cssi/SciSciGPT-SciSciNet huggingface dataset:
Characterization of DNA helicase II from a uvrD252 mutant of Escherichia coli.

The loss of DNA helicase II (UvrD) in Escherichia coli results in sensitivity to UV light and increased levels of spontaneous mutagenesis. While the effects of various uvrD alleles have been analyzed in vivo, the proteins produced by these alleles have not been examined in any detail. We have cloned one of these alleles, uvrD252, and determined the site of the mutation conferring the phenotype. In addition, the protein it encodes has been purified to homogeneity and characterized in vitro. The mutation responsible for the phenotype was identified as a glycine-to-aspartic-acid change in the putative ATP-binding domain. In comparison to wild-type DNA helicase II, the UvrD252 enzyme exhibited reduced levels of ATPase activity and a large increase in the Km for ATP. The ability of UvrD252 to unwind DNA containing single-stranded regions, as well as DNA containing only nicks, was reduced in comparison to that of the wild-type enzyme. Possible interpretations of these results in relation to the phenotypes of the uvrD252 mutant are discussed. This represents the first detailed analysis of the biochemical properties of a mutant DNA helicase II protein. Images
Identification of a Caenorhabditis elegans histone H1 gene family. Characterization of a family member containing an intron and encoding a poly(A)+ mRNA.

The isolation and properties of a gene encoding a histone H1 protein of Caenorhabditis elegans, his-24, are described. The predicted protein sequence is similar to histone H1 proteins of other eukaryotes. However, the gene structure of his-24 is atypical for a histone H1 gene; it contains an intron and encodes a polyadenylated mRNA. A family of approximately five histone H1 genes is defined by cross-hybridization to his-24. All appear to encode polyadenylated mRNAs. One gene is expressed specifically in male germ cells. These histone H1 genes are dispersed individually in the genome, apart from the previously described clusters of core histone genes (H2A, H2B, H3 and H4), which probably all encode non-polyadenylated mRNAs. This histone gene organization, with clustered core histone genes, encoding non-polyadenylated transcripts, and dispersed, histone H1 genes from which it appears only polyadenylated messages arise, suggests that C. elegans is at a stage of evolution of the histone gene family intermediate between lower eukaryotes (e.g. yeast) and the most advanced forms.
Generalized treatment of spatial and temporal column parameters, applicable to gas, liquid and supercritical fluid chromatography : II. Application to supercritical CO2

Abstract Equations derived in Part I [D.E. Martire, J. Chromatogr. , 461 (1989) 165] are used to calculate distribution functions, average densities and column profiles for supercritical fluid chromatography with carbon dioxide as the mobile phase. An approximation for the column-average capacity factor in terms of the local capacity factor is evaluated and conditions are given for its applicability.
Tools for integrated sequence-structure analysis with UCSF Chimera.

Comparing related structures and viewing the structures in the context of sequence alignments are important tasks in protein structure-function research. While many programs exist for individual aspects of such work, there is a need for interactive visualization tools that: (a) provide a deep integration of sequence and structure, far beyond mapping where a sequence region falls in the structure and vice versa; (b) facilitate changing data of one type based on the other (for example, using only sequence-conserved residues to match structures, or adjusting a sequence alignment based on spatial fit); (c) can be used with a researcher's own data, including arbitrary sequence alignments and annotations, closely or distantly related sets of proteins, etc.; and (d) interoperate with each other and with a full complement of molecular graphics features. We describe enhancements to UCSF Chimera to achieve these goals. The molecular graphics program UCSF Chimera includes a suite of tools for interactive analyses of sequences and structures. Structures automatically associate with sequences in imported alignments, allowing many kinds of crosstalk. A novel method is provided to superimpose structures in the absence of a pre-existing sequence alignment. The method uses both sequence and secondary structure, and can match even structures with very low sequence identity. Another tool constructs structure-based sequence alignments from superpositions of two or more proteins. Chimera is designed to be extensible, and mechanisms for incorporating user-specific data without Chimera code development are also provided. The tools described here apply to many problems involving comparison and analysis of protein structures and their sequences. Chimera includes complete documentation and is intended for use by a wide range of scientists, not just those in the computational disciplines. UCSF Chimera is free for non-commercial use and is available for Microsoft Windows, Apple Mac OS X, Linux, and other platforms from http://www.cgl.ucsf.edu/chimera .
Using Excel for White's Test—An Important Technique for Evaluating the Equality of Variance Assumption and Model Specification in a Regression Analysis

There is consensus in the statistical literature that severe departures from its assumptions invalidate the use of regression modeling for purposes of inference. The assumptions of regression modeling are usually evaluated subjectively through visual, graphic displays in a residual analysis but such an approach, taken alone, may be insufficient for assessing the appropriateness of the fitted model. Here, an easy-to-use test of the assumption of equal variance (i.e., homoscedasticity) as well as model specification is provided. Given the importance of the equal-variance assumption (i.e., if uncorrected, severe violations preclude the use of statistical inference and moderate violations result in a loss of statistical power) and given the fact that, if uncorrected, a misspecified or underspecified model could invalidate an entire study, the test developed by Halbert White in 1980 is recommended for supplementing a graphic residual analysis when teaching regression modeling to business students at both the undergraduate and graduate levels. Using this confirmatory approach to supplement a traditional residual analysis has value because students often find that graphic displays are too subjective for determining what constitutes severe from moderate departures from the equal variance assumption or for assessing patterns in plots that might indicate model misspecification or underspecification.
A detector-switched GaAs monolithic time-delay network for the optical control of phased arrays

