270 research outputs found
Quantum phase transition in the dioptase magnetic lattice
The study of quantum phase transitions, which are zero-temperature phase
transitions between distinct states of matter, is of current interest in
research since it allows for a description of low-temperature properties based
on universal relations. Here we show that the crystal green dioptase
Cu_6Si_6O_18 . 6H_2O, known to the ancient Roman as the gem of Venus, has a
magnetic crystal structure, formed by the Cu(II) ions, which allows for a
quantum phase transition between an antiferromagnetically ordered state and a
quantum spin liquid.Comment: 6 pages, 5 figures, EPL, in pres
Structure of Precursor-Bound NifEN: A Nitrogenase FeMo Cofactor Maturase/Insertase
NifEN plays an essential role in the biosynthesis of the nitrogenase iron-molybdenum (FeMo) cofactor (M cluster). It is an α_2β_2 tetramer that is homologous to the catalytic molybdenum-iron (MoFe) protein (NifDK) component of nitrogenase. NifEN serves as a scaffold for the conversion of an iron-only precursor to a matured form of the M cluster before delivering the latter to its target location within NifDK. Here, we present the structure of the precursor-bound NifEN of Azotobacter vinelandii at 2.6 angstrom resolution. From a structural comparison of NifEN with des-M-cluster NifDK and holo NifDK, we propose similar pathways of cluster insertion for the homologous NifEN and NifDK proteins
Dissociation of accumulated genetic risk and disease severity in patients with schizophrenia
Genotype–phenotype correlations of common monogenic diseases revealed that the degree of deviation of mutant genes from wild-type structure and function often predicts disease onset and severity. In complex disorders such as schizophrenia, the overall genetic risk is still often >50% but genotype–phenotype relationships are unclear. Recent genome-wide association studies (GWAS) replicated a risk for several single-nucleotide polymorphisms (SNPs) regarding the endpoint diagnosis of schizophrenia. The biological relevance of these SNPs, however, for phenotypes or severity of schizophrenia has remained obscure. We hypothesized that the GWAS ‘top-10' should as single markers, but even more so upon their accumulation, display associations with lead features of schizophrenia, namely positive and negative symptoms, cognitive deficits and neurological signs (including catatonia), and/or with age of onset of the disease prodrome as developmental readout and predictor of disease severity. For testing this hypothesis, we took an approach complementary to GWAS, and performed a phenotype-based genetic association study (PGAS). We utilized the to our knowledge worldwide largest phenotypical database of schizophrenic patients (n>1000), the GRAS (Göttingen Research Association for Schizophrenia) Data Collection. We found that the ‘top-10' GWAS-identified risk SNPs neither as single markers nor when explored in the sense of a cumulative genetic risk, have any predictive value for disease onset or severity in the schizophrenic patients, as demonstrated across all core symptoms. We conclude that GWAS does not extract disease genes of general significance in schizophrenia, but may yield, on a hypothesis-free basis, candidate genes relevant for defining disease subgroups
Measurement of overall quality of life in nursing homes through self-report: the role of cognitive impairment
Measuring quality of life is a necessity for adequate interventions. This paper concerns the usefulness of six self-report measures for overall quality of life for nursing home residents with various levels of cognitive impairment. It was investigated which proportion of residents from four cognition groups could complete a scale, and internal consistency and construct validity of the scales were studied. Data collection took place in ten Dutch nursing homes (N = 227). The proportion of residents that could complete each scale varied. The Depression List could be administered most often to the cognitively most impaired group (43%; Mini Mental State Examination-scores 0–4). In the three cognition groups with MMSE-score >5, internal consistency of the Depression List, Geriatric Depression Scale and Negative Affect Scale was adequate in all three groups (alpha ≥.68). Intercorrelation was highest for the Philadelphia Geriatric Center Morale Scale, the Depression List, and the Geriatric Depression Scale (rho ≥.65). Nonetheless, self-report scales were not strongly correlated with two observational scales for depression, especially in cognitively severely impaired residents (rho ≤.30). In conclusion, it may not be possible to measure overall quality of life through self-report, and possibly also through observation, in many nursing home residents
Communication, advice exchange and job satisfaction of nursing staff: a social network analyses of 35 long-term care units
Background: The behaviour of individuals is affected by the social networks in which they are embedded. Networks are also important for the diffusion of information and the influence of employees in organisations. Yet, at the moment little is known about the social networks of nursing staff in healthcare settings. This is the first study that investigates informal communication and advice networks of nursing staff in long-term care. We examine the structure of the networks, how they are related to the size of units and characteristics of nursing staff, and their relationship with job satisfaction. Methods: We collected social network data of 380 nursing staff of 35 units in group projects and psychogeriatric units in nursing homes and residential homes in the Netherlands. Communication and advice networks were analyzed in a social network application (UCINET), focusing on the number of contacts (density) between nursing staff on the units. We then studied the correlation between the density of networks, size of the units and characteristics of nursing staff. We used multilevel analyses to investigate the relationship between social networks and job satisfaction of nursing staff, taking characteristics of units and nursing staff into account. Results: Both communication and advice networks were negatively related to the number of residents and the number of nursing staff of the units. Communication and advice networks were more dense when more staff worked part-time. Furthermore, density of communication networks was positively related to the age of nursing staff of the units. Multilevel analyses showed that job satisfaction differed significantly between individual staff members and units and was influenced by the number of nursing staff of the units. However, this relationship disappeared when density of communication networks was added to the model. Conclusions: Overall, communication and advice networks of nursing staff in long-term care are relatively dense. This fits with the high level of cooperation that is needed to provide good care to residents. Social networks are more dense in small units and are also shaped by characteristics of staff members. The results furthermore show that communication networks are important for staff's job satisfaction. (aut. ref.
