cssi/SciSciGPT-SciSciNet huggingface dataset:
The Dust Management Project: Characterizing Lunar Environments and Dust, Developing Regolith Mitigation Technology and Simulants

A return to the Moon to extend human presence, pursue scientific activities, use the Moon to prepare for future human missions to Mars, and expand Earth?s economic sphere, will require investment in developing new technologies and capabilities to achieve affordable and sustainable human exploration. From the operational experience gained and lessons learned during the Apollo missions, conducting long-term operations in the lunar environment will be a particular challenge, given the difficulties presented by the unique physical properties and other characteristics of lunar regolith, including dust. The Apollo missions and other lunar explorations have identified significant lunar dust-related problems that will challenge future mission success. Comprised of regolith particles ranging in size from tens of nanometers to microns, lunar dust is a manifestation of the complex interaction of the lunar soil with multiple mechanical, electrical, and gravitational effects. The environmental and anthropogenic factors effecting the perturbation, transport, and deposition of lunar dust must be studied in order to mitigate it?s potentially harmful effects on exploration systems and human explorers. The Dust Management Project (DMP) is tasked with the evaluation of lunar dust effects, assessment of the resulting risks, and development of mitigation and management strategies and technologies related to Exploration Systems architectures. To this end, the DMP supports the overall goal of the Exploration Technology Development Program (ETDP) of addressing the relevant high priority technology needs of multiple elements within the Constellation Program (CxP) and sister ETDP projects. Project scope, plans, and accomplishments will be presented.
Fast Diffusion and Electrotransport of Cobalt, Iron and Nickel in α-Yttrium

Most rare earth metals including yttrium are commonly purified by vacuum distillation. However, the vapor pressures of iron, cobalt and nickel are close to that of yttrium making their separation from yttrium by that method rather difficult. This study was carried out to determine the feasibility of removing these and similar impurities from yttrium by the electrotransport process as well as a continuation of our studies on the fast diffusion phenomenon.
Superradiance in an Ultracold Thermal Vapor

We report on superradiant Rayleigh scattering in an anisotropic, cold thermal vapor. We identify threshold pump powers and atomic densities for entering the superradiant regime, and observe temporal correlations between light emitted in opposite directions.
H. Paul Santmire Ritualizing Nature: Renewing Christian Liturgy in a Time of Crisis

H. Paul Santmire Ritualizing Nature: Renewing Christian Liturgy in a Time of Crisis (Theology and the Sciences series) Minneapolis: Fortress Press, 2008, xvi + 312 pp. $25.00, ISBN: 978-0-8006-6294...
Well response tests: I. The direct problem

Well response tests usually provide a simple and economical method for the estimation of aquifer characteristics such as transmissivity and storability. This study deals particularly with a well-aquifer system response to slug testing. The fluid (oil or water) level in the well responds to piezometric head fluctuations due to disturbances of the aquifer and to the vertical motion of the well-aquifer system. The authors develop a rigorous mathematical formulation of the direct physical problem, i.e. the problem of calculating the piezometric head when the aquifer transmissivity and storativity are known, based upon the theories of fluid flow in continuum and porous media. An analytical treatment of the resulting three problems is also presented. Furthermore, three types of well responses are possible for slug tests depending upon the relation between the inertial forces and viscous effect of water within the well column: namely, over-damped, under-damped and critically damped. The theory is applicable for all such cases.
Crystal chemistry of cerium titanates, tantalates and niobates

Abstract Cerium dioxide has been found to react with other oxides at high temperatures in an open air environment with the formation of Ce+3, Ce+4 or mixed valence phases. The compound Ce+4Ti2O6 forms with the brannerite structure a =9.804, b =3.758, c =6.914, β=119° 8.7′ , however, with the addition of sodium, the black pseudocubic perovskite compound NaCe+3Ti2O6 is formed, a =3.864 A . Single crystals of the Ce+3Ta7O19 reveal that this compound is hexagonal, P63/mcm, a =6.232, c =19.985 A . Single crystals of the compound Ce+3TaO4 are light green of the LaTaO4-type, P21/c with a =7.618, b =5.531, c =7.767 A , β=100° 56.3 . On oxidizing at low temperature, ≈600°C, the crystals turn black and change to monoclinic, P2/m, a =7.617, b =5.491, c =3.851 A , β=102° 30.5' , with a corresponding change to ≈CeTaO4.174. Another phase which is also light yellow is formed by oxidizing at 350°C for long periods of time and corresponds to CeTaO4.50. The compound CeNb5O14 is orthorhombic Pmnb, a =20.12, b =12.474, c =7.744 A . Ce+3NbO4 has a fergusonite unit cell when quenched to room temperature a =5.544, b =11.434, c =5.177, β=94° 41.8' . On oxidation in air the cell size is a =5.364, b =11.424, c =5.129 A , β93° 22.7' at room temperature and corresponds to ≈CeNbO4.25.
Effects of extreme pressure additive chemistry on rolling element bearing surface durability

