cssi/SciSciGPT-SciSciNet huggingface dataset:
A DEMS Study of the Reduction of CO 2 , CO, and HCHO Pre-Adsorbed on Cu Electrodes: Empirical Inferences on the CO 2 RR Mechanism

The effective abatement of atmospheric carbon through its conversion via electrochemical reduction to pure and oxygenated hydrocarbon fuels relies on the ability to control product selectivity at viable current densities and faradaic efficiencies. One critical aspect is the choice of the electrode and, in the CO_2-reduction electrocatalyst landscape, copper sits as the only metal known to deliver a remarkable variety of reduction products other than carbon monoxide and formic acid. However, much better catalyst performance is needed. The overall energy efficiency of copper is less than 40 %, and its nominal overvoltage at benchmark current densities remains unacceptably large at ca. 1 V. The diversity of the product distribution also becomes a major inconvenience in the likelihood that only one product is desired; unless, of course, if the selectivity window for such product is already known. Several experimental parameters influence the product selectivity of the CO_2 reduction reactions (hereafter referred to as CO_2RR); the more obvious include the composition and the crystal structure of the catalyst surface, the applied potential, the solution pH, and the supporting electrolyte. The documentation, at the atomic level, of the mechanistic origins of the CO_2RR selectivity of copper demands a systematic combination of ex situ, in situ, and operando techniques to interrogate the electrode surface, pristine and modified, prior to, during, and after the reduction reaction; the task includes not only the analysis of reaction-product distributions but also the identification of surface intermediates that serve as the precursor states for each reaction pathway. We recently studied the nature of well-defined Cu(hkl) single-crystal surfaces that, similar to “real-world” catalysts, were handled in air. Such investigation is pertinent since Cu is a well-known scavenger of molecular oxygen; hence, CO_2RR electrocatalysis must first contend with the initial presence of multilayers of disordered copper oxides. It was found that the oxides are actually easily reduced electrochemically back to the metal; in addition, even if the oxided single-crystal surface is severely disordered, cathodic reduction completely regenerates the original ordered structure. Most recently, we discovered that a polycrystalline Cu electrode held at a fixed negative potential in the CO_2RR region in KOH, undergoes stepwise surface reconstruction, first to Cu(111) and then to Cu(100). The results help explain the Cu(100)-like behavior of Cu(pc) in terms of CO_2RR product selectivity. In the work described in this Letter, we have applied differential electrochemical mass spectrometry (DEMS) of pre-adsorbed reactants and intermediates as a complementary experimental approach in the study of the mechanistic pathways for the Cu-catalyzed CO_2 reduction reactions; the reactant was CO_2 and the intermediates were CO and HCHO. The reduction products monitored by mass spectrometry were H_2, CO (from CO_2), CH_4, H_2C=CH_2 and CH_3CH_2OH.
Big Issues Missing from the Presidential Campaign

When it comes to the nation's pressing social problems, there is a depressing gap between both parties' aspirations and the federal resources now available. The nation has moved from an era of $200 billion deficits to equally outsized surpluses, but bipartisan ambitions have paradoxically shrunk. The author reviews problems where money would indisputably make a difference—such as the 44 million Americans with no health insurance, growing inequality in wages and wealth, and the myriad challenges facing urban education—and suggests promising directions for reform that are not being discussed in the presidential campaign. He also analyzes other issues not being debated, such as the size of the defense budget and the burden of payroll taxes, and urges the press to play a role in raising these issues when candidates will not.
Optimal demand response in DC distribution networks

Direct current (DC) power systems have recently been proposed as a promising technology for distribution networks and microgrids. By eliminating unnecessary conversion stages, DC distribution systems can enable seamless integration of natively DC devices such as photovoltaic cells and batteries. Moreover, using DC technologies can overcome several disadvantages of alternating current (AC) distribution systems, such as synchronization requirements, reactive power compensation, and harmonics. Therefore, in this paper, we take the first steps towards designing demand response programs for DC distribution networks. We seek to adjust the internal parameters of various power electronics loads to assure reliable and efficient operation of the DC distribution system. In this regard, we first present an optimization-based foundation for demand response in DC distribution networks. Then, we devise a pricing mechanism to enforce optimal demand response in a distributed fashion. Simulation results are presented to assess the performance and to gain insights into the proposed demand-response paradigm.
Ultra high bandwidth WDM using silicon microring modulators

We report 50 Gbit/s modulation capability using four silicon micro ring modulators within a footprint of 500 µm2. This is the highest total modulation capability shown in silicon using compact micro-ring modulators. Using the proposed techniques, silicon nanophotonic bandwidths can meet the requirements of future CMOS interconnects by using multiple wavelengths to extend beyond single device speeds.
Smart MAS restoration for distribution system with Microgrids

