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Mosquito Larvae (Culex spp.) Startle Responses to Vibration Stimuli [article]

Ellie R. Harrison, William J. Budenberg
2021 bioRxiv   pre-print
AbstractWe explored startle responses of Culex spp. larvae to varying frequencies and durations of vibrations, before investigating habituation (a behavioural learning phenomenon). The startle response consists of a rapid movement to permit escape from a potentially dangerous stimulus. We used the automated Zantiks MWP_vb unit to analyse larval startle responses through the built-in live video tracking. Set within the unit's controlled environmental chamber, we recorded distance travelled by
more » ... larvae. These results were used to optimise the vibration startle response for use in habituation studies. Repeated vibrations appeared to reduce larvae startle responses, although further analysis is required to confirm habituation. This study not only provides an insight into the learning ability of mosquito larvae, but demonstrates the ease, replicability and control conferred by the automated unit. Furthermore, this method is applicable to many other organisms and shows potential for more sophisticated environmental effect testing, such as behavioural toxicology.
doi:10.1101/2021.02.18.431787 fatcat:hl62dnft6bexzbmk4pypl4d2ie

Assessing evolutionary risks of resistance for new antimicrobial therapies

Michael A. Brockhurst, Freya Harrison, Jan-Willem Veening, Ellie Harrison, Grace Blackwell, Zamin Iqbal, Craig Maclean
2019 Nature Ecology & Evolution  
16 New antibiotics are urgently required to combat rising rates of resistance against all existing classes 17 of antimicrobials. We highlight key issues that complicate the prediction of resistance evolution in 18 the real-world and outline the ways in which these can be overcome. 19 20
doi:10.1038/s41559-019-0854-x pmid:30886376 fatcat:pggbdpubnbelng6n6gbs4p5fae

Bacterial evolution: Resistance is a numbers game

James P. J. Hall, Ellie Harrison
2016 Nature Microbiology  
Standfirst Plasmids are well known for spreading antibiotic resistance genes between bacterial strains. Recent experiments show that they can also act as catalysts for evolutionary innovation, promoting rapid evolution of novel antibiotic resistance.
doi:10.1038/nmicrobiol.2016.235 pmid:27819662 fatcat:ky4i7hexurgyla3kpqjbitvgqi

Reoperation for Mitral Stenosis

DWIGHT E. HARKEN, HARRISON BLACK, WARREN J. TAYLOR, WENDELL B. THROWER, LAURENCE B. ELLIS
1961 Circulation  
In this, deliberate, well-controlled, HARKEN, BLACK, TAYLOR, THROWER, ELLIS versatile intracardiac manipulation was impossible owing to poor hemostatic controls.  ... 
doi:10.1161/01.cir.23.1.7 pmid:13711582 fatcat:fitjbsl5vjg53buecbx23nwpda

Positive selection inhibits plasmid coexistence in bacterial genomes [article]

Laura Carrilero, Anastasia Kottara, David Guymer, Ellie Harrison, James Hall, Michael Brockhurst
2020 biorxiv/medrxiv   pre-print
Plasmids play an important role in bacterial evolution by transferring niche adaptive functional genes between lineages, thus driving genomic diversification. Bacterial genomes commonly contain multiple, coexisting plasmid replicons (i.e., plasmid coinfection), which could fuel adaptation by increasing the range of gene functions available to selection and allowing their recombination. However, plasmid coinfection is difficult to explain because the acquisition of plasmids typically incurs high
more » ... fitness costs for the host cell. Here, we show that plasmid coinfection was stably maintained without positive selection for plasmid-encoded gene functions and was associated with compensatory evolution to reduce fitness costs. By contrast, with positive selection, plasmid coinfection was unstable despite compensatory evolution. Positive selection discriminated between differential fitness benefits of functionally redundant plasmid replicons, retaining only the more beneficial plasmid. These data suggest that while the efficiency of negative selection against plasmid fitness costs declines over time due to compensatory evolution, positive selection to maximise plasmid-derived fitness benefits remains efficient. Our findings help to explain the forces structuring bacterial genomes: Coexistence of multiple plasmids in a genome is likely to require either rare positive selection in nature or non-redundancy of accessory gene functions among coinfecting plasmids.
doi:10.1101/2020.09.29.318741 fatcat:36m36xu6arfhbhmc2rsqshn3c4

