Changes in medical stability upon admission to a rehabilitation unit

The implementation of Medicare's prospective payment system in acute care has coincided with a steady increase in medically unstable admissions to our freestanding rehabilitation facility. We investigated the consequences of these admissions by collecting medical information regarding transfers beginning in 1983. Patients requiring transfer back to the acute setting within 1 day of admission were considered medically unstable and their charts were reviewed. The number of patients requiring transfer back within 1 day increased from 1.5% of all first admissions to 3.1% in 1988 (Mantel - Haenszel chi 2 = 8.03, (df = 1), p < .01), but the increase among Medicare patients alone was not significant. This progressive increase was most pronounced in the cerebrovascular accident and spinal cord injury populations. Beginning in 1988, an intensified preadmission evaluation program was implemented, resulting in a significant decline in unstable patient transfers from hospitals where our consultants were on staff. Physiatric consultations at referral institutions decreased the number of unstable patients at admission.     

Perceptual image hashing via feature points: performance evaluation and tradeoffs.

We propose an image hashing paradigm using visually significant feature points. The feature points should be largely invariant under perceptually insignificant distortions. To satisfy this, we propose an iterative feature detector to extract significant geometry preserving feature points. We apply probabilistic quantization on the derived features to introduce randomness, which, in turn, reduces vulnerability to adversarial attacks. The proposed hash algorithm withstands standard benchmark (e.g., Stirmark) attacks, including compression, geometric distortions of scaling and small-angle rotation, and common signal-processing operations. Content changing (malicious) manipulations of image data are also accurately detected. Detailed statistical analysis in the form of receiver operating characteristic (ROC) curves is presented and reveals the success of the proposed scheme in achieving perceptual robustness while avoiding misclassification.     

Optimization free neural network approach for solving ordinary and partial differential equations

Current work introduces a fast converging neural network-based approach for solution of ordinary and partial differential equations. Proposed technique eliminates the need of time-consuming optimization procedure for training of neural network. Rather, it uses the extreme learning machine algorithm for calculating the neural network parameters so as to make it satisfy the differential equation and associated boundary conditions. Various ordinary and partial differential equations are treated using this technique, and accuracy and convergence aspects of the procedure are discussed.

     

Design optimization of high voltage bushing using electric field computations

This paper illustrates the use of electric field computation to optimize the design of gas filled high voltage composite bushings. The United States Navy employs these bushings in high power very low frequency/low frequency transmitting stations. Commercially available 2D and 3D computational packages based on the boundary element method were employed to analyze the electric fields. The optimized design uses both internal and external elements for electric stress grading at critical parts of the bushing. It has been shown that the location and magnitude of the maximum electric field have been optimized which should result in a substantially higher corona free operating voltage     

Using pore space 3D geometrical modelling to simulate biological activity: Impact of soil structure

This study is the follow-up to a previous one devoted to soil pore space modelling. In the previous study, we proposed algorithms to represent soil pore space by means of optimal piecewise approximation using simple 3D geometrical primitives: balls, cylinders, cones, etc. In the present study, we use the ball-based piecewise approximation to simulate biological activity. The basic idea for modelling pore space consists in representing pore space using a minimal set of maximal balls (Delaunay spheres) recovering the shape skeleton. In this representation, each ball is considered as a maximal local cavity corresponding to the “intuitive” notion of a pore as described in the literature. The space segmentation induced by the network of balls (pores) is then used to spatialise biological dynamics. Organic matter and microbial decomposers are distributed within the balls (pores). A valuated graph representing the pore network, organic matter and microorganism distribution is then defined. Microbial soil organic matter decomposition is simulated by updating this valuated graph. The method has been implemented and tested on real data. As far as we know, this approach is the first one to formally link pore space geometry and biological dynamics. The long-term goal is to define geometrical typologies of pore space shape that can be attached to specific biological dynamic properties. This paper is a first attempt to achieve this goal.     

