cssi/SciSciGPT-SciSciNet huggingface dataset:
Regulation of antigen receptor gene assembly by genetic-epigenetic crosstalk.

Many aspects of gene function are coordinated by changes in the epigenome, which include dynamic revisions of chromatin modifications, genome packaging, subnuclear localization, and chromosome conformation. All of these mechanisms are used by developing lymphocytes to regulate the assembly of functional antigen receptor genes by V(D)J recombination. This somatic rearrangement of the genome must be tightly regulated to ensure proper B and T cell development and to avoid chromosomal translocations that cause lymphoid tumors. V(D)J recombination is controlled by a complex interplay between cis-acting regulatory elements that use transcription factors as liaisons to communicate with epigenetic pathways. Genetic–epigenetic crosstalk is a key strategy employed by precursor lymphocytes to modulate chromatin configurations at Ig and Tcr loci and thereby permit or deny access to a single V(D)J recombinase complex. This article describes our current knowledge of how genetic elements orchestrate crosstalk with epigenetic mechanisms to regulate recombinase accessibility via localized, regional, or long-range changes in chromatin.
Surface Normal Modes of Lake Michigan: Calculations Compared with Spectra of Observed Water Level Fluctuations

Abstract Periods and structures of several normal modes of Lake Michigan (including Green Bay) are calculated theoretically, taking into account the Lake's topography and the earth's rotation. The calculations are based on a Galerkin method developed by Rao and Schwab (1976). Even though the calculations give both rotational and gravitational modes, attention is focused primarily on the latter. The calculations show that there are several modes dominant in the main basin of Lake Michigan and some dominant in Green Bay. The lowest Lake Michigan mode has a period of 9.27 h. Green Bay exhibits a (co-oscillating or Hemlholtz) mode with a period 10.35 h. For the modes dominant in the main basin, the periods and structures obtained from theoretical calculations are compared to those deduced from spectral analyses of water level data from various stations around the Lake. The agreement is found satisfactory for several of the lowest modes.
Evidence that all messenger RNA molecules (except histone messenger RNA) contain Poly (A) sequences and that the Poly(A) has a nuclear function.

Abstract The appearance of newly formed messenger RNA in polyribosomes of HeLa cells Is inhibited by over 85% by 3′deoxyadenosine (Penman, Rosbash & Penman, 1970) probably due to the failure of normal attachment of poly(A) to heterogeneous nuclear RNA in the presence of this drug (Darnell, Philipson, Wall & Adesnik, 1971). Results presented here show that the labeled RNA which does reach polysomes in the presence of 3′deoxyadenosine can be characterized as messenger RNA which contains smaller poly(A) segments than normal messenger RNA. The results of the present experiments suggest that all, or almost all, HeLa cell messenger RNA molecules (except for histone messenger RNA) are derived from nuclear RNA molecules which contain poly (A). The 3′deoxyadenosine-sensitive step, presumably the addition of poly(A) to heterogeneous nuclear RNA, occurs in the cell nucleus a few minutes after the DNA-dependent synthesis of the RNA molecule destined to form messenger RNA.
Conformational studies of bovine alkaline phosphatase in hydrophobic interaction and size-exclusion chromatography with linear diode array and low-angle laser light scattering detection

Alkaline phosphatase has been studied in hydrophobic interaction chromatography (HIC), using a bonded C1-ether phase on a silica gel support, together with an aqueous salt gradient. Its behavior under various gradient elution conditions has demonstrated good chromatographic performance and retention of enzymatic activity under aqueous conditions. It has now been studied using linear photodiode array (LDA) spectroscopy in combination with low-angle laser light scattering (LALLS) in gradient elution HIC. HIC-LALLS permitted the use of routine salt gradients for collection of molecular weight information, despite small changes in the baseline, via computerized baseline subtraction. Size-exclusion chromatography (SEC)-LALLS measurements, under various isocratic conditions, meant to mimic HIC elution, have indicated the presence of monomer/dimer, dimer/trimer, or mainly trimer. aggregates of alkaline phosphatase can also be detected under salt gradient HIC conditions, but at lower levels relative to the monomer. This paper also describes the behavior of alkaline phosphatase when detected using LDA under various chromatographic, temperature, and concentration (injected) conditions. The results indicate a facile equilibrium of at least two monomeric forms of alkaline phosphatase of the same molecular weight, which change relative populations as a function of operational conditions. Most interesting is the suggestion that alkaline phosphatase undergoes rapid conformational interconversions on the chromatographic detection time scales, and that these interconverting conformations, concentration dependent, produce a novel dual wavelength ratioing, viz., a pseudo-Gaussian peak mimicking the chromatographic elution profile at either wavelength. The reasons for these observations and their possible use in future high-performance liquid chromatographic biopolymer studies are discussed and described.
Mechanical effects of thermal cycling on US and Australian Synroc B

