1,821 research outputs found
Psychiatric genetics and the structure of psychopathology
For over a century, psychiatric disorders have been defined by expert opinion and clinical observation. The modern DSM has relied on a consensus of experts to define categorical syndromes based on clusters of symptoms and signs, and, to some extent, external validators, such as longitudinal course and response to treatment. In the absence of an established etiology, psychiatry has struggled to validate these descriptive syndromes, and to define the boundaries between disorders and between normal and pathologic variation. Recent advances in genomic research, coupled with large-scale collaborative efforts like the Psychiatric Genomics Consortium, have identified hundreds of common and rare genetic variations that contribute to a range of neuropsychiatric disorders. At the same time, they have begun to address deeper questions about the structure and classification of mental disorders: To what extent do genetic findings support or challenge our clinical nosology? Are there genetic boundaries between psychiatric and neurologic illness? Do the data support a boundary between disorder and normal variation? Is it possible to envision a nosology based on genetically informed disease mechanisms? This review provides an overview of conceptual issues and genetic findings that bear on the relationships among and boundaries between psychiatric disorders and other conditions. We highlight implications for the evolving classification of psychopathology and the challenges for clinical translation
Expression Levels of a Kinesin-13 Microtubule Depolymerase Modulates the Effectiveness of Anti-Microtubule Agents
Chemotherapeutic drugs often target the microtubule cytoskeleton as a means to disrupt cancer cell mitosis and proliferation. Anti-microtubule drugs inhibit microtubule dynamics, thereby triggering apoptosis when dividing cells activate the mitotic checkpoint. Microtubule dynamics are regulated by microtubule-associated proteins (MAPs); however, we lack a comprehensive understanding about how anti-microtubule agents functionally interact with MAPs. In this report, we test the hypothesis that the cellular levels of microtubule depolymerases, in this case kinesin-13 s, modulate the effectiveness of the microtubule disrupting drug colchicine.We used a combination of RNA interference (RNAi), high-throughput microscopy, and time-lapse video microscopy in Drosophila S2 cells to identify a specific MAP, kinesin-like protein 10A (KLP10A), that contributes to the efficacy of the anti-microtubule drug colchicine. KLP10A is an essential microtubule depolymerase throughout the cell cycle. We find that depletion of KLP10A in S2 cells confers resistance to colchicine-induced microtubule depolymerization to a much greater extent than depletion of several other destabilizing MAPs. Using image-based assays, we determined that control cells retained 58% (+/-2%SEM) of microtubule polymer when after treatment with 2 microM colchicine for 1 hour, while cells depleted of KLP10A by RNAi retained 74% (+/-1%SEM). Likewise, overexpression of KLP10A-GFP results in increased susceptibility to microtubule depolymerization by colchicine.Our results demonstrate that the efficacy of microtubule destabilization by a pharmacological agent is dependent upon the cellular expression of a microtubule depolymerase. These findings suggest that expression levels of Kif2A, the human kinesin-13 family member, may be an attractive biomarker to assess the effectiveness of anti-microtubule chemotherapies. Knowledge of how MAP expression levels affect the action of anti-microtubule drugs may prove useful for evaluating possible modes of cancer treatment
Bottom sediments of Lake Rotoma
Lake Rotoma is a deep (70-80 m), oligotrophic, warm monomictic lake of volcanic origin with insignificant stream inflow and no clearly defined outflow. For at least 60 years up to 1972 the lake level fluctuated markedly about an overall rising trend of some 6-10 m. Nearshore profiles are related to the prevailing wave climate superimposed upon the overall rising lake level, shelves being wider, less steep, and deeper about the more exposed eastern and southern shorelines. The outer portions of shelves extending well below modern storm wave base into waters as deep as 15-25 m are relict features from lower lake level stands. Sediments fine from sand-gravel mixtures nearshore to silts in basinal areas. Their composition reflects a composite provenance involving the lavas and tephras