cssi/SciSciGPT-SciSciNet huggingface dataset:
Modes of Calreticulin Recruitment to the Major Histocompatibility Complex Class I Assembly Pathway

Major histocompatibility complex (MHC) class I molecules are ligands for T-cell receptors of CD8+ T cells and inhibitory receptors of natural killer cells. Assembly of the heavy chain, light chain, and peptide components of MHC class I molecules occurs in the endoplasmic reticulum (ER). Specific assembly factors and generic ER chaperones, collectively called the MHC class I peptide loading complex (PLC), are required for MHC class I assembly. Calreticulin has an important role within the PLC and induces MHC class I cell surface expression, but the interactions and mechanisms involved are incompletely understood. We show that interactions with the thiol oxidoreductase ERp57 and substrate glycans are important for the recruitment of calreticulin into the PLC and for its functional activities in MHC class I assembly. The glycan and ERp57 binding sites of calreticulin contribute directly or indirectly to complexes between calreticulin and the MHC class I assembly factor tapasin and are important for maintaining steady-state levels of both tapasin and MHC class I heavy chains. A number of destabilizing conditions and mutations induce generic polypeptide binding sites on calreticulin and contribute to calreticulin-mediated suppression of misfolded protein aggregation in vitro. We show that generic polypeptide binding sites per se are insufficient for stable recruitment of calreticulin to PLC substrates in cells. However, such binding sites could contribute to substrate stabilization in a step that follows the glycan and ERp57-dependent recruitment of calreticulin to the PLC.
Simplicity and complexity in extrapolatwe population forecasting models

The literature on population forecasting reveals a continuing debate over the relative ex post accuracy of forecasts from simple and complex models. In this paper ex ante projections from simple models are used to evaluate the plausibility of point and interval forecasts from a complex cohort‐component model. This paper compares complex with simple forecasts along two dimensions: simplification of input schedules and of the projection models using those input schedules. Projections of vital rates that are the inputs for a cohort‐component projection may be provided by extrapolations of historical trends in age‐specific rates, relational methods that link future age‐specific rates to a general trend variable and a “standard”; schedule, or time series forecasts of the parameters of a functionally specified model schedule. This paper compares point and interval forecasts of fertility patterns that result from such alternative input specifications. Furthermore, the cohort‐component framework may be replaced b...
Fiber-optic confocal microscope using a MEMS scanner and miniature objective lens.

We designed and constructed a single-fiber-optic confocal microscope (SFCM) with a microelectromechanical system (MEMS) scanner and a miniature objective lens. Axial and lateral resolution values for the system were experimentally measured to be 9.55 µm and 0.83 µm respectively, in good agreement with theoretical predictions. Reflectance images were acquired at a rate of 8 frames per second, over a 140 µm×70 µm field-of-view. In anticipation of future applications in oral cancer detection, we imaged ex vivo and in vivo human oral tissue with the SFCM, demonstrating the ability of the system to resolve cellular detail.
On the magnetic field dependence of cyclotron-phonon resonance linewidth

Abstract We have calculated the cyclotron-phonon resonance linewidth due to LO phonon emission scattering in non-degenerate polar semiconductors in the limit kBT ⪡ ℏωc kBT ⪡ ℏωo,where ω c = eB M is the cyclotron frequency and ω0, the frequency of LO phonons. A narrowing ∞ ω −1 2 c is shown for the linewidth at very low temperatures and large magnetic fields.
MULTIPHASE GAS IN GALAXY HALOS: THE O VI LYMAN-LIMIT SYSTEM TOWARD J1009+0713*

We have serendipitously detected a strong O VI-bearing Lyman-limit system (LLS) at z{sub abs} = 0.3558 toward the quasi-stellar object (QSO) J1009+0713 (z{sub em} = 0.456) in our survey of low-redshift galaxy halos with the Hubble Space Telescope's (HST) Cosmic Origins Spectrograph. Its total rest-frame equivalent width of W{sub r} = 835 {+-} 49 mA and column density of log N(O VI) = 15.0 are the highest for an intervening absorber yet detected in any low-redshift QSO sightline, with absorption spanning at least four major kinematic component groups over 400 km s{sup -1} in its rest frame. HST/Wide Field Camera 3 images of the galaxy field show that the absorber is associated with two galaxies lying at 14 and 46 kpc from the QSO line of sight. The absorber is kinematically complex and there are no less than nine individual Mg II components spanning 200 km s{sup -1} in our Keck/HIRES optical data. The bulk of the absorbing gas traced by H I resides in two strong, blended component groups that possess a total log N(H I) {approx_equal} 18-18.8, but most of the O VI is associated with two outlying components with log N(H I) = 14.8 and 16.5. Themore » ion ratios and column densities of C, N, O, Mg, Si, S, and Fe, except the O VI, can be accommodated into a simple photoionization model in which diffuse, low-metallicity halo gas is exposed to a photoionizing field from stars in the nearby galaxies that propagates into the halo at 10% efficiency. In this model, the clouds have neutral fractions of {approx}1%-10% and thus total hydrogen column densities of log N(H) {approx_equal} 19.5. Direct measurement of the gas metallicity is precluded by saturation of the main components of H I, but we constrain the metallicity firmly within the range 0.1-1 Z{sub sun}, and photoionization modeling indirectly indicates a subsolar metallicity of 0.05-0.5 Z{sub sun}. This highly ionized, multiphase, possibly low-metallicity halo gas resembles gas with similar properties in the Milky Way halo and other low-redshift LLS, suggesting that at least some other galaxies have their star formation fueled by metal-poor gas accreting from the intergalactic medium and ionized by the stars in the host galaxy. As observed in the Milky Way high-velocity clouds, the strong detected O VI is not consistent with the photoionization scenario but is consistent with general picture in which O VI arises in interface material surrounding the photoionized clouds or in a hotter, diffuse component of the halo. The appearance of strong O VI and nine Mg II components in this system, and our review of similar systems in the literature, offer some support to this 'interface' picture of high-velocity O VI: the total strength of the O VI shows a positive correlation with the number of detected components in the low-ionization gas.« less
The hydrodynamic response of the York River estuary to Tropical Cyclone Isabel, 2003

