cssi/SciSciGPT-SciSciNet huggingface dataset:
Analysis of the Robot Subsystem Capability for Boulder Extraction in the Asteroid Redirect Mission

The design of the robot subsystem of NASA's Asteroid Redirect Mission presented the unique challenge of retrieving a 20-ton boulder sized sample from the surface of a near Earth asteroid using multiple robot arms mounted to vehicle capable of touching down on the surface of the asteroid. The robot arms planned for use on the mission were based on heritage from Mars rovers and Restore-L satellite servicing to aid in meeting mass, cost, and schedule goals, which put constraints on the design and led to the use of light weight, low stiffness robot arms. The design of the rest of the Capture Module (CAPM) relied on an extensive analysis of the load capability of the robot arms, which utilized a high fidelity model of the robot arm subsystem to evaluate a large number of extraction scenarios and identify impactful modifications to the system that would increase the probably of mission success.
Historias espaciales de disidencia: imaginación, memoria y resistencia en Estambul, Viena y Santiago de Chile, 1938-1945

espanolEste texto presenta una historia de amistad y companerismo entre la austriaca Margarete Schutte-Lihotzky y la chilena Victoria Maier Mayer, dos arquitectas que formaron parte de la resistencia contra el regimen nazi. Al observar estas vidas se abren nuevas formas de escribir historias espaciales de disidencia. EnglishThis research introduces us to a story of friendship and kinship between the Austrian Margarete Schutte-Lihotzky and the Chilean Victoria Maier Mayer, two architects who took part in the resistance against the nazi regime. The observation of their lives open up new ways of writing spatial histories of dissidence.
Book Review, Ellis M. West, The Free Exercise of Religion in America: Its Original Constitutional Meaning (2019)

This is a review of Professor Ellis M. West's 2019 study of the original meaning of "free exercise of religion."
SPECTRAL SHIFTS OF SEMICONDUCTOR CLUSTERS

The shifts of the electronic absorption spectra of GaAs and GaP semiconductor clusters are calculated using accurate pseudopotentials. In the absence of experimental data at present, these calculations provide estimates for the expected spectral shifts in these clusters. In addition, these calculations show that Coulomb interaction between the electron and hole dominates over the confinement energy in small clusters, with the result that the electronic absorption spectra of small clusters exhibit redshift instead of blueshift as the cluster size is decreased.
Intergenerational Solidarity and Being Primary Caregiver for Older Parents in Chinese American Families: Findings From PIETY Study.

Introduction:Guided by the intergenerational solidarity theory, this study examined how different dimension of intergenerational solidarity of adult children associated with their choice of being a...
Superconducting qubits in a flip-chip architecture

Flip-chip architectures have recently enabled significant scaling-up of multi-qubit circuits and have been used to assemble hybrid quantum systems that combine different substrates, for example, for quantum acoustics experiments. The standard flip-chip method uses superconducting galvanic connections between two substrates, typically implemented using sophisticated indium wafer-bonding systems, which give highly reliable and temperature-cyclable assemblies, but are expensive, somewhat inflexible in design, and require robust substrates that can sustain the large compressive forces required to cold-weld the indium bonds. A much simpler method is to assemble dies using very low-force contacts and air-dried adhesives, although this does not provide a galvanic contact between the dies. Here, we demonstrate that the latter technique can be used to reliably couple superconducting qubit circuits, in which the qubits are on separate dies, without the need for a galvanic connection. We demonstrate full vector qubit control of each qubit on each of the two dies, with high-fidelity single-shot readout, and further demonstrate entanglement-generating excitation swaps as well as benchmark a controlled-Z entangling gate between the two qubits on the two dies. This exemplifies a simple and inexpensive assembly method for two-plus-one-dimensional quantum circuit integration that supports the use of delicate or unusually shaped substrates.
Premature separation of the placenta: Ten years' experience

Abstract 1. 1. Data are presented in 201 patients with significant degrees of premature separation of the placenta of infants delivered weighing more than 1,000 grams at Louisville General Hospital during the decade 1955–1964. 2. 2. The incidence of premature separation of the placenta was 1:137 deliveries, or approximately 8 per 1,000. 3. 3. Management followed a regimen emphasizing prompt diagnosis, blood replacement, amniotomy, oxytocic stimulation, and early evacuation of the uterus by the simplest route feasible. 4. 4. There was one maternal death (0.5 per cent), resulting from traumatic injuries sustained in an automobile accident. 5. 5. The uncorrected fetal mortality rate was 46.8 per cent; for infants alive at the time of initial diagnosis, it was 14.6 per cent.
Nonlinear boundary control of non-burning plasma kinetic profiles in cylindrical geometry

The control of kinetic profiles is among the most important problems in fusion reactor research. It is strongly related to a great number of other problems in fusion energy generation such as burn control, transport reduction, confinement time improvement, MHD instability avoidance and high-/spl beta/ or high-confinement operating modes access. We consider in this work a set of nonlinear partial differential equations (PDE's) describing approximately the dynamics of the density and energy profiles in a nonburning plasma. Applying a backstepping design we control the kinetic profiles by means of thermal and density actuation at the boundary. Numerical simulations show that the feedback control law designed using only one step of backstepping can successfully control the kinetic profiles.
Predicting functional sites with an automated algorithm suitable for heterogeneous datasets.

