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Search Results: 1 - 10 of 427460 matches for " M Kate Thomas "
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Contamination of Groundwater Systems in the US and Canada by Enteric Pathogens, 1990–2013: A Review and Pooled-Analysis
Paul Dylan Hynds, M. Kate Thomas, Katarina Dorothy Milena Pintar
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0093301
Abstract: Background Up to 150 million North Americans currently use a groundwater system as their principal drinking water source. These systems are a potential source of exposure to enteric pathogens, contributing to the burden of waterborne disease. Waterborne disease outbreaks have been associated with US and Canadian groundwater systems over the past two decades. However, to date, this literature has not been reviewed in a comprehensive manner. Methods and Principal Findings A combined review and pooled-analysis approach was used to investigate groundwater contamination in Canada and the US from 1990 to 2013; fifty-five studies met eligibility criteria. Four study types were identified. It was found that study location affects study design, sample rate and studied pathogen category. Approximately 15% (316/2210) of samples from Canadian and US groundwater sources were positive for enteric pathogens, with no difference observed based on system type. Knowledge gaps exist, particularly in exposure assessment for attributing disease to groundwater supplies. Furthermore, there is a lack of consistency in risk factor reporting (local hydrogeology, well type, well use, etc). The widespread use of fecal indicator organisms in reported studies does not inform the assessment of human health risks associated with groundwater supplies. Conclusions This review illustrates how groundwater study design and location are critical for subsequent data interpretation and use. Knowledge gaps exist related to data on bacterial, viral and protozoan pathogen prevalence in Canadian and US groundwater systems, as well as a need for standardized approaches for reporting study design and results. Fecal indicators are examined as a surrogate for health risk assessments; caution is advised in their widespread use. Study findings may be useful during suspected waterborne outbreaks linked with a groundwater supply to identify the likely etiological agent and potential transport pathway.
GP Participation and Recruitment of Patients to RCTs: Lessons from Trials of Acupuncture and Exercise for Low Back Pain in Primary Care
Sally E. M. Bell-Syer,Lucy N. Thorpe,Kate Thomas,Hugh MacPherson
Evidence-Based Complementary and Alternative Medicine , 2011, DOI: 10.1093/ecam/nen044
Abstract: The objective of this study was to identify factors associated with general practitioner (GP) participation and the recruitment of people to trials in primary care, based on data from two trials of interventions for treating chronic low back pain. The study was based on data from two randomized controlled trials (RCTs), one involving exercise, the other acupuncture, and subsequent reporting by GPs in a postal questionnaire. The exercise trial achieved 62% recruitment whereas the acupuncture trial achieved 100% recruitment. In both trials GPs most efficient at referring patients were those with a special interest in the subject area, and those known personally to the research team. A follow-up GP questionnaire found that both trials had maintained a high profile with over 80% of GPs, and successful recruitment strategies included project reminder letters, updates and personal contacts. Achieving target recruitment of patients in the acupuncture trial was aided by the deliberate application of lessons learned in the exercise trial, in particular the need to keep initial study entry criteria broad, with subsequent filtering undertaken by the study researcher. In addition the use of effective methods of maintaining the trial profile, the involvement of a GP advisor, the decision to maximize the recruitment of GPs early in the trial and the direct recruitment of interested individual GPs. The successful recruitment of patients to trials in primary care requires careful planning and continuous monitoring from the outset. Prior to starting recruitment, it is useful to identify previous trials in a similar environment in order to learn from their experience and optimize patient recruitment.
Trauma Center-Based Surveillance of Nontraffic Pedestrian Injury among California Children
Thomas M. Rice, MPH, PhD,Roger B. Trent, PhD,Kate Bernacki, MPH,Jennifer K. Rice, MPH
Western Journal of Emergency Medicine : Integrating Emergency Care with Population Health , 2012,
Abstract: Introduction: Every year in the United States, thousands of young children are injured by passengervehicles in driveways or parking areas. Little is known about risk factors, and incidence rates aredifficult to estimate because ascertainment using police collision reports or media sources isincomplete. This study used surveillance at trauma centers to identify incidents and parent interviewsto obtain detailed information on incidents, vehicles, and children.Methods: Eight California trauma centers conducted surveillance of nontraffic pedestrian collisioninjury to children aged 14 years or younger from January 2005 to July 2007. Three of these centersconducted follow-up interviews with family members.Results: Ninety-four injured children were identified. Nine children (10%) suffered fatal injury. Seventychildren (74%) were 4 years old or younger. Family members of 21 victims from this study (23%)completed an interview. Of these 21 interviewed victims, 17 (81%) were male and 13 (62%) were 1 or 2years old. In 13 cases (62%), the child was backed over, and the driver was the mother or father in 11cases (52%). Fifteen cases (71%) involved a sport utility vehicle, pickup truck, or van. Most collisionsoccurred in a residential driveway.Conclusion: Trauma center surveillance can be used for case ascertainment and for collectinginformation on circumstances of nontraffic pedestrian injuries. Adoption of a specific external cause-ofinjurycode would allow passive surveillance of these injuries. Research is needed to understand thecontributions of family, vehicular, and environmental characteristics and injury risk to inform preventionefforts.
