The behavioral development of rats with prenatal hypoinsulinemia

Influence of the prenatal hypoinsulinaemia (streptozocin diabetes) on the behaviour of the offsprings of Wistar rats was studied from 1 to 20 postnatal days. In experimental pups there were slower weight increment, later eye opening, later development of elementary behavioural acts (grooming elements, rearing, sniffing), and later formation of complex behavioural patterns (investigation of an environment) than in the control offsprings of healthy females.     

Iodine-123 labelled nor-beta-CIT binds to the serotonin transporter in vivo as assessed by biodistribution studies in rats

Flavobacterium aurantiacum NRRL B-184 possesses the ability to degrade aflatoxin B1 in solution and in several food items. Aflatoxin B1 is a potent carcinogen that causes significant economic losses to the agricultural and food industry. The role of trace metal ions (Cu2+, Mn2+, Zn2+, and Co2+) were studied in an effort to understand the enzymatic system involved in aflatoxin B1 degradation by F aurantiacum. The effect of divalent chelators (EDTA and 1,10-phenanthroline [OPT]) in the presence of the trace metal ions was studied as well. Aflatoxin B1 (10 microg/ml) was added to 72-h cultures of F aurantiacum that had been washed and resuspended in phosphate buffer (pH 7.0). HPLC was used to determine aflatoxin B1 concentration in these cultures. Incubating cells at 30 degrees C with 1 and 10 mM Cu2+, Mn2+, and Zn2+ significantly decreased aflatoxin B degradation after 4 and 24 h (P < 0.05). Decreased degradation was also observed with 1 and 10 mM Cu2+ and Zn2+ after 48 h and with 0.1 mM Cu2+ after 24 and 48 h. Co2+ did not have a significant effect on aflatoxin B1 degradation. EDTA and OPT did not counter the inhibition in the presence of Cu2+. The addition of 1 mM EDTA countered the inhibition by 1 mM Mn2+ after 4 and 24 h, but 1 mM OPT did not counter the inhibition by 10 mM Mn2+ after 4 and 24 h. OPT countered the inhibition by 1 mM Zn2+ after 4 and 48 h. These trace elements inhibit aflatoxin B1 degradation by F aurantiacum. In addition, their presence necessitates higher concentrations (>1 mM) of EDTA and OPT for the removal of their inhibitory effect.     

Autonomous vehicles

There are various kinds of autonomous vehicles (AV's) which can operate with varying levels of autonomy. This paper is concerned with underwater, ground and aerial vehicles operating in a fully autonomous (nonteleoperated) mode. Further this paper deals with AV's as a special kind of device, rather than full-scale manned vehicles operating unmanned. The distinction is one in which the AV is likely to be designed for autonomous operation rather than being adapted for it as would be the case for manned vehicles. We provide a survey of the technological progress that has been made in AV's, the current research issues and approaches that are continuing that progress, and the applications which motivate this work. It should be noted that issues of control are pervasive regardless of the kind of AV being considered, but that there are special considerations in the design and operation of AV's depending on whether the focus is on vehicles underwater on the ground, or in the air. We have separated the discussion into sections treating each of these categories     

On the Probability of Undetected Error for Linear Block Codes

The problem of computing the probability of undetected error is considered for linear block codes used for error detection. The recent literature is first reviewed and several results are extended. It is pointed out that an exact calculation can be based on either the weight distribution of a code or its dual. Using the dual code formulation, the probability of undetected error for the ensemble of all nonbinary linear block codes is derived as well as a theorem that shows why the probability of undetected error may not be a monotonic function of channel error rate for some poor codes. Several bounds on the undetected error probability are then presented. We conclude with detailed examples of binary and nonbinary codes for which exact results can be obtained. An efficient technique for measuring an unknown weight distribution is suggested and exact results are compared with experimental results.     

Viterbi decoding of the (63, 57) Hamming code-implementation andperformance results

Use of the Viterbi decoder to decode the (63, 57) Hamming code is considered, Implementation and performance of systematic and nonsystematic codes are addressed. It is shown that a Viterbi decoder for the constraint length seven, rate-½ convolutional code can be used to decode both systematic and nonsystematic (63, 57) Hamming codes, but an additional step is needed to complete the decoding of the systematic code. Bounds and simulation results for postdecoding bit-error probability are given and it is shown that the systematic code performs 0.4 dB better than the nonsystematic code. A heuristic explanation is provided     

Characterization of Time Variation on 1.9 GHz Fixed Wireless Channels in Suburban Macrocell Environments

We observed temporal fading on 1.9 GHz fixed wireless channels during short-term measurements at 107 different locations in a suburban macrocell environment characterized by flat terrain and heavy foliage in order to determine how the rate of fading varies with average wind speed and distance. For each location, we estimated: (1) the Ricean K-factor using a momentbased estimator and (2) an equivalent Doppler frequency which is related to the maximum Doppler frequency by a factor that depends upon the shape of the Doppler spectrum. We did so by fitting the measured level crossing rate (LCR) and average fade duration (AFD) distributions to expressions normally justified for mobile wireless links using a method recently proposed by Feick, Valenzuela and Ahumada (2007). As has been observed at other sites, the Ricean K-factor decreased with both average wind speed and distance. However, we found that the equivalent Doppler frequency was effectively uncorrelated with wind speed and noticeably increased with distance. Similar measurements at other sites will be required to determine the extent to which these trends are affected by foliage density and tower height.     

Jamaican vomiting sickness. Biochemical investigation of two cases

We identified methylenecyclopropylacetic acid, a known metabolite of hypoglycin A, in the urine of two patients with Jamaican vomiting sickness. Excretion of unusual dicarboxylic acids such as 2-ethylmalonic, 2-methylsuccinic, glutaric, adipic and dicarboxylic acids with eight and 10 carbon chains were also detected in both patients. The amounts of these dicarboxylic acids were 70 to 1000 times higher than normal. These metabolites have also been identified in urine of hypoglycin-treated rats. This evidence links hypoglycin A to Jamaican vomiting sickness as its causative agent. Urinary excretion of short-chain fatty acids was also increased up to 300 times higher than normal. These results indicate that, despite their clinical and histologic similarities, the cause and biochemical mechanisms of Jamaican vomiting sickness differ distinctly from those of Reye's syndrome in which these abnormal urinary metabolites are not appreciably increased.