Le Synroc B est forme principalement de hollandite de baryum (BaAl 2 Ti 6 O 16 ), de perovskite (CaTiO 3 ) et de zirconolite (CaZrTi 2 O 7 ). Ce materiau est susceptible d'etre utilise pour l'encapsulage de dechets hautement radioactifs. A cet effet on etudie l'influence de cycles thermiques sur la microstructure et la microfissuration
A remark on Yukawa plus boson selfinteraction in two space time dimensions

In this note we show how the results of Glimm and Jaffe [5, 6] on the Yukawa quantum field theory in two space time dimensions may be extended to the case where a boson selfinteraction term is added. Local fields are constructed which do not depend on any cut-off and which have the right (anti)-commutation properties for spacelike separated support of the test functions.
Seismic attenuation tomography using the frequency shift method

We present a method for estimating seismic attenuation based on frequency shift data. In most natural materials, seismic attenuation increases with frequency. The high-frequency components of the seismic signal are attenuated more rapidly than the low-frequency components as waves propagate. As a result, the centroid of the signal's spectrum experiences a downshift during propagation. Under the assumption of a frequency-independent Q model, this downshift is proportional to a path integral through the attenuation distribution and can be used as observed data to reconstruct the attenuation distribution tomographically. The frequency shift method is applicable in any seismic survey geometry where the signal bandwidth is broad enough and the attenuation is high enough to cause noticeable losses of high frequencies during propagation. In comparison to some other methods of estimating attenuation, our frequency shift method is relatively insensitive to geometric spreading, reflection and transmission effects, source and receiver coupling and radiation patterns, and instrument responses. Tests of crosswell attenuation tomography on 1-D and 2-D geological structures are presented.
Anti–tumor necrosis factor agents for rheumatoid arthritis in the setting of chronic hepatitis C infection

Objective To examine the safety of using anti–tumor necrosis factor (TNF) therapy in patients with rheumatoid arthritis (RA) in the setting of hepatitis C virus (HCV) infection. Methods The charts of 5 patients known to have RA requiring anti-TNF therapy as well as established HCV infection were reviewed retrospectively for laboratory data of hepatic parenchymal inflammation and viral proliferation while taking these agents. Results In a mean ± SD followup period of 41 months (± 28.2 months), no patient displayed evidence of sustained elevation of serum aminotransferases during therapy with anti-TNF. Additionally, 1 patient was observed to have a decreased HCV viral load after extended treatment with only anti-TNF (no therapy for HCV). Conclusion Anti-TNF therapy for RA in the setting of HCV appears to be safe and well tolerated without apparent influence on the underlying HCV infection. Therefore, this approach should be further evaluated prospectively for longterm safety.
Observations of anelastic backflow following stress reductions during creep of pure metals

Abstract The anelastic contribution to creep transients in pure f.c.c. metals has been studied by conducting experiments in which nearly the entire applied stress is removed. The observed anelastic strains range from as little as one quarter of the calculated elastic contraction for Pb to 7 or 8 times the elastic contraction for pure Al. The recoverable strains in Cu are generally about equal to the elastic strains. For Al, the magnitude of the recoverable strain increases with prior creep strain. Both the magnitude and kinetics of backflow are similar for polycrystalline and single crystal specimens. Consideration of the kinetics of backflow suggests that there are at least two rate controlling mechanisms which operate during this process. An attempt has been made to determine the physical mechanisms which contribute to creep anelasticity. Based on a qualitative consideration of the kinetics and magnitude of the anelastic transients, the most likely mechanism involves motion of dislocations from subgrain interiors to the subgrain walls and is driven by long range internal back stresses. Other simple mechanisms cannot account for the large recoverable strains, although they may make additional contributions to the overall transient.
Characterizing Metal Phosphonate Surface Coverage Using Surface Second Harmonic Generation. Evidence for the Coexistence of Ordered and Disordered Domains

We report on the use of surface second harmonic generation (SHG) intensity measurements to understand the molecular details of potentially heterogeneous surface coverage. Using a rigid chromophore with a large second-order nonlinear susceptibility (Χ ( 2 ) ) and an adlayer diluent molecule with negligible nonlinear response, the incidence angle dependence of the SHG intensity was determined as a function of surface chromophore coverage. The SHG data at fixed incidence angle suggest that the average orientation of the adsorbed chromophores does not change significantly with surface coverage, resulting in the expected square-law relationship between SHG intensity and loading density. The form of the SHG data points to the presence of more than one domain in the monolayer. The data can be fit successfully using a two-domain model in which the dominant domain is characterized by chromophores oriented along the surface normal and the minority domain is comprised of a nominally random orientational distribution, with the relative amount of the disordered domain decreasing with increasing fractional chromophore coverage.
Midterm safety and efficacy of percutaneous renal cryoablation

