cssi/SciSciGPT-SciSciNet huggingface dataset:
Effective taper criterion for the full veneer crown preparation in preclinical prosthodontics.

PURPOSE: Effective taper criteria must define a realistic, measurable goal that the student can visualize and achieve. Six degrees is widely accepted as the taper criterion for the full veneer crown preparation. However, studies show the actual taper of most preparations to be greater than 12 degrees. The purpose of this study was to determine whether 12 degrees is an effective taper criterion for the full veneer crown preparation in preclinical prosthodontics instruction. MATERIALS AND METHODS: A group of 191 full veneer crown preparations with 6 degrees as the taper criterion, and a group of 130 full veneer crown preparations with 12 degrees as the taper criterion were evaluated. All preparations were accomplished by preclinical dental students working on typodonts under examination conditions. RESULTS: The overall mean taper for each group exceeded the targeted criterion. The overall mean taper for the 6 degrees group was 14,490. When 12 degrees was the criterion, the overall mean taper was 15,580. The t test results indicate significant differences (p < .0001) between the targeted criterion and the actual preparation mean taper in all samples except one: the faciolingual measurements in the 12 degrees group. The faciolingual measurement of 12,920 was not statistically significantly different (.0542) from the targeted criterion of 12 degrees. CONCLUSION: The use of a 12 degrees taper criterion did not result in preclinical students achieving the goal of a 12 degrees taper. However, a 12 degrees criterion is more realistic than a 6 degrees criterion for full veneer crown preparations.
Community Networking and Social Capital: Early Investigations

This paper draws upon an ongoing study pertaining to the early development of one component of a community network in the city of Troy, New York, USA. The component under study is that of a database to be distributed via a community network. Community networking literature posits a relationship between social capital and community networking, stating that community networking should positively affect levels of social capital in a community. This article begins exploring this relationship through reviewing the social capital concept as presented in the literature. Measures are developed from the field of social network analysis and applied to a group of community members involved in this database project. Results show high levels of in-degree centrality correlating with trustworthiness and resource exchange, and betweeness centrality correlating with trustworthiness. Although in-degree centrality proves to be the more useful measure for purposes of studying community networking and social capital, discussion is given to the surprising results found for betweeness centrality.
Hydrogen separation by dense cermet membranes

Novel cermet (i.e. ceramic-metal composite) membranes have been developed to separate hydrogen from mixed gases, particularly product streams generated during coal gasification and/or methane reforming. Hydrogen separation with these membranes is non-galvanic, i.e. it does not use electrodes or an external power supply to drive the separation, and hydrogen selectivity is nearly 100% because the membranes contain no interconnected porosity. The hydrogen permeation rate has been measured as a function of temperature (500-900 °C), membrane thickness ( 22-210 μm), and partial pressure of hydrogen (0.04-1.0 atm) in the feed gas. The hydrogen flux varied linearly with the inverse of membrane thickness, and reached = 20 cm 3 (STP)/min cm 2 for a membrane with a thickness of = 22 μm at 900 °C with 100% H 2 (at ambient pressure) as the feed gas. The results indicate that the hydrogen flux is limited by bulk diffusion and might be higher for a thinner ( < 22 μm) membrane. Some of the membranes were tested in a simulated syngas mixture containing H 2 , CO, CO 2 , and CH 4 , and showed no degradation in performance. Hydrogen flux measurements made in H 2 S-containing atmospheres for times approaching = 270 h showed that a 200-μm-thick cermet membrane was stable in gases containing up to 400 ppm H 2 S. While longer-term studies are needed, these results suggest that the cermet membranes may be suitable for practical hydrogen separation applications.
Refined Folding Mechanism of a Helix-turn-helix Motif

Helix-turn-helix motifs are valuable models for elucidating the protein folding mechanism. The de novo designed helix-turn-helix motif αtα has been studied thoroughly in our group by infrared spectroscopy and circular dichroism, applying site-specific isotopic labels and mutations. This preliminary investigation of αtα has provided detailed site-specific information on its folding mechanism, revealing increased stability in the middle of the helices and unfolding starting from the loose turn and the ends of the helices. The hydrophobic core contributes significantly to the stability of this little protein. To get further information on the folding mechanism of αtα, provided by additional independent probes, Forster resonance energy transfer (FRET) and differential scanning calorimetry (DSC) were employed to monitor thermal unfolding. FRET allows for measuring distances within a protein during its denaturation. In αtα, the intrinsic Trp residue in position 2 at the N-terminus and EDANS attached to the C-terminus served as FRET donor and acceptor, respectively, so end-to-end distances could be obtained. Thermodynamic parameters of a protein can be directly measured using DSC. Therefore, these directly obtained data were used to verify preliminary parameters from spectroscopic measurements. Overall, the results from FRET and DSC measurements were compared to the preliminary data on αtα to refine the proposed picture of its folding mechanism.
Pneumocystis carinii: improved models to study efficacy of drugs for treatment or prophylaxis of Pneumocystis pneumonia in the rat (Rattus spp.).