The Butterfly Fauna Of The Italian Maritime Alps:Results Of The «Edit» Project
Bonelli, Simona, Barbero, Francesca, Casacci, Luca Pietro, Cerrato, Cristiana, Balletto, Emilio (2015): The butterfly fauna of the Italian Maritime Alps: results of the EDIT project. Zoosystema 37 (1): 139-167, DOI: 10.5252/z2015n1a6, URL: http://dx.doi.org/10.5252/z2015n1a
Psychometric properties of instruments to measure the quality of end-of-life care and dying for long-term care residents with dementia
Purpose: Quality of care for long-term care (LTC) residents with dementia at the end-of-life is often evaluated using standardized instruments that were not developed for or thoroughly tested in this population. Given the importance of using appropriate instruments to evaluate the quality of care (QOC) and quality of dying (QOD) in LTC, we compared the validity and reliability of ten available instruments commonly used for these purposes. Methods: We performed prospective observations and retrospective interviews and surveys of family (n = 70) and professionals (n = 103) of LTC decedents with dementia in the Netherlands. Results: Instruments within the constructs QOC and QOD were highly correlated, and showed moderate to high correlation with overall assessments of QOC and QOD. Prospective and retrospective ratings using the same instruments differed little. Concordance between family and professional scores was low. Cronbach's alpha was mostly adequate. The EOLD-CAD showed good fit with pre-assumed factor structures. The EOLD-SWC and FPCS appear most valid and reliable for measuring QOC, and the EOLD-CAD and MSSE for measuring QOD. The POS performed worst in this population. Conclusions: Our comparative study of psychometric properties of instruments allows for informed selection of QOC and QOD measures for LTC residents with dementia. © The Author(s) 2011
Economic evaluation alongside a single RCT of an integrative psychotherapeutic nursing home programme
__Abstract__
There is an 80% prevalence of two or more psychiatric symptoms in psychogeriatric patients. Multiple
psychiatric symptoms (MPS) have many negative effects on quality of life of the patient as well as on caregiver
burden and competence. Irrespective of the effectiveness of an intervention programme, it is important to take into
account its economic aspects
Violent aggression predicted by multiple pre-adult environmental hits
Early exposure to negative environmental impact shapes individual behavior and potentially contributes to any mental disease. We reported previously that accumulated environmental risk markedly decreases age at schizophrenia onset. Follow-up of matched extreme group individuals (≤1 vs. ≥3 risks) unexpectedly revealed that high-risk subjects had >5 times greater probability of forensic hospitalization. In line with longstanding sociological theories, we hypothesized that risk accumulation before adulthood induces violent aggression and criminal conduct, independent of mental illness. We determined in 6 independent cohorts (4 schizophrenia and 2 general population samples) pre-adult risk exposure, comprising urbanicity, migration, physical and sexual abuse as primary, and cannabis or alcohol as secondary hits. All single hits by themselves were marginally associated with higher violent aggression. Most strikingly, however, their accumulation strongly predicted violent aggression (odds ratio 10.5). An epigenome-wide association scan to detect differential methylation of blood-derived DNA of selected extreme group individuals yielded overall negative results. Conversely, determination in peripheral blood mononuclear cells of histone-deacetylase1 mRNA as 'umbrella mediator' of epigenetic processes revealed an increase in the high-risk group, suggesting lasting epigenetic alterations. Together, we provide sound evidence of a disease-independent unfortunate relationship between well-defined pre-adult environmental hits and violent aggression, calling for more efficient prevention
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