cssi/SciSciGPT-SciSciNet huggingface dataset:
Ion-selective self-referencing probes for measuring specific ion flux.

The metal vibrating probe developed in the 1970s to measure electric current is sensitive down to the micro-Amp range but detects only net current due to flow of multiple ions, and is too large to measure from single cells. Electrophysiological techniques which use glass microelectrodes such as voltage clamping can be used on single cells but are also non-specific. Ion-selective probes are glass microelectrodes containing at their tip a small amount of ionophore permeable to a particular ion. The electrode is therefore sensitive to changes in concentration of this ion. If the probe tip is moved at low frequency between two points in a concentration gradient of this ion then the electrochemical potential of the solution inside the electrode fluctuates in proportion to the size of the ion gradient. This fluctuation is amplified and recorded and is used to calculate the actual ion flux using Fick’s law of diffusion. In this mini-review we describe the technique of ion-selective self-referencing microelectrod...
Environmentally friendly processes

Abstract Environmental concerns have raised public awareness of environmental issues and are driving forces for regulation. The impact of regulation on the cost of production is expected to become important in determining the international competitiveness of the US chemical industry. In response to cost pressures, industry has launched a number of initiatives aimed at improving efficiency and reducing environmental impact. Some of these environmental success stories are receiving increased national attention due to programs such as the Presidential Green Chemistry Challenge Awards Program. In addition to traditional metrics for evaluating process performance, such as productivity, environmental considerations increasingly are important in process development. Chemical processes evolve through life cycle phases, beginning with research, and then moving to process engineering, plant operation, and eventually, decommissioning. The number of technology options available for reducing environmental impact are highest early on in the life cycle and then decrease drastically. In contrast, costs associated with resolving an environmental problem typically increase exponentially as the process matures and the scale of equipment gets larger. There is, therefore, a considerable incentive to address and resolve environmental issues early in the life cycle. Chemical reactions responsible for producing high value-added products are, in most cases, also responsible for generating by-products and pollutants. New chemical and biochemical approaches are providing new reaction concepts. As in the development of traditional chemical and petrochemical processes, reaction engineering, broadly defined as the field that quantifies the engineering aspects of chemically reactive systems, is providing enabling tools that accelerate the development of environmentally friendly processes. Core reaction engineering methods are being utilized for kinetic modeling, reactor selection, scale-up, and design. Meanwhile, the research frontiers are providing new reaction engineering tools, from computational chemistry to probe the nature of catalytic active sites to computational fluid dynamics modeling for designing the internals of reaction-separation systems. The long-term goal is to develop processes having 100% raw materials utilization, or zero waste. The near-term strategy for controlling emissions is to institute pollution prevention programs and install cost-effective end-of-pipe technologies. These technologies typically control generic classes of air pollutant emissions such as carbon monoxide, volatile organic compounds (VOCs), nitrogen oxides (NOx) and sulfur oxides (SOx). Technologies for treating wastewater are also available. Over time, a shift in focus is expected, from mere compliance to a point where environmentalism, like safety, is fully integrated into the corporate culture. The present paper discusses the role of reaction engineering in the development of environmentally-friendly processes. Select examples of processes, from the author’s experience, that benefit from reaction engineering will be presented.
Characteristics of commercial power systems to support a prosperous-global economy

Abstract The World Energy Council (WEC) has challenged all decision makers to enable energy prosperity within two generations. Thus, by ∼2050 the global systems should supply 10 billion people approximately 6.7 kilowatts of thermal power per person or 61,360 kWt-h/y-person of energy. The economic equivalent is ∼2 – 3 kWe of electric power per person. The energy must be environmentally clean. The energy must be sufficiently low in cost that the 2 billion poorest people, who now make ≤1,000 $/y-person, can be provided with the new power. Characteristics of 20 terrestrial, 3 space-based, and 3 lunar-based options for commercial global power systems are discussed. It is argued that the Lunar Solar Power System is the only practical option for supplying ∼70 TWt ( T = 1·10 12 ) by 2050 and maintaining that level of power indefinitely.
Kinetics and Mechanism for the Reaction of Cysteine with Hydrogen Peroxide in Amorphous Polyvinylpyrrolidone Lyophiles

Purpose Peroxide impurities play a critical role in drug oxidation. In metal-free aqueous solutions, hydrogen peroxide (H2O2) induced thiol oxidation involves a bimolecular nucleophilic reaction to form a reactive sulfenic acid intermediate (RSOH), which reacts with a second thiol to form a disulfide (RSSR). This study examines the reaction of cysteine (CSH) and H2O2 in amorphous polyvinylpyrrolidone (PVP) lyophiles to explore the possible relevance of the solution mechanism to reactivity in an amorphous glass.
Mars: Evidence for dynamic processes from mariners 6 and 7

