New frequency-dependent edge mode current density approximationsfor TM scattering from a conducting strip grating

Two new frequency-dependent strip-grating current densities are derived for TM mode incidence on a conducting strip grating. The current densities are assumed to be the product of a spatial function and a frequency function. One spatial function is the traditional frequency-independent edge mode current density. The other is found by the use of conformal mapping. The frequency function is derived by use of the radiation integral and the periodic Green's function. The new resultant current densities are both exact for small strip widths. The conformally mapped solution is also valid for wide strips and is exact in the limit as the strip width equals the grating period. Although the solutions are not as accurate as the moment method at all frequencies, they produce computationally faster solutions and offer further insight into strip-grating behavior     

Identification and characterization of srp1, a gene of fission yeast encoding a RNA binding domain and a RS domain typical of SR splicing factors

Smad6 and Smad7 function as intracellular antagonists in transforming growth factor-beta (TGF-beta) signaling. Here we report the isolation of human Smad6, which is closely related to Smad7. Smad6 and Smad7 mRNAs were differentially expressed in lung cancer cell lines and were rapidly and directly induced by TGF-beta1, activin and bone morphogenetic protein-7. Cross-talk between TGF-beta and other signaling pathways was demonstrated by the finding that epidermal growth factor (EGF) induced the expression of inhibitory SMAD mRNA. Moreover, whereas the phorbol ester PMA alone had no effect, it potentiated the TGF-beta1-induced expression of Smad7 mRNA. Ectopic expression of anti-sense Smad7 RNA was found to increase the effect of TGF-beta1, supporting its role as a negative regulator in TGF-beta signaling. Thus, expression of inhibitory Smads is induced by multiple stimuli, including the various TGF-beta family members, whose action they antagonize.     

Diastolic dysfunction and altered energetics in the alphaMHC403/+ mouse model of familial hypertrophic cardiomyopathy

An arginine to glutamine missense mutation at position 403 of the beta-cardiac myosin heavy chain causes familial hypertrophic cardiomyopathy. Here we study mice which have this same missense mutation (alphaMHC403/+) using an isolated, isovolumic heart preparation where cardiac performance is measured simultaneously with cardiac energetics using 31P nuclear magnetic resonance spectroscopy. We observed three major alterations in the physiology and bioenergetics of the alphaMHC403/+ mouse hearts. First, while there was no evidence of systolic dysfunction, diastolic function was impaired during inotropic stimulation. Diastolic dysfunction was manifest as both a decreased rate of left ventricular relaxation and an increase in end-diastolic pressure. Second, under baseline conditions alphaMHC403/+ hearts had lower phosphocreatine and increased inorganic phosphate contents resulting in a decrease in the calculated value for the free energy released from ATP hydrolysis. Third, hearts from alphaMHC403/+ hearts that were studied unpaced responded to increased perfusate calcium by decreasing heart rate approximately twice as much as wild types. We conclude that hearts from alphaMHC403/+ mice demonstrate work load-dependent diastolic dysfunction resembling the human form of familial hypertrophic cardiomyopathy. Changes in high-energy phosphate content suggest that an energy-requiring process may contribute to the observed diastolic dysfunction.     

NeuroNet: collaborative intraoperative guidance and control

Neurophysiological monitoring assesses CNS structure function relationships during surgery. NeuroNet supports remote performance of this task through real time multimodal data processing and multimedia network communication. The system is fully integrated, transparently combining the collection, processing, and presentation of real time data sources, including all physiological monitoring functions, with non real time functions and extensive online database information. Workstations are mounted in instrumentation racks and configured with appropriate electronics to support various data acquisition tasks including electroencephalograms (EEGs), electromyograms (EMGs), and multimodality evoked potentials. Multiple racks can be used in parallel on the same case if the number of variables to be monitored exceeds the capacity of a single tack. The data acquired on these systems is transparently accessible, in real time, across the network for both review and analysis     

Pediatric head injuries and deaths from bicycling in the United States

OBJECTIVE: To estimate the potential benefit of increasing bicycle helmet use among children and adolescents in the United States. DESIGN: All bicycle-related deaths (Multiple Cause-of-Death Public Use Data Tapes, 1989 through 1992) and bicycle-related injuries treated in sampled emergency departments (National Electronic Injury Surveillance System, 1989 through 1993) were used to calculate traumatic brain injury-associated death and head injury rates per 1,000,000 US residents. Preventable injuries and deaths were estimated by calculating the population-attributable risk of head injury due to nonuse of bicycle helmets. PATIENTS: US residents aged 0 through 19 years who were injured or who died as a result of a bicycle crash. RESULTS: An average of 247 traumatic brain injury deaths and 140,000 head injuries among children and adolescents younger than 20 years were related to bicycle crashes each year in the United States. As many as 184 deaths and 116,000 head injuries might have been prevented annually if these riders had worn helmets. An additional 19,000 mouth and chin injuries were treated each year. The youngest age groups had the highest proportions of both head and mouth injuries. CONCLUSION: There continues to be a need to advocate for greater use of bicycle helmets, particularly among young children. Helmet design changes should be considered to prevent mouth injuries.     

Lipopolysaccharide induces sickness behaviour in rats by a vagal mediated mechanism

A 52-year-old man was hospitalized for a right adrenal tumor which had been incidentally found by abdominal CT scan for examination of colon cancer. Laboratory and endocrine findings were within the normal limits except for increased urinary concentrations of noradrenaline and dopamine. Adrenal angiography revealed that the feeding artery of the tumor was the inferior suprarenal artery. Adrenal venous blood sampling studies detected no abnormalities in the concentrations of catecholamine, cortisol or aldosterone. Right adrenalectomy was performed and the tumor was histologically diagnosed as ganglioneuroma. Ganglioneuroma is a benign tumor originating from the sympathetic nerve ganglion. The adrenal origin of the tumor is relatively rare and 60 cases of adrenal ganglioneuroma including our case have been reported in Japan.     

Fragmentation mechanisms of oxofatty acids via high-energy collisional activation

Considerable light has been thrown on the mechanisms of oral tolerance (or, more correctly, orally-induced systemic tolerance) in the past 12-18 months. While it is very clear that T cell anergy and apoptosis can occur after being fed antigen, a major pathway that has been described in different models is the induction of regulatory T cells which secrete transforming growth factor beta. These cells have been designated Th3 cells but their relation to the in-vitro-generated Tr cells, which inhibit tissue-damaging T cell responses in the gut mucosa, is not known. An important discovery is that food antigens have major systemic effects on T cells, similar in many ways to those seen following intravenous injection of soluble antigens. This conceptually moves us away from the notion that there is something special about mucosal (compared to systemic) lymphoid tissue to the notion that it is the type of antigens seen in the gut (i.e. digested, soluble polypeptides) which dictates the types of response seen there. After initial excitement, clinical trials using oral tolerance to treat autoimmune disease have been somewhat disappointing.