cssi/SciSciGPT-SciSciNet huggingface dataset:
Regional Specification during Embryogenesis in the Articulate Brachiopod Terebratalia

The timing of regional specification during embryogenesis in Terebratalia transversa has been examined by isolating animal, vegetal, and lateral halves at developmental stages ranging from prior to fertilization through late gastrula. Animal halves isolated from prior to fertilization through late blastula stages did not gastrulate and did not form endoderm. When these animal halves were isolated from prior to fertilization through early blastula, they formed only ciliated vesicles; however, similar halves from late blastulae frequently formed the ectodermal components of the three larval lobes. Vegetal halves isolated prior to fertilization through late blastula gastrulated, formed endoderm, and differentiated most larval structures; however, comparable isolates from late gastrulae showed a marked decline in the ability to form anterior larval structures. Animal halves isolated at this stage showed a corresponding decline in the ability to form posterior larval structures. These results indicate that during oogenesis, regional differences arise so that the animal half of the oocyte has a much greater ability to form anterior ectodermal structures than do other regions of the oocyte, while only the vegetal region has the capacity to gastrulate. Inductive signals produced by the vegetal region of the embryo act on the animal half to give it the capacity to form ectodermal components of the three larval lobes. This vegetal-inductive influence has played a major role in regional specification by the late blastula stage of development. Pairs of lateral halves isolated from the same oocyte or embryo from prior to fertilization through late blastula frequently gastrulate, form endoderm, and proceed to form all or most of the larval lobes. The late blastula is the first developmental stage where there is a marked decline in the ability of pairs of lateral halves to differentiate larval structures and is the first stage where pairs of halves resembling dorsal and ventral halves appear. This suggests that the axis of bilateral symmetry is also specified by the late blastula stage of development.
The densities of high-purity iron-carbon alloys in the spheroidized condition

The densities were determined for a series of spheroidized then slowly cooled, high-purity iron-carbon alloy specimens containing from 0 to 4.17 pct C. They were found to follow the relationshipρ -1 (cc/g at 23°C) = 0.126988 + (5.036 × 10-4) (wt pct C). Whereas the intercept value coincided with the x-ray specific volume of iron, the extrapolated value at the Fe3C composition was slightly greater than published X-ray specific volumes for Fe3C. The results suggested that the cementite phase in these specimens was slightly iron-rich with respect to Fe3C. Assuming a vacancy-defect structure for the cementite, we were able to roughly estimate its composition. This appears to be a promising method for determining the cementite/(cementite + ferrite) saturation boundary.
Amino acid polymers for biomedical applications. I. Permeability properties of L-leucine DL-methionine copolymers.

A series of DL-methionine/L-leucine copolymers was prepared from the coresponding N-carboxy-anhydrides. The copolymers formed clear flexible films having low water vapor transmission rates. Peroxide oxidation of the pendant methyl-theioethyl groups to methyl-sulfinoethyl groups enhanced the hydrophilic properties of the membranes, and the water vapor transmission rates rapidly increased with an increase in the number of pendant methyl-sulfinoethyl groups. Increasing the leucine content of the membranes produced a 13-fold increase in the carbon dioxide permeability and a 6-fold increase in oxygen permeability, whereas, an increase in the methionine content doubled the carbon dioxide-oxygen separation factor. Synthetic poly (α-amino acids) are very similar to naturally occurring proteins with respect to composition and conformation. Because of these similarities, they are being considered in aerosol spray bandages, synthetic skin applications and as coatings for plastic prostheses. The unusual permeability characteristics of the DL-methionine/L-leucine copolymers make them interesting membranes for possible use in artificial kidney machines and blood oxygenators.
ALD Zirconium Oxide (ZrO2) Thin Films Mechanical/Structural Properties for High-Tech Applications

The nanomechanical and structural properties of atomic layer deposition (ALD) zirconium oxide (ZrO2) films of varying thickness deposited on p-type Si (100) substrates with 200, 300, and 500, ALD deposition cycles were investigated. The 300 ALD deposition cycles ZrO2 films were further annealed at 600 ◦ C. The nanomechanical properties of the films were tested using nanoindentation and the surface morphology was investigated using AFM. The structural and surface properties were explored using field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). We discuss the influence of the deposition technique on the structure and properties of the ZrO2 films resulting from ALD synthesis. The nanoindentation results indicate that the films become consistently softer as the number of ALD deposition cycles increase and the film grows thicker. Further annealing of the films at 600 ◦ C slightly enhanced the hardness and fracture toughness of the films. The annealed ALD films depicted shorter radial cracks compared to the films under the same applied stress, which were not annealed in forming gas.
Kinetic Analysis of the Hydrogenolysis of Lower Polyhydric Alcohols: Glycerol to Glycols

