2,568 research outputs found
The Australian mental health system: An economic overview and some research issues
This article is concerned with the key economic characteristics of Australia's mental health system. First, some brief conceptual and empirical descriptions are provided of Australia's mental health services, both as a total system, and of its two principal components, viz. public psychiatric institutions and private psychiatry services. Expenditures on public psychiatric hospitals clearly demonstrate the effect of deinstitutionalisation. Data from 1984 on private practice psychiatry indicate that per capita utilisation rates peaked in 1996 and have since fallen. Generally, since 1984 gross fees have not risen. However, for both utilisation and fees, there is evidence (of a statistical kind) that there are significant differences between the states of Australia, in these two variables (utilisation and fees). Emphasis is also placed on the economic incentives that arise from health insurance and the heterogeneous nature of mental illness. The effects of these incentives are regarded as by-products of the health insurance mechanism; and another effect, "unmet need" and "met non-need", is a somewhat unique problem of an informational kind. Discussion of many of these issues concludes on a somewhat negative note, e.g. that no empirical results are available to quantify the particular effect that is discussed. This is a manifestation of the lacunae of economic studies of the mental health sector
The trend in mental health-related mortality rates in Australia 1916-2004: implications for policy
Background: This study determines the trend in mental health-related mortality (defined here as the aggregation
of suicide and deaths coded as βmental/behavioural disordersβ), and its relative numerical importance, and to argue
that this has importance to policy-makers. Its results will have policy relevance because policy-makers have been
predominantly concerned with cost-containment, but a re-appraisal of this issue is occurring, and the trade-off
between health expenditures and valuable gains in longevity is being emphasised now. This study examines
longevity gains from mental health-related interventions, or their absence, at the population level. The study sums
mortality data for suicide and mental/behavioural disorders across the relevant ICD codes through time in Australia
for the period 1916-2004. There are two measures applied to the mortality rates: the conventional age-standardised
headcount; and the age-standardised Potential Years of Life Lost (PYLL), a measure of premature mortality.
Mortality rates formed from these data are analysed via comparisons with mortality rates for All Causes, and with
circulatory diseases, cancer and motor vehicle accidents, measured by both methods.
Results: This study finds the temporal trend in mental health-related mortality rates (which reflects the longevity of
people with mental illness) has worsened through time. There are no gains. This trend contrasts with the (known)
gains in longevity from All Causes, and the gains from decreases achieved in previously rising mortality rates from
circulatory diseases and motor vehicle accidents. Also, PYLL calculation shows mental health-related mortality is a
proportionately greater cause of death compared with applying headcount metrics.
Conclusions: There are several factors that could reverse this trend. First, improved access to interventions or
therapies for mental disorders could decrease the mortality analysed here. Second, it is important also that new
efficacious therapies for various mental disorders be developed. Furthermore, it is also important that suicide
prevention strategies be implemented, particularly for at-risk groups. To bring the mental health sector into parity
with many other parts of the health system will require knowledge of the causative factors that underlie mental
disorders, which can, in turn, lead to efficacious therapies. As in any case of a knowledge deficit, what is needed
are resources to address that knowledge gap. Conceiving the problem in this way, ie as a knowledge gap,
indicates the crucial role of research and development activity. This term implies a concern, not simply with basic
research, but also with applied research. It is commonplace in other sectors of the economy to emphasise the
trichotomy of invention, innovation and diffusion of new products and processes. This three-fold conception is also
relevant to addressing the knowledge gap in the mental health sector
A possible method for non-Hermitian and non--symmetric Hamiltonian systems
A possible method to investigate non-Hermitian Hamiltonians is suggested
through finding a Hermitian operator and defining the annihilation and
creation operators to be -pseudo-Hermitian adjoint to each other. The
operator represents the -pseudo-Hermiticity of Hamiltonians.
