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Search Results: 1 - 10 of 122169 matches for " Lucas T. Rasmussen "
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Prevalence of Helicobacter pylori cagA and sabA Genotypes in Patients with Gastric Disease  [PDF]
Jéssica Nunes Pereira, Wilson A. Orcini, Rita L. Peruquetti, Marilia A. C. Smith, Spencer L. M. Pay?o, Lucas T. Rasmussen
Advances in Microbiology (AiM) , 2019, DOI: 10.4236/aim.2019.93017
Abstract: Gastric cancer is one of the most common types of cancer worldwide. Helicobacter pylori is considered one of the most important causes of this condition specially because of its virulence markers as sabA and cagA. Therefore, we aim to investigate the relation between these markers and the gastric diseases in 400 patients who underwent upper digestive endoscopy. To detect the bacteria and its genes by Polymerase Chain Reaction (PCR), the presence of H. pylori was significant when comparing the groups control vs. cancer (p value < 0.0001) OR [95% CI] 12.73 (5.45 - 29.69) and the groups control vs. chronic gastritis (p value < 0.0001) OR [95% CI] 12.99 (7.44 - 22.66). cagA was statistically significant considering its presence when comparing the chronic gastritis vs. cancer groups (p value = 0.0434) OR [95% CI] 2.44 (1.021 - 5.845). Associating both sabA and cagA, we found a statistically significant result (p value < 0.0001) OR [95% CI] 13.68 (3.95 - 47.33) considering the gastritis vs. cancer groups. Helicobacter pylori is directly associated to gastric diseases such as gastritis and cancer and its virulence markers: sabA and cagA increase the injury process to the gastric epithelium making the host more susceptible to cancer.
We Decide, They Decide For Us: Popular Participation as an Issue in Two Nigerian Women's Development Programmes
Emma T. Lucas
Africa Development , 2000,
Abstract: Participation at all levels of organizing, programme development, and implementation is critical if development programmes are to meet a minimum level of success. An examination of the organizational decision-making structure of two Nigerian women's development organizations, Better Life for Rural Women (BLP), a government-sponsored programme, and Country Women's Association of Nigeria (COWAN), a non-governmental programme, reveals fundamental differences in the level of participation of rural women who were the intended beneficiaries. The mission of each focused on the improvement of rural women's lives; however, the success of the non-governmental organization far outweighed the government-sponsored one because of its basic belief in popular participation. BLP was more likely to encourage bureaucratic and individual politically motivated manoeuvres that only delayed and sometimes subverted altogether services that were specifically designed for rural women. COWAN was less likely to experience these barriers, and therefore more readily responded to and engaged rural women as full participants in development projects that focused on improving their lives. Because of political instability, government projects focusing on women are limited. However, their need for development programmes that directly address their concerns is as great as ever. Résumé La participation à tous les niveaux d'organisation, d'élaboration et de mise en uvre de programme est fondamentale si l'on veut assurer aux programmes de développement un minimum de réussite. Un examen de la structure de prise de décisions de deux organisations féminines de développement du Nigeria-Better Life for Rural Women (BLP, un programme soutenu par le gouvernement, et Country Women's Association of Nigeria (COWAN), un programme non-gouvernemental, révèle des différences fondamentales au niveau de la participation des femmes rurales qui sont censées en être les bénéficiaires. La mission de l'un comme de l'autre était axée sur l'amélioration des conditions de vie des femmes en milieu rural ; cependant, la réussite de l'organisation non-gouvernementale a dépassé de loin celle de l'organisation appuyée par l'Etat, en raison de sa croyance profonde en la participation populaire. Si BLP était