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Search Results: 1 - 10 of 403617 matches for " Helen M.; Mackin "
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Sleep disordered breathing in community psychiatric patients
Anderson,Kirstie N.; Waton,Tony; Armstrong,Daniel; Watkinson,Helen M.; Mackin,Paul;
The European Journal of Psychiatry , 2012, DOI: 10.4321/S0213-61632012000200002
Abstract: background and objectives: sleep disturbance is prominent in many neuropsychiatric disorders and may precipitate or exacerbate a range of psychiatric conditions. few studies have investigated sleep disordered breathing and in particular obstructive sleep apnoea in community psychiatric patients and the commonly used screening instruments have not been evaluated in patients with psychiatric disorders. the objective is to evaluate the prevalence of sleep disordered breathing in a community cohort with chronic mental illness on long term psychotropic medication, and to assess the effectiveness of commonly used screening instruments to detect abnormal sleep. methods: 52 patients completed sleep questionnaires and 50 undertook overnight oximetry. results: 52% (n = 26) had sleep-disordered breathing; 20% (n = 10) had moderate/severe sleep apnoea. the epworth sleepiness score and the pittsburgh sleep quality inventory did not predict sleep disordered breathing. conclusions: patients with psychiatric disorders in the community have a high rate of undiagnosed sleep disordered breathing, which is not reliably detected by established sleep disorder screening questionnaires.
A prospective study of monitoring practices for metabolic disease in antipsychotic-treated community psychiatric patients
Paul Mackin, David R Bishop, Helen MO Watkinson
BMC Psychiatry , 2007, DOI: 10.1186/1471-244x-7-28
Abstract: We conducted a prospective cohort study of 106 community-treated psychiatric patients from across the diagnostic spectrum from the Northeast of England to investigate changes in metabolic status and monitoring practices for metabolic and cardiovascular disease. We undertook detailed anthropometric and metabolic assessment at baseline and follow-up, and examined clinical notes and hospital laboratory records to ascertain monitoring practices.A high prevalence of undiagnosed and untreated metabolic disease was present at baseline assessment. Mean follow-up time was 599.3 (SD ± 235.4) days. Body mass index (p < 0.005) and waist circumference (p < 0.05) had significantly increased at follow-up, as had the number of individuals who were either overweight or obese. Fifty-three per cent of individuals had hypertriglyceridemia, and 31% had hypercholesterolemia, but only 7% were receiving lipid-lowering therapy. Monitoring practices were poor. Recording of measures of adiposity occurred in 0% of individuals, and > 50% of subjects had neither blood glucose nor lipids monitored during the follow-up period.This cohort has a high prevalence of metabolic disease and heightened cardiovascular risk. Despite the publication of a number of recommendations regarding physical health screening in this population, monitoring rates are poor, and physical health worsened during the follow-up period.Severe mental illness (SMI) is associated with a significant excess of physical co-morbidity and mortality [1,2], and as such represents a major public health concern. Previous studies have reported a high prevalence of undiagnosed and untreated metabolic disorders and cardiovascular risk factors in patients with SMI [3-7]. Consensus statements from the US [8] and UK [9] have recommended stringent monitoring of metabolic status and cardiovascular risk factors in psychiatric patients receiving antipsychotic drugs, and recently published UK guidelines from the National Institute for Health and Cli
Tracking Differential Gene Expression in MRL/MpJ Versus C57BL/6 Anergic B Cells: Molecular Markers of Autoimmunity
Amy G. Clark,Katherine M. Mackin,Mary H. Foster
Biomarker Insights , 2008,
Abstract: Background: Anergy is a key mechanism controlling expression of autoreactive B cells and a major site for failed regulation in autoimmune diseases. Yet the molecular basis for this differentiated cell state remains poorly understood. The current lack of well-characterized surface or molecular markers hinders the isolation of anergic cells for further study. Global gene profiling recently identified transcripts whose expression differentiates anergic from na ve B cells in model mouse systems. The objective of the current study was to evaluate the molecular and cellular processes that differentiate anergic cells that develop in the healthy C57BL/6 (B6) milieu from those that develop in the autoimmune-prone MRL/MpJ (MRL) background. This approach takes advantage of B6 and MRL mice bearing an anti-laminin Ig transgene with a well characterized anergic B cell phenotype.Results: Global gene expression was evaluated in purified transgenic B cells using Operon version 3.0 oligonucleotide microarray assaying 31,000 oligoprobes. Genes with a 2-fold expression difference in B6 as compared to MRL anergic B cells were identified. Expression of selected genes was confirmed using quantitative RT-PCR. This approach identified 43 probes corresponding to 37 characterized genes, including Ptpn22, CD74, Birc1f/Naip, and Ctla4, as differentially expressed in anergic B cells in the two strains. Gene Ontology classification identified differentiation, cell cycle, proliferation, development, apoptosis, and cell death as prominently represented ontology groups. Ingenuity Pathway Analysis identified two major networks incorporating 27 qualifying genes. Network 1 centers on beta-estradiol and TP53, and Network 2 encompasses RB1, p38 MAPK, and NFkB cell growth, proliferation, and cell cycle signaling pathways.Conclusion: Using microarray analysis we identified 37 characterized genes and two functional pathways engaged in maintenance of B cell anergy for which expression is distorted by underlying autoimmune genetic susceptibility. This approach identifies a new biological role for multiple genes and potential new therapeutic targets in autoimmunity.