Fault Location, Isolation, and Restoration (FLIR) is the key concept of Distribution Automation (DA) in today's Smart Grid arena. A novel hybrid Multi Agent System (MAS) fault restoration solution has been proposed in this paper that uses both centralized and decentralized concepts for fault restoration on feeders with Microgrids. The main goal is to automatically reenergize un-faulted portions of feeders and restore power to as much as customers as possible while maintaining system constraints like voltage limits and loading levels. The proposed MAS concept is designed to be implemented on a couple of circuits in the territory of local utility, Mon Power, under the efforts of a DOE demonstration project named West Virginia Super Circuit (WVSC). The real distribution network is simulated in CYMDIST and Matlab/Simpower whereas the MAS is designed in Java Agent Development Framework (JADE). Simulation results show promising advantages of using proposed MAS solution for fault restoration using Microgrids.
Evidence that the enterococcal polysaccharide antigen gene (epa) cluster is widespread in Enterococcus faecalis and influences resistance to phagocytic killing of E. faecalis.

In previous studies, we cloned a cluster of genes involved in polysaccharide biosynthesis (epa) from Enterococcus faecalis strain OG1RF and showed that this gene cluster mediated synthesis of a polysaccharide in Escherichia coli. Disruption of two open reading frames in the epa gene cluster of OG1RF generated two mutants, TX5179 and TX5180, which were attenuated in a mouse peritonitis model. In the current study, Western blotting was performed with serum from a patient with E. faecalis endocarditis and polysaccharide extracts from OG1RF and the mutants TX5179 and TX5180. OG1RF showed a smear in the high-molecular-weight region and discrete bands in the low-molecular-weight region, which were missing from the mutants; periodate treatment and carbohydrate staining confirmed the polysaccharide nature of this material. In a neutrophil killing assay using OG1RF-absorbed normal human serum, the mutants TX5179 and TX5180, respectively, were 50 and 2.4 times more susceptible to killing than wild-type OG1RF (P ≤ 0.01). With a fluorescence phagocytosis assay, 2.5 to 3 times more of the mutants were taken up by neutrophils than OG1RF (P ≤ 0.001). Finally, with restriction digestion and hybridization under high-stringency conditions, the epa gene cluster of OG1RF (which is also present in the sequenced E. faecalis strain V583) was detected in 12 of 12 other clonally distinct E. faecalis strains tested: a similar polysaccharide pattern was detected for the 12 strains on Western blots using an E. faecalis endocarditis patient serum, and sera from four other patients with E. faecalis endocarditis all reacted with polysaccharide extracts of OG1RF. These results indicate that the epa gene cluster is widespread among E. faecalis and confers some protection against human host defenses.
Ramsey pricing in the presence of risk

This article examines Ramsey (second-best) pricing for a multi-product regulated monopolist when marginal costs fluctuate with a known probability function. When all marginal-cost risk is absorbed by consumers, the degrees of Pratt-Arrow absolute risk aversion and the marginal cost variances in the various markets have an affect on the appropriate Ramsey prices. An analogous result is obtained when investors absorb all of the cost risk. When the cost risk is optimally shared by consumers and investors, the deterministic Ramsey prices are obtained.
Endobronchial brachytherapy: an effective option for palliation of malignant bronchial obstruction

Symptoms resulting from tumors extending to the endobronchial wall are common in patients with lung cancer and significantly impact quality of life. A number of treatment options are available for palliation, including endobronchial brachytherapy, stent placement, laser photoresection, external-beam radiation therapy, and photodynamic therapy. This review will focus on the methodology and role of endobronchial brachytherapy while discussing benefits of other treatment options as additions or alternatives to brachytherapy.
Nucleoprotein complexes from simian virus 40-infected monkey cells: Association of viral DNA with histones and the major viral structural protein

Abstract Nucleoprotein complexes containing progeny SV40 DNA were isolated at 48 hr postinfection from infected permissive cells incubated in normal growth medium ( + ), in growth medium lacking arginine (Arg − ), and in normal growth medium containing 5-bromodeoxyuridine (BrdU + ) and characterized. Virus production in both Arg − and Brdu + cells is markedly inhibited. The complexes were purified by two successive sucrose gradient sedimentations to remove cellular proteins and then by sedimentation onto a cushion of saturated KBr solution to remove contaminating virus and empty capsids. The complexes extracted from Arg + , Arg − , and BrdU + cells were found to have the same sedimentation coefficient of 57 S and the same density of 1.43 g/cm 3 after glutaraldehyde fixation and to contain supercoiled SV40 DNA. The major protein species of the complex are histones and the major viral capsid protein (VP1). The Arg + complex contains predominately histones, whereas the BrdU + complex contains predominately the major capsid protein. The Arg − complex contains substantial amounts of both histones and the major capsid protein. Complexes were also isolated from Arg + cells at different times (24, 34, and 48 hr) after infection and characterized. More VPl, relative to histones, was found in the complex isolated at early than at late time after infection. Thus, the BrdU + and Arg − complexes may represent complexes formed at different times in a lytic infection.
Hazard: an expert system for screening environmental chemicals on carcinogenicity

