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The advancement of lead-free piezoelectric nanogenerators (PENGs) for flexible electronics necessitates designing more efficient systems for improved energy storage capacity. In this light, the effects of patterning BaTiO3 nanotubes within PENG on the electromechanical properties of the device were investigated. The PENGs comprised a sandwich structure of Ti–BaTiO3–graphite–Ti encapsulated in polydimethylsiloxane. Four patterns of vertically aligned BaTiO3 nanotubes were synthesized via the hydrothermal conversion of selectively-anodized TiO2 nanotubes. The highest output voltage reached up to 1.9 V. Decreasing the nanotube array spacing and pattern diameter increased the lateral displacement of BaTiO3 therefore, increasing the output voltage of the device.
An academic makerspace, home to tools and people dedicated to facilitating and inspiring a making culture, is characterized by openness, creativity, learning, design, and community. This nontraditional learning environment has found an immense increase in popularity and investment in the last decade. Further, makerspaces have been shown to be highly gendered, privileging men's and masculine understandings of making. The spike in popularity warrants deeper analysis, examining the value of these spaces for women and if learning is occurring in these spaces, specifically at higher education institutions. We implemented a phenomenologically based interviewing process to capture the making experiences of 20 women students, recruited through purposive and snowball sampling. By eliciting the narratives of women students, we captured how making, designing, and creating evolved through gendered experiences in the university makerspace. Each interview was transcribed and resulted in around 868 pages of single-spaced text transcriptions. The data were analyzed through multiple cycles of open and axial coding for common themes and patterns, where makerspaces create a culture of learning, facilitate students’ design journey, and form a laboratory for creativity. These themes forwarded the creation of a learning model that showcases how design and learning interact in the makerspace. This work demonstrates that women students are engaging learning and inspiration; developing confidence and resilience; and learning how to work with others and collaborate.
The paper presents the effects of Mexico’s conditioned cash-transfers programme (PROSPERA programme, formerly Oportunidades) on household poverty in the Northeast urban areas. The estimate was calculated using the Foster-Greer-Thorbecke Index. We use three poverty lines (i.e. food, capability, and patrimonial poverty) which costs were established by the National Assessment Council of the Social Development Policy. The results show that, in the three lines, the intensity and inequality of poverty diminished. Regarding incidence, only in extreme poverty was found a significant effect, so, there is no evidence to support that cash transfers help households to escape poverty.
Although cognitive subtypes have been suggested in schizophrenia patients, similar analyses have not been carried out in their unaffected siblings. Subtype classification may provide more insight into genetically driven variation in cognitive function.
To investigate cognitive subtypes in siblings.
Cluster analyses were performed in 654 unaffected siblings, on a cognitive battery that included tests of attention, intellectual function, and episodic memory. Resulting subtypes in the siblings were analyzed for cognitive, demographical, and clinical characteristics and compared with that of their proband.
Three sibling subtypes of cognitive function were distinguished: ‘normal’, ‘mixed’, and ‘impaired’. Normal profile siblings (n= 192) were unimpaired on cognitive tests, in contrast to their proband (n= 184). Mixed profile siblings (n= 228) and their probands (n= 222) had a more similar performance pattern. Impaired profile siblings had poorer functional outcomes (n= 234), and their profile was almost identical to that of their proband (n= 223). Probands with cognitively impaired siblings could be distinguished from other schizophrenia patients by their own cognitive performance. They also had poorer clinical characteristics, including achievement of symptomatic remission.
Unaffected siblings of patients with schizophrenia are heterogeneous with respect to cognitive function. The poorer the cognitive profile of the sibling, the higher the level of correspondence with the proband. The sibling's cognitive subtype was predictive for disease course in the proband. Distinguishing cognitive subtypes of unaffected siblings may be of relevance for genetic studies.
Suicide remains the leading cause of premature death in patients with psychotic disorders. The lifetime suicide risk for schizophrenia is approximately 10%.
This study aims to compare the suicide risk over the past decade following recent onset psychosis to findings from the eighties and nineties in the same catchment area and to identify predictors of suicide in the context of the Psychosis Recent Onset Groningen – Survey (PROGR-S).
A medical file search was carried out to determine the current status of all patients admitted between 2000 and 2009. The suicide rate was compared with a study executed in 1973-1988 in the same catchment area. Predictors of suicide were investigated using Cox regression.
