To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Impetigo is common in remote Indigenous children of northern Australia, with the primary driver in this context being Streptococcus pyogenes [or group A Streptococcus (GAS)]. To reduce the high burden of impetigo, the transmission dynamics of GAS must be more clearly elucidated. We performed whole genome sequencing on 31 GAS isolates collected in a single community from children in 11 households with ⩾2 GAS-infected children. We aimed to determine whether transmission was occurring principally within households or across the community. The 31 isolates were represented by nine multilocus sequence types and isolates within each sequence type differed from one another by only 0–3 single nucleotide polymorphisms. There was evidence of extensive transmission both within households and across the community. Our findings suggest that strategies to reduce the burden of impetigo in this setting will need to extend beyond individual households, and incorporate multi-faceted, community-wide approaches.
Although the incidence of invasive group A streptococcal disease in northern Australia is very high, little is known of the regional epidemiology and molecular characteristics. We conducted a case series of Northern Territory residents reported between 2011 and 2013 with Streptococcus pyogenes isolates from a normally sterile site. Of the 128 reported episodes, the incidence was disproportionately high in the Indigenous population at 69·7/100 000 compared to 8·8/100 000 in the non-Indigenous population. Novel to the Northern Territory is the extremely high incidence in haemodialysis patients of 2205·9/100 000 population; and for whom targeted infection control measures could prevent transmission. The incidences in the tropical north and semi-arid Central Australian regions were similar. Case fatality was 8% (10/128) and streptococcal toxic shock syndrome occurred in 14 (11%) episodes. Molecular typing of 82 isolates identified 28 emm types, of which 63 (77%) were represented by four emm clusters. Typing confirmed transmission between infant twins. While the diverse range of emm types presents a challenge for effective coverage by vaccine formulations, the limited number of emm clusters raises optimism should cluster-specific cross-protection prove efficacious. Further studies are required to determine effectiveness of chemoprophylaxis for contacts and to inform public health response.
A triple hurdle model estimates cattle farmer willingness to adopt or expand prescribed grazing on pasture in the United States in response to a hypothetical incentive program. Interest in adoption/expansion is estimated first, then willingness to participate in the program, followed by intensity of participation measured as additional acres enrolled. The supply elasticity of enrolled acres with respect to the incentive is 0.13. Nonpecuniary factors inter alia farmer sentiment about stewardship, current farm management practices, farm location, and education are associated with farmer willingness to participate and with participation intensity.
Mentalizing deficits are a hallmark of the autism spectrum condition (ASC) and a potential endophenotype for atypical social cognition in ASC. Differences in performance and neural activation on the ‘Reading the Mind in the Eyes’ task (the Eyes task) have been identified in individuals with ASC in previous studies.
Performance on the Eyes task along with the associated neural activation was examined in adolescents with ASC (n = 50), their unaffected siblings (n = 40) and typically developing controls (n = 40). Based on prior literature that males and females with ASC display different cognitive and associated neural characteristics, analyses were stratified by sex. Three strategies were applied to test for endophenotypes at the level of neural activation: (1) identifying and locating conjunctions of ASC–control and sibling–control differences; (2) examining whether the sibling group is comparable to the ASC or intermediate between the ASC and control groups; and (3) examining spatial overlaps between ASC–control and sibling–control differences across multiple thresholds.
Impaired behavioural performance on the Eyes task was observed in males with ASC compared to controls, but only at trend level in females; and no difference in performance was identified between sibling and same-sex control groups in both sexes. Neural activation showed a substantial endophenotype effect in the female groups but this was only modest in the male groups.
Behavioural impairment on complex emotion recognition associated with mental state attribution is a phenotypic, rather than an endophenotypic, marker of ASC. However, the neural response during the Eyes task is a potential endophenotypic marker for ASC, particularly in females.
Previous studies have suggested that motivational aspects of executive functioning, which may be disrupted in schizophrenia patients with negative symptoms, are mediated in part by the striatum. Negative symptoms have been linked to impaired recruitment of both the striatum and the dorsolateral prefrontal cortex (DLPFC). Here we tested the hypothesis that negative symptoms are associated primarily with striatal dysfunction, using functional magnetic resonance imaging (fMRI).