: The purpose of this paper is to design an expert system or an intelligent procedure' that purports to screen hazard potentials of environmental chemicals on the basis of structure-activity relationships in the study of chemical carcinogenesis, particularly with respect to analysing the current state of known structural information about chemical carcinogens and predicting the possible carcinogenicity of untested chemicals An analysis of a computerised database of known carcinogens (knowledge base) is being performed using the structure-activity trees in order to test the validity of the tree as a classification scheme (inference engine) and to evaluate trends or patterns that may exist between chemical structure and specificity for target tissue, route of administration, and animal species. Practical applications of the structure-activity tree depend on its eventual validation as a predictor of carcinogenic activity.
September's children: does liberal neutrality fail gay and lesbian kids?

From the standpoint of Rawlsian liberalism, it is argued that parents must be prohibited from curbing the development of a child's agency, including the development of a sense of justice and the ability to author a conception of the good. This paper addresses a case in which children's future agency, as well as their current welfare, is at stake and yet safeguarding that agency and welfare conflicts with another tenet of Rawlsian liberalism, neutrality. Parents who possess, as a part of a comprehensive religious or moral doctrine, a belief that homosexuality is immoral or in some other way inferior to heterosexuality may seek to instill such a belief in their children. For a child of non-heterosexual orientation, the resulting outcome can be devastating. This paper asks if, given the limitations imposed by neutrality, the needs of gay and lesbian minors in such households can be addressed. I examine parents' and children's liberties from Rawls' perspective and explore the plight of gay and lesbian childre...
State measurement and system identification of a cantilever beam using distributed polyvinylidene fluoride (PVDF) film sensors

This paper contains theoretical and experimental results of controlling cantilever beams using distributed sensors. Shape functions for custom-made sensors are derived which allow for the identification and measurement of the states of a distributed system. This proposed technique allows for the direct identification of single-input single-output and multi-input multi-output system models as well as the implementation of full state feedback controllers without state estimation. Simple analog hardware circuits suffice to implement full state feedback controllers. System models can be identified quickly from time domain data for on-line controller adaptation. The suggested system identification method has the capacity to model only the modes of interest without relying on model reduction techniques.
FIXED‐RATIO REINFORCEMENT OF SPACED RESPONDING

Abstract Responses by rats were reinforced with food under a second-order schedule involving fixed-ratio reinforcement of temporally spaced responses. Requirements of 20, 8, and 3 responses were examined. The typical characteristic of spaced responding was maintained under the ratio schedules: interresponse time distributions were similar to those typically seen, and were not noticeably affected by the ratio value. Comparison of total response rate, correct response rate, and accuracy showed correct response rate to be the most consistently affected by changes in the ratio value. Substantial evidence of schedule control was seen only for correct responses. Incorrect response records were erratic, but rates generally declined as reinforcement was approached. Correct response records were characterized by increasing rate as reinforcement was approached. It was suggested that the pattern of fixed-ratio performance revealed may be affected by the behavioral unit examined.
Hyperbolic umbilic diffraction catastrophe and rainbow scattering from spheroidal drops

Short-wavelength scattering from drops whose shapes closely approximate that of an oblate spheroid with a vertical short or symmetry axis have been studied. The drops were illuminated by a horizontally propagating gaussian beam with a wavelength of 633 nm. The drops were observed to scatter in the horizontal rainbow region with patterns like those of hyperbolic-umblic (classification D4(+)) diffraction catastrophes. Visible D4(+) diffraction patterns observed previously include light transmitted by frosted glass surfaces and by liquid lenses clinging to tilted glass plates.
T-cell subsets in multiple sclerosis: Lack of correlation between helper and suppressor T cells and the clinical state

Peripheral blood T-lymphocyte subsets were investigated in a group of 26 multiple sclerosis (MS) patients of different clinical categories and compared to those of 15 normal controls and 7 other patients with known immunoregulatory disorders. In addition 17 well-documented acute relapses in 11 MS patients were also studied, some of whom were tested serially prior to, during, and after the acute attack. Using three different commercial preparations of monoclonal antibodies directed against human T3, T4, and T8 lymphocyte markers, none of the MS patients irrespective of disease category exhibited any changes in the absolute numbers of T-cell subsets or ratios thereof; this was true during either quiescent or active stages of the disease. In contrast, several patients with known immunoregulatory disorders exhibited clear changes in T4/T8 ratios. Factors such as type of patient studied, sampling error, and methods of isolation of mononuclear cells, as well as source of monoclonal antibody, failed to explain the lack of change in T-cell subsets in these patients. Thus, our data fail to confirm the previous reports of a decrease in the absolute numbers of T8 cells or the increase in the T4/T8 ratios in active or quiescent MS patients. These negative findings underscore the need for further studies relating these markers to meaningful functional properties of these cells and their interaction with the relevant target organs.
Mind the Gap: The Shape of the Free Surface of a Rubber-Like Material in Proximity to a Rigid Contactor

