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Search Results: 1 - 10 of 212237 matches for " Lisa L. Drake "
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The Aquaporin Gene Family of the Yellow Fever Mosquito, Aedes aegypti
Lisa L. Drake,Dmitri Y. Boudko,Osvaldo Marinotti,Victoria K. Carpenter,Angus L. Dawe,Immo A. Hansen
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0015578
Abstract: The mosquito, Aedes aegypti, is the principal vector of the Dengue and yellow fever viruses. During feeding, an adult female can take up more than its own body weight in vertebrate blood. After a blood meal females excrete large amounts of urine through their excretion system, the Malpighian tubules (MT). Diuresis starts within seconds after the mosquito starts feeding. Aquaporins (AQPs) are a family of membrane transporters that regulate the flow of water, glycerol and other small molecules across cellular membranes in both prokaryotic and eukaryotic cells. Our aim was to identify aquaporins that function as water channels, mediating transcellular water transport in MTs of adult female Ae. aegypti.
The Fat Body Transcriptomes of the Yellow Fever Mosquito Aedes aegypti, Pre- and Post- Blood Meal
David P. Price, Vijayaraj Nagarajan, Alexander Churbanov, Peter Houde, Brook Milligan, Lisa L. Drake, John E. Gustafson, Immo A. Hansen
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0022573
Abstract: Background The fat body is the main organ of intermediary metabolism in insects and the principal source of hemolymph proteins. As part of our ongoing efforts to understand mosquito fat body physiology and to identify novel targets for insect control, we have conducted a transcriptome analysis of the fat body of Aedes aegypti before and in response to blood feeding. Results We created two fat body non-normalized EST libraries, one from mosquito fat bodies non-blood fed (NBF) and another from mosquitoes 24 hrs post-blood meal (PBM). 454 pyrosequencing of the non-normalized libraries resulted in 204,578 useable reads from the NBF sample and 323,474 useable reads from the PBM sample. Alignment of reads to the existing reference Ae. aegypti transcript libraries for analysis of differential expression between NBF and PBM samples revealed 116,912 and 115,051 matches, respectively. De novo assembly of the reads from the NBF sample resulted in 15,456 contigs, and assembly of the reads from the PBM sample resulted in 15,010 contigs. Collectively, 123 novel transcripts were identified within these contigs. Prominently expressed transcripts in the NBF fat body library were represented by transcripts encoding ribosomal proteins. Thirty-five point four percent of all reads in the PBM library were represented by transcripts that encode yolk proteins. The most highly expressed were transcripts encoding members of the cathepsin b, vitellogenin, vitellogenic carboxypeptidase, and vitelline membrane protein families. Conclusion The two fat body transcriptomes were considerably different from each other in terms of transcript expression in terms of abundances of transcripts and genes expressed. They reflect the physiological shift of the pre-feeding fat body from a resting state to vitellogenic gene expression after feeding.
Aquaporins Are Critical for Provision of Water during Lactation and Intrauterine Progeny Hydration to Maintain Tsetse Fly Reproductive Success
Joshua B. Benoit ,Immo A. Hansen,Geoffrey M. Attardo,Veronika Michalková,Paul O. Mireji,Joel L. Bargul,Lisa L. Drake,Daniel K. Masiga,Serap Aksoy
PLOS Neglected Tropical Diseases , 2014, DOI: 10.1371/journal.pntd.0002517
Abstract: Tsetse flies undergo drastic fluctuations in their water content throughout their adult life history due to events such as blood feeding, dehydration and lactation, an essential feature of the viviparous reproductive biology of tsetse. Aquaporins (AQPs) are transmembrane proteins that allow water and other solutes to permeate through cellular membranes. Here we identify tsetse aquaporin (AQP) genes, examine their expression patterns under different physiological conditions (blood feeding, lactation and stress response) and perform functional analysis of three specific genes utilizing RNA interference (RNAi) gene silencing. Ten putative aquaporins were identified in the Glossina morsitans morsitans (Gmm) genome, two more than has been previously documented in any other insect. All organs, tissues, and body parts examined had distinct AQP expression patterns. Two AQP genes, gmmdripa and gmmdripb ( = gmmaqp1a and gmmaqp1b) are highly expressed in the milk gland/fat body tissues. The whole-body transcript levels of these two genes vary over the course of pregnancy. A set of three AQPs (gmmaqp5, gmmaqp2a, and gmmaqp4b) are expressed highly in the Malpighian tubules. Knockdown of gmmdripa and gmmdripb reduced the efficiency of water loss following a blood meal, increased dehydration tolerance and reduced heat tolerance of adult females. Knockdown of gmmdripa extended pregnancy length, and gmmdripb knockdown resulted in extended pregnancy duration and reduced progeny production. We found that knockdown of AQPs increased tsetse milk osmolality and reduced the water content in developing larva. Combined knockdown of gmmdripa, gmmdripb and gmmaqp5 extended pregnancy by 4–6 d, reduced pupal production by nearly 50%, increased milk osmolality by 20–25% and led to dehydration of feeding larvae. Based on these results, we conclude that gmmDripA and gmmDripB are critical for diuresis, stress tolerance and intrauterine lactation through the regulation of water and/or other uncharged solutes.
