cssi/SciSciGPT-SciSciNet huggingface dataset:
Electrophoretic deposition of phosphor in a thermoreversible gel

— A method to electrophoretically deposit phosphors utilizing a thermoreversible gel was examined. The polymer poly(butyl methacrylate) (PBMA) was mixed with the solvent, isopropanol, in concentrations ranging from 10 to 45 wt.%. Various deposition conditions were investigated, including temperature, polymer concentration, deposit time, and applied voltage. Although electrophoretic deposition of phosphor in a thermoreversible gel has been demonstrated, it does not appear likely that this PBMA system will allow for an adequate amount of phosphor to deposit due to the high viscosity at the required concentration of PBMA for gelation.
Single-electron capture by He 2+ ions from triatomic molecules

Abstract State-selective single-electron capture (SEC) processes in low-energy collisions of He 2+ ions with H 2 O and CO 2 have been studied experimentally at impact energies between 0.1 and 1 keV by means of translational energy-gain spectroscopy. At the lowest collision energy, 100 eV, the energy-gain spectra indicate that the dominant reaction channels are dissociative transfer ionization (DTI), due to SEC into the n =1 states of He + product ions with simultaneous ionization of the target products. As the projectile impact energy is increased, DTI channel remains dominant for the He 2+ –CO 2 collision system. However, for the He 2+ –H 2 O collision system, non-dissociative SEC into n =2 states of He + with production of H 2 O + in the ground state is also observed and found to become the dominant process at collision energies in excess of 800 eV. The energy-gain spectra are interpreted qualitatively in terms of the reaction windows, which are calculated using the Landau–Zener model and the extended version of the classical over-the-barrier model.
Thermal conductivity of pure monoisotopic silicon

The thermal conductivity of pure monoisotopic silicon is estimated by two methods, which give similar results. One estimate, based on the observed thermal conductivity of monoisotopic germanium, yields a maximum of 66 W · cm−1 · K−1 at 22 K. The other estimate, based on measurements of natural silicon and on the theoretical isotope scattering rate, yields 75 W · cm−1 · K−1 at 22 K, an increase of only 45% over the natural crystal. These values are for crystals of approximately 0.5 cm diameter; smaller crystals yield lower values of the maximum conductivity and smaller isotope effects. Silicon cooled to liquid hydrogen temperature seems promising for high-irradiance laser mirrors. The small gain obtained by using monoisotopic silicon would be substantially greater in cases when the generated phonon distribution is athermal and weighted to higher frequencies. The effective heat transport could then be increased by as much as a factor 60 through the use of monoisotopic silicon.
SiGe bipolar transceiver circuits operating at 60 GHz

A low-noise amplifier, direct-conversion quadrature mixer, power amplifier, and voltage-controlled oscillators have been implemented in a 0.12-/spl mu/m, 200-GHz f/sub T/290-GHz f/sub MAX/ SiGe bipolar technology for operation at 60 GHz. At 61.5 GHz, the two-stage LNA achieves 4.5-dB NF, 15-dB gain, consuming 6 mA from 1.8 V. This is the first known demonstration of a silicon LNA at V-band. The downconverter consists of a preamplifier, I/Q double-balanced mixers, a frequency tripler, and a quadrature generator, and is again the first known demonstration of silicon active mixers at V-band. At 60 GHz, the downconverter gain is 18.6 dB and the NF is 13.3 dB, and the circuit consumes 55 mA from 2.7 V, while the output buffers consume an additional 52 mA. The balanced class-AB PA provides 10.8-dB gain, +11.2-dBm 1-dB compression point, 4.3% maximum PAE, and 16-dBm saturated output power. Finally, fully differential Colpitts VCOs have been implemented at 22 and 67 GHz. The 67-GHz VCO has a phase noise better than -98 dBc/Hz at 1-MHz offset, and provides a 3.1% tuning range for 8-mA current consumption from a 3-V supply.
Analytical Expressions for the Readback Signal of Timing-Based Servo Schemes

Timing-based servo (TBS) is a powerful technology widely used in state-of-the-art tape systems for track following. To optimize TBS systems for future operating points with aggressive track-density scaling, an accurate model is needed to characterize how the servo read head geometry, servo format parameters, and magnetic media properties affect the readback signal. In this paper, we derive new analytical closed-form expressions for the readback signal of shielded magneto-resistive (MR) heads scanning over the magnetic transitions of TBS patterns. The expressions, derived via the reciprocity principle, are applicable to arctan-shaped transitions between arbitrarily magnetized areas of a thin-film magnetic medium and are given in the displacement and wavevector domain. We apply these new expressions to analyze isolated transitions as well as multi-transition TBS patterns on longitudinal, non-oriented or perpendicular media. Comparison between experimentally captured servo readback signals and the analytical expressions show an excellent match. By adding electronics and transition jitter noise, the readback signal expressions can be extended to a servo channel model suitable for TBS performance prediction by means of Monte Carlo simulations and/or bounds on the variance of the position-error signal.
Measuring Treatment — Effects in Experimental Cross — Sectional Time Series

