cssi/SciSciGPT-SciSciNet huggingface dataset:
Population differences in the timing of diapause: a test of hypotheses

The reproductive phenology of the freshwater copepod Diaptomus sanguineus differs markedly between populations residing in two Rhode Island ponds. In a permanent pond the population switches abruptly from making subitaneous (immediately hatching) eggs to diapausing eggs at the end of March each year. In contrast, a temporary pond population switches egg types in May, returns to production of subitaneous eggs in June, and concludes the reproductive season by making diapausing eggs in July. An ESS model suggests that the pattern of diapause expected of a copepod population is a function of annual variation in the onset of harsh conditions (catastrophe date). When variation is relatively low, the superior strategy is for diapause to begin a constant period before the mean catastrophe date. When variation is high, females should make first subitaneous eggs and then diapausing eggs irrespective of the expected catastrophe date. With discrete generations, such a population would alternate between egg types. In the permanent pond, variation of catastrophe date the spring onset of planktivory by sunfish is low, whereas in the temporary pond variation of the catastrophe (pond drying) is high. The model predicts well the phenology of the two copepod populations. In the research reported here, we tested the hypothesis that copepods from the permanent pond, which switch to diapause at the same time every year, are cued by the environment to begin diapause (i.e. by photoperiod, temperature, or both), whereas those from the temporary pond make both egg types regardless of environmental conditions. In opposition to our hypothesis, experimental results indicate that diapause in both populations is cued by the environment. The distinct reproductive phenologies documented in the two populations apparently result from the copepods responding to different environmental cues, rather than one being responsive to the environment while the other is not.
Nanosensors: small strains, big gains.

A new approach to sensing mechanical motion allows high-frequency measurements to be made with cantilevers that are smaller than the wavelength of light.
Vibrational Spectra of Polypeptides

Abstract The vibrational spectrum of a polymer reflects its detailed fine structure, and the potential advantages of applying this technique to the complex problems of protein chemistry have been realized for some time. However, until a few years ago only dispersive IR instruments could be used to obtain high quality spectra. Raman spectroscopy was only of marginal significance owing to the weak exciting sources then available. The advent of laser excitation meant that high quality Raman spectra could be obtained in a routine fashion, while in the field of IR spectroscopy the introduction of Fourier transform instruments with an on-line computer capability promises an equivalent breakthrough.
Latex versus iodinated contrast media anaphylaxis in the cardiac cath lab.

A 65-year-old man had bypass surgery 10 years previously with pulmonary artery catheter monitoring. Shortness of breath and mitral regurgitation necessitated repeat left and right heart catheterization using a pulmonary artery catheter. Before any iodinated contrast media exposure, the pulmonary artery catheter was inserted and within 2 min the patient developed anaphylaxis associated ventricular fibrillation. It was discovered that the pulmonary artery catheter used in the cath lab had a latex balloon and that the patient had been exposed to latex 10 years ago. Latex induced anaphylaxis is rarely considered in the differential diagnosis of patients with hypersensitivity reactions in the cath lab, intensive care unit, and operating room. The principal reason for failure to recognize the latex balloon as a potential allergen is that most health professionals are not aware that almost all pulmonary artery catheters contain a latex balloon. The risk of an allergic response to latex is 0.8% for the general population. Others at high risk include those who have had multiple surgical procedures and interventions with repeated latex exposure. Five to 10% of all U.S. health professionals and those performing household duties wearing latex gloves have an allergic response to latex. Latex hypersensitivity is an IgE dependent reaction, while iodinating contrast medium reaction is an IgE independent reaction. If latex hypersensitivity is suggested by pre-procedural history or if the patient falls into a high-risk group, pre-procedural skin testing and/or latex IgE radioallergosorbent (RAST) should be performed.(ABSTRACT TRUNCATED AT 250 WORDS)
Dysregulation of the Polo-Like Kinase Pathway in CD4+ T Cells Is Characteristic of Pathogenic Simian Immunodeficiency Virus Infection

CD4(+) T-cell dysfunction highlighted by defects within the intracellular signaling cascade and cell cycle has long been characterized as a direct and/or indirect consequence of human immunodeficiency virus (HIV) infection in humans and simian immunodeficiency virus (SIV) infection in rhesus macaques (RM). Dysregulation of the M phase of the cell cycle is a well-documented effect of HIV or SIV infection both in vivo and in vitro. In this study the effect of SIV infection on the modulation of two important regulators of the M phase-polo-like kinases Plk3 and Plk1-was investigated. We have previously shown that Plk3 is markedly downregulated in CD4(+) T cells from SIV-infected disease-susceptible RM but not SIV-infected disease-resistant sooty mangabeys (SM), denoting an association of downregulation with disease progression. Here we show that, in addition to the downregulation, Plk3 exhibits aberrant activation patterns in the CD4(+) T cells from SIV-infected RM following T-cell receptor stimulation. Interestingly, in vitro SIV infection of CD4(+) T cells leads to the upregulation, rather than downregulation, of Plk3, suggesting that different mechanisms operate in vitro and in vivo. In addition, CD4(+) T cells from RM with high viral loads exhibited consistent and significant upregulation of Plk1, concurrent with an aberrant activation-induced Plk1 response, suggesting complex mechanisms of SIV-induced M-phase abnormalities in vivo. Altogether this study presents a novel mechanism underlying M-phase defects observed in CD4(+) T cells from HIV or SIV-infected disease-susceptible humans and RM which may contribute to aberrant T-cell responses and disease pathogenesis.
A scalable architecture for visual data exploration