Recently, there has been much interest in the development of photonic techniques for steering microwave phased array radar over multiple microwave bands. In these optically controlled phased array antennas, guided lightwave is used as a carrier for distributing and delaying the microwave signals that drive and "phase-up" the antenna radiation elements. In this paper, we will report on the demonstration of a fully functional GaAs monolithic time-delay network for steering phased arrays from L to X band. Specifically, the monolithic time-delay network integrates the delay lines (curved GaAlAs/GaAs rib-waveguides) and MSM detectors that serve as optoelectronic switches on a GaAs substrate. >
Managed Care and Medicare Reform

A primary goal of many Medicare reform proposals is to move program beneficiaries into managed care plans operated by private insurance companies. Advocates contend that managed care plans, especially health maintenance organizations (HMOs), can save substantial money for the federal government, while also improving the quality of medical care and scope of covered benefits for Medicare enrollees. Should Medicare follow the private sector by adopting managed care-based reforms? This article summarized the claims that are made for and against incorporating managed care into Medicare, and reviews evidence from the program's experience with HMOs on financial savings, benefits coverage, and quality of care. This evidence raises concerns regarding the ability of HMOs to provide adequate care for chronically ill Medicare patients. Moreover, there is considerable uncertainty about the future performance of managed care plans. I therefore conclude that policy makers should move cautiously in embracing managed care and that Medicare should not adopt financial incentives, such as vouchers, that are intended to push beneficiaries into HMOs. However, Medicare beneficiary enrollment in managed care plans is likely to increase substantially in coming years regardless of public policy. It is therefore critical for Medicare to pursue policies that protect the quality of care for elderly and disabled patients in managed care plans; curtail excessive payments to HMOs that result from favorable selection of healthier enrollees; and preserve the current fee-for-service Medicare program.
Ahhotep’s Silver Ship Model: The Minoan Context

The tomb of Ahhotep (I) contained two metal ship models—one gold, the other silver—and a four-wheeled carriage. The models are anomalous in time and material. While the gold model represents a typical papyriform wood- planked Nile vessel, the silver model finds its closest parallels with a contemporaneous Minoan/Cycladic vessel crewed by ten rowers, exemplified by the rowed ship in the Miniature Frieze from the West House in Akrotiri on Thera. This conclusion is further supported by a long tradition of metal ship models in the Aegean. The silver model may be a copy of an actual ship or of a model of a ship. Ahhotep’s models and carriage may represent booty captured by either Kamose or Ahmose during their battles against Avaris (Tell el-Dab’a) and subsequently interred with their mother. If this interpretation is correct, it could indicate a Minoan presence at Tell el-Dab’a during the Hyksos period. DOI:10.2458/azu_jaei_v02i3_wachsmann
Propagation Modes, Equivalent Circuits, and Characteristic Terminations for Multiconductor Transmission Lines with Inhomogeneous Dielectrics

The theory of wave propagation on Iossless multiconductor transmission lines with inhomogeneous dielectrics is developed using matrix analysis. The treatment is concise and complete and has the advantage of identifying propagation modes in a way that permits straightforward physical interpretation. The equivalent circuit for the general line is derived and its application to the solution of wave problems with reflections is demonstrated. Special consideration is given to the problem of characteristically terminating a multiconductor line, i.e., terminating without reflections. The realizability of such a characteristic termination network is discussed, and proofs of realizability are given for the important cases of all lines with homogeneous dielectrics and all three-conductor lines, regardless of dielectric inhomogeneities. Symmetric three-conductor lines are discussed to exemplify the general theory, and an application to the problem of mode conversion on symmetric and asymmetric shielded strip lines is given.
In-Vacuo Surface Analytical Study of Diamond Nucleation on Copper Vs. Silicon

A study was performed on polycrystalline copper versus that of Si(100) utilizing a negative substrate bias to enhance diamond nucleation. The biasing pretreatment and subsequent growth of the diamond were performed via microwave plasma chemical vapor deposition and the initial stages of nucleation were characterized by in-vacuo surface analysis. The biasing pretreatment step proved to have a tremendous influence on the nucleation density pertaining to Si(100) substrates, however, the nucleation density on polycrystalline copper was only increased slightly. A highly graphitic surface coverage of roughly 10A was evident on the copper substrates prior to the detection of diamond and was quite stable in thickness in as early as 15 minutes of biasing. The Si(100) substrates, however, were characterized by the formation of a carbide with some form of nondiamond carbon present on the surface throughout the biasing pretreatment.
Some conceptual approaches to innovative medical ultrasound transducers

Equivalent circuit descriptions suitable for describing the impulse response of transducer systems are considered, and the suitability of the Mason circuit is demonstrated. This description leads to consideration of multilayer structures that are applicable to medical ultrasound transducers. Of several interesting structures, one formed by folding thin plastic piezoelectric materials is shown to have the possibility of uncreased coupling coefficient and reduced resonant frequency compared to the basic film material.
Individual patterns of immunoglobulin development in ten infants