Abstract Rats which were immunosuppressed with adrenal corticosteroids then transtracheally inoculated with Pneumocystis carinii were evaluated as models for study of drug efficacy. Trimethoprim/sulfamethoxazole, known to be effective against Pneumocystis, was given in therapeutic and prophylactic regimens and its long-term effectiveness determined by a protocol to study relapse. Untreated animals uniformly developed severe infection with differences in numbers of organisms between untreated and treated animals being greater than two logs. Therapy or prophylaxis studies could be completed in 6 to 7 weeks. Animals given prophylaxis or therapy with trimethoprim/sulfamethoxazole had few organisms detected in lungs. Numbers of organisms did not increase during the 4 weeks when the animals were continued on immunosuppression after discontinuing treatment as long as reinfection was prevented. These models are useful for evaluating anti-Pneumocystis activity of antimicrobials. Relapse study data suggest that reinfection may have an important role in development of recurrent Pneumocystis pneumonia.
Influence of Chromium Depletion on Intergranular Stress Corrosion Cracking of 304 Stainless Steel

Abstract Direct correlations are made between the extent of chromium depletion at grain boundaries and intergranular stress corrosion cracking (IGSCC) of 304 stainless steel during slow-strain-rate (SSR) tensile tests in 288 °C air-saturated water. IGSCC was found to depend on the minimum chromium concentration, the spacing of carbides, and the width of the chromium-depleted zone at grain boundaries. Modifying any one of these interfacial characteristics impacted intergranular cracking and ductility. Under the conditions of the SSR test, IGSCC sharply increased as the grain boundary chromium concentration dropped below ∼13.5 wt%. The presence of a semicontinuous distribution of carbides at grain boundaries prompted some intergranular cracking and ductility loss without localized chromium depletion. This cracking was eliminated by heat treating to form isolated carbides at boundaries. Very narrow chromium depletion widths (<4 nm) enhanced IGSCC over those observed for stainless steel with semicontinuous ca...
Adverse childhood experiences and repeat induced abortion.

Objective The objective of the study was to characterize the backgrounds of women who have repeat abortions. Study Design In a cross-sectional study of 259 women (mean age, 35.2 ± 5.6 years), the relation between adverse experiences in childhood and risk of having 2 or more abortions vs 0 or 1 abortion was examined. Self-reported adverse events occurring between the ages of 0 and 12 years were summed. Results Independent of confounding factors, women who experienced more abuse, personal safety, and total adverse events in childhood were more likely to have 2 or more abortions vs 0 abortions (odds ratio [OR], 2.56; 95% confidence interval [CI], 1.15–5.71; OR, 2.74; 95% CI, 1.29–5.82; and OR, 1.59; 95% CI, 1.21–2.09, respectively) and vs 1 abortion (OR, 5.83; 95% CI, 1.71–19.89; OR, 2.23; 95% CI, 1.03–4.81; and OR, 1.37; 95% CI, 1.04–1.81, respectively). Women who experienced more family disruption events in childhood were more likely to have 2 or more abortions vs 0 abortions (OR, 1.75; 95% CI, 1.14–2.69) but not vs 1 abortion (OR, 1.16; 95% CI, 0.79–1.70). Conclusion Women who have repeat abortions are more likely to have experienced childhood adversity than those having 0 or 1 abortion.
System Evaluation and Life-Cycle Cost Analysis of a Commercial-Scale High-Temperature Electrolysis Hydrogen Production Plant

Results of a system evaluation and lifecycle cost analysis are presented for a commercial-scale high-temperature electrolysis (HTE) central hydrogen production plant. The plant design relies on grid electricity to power the electrolysis process and system components, and industrial natural gas to provide process heat. The HYSYS process analysis software was used to evaluate the reference central plant design capable of producing 50,000 kg/day of hydrogen. The HYSYS software performs mass and energy balances across all components to allow optimized of the design using a detailed process flow sheet and realistic operating conditions specified the analyst. The lifecycle cost analysis was performed using the H2A analysis methodology developed by the Department of Energy (DOE) Hydrogen Program. This methodology utilizes Microsoft Excel spreadsheet analysis tools that require detailed plant performance information (obtained from HYSYS), along with financial and cost information to calculate lifecycle costs. The results of the lifecycle analyses indicate that for a 10% internal rate of return, a large central commercial-scale hydrogen production plant can produce 50,000 kg/day of hydrogen at an average cost of $2.68/kg. When the cost of carbon sequestration is taken into account, the average cost of hydrogen production increases by $0.40/kg to $3.08/kg.Copyright © 2012 by ASME
Finite basis problems and results for quasivarieties

Let \(\mathcal{K}\) be a finite collection of finite algebras of finite signature such that SP(\(\mathcal{K}\)) has meet semi-distributive congruence lattices. We prove that there exists a finite collection \(\mathcal{K}\)1 of finite algebras of the same signature, \(\mathcal{K}_1 \supseteq \mathcal{K}\), such that SP(\(\mathcal{K}\)1) is finitely axiomatizable.We show also that if \(HS(\mathcal{K}) \subseteq SP(\mathcal{K})\), then SP(\(\mathcal{K}\)1) is finitely axiomatizable. We offer new proofs of two important finite basis theorems of D. Pigozzi and R. Willard. Our actual results are somewhat more general than this abstract indicates.
Fine-grained island style architecture for molecular electronic devices