Abstract Hurricane Isabel made landfall along the North Carolina coast on September 18, 2003 (UTC 17:00) and the storm surge exceeded 2.0 m in many areas of the Chesapeake Bay and in the York River estuary. River flooding occurred subsequently, and the peak river discharge reached 317 and 104 m 3 s −1 in the Pamunkey and Mattaponi rivers, respectively. The York River estuary experienced both storm surge and river flooding during the event and the estuary dynamics changed dramatically. This study investigates the hydrodynamics of the York River estuary in response to the storm surge and high river inflows. A three-dimensional model was used to investigate the changes of estuarine stratification, longitudinal circulation, salt flux mechanisms, and the recovery time required for the estuary to return to its naturally evolved condition without the storm. Results show that the salt flux was mainly caused by advection, which was induced by the barotropic gradient during the storm event. The net salt flux increased by a factor of 30 during the rise of the storm surge. However, the large amount of salt transported into the estuary was quickly transported out of the estuary as the barotropic gradient reversed during the descent of the storm surge. Subsequent high freshwater inflow influenced the estuarine circulation substantially. The estuary changed from a partially mixed estuary to a very stratified estuary for a prolonged period. The model results show that it will take about 4 months for the estuary to recover to its naturally evolved salinity distribution after the impacts of the storm surge and freshwater pulse.
Smearing in an axisymmetric finite element structural analysis application to the GCFR steam generator cavity closure plug

Abstract A methodical technique for smearing material properties in an elastic finite element analysis to derive an approximate axisymmetric model of a structure is presented. In this process, material properties are smeared circumferentially about an axis of symmetry in the structure's outline. Attention is given to the subsequent problem of unsmearing the results to obtain an estimate of circumferential variation in the solution. The scheme is illustrated with an application to an analysis of a GCFR steam generator cavity closure plug.
Antigens in human tumors revealed in suppressed rabbits rendered tolerant to normal human tissues.

Abstract Neonatal exposure of rabbits to protein extracts from normal human tissues resulted in suppression of immune response to the same preparations on second exposure in adult life. These suppressed rabbits were, nevertheless, able to produce antibodies to protein extracts from corresponding tumors, thus evidencing the existence in the tumors of antigens not present in normal counterpart tissues.
Design and experimental results from a 527 GHz gyrotron for DNP-NMR spectroscopy

A 527 GHz gyrotron has been designed and built for an 800 MHz DNP-NMR spectrometer. The gyrotron is designed at the second harmonic (ω=2 ω c ) of the electron cyclotron frequency to produce 20 W continuous microwave power at 527 GHz frequency using a diode type electron gun (V k ∼ 13.0 kV, I b =150 mA). An internal dimpled wall helical cut launcher is designed along with two mirrors and an internal periscope assembly to convert the operating mode in to a fundamental mode, HE 11 , of a corrugated waveguide with mode content of ∼ 93%
Renewal Approximations of the Switched Poisson Processes and Their Applications to Queueing Systems

The switched Poisson process (SPP), also known as the doubly stochastic Poisson process, has been widely used in the modelling of point processes whose rates vary subject to some random mechanism. The class of SPP includes a wide range of both renewal and non-renewal processes with squared coefficients of variation being larger than one. In this paper, we survey various approaches to approximate a non-renewal process by a renewal process. We derive the expressions for the first two moments of the inter-renewal time of a renewal process that approximates the SPP. We illustrate the quality of these approximations with numerical results in queueing applications. We believe that our approximations have potential applications in areas such as reliability, inventory control, telecommunications and maintenance.
Inositol polyphosphate multikinase (ArgRIII) determines nuclear mRNA export in Saccharomyces cerevisiae

The ARGRIII gene of Saccharomyces cerevisiae encodes a transcriptional regulator that also has inositol polyphosphate multikinase (ipmk) activity [Saiardi et al. (1999) Curr. Biol. 9, 1323-1326]. To investigate how inositol phosphates regulate gene expression, we disrupted the ARGRIII gene. This mutation impaired nuclear mRNA export, slowed cell growth, increased cellular [InsP(3)] 170-fold and decreased [InsP(6)] 100-fold, indicating reduced phosphorylation of InsP(3) to InsP(6). Levels of diphosphoinositol polyphosphates were decreased much less dramatically than was InsP(6). Low levels of InsP(6), and considerable quantities of Ins(1,3,4,5)P(4), were synthesized by an ipmk-independent route. Transcriptional control by ipmk reflects that it is a pivotal regulator of nuclear mRNA export via inositol phosphate metabolism.
On endogenous growth with productivity shocks

