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Search Results: 1 - 10 of 477435 matches for " James A Flint "
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Impacto do uso da água de cisternas na ocorrência de episódios diarréicos na popula??o rural do agreste central de Pernambuco, Brasil
Luna, Carlos Feitosa;Brito, Ana Maria de;Costa, André Monteiro;Lapa, Tiago Maria;Flint, James A;Marcynuk, Pasha;
Revista Brasileira de Saúde Materno Infantil , 2011, DOI: 10.1590/S1519-38292011000300009
Abstract: objectives: to evaluate the impact of the use of water-tanks on the occurrence of episodes of diarrhea, comparing the number and duration of episodes among the residents of households with and without water-tanks in the same geographical area. methods: a longitudinal prospective study, nested in a cross-section study comparing two groups (households with and without water-tanks), was carried out in 21 municipalities in the central agreste region of the brazilian state of pernambuco, in 2007. data was gathered over 60 days and included 1,765 individuals. descriptive analysis was carried out using mixed hierarchical models, mann-whitney and kaplan-meyer with the level of significance set at 5%. results: among the 949 individuals with water-tanks, there was a reduction in the risk of the occurrence of episodes of diarrhea of 73% compared with the 816 individuals without water-tanks (rr=0.27; p<0.001). the mean number of episodes registered among residents of households without water-tanks was 0.48 (sc=1.17), compared with 0.08 (sc=0.32) among households with water-tanks (z=-10.26; p<0.001). the mean during of episodes was 1.5 times greater in households without water-tanks (χ2=8.99; p=0.003). conclusions: the findings of this study point to the importance of access to drinking water for the reduction of disease. the occurrence of diarrhea and its concomitant severity indicators-number of episodes and duration-were consistently higher among residents of households without water-tanks.
Detecting & Locating Leaks in Water Distribution Polyethylene Pipes
Maninder Pal,Neil Dixon,James Flint
Lecture Notes in Engineering and Computer Science , 2010,
Abstract:
Emergent honeycomb lattice in LiZn2Mo3O8
Rebecca Flint,Patrick A. Lee
Physics , 2013, DOI: 10.1103/PhysRevLett.111.217201
Abstract: We introduce the idea of emergent lattices, where a simple lattice decouples into two weakly-coupled lattices as a way to stabilize spin liquids. In LiZn2Mo3O8, the disappearance of 2/3rds of the spins at low temperatures suggests that its triangular lattice decouples into an emergent honeycomb lattice weakly coupled to the remaining spins, and we suggest several ways to test this proposal. We show that these orphan spins act to stabilize the spin-liquid in the $J_1-J_2$ honeycomb model and also discuss a possible 3D analogue, Ba2MoYO6 that may form a "depleted fcc lattice."
Population distribution and burden of acute gastrointestinal illness in British Columbia, Canada
M Kate Thomas, Shannon E Majowicz, Laura MacDougall, Paul N Sockett, Suzie J Kovacs, Murray Fyfe, Victoria L Edge, Kathryn Doré, James A Flint, Spencer Henson, Andria Q Jones
BMC Public Health , 2006, DOI: 10.1186/1471-2458-6-307
Abstract: The magnitude and distribution of acute GI in British Columbia (BC), Canada was evaluated via a cross-sectional telephone survey of 4,612 randomly selected residents, conducted from June 2002 to June 2003. Respondents were asked if they had experienced vomiting or diarrhoea in the 28 days prior to the interview.A response rate of 44.3% was achieved. A monthly prevalence of 9.2% (95%CI 8.4 – 10.0), an incidence rate of 1.3 (95% CI 1.1–1.4) episodes of acute GI per person-year, and an average probability that an individual developed illness in the year of 71.6% (95% CI 68.0–74.8), weighted by population size were observed. The average duration of illness was 3.7 days, translating into 19.2 million days annually of acute GI in BC.The results corroborate those from previous Canadian and international studies, highlighting the substantial burden of acute GI.Gastrointestinal illness (GI) is a global public health concern. In developed countries, GI is typically mild and self-limiting, but has considerable economic impact due to high morbidity [1-3]. Recent studies on the burden of GI in the general population of a number of countries have been reported [4-12]. To estimate the burden of GI in the Canadian population, the Public Health Agency of Canada (PHAC; formerly Health Canada) developed the National Studies on Acute Gastrointestinal Illness (NSAGI) initiative in 2000. Population-based studies, designed to describe self-reported, acute GI in selected Canadian populations, are part of this initiative. In March 2002, the PHAC completed the first such population study in the City of Hamilton, Ontario, Canada [13]. In order to determine if the burden of GI was the same across the country, a second population study was completed in the province of British Columbia (BC) in June 2003. Additionally, since public health in Canada is primarily a provincial responsibility, this study was conducted to provide information to BC policy makers. The current paper describes the frequen
