A Recurrent Cooperative/Competitive Field for Segmentation of Magnetic Resonance Brain Imagery

The Grey-White Decision Network is introduced as an application of an on-center, off-surround recurrent cooperative/competitive network for segmentation of magnetic resonance imaging (MRI) brain images. The three layer dynamical system relaxes into a solution where each pixel is labeled as either grey matter, white matter, or "other" matter by considering raw input intensity, edge information, and neighbor interactions. This network is presented as an example of applying a recurrent cooperative/competitive field (RCCF) to a problem with multiple conflicting constraints. Simulations of the network and its phase plane analysis are presented

Users manual for the Automated Performance Test System (APTS)

The characteristics of and the user information for the Essex Automated Performance Test System (APTS) computer-based portable performance assessment battery are given. The battery was developed to provide a menu of performance test tapping the widest possible variety of human cognitive and motor functions, implemented on a portable computer system suitable for use in both laboratory and field settings for studying the effects of toxic agents and other stressors. The manual gives guidance in selecting, administering and scoring tests from the battery, and reviews the data and studies underlying the development of the battery. Its main emphasis is on the users of the battery - the scientists, researchers and technicians who wish to examine changes in human performance across time or as a function of changes in the conditions under which test data are obtained. First the how to information needed to make decisions about where and how to use the battery is given, followed by the research background supporting the battery development. Further, the development history of the battery focuses largely on the logical framework within which tests were evaluated

A Systematic Review of the Health Impacts of Mass Earth Movements (Landslides)

Background. Mass ground movements (commonly referred to as ‘landslides’) are common natural hazards that can have significant economic, social and health impacts. They occur as single events, or as clusters, and are often part of ‘disaster’ chains, occurring secondary to, or acting as the precursor of other disaster events. Whilst there is a large body of literature on the engineering and geological aspects of landslides, the mortality and morbidity caused by landslides is less well documented. As far as we are aware, this is the first systematic review to examine the health impacts of landslides. Methods. The MEDLINE, EMBASE, CINAHL, SCOPUS databases and the Cochrane library were systematically searched to identify articles which considered the health impacts of landslides. Case studies, case series, primary research and systematic reviews were included. News reports, editorials and non-systematic reviews were excluded. Only articles in English were considered. The references of retrieved papers were searched to identify additional articles. Findings. 913 abstracts were reviewed and 143 full text articles selected for review. A total of 27 papers reporting research studies were included in the review (25 from initial search, 1 from review of references and 1 from personal correspondence). We found a limited number of studies on the physical health consequences of landslides. Only one study provided detail of the causes of mortality and morbidity in relation a landslide event. Landslides cause significant mental health impacts, in particular the prevalence of PTSD may be higher after landslides than other types of disaster, though these studies tend to be older with only 3 papers published in the last 5 years, with 2 being published 20 years ago, and diagnostic criteria have changed since they were produced. Discussion. We were disappointed at the small number of relevant studies, and the generally poor documentation of the health impacts of landslides. Mental health impacts were better documented, though some of the studies are now quite old. Further research on the health impacts of landslides needs to be undertaken to support those responding to landslide disasters and to aid disaster risk mitigation advocacy

Identification of atropine-and P2X1 receptor antagonist-reistant, neurogenic contractions of the urinary bladder