Abstract Recent evidence on output convergence across economies has been widely interpreted as falsifying the predictions of endogenous growth theory. This paper shows, however, that nonconvergence is an artifact of the deterministic structure of endogenous growth models: when stochastic factor productivity is introduced, convergence tends to occur despite nondiminishing returns to capital and persistent growth. For the case of constant returns to capital, it is shown that output paths of different economies converge with probability one in single-sector economies. For multi-sectora economies convergence occurs for most plausible specifications of the stochastic process driving productivity. Increasing returns reduce the probability of convergence.
Testis-determining H-Y antigen in XO males of the mole-vole (Ellobius lutescens)

Abstract The XO sex chromosome constitution has been found in both sexes of the mole-vole (Ellobius lutescens) belonging to the rodent family Microtinae. This enigmatic species has apparently been enduring a 50% zygotic lethality. The current serological study revealed the presence in XO males and the absence from XO females of H-Y (histocompatibility Y) antigen. In all the mammalian species studied thus far, the expression of H-Y antigen strictly coincided with the presence of testicular tissue and not necessarily with the presence of the Y chromosome. The testis-organizing function of the H-Y gene appears to have been confirmed. In the mole-vole, X linkage of the testis-organizing H-Y gene is favored over its autosomal inheritance. Only X linkage of the H-Y gene creates a compelling evolutionary need to change the female sex chromosome constitution from XX to XO, and to abandon the dosage compensation by an X inactivation mechanism, so that the nonproductive X H-Y X zygote can be eliminated as an embryonic lethal. With regard to the electrophoretic mobilities of three X-linked marker enzymes, however, a genetic difference between the male-specific X H-Y and the female-specific X was not detected. This might reflect a relatively recent speciation.
Scepticism about moral motives

L'A. defend la these selon laquelle le projet de vaincre le scepticisme concernant la rationalite de la moralite ne peut etre realise qu'en faisant echec au scepticisme concernant les motifs d'action de l'agent. Examinant le motif d'action qui consiste a se soucier d'autrui, l'A. montre que le motif sceptique d'une action non-sceptique conduit l'agent a faire un acte rationnel pour des raisons irrationnelles
Electron-hose instability in the ion-focused regime.

A relativistic electron beam propagating through an ummagnetized, underdense plasma exhibits a transverse instability due to the coupling of the beam centroid to plasma electrons at the ``ion-channel'' edge. The transverse wake field corresponding to this ``electron-hose'' effect is calculated in the ``frozen-field'' approximation for a low-current, cylindrical beam in a radially infinite plasma. The asymptotic growth of beam-centroid oscillations is computed, and the growth length is found to be very rapid, indeed much less than the betatron period of the beam. Results for a radially finite plasma and for a slab beam are noted. Damping and saturation mechanisms are discussed.
Assignment of the agent of Tyzzer's disease to Clostridium piliforme comb. nov. on the basis of 16S rRNA sequence analysis.

The small-subunit rRNA (16S rRNA) sequence of Tyzzer's bacillus (also known as “Bacillus piliformis”) was elucidated by using the polymerase chain reaction followed by reverse transcriptase sequencing. By using maximum-likelihood analysis, a phylogenetic tree was constructed from this and other 16S rRNA sequences available from the first release of the Ribosomal Database Project (G. J. Olsen, R. Overbeek, N. Larsen, T. L. Marsh, M. J. McCaughey, M. A. Maciukenas, W.-M. Kuan, T. J. Macke, Y. Xing, and C. R. Woese, Nucleic Acids Res. 20:2199-2200, 1992). Tyzzer's bacillus grouped with a specific set of anaerobic bacteria, most of which are Clostridium spp. The closest identified relatives are Clostridium coccoides, Clostridium oroticum, Clostridium clostridiiforme, Clostridium symbiosum, and Streptococcus hansenii. Clostridium amino-valericum and “Acetitomaculum ruminis” are also solidly allied with this ensemble. We propose that Tyzzer's bacillus be reclassified as Clostridium piliforme on the basis of its 16S rRNA sequence.
Efficacy of a Randomized Cell Phone-Based Counseling Intervention in Postponing Subsequent Pregnancy Among Teen Mothers