Detailed study of the evolution of the Martian surface on the basis of an analysis of Mariner 6 and 7 photographs of certain features of the equatorial region of Mars. It is concluded that the planet Mars is characterized by an internal dynamic activity on the scale of the interior of the African plate. Cited as evidence are scarps resembling fault scarps in Meridiani Sinus and on the Hellas-Hellespontus border. Ridges associated with craters on the boundary of Hellas and Hellespontus are most easily explained by volcanic activity, and at least some of the associated craters may themselves be of volcanic origin. Ridges on the Hellas-Hellespontus border and part of the wall of Edom seem to bulge out into cratered swellings or domes. A sequence of events is worked out for different parts of Mars, and an attempt is made to develop a crude threefold geologic time scale. The sequence suggests that dynamic activity was confined neither to the earliest nor the latest periods of Martian history.
Implementation of an adaptive refinement technique for the SUPG algorithm

Abstract An adaptive refinement algorithm is developed and implemented for the SUPG method applied to a linear time-dependent advection problem in two space dimensions. Accuracy comparisons and timing results are presented which compare the adaptive solution and the solution obtained using a uniform mesh. The comparisons are made for the well-known rotating cone benchmark problem.
Effects of peer majority on drinking rate

Abstract Two male and 2 female subjects drank beer with 12 confederate models, 6 male and 6 female, in a simulated tavern. Three confederates, either 2 male and 1 female or 2 female and 1 male were assigned to each subject and drank concurrently with that subject. A single subject repeated measures reversal design was used. Condition 1 indicated subject baseline drinking rate. Interventions indicated confederates drinking rate. Each confederate served as a high consumption and a low consumption model. Additionally, each confederate served as a single confederate as well as onehalf of a pair of confederates. Interventions were seperated by returns to baseline. Subjects consistently matched the drinking rate of the pair ofconfederates regardless of whether these confederates modeled a high or low consumption rate and regardless of whether the subjects or confederates were male or female. Implications and suggestions for further research on modelling were presented.
Plebes, dogs, and robots: simulation analysis of the United States military academy reception day

Each June approximately 1200 new cadets (NCs) are welcomed to the United States Military Academy (USMA) during Reception Day (R-Day). Amid the mass shuffling of bodies and the yelling of the upper-class cadet cadre, all 1200 NCs must completely in process. Changes are made to the in processing system in attempt to make it more efficient. However, the effect of these changes can only be gauged once a year during the following R-Day. In an attempt to expedite the refinement process, the R-Day administrators approached our design team to create a simulation model that could be used to analyze the effect of proposed changes to the system prior to R-Day 2002. Using ProModel® simulation software, our team created a simulation of the in processing system and conducted a statistical analysis of the results in order to recommend improvements to the structure of the system.
Distribution of Helium-3 in the Carbo Meteorite

To make it possible to measure the distribution of helium-3 in the Carbo meteorite, found in Mexico in 1923, Prof. C. Frondel kindly gave permission for the thousand-pound specimen, which is the property of the Harvard Museum, to be cut. The sawing was done at the Watertown Arsenal, Watertown, Mass. A slice, 0.5 in. thick, having an area of about 300 in.2, was cut from the centre of the meteorite. Fig. 1 shows a drawing of the slice and of the cross-section of three pieces that had previously been cut from the bottom and now reside in museums. The slice was sectioned into bars, 0.25 in. wide. The helium-3 content was measured in 1-gm. samples taken from the bars at points indicated by the crosses. The bars are shown by fine lines. The bars adjacent to those we sampled were sent to other experimenters.
Velocity analysis of parallel manipulators by truss transformations

Abstract A method of velocity analysis of general parallel manipulators is presented. The method consists of transforming the parallel manipulator to an equivalent variable-geometry truss (VGT), and then generating the set of linear velocity equations that govern the transformed manipulator. VGTs are a special class of parallel manipulators. Their actuation is provided by extensible links terminating in spheric joints. A method for velocity analysis of VGT manipulators will be briefly reviewed. This method employs a connectivity chart to generate a system of linear algebraic equations for the manipulator velocity. In addition to the spheric joints and two-force member links that make up truss actuators, general parallel manipulators commonly contain revolute, prismatic, and cylindric joints and multi-force links, links that are more than two-force members. Further, a number of actuation schemes are possible. This work shows how such general parallel manipulators can be conceptually transformed into equivalent VGTs and thereby allow a straightforward velocity analysis approach. While this approach is applicable to general parallel manipulators, the method is most effective when applied to parallel manipulators with truss-like structures.
Working the Scam: Policing Urban Street Youth in a New World Context

This study examines the environment and worldview of Sgt. T, a veteran officer in charge of a specialized police unit. Sgt. T, along with his staff of officers and social workers, monitors a major transportation hub in a large urban setting for runaway and homeless youth as well as other minors unaccompanied by adults. The author uses skullduggery, first introduced by Sgt. T to mean “nothing is as it appears,” as an interpretative lens and explores both its dangers and its usefulness. This includes the role skullduggery plays in field access and how it is used in managing interpersonal transactions, maintaining authority, and as an organizing worldview. New priorities and new skullduggeries suggest the inevitable extinction of this youth unit, yet broader lessons are at stake. Empirical material, collected in the field, was primarily conversational and narrative.
Understanding disparities in lipid management among patients with type 2 diabetes: gender differences in medication nonadherence after treatment intensification.