In the analysis of individual decision data collected in experimental games problems arise due to repeated measurement and strategic interaction of subjects; namely, that the decisions are non-independent. These problems are common to experimental economists. For example, with respect to repeated measurement Roth argues in The Handbook of Experimental Economics that “not only autocorrelation, but also potential learning effects (diminishing variance by periods) raise questions that need to be addressed in analyzing the data. There remains considerable room for improvement in econometric methods and tests to address these issues.”1
Inequality, Self-Interest, and Public Support for “Robin Hood” Tax Policies:

Influential economic models predict that as inequality increases, the public will demand greater redistribution. However, there is limited research into the determinants of support for redistributive tax increases because such proposals have been so rare in America in recent decades. We use Washington State’s Proposition 1098 to examine how economic self-interest, concerns about inequality, and partisanship influence support for redistributive taxation. The results show that all of these factors influenced support, with strong support among the lower income, indicating that when the distributional implications of policies are clear, citizens can translate their self-interest and broad attitudes into congruent redistributive preferences.
Atmospheric effects in infrared target acquisition modeling

This paper discusses the model's atmospheric components, past efforts to validate a turbulence blur model, current efforts to model turbulence distortion effects, and intended future work to include additional atmospheric effects.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Encapsulation of organic solar cells with ultrathin barrier layers deposited by ozone-based atomic layer deposition

Abstract Ultrathin Al2O3 layers, deposited using atomic layer deposition (ALD), have been utilized as the primary barrier layers for encapsulation of organic solar cells. This work shows that the encapsulation characteristics of a barrier layer can be accentuated by replacing H2O with O3 as the ALD oxidant. The Al2O3 layers deposited using O3 offered superior device encapsulation compared to the films deposited using H2O. The organic solar cell efficiency has also been studied as a function of Al2O3 thickness and effective encapsulation has been monitored for two different ALD temperatures.
An Intensive Study of M 81

Michele Kaufman (at Ohio State University) and I are conducting an extensive observational study of M 81 in order to understand where the various components of the spiral arms lie, how they relate to one another and how they agree with theoretical predictions. The work includes several additional collaborators which depend on the particular study. In the first paper (Bash and Kaufman 1986), we investigate the radio continuum structure of M 81 by means of λ 6-cm and λ 20-cm VLA continuum maps. In paper II (Kaufman et al. 1987), we examine M 81’s H II regions. Paper III (in preparation) investigates the dust lanes and molecular gas. Paper IV will examine the relative location of all of these species with respect to one another and with respect to theoretical predictions while Paper V will examine M 81’s nucleus.
Macroscopic Tool for Measuring Delay Performance in National Airspace System

Airline delays lead to a tremendous loss of time and resources and cost billions of dollars every year in the United States. To explore solutions for reducing delay, it is essential to understand factors causing flight delays and also the network impact of delays at one airport in the National Airspace System (NAS). For air transportation planning and policy purposes, this study concentrates on providing answers from a macroscopic point of view without being distracted by volatile operational details. A set of multivariate equations is proposed to model daily average arrival delay at one airport, and another for the rest of the NAS. The model for the single airport considers independent variables such as deterministic arrival queuing delay, delay at other airports in the NAS, adverse weather (convective and local), and different demand management regimes. The model for the rest of the NAS considers arrival delay as a function of deterministic arrival queuing delay, arrival delay at the single airport, adverse weather (convective and local), and other factors. Observation of the interactions between these two models shows that they can be regressed with an econometric technique: two-stage least squares. This macroscopic framework of delay impact analysis can be used to investigate the network effect of capacity improvement or new demand management strategies at a single airport. Hypothetical scenarios are generated and the systemwide delay reduction is calculated. This is a powerful decision support tool for stakeholders to use in deciding how to allocate resources optimally and to reduce delays.
The congressional foundations of agency performance

When Congress delegates a policy mandate to a regulatory agency, Congress acts as a principal, choosing the institutional arrangements, or the ‘rules of the game’ for agency decision making. Individuals in the agency, acting as agents, take the rules of the game as given and do the best they can within these institutional arrangements. In this paper we develop a simple model that relates the congressional choice of institutional arrangements to two underlying environmental factors — uncertainty and conflict. We suggest that uncertainty and conflict of interest lead Congress, in delegating, to prescribe a greater scope of permissable regulatory activity, a wider array of regulatory instruments, and more confining regulatory procedures. Increased scope and stronger instruments tend to broaden the overall discretionary authority of the agency, while more confining procedures tend to narrow it. We conjecture that with increased uncertainty or conflict the narrowing tendency more than offsets the broadening tendency, for a net decrease in the agency's overall discretionary authority. Lastly, we argue that the performance of a regulatory agency in fulfilling its mandate is determined in large measure by the foundations Congress constructs for the implementation of delegated authority.
Assessment of patient communication skills during OSCE: examining effectiveness of a training program in minimizing inter-grader variability.