Extending Andreussi and Gurtin's [1] pioneering work on the wrinkling of a free surface, we investigate the wrinkling stability of an incompressible elastic-like half-space whose surface is proximate to a contactor. Assuming a plane-strain deformation and accounting for both surface prestress and curvature dependence of the surface free-energy density, we impose balances of forces and torques both in the bulk and on the surface. From the resulting linearized bulk and superficial equations, we derive a quintic dimensionless dispersion relation and perform a parametric study to see when stable or unstable behavior of the free surface is manifested. When compared with the quadratic dispersion relation of Andreussi and Gurtin [1], we see here that the combined effects associated with surface prestress, curvature-dependence of the surface free-energy density, and the interactions between the surface and the proximate contactor always lead to an increased number of linearly stable wrinkled configurations.
Exogenous shikimic acid stimulates rapamycin biosynthesis in Streptomyces hygroscopicus.

A chemically defined medium was developed which satisfies the nutritional needs of theStreptomyces hygroscopicus strain producing the immunosuppressant rapamycin. More than a doubling of rapamycin biosynthesis was observed on addition of 57 mmol/L of exogenous shikimate. The previously observed inhibition of the synthesis by phenylalanine was not reversed by shikimate.
The effect of mood on word recognition

There recently has been an upsurge in studies that have shown the influences of emotional mood on a variety of cognitions. Few studies, however, have demonstrated successfully this influence on perception. This study measured tachistoscopic recognition thresholds of two groups of subjects, a depressed-mood-induced group and a neutral group, for words that were either depres-sively congruent or neutral. The results revealed that recognition thresholds for depressively congruent words were lower for depressively induced subjects than for neutral subjects. These results are discussed in relation to current cognitive theories of emotion.
Coherent Optical Processing In Holographic Microscopy

Optical processing was first used as an integral part of a holographic microscope by McFee. (Ref. 1) Studying crystal growth from the melt, he inserted a field lens in the recording and reconstruction system. Upon reconstruction he could insert a spot diaphragm at the focal point of the lens to accomplish dark field illumination. He could also insert a phase plate at the same location to accomplish phase contrast. These techniques primarily enhance edge contrast in the reconstructed image.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Using orthogonal polynomial scores in summarizing and evaluating longitudinal data collected in phase I and II clinical pharmacology studies

Orthogonal polynomial scores (OPS) is a simple, biologically meaningful approach to characterize longitudinal data in phase I and II clinical pharmacology trials. It describes average, linear, quadratic and higher order polynomial characteristics of each subject's response over time with use of composite scores computed from linear combinations of the observed data. The statistical evaluation of the composite scores is univariate. For studies with a small number of experimental units and with many repeated measures, OPS may offer advantages over the use of summary measures such as the maximum response (MAX), the time at which MAX occurred (TMAX), or the area under the response curve (AUC), and other popular approaches such as time-point-by-time-point, split-plot, and multivariate analyses.
In vitro elimination of specific immunoreactive cells with 5-bromodeoxyuridine

Abstract Human lymphocytes proliferate in vitro in response to soluble antigens to which they are sensitized and to allogeneic lymphocytes. The exposure of stimulated leukocyte cultures to 5-bromodeoxyuridine (BUdR) followed by illumination with visible light results in the virtual elimination of the response as measured by tritiated thymidine incorporation. Treatment with BUdR-light also decreases thymidine incorporation in unstimulated cultures and under certain conditions allows a subsequent normal response to various mitogenic stimuli including PHA, soluble antigens and allogeneic cells. Using this method to selectively eliminate cells responding either to soluble antigens or to allogeneic cells, specificity of these responses was shown.
Optic Nerve Blindness Following Blunt Forehead Trauma

Abstract Seven cases of sudden monocular blindness following frontal head trauma are presented. The average age of these patients was 18 years. Four of the seven patients underwent transethmoid-sphenoid nerve decompression with only one of the four achieving a minor return of vision. None of the three out of six patients who failed to respond to megadose steroids regained vision with optic nerve decompression. Three out of six patients had return of good vision with megadose steroids without optic nerve decompression. Two of these three patients had a delayed loss of vision. One of the three patients with visual return developed visual loss again following a facial fracture reduction, which again responded to megadose steroids without optic nerve decompression. Another patient had visual return on steroids but also required removal of a subperiosteal hematoma to obtain near normal vision. This case differs from our other cases in that subperiosteal hematoma is an unusual complication of these injuries and caused the optic nerve compression in the orbital apex in this case. Review of the literature and our clinical and experimental findings suggest that the etiology of the indirect optic nerve injury is secondary to a stretching, tearing, torsion, or contusion of the nerve caused not only from the momentum of the eyeball and orbital contents being absorbed by the fixed canalicular portion of the optic nerve but also by skeletal distortion caused by forces remote from the initial impact. This is well illustrated by the holographic findings. These injuries cause direct injury to the nerve or vascular compromise from tearing, thrombosis, hematoma, or compression of the small nutrient vessels supplying the optic nerve. Megadose steroids appear to be useful in some cases of traumatic monocular blindness secondary to blunt facial trauma and as an adjunct to or an indication for surgery in others. The authors' recommended indications for optic nerve decompression (transethmoid-sphenoidotomy with removal of the medial wall of the optic canal) following blunt trauma are (1) delayed visual loss following frontal head trauma unresponsive to 12 hours of megadose steroid therapy and (2) initial return of vision with megadose steroids followed by visual decrease while on steroids or with the tapering of steroids.
A direct carbon fuel cell with a molten antimony anode