In this paper a fine-grained island style architecture is proposed based on crossbars of nanowires with diode-logic created by molecular devices. A multiple-bit access mechanism is the main requirement for the clusters in every island style architecture to provide inputs, outputs and configuration bits. Island style FPGA architecture with its rich interconnect capabilities seems to be a proper choice for high-level architectures in nanoscale devices. Providing appropriate access to all clusters inside such architectures to communicate with input, output and configuration signals is the main requirement in these structures. In this paper, a multiple-bit DMUX scheme is proposed to act as CMOS-Nano interface and facilitate the configuration and input/output transfer to the nanoscale crossbar structure of the clusters. Two different architectures for the multiple-bit DMUX are proposed. The first DMUX architecture uses nano-imprint technology to provide the required interconnections between nanowires in the architecture and hence is completely nanoscale while the second architecture uses CMOS wires as select lines of the DMUX. These two architectures are analyzed in terms of area overhead based on the number of CMOS and nanoscale wires used in them. The calculations show that both approaches are area efficient when compared to their CMOS counterpart. The estimates also show that for a wide variety of cluster sizes, area of a cluster, that can be configured as large number of lookup tables (LUTs), is significantly smaller than a single 4-input CMOS LUT (22 nm technology). The proposed nano architecture also has its novelty in structure of the clusters and the way these clusters can be used to implement multiple logic functions on them.
Intralingual injection of lidocaine

The inferior aspect of the tongue is an alternate route for lidocaine injection when one has difficulty obtaining an intravenous line for the administration of drugs during resuscitation. We present two cases in which the intralingual injection of lidocaine was successful during cardiopulmonary resuscitation. One patient developed a lingual hematoma, but no airway obstruction occurred.
Identification of the transformation products of 17α-ethinylestradiol and 17β-estradiol by mass spectrometry and other instrumental techniques

Abstract While it is now well-documented that the synthetic (17α-ethinylestradiol, EE2) and natural (17β-estradiol, E2) estrogens are among the most potent endocrine-disrupting chemicals found in the environment, many of their transformation products (TPs) have not been identified to date. The scarcity of available environmental data on the TPs of EE2 and E2 can be attributed to the difficulty in analyzing trace amounts of previously unknown compounds in the presence of complex environmental matrices. This article presents an overview of current knowledge on the TPs identified from biotic and abiotic degradation studies for these two estrogens and provides a list of the structures of TPs that have been identified to date, resulting from the biodegradation, ozonation, and oxidation of EE2 and E2. We also present the application of liquid chromatography with mass spectrometry (LC-MS), in conjunction with nuclear magnetic resonance spectroscopy (NMR) and X-ray crystallography, in identifying biotic and abiotic TPs of EE2 formed in pure cultures of Nitrosomonas europaea to illustrate how these instrumental techniques can complement each other to identify TPs of estrogens unambiguously.
The Value of a Good Name

This paper discussed different stories that pertains to the importance of identity that could really help an individual in the aspect of data security.
Disorientations: Spanish Colonialism in Africa and the Performance of Identity

Disorientations: Spanish Colonialism in Africa and the Performance of Identity Susan Martin-Marquez New Haven and London, Yale University Press, 2008 445 pp., ISBN: 978-0-300-12520-7 (£45.00 hardba...
The structure of fine-scale scalar mixing in gas-phase planar turbulent jets

Fine-scale scalar mixing in gas-phase planar turbulent jets is studied using measurements of three-component scalar gradient and scalar energy dissipation rate fields. Simultaneous planar Rayleigh scattering and planar laser-induced fluorescence, applied in parallel planes, yield the three-dimensional scalar field measurements. The spatial resolution is sufficient to permit differentiation in all three spatial directions. The data span a range of outer-scale Reynolds numbers from 3290 to 8330. Direct measurement of the thicknesses of scalar dissipation structures (layers) shows that the thicknesses scale with outer-scale Reynolds number as ) plays a significant role in the scalar dissipation process. The present data resolve a range of length scales from the dissipation scales up to nearly the jet full width, and thus can be used in a priori testing of subgrid models for scalar mixing in large-eddy simulations (LES). Comparison of two models for subgrid scalar variance, a scale-similarity model and a gradient-based model, indicates that the scale-similarity model is more accurate at larger LES filter sizes.
Particle physics in ice with IceCube DeepCore

Abstract The IceCube Neutrino Observatory is the world's largest high energy neutrino telescope, using the Antarctic ice cap as a Cherenkov detector medium. DeepCore, the low energy extension to IceCube, is an infill array with a fiducial volume of around 30 MTon in the deepest, clearest ice, aiming for an energy threshold as low as 10 GeV and extending IceCube's sensitivity to indirect dark matter searches and atmospheric neutrino oscillation physics. We will discuss the analysis of the first year of DeepCore data, as well as ideas for a further extension of the particle physics program in the ice with a future PINGU detector.
A small-volume electrophoretic concentrator.

