4,394 research outputs found
Electroconvulsive therapy mediates neuroplasticity of white matter microstructure in major depression.
Whether plasticity of white matter (WM) microstructure relates to therapeutic response in major depressive disorder (MDD) remains uncertain. We examined diffusion tensor imaging (DTI) correlates of WM structural connectivity in patients receiving electroconvulsive therapy (ECT), a rapidly acting treatment for severe MDD. Tract-Based Spatial Statistics (TBSS) applied to DTI data (61 directions, 2.5 mm(3) voxel size) targeted voxel-level changes in fractional anisotropy (FA), and radial (RD), axial (AD) and mean diffusivity (MD) in major WM pathways in MDD patients (n=20, mean age: 41.15 years, 10.32 s.d.) scanned before ECT, after their second ECT and at transition to maintenance therapy. Comparisons made at baseline with demographically similar controls (n=28, mean age: 39.42 years, 12.20 s.d.) established effects of diagnosis. Controls were imaged twice to estimate scanning-related variance. Patients showed significant increases of FA in dorsal fronto-limbic circuits encompassing the anterior cingulum, forceps minor and left superior longitudinal fasciculus between baseline and transition to maintenance therapy (P<0.05, corrected). Decreases in RD and MD were observed in overlapping regions and the anterior thalamic radiation (P<0.05, corrected). Changes in DTI metrics associated with therapeutic response in tracts showing significant ECT effects differed between patients and controls. All measures remained stable across time in controls. Altered WM microstructure in pathways connecting frontal and limbic areas occur in MDD, are modulated by ECT and relate to therapeutic response. Increased FA together with decreased MD and RD, which trend towards normative values with treatment, suggest increased fiber integrity in dorsal fronto-limbic pathways involved in mood regulation
Measuring Coverage of Prolog Programs Using Mutation Testing
Testing is an important aspect in professional software development, both to
avoid and identify bugs as well as to increase maintainability. However,
increasing the number of tests beyond a reasonable amount hinders development
progress. To decide on the completeness of a test suite, many approaches to
assert test coverage have been suggested. Yet, frameworks for logic programs
remain scarce.
In this paper, we introduce a framework for Prolog programs measuring test
coverage using mutations. We elaborate the main ideas of mutation testing and
transfer them to logic programs. To do so, we discuss the usefulness of
different mutations in the context of Prolog and empirically evaluate them in a
new mutation testing framework on different examples.Comment: 16 pages, Accepted for presentation in WFLP 201
A Brownian particle in a microscopic periodic potential
We study a model for a massive test particle in a microscopic periodic
potential and interacting with a reservoir of light particles. In the regime
considered, the fluctuations in the test particle's momentum resulting from
collisions typically outweigh the shifts in momentum generated by the periodic
force, and so the force is effectively a perturbative contribution. The
mathematical starting point is an idealized reduced dynamics for the test
particle given by a linear Boltzmann equation. In the limit that the mass ratio
of a single reservoir particle to the test particle tends to zero, we show that
there is convergence to the Ornstein-Uhlenbeck process under the standard
normalizations for the test particle variables. Our analysis is primarily
directed towards bounding the perturbative effect of the periodic potential on
the particle's momentum.Comment: 60 pages. We reorganized the article and made a few simplifications
of the conten
Hybrid Rules with Well-Founded Semantics
A general framework is proposed for integration of rules and external first
order theories. It is based on the well-founded semantics of normal logic
programs and inspired by ideas of Constraint Logic Programming (CLP) and
constructive negation for logic programs. Hybrid rules are normal clauses
extended with constraints in the bodies; constraints are certain formulae in
the language of the external theory. A hybrid program is a pair of a set of
hybrid rules and an external theory. Instances of the framework are obtained by
specifying the class of external theories, and the class of constraints. An
example instance is integration of (non-disjunctive) Datalog with ontologies
formalized as description logics.
The paper defines a declarative semantics of hybrid programs and a
goal-driven formal operational semantics. The latter can be seen as a
generalization of SLS-resolution. It provides a basis for hybrid
implementations combining Prolog with constraint solvers. Soundness of the
operational semantics is proven. Sufficient conditions for decidability of the
declarative semantics, and for completeness of the operational semantics are
given
Editorial: Biodiversity, Connectivity and Ecosystem Function Across the Clarion-Clipperton Zone: A Regional Synthesis for an Area Targeted for Nodule Mining
Influenza pandemic and professional duty: family or patients first? A survey of hospital employees
BACKGROUND: Conflicts between professional duties and fear of influenza transmission to family members may arise among health care professionals (HCP). METHODS: We surveyed employees at our university hospital regarding ethical issues arising during the management of an influenza pandemic. RESULTS: Of 644 respondents, 182 (28%) agreed that it would be professionally acceptable for HCP to abandon their workplace during a pandemic in order to protect themselves and their families, 337 (52%) disagreed with this statement and 125 (19%) had no opinion, with a higher rate of disagreement among physicians (65%) and nurses (54%) compared with administrators (32%). Of all respondents, 375 (58%) did not believe that the decision to report to work during a pandemic should be left to the individual HCP and 496 (77%) disagreed with the statement that HCP should be permanently dismissed for not reporting to work during a pandemic. Only 136 (21%) respondents agreed that HCW without children should primarily care for the influenza patients. CONCLUSION: Our results suggest that a modest majority of HCP, but only a minority of hospital administrators, recognises the obligation to treat patients despite the potential risks. Professional ethical guidelines allowing for balancing the needs of society with personal risks are needed to help HCP fulfil their duties in the case of a pandemic influenza
Exposure to Tobacco Smoke and Chronic Asthma Symptoms
The objective was to determine if tobacco exposure is associated with year-round asthma symptoms. We analyzed baseline data from a multistate survey of 896 pediatric patients with asthma participating in a randomized controlled trial. Daytime symptoms, nocturnal symptoms, and limitations in activity because of asthma tend to increase during the winter season (p < 0.05 for all comparisons, except spring to winter daytime symptoms). One hundred forty of 896 (16%) children had year-round symptoms (i.e., active asthma symptoms during every season). Using separate multivariate analyses, we found that having a parent who smokes (odds ratio [OR]: 2.22; 95% confidence interval [CI]: 1.35, 3.64) or a member of the household who smokes (OR: 1.94; 95% CI: 1.29, 2.93) was associated with a higher likelihood of year-round symptoms, controlling for region of residence, insurance status, and use of a daily controller medication. Asthma symptoms are more likely to increase in the winter season. In anticipation of these patterns, clinicians should consider initiating controller medication therapy or reinforcing asthma education prior to these time periods for those patients at risk for seasonal exacerbations. Exposure to tobacco smoke is associated with year-round asthma symptoms, highlighting the importance of health care providers identifying and counseling about smoking cessation, especially for children with year-round asthma symptoms. (Pediatr Asthma Immunol 2005; 18[4]:180–188.)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63404/1/pai.2005.18.180.pd
The effects of weather and climate change on dengue
There is much uncertainty about the future impact of climate change on vector-borne diseases. Such uncertainty reflects the difficulties in modelling the complex interactions between disease, climatic and socioeconomic determinants. We used a comprehensive panel dataset from Mexico covering 23 years of province-specific dengue reports across nine climatic regions to estimate the impact of weather on dengue, accounting for the effects of non-climatic factors
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