The direct utilization of carbonaceous fuels is examined in a solid oxide fuel cell (SOFC) with a molten Sb anode at 973 K. It is demonstrated that the anode operates by oxidation of metallic Sb at the electrolyte interface, with the resulting Sb2O3 being reduced by the fuel in a separate step. Although the Nernst Potential for the Sb-Sb2O3 mixture is only 0.75 V, the electrode resistance associated with molten Sb is very low, approximately 0.06 Ωcm2, so that power densities greater than 350 mW cm−2 were achieved with an electrolyte-supported cell made from Sc-stabilized zirconia (ScSZ). Temperature programmed reaction measurements of Sb2O3 with sugar char, rice starch, carbon black, and graphite showed that the Sb2O3 is readily reduced by a range of carbonaceous solids at typical SOFC operating conditions. Finally, stable operation with a power density of 300 mW cm−2 at a potential of 0.5 V is demonstrated for operation on sugar char.
Integration over the unit triangle

An integration formula for polynomial expressions in terms of the unit triangle co-ordinates is presented.
Spin Excitations in a Fermi Gas of Atoms

We have experimentally investigated a spin excitation in a quantum degenerate Fermi gas of atoms. In the hydrodynamic regime the damping time of the collective excitation is used to probe the quantum behavior of the gas. At temperatures below the Fermi temperature we measure up to a factor of 2 reduction in the excitation damping time compared to the classical expectation. In addition, we observe a strong excitation energy dependence for this quantum statistical effect.
In situ Fourier transform infrared (FTIR) investigation of CO2 adsorption onto zeolite materials

The adsorption of CO2 onto five zeolite materials (13X, WEG, AGP, 4A, and 5A) was studied by in situ infrared spectroscopy at 1 atm as a function of the pretreatment temperature (120 and 350 °C) and adsorption temperature (30 and 120 °C). Adsorbed CO2 surface species identified in the current work include physisorbed CO2, bidentate carbonate, bridged bidentate carbonate, monodentate carbonate, and carboxylate. Both pretreatment temperature and CO2 adsorption temperature affected the type and amount of adsorbed CO2 species formed. Materials pretreated at 350 °C, as opposed to 120 °C, had more surface adsorption sites available as evidenced from the resulting more intense IR bands. Physisorbed CO2 was the most abundant species observed. Bridged bidentate carbonate was found to be more stable than bidentate carbonate. Tests involving both CO2 and H2O showed that the two species competed for the same adsorption sites on the zeolite surface.
Object signature curve and invariant shape patches for geometric indexing into pictorial databases

Implicit polynomials (IPs) are among the most effective representations for modeling and recognition of complex geometric shape structures because of their stability, robustness and invariant characteristics. In this paper, we describe an approach for geometric indexing into pictorial databases using IP representations. We discuss in detail a breakthrough in invariant decomposition of a complex object shape into manageable pieces or patches. The self and mutual invariants of those invariant patches can be then used as geometric indexing features vectors. The new concept of invariant signature curve for complex shapes ins developed that captures the semi-global algebraic structure of the object and has the advantage of being able to deal with multi-scale and object occlusion.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Flow birefringence studies in transient flows of a two roll mill for the test-fluid M1

Abstract We have studied the test-fluid M1 in flows generated by a two-roll mill. These flows are linear, and two-dimensional, and the magnitudes of the strain-rates are greater than the vorticity. The polymeric solution is shown to degrade significantly, even for small values of the velocity gradient, as measured by the changes in the macroscopic relaxation time-scales. Consequently, the determination of macroscopic properties such as elongational viscosity based upon the overall pressure difference, or the total force as measured in a spin-line rheometer, may not be representative of the properties of the fresh, undegraded fluid. In this work, the degradation of the test-fluid has been studied as a function of the strength of the velocity gradient for different values of the ratio of the strain-rate to vorticity of the flow. Furthermore, the observed relaxation time-scales have been evaluated based on data for steady state flows, and several transient flow histories such as start-up and cessation of flows, and double-step flows. These flow histories provide us with some insight into the relaxation dynamics of the polymeric structure for different initial conformation states.
Exploratory Whisking by Rat Is Not Phase Locked to the Hippocampal Theta Rhythm