Abstract Lubricant additives have been known to affect rolling element bearing surface durability for many years. Tapered roller bearings were used in fatigue testing of lubricants formulated with gear oil type additive systems. These systems have sulfur- and phosphorus-containing compounds used for gear protection as well as bearing lubrication. Several variations of a commercially available base additive formulation were tested having modified sulfur components. The variations represent a range of “active” extreme pressure (EP) chemistries. The bearing fatigue test results were compared with respect to EP formulation and test conditions. Inner ring near-surface material in selected test bearings was evaluated on two scales: the micrometer scale using optical metallography and the nanometer scale using transmission electron microscopy (TEM). Focused-ion beam (FIB) techniques were used for TEM specimen preparation. Imaging and chemical analysis of the bearing samples revealed near-surface material and tribofilm characteristics. These results are discussed with respect to the relative fatigue lives.
Future Expectations Among Adolescents: A Latent Class Analysis

Future expectations have been important predictors of adolescent development and behavior. Its measurement, however, has largely focused on single dimensions and misses potentially important components. This analysis investigates whether an empirically-driven, multidimensional approach to conceptualizing future expectations can substantively contribute to our understanding of adolescent risk behavior. We use data from the National Longitudinal Survey of Youth 1997 to derive subpopulations of adolescents based on their future expectations with latent class analysis. Multinomial regression then determines which covariates from Bronfenbrenner's ecological systems theory are associated with class membership. After modeling these covariates, we examine whether future expectations is associated with delinquency, substance use, and sexual experience. Our analysis suggests the emergence of four distinct classes labeled the Student Expectations, Student/Drinking Expectations, Victim Expectations, and Drinking/Arrest Expectations classes according to their indicator profiles. These classes differ with respect to covariates associated with membership; furthermore, they are all statistically and differentially associated with at least one adolescent risk behavior. This analysis demonstrates the additional benefit derived from using this multidimensional approach for studying future expectations. Further research is needed to investigate its stability and role in predicting adolescent risk behavior over time.
Rural Bound: Determinants of Metro to Non-Metro Migration in the United States

A general global precept is that agglomeration forces lead to migration from rural to urban areas. Yet for much of the time since the early 1970s, more people have moved from metro to nonmetro U.S. counties. The underlying causes of this pattern have changed over time with economic shocks and changing household preferences. For instance, the post 2000 period has seen a significant decline in domestic migration rates, a significant increase in commodity prices that favor rural areas, and potential changes in the valuation of natural amenities that would affect migration. This article investigates the determinants of U.S. gross migration from metro to nonmetro counties and nonmetro to metro counties for the 1995–2000 and 2005–2009 periods in order to compare the differences in rural to urban and urban to rural migration, as well as compare the 1990s to the 2005–2009 periods. More specifically, the present study extends the literature by more broadly examining the underlying factors associated with deconcentration and economic restructuring arguments of metro to nonmetro migration. The article uses (1) extensive county‐to‐county migration flows and (2) the utility maximization theory that extends the framework of a discrete choice model. The results show that population density, distance to urban areas, industry mix employment growth, natural amenities, and percentage of older people are key factors underlying these migration patterns. We also find a slight fading of effects of natural amenities and population density, and a slight increase in the effects of wage and employment growth from 2005–2009.
Rethinking the Relation between Government Spending and Economic Growth: A Composition Approach to Fiscal Policy Instruction for Principles Students

Standard introductory textbook authors assert that an increase in government spending expands aggregate demand in the short run but also raises the interest rate and, thus, crowds out private investment in the long run. Because the decrease in investment results in a smaller capital stock, potential output or production capacity decreases. The author challenges the standard assertion by dividing government spending into two components: public consumption and public investment. The short-run effects of an increase in government spending are the same for both components but the long-run effects are dramatically different. The author demonstrates the importance of the composition of public spending to long-run economic performance, using the conventional graphs found in the leading principles of economics textbooks.
Subjective well-being evaluations among older Black Americans.

The causal relations among social status and resource, health, and stress factors, and a single-item measure of subjective well-being (i.e., happiness) were examined among a national sample of 581 Black adults aged 55 years and over. Results indicated that although social status and resource factors had a limited impact on happiness ratings, these measures were important in predicting intermediate factors related to health status and satisfaction and stress. Happiness was directly influenced by stress and reported satisfaction with health, whereas the effect of health disability was mediated by stress and health satisfaction. The findings suggest that certain groups of older Blacks (i.e., relatively younger, widowed, and separated) may be at specific risk for diminished well-being. However, adverse health and life conditions, which are determined by status and resources, represent circumstances that further jeopardize the well-being of older Black adults.
Relative Fatou's theorem for (−Δ)α/2-harmonic functions in bounded κ-fat open sets