Influence of basin connectivity on sediment source, transport, and storage within the Mkabela Basin, South Africa
J. R. Miller,G. Mackin,P. Lechler,M. Lord
Hydrology and Earth System Sciences Discussions , 2012, DOI: 10.5194/hessd-9-10151-2012
Abstract: The management of sediment and other non-point source (NPS) pollution has proven difficult, and requires a sound understanding of particle movement through the drainage system. The primary objective of this investigation was to obtain an understanding of NPS sediment source(s), transport, and storage within the Mkabela basin, a representative agricultural catchment within the KwaZulu-Natal Midlands of southeastern South Africa, by combining geomorphic, hydrologic and geochemical fingerprinting analyses. The Mkabela Basin can be subdivided into three distinct subcatchments that differ in their ability to transport and store sediment along the axial valley. Headwater (upper catchment) areas are characterized by extensive wetlands that act as significant sediment sinks. Mid-catchment areas, characterized by higher relief and valley gradients, exhibit few wetlands, but rather are dominated by a combination of alluvial and bedrock channels that are conducive to sediment transport. The lower catchment exhibits a low-gradient alluvial channel that is boarded by extensive riparian wetlands that accumulate large quantities of sediment (and NPS pollutants). Fingerprinting studies suggest that silt- and clay-rich layers found within wetland and reservoir deposits are derived from the erosion of fine-grained, valley bottom soils frequently utilized as vegetable fields. Coarser-grained deposits within both wetlands and reservoirs result from the erosion of sandier hillslope soils extensively utilized for sugar cane, during relatively high magnitude runoff events that are capable of transporting sand-sized sediment off the slopes. Thus, the source of sediment to the axial valley varies as a function of sediment size and runoff magnitude. Sediment export from the basin was limited until the early 1990s, in part because the upper catchment wetlands were hydrologically disconnected from lower parts of the watershed during low- to moderate flood events. The construction of a drainage ditch through a previously unchanneled wetland altered the hydrologic connectivity of the catchment, allowing sediment to be transported from the headwaters to the lower basin where much of it was deposited within the riparian wetlands. The axial drainage system is now geomorphically and hydrologically connected during most events throughout the study basin. The study indicates that increased valley connectivity partly negated the positive benefits of controlling sediment/nutrient exports from the catchment by means of upland based, best management practices.
Potential Range Expansion of the Invasive Red Shiner, Cyprinella lutrensis (Teleostei: Cyprinidae), under Future Climatic Change  [PDF]
Helen M. Poulos, Barry Chernoff
Open Journal of Ecology (OJE) , 2014, DOI: 10.4236/oje.2014.49045
Abstract:

We built climate envelope models under contemporary and future climates to explore potential range shifts of the invasive Red Shiner-Cyprinella lutrensis. Our objective was to estimate aquatic habitat vulnerability to Red Shiner invasion in North America under future climatic change. We used presence records from within the species’ native and invaded distributions, a suite of bioclimatic predictor variables from three climate models (CCCma, CSIRO, and HadCM3), and maximum entropy modeling to generate potential distribution maps for the year 2080. Our model predicted major range expansion by Red Shiner under both low and high carbon emissions scenarios. The models exceeded average area under the receiver operator characteristic curve values of 0.92, indicating good overall model performance. The model predictions fell largely outside of areas of climatic extrapolation (i.e. regions predicted into environments different from training the region) indicating good model performance. The results from this study highlight the large potential range expansion across North America of Red Shiner under future warmer climates.