Background In a previous report (La et al., Proteins, 2005), we have demonstrated that the identification of phylogenetic motifs, protein sequence fragments conserving the overall familial phylogeny, represent a promising approach for sequence/function annotation. Across a structurally and functionally heterogeneous dataset, phylogenetic motifs have been demonstrated to correspond to a wide variety of functional site archetypes, including those defined by surface loops, active site clefts, and less exposed regions. However, in our original demonstration of the technique, phylogenetic motif identification is dependent upon a manually determined similarity threshold, prohibiting large-scale application of the technique.
Regularity of loop group factorization

In the factorization of a Gl(n, C)-valued loop φ into a unitary factor and a factor holomorphic in the disk, it is shown that the two factors each have as much regularity as φ, measured in a variety of function spaces, though with exceptions. This is analogous to known results for Birkhoff factorization, but somewhat different techniques are involved.
The Ford Squeeze-Out

In 1916, Henry Ford announced his intent to indefinitely suspend distribution of nearly all company profits to the shareholders (including himself), as well as continue cutting prices and expanding production on his wildly popular automobile. He claimed that his primary goals were to build ever-cheaper cars and employ more people, with profits being incidental to his plans.This announcement touched off a battle between Ford, the company's controlling shareholder, and the minority shareholders, who would soon see their returns severely curtailed. While much of the press (whom Ford cultivated) saw this as a fight by greedy capitalists versus an untraditional, socially-minded industrialist, Ford's real motivation very likely included a desire to stifle the growth of his most threatening competitorfellow shareholders John and Horace Dodgewho were using Ford dividends to build an effective, rival car company.This battle progressed via the Michigan courts, where the state Supreme Court, in 1919, famously affirmed the business judgment rule and the principle of shareholder primacy. This was a mixed decision for Ford, and it enhanced his determination to shed his minority shareholders.Ford resigned from the company bearing his name and threatened to build a competing firm. The move depressed the value of Ford Motor Co. shares and provided Ford the economic leverage to negotiate the purchase of all outstanding shares at an implied valuation of $255 million. While this represented an unprecedented return on capital for the investors, it was arguably well below the true value of company at the time. The scrap among wealthy businessmen quickly subsided in the public consciousness, but the implications for corporate governance were significant and enduring.
Methods for indole alkaloid synthesis. Iodoxybenzenediphenyldiselenidereagent system for the introduction of oxygen functionality into aspidosperma-type alkaloids

Abstract Oxidation of 1 using PhIO2/(PhSe)2 gave the t -alcohol 10 and the enone 9 . Whereas, similar treatment of 8-oxotabersonine 2 gave the epoxide 12 and the t -alcohol 13 .
Ecological Significance of Mixed-Function Oxidations

(1979). Ecological Significance of Mixed-Function Oxidations. Drug Metabolism Reviews: Vol. 10, No. 1, pp. 35-58.
COMMUNITY DEVELOPMENT EXPERIENCES IN SOUTH DAKOTA AND SOUTH AFRICA

Economic development as a public initiative is traditionally designed to assist designated members of a society in their efforts to adjust to structural change and economic dislocation. The goal of a typical economic development program, while a public interventionist initiative, is to stimulate private sector economic activity, thereby alleviating the stress and damage associated with structural change and economic dislocation; in other words, to help fellow citizens and perhaps neighbours through an economic transition. These are honourable and worthy goals, but even here compassion, empathy, innovative thinking, and resources — especially resources — have their limits.
Seed germination in Halodule wrightii and Syringodium filiforme from Texas and the U.S. Virgin Islands

Abstract Seed germination under laboratory conditions was nearly continuous in both Halodule wrightii Aschers. and Syringodium filiforme Kutz. Halodule seeds that were sieved from sediments in Texas and St. Croix in 1978 continued to germinate for over 3 years in artificial seawater. Syringodium seeds that were collected on reproductive shoots in 1979 continued to germinate for 3 years. The potential longevity of seeds of Halodule and Syringodium may exceed that of seeds of any other seagrass.
The study of the 39K2 Rydberg 1Δg states by CW optical-optical double-resonance spectroscopy