plus encline à encourager les man uvres bureaucratiques et individuelles à motivation politique qui ne faisaient que retarder et parfois détourner simplement les services qui étaient spécialement con us pour les femmes rurales, COWAN, elle, n'était pas exposée à ces goulots d'étranglement, et était donc plus attentive aux femmes qu'elle impliquait pleinement dans les projets de développement qui s'intéressent à l'amélioration de leurs conditions d'existence. En raison de l'instabilité politique, les projets féminins appuyés par le gouvernement sont peu nombreux. Cependant, leur besoin de programmes de développement qui prennent en charge leurs préoccupations, est toujours aussi grand. (Africa Development: 2000
The G4 Genome
Nancy Maizels ,Lucas T. Gray
PLOS Genetics , 2013, DOI: 10.1371/journal.pgen.1003468
Abstract: Recent experiments provide fascinating examples of how G4 DNA and G4 RNA structures—aka quadruplexes—may contribute to normal biology and to genomic pathologies. Quadruplexes are transient and therefore difficult to identify directly in living cells, which initially caused skepticism regarding not only their biological relevance but even their existence. There is now compelling evidence for functions of some G4 motifs and the corresponding quadruplexes in essential processes, including initiation of DNA replication, telomere maintenance, regulated recombination in immune evasion and the immune response, control of gene expression, and genetic and epigenetic instability. Recognition and resolution of quadruplex structures is therefore an essential component of genome biology. We propose that G4 motifs and structures that participate in key processes compose the G4 genome, analogous to the transcriptome, proteome, or metabolome. This is a new view of the genome, which sees DNA as not only a simple alphabet but also a more complex geography. The challenge for the future is to systematically identify the G4 motifs that form quadruplexes in living cells and the features that confer on specific G4 motifs the ability to function as structural elements.
Prevalence of Helicobacter pylori vacA, cagA, dupA and oipA Genotypes in Patients with Gastric Disease  [PDF]
Mayara Luciana Sallas, Jessica Lima Melchiades, Luanna Munhoz Zabaglia, Juliana Ribeiro do Prado Moreno, Wilson Aparecido Orcini, Elizabeth Suchi Chen, Marilia de Arruda Cardoso Smith, Spencer Luiz Marques Pay?o, Lucas Trevizani Rasmussen
Advances in Microbiology (AiM) , 2017, DOI: 10.4236/aim.2017.71001
Abstract: Gastric diseases such as chronic gastritis and gastric cancer are most commonly caused by virulence factors of Helicobacter pylori (H. pylori), such as the vacA, cagA, dupA and oipA genes. Therefore, this study investigated the prevalence and the combination of these virulence factors from patients with gastric diseases. The endoscopic biopsies were obtained from 516 patients with gastric symptoms, 101 of which were from patients with normal gastric tissue, 365 of which were from patients with chronic gastritis, and 50 of which were from patients with gastric cancer. H. pylori and the virulence factors were detected by PCR. The oipA gene exhibited an increased risk for chronic gastritis (p = 0.0296), and the vacA gene demonstrated a risk for gastric cancer from chronic gastritis (p = 0.0002). Based on the combination of the virulence factors, cagA, vacA, dupA and oipA genes exhibited a high prevalence in patients with chronic gastritis and gastric cancer. The cagA+/dupA+ genotype demonstrated a significant correlation in patients with normal gastric mucosa (p = 0.0278). In the chronic gastritis group, a significant association was observed between the cagA+ and the vacA s1m1 genotypes (p < 0.0001), the cagA+/dupA+ genotypes (p = 0.0183), the dupA+/oipA+ genotypes (p < 0.0001), and the dupA+/vacA s1m1 genotypes (p = 0.0008) genotypes. This study revealed a high prevalence of the combination of cagA, vacA, dupA, and oipA genes, which contributed to the risk of developing gastroduodenal diseases. Furthermore, this is the first study to reveal a high prevalence of the oipA gene in H. pylori isolates in Brazil.