Avoiding URL Reference Degradation in Scientific Publications
Desiree P. Kelly,Eric J. Hester,Kathryn R. Johnson,Lauren F. Heilig,Amanda L. Drake,Lisa M. Schilling,Robert P. Dellavalle
PLOS Biology , 2012, DOI: 10.1371/journal.pbio.0020099
Abstract:
Avoiding URL Reference Degradation in Scientific Publications
Desiree P Kelly,Eric J Hester,Kathryn R Johnson,Lauren F Heilig,Amanda L Drake,Lisa M Schilling,Robert P Dellavalle
PLOS Biology , 2004, DOI: 10.1371/journal.pbio.0020099
Abstract:
Identification and Antimicrobial Susceptibility of Yersinia enterocolitica Found in Chitterlings, Raw Milk and Swine Fecal Samples  [PDF]
F. N. Drake, S. Davis, J. Khatiwada, L. Williams
Advances in Microbiology (AiM) , 2018, DOI: 10.4236/aim.2018.810053
Abstract: Foodborne illness is an escalating concern upon public health. The prevalence of Yersinia enterocolitica was assessed in chitterlings, raw milk and swine fecal from North Carolina. Uncleaned thirty chitterling samples procured from a local grocery store, forty-five swine fecal samples, and forty unpasteurized cow milk samples supplied by the University farm were evaluated for the presence of Y. enterocolitica. Isolates identified as presumptive positive were characterized as colonies with a pink or deep-red center on MacConkey and CIN agar, and verified further through polymerase chain reaction (PCR) for the presence of 16S rRNA gene for the Yersinia genera. Results showed that 4.4% swine fecal samples, 7.5% milk samples and 11.3% chitterling samples were presumptive positive for Y. enterocolitica by the direct plating method on selective agars. Of the thirty-chitterling samples examined by PCR for the 16S rRNA gene, 26% samples contained the identification gene for the bacteria of interest. After conducting virulence tests, the fecal samples were revealed as non-pathogenic. Only one of the milk samples were considered pathogenic and consisted of the following virulent genes: Yersinia heat-stable toxin (yst), invasion (inv), attachment invasion locus (ail), virulence regulon transcriptional activator (virF), Yersinia adehesin A (yadA), and the O:3 antigen gene (rfbC). Seven out of the eight (87.5%) chitterling samples were shown to be pathogenic. Disc diffusion was conducted to determine the antimicrobial susceptibility of the isolates. Over half (55.5%) of the antimicrobial agents were found effective, with isolates being completely susceptible to ciprofloxacin, kanamycin, trimethoprim, cefotaxime, and gentamycin. Ampicillin was determined to be least effective, where 84.6% of the samples presented resistance to the drug. Random amplified polymorphic DNA (RAPD) analysis and ERIC-PCR techniques were used to evaluate genetic similarity among the Yersinia isolates. There was approximately 85% similarity between two chitterlings and a fecal isolate during RAPD testing. With ERIC-PCR the largest similarity among all samples was at 95%, which was found between isolates from a chitterling and milk sample. Chitterling samples showed the highest prevalence of Y. enterocolitica compared to the other samples. Cross contamination at the farm level could be the root cause of this pathogen being prevalent in farm animal and food sources, which does pose a risk to public
Cis and Trans Regulatory Mechanisms Control AP2-Mediated B Cell Receptor Endocytosis via Select Tyrosine-Based Motifs
Kathleen Busman-Sahay, Lisa Drake, Anand Sitaram, Michael Marks, James R. Drake
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0054938