Intelligence analysts in the areas of defense and homeland security are now faced with the difficult problem of discerning the relevant details amidst massive data stores. We propose a component-based visualization architecture that is built specifically to encourage the flexible exploration of geospatial event databases. The proposed system is designed to deploy on a variety of display layouts, from a single laptop screen to a multi-monitor tiled-display. By utilizing a combination of parallel coordinates, principal components plots, and other data views, analysts may reduce the dimensionality of a data set to its most salient features. Of particular value to our target applications are understanding correlations between data layers, both within a single view and across multiple views. Our proposed system aims to address the limited scalability associated with coor-dinated multiple views (CMVs) through the implementation of an efficient core application which is extensible by the end-user.
Actors, Athletes, and Astronauts: Political Amateurs in the United States Congress

The U.S. Congress is typically seen as an institution filled with career politicians who have been seasoned by experience in lower levels of political office. In fact, political amateurs have comprised roughly one quarter of the House of Representatives since 1930. The effect of amateurs' inexperience on their political careers, roles in Congress, and impact on the political system has never been analyzed in detail. Written in a lucid style accessible to the nonspecialist, David T. Canon's Actors, Athletes, and Astronauts is a definitive study of political amateurs in elections and in Congress. Canon examines the political conditions that prompt amateurs to run for office, why they win or lose, and whether elected amateurs behave differently from their experienced counterparts. Challenging previous work which presumed stable career structures and progressively ambitious candidates, his study reveals that amateurs are disproportionately elected in periods of high political opportunity, such as the 1930s for Democrats and 1980s for Republicans. Canon's detailed findings call for significant revision of our prevailing understanding of ambition theory and disarm monolithic interpretations of political amateurs. His unique typology of amateurism differentiates among policy-oriented, "hopeless," or ambitious amateurs. The latter resemble their professional counterparts; "hopeless" amateurs are swept into office by strong partisan motivations and decision-making styles of each type vary, affecting their degree of success, but each type of amateur provides a necessary electoral balance by defeating entrenched incumbents rarely challenged by more experienced politicians.
Noradrenaline reversal in canine subcutaneous adipose tissue.

Abstract Although adrenaline reversal is a well known phenomenon, fewer investigations have demonstrated reversal of the vascular response to noradrenaline (NA). The present studies compared subcutaneous adipose tissue vascular responses to intra-arterial NA with those of sympathetic nerve stimulation. Both NA and electrical stimulation produced vasoconstriction in adipose tissue which was reversed to β-adrenergically mediated vasodilation following local α-adrenergic block.
Instruction for Military Air Intercept Control

Two experiments were conducted using a microcomputer simulation to teach military air-intercept control skills. In Experiment I, three experimental training methods were compared to the normal method in which students identify the bearing of the enemy fighter from a friendly fighter and then calculate an intercept heading. Part training was employed to provide intensive training in critical component skills. Time compression was used to speed the simulation after the student provided a solution, so that many more practice trials could be given in each training session. A spatial visualization method of determining the intercept heading was contrasted to the normal method of mathematical calculation. After training, all subjects were tested with the same whole, real-time scenario. Part training with time compression and the spatial visualization method of determining intercepts was more effective than whole, real-time training with the calculation method of determining intercepts. The results suggest a sub...
Morbidity and infant development: a hypothesis

An exploratory assessment was made of the relationship between morbidity during the first six months of life and performance in the Bayley Scales of Mental and Motor Development at eight months of life. The study was conducted in 14 villages of Sui Lin Township, Taiwan, which is a rural agricultural area 180 miles south of Taipei. Prior to the study daily dietary intake of the mothers was estimated to range from 1400 to 2000 kcal and 40 grams of protein. Developmentally the children who were healthy were better off than the children who became ill during the first two trimesters. A striking adverse effect of morbidity was found on both mental and motor scale scores when gastrointestinal and respiratory illness were aggregated. Children without illness plus children who were ill with only one illness in one trimester obtained statistically significantly higher scores than the children who were ill with both types of illness and in both trimesters. These findings were explained as a function of the negative...
Familial translocation resulting in Wolf-hirschhorn syndrome in two related unbalanced individuals: Clinical evaluation of a 39-year-old man with Wolf-Hirschhorn syndrome

