Spatio-temporal EEG source localization using simulated annealing

The estimation of multiple dipole parameters in spatio-temporal source modeling (STSM) of electroencephalographic (EEG) data is a difficult nonlinear optimization problem due to multiple local minima in the cost function. A straightforward iterative optimization approach to such a problem is very susceptible to being trapped in a local minimum, thereby resulting in incorrect estimates of the dipole parameters. Here, the authors present and evaluate a more robust optimization approach based on the simulated annealing algorithm. The complexity of this approach for the STSM problem was reduced by separating the dipole parameters into linear (moment) and nonlinear (location) components. The effectiveness of the proposed method and its superiority over the traditional nonlinear simplex technique in escaping local minima were tested and demonstrated through computer simulations. The annealing algorithm and its implementation for multidipole estimation are also discussed. The authors found the simulated annealing approach to be 7-31% more effective than the simplex method at converging to the true global minimum for a number of different kinds of three-dipole problems simulated in this work. In addition, the computational cost of the proposed approach was only marginally higher than its simplex counterpart. The annealing method also yielded similar solutions irrespective of the initial guesses used. The proposed simulated annealing method is an attractive alternative to the simplex method that is currently more common in dipole estimation applications     

Developmental patterns of acid hydrolases during differentiation of fetal mouse skin

A dye reduction method was developed for estimating total aerobic and/or psychrotrophic bacterial counts in ground beef. The method is based on color changes in indicator disks placed on the meat surface.     

Inhibition of HeLa cell messenger RNA translation by 7-methylguanosine 5'-monophosphate

Translation of HeLa cell RNA containing poly(A) in a wheat germ cell-free system is markedly but incompletely inhibited by 7-methylguanosine 5'-monophosphate (m7G5'p). We have analyzed the translation products synthesized in the presence of different concentrations of m7G5'p and find that translation of all mRNAs is equally inhibited. To demonstrate the specificity of the inhibitor for RNAs with 5'-terminal m7G5' ppp... we show that specific translation products of satellite tobacco necrosis virus RNA, which does not have this 5' terminus, are synthesized in the presence of m7G5' p. Protein synthesis programmed by endogenous mRNA in a HeLa cell-free system is inhibited after a 10-min lag by m7G5' p. Other guanosine nucleotides without the 7-methyl group or with the phosphate in a different position are not inhibitor. We show that translation of all mRNAs is inhibited to a similar extent by m7G5'p in the HeLa cell-free system, by synthesizing 35S-labeled proteins in the presence of different inhibitory concentrations of this nucleotide and analyzing the translation products by electrophoresis and autoradiography. Translation of encephalomyocarditis virus RNA added to the HeLa cell-free system is not inhibited by m7"g5p; this viral RNA does not have this nucleotide at the 5' terminus. This indicates that m7G5'p specifically inhibits translation of mRNAs with the 5' terminus m7G5'ppp... and suggests that initiation of translation of picornavirus RNA may proceed via a mechanism different from that of cellular mRNAs.     

Low levels of beta hexosaminidase A in healthy individuals with apparent deficiency of this enzyme