Spatial analysis of learning and developmental disorders in upper Cape Cod, Massachusetts using generalized additive models
Kate Hoffman, Thomas F Webster, Janice M Weinberg, Ann Aschengrau, Patricia A Janulewicz, Roberta F White, Verónica M Vieira
International Journal of Health Geographics , 2010, DOI: 10.1186/1476-072x-9-7
Abstract: The prevalence of learning and developmental disabilities (LDDs) has increased over the last four decades [1,2]. Current prevalence estimates suggest that 5 to 15% of children in the United States are afflicted with disorders of learning and development, including disorders of memory, reduced IQ, attention deficit hyperactivity disorder (ADHD), autism spectrum disorders, conduct disorders and developmental delays [2-5]. The increased prevalence of LDDs has largely been attributed to improved diagnosis; however, evidence also suggests that the underlying prevalence of dysfunction is increasing [2]. Although the specific mechanisms for learning and developmental disorders remain unclear, much research has been conducted to identify their risk factors. These studies have consistently found that males and children from economic or culturally disadvantaged backgrounds have greater risk of being diagnosed with an LDD [1,6]. Numerous pre-birth risk factors have also been identified including lack of prenatal care; increased maternal age; pre-term delivery; low birth weight and prenatal alcohol, tobacco, and drug use [7-10]. Additional research suggests that the development of learning and developmental disorders is affected by intrinsic causes such as genetic differences in brain structure or biochemical imbalances [11]. However, it has also been suggested that the increased prevalence is attributable, at least in part, to chronic exposures to environmental toxicants [12-15].Brain development begins in utero and continues throughout adolescence. This lengthy developmental period, coupled with its extreme complexity, leaves the developing brain particularly susceptible to adverse effects of chemical exposures [16]. Subtle changes in either structure or function can lead to profound neurological consequences that can persist over a lifetime. Prenatal and early childhood exposures to a number of environmental toxicants such as lead, methylmercury and polychlorinated biphenyls
Who Underreports Smoking on Birth Records: A Monte Carlo Predictive Model with Validation
Thomas G. Land, Anna S. Landau, Susan E. Manning, Jane K. Purtill, Kate Pickett, Lauren Wakschlag, Vanja M. Dukic
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0034853
Abstract: Background Research has shown that self-reports of smoking during pregnancy may underestimate true prevalence. However, little is known about which populations have higher rates of underreporting. Availability of more accurate measures of smoking during pregnancy could greatly enhance the usefulness of existing studies on the effects of maternal smoking offspring, especially in those populations where underreporting may lead to underestimation of the impact of smoking during pregnancy. Methods and Findings In this paper, we develop a statistical Monte Carlo model to estimate patterns of underreporting of smoking during pregnancy, and apply it to analyze the smoking self-report data from birth certificates in the state of Massachusetts. Our results illustrate non-uniform patterns of underreporting of smoking during pregnancy among different populations. Estimates of likely underreporting of smoking during pregnancy were highest among mothers who were college-educated, married, aged 30 years or older, employed full-time, and planning to breastfeed. The model's findings are validated and compared to an existing underreporting adjustment approach in the Maternal and Infant Smoking Study of East Boston (MISSEB). Conclusions The validation results show that when biological assays are not available, the Monte Carlo method proposed can provide a more accurate estimate of the smoking status during pregnancy than self-reports alone. Such methods hold promise for providing a better assessment of the impact of smoking during pregnancy.