Abstract A simple device has been designed to concentrate small volumes of solutions of charged macromolecules by electrophoresis. This device requires less than 2.5 ml of solution and provides concentrate volumes as small as 10 μl. The macroion being concentrated is retained by a high-concentration (30%) polyacrylamide gel. Proteins smaller than myoglobin are not held back effectively by such polyacrylamide concentrations. For these smaller proteins the performance of the device can be enhanced by incorporating charged groups of the same polarity as the macroion into the gel matrix and by reducing the ionic strength of the running buffer. The apparatus has been tested with several protein systems and has been found to concentrate solutions 70- to 100-fold with total yields greater than 70%.
Exogenously administered testosterone maintains spermatogenesis quantitatively in adult rats actively immunized against gonadotropin-releasing hormone

The administration of testosterone via Silastic capsules has been shown previously to maintain advanced spermatid number quantitatively in intact rats in which LH but not FSH was suppressed, but not in hypophysectomized rats, indicating that pituitary factors in addition to LH are required for the quantitative maintenance of spermatogenesis in the rat. The objective of the present study was to examine whether testosterone is capable of maintaining quantitatively normal spermatogenesis in rats in which both LH and FSH are suppressed. Intact adult male rats were actively immunized against GnRH by intradermal injection of GnRH conjugated to human serum globulin; control rats received intradermal injections of saline and adjuvant. Four weeks after the primary immunization, GnRH-immunized rats received the first booster injection and, at the same time, received testosterone-filled polydimethylsiloxane (PDS) implants of 4, 8, 12, or 24 cm or empty implants. Booster injections were repeated every 2 weeks for 8 w...
Calculating blocking probabilities for loss networks based on probabilistic graphical models

Loss networks are a class of resource-sharing models which provide a powerful tool to the analysis and design of many communications and networking systems. For most loss networks of practical interest calculating the exact blocking probabilities is a difficult task. In this paper we present a new framework based on probabilistic graphical models to tackle this task. Specifically, we propose to use factor graphs to model the stationary distribution of product-form loss networks. We also propose to use the sum-product algorithm to compute the marginal distributions and the blocking probabilities of all call classes. Through extensive numerical experiments we show that the sum-product algorithm returns very accurate blocking probabilities and greatly outperforms the reduced load approximation for both single-service and multiservice loss networks with a variety of topologies. In addition, the sum-product algorithm converges very fast and can be implemented in a distributed way
Unusual magnitude and variation of plasma protein-bound iodine values of dairy cattle.

Summary Plasma PBI values of unusual magnitude and variations have been observed in the dairy herd at West Virginia University. The appearance of high PBI values is seasonal, occurring mostly in the late winter and spring. Plasma PBI follows a definite pattern with time by rising to a peak and then declining. A study of management practices revealed that the rise in PBI paralleled the feeding of grass silage to the dairy herd. High PBI levels were not associated with the feeding of excessive quantities of iodine compounds and were not characterized by high levels of plasma inorganic iodine. Fractionation revealed that, whereas some of the PBI was hormonally inactive, the remainder still indicated an unusually high level of circulating thyroid hormone. However, no symptoms of a pathological hyperthyroid condition could be observed in any of the animals studied. Although grass silage was not the sole cause of the elevation of PBI levels, it was capable of maintaining such levels when, normally, other conditions resulted in their decline.
Assessing Laboratory and Field Measurements for Design

Present design methods rely heavily on model basin tests to validate the predictive models used in the design process for offshore structures. Data obtained from laboratory and field test program are closely held by industry; consequently the data analyzed in this study is for nearly similar but not identical deepwater platforms. The findings of this investigation are presented using contour and exceedance probability graphs. The exceedance graphs present exceedance information based upon the measured data with an overly of two different Weibull curve fit models. The first model illustrates the common two-parameter Maximum Likelihood approach, while the second explores the use of a two-parameter least-squares log Weibull model. Neither appears to be entirely satisfactory for the range considered, and the computed coefficients are found to differ only slightly. The most probable maxima are often used to help interpret the limits of experimental data that should be used. Here the most probable maximum was computed as a function Ochi's risk parameter for two different values, as noted in the legend. This study presents some alternate ways of visualizing and interpreting data measured in either laboratory or field studies. The intent here was to highlight some points that should be considered when either interpreting data or when designing measurement programs.
Estimating demand elasticities under rationing

Eliminating rationing in the United Kingdom following the Second World War was a concern for policy-makers because of potentially large fluctuations in post-war prices and the impact on unrationed goods. This study shows that in using virtual prices, elasticities can be estimated from a ‘free’ demand system consistent with observed consumer choices. Substitution estimates without accounting for rationing are misleading. In contrast, using virtual prices and estimating a ‘free’ market system yield results similar to those of the pre-war period. Results show that food rationing affected expenditure across unrationed goods. Rationing on other services had little effect on expenditure across unrationed goods.
Global solubility of the three-dimensional Navier-Stokes equations with uniformly large initial vorticity

