RESUMO

One of the most populated areas of the world is the Metropolitan Zone of the Mexican Valley, which has serious atmospheric pollution problems. To the north of the Metropolitan Zone is the Protected Natural Area Sierra de Guadalupe (PNASG), an area with a high diversity of birds, close to an industrial zone, and poor air quality (AQ). It is known that a poor AQ affects biodiversity. Therefore, this study aimed to evaluate the AQ using O3, CO, NO2, PM10 and PM2.5 polar graphics atmospheric pollutants (PGAP) and the Integrated Air Quality Index (IAQI) to examine its relationship with the structural diversity (SD) and the functional diversity (FD) of the bird community of the PNASG. In autumn-2019 and winter-2020, bird surveys and the PGAP with the pollutant concentrations were performed using data from Mexico City air quality network. The IAQI, SD and FD were estimated. Autumn-2019 registered the worst IAQI (334), the lowest wind speed (1.5 m/s), and the highest PGAP values (90). These worst AQ and the highest PGAP values were outside the PNASG but into a green urban area. This site also showed the highest SD scores (87), reflecting that the green urban areas function as a refuge for birds. The study sites with the best AQ (130.37), the lowest PGAP values (0.1) and the highest FD (0.7) were inside the PNASG. We conclude that a poor AQ minimizes the FD and that the PNASG is an essential buffer and a biological conservation area. The combined use of an integrated index of air quality with the polar graphics and diversity of birds (SD and FD) allow a better interpretation of air quality. It is necessary to establish mechanisms ensuring the conservation of the protected natural areas and green urban areas to improve air quality and biodiversity conservation.

Assuntos

Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Animais , Aves , Cidades , Monitoramento Ambiental , México , Material Particulado/análise

RESUMO

Some bacterial species use a cell-to-cell communication mechanism called Quorum Sensing (QS). Bacteria release small diffusible molecules, usually termed signals which allow the activation of beneficial phenotypes that guarantee bacterial survival and the expression of a diversity of virulence genes in response to an increase in population density. The study of the molecular mechanisms that relate signal molecules with bacterial pathogenesis is an area of growing interest due to its use as a possible therapeutic alternative through the development of synthetic analogues of autoinducers as a strategy to regulate bacterial communication as well as the study of bacterial resistance phenomena, the study of these relationships is based on the structural diversity of natural or synthetic autoinducers and their ability to inhibit bacterial QS, which can be approached with a molecular perspective from the following topics: i) Molecular signals and their role in QS regulation; ii) Strategies in the modulation of Quorum Sensing; iii) Analysis of Bacterial QS circuit regulation strategies; iv) Structural evolution of natural and synthetic autoinducers as QS regulators. This mini-review allows a molecular view of the QS systems, showing a perspective on the importance of the molecular diversity of autoinducer analogs as a strategy for the design of new antimicrobial agents.

Assuntos

Anti-Infecciosos , Percepção de Quorum , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Percepção de Quorum/genética , Virulência

RESUMO

There is increasing evidence that mixed-species forests can provide multiple ecosystem services at a higher level than their monospecific counterparts. However, most studies concerning tree diversity and ecosystem functioning relationships use data from forest inventories (under noncontrolled conditions) or from very young plantation experiments. Here, we investigated temporal dynamics of diversity-productivity relationships and diversity-stability relationships in the oldest tropical tree diversity experiment. Sardinilla was established in Panama in 2001, with 22 plots that form a gradient in native tree species richness of one-, two-, three- and five-species communities. Using annual data describing tree diameters and heights, we calculated basal area increment as the proxy of tree productivity. We combined tree neighbourhood- and community-level analyses and tested the effects of both species diversity and structural diversity on productivity and its temporal stability. General patterns were consistent across both scales indicating that tree-tree interactions in neighbourhoods drive observed diversity effects. From 2006 to 2016, mean overyielding (higher productivity in mixtures than in monocultures) was 25%-30% in two- and three-species mixtures and 50% in five-species stands. Tree neighbourhood diversity enhanced community productivity but the effect of species diversity was stronger and increased over time, whereas the effect of structural diversity declined. Temporal stability of community productivity increased with species diversity via two principle mechanisms: asynchronous responses of species to environmental variability and overyielding. Overyielding in mixtures was highest during a strong El Niño-related drought. Overall, positive diversity-productivity and diversity-stability relationships predominated, with the highest productivity and stability at the highest levels of diversity. These results provide new insights into mixing effects in diverse, tropical plantations and highlight the importance of analyses of temporal dynamics for our understanding of the complex relationships between diversity, productivity and stability. Under climate change, mixed-species forests may provide both high levels and high stability of production.