Objective To assess effectiveness of a training program in reducing inter-grader variability in grading communication skills during an objective structured clinical exam (OSCE). Methods Global communication (GC) skills are assessed by standardized participants (SP) and faculty during each OSCE using a 6 item rubric. Despite criteria delineated in the GC rubric, inter-grader variability was observed. During 2008–2009 academic year, a training program was implemented before each OSCE to achieve more consistent interpretation and grading in GC skills. GC grades between SP and faculty for 2nd and 3rd level student OSCEs during 2008–2009 (post-training) were compared to 2007–2008 (pre-training). Data was analyzed using repeated measures ANOVA. Results 274 and 281 students participated in OSCEs during 2007–2008 and 2008–2009 academic years, respectively. Training significantly (P < .001) decreased grader variability between SPs and faculty. There was a greater mean difference between faculty vs. SP before training (faculty 14.68, SP 15.87) compared to after training (faculty 13.51, SP 13.78). Mean GC scores for both faculty and SPs also decreased significantly after training. Conclusion and practice implications A training program may be necessary to reduce inter-rater variability in assessment of OSCE communication skills if it is to be truly helpful to student pharmacists learning to counsel patients.
Averaging methods in the delayed-logistic equation

The delayed logistic equation is analyzed using the averaging method. Using the transformation of coordinates v=ln N/K it is shown that the first order term in perturbation theory yields N=K exp(r* cos πt/2) when the delay time T exceeds some critical value Tc. The amplitude r* is equal to (40μ/3π − 2)1/2 and μ is an expansion parameter that is proportional to (T − Tc). Comparison of the exponential solution of N and numerical results for the ratio Nmaximum/Nminimum provides a good fit for values of μ larger than the results using the N coordinate as the perturbed coordinate.
Differences in α7 nicotinic acetylcholine receptor binding in motor symptomatic and asymptomatic MPTP-treated monkeys

Abstract We studied [ 125 I]α-bungarotoxin (btx) binding to α7 nicotinic acetylcholine receptors in normal and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) exposed macaque monkeys. [ 125 I]α-Btx binds throughout the normal monkey brain, with the greatest density in the thalamic nuclei and with moderate to low binding in the hippocampus, prefrontal cortex, caudate, putamen, and substantia nigra. Chronic adminstration of low doses of MPTP resulted in animals with stable cognitive deficits without overt parkinsonian motor symptoms. [ 125 I]α-Btx binding in the brains of these animals was significantly increased in the outermost layers of the supplementary motor cortex (area 6M, ~50%), primary motor cortex (area 4, ~112%) and throughout the putamen (~50–72%). In contrast, there was no change in [ 125 I]α-btx binding in the brain regions thought to be involved in mediating the cognitive functions impaired in these monkeys (e.g., the hippocampus, areas 9/46D and 46D of the principal sulcus, and area 24c of the cingulate sulcus). Animals with cognitive dysfunction that received escalating doses of MPTP for >6 months developed motor signs of parkinsonism which were indistinguishable from those seen in animals rendered acutely parkinsonian with short term administration of large doses of MPTP. These two “motor symptomatic” groups had significantly increased [ 125 I]α-btx binding only in the dorsolateral putamen. Immunohistochemical studies showed that the increased [ 125 I]α-btx binding, when observed, was associated with enhanced immunohistochemical staining localized to neurons and was not a result of an astrocytic response to MPTP. These results suggest that the increase in α7 nicotinic acetylcholine receptor expression in the chronic low-dose MPTP treated, motor asymptomatic monkeys may be a part of compensatory processes contributing to the maintained motor functioning in these animals.
Supplementation with selenium and human immune cell functions. II. Effect on cytotoxic lymphocytes and natural killer cells

This study examined the effect of dietary (200 μg/d for 8 wk) supplementation with selenium (as sodium selenite) on the ability of human peripheral blood lymphocytes to respond to stimulation with alloantigen, develop into cytotoxic lymphocytes, and to destroy tumor cells, and on the activity of natural killer cells. The participants in the study were randomized for age, sex, weight, height, and nutritional habits and given selenite or placebo tablets; all participants had a selenium replete status as indicated by their plasma Se levels prior to supplementation. The data indicated that the supplementation regimen resulted in 118% increase in cytotoxic lymphocyte-mediated tumor cytotoxicity and 82.3% increase in natural killer cell activity as compared to baseline values. This apparently was related to the ability of the nutrient to enhance the expression of receptors for the growth regulatory lymphokine interleukin-2, and consequently, the rate of cell proliferation and differentiation into cytotoxic cells. The supplementation regimen did not produce significant changes in the plasma Se levels of the participants. The results indicated that the immunoenhancing effects of selenium in humans require supplementation above the replete levels produced by normal dietary intake.
A Case Study of Neurosis Secondary to Trauma in an Eight-Year-Old Girl Comments on the Tendency for Psychogenic Illness To Become Chronic

This case study deals with an eight-year-old girl who developed persistent abdominal pain and vomiting for which no physiological cause could be discovered. After two months of unsuccessful treatment for her illness, the girl was referred for a psychiatric consultation. During the psychiatric interview, the psychogenic nature of the girl's illness became readily apparent, as did the nature of the conflict which had produced it. The tendency is strong for psychogenic illness, such as this, to become chronic without psychiatric treatment. Many physicians are reluctant to apply clinically basic psychiatric techniques to the treatment of physical illness. A suggestion is made that closer collaboration between psychiatry and other medical specialties could be of great value in preventive medicine.
Spectral statistics of pointer states in open quantum dots

