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Impaired working memory is a core feature of schizophrenia and is linked with altered engagement the lateral prefrontal cortex. Although altered PFC activation has been reported in people with increased risk of psychosis, at present it is not clear if this neurofunctional alteration differs between familial and clinical risk states and/or increases in line with the level of psychosis risk. We addressed this issue by using functional MRI and a working memory paradigm to study familial and clinical high-risk groups. We recruited 17 subjects at ultra-high-risk (UHR) for psychosis, 10 non-affected siblings of patients with schizophrenia (familial high risk [FHR]) and 15 healthy controls. Subjects were scanned while performing the N-back working memory task. There was a relationship between the level of task-related deactivation in the medial PFC and precuneus and the level of psychosis risk, with deactivation weakest in the UHR group, greatest in healthy controls, and at an intermediate level in the FHR group. In the high-risk groups, activation in the precuneus was associated with the level of negative symptoms. These data suggest that increased vulnerability to psychosis is associated with a failure to deactivate in the medial PFC and precuneus during a working memory task, and appears to be most evident in subjects at clinical, as opposed to familial high risk.
Basic Self disturbances (BSD), including changes of the 'pre-reflexive' sense of self and the loss first-person perspective, are characteristic of the schizophrenic spectrum disorders and highly prevalent in subjects at 'ultra high risk' for psychosis (UHR). The current literature indicates that cortical midline structures (CMS) may be implicated in the neurobiological substrates of the 'basic self' in healthy controls.
Neuroanatomical investigation of BSD in a UHR sample
To test the hypotheses :(i) UHR subjects have higher 'Examination of Anomalous Self Experience, EASE' scores as compared to controls, (ii) UHR subjects have neuroanatomical alterations as compared to controls in CMS, (iii) within UHR subjects, EASE scores are directly related to structural CMS alterations.
32 HR subjects (27 antipsychotics-naïve) and 17 healthy controls (HC) were assessed with the 57-items semi-structured EASE interview. Voxel-Based Morphometry (VBM) was conducted in the same subjects, with a-priori Region of Interests (ROIs) defined in the CMS (anterior/posterior cingulate and medial-prefrontal cortex).
Despite high variability in the HR group, the overall EASE score was higher (t-test >0.01, Cohen's d =2.91) in HR (mean=30.15, SD=16.46) as compared to HC group (mean=1.79, SD=2.83). UHR subjects had gray matter reduction in CMS as compared to HC (p>0.05 FWE-corrected). Across the whole sample, lower gray matter volume in the anterior cingulate was correlated with higher EASE scores (p>0.05).
This study provides preliminary evidence that gray matter reductions in the CMS are correlated with BSD in UHR people.
This study evaluated a school-based intervention to enhance adolescent peer relationships and improve functional outcomes, building upon Ed Zigler’s seminal contribution in recognizing the potential of academic contexts to enhance social and emotional development. Adolescents (N = 610) primarily from economically or racially/ethnically marginalized groups were assessed preintervention, postintervention, and at 4-month follow-up in a randomized controlled trial. At program completion, intervention participants reported significantly increased quality of peer relationships; by 4-month follow-up, this increased quality was also observable by peers outside of the program, and program participants also displayed higher levels of academic engagement and lower levels of depressive symptoms. These latter effects appear to have potentially been mediated via participants’ increased use of social support. The potential of the Connection Project intervention specifically, and of broader efforts to activate adolescent peer relationships as potent sources of social support and growth more generally within the secondary school context, is discussed.
Homeless and precariously housed individuals experience a high burden of comorbid illnesses, and excess mortality. Cross-sectional studies report a high rate of cognitive impairment. Long-term trajectories have not been well investigated in this group.
To longitudinally assess risks for premature and/or accelerated cognitive ageing, and the relationship with early mortality in homeless and precariously housed people.
This is a 9-year community-based study of 375 homeless and precariously housed individuals from Vancouver, Canada. Annual cognitive testing assessed verbal learning and memory, and inhibitory control. Linear mixed-effects models examined associations between clinical risk factors (traumatic brain injury, psychotic disorders, viral exposure, alcohol dependence) and cognitive change over 9 years. Cox regression models examined the association between cognition and mortality.
