cssi/SciSciGPT-SciSciNet huggingface dataset:
Stepwise commitment of blast cell fates during the positional specification of the O and P cell lines in the leech embryo

The o and p bandlets of the leech embryo are parallel columns of ectodermal blast cells which are identified by their relative positions, and which during normal embryogenesis follow distinct developmental pathways. A previous study showed that o blast cells are initially capable of following either the O or P pathway, and suggested that commitment to the O pathway depends upon interaction with the adjacent p bandlet. To better understand the nature and timing of this interaction we examined the fate of o blast cells whose p blast cell neighbors had been selectively ablated by photoexcitation of a fluorescent lineage tracer. If an o blast cell has not yet begun its secondary divisions, its normal commitment to the O pathway can be effectively prevented by ablation of the adjacent p bandlet. Comparing the outcome of progressively later lesions reveals that the progeny of the o blast cell become committed to the O pathway in a series of three discrete steps, and that these steps occur around the time of the first three blast cell divisions. Each of the three events affects a different subset of elements within the blast cell clone, and apparently commits those elements to either the O or P pathway depending upon the presence or absence of the other bandlet. These changes in blast cell fate are coextensive with the lesion along the bandlet's length, suggesting that the interaction of the two bandlets is localized to neighboring cells.
Models of Relativistic Hamiltonian Interactions

A model of a relativistically invariant Hamiltonian 2-particle interaction is given. It is classical in the sense of having 6 degrees of freedom. This model shows that the author's earlier general definition of such systems is not vacuous. In this model the forces of interaction die away as the particles are removed from each other.
Smoker-nonsmoker conflict: Using a social psychological framework to understand a current social controversy

Over the past two decades, state and federal restrictions of public smoking have become increasingly common. The resulting controversy has generally focused on the research evidence regarding the physiological effects of second-hand smoke while ignoring relevant psychological aspects of smoker-nonsmoker conflict. In this article 1 review the literature on the psychological consequences of smoker-nonsmoker interaction, interpreting these results from the framework of social psychological research on inter-group conflict. From this review I conclude that: a) smoker- nonsmoker conflict shares many characteristics of other ingroup-outgroup interactions; b) both groups are served by the legislated separation of these groups; and c) such separation can be successfully accomplished only when close attention is paid to subtle environmental cues. Finally, theoretical benefits of studying smoker-nonsmoker conflict from a social psychological perspective are discussed.
Passive control plate for shock-boundary layer interactions

Computational and experimental results are presented for a passive method capable of reducing or completely eliminating the separation region in shock-boundary layer interactions of the type that can result in severe performance degradation due to flow separation in supersonic and hypersonic inlets. The method involves the placement of an embedded plate in the outer portion of the boundary layer, parallel to the wall, so that the incident shock will impinge upon, and be reflected from, its surface. This will lower the pressure gradient in the low-momentum, near-wall region. A porous control plate's effect has also been investigated.
Information Technology and Administrative Reform: Will E-Government Be Different?

This article examines the theoretical ideal of information technology as an instrument of administrative reform and examines the extent to which that ideal has been achieved in the United States. It takes a look at the findings from research about the use and impacts of information technology from the time of the mainframe computer through the PC revolution to the current era of the Internet and e-government. It then concludes that information technology has never been an instrument of administrative reform; rather, it has been used to reinforce existing administrative and political arrangements. It assesses why this is the case and draws conclusions about what should be expected with future applications of information technologies â€” in the time after e-government. It concludes with a discussion of the early evidence about newer applications for automated service delivery, 24/7 e-government, and e-democracy.
Phenotypic Mismatches Reveal Escape from Arms-Race Coevolution

Because coevolution takes place across a broad scale of time and space, it is virtually impossible to understand its dynamics and trajectories by studying a single pair of interacting populations at one time. Comparing populations across a range of an interaction, especially for long-lived species, can provide insight into these features of coevolution by sampling across a diverse set of conditions and histories. We used measures of prey traits (tetrodotoxin toxicity in newts) and predator traits (tetrodotoxin resistance of snakes) to assess the degree of phenotypic mismatch across the range of their coevolutionary interaction. Geographic patterns of phenotypic exaggeration were similar in prey and predators, with most phenotypically elevated localities occurring along the central Oregon coast and central California. Contrary to expectations, however, these areas of elevated traits did not coincide with the most intense coevolutionary selection. Measures of functional trait mismatch revealed that over one-third of sampled localities were so mismatched that reciprocal selection could not occur given current trait distributions. Estimates of current locality-specific interaction selection gradients confirmed this interpretation. In every case of mismatch, predators were “ahead” of prey in the arms race; the converse escape of prey was never observed. The emergent pattern suggests a dynamic in which interacting species experience reciprocal selection that drives arms-race escalation of both prey and predator phenotypes at a subset of localities across the interaction. This coadaptation proceeds until the evolution of extreme phenotypes by predators, through genes of large effect, allows snakes to, at least temporarily, escape the arms race.
The Effect Of Oxygen On Stability In CLAP Glasses