Use of DNA melting simulation software for in silico diagnostic assay design: targeting regions with complex melting curves and confirmation by real-time PCR using intercalating dyes
John P Rasmussen, Christopher P Saint, Paul T Monis
BMC Bioinformatics , 2007, DOI: 10.1186/1471-2105-8-107
Abstract: The SYTO9 melting curve profiles of three species of Naegleria and two species of Cryptosporidium were similar to POLAND and MELTSIM melting simulations, excepting some differences in the relative peak heights and the absolute melting temperatures of these peaks. MELTSIM and POLAND were used to screen sequences from a putative toxin gene in two different species of cyanobacteria and identify regions exhibiting diagnostic melting profiles. For one of these diagnostic regions the POLAND and MELTSIM melting simulations were observed to be different, with POLAND more accurately predicting the melting curve generated in vitro. Upon further investigation of this region with MELTSIM, inconsistencies between the melting simulation for forward and reverse complement sequences were observed. The assay was used to accurately type twenty seven cyanobacterial DNA extracts in vitro.Whilst neither POLAND nor MELTSIM simulation programs were capable of exactly predicting DNA dissociation in the presence of an intercalating dye, the programs were successfully used as tools to identify regions where melting curve differences could be exploited for diagnostic melting curve assay design. Refinements in the simulation parameters would be required to account for the effect of the intercalating dye and salt concentrations used in real-time PCR. The agreement between the melting curve simulations for different species of Naegleria and Cryptosporidium and the complex melting profiles generated in vitro using SYTO9 verified that the complex melting profile of PCR amplicons was solely the result of DNA dissociation. Other data outputs from these simulations were also used to identify the melting domains that contributed to the observed melting peaks for each of the different PCR amplicons.Differentiation of PCR products using DNA melting curve analysis was first demonstrated by Ririe et al [1] with the double-stranded DNA-specific dye SYBR Green I and has since seen widespread adoption in rea
Assessing impacts of climate change, sea level rise, and drainage canals on saltwater intrusion to coastal aquifer
P. Rasmussen, T. O. Sonnenborg, G. Goncear,K. Hinsby
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2013,
Abstract: Groundwater abstraction from coastal aquifers is vulnerable to climate change and sea level rise because both may potentially impact saltwater intrusion and hence groundwater quality depending on the hydrogeological setting. In the present study the impacts of sea level rise and changes in groundwater recharge are quantified for an island located in the Western Baltic Sea. The low-lying central area of the investigated part of the island was extensively drained and reclaimed during the second half of the 19th century by a system of artificial drainage canals that significantly affects the flow dynamics of the area. The drinking water, mainly for summer cottages, is abstracted from 11 wells drilled to a depth of around 20 m into the upper 5–10 m of a confined chalk aquifer, and the total pumping is only 5–6% of the drainage pumping. Increasing chloride concentrations have been observed in several abstraction wells and in some cases the WHO drinking water standard has been exceeded. Using the modeling package MODFLOW/MT3D/SEAWAT the historical, present and future freshwater-sea water distribution is simulated. The model is calibrated against hydraulic head observations and validated against geochemical and geophysical data from new investigation wells, including borehole logs, and from an airborne transient electromagnetic survey. The impact of climate changes on saltwater intrusion is found to be sensitive to the boundary conditions of the investigated system. For the flux-controlled aquifer to the west of the drained area only changes in groundwater recharge impacts the freshwater–sea water interface whereas sea level rise does not result in increasing sea water intrusion. However, on the barrier islands to the east of the reclaimed area, below which the sea is hydraulically connected to the drainage canals, and the boundary of the flow system therefore controlled, the projected changes in sea level, groundwater recharge and stage of the drainage canals all have significant impacts on saltwater intrusion and the chloride concentrations found in abstraction wells.
Tightened constraints on the time-lag between Antarctic temperature and CO2 during the last deglaciation
J. B. Pedro, S. O. Rasmussen,T. D. van Ommen
Climate of the Past (CP) & Discussions (CPD) , 2012,
Abstract: Antarctic ice cores provide clear evidence of a close coupling between variations in Antarctic temperature and the atmospheric concentration of CO2 during the glacial/interglacial cycles of at least the past 800-thousand years. Precise information on the relative timing of the temperature and CO2 changes can assist in refining our understanding of the physical processes involved in this coupling. Here, we focus on the last deglaciation, 19 000 to 11 000 yr before present, during which CO2 concentrations increased by ~80 parts per million by volume and Antarctic temperature increased by ~10 °C. Utilising a recently developed proxy for regional Antarctic temperature, derived from five near-coastal ice cores and two ice core CO2 records with high dating precision, we show that the increase in CO2 likely lagged the increase in regional Antarctic temperature by less than 400 yr and that even a short lead of CO2 over temperature cannot be excluded. This result, consistent for both CO2 records, implies a faster coupling between temperature and CO2 than previous estimates, which had permitted up to millennial-scale lags.