Recently it was shown in [P. Kim, Fatou's theorem for censored stable processes, Stochastic Process. Appl. 108 (1) (2003) 63–92] that Fatou's theorem for transient censored α-stable processes in a bounded C1,1 open set is true. Here we give a probabilistic proof of relative Fatou's theorem for (−Δ)α/2-harmonic functions (equivalently for symmetric α-stable processes) in bounded κ-fat open set where α∈(0,2). That is, if u is positive (−Δ)α/2-harmonic function in a bounded κ-fat open set D and h is singular positive (−Δ)α/2-harmonic function in D, then nontangential limits of u/h exist almost everywhere with respect to the Martin-representing measure of h. This extends the result of Bogdan and Dyda [K. Bogdan, B. Dyda, Relative Fatou theorem for harmonic functions of rotation invariant stable processes in smooth domain, Studia Math. 157 (1) (2003) 83–96]. It is also shown that, under the gaugeability assumption, relative Fatou's theorem is true for operators obtained from the generator of the killed α-stable process in bounded κ-fat open set D through nonlocal Feynman–Kac transforms. As an application, relative Fatou's theorem for relativistic stable processes is also true if D is bounded C1,1-open set.
Diuretics in chronic heart failure — benefits andhazards

Diuretics are indispensable in the management of oedema of chronic heart failure (CHF). When given to patients with congestion, diuretics relieve symptoms and improve cardiac performance. However, the use of diuretics in patients without fluid retention may have deleterious effects because they may decrease stroke volume and blood pressure, resulting in neurohormonal activation. Moreover, the effects of diuretics on electrolyte and metabolic imbalance may trigger ventricular arrhythmias with adverse consequences on survival. Whereas treatment of hypertension with diuretics prevents the development of CHF, no randomized trial has assessed the effects of diuretics on mortality in patients with CHF. Reduced mortality using spironolactone in patients with CHF in the RALES trial may not be related to its diuretic effects. Baseline use of a non-potassium-sparing diuretic in the SOLVD prevention and treatment trials was associated with an increased risk of arrhythmic death. As only limited data are available on improved prognosis with diuretics, long-term randomized mortality trials should be conducted. The recent TORIC study may be the first step in this direction.
Effects of intermittent and continuous ultraviolet light on growth and back-mutation in Ophiostoma

Abstract The effects of irradiation at different temperatures with intermittent and continuous ultraviolet light (UV) on growth rate and back-mutation in Ophiostoma were studied. For a given dose of UV there was no difference in the effects between continuous and intermittent UV. The back-mutation frequency was found to he independent of dose rate indicating a culmative effect of UV.
Does potency predict clinical efficacy? Illustration through an antihistamine model.

Objective The concepts of potency and efficacy are often confused and used interchangeably within the scientific and pharmaceutical industry. It is important that the distinction between the two is understood, and that the terms are defined within their correct context. After reading this article, readers should have an understanding of the relationships between receptor potency and clinical efficacy. Data Sources Following a comprehensive review of the literature using MEDLINE, the author observed a lack of relevant references that relate measurements of potency to clinical efficacy. Therefore, the author reviewed the basic pharmacologic principles of potency using examples from the recent antihistamine literature. Results Potency is an expression of the activity of a drug in terms of the concentration or amount of the drug required to produce a defined effect, whereas clinical efficacy judges the therapeutic effectiveness of the drug in humans. The differing methods of evaluating the activity of antihistamines in vitro and in vivo can lead to inconsistent results, which complicate the use of potency to predict clinical efficacy. Further, as therapeutic behavior is modulated by pharmacokinetic and pharmacodynamic parameters and by further interactions at sites other than the target receptor, it does not necessarily follow that more potent drugs have greater clinical efficacy. Conclusions Although potency can be a good preclinical marker of the therapeutic potential of a drug, clinical efficacy should only be evaluated within the patient population using appropriate outcome measures.
An alternative estimation of tuberculosis incidence from 1980 to 2010: methods from the Global Burden of Disease 2010

Abstract Background Estimating tuberculosis (TB) incidence is difficult; it cannot be measured directly because surveillance systems are incomplete and conducting nationwide surveys of TB incidence would be too expensive. We sought a strictly empirical approach to estimating TB incidence that eliminates reliance upon expert opinion. Methods Our TB incidence model was multistep: (1) model TB incidence with antiretroviral (ARV)-adjusted HIV prevalence and other covariates as independent variables; (2) run a Gaussian process regression on "high income" countries using step 1 estimates as a prior; (3) model the fraction of TB–HIV in TB incidence with ARV-adjusted HIV prevalence as an independent variable; and (4) apply these fractions to our TB incidence predictions to parse out TB–HIV. Findings Since its peak in 2003, the global TB incidence rate has been declining by 1·65% annually. At the 187 country level, annual rates of change vary significantly; from 2000 to 2010, the median annual change was −1·24%, while the bottom and top 5% were 1·53% and −4·56%, respectively. During the past decade, some high-burden countries have made impressive progress; China and Nigeria both saw annual declines in TB incidence rates around 2·8%. Unlike other diseases, TB affects countries across the globe. In 2010, 55 countries in six of seven Global Burden of Disease (GBD) 2010 super regions had TB incidence rates greater than 150 per 100 000 people. In 2010, TB–HIV still accounted for 31·6% (95% CI 31·3–32·0) of all TB cases in sub-Saharan Africa; however, since its 2002 peak, the global TB–HIV incidence rate here has been decreasing by 5·11% annually. Interpretation Measurement is a powerful motivator for action. Case notifications provide the principle input to both the WHO and GBD 2010 analyses but both approaches are less than ideal. Efforts must be made to improve country-level case detection rates so case notifications can become a close proxy for future TB incidence estimations. Funding Bill & Melinda Gates Foundation.
Optical Loss Determination of Sapphire-Bonded Photonic Crystal Laser Cavities by Varying the Number of Photonic Crystal Cladding Periods