Use of a Rabbit Soft Tissue Chamber Model to Investigate Campylobacter Jejuni–Host Interactions
Annika Flint,James Butcher,Cyril Clarke,Denver Marlow,Alain Stintzi
Frontiers in Microbiology , 2010, DOI: 10.3389/fmicb.2010.00126
Abstract: Despite the prevalence of Campylobacter jejuni as an important food borne pathogen, the microbial factors governing its infection process are poorly characterized. In this study, we developed a novel rabbit soft tissue chamber model to investigate C. jejuni interactions with its host. The in vivo transcriptome profile of C. jejuni was monitored as a function of time post-infection by competitive microarray hybridization with cDNA obtained from C. jejuni grown in vitro. Genome-wide expression analysis identified 449 genes expressed at significantly different levels in vivo. Genes implicated to play important roles in early colonization of C. jejuni within the tissue chamber include up-regulation of genes involved in ribosomal protein synthesis and modification, heat shock response, and primary adaptation to the host environment (DccSR regulon). Genes encoding proteins involved in the TCA cycle and flagella related components were found to be significantly down-regulated during early colonization. Oxidative stress defense and stringent response genes were found to be maximally induced during the acute infectious phase. Overall, these findings reveal possible mechanisms involved in adaptation of Campylobacter to the host.
A basin-scale approach for assessing water resources in a semiarid environment: San Diego region, California and Mexico
L. E. Flint, A. L. Flint, B. J. Stolp,W. R. Danskin
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2012,
Abstract: Many basins throughout the world have sparse hydrologic and geologic data, but have increasing demands for water and a commensurate need for integrated understanding of surface and groundwater resources. This paper demonstrates a methodology for using a distributed parameter water-balance model, gaged surface-water flow, and a reconnaissance-level groundwater flow model to develop a first-order water balance. Flow amounts are rounded to the nearest 5 million cubic meters per year. The San Diego River basin is 1 of 5 major drainage basins that drain to the San Diego coastal plain, the source of public water supply for the San Diego area. The distributed parameter water-balance model (Basin Characterization Model) was run at a monthly timestep for 1940–2009 to determine a median annual total water inflow of 120 million cubic meters per year for the San Diego region. The model was also run specifically for the San Diego River basin for 1982–2009 to provide constraints to model calibration and to evaluate the proportion of inflow that becomes groundwater discharge, resulting in a median annual total water inflow of 50 million cubic meters per year. On the basis of flow records for the San Diego River at Fashion Valley (US Geological Survey gaging station 11023000), when corrected for upper basin reservoir storage and imported water, the total is 30 million cubic meters per year. The difference between these two flow quantities defines the annual groundwater outflow from the San Diego River basin at 20 million cubic meters per year. These three flow components constitute a first-order water budget estimate for the San Diego River basin. The ratio of surface-water outflow and groundwater outflow to total water inflow are 0.6 and 0.4, respectively. Using total water inflow determined using the Basin Characterization Model for the entire San Diego region and the 0.4 partitioning factor, groundwater outflow from the San Diego region, through the coastal plain aquifer to the Pacific Ocean, is calculated to be approximately 50 million cubic meters per year. The area-scale assessment of water resources highlights several hydrologic features of the San Diego region. Groundwater recharge is episodic; the Basin Characterization Model output shows that 90 percent of simulated recharge occurred during 3 percent of the 1982–2009 period. The groundwater aquifer may also be quite permeable. A reconnaissance-level groundwater flow model for the San Diego River basin was used to check the water budget estimates, and the basic interaction of the surface-water and groundwater system, and the flow values, were found to be reasonable. Horizontal hydraulic conductivity values of the volcanic and metavolcanic bedrock in San Diego region range from 1 to 10 m per day. Overall, results establish an initial hydrologic assessment formulated on the basis of sparse hydrologic data. The described flow variability, extrapolation, and unique characteristics represent a realistic view