Traumatic brain injury and alcohol dependence were associated with decline in verbal memory. Inhibitory control declined, independent of risk factors and to a greater extent in those who died during the study. Better inhibitory control was associated with a 6.6% lower risk of mortality at study entry, with a 0.3% greater effect for each year of life. For each one-point increase in the Charlson Comorbidity Index score at study entry, the risk of mortality was 9.9% higher, and was consistent across age. Adjusting for comorbidities, inhibitory control remained a significant predictor of mortality.
Findings raise the possibility of a premature onset, and accelerated trajectory, of cognitive ageing in this group of homeless and precariously housed people. Traumatic brain injury, alcohol dependence and cognition could be treatment priorities.
Novel tools for early diagnosis and monitoring of schistosomiasis are urgently needed. This study aimed to validate parasite-derived miRNAs as potential novel biomarkers for the detection of human Schistosoma japonicum infection. A total of 21 miRNAs were initially validated by real-time-polymerase chain reaction (RT-PCR) using serum samples of S. japonicum-infected BALB/c mice. Of these, 6 miRNAs were further validated with a human cohort of individuals from a schistosomiasis-endemic area of the Philippines. RT-PCR analysis showed that two parasite-derived miRNAs (sja-miR-2b-5p and sja-miR-2c-5p) could detect infected individuals with low infection intensity with moderate sensitivity/specificity values of 66%/68% and 55%/80%, respectively. Analysis of the combined data for the two parasite miRNAs revealed a specificity of 77.4% and a sensitivity of 60.0% with an area under the curve (AUC) value of 0.6906 (P = 0.0069); however, a duplex RT-PCR targeting both sja-miR-2b-5p and sja-miR-2c-5p did not result in an increased diagnostic performance compared with the singleplex assays. Furthermore, the serum level of sja-miR-2c-5p correlated significantly with faecal egg counts, whereas the other five miRNAs did not. Targeting S. japonicum-derived miRNAs in serum resulted in a moderate diagnostic performance when applied to a low schistosome infection intensity setting.
Additional crystallographic data are given for the recently reported mineral middlebackite, which has been described for discoveries at Iron Knob in South Australia and Passo di San Lugano near Trento, Italy. The material examined in the present study was from a third finding of the mineral, viz. from a quartz outcrop at Mooloo Downs Station in Western Australia within which it was co-located with the chemically- and structurally-related mineral moolooite, CuIIC2O4·nH2O, reported by Clarke and Williams (1986). In this study, the crystal structure was elucidated independently of the other studies using a combination of the a priori charge flipping and simulated annealing methods with synchrotron radiation diffraction (SRD) powder data. The principal crystal data for the Mooloo Downs material are: space group P21/c with lattice parameters a = 7.2659(18) Å, b = 5.7460(11) Å, c = 5.6806(11) Å, β = 104.588(3)°; Vc = 229.46(18) Å3; empirical formula CuII2C2O4(OH)2 with 2 formula units per unit cell; and calculated density = 3.605 g cm−3. The lattice parameters agree approximately with values given for the other studies, but not within the reported error estimates. The atom coordinates, interatomic distances, and angles for the Mooloo Downs material are compared with those from the other studies using single crystal data, with the values from all three studies agreeing approximately, but again not within the reported uncertainties. The crystal chemistry found for middlebackite received strong confirmation through the synthesis for the first time of di-copper oxalate di-hydroxide. Laboratory X-ray diffraction powder data for the synthetic form of the mineral from this study agree closely with the SRD data for the natural mineral.
To determine the effectiveness and ease of use of an electronic reminder device in reducing urinary catheterization duration.
A randomized controlled trial with a cross-sectional anonymous online survey and focus group.
Ten wards in an Australian hospital.
All hospitalized patients with a urinary catheter.
