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Biomedical subjects

J E Thomas

Publications and source records attributed to J E Thomas.

At least 19 recordsLinked to original sources
PubMed2006

Human milk vacuolating cytotoxin A immunoglobulin A antibodies modify Helicobacter pylori infection in Gambian children.

We collected data, including the weights, urea breath test results, and presence of maternal milk cytotoxin-associated gene-specific and vacuolating cytotoxin A-specific immunoglobulin A monthly from 48 mothers and infants (to 44 weeks of age) in The Gambia. In all, 11 children (23%) had negative urea breath test results, and 37 (77%) had positive results. Weight loss associated with Helicobacter pylori colonization was restricted to children whose mothers did not produce anti-vacuolating cytotoxin A antibodies in their milk (P=.028, by t test).

Adult↗
PubMed2006

Molecular characterization, expression and localization of tropomyosin and paramyosin immunodominant allergens from sheep scab mites (Psoroptes ovis).

cDNAs encoding the immunodominant allergens tropomyosin and paramyosin were amplified from RNA extracted from the sheep scab mite Psoroptes ovis. The tropomyosin cDNA contained an open reading frame (ORF) of 852 bp which encoded a predicted protein with 98% and 97% identity to the house dust mite allergens Der f 10 and Der p 10 respectively. The complete paramyosin ORF generated by RT-PCR was 2625 bp in length and encoded an 875aa predicted protein of 102.6 kDa with 97%, 95% and 89% identity to the paramyosins of Dermatophagoides pteronyssinus (Der p 11), Sarcoptes scabiei and Blomia tropicalis (Blo t 11) respectively. Full length tropomyosin and truncated and full-length paramyosin were expressed as recombinant proteins. IgG and IgE in sera from sheep with a 6-week duration primary infestation of P. ovis did not detect either full-length or truncated recombinant paramyosin. IgG in both infested and naïve sheep sera detected recombinant tropomyosin, suggesting cross-reactivity to tropomyosin and to other invertebrate species to which the sheep may have been exposed. Staining with antibodies directed against tropomyosin and paramyosin was observed throughout sections of P. ovis. Staining was especially prevalent in the anterior sections of the mites, possibly associated with locomotory muscles in this region.

Allergens↗
PubMed2005

Use of in-stream reservoirs to reduce bacterial contamination of rural watersheds.

An investigation into bacterial water quality problems was conducted on an interconnected stream and irrigation system within the Oldman River Basin of southern Alberta, Canada. Levels of indicator bacteria, including fecal coliforms, generic Escherichia coli and fecal streptococci, were repeatedly measured in streams and irrigation return canals of this river basin during the summer of 2001. Bacterial-loading segments of the irrigation/stream system were identified through a comparison of indicator bacteria levels in pairs of upstream and downstream sites. Mann-Whitney U-tests indicated that reservoirs significantly reduced bacterial counts. A temporal comparison of E. coli counts and river discharges suggested that these indicator bacteria do not originate from within in-stream sediments. Site-specific as well as cumulative inputs from a variety of non-point sources are likely to be responsible for the high downstream levels of indicator bacteria in this water system. The use of management practices such as in-stream reservoirs may significantly reduce contamination, and increase the quality of limited rural water supplies to allow their reuse and safe discharge into downstream water sources. The identification of bacteria-loading river/canal segments could also be used to prioritize restoration projects.

Agriculture↗
PubMed2005

Virial theorem and universality in a unitary fermi gas.

Unitary Fermi gases, where the scattering length is large compared to the interparticle spacing, can have universal properties, which are independent of the details of the interparticle interactions when the range of the scattering potential is negligible. We prepare an optically trapped, unitary Fermi gas of 6Li, tuned just above the center of a broad Feshbach resonance. In agreement with the universal hypothesis, we observe that this strongly interacting many-body system obeys the virial theorem for an ideal gas over a wide range of temperatures. Based on this result, we suggest a simple volume thermometry method for unitary gases. We also show that the observed breathing mode frequency, which is close to the unitary hydrodynamic value over a wide range of temperature, is consistent with a universal hydrodynamic gas with nearly isentropic dynamics.

Journal Article↗
PubMed2005

Damping of a unitary Fermi gas.

We measure the temperature dependence of the radial breathing mode in an optically trapped, unitary Fermi gas of 6Li, just above the center of a broad Feshbach resonance. The damping rate reveals a clear change in behavior which we interpret as arising from a superfluid transition. We suggest pair breaking as a mechanism for an increase in the damping rate which occurs at temperatures well above the transition. In contrast to the damping, the frequency varies smoothly and remains close to the unitary hydrodynamic value. At low temperature T, the damping depends on the atom number only through the reduced temperature, and extrapolates to 0 at T = 0.

