A base-band NDS electrode configuration for HACT devices

Heterostructure Acoustic Charge Transport (HACT) devices have been fabricated with a new nondestructive sense (NDS) electrode structure that provides for the recovery of base-band signals without the use of an integrating capacitor. This electrode structure provides an output signal comprising an RF carrier at the SAW frequency, amplitude modulated by the sampled input signal which has been delayed by a period proportional to the output electrodes distance from the input diode. The output of the NDS electrode structure is subsequently demodulated to provide the base-band signal     

Discussion influence of yield surface curvature on flow localization in dilatant plasticity

The results of finite element calculations for a hollow sphere micromodel are used to examine the underlying assumptions and the specific yield functions in the dilatant plasticity theories of Gurson (1977) and Mear and Hutchinson     

Fecal occult blood screening in the Minnesota study: role of chance detection of lesions

BACKGROUND: In the Minnesota Colon Cancer Control Study, annual fecal occult blood testing reduced mortality from colorectal cancer by at least 33.4%. Some attribute a large part of this reduction to chance detection of cancers by colonoscopies; rehydration of guaiac test slides greatly increased positivity and consequently the number of colonoscopies performed. This study was conducted to determine how much of the reduction resulted from chance detection. METHODS: We used a mathematical model developed by Lang and Ransohoff to estimate the proportion of the 33.4% mortality attainable by chance alone. Applying the model requires the specification of five parameters: duration of follow-up, rate of compliance with fecal occult blood testing, rate of compliance with colonoscopy, positivity rate, and efficacy of colonoscopy in reducing colorectal cancer mortality. We took values for four of the five parameters directly from the Minnesota study. For the fifth parameter, efficacy of colonoscopy, we selected a value of 60%, based on the conclusions of another study. Whereas the Lang-Ransohoff model selects persons for colonoscopy by chance alone, those with bleeding cancers would also be selected by sensitive fecal occult blood testing. We therefore adjusted the result of the Lang-Ransohoff model for this dual detectability. RESULTS: We found that 16%-25% of the reduction in colorectal cancer deaths effected by fecal occult blood testing in the Minnesota study was due to chance detection; the remainder was due to sensitive detection. CONCLUSION: Chance played a minor role in the detection of colorectal cancers by fecal occult blood testing in the Minnesota study.     

A GAUSS program for computing the Foulkes-Davis tracking index for polynomial growth curves

Sixty-five patients initially seropositive for IgM anti-phenolic glycolipid-I (PGL-I) antibodies were tested for antibody levels to PGL-I, lipoarabinomannan (LAM), and the 35-kDa protein of Mycobacterium leprae at regular intervals for up to 30 months following the commencement of multidrug therapy (MDT). There was a steady decline in IgM anti-PGL-I and anti-35-kDa antibody levels to a mean of 17% and 14%, respectively, of the starting level at 24 months. The development of type 1 and type 2 reactions or the presence of drug-resistant organisms in a small number of patients had no significant influence on the changes in antibody level. The rate of decline was similar in different disease categories, but a higher proportion of lepromatous patients remained seropositive at the end of 2 years of treatment than borderline tuberculoid patients. By contrast, the mean IgG anti-LAM antibody levels remained stable or increased. Again the occurrence of type 1 or type 2 reactions had no significant effect on antibody level over 2 years. Falls in the IgM anti-PGL-I antibody levels mirrored the falls in the bacterial index in individual patients and provide an additional parameter for monitoring the response to chemotherapy.     

Granulation tissue polyposis associated with carcinoid tumours of the small intestine

We report two patients with ileal carcinoid tumours which were associated with polyps due to mucosal granulation tissue proliferation. In both cases the tumours had extensively infiltrated the small bowel wall and mesentery, and one had hepatic metastases. The mucosal surface of each specimen showed numerous, pale brown, sessile polyps which were restricted to the intestinal segment involved by carcinoid tumour, although not always closely related to neoplastic cells. The polyps were formed by the proliferation of capillaries, smooth muscle cells and myofibroblasts as demonstrated by immunohistochemistry and electronmicroscopy.     