The individual patterns of immunoglobulin development were studied in 10 infants followed daily for 30 days; 7 were followed weekly thereafter for from 2 to 18 months. Synthesis of IgA and IgM and probably also IgG began within the first 4 to 6 weeks of life. In combination with average patterns derived from groups of infants each bled once, the individual patterns provide an adjunctive basis for judging abnormality of immunoglobulin development.
Generalized r-modes of the Maclaurin spheroids

Analytical solutions are presented for a class of generalized r-modes of rigidly rotating uniform density stars—the Maclaurin spheroids—with arbitrary values of the angular velocity. Our analysis is based on the work of Bryan; however, we derive the solutions using slightly different coordinates that give purely real representations of the r-modes. The class of generalized r-modes is much larger than the previously studied “classical” r-modes. In particular, for each l and m we find l−m (or l−1 for the m = 0 case) distinct r-modes. Many of these previously unstudied r-modes (about 30% of those examined) are subject to a secular instability DRIVEN by gravitational radiation. The eigenfunctions of the “classical” r-modes, the l = m+1 case here, are found to have particularly simple analytical representations. These r-modes provide an interesting mathematical example of solutions to a hyperbolic eigenvalue problem.
Reversal of primary hyperoxaluria cardiomyopathy after combined liver and renal transplantation

Abstract This case and those previously reported suggest that oxalate-induced cardiomyopathy should not be considered a contraindication to combined renal and liver transplantation. These patients have a rapid improvement in cardiac function after transplantation, and we have shown pathologic evidence of clearance of myocardial oxalate stores by endomyocardial biopsy. Correlation of our biopsy results with serial technetium-99m MDP scans have confirmed the usefulness of this study for following cardiac oxalate deposits in this setting.
Viscosity of molten fluorozirconates

Abstract The viscosity of a series of molten fluorozirconates with chemical composition of 30BaF 2 60ZrF 4 10RF n (mol%), where R represents Li, Na, K, Ca, Ba, Zn, Pb, Al, Y, La and Th, has been measured as a function of temperature in a nitrogen atmosphere from 550 to 950°C. Their viscous behavior is characterized by a low viscosity relative to normal glass-forming systems and a rapidly increasing activation energy for viscous flow with decreasing temperature. The melts probably consist of short chains or small rings of Zr x F y anions linked together by cations through non-bridging fluorines. Similar to associated liquids, the degree of association increases with decreasing temperature.
Synthesis and Solution Properties of Water-Soluble Sulfonated Cellulose-Based Polymers and Their Polyacrylamide Copolymers

Abstract Water-soluble sulfopropylcellulose (SPC) was synthesized by the reaction of 1,3-propane sultone with sodium cellulose in dioxane. The degree of substitution (0.3-1.0) was calculated by elemental analysis. The corresponding water-soluble polyacrylamide graft copolymer was prepared by Ce4+ ion-initiated graft copolymerization of acrylmide onto sulfopropylcellulose dissolved in dilute nitric acid solution at room temperature under argon. The graft copolymerization was carried out in 0.2 M NaNO3 solution in order to suppress the ionic interaction between the sulfonate ion and eerie ion. The average number of grafts per SPC was found to be 1.1 or less, depending on the reaction conditions.
Modeling of a Possible Conformational Change Associated With the Catalytic Mechanism in the Hammerhead Ribozyme

Here we describe a possible model of the cleavage mechanism in the hammerhead ribozyme. In this model, the 2' hydroxyl of C17 is moved into an appropriate orientation for an in-line attack on the G1.1 phosphate through a change in its sugar pucker from C3' endo to C2' endo. This conformational change in the active site is caused by a change in the uridine turn placing the N2 and N3 atoms of G5 of the conserved core in hydrogen bonding geometry with the N3 and N2 atoms on the conserved G16.2 residue. The observed conformational change in the uridine turn suggests an explanation for the conservation of G5. In the crystal structure of H.M. Pley et al., Nature 372, 68-74 (1994), G5 is situated 5.3A away from G16.2. However, the uridine turn is sufficiently flexible to allow this conformational change with relatively modest changes in the backbone torsion angles (average change of 14.2 degrees). Two magnesium ions were modeled into the active site with positions analogous to those described in the functionally similar Klenow fragment 3'-5' exonuclease (L.S. Beese and T.A. Steitz, EMBO J. 10, 25-33 (1991)), the Group I intron (T.A. Steitz and J.A. Steitz, P.N.A.S. U.S.A. 90, 6498-6502 (1993); R.F. Setlik et al., J. Biomol. Str. Dyn. 10, 945-972 (1993)) and other phosphotransferases. Comparison of this model with one in which the uridine turn conformation was not changed showed that although the changes in the C17 sugar pucker could be modeled, insufficient space existed for the magnesium ions in the active site.
Oxygen consumption, rate of heart beat and ventilatory rate in parietalectomized lizards, Sceloporus occidentalis