Journal Article↗
PubMed2005

Characterisation of Banana streak Mysore virus and evidence that its DNA is integrated in the B genome of cultivated Musa.

We have sequenced the complete genome of an isolate of Banana streak virus from banana cv. 'Mysore' and show that it is sufficiently different from a previously characterised isolate from cv. 'Obino l'Ewai' to warrant recognition as a distinct species, for which the name Banana streak Mysore virus (BSMysV) is proposed. The structure of the BSMysV genome was typical of badnaviruses in general, although ORF I had a non-conventional start codon. Evidence that at least part of the BSMysV genome is integrated in the B genome of cultivated Musa is presented and transmissibility by the mealybug Planococcus citri also demonstrated.

Badnavirus↗
PubMed2005

Interprofessional education in undergraduate healthcare programmes: the reaction of student dietitians.

BACKGROUND: Interprofessional education (IPE) is a novel teaching and learning initiative where students of more than one health profession learn interactively together. However, despite its potential for improving interprofessional relationships, there is little information regarding the participation of student dietitians in IPE. The aim of this paper was to consider the reaction of student dietitians to an IPE course in order to stimulate debate between dietitians regarding the issues relating to IPE. METHODS: Student dietitians participated in an IPE course consisting of seven sessions on communication and ethics in health care together with students of medicine and nursing. Student dietitians completed an evaluation questionnaire following each session that surveyed their reaction to the session using both a Likert scale and free-text comments. RESULTS: Twenty-six student dietitians completed the IPE course. All sessions were rated positively for interest value (P < or = 0.14), learning experience (P < or = 0.036) and value for clinical practice (P < or = 0.05). The limited number of free-text comments indicated some positive experiences regarding interprofessional learning, teaching content and teaching strategy. CONCLUSIONS: This is one of very few evaluations to describe the reaction of student dietitians to IPE. Student dietitians had largely positive reactions to the IPE course. Further research is required to evaluate whether these positive reactions were a direct consequence of the inclusion of students from other health professions and whether these translate into positive effects on learning, behaviour and results. The opportunities for the dietetic profession posed by students' involvement in IPE are discussed.

Adult↗
PubMed2004

Evidence for superfluidity in a resonantly interacting Fermi gas.

We observe collective oscillations of a trapped, degenerate Fermi gas of 6Li atoms at a magnetic field just above a Feshbach resonance, where the two-body physics does not support a bound state. The gas exhibits a radial breathing mode at a frequency of 2837(05) Hz, in excellent agreement with the frequency of nu(H) identical with sqrt[10nu(x)nu(y)/3]=2830(20) Hz predicted for a hydrodynamic Fermi gas with unitarity-limited interactions. The measured damping times and frequencies are inconsistent with predictions for both the collisionless mean field regime and for collisional hydrodynamics. These observations provide the first evidence for superfluid hydrodynamics in a resonantly interacting Fermi gas.

Journal Article↗
PubMed2004

Persistence, distribution, and emission of Telone C35 injected into a Florida sandy soil as affected by moisture, organic matter, and plastic film cover.

With the phase-out of methyl bromide scheduled for 2005, alternative fumigants are being sought. This study of Telone C35, a mixture of (Z)- and (E)-1,3-dichloropropene (1,3-D) with chloropicirin (CP), focuses on its emissions, distribution, and persistence in Florida sandy soil in microplots with different soil-water and organic matter carbon (C) content with and without two different plastic film mulches. The addition of CP did not affect the physical behavior of the isomers of 1,3-D. Slower subsurface dispersion and longer residence time of the mixed fumigant occurred at higher water content. An increase in the percent organic carbon in the soil led to a more rapid decrease for chloropicirin than for 1,3-dichloropene isomers. The use of a virtually impermeable film (VIF) for soil cover provided a more even distribution and longer persistence under all the conditions studied in comparison to polyethylene (PE) film cover or no cover. The conditions of near field capacity water content, low organic matter, and a virtually impermeable film cover yielded optimum conditions for the distribution, emission control, and persistence of Telone C35 in a Florida sandy soil.

Allyl Compounds↗
PubMed2004

Early Helicobacter pylori colonisation: the association with growth faltering in The Gambia.

