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Search Results: 1 - 10 of 144877 matches for " Jillian F Maddox "
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A presentation of the differences between the sheep and goat genetic maps
Maddox Jillian F
Genetics Selection Evolution , 2005, DOI: 10.1186/1297-9686-37-s1-s1
Abstract: The current autosomal version (4.2) of the sheep genetic map comprises 1175 loci and spans ~3540 cM. This corresponds to almost complete coverage of the sheep genome. Each chromosome is represented by a single linkage group, with the largest gap between adjacent loci being 19.8 cM. In contrast the 1998 goat genetic map (the most recently published) is much less well developed spanning 2737 cM and comprising only 307 loci. Only one of the goat chromosomes appears to have complete coverage (chromosome 27), and 16 of the chromosomes are comprised of two or more linkage groups, or a linkage group and one or more unlinked markers. The two maps share 218 loci, and the maps have been aligned using the shared loci as reference points. Overall there is good agreement between the maps in terms of homologous loci mapping to equivalent chromosomes in the two species, with only four markers mapping to non-equivalent chromosomes. However, there are lots of inversions in locus order between the sheep and goat chromosomes. Whilst some of these differences in locus order may be genuine, the majority are likely to be a consequence of the paucity of genetic information for the goat map.
Genetic linkage map of a wild genome: genomic structure, recombination and sexual dimorphism in bighorn sheep
Jocelyn Poissant, John T Hogg, Corey S Davis, Joshua M Miller, Jillian F Maddox, David W Coltman
BMC Genomics , 2010, DOI: 10.1186/1471-2164-11-524
Abstract: Bighorn sheep population-specific maps differed slightly in contiguity but were otherwise very similar in terms of genomic structure and recombination rates. The joint analysis of the two pedigrees resulted in a highly contiguous map composed of 247 microsatellite markers distributed along all 26 autosomes and the X chromosome. The map is estimated to cover about 84% of the bighorn sheep genome and contains 240 unique positions spanning a sex-averaged distance of 3051 cM with an average inter-marker distance of 14.3 cM. Marker synteny, order, sex-averaged interval lengths and sex-averaged total map lengths were all very similar between sheep species. However, in contrast to domestic sheep, but consistent with the usual pattern for a placental mammal, recombination rates in bighorn sheep were significantly greater in females than in males (~12% difference), resulting in an autosomal female map of 3166 cM and an autosomal male map of 2831 cM. Despite differing genome-wide patterns of heterochiasmy between the sheep species, sexual dimorphism in recombination rates was correlated between orthologous intervals.We have developed a first-generation bighorn sheep linkage map that will facilitate future studies of the genetic architecture of trait variation in this species. While domestication has been hypothesized to be responsible for the elevated mean recombination rate observed in domestic sheep, our results suggest that it is a characteristic of Ovis species. However, domestication may have played a role in altering patterns of heterochiasmy. Finally, we found that interval-specific patterns of sexual dimorphism were preserved among closely related Ovis species, possibly due to the conserved position of these intervals relative to the centromeres and telomeres. This study exemplifies how transferring genomic resources from domesticated species to close wild relative can benefit evolutionary ecologists while providing insights into the evolution of genomic structure and
SNPs for Parentage Testing and Traceability in Globally Diverse Breeds of Sheep
Michael P. Heaton, Kreg A. Leymaster, Theodore S. Kalbfleisch, James W. Kijas, Shannon M. Clarke, John McEwan, Jillian F. Maddox, Veronica Basnayake, Dustin T. Petrik, Barry Simpson, Timothy P. L. Smith, Carol G. Chitko-McKown, and the International Sheep Genomics Consortium
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0094851