Adolescent mothers in Washington, DC have a high rate of subsequent teen pregnancies, often within 24 months. Children of teen mothers are at risk for adverse psychosocial outcomes. When adolescents are strongly attached to parents, schools, and positive peers, they may be less likely to repeat a pregnancy. This study tested the efficacy of a counseling intervention delivered by cell phone and focused on postponing subsequent teen pregnancies by strengthening healthy relationships, reproductive practices, and positive youth assets. The objective of this study was to compare time to a repeat pregnancy between the intervention and usual care groups, and, secondarily, to determine whether treatment intensity influenced time to subsequent conception. Primiparous pregnant teens ages 15–19, were recruited in Washington, DC. Of 849 teens screened, 29.3% (n = 249) met inclusion criteria, consented to participate, and completed baseline measures. They were then randomized to the intervention (N = 124) or to usual care (N = 125). Intervention group teens received cell phones for 18 months of counseling sessions, and quarterly group sessions. Follow-up measures assessed subsequent pregnancy through 24 months post-delivery. A survival analysis compared time to subsequent conception in the two treatment groups. Additional models examined the effect of treatment intensity. By 24 months, 31% of the intervention and 36% of usual care group teens had a subsequent pregnancy. Group differences were not statistically significant in intent-to-treat analysis. Because there was variability in the degree of exposure of teens to the curriculum, a survival analysis accounting for treatment intensity was performed and a significant interaction with age was detected. Participants who were aged 15–17 years at delivery showed a significant reduction in subsequent pregnancy with increased levels of intervention exposure (P < 0.01), but not those ≥18 years. Adolescents ≥18 years faced considerable challenges to treatment success. Individual, social, and contextual factors are all important to consider in the prevention of repeat teen pregnancy. Cell phone-based approaches to counseling may not be the most ideal for addressing complex, socially-mediated behaviors such as this, except for selective subgroups. A lack of resources within the community for older teens may interfere with program success.
Proton range and energy in irradiated Type 316 stainless steel

Abstract Cross-section transmission-electron-microscope foils of Type 316 stainless steel have been used t o determine the depth to which voids are formed during proton irradiation at energies between 0.75 and 1.05 MeV. These void depths, which can be determined with an accuracy of t5 percent, have been found to exceed by a rather large amount (∼1 0-4 cm) the results from range-energy data tables prepared specifically for stainless steel. Experimental and micro structural features which could lead to this apparent discrepancy are discussed. It is concluded that the depth to which voids are formed gives a good measure of the proton range at a particular energy. Values of calculated proton energy vs penetration which best agree with the experimental depth data are presented.
Surface Dezincification and Selective Oxidation Induced Heterogeneous Semiconductor Nanowire/Nanofilm Network Junctions

By directly heating a surface-dezincified polycrystalline brass (Cu70Zn30 alloy) in ambient conditions, semiconductor nanostructure networks composed of CuO nanofilm and ZnO nanowires have been successfully fabricated. The dezincification induced by metallographic etching on Cu70Zn30 polycrystalline alloy surface created heterogeneous networks composed of individual Cu-rich micrograin surfaces and surrounding grain boundaries. The comparative thermal oxidation investigations show distinct growth of semiconductor nanowire/nanofilm network junctions on dezincified Cu70Zn30 substrates compared to the random ZnO nanowires growth on nonetched brass substrates. The grain boundary region is mostly dominated by ZnO nanowires, while each grain surface was overgrown with CuO nanofilm, forming nanowire/nanofilm network junctions. The different growth habits of ZnO nanowires and CuO nanofilms are due to composition and geometry distribution difference between dezincified Cu70Zn30 grain surface and grain boundary, res...
A one-dimensional pattern in the cellular slime mould Polysphondylium pallidum

The cellular slime mould Polysphondylium pallidum has a fruiting body with whorls of branches spaced at regular intervals along the stalk (Fig. 1). The spacing between successive whorls is quite regular and under genetic control1. Because stalk cell number per interval correlates strongly with interval length, we have studied the influence of ploidy on the distance between whorls to determine if cell counting could account for the spacing. It is known that diploid spores and amoebae of Dictyostelium discoideum and Polysphondylium violaceum are roughly twice the size of their haploid parents2,3, and we find that stalk cells in P. pallidum follow the same pattern. Our results show that the number of stalk cells between successive whorls in haploids is approximately twice the number in diploids, while the spacing remains the same. This clearly indicates that spacing is not achieved by a cell counting mechanism. Instead, it appears to depend on distance.
The Urban Origins of Suburban Autonomy

The Urban Origins of Suburban Autonomy. By Richardson Dilworth. Cambridge, MA: Harvard University Press, 2005. 280p. $49.95.In his book, Richardson Dilworth takes the familiar argument that cities use development policy to compete for residents in our fragmented metropolitan areas and flips it on its head. In Dilworth's account, development policy is an important causal factor in the creation of the fragmented metropolitan areas in which this competition occurs. His detailed historical accounts of how communities in New York and New Jersey in the late 1800s dealt with issues of incorporation, consolidation, and annexation speak to current interest among urban politics scholars in patterns of suburbanization and the politics of regional coordination. By providing interesting accounts of how a good goes from being defined as private to public (e.g., water, gas), this book may also interest public policy scholars more generally.
Developing the Next Generation of Otolaryngologist-Researchers

The lifeblood of any specialty is innovation and discovery. It is important for the field of otolaryngology and its patients that we identify, recruit, train, and develop the next generation of researchers in otolaryngology. This article describes programs and resources currently available to otolaryngologists in training and early in their career for their development as clinician-scientists. We describe the background of the current generation of National Institutes of Health–funded otolaryngologists and discern where the next generation might come from. Special attention is given to the National Institute on Deafness and Other Communication Disorders, which focuses on supporting research and research training in hearing, balance, smell, taste, voice, speech, and language, and to programs aimed at the development of clinician-scientists.
Eighty Years of Succession in a Noncommercial Plantation on Hawai'i Island: Are Native Species Returning?