Pointer states are thought to control the relationship between quantum system properties and the classical results of measurement. In open quantum dots, they yield measurable conductance resonances. We study the energy level spacing statistics in a perturbed stadium dot, which, when closed, follow the Wigner distribution associated with chaos. In contrast, when the stadium is opened so that only the pointer states localized in the interior remain, the distribution becomes Poissonian, indicating that these states are intimately associated with the regular classical orbits.
Defining digital libraries

Discusses our ongoing interest in debating the concept of the digital library, how to “de‐mystify” the concept, and the importance of being involved in the development of the digital library as it evolves.
Active-Cells for the Construction of Redundant and Configurable Articulated Structures

This paper describes preliminary design and analysis of “active cells” used for the construction of homogeneous actuated electromechanical composite structures made from many of these electromechanical active cells. Each cell consists of a simple rapid-prototyped outer shell containing both a contractile Nitinol element and a return spring, such that these tiny, self-contained contractile engineered cells can serve as the building blocks for larger articulated structures. Each cell occupies approximately 3.0 cm3 in volume. Design considerations are explored that will affect the packing of a number of cells in a mold with a highly elastic binding agent to constrain them. The structures made from these cells can be easily fabricated in a nearly arbitrary shape — by producing an appropriate mold to contain the cells — and can be highly redundant and robust to localized cell failures. The composite structure is actuated via the application of an electrical potential across each of the individual cells, causing the cells to activate through resistive heating. The material properties of the ensemble structure can be varied by changing the properties of the binding material and the return springs of the cells, thus enabling the design of a wide range of stiffness and damping properties.Copyright © 2013 by ASME
Casein kinase ii (protein kinase ck2) regulates serotonin 5-ht3 receptor channel function in ng108-15 cells

We have used whole-cell recording techniques in the mouse neuroblastoma X rat glioma hybrid NG108-15 cell line to test whether protein kinase CK2 (CK2; also known as casein kinase II) modulates the function of the serotonin 5-HT(3) receptor (5-HT(3)R) channel. The rapid application of 5-HT (50 microM) to NG108-15 cells elicits a 5-HT(3)R-mediated inward current response that rapidly reaches peak amplitude and then desensitizes in the continued presence of agonist. Internal dialysis with CK2 (20 micrograms/ml) via the patch pipette significantly increases the amplitude and decreases the rate of desensitization of the 5-HT(3)R-mediated responses. CK2 that had been heat-inactivated has no effect on either the amplitude or the kinetics of desensitization of the 5-HT(3)R responses. These data suggest that dialysis with protein kinase CK2 significantly enhanced current through the 5-HT(3)R channel, and that CK2 may be an important regulator of 5-HT(3)R channel function in the nervous system, possibly serving to facilitate the 5-HT-induced excitation of the cells.
A P-complete graph partition problem

Abstract The Different Than Majority Labelling (DTML) problem has a simple polynomial time sequential algorithm. The labelling given by this algorithm is called the Lexicographical First DTML. In this paper we show that the LF-DTML problem is P-complete. Furthermore, we show that even when restricted to planar graphs, the LF-DTML problem remains P-complete.
Antidepressant use during early pregnancy and the risk of congenital anomalies.

Study Objective To estimate and compare the prevalence of congenital anomalies among the offspring of women exposed and not exposed to antidepressants during early pregnancy. Design Matched cohort study. Data Source United Kingdom's General Practice Research Database. Subjects Women exposed to tricyclic and selective serotonin reuptake inhibitor (SSRI) antidepressants during the first trimester of pregnancy (3276 women) and a sample of women matched in a 2:1 ratio who had no exposure to any antidepressant during the first trimester of pregnancy (6617 women). Measurements and Main Results The prevalence of any congenital anomaly was 31.0 (95% confidence interval [CI] 27.0–35.5) per 1000 pregnancies among women not exposed to antidepressants and 27.2 (95% CI 22.1–33.4) per 1000 pregnancies among women exposed to antidepressants. The relative risk of having a child with an anomaly in mothers who were exposed to tricyclics and SSRIs during the first trimester compared with mothers not exposed to these drugs was 0.9 (95% CI 0.7–1.1). The relative risks for any anomaly among women exposed to antidepressants were 0.9 (95% CI 0.6–1.2) for tricylics and 0.9 (95% CI 0.7–1.2) for SSRIs. We found no statistically significant, stable increases in the risk of specific anomaly subtypes among women exposed to these antidepressants; however, the number of exposed cases was small. Conclusion Exposure to tricyclics and SSRIs during the first trimester of pregnancy was not associated with a statistically significant increased risk of congenital anomalies in the offspring of mothers exposed to these drugs.
Recovering 3-D Shape: Roles of Absolute and Relative Disparity, Retinal Size, and Viewing Distance as Studied with Reverse-Perspective Stimuli