As an example, a non-Hermitian and non--symmetric Hamiltonian with
imaginary linear coordinate and linear momentum terms is constructed and
analyzed in detail. The operator is found, based on which, a real
spectrum and a positive-definite inner product, together with the probability
explanation of wave functions, the orthogonality of eigenstates, and the
unitarity of time evolution, are obtained for the non-Hermitian and
non--symmetric Hamiltonian. Moreover, this Hamiltonian turns out to be
coupled when it is extended to the canonical noncommutative space with
noncommutative spatial coordinate operators and noncommutative momentum
operators as well. Our method is applicable to the coupled Hamiltonian. Then
the first and second order noncommutative corrections of energy levels are
calculated, and in particular the reality of energy spectra, the
positive-definiteness of inner products, and the related properties (the
probability explanation of wave functions, the orthogonality of eigenstates,
and the unitarity of time evolution) are found not to be altered by the
noncommutativity.Comment: 15 pages, no figures; v2: clarifications added; v3: 16 pages, 1
figure, clarifications made clearer; v4: 19 pages, the main context is
completely rewritten; v5: 25 pages, title slightly changed, clarifications
added, the final version to appear in PLOS ON
Effects of surgery on the mental status of older persons. A meta-analytic review
The data bases of 18 empirical studies were combined into one comprehensive data set and subjected to meta-analysis. The following trends were observed: (1) surgery has a significantly decompensating impact on the mental status of older persons, and the average effect size observed is modest (r = .37); (2) for all mental status measures included in the review (cognition, delirium and affect), effect size appears to be significantly moderated by patient age; (3) patient sex may be predictive of the kind of mental impairment that is most likely to occur within an older surgery population, with women manifesting a greater affinity for delirious and men for cognitive decompensation; (4) most existing research within this domain of study is either purely descriptive or anecdotal: of 46 studies reviewed, only 18, or 39.1% of the total published output, were of sufficient methodologic rigor to allow for scientifically valid effect-size computations. The implications of these findings for future research are discussed
Network Physiology reveals relations between network topology and physiological function
The human organism is an integrated network where complex physiologic
systems, each with its own regulatory mechanisms, continuously interact, and
where failure of one system can trigger a breakdown of the entire network.
Identifying and quantifying dynamical networks of diverse systems with
different types of interactions is a challenge. Here, we develop a framework to
probe interactions among diverse systems, and we identify a physiologic
network. We find that each physiologic state is characterized by a specific
network structure, demonstrating a robust interplay between network topology
and function. Across physiologic states the network undergoes topological
transitions associated with fast reorganization of physiologic interactions on
time scales of a few minutes, indicating high network flexibility in response
to perturbations. The proposed system-wide integrative approach may facilitate
the development of a new field, Network Physiology.Comment: 12 pages, 9 figure
Primary and malignant cholangiocytes undergo CD40 mediated Fas dependent Apoptosis, but are insensitive to direct activation with exogenous fas ligand
Introduction
Cholangiocarcinoma is a rare malignancy of the biliary tract, the incidence of which is rising, but the pathogenesis of which remains uncertain. No common genetic defects have been described but it is accepted that chronic inflammation is an important contributing factor. We have shown that primary human cholangiocyte and hepatocyte survival is tightly regulated via co-operative interactions between two tumour necrosis family (TNF) receptor family members; CD40 and Fas (CD95). Functional deficiency of CD154, the ligand for CD40, leads to a failure of clearance of biliary tract infections and a predisposition to cholangiocarcinoma implying a direct link between TNF receptor-mediated apoptosis and the development of cholangiocarcinoma.
Aims
To determine whether malignant cholangiocytes display defects in CD40 mediated apoptosis. By comparing CD40 and Fas-mediated apoptosis and intracellular signalling in primary human cholangiocytes and three cholangiocyte cell lines.
Results
Primary cholangiocytes and cholangiocyte cell lines were relatively insensitive to direct Fas-mediated killing with exogenous FasL when compared with Jurkat cells, which readily underwent Fas-mediated apoptosis, but were extremely sensitive to CD154 stimulation. The sensitivity of cells to CD40 activation was similar in magnitude in both primary and malignant cells and was STAT-3 and AP-1 dependent in both.