Abstract: Hawai‘i’s forest ecosystems are changing rapidly due to a high level of species introductions, and it is an open question whether native species will be maintained. Several studies have explored the potential for native species to succeed in future communities dominated by introduced species in Hawai‘i, but the results have been conflicting and most of the studies have been limited to relatively young forest (<30 yr old). I surveyed a remote, 80-yr-old noncommercial plantation on Hawai‘i Island to determine whether any native tree species were able to succeed in the planted forest. I compared abundance and composition of native species in the plantation to that in a relict, native-dominated forest adjacent to the plantation and located on the same substrate type. After 80 yr, native species constituted just 4.5% of basal area and 12.1% of stem density in the plantation. However, I found that the relative success of native species varied strongly by species. Of nine native species encountered in ...
Energy losses in thermally cycled optical fibers constrained in small bend radii

High energy laser pulses were fired into a 365μm diameter fiber optic cable constrained in small radii of curvature bends, resulting in a catastrophic failure. Q-switched laser pulses from a flashlamp pumped, Nd:YAG laser were injected into the cables, and the spatial intensity profile at the exit face of the fiber was observed using an infrared camera. The transmission of the radiation through the tight radii resulted in an asymmetric intensity profile with one half of the fiber core having a higher peak-to-average energy distribution. Prior to testing, the cables were thermally conditioned while constrained in the small radii of curvature bends. Single-bend, double-bend, and U-shaped geometries were tested to characterize various cable routing scenarios.
Microstructural Investigations Of Fine Grined Co-Hf-C Films

Microstructural investigations have been performed on Co-Hf-C films which show high mu (>2000), high Bs (1.4 T), and high thermal stability (>700 degrees C). The magnetic properties are very sensitive to the volume fraction of HfC particles. After annealing at 700 degrees C, Co-Hf-C films of the optimum composition consist of a mixture of fine FCC-Co and HfC grains. The grain size of FCC-Co is 10 approximately 15 nm and that of HfC is 3 approximately 4 nm. The HfC particles are located at the grain boundaries of FCC-Co. HfC was found to crystallize before the FCC-Co, and the fine dispersion of these particles successfully inhibited the grain growth of the FCC-Co. >
TACOMA: Server and workload management in internet data centers considering cooling-computing power trade-off and energy proportionality

A two-tier Internet data center management scheme, TACOMA, with thermal-aware server provisioning (TASP) in one tier, and thermal-aware workload distribution (TAWD) in the other is proposed. TASP and TAWD coordinate to maximize the energy savings by leveraging the workload dynamics, at coarse and fine time scale, respectively. TACOMA is aware of the QoS constraints, the energy proportionality of servers, and the potential trade-off between cooling and computing power. The obtained energy savings are a combination of suspending idle servers, using servers at their peak efficiency, and avoiding heat recirculation.
Amiodarone Pulmonary Toxicity: Assessment by Bronchoalveolar Lavage

Bronchoalveolar lavage was used to demonstrate morphologic changes in alveolar macrophages characteristic of amiodarone effect in lung tissue obtained by biopsy. This procedure may be useful in the assessment of abnormal chest x-ray findings in patients suspected to have amiodarone toxicity.
Subharmonics of Any Order in Nonlinear Systems of One Degree of Freedom: Application to Subharmonics of Order 1/3

This paper consists of two parts. In the first one we discuss the subharmonics of any order in the case where the nonlinearity enters in the elastic forces. The basic differential equation is with coefficients not necessarily small. The “steady state” and “transient” solutions of the differential equation, and the conditions for the existence of the subharmonics and their stability in a steady state are examined. In the second part of the paper an application is given, namely, the investigation of the subharmonics of order 1/3 according to the theory of the first part. An illustrated example is given, the “inverse problem” is examined, and the conditions for the stability and instability of the “harmonic solution” are found.
The effects of forced serial processing on identification of words and random letter strings

Abstract Skilled readers identified words and random letter strings displayed one letter at a time on the screen of a computer-controlled oscilloscope. Letters were either displayed in a single position, or painted left-to-right in adjacent positions. Adjacent displays were either unmasked, masked by a letter-like pattern following each letter (backward masking) or masked by a pattern preceding each letter (forward masking). Unmasked words were identified with a high degree of accuracy, and accuracy was independent of the exposure duration of the letters over the range 50–200 msec. Masked adjacent word displays and one-position word displays were identified much less accurately, and accuracy was highly dependent on letter exposure duration. In contrast to these results, identification of random strings, or of letters within random strings, was almost unaffected by the presence of the mask and was dependent on letter exposure duration under all display conditions. The results are interpreted as evidence that (a) masking forces subjects to process serial displays one letter at a time, and (b) words, or large segments of words, are habitually processed in parallel, while random strings are processed as a series of individual letters or small chunks.
A digital-to-analog converter with a voltage standard reference

