Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 572(7768): 230-234, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31391559

RESUMO

Groundwater in sub-Saharan Africa supports livelihoods and poverty alleviation1,2, maintains vital ecosystems, and strongly influences terrestrial water and energy budgets3. Yet the hydrological processes that govern groundwater recharge and sustainability-and their sensitivity to climatic variability-are poorly constrained4,5. Given the absence of firm observational constraints, it remains to be seen whether model-based projections of decreased water resources in dry parts of the region4 are justified. Here we show, through analysis of multidecadal groundwater hydrographs across sub-Saharan Africa, that levels of aridity dictate the predominant recharge processes, whereas local hydrogeology influences the type and sensitivity of precipitation-recharge relationships. Recharge in some humid locations varies by as little as five per cent (by coefficient of variation) across a wide range of annual precipitation values. Other regions, by contrast, show roughly linear precipitation-recharge relationships, with precipitation thresholds (of roughly ten millimetres or less per day) governing the initiation of recharge. These thresholds tend to rise as aridity increases, and recharge in drylands is more episodic and increasingly dominated by focused recharge through losses from ephemeral overland flows. Extreme annual recharge is commonly associated with intense rainfall and flooding events, themselves often driven by large-scale climate controls. Intense precipitation, even during years of lower overall precipitation, produces some of the largest years of recharge in some dry subtropical locations. Our results therefore challenge the 'high certainty' consensus regarding decreasing water resources4 in such regions of sub-Saharan Africa. The potential resilience of groundwater to climate variability in many areas that is revealed by these precipitation-recharge relationships is essential for informing reliable predictions of climate-change impacts and adaptation strategies.


Assuntos
Água Subterrânea/análise , Chuva , África Subsaariana , Clima Desértico , Secas/estatística & dados numéricos
2.
Hydrogeol J ; 31(1): 1-6, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36687384

RESUMO

Groundwater's role in maintaining the well-being of the planet is increasingly acknowledged. Only recently has society recognised groundwater as a key component of the water cycle. To improve public understanding and the proper use of groundwater, the hydrogeological community must expand its efforts in groundwater assessment, management, and communication. The International Association of Hydrogeologists (IAH) intends to help achieve the United Nation's water-related Sustainable Development Goals (SDGs) by the adoption of innovative hydrogeological strategies. This essay introduces a topical collection that encapsulates IAH's 2022 'Year for Groundwater'.


Le rôle des eaux souterraines dans le maintien du bien-être de la planète est de plus en plus reconnu. Ce n'est que récemment que la société a reconnu les eaux souterraines comme un élément clé du cycle de l'eau. Pour améliorer la compréhension du public et l'utilisation appropriée des eaux souterraines, la communauté hydrogéologique doit étendre ses efforts en matière d'évaluation, de gestion des eaux souterraines et de communication à leur sujet. L'Association Internationale des Hydrogéologues (AIH) entend contribuer à la réalisation des objectifs du développement durable (ODDs) des Nations unies liés à l'eau par l'adoption de stratégies hydrogéologiques innovantes. Cet essai présente une collection thématique qui résume l''Année pour les eaux souterraines' 2022 de l'AIH.


El papel de las aguas subterráneas para mantener el bienestar del planeta está cada vez más reconocido. Sólo recientemente la sociedad ha reconocido que las aguas subterráneas son un componente clave del ciclo del agua. Para mejorar la comprensión pública y el uso adecuado de las aguas subterráneas, la comunidad hidrogeológica debe aumentar sus esfuerzos en materia de evaluación, gestión y comunicación de las aguas subterráneas. La Asociación Internacional de Hidrogeólogos (AIH) pretende contribuir a la concreción de los Objetivos de Desarrollo Sostenible (ODS) de las Naciones Unidas relacionados con el agua mediante la adopción de estrategias hidrogeológicas innovadoras. Este artículo presenta una colección temática que engloba el 2022 como 'Año Internacional para las Aguas Subterráneas' de la AIH.