Abstract: DNA-based parentage determination accelerates genetic improvement in sheep by increasing pedigree accuracy. Single nucleotide polymorphism (SNP) markers can be used for determining parentage and to provide unique molecular identifiers for tracing sheep products to their source. However, the utility of a particular “parentage SNP” varies by breed depending on its minor allele frequency (MAF) and its sequence context. Our aims were to identify parentage SNPs with exceptional qualities for use in globally diverse breeds and to develop a subset for use in North American sheep. Starting with genotypes from 2,915 sheep and 74 breed groups provided by the International Sheep Genomics Consortium (ISGC), we analyzed 47,693 autosomal SNPs by multiple criteria and selected 163 with desirable properties for parentage testing. On average, each of the 163 SNPs was highly informative (MAF≥0.3) in 48±5 breed groups. Nearby polymorphisms that could otherwise confound genetic testing were identified by whole genome and Sanger sequencing of 166 sheep from 54 breed groups. A genetic test with 109 of the 163 parentage SNPs was developed for matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry. The scoring rates and accuracies for these 109 SNPs were greater than 99% in a panel of North American sheep. In a blinded set of 96 families (sire, dam, and non-identical twin lambs), each parent of every lamb was identified without using the other parent’s genotype. In 74 ISGC breed groups, the median estimates for probability of a coincidental match between two animals (PI), and the fraction of potential adults excluded from parentage (PE) were 1.1×10(?39) and 0.999987, respectively, for the 109 SNPs combined. The availability of a well-characterized set of 163 parentage SNPs facilitates the development of high-throughput genetic technologies for implementing accurate and economical parentage testing and traceability in many of the world’s sheep breeds.
Using comparative genomics to reorder the human genome sequence into a virtual sheep genome
Brian P Dalrymple, Ewen F Kirkness, Mikhail Nefedov, Sean McWilliam, Abhirami Ratnakumar, Wes Barris, Shaying Zhao, Jyoti Shetty, Jillian F Maddox, Margaret O'Grady, Frank Nicholas, Allan M Crawford, Tim Smith, Pieter J de Jong, John McEwan, V Hutton Oddy, Noelle E Cockett, the International Sheep Genomics Consortium
Genome Biology , 2007, DOI: 10.1186/gb-2007-8-7-r152
Abstract: A sheep BAC library, CHORI-243, was constructed and the BAC end sequences were determined and mapped with high sensitivity and low specificity onto the frameworks of the human, dog, and cow genomes. To maximize genome coverage, the coordinates of all BAC end sequence hits to the cow and dog genomes were also converted to the equivalent human genome coordinates. The 84,624 sheep BACs (about 5.4-fold genome coverage) with paired ends in the correct orientation (tail-to-tail) and spacing, combined with information from sheep BAC comparative genome contigs (CGCs) built separately on the dog and cow genomes, were used to construct 1,172 sheep BAC-CGCs, covering 91.2% of the human genome. Clustered non-tail-to-tail and outsize BACs located close to the ends of many BAC-CGCs linked BAC-CGCs covering about 70% of the genome to at least one other BAC-CGC on the same chromosome. Using the BAC-CGCs, the intrachromosomal and interchromosomal BAC-CGC linkage information, human/cow and vertebrate synteny, and the sheep marker map, a virtual sheep genome was constructed. To identify BACs potentially located in gaps between BAC-CGCs, an additional set of 55,668 sheep BACs were positioned on the sheep genome with lower confidence. A coordinate conversion process allowed us to transfer human genes and other genome features to the virtual sheep genome to display on a sheep genome browser.We demonstrate that limited sequencing of BACs combined with positioning on a well assembled genome and integrating locations from other less well assembled genomes can yield extensive, detailed subgene-level maps of mammalian genomes, for which genomic resources are currently limited.Sheep are a major farmed species, producing meat, pelts, and wool. They are closely related to cattle, which is both an advantage and a disadvantage for researchers. Internationally, substantial genomics research is being conducted in cattle, with a large number of cow expressed sequence tag sequences deposited in public