Abstract Three intermediate-lying Rydberg 1Δg states of 39K2 were studied by CW optical-optical double-resonance (OODR) spectroscopy. The absolute vibrational numbering, the Dunham coefficients, the Rydberg-Klein-Rees (RKR) potential curves, and the Franck-Condon factors (FCF) of three (nd)1Δg-B1Πu systems are given. The variation with the principal quantum number n of the contribution of the ndδg Rydberg electron to the binding energy is discussed. In addition, five observed successive (nd)1Δg states included in this work (n = 8, 9, and 10) and the work of Wang et al. (J. Chem. Phys., in press) (n = 6 and 7) are assigned absolute electronic state numbering based on the molecular building-up principle. Furthermore, the dissociation limits, the dissociation energies, and the quantum defects of those (nd)1Δg states are compared with respect to the asymptotic assignments made by Broyer et al. (Chem. Phys. Lett. 99, 206–212, 1983) and by Kowalczyk et al. (Z. Phys. D. 13, 231–240, 1989); our work supports the assignment of Broyer et al.
Image Based Estimation Problems in System Theory: Motion and Shape Estimation of a Planar Textured Surface Undergoing a Rigid Flow

In this paper we consider the problem of motion and shape estimation, of a planar textured surface undergoing a rigid flow, with the aid of a monocular camera. We show that the estimation problem reduces to a specific parameter estimation of a perspective dynamical system. Surprisingly, the above reduction is independent of whether or not the data measured is the brightness pattern which the object produces on the image plane or whether the data observed are points, lines or curves on the image plane produced as a result of discontinuities in the brightness pattern. The basic procedure introduced for parameter estimation is to subdivide the problem into two modules, one for spatial averaging and the other for time averaging. The estimation procedure is carried out with the aid of a new "Realization Theory" for perspective systems.
Development of Ligament-Like Structural Organization and Properties in Cell-Seeded Collagen Scaffolds in vitro

Acute anterior cruciate ligament (ACL) injuries lead to poor joint function, instability, and eventually osteoarthritis if left untreated. Current surgical treatment options are not ideal; however, tissue engineering may provide mechanically sound, biocompatible reconstructions. Collagen fiber scaffolds were combined with fibroblast-seeded collagen gels and maintained in culture for up to 20 days. The tensile and viscoelastic behavior of the constructs closely mimicked that of natural ligament. Constructs’ mechanical and viscoelastic properties did not degrade over time in culture, and peak stress was significantly higher for constructs with embedded fibroblasts. Immunocytochemical and histological analyses demonstrated cell proliferation and ligament-like organization. We have created an engineered tissue that closely approaches key mechanical and viscoelastic properties of the ACL, does not degrade after 20 days in culture, and is histologically similar to the native tissue. This study should aid in developing effective treatments for ACL injury.
Small-molecule delivery by nanoparticles for anticancer therapy

Using nanoparticles for the delivery of small molecules in anticancer therapy is a rapidly growing area of research. The advantages of using nanoparticles for drug delivery include enhanced water solubility, tumor-specific accumulation and improved antitumor efficacy, while reducing nonspecific toxicity. Current research in this field focuses on understanding precisely how small molecules are released from nanoparticles and delivered to the targeted tumor tissues or cells, and how the unique biodistribution of the drug-carrying nanoparticles limits toxicity in major organs. Here, we discuss existing nanoparticles for the delivery of small-molecule anticancer agents and recent advances in this field.
CXXC domain of human DNMT1 is essential for enzymatic activity.

DNA cytosine methylation is one of the major epigenetic gene silencing marks in the human genome facilitated by DNA methyltransferases. DNA cytosine-5 methyltransferase 1 (DNMT1) performs maintenance methylation in somatic cells. In cancer cells, DNMT1 is responsible for the aberrant hypermethylation of CpG islands and the silencing of tumor suppressor genes. Here we show that the catalytically active recombinant DNMT1, lacking 580 amino acids from the amino terminus, binds to unmethylated DNA with higher affinity than hemimethylated or methylated DNA. To further understand the binding domain of enzyme, we have used gel shift assay. We have demonstrated that the CXXC region (C is cysteine; X is any amino acid) of DNMT1 bound specifically to unmethylated CpG dinucleotides. Furthermore, mutation of the conserved cysteines abolished CXXC mediated DNA binding. In transfected COS-7 cells, CXXC deleted DNMT1 (DNMT1ΔCXXC) localized on replication foci. Both point mutant and DNMT1ΔCXXC enzyme displayed significan...
Modeling of sulfide capacities of silicate melts

An examination of the solution chemistry of sulfides in silicates leads to a method for the calculation of the sulfide capacities of silicate melts using the Flory model for polymeric silica chains. Calculations for the CaO−SiO2, FeO−SiO2, and MgO−SiO2 binary systems at 1773 K and 1923 K are shown to be in good agreement with available experimental data and to be more reliable than calculations based on the empirical concept of basicity.
The electric double layer in bone and its influence on stress-generated potentials.