Sapphire-bonded phtonic crystal laser with varying number of photonic crystal periods were studied. The lasing threshold power increases as lattice periods decrease. The quality factor of these cavities were estimated the from lasing threshold data.
Competitive Reaction of Axial Ligands during Biomimetic Oxygenations

Nitrogenous bases have commonly been employed as axial ligands for metalloporphyrins in biomimetic model compounds and catalytic oxygenation chemistry. The addition of bases such as pyridines or imidazoles to metalloporphyrin-catalyzed hydrocarbon oxidation reactions is known to affect catalyst selectivity and turnover rate; this effect has been correlated with the electron-donor ability of the ligand. We have found that the role of pyridine in these reactions is far more involved than that of a simple axial ligand: pyridine is a competitive substrate and is converted in high yield to the N-oxide. Subsequently, both of these species act as ligands to the metal center. Thus, catalytic systems containing oxidizable pyridines involve complex equilibria with multiple forms of ligated catalyst, and kinetic results should be interpreted with caution. Alternatives to free pyridine were tested, including a pyridine “tail” which is covalently attached to the porphyrin.
Visual Texts: Format and the Evolution of English Accounting Texts, 1100–1700:

Emphasis on page design, as an aid to visual accessibility, did not receive attention in modern technical writing until the 1970s. However, accounting documents and instructional texts utilized format and document design strategies as early as the twelfth century to enhance the organization of quantitative data and linear bookkeeping entries. Format in text was used to reflect the arrangement used in oral accounting practices and to produce uniform documents. Thus, format was integral to the rise of pragmatic literacy of the commercial reader. During the Renaissance, these early format strategies received impetus from Ramist method. The result was design strategies that attempted to capture the rigid principles of organization fundamental to commercial accounting. These early accounting documents also illustrate the plain style that would become the focus of the later decades of the seventeenth century. Clarity in language paralleled clarity in page design for the sole purpose of eliminating ambiguity on ...
Particle image velocimetry measurements of the velocity profile in He II forced flow

Measurements of the velocity profile of HeII forced flow within a square cross-section channel are reported. The particle image velocimetry (PIV) technique is used for these measurements with micron scale solid deuterium particles as tracers of the HeII velocity field. Steady state velocity profiles at different bath temperatures clearly show the existence of a turbulent boundary layer in HeII forced flow. These observed velocity profiles are in reasonable agreement with correlations based on measurements in classical fluids.
Aging Alters Zonation in the Adrenal Cortex of Men

Whereas aging has been shown to be associated with striking reductions in circulating levels of adrenal androgens in humans, the alteration in adrenal function that occurs in aging has not been identified. We sought to determine if there are changes in the zonation of the adrenal in aging men by performing histomorphologic analyses of adrenal specimens that had been obtained at autopsy following sudden death due to trauma. We evaluated adrenals from 21 young men (20-29 yrs) and 12 older men (54-90 yrs); inclusion criteria required the presence of medullary tissue in the specimen and fixation within the first 24 hrs postmortem. Sections stained with H/E were examined microscopically and areas of the cortex that included adjacent medullary tissue were chosen for quantitative evaluation by use of a computerized image analysis system. The average width (arbitrary units, pixels) of the zona reticularis and that of the combined zonae fasciculata/glomerulosa were determined from sections stained for reticulum fibers. The zona reticularis represented 37.1 +/- 1.9% of the total cortical width in the young men, which was significantly greater than that of the older men (27.1 +/- 3.3%, P = 0.0082). The zona fasciculata/glomerulosa to zona reticularis ratio in the young men (1.84 +/- 0.15) was significantly less that that of the older men (3.29 +/- 0.47, P = 0.0011). There was no significant difference in the total width of the cortex in young compared to older men. These data suggest that aging results in alterations within the cortex of the adrenals in men such that there is a reduction in the size of the zona reticularis and a relative increase in the outer cortical zones. A reduced mass of the zona reticularis could be responsible for the diminished production of dehydroepiandrosterone and dehydroepiandrosterone sulfate that occurs during aging.
A general infrastructure for basic education course design using the ASPI model

Abstract The issue of the use of ICT(s) in educational institutions raises many interests but also questions. So, is it enough to equip schools with computer equipment and Internet connection to say that the process is launched? While this prospect is promising for a country like Algeria, it will help improve the quality of teaching, the teacher and pupils by providing the means to do more in less time and more independently. But to make such projects succeed, it must provide adequate educational products that fit well and/or complement the curriculum provided for these levels in the school. In this context we propose to adapt a model known as ASPI for the implementation of training device for basic education. ASPI has been designed and proposed for learning environments for adults. As cases of application we chose to test the approach on two subjects: “Road Safety for Children” and “French Language Teaching”. In this work we present the first case study.
Flow cytometric sorting of maize chromosome 9 from an oat-maize chromosome addition line