ABSTRACT A small amount of oxygen is shown to be necessary to form CdF2-LiF-AlF3-PbF2 (CLAP) glasses. Too little oxygen produces order of magnitude increases in crystallization, too much oxygen produces liquid-liquid phase separation.A microcrystallite structure is suggested to explain these results. 1. INTRODUCTION Since the discovery of heavy metal fluoride glasses (HMFG) in 19751 , an extensive worldwide exploratory composition effort has evolved. The underlying goal of much of this work has been to identify more stable compositions. While these empirical experimental studies have examined a large number of HMFG systems, the actual improvements in glass stability have only been modest. Furthermore, the relationship between glass structure and its composition elements is poorly understood; hence the predictive value of any of the theories concerning glass stability is small.Of some controversy is the role of oxygen in these glasses. Oxygen was usually con­ sidered an undesirable element and recently some data2 correlating oxygen concentration with increased scattering losses in fluorozirconate fibers has been presented. The present work suggest oxygen may play a different role in at least one family of HMFG systems, the CdF2-LiF-AlF3-PbF2 (CLAP) system3 , which depends critically upon oxygen for vitreous stability.
Experimental and theoretical model of refractive index artifacts in absorbance detection

Abstract An anomalous signal is often observed upon sample injection in both liquid chromatography and flow-injection analysis using high-sensitivity absorbance detectors. This characteristic detector response, unrelated to sample absorbance, appears to arise from the change in refractive index within the flowcell. The factors affecting the refractive index gradient have been incorporated in a ray-tracing model, where the flowcell is regarded as a dynamic lens. The response predicted by this model correlates well with experimental measurement of the general shape, magnitude, and direction of the refractive index artifact. The proposed model should have wide ranging implications for both flowcell design and chromatographic interpretation of these anomalous signals.
MicroELISA method for measurement of human serum thymosin α1

A microELISA for the estimation of human serum thymosin alpha 1 is described. In this assay, antibody to thymosin alpha 1 is pre-incubated with the standard or serum at 4 degrees C. Unbound antibody in the liquid-phase then binds with solid-phase thymosin alpha 1. The method is sufficiently sensitive for measuring serum levels of thymosin alpha 1 and highly reproducible. The serum levels measured with the microELISA are comparable to serum levels of thymosin alpha 1 determined by the previously described radioimmunoassay for thymosin alpha 1.
Comparison of quantification methods illustrates reduced Pseudomonas aeruginosa activity on nanorough polyvinyl chloride.

Patients on mechanical ventilators for extended periods of time are faced with a high probability of developing ventilator associated pneumonia. Although this has been mostly addressed through the re-engineering of endotracheal tubes (ETTs) with antimicrobial materials, such material coatings may easily delaminate during use. However, the potential exists to apply nanotechnology to the ETT to avoid delamination but implement antibacterial properties. Selecting a protocol to evaluate in vitro material for anti-infection is difficult, partially due to the existence of conflicting reported methods of analysis. In this study, the susceptibility of conventional and nanorough polymeric materials to bacterial biofilm growth were evaluated. After creating nanorough polyvinyl chloride (PVC) ETTs, Pseudomonas aeruginosa biofilms were then grown on sample surfaces during a 24-h culture. Biofilms were then removed and assayed from sample surfaces using a variety of techniques. Comparisons between the different techniques used for biofilm removal indicated that vortexing provided adequate removal of the biofilm from sample surfaces. Most importantly, a protocol following the vortexing method of biofilm and bacteria removal provided an ∼40% lower yield of colony forming units from nanorough PVC compared to conventional PVC. This suggests that Pseudomonas aeruginosa are less adherent on nanorough PVC than conventional PVC. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Competition between Linker Histones and HMG1 for Binding to Four-Way Junction DNA: Implications for Transcription

Both lysine-rich histones and high mobility group proteins 1 and 2 bind to linker DNA in chromatin. While the members of the histone H1 class are considered general repressors of transcription, HMG1/2 are viewed as activators. Using stable four-way junction DNA as a model for cross-overs of linker DNA at the entry and exit to nucleosomes, we show that HMG1 can compete efficiently with H1 for binding to four-way junctions. In contrast, the erythrocyte-specific histone H5 seems to be refractory to displacement by HMG1. The results suggest that replacement of histone H1 by HMG1 may be part of the transcriptional activation by HMG1.
Hot-electron dynamics in SiO2 studied by soft-x-ray-induced core-level photoemission.

The transport properties of 8--18-eV electrons in SiO{sub 2} are studied via the changes induced in the soft-x-ray-induced core-level photoemission peak of the Si 2{ital p} substrate by hot-electron transport through the SiO{sub 2} overlayers. The observed systematic asymmetric broadening of the substrate line shape with overlayer thickness is shown to be caused by phonon excitation during transport through the overlayer. This effect is strongest at 8 eV and rapidly decreases with increasing electron energy over the range from 8 to 16 eV. These strong dependences on energy and oxide thickness allow the determination of absolute energy-dependent scattering rates for electron-phonon and electron-electron scattering. The analysis is based on the reconstruction of the Si 2{ital p} substrate line by means of semiclassical Monte Carlo transport simulations including the electron-phonon interaction and electronic excitation. Acoustic-phonon scattering is found to be the dominant electron-phonon scattering mechanism. This scattering rate decreases slightly with increasing energy. Absolute values in the range from 6{times}10{sup 15} sec{sup {minus}1} (at 8 eV) to 4{times}10{sup 15} sec{sup {minus}1} (at 16 eV) are measured. The reconstruction of the substrate lines requires a deep-inelastic-scattering process, most likely due to electron-hole pair excitation by electron impact. This rate rapidly increases withmore » increasing energy. Values in the range from 2.5{times}10{sup 14} sec{sup {minus}1} (at 8 eV) to 3{times}10{sup 15} sec{sup {minus}1} (at 16 eV) are found. A series of simulations is presented that illustrates the role of various scattering processes in SiO{sub 2} at high electron energies.« less
BWR mechanics and materials technology update