Marriage and Psychological Wellbeing: The Role of Social Support  [PDF]
Laura K. Soulsby, Kate M. Bennett
Psychology (PSYCH) , 2015, DOI: 10.4236/psych.2015.611132
Abstract: The married consistently report better levels of psychological health compared to the unmarried. Using a cross-sectional questionnaire design, this research examines to what extent this relationship between marital status and psychological wellbeing can be explained by perceived social support. The data reveal that, after controlling for demographic variables, number of daily hassles and coping strategies, widowed and divorced adults report significantly poorer psychological health compared to those who remain married. Moreover, while there was limited evidence that perceived social support moderates the association between marital status and psychological wellbeing, perceived social support did emerge as a significant mediator of this relationship. Perceived social support explained the influence of being widowed, divorced and never married on psychological wellbeing, such that lower levels of support in these groups resulted in poorer psychological health. Thus, social support may be an important variable for interventions to minimize the negative consequences of a transition out of marriage.
Long-Term Left Ventricular Remodelling in Rat Model of Nonreperfused Myocardial Infarction: Sequential MR Imaging Using a 3T Clinical Scanner
Muhammad G. Saleh,Sarah-Kate Sharp,Alkathafi Alhamud,Bruce S. Spottiswoode,Andre J. W. van der Kouwe,Neil H. Davies,Thomas Franz,Ernesta M. Meintjes
Journal of Biomedicine and Biotechnology , 2012, DOI: 10.1155/2012/504037
Abstract: Purpose. To evaluate whether 3T clinical MRI with a small-animal coil and gradient-echo (GE) sequence could be used to characterize long-term left ventricular remodelling (LVR) following nonreperfused myocardial infarction (MI) using semi-automatic segmentation software (SASS) in a rat model. Materials and Methods. 5 healthy rats were used to validate left ventricular mass (LVM) measured by MRI with postmortem values. 5 sham and 7 infarcted rats were scanned at 2 and 4 weeks after surgery to allow for functional and structural analysis of the heart. Measurements included ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), and LVM. Changes in different regions of the heart were quantified using wall thickness analyses. Results. LVM validation in healthy rats demonstrated high correlation between MR and postmortem values. Functional assessment at 4 weeks after MI revealed considerable reduction in EF, increases in ESV, EDV, and LVM, and contractile dysfunction in infarcted and noninfarcted regions. Conclusion. Clinical 3T MRI with a small animal coil and GE sequence generated images in a rat heart with adequate signal-to-noise ratio (SNR) for successful semiautomatic segmentation to accurately and rapidly evaluate long-term LVR after MI.
The Enhanced In Vivo Activity of the Combination of a MEK and a PI3K Inhibitor Correlates with [18F]-FLT PET in Human Colorectal Cancer Xenograft Tumour-Bearing Mice
Emma J. Haagensen, Huw D. Thomas, Ian Wilson, Suzannah J. Harnor, Sara L. Payne, Tommy Rennison, Kate M. Smith, Ross J. Maxwell, David R. Newell
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0081763
Abstract: Combined targeting of the MAPK and PI3K signalling pathways in cancer may be necessary for optimal therapeutic activity. To support clinical studies of combination therapy, 3′-deoxy-3′-[18F]-fluorothymidine ([18F]-FLT) uptake measured by Positron Emission Tomography (PET) was evaluated as a non-invasive surrogate response biomarker in pre-clinical models. The in vivo anti-tumour efficacy and PK-PD properties of the MEK inhibitor PD 0325901 and the PI3K inhibitor GDC-0941, alone and in combination, were evaluated in HCT116 and HT29 human colorectal cancer xenograft tumour-bearing mice, and [18F]-FLT PET investigated in mice bearing HCT116 xenografts. Dual targeting of PI3K and MEK induced marked tumour growth inhibition in vivo, and enhanced anti-tumour activity was predicted by [18F]-FLT PET scanning after 2 days of treatment. Pharmacodynamic analyses using the combination of the PI3K inhibitor GDC-0941 and the MEK inhibitor PD 0325901 revealed that increased efficacy is associated with an enhanced inhibition of the phosphorylation of ERK1/2, S6 and 4EBP1, compared to that observed with either single agent, and maintained inhibition of AKT phosphorylation. Pharmacokinetic studies indicated that there was no marked PK interaction between the two drugs. Together these results indicate that the combination of PI3K and MEK inhibitors can result in significant efficacy, and demonstrate for the first time that [18F]-FLT PET can be correlated to the improved efficacy of combined PI3K and MEK inhibitor treatment.