Large numbers of maize chromosome 9 can be collected with high purity by flow cytometric sorting of chromosomes isolated from a disomic maize chromo- some addition line of oat. Metaphase chromosome sus- pensions were prepared from highly synchronized seed- ling root-tips of an oat-maize chromosome-9 addition line (OM9) and its parental oat and maize lines. Chromo- somes were stained with propidium iodide for flow cyto- metric analysis and sorting. Flow-karyotypes of the oat- maize addition line showed an extra peak not present in the parental oat line. This peak is due to the presence of a maize chromosome-9 pair within the genome of OM9. Separation of maize chromosome 9 by flow cytometric sorting of a chromosome preparation from a normal maize line was not possible because of its size similarity (DNA content) to maize chromosomes 6, 7 and 8. How- ever, it is possible to separate maize chromosome 9 from oat chromosomes and chromatids. An average of about 6× 10 3 chromosomes of maize chromosome 9 can be col- lected by flow-sorting from chromosomes isolated from 30 root tips (ten seedlings) of the oat-maize addition line. Purity of the maize chromosome 9, sorted from the oat-maize chromosome addition line, was estimated to be more than 90% based on genomic in situ hybridiza- tion analysis. Sorting of individual chromosomes pro- vides valuable genomic tools for physical mapping, li- brary construction, and gene isolation.
Shear modulates adhesion of ultrasound contrast microbubbles targeted to dysfunctional endothelium

Endothelial dysfunction, as occurs in pre-clinical atherosclerosis and organ transplant rejection, is characterized by increased endothelial cell (EC) surface expression of inflammatory markers including intercellular adhesion molecule-1 (ICAM). Previously, we have shown that lipid-based ultrasound contrast microbubbles (MBs) selectively adhere to inflamed ECs when conjugated to anti-ICAM monoclonal antibodies (Ab). Here, we hypothesized that the adhesion of targeted MBs to ECs from flow is shear-rate dependent. Microbubbles were conjugated via avidin/biotin bridging chemistry to anti-ICAM mAb (60,000 Ab/MB surface density). In a parallel plate chamber, MBs were perfused across coverslips of normal or interleukin-1/spl beta/-activated cultured human coronary artery ECs at selected wall shear rates for 3 min and washed. Adhesion to ECs was quantified in 20 random microscopic fields per coverslip (mean MBs/cell/spl plusmn/SD). Adhesion decreased with increasing shear rate to both normal (100s/sup -1/=0.84/spl plusmn/1.7, 175s/sup -1/=0.58/spl plusmn/0.40, 250s/sup -1/=0.40/spl plusmn/0.45, 350s/sup -1/=0.16/spl plusmn/0.14, 500s/sup -1/=0.04/spl plusmn/0.02) and activated ECs (100s/sup -1/=3.0/spl plusmn/2.7, 175s/sup -1/=2.6/spl plusmn/0.77, 250s/sup -1/=2.1/spl plusmn/1.3, 350s/sup -1/=1.2/spl plusmn/0.90, 500s/sup -1/=0.49/spl plusmn/0.09). Adherence was greater to activated than normal ECs (p<0.001), and decreased with increasing shear rate (p=0.02). These data demonstrate that adhesion of targeted MBs to ECs is highly dependent upon the local shear environment. This relationship has important implications for the design of targeted contrast agents for ultrasonic assessment of endothelial dysfunction.
Capacitor Evaluation for Compact HV Pulse Generation

The size of compact pulsed power generators capable of producing pulses with ~100 ns duration at Gigawatt power levels is primarily determined by the specific energy density of the utilized energy storage medium. Capacitors capable of delivering large pulsed currents at several 10 kV voltage levels have been most frequently used as the energy storage medium for portable pulse generators. To increase the specific energy density of the pulsed power generator, the capacitors are often voltage overstressed at the cost of capacitor life. However, rapid charging (milliseconds) of the capacitor immediately followed by discharging alleviates somewhat of the lifetime problem. For repetitive operation of the pulsed power generator, the charging/discharging energy loss is the more important parameter. The energy, WC, needed to charge a capacitor to a set voltage is measured along with the energy released, WR, by the capacitor under conditions corresponding to a compact Marx generator operating with ~10 Hz rep-rate into a ~20 Ohm load. For the tested capacitors with Mica as dielectric, the capacitor efficiency, eta, i.e. the ratio between WR and WC, is roughly equal to 97% and largely independent of the charging time. Also tested ceramic capacitors revealed an efficiency of ~90% for fast charging and an efficiency of ~94% for slower charging (from ~2 to 35 mus time constant).
The Nation's Tortured Body: Violence, Representation and the Formation of a Sikh “Diaspora.”