Abstract This paper discusses technical results obtained from a variety of important programs underway at General Electric's Nuclear Engineering Division. The principal objective of these programs is to qualify and improve BWR product related technologies that fall broadly under the disciplines of Applied Mechanics and Materials Engineering. The paper identifies and deals with current technical issues that are of general importance to the LWR industry albeit the specific focus is directed to the development and qualification of analytical predictive methods and criteria, and improved materials for use in the design of the BWR. In this paper, specific results and accomplishments are summarized to provide a broad perspective of technology advances. Results are presented in sections which discuss: dynamic analysis and modeling; fatigue and fracture evaluation; materials engineering advances; and flow induced vibration.
Precise control of repeating unit composition in biodegradable poly(3-hydroxyalkanoate) polymers synthesized by Escherichia coli

The composition of medium-chain-length (MCL) poly(3-hydroxyalkanoate) (PHA) biopolymers is normally an uncontrollable random mixture of repeating units with differing side chain lengths. Attempts to generate MCL PHA homopolymers and control repeating unit composition have been published in native PHA-producing organisms but have limited ranges for the different sizes of repeating units that can be synthesized. In this study, a new Escherichia coli-based system that exhibits control over repeating unit composition for both MCL PHAs and short-chain-length (SCL) PHAs has been developed, covering an unprecedented range of repeating units. The fadB and fadJ genes from the β-oxidation pathway were eliminated from the chromosome of E. coli LS5218. The subsequent blockage in β-oxidation caused a buildup of enoyl-CoA intermediates, which were converted to PHAs by an (R)-specific enoyl-CoA hydratase (PhaJ4) and PHA synthase [PhaC1(STQK)] expressed from a plasmid DNA construct. Fatty acid substrates were converted to PHAs with repeating units equal in the number of carbon atoms to the fatty acid substrate. The broad substrate specificities of the PhaJ4 and PhaC1(STQK) enzymes allowed for the production of homopolymers with strict control over the repeating unit composition from substrates of four to twelve carbons in length. Polymers were purified and analyzed by GC, GC-MS, and NMR for structural composition and by DSC, TGA, and GPC for thermal and physical characteristics. This study marks the development of the first single biological system to achieve consistent repeating unit control over such a broad range of repeating units in PHAs.
Democracy and Education after September 11

Millions of words written in the wake of the horrific terror of September 11, 2001 appear to reinforce the feelings of despair at the current state of the world politics. Most analyses seem to offer little hope for the prospects of peace. Indeed, if the so-called 'war on terror' is designed to achieve peace then it is difficult to see how it could be won in any determinate sense, yet the popular media and others in the position of influence seem reluctant to explore alternatives to war. In this essay I argue that many of the current analyses of September 11 and discourses of national security are incapable of delivering the cosmopolitan resources of hope we need to have a better chance of securing peace. I maintain that these resources of hope will not be located in the austere and intrusive regimes of national security; rather, they are more likely to be found in the possibilities of transnational democracy and education.
Changes in excitability of motor cortical circuitry in primary restless legs syndrome

Objective: To investigate the excitability of segmental and suprasegmental systems in patients with primary restless legs syndrome (pRLS) by measuring the cortical silent period (C-SP) and the peripheral silent period (P-SP). Background: There is some evidence that RLS may be the motor manifestation of normal CNS periodicity that becomes disinhibited under certain conditions. The mechanism of this disinhibition is unclear. Design/Methods: Ten patients with pRLS and 10 normal age-matched subjects were studied. The mixed nerve P-SP produced by electrical stimulation of the median and common peroneal nerves was recorded during maximal contraction of the abductor pollicis brevis (APB) and tibialis anterior (TA) muscles. The C-SP produced by a single magnetic shock to motor cortex at 150% of resting threshold was also measured during maximal contraction of the APB and TA muscles. The average of 5 to 10 trials at each site was obtained and compared using Student’s t-test. Results: Resting central motor threshold was not significantly different between pRLS patients and the control group. The average duration of the C-SP was shorter in the APB (74.5 ± 37.7 versus 129.56 ± 35.95 msec, p Conclusion: The supraspinal inhibitory system is impaired in pRLS.
Qui tam actions: fighting fraud against the government

Purpose – This paper seeks to provide auditors, forensic accountants, investigators, regulators, financial managers, lawyers, law enforcement personnel, academics, and others with a basic overview of the steps in and elements of a qui tam legal claim, limitations on a qui tam claim, protection for a whistleblower employee, and the role of qui tam litigation in the fight against fraud.Design/methodology/approach – A sample of types of recent qui tam fraud cases is highlighted for the reader. The steps in filing a qui tam claim are described along with the limitations of pursuing such a lawsuit. The paper includes a statutory and legal case study analysis of each required element of proof in a qui tam claim. Analysis of actual qui tam court cases illustrates the importance of private civil lawsuits in combating fraud committed against the US Government.Findings – This paper provides readers with information about the substantial recoveries earned by successful qui tam plaintiffs. Also, the necessary steps i...
Methods for the production of clinically effective intermediate- and high-purity factor-VIII concentrates.