Review of Survey activities 2012: Drowning of the Miocene Billund delta, Jylland: land–sea fluctuations during a global warming event
Rasmussen, E.S.,Utescher, T.,Dybkj?r, K.
Geological Survey of Denmark and Greenland Bulletin , 2013,
Abstract:
Assessing impacts of climate change, sea level rise, and drainage canals on saltwater intrusion to coastal aquifer
P. Rasmussen,T. O. Sonnenborg,G. Goncear,K. Hinsby
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2013, DOI: 10.5194/hess-17-421-2013
Abstract: Groundwater abstraction from coastal aquifers is vulnerable to climate change and sea level rise because both may potentially impact saltwater intrusion and hence groundwater quality depending on the hydrogeological setting. In the present study the impacts of sea level rise and changes in groundwater recharge are quantified for an island located in the Western Baltic Sea. The low-lying central area of the investigated part of the island was extensively drained and reclaimed during the second half of the 19th century by a system of artificial drainage canals that significantly affects the flow dynamics of the area. The drinking water, mainly for summer cottages, is abstracted from 11 wells drilled to a depth of around 20 m into the upper 5–10 m of a confined chalk aquifer, and the total pumping is only 5–6% of the drainage pumping. Increasing chloride concentrations have been observed in several abstraction wells and in some cases the WHO drinking water standard has been exceeded. Using the modeling package MODFLOW/MT3D/SEAWAT the historical, present and future freshwater-sea water distribution is simulated. The model is calibrated against hydraulic head observations and validated against geochemical and geophysical data from new investigation wells, including borehole logs, and from an airborne transient electromagnetic survey. The impact of climate changes on saltwater intrusion is found to be sensitive to the boundary conditions of the investigated system. For the flux-controlled aquifer to the west of the drained area only changes in groundwater recharge impacts the freshwater–sea water interface whereas sea level rise does not result in increasing sea water intrusion. However, on the barrier islands to the east of the reclaimed area, below which the sea is hydraulically connected to the drainage canals, and the boundary of the flow system therefore controlled, the projected changes in sea level, groundwater recharge and stage of the drainage canals all have significant impacts on saltwater intrusion and the chloride concentrations found in abstraction wells.
Climate change effects on irrigation demands and minimum stream discharge: impact of bias-correction method
J. Rasmussen,T. O. Sonnenborg,S. Stisen,L. P. Seaby
Hydrology and Earth System Sciences Discussions , 2012, DOI: 10.5194/hessd-9-4989-2012
Abstract: Climate changes are expected to result in a warmer global climate, with increased inter-annual variability. In this study, the possible impacts of these climate changes on irrigation and low stream flow are investigated using a distributed hydrological model of a sandy catchment in western Denmark. The IPCC climate scenario A1B was chosen as the basis for the study, and meteorological forcings (precipitation, reference evapotranspiration and temperature) derived from the ECHAM5-RACMO2 regional climate model for the period 2071–2100 was applied to the model. Two bias correction methods, Delta Change and Distribution-Based Scaling, were used to evaluate the importance of the bias correction method. Using the annual irrigation amounts, the minimum stream flow, the median minimum stream flow and the mean stream flow as indicators, the irrigation and the stream flow predicted using the two methods were compared. The study found that irrigation is significantly underestimated and low stream flow in overestimated when using the delta change method, due to the inability of this method to account for changes in inter-annual variability of precipitation and reference ET and the resulting effects on irrigation demands. Additionally, future increases in CO2 are found to have a significant effect on both irrigation and low flow, due to reduced transpiration from plants.
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