal of the Linnean Society. Linnean Society of London》2007,91(1):73-84
Knowledge of the evolutionary processes that shaped a biota is important for both academic and conservation purposes. The objective of the present study is to analyse the mitochondrial genetic variation of Xiphorhynchus fuscus (Aves: Dendrocolaptidae) from the southern Atlantic forest in Brazil and Argentina, and to discuss whether the results support different hypotheses regarding the local intraspecific diversification of this species . We sequenced 575 bp of the control region of 114 specimens collected in the Brazilian states of Bahia, Minas Gerais, Rio de Janeiro, São Paulo, Paraná, and Santa Catarina, and in the province of Misiones in Argentina. We studied the population genetic structure with analysis of molecular variance and the demographic history with multiple regression analysis, coalescence simulations, and demographic tests. Xiphorhynchus fuscus presented a significant population genetic structure (Φst = 0.57). Three mitochondrial lineages were described, one associated with Xiphorhynchus fuscus tenuirostris and the others with Xiphorhynchus fuscus fuscus. The data did not support the primary influence of geographical barriers or rivers in the intraspecific diversification of X. fuscus in the southern Atlantic forest. Instead, the data supported the influence of isolation by geographical distance, recent vicariance events, and demographic expansions apparently related to Pleistocene and Holocene forest dynamics. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 91 , 73–84. 相似文献
165.
MARIA CRISTINA LORENZI MARCO CALDI RITA CERVO 《Biological journal of the Linnean Society. Linnean Society of London》2007,91(3):505-512
Polistes foundresses can behave as facultative social parasites when, instead of founding their own nest, they usurp colonies of the same or a different species and temporary use the host workforce to raise their own brood. Conspecific usurpation appears to be common among Polistes wasps, but nothing is known about the mechanisms that these facultative social parasites use to have themselves accepted within usurped colonies. Using behavioural tests, we studied the chemical strategies employed by females of Polistes nimphus when they behave as facultative social parasites in colonies of the same or of a different species. We hypothesized that usurpers would mark host nests with their own odours and/or acquire host nest odours in order to camouflage their real identity from host workers. Our results indicated that P. nimphus usurpers used different chemical strategies depending on host nest species: they acquired conspecific host odours but marked heterospecific host combs with their own odours. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 91 , 505–512. 相似文献
166.
ANTONIO FLORES-MOYA IVÁN GÓMEZ BENJAMÍN VIÑEGLA MARÍA ALTAMIRANO EDUARDO PÉREZ-RODRÍGUEZ CRISTINA MAESTRE ROSARIO M. CABALLERO & FÉLIX L. FIGUEROA 《The New phytologist》1998,139(4):673-683
The effects of full-spectrum solar radiation and of solar radiation deprived of total u.v. radiation (λ<395 nm) on the endemic Mediterranean red alga Rissoella verruculosa (Bertoloni) J. Agardh were studied in situ in early summer, from sunrise to sunset. Photosynthetic performance, pigment content and the activities of enzymes related to nutrient uptake, were monitored under both radiation conditions throughout a daylight period.
The doses of solar radiation, measured on the day during which the experiments were carried out (24 June 1997), were 9228·25, 1109·70 and 13·03 kJ m−2 for PAR (λ=400–700 nm), u.v.-A (λ=315–400 nm) and u.v.-B (λ=280–315 nm), respectively. Under these conditions, a clear daily variation in photosynthetic performance was found. However, no significant differences were detected between the two radiation conditions. At noon, strong sunlight impaired O2 evolution by 75%, but complete recovery occurred during the afternoon, reaching similar values to those measured in the early morning. By contrast, photoinhibition of optimal quantum yield ( F v / F m ), and the relative electron transport rate was followed by only a slight recovery during the afternoon. The rate of photosynthesis in air (simulating emersion conditions), estimated by CO2 exchange, showed a negative balance at noon, which was accentuated in plants exposed to the full-solar spectrum.
Significant changes in the activities of nitrate reductase and carbonic anhydrase were found throughout the day under both radiation conditions. In thalli receiving solar radiation deprived of u.v., total CA activity decreased throughout the day. However, in thalli exposed to full-spectrum solar radiation, the activity of the enzyme tended to increase in the afternoon, correlating with an increase in NR activity. 相似文献
The doses of solar radiation, measured on the day during which the experiments were carried out (24 June 1997), were 9228·25, 1109·70 and 13·03 kJ m
Significant changes in the activities of nitrate reductase and carbonic anhydrase were found throughout the day under both radiation conditions. In thalli receiving solar radiation deprived of u.v., total CA activity decreased throughout the day. However, in thalli exposed to full-spectrum solar radiation, the activity of the enzyme tended to increase in the afternoon, correlating with an increase in NR activity. 相似文献
167.