Summary. An intermediate- and a high-purity factor-VIII concentrate for clinical use have been prepared on a large scale by cryoethanol precipitation, extraction of the precipitate with tris buffer, and fractionation with polyethylene glycol. With bench-scale fractionation, the intermediate material is 22-fold purified on the average and the mean yield is 63%, while the high-purity factor VIII is 274-fold purified with a mean yield of 62%. With fractionation of 100 1. or more of fresh frozen plasma, the intermediate material shows a 30% yield and 14-30-fold purification; the high-purity factor VIII shows an 18% yield and 125–350-fold purification using 5.8 g/100 ml polyethylene glycol (PEG). A yield of nearly 30% should be possible with PEG, 4–5 g/100 ml. Both factor-VIII preparations are stable for over a year in the lyophilized state at 4°C. Other plasma proteins can be fractionated from the residual plasma by routine Cohn procedures.
Market effects of an “environmental” beverage package tax

Abstract A non-marginal tax on beverage packages was implemented in Sweden. This tax is found to be related to several shifts in the market shares of competing beverage packages. Refillable glass bottle use increases. Non-refillable glass bottle use declines greatly, while cans increase in use. A lack of substitutability between cans and glass containers may explain the increased market share for cans. These results indicate that an environmental tax may have significant effects on consumer package choice in beverage delivery systems.
Characterization of Damage Evolution in SiC Particle Reinforced Al Alloy Matrix Composites by In-Situ X-Ray Synchrotron Tomography

We carried out a detailed investigation of the damage behavior of SiC particle reinforced 2080 Al alloy matrix composites by in-situ X-ray synchrotron tomography. We studied the tensile damage behavior of a peak-aged aluminum matrix composite. The main damage mode was SiC particle fracture with a very small contribution from void growth. The onset of damage takes place very close to the ultimate tensile strength of the composite. Particle fracture damage is stochastic in nature and is confined to a small distance from the fracture plane. Minimal void growth is observed, primarily at pre-existing microscopic voids from processing. Microstructure-based simulations, based on two-dimensional (2-D) images from the tomography data sets, show the importance of particle distribution and morphology on the evolution of plastic strain and damage in the composite.
High-Temperature Decomposition of Brønsted Acid Sites in Gallium-Substituted Zeolites

The dehydroxylation of Bronsted acid sites (BAS) in Ga-substituted zeolites was investigated at temperatures up to 850 °C using X-ray absorption spectroscopy (XAS), Fourier transform infrared spectroscopy (FTIR), and mass spectrometry-temperature programmed desorption (MS-TPD). X-ray absorption near-edge spectroscopy (XANES) revealed that the majority of gallium has tetrahedral coordination even after complete dehydroxylation. The interatomic gallium−oxygen distance and gallium coordination number determined by extended X-ray absorption fine structure (EXAFS) are consistent with gallium in tetrahedral coordination at low T (<550 °C). Upon heating Ga-Beta and Ga−ZSM5 to 850 °C, analysis of the EXAFS showed that 70 and 80% of the gallium was still in tetrahedral coordination. The remainder of the gallium was found to be in octahedral coordination. No trigonal Ga atoms were observed. FTIR measurements carried out at similar temperatures show that the intensity of the OH vibration due to BAS has been eliminat...
The imperative of economics in urban political analysis : a reply to Clarence N. Stone.

I welcome and greatly appreciate the opportunity to reply to Professor Stone’s insightful and provocative article. The section of Professor Stone’s article that bears most directly on my original a...
Hemorrhagic profile of the fibrinolytic alfimeprase after ischemia and reperfusion.

Abstract Objective: Recanalization therapies for ischemic stroke have been slow to change clinical practice because of perceived and published risks of hemorrhage associated with lytic administration. We quantified alfimeprase in an acute ischemia–reperfusion model, as compared with recombinant tissue plasminogen activator, with hemorrhagic transformation as the primary endpoint and infarction volume and blood–brain barrier permeability as secondary endpoints. Methods: Five groups were studied in a blinded fashion: alfimeprase at doses of 0.03 (n=8), 0.1 (n=11) and 0.3 mg/kg (n=8); recombinant tissue plasminogen activator at 1 mg/kg (n=9); carrier infused controls (n=9). The middle cerebral artery was occluded for 5 hours followed by removal of the suture for reperfusion. Drugs were infused immediately following reperfusion over a 10-minute period. Approximately 24 hours later, the animals were anesthetized and decapitated, and the brains were rapidly harvested and frozen. Serial brain sections were obtai...
Boundary element method calculations of the mobility of nonspherical particles—II. Branched chains and flakes