O papel das águas subterrâneas na manutenção do bem-estar do planeta é cada vez mais reconhecido. Só recentemente a sociedade reconheceu as águas subterrâneas como um componente chave do ciclo da água. Para melhorar a compreensão pública e o uso adequado das águas subterrâneas, a comunidade hidrogeológica deve expandir seus esforços na avaliação, gestão e comunicação das águas subterrâneas. A Associação Internacional de Hidrogeólogos (AIH) pretende ajudar a alcançar os Objetivos de Desenvolvimento Sustentável (ODS) das Nações Unidas relacionados à água por meio da adoção de estratégias hidrogeológicas inovadoras. Este ensaio apresenta uma coleção tópica que encapsula o 'Ano para as Águas Subterrâneas' de 2022 da AIH.

3.
Environ Microbiol ; 24(12): 5840-5858, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35706139

RESUMO

The retreat of glaciers in response to climate change has major impacts on the hydrology and ecosystems of glacier forefield catchments. Microbes are key players in ecosystem functionality, supporting the supply of ecosystem services that glacier systems provide. The interaction between surface and groundwaters in glacier forefields has only recently gained much attention, and how these interactions influence the microbiology is still unclear. Here, we identify the microbial communities in groundwater from shallow (<15 m deep) boreholes in a glacial forefield floodplain ('sandur') aquifer at different distances from the rapidly retreating Virkisjökull glacier, Iceland, and with varying hydraulic connectivity with the glacial meltwater river that flows over the sandur. Groundwater communities are shown to differ from those in nearby glacial and non-glacial surface water communities. Groundwater-meltwater interactions and groundwater flow dynamics affect the microbial community structure, leading to different microbial communities at different sampling points in the glacier forefield. Groundwater communities differ from those in nearby glacial and non-glacial surface waters. Functional potential for microbial nitrogen and methane cycling was detected, although the functional gene copy numbers of specific groups were low.


Assuntos
Água Subterrânea , Microbiota , Camada de Gelo/microbiologia , Islândia , Rios
5.
J Environ Manage ; 288: 112384, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33773213

RESUMO

Groundwater resources in South Asian cities are facing immense stress due to over-extraction leading to environmental, social and economic instabilities. The perennial mega rivers of Himalayas form the lifeline for South Asia, underpinning food and water security for a large population both directly and indirectly through exchange with groundwater systems. The present study delineates the spatio-temporal variation in patterns and processes of sub-hourly to annual-scale hydrological exchanges between the Ganges and its adjoining highly exploited aquifer in a urban-peri urban reach. Multivariate statistical analyses established river water-groundwater interaction in this region with ~40% loading of first principal component, i.e river water during monsoon on the shallow aquifer. The part of the aquifer detached from the main confined aquifer show an influence of precipitation (the second principal component) with loading of ~90%. Again the part of the aquifer suffering infiltration of local surface water bodies show effect of precipitation with a second principal loading of ~80%. Fourier transformation is used in the hydrograph to remove influence of heavy urbanization on the hydrographs. This study proves that the phenomenon of infiltrating river water during monsoon plays a primary role in controlling aquifer storage although contaminating the aquifer simultaneously. However, during pre and post-monsoon the flow path reversal helps in maintaining river baseflow. Cross-correlation between the river and piezometric series show increased delay of pressure head propagation of the infiltrating river waterfront, with increasing distance. These observations are also substantiated by stable isotope signatures. The present study provides an understanding of potential groundwater vulnerability resulting from waste water and irrigational contamination through river water intrusion which would eventually lead the government to implement proper water and environmental management policies towards availability of long-term sustainable water resources for the residents.


Assuntos
Água Potável , Água Subterrânea , Poluentes Químicos da Água , Ásia , Cidades , Monitoramento Ambiental , Rios , Estações do Ano , Poluentes Químicos da Água/análise
6.
Hydrogeol J ; 26(2): 367-370, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31983889

RESUMO

The Sustainable Development Goals have set an agenda for transformational change in water access, aiming for secure household connections globally. Despite this goal, communal groundwater supplies are likely to remain the main source of improved water supplies for many rural areas in Africa and South Asia for decades to come. Understanding the poor functionality of existing communal supplies remains, therefore, a priority. A critical first step is to establish a sector-wide definition of borehole supply functionality and a standard method of its assessment.