Richard Ellis Ford Matthews, O.N.Z. 20 November 1921 -- 19 February 1995: Elected F.R.S. 1974

B. D. Harrison
1999 Biographical Memoirs of Fellows of the Royal Society  
Richard (Dick) Ellis Ford Matthews was a distinguished plant virologist, a proud fourth-generation New Zealander, and a man of great energy, enthusiasm and scientific integrity.  ... 
doi:10.1098/rsbm.1999.0020 fatcat:4tre3tbbtngkppltbxosvihuye

Clozapine – fatal constipation more common than fatal agranulocytosis

P Ellis, M Harrison-Woolrych, R McLean
2006 Acta Neuropsychiatrica  
doi:10.1017/s0924270800031148 pmid:27397272 fatcat:wx5lftxuk5bjtjjcluckbmvgay

Rupture of spleen at colonoscopy

W R Ellis, J M Harrison, R S Williams
1979 BMJ (Clinical Research Edition)  
as gastric carcinoma, since a possible intramucosal carcinoma might be detected only on examining the resected specimen.5 Unit and the Department of Surgery, Charing Cross Hospital, London W6 8RF W R ELLIS  ...  , MB, MRCP, registrar (Present address: Department of Therapeutics, City Hospital, Nottingham NG5 IPB) J M HARRISON, BDS, MB, house physician (Present address: Queen Mary's Hospital, Roehampton Lane, London  ... 
doi:10.1136/bmj.1.6159.307-a pmid:421092 pmcid:PMC1597702 fatcat:rt276shyzbfcdnevkqm6s2ouka

Mononeuritis multiplex due to haemorrhage

I E Cole, P D Ellis, M J Harrison
1978 BMJ (Clinical Research Edition)  
, ear, nose, and throat department M J G HARRISON, DM, FRCP, consultant neurologist Intermittent positive-pressure breathing Schlosstein, L, et al, New England_Journal of Medicine, 1973, 288, 704  ...  Ferens Institute of Otolarynogology and Department of Neurologica Studies, The Middlesex Hospital, London Wl I E COLE, FRcs, registrar, ear, nose, and throat department P D M ELLIS, FRCS, senior registrar  ... 
doi:10.1136/bmj.1.6121.1185 pmid:638684 pmcid:PMC1604260 fatcat:4urvjldpajevrepo3hfvm2255a

Public Interest in Microclimate Data in Knoxville, Tennessee, USA

Lisa Mason, Jon Hathaway, Kelsey Ellis, Taylor Harrison
2016 Sustainability  
Ellis conceived and designed the study. Lisa Reyes Mason conducted quantitative data analysis.  ... 
doi:10.3390/su9010023 fatcat:62dzibcybnbj7c3i6lneszwacm

Polylysogeny magnifies competitiveness of a bacterial pathogenin vivo

Nicola Burns, Chloe E. James, Ellie Harrison
2015 Evolutionary Applications  
doi:10.1111/eva.12243 pmid:25926879 pmcid:PMC4408145 fatcat:svb3krqaizdmdosukcdricixfm

Plasmid-mediated horizontal gene transfer is a coevolutionary process

Ellie Harrison, Michael A. Brockhurst
2012 Trends in Microbiology  
Article: Harrison, Ellie and Brockhurst, Michael A. orcid.org/0000-0003-0362-820X (2012) Plasmid-mediated horizontal gene transfer is a coevolutionary process. Trends in microbiology. pp. 262-267.  ... 
doi:10.1016/j.tim.2012.04.003 pmid:22564249 fatcat:toturdttjnfh5p5cobj2qscqi4

The dilution effect limits plasmid horizontal transmission in multispecies bacterial communities [article]