Abstract 1. 1. Mean O 2 consumption of controls at 35°C was 329 μ1/g per hr. 2. 2. Mean rate of heart beat/min of controls at 15,20,25,30 and 35°C was 43, 65,96,140 and 185 respectively. 3. 3. Mean ventilatory rate/min of controls at 15,20,25,30 and 35°C was 25,27, 31,35 and 37 respectively. 4. 4. Values of O 2 consumption, rate of heart beat and ventilatory rate determined for controls, sham-parietalectomized and parietalectomized individuals did not differ significantly ( P > 0·05) between treatments or between day 0 and day 30 within a treatment.
Globalization, Government Ideology, and Income Inequality in Developing Countries

This article examines how globalization, government ideology, and their interaction have shaped income distribution in 59 developing countries from 1975 to 2005. Using pooled time-series data analysis, the results show that globalization, measured by trade flows and foreign direct investment, has significantly expanded income inequality in developing countries. However, countries with leftist government parties and chief executives have experienced significantly smaller income gaps and even moderated the income inequality from increasing world market integration. The results in this article suggest that the traditional role of government ideology for income redistribution, drawn from the experiences of advanced countries, is applicable to the developing world as well. Rather than being diminished by the integration of international markets, the influence of government ideology will continue to play a key role in shaping the outcomes of globalization.
Snake venom metalloproteinases.

Abstract Recent proteomic analyses of snake venoms show that metalloproteinases represent major components in most of the Crotalid and Viperid venoms. In this chapter we discuss the multiple activities of the SVMPs. In addition to hemorrhagic activity, members of the SVMP family also have fibrin(ogen)olytic activity, act as prothrombin activators, activate blood coagulation factor X, possess apoptotic activity, inhibit platelet aggregation, are pro-inflammatory and inactivate blood serine proteinase inhibitors. Clearly the SVMPs have multiple functions in addition to their well-known hemorrhagic activity. The realization that there are structural variations in the SVMPs and the early studies that led to their classification represents an important event in our understanding of the structural forms of the SVMPs. The SVMPs were subdivided into the P-I, P-II and P-III protein classes. The noticeable characteristic that distinguished the different classes was their size (molecular weight) differences and domain structure: Class I (P-I), the small SVMPs, have molecular masses of 20–30 kDa, contain only a pro domain and the proteinase domain; Class II (P-II), the medium size SVMPs, molecular masses of 30–60 kDa, contain the pro domain, proteinase domain and disintegrin domain; Class III (P-III), the large SVMPs, have molecular masses of 60–100 kDa, contain pro, proteinase, disintegrin-like and cysteine-rich domain structure. Another significant advance in the SVMP field was the characterization of the crystal structure of the first P-I class SVMP. The structures of other P-I SVMPs soon followed and the structures of P-III SVMPs have also been determined. The active site of the metalloproteinase domain has a consensus HEXXHXXGXXHD sequence and a Met-turn. The “Met-turn” structure contains a conserved Met residue that forms a hydrophobic basement for the three zinc-binding histidines in the consensus sequence.
A note on supply risk and inventory outsourcing

To fully accommodate the correlations between semiconductor product demands and external information such as the end market trends or regional economy growth, a linear dynamic system is introduced in this paper to improve the forecasting performance in supply chain operations. In conjunction with the generic Gaussian noise assumptions, the proposed state-space model leads to an expectation-maximisation (EM) algorithm to estimate model parameters and predict production demands. When the dimension of external indicators is high, principal component analysis (PCA) is applied to reduce the model order and corresponding computational complexity without loss of substantial statistical information. Experimental study on some real electronic products demonstrates that this forecasting methodology produces more accurate predictions than other conventional approaches, which thereby helps improve the production planning and the quality of semiconductor supply chain management.
Coupled Intrinsic Connectivity Distribution Analysis: A Method for Exploratory Connectivity Analysis of Paired fMRI Data

We present a novel voxel-based connectivity approach for paired functional magnetic resonance imaging (fMRI) data collected under two different conditions labeled the Coupled Intrinsic Connectivity Distribution (coupled-ICD). Our proposed method jointly models both conditions to incorporate additional paired information into the connectivity metric. Voxel-based connectivity holds promise as a clinical tool to characterize a wide range of neurological and psychiatric diseases, and monitor their treatment. As such, examining paired connectivity data such as scans acquired pre- and post-intervention is an important application for connectivity methodologically. When presented with data from paired conditions, conventional voxel-based methods analyze each condition separately. However, summarizing each connection separately can misrepresent patterns of changes in connectivity. We show that commonly used methods can underestimate functional changes and subsequently introduce and evaluate our solution to this problem, the coupled-ICD metric, using two studies: 1) healthy controls scanned awake and under anesthesia, and 2) cocaine-dependent subjects and healthy controls scanned while being presented with relaxing or drug-related imagery cues. The coupled-ICD approach detected differences between paired conditions in similar brain regions as the conventional approaches while also revealing additional changes in regions not identified using conventional voxel-based connectivity analyses. Follow-up seed-based analyses on data independent from the voxel-based results also showed connectivity differences between conditions in regions detected by coupled-ICD. This approach of jointly analyzing paired resting-state scans provides a new and important tool with many applications for clinical and basic neuroscience research.
Thoracocardiography. Part 1: Noninvasive measurement of changes in stroke volume comparisons to thermodilution.

