Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 50
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
PLoS Med ; 17(10): e1003367, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33007052

RESUMO

BACKGROUND: Diabetes outcomes are influenced by host factors, settings, and care processes. We examined the association of data-driven integrated care assisted by information and communications technology (ICT) with clinical outcomes in type 2 diabetes in public and private healthcare settings. METHODS AND FINDINGS: The web-based Joint Asia Diabetes Evaluation (JADE) platform provides a protocol to guide data collection for issuing a personalized JADE report including risk categories (1-4, low-high), 5-year probabilities of cardiovascular-renal events, and trends and targets of 4 risk factors with tailored decision support. The JADE program is a prospective cohort study implemented in a naturalistic environment where patients underwent nurse-led structured evaluation (blood/urine/eye/feet) in public and private outpatient clinics and diabetes centers in Hong Kong. We retrospectively analyzed the data of 16,624 Han Chinese patients with type 2 diabetes who were enrolled in 2007-2015. In the public setting, the non-JADE group (n = 3,587) underwent structured evaluation for risk factors and complications only, while the JADE (n = 9,601) group received a JADE report with group empowerment by nurses. In a community-based, nurse-led, university-affiliated diabetes center (UDC), the JADE-Personalized (JADE-P) group (n = 3,436) received a JADE report, personalized empowerment, and annual telephone reminder for reevaluation and engagement. The primary composite outcome was time to the first occurrence of cardiovascular-renal diseases, all-site cancer, and/or death, based on hospitalization data censored on 30 June 2017. During 94,311 person-years of follow-up in 2007-2017, 7,779 primary events occurred. Compared with the JADE group (136.22 cases per 1,000 patient-years [95% CI 132.35-140.18]), the non-JADE group had higher (145.32 [95% CI 138.68-152.20]; P = 0.020) while the JADE-P group had lower event rates (70.94 [95% CI 67.12-74.91]; P < 0.001). The adjusted hazard ratios (aHRs) for the primary composite outcome were 1.22 (95% CI 1.15-1.30) and 0.70 (95% CI 0.66-0.75), respectively, independent of risk profiles, education levels, drug usage, self-care, and comorbidities at baseline. We reported consistent results in propensity-score-matched analyses and after accounting for loss to follow-up. Potential limitations include its nonrandomized design that precludes causal inference, residual confounding, and participation bias. CONCLUSIONS: ICT-assisted integrated care was associated with a reduction in clinical events, including death in type 2 diabetes in public and private healthcare settings.


Assuntos
Prestação Integrada de Cuidados de Saúde/estatística & dados numéricos , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Adulto , Estudos de Coortes , Feminino , Hong Kong/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Programas e Projetos de Saúde , Modelos de Riscos Proporcionais , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Autocuidado/métodos , Resultado do Tratamento
2.
Appl Environ Microbiol ; 85(15)2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31152014

RESUMO

The prevalence of microbial life in permafrost up to several million years (Ma) old has been well documented. However, the long-term survivability, evolution, and metabolic activity of the entombed microbes over this time span remain underexplored. We integrated aspartic acid (Asp) racemization assays with metagenomic sequencing to characterize the microbial activity, phylogenetic diversity, and metabolic functions of indigenous microbial communities across a ∼0.01- to 1.1-Ma chronosequence of continuously frozen permafrost from northeastern Siberia. Although Asp in the older bulk sediments (0.8 to 1.1 Ma) underwent severe racemization relative to that in the youngest sediment (∼0.01 Ma), the much lower d-Asp/l-Asp ratio (0.05 to 0.14) in the separated cells from all samples suggested that indigenous microbial communities were viable and metabolically active in ancient permafrost up to 1.1 Ma. The microbial community in the youngest sediment was the most diverse and was dominated by the phyla Actinobacteria and Proteobacteria In contrast, microbial diversity decreased dramatically in the older sediments, and anaerobic, spore-forming bacteria within Firmicutes became overwhelmingly dominant. In addition to the enrichment of sporulation-related genes, functional genes involved in anaerobic metabolic pathways such as fermentation, sulfate reduction, and methanogenesis were more abundant in the older sediments. Taken together, the predominance of spore-forming bacteria and associated anaerobic metabolism in the older sediments suggest that a subset of the original indigenous microbial community entrapped in the permafrost survived burial over geological time.IMPORTANCE Understanding the long-term survivability and associated metabolic traits of microorganisms in ancient permafrost frozen millions of years ago provides a unique window into the burial and preservation processes experienced in general by subsurface microorganisms in sedimentary deposits because of permafrost's hydrological isolation and exceptional DNA preservation. We employed aspartic acid racemization modeling and metagenomics to determine which microbial communities were metabolically active in the 1.1-Ma permafrost from northeastern Siberia. The simultaneous sequencing of extracellular and intracellular genomic DNA provided insight into the metabolic potential distinguishing extinct from extant microorganisms under frozen conditions over this time interval. This in-depth metagenomic sequencing advances our understanding of the microbial diversity and metabolic functions of extant microbiomes from early Pleistocene permafrost. Therefore, these findings extend our knowledge of the survivability of microbes in permafrost from 33,000 years to 1.1 Ma.


