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Conventional selected area diffraction patterns as obtained in the TEM present difficulties for identification of materials such as asbestifonn minerals, although diffraction data is considered to be one of the preferred methods for making this identification. The preferred orientation of the fibers in each field of measurement, and the spotty patterns that are obtained, do not readily lend themselves to measurement of the integrated intensity values for each dspacing, and even the d-spacings may be hard to determine precisely because the true center location for the broken rings requires estimation. To overcome these problems, we have implemented an automatic method for diffraction pattern measurement. It automatically locates the center of patterns with high precision, measures the radius of each ring of spots in the pattern, and integrates the density of spots in that ring.
The aim of this study was to examine the metabolic response to feed deprivation up to 48 h in low and high yielding lamb genotypes. It was hypothesised that Terminal sired lambs would have decreased plasma glucose and increased plasma non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHOB) concentrations in response to feed deprivation compared to Merino sired lambs. In addition, it was hypothesised that the metabolic changes due to feed deprivation would also be greater in progeny of sires with breeding values for greater growth, muscling and leanness. Eighty nine lambs (45 ewes, 44 wethers) from Merino dams with Merino or Terminal sires with a range in Australian Sheep Breeding Values (ASBVs) for post-weaning weight (PWT), post-weaning eye muscle depth and post-weaning fat depth (PFAT) were used in this experiment. Blood samples were collected via jugular cannulas every 6 h from time 0 to 48 h of feed deprivation for the determination of plasma glucose, NEFA, BHOB and lactate concentration. From 12 to 48 h of feed deprivation plasma glucose concentration decreased (P < 0.05) by 25% from 4.04 ± 0.032 mmol/l to 3.04 ± 0.032 mmol/l. From 6 h NEFA concentration increased (P < 0.05) from 0.15 ± 0.021 mmol/l by almost 10-fold to 1.34 ± 0.021 mmol/l at 48 h of feed deprivation. Feed deprivation also influenced BHOB concentrations and from 12 to 48 h it increased (P < 0.05) from 0.15 ± 0.010 mmol/l to 0.52 ± 0.010 mmol/l. Merino sired lambs had a 8% greater reduction in glucose and 29% and 10% higher NEFA and BHOB response, respectively, compared to Terminal sired lambs (P < 0.05). In Merino sired lambs, increasing PWT was also associated with an increase in glucose and decline in NEFA and BHOB concentration (P < 0.05). In Terminal sired lambs, increasing PFAT was associated with an increase in glucose and decline in NEFA concentration (P < 0.05). Contrary to the hypothesis, Merino sired lambs showed the greatest metabolic response to fasting especially in regards to fat metabolism.
Under current Australian industry pre-slaughter guidelines, lambs may be off feed for up to 48 h before slaughter. The purpose of this study was to examine what proportion of circulating metabolites at slaughter are due to stress and feed deprivation and if this response differs between Merino and Terminal genotypes. In addition the effect of feed deprivation on carcass weight and meat quality was examined. Jugular blood samples were collected from 88 Merino and Terminal sired lambs at rest and at slaughter following 24, 36 and 48 h of feed deprivation and plasma analysed for glucose, lactate, non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHOB). From the same carcasses hot carcass weight (HCWT) were measured as well as a suite of meat quality traits measured such as M. longissimus lumborum (loin) and M. semitendinosus pH at 24 h postmortem. Loin samples were also analysed for intramuscular fat content and Warner–Bratzer Shear Force. Merino sired lambs had a higher NEFA response compared to Terminal sired lambs at slaughter after 24, 36 and 48 h of feed deprivation, with NEFA levels up to 35% higher than previously reported in the same animals at rest in animal house conditions, whereas BHOB response to feed deprivation was not affected by sire type (P>0.05) and similar to previously reported at rest. In addition to the metabolic effects, increasing feed deprivation from 36 h was associated with a 3% reduction in HCWT and dressing percentage as well as causing increased ultimate pH in the M. semitendinosus in Merino sired lambs. Findings from this study demonstrate that Merino and Terminal sired lambs differ in their metabolic response to feed deprivation under commercial slaughter conditions. In addition, commercial feed deprivation appears to have a negative effect on ultimate pH and carcass weight and warrants further investigation.
