SummaryThe effect of long‐term (30 days) NaCl treatments (100 mM and 200 mM) on the activity of some antioxidant enzymes, level of antioxidant metabolites, water relations and chloroplast ultrastructure, was studied in potato (Solanum tuberosum cv. Désirée) leaves. Salt stress negatively affected relative water content, leaf stomatal conductance and transpiration rate. In treated plants, proline was enhanced, but there was a significant decrease in ascorbate and proteins. Total superoxide dismutase activity was increased. The isozyme patterns detected in native gels from salt‐irrigated plants were not changed although all the isoforms appeared more heavily stained due to higher activity. In contrast, at both levels of NaCl, catalase activity decreased and ascorbate peroxidase activity showed no significant change in comparison with an untreated control. At ultrastructural level, only thylakoid swelling and a decrease in the amount of grana stacking was observed in treated plants. The overall behaviour of the antioxidant enzymes suggests an increase of cellular H2O2 that would contribute to the oxidative stress of potato plants, but which may be alleviated somewhat by the enhanced levels of proline.
Many cyanobacteria produce extracellular polymeric substances (EPS) mainly of polysaccharidic nature. These EPS can remain associated to the cell surface as sheaths, capsules and/or slimes, or be liberated into the surrounding environment as released polysaccharides (RPS). The ability of EPS-producing cyanobacteria to remove heavy metals from aqueous solutions has been widely reported in the literature, focusing mainly on the biotechnological potential. However, the knowledge of the effects of the metals in the cell's survival/growth is still scarce, particularly when they are simultaneously exposed to more than one metal. This work evaluated the effects of different concentrations of Cu 2+ and/or Pb 2+ in the growth/survival of Gloeothece sp. PCC 6909 and its sheathless mutant Gloeothece sp. CCY 9612. The results obtained clearly showed that both phenotypes are more severely affected by Cu 2+ than Pb 2+ , and that the mutant is more sensitive to the former metal than the wild-type. Evident ultrastructural changes were also observed in the wild-type and mutant cells exposed to high levels (10 mg l "1 ) of Cu 2+ . Moreover, in bi-metal systems, Pb 2+ was preferentially removed compared with Cu 2+ , being the RPS of the mutant that is the most efficient polysaccharide fraction in metal removal. In these systems, the simultaneous presence of Cu 2+ and Pb 2+ caused a mutual inhibition in the adsorption of each metal.
Cyanobacteria are important primary producers, and many are able to fix atmospheric nitrogen playing a key role in the marine environment. However, not much is known about the diversity of cyanobacteria in Portuguese marine waters. This paper describes the diversity of 60 strains isolated from benthic habitats in 9 sites (intertidal zones) on the Portuguese South and West coasts. The strains were characterized by a morphological study (light and electron microscopy) and by a molecular characterization (partial 16S rRNA, nifH, nifK, mcyA, mcyE/ndaF, sxtI genes).The morphological analyses revealed 35 morphotypes (15 genera and 16 species) belonging to 4 cyanobacterial Orders/Subsections. The dominant groups among the isolates were the Oscillatoriales. There is a broad congruence between morphological and molecular assignments.The 16S rRNA gene sequences of 9 strains have less than 97% similarity compared to the sequences in the databases, revealing novel cyanobacterial diversity. Phylogenetic analysis, based on partial 16S rRNA gene sequences showed at least 12 clusters. One-third of the isolates are potential N2-fixers, as they exhibit heterocysts or the presence of nif genes was demonstrated by PCR. Additionally, no conventional freshwater toxins genes were detected by PCR screening.
This work shows the holistic effects of different heavy metals on the cells of the highly efficient EPS-producer the cyanobacterium Cyanothece sp. CCY 0110. The growth/survival, EPS production, ultrastructure, protein profiles and stress response were evaluated. The knowledge generated by this study will contribute to the implementation of heavy-metal removal systems based on cyanobacteria EPS or their isolated polymers.
RESUMO Objetivo Análise do conhecimento de idosos acerca da síndrome e do vírus da imunodeficiência humana. Métodos Estudo descritivo, transversal e quantitativo envolvendo 457 idosos da Unidade de Atenção ao Idoso de Uberaba, Minas Gerais, durante 3 meses. Foram aplicados os instrumentos Mini Exame do Estado Mental e o questionário sobre o vírus da imunodeficiência humana para terceira idade e, para a análise, foram usadas medidas de frequência. Resultados A maioria dos participantes eram mulheres (74%), entre 60 a 69 anos (51%). O maior índice de acertos obteve a transmissão por agulhas 96,2% e o menor (45,3%), a transmissão pela picada de mosquito e se a pessoa com o vírus da imunodeficiência humana sempre apresenta sintomas (49,6%). 88,2% deles relataram nunca usar camisinha. Conclusões O nível geral de conhecimento pode ser considerado bom, respondendo ao nosso objetivo. No entanto, foram identificadas lacunas decorrentes da falta de campanhas voltadas exclusivamente para tal público, bem como na conscientização de profissionais.