Assuntos
Bactérias Anaeróbias/metabolismo , Sedimentos Geológicos/microbiologia , Microbiota , Pergelissolo/microbiologia , Filogenia , Sibéria
3.
J Public Health (Oxf) ; 41(3): 476-486, 2019 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-30215743

RESUMO

BACKGROUND: Individual-level deprivation takes into account the non-monetary aspects of poverty that neither income poverty nor socio-economic factors could fully capture; however, it has rarely been considered in existing studies on social inequality in obesity. Therefore, we examined the associations of deprivation, beyond income poverty, with both general and abdominal obesity. METHODS: A territory-wide two-stage stratified random sample of 2282 community-dwelling Hong Kong adults was surveyed via face-to-face household interviews between 2014 and 2015. Deprivation was assessed by a Deprivation Index specific to the Hong Kong population. General obesity was defined as body mass index (BMI) ≥ 25 kg/m2, while abdominal obesity was defined as waist circumference (WC) ≥ 90 cm/80 cm for male/female. Multivariable binary logistic regressions were performed. RESULTS: Deprivation was independently associated with abdominal obesity (odds ratios (OR) = 1.68; 95% confidence intervals (CI): 1.27-2.22); however, no significant association was found with general obesity (OR=1.03; CI: 0.77-1.38). After additional adjustment for BMI, deprivation remained strongly associated with abdominal obesity (OR=2.00; CI: 1.41-2.83); and after further adjustment for WC, deprivation had a marginal inverse association with general obesity (OR=0.72; CI: 0.51-1.01). CONCLUSIONS: Deprivation is an important risk factor of abdominal obesity and plays a critical role in capturing the preferential abdominal fat deposition beyond income poverty.


Assuntos
Povo Asiático/estatística & dados numéricos , Disparidades nos Níveis de Saúde , Obesidade Abdominal/epidemiologia , Pobreza/estatística & dados numéricos , Adolescente , Adulto , Idoso , Hong Kong/epidemiologia , Humanos , Renda , Pessoa de Meia-Idade , Fatores de Risco , Inquéritos e Questionários , Adulto Jovem
4.
Proc Natl Acad Sci U S A ; 113(49): E7927-E7936, 2016 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-27872277