A chromosomal translocation between chromosomes 4 and 8 resulting in Wolf-Hirschhorn syndrome in 2 individuals has been traced through 4 generations of a family. Ascertainment of the family was through a newborn infant with evident Wolf-Hirschhorn syndrome who had an unbalanced chromosomal translocation [46,XY,-4,+der(4),t(4;8) (p15.32;p22)]. Discussion with the family documented a paternal great-uncle who also had a similar phenotype and profound mental retardation. Subsequently this individual was found to have the same unbalanced chromosome constitution as the propositus. The 39-year-old great-uncle is the oldest reported individual with the Wolf-Hirschhorn syndrome. The importance of chromosome evaluation of older individuals with mental retardation syndromes is emphasized.
Gaze-Contingent Video Compression with Targeted Gaze Containment Performance

A delay compensation algorithm is presented for a gaze-contingent video compression system (GCS) with a robust targeted gaze containment (TGC) performance. The TGC parameter allows varying compression levels of a gaze-contingent video stream by controlling its perceptual quality. The delay compensation model is based on the Kalman filter framework that models the human visual system with eye position and velocity data. The model predicts future eye position and constructs a high-quality coded region of interest (ROI) designed to contain a targeted number of gaze samples while reducing perceptual quality in the periphery of that region. Several model parameterization schemes were tested with 21 subjects using a delay range of 0.02 to 2 s and a TGC of 60 to 90%. The results indicate that the model was able to achieve TGC levels with compression of 1.4 to 2.3 times for TGC=90% and compression of 1.8 to 2.5 for TGC=60%. The lowest compression values were recorded for high delays, while the highest compression values were reported during small delays.
Challenge session speakers: Engaging today's genomics resources

Advances in next-generation sequencing platforms have reshaped the landscape of genomic and epigenomic research. Large consortiums such as the ENCyclopedia of DNA Elements (ENCODE), the Roadmap Epigenomics project and The Cancer Genome Atlas (TCGA) have generated tens of thousands of sequencing-based genome-wide data-sets, creating a reference and resource for the scientific community. Small groups of researchers are now able to rapidly obtain huge volumes of genomic data and are in great need of putting their own data in the context of the consortium data for comparison. These data are often accompanied by rich metadata describing the sample and experiment, critical for their interpretation. Fast evolving technologies, such as those interrogating long-range chromatin interactions, are generating new types of data in similarly large volumes. Visualizing, navigating, and interpreting such data in a meaningful way is a daunting challenge. In this presentation I will discuss the present challenges in genomic data visualization and the rapid evolution of Genome Browsers.
Superiority of Minimally Invasive Parathyroidectomy

Because greater than 80% of spontaneous cases of primary hyperparathyroidism are caused by a single adenoma, BCE of the neck, which has long been the approach of choice, is being replaced. Focused parathyroidectomy has been made possible by advances in preoperative parathyroid localization and IOPTH monitoring, which allows confirmation of cure and confirmation of the absence of MGD without visualizing all 4 parathyroids. Several techniques for focused parathyroidectomy exist, but open MIP through an incision of 2 to 3 cm with surgeon-administered locoregional anesthesia seems to improve on the already high success rate and low morbidity associated withimproe on bilateral exploration. In addition, MIP is associated with numerous secondary benefits such as decreased hospital cost, improved patient satisfaction, decreased operative time, and same-day discharge. Bilateral exploration will remain the standard of care for most patients with multigland or syndromic disease. Most patients with sporadic PHPT are candidates for MIP.
Lightweight TiC/Ti wear-resistant coatings for lightweight structural applications

Lightweight coatings based on titanium and titanium carbides produced by plasma spraying can be used to improve and modify the tribomechanical properties of aerospace structural materials. Although plasma-sprayed WC/Co coatings have been applied with success in many cases, such as primary wear-re-sistant materials, their high densities preclude their use in applications that mandate reduction in weight. In the present investigation, the sliding wear resistance of plasma-sprayed, metal-bonded TiC coatings on AI 7075 substrates was studied. Coatings containing 50, 70, and 90 vol% TiC in a Ti matrix produced from physically blended powders of Ti and TiC were compared. Metallographie evaluations showed that dense coatings with good bonding to AI 7075 substrates can be obtained. Coatings from commercial pu-rity (CP) Ti powders sprayed in air under atmospheric conditions, however, indicated considerable oxi-dation of the particles. Under dry sliding conditions, the coefficient of friction (COF) values of the Ti/TiC containing/Al 7075 substrate system were lower than high-velocity oxygen fuel (HVOF) sprayed 75% Cr3C2/25%NiCr coatings on steel and were comparable to coatings of WC/Co. Vacuum plasma-sprayed TiC/Ti coatings with 90 vol% TiC also exhibited better wear resistance than HVOF sprayed 75%Cr3C2/25%NiCr.
Using extrathermodynamic relationships to model the temperature dependence of Henry's law constants of 209 PCB congeners.

Our previous measurements of the temperature de pendencies of Henry's law constants of 26 polychlorinated biphenyls (PCBs) showed a well-defined linear relationship between the enthalpy and the ent...
Comparative Localizing Response of Inflammatory and Irradiated Tissues to Injected Protein.