We combine a numerical, boundary element method with analytical techniques to predict the motion of isolated, nonspherical particles moving at low Reynolds number through a Newtonian fluid. The boundary element method is used to determine the constant components of the resistance matrix (a geometry-specific matrix relating a particle's linear and angular velocities to the applied forces and torques). Once the resistance matrix has been constructed, direct simulation of the translation and rotation of the particle in streaming flow can be performed. Applications in aerosol characterization have led us to do this analysis for agglomerates of spheres, as well as flake-like particles. We obtain excellent agreement with the limited, published, experimental data.
Feedback effects in a laser diode due to Rayleigh backscattering from an optical fibre

Feedback effects in a laser diode due to Rayleigh back-scattering in a 50 m fibre with or without end reflections are reported. Linewidth reduction by more than 200 and wavelength instability on a millisecond scale are observed. An analytical model based on the statistical nature of the back-scattering shows good agreement with the experimental results.
Examples of estimation problems

Two examples of estimation problems are given. In the first example,X 1,X 2 andX 3 are independent random variables withX 1 having a Poisson distribution with mean θ1,X 2 being N(θ1,1) and X3/θ3 having a chi-square distribution withn degrees of freedom. Based on these three observations, an estimator of (θ1,θ2,θ3), strictly better than the standard one (X 1,X 2,X 3/(n+2)), is constructed by solving an inequality. In the second example, we establish a counter-example to the assertion that the lack of a nontrivial solution to a difference inequality (corresponding to the problem of improving upon an estimator δ through an identity of Hudson's (1974,Technical Report No. 58, Stanford University), and Stein's type (1973,Proc. Prague Symp. Asymptotic Statist., 345–381)) implies the admissibility of δ. Implications of these two examples are discussed.
Effect of Thanatophoric Dysplasia Type I Mutations on Fibroblast Growth Factor Receptor 3 Dimerization

Thanatophoric dysplasia type I (TDI) is a lethal human skeletal growth disorder with a prevalence of 1 in 20,000 to 1 in 50,000 births. TDI is known to arise due to five different mutations, all involving the substitution of an amino acid with a cysteine in fibroblast growth factor receptor 3 (FGFR3). Cysteine mutations in receptor tyrosine kinases have been previously proposed to induce receptor cross-linking in the unliganded state, thus emulating the effect of ligand and leading to receptor overactivation. Here, we characterize the effect of three TDI mutations, Arg248Cys, Ser249Cys, and Tyr373Cys, on FGFR3 dimerization in mammalian membranes, in the absence of ligand. We demonstrate that the mutations lead to modest stabilization and structural perturbations of the FGFR3 dimers. Based on available FGFR crystal structures, we argue that the effects of these mutations cannot emulate the effect of the ligand, thus challenging the current understanding of the molecular interactions that underlie TDI.
Excitation modal parameters analysis of grid-connected doubly-fed induction generators

In this paper, effect of excitation control parameters of doubly-fed induction generators on power system voltage stability is discussed. The excitation control of DFIG considered is mainly the constant voltage control and constant power factor control. Simulation test is carried out in Zhangjiakou wind farm in China, and key parameters of excitation control model of DFIG system are studied.
Lateral Oxidation of AlAs for Circular and Inverted Mesa Saturable Bragg Reflectors

A model of the thermal oxidation kinetics that is based on the continuity equation is adapted to the fabrication of circular saturable Bragg reflector (SBR) mesa structures, as well as inverted mesa array structures. A comparison between theoretical calculations and experimental measurements shows good agreement, making the model a useful tool for the controllability of the structure-dependent oxidation process. The model is applied to the wet oxidation of buried AlAs layers for the fabrication of ultra-broadband, high index contrast, III-V/ AlxOy SBRs. The rate of oxidation is found to be dependent not only on the oxidation temperature, but also on oxidation time, mesa geometry, and AlAs layer thickness. The two distinct large-area SBR structures, the circular mesa and the inverted mesa, are fabricated.
Intervention strategies for addressing collective trauma: Healing communities ravaged by racial strife

Drawing from psychoanalytic notions of the relation between trauma and memory, as well as the importance of “giving voice” and representation as essential elements of a healing process for both individual and collective traumatic experience, this article describes three interrelated, psychoanalytically informed interventions in a Texas community where conflict-laden residues of the Jim Crow era continued to affect race relations. The first intervention (the creation of a space within which Jim Crow– and Civil Rights–era narratives could be spoken and explored) and the second intervention (the creation of a documentary film) were closely linked because they were part of a process in which interviews gave testimony about a decisive, transformational experience. The third intervention created a public event where that which had been denied and excommunicated from the dominant narrative of the community's educational history could be “spoken.”
Accelerating hyperfractionation for carcinoma of the head and neck

A lthough control and cure rates for early cancer of the head and neck are good, advanced, unresectable lesions in these sites remain a therapeutic problem, l Induction or adjuvant chemotherapy, alone or in conjunction with conventional irradiation, has not resulted in great improvement] While hyperfractionated radiation therapy regimens have offered some gain in response and local control, toxicity is frequently great. 3'4 At the University of Miami, we have pursued treatment strategies for these tumors that seek to combine effective chemotherapeutic regimens with innovative and more rational approaches to irradiation. In particular, we have sought to exploit the dynamic nature of the various factors governing growth of tumors and normal tissues.
An electrochemical investigation of intermediates and processes involved in the catalytic reduction of dinitrogen by [HIPTN3N]Mo (HIPTN3N = (3,5-(2,4,6-i-Pr3C6H2)2C6H3NCH2CH2)3N).