RESUMO

Subsurface lithoautotrophic microbial ecosystems (SLiMEs) under oligotrophic conditions are typically supported by H2 Methanogens and sulfate reducers, and the respective energy processes, are thought to be the dominant players and have been the research foci. Recent investigations showed that, in some deep, fluid-filled fractures in the Witwatersrand Basin, South Africa, methanogens contribute <5% of the total DNA and appear to produce sufficient CH4 to support the rest of the diverse community. This paradoxical situation reflects our lack of knowledge about the in situ metabolic diversity and the overall ecological trophic structure of SLiMEs. Here, we show the active metabolic processes and interactions in one of these communities by combining metatranscriptomic assemblies, metaproteomic and stable isotopic data, and thermodynamic modeling. Dominating the active community are four autotrophic ß-proteobacterial genera that are capable of oxidizing sulfur by denitrification, a process that was previously unnoticed in the deep subsurface. They co-occur with sulfate reducers, anaerobic methane oxidizers, and methanogens, which each comprise <5% of the total community. Syntrophic interactions between these microbial groups remove thermodynamic bottlenecks and enable diverse metabolic reactions to occur under the oligotrophic conditions that dominate in the subsurface. The dominance of sulfur oxidizers is explained by the availability of electron donors and acceptors to these microorganisms and the ability of sulfur-oxidizing denitrifiers to gain energy through concomitant S and H2 oxidation. We demonstrate that SLiMEs support taxonomically and metabolically diverse microorganisms, which, through developing syntrophic partnerships, overcome thermodynamic barriers imposed by the environmental conditions in the deep subsurface.


Assuntos
Desnitrificação , Ecossistema , Metano/biossíntese , Microbiota , Enxofre/metabolismo , Processos Autotróficos , Carbono/metabolismo , Nitrogênio/metabolismo , África do Sul
5.
Qual Life Res ; 27(8): 2127-2135, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29761348

RESUMO

PURPOSE: In studying health inequality, poverty as measured by income is frequently used; however, this omits the aspects of non-monetary resources and social barriers to achieving improved living standard. Therefore, our study aimed to examine the associations of individual-level deprivation of material and social necessities with general physical and mental health beyond that of income poverty. METHODS: A territory-wide two-stage stratified random sample of 2282 community-dwelling Hong Kong adults was surveyed between 2014 and 2015. Income poverty and a Deprivation Index were used as the main independent variables. General health was assessed using the validated 12-item Short-Form Health Survey version 2, from which physical component summary and mental component summary were derived. RESULTS: Our results in multivariable ordinal logistic regressions consistently showed that, after adjusting for income poverty, socio-demographic and lifestyle factors, being deprived was significantly associated with worse physical (OR 1.66; CI 1.25-2.20) and mental health (OR 1.83; CI 1.43-2.35). Being income poor was also significantly associated with worse mental health (OR 1.63; CI 1.28-2.09) but only marginally with physical health (OR 1.34; CI 1.00-1.80) after adjustments. CONCLUSIONS: Income does not capture all aspects of poverty that are associated with adverse health outcomes. Deprivation of non-monetary resources has an independent effect on general health above and beyond the effect of income poverty. Policies should move beyond endowment and take into account the multidimensionality of poverty, in order to address the problem of health inequality.


Assuntos
Povo Asiático/psicologia , Renda/estatística & dados numéricos , Saúde Mental/normas , Pobreza/psicologia , Qualidade de Vida/psicologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Disparidades nos Níveis de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto Jovem
6.
Int J Behav Med ; 23(5): 561-70, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26979424

RESUMO

PURPOSE: This study aimed at assessing the differences in prevalence rates of common health behavior among adolescents in the five Chinese cities and the influential factors at the contextual and individual levels. METHOD: We compared the standardized rates of three lifestyle behaviors (sedentary, dietary, and physical activity) and three addictive behaviors (cigarette smoking, alcohol consumption, and participation in gambling) among a sample of 13,950 adolescents. The sample was randomly selected from five cities, including Hong Kong, Macau, Taipei, Zhuhai, and Wuhan. Population size, GDP per capita, and literacy at the city level as well as parental monitoring and school performance at the student's level were assessed. Multi-level mixed effect models were used to examine the interaction of individual level factors with study sites. RESULTS: The six health behaviors differed significantly across sites with the highest rates of alcohol consumption in Hong Kong (39.5 %), of cigarette smoking in Macau (9.8 %), and of gambling in Taipei (37.1 %) and Hong Kong (35.9 %). The city-level measures were associated with only a few behavioral measures. Relative to Hong Kong, parental monitoring had stronger association with the three addictive behaviors in the other sites. CONCLUSION: Findings suggest that although the study sites share similar Chinese culture, students in the five cities differed from each other with regard to levels of health behaviors. Relative to the broad socioeconomic development, differences in parental monitoring played a significant role in explaining the observed difference.