Les objectifs du développement durable ont mis en place un programme de changement transformationnel de l'accès à l'eau, visant à assurer des connexions sûres des ménages à l'échelle mondiale. Malgré cet objectif, les approvisionnements en eaux souterraines à l'échelle communale sont susceptibles de demeurer le sujet principal à améliorer pour de nombreuses régions rurales d'Afrique et d'Asie du Sud pour les décennies à venir. La compréhension de la piètre fonctionnalité des approvisionnements existants à l'échelle communale reste donc une priorité. Une première étape cruciale consiste à établir une définition sectorielle de la fonctionnalité de l'approvisionnement par forage et une méthode normalisée de son évaluation.


Los objetivos de desarrollo sostenible han establecido una agenda para un cambio transformacional en el acceso al agua, con la finalidad de establecer conexiones domiciliarias seguras a nivel mundial. A pesar de este objetivo, es probable que los suministros comunales de agua subterránea sigan siendo la principal fuente de mejoras en el abastecimiento de agua para muchas áreas rurales en África y el sur de Asia en las próximas décadas. Entender la funcionalidad deficiente de los suministros comunales existentes sigue siendo, por lo tanto, una prioridad. Un primer paso crítico es establecer una definición sectorial de la funcionalidad del suministro de los pozos y un método estándar para su evaluación.


Os Objetivos de Desenvolvimento Sustentável estabeleceram uma agenda para mudanças de paradigmas no acesso à água, visando abastecimento doméstico em escala global. Apesar desse objetivo, os suprimentos comunitários de águas subterrâneas provavelmente continuarão a ser a principal fonte de abastecimento de água potável para muitas áreas rurais da África e do sul da Ásia por décadas. Compreender a baixa funcionalidade desses atuais suprimentos comunitários torna-se, portanto, prioritária. Um primeiro passo crítico é estabelecer uma definição setorial de funcionalidade de fornecimento de poços e um método padrão de avaliação.

7.
Rheumatology (Oxford) ; 53(4): 650-7, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24324212

RESUMO

OBJECTIVES: For effective health care provision, knowledge of disease prevalence is paramount. There has been no systematic endeavour to establish continent-based AS estimates, however, prevalence is thought to vary by country and background HLA-B27 prevalence. This study aimed to estimate AS prevalence worldwide and to calculate the expected number of cases. METHODS: A systematic literature search was conducted. Prevalence data were extracted and used to calculate the mean prevalence by continent and the expected number of cases based on country-specific prevalence (or, if missing, the prevalence from neighbouring countries). A second estimate was made using the prevalence from countries with similar HLA-B27 prevalences if a country-specific prevalence estimate was not available. RESULTS: The mean AS prevalence per 10,000 (from 36 eligible studies) was 23.8 in Europe, 16.7 in Asia, 31.9 in North America, 10.2 in Latin America and 7.4 in Africa. Additional estimates, weighted by study size, were calculated as 18.6, 18.0 and 12.2 for Europe, Asia and Latin America, respectively. There were sufficient studies to estimate the number of cases in Europe and Asia, calculated to be 1.30-1.56 million and 4.63-4.98 million, respectively. CONCLUSION: This study represents the first systematic attempt to collate estimates of AS prevalence into a single continent-based estimate. In addition, the number of expected cases in Europe and Asia was estimated. Through reviewing the current literature, it is apparent that the continuing conduct of epidemiological studies of AS prevalence is of great importance, particularly as diagnostic capabilities improve and with the recent development of the criteria for axial SpA.


Assuntos
Espondilite Anquilosante/epidemiologia , África/epidemiologia , Ásia/epidemiologia , Europa (Continente)/epidemiologia , Saúde Global , Antígeno HLA-B27/genética , Humanos , América Latina/epidemiologia , América do Norte/epidemiologia , Prevalência , Espondilite Anquilosante/genética
8.
Onco Targets Ther ; 17: 489-496, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38895132

RESUMO

Multiple FGFR inhibitors have demonstrated significant activity in pretreated advanced FGFR2 fusion-positive intrahepatic cholangiocarcinoma. The irreversible pan-FGFR inhibitor futibatinib has the potential to overcome acquired resistance to ATP-competitive FGFR inhibitors in a subset of patients. We present a case of prolonged clinical benefit using FGFR inhibitors sequentially, initially an ATP-competitive inhibitor followed by futibatinib upon progression, for a total of 36 months of FGFR-targeting therapy. This case supports sequential FGFR-targeting therapies for FGFR2 fusion-positive cholangiocarcinoma, with futibatinib acting as rescue therapy after failure of ATP-competitive inhibitors.