Influence of basin connectivity on sediment source, transport, and storage within the Mkabela Basin, South Africa
J. R. Miller, G. Mackin, P. Lechler, M. Lord,S. Lorentz
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2013,
Abstract: The management of sediment and other non-point source (NPS) pollution has proven difficult, and requires a sound understanding of particle movement through the drainage system. The primary objective of this investigation was to obtain an understanding of NPS sediment source(s), transport, and storage within the Mkabela Basin, a representative agricultural catchment within the KwaZulu–Natal Midlands of eastern South Africa, by combining geomorphic, hydrologic and geochemical fingerprinting analyses. The Mkabela Basin can be subdivided into three distinct subcatchments that differ in their ability to transport and store sediment along the axial valley. Headwater (upper catchment) areas are characterized by extensive wetlands that act as significant sediment sinks. Mid-catchment areas, characterized by higher relief and valley gradients, exhibit few wetlands, but rather are dominated by a combination of alluvial and bedrock channels that are conducive to sediment transport. The lower catchment exhibits a low-gradient alluvial channel that is boarded by extensive riparian wetlands that accumulate large quantities of sediment (and NPS pollutants). Fingerprinting studies suggest that silt- and clay-rich layers found within wetland and reservoir deposits of the upper and upper-mid subcatchments are derived from the erosion of fine-grained, valley bottom soils frequently utilized as vegetable fields. Coarser-grained deposits within these wetlands and reservoirs result from the erosion of sandier hillslope soils extensively utilized for sugar cane, during relatively high magnitude runoff events that are capable of transporting sand-sized sediment off the slopes. Thus, the source of sediment to the axial valley varies as a function of sediment size and runoff magnitude. Sediment export from upper to lower catchment areas was limited until the early 1990s, in part because the upper catchment wetlands were hydrologically disconnected from lower parts of the watershed during low to moderate flood events. The construction of a drainage ditch through a previously unchanneled wetland altered the hydrologic connectivity of the catchment, allowing sediment to be transported from the headwaters to the lower basin where much of it was deposited within riparian wetlands. The axial drainage system is now geomorphically and hydrologically connected during events capable of overflowing dams located throughout the study basin. The study indicates that increased valley connectivity partly negated the positive benefits of controlling sediment/nutrient exports from the catchment by means of upland based, best management practices.
Allocating Indivisible Items in Categorized Domains
Erika Mackin,Lirong Xia
Computer Science , 2015,
Abstract: We formulate a general class of allocation problems called categorized domain allocation problems (CDAPs), where indivisible items from multiple categories are allocated to agents without monetary transfer and each agent gets at least one item per category. We focus on basic CDAPs, where the number of items in each category is equal to the number of agents. We characterize serial dictatorships for basic CDAPs by a minimal set of three axiomatic properties: strategy-proofness, non-bossiness, and category-wise neutrality. Then, we propose a natural extension of serial dictatorships called categorial sequential allocation mechanisms (CSAMs), which allocate the items in multiple rounds: in each round, the active agent chooses an item from a designated category. We fully characterize the worst-case rank efficiency of CSAMs for optimistic and pessimistic agents, and provide a bound for strategic agents. We also conduct experiments to compare expected rank efficiency of various CSAMs w.r.t. random generated data.
Intrauterine Infection and Spontaneous Midgestation Abortion: Is the Spectrum of Microorganisms Similar to That in Preterm Labor?
Helen M. McDonald,Helen M. Chambers
Infectious Diseases in Obstetrics and Gynecology , 2000, DOI: 10.1155/s1064744900000314
Abstract: Objective: To determine whether microorganisms associated with intrauterine infection and preterm labor play a contributing role in midgestation abortion.
Market Simulation Displaying Multifractality
Kazuko Yamasaki,Kenneth J. Mackin
Quantitative Finance , 2003,
Abstract: We proposed a market simulation model (micro model) which displays multifractality and reproduces many important stylized facts of speculative markets. From this model we analytically extracted the MMAR model (Multifractal Model of Asset Returns) for the macroscopic limit.
A model of gene-gene and gene-environment interactions and its implications for targeting environmental interventions by genotype
Helen M Wallace
Theoretical Biology and Medical Modelling , 2006, DOI: 10.1186/1742-4682-3-35
Abstract: A new model for gene-gene and gene-environment interactions is developed that abandons the assumptions of the classical twin study, including Fisher's (1918) assumption that genes act as risk factors for common traits in a manner necessarily dominated by an additive polygenic term. Provided there are no confounders, the model can be used to implement a top-down approach to quantifying the potential utility of genetic prediction and prevention, using twin, family and environmental data. The results describe a solution space for each disease or trait, which may or may not include the classical twin study result. Each point in the solution space corresponds to a different model of genotypic risk and gene-environment interaction.The results show that the potential for reducing the incidence of common diseases using environmental interventions targeted by genotype may be limited, except in special cases. The model also confirms that the importance of an individual's genotype in determining their risk of complex diseases tends to be exaggerated by the classical twin studies method, owing to the 'equal environments' assumption and the assumption of no gene-environment interaction. In addition, if phenotypes are genetically robust, because of epistasis, a largely environmental explanation for shared sibling risk is plausible, even if the classical heritability is high. The results therefore highlight the possibility – previously rejected on the basis of twin study results – that inherited genetic variants are important in determining risk only for the relatively rare familial forms of diseases such as breast cancer. If so, genetic models of familial aggregation may be incorrect and the hunt for additional susceptibility genes could be largely fruitless.Some geneticists have predicted a genetic revolution in healthcare: involving a future in which individuals take a battery of genetic tests, at birth or later in life, to determine their individual 'genetic susceptibility' to
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