Assessing the contribution of natural sources to regional atmospheric mercury budgets

Naturally mercury-enriched substrate is a long-lived source of mercury to the global atmospheric mercury cycle. Field flux chambers, laboratory gas exchange chambers and micrometeorological methods may be applied to estimate emissions from these sources. However, field chamber experimental design may affect the magnitude of the fluxes measured, and the laboratory chamber only provides a minimum estimate of flux. Many factors, such as mercury concentration and speciation in substrate, light, precipitation, and temperature, influence the emission of mercury from the substrate. Mercury concentration in the substrate is a dominant factor controlling emissions and may be used to predict emissions from regions of mercury enrichment. Mercury fluxes measured from three areas of natural enrichment and three areas with low levels of mercury enrichment are 1-5 orders of magnitude greater than the value applied to global belts of natural enrichment. Preliminary scaling of emissions from one of these areas and for western North America indicates that mercury enriched areas may be significant sources of mercury to the atmosphere, and that their contribution to regional and global atmospheric budgets needs to be reassessed.     

The effects of reactor coolant system pipe rupture motion on tributary piping and attached equipment

This paper presents a rigorous analysis of a pressurized water reactor coolant system (RCS) to determine time-history excitations of intact equipment and tributary piping attached to the RCS caused by a postulated guillotine rupture in the primary coolant piping. Reactor control rods and drive mechanisms, in core instrumentation guide tubes and reactor coolant pump motor appurtenances are examples of attached equipment which is excited by RCS LOCA induced motions. The surge line, mainsteam lines and emergency core cooling lines are examples of tributary piping similarly affected by RCS LOCA induced motions. The methods described herein include structural and dynamic modeling and analytical techniques used in the non-linear transient dynamic time-history analysis of a 3-D coupled model of the RCS. The results of this analysis are generated for the purpose of defining the excitation for subsequent analysis of intact tributary systems attached to the reactor coolant system in order to evaluate their response to those LOCA induced motions. This paper also presents results of analyses for intact tributary piping subjected to LOCA induced motions and assesses the severity of the response compared to typical seismic response.     

Unified approaches to integrated-service networks–burst and fast packet switching

The increasing demand for communication services, coupled with recent technological advances in communication media and switching techniques, has resulted in a proliferation of new and expanded services. Currently, networks are needed which can transmit voice, data and video services in an application-independent fashion. Unified approaches employ a single switching technique across the entire network bandwidth, thus allowing services to be switched in an application-independent manner. This paper presents a taxonomy of integrated-service networks, including a look at NISDN, while focusing on unified approaches to integrated-service networks. The two most promising unified approaches are burst and fast packet switching. Burst switching is a circuit switching-based approach which allocates channel bandwidth to a connection only during the transmission of ‘bursts’ of information. Fast packet switching is a packet switching-based approach which can be characterized by very high transmission rates on network links and simple, hard-wired protocols which match the rapid channel speed of the network. Both approaches are being proposed as possible implementations for integrated-service networks. We survey these two approaches, and also examine the key performance issues found in fast packet switching. We then present the results of a simulation study of a fast packet switching network.     

Extension of the associated solution model to ternary metal-sulfur melts: Cu-Ni-S

The associated solution model recently applied to four binary metal-sulfur melts, Fe-S, Ni-S, Co-S, and Cu-S, is extended to ternary metal-sulfur melts from those of the binary melts. The proposed equations are used to predict the thermodynamic properties of Cu-Ni-S melts. The predicted values for the activity of sulfur at 1,473 and 1,673 K are in good agreement with the experimental data. Using these data and other pertinent thermodynamic data, two isothermal sections at 1,473 and 1,673 K are calculated. The calculated isothermal sections agree well with the experimental data available in the system.     