Abstract Background Gender differences in dyslipidemia are widely documented, but the contributors to these differences are not well understood. This study examines whether differences in quality of care, intensity of lipid-lowering medication regimen, and medication adherence can explain this disparity. Methods Secondary analysis of medical records data and questionnaires collected from adult patients with type 2 diabetes (n = 1,369) from seven outpatient clinics affiliated with an academic medical center as part of the Reducing Racial Disparities in Diabetes: Coached Care (R2D2C2) study. Primary outcome was low-density lipoprotein (LDL) cholesterol. Findings Women had higher LDL cholesterol levels than men (mean [SD], 101.2 [35.2] vs. 92.3 [33.0] mg/dL; p p = .040) and related to side effects (47.2% vs. 36.8%; p = .024). For all patients, regimen intensity ( p p p p = .45; test for interaction p = .048). Conclusions Despite comparable quality of diabetes care and regimen intensity for lipid management, women with diabetes experienced poorer lipid control than men. Medication nonadherence seemed to be a major contributor to dyslipidemia, particularly for women because of side effects associated with intensifying the lipid-lowering regimen.
What does biologically meaningful mean? A perspective on gene regulatory network validation

Gene regulatory networks (GRNs) are rapidly being delineated, but their quality and biological meaning are often questioned. Here, I argue that biological meaning is challenging to define and discuss reasons why GRN validation should be interpreted cautiously.
Deletion of 3′-Untranslated Region Alters the Level of mRNA Expression of a Neurofilament Light Subunit Transgene

High levels of neurofilament (NF) mRNA expression are attained during early postnatal development and are a major determinant of axonal size. High level NF expression is also dependent upon axonal continuity since NF mRNA levels are down-regulated after nerve transection. This study shows that both postnatal up-regulation and axotomy-induced down-regulation are altered by deletion of 3'-UTR from the mouse light NF subunit (NF-L). Transgenes with (NF-L+) or without (NF-L-) 3'-UTR display similar patterns of neuron-specific expression but differ in their respective levels of expression. Whereas changes in the level of NF-L+ mRNA parallel those of the endogenous mouse NF-L mRNA, changes in the level of NF-L- mRNA differ from the pattern of endogenous NF-L expression during postnatal up-regulation and axotomy-induced down-regulation. Specifically, the NF-L- transgene undergoes a 3-fold aberrant up-regulation between embryonic days 15 (E15) and 18 (E18) and has lost its susceptibility to axotomy-induced down-regulation. Studies of transfected P19 cells show that 3'-UTR deletion leads to a severalfold stabilization of NF-L mRNA and an increase in steady-state mRNA level. The findings support the working hypothesis that the 3'-UTR contains determinants that alter stability and that stabilization of NF-L mRNA regulates the levels of NF-L mRNA in neuronal tissues and cells.
Historical geography II Digital imaginations

In my second report discussing the state of historical geography, I review some of the ways historical geographers have made use of digital technologies and digital media. I also highlight how digital data, research, and presentation are affecting related humanities disciplines and inspiring their practitioners to engage more fully with geographic concepts of space, place, and cartography. I argue that information technologies and digital media can deepen the place of historical geography in the academy and in the public’s eye.
The nexus between finance and manufactured exports in selected Caribbean and Central American countries

This study uncovers several surprising and unexpected policy insights that can help small Caribbean and Central American countries develop a strategy to diversify their export base. The results from causality tests of the nexus between financial development and manufactured exports, show that in 63% of a sample of eight countries, financial development causes manufactured exports and vice versa for the remaining 37%. These results are then used to explore in greater depth potential economy specific structural factors that explain the causality test findings in these countries.
Gender differences in best friendships

Prior investigations of friendship patterns have reported gender differences, with women's same-gender friendships tending to be richer and having a possible therapeutic value, as compared to those of men. Compared to same-gender best friendships, opposite-gender best friendships have been described as less fulfilling for women and more fulfilling for men. The present study explored such differences more fully in a sample of 65 female and 58 male predominantly white college students. Subjects completed four modified versions of P. H. Wright's [(1985) “The Acquaintance Description Form,” In S. F. Duck and D. Pearlman (Eds.), Understanding Personal Relationships: An Interdisciplinarian Approach, London: Sage] Acquaintance Description Form, describing their actual and ideal same-gender best friendships and their actual and ideal opposite-gender best friendships. They also responded to several measures of dysphoria. In the present study, the lowest scores for the friendship scales were reported by male subjects describing same-gender friendships, both ideal and actual. For both male and female subjects, dysphoria was positively correlated with a discrepancy between ideal and actual friendships with same-gender or opposite-gender individuals.
Gluino and squark production in association with gauginos at hadron supercolliders.

