317 research outputs found
Using sea cucumbers to illustrate the basics of zoological nomenclature
In addition to a brief account of the need to have unique and unambiguous scientific names for taxa, this paper, annotated with examples of sea cucumbers, explains the basics of zoological nomenclature. In doing so it aims to reduce the confusion that exists among various breeds of end-users of taxonomists who may not fully understand the seemingly arbitrary and often volatile nature of scientific names. This paper also aims to provide teachers and students with a comprehensible account of the basic principles of zoological nomenclature
Thinking about growth : a cognitive mapping approach to understanding small business development
School of Managemen
Apheresis for collection of Ebola convalescent plasma in Liberia
Purpose: This report describes initiation of apheresis capability in Liberia, Africa to support a clinical trial of convalescent plasma therapy for Ebola Virus Disease. Methods: A bloodmobile was outfitted in the United States as a four-bed apheresis unit with capabilities including pathogen reduction, electronic blood establishment computer system, designated areas for donor counseling and laboratory testing, and onboard electrical power generation. After air transport to Liberia, the bloodmobile was positioned at ELWA Hospital, Monrovia, and connected to the hospital's power grid. Liberian staff were trained to conduct donor screening, which included questionnaire and onsite blood typing and transfusion transmitted infection (TTI) testing, and plasma collection and processing. Results: The bloodmobile was operational within 3 weeks after arrival of the advance team. Of 101 donors who passed the pre-screening questionnaire, 32 were deferred. Twenty-eight of ninty-nine tested survivors were deferred for positive transfusion transmitted infection (TTI) tests; twenty-one were positive for hepatitis B, hepatitis C, or human immunodeficiency virus. The majority of donors had type O blood; all but one were Rh positive. Forty-three survivors donated at least once; eighty-nine apheresis attempts resulted in eighty-one successful collections. Conclusions: Apheresis capability was emergently established in Liberia to support an efficacy trial of Ebola Convalescent Plasma. Extensive cooperation among multinational team members, engineers, logisticians, and blood safety technical personnel at the operational site was required to surmount challenges to execution posed by logistical factors. The high proportion of positive TTI tests supported the use of a pathogen reduction system to enhance product safety
Effects of decoherence and errors on Bell-inequality violation
We study optimal conditions for violation of the Clauser-Horne-Shimony-Holt
form of the Bell inequality in the presence of decoherence and measurement
errors. We obtain all detector configurations providing the maximal Bell
inequality violation for a general (pure or mixed) state. We consider local
decoherence which includes energy relaxation at the zero temperature and
arbitrary dephasing. Conditions for the maximal Bell-inequality violation in
the presence of decoherence are analyzed both analytically and numerically for
the general case and for a number of important special cases. Combined effects
of measurement errors and decoherence are also discussed.Comment: 18 pages, 5 figure
Simulation of muon radiography for monitoring CO2 stored in a geological reservoir
Current methods of monitoring subsurface CO2, such as repeat seismic surveys, are episodic and require highly skilled personnel to acquire the data. Simulations based on simplified models have previously shown that muon radiography could be automated to continuously monitor CO2 injection and migration, in addition to reducing the overall cost of monitoring. In this paper, we present a simulation of the monitoring of CO2 plume evolution in a geological reservoir using muon radiography. The stratigraphy in the vicinity of a nominal test facility is modelled using geological data, and a numerical fluid flow model is used to describe the time evolution of the CO2 plume. A planar detection region with a surface area of 1000 m2 is considered, at a vertical depth of 776 m below the seabed. We find that 1 year of constant CO2 injection leads to changes in the column density of âČ1%, and that the CO2 plume is already resolvable with an exposure time of less than 50 days
Anti-ebola virus antibody levels in convalescent plasma and viral load after plasma infusion in patients with ebola virus disease
Background Ebola virus (EBOV) neutralizing antibody in plasma may reduce viral load following administration of plasma to patients with Ebola virus disease (EVD), but measurement of these antibodies is complex. Methods Anti-EBOV antibody was measured by 2 neutralization and 2 enzyme-linked immunosorbent assays (ELISAs) in convalescent plasma (ECP) from 100 EVD survivor donors in Liberia. Viral load was assessed repetitively in patients with EVD participating in a clinical trial of enhanced standard of care plus ECP. Results All 4 anti-EBOV assays were highly concordant for detection of EBOV antibody. Antibodies were not detected in plasma specimens obtained from 15 of 100 donors, including 7 with documented EBOV-positive reverse-transcription polymerase chain reaction during EVD. Viral load was reduced following each dose in the 2 clinical trial participants who received ECP with higher antibody levels but not in the 2 who received ECP with lower antibody levels. Conclusions Recovery from EVD can occur with absence of detectable anti-EBOV antibody several months after disease onset. ELISAs may be useful to select ECP donors or identify ECP units that contain neutralizing antibody. ECP with higher anti-EBOV antibody levels may have greater effect on EBOV load - an observation that requires further investigation. Clinical Trials Registration NCT02333578
Adding function to the genome of African Salmonella Typhimurium ST313 strain D23580.
