Chemosensory conditioning of Hermissenda crassicornis..

Bite–strike responses of Hermissenda crassicornis, elicited by chemosensory stimulation of the lips, were found to be modified when food extracts were paired with rotation-produced stimulation of the statocysts. Animals that received repeated pairings of an extract of 1 food (conditioned stimulus, CS) with rotation exhibited suppressed bite–strike responses to that food for up to 48 hr after training. This suppression was usually specific to the trained food and was pairing-specific as well. Discriminative conditioning was also demonstrated. Animals trained with 1 CS paired with rotation and a second CS that was unpaired (CS–) showed suppressed bite–strike responses to the first CS. The results demonstrate that Hermissenda can learn to avoid foods that reliably signal an aversive event and may allow an analysis of higher order conditioning phenomena. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

NMR study of galactomannans from the seeds of mesquite tree (Prosopis juliflora (Sw) DC)

The seed gum from Prosopis juliflora is a galactomannan polysaccharide, which is located in the endosperm. Regarding P. juliflora galactomannan structural studies, there are reports on galactose substitutional pattern, but supporting data by NMR correlation studies are scarce. In this work, a procedure to obtain P. juliflora gum without contamination was employed and the gum was studied by NMR spectroscopy. Overall, results show that mesquite seed has a 1.1:1 Man/Gal ratio.     

Parents' emotional availability and infant emotional competence: Predictors of parent-infant attachment and emerging self-regulation.

One-year-old infants (N=62) and their mothers and fathers were observed in free play and teaching sessions in order to examine parents' emotional availability and the infant's emotional competence. Mothers were more emotionally available than fathers, and infants exhibited more effortful attention with mothers than with fathers. Similar relations between parental emotional availability and infant emotional competence were found for mother-infant and father-infant dyads. Change in parental emotional availability covaried with change in infant emotional competence. Individual differences in parental emotional availability and Infant emotional competence were more consistent across contexts than across parents. Infant effortful attention at 12 months was a mediator between maternal emotional availability at 12 months and toddler situational compliance at 16 months. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determination of thermal parameters of poor conductors by transient techniques

The authors compare the transient hot wire method and the parallel wire method of determining thermal conductivity, using the second to find the thermal diffusivity of two materials. The wires are sandwiched between two samples of the material to be investigated. The influence of pressure is also studied in order to identify the measurement conditions that can be easily achieved. A method is chosen to evaluate thermal parameters and to determine the field of data to be used in relation to sample dimensions.     

Radicular compression by brucellar epidural abscess

Fifteen children with protein-energy malnutrition and eight healthy children between the ages of 6 months and 60 months were studied for blood glucose and serum insulin levels in the fasting state and 120 minutes following oral glucose load. The measurements were repeated after normalization of the body weight following 6 weeks of nutritional rehabilitation. The fasting blood glucose increased significantly in the post-treatment period and became comparable to the control value. The abnormal blood glucose response to oral glucose load also normalized. The serum insulin level rose significantly (p < 0.001) in the post-treatment period but failed to normalize. The response to oral glucose load was similar. The observed lower insulin response, despite normoglycemia, after 6 weeks of nutritional rehabilitation indicates persistence of hormonal imbalance which may need a longer duration of rehabilitation for full recovery.     

Mechanical and morphometrical changes in progressive bilateral pneumothorax and pleural effusion in normal rats

A variety of neurotransmitter receptor changes occur after a course of electroconvulsive seizures (ECS) in rats, including an increased density of adenosine A1 sites. Adenosine antagonism has been related to the proconvulsant action of methylxanthines such as caffeine. We determined tonic-clonic seizure duration in rats given ECS with caffeine (0-175 mg/kg, IP) after a course of one or six daily ECS. A single day of ECS did not affect the dose-dependent proconvulsant action of caffeine. After six daily ECS, the proconvulsant action of caffeine was reduced. After nine daily ECS, an A1 antagonist (8-cyclopentyl-1,3-dipropylxanthine) and an A2A antagonist (1-allyl-3,7-dimethyl-8-p-sulfophenylxanthine) showed reduced proconvulsant activity. The results suggest that the reduced proconvulsant action of caffeine after chronic ECS depends on adenosine antagonism.     

Small delay multipath diversity in spread spectrum communication systems

A new double-filter receiver for spread spectrum wireless systems is presented. The receiver exploits the inherent diversity due to the small delay difference between the multipaths which may not be exploited by the conventional RAKE receiver. The bit error rate performances of both the coherent and the noncoherent detectors are analyzed and compared with the ideal RAKE receiver and the matched filter bound. We also examine the best and the worst cases of a three-path fading channel for the proposed receiver. Optimum pulse shapes under various channel conditions are designed. Implementation issues in code-division multiple access systems are discussed. The numerical results show that the proposed receiver achieves significant gains for a given spreading factor under a complexity constraint.