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The current experiment was undertaken to investigate the effect of including white clover (Trifolium repens L.; WC) into perennial ryegrass (Lolium perenne L.; PRG) swards (PRG/WC) receiving 250 kg nitrogen (N) per hectare (ha) per year compared with PRG only swards receiving 250 kg N/ha/year, in an intensive grass-based spring calving dairy production scenario. Forty spring-calving cows were allocated to graze either a PRG/WC or PRG sward (n = 20) from 6 February to 31 October 2012. Fresh herbage was offered daily (17 kg dry matter (DM)/cow) supplemented with concentrate in times of herbage deficit (total supplementation 507 kg/cow). Pre-grazing herbage mass (HM), sward WC content and milk production were measured for the duration of the experiment. Herbage DM intake was estimated in May, July and September. Pre-grazing HM (±s.e.) was similar (1467 ± 173·1 kg DM/ha) for both treatments, as was cumulative herbage production (14 158 ± 769 kg DM/ha). Average WC content of the PRG/WC swards was 236 ± 30 g/kg DM. The PRG/WC cows had greater average daily milk yield and milk solids yield from June onwards. Cumulative milk yield and milk solids yield were greater for the PRG/WC cows compared with the PRG cows (5048 and 4789 ± 34·3 kg milk yield/cow, and 400 and 388 ± 1·87 kg milk solids/cow, respectively). Cows had similar DM intake in all measurements periods (15·1 ± 0·42 kg DM/cow/day). In conclusion, including WC in N-fertilized PRG swards increased milk production from cows grazing the PRG/WC swards compared with PRG, particularly in the second half of the lactation.
The evolutionary history of human malaria parasites (genus Plasmodium) has long been a subject of speculation and controversy. The complete genome sequences of the two most widespread human malaria parasites, P. falciparum and P. vivax, and of the monkey parasite P. knowlesi are now available, together with the draft genomes of the chimpanzee parasite P. reichenowi, three rodent parasites, P. yoelii yoelli, P. berghei and P. chabaudi chabaudi, and one avian parasite, P. gallinaceum.
We present here an analysis of 45 orthologous gene sequences across the eight species that resolves the relationships of major Plasmodium lineages, and provides the first comprehensive dating of the age of those groups.
Our analyses support the hypothesis that the last common ancestor of P. falciparum and the chimpanzee parasite P. reichenowi occurred around the time of the human-chimpanzee divergence. P. falciparum infections of African apes are most likely derived from humans and not the other way around. On the other hand, P. vivax, split from the monkey parasite P. knowlesi in the much more distant past, during the time that encompasses the separation of the Great Apes and Old World Monkeys.
The results support an ancient association between malaria parasites and their primate hosts, including humans.
The prevalance of subclinical Johne's disease was estimated in adult cattle slaughtered at three major abattoirs in south west England. A polymerase chain reaction (PCR) based on IS900 was used to detect Mycobacterium paratuberculosis in intestinal lymph nodes of 1553 cattle. Culture was also carried out on all PCR positive and inconclusive samples. The prevalence of subclinical disease in adult cattle was 3·5% (95% confidence intervals (CI) 2·6–4·7) by PCR and 2·6% (CI 1·8–3·6) by culture. The proportion of the disease in each month ranged from 1·6% (CI 0·2–5·5) in April to 4·6% (CI 2·8–6·9) in November, but the difference was not significant (P > 0·05). The proportion of PCR positive lymph nodes in each abattoir ranged from 2·8% (CI 1·6–4·6) to 4·9% (CI 2·9–7·6), this difference was not significant either (P > 0·05). The prevalence in young cattle was 2·0% (CI 0·6–4·5). The difference between age groups was not statistically significant (P > 0·05).
Amongst a collection of temperature sensitive (TS) mutants of Escherichia coli K-12, some have been found which can grow at the restrictive temperature (42 °C) if the osmotic pressure of the medium is raised by the addition of sodium chloride (1%) or sucrose (12·5%). These mutants are described as temperature sensitive osmotic remedial (TSOR) mutants. At the restrictive temperature they are not osmotically fragile, but do display decreased resistance to inhibitory agents such as deoxycholate, actino-mycin D and acridine orange; they also show release of the periplasmic enzyme ribonuclease. These results indicate a change in the cell's outer permeability barrier. The genes affected in six of the mutants have been located on the E. coli linkage map. The mutations, which occur at loci not previously described, have been named envM–envT to indicate their effect on the cell envelope.