We calculate production cross sections for gluinos and squarks produced in association with charginos and neutralinos at {ital pp} supercollider energies. We show that, with rather stiff cuts, a signal for {ital {tilde g}{tilde Z}}{sub 1} and {ital {tilde q}{tilde Z}}{sub 1} may be isolated from the standard-model background as well as from other supersymmetric processes; this channel may offer the best hope of a gluino mass measurement. We also estimate potential signal rates from hemispherically separated multilepton-plus-jet events that result if the chargino or neutralino decays via the purely leptonic mode.
Differential Effects of Mental Health Problems Among Truant Youths

Research indicates at-risk youth are more likely to experience emotional and psychological problems. Young people who are often truant from school represent a group of at-risk youth, but one for which mental health issues are understudied. This study examined heterogeneity of mental health problems among a sample of 300 truant adolescents using latent class analysis (LCA). LCA indicated the sample of truants was best represented by four latent subgroups of youth with low mental health problems; high depression, low mania; high mania, low depression; and high depression and mania. These subgroups were examined in relation to sociodemographic and psychosocial measures at baseline and after truancy offenses. Results indicated general and unique differences in these covariates across the four latent classes. Service and practice implications of better understanding mental health issues of truant youth are discussed.
20: Delayed Immune Recovery after Umbilical Cord Blood Transplantation (UCBT) Is Characterized By Thymic Regeneration Failure

DELAYED IMMUNE RECOVERY AFTER UMBILICAL CORD BLOOD TRANSPLANTATION (UCBT) IS CHARACTERIZED BY THYMIC REGENERATION FAILURE Krishna V. Komanduri, Lisa S. St. John, Susan Bryan, Sean Martin, John D. McMannis, Jeffrey J. Molldrem, Richard E. Champlin, Laurence J. Cooper, Laura Worth, Demetrios Petropoulos, Chitra Hosing, Daniel M. Couriel, Marcos de Lima, Elizabeth J. Shpall Dept. of Blood and Marrow Transplantation, Univ. of Texas M.D. Anderson Cancer Center, Houston, TX
The lac permease of Escherichia coli: site-directed mutagenesis studies on the mechanism of β-galactoside/H+ symport

Abstract In this communication, we summarize site-directed mutagenesis studies of the lac permease from Escherichia coli , a prototypic H + -coupled active transport protein. We classify mutant permeases by phenotype, and suggest possible roles for some individual residues in the mechanism of H + /lactose symport. Although high-resolution structural information is not presently available, kinetic analysis of the partial reactions catalysed by the mutant permeases, as well as biophysical studies, suggest an evolving model for the mechanism of H + /lactose symport.
Preliminary observations on the acute inflammatory reaction in the Pacific oyster, Crassostrea gigas (Thunberg)

Abstract The present study was initiated to study the acute inflammatory process in the oyster, Crassostrea gigas (Thunberg), elicited by injection of turpentine into the tissues. Gross examination revealed a small greenish-yellow area of pus present in all oysters 40 hours after the injection. Histologically, the various pathological changes observable after the injection of turpentine were edema, a general leucocytic infiltration of the tissues, and congestion of the small blood channels after 8 hours. By 16 hours there was a marked vascular dilatation with pavementing of the larger vessel walls by leucocytes and a cellular exudation and migration of leucocytes toward the source of irritation at 24 hours. A thick wall of leucocytes around the wound was characteristic after 48 hours. The appearance of multinucleate giant cells began at 64 hours, as did the mass migration of leucocytes across the epithelial borders of the digestive system. By 72 hours, the digestive tubule secretory epithelium was reduced to a low cuboidal epithelium. At this time pus was becoming a prominent feature in the injured area. Necrotic changes in the gonadal area associated with edema, heavy leucocytic infiltration, distention of the gonadal ducts, and walls of leucocytes forming around the necrotic gonadal areas were observed 72 hours after injection. A distinct abscess was first observed after 88 hours and abscesses were found in almost all oysters from 88 hours through 216 hours. The consistent characteristics of the abscesses were a central area of liquefaction necrosis, surrounded by an area of necrotic leucocytes, with an area of viable appearing leucocytes around the periphery of the lesion. The abscesses were usually in the digestive tubule area and in most instances appeared well confined, even though they lacked any observable signs of fibrous encapsulation. Some oysters exhibited an ulceration of the stomach or intestinal lining. This phenomenon was not observed before 88 hours after injection, the same time at which abscesses were first noticeable.
Determining the Diameter of Functionalized Single-Walled Carbon Nanotubes with 13C NMR: A Theoretical Study

NMR chemical shifts of N-R-functionalized (n, 0) single-walled carbon nanotubes (SWNTs) with n = 11, 13-17 were computed from first principles. The chemical shifts of functionalized carbons at a bond diagonal to the SWNT axis are strongly dependent upon the C-C distance in the C-NR-C moiety. This distance, in turn, is sensitive to the SWNT radius. Monitoring these shifts could therefore help to determine the diameter distribution within a sample. Proton shifts are also reported.
A carbon-14 tracer study of the dehydrocyclization of n-heptane