Paranoia is one of the commonest symptoms of psychosis but has rarely been studied in a population at risk of developing psychosis. Based on existing theoretical models, including the proposed distinction between ‘poor me’ and ‘bad me’ paranoia, we aimed to test specific predictions about associations between negative cognition, metacognitive beliefs and negative emotions and paranoid ideation and the belief that persecution is deserved (deservedness).
We used data from 117 participants from the Early Detection and Intervention Evaluation for people at risk of psychosis (EDIE-2) trial of cognitive–behaviour therapy, comparing them with samples of psychiatric in-patients and healthy students from a previous study. Multi-level modelling was utilized to examine predictors of both paranoia and deservedness, with post-hoc planned comparisons conducted to test whether person-level predictor variables were associated differentially with paranoia or with deservedness.
Our sample of at-risk mental state participants was not as paranoid, but reported higher levels of ‘bad-me’ deservedness, compared with psychiatric in-patients. We found several predictors of paranoia and deservedness. Negative beliefs about self were related to deservedness but not paranoia, whereas negative beliefs about others were positively related to paranoia but negatively with deservedness. Both depression and negative metacognitive beliefs about paranoid thinking were specifically related to paranoia but not deservedness.
This study provides evidence for the role of negative cognition, metacognition and negative affect in the development of paranoid beliefs, which has implications for psychological interventions and our understanding of psychosis.
The high rate of depression among children of depressed mothers is well known. Suggestions that improvement in maternal acute depression has a positive effect on the child have emerged. However, data on the mechanisms of change have been sparse. The aim was to understand how remission and relapse in the mother might explain the changes in the child's outcome.
Participants were 76 depressed mothers who entered into a medication clinical trial for depression and 135 of their eligible offspring ages 7–17 years. The mothers and children were assessed at baseline and periodically over 9 months by independent teams to understand the relationship between changes in children's symptoms and functioning and maternal remission or relapse. The main outcome measures were, for mothers, the Hamilton Depression Rating Scale (HAMD), the Social Adjustment Scale (SAS) and the Parental Bonding Instrument (PBI) and, for children, the Children's Depression Inventory (CDI), the Columbia Impairment Scale (CIS), the Multidimensional Anxiety Scale for Children (MASC) and the Children's Global Assessment Scale (CGAS).
Maternal remission was associated with a decrease in the child's depressive symptoms. The mother's subsequent relapse was associated with an increase in the child's symptoms over 9 months. The effect of maternal remission on the child's improvement was partially explained by an improvement in the mother's parenting, particularly the change in the mother's ability to listen and talk to her child, but also reflected in her improvement in parental bonding. These findings could not be explained by the child's treatment.
A depressed mother's remission is associated with her improvement in parenting and a decrease in her child's symptoms. Her relapse is associated with an increase in her child's symptoms.
The river Tay receives water from an area covering over 2500 square miles of Scotland and has a discharge which is greater than that of the Severn and the Thames combined. It is, in addition, the least polluted of our major British rivers today. It thus provides a composite sample of the waters draining through much of east central Scotland, it provides a baseline for studies on other major British rivers, and with the impending upsurge in industrial activity along the Scottish east coast with the discovery of oil and gas in the North Sea, the importance of having a baseline against which future environmental changes can be measured is now a matter of urgency.
A wide variety of plant-microbe nitrogen-fixing symbioses which include cyanobacteria as the nitrogenfixing partner exist. While some information has been gathered on the biochemical changes in the cyanobacterium upon entering into symbiosis, very little is known about the accompanying changes at the genetic level. Much of our present knowledge of the organisation and control of expression of nitrogenfixation (nif) genes is derived from studies of the free-living diazotroph Klebsiella pneumoniae. This organism thus provides a model system and source of experimental material for the genetic analysis of symbiotic nitrogen fixation. We describe the use of cloned K. pneumoniae genes for nitrogen fixation and its regulation in the genetic analysis' of nitrogen fixation in cyanobacteria which can enter into symbiosis with plants. These studies reveal some dissimilarities in the organisation of nif genes and raise questions as to the genetic control of nitrogen fixation in symbiosis.