Water-balance and groundwater-flow estimation for an arid environment: San Diego region, California
L. E. Flint,A. L. Flint,B. J. Stolp,W. R. Danskin
Hydrology and Earth System Sciences Discussions , 2012, DOI: 10.5194/hessd-9-2717-2012
Abstract: The coastal-plain aquifer that underlies the San Diego City metropolitan area in southern California is a groundwater resource. The understanding of the region-wide water balance and the recharge of water from the high elevation mountains to the east needs to be improved to quantify the subsurface inflows to the coastal plain in order to develop the groundwater as a long term resource. This study is intended to enhance the conceptual understanding of the water balance and related recharge processes in this arid environment by developing a regional model of the San Diego region and all watersheds adjacent or draining to the coastal plain, including the Tijuana River basin. This model was used to quantify the various components of the water balance, including semi-quantitative estimates of subsurface groundwater flow to the coastal plain. Other approaches relying on independent data were used to test or constrain the scoping estimates of recharge and runoff, including a reconnaissance-level groundwater model of the San Diego River basin, one of three main rivers draining to the coastal plain. Estimates of subsurface flow delivered to the coastal plain from the river basins ranged from 12.3 to 28.8 million m3 yr 1 from the San Diego River basin for the calibration period (1982–2009) to 48.8 million m3 yr 1 from all major river basins for the entire coastal plain for the long-term period 1940–2009. This range of scoping estimates represents the impact of climatic variability and realistically bounds the likely groundwater availability, while falling well within the variable estimates of regional recharge. However, the scarcity of physical and hydrologic data in this region hinders the exercise to narrow the range and reduce the uncertainty.
The Active Site of a Carbohydrate Esterase Displays Divergent Catalytic and Noncatalytic Binding Functions
Cedric Montanier,Victoria A. Money,Virginia M. R. Pires,James E. Flint,Benedita A. Pinheiro,Arun Goyal,José A. M. Prates,Atsushi Izumi,Henrik St?lbrand,Carl Morland,Alan Cartmell,Katarina Kolenova,Evangelos Topakas,Eleanor J. Dodson,David N. Bolam,Gideon J. Davies,Carlos M. G. A. Fontes,Harry J. Gilbert
PLOS Biology , 2012, DOI: 10.1371/journal.pbio.1000071
Abstract: Multifunctional proteins, which play a critical role in many biological processes, have typically evolved through the recruitment of different domains that have the required functional diversity. Thus the different activities displayed by these proteins are mediated by spatially distinct domains, consistent with the specific chemical requirements of each activity. Indeed, current evolutionary theory argues that the colocalization of diverse activities within an enzyme is likely to be a rare event, because it would compromise the existing activity of the protein. In contrast to this view, a potential example of multifunctional recruitment into a single protein domain is provided by CtCel5C-CE2, which contains an N-terminal module that displays cellulase activity and a C-terminal module, CtCE2, which exhibits a noncatalytic cellulose-binding function but also shares sequence identity with the CE2 family of esterases. Here we show that, unlike other CE2 members, the CtCE2 domain displays divergent catalytic esterase and noncatalytic carbohydrate binding functions. Intriguingly, these diverse activities are housed within the same site on the protein. Thus, a critical component of the active site of CtCE2, the catalytic Ser-His dyad, in harness with inserted aromatic residues, confers noncatalytic binding to cellulose whilst the active site of the domain retains its esterase activity. CtCE2 catalyses deacetylation of noncellulosic plant structural polysaccharides to deprotect these substrates for attack by other enzymes. Yet it also acts as a cellulose-binding domain, which promotes the activity of the appended cellulase on recalcitrant substrates. The CE2 family encapsulates the requirement for multiple activities by biocatalysts that attack challenging macromolecular substrates, including the grafting of a second, powerful and discrete noncatalytic binding functionality into the active site of an enzyme. This article provides a rare example of “gene sharing,” where the introduction of a second functionality into the active site of an enzyme does not compromise the original activity of the biocatalyst.