Assuntos
Comportamento Aditivo/epidemiologia , Comportamentos Relacionados com a Saúde , Estilo de Vida , Adolescente , Consumo de Bebidas Alcoólicas/epidemiologia , Povo Asiático , Criança , Feminino , Hong Kong/epidemiologia , Humanos , Macau , Masculino , Prevalência , Fumar/epidemiologia
7.
Ann Fam Med ; 13 Suppl 1: S42-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26304971

RESUMO

PURPOSE: We examined the effects of participating in a "train-the-trainer" program and being a peer supporter on metabolic and cognitive/psychological/behavioral parameters in Chinese patients with type 2 diabetes. METHODS: In response to our invitation, 79 patients with fair glycemic control (HbA1c <8%) agreed to participate in a "train-the-trainer" program to become peer supporters. Of the 59 who completed the program successfully, 33 agreed to be peer supporters ("agreed trainees") and were each assigned to support 10 patients for 1 year, with a voluntary extension period of 3 additional years, while 26 trainees declined to be supporters ("refused trainees"). A group of 60 patients with fair glycemic control who did not attend the training program and were under usual care were selected as a comparison group. The primary outcome was the change in average HbA1c levels for the 3 groups from baseline to 6 months. RESULTS: At 6 months, HbA1c was unchanged in the trainees (at baseline, 7.1 ± 0.3%; at 6 months, 7.1 ± 1.1%) but increased in the comparison group (at baseline, 7.1 ± 0.5%; at 6 months, 7.3 ± 1.1%. P = .02 for between-group comparison). Self-reported self-care activities including diet adherence and foot care improved in the trainees but not the comparison group. After 4 years, HbA1c remained stable among the agreed trainees (at baseline, 7.0 ± 0.2%; at 4 years: 7.2 ± 0.6%), compared with increases in the refused trainees (at baseline, 7.1 ± 0.4%; at 4 years, 7.8 ± 0.8%) and comparison group (at baseline, 7.1 ± 0.5%; at 4 years, 8.1 ± 0.6%. P = .001 for between-group comparison). CONCLUSIONS: Patients with diabetes who engaged in providing ongoing peer support to other patients with diabetes improved their self-care while maintaining glycemic control over 4 years.


Assuntos
Aconselhamento/educação , Diabetes Mellitus Tipo 2/terapia , Grupo Associado , Autocuidado/métodos , Apoio Social , Adolescente , Adulto , Idoso , Glicemia/análise , China , Aconselhamento/métodos , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/psicologia , Educação/métodos , Feminino , Hemoglobinas Glicadas/análise , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente/psicologia , Autocuidado/psicologia , Adulto Jovem
8.
J Am Med Inform Assoc ; 31(8): 1631-1637, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38867279

RESUMO

OBJECTIVE: To explore the feasibility and challenges of mapping between SNOMED CT and the ICD-11 Foundation in both directions, SNOMED International and the World Health Organization conducted a pilot mapping project between September 2021 and August 2022. MATERIALS AND METHODS: Phase 1 mapped ICD-11 Foundation entities from the endocrine diseases chapter, excluding malignant neoplasms, to SNOMED CT. In phase 2, SNOMED CT concepts equivalent to those covered by the ICD-11 entities in phase 1 were mapped to the ICD-11 Foundation. The goal was to identify equivalence between an ICD-11 Foundation entity and a SNOMED CT concept. Postcoordination was used for mapping to ICD-11. Each map was done twice independently, the results were compared, and discrepancies were reconciled. RESULTS: In phase 1, 59% of 637 ICD-11 Foundation entities had an exact match in SNOMED CT. In phase 2, 32% of 1893 SNOMED CT concepts had an exact match in the ICD-11 Foundation, and postcoordination added 15% of exact match. Challenges encountered included non-synonymous synonyms, mismatch in granularity, composite conditions, and residual categories. CONCLUSION: This pilot project shed light on the tremendous amount of effort required to create a map between the 2 coding systems and uncovered some common challenges. Future collaborative work between SNOMED International and WHO will likely benefit from its findings. It is recommended that the 2 organizations should clarify goals and use cases of mapping, provide adequate resources, set up a road map, and reconsider their original proposal of incorporating SNOMED CT into the ICD-11 Foundation ontology.