9.
Cogn Behav Ther ; 42(3): 193-202, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23697597

RESUMO

The fear of arousal sensations characterizes some anxiety disorders and is a core feature of an established risk factor for anxiety and related disorders (i.e. anxiety sensitivity; Taylor, 1999). Anxiety sensitivity (AS) refers to a fear of anxiety-related bodily sensations stemming from beliefs that these have catastrophic consequences. Interoceptive exposure (IE; repeated exposure to feared arousal sensations) has been shown to decrease AS. The 33-item Hyperventilation Questionnaire (HVQ; Rapee & Medoro, 1994) measures state levels of cognitive, affective, and somatic responses to IE and arousal induction exercises more generally. The aim of the present set of studies was to develop and evaluate a brief version of the HVQ, the HVQ-B, in order to facilitate its use in research and clinical settings. In Study 1, three existing data sets that used the long version of the HVQ were combined to select the items to be retained for the HVQ-B. In Study 2, the 18-item HVQ-B was administered and its psychometric properties were evaluated. In Study 3, a confirmatory factor analysis (CFA) was performed on the 18 items of the HVQ-B. The HVQ-B demonstrated excellent psychometric properties, and accounted for most of the variance of the questionnaire's longer version. CFA indicated a reasonably good fit of the three-factor measurement model. Finally, the HVQ-B was able to distinguish between responses to arousal induction exercises by high versus low AS participants. The HVQ-B is a useful tool to assess cognitive, affective, and somatic responsivity to arousal sensations in both research and practice.


Assuntos
Transtornos de Ansiedade/diagnóstico , Ansiedade/diagnóstico , Hiperventilação/diagnóstico , Inquéritos e Questionários , Adolescente , Adulto , Ansiedade/psicologia , Transtornos de Ansiedade/psicologia , Nível de Alerta , Medo/psicologia , Feminino , Humanos , Hiperventilação/psicologia , Masculino , Psicometria
10.
Sci Total Environ ; 858(Pt 3): 159765, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36309251

RESUMO

Groundwater is an essential resource for natural and human systems throughout the world and the rates at which aquifers are recharged constrain sustainable levels of consumption. However, recharge estimates from global-scale models regularly disagree with each other and are rarely compared to ground-based estimates. We compare long-term mean annual recharge and recharge ratio (annual recharge/annual precipitation) estimates from eight global models with over 100 ground-based estimates in Africa. We find model estimates of annual recharge and recharge ratio disagree significantly across most of Africa. Furthermore, similarity to ground-based estimates between models also varies considerably and inconsistently throughout the different landscapes of Africa. Models typically showed both positive and negative biases in most landscapes, which made it challenging to pinpoint how recharge prediction by global-scale models can be improved. However, global-scale models which reflected stronger climatic controls on their recharge estimates compared more favourably to ground-based estimates. Given this significant uncertainty in recharge estimates from current global-scale models, we stress that groundwater recharge prediction across Africa, for both research investigations and operational management, should not rely upon estimates from a single model but instead consider the distribution of estimates from different models. Our work will be of particular interest to decision makers and researchers who consider using such recharge outputs to make groundwater governance decisions or investigate groundwater security especially under the potential impact of climate change.


Assuntos
Humanos , África
11.
Lancet Reg Health Eur ; 33: 100706, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37601339

RESUMO

This is the first report comparing EULAR and national treatment recommendations for PsA patients across Europe, and the first this decade to compare ASAS-EULAR and national treatment recommendations in axSpA patients. An electronic survey was completed from October 2021-April 2022 by rheumatologists in 15 European countries. One and four countries followed all EULAR and ASAS-EULAR recommendations, respectively. Five countries had no national treatment recommendations for PsA and/or axSpA, but followed other regulations. In several countries, national treatment recommendations predated the most recent EULAR/ASAS-EULAR recommendations. Entry criteria for starting biologic/targeted synthetic disease-modifying anti-rheumatic drugs varied considerably. In several countries, for PsA patients with significant skin involvement, interleukin-17 inhibitors were not given preference. The positioning of Janus Kinase inhibitors differed and Phosphodiesterase-4 inhibitors were not in use/reimbursed in most countries. This study may motivate European countries to update their national treatment recommendations, to align them better with the latest international recommendations.

