Analysis of EMG and acceleration signals for quantifying the effects of deep brain stimulation in Parkinson's disease

Deep brain stimulation (DBS) is effective in reducing motor symptoms in Parkinson's disease (PD). However, objective methods for quantifying its efficacy are lacking. We present a principal component (PC)-based tracking method for quantifying the effects of DBS in PD by using electromyography (EMG) and acceleration measurements. Ten parameters capturing PD characteristic signal features were initially extracted from isometric EMG and acceleration recordings. Using a PC approach, the original parameters were transformed into a smaller number of PCs. Finally, the effects of DBS were quantified by examining the PCs in a low-dimensional feature space. The EMG and acceleration data from 13 PD patients with DBS ON and OFF, and 13 healthy age-matched controls were used for analysis. Clinical evaluation of patients showed that their motor symptoms were effectively reduced with DBS. The analysis results showed that the signal characteristics of 12 patients were more similar to those of the healthy controls with DBS ON than with DBS OFF. These observations indicate that the PC-based tracking method can be used to objectively quantify the effects of DBS on the neuromuscular function of PD patients. Further studies are suggested to estimate the clinical sensitivity of the method to different types of PD.     

Partially hidden Markov models

Partially hidden Markov models (PHMM) are introduced. They differ from the ordinary HMMs in that both the transition probabilities of the hidden states and the output probabilities are conditioned on past observations. As an illustration they are applied to black and white image compression where the hidden variables may be interpreted as representing noncausal pixels     

Fast universal coding with context models

A universal code using context models is constructed, which is optimal in the strong sense that the mean per symbol code length approaches asymptotically the entropy of any data generating tree machine at the fastest possible rate. The number of coding operations required is O (n log log n) for a string of length n, which is much less than in the earlier codes using context models. This is made possible by two new results. The first is a theorem stating that the updates required for universality need be done only once for each batch, the length of which grows at nearly exponential rate in the number of batches. The second is a fast implementation of the tree-building part in algorithm context     

Dynamic modeling of a multiple hearth furnace for kaolin calcination

A dynamic model of a multiple hearth kaolin calciner has been developed and is presented in this article. This model describes the physical‐chemical phenomena taking place in the six furnace parts: the solid phase, gas phase, walls, cooling air, rabble arms, and the central shaft. The solid phase movement, in particular, is described by a novel mixing model. The mixing model divides the solid bed in a hearth into volumes and the distribution of their contents, after one full central shaft rotation, is identified by the pilot experiments. First, the model is validated by the industrial data, and then the dynamics of the multiple hearth furnace is studied by introducing step changes to the three manipulated variables: the feed rate, and the gas, and air flows supplied. The responses of the gas phase temperature and solid bed component profiles are analysed and the results are discussed. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3683–3698, 2015     

Effect of hot drawing on properties of wet‐spun poly(L,D‐lactide) copolymer multifilament fibers

Polylactide stereocopolymer multifilament fibers were prepared by wet spinning and subsequent hot drawing. The stereocopolymers were poly‐(L,D ‐lactide) [P(L,D )LA], L/D ratio 96/4, and poly‐(L,DL ‐lactide) [P(L,DL )LA], L/DL ratio 70/30. They were dissolved in dichloromethane and coagulated in a spin bath containing ethanol. The hot‐drawing temperature was 65°C. The draw ratios (DR) were upto 4.5 to the P(L,D )LA 96/4 filaments and upto 3 to the P(L,DL )LA 70/30 filaments. Wet spinning decreased crystallinities of both copolymers. Hot drawing increased the crystallinity of the P(L,D )LA 96/4 filament but not to the level of the original copolymer, whereas the as‐spun and the hot‐drawn P(L,DL )LA 70/30 filaments were amorphous. The filament diameter, tenacity, Young's modulus, and elongation at break were dependent on the DR. The maximum tenacity (285 MPa) and Young's modulus (2.0 GPa) were achieved with the P(L,D )LA 96/4 filament at the DR of 4.5. Respectively, the maximum tenacity of the hot‐drawn P(L,DL )LA 70/30 filament was 175 MPa and Young's modulus 1.3 GPa at the DR of 3. Hot drawing slowed down in vitro degradation rate of both stereocopolymer filaments. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

A New Technique for Recording High-Voltage Transients in Telephone Networks

Some basic difficulties in the protection of telephone networks against dangerous overvoltage disturbances such as lightning are discussed, and a new method for measuring and recording such transients is presented. The method essentially consists of measuring the analog disturbance signals, converting and coding their temporal values into digital numbers easily available to shift register memories and subsequently recording the results either with a teleprinter for computer analysis and statistical abstracts or with axy-recorder for a human observer. The instrument is capable of recording disturbance amplitudes of 0.1-MHz spectral content linearly with an 300-V interval up to voltages of 5 kV, the sampling rate of the A/D converter used for the recording being adjustable to values of 500 kHz, 1 MHz or 2 MHz. The digital circuits of the instrument use positive logic and are realized for the most part by TTL and MOS technologies.     

DNA sequence compression - Based on the normalized maximum likelihood model

Genomic data provide challenging problems that have been studied in a number of fields such as statistics, signal processing, information theory, and computer science. This article shows that the methodologies and tools that have been recently developed in these fields for modeling signals and processes appear to be most promising for genomic research     

Palladium-Catalyzed Domino Reaction for the Synthesis of 3-Amino 1,2,4-Benzothiadiazine 1,1-Dioxides

A palladium-catalyzed domino reaction of 2-azidosulfonamides and isocyanides enables the synthesis of 3-amino-substituted 1,2,4-benzothiadiazine 1,1-dioxides at room temperature. By applying commercially available Pd(dba)₂ in catalyst loadings as low as 1.0 mol%, a variety of 21 differently substituted 2H-1,2,4-benzothiadiazine 1,1-dioxides can be prepared within 2 h. Moreover, the developed protocol gives access to the related 4H heterocycles.     

Hospital- and patient-related characteristics determining length of hospital stay for hip and knee replacements

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are among the most prestigious health care technologies. Their popularity has grown rapidly, and an increasing proportion of health care resources is allocated to them. We studied patient- and hospital-related factors that cause variation in a major determinant of hospital costs, the length of hospital stay (LOS) for THA and TKA. We gathered data on 10,288 hip and 5,173 knee patients with primary or secondary arthrosis from the Finnish Arthroplasty Register, which we linked with the Finnish Hospital Discharge Register. Patient- and hospital-related variations in LOS were explained using regression models. Of the patient-related factors, complications caused the greatest prolongation of hospital stay, but patient's age, gender, and charge category also influenced LOS. Hospital-related factors were major causes of LOS variation. In the hospitals the average case-mix-adjusted LOS ranged from less than a week to 3 weeks. The number of arthroplasties performed in hospital was inversely related to LOS. The within-hospital LOS figures for THA and TKA were strikingly similar and persistent.