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D Fenton

Publications and source records attributed to D Fenton.

14 recordsLinked to original sources
PubMed2007

Individual and collective doses from cosmic radiation in Ireland.

This paper assesses the individual and collective doses in Ireland due to cosmic radiation. Information on the exposure to cosmic radiation at ground level is reviewed and published data on the frequency of routes flown by Irish residents is used to calculate the dose due to air travel. Occupational exposure of aircrew is also evaluated. Experimental data on cosmic radiation exposure at ground level is in good agreement with international estimates and the average individual dose is calculated as 300 microSv annually. Published data on international air travel by Irish residents shows a 50% increase in the number of flights taken between 2001 and 2005. This increase is primarily on short-haul flights to Europe, but there have been significant percentage increases in all long-haul flights, with the exception of flights to Africa. The additional per capita dose due to air travel is estimated to be 45 muSv, of which 51% is accumulated on European routes and 34% on routes to the United States. Exposure of aircrew to cosmic radiation is now controlled by legislation and all airlines holding an Air Operator's Certificate issued by the Irish Aviation Authority are required to report annually the doses received by their employees in the previous year. There has been a 75% increase in the number of aircrew receiving doses >1 mSv since 2002. In 2004 and 2005 the average individual doses received by Irish aircrew were 1.8 and 2.0, mSv, respectively. The corresponding per caput dose for the entire population is <3 muSv. While this is low compared with the per caput doses from other sources of cosmic radiation, aircrew exposure represents a higher collective dose than any other identified group of exposed workers in Ireland.

Aircraft↗
PubMed2006

Radon in Irish schools: the results of a national survey.

This paper presents the results of a survey of radon concentrations in Irish primary and post-primary schools. The objective of this survey was to assess the distribution of radon in Irish schools and to identify those requiring remedial work to reduce radon exposure to children and staff. All primary and post-primary schools were invited to participate in the survey. Indoor radon concentrations were measured during the academic year using integrating passive alpha track-etch detectors with a measurement period from three to nine months. The survey was carried out on a phased basis from 1998 to 2004 and is one of the most comprehensive of its kind undertaken in Europe. Measurements were completed in 38 531 ground floor classrooms and offices in 3826 schools, representing over 95% of the approximate 4000 primary and post-primary schools in Ireland. Of these, 984 schools had radon concentrations greater than 200 Bq m(-3) in 3028 rooms and 329 schools had radon concentrations in excess of 400 Bq m(-3) in 800 rooms. The average radon concentration in schools was 93 Bq m(-3). This results in an annual average effective dose to an Irish child from exposure to radon of 0.3 mSv per year, assuming that the long-term radon concentration is equal to the radon concentration present during the working hours and that the annual average occupancy is 1000 h per year. A programme of remediation of schools with radon concentrations above 200 Bq m(-3) has been put in place.

Adolescent↗
PubMed2004

Distribution of contaminants in biota and sediments in the Musquash Estuary, Atlantic Canada, marine protected area site initiative and contaminant exclusion zone.

The Musquash Estuary, one of the last ecologically intact estuaries in New Brunswick, has been designated an area of interest for a marine protected area (MPA) under the Oceans Act. The area has been assessed for contaminant background levels as required for establishing MPA environmental quality. American lobster (Homarus americanus), blue mussel (Mytilus edulis) and sediments were collected for assessing contaminant levels and distribution in the harbour. Levels of contaminants from the indicator species and the abiotic component have shown: (1) two extremes of high and low Cu and Ag in lobster from the area; and (2) lower metal levels in inner Musquash Harbour sediments and mussels than in those from the harbour mouth. These suggest that deposition of contaminants into the Musquash MPA site was due to transport of contaminants by coastal currents from upstream coastal industrial activities. This reverse trend with higher contaminant levels in the biotic and abiotic components in the outer harbour than in the inner harbour differs from a contaminated harbour and suggests that a contaminant exclusion zone should be considered for controlling contamination from nearby coastal and estuarine industrial sites to protect the sensitive habitats within the marine protected area.

Animals↗
PubMed2004

Current status of programmes to measure and reduce radon exposure in Irish workplaces.