When viewing reverspective stimuli, data-driven signals such as disparity, motion parallax, etc, help to recover veridical three-dimensional (3-D) shape. They compete against schema-driven influences such as experience with perspective, foreshortening, and other pictorial cues that favor the perception of an illusory depth inversion. We used three scaled-size versions of a reverspective to study the roles of retinal size, binocular disparity, and viewing distance--that influences both vergence and accommodation--in recovering the true 3-D shape. Experiment 1 used three conditions, in each of which a parameter was kept fixed across the three stimulus sizes: (a) fixed retinal size, (b) fixed viewing distance, (c) fixed disparity. The predominance of the veridical percept was recorded. Generally, the illusion strength was the same when the viewing distance was fixed, despite significantly different disparities and retinal sizes; conversely, illusion strength changed significantly in fixed-disparity and fixed-retinal-size conditions. Experiment 2 confirmed the results of experiment 1b (roughly equal performances for fixed viewing distance, independent of size) for two additional distances. Viewing distance and "scaled disparity" (disparity divided by retinal size) are good predictors of the data trends. We propose that disparity scaling is supported by both mathematical and 3-D shape considerations.
Ranked set sampling: an auditing application

This study compares the statistical precision of simple random sampling with balanced ranked set sampling in an inventory valuation scenario. Computer simulation is used to calculate standard errors for the ranked set sampling mean, and those standard errors are then compared to the corresponding standard error achieved under simple random sampling. Results indicate that required sample sizes for a given precision are much smaller under ranked set sampling than under simple random sampling. This implies that simple random sampling is inferior to ranked set sampling in auditing scenarios involving the measurement of time consuming or difficult to gather data such as inventory observations, receivable confirmations, etc. Accordingly, auditors using ranked set sampling in lieu of simple random sampling can achieve the significant cost reductions associated with smaller sample sizes without sacrificing audit quality. This is a significant finding because current auditing practice is still using the simple random sampling methodology.
Lipids of potato tubers. III. Effect of growth and storage on lipid content of the potato tuber

The effect of physiological changes on the lipid content of six varieties of potato tubers was studied. No significant varietal differences were observed. A marked decrease occurred in the amount of total lipid and fatty acids during the initial weeks of growth, followed by a levelling off during maturation and subsequent storage at 5 oC. After 6 months' storage, the early maturing varieties revealed a large degree of sprouting with an accumulation in both total lipid and fatty acid content. Palmitic, linoleic and linolenic acids represented 95% of the fatty acids and throughout these studies the relative proportions of the major fatty acids remained constant. Chromatographic analysis demonstrated very little change in the polar lipids, but minor trends among the neutral lipid classes were detected. In the early stages of growth of the tuber the triglyceride level fell rapidly, but later, following the break of dormancy in the stored tuber, there was a regeneration of triglyceride accompanied by a noticeable rise in sterol and carotenoid content.
Structures, Energies, and Electrostatics for Methane Complexed with Alumina Clusters

Ab initio calculations were used to investigate properties of complexes formed from the association of CH4 with Al2O3, Al4O6, and Al8O12 alumina clusters. Methane attaches to a surface Al atom of t...
Knowledge and skills needed by community members

Abstract Knowledge and skills needed by lay participants in community development were proposed by 14 community development (CD) consultants around 10 topical areas. One hundred knowledge and skills statements resulted. The importance of these statements for lay participants in CD was judged by 116 CD youth leaders and 117 CD adult specialists. Judgments were subjected to factor analysis, and nine factors emerged. An analysis of statement mean scores showed an additional 17 individual statements were judged important. The factors and individual statements provide a viable base for the development of training programs for lay CD participants.
Paclitaxel and platinum chemotherapy for ovarian carcinoma during pregnancy.

Abstract Background. Ovarian cancer diagnosed during pregnancy is uncommon. Paclitaxel-based chemotherapy during pregnancy has not been reported previously. Case. A woman with ascites and an adnexal mass diagnosed during pregnancy at 27 weeks gestational age underwent a laparotomy with cytoreductive surgery and was diagnosed with stage IIIC papillary serous ovarian adenocarcinoma. She was treated with three cycles of paclitaxel and cisplatin during pregnancy. At 37 weeks, she underwent a cesarean section, abdominal hysterectomy, and cytoreduction. Three additional cycles of chemotherapy were given. She developed a recurrence within 6 weeks of completing chemotherapy. She received several cycles of chemotherapy, but died of recurrent cancer 29 months after diagnosis. The infant has normal growth and development at 30 months of age. Conclusion. This is the first reported case of paclitaxel use during pregnancy.
Security Analysis of Compromised-Neighbor-Tolerant Networks Using Stochastics

A stochastic model is introduced to investigate the security of network systems based on their vulnerability graph abstractions. Instead of doing traditional security analysis, this paper employs the increasing convex order to study the underlying vulnerability graph. The results of this paper can provide an insight on designing a more secure system, as well as an insight on enhancing the security of an existing system.
Recent heart failure trials of neurohormonal modulation (OVERTURE and ENABLE): approaching the asymptote of efficacy?