Assuntos
Classificação Internacional de Doenças , Systematized Nomenclature of Medicine , Projetos Piloto , Humanos
9.
Environ Microbiol ; 14(9): 2272-82, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22779750

RESUMO

Drylands are the largest terrestrial biome on Earth and a ubiquitous feature is desert pavement terrain, comprising rocks embedded in the mineral soil surface. Quartz and other translucent rocks are common and microbial communities termed hypoliths develop as biofilms on their ventral surfaces. In extreme deserts these represent major concentrations of biomass, and are emerging as key to geobiological processes and soil stabilization. These highly specialized communities are dominated by cyanobacteria that support diverse heterotrophic assemblages. Here we identify global-scale trends in the ecology of hypoliths that are strongly related to climate, particularly with regard to shifts in cyanobacterial assemblages. A synthesis of available data revealed a linear trend for colonization with regard to climate, and we suggest potential application for hypoliths as 'biomarkers' of aridity on a landscape scale. The potential to exploit the soil-stabilizing properties of hypolithic colonization in environmental engineering on dryland soils is also discussed.


Assuntos
Fenômenos Fisiológicos Bacterianos , Biodiversidade , Clima Desértico , Microbiologia do Solo , Biomassa
10.
J Community Health ; 37(1): 144-52, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21674257

RESUMO

Despite global progress in tobacco control, data are needed for subgroups with increased risk of tobacco use for more effective smoking prevention. Survey data from a random sample of 6,486 youth in grades 7, 8 and 9 were derived from the project Chinese Student Health Survey. Prevalence and hazards of smoking onset were compared by gender and immigrant status. Mediation analysis was used to assess factors that may mediate the impact of immigrant status on smoking. Immigrant students had a much higher risk of hazards of smoking initiation than non-immigrant students. Parental monitoring and parental smoking significantly mediated the effect of immigrant status on early smoking onset. In addition, gender differences in the prevalence of smoking and hazards of smoking onset in our study were smaller than those reported by others targeting non-Hong Kong Chinese youth. Findings of this study imply that immigrant children and girls in Hong Kong are at increased risk to tobacco use. Special attention should be paid to these subgroups for prevention intervention. Prevention intervention for immigrant children should address parental smoking and parental monitoring. Reduced gender difference in smoking among Hong Kong youth suggests an emerging trend for more Chinese girls on the Mainland to smoke along with the rapid socioeconomic development.


Assuntos
Emigrantes e Imigrantes/psicologia , Fumar/psicologia , Adolescente , Distribuição por Idade , Criança , Depressão/epidemiologia , Emigrantes e Imigrantes/estatística & dados numéricos , Feminino , Hong Kong/epidemiologia , Humanos , Masculino , Relações Pais-Filho , Medição de Risco , Distribuição por Sexo , Fumar/epidemiologia
11.
Proc Natl Acad Sci U S A ; 106(47): 19964-9, 2009 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-19850879

RESUMO

The McMurdo Dry Valleys in Antarctica are a cold hyperarid polar desert that present extreme challenges to life. Here, we report a culture-independent survey of multidomain microbial biodiversity in McKelvey Valley, a pristine example of the coldest desert on Earth. We demonstrate that life has adapted to form highly-specialized communities in distinct lithic niches occurring concomitantly within this terrain. Endoliths and chasmoliths in sandstone displayed greatest diversity, whereas soil was relatively depauperate and lacked a significant photoautotrophic component, apart from isolated islands of hypolithic cyanobacterial colonization on quartz rocks in soil contact. Communities supported previously unreported polar bacteria and fungi, but archaea were absent from all niches. Lithic community structure did not vary significantly on a landscape scale and stochastic moisture input due to snowmelt resulted in increases in colonization frequency without significantly affecting diversity. The findings show that biodiversity near the cold-arid limit for life is more complex than previously appreciated, but communities lack variability probably due to the high selective pressures of this extreme environment.