Working-memory load-dependent activation and gray matter volumes of the striatum and DLPFC were measured using a region-of-interest (ROI) approach, in 147 schizophrenia patients and 160 healthy controls. In addition to testing for a linear relationships between striatal function and negative symptoms, we chose a second, categorical analytic strategy in which we compared three demographically and behaviorally matched subgroups: patients with a high burden of negative symptoms, patients with minimal negative symptoms, and healthy subjects.
There were no differences in striatal response magnitudes between schizophrenia patients and healthy controls, but right DLPFC activity was higher in patients than in controls. Negative symptoms were inversely associated with striatal, but not DLPFC, activity. In addition, patients with a high burden of negative symptoms exhibited significantly lower bilateral striatal, but not DLPFC, activation than schizophrenia patients with minimal negative symptoms. Working memory performance, antipsychotic exposure and changes in gray matter volumes did not account for these differences.
These data provide further evidence for a robust association between negative symptoms and diminished striatal activity. Future work will determine whether low striatal activity in schizophrenia patients could serve as a reliable biomarker for negative symptoms.
We have grown a series of Ge and graded Si1-xGex epilayers on (100)Si substrates by MBE under different conditions. The quality of the layers has been characterized by cross-sectional TEM, Rutherford backscattering/ channeling and x-ray diffraction. This work addresses the optimization of growth temperature, (300–700°C) an evaluation of compositional grading, the effect of the incorporation of strained layer superlattice dislocation filters and post growth anneal cycles. Particular attention has been paid to grading GexSi1-x, x = 0 to 1 and the growth morphology of intermediate alloy epilayers.
The increased prevalence of diabetes in schizophrenia is partly
attributed to antipsychotic treatment, in particular second-generation
antipsychotics, but the evidence has not been systematically
Systematic review and meta-analysis comparing diabetes risk for different
antipsychotics in people with schizophrenia.
We searched MEDLINE, PsycINFO, EMBASE, International Pharmaceutical
Abstracts, CINAHL and Web of Knowledge until September 2006. Studies were
eligible for inclusion if the design was cross-sectional, case-control,
cohort or a controlled trial in individuals with schizophrenia or related
psychotic disorders, where second-generation antipsychotics (defined as
clozapine, olanzapine, risperidone and quetiapine) were compared with
first-generation antipsychotics and diabetes was an outcome. Data were
pooled using random effects inverse variance weighted meta-analysis.
Of the studies that met the inclusion criteria (n=14), 11 had sufficient
data to include in the meta-analysis. Four of these were retrospective
cohort studies. The relative risk of diabetes in patients with
schizophrenia prescribed one of the second-generation v.
first-generation antipsychotics was 1.32 (95% CI 1.15-1.51). There were
insufficient data to include aripiprazole, ziprasidone and amisulpride in
There is tentative evidence that the second-generation antipsychotics
included in this study are associated with a small increased risk for
diabetes compared with firstgeneration antipsychotics in people with
schizophrenia. Methodological limitations were found in most studies,
leading to heterogeneity and difficulty interpreting data. Regardless of
type of antipsychotic, screening for diabetes in all people with
schizophrenia should be routine.
We have identified and partially sequenced 8 ABC transporters from an EST dataset of Sarcoptes scabiei var. hominis, the causative agent of scabies. Analysis confirmed that most of the known ABC subfamilies are represented in the EST dataset including several members of the multidrug resistance protein subfamily (ABC-C). Although P-glycoprotein (ABC-B) sequences were not found in the EST dataset, a partial P-glycoprotein sequence was subsequently obtained using a degenerate PCR strategy and library screening. Thus a total of 9 potential S. scabiei ABC transporters representing the subfamilies A, B, C, E, F and H have been identified. Ivermectin is currently used in the treatment of hyper-infested (crusted) scabies, and has also been identified as a potentially effective acaricide for mass treatment programmes in scabies-endemic communities. The observation of clinical and in vitro ivermectin resistance in 2 crusted scabies patients who received multiple treatments has raised serious concerns regarding the sustainability of such programmes. One possible mechanism for ivermectin resistance is through ABC transporters such as P-glycoprotein. This work forms an important foundation for further studies to elucidate the potential role of ABC transporters in ivermectin resistance of S. scabiei.