National legislation, which implements European Council Directive 96/29/EURATOM in Ireland, sets a reference level of 400 Bq m(-3) averaged over any 3 month period for radon exposure in the workplace and also empowers the Radiological Protection Institute of Ireland to direct employers to have radon measurements carried out. This legislation came into effect in May 2000. Radon measurements have already been completed in show caves and other underground workplaces. Between 1998 and 2001, over 33 800 individual radon measurements were carried out in all ground floor offices and classrooms in 3444 schools nationwide as part of a programme undertaken jointly with the Department of Education and Science. Where the average indoor radon concentration in one or more rooms exceeded 200 Bq m(-3), remedial measures were implemented. For concentrations up to 400 Bq m(-3) this involved increased ventilation while for higher concentrations an active sump was normally installed. The results of the survey, as well as the effectiveness of the different remedial strategies, are discussed. In the case of other above ground workplaces, different approaches have been adopted. As a first step, workplaces in two known high radon areas were directed to have radon measurements carried out. This programme had limited success because of problems in obtaining accurate workplace databases and a general lack of awareness on the part of employers of the issues involved. From a sample of 2610 employers directed to measure radon, only 408 actually completed measurements and 37 workplaces were identified as having average 3 month average radon concentrations above 400 Bq m(-3). A total of 1356 employers ignored all correspondence, some of which was sent by registered post and signed for on receipt. Current initiatives are focused on the provision of information and include newspaper advertising as well as publications aimed specifically at both employer and employee representative groups. The ability to provide accurate information that encourages both measurement and remediation is seen as central to an effective radon workplace programme.

Environmental Exposure↗
PubMed2004

A chromosome bin map of 2148 expressed sequence tag loci of wheat homoeologous group 7.

The objectives of this study were to develop a high-density chromosome bin map of homoeologous group 7 in hexaploid wheat (Triticum aestivum L.), to identify gene distribution in these chromosomes, and to perform comparative studies of wheat with rice and barley. We mapped 2148 loci from 919 EST clones onto group 7 chromosomes of wheat. In the majority of cases the numbers of loci were significantly lower in the centromeric regions and tended to increase in the distal regions. The level of duplicated loci in this group was 24% with most of these loci being localized toward the distal regions. One hundred nineteen EST probes that hybridized to three fragments and mapped to the three group 7 chromosomes were designated landmark probes and were used to construct a consensus homoeologous group 7 map. An additional 49 probes that mapped to 7AS, 7DS, and the ancestral translocated segment involving 7BS also were designated landmarks. Landmark probe orders and comparative maps of wheat, rice, and barley were produced on the basis of corresponding rice BAC/PAC and genetic markers that mapped on chromosomes 6 and 8 of rice. Identification of landmark ESTs and development of consensus maps may provide a framework of conserved coding regions predating the evolution of wheat genomes.

Chromosome Mapping↗
PubMed1998

Fatal cytophagic panniculitis and haemophagocytic syndrome.

We present two fatal cases of cytophagic panniculitis (CP) and haemophagocytic syndrome (HPS). In the first of these, there was an underlying T-cell lymphoma but in the second no associated disease was found. HPS is a frequently fatal disorder of immune regulation, characterized by fever, histiocytic haemophagocytosis, hepatosplenomegaly, pancytopenia, hypertriglyceridaemia and coagulopathy; CP is a less common manifestation. A number of benign and malignant conditions may present with HPS, the clinical findings and investigations aiding in determining an underlying disorder. Therapy is both supportive and directed at any associated illness, but often very difficult as diagnosis is delayed.

Adult↗
PubMed1993

Effect of retinoids on follicular cells.