The revolution in heart failure treatment brought about by the success of angiotensin converting enzyme (ACE) inhibitors firmly established the neurohormonal hypothesis of heart failure. Many trials have demonstrated the importance of inhibition of the renin-angiotensinaldosterone system (RAAS), and have encouraged investigators to ask whether further inhibition of other neurohormonal systems might be beneficial. The tremendous morbidity and survival advantage afforded by betaadrenergic receptor blockers has supported this hypothesis for many clinicians (although others might argue that much of the mechanism of beta-blockers is due to RAAS suppression). The recently reported results from ValHeFT (Valsartan Heart Failure Trial) provide an interesting perspective on this issue, where there was no apparent significant additional benefit to the administration of an angiotensin receptor antagonist in the patients already receiving an ACE inhibitor and beta-adrenergic receptor blockade. Two very important and informative trials that tested new approaches to neurohormonal modulation in the treatment of heart failure were presented at the recent 2002 American College of Cardiology Scientific Sessions in Atlanta: OVERTURE (Omapatrilat versus Enalapril Randomized Trial of Utility in Reducing Events) and ENABLE (Endothelin Antagonism with Bosentan and Lowering of Events).
Artemisinin concentration and antioxidant capacity of Artemisia annua distillation byproduct

Abstract Artemisia annua is mostly known as the source of artemisinin, the raw material for the production of artemisinin-based combination therapy, used against drug-resistant Plasmodium falciparum where malaria is endemic. Artemisinin is also effective against helminthic and protozoan parasites that afflict both humans and livestock. Besides being the only commercial source of artemisinin, the plant contains a pleasantly aromatic essential oil valued in perfumery and cosmetics. However, multi-use of the leaf biomass for the production of artemisinin, essential oil, and antioxidants has never been investigated. The objectives of this research were to evaluate the effect of distillation time of A. annua biomass on essential oil yield, artemisinin concentration, and antioxidant capacity of the plant residue from distillation (PRD). Results demonstrated that leaf biomass can be explored for both essential oil and as a source of antioxidants, but the PRD is devoid of artemisinin. The high antioxidant capacity of the PRD (75% of the control samples) suggests that the industrial byproduct used to produce the essential oil is also a potential source of antioxidants for use as a livestock feed supplement or as a source of compounds for the nutraceuticals market.
Oxidant Mechanisms in Gentamicin Nephrotoxicity

Acute renal failure is a major complication of aminoglycoside antibiotics, which are widely used in the treatment of gram-negative infections. Sequential reduction of oxygen along the univalent pathway leads to the generation of superoxide anion, hydrogen peroxide, hydroxyl radical, and water. A large body of in vitro and in vivo evidence indicates that these partially reduced oxygen metabolites are important mediators of gentamicin nephrotoxicity. Gentamicin has been shown to enhance the generation of superoxide anion and hydrogen peroxide by renal cortical mitochondria. The interaction between superoxide anion and hydrogen peroxide in the presence of metal catalyst can lead to the generation of hydroxyl radical. Gentamicin has been shown to lead to release of iron from renal cortical mitochondria and to enhance generation of hydroxyl radical. These in vitro observations have been supported by in vivo studies in which scavengers of reactive oxygen metabolites and iron chelators have shown to be protective in gentamicin induced acute renal failure. There is evidence to suggest that studies may have broader implication in being relevant to other aminoglycosides including streptomycin and being applicable to other major toxicity of aminoglycoside such as ototoxicity.
On achievable error exponents for watermarking

Probability-of-error exponents have recently been derived for watermarking systems based on spread-spectrum and quantization-index modulation methods. This paper takes this work one step further and presents minmax error exponents for any embedding scheme and any attack (subject to distortion constraints) at all rates below capacity. The decoders used are universal: they do not know the attck used. Randomized codes outperform deterministic codes, except in the case of memoryless attacks where the same performance is obtained using either kind of code.
Spatial distribution of phosphate species in mature and newly generated mammalian bone by hyperspectral Raman imaging

Hyperspectral Raman images of mineral components of trabecular and cortical bone at 3 μm spatial resolution are presented. Contrast is generated from Raman spectra acquired over the 600-1400 cm-1 Raman shift range. Factor analysis on the ensemble of Raman spectra is used to generate descriptors of mineral components. In trabecular bone independent phosphate (PO4-3) and monohydrogen phosphate (HPO4-2) factors are observed. Phosphate and monohydrogen phosphate gradients extend from trabecular packets into the interior of a rod. The gradients are sharply defined in newly regenerated bone. There, HPO4-2 content maximizes near a trabecular packet and decreases to a minimum value over as little as a 20 μm distance. Incomplete mineralization is clearly visible. In cortical bone, factor analysis yields only a single mineral factor containing both PO4-3 and HPO4-2 signatures and this implies uniform distribution of these ions in the region imaged. Uniform PO4-3 and HPO4-2 distribution is verified by spectral band integration. © 1999 Society of Photo-Optical Instrumentation Engineers.
A novel adherence assay for Bordetella pertussis using tracheal organ cultures

In a novel adherence model using tracheal rings removed from Papio anubis, we have demonstrated a functional role for the fimbriae of Bordetella pertussis. When compared to wild-type strains, B. pertussis mutants specifically deficient in fimbriae adhered less well to the tracheal rings but better to Vero (Green monkey kidney) cells. In contrast, mutants deficient in filamentous haemagglutinin (FHA) production had reduced adherence to both Vero cells and the tracheal rings. These observations indicate that the fimbriae of B. pertussis, like those of many other bacterial pathogens, may play an important role in the initial stages of colonisation.
Developing an Advanced Life Support System for the Flexible Path into Deep Space