The rat has a strong 6–9 Hz rhythm of electrical activity in the hippocampus, known as the theta rhythm. Exploratory whisking, i.e., the rhythmic movement of the rat’s vibrissas to acquire tactile information, occurs within the same frequency range as the theta rhythm and provides a model system to examine the relationship between theta rhythm and active sensory movements. In particular, it has been postulated that these two rhythms are phase locked as a means to synchronize sensory and hippocampal processing. We tested this hypothesis in rats trained to whisk in air. Theta activity was measured via field electrodes in the hippocampus, and whisking was measured via the mystacial electromyogram. We calculated the spectral coherence between these two signals as a means to quantify the extent of phase locking. First, we found that the fraction of epochs with high coherence is not significantly greater than that expected by chance (seven of eight animals and as a population average). Second, we found that the trial-averaged coherence is low (coherence,
A retroviral promoter is sufficient to convert proto-src to a transforming gene that is distinct from the src gene of Rous sarcoma virus.

Abstract The src genes of four natural isolates of avian sarcoma viruses differ from cellular proto-src in two genetic substitutions: the promoter of the cellular gene is replaced by a retroviral counterpart, and at least six codons from the 3' terminus are replaced by retroviral or heterologous cell-derived elements. Since virus constructs with a complete proto-src coding region failed to transform avian cells but acquired transforming function by point mutations of various codons, it has been proposed that point mutation is sufficient to convert proto-src to a transforming gene. However, promoter substitution is sufficient to convert two other proto-onc genes, proto-ras and proto-myc, to retroviral transforming genes. In view of this, we have reexamined whether promoter substitution, point mutation, or both are necessary to convert proto-src into a retroviral transforming gene. It was found that a recombinant virus (RpSV), in which the src gene of Rous sarcoma virus (RSV) was replaced by the complete coding region of proto-src, transformed quail and chicken embryo cells. The oncogene of RpSV differs from the src gene of RSV in three genetic properties: (i) it is weaker--e.g., transformed cells are flatter; (ii) it is slower--e.g., focus formation takes 9 to 12 days compared to 4 days for RSV; and (iii) its host range is narrower than that of RSV--e.g., only subsets of heterogeneous embryo cells are transformed by RpSV even after weeks or months. Replacement of the proto-src 3' terminus of RpSV by that of src from RSV generates a recombinant virus (RpvSV) that equals RSV in transforming function. It is concluded that a retroviral promoter, naturally substituted via illegitimate recombination with retroviruses, is sufficient to convert at least three proto-onc genes, src, myc, and ras, to retroviral transforming genes.
Clay minerals in delta deposits and organic preservation potential on Mars

Clay-rich sedimentary deposits are often sites of organic matter preservation and have therefore been sought in Mars exploration. However, regional deposits of hydrous minerals, including phyllosilicates and sulphates are not typically associated with valley networks and layered sediments that provide geomorphic evidence of surface water transport on early Mars. The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) has recently identified phyllosilicates within three lake basins with fans or deltas that indicate sustained sediment deposition: Eberswalde crater Holden crater and Jezero crater. Here we use high-resolution data from the Mars Reconnaissance Orbiter (MRO) to identify clay-rich fluvial–lacustrine sediments within Jezero crater, which has a diameter of 45 km. The crater is an open lake basin on Mars with sedimentary deposits of hydrous minerals sourced from a smectite-rich catchment in the Nili Fossae region. We find that the two deltas and the lowest observed stratigraphic layer within the crater host iron–magnesium smectite clay. Jezero crater holds sediments that record multiple episodes of aqueous activity on early Mars. We suggest that this depositional setting and the smectite mineralogy make these deltaic deposits well suited for the sequestration and preservation of organic material.
Formulating management policies for value engineering/value analysis

This paper is an introduction to social judgment theory for productivity researchers and managers. It offers a useful theoretical and methodological basis for formulating and analyzing policies for value engineering/value analysis. Assignment of value to a product, process, or service is matter of an individual exercising his or her own judgment, which may vary from person to person. Subjectivity plays an important role in the assessment of value. Social judgment theory offers a theoretical framework that will prove useful to researchers in the study of the value engineering/value analysis process. The paper describes a computerized procedure for identification, measurement, and reporting of judgmental sources of value assessment. This information proves invaluable in the development and implementation of management policies for new product, process, or service development and for productivity improvements. A case study is provided as an example of how the procedure described here can be used for both research and practical application purposes. The results of the case study demonstrate that analyses of judgments and interactive computer graphics offer useful tools that serve as policy aids for the managers assessing value.
Anti‐DNA autoreactivity in C4‐deficient mice