SummaryRapid production of IF has been demonstrated in bovine leucocyte cultures. Such production was also greater after 7 to 12 days of cultivation. Under the experimental conditions employed IF was formed before NDV multiplication. From these data obtained, the role of phagocytic cells in vivo was discussed.
Use of State Police Services for Local Policing: The Case of New Jersey

All states in the New England and Middle Atlantic regions of the United States provide State Police services without charge to municipalities without full-time local police departments. Efficiency and equity issues have resulted from this tradition and the development of local police departments or shared departments across neighboring municipalities in rural and exurban areas has been discouraged. These problems will diminish in scope as municipalities receiving the State Police subsidy opt out of the program and adopt local policing. We examine this potential by estimating models of the municipal decision to use the State Police for local policing among New Jersey municipalities with less than 15,000 population. We find that the elasticities of the decision to use the State Police for local policing with respect to population and median family income to be −1.1 and −2.3, respectively. If recent income and population trends in New Jersey municipalities using the State Police continue, our upper range estimate is that about 20 of the 90 municipalities using the State Police will opt out of the program in the next decade.
A review of studies reporting on complications of upper urinary tract stone ablation using the holmium:YAG laser

Summary Purpose A review of the literature of studies reporting complications of ureteroscopic urinary tract stone ablation using the holmium:YAG laser was performed. Patients and methods Electronic databases were searched using specific keywords to identify relevant studies. Reference lists of identified articles were scrutinised for other studies and searches were conducted using the names of authors known to have published widely in this field. Two reviewers assessed retrieved articles for inclusion criteria. Patients Results Overall, 48 studies published between 1994 and 2007 were included. Half were published since 2000. In total, 4454 patients were identified. Around half of studies were performed in North America (25). The number of patients per study varied from 8 to 598. The study populations were very heterogeneous in terms of stone position and size, and ureteroscope size and rigidity. Overall, 303 (6.8%) complications were identified. Post-operative ureteric stricture and perforation rates were both 1.0%. There were only six major complications identified (0.1%). The post-operative sepsis rate was 2% and one death was reported. Conclusions Upper urinary tract stone ablation using the holmium:YAG laser is both safe and reliable. Follow-up imaging to detect procedure-specific complications would not appear to be routinely indicated given this low complication rate.
Linear wave-vector dependence of optical phonon frequencies in bismuth germanium oxide in the vicinity of the Brillouin zone center

Triply degenerate $F$ modes in the Raman spectrum of ${\mathrm{Bi}}_{12}$Ge${\mathrm{O}}_{20}$, which has the cubic point-group symmetry $T$, are studied as a function of the magnitude of the phonon wave vector $\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}$. The small splittings due to the long-range polarization field (LO-TO splitting) and linear $\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}$ effects near the zone center are resolved using the high resolution of a piezoelectrically scanned Fabry-Perot interferometer, with samples cooled to liquid-helium temperatures. Uniaxial stress is used as an external perturbation to characterize these effects further. Combining group-theoretical arguments with time-reversal symmetry, we derive expressions for the frequencies and the polarizability tensors of the $F$ modes including the effects of linear $\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}$ dependence, LO-TO splitting, and uniaxial stress. The experimental results are in excellent agreement with theory.
On the DNA polymerase-a mutant: immunofluorescence assay of UV-induced thymidine dimers in Aphr-4-2 cells.

Aphidicolin inhibits purified DNA polymerases-a and -d in vitro and inhibits mitosis in animal cells. The Chinese hamster V79 cell mutant, Aphr-4-2, was selected for its ability to form colonies in cultured medium supplemented with 1.0 µM aphidicolin. At this concentration, the parental wild-type V79 cells (clone 743x) have a survival rate of <10−7. The mutant DNA polymerase-a is resistant to aphidicolin at concentrations that are inhibitory to the wild-type V79 DNA polymerase-a. The apparent Km for dCTP of the mutant DNA polymerase-a is consistently lower than that of the wild-type DNA polymerase-a. This mutant exhibits slow growth, mutator activity, hypersensitivity, and hypermutability to UV. We wanted to know the basis of UV hypersensitivity in this mutant. Using the antisera (UV2) raised against UV-induced thymidine dimers and a sensitive immunofluorescence assay to measure UV-induced thymidine dimers and with detection in ACAS 570 Workstation, we observed that 50% of the thymidine dimers disappeared within 5 h after irradiation and more than 80% of the dimers were removed within 24 h in both cell lines. These results indicate that the recognition, incision, and excision steps in nucleotide excision repair pathway are normal in the mutant. In order to know if there is a difference in DNA polymerase-a or -d activities in the parental V79(wt) and Aphr-4-2 cells, DNA polymerases were partially purified from the parental and the mutant cells using sequential centrifugation and column chromatographies on DEAE-cellulose (DE23 and DE52) to remove DNA polymerases-beta and -gamma. More than 90% of the enzymatic activities from both cells showed characteristics of DNA polymerase-a type on the basis of these criteria: sensitivity to butyl phenyl dGTP (1 µM) and to IgG raised against DNA polymerase-a (SJK 132-20). The results indicate that DNA replication involving a mutant DNA polymerase-a with altered affinity for dCTP may be responsible for the UV sensitivity and mutability of the mutant.
Blockage correction in three-dimensional wind tunnel testing based on the wall signature method