Abstract: Following antigen recognition, B cell receptor (BCR)-mediated endocytosis is the first step of antigen processing and presentation to CD4+ T cells, a crucial component of the initiation and control of the humoral immune response. Despite this, the molecular mechanism of BCR internalization is poorly understood. Recently, studies of activated B cell-like diffuse large B cell lymphoma (ABC DLBCL) have shown that mutations within the BCR subunit CD79b leads to increased BCR surface expression, suggesting that CD79b may control BCR internalization. Adaptor protein 2 (AP2) is the major mediator of receptor endocytosis via clathrin-coated pits. The BCR contains five putative AP2-binding Yxx? motifs, including four that are present within two immunoreceptor tyrosine-based activation motifs (ITAMs). Using a combination of in vitro and in situ approaches, we establish that the sole mediator of AP2-dependent BCR internalization is the membrane proximal ITAM Yxx? motif in CD79b, which is a major target of mutation in ABC DLBCL. In addition, we establish that BCR internalization can be regulated at a minimum of two different levels: regulation of Yxx? AP2 binding in cis by downstream ITAM-embedded DCSM and QTAT regulatory elements and regulation in trans by the partner cytoplasmic domain of the CD79 heterodimer. Beyond establishing the basic rules governing BCR internalization, these results illustrate an underappreciated role for ITAM residues in controlling clathrin-dependent endocytosis and highlight the complex mechanisms that control the activity of AP2 binding motifs in this receptor system.
Extracting unrecognized gene relationships from the biomedical literature via matrix factorizations
Hyunsoo Kim, Haesun Park, Barry L Drake
BMC Bioinformatics , 2008, DOI: 10.1186/1471-2105-9-211
Abstract:
Breeding dispersal by Ross's geese in the Queen Maud Gulf metapopulation
Drake, k. L.,Alisauskas, R. T.
Animal Biodiversity and Conservation , 2004,
Abstract: We estimated rates of breeding philopatry and complementary dispersal within the Queen Maud Gulf metapopulation of Ross's Geese (Chen rossii) using multistate modeling of neckband observations at five breeding colonies, 1999-2003. Probability of philopatry was female-biased, but varied among colonies. Probabilies of annual movement among breeding colonies ranged 0.02 to 0.14 for females and 0.12 to 0.38 for males and was substantially higher than expected. These estimates (1) underscore the potential for dispersal to alter breeding distribution, (2) demonstrates that the influence of immigration on colony-specific rates of population growth is nontrivial, and (3) provides behavioral evidence for extensive gene flow among subpopulations. Sex differences in apparent survival estimated from multistate models likely resulted from a combination of higher rates of neckband loss by males compared to females, and higher rates of permanent emigration by males from our study area.
Infrared Observations During the Secondary Eclipse of HD 209458 b II. Strong Limits on the Infrared Spectrum Near 2.2 Microns
L. Jeremy Richardson,Drake Deming,Sara Seager
Physics , 2003, DOI: 10.1086/378390
Abstract: We report observations of the transiting extrasolar planet, HD 209458 b, designed to detect the secondary eclipse. We employ the method of `occultation spectroscopy', which searches in combined light (star and planet) for the disappearance and reappearance of weak infrared spectral features due to the planet as it passes behind the star and reappears. Our observations cover two predicted secondary eclipse events, and we obtained 1036 individual spectra of the HD 209458 system using the SpeX instrument at the NASA IRTF in September 2001. Our spectra extend from 1.9 to 4.2 microns with a spectral resolution of 1500. We have searched for a continuum peak near 2.2 microns (caused by CO and water absorption bands), as predicted by some models of the planetary atmosphere to be approximately 6E-4 of the stellar flux, but no such peak is detected at a level of about 3E-4 of the stellar flux. Our results represent the strongest limits on the infrared spectrum of the planet to date and carry significant implications for understanding the planetary atmosphere. In particular, some models that assume the stellar irradiation is re-radiated entirely on the sub-stellar hemisphere predict a flux peak inconsistent with our observations. Several physical mechanisms can improve agreement with our observations, including the re-distribution of heat by global circulation, a nearly isothermal atmosphere, and/or the presence of a high cloud.
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