Grid refinement tests of a least-squares finite element method for advective transport of reactive species

A time splitting least-squares finite element method (LSFEM) and the ‘stiff ODEs’ solver LSODE are used to simulate the advective transport of reactive species. Specifically, the rotating cone problem with chemical reactions serves as a model to test the algorithm. A non-linear filter is used to suppress spurious oscillations at each advective time step. All simulations are carried out by using linear and quadratic elements on two mesh systems. Results from the coarse mesh system suggest that the use of robust numerical methods alone will not be able to provide accurate results and point to the need of grid refinement. The grid refinement tests are evaluated by pollutant peak concentrations, pollutant concentration distributions, average relative errors, species mass conservation and distribution ratios and CPU times. Results from the fine mesh system are satisfactory and imply that accurate simulations of the transport of reactive species require adequate grid resolution and robust numerical methods for each individual advective and reactive step.     

Signet-ring cell melanoma mimicking adenocarcinoma. A case report

The fine needle aspiration findings in a lymph node involved by signet-ring cell melanoma, a very rare variant of malignant melanoma, are reported. The patient had a history of superficial spreading melanoma of the right foot, treated 10 years earlier by below-the-knee amputation. He presented with a right groin mass. Fine needle aspiration of the mass yielded poorly cohesive, large cells with eccentric nuclei and abundant, eosinophilic cytoplasm; many of them exhibited a signet-ring appearance. Melanin pigments were identified in a small proportion of tumor cells, and a diagnosis of metastatic melanoma was made. The subsequent lymph node excision revealed a metastatic tumor composed of polygonal and signet-ring cells that were positive for S-100 protein and HMB-45 but not cytokeratin. Nearly all reported cases of signet-ring cell melanoma occurred as metastatic or recurrent disease. It is important not to mistake signet-ring cell melanoma for adenocarcinoma in aspiration cytology, and a constellation of clinical features and of histochemical and immunohistochemical findings enables a correct diagnosis to be reached.     

Effect of signal transition variation on bit synchronizerperformance

The effect of the signal transition variation, due to the signal transition density, data asymmetry, and sinusoidal modulation, on the performance of the data transition tracking loop (DTTL) symbol synchronizer is addressed. These factors will affect the DTTL performance, such as the clock jitter and the cycle slippage rate, and unnecessary system loss may result if the system parameters are not well selected. Given the background of C. S. Tsang and W. C. Lindsey (1986), this result can serve as an engineering design guideline for the DTTL in the context of the signal transition variation     

Knowledge of tuberculosis in high-risk populations: survey of inner city minorities

SETTING: Educational programs targeted toward individuals at risk for tuberculosis are needed. As an initial step in developing future programs, the present study was designed to determine the baseline knowledge about tuberculosis in at-risk individuals. METHODS: Face-to-face surveys were conducted with 505 minority subjects in the Kansas City Metropolitan area; health care providers were excluded. Thirty-six queries directed toward self-perceived and actual tuberculosis knowledge were asked. Data were tabulated and per cent correct response was determined. RESULTS: Completed surveys were available from 505 subjects: 342 females and 163 males. Most (97%) of the subjects were African Americans, with 57% between the ages of 21-40. Over two-thirds were high school graduates, and 77% reported an estimated total household annual income of <$20000. Self-perceived knowledge about tuberculosis was rated as 'little' or 'nothing' by 60% of respondents. The overall correct response score was 61%, with 55% correct response to queries related to etiology, 53% for identification of high-risk populations, 57% for possible routes of transmission, 89% for symptoms, and 49% for treatment. Males, those with annual incomes >$20000, and individuals 51-70 years old had the highest scores. CONCLUSIONS: In this high-risk inner-city population surveyed, knowledge deficits in the etiology, transmission, and treatment of tuberculosis were identified.     

NMR structure of a protein kinase C-gamma phorbol-binding domain and study of protein-lipid micelle interactions

Classical protein kinase C (PKC) family members are activated by the binding of various ligands to one of several cysteine-rich domains of the enzyme. The natural agonist, diacylglycerol (DAG), and the natural product superagonist, phorbol dibutyrate (PDB), activate the enzyme to produce wide-ranging physiological effects. The second cysteine-rich (Cys2) domain of rat brain PKC-gamma was expressed and labeled with 15N and 13C, and the solution structure was determined to high resolution using multidimensional heteronuclear NMR methods. The phorbol binding site was identified by titrating this domain with phorbol-12,13-dibutyrate (PDB) in the presence of organic cosolvents. Titrations of this domain with lipid micelles, in the absence and presence of phorbols, indicate selective broadening of some resonances. The observed behavior indicates conformational exchange between bound and free states upon protein-micelle interaction. The data also suggest that half of the domain, including the phorbol site and one of the zinc sites, is capable of inserting into membranes.     

Endometrial responses to hormone replacement therapy: histological features compared with those of late luteal phase endometrium

We evaluated the histological features of the endometrium in relation to the bleeding pattern in a group of women receiving oral cyclical combined hormone replacement therapy (HRT), and compared the histological features with those of luteinizing hormone (LH)-dated endometrial biopsies obtained from healthy women at the time of sterilization. A total of 103 women completed 6 months of HRT therapy. All received a regimen of 2 mg oestradiol valerate daily, with 1 mg norethisterone added for the last 12 days of every 28-day cycle. Endometrial biopsies were scheduled for the end of the study (days 27-29 of the last cycle of therapy). Using the classical histological criteria, secretory endometrial changes were demonstrated in the majority (n = 89) of cases. The remaining were insufficient or inactive (n = 12), proliferative (n = 1) or atrophic (n = 1). Forty-nine women had a mean cycle length of less than 29 days (early bleeders), 50 women experienced cycles of more than 29 days (late bleeders) and four did not experience any bleeding. When the individual histological structures were examined, using image analysis, there were no statistically significant differences in the histological features when the long cycles in early bleeders were compared with those in late bleeders. LH-dated endometrium showed a high degree of homogeneity that was consistent with cycle day as described by the classic criteria, but HRT-treated endometrium exhibited a wide range of variability. HRT-treated endometrium from the subset of women who bled on or after day 29, and whose biopsies were obtained before the onset of bleeding, differed significantly from the endometrium taken at the corresponding phase of the physiological cycle. We conclude that the use of classical histological criteria, which are used in relation to the physiological cycle, in the study of HRT-treated endometria is inappropriate.     

Chief State School Officers rank barriers to implementing comprehensive school health education

Council of Chief State School Officers (CCSSO) members were surveyed to determine their perception of barriers to implementing comprehensive school health education. CCSSO members were asked to prioritize the barriers and offer recommendations to overcome the barriers. A structured response, paired-comparison survey instrument was developed and mailed to 56 of 57 CCSSO members. Eighty-two percent of the members responded. CCSSO members perceived lack of administrative commitment as the number one barrier. Lack of adequately prepared teachers and insufficient time in the school day ranked second and third, respectively. While CCSSO members offered no recommendations for overcoming the number one barrier, recommendations to overcome other barriers included high-quality and more available preservice and inservice programs for teachers.