It has been demonstrated that topical application of all-trans retinoic acid and other retinoids can alter the hair-growth cycle in the C3H mouse model. The anagen phase is prolonged and the telogen phase is shortened. This effect is similar to the effect of minoxidil on the hair-cycle dynamics in this animal model. The levels of cellular retinoic acid binding protein measured by radioreceptor assay in whole skin of C3H mice were higher during anagen and lower during telogen. Topical application of certain retinoids caused elevated levels of cellular retinoic acid-binding protein (cRABP) in the whole skin homogenates during both phases of the cycle. Of the retinoids tested, those most effective in altering the levels of cRABP in the skin of the mice were also capable of significantly altering the hair-cycle dynamics. There appeared to be a relationship between the ability of retinoid to increase cRABP, increase 3H-thymidine incorporation, and alter the dynamics of the hair cycle. Only cRABP-II is detectable in human cultured dermal fibroblasts and dermal papilla cells. Dermal fibroblasts showed higher amounts of cRABP-II as compared to dermal papilla cells. The difference in cRABP-II expression might explain a distinct response to RA by these two cell populations. Whether the difference in expression of cRABP-II might be of physiologic importance remains to be determined. Treatment of human dermal papilla cells in culture with retinoic acid does not appear to affect proliferation, at least at the doses tested.

Animals↗
PubMed1992

Cysteine to serine substitutions in basic fibroblast growth factor: effect on inclusion body formation and proteolytic susceptibility during in vitro refolding.

We have investigated the effect of cysteine to serine substitutions in human basic fibroblast growth factor (bFGF) on the formation of inclusion bodies in Escherichia coli. Using a temperature-sensitive expression, system, about 30% of human bFGF, which contains four cysteines at positions 26, 70, 88, and 93, is deposited into inclusion bodies. A single mutation at position 88 and a double mutation at positions 70 and 88 do not greatly alter the partition of bFGF into soluble and insoluble cell fractions. However, a single substitution of cysteine 70 by serine decreases the fraction of soluble bFGF significantly. When cysteines 26 and 93 (conserved among related growth factors) are replaced by serines, no soluble bFGF is formed in E. coli. Cysteine to serine substitutions also affect proteolytic susceptibility of bFGF during in vitro refolding from crude inclusion bodies. About 60% of human bFGF is lost to proteolytic degradation during in vitro refolding. Replacement of cysteines by serines increases the total recovery of bFGF, although more aggregates are formed during refolding. Ser-88-bFGF was expressed at the highest level, gave the highest soluble fraction in vivo, and exhibited the greatest fractional recovery and was recovered with the largest insoluble fraction after in vitro refolding. Thermal stability experiments at 42 degrees C and 70 degrees C revealed that cysteine to serine substitutions did not cause aggregation of the folded protein in vitro.

Base Sequence↗
PubMed1989

A large outbreak of Salmonella enteritidis phage type 4 associated with eggs from overseas.

In February 1989 the largest reported outbreak to date in the United Kingdom of Salmonella enteritidis phage type 4 (PT4) infection occurred following a wedding reception at a hotel. One hundred and seventy-three people met the case definition of illness of whom 118 had the organism isolated from their stools. A further 17 were found to be S. enteritidis PT4 positive, but were asymptomatic. Lightly-cooked, egg-based sauces were the epidemiologically proven vehicles of infection. Investigations showed this outbreak to be the first to implicate imported European eggs as the source of infection. An unusual feature of this outbreak was a reported incubation period of less than 3 h for some of the confirmed cases of salmonellosis.

Animals↗
PubMed1984

Application of recombinant DNA technologies to studies on chicken growth hormone.

Messenger RNA isolated from chicken pituitaries was used to construct a chicken pituitary cDNA library. A chicken growth hormone cDNA clone was isolated using 32P-labeled mammalian growth hormone cDNA probes. The amino acid sequence (derived from the DNA sequence) of the mature form of chicken growth hormone shows 77% homology with that of bovine growth hormone. The chicken growth hormone cDNA clone was used to generate a vector capable of producing chicken growth hormone in Escherichia coli. The recombinant E. coli-derived chicken growth hormone was similar to pituitary chicken growth hormone in several biochemical and immunological properties. The recombinant-derived hormone has been used to establish a sensitive radioimmunoassay for growth hormone determinations made from chicken sera. The chicken growth hormone gene has also been introduced into a retroviral vector capable of establishing productive infections of chicken cells both in in vitro and in vivo. The resulting infections are accompanied by the production of radioimmunoassay-detectable growth hormone. The concentrations of growth hormone in sera of Leghorn chickens infected with the recombinant retrovirus are three- to tenfold higher than in control animals.

Amino Acid Sequence↗
PubMedDate not supplied

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Humans↗