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3.
Sensors (Basel) ; 19(16)2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31394848

RESUMO

Southern African savannas are an important dryland ecosystem, as they account for up to 54% of the landscape, support a rich variety of biodiversity, and are areas of key landscape change. This paper aims to address the challenges of studying this highly gradient landscape with a grass-shrub-tree continuum. This study takes place in South Luangwa National Park (SLNP) in eastern Zambia. Discretely classifying land cover in savannas is notoriously difficult because vegetation species and structural groups may be very similar, giving off nearly indistinguishable spectral signatures. A support vector machine classification was tested and it produced an accuracy of only 34.48%. Therefore, we took a novel continuous approach in evaluating this change by coupling in situ data with Landsat-level normalized difference vegetation index data (NDVI, as a proxy for vegetation abundance) and blackbody surface temperature (BBST) data into a rule-based classification for November 2015 (wet season) that was 79.31% accurate. The resultant rule-based classification was used to extract mean Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI values by season over time from 2000 to 2016. This showed a distinct separation between each of the classes consistently over time, with woodland having the highest NDVI, followed by shrubland and then grassland, but an overall decrease in NDVI over time in all three classes. These changes may be due to a combination of precipitation, herbivory, fire, and humans. This study highlights the usefulness of a continuous time-series-based approach, which specifically integrates surface temperature and vegetation abundance-based NDVI data into a study of land cover and vegetation health for savanna landscapes, which will be useful for park managers and conservationists globally.


Assuntos
Conservação dos Recursos Naturais , Pradaria , Imagens de Satélites/métodos , Clima , Florestas , Humanos , Análise de Componente Principal , Estações do Ano , Máquina de Vetores de Suporte , Temperatura , Zâmbia
4.
Prim Dent J ; 6(4): 46-51, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29258641

RESUMO

Removable dentures are worn by 20% of the UK population and two thirds of these individuals have denture stomatitis. Poor oral hygiene is commonplace among this group, as is smoking and xerostomia, which also contribute to the development of denture stomatitis. A complex polymicrobial biofilm is able to proliferate on the surface of denture materials and matures to form visible denture plaque. This denture plaque biofilm stimulates a local inflammatory process that is detectable clinically as erythema, and hyperplasia. Systemically, denture plaque represents a potential risk factor for systemic disease, in particular aspiration pneumonia. Respiratory pathogens have been detected in the denture plaque and overnight denture wear has been linked to an increased risk of aspiration pneumonia. There is a general lack of evidence on the adequate management of denture stomatitis and we present a protocol for use in the primary care setting.


Assuntos
Odontologia Geral , Higiene Bucal , Estomatite sob Prótese , Biofilmes , Placa Dentária/complicações , Humanos , Fatores de Risco , Fumar/efeitos adversos , Estomatite sob Prótese/etiologia , Estomatite sob Prótese/microbiologia , Estomatite sob Prótese/prevenção & controle , Estomatite sob Prótese/terapia , Xerostomia/complicações
5.
J Prosthodont ; 25(2): 99-104, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26260391

RESUMO

PURPOSE: Recent studies have established a relationship between dental plaque and pulmonary infection, particularly in elderly individuals. Given that approximately one in five adults in the UK currently wears a denture, there remains a gap in our understanding of the direct implications of denture plaque on systemic health. The aim of this study was to undertake a comprehensive evaluation of putative respiratory pathogens residing upon dentures using a targeted quantitative molecular approach. MATERIALS AND METHODS: One hundred and thirty patients' dentures were sonicated to remove denture plaque biofilm from the surface. DNA was extracted from the samples and was assessed for the presence of respiratory pathogens by quantitative polymerase chain reaction (qPCR). Ct values were then used to approximate the number of corresponding colony forming equivalents (CFEs) based on standard curves. RESULTS: Of the dentures, 64.6% were colonized by known respiratory pathogens. Six species were identified: Streptococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, Haemophilus influenzae B, Streptococcus pyogenes, and Moraxella catarrhalis. P. aeruginosa was the most abundant species followed by S. pneumoniae and S. aureus in terms of average CFE and overall proportion of denture plaque. Of the participants, 37% suffered from denture stomatitis; however, there were no significant differences in the prevalence of respiratory pathogens on dentures between healthy and inflamed mouths. CONCLUSIONS: Our findings indicate that dentures can act as a reservoir for potential respiratory pathogens in the oral cavity, thus increasing the theoretical risk of developing aspiration pneumonia. Implementation of routine denture hygiene practices could help to reduce the risk of respiratory infection among the elderly population.


