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711.
Francis Hassard Jasmine H. Sharp Helen Taft Lewis LeVay John P. Harris James E. McDonald Karen Tuson James Wilson David L. Jones Shelagh K. Malham 《Food and environmental virology》2017,9(2):123-141
We review the risk of norovirus (NoV) infection to the human population from consumption of contaminated shellfish. From a UK perspective, risk is apportioned for different vectors of NoV infection within the population. NoV spreads mainly by person-to-person contact or via unsanitary food handling. NoV also enters the coastal zone via wastewater discharges resulting in contamination of shellfish waters. Typically, NoV persists in the marine environment for several days, with its presence strongly linked to human population density, wastewater discharge rate, and efficacy of wastewater treatment. Shellfish bioaccumulate NoV and current post-harvest depuration is inefficient in its removal. While NoV can be inactivated by cooking (e.g. mussels), consumption of contaminated raw shellfish (e.g. oysters) represents a risk to human health. Consumption of contaminated food accounts for 3–11% of NoV cases in the UK (~74,000 cases/year), of which 16% are attributable to oyster consumption (11,800 cases/year). However, environmental and human factors influencing NoV infectivity remain poorly understood. Lack of standard methods for accurate quantification of infective and non-infective (damaged) NoV particles represent a major barrier, hampering identification of an appropriate lower NoV contamination limit for shellfish. Future management strategies may include shellfish quality assessment (at point of harvest or at point of supply) or harvesting controls. However, poor understanding of NoV inactivation in shellfish and the environment currently limits accurate apportionment and risk assessment for NoV and hence the identification of appropriate shellfish or environmental quality standards. 相似文献
712.
713.
We report the detection of a mosaic triple trisomy, 46, XY/49, XY, + 13, +20, +21, in two amniotic fluid specimens obtained from a pregnancy that yielded a normal infant. Traditional cytogenetic methods failed to detect the abnormal cell lineage in fetal blood, foreskin, amnion, umbilical cord, and three different biopsies of the chorion. In addition, fluorescence in situ hybridization study of cells from a buccal smear showed no evidence of cells with three copies of chromosome 20. 相似文献
714.
The exogenous application of chemical repellents is widespread in birds, but endogenous production is exceedingly rare. We herein report a new class of avian defensive compounds isolated from the feathers and volatile odor of the crested auklet (Aethia cristatella). Mass spectra indicate that n-hexanal, n-octanal, n-decanal, Z-4-decenal and a 12-carbon unsaturated aldehyde comprise the auklet odorant. Octanal and hexanal are also secreted in the repugnant metasternal gland emissions of heteropteran insects and are known to be potent invertebrate repellents. We suggest that the auklet odorant functions as an ectoparasite repellent and a signal of mate quality. This would represent a rare and direct link between vigor, quality and parasite resistance, one of several putative bases for mate selection. This is the first report of defensive compounds produced by a seabird or colonial bird and one of the few examples of chemical defense in a polar or subpolar marine vertebrate. 相似文献
715.
The relationship between adaptation and mitigation in managing climate change risks: a regional response from North Central Victoria,Australia 总被引:1,自引:0,他引:1
Roger N. Jones Paul Dettmann Geoff Park Maureen Rogers Terry White 《Mitigation and Adaptation Strategies for Global Change》2007,12(5):685-712
This two-part paper considers the complementarity between adaptation and mitigation in managing the risks associated with
the enhanced greenhouse effect. Part one reviews the application of risk management methods to climate change assessments.
Formal investigations of the enhanced greenhouse effect have produced three generations of risk assessment. The first led
to the United Nations Intergovernmental Panel on Climate Change (IPCC), First Assessment Report and subsequent drafting of
the United Nations Framework Convention on Climate Change. The second investigated the impacts of unmitigated climate change
in the Second and Third IPCC Assessment Reports. The third generation, currently underway, is investigating how risk management
options can be prioritised and implemented. Mitigation and adaptation have two main areas of complementarity. Firstly, they
each manage different components of future climate-related risk. Mitigation reduces the number and magnitude of potential
climate hazards, reducing the most severe changes first. Adaptation increases the ability to cope with climate hazards by
reducing system sensitivity or by reducing the consequent level of harm. Secondly, they manage risks at different extremes
of the potential range of future climate change. Adaptation works best with changes of lesser magnitude at the lower end of
the potential range. Where there is sufficient adaptive capacity, adaptation improves the ability of a system to cope with
increasingly larger changes over time. By moving from uncontrolled emissions towards stabilisation of greenhouse gases in
the atmosphere, mitigation limits the upper part of the range. Different activities have various blends of adaptive and mitigative
capacity. In some cases, high sensitivity and low adaptive capacity may lead to large residual climate risks; in other cases,
a large adaptive capacity may mean that residual risks are small or non-existent. Mitigative and adaptive capacity do not
share the same scale: adaptive capacity is expressed locally, whereas mitigative capacity is different for each activity and
location but needs to be aggregated at the global scale to properly assess its potential benefits in reducing climate hazards.
This can be seen as a demand for mitigation, which can be exercised at the local scale through exercising mitigative capacity.