Assuntos
Bactérias , Cianobactérias , Clima Desértico , Fungos , Microbiologia do Solo , Regiões Antárticas , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Cianobactérias/classificação , Cianobactérias/genética , Cianobactérias/isolamento & purificação , Ecossistema , Meio Ambiente , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética
12.
Comput Inform Nurs ; 30(12): 672-9, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22872044

RESUMO

Diabetes is a global public health problem. Maintaining optimal glycemic control is critical for minimizing associated long-term complications and achieving better quality of life. Effective diabetes self-management education is one key component to enhance diabetes clients' self-management capabilities. The research team established a "Caring for Yourself-Managing Your Diabetes" Web site, which contained 35 video clips about diabetes management. The aim of this study was to evaluate user satisfaction with the Web-based diabetes self-management education program. A convenience sample of 100 diabetes clients (mean age, 61.5 [SD, 10.7] years) was invited to view one of the video clips via a laptop computer. A modified version of the Computer-Aided Learning Evaluation Questionnaire and the End-User Computing Satisfaction Questionnaire was used to evaluate participants' satisfaction with the program. The results indicate that participants were satisfied with the format, content, and accuracy of the Web-based diabetes education program. Some participants suggested adding different types of exercises that are specific to the needs of client groups and more explanation of diabetes medications. The results of this study support the use of computer-assisted learning as a promising method for delivering diabetes self-management education, which is satisfactory to diabetes clients.


Assuntos
Instrução por Computador , Diabetes Mellitus/terapia , Internet , Educação de Pacientes como Assunto/métodos , Satisfação do Paciente/estatística & dados numéricos , Autocuidado , Idoso , Estudos Transversais , Feminino , Hong Kong , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Programas e Projetos de Saúde
13.
Microb Ecol ; 59(4): 689-99, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-19937324

RESUMO

The morphology of endolithic colonization in a limestone escarpment and surrounding rocky debris (termed float) at a high-altitude arid site in central Tibet was documented using scanning electron microscopy. Putative lichenized structures and extensive coccoid bacterial colonization were observed. Absolute and relative abundance of rRNA gene signatures using real-time quantitative polymerase chain reaction and phylogenetic analysis of environmental phylotypes were used to characterize community structure across all domains. Escarpment endoliths were dominated by eukaryotic phylotypes suggestive of lichenised associations (a Trebouxia lichen phycobiont and Leptodontidium lichen mycobiont), whereas float endoliths were dominated by bacterial phylotypes, including the cyanobacterium Chroococcidiopsis plus several unidentified beta proteobacteria and crenarchaea. Among a range of abiotic variables tested, ultraviolet (UV) transmittance by rock substrates was the factor best able to explain differences in community structure, with eukaryotic lichen phylotypes more abundant under conditions of greater UV-exposure compared to prokaryotes. Variously pigmented float rocks did not support significantly different communities. Estimates of in situ carbon fixation based upon (14)C radio-labelled bicarbonate uptake indicated endolithic productivity of approximately 2.01 g C/m(2)/year(-1), intermediate between estimates for Antarctic and temperate communities.


Assuntos
Altitude , Bactérias/isolamento & purificação , Carbonato de Cálcio/análise , Microbiologia Ambiental , Bactérias/classificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Clima Desértico , Geografia , Filogenia , RNA Bacteriano/análise , RNA Ribossômico/análise , Tibet
14.
Microb Ecol ; 60(4): 730-9, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20336290

RESUMO

The hypolithic microbial community associated with quartz pavement at a high-altitude tundra location in central Tibet is described. A small-scale ecological survey indicated that 36% of quartz rocks were colonized. Community profiling using terminal restriction fragment length polymorphism revealed no significant difference in community structure among a number of colonized rocks. Real-time quantitative PCR and phylogenetic analysis of environmental phylotypes obtained from clone libraries were used to elucidate community structure across all domains. The hypolithon was dominated by cyanobacterial phylotypes (73%) with relatively low frequencies of other bacterial phylotypes, largely represented by the chloroflexi, actinobacteria, and bacteriodetes. Unidentified crenarchaeal phylotypes accounted for 4% of recoverable phylotypes, while algae, fungi, and mosses were indicated by a small fraction of recoverable phylotypes.