12.
Environ Sci Technol ; 46(24): 13193-201, 2012 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-23153272

RESUMO

Recent observations that subsurface bacteria quickly adsorb metal contaminants raise concerns that they may enhance metal transport, given the high mobility of bacteria themselves. However, metal adsorption to bacteria is also reversible, suggesting that mobility within porous medium will depend on the interplay between adsorption-desorption kinetics and thermodynamic driving forces for adsorption. Till now there has been no systematic investigation of these important interactions. This study investigates the thermodynamic and kinetic controls of cotransport of Pantoea agglomerans cells and Zn in quartz and iron-oxide coated sand (IOCS) packed columns. Batch kinetic studies show that significant Zn sorption on IOCS takes place within two hours. Adsorption onto P. agglomerans surfaces reaches equilibrium within 30 min. Experiments in flow through quartz sand systems demonstrate that bacteria have negligible effect on zinc mobility, regardless of ionic strength and pH conditions. Zinc transport exhibits significant retardation in IOCS columns at high pH in the absence of cells. Yet, when mobile bacteria (non attached) are passed through simultaneously with zinc, no facilitated transport is observed. Adsorption onto cells becomes significant and plays a role in mobile metal speciation only once the IOCS is saturated with zinc. This suggests that IOCS exhibits stronger affinity for Zn than cell surfaces. However, when bacteria and Zn are preassociated on entering the column, zinc transport is initially facilitated. Subsequently, zinc partly desorbs from the cells and redistributes onto the IOCS as a result of the higher thermodynamic affinity for IOCS.


Assuntos
Compostos Férricos/química , Pantoea/citologia , Pantoea/metabolismo , Dióxido de Silício/química , Zinco/química , Adsorção , Biodegradação Ambiental , Cinética , Movimento , Termodinâmica
13.
Rheumatol Int ; 32(6): 1761-8, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21442165

RESUMO

Systemic inflammation may be a common process that underpins both atherosclerosis and extra-articular features (ExRA) of rheumatoid arthritis (RA). We evaluated the relationship between ExRA and arterial dysfunction in 114 consecutive patients with RA (82% women) without overt arterial disease aged 40-65 years. A trained research nurse undertook 'SphygmoCor' pulse wave analysis (PWA) using radial applanation tonometry to measure the extent (augmentation index, AIX%) and timing (reflected wave transit time, RWT, msec) of aortic wave reflection. Assessment included fasting blood sample, patient questionnaire and medical record review. Mean differences were adjusted for age, sex, mean blood pressure, smoking pack-years, fasting cholesterol, Stanford HAQ score and erythrocyte sedimentation rate. Mean age was 54 (SD 7) and median RA duration 10 (IQR 4-17) years. There was a trend for arterial dysfunction (higher AIX%; lower RWT) to increase as the number of ExRA features rose, but no difference in AIX% (-0.5, 95%CI -2.8 to 1.8, P = 0.65) or RWT (0.3 ms, 95%CI -3.6 to 4.2, P = 0.86) between 'any ExRA' and 'no ExRA'. Arterial dysfunction was not associated with the presence of rheumatoid nodules, Sjogren's syndrome or carpal tunnel syndrome. Our study was too small to determine whether severe ('Malmo') ExRA (vasculitis, pericarditis, episcleritis) was truly associated with a higher AIX% (3.8, 95%CI -2.3 to 9.9, P = 0.22) and lower RWT (-5.5 ms 95%CI -13.1 to 2.1, P = 0.16). While arterial dysfunction may be associated with the number of ExRA features and severe ExRA, it does not appear to be associated with other ExRA features.