Salmonella Typhimurium sequence type (ST) 313 causes invasive nontyphoidal Salmonella (iNTS) disease in sub-Saharan Africa, targeting susceptible HIV+, malarial, or malnourished individuals. An in-depth genomic comparison between the ST313 isolate D23580 and the well-characterized ST19 isolate 4/74 that causes gastroenteritis across the globe revealed extensive synteny. To understand how the 856 nucleotide variations generated phenotypic differences, we devised a large-scale experimental approach that involved the global gene expression analysis of strains D23580 and 4/74 grown in 16 infection-relevant growth conditions. Comparison of transcriptional patterns identified virulence and metabolic genes that were differentially expressed between D23580 versus 4/74, many of which were validated by proteomics. We also uncovered the S. Typhimurium D23580 and 4/74 genes that showed expression differences during infection of murine macrophages. Our comparative transcriptomic data are presented in a new enhanced version of the Salmonella expression compendium, SalComD23580: http://bioinf.gen.tcd.ie/cgi-bin/salcom_v2.pl. We discovered that the ablation of melibiose utilization was caused by three independent SNP mutations in D23580 that are shared across ST313 lineage 2, suggesting that the ability to catabolize this carbon source has been negatively selected during ST313 evolution. The data revealed a novel, to our knowledge, plasmid maintenance system involving a plasmid-encoded CysS cysteinyl-tRNA synthetase, highlighting the power of large-scale comparative multicondition analyses to pinpoint key phenotypic differences between bacterial pathovariants
Thick-film technology for ultra high vacuum interfaces of micro-structured traps
We adopt thick-film technology to produce ultra high vacuum compatible
interfaces for electrical signals. These interfaces permit voltages of hundreds
of Volts and currents of several Amperes and allow for very compact vacuum
setups, useful in quantum optics in general, and especially for quantum
information and quantum simulations using miniaturized traps for ions or
neutral atoms. Such printed circuits can also be useful as pure in-vacuum
devices. We demonstrate a specific interface, which provides eleven current
feedthroughs, more than 70 dc feedthroughs and a feedthrough for radio
frequencies. We achieve a pressure in the low 1e-11mbar range and demonstrate
the full functionality of the interface by trapping chains of cold ytterbium
ions, which requires all of the signals mentioned above being present. In
addition, a versatile multi-channel device for supplying precise time-dependent
voltages has been developed.Comment: 8 pages, 7 figures added references to recent literature about
microwave anipulated ions and fast shuttlin
White matter hyperintensities are seen only in GRN mutation carriers in the GENFI cohort
Genetic frontotemporal dementia is most commonly caused by mutations in the progranulin (GRN), microtubule-associated protein tau (MAPT) and chromosome 9 open reading frame 72 (C9orf72) genes. Previous small studies have reported the presence of cerebral white matter hyperintensities (WMH) in genetic FTD but this has not been systematically studied across the different mutations. In this study WMH were assessed in 180 participants from the Genetic FTD Initiative (GENFI) with 3D T1- and T2-weighed magnetic resonance images: 43 symptomatic (7 GRN, 13 MAPT and 23 C9orf72), 61 presymptomatic mutation carriers (25 GRN, 8 MAPT and 28 C9orf72) and 76 mutation negative non-carrier family members. An automatic detection and quantification algorithm was developed for determining load, location and appearance of WMH. Significant differences were seen only in the symptomatic GRN group compared with the other groups with no differences in the MAPT or C9orf72 groups: increased global load of WMH was seen, with WMH located in the frontal and occipital lobes more so than the parietal lobes, and nearer to the ventricles rather than juxtacortical. Although no differences were seen in the presymptomatic group as a whole, in the GRN cohort only there was an association of increased WMH volume with expected years from symptom onset. The appearance of the WMH was also different in the GRN group compared with the other groups, with the lesions in the GRN group being more similar to each other. The presence of WMH in those with progranulin deficiency may be related to the known role of progranulin in neuroinflammation, although other roles are also proposed including an effect on blood-brain barrier permeability and the cerebral vasculature. Future studies will be useful to investigate the longitudinal evolution of WMH and their potential use as a biomarker as well as post-mortem studies investigating the histopathological nature of the lesions
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