Long duration human missions beyond low Earth orbit, such as a permanent lunar base, an asteroid rendezvous, or exploring Mars, will use recycling life support systems to preclude supplying large amounts of metabolic consumables. The International Space Station (ISS) life support design provides a historic guiding basis for future systems, but both its system architecture and the subsystem technologies should be reconsidered. Different technologies for the functional subsystems have been investigated and some past alternates appear better for flexible path destinations beyond low Earth orbit. There is a need to develop more capable technologies that provide lower mass, increased closure, and higher reliability. A major objective of redesigning the life support system for the flexible path is achieving the maintainability and ultra-reliability necessary for deep space operations.
Up-regulation of histidine decarboxylase expression and histamine content in B16F10 murine melanoma cells.

Objective and design This study was conducted to determine if differences in histidine decarboxylase expression and histamine levels exist between B16F10 melanoma cells and non-cancerous Melan-A melanocytes.
Importance of MEK-1/-2 signaling in monocytic and granulocytic differentiation of myeloid cell lines

Activation of the MEK/ERK/MAP kinase signaling pathway promotes the proliferation and survival of hematopoietic cells. The kinases MEK-1, MEK-2, ERK-1/MAPK and ERK-2/MAPK are activated by phosphorylation at specific sites, and these events can be monitored using phospho-specific antibodies. In this report we examined the importance of the MEK/ERK/MAP kinase pathway in the monocytic and granulocytic differentiation of myeloid cell lines. Induction of monocytic differentiation in HL-60 cells by treatment with phorbol 12-myristate 13-acetate (PMA) led to rapid and sustained activation of MEK-1/-2, ERK-1/MAPK and ERK-2/MAPK, while induction of granulocytic differentiation by retinoic acid (RA) caused similar activation of MEK-1/-2 and ERK-2/MAPK, but not ERK-1/MAPK. The total levels of these kinases were not affected during the course of differentiation along either pathway. Pretreatment of cells with 5 microM of the MEK-1/-2-specific inhibitor U0126 abrogated PMA- or RA-induced activation of ERK-1/MAPK and ERK-2/MAPK. Importantly, pretreatment of HL-60 cells with U0126 was found to potently inhibit both monocytic and granulocytic differentiation, as assessed by cytochemical staining for non-specific esterase or nitroblue tetrazolium reduction, flow cytometric analysis of myeloid surface markers, and immunoblotting for the cell cycle inhibitor p21 WAF1/Cip1. Similar results were seen in U937 cells, where U0126 inhibited PMA-induced monocytic differentiation, and in 32D cells, where G-CSF-induced granulocytic differentiation was inhibited by U0126 pretreatment. Additional experiments revealed that inhibition of MEK-1/-2 in HL-60 cells resulted in nearly complete inhibition of differentiation-induced cell death during monocytic differentiation. By contrast, U0126 only partially inhibited cell death resulting from granulocytic differentiation. Taken together, our findings demonstrate that the MEK/ERK/MAP kinase signaling pathway is activated, and plays a critical role, during both monocytic and granulocytic differentiation of myeloid cell lines.
An Alternative Form of Replication Protein A Expressed in Normal Human Tissues Supports DNA Repair

Replication protein A (RPA) is a heterotrimeric protein complex required for a large number of DNA metabolic processes, including DNA replication and repair. An alternative form of RPA (aRPA) has been described in which the RPA2 subunit (the 32-kDa subunit of RPA and product of the RPA2 gene) of canonical RPA is replaced by a homologous subunit, RPA4. The normal function of aRPA is not known; however, previous studies have shown that it does not support DNA replication in vitro or S-phase progression in vivo. In this work, we show that the RPA4 gene is expressed in normal human tissues and that its expression is decreased in cancerous tissues. To determine whether aRPA plays a role in cellular physiology, we investigated its role in DNA repair. aRPA interacted with both Rad52 and Rad51 and stimulated Rad51 strand exchange. We also showed that, by using a reconstituted reaction, aRPA can support the dual incision/excision reaction of nucleotide excision repair. aRPA is less efficient in nucleotide excision repair than canonical RPA, showing reduced interactions with the repair factor XPA and no stimulation of XPF-ERCC1 endonuclease activity. In contrast, aRPA exhibits higher affinity for damaged DNA than canonical RPA, which may explain its ability to substitute for RPA in the excision step of nucleotide excision repair. Our findings provide the first direct evidence for the function of aRPA in human DNA metabolism and support a model for aRPA functioning in chromosome maintenance functions in nonproliferating cells.
Estrogen Increases Menopausal Host Susceptibility to Experimental Ascending Urinary-Tract Infection