The thoracocardiograph (TCG) is a new noninvasive monitoring device that measures cardiac oscillations transmitted to the external surface of the thorax. It consists of 2.5 cm in height, elastic inductive plethysmographic transducers placed transversely in the proximity of the xiphoid process to provide changes in cross-sectional area on a transverse plane across the minor ventricular axis. Cardiac oscillations synchronous with each heart beat are extracted from the respiratory signal during breathing with an ensemble-averaging technique using the electrocardiograph as a trigger pulse. The average cardiac waveform at locations near the xiphoid process in normal humans has the appearance of a ventricular volume curve. The latter is also found in the majority of patients with heart disease although in some, outward (dyskinetic) rather than inward motion during systole occurs at one or more locations of the TCG transducers. As in echocardiography, such findings are consistent with ischemic or scarred myocardium invalidating computation of changes in stroke volume from such sites. In anesthetized dogs and critically ill patients with normal ventricular wall motion, changes in TCG derived ventricular volume waveform amplitudes agreed well with changes of thermodilution estimates of stroke volume during atrial pacing and fluid loading in the dogs on the one hand and with application of extrinsic positive end-expiratory pressure (PEEP) in patients on the other hand. Thoracocardiography has the potential for noninvasive, continuous monitoring of stroke volume and cardiac output as well as for detection of ischemic or scarred myocardium. (Chest 1991; 99:613–22)
A genome-wide RNAi screen identifies novel targets of neratinib resistance leading to identification of potential drug resistant genetic markers

Neratinib (HKI-272) is a small molecule tyrosine kinase inhibitor of the ErbB receptor family currently in Phase III clinical trials. Despite its efficacy, the mechanism of potential cellular resistance to neratinib and genes involved with it remains unknown. We have used a pool-based lentiviral genome-wide functional RNAi screen combined with a lethal dose of neratinib to discover chemoresistant interactions with neratinib. Our screen has identified a collection of genes whose inhibition by RNAi led to neratinib resistance including genes involved in oncogenesis (e.g. RAB33A, RAB6A and BCL2L14), transcription factors (e.g. FOXP4, TFEC, ZNF), cellular ion transport (e.g. CLIC3, TRAPPC2P1, P2RX2), protein ubiquitination (e.g. UBL5), cell cycle (e.g. CCNF), and genes known to interact with breast cancer-associated genes (e.g. CCNF, FOXP4, TFEC, several ZNF factors, GNA13, IGFBP1, PMEPA1, SOX5, RAB33A, RAB6A, FXR1, DDO, TFEC, OLFM2). The identification of novel mediators of cellular resistance to neratinib could lead to the identification of new or neoadjuvant drug targets. Their use as patient or treatment selection biomarkers could make the application of anti-ErbB therapeutics more clinically effective.
Lateral hypothalamic stimulation: Stimulus-bound eating and self-deprivation ☆

Research was undertaken in an attempt to clarify the relationship between stimulus-bound eating and self-deprivation produced by electrical stimulation of the lateral hypothalamus. It was hypothesized that if these two phenomena are mediated through a common population of feeding-related neurons, a significant correlation should be observed between these two behaviors. No significant relationship was discovered among the rats tested for both stimulus-bound eating and self-deprivation. Although this finding by itself does not rule out some role for feeding-related neural elements in stimulus-bound eating and self-deprivation, the present results provide no support for this view and suggest alternative explanations should be sought.
Selenium distribution and mode of occurrence in the Kanawha Formation, southern West Virginia, U.S.A.

Abstract Selenium concentrations were measured in five rock cores from a mine in Boone County, West Virginia to determine their relationship to sulfur, rock type and stratigraphic location. The samples spanned the Winifrede and Coalburg coal beds of the Middle Pennsylvania upper Kanawha Formation and included coals and clastic lithologies. The coals generally contained the highest concentrations of Se and the sandstones the lowest. No correlation was observed between total Se and sulfur concentrations for either the entire data set or for individual lithologies. Better correlations were identified for log concentrations between total Se and total organic carbon. Principal component analysis identified a strong sulfur–acid component, interpreted to be due to sulfide mineral presence, which correlates well with S but not with Se. Coal sample chemistry is more likely to load onto this component while clastic rock chemistry is more likely to load onto the second, non-sulfur component. Se concentrations load onto both components indicating they are not controlled by a single overriding chemistry. Selective extractions indicate that Se is distributed between both sulfide and organically-bound fractions, as defined by the test. Overall, the lack of correlation between Se and S, the distribution of Se among extracted fractions, and the loading of Se onto both sulfur and non-sulfur components support that the Se in these rock layers is distributed in more than one chemically-bound form. Non-coal rock units with the highest concentrations of Se were found adjacent to coal beds, suggesting that redistribution of Se may have occurred post-deposition. The acidic domed swamps that formed these coals were low in sulfur and a reasonable chemical setting to accumulate Se if it were introduced. The preservation of Se in the domed swamp peat coupled with post-depositional redistribution may partly explain the data presented.
Mechanism of efficient transfection of the nasal airway epithelium by hypotonic shock