This paper is a survey of results concerning the three-dimensional Navier-Stokes and Euler equations with initial data characterized by uniformly large vorticity. The existence of regular solutions of the three-dimensional Navier-Stokes equations on an unbounded time interval is proved for large initial data both in and in bounded cylindrical domains. Moreover, the existence of smooth solutions on large finite time intervals is established for the three-dimensional Euler equations. These results are obtained without additional assumptions on the behaviour of solutions for . Any smooth solution is not close to any two-dimensional manifold. Our approach is based on the computation of singular limits of rapidly oscillating operators, non-linear averaging, and a consideration of the mutual absorption of non-linear oscillations of the vorticity field. The use of resonance conditions, methods from the theory of small divisors, and non-linear averaging of almost periodic functions leads to the limit resonant Navier-Stokes equations. Global solubility of these equations is proved without any conditions on the three-dimensional initial data. The global regularity of weak solutions of three-dimensional Navier-Stokes equations with uniformly large vorticity at is proved by using the regularity of weak solutions and the strong convergence.
Physical activity and sedentary behavior in adolescents with type 1 diabetes.

The purpose of this study was to describe the associations between levels of physical activity measured by accelerometry and changes in fitness, body composition, lipids, and glucose control (i.e., glycosolated hemoglobin [A1C]) in a sample of 16 adolescents with type 1 diabetes participating in a personalized exercise program. More sedentary activity was associated with lower fitness and fat free mass and increased total cholesterol, low-density lipoprotein (LDL-c), and triglycerides (p < .05). Greater amounts of moderate to vigorous activity were associated with higher fitness and fat free mass, and decreased total cholesterol, LDL-c, triglycerides, and A1C (p < .05). Findings support the beneficial effects of increased moderate activity and decreased sedentary behavior to reduce cardiovascular risks and improve glucose control in adolescents with type 1 diabetes.
Progress in burn treatment and the use of artificial skin

Recently improved survival from thermal injuries has been demonstrated both in children and adults. This increase in burn injury survival rates is the result of multiple changes in treatment; probably the most important changes are, first, a more aggressive management of the wound with prompt excision of devitalized tissues and immediate closure of the wound, and, second, a better understanding and management of metabolic, immunologic, and nutritional aspects of the injuried patient. Artificial skin is a very important additional treatment modality that has more recently become available and promises to contribute significantly to improvements in wound management and survival rates by its ability to physiologically close a burn wound immediately after its excision.
Epidemiology of acute drug intoxications: patient characteristics, drugs, and medical complications.

(1974). Epidemiology of Acute Drug Intoxications: Patient Characteristics, Drugs, and Medical Complications. Clinical Toxicology: Vol. 7, No. 5, pp. 513-530.
Weak solutions to Stefan problems with prescribed convection

This paper deals with the equation \[ w_t + {\operatorname{div}}({\bf v}w - \nabla \alpha (w)) = g,\] which is to hold in a smooth, bounded domain $G \subset \mathbb{R}^n $. The function $\alpha :\mathbb{R} \to \mathbb{R}$ is uniformly Lipschitz and ondecreasing, but may be identically zero. For certain smooth functions ${\bf v}:\bar G \to \mathbb{R}^n $ satisfying ${\operatorname{div}}({\bf v}) \geqq 0$, there are integral solutions to the Cauchy problem associated with this equation, provided the boundary conditions on w are chosen appropriately. We prove that these integral solutions are weak solutions in the usual sense. Moreover, these weak solutions are unique; hence the notion of a weak solution is adequate for problems of this type.
Modulation of insulin secretion by the autonomic nervous system1

Abstract Control of insulin secretion by the sympathetic and parasympathetic branches of the autonomie nervous system as a function of both neural input magnitude and glucose concentration was assessed. Theoretical studies using a mathematical model of insulin secretion and experimental measurements of insulin secretion from rat pancreatic islets exposed to norepinephrine and/or acetylcholine were performed. Computer simulations suggested that simultaneous exposure of the pancreas to sympathetic and parasympathetic inputs resulted in enhanced, inhibited or unchanged insulin secretion depending on the absolute and relative magnitudes of the neural inputs and the glucose concentration. Experimental conditions for sympathetic dominance (net inhibition) at 10 mM glucose were defined by computer simulation and were experimentally verified. Thus, autonomie neural control of insulin secretion is a complex function of glucose concentration and the absolute and relative magnitudes of the neural inputs applied to the pancreas. Therefore, the autonomic nervous system has the potential to regulate the amount of insulin secreted in response to glucose and, hence, food intake and body weight in a very subtle manner.
Apparent chemotherapeutic cure of malignant lymphoma.

Two patients with disseminated malignant lymphoma responded to limited chemotherapy and have remained free of disease for 11 and 8 years, respectively, after discontinuing chemotherapy. Both cases had initial clinical and histologic features for a grave prognosis. In view of the accumulating evidence of the presence of malignant lymphoid cells in the circulation when the disease appears still localized, the hypothesis is made that the “cure” of lymphoma is not due to a destruction of all tumor cells but rather to biological alteration in large numbers of lymphoma cells. These alterations induce immunologic reactions by the host that eliminate or contain the remaining tumor cells.
Polymeric silsesquioxanes: degree-of-intramolecular-condensation measured by mass spectrometry