Quantitative Assessment of a Peer-to-peer Cooperative Infrastructure Using Stochastic Well-Formed Nets

Traditional support tools for software engineers, normally based on a client-server architecture, are unsuitable to deal with the new issues emerging from the current (and future) cooperative work scenarios (where connectivity is intrinsically transient, the number of interacting partners dynamically changes, etc.). This paper presents a quantitative assessment of a fully decentralized, peer-to-peer, cooperative infrastructure. Stochastic Well-Formed Nets (SWNs) modelling the new peer-to-peer architecture, and a traditional (client-server) one, are developed and analysed: we used SWNs for their ability to directly exploit the symmetries intrinsically present in the modelled systems, thus greatly reducing the complexity of the analysis. The main goal is to compare the impact of the two alternative protocols on the collaborative work. Together with the performance figures of interest, methodological issues concerning the choice of the most appropriate model abstraction level, the adoption of a compositional modelling approach, and the management of the model complexity are also discussed.     

Fourier transform infrared-probed O(3P) microreactor: demonstration with ethylene reactions in argon matrix

To demonstrate the development of an oxygen atom microreactor in the form of liquid-helium-cooled solid argon matrix deposited on an infrared (IR) window, the oxidation of ethylene by mobile O atoms has been investigated. O atom diffusion through the argon matrix is confirmed and used to examine ethylene-oxygen atom reactions. In a bench-scale matrix isolation system probed with a Fourier transform infrared (FT-IR) spectrometer, matrices of solid Ar at 8-10 K doped with NO2 and ethylene have been prepared on a ZnSe window within an evacuated cryostat. The matrices have been photolyzed using 350-450 nm photons, and the reaction products resulting from the reaction of O(3P), one of the photolysis products of NO2, with ethylene have been identified using FT-IR and a Gaussian 98W simulation program. These products include oxirane, acetaldehyde, ethyl nitrite radical, and ketene. The temperature effect in the range of 10-30 K on the products formed has also been investigated. The reaction mechanisms are discussed and the viability of the solid Ar matrix being a low temperature microreactor to examine reaction mechanisms of mobile oxygen atoms is elaborated.     

Sexuality in head and neck cancer patients

We describe a patient with Hirschsprung disease and autism. High-resolution karyotyping indicated that the patient has an interstitial deletion of 20p11.22-p11.23. Microsatellite analysis showed a deletion involving a 5-6 cM region from the maternally derived chromosome 20. The deleted region is proximal to, and does not overlap, the recently characterized Alagille syndrome region. This region of 20p has not yet been implicated in Hirschsprung disease or autism. However, this region contains several genes that could plausibly contribute to any phenotype that includes abnormal neural development.     

Maternal-fetal transfers: indications, appropriateness, and cost

The objective of this study was to assess the indications, appropriateness, and cost of maternal-fetal transfers to a tertiary care facility in an era of managed care. Our perinatal database was reviewed from January 1, 1996 through June 30, 1997 to determine maternal and fetal indications for transfer, referring institution characteristics, utilization of tertiary level services, and cost of transfer. There were 273 transfers from 53 referring hospitals ranging in distance from <20 miles (n = 102) to >100 miles (n = 41). Thirty-one patients were transferred by air (average cost $7656), 238 by ground (average cost $920), 4 by private car. The referring diagnosis was preterm premature rupture of membranes (PPROM) (n = 80), preterm labor (n = 76), preeclampsia (n = 42), medical complications (n = 25), or other (n = 50). Mean gestational age (GA) at transfer was 28.5+/-5.5 weeks. Patients were referred from hospitals with a self-designated nursery level I (n = 115), II (n = 111), III (n = 45), or none (n = 2). In 42 patients, (15%) no maternal or fetal indication for hospital transfer was identified after evaluation at the tertiary center. The most common referring misdiagnoses were preterm labor (n = 25), PPROM (n = 10) and preeclampsia (n = 3). One hundred and sixty-five patients delivered during transfer admission (mean GA = 29.6+/-4.8 weeks); 79 infants (48%) required admission to a level III, and 52 (31%) to a level II nursery. Most patients require the services of a tertiary facility after maternal fetal transfer. If delivered during transfer admission, the majority of neonates require care in an intermediate or intensive care nursery.