The common denominator of the different meanings of dizziness is a disturbance of spatio-postural orientation, which indicates an imminent danger of fall. H?henschwindel (fear of hights) with grasping and holding in the primate is instinctive behavior caused by a visual cliff or sudden dizziness. Because of the many possible meanings of dizziness, the case history is important for differential diagnosis. Vertiginous and non-vertiginous dizziness, black out and unsteady gait without vertigo should be distinguished. In addition, the duration and time course of the attack, releasing mechanisms and accompanying symptoms of dizziness should be explored. In recurrent dizziness without hearing loss, vestibular, vascular, cardial and epileptic disorders should be considered as well as intoxication, cerebral tumor, cerebellar hemangioblastoma, multiple sclerosis, neurosis and psychosis. Epileptic dizziness occurs not only in the prodromal stage of grand mal attacks and in temporal lobe epilepsy, but also in petit mal absences of short duration (less than 5 s) in which the blurring of consciousness is not apparent; absences of short duration are easily overlooked in childhood. Besides the objective history obtained from the patient's relatives, EEG-recording when falling asleep in the morning after one night of sleep deprivation are the best means for the diagnosis of epilepsia. Spontaneous nystagmus after complete exclusion of visual fixation is a physiological phenomenon. For differential diagnosis between physiological and pathological spontaneous nystagmus, Frenzel's spectacles in the dark room are indispensable. The distinction of spontaneous nystagmus in the narrower sense, gaze nystagmus and fixation nystagmus is discussed. The diagnostic importance of the direction of nystagmus is mentioned. Jerking nystagmus may be congenital. Pendular nystagmus may be acquired. Therefore, additional criteria for the differential diagnosis between congenital and acquired nystagmus are necessary.     

The doctor, the pill and lipaemic disorders. Reflections following an investigation (author's transl)

Blood lipids were determined in 82 women about to become oral contraceptive users and nonusers, 21 women taking sequential pills, and 1067 women taking combined pills for 2 months to 6 years. Results were reported as number and percent above the normal limits taken as: 7 gm/liter for total lipids, 2.6 gm/liter for total cholesterol, and 1.5 gm/liter triglycerides. There were 4 cases of hypertriglyceridemia among the non-pill-users, or 4.8% abnormal. The sequential pill users had 2 with high cholesterol, 3 with high triglycerides, and 1 with mixed hyperlipidemia, or 30% abnormal. Those using combined pills had a total 6.2% abnormal, including 28 (2.6%) with hypercholesterolemia, 29 (2.7%) with hypertriglyceridemia, and 10 (.9%) with mixed hyperlipidemia. The mixed hyperlipidemia is the most dangerous with respect to risk of thromboembolism. Women with abnormal blood lipids should take low-dose pills, follow a low fat and carbohydrate diet, and stop oral contraception if the levels are frankly abnormal.     

Contractile events during inflammation

Contractile events during wound healing. During granulation tissue contraction, fibroblasts develop characteristics typical of smooth muscle; (1) they contain an extensive cytoplasmic fibrillar system, (2) they show immunofluorescent labeling of anti-actin antibodies, (3) there are cell and cell to stroma attachments, (4) strips of granulation tissue, when tested pharmacologically in vitro, behave similarly to smooth muscle. These data support the view that under certain conditions, fibroblasts can differentiate into a cell type structurally and functionally similar to smooth muscle and this cell, the 'myofibroblast', plays an important role in connective tissue contraction. During epithelialization, epidermal cells develop an extensive cytoplasmic contractile apparatus which has morphological and immunological characteristics similar to those of myofibroblasts. Such apparatus disappears as soon as epithelialization is completed. It is proposed that such a contractile apparatus plays a role in cell motility enabeling individual cells to rearrange themselves in an appropriate pattern. In conclusion, significant amounts of contractile proteins may be synthetized by fibroblasts and epithelial cells during wound healing and may play an important role in this process.     

4-aminobiphenyl, 2-naphthylamine, and analogs: analytical properties and trace analysis in five substrates

Methods for monitoring trace levels of 4-aminobiphenyl, 2-naphthylamine, and their hydrochloride salts in waste water, microbiological growth media, potable water, human urine, and mouse blood utilizing spectrophotofluorometry (SPF) are described. The salient elements of the methods are extraction of the residues as the free amine with benzene, rapid cleanup on an alumina column, and quantification of the free amine in methanol via SPF. Potable water solutions of the salts are diluted with 0.01 N aqueous HCL and quantified directly by SPF. Ancillary analytical information concerning gas chromatography of the free amines, partitioning properties of the compounds between solvent pairs, their solubility and stability in water, and thin-layer chromatographic data is presented. The compositions of various admixtures of 1- and 2-naphthylamine or their salts were determined by using SPF with calculations based on simultaneous equations.