Abstract The degree-of-intramolecular-condensation, defined as the number of residual silanol (Si–OH) groups per oligomer, for a variety of silsesquioxane polymers was measured by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Condensation of the Si–OH groups of a given silsesquioxane oligomer leads to the formation of intramolecular Si–O–Si bridges accompanied by the loss of water. This elimination reaction is easily identified via high resolution time-of-flight mass spectrometry. Various polymeric silsesquioxanes were prepared from the corresponding trialkoxyorganosilanes by hydrolysis–condensation reactions at moderate temperatures (25–65°C) in aqueous acetone with catalytic amounts of formic acid. An n -decyl-silsesquioxane was found to have the highest degree-of-intramolecular-condensation with lower degrees found in n -propyl and in 3-methacryloxypropyl silsesquioxanes. An n -propyl silsesquioxane synthesized without a catalyst was found to have the lowest degree-of-intramolecular-condensation of all as well as the lowest overall molecular mass. In all cases the number of intramolecular Si–O–Si bridges per oligomer was found to be a linear function of the number of repeat units in the oligomer. This linear relationship is discussed in light of theories of intramolecular interactions and bonding in isolated chains.
Alendronate treatment for infants with osteogenesis imperfecta: demonstration of efficacy in a mouse model.

Recent non-placebo-controlled studies of the bisphosphonate pamidronate have shown it to be effective in reducing fractures and improving bone density in infants and children with osteogenesis imperfecta (OI). To evaluate the effects of bisphosphonate treatment in a controlled study, the oim/oim mouse model of OI was studied. Nursing infant mouse pups (∼ 2 wk old) with moderate to severe OI (oim/oim mouse) and age- and background-matched control mice (+/+) were treated either with the third-generation bisphosphonate alendronate (ALN), or with saline. Fracture risk, bone quality, and growth were evaluated over a 12-wk treatment period. ALN at a dose of 0.03 mg/kg/d or saline was administered via s.c. injection to infant oim/oim and wild-type (+/+) mice from 2 to 14 wk of age (n = 20 per subgroup). The average number of fractures sustained by the ALN-treated oim/oim mice was reduced significantly compared with the untreated oim/oim mice (0.7 ± 0.7 fractures/mouse versus 2.0 ± 0.2 fractures/mouse). Bone density increased significantly in the femur and the spine with treatment (2.0 ± 0.5 versus 1.2 ± 0.5 in femur and 2.1 ± 0.5 versus 1.6 ± 0.5 in spine). Histologic evaluation revealed the percentage of metaphyseal tibial bone increased significantly with treatment in both +/+ and oim/oim mice. Mechanical testing revealed an increase in structural stiffness for both treated +/+ and oim/oim mice compared with untreated animals. None of the material properties examined were significantly altered with treatment, nor was spinal curvature affected. Weight gain and long bone growth were comparable in the treated and untreated oim/oim mice. In wild-type mice, femur lengths were significantly shorter in the treated mice compared with untreated counterparts. This animal study demonstrates that treatment of OI in mice as early as 2 wk of age with ALN appears to be effective in reducing fractures and increasing bone properties. Based on the data from this study, ALN therapy in infants with OI should prove to be effective.
Ten year experience with human lung transplantation from non-heart beating donors

determine the number of lobar donors who were evaluated and the primary reason for not being accepted. A total of 220 (138 M:82 F) were referred for lobar donor evaluation by potential recipients and their families. 164 pts (almost 75%) were not accepted as lobar donors. The average number was 8 (range 2-29) potential donors screened per lung transplant candidate. The primary reasons for not accepting a lobar donor: decreased expiratory flows 55 pts (33.5%); height 32 pts (19.5%); did not want to donate 18 pts (11%); not accepted for miscellaneous medical/social reasons by transplant team 18 pts (11%); too obese 12 pts (7.3%); and too old 9 pts (5.5%). Although 2/total 28 (7%) lobar recipients required only 2 donors screened, the majority of lobar candidates required more donor evaluations. While lobar transplant is an option for critically ill patients, the need to evaluate more than 2 potential donors, as well as the time necessary to properly screen lobar donors safely, supports the concept that this surgery should not be considered as a routine emergent procedure. Living lobar transplant requires the ability to screen multiple potential donors in a timeeffective manner to maintain both cost effectiveness and recipient/ donor safety.
Influence of L2 proficiency on speech movement variability: Production of prosodic contrasts by Bengali–English speakers

This paper examines the influence of age of immersion and proficiency in a second language on speech movement consistency in both a first and a second language. Ten monolingual speakers of English and 20 Bengali–English bilinguals (10 with low L2 proficiency and 10 with high L2 proficiency) participated. Lip movement variability was assessed based on bilingual participants’ production of four real and four novel words embedded in Bengali (L1) and English (L2) sentences. Lip movement variability was evaluated across L1 and L2 contexts for the production of real and novel words with trochaic and iambic stress pattern. Adult bilinguals produced equally consistent speech movement patterns in their production of L1 and L2 targets. Overall, speakers’ L2 proficiency did not influence their movement variability. Unlike children, the speech motor systems of adult L2 speakers exhibit a lack of flexibility which could contribute to their increased difficulties in acquiring native-like pronunciation in L2.
The Dynamic Characteristics of Color-Coded S-Potentials