Stress-generated potential (SGP) studies in fluid-filled bone have been interpreted in terms of streaming potential theory. Variations in fluid conductivity and viscosity are in agreement with this theory. Experimental results also indicate that the zeta potential of bone is dependent upon the ion concentration of the fluid. In fact, the zeta potential is seen to reverse polarity at sufficiently high concentrations of NaCl and KCl. This observation indicates that the electric double layer at the fluidbone matrix interface is an important region contributing to electromechanical effects in bone. The double layer may also have an effect on piezoelectric studies in dry bone since the charged species remain on the matrix after the bone specimens are dried.
Relationship Between Physical Fitness, Age. And Attentional Capacity

This study investigated the relationships between physical fitness, cognitive performance, and age. Sixty adults, ranging in age from 18 to 90 years, participated in the study. Physical fitness was...
Stability correction functions for the mean wind speed and temperature in the unstable surface layer

In accordance with a theoretical analysis by Kader and Yaglom, interpolation expressions are proposed for the Monin-Obukhov functions for the wind speed and temperature profiles under unstable conditions in the surface layer of the atmospheric boundary layer. The values of the parameters are adjusted to agree with earlier work under weak instability, as reviewed by Hogstrom. The resulting formulations are valid for considerably larger values of their argument than those that were hitherto available. Their advantage is that they yield concise and closed-form stability correction functions which can be readily applied in profile analysis and model calculations.
Railroad Mergers and the Language of Unification

Introduction Legacy of Merger The Financial Imbroglio: Impetus for Change The Federal Initiative: Tale of Consolidation Private Sector Combinations: Assessing Rationalization Rise of the Eastern Giants Mastadons of the West Railroad Holding Companies: Keys to Diversification Intermodal Mania The New Railroads: Toward the 21st Century Conclusion: A Universal Language Appendix A: Maps of Railroad Lines Appendix B: Flow Charts of Railroad Corporate Structures Selected Bibliography Index
The treatment of advanced endometrial cancer with hydroxyprogesterone caproate

In 314 women with progressing advanced adenocarcinoma of the uterine corpus (endometrial cancer) no longer responding to established anticancer measures, hydroxyprogesterone caproate (1.0 or more g/wk intramuscularly for 4 or more wk) induced in 37.0% an objective response (averaging 20 mo in duration) consisting of regression in 30.2% and arrest of the disease in 6.8%. These responders survived an average of 27 mo, over four times as long as the nonresponders. The incidence of responders was significantly greater in patients with slowly growing tumors, in those treated for 12 or more wk, and for patients with rapidly growing tumors in the younger women. The objective response rate was not influenced significantly by obesity, by the amount of hydroxyprogesterone caproate per week, or by the discontinuation of the progestational therapy during an objective response. Other findings suggest that the efficacy may have been decreased in Negro women, increased in women with no prior radiation but with cancerous involvement only in the nonpulmonary areas, increased in women with prior radiation and metastatic lesions limited to the pulmonary area, decreased by prior radiation therapy in women with nonpulmonary lesions but not in those with pulmonary metastases, and increased in women given radiation concomitantly but not influenced in those given other anticancer therapy simultaneously. After 13 yr of observation, 13.4% of the women appeared to be potentially “cured”; no significant distinctive pattern of characteristics could be discovered by which a woman who achieved the “cured” status could have been selected in advance. These factors concerning efficacy and potential “cure” need further study. Hydroxyprogesterone caproate (up to 7.0 g/wk) was safe and well tolerated; undesirable manifestations occurred infrequently.
Dynamic factor analysis of surface water management impacts on soil and bedrock water contents in Southern Florida Lowlands

Summary As part of the C111 spreader canal project, structural and operational modifications involving incremental raises in canal stage are planned along one of the major canals (i.e., C111) separating Everglades National Park and agricultural production areas to the east of the park. This study used Dynamic Factor Analysis (DFA) as an alternative tool to physically based models to explore the relationship between different hydrologic variables and the effect of proposed changes in surface water management on soil and bedrock water contents in south Florida. To achieve the goal, objectives were to: (1) use DFA to identify the most important factors affecting temporal variation in soil and bedrock water contents, (2) develop a simplified DFA based regression model for predicting soil and bedrock water contents as a function of canal stage and (3) assess the effect of the proposed incremental raises in canal stage on soil and bedrock water contents. DFA revealed that five common trends were the minimum required to describe unexplained variation in the 11 time series studied. Introducing canal stage, water table evaporation and net recharge resulted in lower Akaike information criterion (AIC) and higher Nash–Sutcliffe ( C eff ) values. Results indicated that canal stage significantly ( t > 2) drives temporal variation in soil and bedrock water contents, which was represented as scaled frequency while net surface recharge was significant in seven out of the 11 time series analyzed. The effect of water table evaporation was not significant at all sites. Results also indicated that the most important factor influencing temporal variation in soil and bedrock water contents in terms of regression coefficient magnitude was canal stage. Based on DFA results, a simple regression model was developed to predict soil and bedrock water contents at various elevations as a function of canal stage and net recharge. The performance of the simple model ranged from good ( C eff ranging from 0.56 to 0.74) to poor ( C eff ranging from 0.10 to 0.15), performance was better at sites with smaller depths to water table (
Propofol versus midazolam and meperidine for conscious sedation in GI endoscopy

