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Background: Effects of stroke at the cellular and sub-cellular level remain poorly understood by conventional techniques. We use synchrotron-based imaging techniques to study elemental and biochemical changes in the infarct and penumbra after stroke in an experimental model. Methods: Ischemic stroke is induced in mice using the previously validated photothrombotic model. Animals are sacrificed at various time-points after stroke. Fourier transform infrared spectroscopic imaging (FTIRI) is used to gather sub-cellular (<1 µm spatial resolution) imaging data of lipid oxidation and protein aggregation in the areas of interest. X-ray fluorescence (XRF) imaging is used to image the distribution of bio-important elements at the cellular and sub-cellular spatial resolutions. Routine histology and immunohistochemistry are used to co-localize cell-types to areas of interest. Results: Preliminary XRF results indicate significant reduction in the concentration of multiple elements in the infarct, compared to the penumbra, at day 1 post-stroke. Some elements begin to return to normal concentration in the penumbra at day 3. FTIRI data shows that lipid and total protein levels decrease, while aggregate protein levels increase in the penumbra. Conclusions: Multi-modality synchrotron imaging can be used to map elements as well as bio-molecules in a stroke model. A better understanding of these changes can guide therapeutic interventions after stroke.
To estimate the prevalence of underweight between 1998 and 2006 in Liverpool schoolchildren aged 9–10 years using recently published underweight cut-off points.
Design and setting
Stature and body mass data collected at the Liverpool SportsLinx project’s fitness testing sessions were used to calculate BMI.
Data were available on 26 782 (n 13 637 boys, 13 145 girls) participants.
Overall underweight declined in boys from 10·3 % in 1998–1999 to 6·9 % in 2005–2006, and all sub-classifications of underweight declined, in particular grade 3 underweight, with the most recent prevalence being 0·1 %. In girls, the prevalence of underweight declined from 10·8 % in 1998–1999 to 7·5 % in 2005–2006. The prevalence of all grades of underweight was higher in girls than in boys. Underweight showed a fluctuating pattern across all grades over time for boys and girls, and overall prevalence in 2005–2006 represents over 200 children across the city.
Underweight may have reduced slightly from baseline, but remains a substantial problem in Liverpool, with the prevalence of overall underweight being relatively similar to the prevalence of obesity. The present study highlights the requirement for policy makers and funders to consider both ends of the body mass spectrum when fixing priorities in child health.
To describe the eating habits of children in Liverpool and compare two age groups that bridge the transition from primary to secondary school.
Two cross-sectional studies carried out one year apart using a food intake questionnaire that records whether or not each child claims to have eaten specific marker foods on the previous day.
Primary and secondary schools in Liverpool.
Six hundred and forty-nine children aged 11 or 12 years and 3556 children aged 9 or 10 years.
Fewer older children ate breakfast (68–82%), especially the girls, and not eating breakfast was associated with eating on the way to school in the younger children. More of the older girls ate nothing at breakfast or on the way to school. Overall, the less desirable foods were reported to have been eaten by more children, of both ages, than the more desirable foods. Fruit, however, was mentioned by most children (69–77%) but the next 10 foods mentioned by most children were all less desirable ones. Only 31% of primary and 21% of secondary children ate both fruit and vegetables but 23% of primary and 26% of secondary children ate neither fruit nor vegetables. Overall, more of the girls of both age groups claimed to have eaten foods that would normally be encouraged.
Food choice changes appreciably between primary and secondary school and, in some key respects, for the worse. In particular, far more children of both age groups need to be eating fruit and vegetables every day.
We examined the genetic architecture of four fitness-related traits (reproductive success, ovariole
number, body size and early fecundity) in a panel of 98 Oregon-R × 2b3 recombinant inbred lines
(RILs). Highly significant genetic variation was observed in this population for female, but not
male, reproductive success. The cross-sex genetic correlation for reproductive success was 0·20,
which is not significantly different from zero. There was significant genetic variation segregating in
this cross for ovariole number, but not for body size or early fecundity. The RILs were genotyped
for cytological insertion sites of roo transposable elements, yielding 76 informative markers with an
average spacing of 3·2 cM. Quantitative trait loci (QTL) affecting female reproductive success and
ovariole number were mapped using a composite interval mapping procedure. QTL for female
reproductive success were located at the tip of the X chromosome between markers at cytological
locations 1B and 3E; and on the left arm of chromosome 2 in the 30D–38A cytological region.
Ovariole number QTL mapped to cytological intervals 62D–69D and 98A–98E, both on the third
chromosome. The regions harbouring QTL for female reproductive success and ovariole number
were also identified as QTL for longevity in previous studies with these lines.
The relationship between initial population density
of Globodera pallida and yield was examined for
five genotypes of potato at four different experimental sites;
two in Scotland and two in England. The
experiments at each site were conducted in two stages. The
experimental area was first manipulated
using resistant and susceptible potato cultivars to give
plots with different nematode population
densities to act as the initial populations
(Pi) for the second stage. The main
experiment was conducted using a range of host genotypes
that differed in their tolerance and susceptibility. The
utility of an inverse linear model relating yield to
initial population density was confirmed as were
differences in cultivar tolerance. Site differences in
yield loss were also observed. It was found that the
model could be modified to include the partitioning of
genotype and site effects. The implications of
this in terms of developing further models to predict
yield loss and nematode population dynamics are discussed.