The protective effect of estrogen replacement on ascending urinary-tract infection (UTI) is controversial. We designed a study using an experimental model of UTI in which surgically menopausal mice were supplemented with estrogen and the susceptibility to UTI was evaluated after experimental Escherichia coli infection. The mean rate of E. coli infection in the group not treated with estrogen was 2 x 10(4) cfu/g of renal tissue, compared with 9 x 10(8) cfu/g (P<.001) in the estrogen-treated group. Surprisingly, despite the hypothesis that estrogen would protect mice from infection, estrogen treatment significantly increased the susceptibility of the mice to ascending UTI.
The 2014 Nucleic Acids Research Database Issue and an updated NAR online Molecular Biology Database Collection

The 2014 Nucleic Acids Research Database Issue includes descriptions of 58 new molecular biology databases and recent updates to 123 databases previously featured in NAR or other journals. For convenience, the issue is now divided into eight sections that reflect major subject categories. Among the highlights of this issue are six databases of the transcription factor binding sites in various organisms and updates on such popular databases as CAZy, Database of Genomic Variants (DGV), dbGaP, DrugBank, KEGG, miRBase, Pfam, Reactome, SEED, TCDB and UniProt. There is a strong block of structural databases, which includes, among others, the new RNA Bricks database, updates on PDBe, PDBsum, ArchDB, Gene3D, ModBase, Nucleic Acid Database and the recently revived iPfam database. An update on the NCBI's MMDB describes VAST+, an improved tool for protein structure comparison. Two articles highlight the development of the Structural Classification of Proteins (SCOP) database: one describes SCOPe, which automates assignment of new structures to the existing SCOP hierarchy; the other one describes the first version of SCOP2, with its more flexible approach to classifying protein structures. This issue also includes a collection of articles on bacterial taxonomy and metagenomics, which includes updates on the List of Prokaryotic Names with Standing in Nomenclature (LPSN), Ribosomal Database Project (RDP), the Silva/LTP project and several new metagenomics resources. The NAR online Molecular Biology Database Collection, http://www.oxfordjournals.org/nar/database/c/, has been expanded to 1552 databases. The entire Database Issue is freely available online on the Nucleic Acids Research website (http://nar.oxfordjournals.org/).
Influence of endurance exercise training status and gender on postexercise hypotension

In sedentary individuals, postexercise hypotension after a single bout of aerobic exercise is due to a peripheral vasodilation. Endurance exercise training has the potential to modify this response...
Assessing Student Learning Outcomes in United States Government Courses.

This study employs the Solomon Four-Group Design to measure student knowledge of the United States government and student knowledge of current events at the beginning of a U.S. government course and at the end. In both areas, knowledge improves significantly. Regarding knowledge of the U.S. government, both males and females improve at similar rates, those with higher and lower GPAs improve at similar rates, and political science majors improve at similar rates to non-majors. Regarding current events, males and females improve at similar rates. However, those with higher GPAs and political science majors improve more than others.
Cell and molecular regulation of endothelin-1 production during hepatic wound healing.

During hepatic wound healing, activation of key effectors of the wounding response known as stellate cells leads to a multitude of pathological processes, including increased production of endothelin-1 (ET-1). This latter process has been linked to enhanced expression of endothelin-converting enzyme-1 (ECE-1, the enzyme that converts precursor ET-1 to the mature peptide) in activated stellate cells. Herein, we demonstrate up-regulation of 56- and 62-kDa ECE-1 3′-untranslated region (UTR) mRNA binding proteins in stellate cells after liver injury and stellate cell activation. Binding of these proteins was localized to a CC-rich region in the proximal ECE-1 3′ UTR base pairs (the 56-kDa protein) and to a region between 60 and 193 base pairs in the ECE-1 3′ UTR mRNA (62 kDa). A functional role for the 3′ UTR mRNA/protein interaction was established in a series of reporter assays. Additionally, transforming growth factor-β1, a cytokine integral to wound healing, stimulated ET-1 production. This effect was due to ECE-1 mRNA stabilization and increased ECE-1 expression in stellate cells, which in turn was a result of de novo synthesis of the identified 56- and 62-kDa ECE-1 3′ UTR mRNA binding proteins. These data indicate that liver injury and the hepatic wound healing response lead to ECE-1 mRNA stabilization in stellate cells via binding of 56- and 62-kDa proteins, which in turn are regulated by transforming growth factor-β. The possibility that the same or similar regulatory events are present in other forms of wound healing is raised.
Cochlear implantation in late childhood and adolescence: is there such a thing as 'too late'?

Cochlear implantation has significantly positively, impacted the lives of deaf individuals internationally. The device that converts acoustic energy into electrical stimulation bypassing endogenous...
A Cause and Cure of Hfe Instability in Shallow Junction Bipolar Microwave Transistors

Bipolar microwave transistors with Ti/Pt/Au contact metalization have shown a reversible degradation in current gain (Hfe) due to high temperature storage (HTS) stress at 240 degrees Celcius for 24 to 48 hours. A model for current gain in shallow junction bipolar transistors is described. The model shows that Hfe of such devices is dependent on the properties of the metal-silicon interface at the emitter. The cause of the reversible Hfe degradation has been found to be hydrogen absorption and desorption in the Ti contact metallization which causes shifts in the Schottky barrier potential of the Ti/Si contact with consequent changes in the surface recombination velocity at the emitter. A new contact metallization of TiW/Au has been developed which exhibits no drift in Hfe.