The production of ethylene glycol and propylene glycol from higher polyhydric alcohols has been parametrically examined numerous times. However, efforts to develop improved catalyst systems require a better understanding of the reaction mechanism. Glycerol conversion to the glycols represents an initial system for developing an improved mechanistic understanding of the conversion of the more complex higher polyhydric alcohols. Batch reactor studies with ruthenium on carbon catalysts were performed at two pH levels to obtain kinetic data. Langmuir−Hinshelwood-type models were developed from the experimental data to describe the hydrogenolysis of glycerol into ethylene glycol and propylene glycol as well as further degradation of the glycols. Detailed information on the competitive adsorption coefficients for the reaction species was determined, which led to conclusions about the limitations of previous parametric analysis.
Carcinoid tumor of the vermiform appendix with Cushing's syndrome. Ultrastructural study of a case

A young woman with Cushing's syndrome recovered after removal of an appendiceal carcinoid tumor which contained ACTH in excess. The tumor was not associated with any features suggestive of serotonin production although the neoplastic cells were argyrophilic and demonstrated a positive argentaffin reaction. The cells contained pleomorphic dense granules and had other cytoplasmic characteristics of the enterochromaffin or argentaffin cells that are typically found in midgut derivatives. They displayed 4 ultrastructural features of polypeptide hormone-producing cells which are a high content of free ribosomes, low levels of rough endoplasmic reticulum, electron dense mitochondria, and membrane-bound secretion vesicles. However, they lacked one important ultrastructural feature of such cells, namely high levels of smooth endoplasmic reticulum in the form of vesicles. A sixth ultrastructural characteristic of polypeptide hormone-secreting cells, fixation lability of mitochondria, could not be assessed from the material available for study.
Microbiologic Diagnosis of Ventilator-Associated Pneumonia

No single test will provide all the information needed to diagnose ventilator-associated pneumonia (VAP), and the clinician must use multiple clinical criteria for the diagnosis. The use of culture techniques allows one to enhance the sensitivity and specificity of the diagnosis of pneumonia. In addition, the clinician can be kept up to date about potential new pathogens as they occur in the intensive care unit. Knowledge of the local flora allows one to make a better choice of empiric therapy for VAP.
The matrix metalloproteinase inhibitor BB-94 limits expansion of experimental abdominal aortic aneurysms

Abstract Purpose: Matrix metalloproteinases (MMPs) are proteolytic enzymes that can degrade the extracellular matrix of the aortic wall and lead to the formation of abdominal aortic aneurysms (AAAs). MMP inhibitors are a class of drugs that were developed to inhibit the activity of these proteolytic enzymes and are currently being studied as a way to control inflammatory diseases and cancer metastases. In this project, BB-94 (also known as batimastat), a specific inhibitor of MMPs, was evaluated for its ability to control aneurysmal growth in an experimental AAA model. Methods: Experimental AAAs were created in a standard rat model by perfusing elastase into an isolated segment of aorta. The rats then were randomized to postoperatively undergo treatment daily with the MMP inhibitor BB-94 or the carrier control solution. Measurements of the aortic diameter were made at the time of initial surgery and at the time of death on postoperative day 7. Aortic tissue was obtained for histologic examination, elastin evaluation, and MAC 1-α antibody staining to evaluate the inflammatory response. Results: The rats that underwent treatment with BB-94 had significantly less aneurysmal dilatation and a 113% increase in aortic size, as compared with the control rats that had a 157% increase ( P = .026). Histologic examination of the harvested aortas and grading of the elastin content showed a significantly greater elastin preservation in those rats that were treated with BB-94 as compared with the control rats ( P = .036). MAC 1-α antibody staining showed an attenuation of the inflammatory response in the group of rats that underwent treatment with BB-94. Morphologic examination also revealed that the control of the inflammatory response correlated with the areas of elastin preservation. Conclusion: MMP inhibition with BB-94 limited the expansion of AAAs in this rat model. BB-94 appears to work not only as a direct pharmacologic inhibitor of MMPs but also as an interference with the inflammatory response seen in AAAs. Control of the inflammatory response was an unexpected result and may be related to the alterations in feedback mechanisms that are related to extracellular matrix degradation. Because this class of drugs is presently being developed to control the MMP inflammatory response seen with arthritis, these drugs also may ultimately serve as a pharmacologic treatment for patients with AAAs. (J Vasc Surg 1999;29:130-9.)
Glucocorticoid-induced osteoporosis in men

Osteoporosis and fractures are a common consequence of glucocorticoid therapy for inflammatory disorders. Men fracture approximately 10 yr later in life than women and receive less attention as regards osteoporosis risk, including in glucocorticoid-induced osteoporosis (GIOP). In addition, while men are less likely to have certain rheumatologic disorders often treated with glucocorticoids, men are more likely to have chronic obstructive pulmonary disease, inflammatory bowel disease, and organ transplantation as reasons for use of oral glucocorticoids. Attempts to improve recognition of GIOP in general have not been successful, and since men are considered less at risk for osteoporosis in general, attention to men with GIOP is even less. Evaluation of GIOP is similar in men and women, and most modern treatment studies of GIOP have included men. Thus, alendronate, risedronate, and zoledronic acid are Food and Drug Administration (FDA)-approved bisphosphonates for GIOP in men. Teriparatide is also FDA-approved for GIOP. In one 36-month trial of teriparatide vs alendronate for GIOP in men and women, the anabolic agent led to a greater increase in bone density and was associated with a lower incidence of morphologic vertebral fractures. Thus, while good management is available for GIOP, recognition of men at risk is the most important step in improving outcomes.
Simulating the Compton-Getting Effect for Hydrogen Flux Measurements: Implications for IBEX-Hi and -Lo Observations

The Interstellar Boundary EXplorer (IBEX), launched in 2008 October, has improved our understanding of the solar wind-local interstellar medium interaction through its detection of neutral atoms, particularly that of hydrogen (H). IBEX is able to create full maps of the sky in six-month intervals as the Earth orbits the Sun, detecting H with energies between ∼0.01 and 6 keV. Due to the relative motion of IBEX to the solar inertial frame, measurements made in the spacecraft frame introduce a Compton-Getting (CG) effect, complicating measurements at the lowest energies. In this paper we provide results from a numerical simulation that calculates fluxes of H atoms at 1 AU in the inertial and spacecraft frames (both ram and anti-ram), at energies relevant to IBEX-Hi and -Lo. We show theory behind the numerical simulations, applying a simple frame transformation to derived flux equations that provides a straightforward way to simulate fluxes in the spacecraft frame. We then show results of H energetic neutral atom fluxes simulated at IBEX-Hi energy passbands 2-6 in all frames, comparing with IBEX-Hi data along selected directions, and also show results simulated at energies relevant to IBEX-Lo. Although simulations at IBEX-Hi energies agree reasonably well with the CG correctionmore » method used for IBEX-Hi data, we demonstrate the importance of properly modeling low energy H fluxes due to inherent complexities involved with measurements made in moving frames, as well as dynamic radiation pressure effects close to the Sun.« less
EFFECTS OF ULTRAVIOLET RADIATION ON PHOTOSYNTHESIS IN THE SUBTROPICAL MARINE DIATOM, CHAETOCEROS GRACILIS (BACILLARIOPHYCEAE)1

ARSTRACT Acclimation to ambient ultraviolet radiation (UVR) was examined in a subtropical marine diatom, Chaetoceros gracilis Schutt. Short-term exposure to UVR (<24 h) reduced the efficiency of photosynthetic energy conversion, carbon fixation, activity of 1,5-bisphosphate carboxylase-loxygenase (RUBISCO), and the rapid turnover of the putative Dl reaction center (32 kda) protein, whereas longer-term exposure to ambient UVR (24–48 h) revealed a steady-state acclimation, defined as recovery of carbon fixation and RUBISCO activity to rates equivalent to treatments without exposure to UVR. The turnover of D1 and chlorophyll a (Chl a) remained high during exposure to UVR. Efficiency of energy conversion by photosystem II, measured with double flash (pump and probe) fluorometry, increased by 24% in cells acclimated to UVR. Acclimation to UVR had no detectable effect on the functional absorption cross-section or cellular concentrations of Chl a, Chl c, or total carotenoids. However, the maximum rate of carbon fixation was reduced by UVR on a Chl a basis but remained unaffected on a per-cell basis. Response to UVR exposure in this subtropical diatom has two components: a short-term inhibitory response and a longer-term acclimation process that ameliorates the inhibition of carbon fixation.
Pricing of Services: An Interdisciplinary Review

Basic theories and widely held beliefs about pricing in the fields of economics and cost accounting are reviewed, but found not to have total relevance to the pricing of services. Marketing principles reviewed offer some guidelines to the pricing problem, which is rooted in service characteristics. A pricing procedure is suggested. The purpose of this article is to show how the service price decision is uniquely constrained by environmental and product characteristics, and to review the price-related literature of several disciplines.
North American Labor History Conference

The eighteenth annual North American Labor History Conference took place in Detroit, Michigan, on October 17-19, 1996. Detroit, with its rich legacy of labor organizing, has been greatly affected by national and global economic transformations. It symbolizes the challenges facing both labor organizations and historians. Two major themes of the conference aimed at addressing these challenges. One was the problem of historical memory? how it is produced and used. The second, related to issues of memory, was the need to expand definitions of worker and work experience. Labor history is now examining communities, not just sites of waged production, as locations in which class identities are forged. Recovery and incorpora tion of individual voices is essential to understanding relationships between community, identity, and experience. Several participants explored the recovery of memory. Some discussed the methodological challenges of working with different sources, from oral histories to fiction, from graphic arts to African nicknames for colonial-era labor bosses. Their studies also raised questions about the links between memory and the effectiveness of organizing efforts. What issues, symbols, and language have resonance for particular groups of workers? Presenta tions emphasized diversity. Laurie Green (University of Chicago) de scribed African-Americans in Memphis who sought to escape the planta tion mentality of their rural past and infused their labor struggles with concern for broader social rights. Tony Buba and Raymond Henderson, coproducers of a documentary about black steelworkers, also found that their subjects placed labor experiences in a much larger social context. As they put it, "each interview was larger than the mill." Like the paper of Derek Valliant (University of Chicago), their "Struggles in Steel" demon strated that black and white workers often had very different memories. Tom Sugrue (University of Pennsylvania) found similar disparities in his
A Modular Dynamic Simulation Approach to the Reconstruction of Automobile Accidents

La simulation numerique dynamique des accidents d'automobiles peut jouer un role important dans la reconstruction du mouvement des vehicules. On propose une approche modulaire, ou des modules numeriques individuels sont utilises de facon interactive pour reconstruire les evenements physiques d'un accident dans des phases separees
An fMRI investigation of working memory and its relationship with cardiorespiratory fitness in pediatric posterior fossa tumor survivors who received cranial radiation therapy

Background The present study investigated the relationship between cardiorespiratory fitness and executive functioning in pediatric brain tumor survivors who received cranial radiation. This population is known to show executive dysfunction and lower rates of aerobic exercise compared to peers. Procedure Nine adolescent survivors of pediatric posterior fossa tumor completed an n-back working memory task during a functional MRI scan, as well as cardiorespiratory fitness testing on a cycle ergometer. Results Neuroimaging findings indicated typical activation patterns associated with working memory, mainly in the frontal–parietal network. Higher cardiorespiratory fitness was related to better performance on a behavioral measure of working memory and more efficient neural functioning. Conclusions This study provides preliminary evidence that cardiorespiratory fitness may be related to executive functioning, particularly working memory, in pediatric brain tumor survivors. Descriptions of the brain regions recruited for working memory by pediatric brain tumor survivors may be used to inform future interventions or indicators of treatment efficacy. Pediatr Blood Cancer 2013; 60: 669–675. © 2012 Wiley Periodicals, Inc.
Towards Microeconomics of Innovation: Growth Engine Hallmark of Market Economics

The Bourgeoisie (i.e., capitalism) cannot exist without constantly revolutionizing the instruments of production. Conservation of the old modes of production in unaltered form was, on the contrary, the first condition of existence for all earlier industrial classes. The bourgeoisie, during its rule of scarce one hundred years has created more massive and more colossal productive forces than have all preceding generations together. It has accomplished wonders far surpassing Egyptian pyramids, Roman aqueducts and Gothic cathedrals...
Population Decline of White Locoweed

Many Astragalus and Oxytropis species are en- demic (growing on speci c soils and geo- graphical areas), but white locoweed (Oxytro- pis sericea) is the most widespread locoweed in the western United States, growing on short-grass prairies and eastern foothills of the Rocky Mountains from Montana to New Mexico. Its preferred habitat is rocky soils,1 where its long taproot can access deep percolated water allowing it to survive drought, temperature, and wind stress. DOI: 10.2458/azu_rangelands_v34i5_graham
Subplantation model for film growth from hyperthermal species: Application to diamond.

A model for film growth from hyperthermal (\ensuremath{\approxeq}1--${10}^{3}$ eV) species impinging on substrates is proposed. The process includes subsurface implantation, energy loss, preferential displacement of atoms with low displacement energies (${E}_{d}$) leaving high ${E}_{d}$ atoms undisplaced, and sputtering of substrate material. Epitaxial growth and preferred orientation result from the angular dependence of the ${E}_{d}$ and the host mold effect. The model, supported by ion trajectory calculations and experimental data, is applied to diamond film formation from ${\mathrm{C}}^{+}$ ions.
Optimal Integrated Control of Univoltine Pest Populations with Age Structure

A procedure is presented for calculating optima integration and timing of biological, chemical and cultural methods for control of a univoltine pest population in a random environment. The procedure describes a system of high dimension by two nested models: a stochastic dynamic programming problem with four state variables and a more detailed differential equation model describing the effect of management and weather on population demography and crop yield. A computational algorithm is presented which reduces computation requirements for the population model from about 1013 operations to 106 operations for a typical example. Results are presented from the application of the method to control the alfalfa weevil by a combination of insecticide applications, early harvesting, and biological control provided by a parasite.
Special Education Teacher Education: A Perspective on Content Knowledge

The passage of No Child Left Behind and the Individuals with Disabilities Education Act has strengthened the conditions for instructional accountability for all learners. The standards-based approach promulgated by curriculum and state assessments is central to the accountability of conditions in today's schools; however, national and state data continue to document a performance gap between students with learning disabilities (LD) and their nondisabled peers. Building on 5 years of experience in developing and testing the Blending Assessment with Instruction Program in mathematics, we present three basic principles that are essential to ensuring that students with LD achieve curriculum standards: (1) instruction must be aligned with curriculum standards, (2) teachers' content knowledge is essential to translating curriculum standards into aligned instruction, and (3) instructional methodology should receive greater attention during teacher preparation.
Effect of planting date on time and rate of nitrogen accumulation by maize (Zea mays L.).

Effects of environment on time and rate of nutrient accumulation by crops affects fertilizer nutrient use efficiency. The effect of planting date on rate, time and amount of nitrogen (N) accumulated by maize from a Hamerly cl soil (Aeric Calciaquoll) was examined with and without supplemental irrigation. Maize was planted on three dates spaced at 2-to 3-week, intervals; the earliest planting date was 1 May in 1984 and 1985. N accumulation was examined as uni- and diphasic tanh[k(time)] functions and solved for total N accumulation at harvest, time of maximum N accumulation rate and the time coefficient of N accumulation. A diphasic function, which indicates two periods of intense N accumulation, provided the closest agreement with observed N accumulation. As planting was delayed, time required to reach maximum N accumulation rates, τ (uniphasic) or τ1 and τ2 (diphasic), decreased from an average of nearly 75 to 42 days (uniphasic) and from nearly 65 to 35 days and 100 to 75 days after planting for τ1 and τ2, respectively. Maximum N accumulation rates increase from about 59 to 75 mg N plant−1 day−1 (uniphasic) or 35 to 65 mg N plant−1 day−1 and 20 to 70 mg N plant−1 day−1 for the first and second maxima in the diphasic model, respectively. Average maximum total N accumulation ranged from 2.85 g N plant−1 for early plantings to 1.5 g N plant−1 for plantings made on 25 June. The time coefficient, k (uniphasic) or k1 (diphasic), tended to increase from average values of about 0.04 to > 0.09 day−1 for k and from about 0.04 to > 0.105 day−1 for k1. The second time coefficient, k2, of the diphasic function varied widely between about 0.075 to > 0.12 day−1 and showed complex relationships with planting date. Periods of N accumulation shortened and intensity of N accumulation increased as the time coefficient increased.
Numeric comparison in a visually-guided manual reaching task

Nearly all studies on perception and cognition have used discrete responses to infer internal cognitive processes. In the current study, we demonstrate that visually-guided manual reaching can provide new opportunities to access internal processes over time. In each trial, participants were required to compare a single digit Arabic number presented on the center square with the standard, 5. Participants were asked to reach and touch one of three squares on the screen with their index finger while their hand movement trajectories were recorded: the left square for 1-4, the center for 5, and the right for 6-9. Direct evidence for an analogue representation of numbers was found in early as well as in later portions of hand trajectories, showing systematic shifts in position for small differences in numerical magnitude.
Quantum orders in an exact soluble model.

We find all the exact eigenstates and eigenvalues of a spin-$1/2$ model on square lattice: $H=16g\ensuremath{\sum}_{\mathbit{i}}{S}_{\mathbit{i}}^{y}{S}_{\mathbit{i}+\stackrel{^}{\mathbit{x}}}^{x}{S}_{\mathbit{i}+\stackrel{^}{\mathbit{x}}+\stackrel{^}{\mathbit{y}}}^{y}{S}_{\mathbit{i}+\stackrel{^}{\mathbit{y}}}^{x}$. We show that the ground states for $gl0$ and $gg0$ have different quantum orders described by $Z2A$ and $Z2B$ projective symmetry groups. The phase transition at $g=0$ represents a new kind of phase transition that changes quantum orders but not symmetry. Both the $Z2A$ and $Z2B$ states contain ${Z}_{2}$ lattice gauge theories at low energies. They have robust topologically degenerate ground states and gapless edge excitations.
Animal models of serotonergic psychedelics.

The serotonin 5-HT2A receptor is the major target of psychedelic drugs such as lysergic acid diethylamide (LSD), mescaline, and psilocybin. Serotonergic psychedelics induce profound effects on cognition, emotion, and sensory processing that often seem uniquely human. This raises questions about the validity of animal models of psychedelic drug action. Nonetheless, recent findings suggest behavioral abnormalities elicited by psychedelics in rodents that predict such effects in humans. Here we review the behavioral effects induced by psychedelic drugs in rodent models, discuss the translational potential of these findings, and define areas where further research is needed to better understand the molecular mechanisms and neuronal circuits underlying their neuropsychological effects.
Finite temperature effects in Coulomb blockade quantum dots and signatures of spectral scrambling

The conductance in Coulomb blockade quantum dots exhibits sharp peaks whose spacings fluctuate with the number of electrons. We derive the temperature dependence of these fluctuations in the statistical regime and compare with recent experimental results. The scrambling due to Coulomb interactions of the single-particle spectrum with the addition of an electron to the dot is shown to affect the temperature dependence of the peak spacing fluctuations. Spectral scrambling also leads to saturation in the temperature dependence of the peak-to-peak correlator, in agreement with recent experimental results. The signatures of scrambling are derived using discrete Gaussian processes, which generalize the Gaussian ensembles of random matrices to systems that depend on a discrete parameter---in this case, the number of electrons in the dot.
Geodetic slip rate for the eastern California shear zone and the recurrence time of Mojave desert earthquakes

WHERE the San Andreas fault passes along the southwestern margin of the Mojave desert, it exhibits a large change in trend, and the deformation associated with the Pacific/North American plate boundary is distributed broadly over a complex shear zone. The importance of understanding the partitioning of strain across this region, especially to the east of the Mojave segment of the San Andreas in a region known as the eastern California shear zone (ECSZ), was highlighted by the occurrence (on 28 June 1992) of the magnitude 7.3 Landers earthquake in this zone. Here we use geodetic observations in the central Mojave desert to obtain new estimates for the rate and distribution of strain across a segment of the ECSZ, and to determine a coseismic strain drop of ∼770 µrad for the Landers earthquake. From these results we infer a strain energy recharge time of 3,500–5,000 yr for a Landers-type earthquake and a slip rate of ∼12mm yr−1 across the faults of the central Mojave. The latter estimate implies that a greater fraction of plate motion than heretofore inferred from geodetic data is accommodated across the ECSZ.
Ionization of five aqueous fluorobenzoic acids: Conductance and thermodynamics

The three monofluorobenzoic acids together with 2,4-difluoro and 2,6-difluorobenzoic acids in aqueous solution are the subject of precision conductance measurements. The experimental data are analyzed to give ionization constants and limiting conductances at temperatures from 0 to 100°C. Walden products for the acid anions are derived from the limiting conductances while the ionization consatants are fitted by statistical methods to the function pK a (m)=A+B/T+ C logT+DT. Only the 2,6- acid requires the fourth term of the function to fit the data to a precision of better than 0.03%. Mathematical analysis of the pK function gives the standard changes in enthalpy, entropy, and heat capacity. All the acids studied are more acidic than the parent, benzoic acid, as well as more acidic than the isoelectronic methylbenzoic acids. In general the increased acidity is tied to decreases in enthalpy while entropy changes on ionization differn little from those found for the parent acid.
Intranuclear virus-like bodies in the amoeboflagellate Naegleria gruberi.

SYNOPSIS. Intranuclear virus-like bodies were seen in cultures of the EG strain of Naegleria gruberi from soil. Introduction of these virus-like particles into cultures seemed to coincide with use of chicken embryo extract as a supplement in culture media used to maintain axenic amoebae in the laboratory; the appearance of the virus-like units is triggered by transfer of axenic lines of N. gruberi EG into monobacterial culture medium. The particles, ∼ 100 nm in diameter, are mainly restricted to the nucleus of the cell. Passage of particles from the nucleoplasm into the cytoplasm is suggested by theit association with tubular projections from the nuclear membrane, and particles have been seen in the cytoplasm of the amoebae. The virus-like bodies resemble reovirus.
Changes in heat shock protein synthesis and heat sensitivity during mouse thymocyte development.

Heat shock protein synthesis was examined in mouse thymocytes at three stages of development: early embryonic thymocytes, which are CD4−CD8−, adult thymocytes, which are primarily CD4+CD8+, and mature spleen T cells, which are CD4+CD8− or CD4−CD8+. After either a 41°C or 42°C heat shock, the synthesis of the maior heat-inducible protein (hsp68) was elevated during the first hour of recovery but then decreased abruptly in thymocytes from adult mice. In contrast, the synthesis of hsp68 continued for up to 4 h after heating embryonic mouse thymocytes or mature spleen T cells. The more rapid termination ofthe heat shock response in the adult thymocytes was not the result of eitherless heat damage or more rapid repair since the recovery of general protein synthesis was more severely delayed in these cells. As well, the double positive CD4+CD8+ cells were more sensitive to hyperthermia than either the double negative CD4−CD8− or single positive CD4+CD8− or CD4−CD8+ cells. Exposure of fetal thymus organ cultures to elevated temperature revealed that the double negative thymocytes were able to survive and differentiate normally following a heat shock treatment that was lethal for the double positive thymocytes. Exposure of thymocytes from adult mice to elevated temperatures induced apoptotic cell death. This was evident by the cleavage of DNA into oligonucleosome-sized fragments. Quantitation of the extent of DNA fragmentation and the number of apoptotic cells by flow cytometry demonstrated that the extent of apoptotic cell death was related to the severity of the heat stress. Double positive (CD4+CD8+) thymocytes are selected on the basis of their T-cell antigen receptor (TCR). Most of these cells are negatively selected and die within the thymus by an active process of cell deletion known as apoptosis. Restricting hsp synthesis in response to stress might be essential during developmental processes in which cell maturation is likely to result in death rather than functional differentiation. © 1993Wiley-Liss, Inc.
Metal concentrations in surface sediments of boston harbor—Changes with time

Abstract The concentrations of metals in surface sediments of Boston Harbor have decreased during the period 1977–1993. This conclusion is supported by analysis of: (1) surface sediments collected at monitoring stations in the outer harbor between 1977 and 1993; (2) metal concentration profiles in sediment cores from depositional areas of the harbor; and (3) historical data from a contaminated-sediment database, which includes information on metal and organic contaminants and sediment texture. The background and matrix-corrected concentrations of lead (Pb) measured in the surficial layer (0–2 cm) of cores decreased by an average of 46%±12% among four locations in the outer harbor during the 16 y period. Chromium (Cr), copper (Cu), mercury (Hg), silver (Ag), and zinc (Zn) exhibited similar trends. Results from our sediment sampling are supported by historical data that were compiled from diverse sources into a regional sediment database. This sediment database contains approximately 3000 samples; of these, about 460 samples were collected and analyzed for Cu, Hg, or Zn and many other sediment parameters in Boston Harbor surface sediments between 1971–1993. The database indicates that the concentrations of these three metals also decreased with time in Boston’s Inner Harbor. The decreases in metal concentrations that are observed in more recent years parallel a general decrease in the flux of metals to the harbor, implemented by: (1) ending the sewage sludge discharge to the Harbor in December, 1991; (2) greater source reduction (e.g. recovery of silver from photographic processing) and closing or moving of industries; (3) improvements in wastewater handling and sewage treatment; and (4) diminishing use of lead in gasoline beginning about 1973. Despite the general decrease in metal concentrations in Boston Harbor surface sediments, the concentrations of Ag and Hg measured at some outer harbor stations in 1993 were still at, or above, the level associated with frequent adverse effects to marine organisms (guidelines are: Ag 3.7 μ g g −1 , Hg 1.17 μ g g −1 , from Long et al., 1995 ). Concentrations of the other metals listed were in the range considered to occasionally induce adverse biological effects.
Probabilistic Numerical Analysis of Large, Complex, Structural Dynamic System Models

In recent years, great progress has been made in the construction and solution of large finite element models of complex structural dynamic systems. For example, structural models with millions of degrees of freedom are being built and used to approximate responses of structural systems. Further, great progress is being made in stochastic system analysis. Techniques for the construction of stochastic system models have been developed and solution techniques proposed. However, the two areas have not been combined, on a large scale, because stochastic finite element approaches appear very intrusive in their pure form. That is, substantial modifications of deterministic finite element codes are required to accommodate stochastic analysis. In view of this, a technique that uses the techniques of stochastic finite elements in a non-intrusive manner is required. This research provides one such approach. Specifically, the problem is divided into three parts: (1) model structural dynamic excitations using traditi...
Local Government Procurement of CPA Audit Services: The Role of the States

Recent studies have raised serious concerns about the quality of governmental audits by independent CPAs. Part of the problem is that many governmental units do not use effective audit procurement procedures. This article examines current state guidelines for the procurement of CPA audit services by local governments and recommends an expansion of the states' role in this area.
Isotope scrambling and error magnification in multiple-spiking isotope dilution

The purpose of performing multiple spiking isotope dilution is to quantify interconverting substances. This feature has been utilized in analytical chemistry now for more than a decade. In this manuscript we show that the interconversion of analytes is inevitably accompanied by the gradual loss of information that can be extracted from the isotope patterns. Therefore, any corrections for analyte interconversion are performed at the expense of the precision of the obtained amount of interconverting analytes. Consequently, there is a natural, predictable limit to the applicability of multiple-spiking isotope dilution methods that can be summarized into a simple equation.
Very weak Bernoulli for amenable groups

We strengthen Folner Independence (defined in an earlier paper) to a criterion (which we call Very Weak Bernoulli) and prove that this new condition is equivalent to Finitely Determined.
Gas Turbine Heat Transfer: Ten Remaining Hot Gas Path Challenges

The advancement of turbine cooling has allowed engine design to exceed normal material temperature limits, but it has introduced complexities that have accentuated the thermal issues greatly. Cooled component design has consistently trended in the direction of higher heat loads, higher through-wall thermal gradients, and higher in-plane thermal gradients. The present discussion seeks to identify ten major thermal issues, or opportunities, that remain for the turbine hot gas path (HGP) today. These thermal challenges are commonly known in their broadest forms, but some tend to be little discussed in a direct manner relevant to gas turbines. These include uniformity of internal cooling, ultimate film cooling, microcooling, reduced incident heat flux, secondary flows as prime cooling, contoured gas paths, thermal stress reduction, controlled cooling, low emission combustor-turbine systems, and regenerative cooling. Evolutionary or revolutionary advancements concerning these issues will ultimately be required in realizable engineering forms for gas turbines to breakthrough to new levels of performance. Herein lies the challenge to researchers and designers. It is the intention of this summary to provide a concise review of these issues, and some of the recent solution directions, as an initial guide and stimulation to further research.
Simultaneous potential and circuit solution for 1D bounded plasma particle simulation codes

Abstract A general second-order accurate method for solving the combined potential and circuit equations in a one-dimensional electrostatic bounded plasma PIC simulation is presented. The boundary conditions include surface charge on the electrodes, which are connected to a series RLC circuit with driving terms V ( t ) or I ( t ). The solution is obtained for planer, cylindrical, and spherical electrodes. The results is a tridiagonal matrix which is readily solved using well-known methods. The methods is implemented in the codes PDP1 (plasma device planar 1D), PDC1 (cylindrical), and PDS1 (spherical).
Self-assembled LiFePO4 nanowires with high rate capability for Li-ion batteries

Controlling the dimensions in the nanometer scale of olivine-type LiFePO4 has been regarded as one of the most effective strategies to improve its electrochemical performance for Li-ion batteries. In this communication, we demonstrate a novel LiFePO4 nanoarchitecture, which is composed of self-assembled single-crystalline nanowires and exhibits good rate capability with a reversible capacity of ∼110 mA h g−1 at a current rate of 30 C, and a stable capacity retention of ∼86% after 1000 cycles at a current rate of 10 C.
Towards a dynamic (FORTRAN) programming system

A major deficiency of programming languages, when compared to natural languages, is the inability of programming languages to adapt to improved means of communicating thoughts. A means of alleviating this difficulty in a FORTRAN environment, is presented.
Variations in body image as a function of achievement level in school performance.

Summary.-Guided by the hypothesis that underachieving children would have significantly lower barrier scores than normally achieving children, 76 seventh grade underachievers in a residential school were compared with 85 average boys. The hypothesis was borne out: underachievers did have lower barrier scores. Contrary to prediction, however, the battier scores of the underachieving group did not improve significantly over a 3-mo. period of intense therapeucically oriented treatment in a special residential school. Research on the perception of one's body boundaries in relation to one's environment led S. Fisher and Cleveland (1958) to the identification of a cluster of characteristics which have been shown to correlate with definitiveness of these boundaries. Included in this cluster of characteristics, known as "self-steering behavior," are traits of high achievement motivation (R. Fisher, 1966a; Rust & Ryan, 1953), task completion (S. Fisher & Cleveland, 1958), ability to tolerate stress (Shipman, 1963 ), acting out behavior (Megargee, 1965), and independence in group interaction (S. Fisher & Cleveland, 1958). The methodology used in this line of research employs a measure called the "barrier score" which is used to assess the definitiveness of one's body boundaries. Of particular importance for the present study are the findings showing the barrier score to be: (a) related to children's achievement motivation, as measured by discrepancies between intelligence scores, and school grades (p < .O1 by x2 test) and by teachers' adjective descriptions of boys' characteristics (p < ,001; R. Fisher, 1966a); (b) related to children's tendencies to be impulsive, i.e., less attentive and involved in school-related tasks, rather than "analytically reflective", i.e., showing greater concentration and less distractability (R. Fisher, 1966b) ; (c) alterable, at least in alcoholics, as a result of therapeutic experiences (Cleveland & Sikes, cited in S. Fisher, 1970). On the basis of these findings, it seemed appropriate to determine if changes in barrier scores occurred in a group of students in a special educational program for underachievers at a residential school for underachieving boys (North Carolina Advancement School). The aim is to create a therapeuticwithin-academic environment in classrooms. Two hypotheses were tested: first, barrier scores of underachieving boys sent to this residential school would be significantly lower initially than those of boys the same age in a public school. Second, it was hypothesized that, as a result of 3 mo. of therapeutic experience in the residential school (involving individoal and group counseling), the under
Novel bunyavirus in domestic and captive farmed animals, Minnesota, USA.

To the Editor: Xing et al. (1) conclude that evidence of infection with a severe fever with thrombocytopenia syndrome (SFTS)–like virus or Heartland-like virus (HRTV) was found in many captive large mammals from much of Minnesota, raising the specter of widespread distribution of a novel pathogen. Although it is likely that HRTV can be found beyond the areas in northwestern Missouri, where it was discovered (2), we contend that this conclusion is not substantiated by the data presented by Xing et al., which were generated by an assay that was developed to diagnose SFTS virus infections in China (1,3). The study used an ELISA developed for an SFTS virus recombinant nucleocapsid protein that detects SFTS-reactive antibodies (3). The conclusions reached by Xing et al. are based on the assumption that the SFTS assay developed in China will cross-react with HRTV antibodies (1). This assumption remains unsupported because the SFTS assay has not been evaluated for cross-reaction with antibodies to other non-SFTS members of the genus Phlebovirus (1,3). In addition, it is well recognized that serologic tests, like the ELISA, are often group reactive (4), requiring neutralization tests to confirm antibody presence and provide specificity. Alternative explanations include the possibility that positive results from testing by Xing et al. may have been caused by cross-reaction with antibodies directed against other known tick-associated phleboviruses endemic to North America, such as Lone Star virus (5), which is not known to be pathogenic. In the absence of confirmatory data generated by an independent method, the report by Xing et al. (1) should be considered speculative. Reports suggesting substantial expansion in the geographic range of a pathogenic organism should be based on rigorously validated laboratory methods.
Assessment of Post-Traumatic Stress Disorder in Older Adults: A Critical Review

Abstract Three trauma-related areas (combat, natural and man-made disasters, and the Holocaust) are reviewed to ascertain the extent to which assessment of Post-Traumatic Stress Disorder has been carried out with an older adult population. Investigations that include subjects who are at least 50 years of age were considered for selection in each area. Although no single assessment strategy emerged as a reliable evaluative tool, many studies in the three areas found that older adults meet diagnostic criteria for PTSD-delayed onset as long as 45 years after experiencing such trauma. Lack of consistency in the findings is discussed in terms of methodological problems, differing theoretical perspectives, and revisions in the criteria for diagnosis from DSM-III to DSM-III-R. Recommendations for future research are made with proposed DSM-IV changes in criteria and subtype considered.