Linear prediction analysis of speech based on set-membership theory

When computing linear prediction (LP) parameters of speech, large numbers of data are uninformative in a certain set-theoretic sense, and the expense of updating the estimates at these times can be avoided. “Set-membership” (SM) identification is formulated as a weighted recursive covariance LP problem with a special criterion for dynamic weight determination. An algorithm is developed which can be implemented on a systolic processor if desired, but which retains a simple interpretation as a specially weighted convariance LP method. The algorithm is applied to identification of the LP parameters of real speech data, and a number of practical issues are discussed. The potential for an adaptive strategy and other open research questions generated by the experimental work are discussed in the conclusions.     

Water Based Silicone Elastomer Controlled Release Tablet Film Coating IV Process Evaluation

The processing conditions in an air suspension column were found to be critical in producing controlled release polyethylene glycol-silicone elastomer tablet film coatings. The coating equipment used was also shown to play a major role in determining the permeability of the resultant tablet coatings. This pronounced process dependent phenomenon was explained by the film layering mechanism involved in the formation of the polyethylene glycol containing silicone elastomer coating on tablets.     

Water based silicone elastomer controlled release tablet film coating VI: The effect of tablet shape

The silicone elastomer latex containing colloidal silica and poloyoxyethylene glycol 8,000 was shown to produce controlled released film coating on potassium chloride tablets with different shapes. The tablet shape did not affect the zero-order release characteristic of the active ingredinent from the coated tablests. With the same coating weight, the capsule shaped tablets exhibited a faster drug release rate as compared to the oval and round deep-cup shaped tablets.     

Initial stages of the GaN growth on oxidized silicon

Initial stages of the GaN layer growth during an HVPE process at 520°C on an oxidized silicon substrate were studied by atomic force microscopy. It was established that (i) the growth of GaN islands is controlled by the surface diffusion and (ii) the nucleus size distribution on the surface significantly changes when the growth time increases from 10 to 200 min: during this period of time, the average nucleus size increases from 15 to 400 nm and their size scatter becomes 20 times as large as the initial size distribution width. The experimentally determined growth rate of the GaN nuclei and the nucleus size distribution are in good agreement with theoretical calculations.     

Information-compressed structure of an edge laser speckle pattern

A correlation is established experimentally between the real “faceted” structure of the cutting area of a blade according to electron microscopy data and the spatial quantization of an image of the recorded speckle field (upon the maximum compression of the recorded information to logical zeroes and ones) in coherent optical analyses of the diffraction effect at the blade edge. This correlation may prove useful for solving the inverse technical problem (with equally justified variants of concepts for the theoretical modeling of a specific situation). Pis’ma Zh. Tekh. Fiz. 23, 42–46 (October 12, 1997)     

Hepatobiliary complications of idiopathic intestinal inflammations

Extraintestinal manifestations and metabolic complications are very frequent in patients with idiopathic inflammations of the gut and are encountered in at least 35% of these patients. In Crohn's disease extraintestinal manifestations are more frequent than in ulcerative colitis, in particular when the large bowel is affected. Metabolic complications are the result of inflammatory changes of the small intestine or develop as a result of the reduced reabsorption surface of the gut. As to the relationship to the activity of the idiopathic inflammation of the gut, extraintestinal manifestations can be differentiated into those which depend on the activity of the basic disease and those which lack this dependence. From the aspect of a long-term prognosis extraintestinal manifestation independent on the activity of the inflammation of the gut are much more serious, because as a rule they have a long-term and usually progressive trend. The most serious extraintestinal complication is primary sclerotizing cholangitis which in the majority of patients leads to destruction of the biliary pathways and the development of biliary cirrhosis. Depending on the predominantly affected site of the biliary system, primary sclerotizing cholangitis is divided into three types. It is encountered much more frequently in ulcerative colitis than in Crohn's disease. Treatment of primary sclerotizing cholangitis is not very effective. At present it appears that the only drug with an effect on the course of the disease is long-term administration of urodesoxycholic acid. For patients with manifestations of hepatic insufficiency the only solution is transplantation of the liver. In all patients where the diagnosis of primary sclerotizing cholangitis was established, at the same time the possibility of inclusion in a transplantation programme should be considered. The relationship between sclerotizing cholangitis and pericholangitis has not been resolved conclusively. At present the majority of authors is inclined to believe that pericholangitis is part of changes associated with sclerotizing cholangitis. Other hepatobiliary complications of idiopathic inflammations of the gut such as cholelithiasis and parenchymatous liver damage, steatosis of the liver and chronic autoimmune hepatitis are not such a serious problem as sclerotizing cholangitis.     

Sudden cardiac death in the adult with congenital heart disease

Preliminary results of a review of sudden cardiac death in the adult with congenital heart disease were presented at the Canadian Adult Congenital Heart (CACH) Network meeting during the Canadian Cardiovascular Society's annual meeting in October 1994. Of 125 patients who were known to have died, sufficient details were available for 92 to determine the circumstance of death. Sudden death occurred in 23 patients (estimated incidence 5.3 per 1000 patients followed per year) at an average age of 33.5 +/- 11.9 years. Surgical procedures included intracardiac repair in 12, palliative procedures in only six and no cardiac surgery in six. Nine patients with sudden death had Eisenmenger syndrome. Right or left ventricular abnormalities were present in 15 of 21 patients with premorbid echocardiographic evaluation. A prior history of ventricular arrhythmia was available in only three patients. Sudden death is a significant cause of mortality in adults with congenital heart disease. Determination of risk factors will be an important aspect of the patient database under development by the CACH Network.     

Risk factors for pulmonary tuberculosis in bone marrow transplant recipients

Little is known about the profile of infection with Mycobacterium tuberculosis in bone marrow transplant (BMT) recipients. Of five BMT series with a total of more than 5,000 patients, only 10 cases of M. tuberculosis infection were described, with an overall incidence of 0.19%. We have conducted a prospective evaluation of 183 consecutive BMT recipients, and 10 patients were found to develop pulmonary tuberculosis post-BMT, yielding an incidence of 5.5%. We described the clinical features of these 10 patients, and analyzed the risk factors for development of tuberculosis using age- and sex-matched case control subjects who did not develop the disease. The median age of the 10 patients who developed tuberculosis was 29 yr (range, 17 to 40 yr). The median time for onset of symptoms was 150 d (range, 23 to 550 d), mainly presenting with fever and cough, with infiltrates on chest radiograph. Respiratory tract specimens, mostly sputum, yielded positive smears for acid-fast bacilli in three and positive M. tuberculosis culture in eight, whereas lung tissue histology was the first diagnostic test in two patients. Treatment with standard antituberculosis drugs for a longer duration was highly effective, with no excessive side effects. Risk factors identified for development of tuberculosis included allogeneic BMT (p < 0.05, relative risk [RR] = 23.7), total body irradiation (p < 0. 05, RR = 4.9), and chronic graft-versus-host disease (GVHD) (p < 0. 05, RR = 3.6). It is postulated that chronic GVHD predisposed to development of tuberculosis mainly via disruption of host reconstitution of immune defenses against M. tuberculosis.