Purpose Many series evaluating oncologic efficacy of renal mass cryoablation are limited due to follow-up time of less than 12 months. Given the relatively slow growth kinetics of renal cell carcinoma (RCC), clinical success may be overestimated at this early timepoint. We reviewed outcomes on patients with no less than 12 months follow-up. Materials and Methods We reviewed patients seen at our multi-disciplinary Small Renal Mass Center treated with percutaneous cryoablation from February 2008-July 2011. Patients were followed by Urology and Interventional Radiology with CT and/or MRI q4 months for year 1, q6 months for year 2, and annually thereafter. Tumors were evaluated by size and location (exophytic, mixed, or central). Absence of previously identified contrast enhancement was used to define clinical success. Results Under CT guidance, 49 masses in 47 patients were treated in 49 sessions using 2-5 cryoprobes (Healthtronics, Austin, TX). One patient with 2 tumors had simultaneous ablation while another developed a second tumor 15 months after successful cryoablation. Mean tumor diameter was 2.7 +/- 0.8 cm (range: 1.1 - 4.9 cm). Twenty six masses (53%) were exophytic, 20 (41%) were mixed and 3 (6%) were central. Clinical success was achieved in 48/49 tumors (98%). One patient developed local progression 13 months after ablation, and underwent successful salvage cryoablation with no residual disease at 19 additional months (32 months total). Mean follow-up time was 27 +/- 10 months (median 27 months; range 12-49 months). 30 patients (64%) had greater than 2 years follow-up. 19 (40%) and 11 (24%) had 24-36 months and > 36 months follow-up, respectively. Metastasis and disease-free survival were 100%. One patient died of a second malignancy for an overall survival of 98%. Three minor complications occurred (6%). All were perinephric hematomas that did not require additional management. Conclusion Percutaneous renal cryoablation demonstrates durable oncologic outcomes at a median of 27 months follow-up and represents an effective, minimally-invasive treatment option for small renal masses. The solitary local progression was salvaged with repeat treatment. Complications were rare and managed conservatively.
Course of chronic obstructive pulmonary disease following first onset of respiratory failure.

The advent of respiratory failure is an important indicator of prognosis in the late natural course of chronic obstructive pulmonary disease. The course of 30 patients with chronic obstructive pulmonary disease following the first episode of respiratory failure has been documented. The data presented are consonant with a severely restricted life expectancy following the first episode of respiratory failure. An episode of right ventricular failure from cor pulmonale is an additional adverse influence on the prognosis of chronic obstructive pulmonary disease. In this series, 66 percent of the patients died within two years after the first episode of respiratory failure, or about seven years from the onset of chronic obstructive pulmonary disease.
Shifts in a pacific ocean fish assemblage : the potential influence of exploitation

As in many regions of the world, marine fishes and invertebrates along the Pacific coast of the United States have long been subjected to overexploitation. Despite this history, however, we lack basic information on the current status of many fishes along this coastline. We used data from a quarter century of fishery- independent, coast-wide trawl surveys to study systematically the demersal fish assemblages along the U.S. Pacific coast. We documented fundamental shifts in this fish assemblage. Average fish size, across a diversity of species, has declined 45% in 21 years. There have been major shifts in the constituent species of the assemblage, with some species achieving annual population growth rates of >10% and others declining in excess of 10% per year. Annual rate of change in population size appeared to be a function of life history interacting with fishing pressure. Negative trends in population size were particularly apparent in rockfish (Sebastes spp.). However, across all taxa examined, trends in population size were associated with size of maturity, maximum size, and growth rate. Trends in population size were associated inversely with harvest levels, but stocks that mature late tended to decline faster than would be predicted by catch rates alone. Our results are disquieting because they raise the possibility that fishing-induced phase shifts in fish communities may affect the recovery of fishes, even after the implementation of severe fishing restrictions.
Microfabricated water-immersible scanning mirror with a small form factor for handheld ultrasound and photoacoustic microscopy

Microscanning mirrors that can operate reliably under water are useful in both ultrasound and photoacoustic microscopic imaging, where fast scanning of focused high-frequency ultrasound beams is desired for pixel-by-pixel data acquisition. We report the development of a new microfabricated water-immersible scanning mirror with a small form factor. It consists of an optically and acoustically reflective mirror plate which is supported by two flexible polymer hinges and driven by an integrated electromagnetic microactuator. It can achieve 1-axis scanning of ±12.1 deg at a resonant frequency of 250 Hz in air and 210 Hz in water, respectively. By optimizing the design and enhancing the fabrication with high-precision optical three-dimensional printing, the overall size of the scanning mirror module is less than 7 mm×5 mm×7 mm. The small form factor, large scanning angle, and high-resonant frequency of the new water-immersible scanning mirror make it suitable for building compact handheld imaging probes for in vivo high-speed and wide-field ultrasound and photoacoustic microscopy.
Black and Blue: African Americans, the Labor Movement, and the Decline of the Democratic Party – By Paul Frymer

Although the phrase “institutional racism” has been in most scholars' vocabularies for many years, Paul Frymer emphasizes that Americans still too readily see racism as individual pathology rather ...
A Data Storage Method Based on Query Processing Region in Wireless Sensor Networks