An electronic reminder system, the CATH TAG, applied to urinary catheter bags to prompt removal of urinary catheters.
Catheterization duration and perceptions of nurses about the ease of use.
A Cox proportional hazards model was used to assess the rate of removal of catheters. A phenomenological approach underpinned data collection and analysis methods associated with the focus group.
In total, 1,167 patients with a urinary catheter were included. The mean durations in control and intervention phases were 5.51 days (95% confidence interval [CI], 4.9–6.2) and 5.08 days (95% CI, 4.6–5.6), respectively. For patients who had a CATH TAG applied, the hazard ratio (HR) was 1.02 (95% CI, 0.91–1.14; P = .75). A subgroup analysis excluded patients in an intensive care unit (ICU), and the use of the CATH TAG was associated with a 23% decrease in the mean, from 5.00 days (95% CI, 4.44–5.56) to 3.84 days (95% CI, 3.47–4.21). Overall, 82 nurses completed a survey and 5 nurses participated in a focus group. Responses regarding the device were largely positive, and benefits for patient care were identified.
The CATH TAG did not reduce the duration of catheterization, but potential benefits in patients outside the ICU were identified. Electronic reminders may be useful to aid prompt removal of urinary catheters in the non-ICU hospital setting.
It is unclear how individual differences in parenting and brain development interact to influence adolescent mental health outcomes. This study examined interactions between structural brain development and observed maternal parenting behavior in the prediction of adolescent depressive symptoms and psychological well-being. Whether findings supported diathesis-stress or differential susceptibility frameworks was tested. Participants completed observed interactions with their mothers during early adolescence (age 13), and the frequency of positive and aggressive maternal behavior were coded. Adolescents also completed structural magnetic resonance imaging scans at three time points: mean ages 13, 17, and 19. Regression models analyzed interactions between maternal behavior and longitudinal brain development in the prediction of late adolescent (age 19) outcomes. Indices designed to distinguish between diathesis-stress and differential susceptibility effects were employed. Results supported differential susceptibility: less thinning of frontal regions was associated with higher well-being in the context of low levels of aggressive maternal behavior, and lower well-being in the context of high levels of aggressive maternal behavior. Findings suggest that reduced frontal cortical thinning during adolescence may underlie increased sensitivity to maternal aggressive behavior for better and worse and highlight the importance of investigating biological vulnerability versus susceptibility.
Metacognition is the capacity to evaluate and control one’s own cognitive processes. Metacognition operates over a range of cognitive domains, such as perception and memory, but the neurocognitive architecture supporting this ability remains controversial. Is metacognition enabled by a common, domain-general resource that is recruited to evaluate performance on a variety of tasks? Or is metacognition reliant on domain-specific modules? This article reviews recent literature on the domain-generality of human metacognition, drawing on evidence from individual differences and neuroimaging. A meta-analysis of behavioral studies found that perceptual metacognitive ability was correlated across different sensory modalities, but found no correlation between metacognition of perception and memory. However, evidence for domain-generality from behavioral data may suffer from a lack of power to identify correlations across model parameters indexing metacognitive efficiency. Neuroimaging data provide a complementary perspective on the domain-generality of metacognition, revealing co-existence of neural signatures that are common and distinct across tasks. We suggest that such an architecture may be appropriate for “tagging” generic feelings of confidence with domain-specific information, in turn forming the basis for priors about self-ability and modulation of higher-order behavioral control.
The development of laser wakefield accelerators (LWFA) over the past several years has led to an interest in very compact sources of X-ray radiation – such as “table-top” free electron lasers. However, the use of conventional undulators using permanent magnets also implies system sizes which are large. In this work, we assess the possibilities for the use of novel mini-undulators in conjunction with a LWFA so that the dimensions of the undulator become comparable with the acceleration distances for LWFA experiments (i.e., centimeters). The use of a prototype undulator using laser machining of permanent magnets for this application is described and the emission characteristics and limitations of such a system are determined. Preliminary electron propagation and X-ray emission measurements are taken with a LWFA electron beam at the University of Michigan.