Abstract n -Heptane containing n -heptane-4-C 14 was dehydrocyclized over unsupported chromia and two different chromia-alumina catalysts in an effort to learn more about the intermediate(s) formed on the catalyst surface during cyclization. The relative radioactivity in the methyl position and ring positions 1, 2, and 3 was determined. These results are compared to the results expected from mechanisms proposed by previous workers. The results of this study can be interpreted to support the Twigg mechanism if some isomerization reaction is allowed. A possible reaction path is proposed which can explain the C 14 distribution obtained experimentally for cyclization of n -heptane-1-C 14 and n -heptane-4-C 14 .
A COMPREHENSIVE REVIEW OF ENDANGERED SPECIES ACT RECOVERY PLANS

Endangered Species Act recovery plans have come under increased scrutiny in both political and academic arenas as species are continually added to the endangered species list but few are removed. To promote more effective recovery planning, the Society for Conservation Biology, in partnership with the U.S. Fish and Wildlife Service and the National Center for Ecological Analysis and Synthesis, sponsored a collaborative project among 19 universities to systematically review a large representative sample of recovery plans. The primary goals of the project were to gather data about the content and characteristics of each sampled recovery plan; to analyze these data to identify important differences, patterns, and trends among the population of plans; and to use these results to inform recommendations for how the recovery planning process could be improved. We developed and used a detailed data collection Instrument to consider and characterize specific attributes of each sampled recovery plan. Topics covered...
Valence Issues in African Elections Navigating Uncertainty and the Weight of the Past

Previous analyses of African politics have mistaken parties’ dearth of position taking on issues as an absence of substantive electoral debate. The authors demonstrate that political parties tackle...
SKF 38393 enhances odor detection performance

The purpose of this study was to determine the influence of the D1-selective partial agonist SKF 38393 on the odor detection performance of rats using high precision olfactometry and a go/no-go operant task. Previous studies have found that the D2 receptor partial agonist quinpirole decreases such performance, but the influences of D1 receptor activation are unknown. In experiment 1, such detection performance to the odorant ethyl acetate was enhanced by SKF 38393, relative to saline, in male rats at 7.5 and 10.0 mg/kg IP dose levels, but not at the lower doses of 1.0, 2.5, and 5.0 mg/kg. In experiment 2, this enhancement was replicated at the 7.5 and 10.0 mg/kg doses and was shown to occur at the 12.5 mg/kg dose as well. In experiment 3, similar enhancement was shown for the odorant eugenol in female rats at the 7.5, 10.0 and 12.5 mg/kg doses, suggesting this effect is neither sex-specific nor confined to the odorant ethyl acetate. In experiment 4, a 0.025 mg/kg dose of the D1 receptor antagonist SCH 23390 depressed the enhancement produced to ethyl acetate by 7.5 mg/kg SKF 38393 to control levels. Overall, these data demonstrate that, in contrast to quinpirole, SKF 38393 improves odor detection performance in the rat and that this phenomenon can be attenuated by the D1 receptor blocker SCH 23390.
Electrical engineering as it will be

To solve the greater problems to be faced by the electrical engineer of the future, he must learn to work with a team of technicians, some of whom will undoubtedly be women. Engineers will also be the intellectual community leaders who will be called upon to turn out more ideas.
Numerical simulations of radiatively driven dusty winds

[abridged] Radiation pressure on dust grains may be an important mechanism in driving winds in a wide variety of astrophysical systems. However, the efficiency of the coupling between the radiation field and the dusty gas is poorly understood in environments characterized by high optical depths. We present a series of idealized numerical experiments, performed with the radiation-hydrodynamic code ORION, in which we study the dynamics of such winds and quantify their properties. We find that, after wind acceleration begins, radiation Rayleigh-Taylor instability forces the gas into a configuration that reduces the rate of momentum transfer from the radiation field to the gas by a factor ~ 10 - 100 compared to an estimate based on the optical depth at the base of the atmosphere; instead, the rate of momentum transfer from a driving radiation field of luminosity L to the gas is roughly L/c multiplied by one plus half the optical depth evaluated using the photospheric temperature, which is far smaller than the optical depth one would obtain using the interior temperature. When we apply our results to conditions appropriate to ULIRGs and star clusters, we find that the asymptotic wind momentum flux from such objects should not significantly exceed that carried by the direct radiation field, L/c. This result constrains the expected mass loss rates from systems that exceed the Eddington limit to be of order the so-called "single-scattering" limit, and not significantly higher. We present an approximate fitting formula for the rate of momentum transfer from radiation to dusty gas through which it passes, which is suitable for implementation in sub-grid models of galaxy formation. Finally, we provide a first map of the column density distribution of gas in a radiatively-driven wind as a function of velocity, and velocity dispersion.
Efficient Resource Allocation on the Basis of Priorities