Assuntos
Placa Dentária , Infecções por Pseudomonas , Prótese Total , Humanos , Pseudomonas aeruginosa , Staphylococcus aureus , Estomatite sob Prótese
6.
J Periodontol ; 84(12): 1827-37, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23327719

RESUMO

BACKGROUND: Polycystic ovarian syndrome (PCOS) is a hormonal disorder of females of reproductive age that impacts their oral and systemic health. The aim of this study is to evaluate interleukin-17A (IL-17A), IL-17F, IL-17A/F, and IL-17E (IL-25) levels in gingival crevicular fluid (GCF), saliva, and serum of non-obese females with PCOS and with either a clinically healthy periodontium or gingivitis. METHODS: Thirty-one females with PCOS, 30 females with PCOS and gingivitis, and 12 systemically and periodontally healthy females participated in the study. Clinical periodontal measurements, body mass index, and Ferriman-Gallwey score (FGS) (a measure of hirsutism in females) were recorded. Circulating levels of sex hormones, cortisol, and insulin were also determined. Levels of IL-17 cytokines were measured by enzyme-linked immunosorbent assay. RESULTS: The general linear model multivariate analysis, adjusting for age or plaque index, showed that the two groups with PCOS had higher concentrations of IL-17A, IL-17F, and IL-17A/F in serum and higher levels of IL-17A and IL-17F in GCF and saliva but lower serum IL-17E than systemically healthy females. Levels of IL-17E were lowest in females with PCOS and gingivitis who also had the highest FGS. Serum IL-17A and IL-17F levels correlated positively with FGS and periodontal probing depth (all ρ >0.33; P <0.005). Serum IL-17E showed the reverse relationship and also correlated negatively with IL-17A (ρ >-0.28; P <0.05). CONCLUSIONS: IL-17 levels are altered in non-obese females with PCOS and may influence gingival inflammation. Additional studies are warranted to clarify the relationship between PCOS and gingivitis.


Assuntos
Gengivite/imunologia , Interleucina-17/análise , Síndrome do Ovário Policístico/imunologia , 17-alfa-Hidroxiprogesterona/sangue , Adolescente , Adulto , Fatores Etários , Índice de Massa Corporal , Sulfato de Desidroepiandrosterona/sangue , Índice de Placa Dentária , Feminino , Líquido do Sulco Gengival/imunologia , Gengivite/sangue , Hirsutismo/classificação , Humanos , Hidrocortisona/sangue , Insulina/sangue , Interleucina-17/sangue , Índice Periodontal , Bolsa Periodontal/classificação , Periodonto/imunologia , Síndrome do Ovário Policístico/sangue , Saliva/imunologia , Testosterona/sangue , Adulto Jovem
7.
Arthritis Res Ther ; 9(3): R46, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17501992

RESUMO

It has been postulated that bacteria attached to the surface of prosthetic hip joints can cause localised inflammation, resulting in failure of the replacement joint. However, diagnosis of infection is difficult with traditional microbiological culture methods, and evidence exists that highly fastidious or non-cultivable organisms have a role in implant infections. The purpose of this study was to use culture and culture-independent methods to detect the bacteria present on the surface of prosthetic hip joints removed during revision arthroplasties. Ten consecutive revisions were performed by two surgeons, which were all clinically and radiologically loose. Five of the hip replacement revision surgeries were performed because of clinical infections and five because of aseptic loosening. Preoperative and perioperative specimens were obtained from each patient and subjected to routine microbiological culture. The prostheses removed from each patient were subjected to mild ultrasonication to dislodge adherent bacteria, followed by aerobic and anaerobic microbiological culture. Bacterial DNA was extracted from each sonicate and the 16S rRNA gene was amplified with the universal primer pair 27f/1387r. All 10 specimens were positive for the presence of bacteria by both culture and PCR. PCR products were then cloned, organised into groups by RFLP analysis and one clone from each group was sequenced. Bacteria were identified by comparison of the 16S rRNA gene sequences obtained with those deposited in public access sequence databases. A total of 512 clones were analysed by RFLP analysis, of which 118 were sequenced. Culture methods identified species from the genera Leifsonia (54.3%), Staphylococcus (21.7%), Proteus (8.7%), Brevundimonas (6.5%), Salibacillus (4.3%), Methylobacterium (2.2%) and Zimmermannella (2.2%). Molecular detection methods identified a more diverse microflora. The predominant genus detected was Lysobacter, representing 312 (60.9%) of 512 clones analysed. In all, 28 phylotypes were identified: Lysobacter enzymogenes was the most abundant phylotype (31.4%), followed by Lysobacter sp. C3 (28.3%), gamma proteobacterium N4-7 (6.6%), Methylobacterium SM4 (4.7%) and Staphylococcus epidermidis (4.7%); 36 clones (7.0%) represented uncultivable phylotypes. We conclude that a diverse range of bacterial species are found within biofilms on the surface of clinically infected and non-infected prosthetic hip joints removed during revision arthroplasties.


Assuntos
Infecções Bacterianas/microbiologia , Biofilmes , Prótese de Quadril/microbiologia , Técnicas Microbiológicas/métodos , Infecções Relacionadas à Prótese/microbiologia , RNA Ribossômico 16S/isolamento & purificação , Humanos , Reação em Cadeia da Polimerase , Reoperação
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