A Genome Wide Survey of SNP Variation Reveals the Genetic Structure of Sheep Breeds
James W. Kijas, David Townley, Brian P. Dalrymple, Michael P. Heaton, Jillian F. Maddox, Annette McGrath, Peter Wilson, Roxann G. Ingersoll, Russell McCulloch, Sean McWilliam, Dave Tang, John McEwan, Noelle Cockett, V. Hutton Oddy, Frank W. Nicholas, Herman Raadsma, for the International Sheep Genomics Consortium
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0004668
Abstract: The genetic structure of sheep reflects their domestication and subsequent formation into discrete breeds. Understanding genetic structure is essential for achieving genetic improvement through genome-wide association studies, genomic selection and the dissection of quantitative traits. After identifying the first genome-wide set of SNP for sheep, we report on levels of genetic variability both within and between a diverse sample of ovine populations. Then, using cluster analysis and the partitioning of genetic variation, we demonstrate sheep are characterised by weak phylogeographic structure, overlapping genetic similarity and generally low differentiation which is consistent with their short evolutionary history. The degree of population substructure was, however, sufficient to cluster individuals based on geographic origin and known breed history. Specifically, African and Asian populations clustered separately from breeds of European origin sampled from Australia, New Zealand, Europe and North America. Furthermore, we demonstrate the presence of stratification within some, but not all, ovine breeds. The results emphasize that careful documentation of genetic structure will be an essential prerequisite when mapping the genetic basis of complex traits. Furthermore, the identification of a subset of SNP able to assign individuals into broad groupings demonstrates even a small panel of markers may be suitable for applications such as traceability.
The Impact of Multidisciplinary Care in a Large Volume Robot-Assisted Radical Prostatectomy Program: A Paradoxical Stage Migration toward More Aggressive Disease  [PDF]
Jospeh F. Renzulli II, Michael M. Maddox, Omar Nadeem, Simone Thavaseelan, Gyan Pareek, Anthony E. Mega
Open Journal of Internal Medicine (OJIM) , 2014, DOI: 10.4236/ojim.2014.44017
Abstract: Introduction: With the widespread use of robot-assisted radical prostatectomy (RARP), a stage migration to less aggressive prostate cancer (CaP) may be expected in pathological specimens due to over-treatment of low risk disease. It is unclear whether implementation of a multidisciplinary clinic (MDC) model would offset this phenomenon. We sought to analyze our database for possible stage migration in prostatectomy specimens in the setting of MDC. Methods: A total of 262 patients who underwent open prostatectomy (OP) from 2004 to 2006 and 757 patients who underwent RARP from 2007 to 2011 were identified from our prospective database. The implementation of MDC occurred concurrently at the time of RARP initiation. Demographic data, pathology, positive margin rates along with standard CaP reporting data were recorded. The two groups were compared with regards to percentage of cases stratified by Gleason grade. Results: The number of CaP cases managed at our institution increased considerably after the introduction of robotics and MDC. There was a significant decrease in the patients with Gleason 6 CaP undergoing RARP as compared with OP (p = 0.001). Additionally, RARP was performed on a significantly greater percentage of Gleason 7 disease (p < 0.001). When comparing pathological stage, there was a significant increase in the incidence of pT3 disease following RARP (p < 0.0001). Conclusions: The introduction of a MDC and minimally invasive radical prostatectomy did not result in an increased application of surgery for the treatment of low risk prostate cancer. This highlights the importance of MDC in a large volume RARP program.