Abstract OBJECTIVE: Propofol (2,6-diisopropyl phenol) is a relatively new intravenous sedative hypnotic with an ideal pharmacokinetic profile for conscious sedation. In this study, we compared the safety and efficacy of propofol versus the conventional regimen of midazolam and meperidine for conscious sedation in GI endoscopy. METHODS: In this prospective study, 274 patients that included many elderly patients with multiple comorbid conditions underwent GI endoscopic procedures at our hospital. A total of 150 patients received propofol (20–120 mg) and fentanyl (0.25–1.5 mg). The control group of 124 patients was given midazolam (2–6 mg) and meperidine (25–75 mg). The dose of medication was titrated according to patient need and the duration of the procedure. A “comfort score” on a scale of 1–4 assessed the efficacy of the drugs based on pain or discomfort to the patient and ease of endoscopy. A “sedation score” was used to assess the degree of sedation on a scale of 1–5. The Aldrete score was used to measure recovery from anesthesia at 5 and 10 min after the procedure. RESULTS: After controlling for age, American Society of Anesthesiologists’ Physical Status Classification (ASA grade), and type and duration of procedure, logistic regression analysis determined that propofol resulted in 2.04 times better patient comfort ( p = 0.033, 95% CI = 1.058–3.923). Propofol was 1.84 times more likely to produce deeper sedation than the regimen of midazolam and meperidine ( p = 0.027, 95% CI = 1.071–3.083). The recovery from sedation was faster in patients receiving propofol, although this did not reach statistical significance. The safety parameters between the two groups were comparable. CONCLUSION: Propofol was associated with a statistically significant improvement in comfort and sedation score when compared to midazolam and meperidine.
WebSphere Studio overview

In this paper we provide an overview of IBM WebSphere Studio, a family of tools for developing distributed applications for J2EE™ servers for state-of-the-art information technology systems. In today's business environment such systems are complex, comprise multiple platforms, and make use of a wide range of technologies and standards. Through a representative development scenario we illustrate the way WebSphere Studio satisfies the challenging requirements for a modern integrated development environment. The scenario covers a variety of technologies and standards, including database access, Web services standards, Enterprise JavaBeans™ implementation, integrated application testing, Web page design, and performance optimization. We also describe the Eclipse Modeling Framework, the open source technology base on which WebSphere Studio is built.
57Fe Mössbauer studies on Si-substituted Er2Fe17

Abstract The compound Er 2 Fe 17 crystallizes in the hexagonal Th 2 Ni 17 structure, and is ordered magnetically with a Curie temperature T c of 305 K. We have investigated the effect of substituting small amounts of Si for Fe on the magnetic behavior of this compound by low temperature 57 Fe Mossbauer spectroscopy and magnetization measurements. Fe can be replaced by Si to form Er 2 Fe 17−x Si x alloys with x up to 3.0 without changing the crystal structure, though a small amount of a second phase appears in X = 3.0 sample. The substitution of Si causes a decrease in the average Fe magnetic moment. The lattice parameters decrease upon Si substitution, and T c increase from 305 K for x = 0 to 498 K for x = 3.0. 57 Fe Mossbauer spectroscopy measurements indicates no preferential subtitution of Si among the four crystallographically different Fe sites.
Selection for Body Weight at Eight Weeks of Age 12. Egg Production in Selected and Relaxed Lines

Abstract Correlated responses in egg production patterns were studied in lines of White Plymouth Rocks selected bidirectionally for juvenile body weight and in their respective relaxed lines. The production traits measured were the numbers and percentage hen-day production of normal, double-yolked, broken, ovulatory defective, and total defective eggs and yolks. Increasing the photoperiod beyond 14 hours in a 24-hour period from 119 days of age did not have a consistent effect on either body weight or reproductive traits. The frequency of various defective egg-types was significantly higher in the high weight than in the low weight lines. Relaxing selection for high body weight resulted in fewer double yolked and the total number of defective eggs, while relaxing selection for low body weight has no influence on any of the abnormal egg-types. The average heritability estimates for percentage hen-day production of normal eggs and yolks were similar. Heritability estimates of the total defective eggs were moderate to high and the genetic correlations among traits were generally larger than the phenotypic correlations. The negative phenotypic correlation between age at sexual maturity and percentage hen-day production of normal eggs was due to a negative environmental correlation between these traits. Early sexual maturity was genetically associated with a higher rate of normal egg production when feed restriction was moderate, while it tended to be opposite under a relatively severe feed restriction. Environmental factors that delayed sexual maturity had no significant influence on the production of defective eggs. The positive association between the production of normal eggs and yolks to January 1 was largely genetic, whereas the negative relationship between normal and defective egg production was primarily environmental. The low magnitude of phenotypic and environmental correlations among body weight and defective eggs suggest that under restricted feeding regimes defective egg production is largely independent of growth rate. There was evidence to indicate that non-additive genetic effects contribute to environmental correlations of percentage hen-day production of defective eggs with body weight and with age at sexual maturity. Furthermore, it is inferred that a genetic approach to the problem of defective eggs is realistic.
Uredinales of Costa Rica Based on Collections by E. W. D. Holway

(1918). Uredinales of Costa Rica Based on Collections by E. W. D. Holway. Mycologia: Vol. 10, No. 3, pp. 111-154.
A Solid State Directional Gamma Detector

A solid-state gamma-ray detector has been developed which exhibits directionality. Four PIN diode detectors are backed with Pb and arranged in a square array which exhibits an angular response to gamma rays. The high-Z material provides directionality and also enhances the sensitivity of the detectors to high-energy gammas by means of the x-ray fluorescence accompanying photon interactions in the backing. The array responses are used to identify the quadrant containing the source and obtain the radiation level. Ratios of the counting rates in opposite pairs of detectors are used to determine the angular position of the source within the quadrant.
Magnetospheric plasma modeling (0-100 keV)

Spacecraft surface charging, which is primarily a current balance phenomenon, is in general a function of the dominant currents to and from the vehicle's surface. Within the near-earth magnetosphere the dominant currents to the surface are the ambient space plasma fluxes between approximately 0 and 100 keV. A major effort to understand the near-earth environment was initiated when spacecraft charging became a major issue. The present paper has the objective to summarize the basic features of the models which have resulted from this effort. A description is given of four categories of models, based primarily on the degree of empirical and theoretical input. Types of quantitative models are discussed, taking into account definitions, statistical models, analytic models, static models, and time-dependent models. Engineering models are also considered, giving attention to baseline models and 'worst-case' models.
Feeding behavior of the medicinal leech,Hirudo medicinalis L.

1. We have investigated the organization of feeding behavior by the medicinal leech,Hirudo medicinalis L. Hungry leeches position themselves at the water surface when they are in a resting state, and they are alerted by either mechanical or photic stimuli. 2. Alerted leeches orient into water waves and swim toward their apparent source with accuracy. They also exhibit an optokinetic orientation by swimming into moving bars of light. 3. Swimming ceases whenHirudo contact any surface which they explore by crawling, and upon finding a warm region, they bite. Biting has a thigmotactic component and a temperature preference of 37–40 °C. 4. Hirudo ingest blood meals averaging 8.9 times their initial weight. After feeding, leeches seek deeper water by crawling and they avoid warm surfaces. 5. Feeding by the medicinal leech has several behavioral alternatives which can be employed once the leech is alerted. Further, the act of feeding, itself, substantially alters the behavior of this sanguivorous annelid.
Work and retirement among a cohort of older men in the United States, 1966-1983.

Multivariate increment-decrement working life tables are estimated for a cohort of older men in the United States for the period 1966–1983. The approach taken allows multiple processes to be simultaneously incorporated into a single model, resulting in a more realistic portrayal of a cohort’s late-life labor force behavior. In addition, because the life table model is developed from multivariate hazard equations, we identify the effects of sociodemographic characteristics on the potentially complex process by which the labor force career is ended. In contrast to the assumed homogeneity of previous working life table analyses, the present study shows marked differences in labor force mobility and working and nonworking life expectancy according to occupation, class of worker, education, race, and marital status. We briefly discuss the implications of these findings for inequities of access to retirement, private and public pension consumption, and future changes in the retirement process.
Instrument to measure the bidirectional reflectance distribution function of surfaces

A new instrument to measure the in situ bidirectional reflectance distribution function (BRDF) of surfaces is described. This instrument measures the BRDF for eight illumination angles from 0 to 65 deg, three colors (475, 570, and 658 nm), and at over 100 selected viewing angles. The viewing zenith angles range from 5 to 65 deg, and the azimuth angles, relative to the illumination direction, range from 0 to ±180 deg. Many tests of the system have been run and show that for flat surfaces the BRDF of a sample surface can be measured with a precision of 1–5% and an accuracy of 10% of the measured reflectance. The BRDF for a dry and wet sand sample is presented as a demonstration of the instrument.
Ultraviolet and Infrared Spectrophotometric Analysis of an Insect Repellent Mixture

A spectrophotometric procedure employing measurements in both the ultraviolet and infrared regions was developed to determine the concentrations of N-butyl acetanilide, benzyl benzoate, 2-ethyl, 2-butyl propanediol-1,3 and Tween 80, in a mixture containing only these four components. The first two components have relatively strong absorptivities in the ultraviolet at 227.5 and 280.3 milli-microns, while the latter two have absorption bands at the infrared wavelengths, 8.99 and 9.60 microns. By substituting the absorptivities at these wavelengths in a set of four simultaneous equations, the percentage of each component in an insect repellent mixture is calculated.
Comparative survival curve analysis in sickle cell disease

In a typical followup study of a chronic disease patients enter and leave the study throughout its course. The usual Kaplan-Meier estimate of survival probability as a function of chronological age assumes that all patients are at equal risk from the beginning of the study irrespective of their age at entry. We proposed a modification of the Kaplan-Meier estimate which takes into account patients entering the study after commencement by treating them as ''negative losses''. In this paper the usual Kaplan-Meier estimate is compared with our modification of the Kaplan-Meier estimate by applying each method to a data base of an ongoing study of 525 sickle cell disease patients. The data base was subdivided into groups by sex and hemoglobin type. We found that the usual Kaplan-Meier estimate has a lower resolution between groups than the modified Kaplan-Meier estimate, particularly when the true differences between groups are not great. In this sample male Hb SS patients had a better overall prognosis than female patients; a less acute form of the disorder associated with Hb SC, as expected, had a significantly higher survival than either the female or male SS patients. These subgroup and group differences were more clearly shown by the modified Kaplan-Meier estimate.
The intact strontium ranelate complex stimulates osteoblastogenesis and suppresses osteoclastogenesis by antagonizing NF-κB activation

Strontium ranelate, a pharmaceutical agent shown in clinical trials to be effective in managing osteoporosis and reducing fracture risk in postmenopausal women, is relatively unique in its ability to both blunt bone resorption and stimulate bone formation. However, its mechanisms of action are largely unknown. As the nuclear factor-kappa B (NF-κB) activation antagonists both stimulate osteoblastic bone formation and repress osteoclastic bone resorption, we hypothesized that strontium ranelate may achieve its anabolic and anti-catabolic activities by modulating NF-κB activation in bone cells. In this study, osteoclast and osteoblast precursors were treated with intact strontium ranelate or its individual components sodium ranelate and/or strontium chloride, and its effect on in vitro osteoclastogenesis and osteoblastogenesis and on NF-κB activation quantified. Although the activity of strontium ranelate has been attributed to the release of strontium ions, low dose intact strontium ranelate complex, but not sodium ranelate and/or strontium chloride, potently antagonized NF-κB activation in osteoclasts and osteoblasts in vitro, and promoted osteoblast differentiation while suppressing osteoclast formation. Taken together, our data suggest a novel centralized mechanism by which strontium ranelate promotes osteoblast activity and suppresses osteoclastogenesis, based on suppression of NF-κB signal transduction. We further demonstrate that the biological actions of strontium ranelate may be related to low dose of the intact molecule rather than dissociation and release of strontium ions, as previously thought. These data may facilitate the development of additional novel pharmacological agents for the amelioration of osteoporosis, based on NF-κB blockade.
Kinetic folding and assembly mechanisms differ for two homologous heptamers

Abstract Here we investigate the time-resolved folding and assembly mechanism of the heptameric co-chaperonin protein 10 (cpn10) in vitro . The structure of cpn10 is conserved throughout nature: seven β-barrel subunits are non-covalently assembled through β-strand pairings in an overall doughnut-like shape. Kinetic folding/assembly experiments of chemically denatured cpn10 from Homo sapiens ( hm cpn10) and Aquifex aeolicus ( Aa cpn10) were monitored by far-UV circular dichroism and fluorescence. We find the processes to be complex, involving several kinetic steps, and to differ between the mesophilic and hyper-thermophilic proteins. The hm cpn10 molecules partition into two parallel pathways, one involving polypeptide folding before protein–protein assembly and another in which inter-protein interactions take place prior to folding. In contrast, the Aa cpn10 molecules follow a single sequential path that includes initial monomer misfolding, relaxation to productive intermediates and, subsequently, final folding and heptamer assembly. An A. aeolicus variant lacking the unique C-terminal extension of Aa cpn10 displays the same kinetic mechanism as Aa cpn10, signifying that the tail is not responsible for the rapid misfolding step. This study demonstrates that molecular details can overrule similarity of native-state topology in defining apparent protein-biophysical properties.
Statistical physics and economic fluctuations: do outliers exist?

Abstract We present an overview of recent research applying ideas of statistical physics to try to better understand puzzles regarding economic fluctuations. One of these puzzles is how to describe outliers, phenomena that lie outside of patterns of statistical regularity. We review evidence consistent with the possibility that such outliers may not exist. This possibility is supported by recent analysis by Plerou et al. of a database containing the bid, ask, and sale price of each trade of every stock. Further, the data support the picture of economic fluctuations, due to Plerou et al., in which a financial market alternates between being in an “equilibrium phase” where market behavior is split roughly equally between buying and selling, and an “out-of-equilibrium phase” where the market is mainly either buying or selling.
Ontogenesis of gonadotropin-releasing hormone neurons: a model for hypothalamic neuroendocrine cell development.

The vertebrate hypothalamo-pituitary-gonadal (HPG) axis is the anatomical framework responsible for reproductive competence and species propagation. Essential to the coordinated actions of this three-tiered biological system is the fact that the regulatory inputs ultimately converge on the gonadotropin-releasing hormone (GnRH) neuronal system, which in rodents primarily resides in the preoptic/hypothalamic region. In this short review we will focus on: 1) the general embryonic temporal and spatial development of the rodent GnRH neuronal system, 2) the origin(s) of GnRH neurons, and 3) which transcription - and growth factors have been found to be critical for GnRH neuronal ontogenesis and cellular fate-specification. Moreover, we ask the question whether the molecular and cellular mechanisms involved in GnRH neuronal development may also be play a role in the development of other hypophyseal secreting neuroendocrine cells in the hypothalamus.
Multi-wavelength visible light communication system design