The redox properties of [HIPTN3N]Mo complexes (where HIPTN3N = (3,5-(2,4,6-i-Pr3C6H2)2C6H3NCH2CH2)3N) involved in the catalytic dinitrogen reduction cycle were studied using cyclic voltammetry in fluorobenzene with Bu4NPF6 as the electrolyte. MoN2 (Mo = [HIPTN3N]Mo, E1/2 = −1.96 V vs. Fc+/Fc at a Pt electrode), Mo≡N (E1/2 = −2.68 V vs. Fc+/Fc (Pt)), and [Mo(NH3)]BAr′4 (Ar′ = 3,5-(CF3)2C6H3, E1/2 = −1.53 V vs. Fc+/Fc (Pt)) each undergo a chemically reversible one-electron reduction, while [MoNNH2]BAr′4 (E1/2 = −1.50 V vs. Fc+/Fc (Pt)) and [MoNH]BAr′4 (E1/2 = −1.26 V vs. Fc+/Fc (Pt)) each undergo a one-electron reduction with partial chemical reversibility. The acid employed in the catalytic reduction, [2,4,6-collidinium]BAr′4, reduces irreversibly at −1.11 V vs. Fc+/Fc at Pt and at −2.10 V vs. Fc+/Fc at a glassy carbon electrode. The reduction peak potentials of the Mo complexes shift in the presence of acids. For example, the reduction peak for MoN2 in the presence of [2,4,6-collidinium]BAr′4 at a glassy carbon electrode shifts positively by 130 mV. The shift in reduction potential is explained in terms of reversible hydrogen bonding and/or protonation at a nitrogen site in Mo complexes. The significance of productive and unproductive proton-coupled electron transfer reactions in the catalytic dinitrogen reduction cycle is discussed.
Efficacy of adenosine in terminating catecholamine-dependent supraventricular tachycardia

Abstract The purpose of this study was to determine if adenosine is equally effective in terminating catecholamine-dependent and independent supraventricular tachycardia (SVT). The effect of adenosine on termination of SVT was studied in 21 patients: 12 with atrioventricular (AV) reciprocating tachycardia, and 9 with AV node reentrant tachycardia. Group 1 comprised 13 patients who had SVT induced in the absence of exogenous catecholamines, whereas group 2 comprised 8 who needed isoproterenol (1.6 ± 0.4 p,g/min) for induction. There was no statistical difference between the 2 groups regarding age, weight, mean arterial pressure during sinus rhythm and SVT, cycle length of SVT, or norepinephrine and epinephrine levels during sinus rhythm and SVT. Cycle length during sinus rhythm was significantly decreased in group 2. The mean dose of adenosine needed to terminate SVT was 52 ± 6 μg/kg of body weight in group 1, and 61 ± 12 μg/kg in group 2 (p > 0.05). In addition to isoproterenol not altering the minimal dose of adenosine necessary to terminate SVT, there was also no correlation between the dose of adenosine (mean 55 ± 6 μg/kg) of each patient, and the corresponding endogenous epinephrine (273 ± 59 pg/ml) (r = −0.19) and norepinephrine (400 ± 58 pg/ml) (r = 0.01) levels during SVT, or cycle length of SVT (323 ± 9 ms) (r = −0.35). The results show that adenosine is equally effective in terminating catecholamine-independent and independent SVT; higher adenosine doses should not be needed to manage catecholamine-dependent SVT. In addition, the results suggest that adenosine may exert its effects on AV node conduction primarily through its effects on adenosine-sensitive potassium channels.
Multiscale Diffusion Measurements in Biological Gels Using Photoactivatable Fluorescent Nanoparticles

Diffusion through biological gels is crucial for effective nanoparticle drug delivery. In this work, we develop a method to measure diffusivity over a large range of length scales -- from tens of nanometers to tens of microns -- using photoactivatable nanoparticle probes. Nanoparticles composed of block copolymers of poly(lactic-co-glycolic acid) (PLGA) and polyethylene glycol (PEG) were synthesized and confirmed to possess dense PEG coatings that resist bioadhesion, and these particles were conjugated with caged rhodamine to make them photoactivatable. Using confocal microscopy, we activated a region of these particles with a brief, targeted exposure to UV light, uncaging the rhodamine and causing the particles to become fluorescent. We observed their collective diffusion over tens of minutes and tens of microns, thus obtaining a measure of their diffusivity. This technique is complementary to traditional multiple particle tracking (MPT); it extends the range over which particle motion can be directly observed. We confirmed the accuracy of this technique with reference to MPT measurements and the known diffusivity of particles in water. We applied the method to a model fibrin gel system, and found that both our method and MPT measurements show an immobile fraction of particles and mobile fraction that diffuses over long scales. Finally, we examined nanoparticle diffusion in sputum collected from cystic fibrosis patients, and we measured particle diffusion over distances relevant to drug delivery in the lungs. Coupled with traditional MPT, this technique enables multiscale characterization of particle mobility in complex biological fluids
GRETL: an econometrics package for teaching and research