Assuntos
Aorta/fisiopatologia , Artrite Reumatoide/complicações , Doenças Vasculares/etiologia , Adulto , Idoso , Artrite Reumatoide/diagnóstico , Pressão Sanguínea , Síndrome do Túnel Carpal/etiologia , Feminino , Humanos , Modelos Lineares , Masculino , Manometria , Pessoa de Meia-Idade , Fluxo Pulsátil , Estudos Retrospectivos , Nódulo Reumatoide/etiologia , Medição de Risco , Fatores de Risco , Escócia , Índice de Gravidade de Doença , Síndrome de Sjogren/etiologia , Doenças Vasculares/diagnóstico , Doenças Vasculares/fisiopatologia
14.
Sci Total Environ ; 828: 154283, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35247396

RESUMO

In Africa groundwater is the principal source of drinking water (https://washdata.org/) and has significant potential to improve food production as a source of irrigation water. Although volumes of stored groundwater are high when compared to surface water, not all the available groundwater is suitable for irrigation. One of the principal factors that limit the development of groundwater is salinity, but quantitative evidence regarding the scale of salinization in Africa has been lacking. This paper presents an initial analysis of the extent of groundwater salinization in Africa, bringing together groundwater salinity data (n = 12,255) from across the continent. In our dataset c.80% of the samples have electrical conductivity values less than 2000 µS/cm. Samples with high conductivity values of more than 2000 µS/cm are restricted to limited geological and climatic environments. The data reveals salinity does not affect the water security status of most countries in Africa. However, salinity compounds water insecurity issues in arid low groundwater recharge environments. The paper discusses the role of anthropogenic processes such as river valley water resources development, extensive groundwater pumping, inter-basin groundwater transfer, and irrigation in altering the salinity of groundwater bodies. The paper further elucidates the origin of groundwater salinity by critically reviewing the natural and human-induced factors that control the salinization of the various groundwater bodies across Africa. Existing case studies reveal several causes of salinization, including i) human-induced salinization, ii) climate and hydrological change-induced paleo groundwater salinity, iii) rock dissolution, and iv), saltwater encroachment.


Assuntos
Água Potável , Água Subterrânea , Poluentes Químicos da Água , Água Potável/análise , Monitoramento Ambiental , Água Subterrânea/análise , Humanos , Salinidade , Poluentes Químicos da Água/análise
15.
J Alzheimers Dis ; 85(2): 889-903, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34897095

RESUMO

BACKGROUND: Infections by bacterial or viral agents have been hypothesized to influence the etiology of neurodegenerative diseases. OBJECTIVE: This study examined the potential presence of Borrelia burgdorferi spirochete, the causative agent of Lyme disease, in brain autopsy tissue of patients diagnosed with either Alzheimer's (AD) or Parkinson's diseases. METHODS: Brain tissue sections from patients with age-matched controls were evaluated for antigen and DNA presence of B. burgdorferi using various methods. Positive Borrelia structures were evaluated for co-localization with biofilm and AD markers such as amyloid and phospho-tau (p-Tau) using immunohistochemical methods. RESULTS: The results showed the presence of B. burgdorferi antigen and DNA in patients with AD pathology and among those, one of them was previously diagnosed with Lyme disease. Interestingly, a significant number of Borrelia-positive aggregates with a known biofilm marker, alginate, were found along with the spirochetal structures. Our immunohistochemical data also showed that Borrelia-positive aggregates co-localized with amyloid and phospho-tau markers. To further prove the potential relationship of B. burgdorferi and amyloids, we infected two mammalian cell lines with B. burgdorferi which resulted in a significant increase in the expression of amyloid-ß and p-Tau proteins in both cells lines post-infection. CONCLUSION: These results indicate that B. burgdorferi can be found in AD brain tissues, not just in spirochete but a known antibiotics resistant biofilm form, and its co-localized amyloid markers. In summary, this study provides evidence for a likely association between B. burgdorferi infections and biofilm formation, AD pathology, and chronic neurodegenerative diseases.