about the lake, as well as intralake diatom frustules and organic matter. The distribution pattern of surficial bottom sediments is an interplay between grains of both biological and terrigenous origin, supplied presently and in the past by a variety of processes, that have been dispersed either by the modern hydrodynamic regime or by former ones associated with lower lake levels. These interrelationships are structured by erecting 5 process-age sediment classes in the lake, namely neoteric, amphoteric, proteric, palimpsest, and relict sediments, analogous to categories postulated for sediments on oceanic continental shelves. Short-core stratigraphy includes the Kaharoa (A.D. -1020) and Tarawera (A.D. 1886) tephras. The rates of sedimentation of diatomaceous silts in basinal areas have more than doubled since the Tarawera eruption, indicating an overall increase in the fertility level of lake waters associated, perhaps, with recent farm development in the catchment
The developmental dynamics of terrorist organizations
We identify robust statistical patterns in the frequency and severity of
violent attacks by terrorist organizations as they grow and age. Using
group-level static and dynamic analyses of terrorist events worldwide from
1968-2008 and a simulation model of organizational dynamics, we show that the
production of violent events tends to accelerate with increasing size and
experience. This coupling of frequency, experience and size arises from a
fundamental positive feedback loop in which attacks lead to growth which leads
to increased production of new attacks. In contrast, event severity is
independent of both size and experience. Thus larger, more experienced
organizations are more deadly because they attack more frequently, not because
their attacks are more deadly, and large events are equally likely to come from
large and small organizations. These results hold across political ideologies
and time, suggesting that the frequency and severity of terrorism may be
constrained by fundamental processes.Comment: 28 pages, 8 figures, 4 tables, supplementary materia
Stochastic Gravity: A Primer with Applications
Stochastic semiclassical gravity of the 90's is a theory naturally evolved
from semiclassical gravity of the 70's and 80's. It improves on the
semiclassical Einstein equation with source given by the expectation value of
the stress-energy tensor of quantum matter fields in curved spacetimes by
incorporating an additional source due to their fluctuations. In stochastic
semiclassical gravity the main object of interest is the noise kernel, the
vacuum expectation value of the (operator-valued) stress-energy bi-tensor, and
the centerpiece is the (stochastic) Einstein-Langevin equation. We describe
this new theory via two approaches: the axiomatic and the functional. The
axiomatic approach is useful to see the structure of the theory from the
framework of semiclassical gravity. The functional approach uses the
Feynman-Vernon influence functional and the Schwinger-Keldysh close-time-path
effective action methods which are convenient for computations. It also brings
out the open systems concepts and the statistical and stochastic contents of
the theory such as dissipation, fluctuations, noise and decoherence. We then
describe the application of stochastic gravity to the backreaction problems in
cosmology and black hole physics. Intended as a first introduction to this
subject, this article places more emphasis on pedagogy than completeness.Comment: 46 pages Latex. Intended as a review in {\it Classical and Quantum
Gravity
Effect of a natural extract of chicken combs with a high content of hyaluronic acid (Hyal-Joint®) on pain relief and quality of life in subjects with knee osteoarthritis: a pilot randomized double-blind placebo-controlled trial
<p>Abstract</p> <p>Background</p> <p>Intra-articular hyaluronic acid represents a substantive addition to the therapeutic armamentarium in knee osteoarthritis. We examined the effect of dietary supplementation with a natural extract of chicken combs with a high content of hyaluronic acid (60%) (Hyal-Joint<sup>®</sup>) (active test product, AP) on pain and quality of life in subjects with osteoarthritis of the knee.</p> <p>Methods</p> <p>Twenty subjects aged ≥40 years with knee osteoarthritis (pain for at least 15 days in the previous month, symptoms present for ≥6 months, Kellgren/Lawrence score ≥2) participated in a randomized double-blind controlled trial. Ten subjects received AP (80 mg/day) and 10 placebo for 8 weeks. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and quality of life by the Short Form-36 (SF-36v2) were administered at baseline and after 4 and 8 weeks of treatment.</p> <p>Results</p> <p>WOMAC pain (primary efficacy variable) was similar in both study groups (mean [SD]) with 6.6 (4.0) points in the AP group and 6.4 (2.7) in the placebo group (<it>P </it>= 0.943). As compared with baseline, subjects in both groups showed statistically significant improvements in WOMAC pain, stiffness, physical function subscales, and in the aggregate score, but the magnitude of changes was higher in the AP group for WOMAC physical function (-13.1 [12.0] vs. -10.1 [8.6], <it>P </it>= 0.575) and total symptoms (-18.6 [16.8] vs. -15.8 [11.4], <it>P </it>= 0.694). At 4 weeks, statistically significant mean changes compared with baseline were observed in the SF-36v2 scales of role-physical, bodily pain, social functioning and role-emotional among subjects in the AP group, and in physical functioning, bodily pain, and social functioning in the placebo group. At 8 weeks, changes were significant for role-physical, bodily pain, and physical component summary in the AP group, and for physical functioning and role-emotional in the placebo arm. Changes in bodily pain and social functioning were of greater magnitude in subjects given AP.</p> <p>Conclusion</p> <p>This pilot clinical trial showed that daily supplementation with oral hyaluronic acid from a natural extract of chicken combs (Hyal-Joint<sup>®</sup>) was useful to enhance several markers of quality of life in adults with osteoarthritis of the knee. The results warrant further study in larger sample sizes.</p
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Evaluating the Clinical Feasibility of an Artificial Intelligence-Powered, Web-Based Clinical Decision Support System for the Treatment of Depression in Adults: Longitudinal Feasibility Study.
BACKGROUND: Approximately two-thirds of patients with major depressive disorder do not achieve remission during their first treatment. There has been increasing interest in the use of digital, artificial intelligence-powered clinical decision support systems (CDSSs) to assist physicians in their treatment selection and management, improving the personalization and use of best practices such as measurement-based care. Previous literature shows that for digital mental health tools to be successful, the tool must be easy for patients and physicians to use and feasible within existing clinical workflows. OBJECTIVE: This study aims to examine the feasibility of an artificial intelligence-powered CDSS, which combines the operationalized 2016 Canadian Network for Mood and Anxiety Treatments guidelines with a neural network-based individualized treatment remission prediction. METHODS: Owing to the COVID-19 pandemic, the study was adapted to be completed entirely remotely. A total of 7 physicians recruited outpatients diagnosed with major depressive disorder according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria. Patients completed a minimum of one visit without the CDSS (baseline) and 2 subsequent visits where the CDSS was used by the physician (visits 1 and 2). The primary outcome of interest was change in appointment length after the introduction of the CDSS as a proxy for feasibility. Feasibility and acceptability data were collected through self-report questionnaires and semistructured interviews. RESULTS: Data were collected between January and November 2020. A total of 17 patients were enrolled in the study; of the 17 patients, 14 (82%) completed the study. There was no significant difference in appointment length between visits (introduction of the tool did not increase appointment length; F2,24=0.805; mean squared error 58.08; P=.46). In total, 92% (12/13) of patients and 71% (5/7) of physicians felt that the tool was easy to use; 62% (8/13) of patients and 71% (5/7) of physicians rated that they trusted the CDSS. Of the 13 patients, 6 (46%) felt that the patient-clinician relationship significantly or somewhat improved, whereas 7 (54%) felt that it did not change. CONCLUSIONS: Our findings confirm that the integration of the tool does not significantly increase appointment length and suggest that the CDSS is easy to use and may have positive effects on the patient-physician relationship for some patients. The CDSS is feasible and ready for effectiveness studies. TRIAL REGISTRATION: ClinicalTrials.gov NCT04061642; http://clinicaltrials.gov/ct2/show/NCT04061642
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