The Nation's Tortured Body: Violence, Representation and the Formation of. Sikh “Diaspora.” Brian Keith Axel. Durham, NC: Duke University Press, 2001. 297 pp.
Bone Regeneration via a Mineral Substrate and Induced Angiogenesis

Angiogenesis and biomineral substrates play major roles in bone development and regeneration. We hypothesized that macroporous scaffolds of biomineralized 85:15 poly(lactide-co-glycolide), which locally release vascular endothelial growth factor-165 (VEGF), would direct simultaneous regeneration of bone and vascular tissue. The presence of a bone-like biomineral substrate significantly increased regeneration of osteoid matrix (32 +/- 7% of total tissue area; mean +/- SD; p < 0.05) and mineralized tissue (14 +/- 2%; P < 0.05) within a rat cranium critical defect compared with a non-mineralized polymer scaffold (19 +/- 8% osteoid and 10 +/- 2% mineralized tissue). Further, the addition of VEGF to a mineralized substrate significantly increased the generation of mineralized tissue (19 +/- 4%; P < 0.05) compared with mineralized substrate alone. This appeared to be due to a significant increase in vascularization throughout VEGF-releasing scaffolds (52 +/- 9 vessels/mm(2); P < 0.05) compared with mineralized scaffolds without VEGF (34 +/- 4 vessels/mm(2)). Surprisingly, there was no significant difference in total osteoid between the two samples, suggesting that increased vascularization enhances mineralized tissue generation, but not necessarily osteoid formation. These results indicate that induced angiogenesis can enhance tissue regeneration, supporting the concept of therapeutic angiogenesis in tissue-engineering strategies.
Inhibitors of Catalase-Amyloid Interactions Protect Cells from β-Amyloid-Induced Oxidative Stress and Toxicity

Compelling evidence shows a strong correlation between accumulation of neurotoxic β-amyloid (Aβ) peptides and oxidative stress in the brains of patients afflicted with Alzheimer disease (AD). One hypothesis for this correlation involves the direct and harmful interaction of aggregated Aβ peptides with enzymes responsible for maintaining normal, cellular levels of reactive oxygen species (ROS). Identification of specific, destructive interactions of Aβ peptides with cellular anti-oxidant enzymes would represent an important step toward understanding the pathogenicity of Aβ peptides in AD. This report demonstrates that exposure of human neuroblastoma cells to cytotoxic preparations of aggregated Aβ peptides results in significant intracellular co-localization of Aβ with catalase, an anti-oxidant enzyme responsible for catalyzing the degradation of the ROS intermediate hydrogen peroxide (H2O2). These catalase-Aβ interactions deactivate catalase, resulting in increased cellular levels of H2O2. Furthermore, small molecule inhibitors of catalase-amyloid interactions protect the hydrogen peroxide-degrading activity of catalase in Aβ-rich environments, leading to reduction of the co-localization of catalase and Aβ in cells, inhibition of Aβ-induced increases in cellular levels of H2O2, and reduction of the toxicity of Aβ peptides. These studies, thus, provide evidence for the important role of intracellular catalase-amyloid interactions in Aβ-induced oxidative stress and propose a novel molecular strategy to inhibit such harmful interactions in AD.
Epistasis can facilitate the evolution of reproductive isolation by peak shifts: a two-locus two-allele model.

The influence of epistasis on the evolution of reproductive isolation by peak shifts is studied in a two-locus two-allele model of a quantitative genetic character under stabilizing selection. Epistasis is introduced by a simple multiplicative term in the function that maps gene effects onto genotypic values. In the model with only additive effects on the trait, the probability of a peak shift and the amount of reproductive isolation are always inversely related, i.e., the higher the peak shift rate, the lower the amount of reproductive isolation caused by the peak shift. With epistatic characters there is no consistent relationship between these two values. Interestingly, there are cases where both transition rates as well as the amount of reproductive isolation are increased relative to the additive model. This effect has two main causes: a shift in the location of the transition point, and the hybrids between the two alternative optimal genotypes have lower average fitness in the epistatic case. A review of the empirical literature shows that the fitness relations resulting in higher peak shift rates and more reproductive isolation are qualitatively the same as those observed for genes causing hybrid inferiority.
Developing Mentor/Induction Year Teacher Dyads in a Generic Special Education Teacher-Training Program

First year teaching is a difficult and professionally threatening period in any teacher's career, particularly special education teachers. Many human service fields use mentorship during the novice years for improving job satisfaction and promoting retention. Because of the shortages of certified special education teachers, the value of providing mentors to induction year teachers was explored. The purposes of this pilot study were (a) to examine the perceptions of mentor characteristics, (b) to develop a training workshop, and (c) to gather preliminary data on the effects of mentor/protege training. Results indicated that (a) perceptions of important mentor characteristics changed with training, (b) all novices valued having a mentor, and (c) most mentor/ novice pairs met regularly. The implications and the educational importance of the findings are discussed.
Roepke Lecture in Economic Geography Venture Capital in the “Periphery”: The New Argonauts, Global Search, and Local Institution Building