Assuntos
Doença de Alzheimer/microbiologia , Doença de Alzheimer/patologia , Borrelia burgdorferi/isolamento & purificação , Encéfalo/microbiologia , Encéfalo/patologia , Idoso , Doença de Alzheimer/metabolismo , Proteínas Amiloidogênicas/metabolismo , Amiloidose/patologia , Biofilmes/efeitos dos fármacos , Biomarcadores/metabolismo , Borrelia burgdorferi/genética , Linhagem Celular Tumoral , DNA Bacteriano , Humanos , Neuroborreliose de Lyme/complicações , Proteínas tau/metabolismo
16.
Sci Total Environ ; 750: 141284, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33182170

RESUMO

Regular monitoring of drinking water quality is vital to identify contamination of potable water supplies. Testing for microbial contamination is important to prevent transmission of waterborne disease, but establishing and maintaining a water quality monitoring programme requires sustained labour, consumables and resources. In low resource settings such as developing countries, this can prove difficult, but measuring microbial contamination is listed as a requirement of reaching the UN's Sustainable Development Goal 6 for water and sanitation. A nine-month water quality monitoring programme was conducted in rural Malawi to assess the suitability of tryptophan-like fluorescence (TLF), an emerging method for rapidly detecting microbial contamination, as a drinking water quality monitoring tool. TLF data was compared with thermotolerant coliforms (TTCs, E. coli) and inorganic hydrochemical parameters. A large (n = 235) temporal dataset was collected from five groundwater drinking water sources, with samples collected once or twice weekly depending on the season. The results show that TLF can indicate a broader contamination risk but is not as sensitive to short term variability when compared to other faecal indicators. This is likely due to a broad association of TLF with elevated DOC concentrations from a range of different sources. Elevated TLF may indicate preferential conditions for the persistence of TTCs and/or E. coli, but not necessarily a public health risk from microbial contamination. TLF is therefore a more precautionary risk indicator than microbial culturing techniques and could prove useful as a high-level screening tool for initial risk assessment. For widespread use of TLF to be successful, standardisation of TLF values associated with different levels of risk is required, however, this study highlights the difficulties of equating TLF thresholds to TTCs or E. coli data because of the influence of DOC/HLF on the TLF signal.


Assuntos
Água Potável , Monitoramento Ambiental , Escherichia coli , Fluorescência , Humanos , Malaui , Triptofano , Microbiologia da Água , Qualidade da Água , Abastecimento de Água
17.
Water Res ; 206: 117734, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34655933

RESUMO

Faecal indicator organisms (FIOs) are limited in their ability to protect public health from the microbial contamination of drinking water because of their transience and time required to deliver a result. We evaluated alternative rapid, and potentially more resilient, approaches against a benchmark FIO of thermotolerant coliforms (TTCs) to characterise faecal contamination over 14 months at 40 groundwater sources in a Ugandan town. Rapid approaches included: in-situ tryptophan-like fluorescence (TLF), humic-like fluorescence (HLF), turbidity; sanitary inspections; and total bacterial cells by flow cytometry. TTCs varied widely in six sampling visits: a third of sources tested both positive and negative, 50% of sources had a range of at least 720 cfu/100 mL, and a two-day heavy rainfall event increased median TTCs five-fold. Using source medians, TLF was the best predictor in logistic regression models of TTCs ≥10 cfu/100 mL (AUC 0.88) and best correlated to TTC enumeration (ρs 0.81), with HLF performing similarly. Relationships between TLF or HLF and TTCs were stronger in the wet season than the dry season, when TLF and HLF were instead more associated with total bacterial cells. Source rank-order between sampling rounds was considerably more consistent, according to cross-correlations, using TLF or HLF (min ρs 0.81) than TTCs (min ρs 0.34). Furthermore, dry season TLF and HLF cross-correlated more strongly (ρs 0.68) than dry season TTCs (ρs 0.50) with wet season TTCs, when TTCs were elevated. In-situ TLF or HLF are more rapid and resilient indicators of faecal contamination risk than TTCs.


Assuntos
Água Potável , Água Subterrânea , Monitoramento Ambiental , Fezes , Espectrometria de Fluorescência , Microbiologia da Água
18.
Rheumatology (Oxford) ; 49(7): 1383-90, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20400759