Part two of the paper deals with the situation where regional bodies aim to maximise the benefits of managing climate risks
by integrating adaptation and mitigation measures at their various scales of operation. In north central Victoria, Australia,
adaptation and mitigation are being jointly managed by a greenhouse consortium and a catchment management authority. Several
related studies investigating large-scale revegetation are used to show how climate change impacts and sequestration measures
affect soil, salt and carbon fluxes in the landscape. These studies show that trade-offs between these interactions will have
to be carefully managed to maximise their relative benefits. The paper concludes that when managing climate change risks,
there are many instances where adaptation and mitigation can be integrated at the operational level. However, significant
gaps between our understanding of the benefits of adaptation and mitigation between local and global scales remain. Some of
these may be addressed by matching demands for mitigation (for activities and locations where adaptive capacity will be exceeded)
with the ability to supply that demand through localised mitigative capacity by means of globally integrated mechanisms. 相似文献
716.
Duarte-Davidson R Wilson SC Jones KC 《Environmental pollution (Barking, Essex : 1987)》1994,84(1):79-87
Polychlorinated biphenyl (PCB) and SigmaDDT (i.e. p,p'-DDT + p,p'-DDE = p,p'-DDD) concentrations were determined from the analysis of 115 Welsh breast milk samples collected in 1990 and 1991. Fifty PCB congeners were screened, of which 24 were identified in most samples. The PCB congener pattern was consistent between individual milk samples, with IUPAC congeners 28, 138, 153 and 180 being the most abundant and accounting for an average of 50% of the SigmaPCB concentrations determined. PCB concentrations varied between 2 and 70 ng g(-1) whole milk, were positively correlated with age, and negatively correlated with the total lactation period and with the percent lipid content of the milk. PCB pattern distributions differed between milk and adipose tissue samples. Human milk had a higher proportion of tri- (18 and 28), tetra- (44, 52 and 66) and pentachlorinated biphenyls (101) compared to human adipose tissue. SigmaDDT concentrations ranged from 0.3 to 71 ng g(-1) of whole milk, with p,p'-DDE contributing towards an average of 92% of the SigmaDDT concentrations. SigmaDDT levels were also positively correlated with age and negatively associated with the lactation period, though these correlations were rather weak. No significant differences in the SigmaPCB and SigmaDDT concentrations were noted between milk samples from donors living in rural and urban locations, or between the subjects' body weight, smoking habits or diet. 相似文献
717.
718.
The value of using gamma glutamyl transferase (GT) to select amniotic fluids for karyotyping from patients at low risk of chromosome defects is assessed. This paper reports on 16 pregnancies with fetal trisomy 21 and compares these to two previous reports of GT in fetal trisomy 21. The value of GT is contrasted to the value of AFP in selecting liquors for karyotyping. 相似文献
719.
The alpha subunit of human chorionic gonadotropin (alpha-hCG), human chorionic gonadotropin (hCG) and alpha fetoprotein (AFP) were measured in the serum of 25 women with chromosomally abnormal fetuses between 18 and 25 weeks of gestation and in 74 normal pregnancies. AFP levels less than 0.5 multiples of the median (MoM) or greater than 2.5 MoM were observed in 24 per cent of the abnormal pregnancies and in 6.76 per cent of the normal pregnancies. A low concentration of hCG (< 0.25 MoM) was observed in 8 per cent of abnormals and in 2.7 per cent of normals while an elevated concentration of hCG (>2.5 MoM) was observed in 56 per cent of abnormals and in 1.35 per cent of normals. Elevated hCG-alpha (>2.5 MoM) was observed in 28 per cent of abnormals and in none of the normals. Determination of elevated levels of hCG-alpha or hCG resulted in detection of 68 per cent of pregnancies with chromosomally abnormal fetuses with a false positive rate of 1.35 per cent. Determination of both elevated and depressed gonadotropin levels resulted in detection of 76 per cent of abnormal pregnancies with a false positive rate of 4.05 per cent. Measurement of hCG and hCG-alpha in maternal serum samples can be used as a screening procedure for detecting pregnancies at risk for fetal chromosome abnormalities. 相似文献
720.
Carrie Jones Carol Booth Debra Rita Lydia Jazmines Rhonda Spiro Brian McCulloch Christopher McCaskill Lisa G. Shaffer 《黑龙江环境通报》1995,15(9):843-848
We report a case of maternal uniparental disomy of chromosome 10 discovered after chorionic villus sampling (CVS). Direct preparations revealed mosaic trisomy 10, while cultured CVS cells, as well as amniotic fluid cells, showed only a normal 46,XY complement. DNA analysis using microsatellite markers showed both chromosomes 10 to have been inherited from the mother. The pregnancy was complicated by polyhydramnios. A phenotypically normal male infant of appropriate size was delivered by Caesarean section at 41 weeks' gestation. Since only the direct preparations showed trisomy 10, this case illustrates the importance of CVS direct preparations in the detection of pregnancies at risk of uniparental disomy (UPD). Although the increased frequency of confined placental mosaicism (CPM) diagnosed when direct preparations are performed has been viewed negatively, identification of both CPM and UPD may have biological and clinical significance for a pregnancy. Even though only a single case of maternal disomy 10 is reported here, the apparently normal phenotype provides evidence that there are no major imprinted loci on chromosome 10 that affect in utero growth and development. However, other potential effects such as mental retardation will require long-term follow-up of this as well as additional cases. 相似文献