Many institutions allocate resources by non-market mechanisms based on priorities. In this paper, we introduce a model of resource allocation on the basis of priorities and address the following questions: Is it possible to allocate resources on the basis of any priority structure? If yes, when can we do this Pareto efficiently, without creating incentives for manipulation and consistently across different groups of agents and resource levels? We adopt a basic indivisible-objects model with a finite number of object types and a finite quota of goods of each type. Some interesting examples are the determination of access to education, allocation of graduate houses, offices or tasks. Agents are assumed to have strict preferences over object types and remaining unassigned. An assignment is an allocation of the objects to the agents such that every agent receives at most one object. A rule associates an assignment to each preference profile. We formalize a priority structure to be a collection of strict priority rankings of individuals indexed by the object types where i a j would be read as “i has higher priority for object a than j”. We assume that the priority structure is exogenously fixed and allow the preferences of the agents to vary. A rule is said to violate a priority of i for a if there is a preference profile under which i envies j who is assigned a and ∗Publication Information: Econometrica, 70(6), November 2002, 2489-2497. The copyright to this article is held by the Econometric Society, http://www.econometricsociety.org. It may be downloaded, printed and reproduced only for personal or classroom use. Absolutely no downloading or copying may be done for, or on behalf of, any for-profit commercial firm or other commercial purpose without the explicit permission of the Econometric Society. For this purpose, contact Julie P. Gordon, Executive Director of the Society, at: jpg@northwestern.edu. †I would like to thank Faruk Gul, Wolfgang Pesendorfer, the co-editor, the four anonymous referees, and the participants of the micro theory lunch seminar in Princeton University for their comments and suggestions.
Multiple decision-making criteria in the transport and burial of hazardous and radioactive wastes

We evaluate the application of various statistical measures for the identification of optimal financial strategies in environmental projects that may be burdened by the consequences of low-probability, high-cost events. Our particular application lies in the area of transport and burial of hazardous and radioactive wastes but our approach applies to a wide range of problems where the utility structure is of the form of gains minus losses, and where limited and/or catastrophic failures may be encountered. We utilize four statistical measures, the expected value, variance, volatility and cumulative probability to compare the outcomes of limited and catastrophic spills. The maximum expected monetary value which is frequently used in the environmental and gas and oil industries as the sole criterion for the selection of optimum actions is seen to lead to erroneous decisions and fails to unambiguously differentiate the economic consequences of limited and catastrophic failures in a project. We demonstrate that unwarranted inclusion of catastrophic scenarios into the decision-making analysis can substantially alter the perspective of a project and guide a corporation away from an investment that could be profitable even under a limited liability case. We conclude by providing a decision-making procedure for cases where the probabilities associated with future events and/or the monetary returns are characterized not by sharp estimates but rather are represented by a range of values.
Inelastic axial shear response of metal-matrix composites with functionally graded isotropic interfacial layers

Abstract The influence of isotropic interfacial microstructures on the effective axial shear response of a SiC/Ti composite system is considered using a recently developed analytical model. The analytical formulation is based on the multiple concentric cylinder assemblage consisting of an arbitrary number of elastic or elastoplastic layers. The ability of the model to consider any possible morphology changes allows the investigation of the influence of a wide variety of interfacial microstructures to be carried out in an efficient fashion. It will be shown that the introduction of graded interfacial microstructures can be used to control the evolution and magnitude of the inelastic deformations and stresses in the Ti alloy matrix.
The Association Between Long-term Diabetic Control and Early Retinopathy

A study was performed to determine the relationship between level of long-term antecedent diabetic control and early diabetic retinopathy changes. Fifty-eight insulin dependent diabetics aged 14 to 17 1/2 years, with duration of diabetes of at least 8 years, were studied. Glycosylated hemoglobins were assessed a mean of 8.5 times per patient, over a mean period of 3.1 years, representing 28% of the mean duration of diabetes in this patient population. Fluorescein angiography, obtained according to a standardized technique, was assessed in masked fashion for number of microaneurysms, presence of abnormal areas of capillary nonperfusion, and presence of intraretinal dye leakage. Sixty-four percent of the study population showed some evidence of retinopathy. There was a high correlation found between degree of metabolic control as measured by glycosylated hemoglobin level, and presence of early retinopathy changes as defined by angiography.
An enantiomeric discrimination in aqueous mixed chiral micelles through hydrogen bonding

Abstract Self-assembling molecular receptor comprising a chiral surfactant amide placed in a rigid micellar environment recognizes the different amide enantiomeric forms in water solution by means of hydrogen bonding.
Electronegativity: Chemical Hardness I

It has been suggested that the absolute hardness of density functional theory be identified with the chemical hardness of Pearson's principle of hard and soft acids and bases. It is unclear whether...
Predictors and Outcome of Readmission after Laparoscopic Intestinal Surgery

Background Previous studies have failed to identify predictors of early readmission after major intestinal operations. The objectives of this study were to determine readmission rates, outcomes, and predictors of readmission for patients undergoing laparoscopic colon and rectal operations.
Turkey embryo staging from cleavage through hypoblast formation