With extensive applications of wireless sensor networks (WSNs), a WSN system with single function such as sea-monitoring and accident succor is expected to supply much more abilities for effective periodic queries or ad hoc queries, because some applications require real-time queries since the results should be returned before deadlines. Meanwhile, efficient data storage technique is always necessary to save energy in the query procedure. For these reasons, we propose a new data storage technique based on query processing region. A query processing region is developed to store the data by using an indexing strategy and to process the queries in real time, and the model for the process of query processing is also built. The simulation results show that this method can process both periodic queries and ad hoc queries with less energy before deadlines.
Temporal influences upon spatial shopping behavior of consumers

Consumers invest time and money in their shopping activities and they derive pleasure as well as goods from shopping. Consumer selection of retail stores reflects their perceptions of prices, distances, the time required to complete the desired purchases and the extent to which they enjoy shopping itself. This paper develops a model which incorporates these phenomena. The model implies that stores selling the same product may offer shopping experiences which appeal to customer groups with differing time needs. As a result, lower order stores may successfully locate adjacent to higher order stores because consumers exhibit different attitudes to time.
Proportional fuzzy logic controller: classical proportional-plus-derivative like response

The objective of this paper is to demonstrate that the systems compensated by a proportional fuzzy logic controller (PFLC) are capable of producing responses similar to those obtained from the systems compensated by a classical proportional-plus-derivative (PD) controller. Analysis of the output equation of a fuzzy logic controller (FLC) shows that the PFLC output is a linear combination of the inputs over different ranges of operations. This linear combination for each specific range of operation can be designed to provide overshoot and rise time reduction similar to those obtained from the classical proportional-plus-derivative (PD) controller but without the derivative input. Simulations of a control system demonstrate the improved performance of the PFLC over the classical proportional controller.
Identification of Potent Inhibitors of the Trypanosoma brucei Methionyl-tRNA Synthetase via High-Throughput Orthogonal Screening:

Improved therapies for the treatment of Trypanosoma brucei, the etiological agent of the neglected tropical disease human African trypanosomiasis, are urgently needed. We targeted T. brucei methionyl-tRNA synthetase (MetRS), an aminoacyl- tRNA synthase (aaRS), which is considered an important drug target due to its role in protein synthesis, cell survival, and its significant differences in structure from its mammalian ortholog. Previous work using RNA interference of MetRS demonstrated growth inhibition of T. brucei, further validating it as an attractive target. We report the development and implementation of two orthogonal high-throughput screening assays to identify inhibitors of T. brucei MetRS. First, a chemiluminescence assay was implemented in a 1536-well plate format and used to monitor adenosine triphosphate depletion during the aminoacylation reaction. Hit confirmation then used a counterscreen in which adenosine monophosphate production was assessed using fluorescence polarization technology. In addition, a miniaturized cell viability assay was used to triage cytotoxic compounds. Finally, lower throughput assays involving whole parasite growth inhibition of both human and parasite MetRS were used to analyze compound selectivity and efficacy. The outcome of this high-throughput screening campaign has led to the discovery of 19 potent and selective T. brucei MetRS inhibitors.
A Model Study of the Air–Sea Interaction Associated with the Climatological Aspects and Interannual Variability of the South Asian Summer Monsoon Development

The climatological characteristics and interannual variations of the development of the South Asian summer monsoon (SASM) in early summer are studied using output from a 200-yr simulation of a coupled atmosphere‐ocean general circulation model (CM2.1). Some of the model results are compared with corresponding observations. Climatological charts of the model and observational data at pentadal intervals indicate that both the precipitation and SST signals exhibit a tendency to migrate northward. Enhanced monsoonal precipitation at a given site is accompanied by a reduction in incoming shortwave radiation and intensification of upward latent heat flux, and by oceanic cooling. An extended empirical orthogonal function analysis is used to identify the dates for initiation of the northward march of SASM in individual summers. It is noted that early monsoon development prevails after
Ranchero overview and expectations for performance at currents over 50 MA (LA-UR 11-04345)

Ranchero is a coaxial magnetic flux compression generator (FCG) initiated simultaneously on-axis, which is intended to produce currents approaching 100 MA. We continue with both applications and development, striving for both cost effectiveness and high performance. In this paper we discuss on-going work, provide details of the sophisticated detonation system, and show high current predictions from our active modeling effort. We intend further tests that will push the limits of Ranchero performance.
Silver mean conjectures for 15-dimensional volumes and 14-dimensional hyperareas of the separable two-qubit systems

Extensive numerical integration results lead us to conjecture that the silver mean, that is, �Ag = √ 2−1 ≈ .414214 plays a fundamental role in certain geometries (those given by monotone metrics) imposable on the 15-dimensional convex set of two-qubit systems. For example, we hypothesize that the volume of separable two-qubit states, as measured in terms of (four times) the minimal
The yeast homolog to mouse tcp-1 affects microtubule-mediated processes