An improved wall interference assessment and correction method for three-dimensional wind tunnel testing is presented. Blockage corrections on the surface of a test article are calculated based on a limited number of wall pressure measurements. These measurements are combined with a signature analysis procedure and influence functions to determine an equivalent test article and wake representation. Pressure coefficient corrections are calculated based on this equivalent body. The signature analysis procedure is modified to improve the on-line operation of the wall signature method. A new geometry of the equivalent body is introduced which can be combined with existing panel codes more effectively. The calculation of influence functions and the determination of pressure coefficient corrections are based on a panel code. Therefore it is possible to apply the present method to any closed tunnel cross section. A numerical simulation of the idealized flow field of a wing and its wake in a rectangular wind tunnel is used to verify the improved wall signature method. The present method is considered to calculate blockage corrections in the NASA/ARC 12ft Pressure Wind Tunnel.
Establishing the level of service for public emergency ambulance systems.

Abstract A comprehensive approach to establishing the level of service for an emergency ambulance system is proposed. The approach uses an optimal ambulance deployment model to generate promising ambulance systems for various fleet sizes. These systems in turn are compared to a baseline (the existing system) and cost-effectiveness ratios are calculated to combine system cost and intangible benefits. The resulting ratios are used to screen the alternative systems for an appropriate level of service. The approach is used by the City of Austin, Texas to select an ambulance system.
Low-pass filtered least squares estimators of cointegrating vectors

Abstract This paper proposes a class of low-pass filtered least squares estimators of cointegrating vectors. It is shown that (1) the filtered least squares estimators may reduce the second order bias; (2) while the filtered fully modified least squares estimators share the same asymptotic efficiency as the fully modified least squares estimators, the filtered fully modified least squares may gain efficiency in finite samples; and (3) the filtered fully modified Wald tests have asymptotic χ 2 distributions. A Monte Carlo study indicates that the finite sample properties are consistent with the asymptotic results, and, in particular, the filtering method for removing high-frequency components significantly improves OLS and FMLS cointegrating estimators, with the gains from filtering being significant in finite samples.
A Search for Radio Transients at 0.33 GHz in the GC

We report on a search for transient and variable radio sources in the Galactic center using a number of 327 MHz VLA observations made during the 1990's, and a series of monthly VLA observations made during Spring and Summer 2002. A typical yield of compact sources in a given epoch is roughly 200. We have detected one new bright radio transient, GCRT J1746–2757, located only 1.1 degrees north of the Galactic center. We discuss our on-going transient monitoring program and the implications of this work for constraining the Galactic center population of transients.
Regularity of components in optimal design problems with perimeter penalization

We consider minimal energy configurations of mixtures of two materials in $\Omega\subset\mathbb{R}^2$ , where the energy includes a penalty on the length of the interface between the materials. We show that, for one of the materials, the boundary of each component is smooth, and we prove the existence of an upper bound on the relative distances between components.
A Dynamic Procedure for the Lagrangian Averaged Navier-Stokes- Model of Turbulent Flows

A dynamic procedure for the Lagrangian Averaged Navier-Stokes- (LANS- ) equations is developed where the variation in the parameter in the direction of anisotropy is determined in a self-consistent way from data contained in the simulation itself. In order to derive this model, the incompressible Navier-Stokes equations are Helmholtz-filtered at the grid and a test filter levels. A Germano type identity is derived by comparing the filtered subgrid scale stress terms with those given in the LANS- equations. Assuming constant in homogenous directions of the flow and averaging in these directions, results in a nonlinear equation for the parameter , which determines the variation of in the non-homogeneous directions or in time. Consequently, the parameter is calculated during the simulation instead of a pre-defined value. In order to evaluate the applicability of the dynamic LANS- model in anisotropic turbulence, a priori test of a turbulent channel flow is performed. It is found that the parameter changes in the wall normal direction. Near a solid wall, the length scale is seen to depend on the distance from the wall with a vanishing value at the wall. On the other hand, away from the wall, where the turbulence is more isotropic, approaches an almost constant value. Furthermore, the behavior of the subgrid scale stresses in the near wall region is captured accurately by the dynamic LANS- model. The dynamic LANS- model has the potential to extend the applicability of the LANS- equations to more complicated anisotropic flows.
Escherichia coli phosphoenolpyruvate carboxylase: kinetics and mechanism of inactivation.