The longevity of filarial nematodes is dependent on secreted immunomodulatory products. Previous investigation of one such product, ES-62, has suggested a critical role for post-translationally attached phosphorylcholine (PC) moieties. In order to further investigate this, ES-62 lacking PC was produced, using the Pichia pastoris recombinant gene expression system. Unlike parasite-derived ES-62, which is tetrameric the recombinant material was found to consist of a mixture of apparently stable tetramers, dimers and monomers. Nevertheless, the recombinant protein was considered to be an adequate PC-free ES-62 as it was recognized by existing antisera against the parasite-derived protein. However, subsequent to this, recognition of parasite-derived ES-62 by antibodies produced against the recombinant protein was found to be absent. In an attempt to explain this, recombinant ES-62 was subjected to structural analysis and was found to (i) contain 3 changes in amino acid composition; (ii) demonstrate significant alterations in glycosylation; (iii) show major differences in protein secondary structure. The effects of these alterations in relation to the observed change in immunogenicity were investigated and are discussed. The data presented clearly show that recognition by existing antibodies is insufficient proof that recombinant proteins can be used to mimic parasite-derived material in studies on nematode immunology and vaccination.
A major short coming of current research into personality is its failure to explore the relationship between theories of general personality and mental disorder.
To provide preliminary data to address this deficit.
In the first of two studies, we examined the relationship between the Neuroticism, Extraversion and Other – Five-Factor Inventory (NEO–FFI) and DSM personality disorders in a consecutive series of mentally disordered offenders. In the second, we sought to separate the personality dimension neuroticism from symptoms of depressive disorder in a sample of subjects with current depression.
Factors from the NEO–FFI were associated with different personality disorders in a predictable manner (first study). It was possible to identify a component of neuroticism (i.e. ‘worry’) that could be separated from depressive symptoms (second study).
Theories of general personality theory can enlighten and refine descriptions of abnormal mental states by informing both their aetiology and their prognosis.
The preweaning growth and carcass characteristics offour lamb genotypes were analysed for variation attributable to the intrauterine cohabitant (IUC) phenomenon, where within-sex variation is attributed to the sex of a twin's womb-mate. The four genotypes resulted from the following matings: Poll Dorset rams × Merino ewes, Poll Dorset rams × (Border Leicester × Merino) ewes, Texel rams × Merino ewes and Texel rams × (Border Leicester × Merino) ewes. Four hundred and twenty twin lambs participated in the preweaning study and of these, 209 were slaughtered to generate carcass data. Some of these genotypes displayed within-sex variation in weaning weight and fat score, preweaning average daily gain, skin-fold thickness, carcass fatness and eye muscle dimensions attributable to the IUC phenomenon. Genotypic differences in the responses of lambs to the IUC phenomenon were also observed. The IUC phenomenon appears to involve prenatal programming, an hypothesis that attributes postnatal characteristics to events during differentiation. The IUC phenomenon is analogous to the intrauterine position phenomenon in fecund mammals, where variations in prenatal steroid concentrations programme for permanent alterations in postnatal reproductive characteristics. The growth responses reported in this paper provide evidence of variation due to prenatal programming. While the magnitude of the responses to the IUC phenomenon were not large, the data presented indicate that under field conditions, the magnitude of growth responses to the IUC phenomenon may be as great as those observed between breeds. If so, further examination of the role that an animal's IUC may have on its subsequent performance could aid the development of more sensitive indices for breed evaluation and progeny selection.
Previous in vivo studies of schizophrenia with dopamine D2 receptor radioligands have yielded contradictory results. No prior study has used multiple scans to examine within-subject clinical change.
Twenty-one patients were studied with -iodobenzamide single photon emission computed tomography about two weeks after neuroleptic withdrawal. Thirteen of the 21 completed a second scan about four weeks after neuroleptic withdrawal. Sixteen controls were scanned for comparison.
There was no significant difference between groups in -iodobenzamide uptake at either scanning session. No significant correlations with demographic variables (age, illness duration, drug-free period), or clinical ratings (positive and negative symptoms, movement disorder) were observed at either scanning session. There was a significant correlation between change in -iodobenzamide uptake and change in negative symptom ratings for the subjects who underwent two scans (r=0.72, P < 0.05)
Worsening of negative symptoms may be associated with increased availability of striatal D2 receptors, perhaps because of decreased concentrations of endogenous dopamine.