Commercially available 20-bit digital-to-analog converters (DACs) have the potential to impact the field of low-frequency voltage metrology. We measured a linearity of ±6 µV (±0.6 µV/V full scale) over the 10 V range for such a DAC with a Zener voltage standard in use as its external 10 V reference. This result is a first step toward implementing such a DAC as an ac synthesized source, whose accuracy and stability could be established by a dc voltage standard reference.
Autoxidation of fatty acid monolayers adsorbed on silica gel. IV. Effects of antioxidants1

Inclusion of α- or γ-tocopherol in linoleic acid monolayers deposited on a silica gel surface introduced a definite induction period before the initiation of rapid autoxidation, as measured by the disappearance of linoleic acid. The length of the inducation period was found to be proportional to the amounts of tocopherol incorporated at the concentration range tested, and the protection was generally efficient with little loss of linoleic acid to autoxidation. At the onset of the rapid autoxidation, approximately 12% of the tocopherol remained, and most of this was destroyed after an additional short period. γ-Tocohperol, at the same concentration, was found to be 1.4 times as effective as the α-isomer. 3-(ω-Carboxynonyl)-4-methoxy-5-pentylphenol, the synthesis of which is described here, did not introduce a detectable induction period, but rather reduced the overall rate of autoxidation throughout a very long period.
Real-time monitoring of the laser hot-wire welding process

Abstract The laser hot-wire welding process was investigated in this work. The dynamics of the molten pool during welding was visualized by using a high-speed charge-coupled device (CCD) camera assisted by a green laser as an illumination source. It was found that the molten pool is formed by the irradiation of the laser beam on the filler wire. The effect of the hot-wire voltage on the stability of the welding process was monitored by using a spectrometer that captured the emission spectrum of the laser-induced plasma plume. The spectroscopic study showed that when the hot-wire voltage is above 9 V a great deal of spatters occur, resulting in the instability of the plasma plume and the welding process. The effect of spatters on the plasma plume was shown by the identified spectral lines of the element Mn I. The correlation between the Fe I electron temperature and the weld-bead shape was studied. It was noted that the electron temperature of the plasma plume can be used to real-time monitor the variation of the weld-bead features and the formation of the weld defects.
Accumulation of some metals by legumes and their extractability from acid mine spoils

A greenhouse study was conducted to investigate the growth (dry matter yield) of selected legume cover crops; phytoaccumulation of metals such as Zn, Mn, Pb, Cu, Ni, and Al; and extractability of heavy metals from three different Alabama acid mine spoils. The spoils were amended based on soil test recommended levels of N, P, K, Ca, and Mg prior to plant growth. Metals were extracted by three extractants (Mehlich 1, DTPA, and 0.1 M HCl) and values correlated with their accumulation by the selected legumes(.)
Ethanol-induced changes in astrocyte gene expression during rat central nervous system development.

Disruption of spatial and temporal patterns of gene expression in cells of the developing brain could result in abnormal development. We report that briefly exposing neonatal rats to a moderate dose of ethanol on postnatal days 5 through 7 caused a large, specific increase in glial fibrillary acidic protein (GFAP) mRNA and GFAP. Astrocytes of the cerebral cortex were apparently more sensitive to this effect of ethanol than astrocytes in several other brain regions. As a first step in the characterization of an in vitro model of ethanol's effect on GFAP gene expression, ethanol was added to the media of primary cultures of cortical astrocytes in a pattern of exposure and at concentrations equal to pups' peak blood levels. This resulted in an increase in GFAP mRNA whose magnitude and specificity mirrored that observed in the animal model. Together, these results suggest that even brief exposure to ethanol can alter gene expression in astrocytes, and forms the foundation for further characterization of an in vitro model that may be used to determine the mechanism of this effect.
The Effects of Hall and Ion Slip on the Electrical Conductivity of Partially Ionized Gases for Magnetohydrodynamic Re-Entry Vehicle Application

The presence of a partially ionized gas around a hypersonic vehicle permits the application of magnetehydrodynamic (MHD) devices during re-entry. The operation of such MHD devices on a re-entry vehicle will largely depend on the magnitude of the electrical conductivity of the gas between the electrodes. In some cases it may be necessary to seed the air in order to insure high conductivity. The operation of the re-entry vehicle at relatively low gas densities and high magnetic fields will produce Hall and ion slip effects which may materially reduce the effective conductivity between the electrodes. The electrical conductivity including Hall and ion slip effects for air is presented for a wide range of pressures and temperatures and for a typical re-entry vehicle, with and without seeding. The electrical conductivity is evaluated for equilibrium conditions considering the number density and collision cross sections for electrons, neutrals, and ions. The Hall and ion slip effects are evaluated from the degree of ionization, the cyclotron frequency, and the time between collisions for electrons, neutrals, and ions.
Optically Detected Coherent Transients in Nuclear Hyperfine Levels.