Conclusions
1) Both primary and malignant cholangiocytes are relatively resistant to Fasβmediated killing but show exquisite sensitivity to CD154, suggesting that the CD40 pathway is intact and fully functional in both primary and malignant cholangiocytes 2) The relative insensitivity of cholangiocytes to Fas activation demonstrates the importance of CD40 augmentation of Fas dependent death in these cells. Agonistic therapies which target CD40 and associated intracellular signalling pathways may be effective in promoting apoptosis of malignant cholangiocytes
Optimality of mutation and selection in germinal centers
The population dynamics theory of B cells in a typical germinal center could
play an important role in revealing how affinity maturation is achieved.
However, the existing models encountered some conflicts with experiments. To
resolve these conflicts, we present a coarse-grained model to calculate the B
cell population development in affinity maturation, which allows a
comprehensive analysis of its parameter space to look for optimal values of
mutation rate, selection strength, and initial antibody-antigen binding level
that maximize the affinity improvement. With these optimized parameters, the
model is compatible with the experimental observations such as the ~100-fold
affinity improvements, the number of mutations, the hypermutation rate, and the
"all or none" phenomenon. Moreover, we study the reasons behind the optimal
parameters. The optimal mutation rate, in agreement with the hypermutation rate
in vivo, results from a tradeoff between accumulating enough beneficial
mutations and avoiding too many deleterious or lethal mutations. The optimal
selection strength evolves as a balance between the need for affinity
improvement and the requirement to pass the population bottleneck. These
findings point to the conclusion that germinal centers have been optimized by
evolution to generate strong affinity antibodies effectively and rapidly. In
addition, we study the enhancement of affinity improvement due to B cell
migration between germinal centers. These results could enhance our
understandings to the functions of germinal centers.Comment: 5 figures in main text, and 4 figures in Supplementary Informatio
Pressure-Induced Amorphization of Small Pore Zeolites-the Role of Cation-H2O Topology and Anti-glass Formation
Systematic studies of pressure-induced amorphization of natrolites (PIA) containing monovalent extra-framework cations (EFC) Li+, Na+, K+, Rb+, Cs+ allow us to assess the role of two different EFC-H2O configurations within the pores of a zeolite: one arrangement has H2O molecules (NATI) and the other the EFC (NAT(II)) in closer proximity to the aluminosilicate framework. We show that NAT(I) materials have a lower onset pressure of PIA than the NAT(II) materials containing Rb and Cs as EFC. The onset pressure of amorphization (P-A) of NAT(II) materials increases linearly with the size of the EFC, whereas their initial bulk moduli (P-1 phase) decrease linearly. Only Cs- and Rb-NAT reveal a phase separation into a dense form (P-2 phase) under pressure. High-Angle Annular Dark Field Scanning Transmission Electron Microscopy (HAADF-STEM) imaging shows that after recovery from pressures near 25 and 20 GPa long-range ordered Rb-Rb and Cs-Cs correlations continue to be present over length scales up to 100 nm while short-range ordering of the aluminosilicate framework is significantly reduced-this opens a new way to form anti-glass structuresopen
Surgeon volume and 30 day mortality for brain tumours in England.
BACKGROUND: There is evidence that surgeons who perform more operations have better outcomes. However, in patients with brain tumours, all of the evidence comes from the USA. METHODS: We examined all English patients with an intracranial neoplasm who had an intracranial resection in 2008-2010. We included surgeons who performed at least six operations over 3 years, and at least one operation in the first and last 6 months of the period. RESULTS: The analysis data set comprised 9194 operations, 163 consultant neurosurgeons and 30 centres. Individual surgeon volumes varied widely (7-272; median=46). 72% of operations were on the brain, and 30 day mortality was 3%. A doubling of surgeon load was associated with a 20% relative reduction in mortality. Thirty day mortality varied between centres (0Β·95-8Β·62%) but was not related to centre workload. CONCLUSIONS: Individual surgeon volumes correlated with patient 30 day mortality. Centres and surgeons in England are busier than surgeons and centres in the USA. There is no relationship between centre volume and 30 day mortality in England. Services in the UK appear to be adequately arranged at a centre level, but would benefit from further surgeon sub-specialisation
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