The main barrier to gene transfer in the airway epithelium is the low rate of apical endocytosis limiting naked DNA uptake. Deionized water is known to stimulate the exocytosis of numerous intracellular vesicles during hypotonic cell swelling, in order to expand plasma membrane and prevent cell lysis. This is followed by the phase of regulatory volume decrease (RVD), during which the excess plasma membrane is retrieved by intensive endocytosis. Here we show that the more hypotonic the DNA solution, the higher the transfection of the nasal tissue. P2 receptors are known to be involved in RVD and we demonstrate that some P2 agonists and a P2 antagonist impair transfection in a time-dependent manner. Our study strongly suggests that the nasal airway epithelial cells take up plasmid DNA in deionized water during RVD, within approximately half an hour. Our simple gene delivery system may constitute a promising method for respiratory tract gene therapy.
Ashbery's They Dream Only of America and Definition of Blue

(2006). Ashbery's They Dream Only of America and Definition of Blue. The Explicator: Vol. 65, No. 1, pp. 47-50.
Nonreactive molecular dynamics force field for crystalline hexahydro-1,3,5-trinitro-1,3,5 triazine

An empirical nonreactive force field has been developed for molecular dynamics (MD)/Monte Carlo simulation of the formation, diffusion, and agglomeration of point defects in the crystal lattice of the α modification of hexahydro-1,3,5-trinitro-1,3,5 triazine (RDX) using flexible molecules. Bond stretching and angle bending are represented by Morse and harmonic functions, and torsion by a truncated cosine series. Nonbonded interactions, both inter- and intramolecular, are described by Buckingham potentials separately parametrized. Intermolecular electrostatic interactions are treated via a Coulomb term coupled with a smooth 15.0A cutoff radius. Parameters were taken in part from earlier published works and were determined partly by fitting to known molecular and crystal properties of RDX. In MD simulations at constant pressure and temperature, the model was able to stabilize and maintain the correct crystal structure, symmetry, and molecular conformation of α-RDX. Vibrational frequencies, lattice binding e...
Phonons, saddle points, and resonances in Nb

The dip observed in the [100] branch in Nb and its absence in Mo is ascribed to the $d\ensuremath{-}p$ intervalley electron-phonon scattering of electrons near the saddle points at $\frac{(0.5,0.5,0)\ensuremath{\pi}}{a}$; to states near $\frac{(0.5,\ensuremath{-}0.5,0)\ensuremath{\pi}}{a}$ (but outside the Fermi surface) and corresponding symmetry combinations.
A127: Validating Popliteal Lymph Node Phenotype and Bin Expansion as Biomarkers of Rheumatoid Arthritis Knee Flare in Clinical Pilot Studies

Background/Purpose: Factors precipitating joint flare in rheumatoid arthritis (RA) patients are poorly understood. Contrast enhanced (CE) MRI studies in murine models have identified popliteal lymph node (PLN) phenotypes that correlate with arthritic flare in the adjacent knee defined by a sudden increase in synovial volume and focal erosions. Prior to flare, the PLN expands in size and CE due to increased lymph volume and accumulation of CD23+CD21hiCD1dhi B cells (Bin). Arthritic flare following PLN collapse is characterized by decreased CE and translocation of Bin to the paracortical sinuses with loss of efferent lymphatic drainage. To validate lymphatic biomarkers in RA, we performed pilot studies to demonstrate the feasibility of detecting expanding and collapsed PLN via CE-MRI. We analyzed PLN from RA patients undergoing total knee replacement or amputation for ischemic limbs in patients without RA. Methods: RA patients experiencing knee flare had a 3T CE-MRI prior to initiation of biologic therapy. PLN and synovium volumes were measured with Amira. PLN from RA patients and amputees were harvested, cells were stained and examined by flow cytometry. Results: MRI and 3D volume rendering of a representative flaring knee from early vs. long-standing RA (Fig. 1) show evidence of expanding PLN (n = 3; 3.57, 1.23, 2.2 cm3) adjacent to highly vascular synovitis (203.40 cm3). In contrast, knee flare in longstanding RA (>30 yrs) presents with collapsed PLN (n = 2; 0.24, 0.16 cm3) adjacent to pannus (159.88 cm3) that contains both bright (vascular) and dark (necrotic) regions on MRI. Flow cytometry confirmed large numbers of Bin-like cells (CD23hiCD21hi) in RA vs. non-RA PLN. Clinical endpoints measured by disease activity score (25% improvement) and C-reactive protein levels (40% decrease) preliminarily show a correlation between effective therapy and CE-MRI changes. Conclusion: We present evidence that similar to murine inflammatory arthritis, knee flare in RA is modulated by altered dynamics of draining lymph nodes and lymphatic vessels. We found that the flare in early arthritis is characterized by extensive joint inflammation that appears to exceed the capacity of expanded lymphatics. In contrast, knee flare in long-standing arthritis is associated with loss of lymphatic drainage, which in mice, is caused by loss of the lymphatic pulse and clogging of efferent lymphatics by Bin cells. Additional studies are warranted to demonstrate the reliability of these findings of knee flare in early vs. chronic RA. Figure 1. Representative images of MRI and corresponding 3D rendering from RA patients with knee flare shows inflamed synovium with bright PLN in the T2 fat-suppressed MRI (A) and uniform inflammatory tissue and large PLN (B) in early RA. In contrast, note marked focal erosions in the proton density weighted MRI (C) and patchy synovium with collapsed PLN (D) in long-standing RA.
DEPENDENCE OF TRANS-1-(2-ANTHRYL)-2-PHENYLETHENE CONFORMER-SPECIFIC FLUORESCENCE SPECTRA AND FUMARONITRILE QUENCHING RATE CONSTANTS ON TEMPERATURE