A linear analysis approach has been applied to determine the dynamic characteristics of the color-coded S-potentials. Using a sinusoidally modulated light stimulus it could be shown that the monophasic S-potential as well as each of the different components of biphasic and triphasic S-potentials behaves linearly. However, for high modulation depths and high average intensities nonlinear effects, such as saturation, become obvious. The transfer characteristics of the monophasic potentials and each component of the biphasic and triphasic potentials are indistinguishable. Their latencies, however, differ. These findings suggest that the three different types of S-potentials not only originate from functionally comparable cells but also that the dynamic characteristics of the cells presynaptic to the S-potential sources are identical.
Acoustic echo cancellation based on independent component analysis and integrated residual echo enhancement

This paper examines the technique of using a memoryless noise-suppressing nonlinearity in the adaptive filter error feedback-loop of an acoustic echo canceler (AEC) based on normalized least-mean square (NLMS) when there is an additive noise at the near-end. It will be shown that introducing the nonlinearity to “enhance” the filter estimation error is well-founded in the information-theoretic sense and has a deep connection to the independent component analysis (ICA). The paradigm of AEC as a problem that can be approached by ICA leads to new algorithmic possibilities beyond the conventional LMS family of techniques. In particular, a right combination of the error enhancement procedure and a properly implemented regularization procedure enables the AEC to be performed recursively and continuously in the frequency domain when there are both ambient noise and double-talk even without the double-talk detection (DTD) or the voice activity detection (VAD) procedure.
LOW GLUCOSE UTILIZATION AND HIGH LACTATE PRODUCTION IN THE ALZHEIMER'S DISEASE BRAIN

Background: Age-related changes in the cerebral white matter (WM) have been demonstrated in cognitively intact elderly, and are associated with cognition. The etiology of microstructuralWMdegeneration and its relation to cerebral blood flow (CBF) and white matter hyperintensities (WMH) are uncertain.Methods: 61 cognitively intact elderly volunteers (mean age 85, CDR 0) underwent 3T MRI Q2TIPS pulsed arterial spin labeling (PASL), diffusion tensor imaging (DTI), and cognitive assessment. Voxelwise Tract-Based Spatial Statistics (TBSS) was performed. A general linear model using permutation-based nonparametric testing (FSLRANDOMIZE) examined regional associations betweenWMCBF,WMHs, and microstructural measures. WMHs and WM CBF were examined in relation to fractional anisotropy using both voxel-based and mean WMH volume and WM CBF values. Region of interest (ROI) analyses included atlas-based segmentation of the corpus callosum (CC), limited to the TBSS-derived WM skeleton, and examined CC integrity in relation to cognitive function. Analyses were corrected for partial volume effects and adjusted for age and gender. Matched pairs t-test examined differences in anterior and poster WM integrity.Results: In TBSS voxel-based analysis, associations between WM integrity and WMHs were observed in regions commonly associated with small vessel ischemic disease, along the periventricular WM tracts. WM integrity was significantly decreased in relation to lowerWMperfusion in similar regions. Findings were largely replicated when WMH and WM CBF were entered into the model as mean values, rather than voxel-wise analysis. In addition, clusters of decreased WM integrity were seen in areas of normal appearing white matter in the anterior and posterior cc and WM tracts in the frontal and parietal lobes. ROI analyses showed greater WM integrity disruption in the anterior compared with posterior CC. Anterior CC integrity was associated with performance on executive and memory function tests. Conclusions: Greater WMH and lower WM perfusion are independently associated with decreased WM integrity both within and outside of commonly observedWMlesions.Anterior> poster cc involvement may represent greater susceptibility of this region to hypoperfusion.WMCBF may serve as a potentiallymodifiable target in trials aimed at preserving cognitive function in elderly individuals, prior to cognitive impairment.
Crystal Structure of [(C2H5)4N]4Cu7Cl14O2: A Cu14Cl28O48−Cluster

The synthesis and crystal structure of a novel copper(ll) halide cluster, (Et4N)8Cu14Cl28O4, is reported. The cluster anion Cu14Cl28O4 8− can be Viewed as being formed by the dimerization of two Cu7Cl14O2 4− fragments. The hypothetical precursor anion of this latter cluster, Cu7Cl15O2 5− in tum can be viewed as being formed from. the known parent Cu7Cl14O2 4− cluster anions by fusion of pairs across a common CuCI3 face. The fusion and dimenzation processes cause substantial distortion of the trigonal bipyramidal coordmation geometry of the copper(II) ions in the parent cluster. For three of the copper(II) ions this Yields a 4+1 geometry distinct from either trigonal blpyramldal or square pyramidal. The dimerization of the two Cu7 clusters forces a severe distortion upon one additional copper(II) ion, this time towards a tetrahedral geometry. The implications of these distortions for the catalytic properties reactivities and magnetic behaviour of the parent complex are discussed.
Talk about Talking