The Active Site of a Carbohydrate Esterase Displays Divergent Catalytic and Noncatalytic Binding Functions
Cedric Montanier equal contributor,Victoria A Money equal contributor,Virginia M. R Pires,James E Flint,Benedita A Pinheiro,Arun Goyal,José A. M Prates,Atsushi Izumi,Henrik St?lbrand,Carl Morland,Alan Cartmell,Katarina Kolenova,Evangelos Topakas,Eleanor J Dodson,David N Bolam,Gideon J Davies ,Carlos M. G. A Fontes,Harry J Gilbert
PLOS Biology , 2009, DOI: 10.1371/journal.pbio.1000071
Abstract: Multifunctional proteins, which play a critical role in many biological processes, have typically evolved through the recruitment of different domains that have the required functional diversity. Thus the different activities displayed by these proteins are mediated by spatially distinct domains, consistent with the specific chemical requirements of each activity. Indeed, current evolutionary theory argues that the colocalization of diverse activities within an enzyme is likely to be a rare event, because it would compromise the existing activity of the protein. In contrast to this view, a potential example of multifunctional recruitment into a single protein domain is provided by CtCel5C-CE2, which contains an N-terminal module that displays cellulase activity and a C-terminal module, CtCE2, which exhibits a noncatalytic cellulose-binding function but also shares sequence identity with the CE2 family of esterases. Here we show that, unlike other CE2 members, the CtCE2 domain displays divergent catalytic esterase and noncatalytic carbohydrate binding functions. Intriguingly, these diverse activities are housed within the same site on the protein. Thus, a critical component of the active site of CtCE2, the catalytic Ser-His dyad, in harness with inserted aromatic residues, confers noncatalytic binding to cellulose whilst the active site of the domain retains its esterase activity. CtCE2 catalyses deacetylation of noncellulosic plant structural polysaccharides to deprotect these substrates for attack by other enzymes. Yet it also acts as a cellulose-binding domain, which promotes the activity of the appended cellulase on recalcitrant substrates. The CE2 family encapsulates the requirement for multiple activities by biocatalysts that attack challenging macromolecular substrates, including the grafting of a second, powerful and discrete noncatalytic binding functionality into the active site of an enzyme. This article provides a rare example of “gene sharing,” where the introduction of a second functionality into the active site of an enzyme does not compromise the original activity of the biocatalyst.
Relative Roles of TGF-β and IGFBP-5 in Idiopathic Pulmonary Fibrosis
A. Sureshbabu,E. Tonner,G. J. Allan,D. J. Flint
Pulmonary Medicine , 2011, DOI: 10.1155/2011/517687
Abstract: Although most evident in the skin, the process of scarring, or fibrosis, occurs in all major organs because of impaired epithelial self-renewal. No current therapy exists for Idiopathic pulmonary fibrosis. The major profibrotic factor is TGF-β1 and developing inhibitors is an area of active research. Recently, IGFBP-5 has also been identified as a profibrotic factor, and studies suggest that, while both TGF-β1 and IGFBP-5 activate mesenchymal cells to increase collagen and fibronectin production, their effects on epithelial cells are distinct. TGF-β1 induces cell death and/or EMT in the epithelial cells, exacerbating the disruption of tissue architecture. In contrast, IGFBP-5 induces epithelial cell spreading over collagen or fibronectin matrices, increases secretion of laminin, the epithelial basement membrane, and enhances the survival of epithelial cells in nutrient-poor conditions, as exists in scar tissue. Thus, IGFBP-5 may enhance repair and may be an important target for antifibrotic therapies. 1. Introduction Idiopathic Pulmonary fibrosis (IPF) is a nonneoplastic chronic lung syndrome that is characterized by aberrant accumulation of fibroblasts/myofibroblasts and progressive abnormal remodelling of lung parenchyma, with subsequent scarring and disruption of its structure and function. It belongs to a broad category of 200 disorders called diffuse pulmonary lung diseases (DPLDs) or simply interstitial lung diseases (ILDs). This is further classified into a subgroup known as idiopathic interstitial pneumonia (IIP), where IPF is one of the seven diseases, being the most prevalent and pernicious disorder. It is subclassified with a pathological condition known as usual interstitial pneumonia (UIP). Major symptoms include chronic dyspnea (shortness of breath) induced by 6-minute walk test, persistent dry cough, reduced lung volume, and impaired gas exchange. Constitutional symptoms include weight loss, fatigue, finger clubbing, and general malaise [1]. IPF has a poor prognosis and is five times more prevalent than cystic fibrosis and amyotrophic lateral sclerosis, with no FDA approved treatments. Despite considerable recent progress, current treatment regimens are largely unpromising with a median survival rate of less than three years from the date of diagnosis [2]. The precise mechanisms involved in the pathogenesis of IPF have not been completely understood. Here, in this paper, we attempt to highlight the pathology of pulmonary fibrogenesis from its history, possible cellular and molecular mechanisms, and draw comparisons between the major
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