The quenching of trans-1-(2-anthryl)-2-phenylethene (t-APE) fluorescence by fumaronitrile (FN) was determined as a function of excitation wavelength (λexc) and temperature (5.0 ≤ T ≤ 80.0 °C). Principal component analysis with self-modeling (PCA-SM) was applied separately to the fluorescence spectra at each temperature. Resolved pure conformer fluorescence spectra were based on the condition that Stern−Volmer quenching constants for each conformer be λexc-independent. A shoulder at the blue edge of the spectra of the more extended, s-trans conformer (t-APEB) becomes more pronounced with increasing temperature revealing fluorescence from a thermally populated S2 state. Similar, but more subtle changes are evident in the spectra of the s-cis conformer (t-APEA). Both sets of resolved spectra exhibit blue shifts and broadening as the temperature is increased. These spectral changes are reflected in the shape of the eigenvectors obtained from the PCA of each set of spectra and prevent their resolution into S2 ...
Subcritical convective instability. Part 1. Fluid layers

This paper elaborates on the assertion that energy methods provide an always mathematically rigorous and a sometimes physically precise theory of sub-critical convective instability. The general theory, without explicit solutions, is used to deduce that the critical Rayleigh number is a monotonically increasing function of the Nusselt number, that this increase is very slow if the Nusselt number is large, and that a fluid layer heated from below and internally is definitely stable when $RA 1708/(N_s + 1)$ where N s is a heat source parameter and $\widetilde{RA}$ is a critical Rayleigh number. This last problem is also solved numerically and the result compared with linear theory. The critical Rayleigh numbers given by energy theory are slightly less than those given by linear theory, this difference increasing from zero with the magnitude of the heat-source intensity. To previous results proving the non-existence of subcritical instabilities in the absence of heat sources is appended this result giving a narrow band of Rayleigh numbers as possibilities for subcritical instabilities.
Dynamic analysis of the effects access rule modifications have upon security

A technique is presented for analyzing the relationships among the predicates in a predicate-based security model for database management systems. The principal tool of the technique is the Boolean difference, which is used to examine the relationships among the predicates when users are allowed to be members of more than one user group. The effects of deleting or adding predicates on the user group definition are identified by the technique. The technique is most valuable to information security authorizers who define and maintain access-control rules.
Human endothelial cell damage induced by interactions between polymorphonuclear leukocytes and immune complex-coated erythrocytes.

We have examined, in vitro, the effects of autologous erythrocytes (RBC) coated with soluble immune complexes (RBC-IC) on the interactions of polymorphonuclear leukocytes (PMN) with human endothelial cell (EC) cultures. RBC-IC were prepared by incubating human RBC with soluble immune complexes, prepared with keyhole limpet hemocyanin (KLH) and rabbit anti-KLH in antigen excess, using normal human serum as a complement source. Several parameters believed to be related to EC-PMN interactions, including adherence of PMN to EC, detachment of EC after incubation with media harvested from RBC-IC-stimulated PMN, and the release of 2-deoxy-d-[3H]glucose from damaged EC, were investigated. The proportion of PMN adhering to EC increased in direct proportion to the number of RBC-IC used to stimulate PMN. Media harvested from PMN stimulated with RBC, RBC incubated with complement, RBC-IC, or opsonized zymosan caused variable degrees of detachment of cultured EC. The percentage of EC detached was directly related to the intensity of the PMN degranulation as measured by lysozyme release with a correlation coefficient of 0.935, comparing the natural log of the lysozyme released to the percentage EC detachment. Finally, RBC-IC added to PMN and EC induced PMN-mediated EC damage as measured by the release of 2-deoxy-d-[3H]glucose from the labeled EC. The release of 2-deoxy-d-[3H]glucose from the labeled EC was directly related to the number of RBC-IC used to stimulate the PMN. These data indicate that RBC-IC are able to stimulate the type of interactions between PMN and EC that are believed to cause EC damage and may play a role in the initiation or exacerbation of inflammatory vascular lesions.
Rising–falling mercury pollution causing the rising–falling IQ of the Lynn–Flynn effect, as predicted by the antiinnatia theory of autism and IQ

A fundamental principle of the antiinnatia theory of autism and IQ is that the same factors (genetic and environmental) which in extreme high levels cause autism, in more modal levels cause increased IQ. And the factors which generally cause raised IQ, in extreme levels cause autism. The antiinnatia theory further proposed that molecules randomly part-time binding to DNA and thereby reducing gene-expression would cause autism (and in less high levels cause raised IQ). Studies have found that mercury binds dose-dependently to DNA thereby reducing gene-expression, and thus the theory predicts that mercury pollution would cause raised IQ (such as the Flynn effect). This appears contrary to the standard assumption that mercury pollution causes decrements of IQ. In this study, data from the Upper Fremont glacier finds considerable overall correspondence between changes of mercury pollution and changes of IQ. In respect of both mercury and IQ there was roughly-speaking 100 years of increase followed by 15 years of decrease in at least five countries. But mercury pollution is likely to be causing serious harms other than decrements of population averages of IQ.
Rotation matrices for vertex maps on graphs

