Interpretation of regional geochemistry using optimal interpolation parameters

A collection of data analysis procedures is presented which are derived from estimation of geographic interpolation parameters. Several interpolation models are discussed along with a procedure to obtain the best model. The power parameter, p, and the search radius, c, are the standard parameters in inverse distance weighting interpolation which is appropriate for sampling patterns that are not highly irregular. The power parameter is shown to characterize the regional behavior of geochemical measurements. This characterization process can be used to associate similar types of geochemical measurements, produce optimal contour maps, derive meaningful residual maps, and highlight unusual geochemical areas by a weighted sum variable. The computer program. BESTP, (used to estimate the optimum inverse distance weighting interpolation parameters) is presented, along with an example using reconnaissance groundwater data from the Plainview Quadrangle, Texas.     

Sexual and reproductive health among primary and secondary school pupils in Mwanza, Tanzania: need for intervention

A cross-sectional questionnaire survey was conducted among 892 randomly selected pupils, aged 12 and above, attending 18 primary schools (PS) and five secondary schools (SS) in four communities of Mwanza Region in Tanzania. The goals were to assess the level of knowledge adolescents have about sexual and reproductive health (SRH), to assess the magnitude of SRH problems and to help design appropriate interventions. Median age of respondents was 15 years (range 12-20 years) and 14 years (range 12-19 years) for PS boys and girls, respectively, and 19 years (range 16-24 years) and 17 years (range 14-19 years) for SS boys and girls. Eighty per cent of PS boys and 68% of PS girls were already sexually active; the corresponding figures were 89% for SS boys and 48% for SS girls. Vaginal sex was the most common first sexual act reported by SS pupils, but 40% of PS pupils reported orogenital sex and 9% of PS pupils reported anal sex as their first sexual act. Almost half of PS girls have had sex with adults, including teachers and relatives. 'Forced sex' was reported by nearly half of PS and SS girls. Fourteen per cent of PS girls had already been pregnant, and over half of these pregnancies ended in illegally induced abortions. Despite a rather high (30%) lifetime rate of condom use, 33% and 25% of PS boys and girls, respectively, reported past experience of sexually transmitted diseases (STDs). STD rates were lower among SS pupils who had a better knowledge of STDs/HIV and fertility issues and reported higher condom use. The survey demonstrated the great vulnerability of school-going adolescents of Mwanza Region to consequences of sexual intercourse. The response should urgently come in the from of comprehensive adolescent SRH programmes.     

High resolution negative tone molecular resist based on di-functional epoxide polymerization

There is an urgent demand for higher performance resists with superior resolution, sensitivity, and line edge roughness for both electron-beam and extreme ultraviolet lithography applications. Chemically amplified resists provide superior sensitivity compared to non-chemically amplified resists, but often suffer from resolution limitations and poor line edge roughness. A new class of negative tone chemically amplified molecular resists has been developed based on epoxide cross-linking that combines high sensitivity with low line edge roughness and excellent resolution. The most recent compound of this class (2-Ep) simultaneously demonstrates resolution of 25 nm half-pitch, sensitivity of 38 μC/cm², and line edge roughness (3σ) of 2.9 nm under 100 keV e-beam exposure.     

Tracer monitored titrations: measurement of total alkalinity

We introduce a new titration methodology, tracer monitored titration (TMT), in which analyses are free of volumetric and gravimetric measurements and insensitive to pump precision and reproducibility. Spectrophotometric monitoring of titrant dilution, rather than volume increment, lays the burden of analytical performance solely on the spectrophotometer. In the method described here, the titrant is a standardized mixture of acid-base indicator and strong acid. Dilution of a pulse of titrant in a titration vessel is tracked using the total indicator concentration measured spectrophotometrically. The concentrations of reacted and unreacted indicator species, derived from Beer's law, are used to calculate the relative proportions of titrant and sample in addition to the equilibrium position (pH) of the titration mixture. Because the method does not require volumetric or gravimetric additions of titrant, simple low-precision pumps can be used. Here, we demonstrate application of TMT for analysis of total alkalinity (A(T)). High-precision, high-accuracy seawater A(T) measurements are crucial for understanding, for example, the marine CaCO3 budget and saturation state, anthropogenic CO2 penetration into the oceans, calcareous phytoplankton blooms, and coral reef dynamics. We present data from 286 titrations on three types of total alkalinity standards: Na2CO3 in 0.7 mol kg x soln(-1) NaCl, NaOH in 0.7 mol kg x soln(-1) NaCl, and a seawater Certified Reference Material (CRM). Based on Na2CO3 standards, the accuracy and precision are +/-0.2 and +/-0.1% (4 and 2 micromol kg x soln(-1) for A(T) approximately 2100-2500 micromol kg x soln(-1), n = 242), using low-precision solenoid pumps to introduce sample and titrant. Similar accuracy and precision were found for analyses run 42 days after the initial experiments. Excellent performance is achieved by optimizing the spectrophotometric detection system and relying upon basic chemical thermodynamics for calculating the equivalence point. Although applied to acid-base titrations in this paper, the approach should be generally applicable to other types of titrations.     