The status of 424 of the 614 patients was known in July 2014. Suicide occurred in 2.4% of the patients with psychotic disorders (n=10; mean follow-up 5.6 years); 6 out of 10 suicides took place within two years. Within two decades, the suicide rate dropped from 11% (follow-up 15 years, 8.5% after 5 years) to 2.4%. The Standardized Mortality Rate (SMR) of suicides compared with the general population was 41.6. A higher age was the only significant predictor for suicide. Neuroticism, living situation, disorganized and negative symptoms, and passive coping style showed a trend for significance. A significant reduction in the suicide rate was found for people with psychosis over the past decades.
A considerable drop in suicide rate was found. Given the high SMR, suicide research should have the highest priority.
Although antipsychotics are widely prescribed, their effect of on improving poor illness insight in schizophrenia has seldom been investigated and therefore remains uncertain. This paper examines the effects of low dose haloperidol, amisulpride, olanzapine, quetiapine, and ziprasidone on insight in first-episode schizophrenia, schizoaffective disorder, or schizophreniform disorder.
The effects of five antipsychotic drugs in first episode psychosis on insight were compared in a large scale open randomized controlled trial conducted in fourteen European countries: the European First-Episode Schizophrenia Trial (EUFEST). Patients with at least minimal impairments in insight were included in the present study (n=455). Insight was assessed with item G12 of the Positive and Negative Syndrome Scale (PANSS), administered at baseline and at 1, 3, 6, 9, and 12 months after randomization.
The use of antipsychotics was associated with clear improvements in insight, independent of other symptoms. This effect was most pronounced in the first three months of treatment, with quetiapine being significantly less effective than other drugs.
Use of antipsychotics was associated with an improvement in insight, over and above their effects on other symptoms of schizophrenia. Effects of spontaneous improvement cannot be ruled out due to the lack of a placebo control group, although such a large spontaneous improvement seems unlikely. Notably, the improvement of insight was less pronounced for quetiapine compared to haloperidol, amisulpride, olanzapine, quetiapine, and ziprasidone.
Repetitive Transcranial Magnetic Stimulation (rTMS) of the frontal cortex has been shown to improve negative symptoms in schizophrenia in a number of small studies, although inconsistent results have also been reported. Neuroimaging has shown bilateral hypofrontality in schizophrenia, and rTMS may improve brain activation. We therefore aimed to investigate whether 10 Hz stimulation of the bilateral dorsolateral prefrontal cortex during 3 weeks would yield substantial treatment effects and would improvement of frontal activation.
This study concerned a multicenter double-blind randomized controlled trial in 32 patients with schizophrenia or schizoaffective disorder. All had moderate to severe negative symptoms (Positive and Negative Syndrome Scale (PANSS) negative subscale ≥ 15). Patients were randomized to a 3-week course of active or sham rTMS. Primary outcome was severity of negative symptoms as measured with the Scale for the Assessment of Negative Symptoms (SANS) and the PANSS negative symptom score. Twenty-four patients participated in the pre- and posttreatment fMRI measurement. Analyses concerned changes in brain activation as measured with functional magnetic resonance imaging (fMRI) during the Tower of London (ToL) task from pre-treatment to post-treatment.
Brain activation increased more in the active group in the right DLPFC and the right medial frontal gyrus as compared to the sham group. Different activation change was also found in the left posterior cingulate, with decreased activation in the active and increased activation in the sham group. The changes in brain activation were accompanied by a significant improvement of negative symptoms in the treatment group (p=0.04).
Our findings suggest that treatment with rTMS over the DLPFC may potentially increase task-related activation in frontal areas and improve negative symptoms in patients with schizophrenia.
To complete an up-to-date meta-analysis of studies investigating the correlation between insight and various measures of neurocognition in psychosis.
We completed a comprehensive literature search using Pubmed and ‘Web of Science’. After applying inclusion and exclusion criteria we isolated 34 papers published on this topic since 2004. This list was then added to those published prior to 2004 that had been found in an earlier meta-analysis performed by our group to give a complete collection of 69 papers. Metaanalysis of data was performed in the Comprehensive Meta-Analysis software using random effects models.