In his usual clear and persuasive way, Daniel Callahan examines what he suspects is "a natural antagonism between ethics and science" (Scannings: "The Ethics Backlash," Hastings Center Report, August 1975). I have to agree with most of what he says even though I am an ex-researcher (although, alas, I never reached such eminence as to be "accused of immortality"), and although I am one of "the insecure and the aggressive (who) dote on each other's excesses."1 I am concerned, however, by his rather cavalier dismissal of "failure in communication" as a major cause for the distrust if not hostility that separates the two camps. Obvious it is, to invoke "failure in communication" as an explanation, and trite too, but "glib"?too smooth and fluent to be convincing, and so superficial as to mislead and to obscure more important reasons? Would Callahan so stigmatize the advice of his comrades in ethics: "Scientists and their critics must not merely state their positions, they must come to understand each other's point of view."2 And, "Finally, the forum did make evident how necessary it is to educate the profession and the public on these (ethical) issues."3 Granted that mere communication will not in itself make the "tensions and frictions... go away"; more words may indeed mean just more shouting. Granted also that some innate differences may characterize ethicists and scientists. Yet, why not tackle the therapeutically susceptible issue rather than proclaiming once and for all that it is so ordained? Earlier this year the first issue of the Journal of Medical Ethics appeared. Such a publication may well serve parochial interests, but will a Journal of Medical Ethics promote ethical medicine? The chances are negligible, for those whose performance this publication would uplift never see its contents. But when ethicists write in medical journals -as officers and fellows of the Institute fortunately have done-then exposure of the physician-scientist is fostered and conversion at least a possibility. The Hastings Center Report by virtue of its catholic dissemination to the professions serves a similar purpose. And, come to think of it, would the Report or even its sponsoring Institute exist did not its Director also believe in the value-excuse the word, Daniel-of communication? Franz J. Ingelfinger, M.D. Editor, New England Journal of Medicine Boston
Developing a broader approach to management of infection control breaches in health care settings

Our experiences with health departments and health care facilities suggest that questions surrounding instrument reprocessing errors and other infection control breaches are becoming increasingly common. We describe an approach to management of these incidents that focuses on risk of bloodborne pathogen transmission and the role of public health and other stakeholders to inform patient notification and testing decisions.
Multi-scale reliability analysis and updating of complex systems by use of linear programming

Complex systems are characterized by large numbers of components, cut sets or link sets, or by statistical dependence between the component states. These measures of complexity render the computation of system reliability a challenging task. In this paper, a decomposition approach is described, which, together with a linear programming formulation, allows determination of bounds on the reliability of complex systems with manageable computational effort. The approach also facilitates multi-scale modeling and analysis of a system, whereby varying degrees of detail can be considered in the decomposed system. The paper also describes a method for computing bounds on conditional probabilities by use of linear programming, which can be used to update the system reliability for any given event. Applications to a power network demonstrate the methodology.
Hybrid Neuro-Fuzzy Application in Short-Term Freeway Traffic Volume Forecasting

A hybrid neuro-fuzzy application for short-term freeway traffic volume forecasting was developed. The hybrid model consists of two components: a fuzzy C-means (FCM) method, which classifies traffic flow patterns into a couple of clusters, and a radial-basis-function (RBF) neural network, which develops forecasting models associated with each cluster. The new hybrid model was compared with previously developed clustering-based RBF models. In addition, the dynamic linear model was studied for comparison. The study results showed that the clustering-based hybrid method did not produce time-lag phenomena, whereas the dynamic linear model and the RBF model without clustering revealed apparent time-lag phenomena. The forecasting performance for freeway traffic volumes from the San Antonio, Texas, TransGuide system shows that even though the hybrid of the FCM and RBF models appears to be promising, additional research efforts should be devoted to achieving more reliable traffic forecasting.
Approaching Near Optimal Detection Performance via Stochastic Resonance

This paper considers the stochastic resonance (SR) effect in the two hypotheses signal detection problem. Performance of a SR enhanced detector is derived in terms of the probability of detection PD and the probability of false alarm P FA . Furthermore, the conditions required for potential performance improvement using SR are developed. Expression for the optimal stochastic resonance noise pdf which renders the maximum P D without increasing P FA is derived. By further strengthening the conditions, this approach yields the constant false alarm rate (CFAR) receiver. Finally, detector performance comparisons are made between the optimal SR noise, Gaussian, Uniform and optimal symmetric pdf noises.
Paucity of Genetic Variation at an MHC Class I Gene in Massachusetts Populations of the Diamond-backed Terrapin (Malaclemys terrapin): A Cause for Concern?

Abstract The Diamond-backed Terrapin (Malaclemys terrapin), endemic to the brackish marshes of the eastern and Gulf of Mexico coasts of the United States, is a threatened species in Massachusetts with populations suffering drastic declines in the late 19th and early 20th centuries. To assess the potential effects of population bottlenecks on contemporary levels of genetic variation, we analyzed 219 bp of a major histocompatibility complex class I gene region (MHCI) by direct sequencing and single-strand conformational polymorphism analysis and six microsatellite loci from three locations around Cape Cod, Massachusetts. No variation was found at the MHCI, despite finding appreciable levels of variation within and among populations at the microsatellite loci. We discuss alternative explanations for these results, and we propose that the lack of variation at the MHCI may be due to the effects of selection rather than demographic changes in terrapin populations.