W. V. Holt, Senior Research Fellow, Institute of Zoology Zoological Society of London, and heads the Reproductive Biology Group,
A. R. Pickard, Institute of Zoology, Zoological Society of London, Regent's Park, London NW RY, U.K.,
J. C. Rodger, Cooperative Research Centre for Conservation & Management of Marsupials, School of Biological & Chemical Sciences, University of Newcastle, Callaghan, NSW 2308, Australia,
D. E. Wildt, Conservation & Research Center, National Zoological Park, Smithsonian Institution, Front Royal, VA 22630 and Washington, DC 20008, U.S.A.
Anyone reading the contributions that together make up this book should be impressed by the web of interdisciplinary interactions that springs unbidden from the pages. Chapters about genetic aspects of small populations, whether involving animals in the wild or in zoos, introduce concepts that help us appreciate the need for strong management policies. Accounts of reintroduction programmes, where the genetic principles are applied in practice, succeed in highlighting the complexities of returning animals to nature while, in some cases, requiring other species to be controlled as pests or over-abundant populations. Assessing behaviour or reproductive hormone status without the need for intrusion provides crucial information about the reproductive status of wild populations, as well as helping curators to manage captive animals to high welfare standards. At the heart of this wonderful web of integrative science lies the high priority of always needing to understand the fundamental biology of the species in question.
As discussed by Wildt et al. in the first chapter, the discipline of reproduction is often perceived as ‘techno-based’, with little to offer to real conservation. This, combined with a natural suspicion in the conservation community of ‘quick-fixes’, has left the field with an image of limited utility (mostly for combating human infertility or accelerating livestock production) or, worse, occasional gee-whiz births published only in newspapers. One of our intentions in compiling this book was to rid the Earth of this impression forever.
Testicular and ovarian development in neonatal and juvenile harbour porpoises Phocoena phocoena was examined, using tissue from animals (males n = 65 and females n = 10) stranded or caught off the coast of England and Wales. Classification of the animals according to their stage of sexual development was undertaken using characteristics of gonadal morphology. Developmental correlates of the immature testis were increased incidence of prespermatogonia in seminiferous tubules, and the increasing proportion of testicular volume occupied by the seminiferous tubules. Using a low magnification (×200) assessment of testis sections, immature specimens could be grouped into three developmentally distinct classes, based on the relative amounts of interstitial and seminiferous tubule tissue and the frequency of prespermatogonia. Adult testes, showing either active spermatogenesis or seasonal quiescence, could be clearly distinguished from immature testes using histological criteria such as the presence of spermatocytes and spermatids. This classification system was used to determine relationships between testicular development and body size: males were classified as immature when they had body lengths < 135 cm and body weights < 30 kg; mature males always exceeded 140 cm in length and 40 kg in weight; and a transitional group, which was regarded as juvenile, had body lengths between 110 and 140 cm and body weights between 20 and 40 kg. Ovarian morphology was used to distinguish neonatal and juvenile females. Neonates displayed characteristic cords of naked ova which dispersed as development progressed. Neonatal animals had body lengths < 100 cm and body weights < 18 kg; within this group (n = 5) there were significant (P < 0.01) left-right asymmetries in the number of naked ova present, the left ovary containing nearly twice as many ova as the right. Although this difference was not apparent in females with body lengths > 100 cm and body weights between 19 and 30 kg (juveniles) it could be related to the almost total asymmetry of ovulation from the left ovary in this species (Harrison, Brownwell & Boice, 1972).
Antibodies to type II collagen have been reported by some authors to be raised in patients with Ménière's disease. In this study the antibody levels to type I and II collagen have been measured in 37 patients with Ménière's disease and 20 controls, using a solid-phase, double-antibody, enzyme-linked, immunoassay. No significant difference in antibody levels between the two groups was found. These findings do not support previously reported work which suggests that some cases of Ménière's disease are due to type II collagen autoimmunity.
The addition of simple aldehydes brought about large increases in the heat stability of both skim-milk and concentrated skim-milk over a comparatively wide milk–pH range. The coagulation time–pH minima of type A milks were completely removed by aldehyde treatment. Some sugars, which react readily as aldehydes on heating, were also shown to stabilize concentrated milk to prolonged heat treatment at 120 °C.
Email your librarian or administrator to recommend adding this to your organisation's collection.