The progressive development of the turkey embryo from first cleavage through hypoblast formation was examined in order to determine the applicability of a chicken embryo staging procedure. It was concluded that the temporal and spatial events associated with the development of the early turkey embryo are sufficiently different from those of the chicken embryo to warrant a separate staging procedure. Cleavage is asynchronous and often results in asymmetrical segmentation. Unlike the chicken embryo, which at oviposition has already formed the area pellucida and area opaca and is classified as a Stage X embryo, the turkey embryo at oviposition is only at the beginning of area pellucida formation and is classified as a Stage VII embryo. After about 3 hr of incubation and prior to completion of the area pellucida, hypoblast formation begins at the posterior end, thereby establishing the bilaterally symmetrical pattern of the embryo. When viewed from the dorsal surface, an opaque region is observed at the center of the area pellucida. This opacity is unique to the turkey embryo and is referred to as the area alba. When viewed from the ventral surface, the area alba appears to be composed of large whitish cells. To conclude, the rate of turkey embryo development through the completion of hypoblast formation, which consists of 11 stages, lags behind that of the chicken. Furthermore, the organization as well as origin of the area pellucida and hypoblast observed in the turkey embryo differ from that of the chicken embryo. © 1993 Wiley-Liss, Inc.
Heteroepitaxial CdTe(111) grown by MBE on nominally flat and misoriented Si(001) substrates : characterization by electron microscopy and optical methods

Abstract Transmission electron microscopy (TEM), and low temperature reflectance and photoluminescence (PL) have been used to characterize heteroepitaxial CdTe(111) layers grown by molecular beam epitaxy directly onto nominally flat and misoriented Si(001) substrates. TEM observations confirmed that 1° offcut toward [110] in the Si(001) substrate suppressed formation of double domains, while increasing the azimuthal angle of the offcut relative to [110] suppressed twin formation. Under optimized growth conditions, residual twinning defects disappeared within about 2 μm from the substrate. Atomic-scale details of interfaces in this system were successfully recorded. Clear splitting of exciton states at the direct gap in optical reflectance and PL spectra demonstrated the existence of residual biaxial tensile strain of about 7 × 10 −4 in the CdTe layers, due to thermal expansion mismatch. A strain-shifted neutral acceptor-bound exciton peak dominated the 1.7 K photoluminescence spectrum, together with donor-to-acceptor and band-to-acceptor transitions involving a 49 meV shallow acceptor level. The sharpness of bound exciton peaks (about 0.6 meV full width at half maximum) supported the high layer quality.
The EGR family of transcription-regulatory factors: progress at the interface of molecular and systems neuroscience

The EGR family of transcription regulatory factors, which is implicated in orchestrating the changes in gene expression that underlie neuronal plasticity, has attracted the attention of both molecular and systems neuroscientists. In this article, the advances made in both these fields of research are reviewed. Recent systems-based studies underscore the remarkable sensitivity and specificity of the induction of the expression of genes encoding EGR-family members in naturally occurring plasticity paradigms. However, they also challenge conventional views of the role of this family in plasticity. Recent molecular studies have identified the gonadotropin subunit, luteinizing hormone beta, as an EGR1-regulated gene in vivo and uncovered an essential role for EGR3 in muscle-spindle development. In addition, the discovery of novel proteins that are capable of suppressing EGR-mediated transcription cast doubt over the prevalent assumption that changes in EGR mRNA or protein levels provide an accurate measure of EGR-driven transcriptional activity.
Differential expression of alternative 5' untranslated regions in mRNAs encoding rat insulin-like growth factor I

Abstract Rat insulin-like growth factor I (IGF-I) cDNAs contain three alternative 5' untranslated sequences (termed class A, B, and C), which are associated with an identical coding region for the mature IGF-I peptide. A solution hybridization/RNase protection assay was used to simultaneously quantitate the relative abundance of IGF-I transcripts with the different 5' untranslated regions. In all the tissues studied, transcripts with the class C 5' untranslated region were most abundant. In contrast, both class A and B transcripts were tissue specific. Class A transcripts were present in moderate abundance in liver; in low abundance in kidney, lung, testes, and stomach; and were undetectable in muscle, heart, and brain; whereas class B transcripts were detected only in liver. These three classes of 5' untranslated region were also regulated independently by growth hormone. In liver, heart, kidney, and lung, growth hormone increased the abundance of class C transcripts 2- to 3-fold. In liver, growth hormone increased the abundance of the class A and B transcripts 6- to 7-fold. In lung and kidney, on the other hand, the abundance of class A transcripts was not affected by growth hormone. Thus, rat IGF-I gene transcripts contain one of three alternative 5' untranslated regions, which are expressed in a tissue-specific manner and are differentially regulated by growth hormone. Finally, cDNA probes unique to two of the three 5' untranslated regions hybridized to all three major species of IGF-I mRNA typically seen on RNA blots with a coding region probe.
Comparison of the ProSpecT and Color Vue enzyme-linked immunoassays for the detection of Cryptosporidium in stool specimens