Abstract In dilute solution phosphoenolpyruvate carboxylase of Escherichia coli undergoes a spontaneous inactivation that can be described mathematically by a two-component declining exponential equation. The rate constant for the decay of the first component is 3.05 ± 0.52 × 10−2 min−, whereas that for the second component is variable, smaller in magnitude, and dependent upon the dilution conditions. Analysis of the coefficients for the exponential equation suggests that the decline of enzymatic activity with time is a function of the initial concentrations of catalytically active dimer and tetramer. From the concentrations of these two species, as determined from their initial activities, an equilibrium constant of 3 × 10−7 m for the tetramer-dimer dissociation was determined. The diluted enzyme exhibits properties similar to those ascribed to hysteretic enzymes. The appearance of hysteresis is a function of the time after dilution and the presence of modifiers of catalytic activity, i.e., it is not present immediately after dilution and can be prevented from occurring if aspartate is present in the dilution buffer. The data are consistent with a scheme in which dimeric and tetrameric forms of the enzyme undergo inactivation by dissociation to monomers. The tetramer can dissociate directly to monomers and become inactivated or it can dissociate first to dimers than to monomers before undergoing inactivation. Monomer-to-dimer reassociation occurs to form a catalytically active species, but monomer-to-tetramer reassociation to an active species is not apparent. Hysteresis is presumed to result from reversible isomerization of the monomeric species to a form that can also result in an irreversibly inactivated enzyme.
Popular Perceptions of Soviet Politics in the 1920s: Disenchantment of the Dreamers

The heart of Olga Velikanova's latest book consists of three case studies designed to shed light on the relationship between the ruling party and Soviet society in the 1920s: the war scare of 1927;...
Contextualizing Personal Experience: The Role of Mass Media

This study considers competing theories concerning the role of mass media in hindering or facilitating the translation of personal experiences into political preferences. Using national survey and media content data that allow evaluations of both media coverage and individual patterns of media use, this study evaluates the influence of mass media on the direct impact of personal experiences on presidential performance as Ronald Reagan completed his second term in office, and on the indirect impact of personal experiences by means of their impact on collective-level issue judgments. Exposure to unemployment news appears to strengthen the impact of personal experiences on presidential performance ratings. Heavy unemployment coverage also increases the extent to which perceptions of national unemployment conditions are generalized from personal experience. Overall, results suggest that mass media may counter the tendency to morselize personal experiences and help legitimize the translation of private interes...
Aligning emission tomography and MRI images by optimizing the emission-tomography image reconstruction objective function

An important approach to reconstructing PET and SPECT (PET/SPECT) radiotracer images is to utilize high-resolution information from registered MRI or CT (MRI/CT) images. These methods depend on accurate registration of PET/SPECT and MRI/CT images. Herein, we consider registration via optimization of a PET/SPECT image-reconstruction objective function which includes the registration parameters. Potential benefits of this approach include 1) modeling, within the registration process, of PET/SPECT noise and PET/SPECT acquisition effects such as limited spatial resolution, perhaps resulting in more accurate registration and 2) a natural framework for calculating joint uncertainties in registration parameters and radiotracer activity. In cases where the structures imaged by MRI/CT (e.g., gray matter and white matter in the brain) strongly influence the radiotracer distribution, the relatively small number of variables comprised of alignment parameters and regional radiotracer mean activities may account for, not all, but much of the estimable radiotracer distribution, and it may be useful to develop methods for rapid, highly accurate estimation of these few parameters, ultimately embedding such estimation within more general estimation of the full radiotracer distribution. Herein we develop Levenberg-Marquardt simultaneous estimation of regional radiotracer mean activities and the six 3D rigid body translation and rotation alignment parameters. The method is tested by a computer-simulation study. With a PET/SPECT scanner spatial resolution of 0.2 cm FWHM, this study shows translational registration errors of about 0.002 cm and rotational errors which are fractions of a degree. For small regions, estimates of regional mean activities are much closer to true values than are estimates obtained by OSEM using PET/SPECT projection data only.
Motion planning for concentric tube robots using mechanics-based models

Concentric tube robots have the potential to enable new minimally invasive surgical procedures by curving around anatomical obstacles to reach difficult-to-reach sites in body cavities. Planning motions for these devices is challenging in part due to their complex kinematics; concentric tube robots are composed of thin, pre-curved, telescoping tubes that can achieve a variety of shapes via extension and rotation of each of their constituent tubes. We introduce a new motion planner to maneuver these devices to clinical targets while minimizing the probability of colliding with anatomical obstacles. Unlike prior planners for these devices, we more accurately model device shape using mechanics-based models that consider torsional interaction between the tubes. We also account for the effects of uncertainty in actuation and predicted device shape. We integrate these models with a sampling-based approach based on the Rapidly-Exploring Roadmap to guarantee finding optimal plans as computation time is allowed to increase. We demonstrate our motion planner in simulation using a variety of evaluation scenarios including an anatomy-based neurosurgery case that requires maneuvering to a di#cult-to-reach brain tumor at the skull base.
Optimal feedback control design for discrete-event systems using simulated annealing

Abstract We propose a formulation and computational algorithm for the design of feedback controls for discrete-event dynamical systems with cyclic behavior. Models for the process and controller are expressed using timed and untimed Petri nets, respectively. Performance specifications are given in terms of forbidden states. Numerical solution for an optimal feedback controller is found by simulated annealing. These procedures are demonstrated for a literature benchmark problem, and for supervisory control of a pipeless batch plant.
SVD-QR-T FCM Approach for Virtual MIMO Channel Selection in Wireless Sensor Networks