Assuntos

Ecossistema , Árvores , Biodiversidade , Florestas , Panamá , Clima Tropical

RESUMO

Serotype 1 is one of the most common causes of pneumococcal disease worldwide. Pneumococcal protein vaccines are currently being developed as an alternate intervention strategy to pneumococcal conjugate vaccines. Pre-requisites for an efficacious pneumococcal protein vaccine are universal presence and minimal variation of the target antigen in the pneumococcal population, and the capability to induce a robust human immune response. We used in silico analysis to assess the prevalence of seven protein vaccine candidates (CbpA, PcpA, PhtD, PspA, SP0148, SP1912, SP2108) among 445 serotype 1 pneumococci from 26 different countries, across four continents. CbpA (76%), PspA (68%), PhtD (28%), PcpA (11%) were not universally encoded in the study population, and would not provide full coverage against serotype 1. PcpA was widely present in the European (82%), but not in the African (2%) population. A multi-valent vaccine incorporating CbpA, PcpA, PhtD and PspA was predicted to provide coverage against 86% of the global population. SP0148, SP1912 and SP2108 were universally encoded and we further assessed their predicted amino acid, antigenic and structural variation. Multiple allelic variants of these proteins were identified, different allelic variants dominated in different continents; the observed variation was predicted to impact the antigenicity and structure of two SP0148 variants, one SP1912 variant and four SP2108 variants, however these variants were each only present in a small fraction of the global population (<2%). The vast majority of the observed variation was predicted to have no impact on the efficaciousness of a protein vaccine incorporating a single variant of SP0148, SP1912 and/or SP2108 from S. pneumoniae TIGR4. Our findings emphasise the importance of taking geographic differences into account when designing global vaccine interventions and support the continued development of SP0148, SP1912 and SP2108 as protein vaccine candidates against this important pneumococcal serotype.

Assuntos

Variação Antigênica , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/administração & dosagem , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/patogenicidade , África , Alelos , Sequência de Aminoácidos , Antígenos de Bactérias/química , Antígenos de Bactérias/imunologia , Ásia , Proteínas de Bactérias/química , Proteínas de Bactérias/imunologia , Europa (Continente) , Geografia , Saúde Global , Humanos , Modelos Moleculares , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/patologia , Infecções Pneumocócicas/virologia , Vacinas Pneumocócicas/biossíntese , Vacinas Pneumocócicas/genética , Vacinas Pneumocócicas/imunologia , Sorogrupo , América do Sul , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/imunologia , Cobertura Vacinal/estatística & dados numéricos , Vacinas de Subunidades Antigênicas , Virulência

RESUMO

BACKGROUND: Measuring the structural diversity of compound databases is relevant in drug discovery and many other areas of chemistry. Since molecular diversity depends on molecular representation, comprehensive chemoinformatic analysis of the diversity of libraries uses multiple criteria. For instance, the diversity of the molecular libraries is typically evaluated employing molecular scaffolds, structural fingerprints, and physicochemical properties. However, the assessment with each criterion is analyzed independently and it is not straightforward to provide an evaluation of the "global diversity". RESULTS: Herein the Consensus Diversity Plot (CDP) is proposed as a novel method to represent in low dimensions the diversity of chemical libraries considering simultaneously multiple molecular representations. We illustrate the application of CDPs to classify eight compound data sets and two subsets with different sizes and compositions using molecular scaffolds, structural fingerprints, and physicochemical properties. CONCLUSIONS: CDPs are general data mining tools that represent in two-dimensions the global diversity of compound data sets using multiple metrics. These plots can be constructed using single or combined measures of diversity. An online version of the CDPs is freely available at: https://consensusdiversityplots-difacquim-unam.shinyapps.io/RscriptsCDPlots/.Graphical AbstractConsensus Diversity Plot is a novel data mining tool that represents in two-dimensions the global diversity of compound data sets using multiple metrics.