This article examines the growing importance of global, or external, search networks that firms and other actors rely on to locate collaborators who can solve part of a problem they face or require part of a solution they may be able provide. We focus on the creation in emerging economies of venture capital—an institution that is organized to search systematically for, and foster the development of, firms and industries that can, in turn, collaborate in codesign. The article examines the case of Taiwan, where first-generation immigrant professionals from U.S. technology industries have collaborated with their home-country counterparts to develop the context for entrepreneurial development. It refers to the members of these networks as the new Argonauts, an allusion to the ancient Greek Jason and the Argonauts, who searched for the Golden Fleece. We also argue that the most significant contributions of these skilled professionals to their home countries are not direct transfers of technology or knowledge, but participation in external search and domestic institutional reform. The new Argonauts are ideally positioned to search beyond prevailing routines to identify opportunities for complementary “peripheral” participation in the global economy and to work with public officials to adapt and redesign relevant institutions and firms in their native countries. They are, therefore, exemplary protagonists of “self-discovery”—the process by which an enterprise or entrepreneur determines which markets it can serve—and of a microlevel institutional reform that can, diffusing and cascading, ultimately produce wider structural transformations.
Optimal Control for Terminal Guidance of Autonomous Parafoils

This paper deals with the development of guidance, navigation and control algorithms for a prototype of a miniature aerial delivery system capable of high-precision maneuvering and high touchdown accuracy. High accuracy enables use in precision troop resupply, sensor placement, urban warfare reconnaissance, and other similar operations. Specifically, this paper addresses the terminal phase, where uncertainties in winds cause most of the problems. The paper develops a six degree-offreedom model to adequately address dynamics and kinematics of the prototype delivery system and then reduces it to a two degrees-of-freedom model to develop a model predictive control algorithm for reference trajectory tracking during all stages. Reference trajectories are developed in the inertial coordinate frame associated with the target. The reference trajectory during terminal guidance, just prior to impact, is especially important to the final accuracy of the system. This paper explores an approach for generating reference trajectories based on the inverse dynamics in the virtual domain. The method results in efficient solution of a two-point boundary-value problem onboard the aerial delivery system allowing the trajectory to be generated at a high rate, mitigating effects of the unknown winds. This paper provides derivation of the guidance and control algorithms and present analysis through simulation.
Formic acid dehydrogenation on au-based catalysts at near-ambient temperatures.

Formic acid (HCOOH) is a convenient hydrogen carrier in fuel cells designed for portable use. Recent studies have shown that HCOOH decomposition is catalyzed with Ru-based complexes in the aqueous phase at near-ambient temperatures. HCOOH decomposition reactions are used frequently to probe the effects of alloying and cluster size and of geometric and electronic factors in catalysis. These studies have concluded that Pt is the most active metal for HCOOH decomposition, at least as large crystallites and extended surfaces. The identity and oxidation state of surface metal atoms influence the relative rates of dehydrogenation (HCOOH {yields} H{sub 2} + CO{sub 2}) and dehydration (HCOOH {yields} H{sub 2}O + CO) routes, a selectivity requirement for the synthesis of CO-free H{sub 2} streams for low-temperature fuel cells. Group Ib and Group VIII noble metals catalyze dehydrogenation selectively, while base metals and metal oxides catalyze both routes, either directly or indirectly via subsequent water-gas shift (WGS) reactions.
The influence of ibuprofen on fracture repair: Biomechanical, biochemical, histologic, and histomorphometric parameters in rats

Ibuprofen is a widely used cyclo-oxygenase inhibitor in clinical practice. It has been demonstrated by others to have an inhibitory effect on fracture repair in animals. In the present study, we were unable to demonstrate any significant alterations in fracture biomechanics as measured by torsion testing and fracture stage in mature Sprague-Dawley rats treated with 30 mg/kg/day oral dose of ibuprofen, starting 3 days following fracture, over a 12-week time interval. Fracture histology and serum osteocalcin levels were no different in treated animals than control animals. Furthermore, histomorphometric parameters of bone remodeling, including bone volume and bone formation rate in the intact tail vertebrae of these animals with unilateral femur fractures, were no different between treated and control animals.
Effect of varying concentrations of dietary crude protein and metabolizable energy on laying performance of Pearl Grey guinea fowl hens.

This study was conducted to evaluate optimum dietary concentrations of ME and CP for egg production performance of the Pearl Gray guinea fowl laying hens. In a 2 x 3 factorial arrangement, 360 Pearl Gray guinea fowl replacement pullets (22 wk of age) were randomly assigned to experimental diets with 2,800 and 2,900 kcal of ME/kg of diet, each containing 14, 16, and 18% CP, respectively. Each dietary treatment was replicated 4 times, and feed and water were provided ad libitum. Experimental birds were raised in laying cages and received 16 h of light throughout the study period. The birds were observed for feed consumption, hen-day egg production (HDEP), egg weight (EW), egg mass (EM), feed conversion ratio, internal egg quality, shell thickness (ST), and BW at the end of each 28-d lay period at 26 to 50 wk of age and at 62 to 86 wk of age. Mortality was recorded as it occurred. Mean HDEP, EW, EM, and ST were higher (P 0.05). Overall, diets composed of 2,800 kcal of ME/kg of diet and 14% CP were utilized more efficiently by the Pearl Gray guinea fowl laying hens at 26 to 50 and 62 to 86 wk of age.
Estrogen Metabolism by Cytochrome P450 1B1 Modulates the Hypertensive Effect of Angiotensin II in Female Mice