A Saccharomyces cerevisiae homolog to Drosophila melanogaster and mouse Tcp-1 encoding tailless complex polypeptide 1 (TCP1) has been identified, sequenced, and mapped. The mouse t complex has been under scrutiny for six decades because of its effects on embryogenesis and sperm differentiation and function. TCP1 is an essential gene in yeast cells and is located on chromosome 4R, linked to pet14. The TCP1-encoded proteins in yeast, Drosophila, and mouse cells share between 61 and 72% amino acid sequence identities, suggesting a primordial function for the TCP1 gene product. To assess function, we constructed a cold-impaired recessive mutation (tcp1-1) in the yeast gene. Cells carrying the tcp1-1 mutation grew linearly rather than exponentially at the restrictive temperature of 15 degrees C with a generation time of approximately 32 h in minimal medium. Both multinucleate and anucleate cells accumulated with time, suggesting that the linear growth kinetics may be explained by the generation of anucleate buds incapable of further cell division. In addition, the multinucleate and anucleate cells contained morphologically abnormal structures detected by anti-alpha-tubulin antibodies. The kinetics of appearance of these abnormalities suggest that they are a direct consequence of loss of function of the TCP1 protein and not a delayed, indirect consequence of cell death. We also observed that strains carrying tcp1-1 were hypersensitive to antimitotic compounds. Taken together, these observations imply that the TCP1 protein affects microtubule-mediated processes.
A Photonic Crystal Protein Hydrogel Sensor for Candida albicans

We report two-dimensional (2D) photonic crystal (PC) sensing materials that selectively detect Candida albicans (C. albicans). These sensors utilize Concanavalin A (Con A) protein hydrogels with a 2D PC embedded on the Con A protein hydrogel surface, that multivalently and selectively bind to mannan on the C. albicans cell surface to form crosslinks. The resulting crosslinks shrink the Con A protein hydrogel, reduce the 2D PC particle spacing, and blue-shift the light diffracted from the PC. The diffraction shifts can be visually monitored, measured with a spectrometer, or determined from the Debye diffraction ring diameter. Our unoptimized hydrogel sensor has a detection limit of around 32 CFU/mL for C. albicans. This sensor distinguishes between C. albicans and those microbes devoid of cell-surface mannan such as the gram-negative bacterium E. coli. This sensor provides a proof-of-concept for utilizing recognition between lectins and microbial cell surface carbohydrates to detect microorganisms in aqueous environments.
Worst-case vs. algorithmic average-case complexity in the polynomial-time hierarchy

We show that for every integer k>1, if Σk, the k'th level of the polynomial-time hierarchy, is worst-case hard for probabilistic polynomial-time algorithms, then there is a language L ∈Σk such that for every probabilistic polynomial-time algorithm that attempts to decide it, there is a samplable distribution over the instances of L, on which the algorithm errs with probability at least 1/2–1/poly(n) (where the probability is over the choice of instances and the randomness of the algorithm). In other words, on this distribution the algorithm essentially does not perform any better than the algorithm that simply decides according to the outcome of an unbiased coin toss.
Choosing between predictors of fractures.

The identification of those at highest risk of osteoporotic fractures is a clinical goal that requires appropriate statistical comparisons of potential predictors of fractures. This article provides a formal approach for comparing individual predictors (e.g., bone mass at one site vs bone mass at another), or sets of predictors (e.g., bone mass vs other risk factors), and contrasts newer methods, such as bootstrapping, to receiver-operating-characteristics (ROC) curves, which have been previously used. The advantages of the bootstrapping approach are illustrated using time-to-fracture data from a published study demonstrating the use of baseline bone mass measurements in the prediction of fractures in 521 subjects with variable lengths of follow-up, extending to 12.5 years. Bone mineral density (BMD) was shown to be significantly better than bone mineral content (BMC) in predicting fractures in free-living subjects, but not in retirement-community subjects. Bone mineral apparent density (BMAD) was also compared with BMC and BMD and shown not to improve fracture prediction in these subjects.
On Capitol Hill: The Struggle to Reform Congress and Its Consequences, 1948–2000

On Capitol Hill: The Struggle to Reform Congress and Its Consequences, 1948–2000. By Julian E. Zelizer. New York: Cambridge University Press, 2004. 376p. $30.00. Julian Zelizer's book joins a number of others that have been taking up the issue of congressional reform. Recent books by political scientists E. Scott Adler ( Why Congressional Reforms Fail, 2002), Nelson Polsby ( How Congress Evolves, 2003), and Eric Schickler ( Disjointed Pluralism, 2001) are among a growing list that seeks to explain the success or failure of congressional reforms during the twentieth century. One of the interesting aspects of these books is that they are authored by mostly younger scholars who are reassessing, and sometimes seriously challenging, a genre of scholarship that was pioneered during the seventies by such scholars as Lawrence Dodd, Bruce Oppenheimer, Barbara Sinclair, and James Thurber, to name a few, many of whom were American Political Science Association Congressional Fellows working in Congress during the period of substantial congressional reform in the 1970s.
IDL software package for absolute quantification of myocardial blood flow based on [N-13] ammonia PET data