Using optical detection, we have observed rf nutation, free-induction decay, and echoes, on the 16.70-MHz nuclear hyperfine transition of dilute ${\mathrm{Pr}}^{3+}$ in La${\mathrm{F}}_{3}$ at 2 K. From a comparison of free-induction decay and echo decay we find that the previously observed linewidth of 200 kHz is inhomogeneous and that the homogeneous width is 19 kHz. On the basis of these measurements it is suggested that optical dephasing times for the $^{1}D_{2}\ensuremath{\leftrightarrow}^{3}H_{4}$ and $^{3}P_{0}\ensuremath{\leftrightarrow}^{3}H_{4}$ transitions are as long as \ensuremath{\sim}20 \ensuremath{\mu} sec.
Metallobiology: Zinc differently

An extracellular ejection of zinc, known as a zinc spark, is triggered by the fertilization of a mammalian egg; however, the origin of this zinc was not clear. Now, a combination of four complementary techniques has revealed the source and provided an unprecedented quantification of the distribution of zinc in a maturing mammalian oocyte.
A Probabilistic Approach to Perceptual Grouping

We present a general framework for determining probability distributions over the space of possible image feature groupings. The framework can be used to find several of the most probable partitions of image features into groupings, rather than just returning a single partition of the features as do most feature grouping techniques. In addition to the groupings themselves, the probability of each partition is computed, providing information on the relative probability of multiple partitions that few grouping techniques offer. In determining the probability distribution of groupings, no parameters are estimated, thus eliminating problems that occur with small data sets and outliers such as the compounding of errors that can occur when parameters are estimated and the estimated parameters are used in the next grouping step. We have instantiated our framework for the two special cases of grouping line segments into straight lines and for grouping bilateral symmetries with parallel axes, where bilateral symmetries are formed by pairs of edges. Results are presented for these cases on several real images.
Strategy hubs: next-generation domain portals with search procedures

Current search tools on the Web, such as general-purpose search engines (e.g. Google) and domain-specific portals (e.g. MEDLINEplus), do not provide search procedures that guide users to form appropriately ordered sub-goals. The lack of such procedural knowledge often leads users searching in unfamiliar domains to retrieve incomplete information. In critical domains such as in healthcare, such ineffective searches can have dangerous consequences. To address this situation, we developed a new type of domain portal called a Strategy Hub. Strategy Hubs provide the critical search procedures and associated high-quality links that enable users to find comprehensive and accurate information. This paper describes how we collaborated with skin cancer physicians to systematically identify generalizeable search procedures to find comprehensive information about melanoma, and how these search procedures were made available through the Strategy Hub for healthcare. A pilot study suggests that this approach can improve the efficacy, efficiency, and satisfaction of even expert searchers. We conclude with insights on how to refine the design of the Strategy Hub, and how it can be used to provide search procedures across domains.
The Calculus of Cures

More than half of the 139 drugs approved by the FDA since 2009 are for orphan diseases and cancers. By addressing economic and business factors that play a role in this disproportion, we can work to avoid systematically underinvesting in drugs in other key areas of medicine.
Chronic oral toxicity of Ponceau 3R.

The results of two-year oral toxicity studies with Ponceau 3R using two strains of rats have been presented. Dosage levels were 5.0, 2.0, 1.0, and 0.5% for Osborne-Mendel rats and one dosage level of 2.0% for Bethesda Black rats. Preliminary results of the continuing dog and mouse studies are reported. Ponceau 3R at 5.0, 2.0, 1.0, and 0.5% of the diet produced high mortality, growth inhibition, and increased weight of the liver and kidneys. Malignant liver tumors occurred in both strains of rats at all dietary levels of Ponceau 3R, statistically significant (P < 0.01) in comparison with the controls at the 5.0% level of the Osborne-Mendel rats and the 2.0% level of the Bethesda Black animals. Incidence of benign liver tumors was also significant for all test levels. Marked weight loss and high mortality have been observed in dogs fed Ponceau 3R at dosage levels of 2.0% and 1.0%. After a feeding period of 32 weeks, changes in the liver were the most pronounced tissue changes. Increased mortality of C3HeBFe mice has been observed on 2.0% and 1.0% feeding levels. Hepatic adenomas and carcinomas have been observed on the 2.0% level.
Biotransformation and Excretion: In Vivo Studies Utilizing Stable Isotopes and Nuclear Magnetic Resonance

Specific 13C labeling in combination with nuclear magnetic resonance (NMR) spectroscopy is a powerful tool for the study of metabolism. Nuclear magnetic resonance allows both the extent and distribution of 13C labels in metabolites to be quantified without the need to isolate or degrade them. In addition, NMR is nonperturbing to living cells, allowing real-time observation of metabolic processes. To date, the application of 13C-NMR to in vivo studies has been confined to the study of metabolic processes in cell suspensions, perfused organs, and small animals. The continuing development of large-bore high field magnets and surface coils will, in principle, allow in vivo metabolic studies to be extended to humans.
Hypoxia imaging-directed radiation treatment planning