The process of pollination and fertilisation in flowering plants involves a series of interactive events between male and female cells. One of the earliest stages in the process of fertilisation is the recognition, and acceptance or rejection, of pollen grains alighting on the stigma of the recipient plant. Self-incompatibility (SI) involves these processes. Prevention of self-fertilisation is accomplished by the inhibition of pollen that has the same incompatibility phenotype as that of the stigma on which it lands. These highly specific recognition events are both developmentally expressed and tissue-specific. Investigation of the molecular basis of the expression and regulation of the S-genes, and the mode of action of their products, therefore, provides a model system for the study of gene expression and cellular recognition in flowering plants.
There is currently considerable interest in the elucidation of the molecular basis of SI and much work has been carried out in an attempt to identify the molecules involved in this interaction, especially those on the female side. S-linked glycoproteins from styles and stigmas, and the genes that encode them, have been identified and cloned. Less progress has been made with the pollen component. We aim to look at what is currently known about SI, with a view to examining what is known about the mechanism of this response.
What is known about the pistil and pollen components?
Identification and characterisation of stigmatic S-linked glycoproteins
There have been a number of studies carried out on proteins which have been isolated from stigmatic/stylar tissues.
Laboratory apparatus and techniques are described for the rearing and insecticidal treatment of whitefly, Bemisia tabaci Gennadius, under simulated field conditions. Insects were reared on cotton plants inside large population cages and treated from an overhead sprayer. The effects of these treatments were assessed accurately, without interfering with insects or plants, by monitoring adult numbers with an endoscope over one or more generations. Examples of single-generation and multiple-generation tests with cypermethrin are described. The apparatus is suitable for testing strategies for delaying the selection of resistance (e.g. using insecticides applied singly, alternately, or in mixture, at various application rates and frequencies), for controlling populations already resistant to insecticides, and for integrated pest management using chemical and biological control agents together.
The effects of hogpotato interference on cotton and of the crop on the weed were measured under field conditions in four environments. Full-season interference from 105 ± 21 hogpotato plants/m2 reduced cotton plant height by 14 to 44%. Conversely, weed dry weight was reduced 54% through full-season interference from cotton. Lint yield reductions in cotton ranged from 31 to 98% following full-season weed interference. Interference during the first 7 weeks of crop growth reduced lint yield by approximately 40%; however, interference after 7 weeks of weed-free maintenance did not affect lint yield. Interference reduced boll size in 3 of 4 yr, lint percent in 2 of 4, and boll number in the only year it was measured. Cotton fiber length, uniformity index, and micronaire were reduced by full-season interference in 1 of 2 yr; however, fiber strength was not affected in either year. Significant use of soil water by hogpotato occurred at 120 cm and deeper in the soil while cotton used water primarily in the upper 75 cm.
Duration and density experiments were conducted in the field to measure horsenettle (Solanum carolinense L. # SOLCA) interference with Spanish and runner-type peanuts (Arachis hypogaea L. ‘Pronto’ and ‘Florunner′). Spanish peanut yield generally was higher with 6 to 8 weeks of weed-free maintenance. Horsenettle interference for 6 to 8 weeks did not decrease the yield of Spanish peanuts, and interference for 6 weeks did not decrease yields of runner peanuts. Weed-free maintenance for 2 or more weeks allowed increased runner peanut yield when compared to weedy plots. Linear regression predicted a 69 kg/ha Spanish peanut yield increase for each week of weed-free maintenance. Linear regression predicted a Spanish peanut yield reduction of 40 kg/ha for each week of weed interference in 1983, the only year in which the slopes of the regressions were statistically significant Curvilinear equations with the runner-type cultivar predicted an 81 kg/ha yield increase or 96 kg/ha decrease for each week of weed-free maintenance or weed interference, respectively. In 1 of 2 yr, Spanish peanut yield was reduced by horsenettle at a density of 32 plants/10 m of row.
Of the surface antigens identified by radio-iodination, two-dimensional gel analyses showed no similarities between those of Schistosoma haematobium and Schistosoma mansoni, thus providing a basis for the species specificity of these antigens described previously (Simpson, Knight, Hagan, Hodgson, Wilkins & Smithers (1985) Parasitology 90, 499–508). The surface antigens of S. haematobium were glycosylated and comprised an acidic polypeptide of Mr 17000 as well as a complex set of polypeptides of approximate pI 6–7, which resolved in the Mr range 20000–30000. At least one of the lower Mr forms of this complex is also present in the adult worm. Limited cross-reaction was observed with S. mansoni infection sera and this may be due to a shared carbohydrate epitope. In contrast, extensive cross-reaction was observed using sera from mice immunized with S. bovis. This pattern parallels the species-specificity of vaccine-induced immunity. Extensive cross-reaction was also observed within cell-free translation products of m-RNA from adult worms of S. haematobium and S. mansoni by use of heterologous human infection sera. The few antigens which were species-specific may represent surface antigens.
Acid-scarified hogpotato (Hoffmanseggia densiflora Benth. ex. Gray # HOFDE) seed incubated in distilled water germinated at least 94% when incubated at constant 15, 20, 30 C, and at alternate 20/30 C (20 C for 16 h and 30 C for 8 h) temperatures. Highest germination in buffered solutions occurred at pH 5.0 and 6.0 with reduced germination at lower and higher pH levels. Sodium chloride concentrations of 50 mM and greater reduced the germination rate. Percent germination after 9 days was reduced at NaCl concentrations of 100 mM and greater. Radicle lengths measured after 3 days were significantly reduced with increasing NaCl concentration. Twenty-day-old hogpotato seedlings having three true leaves were able to resprout after topgrowth removal. Regrowth occurred on 15% of the seedlings approximately 15 days after top removal.