RESUMO

OBJECTIVES: To describe quality of life (QoL) in an ANCA-associated vasculitis (AAV) cohort and make comparisons with a general population sample. In addition, we aimed to take preliminary steps to identify potential disease and psycho-social factors which may determine QoL impairment. METHODS: A population-based case-control study was designed. All AAV patients resident in Grampian, Scotland, were invited to participate as cases. Controls were identified from a random sample of persons registered with four local general practices. Participants completed a questionnaire comprising validated generic and symptom-specific tools in the assessment of QoL. In addition, all cases were clinically assessed and putative disease factors recorded. Cases and controls were compared and, in addition, disease and psycho-social associations were explored for identified QoL impairments. RESULTS: In total, 74/90 (82%) cases and 781/2000 (39%) controls participated. Cases reported a significant impairment in physical health (P < 0.0001), but not mental health (P = 0.85), compared with controls, as measured by Short Form-8 (SF-8). Following adjustment for age and sex, persons with AAV were more than twice as likely to report mild/moderate fatigue [odds ratio (OR) 2.0; 95% CI 1.1, 3.8] or severe fatigue (OR 2.5; 95% CI 1.4, 4.5) compared with controls. Furthermore, among cases, fatigue was found to be strongly associated with impaired physical health (P < 0.0001), while disease factors such as disease activity and damage were not (P = 0.60 and 0.27, respectively). CONCLUSIONS: Patients with AAV report impaired physical but not mental health. Specifically, fatigue is a principal complaint and appears to be a major determinant of impaired QoL.


Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/complicações , Fadiga/etiologia , Qualidade de Vida/psicologia , Índice de Gravidade de Doença , Adulto , Idoso , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/fisiopatologia , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/psicologia , Fadiga/fisiopatologia , Fadiga/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escócia , Estatística como Assunto , Inquéritos e Questionários
19.
Sci Total Environ ; 744: 140674, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-32755770

RESUMO

Faecally-contaminated drinking water is a risk to human health, with the greatest risks to those living in developing countries. UN Sustainable Development Goal 6 aims to address this issue. Tryptophan-like fluorescence (TLF) shows potential as a rapid method for detecting microbial contamination in drinking water, which could reduce the spread of waterborne diseases. This study is the first to investigate the effectiveness of TLF for a large-scale survey using a randomised, spot-sampling approach. The large-scale survey took place in Malawi, sub-Saharan Africa, in the dry season (n = 183). A subset of sources were revisited at the end of the following wet season (n = 41). The effectiveness of TLF was assessed by comparing TLF results to thermotolerant coliforms (TTC), humic-like fluorescence (HLF), inorganic hydrochemical data and sanitary risk scores. The most prominent differences in microbial water quality were observed between source types, with little variation between districts and seasons. TLF, TTCs, turbidity and sanitary risk scores were all elevated at alternative sources (shallow wells and tap stands) compared to hand-pumped boreholes. In the dry season, 18% of hand-pumped boreholes showed TTC contamination, which increase to 21% in the wet season. Groundwater recharge processes are likely responsible for seasonal variability of inorganic hydrochemistry at hand-pumped boreholes. TLF was able to distinguish no and low WHO risk classes (TTC 0-9 cfu/100 mL) from medium, high and very high risk classes (TTC 10 - >1000 cfu/100 mL). TLF failed to distinguish between no and low risk classes, which limits the use of TLF for assessing water quality to drinking water standards. This dataset indicates that HLF may raise baseline TLF for samples with low TLF values, increasing false positives. Therefore, TLF is better suited as a rapid high-level water quality screening tool to assess moderate and high levels of faecal contamination.


Assuntos
Água Potável , Monitoramento Ambiental , Humanos , Malaui , Estações do Ano , Inquéritos e Questionários , Triptofano , Microbiologia da Água , Qualidade da Água , Abastecimento de Água
20.
Nat Commun ; 11(1): 1279, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32152271

RESUMO

Climate change and urbanization can increase pressures on groundwater resources, but little is known about how groundwater quality will change. Here, we use a global synthesis (n = 9,404) to reveal the drivers of dissolved organic carbon (DOC), which is an important component of water chemistry and substrate for microorganisms that control biogeochemical reactions. Dissolved inorganic chemistry, local climate and land use explained ~ 31% of observed variability in groundwater DOC, whilst aquifer age explained an additional 16%. We identify a 19% increase in DOC associated with urban land cover. We predict major groundwater DOC increases following changes in precipitation and temperature in key areas relying on groundwater. Climate change and conversion of natural or agricultural areas to urban areas will decrease groundwater quality and increase water treatment costs, compounding existing constraints on groundwater resources.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA