cssi/SciSciGPT-SciSciNet huggingface dataset:
Material characterization of high-toughness steel

Abstract Designers have long recognized the inherent structural efficiency and economy associated with non-redundant bridge systems. Presently, steel bridge structures with non-redundant tension members, labeled as fracture critical members (FCMs), are subjected to more stringent design, material, fabrication, and inspection requirements. FCM requirements are contained in the AASHTO/AWS Fracture Control Plan (FCP) and Code of Federal Regulations (CFRs). The consequence of the requirements, in particular as related to the associated in-service inspection costs, is a higher life-cycle cost when compared to redundant steel bridge structures. However, significant advances have been made over the past 40 years since the original AASHTO/AWS FCP was introduced. Advances in the understanding of fracture mechanics, material and structural behavior, and fatigue crack initiation and growth as well as advancements in fabrication and inspection technologies have allowed other industries to address fracture in a more integrated manner. One-step toward an integrated FCP is to take advantage of the superior fracture toughness of modern steels. While increased fracture toughness is a performance benefit often highlighted for modern steels, there is a lack of fundamental test data and material characterization studies. A large test program was conducted focused on the use of high-toughness steels routinely used in bridge fabrication to establish rational inspection intervals for members traditionally classified as fracture critical. The project was comprised of small-scale material testing, full-scale fracture testing of steel bridge axial and bending members, three-dimensional finite element modeling, and an analytical parametric study. Material characterization results, which included tensile testing, chemistry, Charpy v-notch (CVN) impact testing, percent shear measurement, reference temperature determination, and ductile tearing initiation testing, are presented. Test results showed some of the steels tested demonstrated larger than expected CVN scatter in the transition region. Most importantly, the research revealed for the steels tested the master curve created using Charpy-sized SE(B) specimens resulted in an overestimate of fracture toughness compared to 1 T SE(B) specimens.
Oxidation of ketene‐S,S‐acetals, thioacetals, and thioketals by dimethyldioxirane: A convenient method for the preparation of bis‐sulfones

The oxidation of a series of ketene-S,S-acetals, 2a–f, and a series of thioacetals and thioketals, 4a–g, with a fourfold or greater excess of dimethyldioxirane, 1, produced the corresponding bis-sulfones 3a–f and 5a–g in excellent yields. The reaction of the bis-sulfides with one, two, and three equivalents of 1 yielded monosulfoxides, bis-sulfoxides, and sulfoxide-sulfones, respectively, as the major products. The order of addition of the reactants as well as the temperature of the reaction mixture changed the product distributions. The use of low-temperature, rapid stirring and the addition of the dioxirane solution to the bis-sulfide maximized the yield of the major product. The results are consistent with an electrophilic oxygen-atom transfer mechanism in which the rate of sulfide oxidation is much faster than oxidation of sulfoxide to sulfone. However, sulfoxide oxidation is of a sufficient rate such that local concentration effects affect the results.
Gender and Division of Labor Associated with Dying, Burial, and Mourning in Early America

During the colonial period, and the years of the new republic, death most frequently occurred in the home. Members of communities engaged in a system of mutual aid by helping families at a time of loss. Women cared for the sick and dying and prepared the body for burial.4 Men built coffins, as an extension of the cabinet making trade. The local sexton dug the grave. On the day of the funeral, men transported the coffin to the burial site. Women participated in the funeral service by providing hospitality to mourners and taking part in the procession. Women and men participated in mourning rituals by donning attire and following mourning etiquette based on religion and social status. These gendered divisions of labor and social expectations represented the specified gender roles within colonial society. Although the rituals associated with death and dying particularly in functions outside the home were dominated by men, women still carved out their own place in these rituals based on gender roles of the time.
Health Status among African Americans: Do Social Capital and Financial Satisfaction Make a Difference?

The purpose of the current study was to investigate whether various types of social capital influence self-rated health among African Americans, while accounting for objective and subjective econom...
CHAPTER 5 – SOLVING EQUATIONS

Publisher Summary This chapter discusses three methods for solving equations: (1) the bisection method, (2) the secant method, and (3) Newton's methods. To speed up the rate of convergence of the estimation of roots, there are several methods available. The first of these is the secant method. In this method, the function is computed at two points. A linear approximation, the secant line, is then passed through these two points. The place where this straight line passes through the x-axis is then used for the next estimate of the root of the original function. The chapter also presents a program that combines the options of graphing of a function together with the estimation of the roots of the equation. In designing such a program, it is important to use subroutines as this provides the original programmer and user with the maximum degree of flexibility.
Research Committee Update

Abstract Building on past workshops focused on distributed acoustic sensing (DAS), the SEG Research Committee plans to organize a DAS-focused postconvention workshop in 2020 titled “DAS: Advances i...
Is My Home Smart or Just Connected

The smart home market will approach 40 billion USD (United States dollars) by 2020 and household penetration to reach 47.40% in 2023. Experts say that we will move from turning lights on and off by giving a voice assistant commands to a smart home that collects, analyzes and acts upon information, turning our smart devices into intelligent homes. As homes become more intelligent with the use of artificial intelligence (AI), will the inhabitants understand what that might mean and what makes a device or home smart? Between February and June of 2019, we conducted semi-structured interviews of 40 smart home consumers to understand their perceptions of smart homes. During the interview we asked them what the Internet of Things (IoT) meant, what makes a smart device, what makes a smart home. Overall, participants were unfamiliar with the term IoT. We coded the responses with major codes. Reasons that participants said made devices smart: they were connected to the internet, were programmable, and had some type of learning component (e.g., natural language processing, machine learning, learn over time). Participants said the following made homes smart: have smart devices, connected, made life easier, were programmable and they could control devices in the home. Only a few participants included learning into their descriptions of smart homes. As smart devices and smart homes mature into an intelligent home driven by artificial intelligence, it is critical for consumers to understand the implications of use.
IoT for predictive assets monitoring and maintenance: An implementation strategy for the UK rail industry

Abstract With about 100% increase in rail service usage over the last 20 years, it is pertinent that rail infrastructure continues to function at an optimal level to avoid service disruptions, cancellations or delays due to unforeseen asset breakdown. In an endeavour to propose a strategy for the implementation of Internet of Things (IoT) in rail asset maintenance, a qualitative methodology was adopted through a series of focus-group workshops to identify the priority areas and enabling digital technologies for IoT implementation. The methods of data collection included audio recording, note-taking, and concept mapping. The audio records were transcribed and used for thematic analysis, while the concept maps were integrated for conceptual modelling and analysis. This paper presents an implementation strategy for IoT for rail assets maintenance with focus on priority areas such as real-time condition monitoring using IoT sensors, predictive maintenance, remote inspection, and integrated asset data management platform.
Strength, plasticity, thermal stability and strain rate sensitivity of nanograined nickel with amorphous ceramic grain boundaries

Abstract A large fraction of grain boundaries imparts high strength to nanocrystalline (NC) metals but causes the poor thermal stability of microstructures and a significant reduction of strength with increasing deformation temperature. Stabilizing the microstructure is thus desired. In this work, we self-patterned 1–2 nm thick amorphous ceramic SiOC as grain boundaries in NC Ni with grain size of 13 nm through co-sputtering 75 at.%-Ni and 25 at.%-SiOC, producing Ni-SiOC amorphous ceramic reinforced metals (Ni-SiOC ACRMs) with a core-shell structure. Microscopic characterizations of Ni-SiOC ACRMs before and after 400 °C annealing and after compression deformation confirmed the thermally and mechanically stable core-shell structure. Mechanical properties, such as stress-strain responses and strain rate sensitivity of Ni-SiOC ACRMs over a range of temperatures from room temperature (RT) to 400 °C were measured using in situ micropillar testing in a scanning electron microscope (SEM). We demonstrated that amorphous ceramic SiOC grain boundaries impart a high strength (2.5 GPa at RT and 1.6 GPa at 400 °C), large compressive plasticity (uniform compression strain greater than 35% without shear instability) and thermal stability to Ni-SiOC ACRMs. High strain rate sensitivity (0.015 at RT to 0.042 at 400 °C), small activation volume (about 13b3) and no obvious strain hardening/softening behavior suggest that plastic deformation is accommodated by dislocation slips in Ni grains. Amorphous ceramic grain boundaries act as strong barriers and sinks for impeding and trapping dislocations, strengthening the ACRMs and promoting plastic co-deformation between Ni nanograins and amorphous ceramic grain boundaries; the accumulated dislocations are smeared along the amorphous-crystal interfaces, preventing formation of localized shear bands across multiple nanograins.
Enhancing wound healing dressing development through interdisciplinary collaboration

The process of wound healing includes four phases: Hemostasis, inflammation, proliferation, and remodeling. Many wound dressings and technologies have been developed to enhance the body's ability to close wounds and restore the function of damaged tissues. Several advancements in wound healing technology have resulted from innovative experiments by individual scientists or physicians working independently. The interplay between the medical and scientific research fields is vital to translating new discoveries in the lab to treatments at the bedside. Tracing the history of wound dressing development reveals that there is an opportunity for deeper collaboration between multiple disciplines to accelerate the advancement of novel wound healing technologies. In this review, we explore the different types of wound dressings and biomaterials used to treat wounds, and we investigate the role of multidisciplinary collaboration in the development of various wound management technologies to illustrate the benefit of direct collaboration between physicians and scientists.
Preoperative vaginal estrogen and midurethral sling exposure: a retrospective cohort study.

We evaluated whether the use of estrogen vaginally prior to synthetic midurethral sling insertion mediates the risk of mesh exposure. A secondary aim was to evaluate other factors that may be associated with mesh exposure. We performed a retrospective cohort study of patients undergoing midurethral sling insertion from January to December 2010 within the Southern California Permanente Medical Group. Women who used estrogen vaginally prior to surgery were classified as those who filled a prescription between 1 and 45 days before surgery or whose medical records indicated its use at the time of preoperative evaluation. Logistic regression analysis was used to calculate odds ratios (OR) and 95 % confidence intervals (CI) for factors associated with mesh exposure while controlling for confounding variables. A total of 1544 patients met inclusion criteria, of whom 248 (16.1 %) used estrogen vaginally prior to surgery. Mean age was 53.7 years (range 27–89). Thirty-seven (2.4 %) women were diagnosed with mesh exposure, of whom 19 underwent surgical reoperation. In multivariate logistic regression analysis, preoperative use of estrogen vaginally was not associated with the risk of mesh exposure (OR 0.79, CI 0.26–2.38, p = 0.67). Age, body mass index, menopausal status, use of hormone replacement therapy, smoking status, and diabetes were not associated with risk of mesh exposure. Preoperative use of estrogen vaginally did not appear to mediate the risk of mesh exposure following midurethral sling placement in this cohort.
Three Arguments from Temporary Intrinsics

The Argument from Temporary Intrinsics is one of the canonical arguments against endurantism. I show that the two standard ways of presenting the argument have limited force. I then present a new version of the argument, which provides a more promising articulation of the underlying objection to endurantism. However, the premises of this argument conflict with the gauge theories of particle physics, and so this version of the argument is no more successful than its predecessors. I conclude that no version of the Argument from Temporary Intrinsics gives us a compelling reason to favor one theory of persistence over another.
Reconciling multiple IPsec and firewall policies

Manually configuring large firewall policies can be a hard and error-prone task. It is even harder in the case of IPsec policies that can specify IP packets not only to be accepted or discarded, but also to be cryptographically protected in various ways. However, in many cases the configuration task can be simplified by writing a set of smaller, independent policies that are then reconciled consistently. Similarly, there is often the need to reconcile policies from multiple sources into a single one. In this paper, we discuss the issues that arise in combining multiple IPsec and firewall policies and present algorithms for policy reconciliation.
HEMOSTATIC DISORDERS IN CHILDREN WITH CYANOTIC CONGENITAL HEART DISEASE (CCHD)

Bleeding and coagulation disorders in CCHD have been described, the precise mechanisms are not well defined. We utilized newer sensitive methods to study the hemostatic system in 10 cases of CCHD at the time of routine cardiac evaluation. Besides CBC the evaluation included PT,PTT, fibrinogen(Fbgn), fibrinopeptide A (FPA), plasminogen(Plg), α2-antiplasmin(α2-AP), Bβ1542 related peptide(BβRP) a sensitive indicator of fibrinolysis, thromboxane B2(T×B2), antithrombin III(AT-III), α2-macroglobulin(α2-Mac), and factors II,X,XI,XII. Results are shown in the following table: The elevated FPA levels reflect activation of the hemostatic system leading to thrombin generation and Fbgn cleavage. This activation is not detected if routine coagulation tests are used. Fibrinolysis is not activated as reflected by the normal levels of BβRP, Plg, α2-AP. Fbgn, factorsII and X are normal but the contact factors XI,XII are low(54%, 40%). There is marked platelet activation indicated by elevated T×B2. These parameters did not correlate with hematocrit,PT or PTT. Therefore marked activation of the hemostatic system(humoral, platelet) is present in CCHD.
Three patterns in java unit testing

This paper discusses three unit-testing techniques. These are test probe, ipecac, and test hierarchies. Each of these patterns [1] explores a different area of the interaction of white- and black-box testing. The first two techniques, test probe and ipecac, allow internal implementations to be conveniently exposed to test code without compromising production code integrity. The latter provides a pattern for testing class hierarchies in production code, and a way to move from white-box to black-box testing while refactoring.
Critical issues in newborn intensive care: a conference report and policy proposal.

This article presents several cases and certain key clinical-ethical questions associated with the provision of neonatal intensive care. Summaries of five papers on major considerations affecting these issues are included. The authors propose a moral policy stating areas of responsibility and ethical guidelines for decisions about care of newborn infants.
Cell Salvage Transfusion Therapy for Open Reduction and Internal Fixation of Traumatic Pelvic and Acetabulum Fractures: An Analysis of Costs and Outcomes

Objectives: To evaluate the benefits of Cell Salvage (CS) therapy in patients with traumatic pelvis and/or acetabulum fractures. Design: Retrospective cohort study. Data collected from medical records and radiographs. Setting: Level-1 trauma center. Patients/Participants: 157 patients with traumatic pelvis and/or acetabulum fractures treated operatively under the care of one surgeon between 2008 and 2012 were included. Exclusion criteria included nonsurgical patients and those treated with percutaneous fixation. Intervention: All patients underwent open reduction internal fixation of their pelvis and/or acetabulum fractures. The use of cell salvage therapy was randomly selected for trauma patients based on the availability of the system. Main Outcome Measurements: Volume of allogeneic blood transfused (ABT), estimated blood loss (EBL), hemoglobin (Hb) levels preoperatively and postoperatively, and blood-related costs to the patient. Results: CS was used in 89 cases (56.7%) with an average volume of 86 mL. There was a significantly higher ABT in the CS group than the no CS group (625 vs. 376 mL, p 500 mL) in which case there was a significantly higher volume of salvaged blood than patients with low blood loss (162 vs. 27 mL, p 7 days to surgery (135 vs. 64 mL, p < 0.05). The cost difference of $1,375 was seen between the two groups, favoring the No CS group. Conclusions: Our results suggest limited overall benefit to the use of CS in patients treated with ORIF for traumatic pelvis and acetabulum fractures. Journal of Nature and Science, 1(5):e99, 2015
Phonosurgery techniques after partial laryngectomy

Voice quality considerations in patients undergoing partial laryngectomy are secondary to oncological surgery. The need for adequate airway and swallow also precedes voice considerations. However, after the cancer has been cured, dysphonia becomes a major impact on the quality of life. This prompts many patients to seek further treatment for improving voice after partial laryngectomy. The laryngectomy defect is variable and may result in defects of hard or soft tissue. This study will describe four operative techniques to rehabilitate the voice after partial laryngectomy. The techniques used are those from phonosurgery and include buccal mucosal graft implantation and resurfacing, lipoinjection, laryngeal skeleton reconstruction, and thyroplasty with medialization laryngoplasty. Successful phonosurgical rehabilitation should consider the needs of the patient, a complete analysis of the preoperative defect during phonation, and analysis of the defect with computer tomographic scan evaluation of the larynx.
Calcium transport in isolated bone cells. I. Bone cell isolation procedures

Bone cells were isolated by collagenase-hyaluronidase digestion of 19–20 day-old fetal rat calvaria. It is shown that contamination from calcified matrix can give erroneously high values for total cell calcium and can mask intracellular calcium exchange. Filtration of the cell suspension through 35 μ mesh nylon net and a five minute treatment with a cold pH 6.0 isotonic salt solution removed the contamination. Total calcium for cells prepared in this manner was 16.8 mmoles/kg wet weight. 45Ca uptake studies revealed an active component of calcium exchange.
Trapped in Poor Places? An Assessment of the Residential Spatial Patterns of Housing Choice Voucher Holders in 2004 and 2008

ABSTRACT This study examines the residential spatial patterns of Housing Choice Voucher holders in Western New York in 2004 and 2008 (n = 4,600 and n = 4,759, respectively). It seeks to answer two questions: Has the concentration of voucher holders in impoverished and same race neighborhoods diminished overtime; and are voucher holders, particularly African Americans, relocating in patterns that would lead to reghettoization or the reconcentration of race and poverty? This type of residential pattern puts voucher holders at risk for resettling in neighborhoods that limit economic and social mobility. Data from the public housing agency contracted to distribute Housing Choice Vouchers were examined. Exploratory spatial analysis techniques were used to identify spatial outliers and to form a hypothesis on spatial patterns of relocation. Spatial clustering analyses were conducted to test the hypothesis on the reghettoization of African American voucher holders in recently relocated neighborhoods. Analyses in...
A statistical model for the optimization of dsc performance in the evaluation of drugs for preformulation studies

Differential scanning calorimetry (DSC) is a thermal analytical tool for preformulation studies. Extrapolated melting temperature (TP) and heat of fusion (ΔHf) can be used as parameters for optimizing the DSC performance. Two model pharmaceuticals acetaminophen and nicotinamide are used in this study. Using a factorial design for the experimental model and matrix analysis the results, the effect of sample mass, heating rate and the nitrogen flow rate were evaluated on the ΔHf values and TP values. Two levels for each of the procedural variables were used as a balanced experimental design with two sample sizes, two heating rates and two nitrogen flow rates. It was found that the change in the heating rate caused significant changes in the ΔHf values but not the Tp values for acetaminophen. However, no significant effect was found for the Tp value but ΔHf value was affected to a certain extent for nicotinamide.
A Structural Multi-Mechanism Damage Model for Cerebral Arterial Tissue

Early stage cerebral aneurysms are characterized by the disruption of the internal elastic lamina. The cause of this breakdown is still not understood, but it has been conjectured to be due to fatigue failure and/or by a breakdown in homeostatic mechanisms in the wall arising from some aspect of the local hemodynamics and wall tension. We propose to model this disruption using a structural damage model. It is built on a previously introduced nonlinear, inelastic multi-mechanism model for cerebral arteries (2005, "An Inelastic Multi-Mechanism Constitutive Equation for Cerebral Arterial Tissue, " Biomech. Model. Mechanobiol., 4(4), pp. 235-248), as well as a recent generalization to include the wall anisotropy (2009, "A Structural Multi-Mechanism Constitutive Equation for Cerebral Arterial Tissue, " Int. J. Solids Struct., 46(14-15), pp. 2920-2928). The current model includes subfailure damage of the elastin, represented by changes in the tissue mechanical properties and unloaded reference length. A structural model is used to characterize the gradual degradation, failure of elastin, and recruitment of anisotropic collagen fibers. The collagen fibers are arranged in two helically oriented families with dispersion in their orientation. Available inelastic experimental data for cerebral arteries are used to evaluate the constitutive model. It is then implemented in a commercial finite element analysis package and validated using analytical solutions with representative values,for cerebral arterial tissue.
Neural network tomography: Network replication from output surface geometry

Multilayer perceptron networks whose outputs consist of affine combinations of hidden units using the tanh activation function are universal function approximators and are used for regression, typically by reducing the MSE with backpropagation. We present a neural network weight learning algorithm that directly positions the hidden units within input space by numerically analyzing the curvature of the output surface. Our results show that under some sampling requirements, this method can reliably recover the parameters of a neural network used to generate a data set.
Lossless compression for three-dimensional images

We investigate and compare the performance of several three-dimensional (3D) embedded wavelet algorithms on lossless 3D image compression. The algorithms are Asymmetric Tree Three-Dimensional Set Partitioning In Hierarchical Trees (AT-3DSPIHT), Three-Dimensional Set Partitioned Embedded bloCK (3D-SPECK), Three-Dimensional Context-Based Embedded Zerotrees of Wavelet coefficients (3D-CB-EZW), and JPEG2000 Part II for multi-component images. Two kinds of images are investigated in our study -- 8-bit CT and MR medical images and 16-bit AVIRIS hyperspectral images. First, the performances by using different size of coding units are compared. It shows that increasing the size of coding unit improves the performance somewhat. Second, the performances by using different integer wavelet transforms are compared for AT-3DSPIHT, 3D-SPECK and 3D-CB-EZW. None of the considered filters always performs the best for all data sets and algorithms. At last, we compare the different lossless compression algorithms by applying integer wavelet transform on the entire image volumes. For 8-bit medical image volumes, AT-3DSPIHT performs the best almost all the time, achieving average of 12% decreases in file size compared with JPEG2000 multi-component, the second performer. For 16-bit hyperspectral images, AT-3DSPIHT always performs the best, yielding average 5.8% and 8.9% decreases in file size compared with 3D-SPECK and JPEG2000 multi-component, respectively. Two 2D compression algorithms, JPEG2000 and UNIX zip, are also included for reference, and all 3D algorithms perform much better than 2D algorithms.
Conceptual analysis and design of a partitioned multifunctional smart insulation

Building insulation performance in walls and roofs is typically assessed in terms of its R-value, a metric related to its ability to resist heat flow under steady state conditions. Past and present efforts by numerous researchers have resulted in a continued increase in achievable R-values. However, for most climates, there are times during a typical day and throughout a calendar year where it would be advantageous to enable switching between highly insulated and conductive states. A large energy savings potential exists for such an adaptive insulation by decreasing the load imposed on the heating or cooling system; however, practical realizations of adaptive insulation have not been fully developed. A new multifunctional insulation is presented in this paper where thin polymer membranes are positioned within a wall to create layers of air such that the role of natural convection becomes negligible. The heat passing through the wall must therefore travel through alternating layers of stagnant air and polymer membrane. To achieve the low R-value condition, the air is removed and the layers are compressed, essentially leaving only conduction through the polymer membranes. The focus of this paper is the analysis of such a multilayered wall in both the insulated and conductive states. Design strategies are presented for selecting suitable materials and wall geometry. The conceptual analysis presented here provides the framework for future studies focused on fabrication and experimental design of such a multifunctional smart insulation.
Trout affect the density, activity and feeding of a larval plethodontid salamander

Summary 1. Ecologists have struggled to describe general patterns in the impacts of predators on stream prey, particularly at large, realistic spatial and temporal scales. Among the confounding variables in many systems is the presence of multiple predators whose interactions can be complex and unpredictable. 2. We studied the interactions between brook trout (Salvelinus fontinalis) and larval two-lined salamanders (Eurycea bislineata), two dominant vertebrate predators in New England stream systems, by examining patterns of two-lined salamander abundance in stream reaches above and below waterfalls that are barriers to fish dispersal, by measuring the effects of trout on salamander density and activity using a large-scale manipulation of brook trout presence, and by conducting a small-scale laboratory experiment to study how brook trout and larval two-lined salamanders affect each other's prey consumption. 3. We captured more salamanders above waterfalls, in the absence of trout, than below waterfalls where trout were present. Salamander density and daytime activity decreased following trout addition to streams, and salamander activity shifted from aperiodic to more nocturnal with fish. Analysis of stomach contents from our laboratory experiment revealed that salamanders eat fewer prey with trout, but trout eat more prey in the presence of salamanders. 4. We suggest that as predators in streams, salamanders can influence invertebrate prey communities both directly and through density- and trait-mediated interactions with other predators.
Experiences in service-learning pedagogy: lessons for recruitment and retention of under represented groups

In this poster, we summarize results from the Carnegie Mellon University Information Systems in the Community Summer Institute, which is an intensive service-learning experience in information systems (IS) for students from Historically Black Colleges and Universities (HBCUs).
A reliable synthesis of 3β-acetoxy-6-nitrocholest-5-ene

Abstract A consistently reproducible method for the preparation of the title compound by the nitration of cholesteryl acetate is given.
Capacity factors and solar job creation

We discuss two main job creation statistics often used by solar advocates to support increased solar deployment. Whilst overall solar technologies have a tendency to be labor-intensive, we find that the jobs per gigawatt hour statistic is relatively mis-leading as it has a tendency to reward technologies that have a low capacity factor. Ultimately the lower the capacity factor the more amplified the solar job creation number.
Optimality under noise: higher memory strategies for the alternating prisoner's dilemma.

Abstract The Alternating Prisoner's Dilemma is a variant of the iterated Prisoner's Dilemma in which the players alternate in the roles of actor and recipient. We searched for strategies which are “optimal” in the Alternating Prisoner's Dilemma with noise (a non-zero probability that a player's decision will be transmitted incorrectly). In order to achieve success against a variety of other strategies, a strategy must be “self-cooperating” (able to achieve mutual cooperation with its clone), “C-exploiting” (able to exploit unconditional cooperators), and “D-unexploitable” (able to resist exploitation by defectors). It must also have high evolutionary “dominance”, a general measure of evolutionary performance which considers both resistance to invasion and the ability to invade other strategies. A strategy which meets these optimality criteria can evolve cooperation by invading a population of defectors and establishing a stable cooperative society. Most of the strategies commonly discussed in the Alternating Prisoner's Dilemma literature are low-memory strategies such as Tit For Tat, Pavlov, and Firm But Fair, but none of these strategies can simultaneously meet all of the optimality criteria. However, we discovered a class of higher memory “Firm Pavlov” strategies, which not only meet our stringent optimality criteria, but also achieve remarkable success in round-robin tournaments and evolutionary interactions. These higher memory strategies are friendly enough to cooperate with their clone, pragmatic enough to exploit unconditional cooperators, and wary enough to resist exploitation by defectors: they are truly “optimal under noise” in the Alternating Prisoner's Dilemma.
Nitrogen and phosphorus availability in oak forest stands exposed to contrasting anthropogenic impacts

We compared soil N and P availability in similar oak forest stands located in either an urban or a rural area. To compare N and P availability in the urban and rural soils, we measured: (1) net N-mineralization potential and extractable inorganic P; (2) plant demand for NH4+, NO3− and PO43− using a root nutrient uptake bioassay; and (3) N and P acquisition by red oak (Quercus rubra L.) seedlings grown in the contrasting soils. Although net N-mineralization potential did not differ between the urban and rural soils, we found a 5-fold increase in net nitrification in urban compared to rural soils. Despite an apparent trend toward lower labile inorganic P in the urban versus the rural soils, the treatment means did not differ statistically. Root nutrient uptake bioassays indicated that demand for NH4+ was higher (i.e. availability lower) in the urban than in the rural soils in 1995, but did not differ in 1996. A trend toward greater root demand for NO3− in the rural than the urban soils was observed but the means did not differ significantly. We also found that demand for PO43− was significantly higher in oak roots collected from the urban compared to the rural soils in both 1995 and 1996. Total seedling N content (mg N in tissue) and leaf N concentration were significantly lower in Q. rubra seedlings grown in urban compared to rural soils, with decreased N content associated with lower leaf, stem and tap root nitrogen. Leaf and stem P contents were also significantly lower in urban-grown Q. rubra seedlings compared to rural-grown seedlings. We found no differences in tissue P concentration between urban and rural seedlings. Together our results suggest that soil P and, to a lesser degree, N availability is lower in the urban than the rural stands and that these differences are associated with anthropogenic impacts. We discuss the potential for differences in litter quality, exotic earthworms and N deposition between the urban and rural soils to lower soil N and P availability in the urban forest stands.
Dental sensory receptor structure in human teeth.

Abstract Electron microscopy was used to study normal human extracted teeth in order to define the junctions between sensory nerve endings and other cells in external pulp and inner dentin at the crown tip. Two sets of associated cells were found: (1) Connective tissue cells. The pulpal fibroblast network made occasional desmosome junctions with the odontoblast network, and the cells of each network formed many gap junctions and desmosomes with one another. (2) Nerve endings. The terminal axons formed a succession of appositions with each other or with Schwann cells in the plexus of Raschkow and the cell-free zone, possibly with fibroblasts inthe cell-free zone and odontoblast layer, and with odontoblasts in the odontoblast layer, predentin and dentin. The appositions between nerve endings and their companion cells at all levels usually maintained a regular intercellular spacing of at least 15–20 nm. In predentin and dentin, axons could be easily identified by their distinctive vesicles and mitochondria, and they often occurred within clusters of adjacent dentinal tubules; in the odontoblast layer axon identification was much more difficult. Axo-axonic appositions were found in the plexus of Raschkow, the cell-free zone, predentin and dentin; in many cases, bare axons were separated from each other only by a 5–10 nm extracellular space. Dental sensory mechanisms are discussed in relation to these observations.
Instrumentation developments in scanning soft x‐ray microscopy at the NSLS (invited)

The Scanning Transmission Soft X‐ray Microscope at the NSLS has been instrumented for the following new forms of imaging: (1) XANES microscopy for the mapping of chemical constituents and for absorption spectroscopy of small specimen areas; (2) luminescence microscopy for locating visible light emitting labels at the resolution determined by the size of the x‐ray microprobe; and (3) dichroism microscopy for mapping the alignment of molecules whose absorption spectra are polarization dependent. Since the instrument is used mostly for the imaging of biological and other radiation sensitive materials, a cryostage is being planned to accommodate frozen hydrated specimens.
Spontaneous CdTe --> alloy --> CdS transition of stabilizer-depleted CdTe nanoparticles induced by EDTA.

CdTe nanoparticles stabilized by l-cysteine are chemically transformed into CdS nanoparticles of the same diameter via an intermediate CdTeS alloy without any auxiliary source of sulfur. The reaction is induced by ethylenediaminetetraacetic acid dipotassium salt dehydrate (EDTA), which was demonstrated experimentally to act as a catalyst by partially removing thiol stabilizers from the nanoparticle surface. It is hypothesized that addition of EDTA facilitates Te2- release, and oxidation of Te2- drives the nanoparticle transition process. Unlike many reports on reactions catalyzed by nanocolloids, this is likely to be the first observation of a catalytic reaction in which nanoparticles function as a substrate rather than a catalyst. It opens new pathways for the synthesis of novel nanoscale II−VI and other semiconductors and represents an interesting case of chemical processes in nanocolloids with reactivity increased by depletion of the surface layer of thiol stabilizers. This includes but is not limited ...
Calculation of heavy ion e{sup +}e{sup -} pair production to all orders in Z{alpha}

The heavy ion cross section for continuum e{sup +}e{sup -} pair production has been calculated to all orders in Z{alpha}. The formula resulting from an exact solution of the semiclassical Dirac equation in the ultrarelativistic limit is evaluated numerically. An energy-dependent spatial cutoff of the heavy ion potential is used, leading to an exact formula agreeing with the known perturbative formula in the ultrarelativistic, perturbative limit. Cross sections and sample momentum distributions are evaluated for heavy ion beams at SPS, RHIC, and LHC energies. e{sup +}e{sup -} pair production probabilities are found to be reduced from perturbation theory with increasing charge of the colliding heavy ions and for all energy and momentum regions investigated.
Effect of Flow-Rate and Sample-Size on Column Efficiency in Gas-Liquid Chromatography

THERE have been a number of investigations as to the effect of carrier gas flow-rate on separation and column efficiency in gas-liquid chromatographic systems1–4. Many of the results present contradictory pictures of the effect exerted by this parameter. Keulemans1 states, “for a certain set of operational conditions there is an optimum linear gas velocity, but the optimum is very flat and the gas rate is consequently not a highly critical parameter”. James and Martin2 have shown that column efficiency is sensitive to flow-rate and that a decrease in flow-rate increases column efficiency. Their results show a 27 per cent increase in column efficiency when the flow-rate was decreased from 24 to 10 ml./min. Bethea and Wheelock3 reported that column efficiency, as measured by the H.E.T.P., is approximately tripled by raising the flow-rate from 5 to 27.5 ml./min. They found that increasing the flow-rate beyond the latter point gave only meagre increases in efficiency.
Civic Education: What Schools Can Do to Encourage Civic Identity and Action

The timeliness of civic education for American youth is discussed. Particular attention is given to the history of calls for civic education, the state of civic education in schools today, particularly those serving youth in disadvantaged contexts, and the specific ways in which schools can better address the civic education needs of contemporary youth. Findings from research are synthesized around three strategic moves: 1) Promote public discussion and debate of critical issues; 2) Provide quality extracurricular and student government activities; and 3) Build on particular types of service that have proven to enhance civic participation in and identity with one's community. It is concluded that these activities can provide factual knowledge of history and government and encourage students to partake in active practices of the daily life of being citizens.
Subchronic administration of technical pentachlorophenol to lactating dairy cattle: performance, general health, and pathologic changes.

Abstract Technical grade pentachlorophenol (penta) was fed subchronically to lactating dairy cattle to establish whether exposure approximating farm environments containing substantial penta-treated wood represents a hazard to animal health. Four Holstein cattie in early lactation were fed .2mg penta/kg body weight per day for 75 to 84 days followed by 2mg penta/kg body weight per day for 56 to 60 days. Each treated cow was paired with a control cow of equivalent stage of lactation. Milk production, feed intake, and body weight were not affected by either dose except that treated cattle were more efficient converters of feed to milk during the early stage of the 2mg/kg period. Neither milk fat production nor somatic cell count in milk were affected by exposure to penta. Postmortem examination revealed enlargement of liver, lungs, kidneys, and adrenals and thickening of the urinary bladder wall. Chronic interstitial nephritis and subacute urocystitis were the major pathologic changes in penta-treated cattle. In vitro testing of kidney slices confirmed significant loss of renal function. The relationship of lesions to administration of penta is not clear.
Neostriatal and globus pallidus stimulation induced inhibitory postsynaptic potentials in entopeduncular neurons in rat brain slice preparations

Abstract Recent anatomical studies revealed that the entopeduncular nucleus of the rat receives GABAergic inputs from both the neostriatum and the globus pallidus. The present study was undertaken to reveal the physiological features of these inputs using the intracellular recording method in rat brain slice preparations. Most of the entopeduncular nucleus neurons generated repetitive firing without spike accommodation with intracellular current stimulation and thus were classified as Type-I. A small number of neurons were classified as Type-II since they generated spikes with pronounced accommodation. Most of the Type-I, but none of Type-II, entopeduncular nucleus neurons exhibited monosynaptic GABAergic inhibitory postsynaptic potentials (IPSPs) after stimulation of the neostriatum and the globus pallidus. Neostriatal stimulation induced long latency IPSPs while pallidal stimulation induced long latency IPSPs compounded with short latency IPSPs. The IPSPs were mediated by GABA A receptors. The unitary IPSPs to striatal stimulation were small while those to pallidal stimulation were large in amplitude and able to reset ongoing rhythmic firing. The short latency IPSPs induced by pallidal stimulation reversed at a somatic membrane potential that was a few millivolts more depolarized than the long latency IPSPs, suggesting that the striatal inputs were evoked in more distal portions of the neurons than the pallidal inputs. Repetitive activation of these inputs resulted in a poor amplitude summation but a prolongation of the duration of the IPSPs. The results of the present study indicate that the pallidal projection to the entopeduncular nucleus is physiologically significant and that the neostriatum and the globus pallidus play important roles in controlling the activity of the entopeduncular nucleus, although in different ways.
Water Transport in the Cloaca of Lizards: Active or Passive?

The withdrawal of water from the lizard cloaca can be a passive process resulting from the colloidal osmotic pressure of the plasma proteins. The forces necessary to withdraw water from lizard urine, the forces prevailing within the cloaca in vivo, and the counterbalancing of these forces by a protein solution placed in the cloaca all are in accord with this hypothesis.
Capillary Surfaces: Stability from Families of Equilibria with Application to the Liquid Bridge

A method for determining the stability of general static capillary surfaces is illustrated by application to the liquid bridge. Axisymmetric bridges with fixed contact lines under gravity are parametrized by three quantities: bridge length L, bridge volume V, and Bond number B. The method delivers i) stability envelopes in the {L,V,B,} parameter space for constant pressure and constant volume disturbances (recovering classical and generating new results), ii) the number of unstable modes for any equilibrium (state of instability) once the stability of one equilibrium state is known, based on, iii) a demonstration that all known families of equilibria are ultimately connected. The state of instability of an equilibrium shape relative to its neighbors is immediate from a plot of volume V versus pressure p, a "preferred" bifurcation diagram. The preferred diagram method gives stronger results than classical bifurcation theory based on properties of eigenvalues of the Jacobi equation for problems with a variational formulation. Application to other capillary surfaces including drops and nonaxisymmetric shapes is discussed. In addition, motivated by general tangency considerations, an invariant wavenumber classification is introduced and used to label the numerous families of liquid bridge equilibria.
Effects of fire on the vegetation of a lowland heathland in North-western Italy

This study focuses on the effect of fire on lowland heathlands at the extreme southern edge of their European distribution (Vauda Nature Reserve, NW Italy). Forty-nine plots (50 m radius) were surveyed between 1999 and 2006. Each year, fire occurrences were recorded and per cent cover of four vegetation types (grassland, heath, low shrubland, and tall shrubland) was estimated in each plot. Vascular plant species richness was also recorded in 255, 1 m2 quadrats. After a fire, grassland vegetation expanded, but then declined rapidly as heath and shrubland recovered: 7 years after a fire, tall shrubland encroached on to more than 40% of the plots, and grassland declined from 50% to 20% cover. Between 1999 and 2006, Betula pendula shrubland greatly expanded, while grassland decreased over most of the Reserve, even where fire frequency was high. Tall shrubland had low plant diversity and was dominated by widespread species of lower conservation value. By contrast, early successional vegetation (grassland and low shrubland) had higher richness and more narrowly distributed species, indication that the development of tall shrubland causes significant species loss in the heathland. Italian lowland heathlands are characterized by high rates of shrubland encroachment that threatens both habitat and species diversity. Burning frequencies of once in 3–6 years seem appropriate in this habitat, but burning alone might not suffice without actions to increase herbivore grazing.
Catalytic Transamidation Reactions Compatible with Tertiary Amide Metathesis under Ambient Conditions

The carbon-nitrogen bond of carboxamides is extremely stable under most conditions. The present study reveals that simple zirconium- and hafnium-amido complexes are highly efficient catalysts for equilibrium-controlled transamidation reactions between secondary amines and tertiary amides. In a number of cases, transamidation proceeds rapidly at room temperature. We find that these new catalysts are sufficiently active to promote the metathesis of tertiary amides, which arises from successive transamidation cycles. The catalytic activities we observe are unprecedented and represent a substantial step toward a long-range goal of conducting equilibrium-controlled reactions with carboxamides.