Effects of estrogens and progestins on high density lipoproteins

High density lipoprotein (HDL) levels are known to be higher in women than in men, and to increase with estrogen use. To assess the effects of estrogens on HDL subspecies, analytic ultracentrifuge measurements of HDL were compared in 11 menopausal estrogen users and 16 controls. The difference in mean schlieren patterns between the groups showed a significantly higher level of HDL with flotation rate (F _1.20 ^o )>1.5 (predominantly HDL₂) in the users. This was similar to the difference in HDL seen between nonusers of hormones and age-matched males. A previous study had shown that users of combination oral contraceptives had increased levels of HDL with F _1.20 ^o ≤3.5 (primarily HDL₃) suggesting that the estrogen effect on HDL is altered by the presence of added progestin. The progrestin effect was studied here in more detail in two women with type V hyperlipoproteinemia treated with norethindrone acetate. Reduction in serum triglyceride was accompanied by a reduction in HDL, predominantly in the less dense species (HDL₂). Among groups of oral contraceptive and noncontraceptive estrogen and progestin users whose HDL-cholesterol levels have been reported recently, there was a direct correlation (r=0.86, p<.001) between mean HDL-cholesterol and triglyceride levels. Endogenous hormonal influences on HDL were assessed by serum hormone and lipoprotein measurements at weekly intervals during two consecutive menstrual cycles in four healthy females. An increase in HDL of highest flotation rate (F _1.20 ^o 5–9) was seen, which corresponded with the time of ovulation raising the possibility of pituitary as well as gonadal hormone effects on HDL.     

Parsing an extension to CODASYL FORTRAN DML

The FORTRAN data manipulation language specified by CODASYL requires that parameters be identified by keywords and appear in a prescribed order. These restrictions can largely be removed. A method of parsing the resultant data manipulation language using database structures is described.     

Contextual Classification of Multispectral Remote Sensing Data Using a Multiprocessor System

A statistical model of spatial context is described and procedures for classifying remote sensing data using a context classifier are outlined. Experimental results are presented. Because the computational requirements of the context classifier are very large, its implementation on multiprocessor systems is investigated. Some of the special considerations necessary for such implementations are described, with particular reference to implementation on an array of Control Data Corporation Flexible Processors.     

Direct cloning of human parathyroid hyperplasia cells in soft-agar culture

Parathyroid specimens removed from patients with clinical hyperparathyroidism were cultured in a two-layer soft-agar system. Four patients had parathyroid hyperplasia and one had a parathyroid adenoma. Colonies grew from single-cell suspensions of each specimen. Plating efficiency ranged from 0.001 to 0.05%. No colonies grew from normal bovine parathyroid specimens. Parathormone was detected in 0.9% NaCl solution incubated with the culture plates of three of the four human specimens tested. Parathormone levels determined by radioimmunoassay ranged from 10.4 < 100 ng/ml. Plates tested serially showed a progressive rise in parathormone levels with time and an increase in colony size and number. Microscopic evaluation of the cellular layer showed clusters of cells morphologically consistent with parathyroid origin. Colonies remained viable for approximately 3 weeks. These data confirm that malignancy of tissue in vivo is not necessary for colony formation in agar and that human parathyroid hyperplasia or adenoma cells produce and secrete parathormone in this system.     

Psychological consequences of intervention in the birth process.

Investigated relationships between type of birth (spontaneous vaginal, forceps, and cesarean) and maternal psychological functioning and attitudes toward the infant. At specific time points throughout pregnancy and up to 3 mo postpartum, 253 women (mean age 28.21 yrs) completed measures assessing personality characteristics, psychological functioning and attitudes toward labor, birth, and the baby. After the birth of their babies, the women were categorized according to the type of birth experienced. There were no significant differences among the 3 birth groups in terms of their demographic status or psychological functioning in the prenatal period. The only measures that significantly differentiated the 3 birth groups were those relating to their birth experience. Contrary to reports in the published literature, type of birth was not found to be a major determinant of either maternal adjustment or psychological functioning in the postpartum period. (French abstract) (50 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)