Mice lacking the classical complement component C4 (C4–/–) were evaluated for autoreactivity because classical complement deficiencies are major risk factors for human systemic lupus erythematosus (SLE). Naive, 6-month-old C4–/– mice have significantly more IgM anti-double-strand DNA antibodies than C4+/+ controls. By 9 months, IgG anti-dsDNA antibodies are increased and this spontaneous autoreactivity is evident across a mixture of genetic backgrounds. C4+/– heterozygous mice also develop autoantibodies, reminiscent of the high incidence of partial C4 deficiency observed in human SLE. Kidneys of C4–/– mice have glomerular immune complexes, but progressive renal disease is not apparent in unmanipulated animals. Nonetheless, splenicB cells from C4–/– and not C4+/+ mice as young as 3 months can be triggered to secrete IgM anti-dsDNA antibodies in vitro, before autoantibody titers are significantly elevated in vivo. These findings suggest that C4 normally helps prevent early stages of autoimmune disease and that C4 deficiency predisposes to abnormal regulation of autoreactive B cells.
Developing Attention: Behavioral and Brain Mechanisms

Brain networks underlying attention are present even during infancy and are critical for the developing ability of children to control their emotions and thoughts. For adults, individual differences in the efficiency of attentional networks have been related to neuromodulators and to genetic variations. We have examined the development of attentional networks and child temperament in a longitudinal study from infancy (7 months) to middle childhood (7 years). Early temperamental differences among infants, including smiling and laughter and vocal reactivity, are related to self-regulation abilities at 7 years. However, genetic variations related to adult executive attention, while present in childhood, are poor predictors of later control, in part because individual genetic variationmay have many small effects and in part because their influence occurs in interaction with caregiver behavior and other environmental influences. While brain areas involved in attention are present during infancy, their connectivity changes and leads to improvement in control of behavior. It is also possible to influence control mechanisms through training later in life. The relation between maturation and learning may allow advances in our understanding of human brain development.
Boundaries and breakdowns: applying Agar's concept of ethnography to observations in a pediatric clinic.

This paper discusses a methodology for observing and describing interactions between clinicians and patients in an innercity pediatric clinic serving families of diverse ethnicity. The framework is derived from Michael Agar's concept of ethnography as an interpretive, problem-resolving method. In Agar's model, the participant-observer moves cognitively and analytically from focusing on breakdown (awareness of a problem in understanding) to resolution (applying knowledge structures or schemas to bounded phenomena or strips) and utimately to coherence. This framework applies not only to describing what the ethnographer does, but also stages in the clinician's efforts to communicate. Awareness of repeated breakdowns allows the ethnographer to document fundamental differences in expectations and premises that affect communication between clinician and patient. Two major types of breakdowns are discussed: those occurring between clinic staff and families, and those occurring between staff and ethnographer. Ter...
Steady state minority carrier lifetime and defect level occupation in thin film CdTe solar cells

Abstract A model consisting of Shockley Read Hall (SRH) recombination under steady state conditions of constant photon injection is proposed in this work to study the steady state minority carrier lifetime in CdS/CdTe thin film solar cells. The SRH recombination rate versus optical injection level is analytically approximated in the junction and neutral regions. In the neutral region, it is found that the recombination rate through certain defect levels has one constant value under lower optical injection conditions and another constant value under higher optical injection conditions with the transition occurring at a critical optical injection level. By simultaneously solving the equations of charge neutrality, charge conservation and SRH recombination in the neutral region, it is found that the compensation of doping and the reduction of minority carrier lifetime by donors in the p-type semiconductor can each be remedied by optical injection. It is also demonstrated that this optical-dependent SRH recombination is significant in large bandgap thin films. The measured minority carrier diffusion length in a CdS/CdTe solar cells, as determined from the steady-state photo-generated carrier collection efficiency, shows the predicted transition of minority carrier lifetime versus optical injection level. A numerical fitting of the indirectly-measured minority carrier lifetime by assuming the minority carrier mobility gives a non-intuitive picture of the p–n junction with a low free hole concentration but a narrow depletion region width.
Folate‐targeted imaging of activated macrophages in rats with adjuvant‐induced arthritis

Objective To determine whether overexpression of the high-affinity folate receptor (FR) on activated macrophages can be exploited to selectively target imaging agents to sites of inflammation in rats with adjuvant-induced arthritis (AIA). Methods Folic acid was conjugated to a 99mTc chelator (the complex termed EC20), and its distribution was visualized using gamma scintigraphy in healthy rats, rats with AIA, and arthritic rats that had been depleted of macrophages. To confirm that uptake was mediated by the FR, excess folic acid competition studies were conducted, and tissue FR levels were quantitated using a radioligand binding assay. Flow cytometry was also used to investigate uptake of folate conjugates into macrophages of both arthritic and healthy rats. Results EC20 concentrated in the arthritic extremities of diseased rats but not in the extremities of healthy rats. The intensity of images of affected tissues was greatly reduced in the presence of excess competing folic acid. The livers and spleens of arthritic animals also showed enhanced uptake of EC20 and increased levels of FR. Depletion of macrophages from arthritic animals reduced tissue FR content and concomitantly abolished uptake of EC20. In addition, macrophages isolated from livers of rats with AIA exhibited a significantly higher binding capacity for folate conjugates than did macrophages obtained from healthy rats. Conclusion Although EC20 is currently undergoing clinical evaluation for use in the imaging of ovarian carcinomas, the present results suggest that it may also be useful for assaying the participation of activated macrophages in inflammatory processes such as rheumatoid arthritis.
Protein kinase C regulates cytokine-induced tissue factor transcription and procoagulant activity in human endothelial cells