In this paper, we present singular-value decomposition- QR with threshold (SVD-QR-T) algorithm to select a subset of channels in virtual MIMO wireless sensor networks (WSN) in order to reduce its complexity and cost. SVD- QR-T selects best subset of transmitters while keeping all receivers active. The threshold is adaptive by means of fuzzy c-mean (FCM). Under the constraint of the same total transmission power, this approach is compared against the case without channel selection in terms of capacity, bit error rate (BER) and multiplexing gain in the presence of water-filling as well without. It is shown that in spite of less multiplexing gain, when water-filling is applied, SVD- QR-T FCM provides lower BER at moderate to high SNR; in case of equal transmission power allocation, SVD-QR-T FCM achieves higher capacity at low SNR and lower BER. In general, it provides satisfying performances compared to the case without channel selection but reduced cost and resource.
Detection of phase transitions in heavy silane by i.r. spectroscopy

Abstract An i.r. spectroscopic study of SiHD 3 isolated in SiD 4 reveals an apparent second-order phase transition at 38 K. In the lowest-temperature phase the SiD 4 molecules probably occupy two sites of C 1 symmetry. Between 38 K and 67 K the SiD 4 molecules probably occupy one site of C s symmetry.
Fuzzy neural network for invariant optical pattern recognition

A novel fuzzy neural network (FNN) model for invariant pattern recognition is presented that combines fuzzy set reasoning and artificial neural network techniques. The presented FNN consists of three blocks: fuzzifier, fuzzy perceptron, and defuzzifier. It fuzzifies the input patterns and trains the interconnection weights according to membership functions instead of traditional binary values. The proposed FNN has been applied to 2-D binary-image pattern recognition under shift and some other types of distortions. In comparison with the classical multilayer perceptron, the FNN possesses a higher recognition rate and is more robust to input distortions.
Performance of the SLC polarized electron source and injector with the SLAC 3 km linac configured for fixed target experiments

The SLC polarized electron source (PES) can be modified to produce /spl mu/sec-long pulses for injection into the unSLEDed SLAC 3 km linac, with a duty factor considerably higher than for SLC. Such beams are desirable for fixed target experiments at SLAC requiring polarized electron beams of up to 50 mA within an energy spread of 0.5%, at energies of up to 26 GeV. During the fall of 1992, the SLAC linac was operated continuously for two months unSLEDed with the PES dye laser (715 nm) modified to produce a 1 /spl mu/ec pulse at 120 Hz. An AlGaAs photocathode was installed in the electron gun to achieve 40% polarization, and a prebuncher was added to the SLC injector to improve capture for long pulse beams. We discuss the performance of the polarized electron beam for long pulse operation. >
Characterization of the Mycobacterium tuberculosis phagosome and evidence that phagosomal maturation is inhibited.

We have used the cryosection immunogold technique to study the composition of the Mycobacterium tuberculosis phagosome. We have used quantitative immunogold staining to determine the distribution of several known markers of the endosomal-lysosomal pathway in human monocytes after ingestion of either M. tuberculosis, Legionella pneumophila, or polystyrene beads. Compared with the other phagocytic particles studied, the M. tuberculosis phagosome exhibits delayed clearance of major histocompatibility complex (MHC) class I molecules, relatively intense staining for MHC class II molecules and the endosomal marker transferrin receptor, and relatively weak staining for the lysosomal membrane glycoproteins, CD63, LAMP-1, and LAMP-2 and the lysosomal acid protease, cathepsin D. In contrast to M. tuberculosis, the L. pneumophila phagosome rapidly clears MHC class I molecules and excludes all endosomal-lysosomal markers studied. In contrast to both live M. tuberculosis and L. pneumophila phagosomes, phagosomes containing either polystyrene beads or heat-killed M. tuberculosis stain intensely for lysosomal membrane glycoproteins and cathepsin D. These findings suggest that (a) M. tuberculosis retards the maturation of its phagosome along the endosomal-lysosomal pathway and resides in a compartment with endosomal, as opposed to lysosomal, characteristics; and (b) the intraphagosomal pathway, i.e., the pathway followed by several intracellular parasites that inhibit phagosome-lysosome fusion, is heterogeneous.
Rebuilding the requirements process for aging avionics

Avionics systems developed to military standards are becoming very expensive to operate and support. Acquisition reform has eliminated many of these standards and promoted replacement of these aging avionics with commercial off the shelf (COTS) items using an open system architecture where applicable. In order to develop and procure a replacement system, the requirements must be defined. If the original requirements can be found, they must be analyzed to determine whether changes are needed to meet the needs of the end user.
Less-restrictive, patient-specific radiation safety precautions can be safely prescribed after permanent seed implantation.