Let G be a finite connected graph. Suppose is a map homotopic to the identity that permutes the vertices. For such a map, a rotation matrix is defined and the basic properties of this matrix are given. It is shown that this matrix generalizes some of the information given by the rotation interval, which is defined when the graph is a circle, to more general graphs.
Surface States for a Molecular Orbital Model Hamiltonian: Resolvent Methods and Application to Zinc Blende

A careful discussion is given of the application of the resolvent or Koster-Slater method to a surface-state problem described by a model Hamiltonian of the tight-binding type. Because of a special symmetry, peculiar to the surface-state problem, it is possible to reduce the degree of the characteristic determinant by a factor of 2. The usual, "truncation" method of doing this is shown to sometimes lead to spurious solutions. The origin and properties of these are determined and a prescription for recognizing them presented. An alternative, "pre-severed" approach to the reduction of the determinant is described. This latter is less useful for numerical calculation, but has advantages in obtaining analytical results. The general form of the surface-state wave function is derived from the integral representation of the resolvent. It proves possible to characterize this form using only simple properties of the bulk band structure as represented by the model Hamiltonian. This then permits the popular "ansatz" method of treating the surface states to be routinely used in problems having an arbitrary degree of complexity. The results of the general discussion are applied to determine the surface states associated with the (110) cleavage face of a semiconductor having the zinc-blende structure. The "pre-severed" resolvent method is used to derive some preliminary analytical results, and a program is set up for the numerical calculation of the surface-state properties for more realistic models of the surface perturbation.
Virial equation of state of water based on Wertheim's association theory.

Wertheim’s multidensity formalism for pairwise additive molecular interaction is extended to handle nonadditive contributions and is applied to formulate an equation of state (WEOS) for the Gaussian-charge polarizable model (GCPM) of water, with cluster integrals appearing in the theory calculated via the Mayer sampling Monte Carlo method. At both sub- and supercritical temperatures, the equation of state of GCPM water obtained from WEOS converges well to Monte Carlo simulation data, and performs significantly better than the conventional virial treatment (VEOS). The critical temperature for GCPM water using a fourth-order WEOS is given to within 1.3% of the established value, compared to a 17% error shown by fifth-order VEOS; as seen in previous applications, the critical density obtained from both VEOS and WEOS significantly underestimates the true critical density for GCPM water. Examination of the magnitudes of the computed cluster diagrams at the critical density finds that negligible contributions a...
Gordon Bell: Building Blocks of Computing

Gordon Bell describes how the minicomputer served as a building block for computing-enabled innovation and the eventual evolution of computing applications. The first Web extra at http://youtu.be/NFiWx_OBAXU is an audio recording of Charles Severance's Computing Conversations column, in which he discusses his interview with Gordon Bell about how the minicomputer served as a building block for computing-enabled innovation and the eventual evolution of computing applications. The second Web extra at http://youtu.be/8skBtQS-VVE is a video interview with Gordon Bell about how the minicomputer served as a building block for computing-enabled innovation and the eventual evolution of computing applications.
Elimination of a brain tract increases errors in pathfinding by follower growth cones in the zebrafish embryo

The early zebrafish brain contains a simple axon scaffold of longitudinal tracts connected by commissures. Neurons in the nucleus of the posterior commissure (nuc PC) project growth cones along a specific route in this axonal scaffold, raising the possibility that specific axons in the early scaffold guide nuc PC growth cones. We tested this possibility by analyzing the behavior of nuc PC growth cones in embryos in which a portion of the scaffold, normally traversed by nuc PC growth cones, was surgically prevented from forming. Under these conditions nuc PC growth cones extended along both normal and aberrant pathways. This suggests that specific axons do provide guidance cues, since their removal leads to errors. However, these cues are not obligatory, since some growth cones still followed normal pathways.
Effect of quantitative feedback on student performance on the National Board Medical Examination in an obstetrics and gynecology clerkship

Objective The purpose of this study was to determine whether regular quantitative feedback improved medical student performance on the National Board of Medical Examiners Obstetrics and Gynecology subject test. Study Design We examined the effect of including regular quantitative feedback (in the form of biweekly quizzes) in the obstetrics and gynecology clerkship on student performance on the National Board of Medical Examiners Obstetrics and Gynecology examination at the University at Buffalo. Results Students who completed the clerkship format including the regular feedback scored significantly higher than students who completed the clerkship without feedback (70.3 ± 7.1 vs 68.2 ± 8.6; P t test). The number of students failing the examination was significantly reduced from 6.39% to 0.47% (χ 2 test; P Conclusion Introduction of regular quantitative feedback significantly improved student performance on the National Board of Medical Examiners test, and resulted in a significant decrease in the number of students failing the course.