Abstract Interleukin-lα (IL-lα) and tumor necrosis factor-α (TNF-α) induce tissue factor in endothelium, which results in activation of the coagulation cascade. Despite extensive investigation, in which various stimuli that induce tissue factor have been defined, the intracellular processes that control tissue factor expression are not well understood. It has been proposed that protein kinase C regulates tissue factor expression primarily because phorbol myristate acetate, the protein kinase C activator, induces tissue factor expression. In this study we examined whether IL-1α- or TNF-α-stimulated tissue factor production is regulated through a protein kinase C-dependent mechanism. Northern blot analysis showed that cytokine-induced tissue factor mRNA was significantly reduced in human umbilical vein endothelial cells treated with calphostin C, a specific protein kinase C inhibitor. Tissue factor functional activity was decreased in the presence of calphostin C as well. Calphostin C also inhibited phorbol myristate acetate-induced tissue factor expression. In contrast, calphostin C did not alter cytokine induction of E-selectin or prostacyclin release. Because calcium stimulates protein kinase C binding to the membrane and its resulting catalytic activity, human umbilical vein endothelial cells were exposed to IL-1α or TNF-α in the presence of calcium ionophore A23187. A23187 had little effect alone but significantly augmented cytokine stimulation of tissue factor mRNA. Okadaic acid, a phosphatase inhibitor, increased cytokine-induced tissue factor mRNA compared with cytokine alone, which suggests that a phosphorylation event is important in tissue factor expression. These results indicate that protein kinase C is involved in cytokine activation of endothelial cell tissue factor expression.
Computer-aided design applications on microcomputers

A microcomputer-based, two-dimensional CAD system has been developed and implemented for a specific manufacturing environment, namely, the small manufacturer. This work began with a system for the design of multiple-spindle drill heads. A subset of Lockheed's CADAM system was emulated on a microcomputer to demonstrate the feasibility of this approach. Facilities were provided for drawing and erasing points, lines, and circles; relimiting and cornering; offsetting; windowing; and filing. CADAM's user interface was provided with a vertical menu, function keys, prompts, and color highlighting. A brief overview is also presented of system specifications and capabilities of a full-function three-dimensional CAD system for IBM PC microcomputers.
Detecting traffic accident clusters with network kernel density estimation and local spatial statistics: an integrated approach

Kernel density estimation (KDE) has long been used for detecting traffic accident hot spots and network kernel density estimation (NetKDE) has proven to be useful in accident analysis over a network space. Yet, both planar KDE and NetKDE are still used largely as a visualization tool, due to the missing of quantitative statistical inference assessment. This paper integrates NetKDE with local Moran’I for hot spot detection of traffic accidents. After density is computed for road segments through NetKDE, it is then used as the attribute for computing local Moran’s I. With an NetKDE-based approach, conditional permutation, combined with a 100-m neighbor for Moran’s I computation, leads to fewer statistically significant “high-high” (HH) segments and hot spot clusters. By conducting a statistical significance analysis of density values, it is now possible to evaluate formally the statistical significance of the extensiveness of locations with high density values in order to allocate limited resources for accident prevention and safety improvement effectively.
Near-Infrared Polarimetry and Photometry of Recent Comets

We present near-infrared (2.2 μm) imaging polarimetry and near-infrared photometry for recent comets. The 2.2 μm polarization as a function of phase angle is 1%–2% higher than typical comet visual narrowband red polarization. This implies a general, but weak, trend to higher polarization at wavelengths longer than 0.7 μm. As found with visual narrowband red polarimetry, comets appear to divide into a high- and a low-polarization class at 2.2 μm as well. The high-polarization class is characterized by moderate to strong mid-infrared silicate emission, while the low-polarization class is characterized by weak to absent silicate emission. In contrast to C/1995 O1 (Hale-Bopp) and some other dusty comets, no significant grain population radial gradient is seen in any of the polarization maps for the six comets in our sample with near-infrared imaging polarimetry. Our analysis of previously published Hale-Bopp data shows that the polarization at 40° phase angle varies by only about a factor of 1.6 from 0.3 to 2.2 μm and is nearly flat from 0.7 to 2.2 μm. Any model of comet dust must reproduce this weak wavelength dependence.