Visible light communication (VLC) is achieved by modulation of one or more spectral components in the visible spectrum (≈380–780 um). The use of this range provides an opportunity to exploit an otherwise untapped medium that is used in human lighting. Most VLC systems constructed to date focus on using a broad visible band generated by phosphor-converted light emitting diodes, or by filtering to isolate the blue component from these sources. Multi-wavelength systems consider additional wavelength bands that are combined to produce the desired communications capacity and lighting output. This color combining, or mixing, realizes desired color temperature and intensity and represents a form of wavelength-division multiplexing. This paper investigates the relationships between the colors comprising the lighting source for a range of lighting states, the spectral separation of communication channels, the relative intensities required to realize lighting states, how modulation can be most effectively mapped to the available color channels, and the design of an optical filtering approach to maximize signal to noise ratio while minimizing crosstalk at the receiver. Simulation results based on a three colored VLC system are discussed using orthogonal frequency division multiplexing for each color. It is shown that the system is the most power efficient at 6250 K correlated color temperature, with transmitter spectral spread of 5 nm and filter transmittance width of 40 nm.
Matching index of refraction using a diethyl phthalate/ethanol solution for in vitro cardiovascular models

Experiments studying cardiovascular geometries require a working fluid that matches the high index of refraction of glass and silicone, has a low viscosity, and is safe and inexpensive. A good candidate working fluid is diethyl phthalate (DEP), diluted with ethanol. Measurements were made of index of refraction and viscosity of varied dilutions at a range of temperatures, and empirical models are proposed. Material compatibility tests showed that only specific formulations of ABS, acrylic, vinyl and PVC are compatible. A silicone elastomer additionally tested negative for change in compliance with DEP exposure.
Is our vacuum metastable

In spontaneously broken gauge theories of particle interactions there are sometimes several local minima of the effective potential. Any of these minima can serve as a vacuum in the sense that we can expand the fields around their values at the minimum, interpret the quantized fluctuations around the minimum as particles, and compare the properties of these particles with experiment. One might think that only the state with absolutely minimum energy could be what we ordinarily call our vacuum, as the other local minima will inevitably decay into this lowest one. However, this is not necessarily the case, because it is possible for the lifetime of a metastable vacuum to be very long, even when compared with the age of the Universe. Furthermore, the energy densities available in present laboratory or astrophysical environments are much less than the barriers which exist in field space between the different local minima, and so we have no direct sensitivity to the presence of a possibly lower vacuum state. (A possible exception to this are magnetic monopoles which do probe the large field region.) If it is not the absolute minimization of the effective potential, what does determine the present vacuum state of the Universe? We argue here that it is determined cosmologically by the dynamical evolution of the Universe from the hot, dense phase which existed shortly after the big bang to the present1,2.
EFFECT OF IMMUNIZATION ON TISSUE SUSCEPTIBILITY TO VACCINIA VIRUS IN VITRO.

Abstract Spleen and kidney cells from rabbits immunized with infectious vaccinia virus and from nonimmunized controls were grown in culture and challenged with the same virus at various time intervals after seeding. The extent of virus multiplication throughout a 4-day period was measured. Cultures of kidney cells from the immunized and nonimmunized animals challenged 3–5 days after seeding, showed similar rises in infectivity titers. In contrast, the infectivity titers in spleen cultures from immunized animals were significantly lower than in corresponding control cultures when challenged 2–3 days after seeding. The lowered susceptibility was not found to be due to the presence of neutralizing antibodies, nor due to a diminished capacity to adsorb the virus. The difference in susceptibility of the spleen cultures was not observed when herpes simplex virus was used for challenge. The nature of the acquired resistance is discussed.
Body image, social comparison, and eating disturbance: a covariance structure modeling investigation.

Objective To evaluate the role of appearance-based social comparison processes as a possible mediational link between developmental factors (negative social feedback, i.e., teasing about appearance; biological status, i.e.,early physical maturation) and levels of body dissatisfaction, eating disturbance, and global psychological functioning. Method In this study of 173 female undergraduates, covariance structure modeling (CSM) was used to examine direct and mediational relationships among these variables. Results Appearance-based social comparison mediated the effect of appearance-related teasing on body image and eating disturbance; body image mediated the effect of teasing on eating disturbance; eating disturbance had a direct effect on overall psychological functioning. Discussion Implications for devising and testing other theoretical models are discussed. © 1999 John Wiley & Sons, Inc. Int J Eat Disord 26: 43–51, 1999.
Social science and social physics

Social science was born with the ambition to be social physics. In the hands of Galton, Pearson, and their successors, it became instead a search for causal explanations that are of a different logical kind from the explanations provided by celestial mechanics. Many critics of social science continue to demand that the social sciences produce systematic theories explaining social phenomena from general laws. The demand is inappropriate, and is not satisfied by many sciences that provide causal explanations without providing general laws. The unity of the sciences derives from a common conception of rational inquiry, rather than from sameness of technique or theoretical structure.