Purpose – Model estimation gives students insights beyond what they can gain from textbook presentations. This paper introduces a way to make doing this easier and more effective. It introduces the program Gnu Regression, Econometrics and Time‐series Library (GRETL) which may be downloaded free of charge, and which students can place on their computers quickly and easily. Using GRETL to produce ordinary least squares (OLS) estimates is an easy, intuitive exercise. Therefore, instructors may assign such exercises without taking a large amount of time to introduce the computer and OLS estimation. GRETL, though designed to facilitate instruction, has grown into a full econometrics package that instructors can use as a research tool as well as an instructional aid.Design/methodology/approach – The paper provides an overview of GRETL's accessibility and its capabilities. Next it addresses the use of GRETL for instructional purposes. Then it shows how GRETL can be used as a research tool.Findings – The paper sh...
Discovery of Two New HCN Maser Lines in Five Carbon Stars

A survey with the Heinrich Hertz Submillimeter Telescope of HCN emission from mass-losing carbon stars has revealed masers in the J = 3-2 and 4-3 transitions of the (011c0) vibrational bending mode. These lines have not previously been known to show maser action. Five stars—R Scl, V384 Per, R Lep, Y CVn, and V Cyg—out of 12 observed were detected as masers. Allowing for evidence of variability, this detection rate suggests that these HCN lines are masers at least some of the time in the majority of mass-losing carbon stars. The line widths and velocities imply that the maser action occurs in gas close to the star, where the circumstellar envelope is just being accelerated outward.
Improvements in Urban Air Quality: Case Studies from New York State, USA

Air quality levels vary over regions due to meteorological factors, proximity to sources, and local conditions (i.e., topography). The Northeast USA is subjected to pollution inputs from both local sources and those from the upwind Midwest USA that are transported by prevailing meteorological patterns. With the passage of the Clean Air Act in 1970 and the establishment of the National Ambient Air Quality Standards (NAAQS), national levels of air pollutants have declined significantly. Our study compared air quality time trends between five of the largest cities within New York State (Albany, Buffalo, New York City, Rochester, and Syracuse) and statewide means to national trends. Data were obtained from the NYS Department of Environmental Conservation (DEC) Bureau of Air Quality Surveillance for six criteria pollutants: carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), particulate matter (PM2.5), and lead (Pb). Regional Kendall tests found significant downward trends for each pollutant statewide from 1980 to 2007, while trends by city varied by decade and pollutant. The evaluation of historical trends of pollution in industrialized nations is useful in showing recent air quality improvements and also in the understanding what can be the result in air pollutant controls in those developing nations currently experiencing high levels of pollution.
A study of economic indicators in rail freight traffic cycles 1950–76

Abstract This paper examines the characteristics of rail freight traffic cycles from 1950 to 1976. Both the NBER's statistical indicator approach and time series approach are used to identify the leading indicators of rail freight traffic cycles from a set of leading economic indicators published by the Department of Commerce. The concepts and empirical results obtained by these two procedures are compared and contrasted. The interesting findings are: (1) the composite index of 12 leading indicators performs very well as a qualitative and quantitative predictor and (2) the empirical results obtained by the NBER approach are, in general, consistent with those obtained by the time series approach.
Erythroblastosis fetalis due to anti-S antibody.

Summary Hemolytic disease of the newborn infantdue to isosensitization by the S blood group factor in an Rh-positive mother resulted in postnatal hyperbilirubinemia and a “late anemia” syndrome in the infant. In our case, as well as in two of the three previously reported cases, the isosensitized pregnancy followed previous blood transfusions.
An investigation of the putative photosynthesis of ammonia on iron-doped titania and other metal oxides

Abstract The reported heterogenous photocatalytic sythesis of NH 3 from N 2 and H 2 O in the presence of iron-doped TiO 2 or other semiconducting metal oxides has been investigated. Skepticism about this thermodynamically and mechanistically daunting process is appropriate, and the results reported here support a skeptical position. To assess the reproducibility of the results obtained by previous workers, we performed a large number of experiments under various conditions similar to those employed with apparent success by others. We also carried out 15 N isotope labelling experiments in which the lower limit of detection was around 0.2–1 nmol of added 15 NH 3 in 10 μmol of natural ammonia, i.e. two to three orders of magnitude below the levels reported in successful syntheses by others. All the catalysts tested promoted the photo-oxidation of ammonia under the conditions said to give ammonia photosynthesis. Photocatalytic nitrogen fixation was not found in any of the experiments, although in some cases results were obtained that could have been mistaken for nitrogen fixation. Our results suggest that the reported putative reaction does not occur. We recommend that any further research in this area should be based on standards of demonstration as rigorous as those applied in experiments on the biological fixation of nitrogen.
Protein purification by affinity binding to unilamellar vesicles.