To determine the role of cytochrome P450 (CYP) 1B1 in the sex difference in response to angiotensin II (Ang II)-induced hypertension, female Cyp1b1(+/+) and Cyp1b1(-/-) mice were infused with Ang II (700 ng/kg per minute) or vehicle with or without ovariectomy. In addition, mice were treated with the CYP1B1 inhibitor, 2,3',4,5'-tetramethoxystilbene (TMS; 300 μg/kg IP, every third day), and 17-β estradiol metabolites, 2-hydroxyestradiol (2-OHE), 4-OHE, or 2-methoxyestradiol (1.5 mg/kg per day IP, for 2 weeks) and systolic blood pressure (SBP) measured. Ang II increased SBP more in Cyp1b1(-/-) than in Cyp1b1(+/+) mice (119±3-171±11 versus 120±4-149±4 mm Hg; P<0.05). Ang II caused cardiovascular remodeling and endothelial dysfunction and increased vascular reactivity and oxidative stress in Cyp1b1(-/-) but not in Cyp1b1(+/+)mice. The Ang II-induced increase in SBP was enhanced by ovariectomy and TMS in Cyp1b1(+/+) but not in Cyp1b1(-/-) mice. 2-OHE did not alter Ang II-induced increase in SBP in Cyp1b1(+/+) mice but minimized it in Cyp1b1(-/-) mice, whereas 4-OHE enhanced Ang II-induced increase in SBP in Cyp1b1(+/+) mice but did not alter the increased SBP in Cyp1b1(-/-) mice. 2-OHE-derived catechol-O-methyltransferase metabolite, 2-methoxyestradiol, inhibited Ang II-induced increase in SBP in Cyp1b1(-/-) mice. Ang II increased plasma levels of 2-methoxyestradiol in Cyp1b1(+/+) but not in Cyp1b1(-/-) mice and increased activity of cardiac extracellular signal-regulated kinase 1/2, p38 mitogen-activated kinase, c-Src, and Akt in Cyp1b1(-/-) but not in Cyp1b1(+/+) mice. These data suggest that CYP1B1 protects against Ang II-induced hypertension and associated cardiovascular changes in female mice, most likely mediated by 2-methoxyestradiol-inhibiting oxidative stress and the activity of these signaling molecules.
Little Help from Article on Anaboiic Steroids

In Reply.— Thank you for your letter regarding the article, "Anabolic Steroid Use by Male Adolescents," published in the June 1989 issue Pediatrics. I will attempt to address each of your concerns. The intent of the article was: (1) to inform health care providers about the prevalence of use of anabolic steroids in a population of 11th grade male students, (2) to increase provider awareness of the knowledge and some of the beliefs held by steroid users, and (3) to encourage providers to become knowledgeable about these drugs, so that they might be able to offer more appropriate guidance to the teenager in the clinical setting.
Efficient generation of graphical partitions

Abstract Given a positive even integer n, we show how to generate the set G(n) of graphical partitions of n, that is, those partitions of n which correspond to the degree sequences of simple, undirected graphs. The algorithm is based on a recurrence for G(n), and the total time used by the algorithm, independent of output, is O (¦G(n)¦) , which is constant average time per graphical partition. This is the first algorithm shown to achieve such efficiency for generating G(n) and the direct approach differs from earlier ‘generate and reject’ schemes and the ‘interval/gap’ approach.
High-resolution and large dynamic range nanomechanical mapping in tapping-mode atomic force microscopy

High spatial resolution imaging of material properties is an important task for the continued development of nanomaterials and studies of biological systems. Time-varying interaction forces between the vibrating tip and the sample in a tapping-mode atomic force microscope contain detailed information about the elastic, adhesive, and dissipative response of the sample. We report real-time measurement and analysis of the time-varying tip-sample interaction forces with recently introduced torsional harmonic cantilevers. With these measurements, high-resolution maps of elastic modulus, adhesion force, energy dissipation, and topography are generated simultaneously in a single scan. With peak tapping forces as low as 0.6 nN, we demonstrate measurements on blended polymers and self-assembled molecular architectures with feature sizes at 1, 10, and 500 nm. We also observed an elastic modulus measurement range of four orders of magnitude (1 MPa to 10 GPa) for a single cantilever under identical feedback conditions, which can be particularly useful for analyzing heterogeneous samples with largely different material components.
Monolithic DC-DC converter analysis and MOSFET gate voltage optimization

The design of an efficient monolithic buck converter is presented in this paper. A low swing MOSFET gate drive technique is proposed that improves the efficiency characteristics of a DC-DC converter. A model of the parasitic impedances of a buck converter is developed. With this model, a design space is described which characterizes the integration of both active and passive devices of a buck converter onto the same die based on a 0.18 /spl mu/m CMOS technology. The optimum gate voltage swing of a power MOSFET that maximizes efficiency is shown to be lower than a standard full voltage swing. An efficiency of 88% at a switching frequency of 102 MHz is achieved for a voltage conversion from 1.8 volts to 0.9 volts with a low swing DC-DC converter. The power dissipation of a low swing DC-DC converter is reduced by 24.5%, improving the efficiency by 3.9% as compared to a full swing DC-DC converter.