Genetic control of immunity to Heligmosomoides polygyrus: presentation of promiscuous antigens to parasite-specific T cell hybridomas

The role of MHC class II in the presentation of Heligmosomoides polygyrus antigens has been investigated, using a number of T cell hybridomas produced in A and E positive and negative mice. By using fixed and irradiated antigen presenting cells (APC), further evidence has emerged, to support earlier data, that there can be differential processing requirements during the presentation of H. polygyrus antigens by A and E molecules. In concordance with these earlier observations, this work provides further evidence than individual T cells can respond to antigen when presented by more than one MHC molecule. Previously, this evidence has been restricted to individual MHC molecules of the same haplotype, but these data show that H. polygyrus produces antigens which can be presented by both syngeneic and allogeneic MHC molecules. These antigens do not appear to be synonymous with the previously described H. polygyrus superantigen, as presentation is restricted to specific MHC haplotypes. It is proposed that H. polygyrus may produce these antigenic molecules as part of its strategy to manipulate the host immune system.     

Gigabit pulse position bistability in semiconductor lasers

The paper briefly reviews the major forms of optical bistability in active optical devices compatible for use in gigabit optical communication systems, and reports an entirely new optical bistability for the first time. Unlike previous devices, the two bistable states of the optical device are each a series of picosecond optical pulses at 1 GHz or greater repetition rates, and are distinguished by a half period temporal shift between their temporal positions in relation to a clock pulse. The bistable device is based on a gain switched semiconductor laser. Theoretical studies suggest 100-ps switching speeds might be achieved, and experimental results are reported indicating optically triggered switching times of 500 ps.     

The ontogeny and significance of infants' facial expressions in the first 9 months of life.

Four studies examined aspects of the differential emotions theory (DET) hypothesis of expressive behavior development. In Study 1, facial-expressive movements of 108 2.5–9-mo-old infants were video recorded in positive and negative mother–infant interactions (conditions). As expected, Max-specified full-face and partial expressions of interest, joy, sadness, and anger were morphologically stable between the 2 ages. Studies 1 and 2 confirmed predicted differential responding to mother sadness and anger expressions and to composite positive and negative conditions. Discrete negative expressions exceeded negative blends, and the amount of both expression types remained stable across ages. Studies 3 and 4 provided varying degrees of support for the social validity of Max-specified infant negative affect expressions. Conclusions include revisions and clarifications of DET. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modulation of embryonic glutathione peroxidase activity and phenytoin teratogenicity by dietary deprivation of selenium in CD-1 mice

Selenium (Se)-dependent and -independent glutathione (GSH) peroxidases detoxify H2O2 and lipid hydroperoxides, which may mediate the teratogenicity of phenytoin and related xenobiotics. To test this hypothesis, CD-1 mice were placed on Se-deficient diets for 15, 25 or 40 days and bred so that the day of analysis corresponded to gestational day 11. In Se-replete control animals, embryonic peroxidase activities were only 5% of activities in maternal liver (P < .05). After 15 days of Se deprivation, maternal activities for H2O2 (reflecting Se-dependent peroxidase) and cumene hydroperoxide (CmOOH) (reflecting both Se-dependent and -independent peroxidases) were reduced to 20% (P < .05) and 35% of controls, respectively. At this time, the incidence of fetal cleft palates initiated by phenytoin (55 mg/kg intraperitoneally on gestational days 11, 12 and 13) was doubled, from 12% to 25% (P < .05). Selenite rescue (Na2SeO3, 350 micrograms/kg intraperitoneally on day 9) restored maternal and embryonic peroxidase activities and completely inhibited phenytoin-initiated postpartum lethality and fetal resorptions in animals that had been Se depleted for 15 days. After 40 days of Se deprivation, maternal and embryonic peroxidase/H2O2 activities were reduced to < 1% and 27% of Se-replete controls, respectively. In contrast, maternal peroxidase/CmOOH activity was increased to 70% of controls, reflecting induction of Se-independent peroxidase, compared with that with 15 days' depletion. Phenytoin-initiated cleft palates with 40 days' depletion appeared to be reduced (16%) compared with Se-replete controls (24%) (P < .07). In 40-day Se-depleted animals given selenite rescue, the 10% incidence of cleft palates was significantly lower than that in the 40-day Se-replete group (24%) but not the Se-depleted group (16%). This is the first demonstration of reduced Se-dependent GSH peroxidase activities in embryonic tissues with dietary Se-deprivation. The results implicate reactive oxygen species and lipid hydroperoxides in the mechanism of phenytoin teratogenicity and suggest that GSH peroxidases are important embryoprotective enzymes.