Overall our sample included 5127 patients with psychosis across 69 studies. We performed analyses for overall cognition, IQ, memory, executive function and specifically the Wisconsin Card Sorting Test (WCST). We found a small but highly significant correlation between insight and each measure of neurocognition in all patients with psychosis (mean weighted r = 0.13–0.16 across domains, p < 0.001). When restricted to those patients with diagnosis of schizophrenia (n = 1708) the strength of correlation in each domain increased slightly (mean weighted r = 0.14–0.18, p < 0.01). We found no evidence of significant publication bias.
In this comprehensive meta-analysis we found a small but robust correlation between insight and a variety of neurocognitive domains in patients with psychosis. We believe that this data supports the role of neurocognitive processes in some aspects of insight but believe that a more precise experimental approach is required to elucidate the exact mechanisms of this relationship.
Factor analyses of large datasets have established two dimensions of negative symptoms: expressive deficits and a motivation. This distinction is of relevance as the dimensions differ in their cognitive and clinical correlates (e.g. with regard to functional outcome). Using functional MRI, we examined the neural correlates of the two negative symptom dimensions with brain activation during social-emotional evaluation. Patients with schizophrenia (n = 38) and healthy controls (n = 20) performed the Wall of Faces task during fMRI, which measures emotional ambiguity in a social context by presenting an array of faces with varying degrees of consistency in emotional expressions. More specifically, appraisal of facial expressions under uncertainty. We found severity of expressive deficits to be negatively correlated with activation in thalamic, prefrontal, precentral, parietal and temporal brain areas during emotional ambiguity (appraisal of facial expressions in an equivocal versus an unequivocal condition). No association was found for a motivation with these neural correlates, in contrast to a previous fMRI study in which we found a motivation to be associated with neural correlates of executive (planning) performance. We also evaluated the effects of medication and neurostimulation (rTMS treatment over the lateral prefrontal cortex) on activation during the social–emotional ambiguity task. The medication comparison concerned an RCT of aripiprazole versus risperidone. Compared to risperidone, aripiprazole showed differential involvement of frontotemporal and frontostriatal circuits in social-emotional ambiguity. We conclude that deconstruction of negative symptoms into more homogeneous components and investigating underlying neurocognitive mechanisms can potentially shed more light on their nature and may ultimately yield clues for targeted treatment.
Early-onset first-episode psychosis (FEP) and high functioning autism spectrum disorders (ASD) are complex neuro–developmental disorders that share symptomatology but it is not clear if they also share neurobiological abnormalities (Chisholm et al., 2015). We examined thickness, surface area and volume in a direct comparison of children and adolescents with FEP (onset before 18 years), high-functioning ASD, and healthy subjects.
Magnetic resonance imaging scans of 85 participants (30 ASD, 29 FEP, 26 healthy controls, age range 10–18 years) were obtained from the same MR scanner using the same acquisition protocol. The FreeSurfer analysis suite was used to quantify vertex-wise estimates of the metrics thickness, surface area, and volume.
ASD and FEP had spatially overlapping insular deficits for each metric. The transdiagnostic overlap of deficits was greatest for volume (55% of all insular vertices) and smallest for thickness (18%). Insular thickness and surface area deficits did not overlap in ASD and overlapped only in 8% of all insular vertices in FEP.
Morphological insular deficits are common to FEP and high functioning ASD when compared to healthy participants. The pattern of deficits was similar in both disorders, i.e. a largely non-overlap of insular thickness and surface area. The non-overlap provides further evidence that these metrics represent two independent outcomes of corticogenesis, both of which are affected in FEP and ASD.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
Approximately 50% of patients with schizophrenia shows deficits in motivation and initiation of goal-directed behavior, which are suggestive of reward system dysfunction. We conducted a meta-analysis of neuroimaging studies reporting on the neural correlates of reward processing and negative symptoms in schizophrenia. A significant mean weighted correlation was observerd, revealing deficits in activation of reward neurocircuitry. A more specific findings is comprised activation of the ventral striatum, involved in anticipation of reward, and structures that play a critical role in the ability to represent the value of outcomes and plans. In a study of VTA connectivity in the resting state in a large group of patients with schizophrenia, we found reduced connectivity with lateral prefrontal, temporal and parietal regions to be associated with higher degrees of apathy. Apathy belongs to the most debilitating symptoms of schizophrenia and represents a significant unmet need in its treatment. Quantitative integration of published findings suggests that treatment with noninvasive magnetic brain stimulation can improve negative symptoms. Previous PET-studies have shown that such stimulation may target circuits with dopaminergic innervation. A behavioral treatment approach that may also target reward-related circuits will also be discussed briefly. It can be concluded that recent results regarding reward and motivated behavior in schizophrenia have clinical implications and may help develop novel treatment strategies.