Presents a semi-automated software package to quantify myocardial blood flow (MBF) based on data obtained from a dynamic PET scan using [N-13] ammonia as tracer. The software package is written in IDL 5.0 and uses an external FORTRAN routine to perform fitting of dynamic time-activity curves obtained from small regions over the myocardium. The package includes correction for patient motion, automated definition of multiple regions and display of absolute MBF in polar map format. The effects of partial volume and blood to tissue cross-contamination are accounted for by optimizing the radial position of regions to meet fundamental assumptions of the underlying three-compartmental kinetic model. All sampled regions are saved to file to allow repeated post-processing runs. Following determination of MBF for small regions of the myocardium, a polar map display is created and the user can select large anatomical regions consisting of multiple smaller sampled regions. All corresponding time-activity curves are retrieved from file and averaged. The fitting is then performed for the averaged time-activity curve. This approach allows the extraction of time-activity curves with good statistics for clinically meaningful sections of the myocardium. Interobserver reproducibility for the determination of MBF was excellent (r=0.96).
Thrombopoietin, the ligand for the Mpl receptor, synergizes with steel factor and other early acting cytokines in supporting proliferation of primitive hematopoietic progenitors of mice.

Recently. the ligand for the Mpl receptor (ML) was identified to be thrombopoietin, the principal regulator of megakaryocytopoiesis and thrombopoiesis. We examined the effects of ML, as a single factor or in combinations with early acting factors such as steel factor {SF), interleukin (ILI-3, IL-11, IL6, and granulocyte colony-stimulating factor [G-CSF), on colony formation from primitive progenitors of mice. Cells enriched for cell cycle dormant primitive progenitors ware isolated from bone marrow cells of 5-fluorouracil (5-FU)treated mice by a combination of Nycodenr density gradient separation, immunomagnetic selection for lineage-negative cells, and fluorescence-activated cell sorter (FACS) sorting for Ly-6A/EfKit+ cells. ML, in the presence of erythropoietin, could support the formation of only a few megakaryocyte colonies. However, ML acted synergistically with SF or IL-3 to support the formation of multiple types of hematopoietic colonies including multilineage colonies. Effects of the comOR HEMATOPOIETIC STEM cells to proliferate and F mature in multiple lineages, coordinated support by several cytokines is required. Using clonal cell culture assays, we have characterized cytokine interactions regulating the proliferation of primitive progenitors (see review'). Based on their functional similarities, these cytokines may be classified into three groups. Interleukin-3 (IL-3),* IL-43 and granulocyte-macrophage colony-stimulating factor (GM-CSF)4~' appear to form one group since, as single agents, these cytokines can support the proliferation of multipotential progenitors after they exit from the cell-cycle dormancy state (Go period). IL-6: IL-11: granulocyte-CSF (GCSF),' leukemia inhibitory factor (LIF)9,'0 and IL-12",'* form the second group. These cytokines, which are related to each other through similarities in their structure or in the structure of their receptors, appear to be involved in triggering of the cell cycle-dormant multipotential progenitors by synergizing with IL-3 or steel factor (SF; the ligand for Kit). SF".I3,l4 and the ligand for Flt3Flk2 (=)I5 form the third group. These ligands can interact synergistically with the cytokines in the first and second groups, with minor exception^.'^-'^ Combinations of two factors within a group, however, do not support colony formation from cells in Go.
Framework models of ion permeation through membrane channels and the generalized King-Altman method.

A modern approach to studying the detailed dynamics of biomolecules is to simulate them on computers. Framework models have been developed to in- corporate information from these simulations in order to calculate properties of the biomolecules on much longer time scales than can be achieved by the simula- tions. They also provide a simple way to think about the simulated dynamics. This article develops a method for the solution of framework models, which generalizes the King-Altman method of enzyme kinetics. The generalized method is used to construct solutions of two framework models which have been introduced previ- ously, the single-particle and Grotthuss (proton conduction) models. The solution of the Grotthuss model is greatly simplified in comparison with direct integration. In addition, a new framework model is introduced, generalizing the shaking stack model of ion conduction through the potassium channel.
Pediatrics in the community: community pediatrics training initiative (CPTI)

Our inaugural story for Pediatrics in the Community was in the January 2007 edition of Pediatrics in Review. Dr Robert Haggerty provided the historical rationale for community pediatrics training (CPT) as part of that feature. Now, 1 year later, we asked Dr Jeff Kaczorowski, Director of the CPTI at the American Academy of Pediatrics (AAP), to describe the present and future of CPT. As the stories in this series have shown, some residents are having wonderful community experiences already and making a difference in the lives of children in their communities. The challenge is how to make such experiences available to all pediatric residents and pediatricians.-C. Andrew Aligne, MD, MPH, Section Editor.
High-Resolution Simulation of Hurricane Bonnie, 1998: Part 2, Water Budget