Detection of nanoscale etch and ash damage to nanoporous methyl silsesquioxane using electrostatic force microscopy

We have used electrostatic force microscopy (EFM) to detect nanoscale dielectric constant variations resulting from damascene processing of blanket and patterned films of nanoporous methyl silsesquioxane (MSQ) (k = 2.2). Ash processing can cause significant degradation of the dielectric constant for both blanket and patterned MSQ films if the film is exposed to moisture. We have observed that this degradation is reversible because the apparent dielectric constant of the ashed film is nearly the same as the as-deposited film if the film is baked at 80-150 °C. Reactive ion etching (RIE) causes ∼100 nm deep side wall damage in patterned samples as well as leaving a redeposited layer that has a higher dielectric constant. We also present some initial results that show the strength of the EFM signal is humidity dependent.     

Dynamically anchored conferencing handoff for dual-mode cellular/WLAN handsets

In this paper we consider vertical handoff for enterprise-based dual-mode (DM) cellular/WLAN handsets. When the handset roams out of WLAN coverage, the DM's cellular interface is used to maintain the call by anchoring it through an enterprise PSTN gateway/PBX. Soft handoff can be achieved in this case if the gateway supports basic conference bridging, since a new leg of the call can be established to the conference bridge while the existing media stream path is active. Unfortunately this requires that all intra-enterprise calls be routed through the gateway when the call is established. In this paper we consider a SIP based architecture to perform conferenced dual-mode handoff and propose a much more scalable mechanism for short-delay environments, whereby active calls are handed off into the conference bridge prior to the initiation of the vertical handoff. Results are presented which are taken from a dual-mode handset testbed, from analytic models, and from simulations which characterize the scalability of the proposed mechanism. Mohammed Smadi received the B.Eng and Mgmt and M.A.Sc degrees in Computer Engineering from McMaster University in Hamilton, Ontario, Canada. Mohammed received an NSERC doctoral award in 2005 and is currently a Ph.D. student at the Wireless Networking Group at McMaster University. Terence D. Todd received the B.A.Sc, M.A.Sc and Ph.D. degrees in Electrical Engineering from the University of Waterloo, Waterloo, Ontario, Canada. While at Waterloo he spent 3 years as a Research Associate with the Computer Communications Networks Group (CCNG). He is currently a Professor of Electrical and Computer Engineering at McMaster University in Hamilton, Ontario, Canada. Professor Todd spent 1991 on research leave in the Distributed Systems Research Department at AT&T Bell Laboratories in Murray Hill, NJ. He also spent 1998 on research leave at The Olivetti and Oracle Research Laboratory in Cambridge, England. While at ORL he worked on the piconet project which was an early embedded wireless network testbed. Dr. Todd’s research interests include metropolitan/local area networks, wireless communications and the performance analysis of computer communication networks and systems. He is a past Editor of the IEEE/ACM Transactions on Networking and currently holds the NSERC/RIM/CITO Chair on Pico-Cellular Wireless Internet Access Networks. Dr. Todd is a Professional Engineer in the province of Ontario and a member of the IEEE. Vytas Kezys was born in Hamilton, Canada in 1957. He received the B.Eng. degree in Electrical Engineering from McMaster University, Canada, in 1979. From 1979 to 1998, Mr. Kezys was involved in radar and communications research as Principal Research Engineer at the Communications Research Laboratory, McMaster University. While at McMaster, his research activities included array signal processing for low-angle tracking radar, radar signal processing, and smart antennas for wireless communications. Mr. Kezys was founder and President of TalariCom Inc., a start-up company that developed cost effective smart antenna technologies for broadband wireless access applications. Currently, Mr. Kezys is Director of Advanced Products at Research in Motion in Waterloo, Canada. Vahid S. Azhari received his B.S. and M.S. from the Department of Electrical and Computer Engineering, IUST and University of Tehran, Iran, in 2000 and 2003 respectively. His M.S. research focused on designing scheduling algorithms for switch fabrics. He also worked for two years for the Iranian Telecommunication Research Centre on developing software for SDH switches. He is currently pursuing his Ph.D. degree at the Wireless Networking Laboratory, McMaster University, Canada. His main area of research includes handoff management in integrated wireless networks, WLAN deployment techniques, and wireless mesh networks. Dongmei Zhao received the Ph.D. degree in Electrical and Computer Engineering from the University of Waterloo, Waterloo, Ontario, Canada in June 2002. Since July 2002 she has been with the Department of Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada where she is an assistant professor. Dr. Zhao’s research interests include modeling and performance analysis, quality-of-service provisioning, access control and admission control in wireless cellular networks and integrated cellular and ad hoc networks. Dr. Zhao is a member of the IEEE.     

The effect of prepartum injection of vitamin E on health in transition dairy cows

The objective of this study was to investigate parenteral vitamin E for the prevention of peripartum disease in dairy cows. A randomized clinical trial was conducted in 21 commercial dairy herds. Cows (n = 1142) were randomly assigned to receive either a single subcutaneous injection of 3000 IU of vitamin E, or placebo, 1 wk before expected calving. Serum alpha-tocopherol was significantly increased in treated cows at 7 and 14 d, but not at 21 d after injection. Overall, there were no significant differences between treatment groups in the incidence of retained placenta, clinical mastitis, metritis, endometritis, ketosis, displaced abomasum, or lameness. However, there was a conditional benefit of treatment for reduction of the incidence of retained placenta. Cows with marginal pretreatment vitamin E status (serum alpha-tocopherol to cholesterol mass ratio < 2.5 x 10(-3)) that received an injection of vitamin E tended to have reduced risk of retained placenta. However, in cows with adequate serum vitamin E, there was no reduction in the incidence of any disease. For clinical application, primiparous animals were most likely to benefit from prepartum injection of vitamin E.