Objective: to examine adolescents' perception about spirituality, religion and personal beliefs in their lives due to cancer and a possible strategy for coping with the disease. Method: qualitative research, both descriptive and exploratory. The data were collected by means of a personal semi-structured interview, and the categories were analyzed by content analyzes. Results: nine adolescents who were undergoing cancer treatment at one of the two institutions located Uberaba, Brazil, participated in the study. Based on the analysis and interpretation of results, it was possible to systematize them according to four categories: spiritual history of the individual; faith and belief; importance of spirituality in their lives, and the community acting as a spiritual supporter. Most adolescents referred to spirituality as being an important tool for dealing with the disease, especially concerning religious rituals and community support. Conclusion: spirituality creates hope for adolescents, which helps them to cope with cancer-related diffi culties and contribute to the search for the meaning of life. Key words: Adolescent; Cancer; Spirituality. RESUMO Objetivo: analisar a concepção dos adolescentes a respeito da espiritualidade, religiosidade e crenças pessoais presentes em suas vidas devido ao câncer e como estratégia de enfrentamento da doença. Método: pesquisa qualitativa, do tipo descritiva e exploratória. Os dados foram coletados através de um roteiro de entrevista semi-estruturado, as categorias foram defi nidas segundo a análise de conteúdo. Resultados: participaram nove adolescentes que estavam em tratamento oncológico em duas instituições na cidade de Uberaba, Minas Gerais. Os dados foram sistematizados em quatro categorias: história espiritual do indivíduo; fé e crença; importância da espiritualidade em sua vida; e a comunidade enquanto apoio espiritual. A maioria dos adolescentes referiu a espiritualidade importante no enfrentamento a doença, especialmente a partir de rituais religiosos e apoio da comunidade. Conclusão: a espiritualidade gera esperança para os adolescentes, auxiliando no enfrentamento das difi culdades relacionadas ao câncer e na busca pelo sentido da vida. Descritores: Adolescente; Câncer; Espiritualidade. RESUMEN Objetivo: examinó la percepción de los adolescentes acerca de la espiritualidad, la religión y las creencias personales en sus vidas por el cáncer y una posible estrategia para hacer frente a la enfermedad. Método: se realizó una investigación cualitativa, descriptivo y exploratorio, del guión de la entrevista semi-estructurada sobre la base de las literaturas afi nes, lo que permitió la defi nición de categorías, analizadas desde la perspectiva del análisis de contenido. Resultados: asistió a nueve jóvenes que fueron sometidos a tratamiento contra el cáncer en las dependencias de ambas instituciones ubicadas en la ciudad de Uberaba, Minas Gerais, Brasil. A partir del análisis fue posible sistematizar de acuerdo a cuatro categorías: historia espiritual de la persona, l...
Cyanobacteria represent one of the most common members of the sponge-associated bacterial community and are abundant symbionts of coral reef ecosystems. In this study we used Transmission Electron Microscopy (TEM) and molecular techniques (16S rRNA gene marker) to characterize the spatial distribution of cyanobionts in the widely dispersed marine intertidal sponge Hymeniacidon perlevis along the coast of Portugal (Atlantic Ocean). We described new sponge associated cyanobacterial morphotypes (Xenococcus-like) and we further observed Acaryochloris sp. as a sponge symbiont, previously only reported in association with ascidians. Besides these two unique cyanobacteria, H. perlevis predominantly harbored Synechococcus sp. and uncultured marine cyanobacteria. Our study supports the hypothesis that the community of sponge cyanobionts varies irrespective of the geographical location and is likely influenced by seasonal fluctuations. The observed multiple cyanobacterial association among sponges of the same host species over a large distance may be attributed to horizontal transfer of symbionts. This may explain the absence of a co-evolutionary pattern between the sponge host and its symbionts. Finally, in spite of the short geographic sampling distance covered, we observed an unexpected high intra-specific genetic diversity in H. perlevis using the mitochondrial genes ATP6 (π = 0.00177), COI (π = 0.00241) and intergenic spacer SP1 (π = 0.00277) relative to the levels of genetic variation of marine sponges elsewhere. Our study suggests that genotypic variation among the sponge host H. perlevis and the associated symbiotic cyanobacteria diversity may be larger than previously recognized.
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