Abstract The fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) is used to simulate Hurricane Bonnie at high resolution (2-km spacing) in order to examine budgets of water vapor, cloud condensate, and precipitation. Virtually all budget terms are derived directly from the model (except for the effects of storm motion). The water vapor budget reveals that a majority of the condensation in the eyewall occurs in convective hot towers, while outside of the eyewall most of the condensation occurs in weaker updrafts, indicative of a larger role of stratiform precipitation processes. The ocean source of water vapor in the eyewall region is only a very small fraction of that transported inward in the boundary layer inflow or that condensed in the updrafts. In contrast, in the outer regions, the ocean vapor source is larger owing to the larger area, counters the drying effect of low-level subsidence, and enhances the moisture transported in towa...
Molecular structure heterogeneity of gramicidin analogs incorporated into SDS micelles: a NMR study

Abstract The effects of glycine, alanine and valine substitution for leucine upon the species heterogeneity of gramicidin A incorporated into SDS micelles have been investigated. The sequential replacement of the leucine residues at positions 10, 12 and 14 produced multiple β-helical forms of the gramicidin A analogs as shown by 1 H NMR spectroscopy. These results reveal the complexity of the interaction of amino acid residue side chain with the SDS micelle environment in controlling the formation of a single channel species or multiple helical forms. Clearly, a potential problem may arise if one assumes that the solubilization of the peptide, gramicidin, in micelles indicates the existence of a single form of the peptide.
Performance of DS-SS-CDMA systems using partial power control and a base station antenna array

We explore the use of an adaptive antenna array at a DS-SS-CDMA base station receiver to enhance uplink receiver performance and lessen the near/far effect due to transmit power control errors among the system users. Results are presented in terms of average bit-error rate and average outage probability. A signal model is formulated which allows limits on power control error and assumes multiple, spatially constrained sources exist in a single circular cell. Simulation results show that an adaptive antenna array at the base station receiver can compensate for transmit power control error described by this signal model.
Predicting acceptance of Software Process Improvement

Software Process Improvement (SPI) initiatives induce organizational change, by introducing new tools, techniques and work practices. Organizations have to address acceptance issues such as resistance to change, compatibility and fear of adverse consequences. Social psychology literature includes the Technology Acceptance Model (TAM) and the Theory of Planned Behavior (TPB), which study such adoption issues and predict intention to use and actual usage of workplace technology. Some constructs of these models could be applied to software organizations to make it easier for them to counter the initial resistance and to assimilate process improvement into the work culture. To increase applicability of these models to the SPI context, some additional constructs are proposed, by taking into account organizational culture, the impact of changes caused by SPI and the unique characteristics of software developers.
Direct Observation Assessment of Milestones: Problems with Reliability.

Introduction: Emergency medicine (EM) milestones are used to assess residents’ progress. While some milestone validity evidence exists, there is a lack of standardized tools available to reliably assess residents. Inherent to this is a concern that we may not be truly measuring what we intend to assess. The purpose of this study was to design a direct observation milestone assessment instrument supported by validity and reliability evidence. In addition, such a tool would further lend validity evidence to the EM milestones by demonstrating their accurate measurement. Methods: This was a multi-center, prospective, observational validity study conducted at eight institutions. The Critical Care Direct Observation Tool (CDOT) was created to assess EM residents during resuscitations. This tool was designed using a modified Delphi method focused on content, response process, and internal structure validity. Paying special attention to content validity, the CDOT was developed by an expert panel, maintaining the use of the EM milestone wording. We built response process and internal consistency by piloting and revising the instrument. Raters were faculty who routinely assess residents on the milestones. A brief training video on utilization of the instrument was completed by all. Raters used the CDOT to assess simulated videos of three residents at different stages of training in a critical care scenario. We measured reliability using Fleiss’ kappa and interclass correlations. Results: Two versions of the CDOT were used: one used the milestone levels as global rating scales with anchors, and the second reflected a current trend of a checklist response system. Although the raters who used the CDOT routinely rate residents in their practice, they did not score the residents’ performances in the videos comparably, which led to poor reliability. The Fleiss’ kappa of each of the items measured on both versions of the CDOT was near zero. Conclusion: The validity and reliability of the current EM milestone assessment tools have yet to be determined. This study is a rigorous attempt to collect validity evidence in the development of a direct observation assessment instrument. However, despite strict attention to validity evidence, inter-rater reliability was low. The potential sources of reducible variance include rater- and instrument-based error. Based on this study, there may be concerns for the reliability of other EM milestone assessment tools that are currently in use.
Headlamp luminous intensity matrix adjustment factors for modeling traffic sign performance

There have been a series of recent national activities that have increased the awareness of performance of traffic signs at night. Also, transportation agencies now have more choices than ever in the selection of retroreflective sign sheeting materials for traffic signs. Accompanying these changes is an increased ability to model the photometric performance of sign materials and predict the luminance that associated with a specific set of conditions. The headlamps may be the one factor that is the most idealized parameter in the photometric modeling process. This paper reviews work on traffic sign luminance modeling and describes how headlamp photometric data are used in these models. It also describes illuminance measurements made of a sample of 46 U.S. passenger cars and light trucks with clean and dirty headlamps. Subsequent modeling of headlamp performance, including an assessment of the impact of dirt on sign luminance is described. Recommendations are presented that can be used to adjust headlamp luminous intensity matrices to yield candela levels at typical sign geometries representing measured candelas from a pseudo random selection of vehicles.
Single-Particle Absorption Spectroscopy by Photothermal Contrast