BACKGROUND: Helicobacter pylori is one of the commonest causes of chronic infection of mankind, yet the natural history of acute infection is poorly understood. Some studies suggest that gastric colonisation with H pylori is associated with suboptimal nutrition and growth in childhood. AIMS: To describe the clinical features of early H pylori colonisation and assess its role in the development of infant malnutrition and growth faltering. METHODS: Two consecutive prospective longitudinal cohort studies were conducted at the Medical Research Council Laboratories in a rural community in The Gambia, West Africa. The first birth cohort of 125 infants was followed by a second of 65 children from the same community. H pylori colonisation was detected by sequential 13C urea breath tests, and infant growth was monitored by serial measurements. RESULTS: Children with early H pylori colonisation became significantly lighter, shorter, and thinner than their peers in late infancy. The association was found in both cohorts. No socioeconomic or demographic confounding variables were identified to explain this, and the weight deficit was no longer detectable when the children were aged 5-8 years. CONCLUSIONS: Results suggest that H pylori colonisation in early infancy predisposes to the development of malnutrition and growth faltering, although the effect did not persist into later childhood.

Breath Tests↗
PubMed2004

Flies and Helicobacter pylori infection.

Houseflies have been proposed to be a reservoir and vector for Helicobacter pylori. We assessed the effect of insecticide spraying in villages in The Gambia on H. pylori infection in young children. Effective control of flies did not prevent infection with H. pylori.

Animals↗
PubMed2003

Prevalence of Escherichia coli O157:H7 and Salmonella spp. in surface waters of southern Alberta and its relation to manure sources.

The Oldman River watershed in southern Alberta, Canada, is an extensively irrigated region in which intensive agricultural practices have flourished. Concern over water quality in the basin has been expressed because of high levels of enteric disease indigenous to the region. To address these concerns, we conducted a 2-year study to estimate the prevalence of Escherichia coli O157:H7 and Salmonella spp. in surface water within the basin. This study is the first of its kind to identify E. coli O157:H7 repeatedly in surface water collected from a Canadian watershed. Prevalence of E. coli O157:H7 and Salmonella spp. in water samples was 0.9% (n = 1,483) and 6.2% (n = 1,429), respectively. While data examined at a regional level show a relationship between high livestock density and high pathogen levels in southern Alberta, statistical analysis of point source data indicates that predicted manure output from bovine, swine, and poultry feeding operations was not directly associated with either Salmonella spp. or E. coli O157:H7 prevalence. However, geography and weather variables, which are likely to influence bacterial runoff, were not considered in this model. We also postulate that variations in time, amount, and frequency of manure application onto agricultural lands may have influenced levels of surface-water contamination with these bacterial pathogens.

Alberta↗
PubMed2003

Thermoluminescence dosimetry in the Caribbean.

The results of five years of radiation monitoring of 590 radiation workers in Jamaica and an additional 88 in Barbados and The Turks and Caicos Islands show that the annual dose absorbed by Caribbean radiation workers is, with a single exception, well within the internationally accepted limits of 20 mSv per year. There were few cases of relatively high exposures. The dose equivalent of the radiation workers by category agrees with international trends; workers in nuclear medicine receive the highest doses and dental radiologists the lowest. The collective Effective Dose Equivalent has been calculated for each of the monitored populations and certain trends identified. The risk for development of fatal cancers from the occupational doses reported was very low. Consistent monitoring will identify aberrant conditions quickly and help maintain that record.

Caribbean Region↗
PubMed2002

Observation of a strongly interacting degenerate Fermi gas of atoms.

We report on the observation of a highly degenerate, strongly interacting Fermi gas of atoms. Fermionic lithium-6 atoms in an optical trap are evaporatively cooled to degeneracy using a magnetic field to induce strong, resonant interactions. Upon abruptly releasing the cloud from the trap, the gas is observed to expand rapidly in the transverse direction while remaining nearly stationary in the axial direction. We interpret the expansion dynamics in terms of collisionless superfluid and collisional hydrodynamics. For the data taken at the longest evaporation times, we find that collisional hydrodynamics does not provide a satisfactory explanation, whereas superfluidity is plausible.

Journal Article↗
PubMed2002

All-optical production of a degenerate Fermi gas.

We achieve degeneracy in a mixture of the two lowest hyperfine states of 6Li by direct evaporation in a CO2 laser trap, yielding the first all optically produced degenerate Fermi gas. More than 10(5) atoms are confined at temperatures below 4 microK at full trap depth, where the Fermi temperature for each state is 8 microK. This degenerate two-component mixture is ideal for exploring mechanisms of superconductivity ranging from Cooper pairing to Bose-Einstein condensation of strongly bound pairs.

Journal Article↗