Feasibility, Tolerability, Safety and Efficacy of a Pantothenic Acid Based Dietary Supplement in Subjects with Mild to Moderate Facial Acne Blemishes  [PDF]
Jillian L. Capodice
Journal of Cosmetics, Dermatological Sciences and Applications (JCDSA) , 2012, DOI: 10.4236/jcdsa.2012.23026
Abstract: Objective: It has been suggested that pantothenic acid may have antibacterial and skin softening activity. The aim of this study was to explore the feasibility, tolerability, safety and preliminary efficacy of oral administration of a dietary supplement containing pantothenic acid in healthy human males and females with mild to moderate facial acne vulgaris. Methods: An open-label, single arm study of healthy adults who had been previously diagnosed with mild to moderate acne vulgaris was performed. Subjects were asked to take the study agent, a dietary supplement containing pantothenic acid, for eight weeks. The primary endpoint of the study was to assess the feasibility of oral administration of the study agent in subjects over an eight week period. Safety and tolerability were measured utilizing the assessment of adverse events by the National Cancer Institute’s Common Criteria for Adverse Event Reporting. Secondary endpoints measuring the efficacy of an oral panthothetic acid dietary supplement for the treatment of mild to moderate facial acne utilized changes in the extent of global facial skin blemishes, assessment of quality of life utilizing the Dermatology Life Quality Index (DLQI) and analysis of questions about the subject's beliefs and attitudes towards skin care and lifestyle. Results: Eleven subjects were enrolled and ten completed the study (90.9%). There were no reported adverse events. Of the 10 evaluable subjects, the average age (mean ± SD) was 31.8 ± 8. Analysis of the global number of skin blemishes demonstrated a significant mean reduction in lesion count following the use of the study agent at week 8 (endpoint) (11.18 ± 6.38, p = 0.02) compared to the average number of baseline blemishes (20.45 ± 10.44). DLQI scores were significantly lower at week 8 vs. baseline (p = 0.0194). Conclusions: The results from this study indicated that the administration of a pantothenic based dietary supplement in healthy human adults with mild to moderate acne vulgaris is feasible, safe and well tolerated. Secondary analysis shows that administration of the study agent significantly reduced global facial blemishes. Further randomized, placebo-controlled trials are warranted.
Quantitative determination of elemental sulfur at the arsenopyrite surface after oxidation by ferric iron: mechanistic implications
Molly M McGuire, Jillian F Banfield, Robert J Hamers
Geochemical Transactions , 2001, DOI: 10.1186/1467-4866-2-25
Abstract: Arsenopyrite, FeAsS (a derivative of the marcasite structure), is the most common arsenic-bearing mineral. Under oxidizing conditions, either occurring naturally or as a result of mining processes, the mineral produces arsenite (AsO33-), arsenate (AsO43-), and sulfate (SO42-), [1-3] thus contributing to the acidification of water as well as the release of soluble arsenic species. Despite the potential environmental and health hazards posed by the oxidative dissolution of arsenopyrite, the mineral has received far less attention in the laboratory than pyrite (FeS2), the most studied of the sulfide minerals.In acidic environments, the rate of sulfide mineral dissolution is typically limited by the supply of ferric iron, Fe3+; however, in the presence of iron-oxidizing microorganisms, the supply of ferric iron is continuously replenished by microbial oxidation of the ferrous iron released from sulfide minerals.[4] Despite the importance of oxidation by ferric iron in natural systems, many of the fundamental details of the oxidation of arsenopyrite by Fe3+ under acidic conditions still remain unclear. One critical issue is the stoichiometry of the reaction with respect to the sulfur species. The literature is divided about whether the majority of the sulfur from the mineral is released into solution as sulfoxy anions[5,6] [in a scheme similar to eqn. (1)], or whether a substantial amount of the sulfur remains as insoluble elemental sulfur (S8) at the mineral surface[7,8] [as shown in eqn. (2)]:FeAsS + 11Fe(III) → 12Fe(II) + As(III) + S(VI) (1)FeAsS + 5Fe(III) → As(III) + 6Fe(II) + S(0) (2)Previous efforts to characterize the arsenopyrite surface by scanning electron microscopy (SEM) after leaching reactions with ferric iron found no evidence of elemental sulfur on the mineral surface.[5,7] Other studies, using X-ray photoelectron spectroscopy (XPS), did not detect elemental sulfur on arsenopyrite surfaces that were exposed to mine wastewaters.[1]In contrast, Raman spect
Associations between Psychosocial and Physiological Factors and Diabetes Health Indicators in Asian and Pacific Islander Adults with Type 2 Diabetes
Dongmei Li,Jillian Inouye,Jim Davis,Richard F. Arakaki