Removing effects of sample heterogeneity through single-molecule and single-particle techniques has advanced many fields. While background free luminescence and scattering spectroscopy is widely used, recording the absorption spectrum only is rather difficult. Here we present an approach capable of recording pure absorption spectra of individual nanostructures. We demonstrate the implementation of single-particle absorption spectroscopy on strongly scattering plasmonic nanoparticles by combining photothermal microscopy with a supercontinuum laser and an innovative calibration procedure that accounts for chromatic aberrations and wavelength-dependent excitation powers. Comparison of the absorption spectra to the scattering spectra of the same individual gold nanoparticles reveals the blueshift of the absorption spectra, as predicted by Mie theory but previously not detectable in extinction measurements that measure the sum of absorption and scattering. By covering a wavelength range of 300 nm, we are furth...
A Hyperparasitic Blyttiomyces

A new species of Blyttiomyces, B. rhizophlyctidis, is described and discussed. It is readily distinguished from all other previously known species of the genus by its angular or tubercular sporangi...
Singular Cardinals and the Generalized Continuum Hypothesis

(1977). Singular Cardinals and the Generalized Continuum Hypothesis. The American Mathematical Monthly: Vol. 84, No. 2, pp. 108-113.
Thoughts on Yoram Hazony's The Philosophy of Hebrew Scripture

ABSTRACTThis article focuses on two claims in Yoram Hazony's book The Philosophy of Hebrew Scripture: (1) that Hebrew Scripture contains a philosophy and (2) that this philosophy renders the conventional distinction between Jerusalem and Athens untenable insofar as it is a distinction that falls outside the purview of Hebrew Scripture.
Undifferentiated carcinoma with lymphoid stroma of the major salivary glands.

Undifferentiated carcinoma with lymphoid stroma or lymphoepithelial carcinoma of the major salivary glands is a demographically and histopathologically unique malignancy. Although whites may have t...
Evaluation of Left Ventricular Diastolic Function

Doppler echocardiography can provide insight into the diastolic properties of the left ventricle. The hemodynamic origins of the diastolic mitral flow velocity profile are reviewed and Doppler information is compared to other measures of left ventricular diastolic function. Factors affecting the mitral diastolic flow velocity in both normal populations and pathologic conditions are discussed and the reported normal indexes of diastolic transmitral velocity are criticized.
Glutamate Toxicity in Lung and Airway Disease

1. Experimental glutamate toxicity can occur in the respiratory system. Acute administration of high concentrations of glutamate or glutamate agonist NMDA can elicit high-permeability pulmonary edema and airway constriction. 2. Endogenous glutamate receptor activation may play a key role in mediating oxidant lung injury, and airway hyper-responsiveness, a major feature of bronchial asthma. 3. NMDA receptor subunits have now been identified and their distribution characterized in rat lungs and airways. Cellular localization and the definition of possible physiological regulatory functions are subjects of future investigation. 4. Understanding glutamate signaling should lead to the introduction of novel strategies for the management of lung and airway diseases which have glutamate toxicity as a pathogenetic mechanism.
Stream–Groundwater Interactions

Streams and their surrounding catchments exchange water and solutes on a range of physical scales. Exchange with the stream may extend into the interstitial areas of the streambed, the hyporheic zone, the riparian area, or the catchment's groundwater flow system. Even at the smaller scales, the exchanges significantly influence solute transport, nutrient cycling, and the aquatic ecosystem. Over the recent decades, considerable attention has been given to the solute transport aspects of stream–groundwater interactions. Stream–groundwater interactions are now being recognized as practical matters to be considered in environmental issues, such as stream restoration and fish habitat. In this chapter, the emphasis is on introducing (1) the breadth of hydrologic interactions between streams and groundwater and (2) the importance of interpreting these interactions to understanding stream chemistry and ecology.
Teaching Students with Combined Behavioral Disorders and Mental Retardation To Lead Their Own IEP Meetings.

For students with combined cognitive limitations and behavioral disorders (BD), postschool outcomes are poor; their lives are marked by a lack of independence and empowerment. A major goal of special education is to develop successful models to promote individual independence and empowerment for students. The individualized education program (IEP) planning meeting provides opportunities for students to develop critical skills for self-management, self-advocacy, goal setting, and choice making. This research extended the work of Snyder and Shapiro (1997) and examined the effectiveness of teaching adolescent students with mental retardation and BD to lead their own IEP meetings. Five students learned to (a) introduce others at their IEP meetings, (b) review their past IEP goals, (c) discuss their future IEP goals, and (d) close their meetings. The students rated the instruction as acceptable. Implications and limitations of the investigation are discussed.