Two factors of negative symptoms in schizophrenia have been consistently described based on factor analysis, “expressive deficits” and “social amotivation”. We aimed to investigate the putatively differential involvement of self-related networks, as measured with BOLD fMRI during a self-evaluation task, in two dimensions of negative symptoms in schizophrenia (reduced expression and social amotivation).
Forty-five patients with a diagnosis of schizophrenia participated in an fMRI study in which they performed a self-evaluation task. The task comprised a self-reflection, close other-reflection, and a semantic (baseline) condition. We compared correlates of Expressive versus Social amotivation factors (summed items from the PANSS interview) for the contrasts self-baseline and self-other. Significance threshold was set at P < 0.05 family-wise error (FEW) corrected.
Social amotivation correlated significantly with self-evaluation vs. baseline in right and left ACC, and in the sulcus of frontal lateral lobe between inferior frontal triangularis and middle frontal gyrus. This was also significant, but less pronounced, in the direct comparison of social amotivation vs. expressive deficits scores (for the self-baseline contrast). No activation differences survived critical thresholds for the self-other contrast.
Differential neural correlates for the two dimensions of negative symptoms support the validity of this distinction based on factor analyses. Intact functioning of brain circuitry for self-referential processing may be of relevance to actively seek social interaction.
Disclosure of interest
The author has not supplied his declaration of competing interest.
Little is known about changes in brain functioning after first-episode psychosis (FEP). Such knowledge is important for predicting the course of disease and adapting interventions. Functional magnetic resonance imaging has become a promising tool for exploring brain function at the time of symptom onset and at follow-up.
A systematic review of longitudinal fMRI studies with FEP patients according to PRISMA guidelines. Resting-state and task-activated studies were considered together.
Eleven studies were included. These reported on a total of 236 FEP patients were evaluated by two fMRI scans and clinical assessments. Five studies found hypoactivation at baseline in prefrontal cortex areas, two studies found hypoactivation in the amygdala and hippocampus, and three others found hypoactivation in the basal ganglia. Other hypoactivated areas were the anterior cingulate cortex, thalamus and posterior cingulate cortex. Ten out of eleven studies reported (partial) normalization by increased activation after antipsychotic treatment. A minority of studies observed hyperactivation at baseline.
This review of longitudinal FEP samples studies reveals a pattern of predominantly hypoactivation in several brain areas at baseline that may normalize to a certain extent after treatment. The results should be interpreted with caution given the small number of studies and their methodological and clinical heterogeneity.
Identifying benthic substrates is important to researchers studying aquatic organisms in fresh and salt water systems. Benthic substrates are often not visible from the surface making it necessary to find another method to gather these data. Previous research has demonstrated that low cost side-scan sonar is a reliable way to identify hard substrates, such as rock and gravel, in a small, freshwater stream. In this study, the reliability of the side-scan sonar to accurately identify softer substrates such as grass and mud was tested in a large, brackish lagoon system. A total area of 11.55 km2 was surveyed with the sonar. Videos and pictures were taken at various points to groundtruth the sonar images and provide a measure of accuracy. Five substrate types were identified: dense seagrass, sparse seagrass, mangrove soil, mangrove soil with rock, and silt. Unidentifiable substrates were classified as unknown. A manually zoned benthic substrate map was created from the sonar recordings. Dense seagrass was most accurately identified. Sparse seagrass was the least accurately identified. A bathymetric map was also created from the sonar recordings.
The importance of the hippocampus and amygdala for disrupted emotional memory formation in depression is well-recognized, but it remains unclear whether functional abnormalities are state-dependent and whether they are affected by the persistence of depressive symptoms.
Thirty-nine patients with major depressive disorder and 28 healthy controls were included from the longitudinal functional magnetic resonance imaging (fMRI) sub-study of the Netherlands Study of Depression and Anxiety. Participants performed an emotional word-encoding and -recognition task during fMRI at baseline and 2-year follow-up measurement. At baseline, all patients were in a depressed state. We investigated state-dependency by relating changes in brain activation over time to changes in symptom severity. Furthermore, the effect of time spent with depressive symptoms in the 2-year interval was investigated.
Symptom change was linearly associated with higher activation over time of the left anterior hippocampus extending to the amygdala during positive and negative word-encoding. Especially during positive word encoding, this effect was driven by symptomatic improvement. There was no effect of time spent with depression in the 2-year interval on change in brain activation. Results were independent of medication- and psychotherapy-use.
Using a longitudinal within-subjects design, we showed that hippocampal–amygdalar activation during emotional memory formation is related to depressive symptom severity but not persistence (i.e. time spent with depression or ‘load’), suggesting functional activation patterns in depression are not subject to functional ‘scarring’ although this hypothesis awaits future replication.
Currently, the types and distribution of the lesions induced in the central nervous system (CNS) by Trypanosoma cruzi remain unclear as the available evidence is based on fragmented data. Therefore, we developed a systematic review to analyse the main characteristics of the CNS lesions in non-human hosts infected. From a structured search on the PubMed/Medline and Scopus platforms, 32 studies were retrieved, subjected to data extraction and methodological bias analysis. Our results show that the most frequent alterations in the CNS are the presence of different forms of T. cruzi and intense lymphocytes infiltrates. The encephalon is the main target of T. cruzi, and inflammatory changes in the CNS are more frequent and severe in the acute phase of infection. The parasite's genotype and phenotype are associated with the tropism and severity of the CNS lesions. The methodological limitations found in the studies were divergences in inoculation pathways, under-reporting of animal age and weight, sample calculation strategies and histopathological characterization. Since the changes were dependent on the pathogenicity and virulence of the T. cruzi strains, the genotype and phenotype characterization of the parasite are extremely relevant to predict changes in the CNS and the neurological manifestations associated with Chagas’ disease.
Disturbances in emotion regulation (ER) are characteristic of both patients with bipolar disorder (BD) and schizophrenia (SZ). We investigated the temporal dynamics of brain activation during cognitive ER in BD and SZ to understand the contribution of temporal characteristics of disturbed ER to their unique and shared symptomatology.
Forty-six participants performed an ER-task (BD, n = 15; SZ, n = 16; controls, n = 15) during functional magnetic resonance imaging, in which they were instructed to use cognitive reappraisal techniques to regulate their emotional responses. Finite impulse response modeling was applied to estimate the temporal dynamics of brain responses during cognitive reappraisal (v. passive attending) of negative pictures. Group, time, and group × time effects were tested using multivariate modeling.
We observed a group × time interaction during ER in the ventrolateral prefrontal cortex (VLPFC), supplementary motor area (SMA) and inferior occipital gyrus. Patients with SZ demonstrated initial hyper-activation of the VLPFC and SMA activation that was not sustained in later regulatory phases. Response profiles in the inferior occipital gyrus in SZ showed abnormal activation in the later phases of regulation. BD-patients showed general blunted responsivity in these regions.
These results suggest that ER-disturbances in SZ are characterized by an inefficient initialization and failure to sustain regulatory control, whereas in BD, a failure to recruit regulatory resources may represent initial deficits in formulating adequate representations of the regulatory needs. This may help to further understand how ER-disturbances give rise to symptomatology of BD and SZ.
Studies investigating the underlying mechanisms of hallucinations in patients with schizophrenia suggest that an imbalance in top-down expectations v. bottom-up processing underlies these errors in perception. This study evaluates this hypothesis by testing if individuals drawn from the general population who have had auditory hallucinations (AH) have more misperceptions in auditory language perception than those who have never hallucinated.
We used an online survey to determine the presence of hallucinations. Participants filled out the Questionnaire for Psychotic Experiences and participated in an auditory verbal recognition task to assess both correct perceptions (hits) and misperceptions (false alarms). A hearing test was performed to screen for hearing problems.
A total of 5115 individuals from the general Dutch population participated in this study. Participants who reported AH in the week preceding the test had a higher false alarm rate in their auditory perception compared with those without such (recent) experiences. The more recent the AH were experienced, the more mistakes participants made. While the presence of verbal AH (AVH) was predictive for false alarm rate in auditory language perception, the presence of non-verbal or visual hallucinations were not.
The presence of AVH predicted false alarm rate in auditory language perception, whereas the presence of non-verbal auditory or visual hallucinations was not, suggesting that enhanced top-down processing does not transfer across modalities. More false alarms were observed in participants who reported more recent AVHs. This is in line with models of enhanced influence of top-down expectations in persons who hallucinate.