Nursing Research and Practice , 2013, DOI: 10.1155/2013/703520
Abstract: The associations between psychosocial and physiological factors and diabetes’ health indicators have not been widely investigated among Asians and Pacific Islanders. We hypothesize that health behaviour and depression are directly or indirectly associated with diabetes’ health indicators such as BMI, glycemic control, general health, and diabetes quality of life. Our hypothesis was tested through a structural equation modelling (SEM) approach. Questionnaires that assessed health behaviour, depression, general health, diabetes quality of life, and haemoglobin A1c (HbA1c), along with patients’ demographic information, were obtained from 207 Asian and Pacific Islander adults with type 2 diabetes. IBM SPSS Amos 20 was used for the SEM analysis at 5% level of significance, and the goodness fit of the SEM model was also evaluated. The final SEM model showed that diet and exercise and foot care had positive associations, while depression had a negative association with diabetes’ health indicators. The results highlighted the importance of exercise and depression in diabetes patients’ BMI, glycemic control, general health, and quality of life, which provide evidence for the need to alleviate patients’ depression besides education and training in diet and exercise in future intervention studies among Asians and Pacific Islanders with type 2 diabetes. 1. Introduction Diabetes is a chronic disease that affects about 11.3% of all people aged 20 years and older in the USA [1] and a growing epidemic within ethnic minority populations including Pacific Islanders and Asian Americans [2]. Health behaviours such as diet, exercise, and depression contribute to diabetes’ health indicators such as BMI, glycemic control, quality of life, and general well-being. Previous studies demonstrated the direct association between health behavior and glycemic control [3–6]. A current study also found that physical exercise can control, prevent, or delay the onset of type 2 diabetes by markedly improving the low insulin sensitivity in at-risk patients [7]. A recent intervention programme conducted in Australia revealed the negative association between exercise and depression [8]. They found that overweight participants with heart disease and diabetes were less likely to report depressive symptoms after adjusting for treatment group and weight change, if they met recommendations for total duration of exercise. An important relationship between depressive symptoms and a heightened metabolic risk for type 2 diabetes, including prediabetes and impairment of β-cell function relative to
Loss of glutathione homeostasis associated with neuronal senescence facilitates TRPM2 channel activation in cultured hippocampal pyramidal neurons
Jillian C Belrose, Yu-Feng Xie, Lynn J Gierszewski, John F MacDonald, Michael F Jackson
Molecular Brain , 2012, DOI: 10.1186/1756-6606-5-11
Abstract: In whole-cell voltage-clamp recordings, we observe that TRPM2 current density increases in cultured pyramidal neurons over time in vitro. The observed increase in current density was prevented by treatment with NAC, a precursor to GSH synthesis. Conversely, treatment of cultures maintained for 2 weeks in vitro with L-BSO, which depletes GSH by inhibiting its synthesis, augments TRPM2 currents. Additionally, we demonstrate that GSH inhibits TRPM2 currents through a thiol-independent mechanism, and produces a 3.5-fold shift in the dose-response curve generated by ADPR, the intracellular agonist for TRPM2.These results indicate that GSH plays a physiologically relevant role in the regulation of TRPM2 currents in hippocampal pyramidal neurons. This interaction may play an important role in aging and neurological diseases associated with depletion of GSH.Aging is a major risk factor for developing several neurodegenerative diseases. Although the precise reasons are poorly understood, a growing body of evidence suggests that age-related cognitive decline is associated with stereotypic changes in cellular homeostasis which ultimately lead to impaired neuronal function [1]. A leading hypothesis suggests that increased oxidative stress associated with aging predisposes neurons to dysregulated intracellular Ca2+ homeostasis in response to disease causing factors [2]. Accordingly, understanding the relation between oxidative stress and altered Ca2+ homeostasis may provide valuable insight into mechanisms underlying neurodegenerative disease.Glutathione (GSH), the most abundant intracellular reducing agent [3], plays an important role in limiting cellular damage by reactive oxygen and nitrogen species generated as a by-product of aerobic metabolism. Cellular levels of GSH are known to decrease with age [4-9] and the resulting decline in antioxidant defence is viewed as a risk factor contributing to the increased susceptibility to neurodegenerative disease associated with aging.
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