Evidence Based Selection of Commonly Used RT-qPCR Reference Genes for the Analysis of Mouse Skeletal Muscle
Kristen C. Thomas, Xi Fiona Zheng, Francia Garces Suarez, Joanna M. Raftery, Kate G. R. Quinlan, Nan Yang, Kathryn N. North, Peter J. Houweling
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0088653
Abstract: The ability to obtain accurate and reproducible data using quantitative real-time Polymerase Chain Reaction (RT-qPCR) is limited by the process of data normalization. The use of ‘housekeeping’ or ‘reference’ genes is the most common technique used to normalize RT-qPCR data. However, commonly used reference genes are often poorly validated and may change as a result of genetic background, environment and experimental intervention. Here we present an analysis of 10 reference genes in mouse skeletal muscle (Actb, Aldoa, Gapdh, Hprt1, Ppia, Rer1, Rn18s, Rpl27, Rpl41 and Rpl7L1), which were identified as stable either by microarray or in the literature. Using the MIQE guidelines we compared wild-type (WT) mice across three genetic backgrounds (R129, C57BL/6j and C57BL/10) as well as analyzing the α-actinin-3 knockout (Actn3 KO) mouse, which is a model of the common null polymorphism (R577X) in human ACTN3. Comparing WT mice across three genetic backgrounds, we found that different genes were more tightly regulated in each strain. We have developed a ranked profile of the top performing reference genes in skeletal muscle across these common mouse strains. Interestingly the commonly used reference genes; Gapdh, Rn18s, Hprt1 and Actb were not the most stable. Analysis of our experimental variant (Actn3 KO) also resulted in an altered ranking of reference gene suitability. Furthermore we demonstrate that a poor reference gene results in increased variability in the normalized expression of a gene of interest, and can result in loss of significance. Our data demonstrate that reference genes need to be validated prior to use. For the most accurate normalization, it is important to test several genes and use the geometric mean of at least three of the most stably expressed genes. In the analysis of mouse skeletal muscle, strain and intervention played an important role in selecting the most stable reference genes.
Molecular gas heating mechanisms, and star formation feedback in merger/s tarbursts: NGC 6240 and Arp 193 as case studies
Padelis P. Papadopoulos,Zhi-Yu Zhang,E. M. Xilouris,Axel Weiss,Paul van der Werf,Frank. P. Israel,Thomas. R. Greve,Kate G. Isaak,Yu Gao
Physics , 2014, DOI: 10.1088/0004-637X/788/2/153
Abstract: We used the SPIRE/FTS instrument aboard the Herschel Space Observatory (HSO) to obtain the Spectral Line Energy Distributions (SLEDs) of CO from J=4-3 to J=13-12 of Arp 193 and NGC 6240, two classical merger/starbursts selected from our molecular line survey of local Luminous Infrared Galaxies (LIRGs: L_{IR}>=10^{11} L_{sol}). The high-J CO SLEDs are then combined with ground-based low-J CO, {13}CO, HCN, HCO+, CS line data and used to probe the thermal and dynamical states of their large molecular gas reservoirs. We find the two CO SLEDs strongly diverging from J=4-3 onwards, with NGC6240 having a much higher CO line excitation than Arp193, despite their similar low-J CO SLEDs and L_{FIR}/L_{CO,1-0}, L_{HCN}/L_{CO} (J=1-0) ratios (proxies of star formation efficiency and dense gas mass fraction). In Arp193, one of the three most extreme starbursts in the local Universe, the molecular SLEDs indicate a small amount ~(5-15)% of dense gas (n>=10^{4}cm^{-3}) unlike NGC6240 where most of the molecular gas (~(60-70)%) is dense n~(10^4-10^5)cm^{-3}. Strong star-formation feedback can drive this disparity in their dense gas mass fractions, and also induce extreme thermal and dynamical states for the molecular gas.In NGC6240, and to a lesser degree in Arp193, we find large molecular gas masses whose thermal states cannot be maintained by FUV photons from Photon Dominated Regions (PDRs). We argue that this may happen often in metal-rich merger/starbursts, strongly altering the initial conditions of star formation. ALMA can now directly probe these conditions across cosmic epoch, and even probe their deeply dust-enshrouded outcome, the stellar IMF averaged over galactic evolution.
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