Two enzyme-linked immunosorbent assays, the ProSpecT (Al-exon, Sunnyvale, CA, USA) and the Color Vue (Seradyn, Indianapolis, IN, USA) were compared for their ability to detect Cryptosporidium in 236 formalin-fixed stool specimens using the Merifluor C/G (Meridian, Cincinnati, OH, USA) stain as the reference method. The initial sensitivities of the ProSpecT and the Color Vue were 96.0% and 76.0%, which upon repeat testing of all discrepancies remained at 96.0% for the ProSpecT and decreased to 72.0% for the Color Vue. There were 25 (11%) specimens positive by the reference method. Initially, there were five false positive specimens by the ProSpecT, only one of which remained positive on retesting. The specificity of the Color Vue was 100% for the initial and repeated results, whereas the ProspecT had an initial specificity of 97.6% that increased to 99.5% upon repeat testing. The enzyme-linked immunosorbent assays offered the advantages of objectivity, batch testing, and, in the case of the ProSpecT, an acceptable sensitivity.
A novel spectral tuning in the short wavelength-sensitive (SWS1 and SWS2) pigments of bluefin killifish (Lucania goodei).

Abstract The molecular bases of spectral tuning in the UV-, violet-, and blue-sensitive pigments are not well understood. Using the in vitro assay, here we show that the SWS1, SWS2-A, and SWS2-B pigments of bluefin killifish ( Lucania goodei ) have the wavelengths of maximal absorption ( λ max 's) of 354, 448, and 397 nm, respectively. The spectral difference between the SWS2-A and SWS2-B pigments is largest among those of all currently known pairs of SWS2 pigments within a species. The SWS1 pigment contains no amino acid replacement at the currently known 25 critical sites and seems to have inherited its UV-sensitivity directly from the vertebrate ancestor. Mutagenesis analyses show that the amino acid differences at sites 44, 46, 94, 97, 109, 116, 118, 265, and 292 of the SWS2-A and SWS2-B pigments explain 80% of their spectral difference. Moreover, the larger the individual effects of amino acid changes on the λ max -shift are, the larger the synergistic effects tend to be generated, revealing a novel mechanism of spectral tuning of visual pigments.
Surgical Management of Lateral Luxation and Subluxation of the Canine Radial Head

The causes and pathogenesis of radial head luxation and subluxation are reviewed. A surgical technique is described for repair of the condition that permits direct visualization of the joint, reestablishment of normal joint anatomy by ulnar osteotomy, and stabilization of the radioulnar articulation with a lag screw. Two clinical cases are presented.
The role of maternal Activin-like signals in zebrafish embryos

Maternal Activin-like proteins, a subgroup of the TGF-β superfamily, play a key role in establishing the body axes in many vertebrates, but their role in teleosts is unclear. At least two maternal Activin-like proteins are expressed in zebrafish, including the Vg1 orthologue, zDVR-1, and the nodal-related gene, Squint. Our analysis of embryos lacking both maternal and zygotic squint function revealed that maternal squint is required in some genetic backgrounds for the formation of dorsal and anterior tissues. Conditional inactivation of the ALK4, 5 and 7 receptors by SB-505124 treatment during the cleavage stages ruled out a role for maternal Squint, zDVR-1, or other Activin-like ligands before the midblastula transition, when the dorsal axis is established. Furthermore, we show that maternal Squint and zDVR-1 are not required during the cleavage stages to induce zygotic nodal-related gene expression. nodal-related gene expression decreases when receptor inhibition continues past the mid-blastula transition, resulting in a progressive loss of mesoderm and endoderm. We conclude that maternally expressed Activin-like signals do not act before the mid-blastula transition in zebrafish, but do have a variably penetrant role in the later stages of axis formation. This contrasts with the early role for these signals during Xenopus development.
Rapid diversification in the North American minnow genus Nocomis

Abstract Diversification rates among stream fishes are likely governed by geographical factors that impact connectivity among and between stream systems. Herein we investigate rates of diversification within species of River Chubs, Nocomis, a monophyletic group of stream fishes distributed throughout the drainage basins of the Mississippi River, Atlantic Slope and Gulf Coast. We used nucleotide sequences of two protein-coding nuclear genes (IRBP and rhodopsin) and one mitochondrial gene (cytochrome b) to generate a phylogenetic hypothesis of population-level relationships within and among species. Results of molecular analyses suggest that morphological and meristic treatments of Nocomis have underestimated species diversity within the group. Tree-based Bayesian methods and diversification statistics were implemented to model the rate of evolutionary change along lineages and estimate divergence dates among phylogroups. Significantly elevated rates of cladogenesis are observed among coastally distributed populations 2–3 million years before present. This period was dominated by dramatic sea level fluctuations that suggest a period of climatic instability. Climatic instability and other factors may have driven the burst of rapid diversification observed in Nocomis. Results generated in this study reinforce faunistic and geologic arguments for the hypothesized existence of extinct rivers, such as White’s River and the Appalachian River.