Acetylcholine and ATP are excitatory cotransmitters in parasympathetic nerves. We used P2X1 receptor antagonists to further characterize the purinergic component of neurotransmission in isolated detrusor muscle of guinea pig urinary bladder. In the presence of atropine (1 μm) and prazosin (100 nm), pyridoxalphosphate-6-azophenyl-2′,4′-disulfonic acid (PPADS) (0.1–100 μm) and suramin (1–300 μm) inhibited contractions evoked by 4 Hz nerve stimulation in a concentration-dependent manner (IC50 of 6.9 and 13.4 μm, respectively). Maximum inhibition was 50–60%, which was unaffected by coadministration of the ectonucleotidase inhibitor ARL67156 (6-N,N-diethyl-d-β,γ-dibromomethyleneATP) (100 μm). The remaining responses were abolished by tetrodotoxin (1 μm). PPADS and suramin also reduced contractions to exogenous ATP (300 μm) by 40–50%, but abolished those to the P2X1 agonist α,β-methyleneATP (α,β-meATP) (1 μm). The P2X1 antagonists reactive blue 2, NF279 (8,8′-[carbonylbis(imino-4,1-phenylenecarbonylimino-4,1-phenylenecarbonylimino)] bis-1,3,5-naphthalenetrisulfonic acid), MRS2159 (pyridoxal-α5-phosphate-6-phenylazo-4′-carboxylic acid) (100 μm), and NF449 [4,4′,4,4-(carbonylbis(imino-5,1,3-benzenetriylbis(carbonylimino)))tetrakis-benzene-1,3-disulfonic acid] (3 μm) abolished contractions to α,β-meATP (1 μm; n = 4–5), but only reduced contractions evoked by 4 Hz nerve stimulation by ∼40–60% (n = 4–6) and ATP by 30–60% (n = 4–7). However, prolonged exposure to α,β-meATP (50 μm) abolished contractions evoked by all three stimuli (n = 5–12). PPADS (100 μm) and suramin (300 μm) reduced the peak neurogenic contraction of the mouse urinary bladder to 30–40% of control. At the same concentrations, the P2X1 antagonists abolished the nonadrenergic, purinergic component of neurogenic contractions in the guinea pig vas deferens (n = 4–5). Thus, P2X1 receptor antagonists inhibit, but do not abolish, the noncholinergic component of neurogenic contractions of guinea pig and mouse urinary bladder, indicating a second mode of action of neuronally released ATP. This has important implications for treatment of dysfunctional urinary bladder, for which this atropine- and P2X1 antagonist-resistant site represents a novel therapeutic target

Transforming fixed-length self-avoiding walks into radial SLE_8/3

We conjecture a relationship between the scaling limit of the fixed-length ensemble of self-avoiding walks in the upper half plane and radial SLE with kappa=8/3 in this half plane from 0 to i. The relationship is that if we take a curve from the fixed-length scaling limit of the SAW, weight it by a suitable power of the distance to the endpoint of the curve and then apply the conformal map of the half plane that takes the endpoint to i, then we get the same probability measure on curves as radial SLE. In addition to a non-rigorous derivation of this conjecture, we support it with Monte Carlo simulations of the SAW. Using the conjectured relationship between the SAW and radial SLE, our simulations give estimates for both the interior and boundary scaling exponents. The values we obtain are within a few hundredths of a percent of the conjectured values

Computer aids for worst case electronic circuit design

Computer aids for worst case electronic circuit desig

The Effects of Praise Notes on the Disruptive Behaviors of Elementary Students with Emotional and Behavioral Disorders in a Residential Setting

In this study, the effects of two secondary tier positive behavioral support strategies, teacher praise notes (TPNs) and peer praise notes (PPNs), were investigated using an alternating treatments single-subject design in residential classroom settings with eight elementary students with emotional and behavioral disorders (E/BD) in grades one through five who displayed disruptive behaviors. These students were selected based on the following criteria: (a) identified as using attention-seeking behaviors to disrupt classroom instruction, and (b) accrued an average of three or more office discipline referrals (ODRs) during classroom instruction since the beginning of the semester. Teacher praise notes are notes written by the teacher to a student regarding observed appropriate classroom behaviors while peer praise notes are written by the students to peers of their choice regarding observed appropriate behaviors. The type of praise notes were counterbalanced across each session. Duration recording was used to record the length of disruption per student during all sessions. Data were analyzed by visual analysis. The results suggest that TPNs and PPNs decreased disruptive behaviors of the students with E/BD in a residential setting; however, there was minimal to no fractionation between the two interventions. Limitations and future for research directions are discussed

Computing the Loewner driving process of random curves in the half plane

We simulate several models of random curves in the half plane and numerically compute their stochastic driving process (as given by the Loewner equation). Our models include models whose scaling limit is the Schramm-Loewner evolution (SLE) and models for which it is not. We study several tests of whether the driving process is Brownian motion. We find that just testing the normality of the process at a fixed time is not effective at determining if the process is Brownian motion. Tests that involve the independence of the increments of Brownian motion are much more effective. We also study the zipper algorithm for numerically computing the driving function of a simple curve. We give an implementation of this algorithm which runs in a time O(N^1.35) rather than the usual O(N^2), where N is the number of points on the curve.Comment: 20 pages, 4 figures. Changes to second version: added new paragraph to conclusion section; improved figures cosmeticall