Abstract Purpose To use radiation exposure rate measurements to determine patient-specific radiation safety instructions with the aim of reducing unnecessary precaution times and to evaluate potential doses to members of the public. Methods and Materials Radiation exposure rate measurements were obtained from 1279 patients with Stage T1-2 prostate cancer who underwent transperineal 125I or 103Pd seed implantation from January 1995 through July 2008. An algorithm was developed from these measurements to determine the required precaution times to maintain public effective doses below 50% of the limits for specific exposure situations. Results The median air kerma rates at 30 cm from the anterior skin surface were 4.9 μGy/h (range: 0.1–31.5) for 125I and 1.5 μGy/h (range: 0.02–14.9) for 103Pd. The derived algorithms depended primarily on the half-life Tp, the measured exposure rate at 30 cm, and specific exposure situation factors. For the typical 103Pd patient, no radiation safety precautions are required. For the typical 125I patient, no precautions are required for coworkers, nonpregnant adults who do not sleep with the patient, or nonpregnant adults who sleep with the patient. Typical 125I patients should only avoid sleeping in the “spoon” position (i.e., in contact) with pregnant adults and avoid holding a child for long periods of time in the lap for about 2 months. Conclusions The large number of cases available for this study permitted the development of an algorithm to simply determine patient-specific radiation safety instructions. The resulting precaution times are significantly less restrictive than those generally prescribed currently.
mTOR drives its own activation via SCF(βTrCP)-dependent degradation of the mTOR inhibitor DEPTOR.

Summary The activities of both mTORC1 and mTORC2 are negatively regulated by their endogenous inhibitor, DEPTOR. As such, the abundance of DEPTOR is a critical determinant in the activity status of the mTOR network. DEPTOR stability is governed by the 26S-proteasome through a largely unknown mechanism. Here we describe an mTOR-dependent phosphorylation-driven pathway for DEPTOR destruction via SCF βTrCP . DEPTOR phosphorylation by mTOR in response to growth signals, and in collaboration with casein kinase I (CKI), generates a phosphodegron that binds βTrCP. Failure to degrade DEPTOR through either degron mutation or βTrCP depletion leads to reduced mTOR activity, reduced S6 kinase activity, and activation of autophagy to reduce cell growth. This work expands the current understanding of mTOR regulation by revealing a positive feedback loop involving mTOR and CKI-dependent turnover of its inhibitor, DEPTOR, suggesting that misregulation of the DEPTOR destruction pathway might contribute to aberrant activation of mTOR in disease.
Signaling Mediated by the Cytosolic Domain of Peptidylglycine α-Amidating Monooxygenase

The luminal domains of membrane peptidylglycine α-amidating monooxygenase (PAM) are essential for peptide α-amidation, and the cytosolic domain (CD) is essential for trafficking. Overexpression of membrane PAM in corticotrope tumor cells reorganizes the actin cytoskeleton, shifts endogenous adrenocorticotropic hormone (ACTH) from mature granules localized at the tips of processes to the TGN region, and blocks regulated secretion. PAM-CD interactor proteins include a protein kinase that phosphorylates PAM (P-CIP2) and Kalirin, a Rho family GDP/GTP exchange factor. We engineered a PAM protein unable to interact with either P-CIP2 or Kalirin (PAM-1/K919R), along with PAM proteins able to interact with Kalirin but not with P-CIP2. AtT-20 cells expressing PAM-1/K919R produce fully active membrane enzyme but still exhibit regulated secretion, with ACTH-containing granules localized to process tips. Immunoelectron microscopy demonstrates accumulation of PAM and ACTH in tubular structures at the trans side of the Golgi in AtT-20 cells expressing PAM-1 but not in AtT-20 cells expressing PAM-1/K919R. The ability of PAM to interact with P-CIP2 is critical to its ability to block exit from the Golgi and affect regulated secretion. Consistent with this, mutation of its P-CIP2 phosphorylation site alters the ability of PAM to affect regulated secretion.
A No-Go Theorem About Rotation in Relativity Theory

Within the framework of general relativity, in some cases at least, it is a delicate and interesting question just what it means to say that an extended body is or is not "rotating". It is so for two reasons. First, one can easily think of different criteria of rotation. Though they agree if the background spacetime structure is sufficiently simple, they do not do so in general. Second, none of the criteria fully answers to our classical intuitions. Each one exhibits some feature or other that violates those intuitions in a significant and interesting way. The principal goal of the paper is to make the second claim precise in the form of a modest no-go theorem.
Differential GPS reference station algorithm-design and analysis

The global positioning system (GPS) allows properly equipped users to determine their position based on the measured pseudoranges to at least four satellites. Differential GPS operation (DGPS) uses a reference station at a known location to calculate and broadcast pseudorange corrections to local users, resulting in improved user position accuracy. DGPS accuracy is limited by the ability of the reference station to remove the effects of receiver measurement noise and multipath errors from the broadcast corrections. This article presents two new algorithms for DGPS reference station design. The accuracy of the algorithms is analyzed both theoretically and experimentally. The single and two frequency reference station algorithms, respectively, achieve 6 dB and >20 dB improvement relative to the raw corrections.