When comparing large numbers of TEM micrographs of insoluble additives in polymer-based nanocomposite systems, the ability to determine or estimate the dispersion quality (i.e. uniformity of size and/or spatial distribution) is often difficult. The objective of this study was to develop a method to quantify dispersions observed in TEM micrographs that enables both a numerical “ranking” to be assigned to individual dispersions as well as tabulation a multitude of images acquired over time. Several methods were reviewed and applied to a set of TEM dispersion images of an insoluble additive in polystyrene. Projected area diameter, particle area, and Euclidean distance between particle centroids were chosen from all the particle size distribution and spatial distribution parameters present in the literature, but none successfully yielded a quantitative indicator of dispersion quality for the micrographs. In contrast, generating cumulative volume percent curves for each sample appeared to be a preferred method of quantifying and comparing dispersions in TEM micrographs. The volume diameter values obtained by this method can be used for “ranking” and tabulation of dispersion quality and account for both “good” additive dispersions (i.e. those with small domains of a narrow size range around 1 μm or less) and “bad” additive dispersions (i.e. those with non-uniform domains ranging in size by several microns or more). As a result, the numerical values generated by this method can be used to quantitatively determine correlations between the dispersion quality of nanoparticles in polymer-based nanocomposite materials and various macroscale physical and/or performance properties of such materials. This method’s precision was statistically determined to decrease with increasing particle size and be heavily dependent on representative sampling.
Toxic anterior segment syndrome (TASS), a complication of cataract surgery, is a sterile inflammation of the anterior chamber of the eye. An outbreak of TASS was recognized at an outpatient surgical center and its affiliated hospital in December 2002.
Medical records of patients who underwent cataract surgery during the outbreak were reviewed, and surgical team members who participated in the operations were interviewed. Potential causes of TASS were identified and eliminated. Feedwater from autoclave steam generators and steam condensates were analyzed by use of spectroscopy and ion chromatography.
During the outbreak, 8 (38%) of 21 cataract operations were complicated by TASS, compared with 2 (0.07%) of 2,713 operations performed from January 1996 through November 2002. Results of an initial investigation suggested that cataract surgical equipment may have been contaminated by suboptimal equipment reprocessing or as a result of personnel changes. The frequency of TASS decreased (1 of 44 cataract operations) after reassignment of personnel and revision of equipment reprocessing procedures. Further investigation identified the presence of impurities (eg, sulfates, copper, zinc, nickel, and silica) in autoclave steam moisture, which was attributed to improper maintenance of the autoclave steam generator in the outpatient surgical center. When impurities in autoclave steam moisture were eliminated, no cases of TASS were observed after more than 1,000 cataract operations.
Suboptimal reprocessing of cataract surgical equipment may evolve over time in busy, multidisciplinary surgical centers. Clinically significant contamination of surgical equipment may result from inappropriate maintenance of steam sterilization systems. Standardization of protocols for reprocessing of cataract surgical equipment may prevent outbreaks of TASS and may be of assistance during outbreak investigations.
Cysteine proteinases have been implicated in the protection conferred by vaccination with detergent-soluble extracts of
Haemonchus contortus. In the present study, antisera from sheep refractory to Haemonchus challenge following vaccination
with a ‘proteinase-enriched’ Haemonchus gut membrane extract, were employed to screen a cDNA expression library of
the adult parasite. This resulted in the isolation of 3 cDNAs (designated hmcp1, 4 and 6) encoding cathepsin B-like
cysteine proteinases. Immunocytochemical studies specifically localized the products of these genes to the microvillar
surface of the parasite's gut and RT–PCR experiments revealed that these were developmentally regulated, being expressed
exclusively during the blood-feeding parasitic stages. In addition, a generic PCR approach was adopted in order to identify
the predominant cysteine proteinases in a UK strain of Haemonchus. A panel of 5 cDNAs, including hmcp1 and 4, was
amplified in this way. Genomic Southern blot analysis indicated that some of these enzymes were encoded by single-copy
genes, whereas others were encoded by multi-copy genes. Subsequent sequence analysis revealed that the proteases
identified in this study were distinct from those previously reported in USA strains of the parasite.