Assuntos
Bactérias/isolamento & purificação , Ecossistema , Sedimentos Geológicos/microbiologia , Altitude , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , DNA Bacteriano/genética , Dados de Sequência Molecular , Filogenia , Quartzo/metabolismo , RNA Ribossômico 16S/genética , Tibet
15.
Environ Microbiome ; 15(1): 8, 2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33902738

RESUMO

BACKGROUND: Exceptional preservation of endogenous organics such as collagens and blood vessels has been frequently reported in Mesozoic dinosaur fossils. The persistence of these soft tissues in Mesozoic fossil bones has been challenged because of the susceptibility of proteins to degradation and because bone porosity allows microorganisms to colonize the inner microenvironments through geological time. Although protein lability has been studied extensively, the genomic diversity of microbiomes in dinosaur fossil bones and their potential roles in bone taphonomy remain underexplored. Genome-resolved metagenomics was performed, therefore, on the microbiomes recovered from a Late Cretaceous Centrosaurus bone and its encompassing mudstone in order to provide insight into the genomic potential for microbial alteration of fossil bone. RESULTS: Co-assembly and binning of metagenomic reads resulted in a total of 46 high-quality metagenome-assembled genomes (MAGs) affiliated to six bacterial phyla (Actinobacteria, Proteobacteria, Nitrospira, Acidobacteria, Gemmatimonadetes and Chloroflexi) and 1 archaeal phylum (Thaumarchaeota). The majority of the MAGs represented uncultivated, novel microbial lineages from class to species levels based on phylogenetics, phylogenomics and average amino acid identity. Several MAGs from the classes Nitriliruptoria, Deltaproteobacteria and Betaproteobacteria were highly enriched in the bone relative to the adjacent mudstone. Annotation of the MAGs revealed that the distinct putative metabolic functions of different taxonomic groups were linked to carbon, nitrogen, sulfur and iron metabolism. Metaproteomics revealed gene expression from many of the MAGs, but no endogenous collagen peptides were identified in the bone that could have been derived from the dinosaur. Estimated in situ replication rates among the bacterial MAGs suggested that most of the microbial populations in the bone might have been actively growing but at a slow rate. CONCLUSIONS: Our results indicate that excavated dinosaur bones are habitats for microorganisms including novel microbial lineages. The distinctive microhabitats and geochemistry of fossil bone interiors compared to that of the external sediment enrich a microbial biomass comprised of various novel taxa that harbor multiple gene sets related to interconnected biogeochemical processes. Therefore, the presence of these microbiomes in Mesozoic dinosaur fossils urges extra caution to be taken in the science of paleontology when hunting for endogenous biomolecules preserved from deep time.

16.
Microbiol Resour Announc ; 9(21)2020 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-32439668

RESUMO

The role of archaeal ammonia oxidizers often exceeds that of bacterial ammonia oxidizers in marine and terrestrial environments but has been understudied in permafrost, where thawing has the potential to release ammonia. Here, three thaumarchaea genomes were assembled and annotated from metagenomic data sets from carbon-poor Canadian High Arctic active-layer cryosols.

17.
Extremophiles ; 13(3): 533-40, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19347567

RESUMO

A thermophilic microbial mat with a relatively simple morphological composition was used to study the expression of key metabolic genes between mat layers. Mats comprised Roseiflexus castenholzii, Synechococcus sp., a Sphingomonas-like proteobacterial taxon and an unidentified member of the Thermotogae as determined by 16S rRNA phylotypes. The diversity of expressed loci for key genes involved in oxygenic photosynthesis (cbbL), anoxygenic photosynthesis (pufM) and nitrogen fixation (nifH) was assessed. The cyanobacterial surface layer supported two cbbL transcripts, with closest phylogenetic affinity to those from the cyanobacterium Synechococcus sp. and a proteobacterium Nitrobacter sp. This indicates that both photoautotrophic and chemolithoautotrophic carbon dioxide fixation may occur in this mat layer. Lower layers did not support cbbL transcripts. Anoxygenic photosynthesis was indicated by a single pufM transcript with closest affinity to that of R. castenholzii. Expression occurred in all layers beneath the cyanobacterial surface layer. Expression of a single nifH transcript with closest affinity to a proteobacterial nitrogenase occurred in samples throughout all mat layers.


