Alcoholism at the time of injury among trauma center patients: Vehicular crash victims compared with other patients

A structured in-depth interview employing standardized criteria was used to determine the prevalence of lifetime and current alcohol dependence (alcoholism) in unselected consecutive patients admitted to a regional Level I trauma center. Of 629 patients, 157 (25.0%) were current alcoholics at the time of injury. An additional 87 (13.8%) were diagnosed as lifetime non-current alcoholics. There was no significant difference in the rates of current alcohol dependence among patients injured in vehicular crashes (23.5%), other unintentional trauma victims (29.3%), and those injured as a result of violence (24.6%). Of BAC + (blood alcohol concentration positive) patients, 54.5% were current alcoholics. However, 14.4% of alcohol-negative patients were also diagnosed as alcohol dependent.     

On instrumental variable estimation of sinusoid frequencies and the parsimony principle

Multiple sinusoids in noise can be modeled as an ARMA process with the AR parameters satisfying certain symmetry relations. According to the "parsimony principle" the constraints on the AR parameters should he taken into account to get improved estimation accuracy. It is shown in this note that when estimating the AR parameters by a general instrumental-variable method, such a parsimony does not necessarily apply. However, the parsimony principle does hold when an optimal instrumental-variable method is used.     

Optimal high-order Yule-Walker estimation of sinusoidal frequencies

The asymptotic properties of sinusoidal frequency estimators based on the high-order Yule-Walker (HOYW) equations were analyzed recently. The results of that analysis are used to propose two classes of frequency estimators; one class uses singular value decomposition, and the other uses a sparse matrix solution. Both classes entail two estimation steps: the first step generates initial estimates which are used to obtain an optimal weighting matrix, and the second step generates an optimally weighted estimate. Each two-step method produces asymptotically minimum variance estimates over all estimators of their class. The implementation of the proposed estimators is described in detail, and numerical examples are presented to evaluate their performance     

Isoniazid poisoning: Pharmacokinetics and effect of hemodialysis in a massive ingestion

Isoniazid is a rare overdose that causes seizures and there is limited evidence to guide treatment. We report a 20‐year‐old female migrant who presented with recurrent seizures after ingesting 25 g of isoniazid. She was treated with activated charcoal, repeated doses of midazolam for the seizures, and given multiple doses of pyridoxine (14 mg), limited by availability. She was admitted to intensive care, and 5.5 hours post‐ingestion, she was commenced on continuous veno‐venous hemodiafiltration (CVVHDF). She was extubated after 24 hours and CVVHDF was ceased 6 hours later (30 hours post‐overdose). Her renal function remained normal and her initial lactate was the highest at 2.3. She made a full recovery. Five plasma samples were collected before, during, and after CVVHDF, and isoniazid was quantified with liquid chromatography‐tandem mass spectrometry. A pharmacokinetic analysis of time‐isoniazid concentration data was fitted to a two‐compartment model with first‐order input (with fixed k_a) with the effect of CVVHDF modeled as a time‐dependent covariate. This suggested that there was initially good clearance with CVVHDF (4 times endogenous clearance), which rapidly declined within hours.     

State-space and Yule-Walker approaches to pole estimation

The pole estimates provided by the state-space and Yule-Walker approaches are shown to coincide in the cases where the Hankel matrix of sample covariances used by both methods has full column rank.<>     

Alcohol and other drugs: an assessment of testing and clinical practices in U.S. trauma centers

The PsaC protein binds two 4Fe-4S centers, FA and FB, in the photosystem I (PSI) protein complex. In the T398 strain of Anabaena variabilis ATCC 29413, the psaC gene encoding this protein has been insertionally inactivated by the introduction of a neomycin resistance gene cartridge in the coding region. Photosystem I complex was purified through native gel electrophoresis of beta-dodecyl maltoside solubilized thylakoid membranes from wild-type and T398 strains of Anabaena 29413. The PSI complex from T398 strain retained functionally active P700, the reaction center chlorophylls. Interestingly, purified PSI complex from T398 cells lacked the PsaD, PsaE, and PsaL polypeptides. Western analysis with polyclonal antibodies raised against these proteins indicated that the two stromal exposed polypeptides, PsaD and PsaE, are absent in isolated thylakoid membranes from T398 cells. The PsaL polypeptide could be detected at a level comparable to that in wild-type thylakoid membranes, although it is absent in the PSI preparation from the mutant. These observations suggest that the PsaC protein is essential for the stable association of PsaD and PsaE, two hydrophilic, extrinsic polypeptides. Moreover, PsaL, a hydrophobic protein is loosely associated with PSI and is lost during the isolation of the PSI complex.     

Optimal instrumental variable estimation and approximate implementations

The accuracy properties of instrumental variables (IV) methods are investigated. Extensions such as prefiltering of data and use of additional instruments are included in the analysis. The parameter estimates are shown to be asymptotically Gaussian distributed. An explicit expression is given for the covariance matrix of their distribution. The covariance matrix is then taken as a (multivariable) measure of accuracy. It is shown how it can be optimized by an appropriate selection of instruments and prefilter. The so obtained optimal instrumental variable estimates cannot be used directly since the true system and the statistical properties of the disturbance must be known in order to compute the optimal instruments and prefilters. A multistep procedure consisting of three or four simple steps is then proposed as a way to overcome this difficulty. This procedure includes modeling of the disturbance as an ARMA process using a statistically efficient method such as a prediction error method. The statistical properties of the estimates obtained with the multistep procedure are also analyzed. Those estimates are shown to be asymptotically Gaussian distributed as well. The covariance matrix of the estimation errors is compared to that corresponding to a prediction error method. For some model structures these two approaches give the same asymptotic accuracy. The conclusion is that the multistep procedure, which is quite easy to implement and also has nice uniqueness properties, can be viewed as an interesting alternative to prediction error methods.     

On Di's and subspace fitting approaches to direction estimation

The article relates the method for direction estimation in possibly coherent scenarios, which was proposed by Di (1985), to the class of subspace fitting (SSF) methods recently introduced in the literature. It also makes some general comments on the SSF class     

Asymmetrical principal component analysis for video coding

Principal component analysis (PCA) can be used to encode video sequences at extremely low bit rates, e.g. 34.6 dB (PSNR) at 4.2 kbit/s. The same eigenvectors are used for encoding and decoding for this coding. Introduced is a coding scheme where eigenvectors for only part of the video frames are used for encoding but the eigenvectors for the entire frame are used for decoding. This is called asymmetric PCA coding. This reduces the complexity of encoding by ap5 times and at the same time increases the reconstruction quality for the facial part of the video with 0.4 dB (PSNR)..