Vaccination of lambs with the membrane-bound (S3) thiol-Sepharose
binding protein (TSBP) fraction derived from the
gut of Haemonchus contortus confers significant protection against
homologous challenge. The S3 TSBP peptide profile
is dominated by a major protein of ca. 60 kDa which is strongly
recognized by antisera from sheep demonstrably protected
following immunization with S3 TSBP. In an attempt to identify this protein,
sera from protected lambs were employed
to screen a λgt11 cDNA library of the adult parasite and resulted
in the isolation of numerous clones encoding a homologue
of the mitochondrial enzyme, glutamate dehydrogenase (GDH). GDH enzyme
activity was readily demonstrable in
S3 TSBP material and immunolocalization studies showed that the enzyme
was localized to the cytoplasm of the parasite's
gut. Furthermore, the enzyme appeared to be developmentally regulated,
with both GDH mRNA and protein expressed
almost exclusively during the blood-feeding parasitic stages.
The swelling behaviour and hydraulic conductivity of Na-bentonite powder and bentonite-sand mixtures (10 and 20% of bentonite by dry weight) have been measured with distilled water and various salt solutions (0.01, 0.1 and 1 mol/l concentrations), It was found that in dilute solutions, the bentonite in mixtures subjected to small confining stresses swells sufficiently to separate the sand particles and reach a clay void ratio similar to that achieved by bentonite alone. At high stresses, or in strong solutions, the bentonite in a mixture has insufficient swelling capacity to force the sand particles apart and swelling is limited by the sand pore volume. The hydraulic conductivity of a mixture depends on the bentonite void ratio, and the porosity and tortuosity of the sand matrix. A design model is proposed to predict the engineering properties of a mixture over a range of confining stresses from the properties of its constituents and the permeant.
Thirty schizophrenic patients (20 medicated, 10 off medication) were compared with 30 normal controls subjects matched for age, sex, handedness and intelligence. During the performance of a frontal activation task, normal subjects showed increased interhemispheric coherence between anterior brain regions. Schizophrenic patients did not show the same amount of bilateral anterior activation. During the performance of right hemisphere cognitive activation tasks, normal subjects and medicated schizophrenic patients showed significantly reduced bilateral interhemispheric coherence patterns, while the drug-free schizophrenic patients showed a trend towards this same pattern. It is suggested that these findings provide additional evidence for an aberrant functional organization of the brain in schizophrenia.
The prevalence of anxiety disorders in 294 patients who survived to four months in the Perth Community Stroke Study (Perth, Australia), and a follow-up of these patients at 12 months, are presented.
Diagnoses are described both in the usual DSM hierarchic format and by a non-hierarchic approach. Adoption of the hierarchic approach alone greatly underestimates the prevalence of anxiety disorders.
Most cases were of agoraphobia, and the remainder were generalised anxiety disorder. The prevalence of anxiety disorders alone was 5% in men and 19% in women; in community controls, it was 5% in men and 8% in women. Adopting a non-hierarchic approach to diagnosis gave a prevalence of 12% in men and 28% in women. When those who showed evidence of anxiety disorder before stroke were subtracted, the latter prevalence was 9% in men and 20% in women.
One-third of the men and half of the women with post-stroke anxiety disorders showed evidence of either depression or an anxiety disorder at the time of the stroke. At 12 month follow-up of 49 patients with agoraphobia by a non-hierarchic approach, 51 % had recovered, and equal proportions of the remainder had died or still had agoraphobia. The only major difference in outcome between those with anxiety disorder alone and those with comorbid depression was the greater mortality in the latter.
The Perth Community Stroke Study (PCSS) was a population-based study of the incidence, cause, and outcome of acute stroke.
Subjects from the study were assessed initially, by examination and interview, and at four- and 12-month follow-ups to determine differences in prevalence of depression between the sexes and between patients with first-ever and recurrent strokes.
The prevalence of depressive illness four months after stroke in 294 patients from the PCSS was 23% (18–28%), 15% (11–19%) major depression and 8% (5–11 %) minor depression. There were no significant differences between the sexes or between patients with first-ever and recurrent strokes. With a non-hierarchic approach to diagnosis of those with depression, 26% of men and 39% of women had an associated anxiety disorder, mainly agoraphobia. Nine per cent of male and 13% of female patients interviewed had evidence of depression at the time of the stroke. Twelve months after stroke 56% of the men were still depressed (40% major and 16% minor), as were 30% of the women (12% major and 18% minor).
The prevalence of depression after stroke was comparable with that reported from other studies, and considerably less than that reported from in-patient and rehabilitation units.