Assuntos
Bactérias/genética , Genes Bacterianos , Bactérias/classificação , Bactérias/metabolismo , Eletroforese em Gel de Poliacrilamida , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética
18.
Extremophiles ; 13(1): 139-49, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19023516

RESUMO

Despite detailed study of selected thermophilic taxa, overall community diversity of bacteria in thermophilic mats remains relatively poorly understood. A sequence-based survey of bacterial communities from several hot spring locations in central Tibet was undertaken. Diversity and frequency of occurrence for 140 unique 16S rRNA gene phylotypes were identified in clone libraries constructed from environmental samples. A lineage-per-time plot revealed that individual locations have evolved to support relatively large numbers of phylogenetically closely related phylotypes. Application of the F ( ST ) statistic and P test to community data was used to demonstrate that phylogenetic divergence between locations was significant, thus emphasizing the status of hot springs as isolated habitats. Among phylotypes, only the Chlorobi were ubiquitous to all mats, other phototrophs (Cyanobacteria and Chloroflexi) occurred in most but not all samples and generally accounted for a large number of recovered phylotypes. Phylogenetic analyses of phototrophic phylotypes revealed support for location-specific lineages. The alpha, beta and gamma proteobacteria were also frequently recovered phyla, suggesting they may be abundant phylotypes in mats, a hitherto unappreciated aspect of thermophilic mat biodiversity. Samples from one location indicated that where phototrophic bacteria were rare or absent due to niche disturbance, the relative frequency of proteobacterial phylotypes increased.


Assuntos
Bactérias/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Biomassa , Filogenia , RNA Ribossômico 16S/genética , Especificidade da Espécie , Tibet
19.
Stud Health Technol Inform ; 264: 1486-1487, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31438194

RESUMO

Terminology binding has been adopted in Hong Kong Hospital Authority to link terminology component to clinical information models. This linkage facilitates structured data capturing and streamlines clinical workflow. With information models and data representation standards in place, data interoperability and data integration can be maintained for seamless patient care delivery.


Assuntos
Hospitais , Hong Kong , Humanos
20.
FEMS Microbiol Ecol ; 95(10)2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31437264

RESUMO

Certain microorganisms survive long periods of time as endospores to cope with adverse conditions. Since endospores are metabolically inactive, the extent of aspartic acid (Asp) racemization will increase over time and might kill the spores by preventing their germination. Therefore, understanding the relationship between endospore survivability and Asp racemization is important for constraining the long-term survivability and global dispersion of spore-forming bacteria in nature. Geobacillus stearothermophilus was selected as a model organism to investigate racemization kinetics and survivability of its endospores at 65°C, 75°C and 98°C. This study found that the Asp racemization rates of spores and autoclaved spores were similar at all temperatures. The Asp racemization rate of spores was not significantly different from that of vegetative cells at 65°C. The Asp racemization rate of G. stearothermophilus spores was not significantly different from that of Bacillus subtilis spores at 98°C. The viability of spores and vegetative cells decreased dramatically over time, and the mortality of spores correlated exponentially with the degree of racemization (R2 = 0.9). This latter correlation predicts spore half-lives on the order of hundreds of years for temperatures typical of shallow marine sediments, a result consistent with studies about the survivability of thermophilic spores found in these environments.


Assuntos
Ácido Aspártico/metabolismo , Geobacillus stearothermophilus/metabolismo , Esporos Bacterianos/crescimento & desenvolvimento , Ácido Aspártico/química , Bacillus subtilis/genética , Bacillus subtilis/crescimento & desenvolvimento , Bacillus subtilis/metabolismo , Geobacillus stearothermophilus/crescimento & desenvolvimento , Cinética , Viabilidade Microbiana , Esporos Bacterianos/metabolismo , Esterilização , Temperatura
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA