345 research outputs found
Auditory verbal hallucinations and childhood trauma subtypes across the psychosis continuum:a cluster analysis
Introduction: A strong link between voice-hearing experience and childhood trauma has been established. The aim of this study was to identify whether there were unique clusters of childhood trauma subtypes in a sample across the clinical spectrum of auditory verbal hallucinations (AVH) and to examine clinical and phenomenological features across these clusters. Methods: Combining two independent international datasets (the Netherlands and Australia), childhood trauma subtypes were examined using hierarchical cluster analysis. Clinical and phenomenological characteristics were compared across emerging clusters using MANOVA and chi-squared analyses. Results: The total sample (n = 413) included 166 clinical individuals with a psychotic disorder and AVH, 122 non-clinical individuals with AVH and 125 non-clinical individuals without AVH. Three clusters emerged: (1) low trauma (n = 299); (2) emotion-focused trauma (n = 71); (3) multi-trauma (n = 43). The three clusters differed significantly on their AVH ratings of amount of negative content, with trend-level effects for loudness, degree of negative content and degree of experienced distress. Furthermore, perceptions of voices being malevolent, benevolent and resistance towards voices differed significantly. Conclusion: The data revealed different types of childhood trauma had different relationships between clinical and phenomenological features of voice-hearing experiences. Thus, implicating different mechanistic pathways and a need for tailored treatment approaches
The merit of high-frequency data in portfolio allocation
This paper addresses the open debate about the usefulness of high-frequency (HF) data in large-scale portfolio allocation. Daily covariances are estimated based on HF data of the S&P 500 universe employing a blocked realized kernel estimator. We propose forecasting covariance matrices using a multi-scale spectral decomposition where volatilities, correlation eigenvalues and eigenvectors evolve on different frequencies. In an extensive out-of-sample forecasting study, we show that the proposed approach yields less risky and more diversified portfolio allocations as prevailing methods employing daily data. These performance gains hold over longer horizons than previous studies have shown
Appropriate medication use in Dutch terminal care:study protocol of a multicentre stepped-wedge cluster randomized controlled trial (the AMUSE study)
Background: Polypharmacy is common among patients with a limited life expectancy, even shortly before death. This is partly inevitable, because these patients often have multiple symptoms which need to be alleviated. However, the use of potentially inappropriate medications (PIMs) in these patients is also common. Although patients and relatives are often willing to deprescribe medication, physicians are sometimes reluctant due to the lack of evidence on appropriate medication management for patients in the last phase of life. The aim of the AMUSE study is to investigate whether the use of CDSS-OPTIMED, a software program that gives weekly personalized medication recommendations to attending physicians of patients with a limited life expectancy, improves patients’ quality of life. Methods: A multicentre stepped-wedge cluster randomized controlled trial will be conducted among patients with a life expectancy of three months or less. The stepped-wedge cluster design, where the clusters are the different study sites, involves sequential crossover of clusters from control to intervention until all clusters are exposed. In total, seven sites (4 hospitals, 2 general practices and 1 hospice from the Netherlands) will participate in this study. During the control period, patients will receive ‘care as usual’. During the intervention period, CDSS-OPTIMED will be activated. CDSS-OPTIMED is a validated software program that analyses the use of medication based on a specific set of clinical rules for patients with a limited life expectancy. The software program will provide the attending physicians with weekly personalized medication recommendations. The primary outcome of this study is patients’ quality of life two weeks after baseline assessment as measured by the EORTC QLQ-C15-PAL questionnaire, quality of life question.Discussion: This will be the first study investigating the effect of weekly personalized medication recommendations to attending physicians on the quality of life of patients with a limited life expectancy. We hypothesize that the CDSS-OPTIMED intervention could lead to improved quality of life in patients with a life expectancy of three months or less. Trial registration: This trial is registered at ClinicalTrials.gov (NCT05351281, Registration Date: April 11, 2022).</p
Appropriate medication use in Dutch terminal care:study protocol of a multicentre stepped-wedge cluster randomized controlled trial (the AMUSE study)
Background: Polypharmacy is common among patients with a limited life expectancy, even shortly before death. This is partly inevitable, because these patients often have multiple symptoms which need to be alleviated. However, the use of potentially inappropriate medications (PIMs) in these patients is also common. Although patients and relatives are often willing to deprescribe medication, physicians are sometimes reluctant due to the lack of evidence on appropriate medication management for patients in the last phase of life. The aim of the AMUSE study is to investigate whether the use of CDSS-OPTIMED, a software program that gives weekly personalized medication recommendations to attending physicians of patients with a limited life expectancy, improves patients’ quality of life. Methods: A multicentre stepped-wedge cluster randomized controlled trial will be conducted among patients with a life expectancy of three months or less. The stepped-wedge cluster design, where the clusters are the different study sites, involves sequential crossover of clusters from control to intervention until all clusters are exposed. In total, seven sites (4 hospitals, 2 general practices and 1 hospice from the Netherlands) will participate in this study. During the control period, patients will receive ‘care as usual’. During the intervention period, CDSS-OPTIMED will be activated. CDSS-OPTIMED is a validated software program that analyses the use of medication based on a specific set of clinical rules for patients with a limited life expectancy. The software program will provide the attending physicians with weekly personalized medication recommendations. The primary outcome of this study is patients’ quality of life two weeks after baseline assessment as measured by the EORTC QLQ-C15-PAL questionnaire, quality of life question.Discussion: This will be the first study investigating the effect of weekly personalized medication recommendations to attending physicians on the quality of life of patients with a limited life expectancy. We hypothesize that the CDSS-OPTIMED intervention could lead to improved quality of life in patients with a life expectancy of three months or less. Trial registration: This trial is registered at ClinicalTrials.gov (NCT05351281, Registration Date: April 11, 2022).</p
Learning curves for pediatric laparoscopy: how many operations are enough? The Amsterdam experience with laparoscopic pyloromyotomy
Few studies on the surgical outcomes of open (OP) versus laparoscopic pyloromyotomy (LP) in the treatment of hypertrophic pyloric stenosis have been published. The question arises as to how many laparoscopic procedures are required for a surgeon to pass the learning curve and which technique is best in terms of postoperative complications. This study aimed to evaluate and quantify the learning curve for the laparoscopic technique at the authors' center. A second goal of this study was to evaluate the pre- and postoperative data of OP versus LP for infantile hypertrophic pyloric stenosis. A retrospective analysis was performed for 229 patients with infantile hypertrophic pyloric stenosis. Between January 2002 and September 2008, 158 infants underwent OP and 71 infants had LP. The median operating time between the OP (33 min) and LP (40 min) groups was significantly different. The median hospital stay after surgery was 3 days for the OP patients and 2 days for the LP patients (p = 0.002). The postoperative complication rates were not significantly different between the OP (21.5%) and LP (21.1%) groups (p = 0.947). Complications were experienced by 31.5% of the first 35 LP patients. This rate decreased to 11.4% during the next 35 LP procedures (p = 0.041). Two perforations and three conversions occurred in the first LP group, compared with one perforation in the second LP group. The number of complications decreased significantly between the first and second groups of the LP patients, with the second group of LP patients quantifying the learning curve. Not only was the complication rate lower in the second LP group, but severe complications also were decreased. This indicates that the learning curve for LP in the current series involved 35 procedure
Early maternal deprivation affects dentate gyrus structure and emotional learning in adult female rats
Rationale: Stress elicits functional and structural changes in the hippocampus. Early life stress is one of the major risk factors for stress-related pathologies like depression. Patients suffering from depression show a reduced hippocampal volume, and in women, this occurs more often when depression is preceded by childhood trauma. However, the underlying mechanisms that account for a reduced hippocampal volume are unknown. Objective: We examined the effects of maternal absence on structure and function of the hippocampus in female offspring. Methods: We studied whether 24 h of maternal deprivation (MD) on postnatal day 3 altered adult neurogenesis, individual neuronal morphology and dentate gyrus (DG) structure in young adult female rats. In addition, functional alterations were addressed by studying synaptic plasticity in vitro, and spatial as well as emotional learning was tested. Results: Adult females that were subjected to MD revealed significant reductions in DG granule cell number and density. In addition, DG neurons were altered in their dendritic arrangement. No effects on the rate of adult neurogenesis were found. Furthermore, MD did not alter synaptic plasticity in vitro, neither under normal nor high-stress conditions. In addition, spatial learning and contextual fear conditioning were comparable between control and MD animals. However, MD animals showed an improved amygdala-dependent fear memory. Conclusion: Although early life stress exposure did not impair hippocampus-dependent functioning in female offspring, it irreversibly affected DG structure by reducing cell numbers. This may be relevant for the reduced hippocampal volume observed in depression and the increased vulnerability of women to develop depression
Co-Transport of Polycyclic Aromatic Hydrocarbons by Motile Microorganisms Leads to Enhanced Mass Transfer under Diffusive Conditions.
The
environmental chemodynamics of hydrophobic organic chemicals
(HOCs) are often rate-limited by diffusion in stagnant boundary layers.
This study investigated whether motile microorganisms can act as microbial
carriers that enhance mass transfer of HOCs through diffusive boundary
layers. A new experimental system was developed that allows (1) generation
of concentration gradients of HOCs under the microscope, (2) exposure
and direct observation of microorganisms in such gradients, and (3)
quantification of HOC mass transfer. Silicone O-rings were integrated
into a Dunn chemotaxis chamber to serve as sink and source for polycyclic
aromatic hydrocarbons (PAHs). This resulted in stable concentration
gradients in water (>24 h). Adding the model organism <i>Tetrahymena
pyriformis</i> to the experimental system enhanced PAH mass transfer
up to hundred-fold (benzo[a]pyrene). Increasing mass transfer enhancement
with hydrophobicity indicated PAH co-transport with the motile organisms.
Fluorescence microscopy confirmed such transport. The effective diffusivity
of <i>T. pyriformis</i>, determined by video imaging microscopy,
was found to exceed molecular diffusivities of the PAHs up to four-fold.
Cell-bound PAH fractions were determined to range from 28% (naphthalene)
to 92% (pyrene). Motile microorganisms can therefore function as effective
carriers for HOCs under diffusive conditions and might significantly
enhance mobility and availability of HOCs
Haploinsufficiency of EHMT1 improves pattern separation and increases hippocampal cell proliferation
Contains fulltext :
169681.pdf (publisher's version ) (Open Access)Heterozygous mutations or deletions of the human Euchromatin Histone Methyltransferase 1 (EHMT1) gene are the main causes of Kleefstra syndrome, a neurodevelopmental disorder that is characterized by impaired memory, autistic features and mostly severe intellectual disability. Previously, Ehmt1+/- heterozygous knockout mice were found to exhibit cranial abnormalities and decreased sociability, phenotypes similar to those observed in Kleefstra syndrome patients. In addition, Ehmt1+/- knockout mice were impaired at fear extinction and novel- and spatial object recognition. In this study, Ehmt1+/- and wild-type mice were tested on several cognitive tests in a touchscreen-equipped operant chamber to further investigate the nature of learning and memory changes. Performance of Ehmt1+/- mice in the Visual Discrimination &Reversal learning, object-location Paired-Associates learning- and Extinction learning tasks was found to be unimpaired. Remarkably, Ehmt1+/- mice showed enhanced performance on the Location Discrimination test of pattern separation. In line with improved Location Discrimination ability, an increase in BrdU-labelled cells in the subgranular zone of the dentate gyrus was observed. In conclusion, reduced levels of EHMT1 protein in Ehmt1+/- mice does not result in general learning deficits in a touchscreen-based battery, but leads to increased adult cell proliferation in the hippocampus and enhanced pattern separation ability
Towards Customary Legal Empowerment
Rule of Law and Development: Formation, Implementation and Improvement of Law and Governance in Developing Countrie
Structural and Thermodynamic Approach to Peptide Immunogenicity
In the conventional paradigm of humoral immunity, B cells recognize their cognate antigen target in its native form. However, it is well known that relatively unstable peptides bearing only partial structural resemblance to the native protein can trigger antibodies recognizing higher-order structures found in the native protein. On the basis of sound thermodynamic principles, this work reveals that stability of immunogenic proteinlike motifs is a critical parameter rationalizing the diverse humoral immune responses induced by different linear peptide epitopes. In this paradigm, peptides with a minimal amount of stability (ΔGX<0 kcal/mol) around a proteinlike motif (X) are capable of inducing antibodies with similar affinity for both peptide and native protein, more weakly stable peptides (ΔGX>0 kcal/mol) trigger antibodies recognizing full protein but not peptide, and unstable peptides (ΔGX>8 kcal/mol) fail to generate antibodies against either peptide or protein. Immunization experiments involving peptides derived from the autoantigen histidyl-tRNA synthetase verify that selected peptides with varying relative stabilities predicted by molecular dynamics simulations induce antibody responses consistent with this theory. Collectively, these studies provide insight pertinent to the structural basis of immunogenicity and, at the same time, validate this form of thermodynamic and molecular modeling as an approach to probe the development/evolution of humoral immune responses
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