Anastasia Kottara, Laura Carrilero, Ellie Harrison, James Peter John Hall, Michael Brockhurst
2021 bioRxiv   pre-print
Hall JP, Harrison E, Lilley AK, Paterson S, Spiers AJ et al.  ...  Ed. 2). 26 . 26 Carrilero L, Kottara A, Guymer D, Harrison E, Hall JP, Brockhurst MA.  ... 
doi:10.1101/2021.05.18.444624 fatcat:fy6c4qua25blbhhtkeph434wme

A nanogram-level colloidal gold single reagent quantitative protein assay

Gerald Harrison, Patrick Haffey, Ellis E. Golub
2008 Analytical Biochemistry  
We have developed a nanogram level quantitative protein assay based on the binding of colloidal gold to proteins adhered to nitrocellulose paper. The protein-gold complex produces a purple color proportional to the amount of protein present, and the intensity of the stain is quantified by densitometry. Typical assays require minimal starting material (10 -20 μl) containing 2 -5 μg protein. A small volume (2 μl) of protein solution is applied to nitrocellulose paper in a grid array, and dried.
more » ... e nitrocellulose is incubated in colloidal gold suspension with gentle agitation (4-16 h), rinsed with water and scanned. Densitometric analysis of the scanned images allows quantitation of the unknown sample protein concentration by comparison with protein standards placed on the same nitrocellulose grid. The assay requires significantly less sample than conventional protein assays. In this report, the Golddots assay is calibrated against weighed protein samples, and compared with the Pierce Micro BCA protein assay kit. In addition, the assay is evaluated with several known proteins with different physical properties.
doi:10.1016/j.ab.2008.05.009 pmid:18539124 pmcid:PMC2497003 fatcat:nthkcdwcl5g4llbd3k7dpya57i

Mobile Compensatory Mutations Promote Plasmid Survival

Martin Zwanzig, Ellie Harrison, Michael A. Brockhurst, James P. J. Hall, Thomas U. Berendonk, Uta Berger, Rachel J. Dutton
2019 mSystems  
The global dissemination of plasmids encoding antibiotic resistance represents an urgent issue for human health and society. While the fitness costs for host cells associated with plasmid acquisition are expected to limit plasmid dissemination in the absence of positive selection of plasmid traits, compensatory evolution can reduce this burden. Experimental data suggest that compensatory mutations can be located on either the chromosome or the plasmid, and these are likely to have contrasting
more » ... fects on plasmid dynamics. Whereas chromosomal mutations are inherited vertically through bacterial fission, plasmid mutations can be inherited both vertically and horizontally and potentially reduce the initial cost of the plasmid in new host cells. Here we show using mathematical models and simulations that the dynamics of plasmids depends critically on the genomic location of the compensatory mutation. We demonstrate that plasmid-located compensatory evolution is better at enhancing plasmid persistence, even when its effects are smaller than those provided by chromosomal compensation. Moreover, either type of compensatory evolution facilitates the survival of resistance plasmids at low drug concentrations. These insights contribute to an improved understanding of the conditions and mechanisms driving the spread and the evolution of antibiotic resistance plasmids. IMPORTANCE Understanding the evolutionary forces that maintain antibiotic resistance genes in a population, especially when antibiotics are not used, is an important problem for human health and society. The most common platform for the dissemination of antibiotic resistance genes is conjugative plasmids. Experimental studies showed that mutations located on the plasmid or the bacterial chromosome can reduce the costs plasmids impose on their hosts, resulting in antibiotic resistance plasmids being maintained even in the absence of antibiotics. While chromosomal mutations are only vertically inherited by the daughter cells, plasmid mutations are also provided to bacteria that acquire the plasmid through conjugation. Here we demonstrate how the mode of inheritance of a compensatory mutation crucially influences the ability of plasmids to spread and persist in a bacterial population.
doi:10.1128/msystems.00186-18 pmid:30944871 pmcid:PMC6446977 fatcat:vuefgrsagjcvzpmtf3hctpajby
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