Increasing evidence supports the role of the tumor microenvironment in modulating cancer behavior. Tissue hypoxia, an important and common condition affecting the tumor microenvironment, is well established as a resistance factor in radiotherapy. Increasing evidence points to the ability of hypoxia to induce the expression of gene products, which confer aggressive tumor behavior and promote broad resistance to therapy. These factors suggest that determining the presence or absence of tumor hypoxia is important in planning cancer therapy. Recent advances in PET hypoxia imaging, conformal radiotherapy, and imaging-directed radiotherapy treatment planning now make it possible to perform hypoxia-directed radiotherapy. We review the biological aspects of tumor hypoxia and PET imaging approaches for measuring tumor hypoxia, along with methods for conformal radiotherapy and image-guided treatment, all of which provide the underpinnings for hypoxia-directed therapy. As a case example, we review emerging data on PET imaging of hypoxia to direct radiotherapy.
Identification of Sialosylparagloboside as the Erythrocyte Receptor for an ‘Anti‐p’ Antibody

A human antibody which preferentially agglutinates p erythrocytes is inhibited specifically by the glycolipid sialosylparagloboside, NeuNAc (alpha,2 leads to 3)Gal(beta,1 leads t0 4)GlcNAc(beta,1 leads to 3)Gal(beta,1 leads to 4)Glc-Cer and forms a precipitin band with this compound in agarose gel. Erythrocytes treated with neuraminidase are no longer agglutinated by this antibody, but the agglutination is not affected by papain treatment. Sialosylparagloboside is not a biosynthetic precursor of any of the P antigens, but it contains the lacto-N-neotetraose structure which is also present in the P1 glycolipid.
Gene transfer for erectile dysfunction: will this novel therapy be accepted by urologists?

Purpose of review The purpose of this review is to update the results of the only phase 1 erectile dysfunction gene transfer trial and based upon those results present the outcome of a web-based survey that studied whether or not knowledgeable in the field urologists would use gene transfer in their patients once approved for use by the US Food and Drug Administration. Recent findings The results of the clinical trials showed no transfer-related serious adverse events. The response to 10 questions of a web-based survey indicates that gene transfer as a first or second-line therapy for practicing urologists would be well accepted. Summary Practicing, experienced urologists, after the US Food and Drug Administration approval, are willing to employ gene transfer therapies in their patients, be it men who have failed or dissatisfied with other treatments or as shown in up to one-third of men as a first therapy. That outcome portends for rapid adaptation and active participation into the medical practice for maxi-K or other specific gene transfer, stem cell, or combinations that will be developed in the future.
Binding of squalene, lanosterol, desmosterol, and cholesterol to proteins in brain and liver 105,000 g supernatant fractions: evidence for specific binding sites.

The binding of squalene, lanosterol, desmosterol, and cholesterol to proteins in 105,000 g supernatant fraction (S105) from brain and liver of rats was investigated. The S105 fractions from both tissues contain specific binding sites for sterols, which are sensitive to trypsin. The dissociation constants for squalene and sterol protein complexes were in the range of 10−6 M and were not appreciably different for proteins in brain and liver S105. Competition studies revealed that both brain and liver S105 contain one receptor protein which binds lanosterol and is specific for methyl sterols, and a second receptor which binds both desmosterol and cholesterol. Binding of 7-dehydrocholesterol reported by others must occur at a third independent site since this compound does not interfere with the binding of lanosterol, desmosterol, or cholesterol. Although binding of squalene to proteins in brain and liver S105 does occur, we were unable to show the specificity of squalene binding. The concentration of desmosterol and cholesterol binding sites, which ranged from 6 to 10 nmol/mg protein, was 3- to 5-fold higher than the concentration of squalene and lanosterol binding sites (1.6–2.3 nmol/mg protein). The brain S105 from suckling rats contained fewer binding sites for desmosterol and cholesterol than the brain S105 from weaned rats. However, the concentration of lanosterol binding sites in brain S105 did not show an age-dependent change. The receptor proteins in brain and liver appear to be identical.
Photoinduced and thermal reactions of molecular σ radical cations of some branched alkanes in low-temperature matrices: An ESR study

Abstract The photoinduced and thermal reactions of σ radical cations of methyl-substituted propanes and butanes in the condensed phases have been characterized by ESR. Photoelimination of CH4 giving olefinic π radical cations commonly takes place except for H2 elimination from isobutane radical cations. The thermal reactions of methyl-substituted butane radical cations in CFCl2CF2Cl were found to be deprotonation from the CH3 group to give primary alkyl radicals.
Lymphocyte potentiation factors secreted in vitro by tonsil lymphocytes.

Abstract At the time of their ablation, human tonsils contained some lymphocytes which incorporated [ 3 H]thymidine during short-term culture. The extent of proliferation seemed to be a characteristic of the individual organ pairs. Tonsil cells also secreted during culture at least three soluble factors. One factor suppressed proliferation of human PBL treated with Con A, another factor augmented the proliferation, and the third factor was mitogenic for unstimulated PBL. Mitogenic factor was demonstrable in the presence of supernatants which expressed suppressor activity, but the augmentor could not be demonstrated in such supernatants until it was physically separated from the suppressor by gel filtration or by anion-exchange chromatography. The dose-response curves for the augmentor and mitogenic factor, both of which were simultaneously present in the supernatant, were different. The expression of one of these activities, however, did not require expression of the other. Both augmentor and mitogenic factor were nondialyzable. The augmentor had a molecular weight of about 30,000 and eluted from DEAE-cellulose in 150–250 m M NaCl.