HIROTAKE ONO YOKO KAWA MARIA SANO MASARU ITO ATSUKO TAKANO YASUO KUBOTA JIRO MATSUMOTO MASAKO MIZOGUCHI 《Pigment cell & melanoma research》1998,11(5):291-298
Stem cell factor (SCF) has been suggested to be indispensable for the development of neural crest cells into melanocytes because Steel mutant mice (i.e., Sl/Sf1) have no pig-mented hairs. On the other hand, it has been demonstrated that the addition of endothelin 3 (ET-3) or TPA to neural crest cell cultures can induce melanocyte differentiation without addition of extrinsic SCF. In this study, we excluded the influence of intrinsic SCF by using SI/SI mouse embryos to study more precisely the effects of natural cytokines, such as extrinsic soluble SCF or ET-3, or chemical reagents, such as TPA or cholera toxin. We found that SCF is supplied within the wild-type neural crest explants and that ET-3 cannot induce melanocyte differentiation or proliferation without SCF. These results indicate that SCF plays a critical role in survival or G1/S entry of melanocyte progenitors and that SCF initially stimulates their proliferation and then ET-3 accelerates their proliferation and differentiation. TPA has the ability to elicit neural crest cell differentiation into melanocytes without exogenously added SCF but it is not as effective as SCF because many more melanocytes developed in the wild-type neural crest explants cultured with TPA. 相似文献
168.
MARIA GABRIELA CUEZZO 《Zoological Journal of the Linnean Society》2003,138(4):449-476
The monophyly of the land snail family Camaenidae has been in doubt due to a disjunct bihemispheric distributional pattern and to the lack of morphological synapomorphies. A cladistic analysis is presented using an ingroup composed of representatives of the three subfamilies distributed in Australia and 52 other species with American distribution. Bradybaenidae, Helicidae and Helminthoglyptidae were used as outgroups. Fifty morphological characters were treated as unordered and analysed using Pee-Wee ver. 2.9, a program for parsimony analysis using implied weights. The results of the analysis support Camaenidae as a monophyletic family (synapomorphies: oval genital orifice, absence of penial sheath). Two of the three Australasian subfamilies, Sinumeloninae and Camaeninae, are monophyletic in the strict consensus tree. The American taxa are classified in eight genera and arranged into two main clades. Caracolus is proposed as the sister group of the American Continental Camaenidae. The genus Solaropsis , previously excluded from this family by different authors, is reassigned to Camaenidae. Shell characters proved to be phylogenetically informative in defining Pleurodonte , Caracolus , Solaropsis , Isomeria and Labyrinthus . © 2003 The Linnean Society of London, Zoological Journal of the Linnean Society, 2003, 138, 449–476. 相似文献
169.
SORAYA C M LEAL-BERTIOLI ALETÉIA V PASCOAL PATRÍCIA M GUIMARÃES MARIA F GROSSI DE SÁ REJANE L GUIMARÃES DAMARES C MONTE DAVID J BERTIOLI 《The Annals of applied biology》2003,143(3):349-357
The protein Tarin 1, from Colocasia esculenta, was expressed in Nicotiana tabacum. Bioassays were done on plants expressing Tarin 1 at different levels using Spodoptera frugiperda larvae, various bacteria and fungi and the root‐knot nematode Meloidogyne javanica. It was found that S. frugiperda larvae fed on transformed plants had retarded and lower pupation, lower accumulated biomass and higher mortality rate than larvae fed on control plants. Also, Tarin 1 was found to inhibit the growth in vitro of Pseudomonas syringae pv. tomato. For Meloidogyne javanica, both relative replication and root damage were greater in control plants than in transformed plants, but the results were not statistically significant. This work illustrates the effects of plants expressing Tarin 1, on the growth and development of insects and bacteria, and shows its potential for pest management. 相似文献
170.
Molecular and morphological differentiation between steganacarid mites (Acari: Oribatida) from the Canary islands 总被引:1,自引:0,他引:1
ANNA MARIA AVANZATI MARIELLA BARATTI FABIO BERNINI F.L.S. 《Biological journal of the Linnean Society. Linnean Society of London》1994,52(4):325-340
Two steganacarid species, Steganacarus ( Steganacarus ) tenerifensis and S . ( S .) carlosi , the first endemic to Tenerife and the second to La Gomera and Tenerife, were found to have such wide morphological variability as to cast doubt on their specific limits. Cluster analysis and MDS ordering were used to quantify morphological variation, and biochemical procedures were used to assess genetic variation in the two entities. The results revealed disagreement between the morphological and genetic data as reported in previous studies on steganacarid mites. Morphological traits were highly heterogeneous in the Canary island populations and genetic structure was homogeneous with very low heterozygosity. The separation of the two Canary island species, not to mention the phenotypes close to carlosi , is difficult to justify due to their very high genetic identity. The presence of morphological intermediates suggests the same conclusion. However, the sympatry of some phenotypes and previous data on this animal group are a source of doubt and suggest that further investigations are needed before conclusions can be reached in this regard. Correlations between morphological differentiation and known palaeogeographic events are suggested in the light of the possible evolutionary history of the steganacarid mites on the Canary islands. 相似文献