A novel purification technique is proposed which employs affinity-ligand-modified liposomes to specifically purify bioactive macromolecules from solution. This process is demonstrated with avidin as the model biomolecule and biotin as the affinity ligand. Biotin is covalently bound to the surface of small unilamellar vesicles composed of dimyristoyl phosphatidylcholine (DMPC) and dimyristoyl phosphatidylethanolamine (DMPE). The number of accessible binding sites on the liposomes is determined by titration with avidin, and the kinetics of binding are evaluated by monitoring the concentration of free avidin in solution after the addition of biotinylated liposomes. The specificity of the process is determined by following the affinity binding of avidin to biotinylated liposomes in the presence of model impurities (i.e., lysozyme and cytochrome C). Liposome-bound avidin is separated from the impurities by ultrafiltration through a membrane which retains the liposomes.
Properties of Thin Polyimide Films

Polyimide is receiving increasing interest as a possible insulator on semiconductor devices, replacing . Several commercially available polyimides have been characterized by testing films of them for electric breakdown strength, conductivity, adhesion, and other properties. The results of these tests are summarized, and the polyimides are compared to sputtered .
Synchronization of fluxon motion on Shapiro steps in Josephson junctions

Abstract We demonstrate that shuttling fluxons can exist on Shapiro steps in open ended long Josephson junctions driven by a large amplitude, high frequency, electric field if the junction is described by the overlap geometry. If a small amplitude, low frequency, magnetic field is applied to the system we further demonstrate that the frequency of the shuttling fluxon may phase-lock to a subharmonic of the frequency of the magnetic field. Analytical expressions for the range of phase-locking in bias current are evaluated and excellent agreement is found when these are compared to the results of direct numerical simulations of the perturbed sine-Gordon equation, modeling the junction.
Dose effect of mucosal adjuvant LT(R192G) on the induction of Th1 and Th2 immunity

Abstract Rationale The balance between Th 1 and Th 2 immune response can affect disease manifestations. In vaccination, the type of antigen and adjuvant as well as the antigen dose can alter this balance. To determine if the amount of adjuvant has an effect on Th 1 /Th 2 polarization, mice were immunized with a fixed antigen dose and varying adjuvant doses. Methods C3H/HeJ mice were immunized intranasally with 2.5μg/dose of HIV 1 reverse transcriptase (RT) antigen and either 1μg/ or 10μg/dose of the heat-labile E.coli enterotoxin LT(R192G) adjuvant three times at weekly intervals and sacrificed 1-2 weeks later. RT-specific IgG1 and IgG2a from serum were measured by ELISA. ELISPOT and flow cytometry for IFN-γ and IL-4 were performed with splenic and mesenteric lymph node cells. Results At low adjuvant dose (1μg), there was predominately IgG2a production with IgG2a/IgG1 ratio of 24 (SEM ± 7.8); at high adjuvant dose (10μg) there was a 28-fold increase in IgG1 with an IgG2a/IgG1 of 1.7 (SEM ± 0.7) (n=7, p Conclusions In mucosal immunization, the adjuvant dose can shift the balance of the resulting antigen-specific Th 1 and Th 2 immune response as evidenced by changes in antibody and cytokine profiles. A low dose of LT(R192G) favors a Th 1 polarization with an elevation in IgG2a and IFN-γ. At high dose, there is an increased production in IgG1 and IL-4 suggesting a Th 2 component.
Extraventricular neurocytomas: pathologic features and clinical outcome.

Neurocytic neoplasms usually arise within the lateral ventricles, generally as circumscribed, slowly growing masses curable by total resection. Both subtotal resection and histologic atypia are associated with an increased risk of recurrence. In contrast, neurocytic neoplasms situated within brain p
Every finite group is the automorphism group of some perfect code

Abstract In this paper we prove the every finite group is isomorphic to the full automorphism group of some perfect binary single error correcting code.
Energy Efficient Network Reconfiguration for Mostly-Off Sensor Networks

A new class of sensor network applications are mostly off. Exemplified by Intel's FabApp, in these applications the network alternates between being off for hours or weeks, then activating to collect data for a few minutes. While configuration of traditional sensornet applications is occasional and so need not be optimized, these applications may spend half their time while awake configuring, so they require new approaches to quickly restart after a long downtime, in effect, "sensor network suspend and resume". While there are many network services that may need to be restarted, this paper focuses on the key question of when the network can determine that all nodes are now awake and ready to interact. Current resume approaches assume worst-case clock drift and so must conservatively take minutes to reconfigure after a month-long sleep. We propose two energy efficient reconfiguration protocols to address this challenge. The first approach is low-power listening with flooding, where the network restarts quickly by flooding a control message as soon as one node can determine the whole network is up. The second protocol uses local update with suppression, where nodes only notify their one-hop neighbors about the network state, avoiding the cost of flooding. Both protocols are fully distributed algorithms. Through analysis and simulations, we show that both protocols are more energy efficient than current approaches. Flooding works best in sparse networks with 6 neighbors or less, while local update with suppression works best in dense networks (more than 6 neighbors)