cssi/SciSciGPT-SciSciNet huggingface dataset:
Fast-folding eriments and the topography of protein folding energy landscapes

The rapid folding of certain proteins can be described theoretically using an energy landscape in the shape of a folding funnel. New techniques have allowed the examination of fast-folding events that occur in microseconds or less, and have tested the predictions of the theoretical models.
Major centers of motion in the large ribosomal RNAs

Major centers of motion in the rRNAs of Thermus thermophilus are identified by alignment of crystal structures of EF-G bound and EF-G unbound ribosomal subunits. Small rigid helices upstream of these ‘pivots’ are aligned, thereby decoupling their motion from global rearrangements. Of the 21 pivots found, six are observed in the large subunit rRNA and 15 in the small subunit rRNA. Although the magnitudes of motion differ, with only minor exceptions equivalent pivots are seen in comparisons of Escherichia coli structures and one Saccharomyces cerevisiae structure pair. The pivoting positions are typically associated with structurally weak motifs such as non-canonical, primarily U-G pairs, bulge loops and three-way junctions. Each pivot is typically in direct physical contact with at least one other in the set and often several others. Moving helixes include rRNA segments in contact with the tRNA, intersubunit bridges and helices 28, 32 and 34 of the small subunit. These helices are envisioned to form a network. EF-G rearrangement would then provide directional control of this network propagating motion from the tRNA to the intersubunit bridges to the head swivel or along the same path backward.
Estrogen-mediated activation of non-genomic pathway improves macrophages cytokine production following trauma-hemorrhage.

Although 17β-estradiol (E2) attenuates the alterations in Kupffer cells and splenic macrophages (MΦ) cytokine production following trauma-hemorrhage, the mechanism by which this occurs remains unknown. Utilizing a cell-impermeable E2 conjugated with BSA (E2-BSA), we examined the non-genomic effects of E2 on the above two cell population cytokine production, MAPK and transcription factors activation following trauma-hemorrhage. Male Sprague–Dawley rats underwent trauma-hemorrhage (mean BP 40 mmHg for 90 min, then resuscitation). E2, E2-BSA (1 mg/kg E2) with or without an estrogen receptor antagonist (ICI 182,780), or vehicle was administrated during resuscitation. Two hrs thereafter, Kupffer cells and SMΦ production of IL-6, TNF-α, and IL-10, activation of MAPK (p38, ERK-1/2, and JNK), and transcription factors (NF-κB and AP-1) were determined. IL-6, TNF-α, and IL-10 productive capacity, MAPK, and transcription factors activation increased in Kupffer cells while they decreased in SMΦ following trauma-hemorrhage. However, E2 administration normalized all of these alterations. Although E2-BSA also attenuated the alterations in cytokine production/transcription factors, the values were higher in Kupffer cells and lower in SMΦ compared to shams. In contrast, E2-BSA prevented trauma-hemorrhage-mediated changes in MAPK activation to the same extent as E2. Co-administration of ICI 182,780 abolished E2-BSA effects. Although some MAPK inhibitors suppressed cytokine production, the inhibitor effectiveness was dependent on cytokine, cell type and animal condition (trauma-hemorrhage or sham). Thus, E2 effects on Kupffer cells and SMΦ cytokine production and transcription factors activation following trauma-hemorrhage are mediated at least in part via non-genomic pathway and these non-genomic effects are likely mediated via MAPK pathways. J. Cell. Physiol. 214: 662–672, 2008. © 2007 Wiley-Liss, Inc.
Laser machining for secondary finishing applications

A laser-based technique for finishing axisymmetric parts is presented which allows the efficient finishing of polymers and ceramics without tool wear, tool breakage, or cutting forces. In this process, a laser beam impinges tangentially onto the surface of a cylindrical workpiece. A flexible machine tool can be developed to grind parts of differing geometries and materials by changing process parameters instead of setups or machines, as well as integrate primary machining and secondary finishing in one machine tool. The precision of laser finishing can be enhanced by using oblique beam impingement angles. Initial results show that R a values less than 1 μm can be achieved on PMMA workpieces with a fixed beam. This paper presents the elements of the laser machine tool and preliminary results on parametric dependencies for laser finishing of polymer workpieces.
CNT X-ray source array for detection and treatment of cancer

We recently developed a new spatially distributed x-ray source array technology utilizing the carbon nanotubes (CNTs) as the electron field emitters. The technology with flexible source configuration and digital control of radiation opens up new possibilities for designing x-ray tomography scanners with enhanced resolution and scanning speed, and for developing novel radiotherapy systems. Several imaging and radiation therapy systems are currently at different stages of development. A stationary digital tomosynthesis scanner for detection of human breast tumor has been demonstrated which offers a higher spatial resolution, a faster scanning speed, and potentially a higher sensitivity for micro-calcification compared to the current rotating-gantry tomosynthesis scanners. We have also initiated an effort on microbeam radiotherapy, which is an experimental and preclinical technique that has been shown in synchrotron based animal studies to be effective for eradication of brain tumor while sparing normal tissue. In this talk we will provide an update on the status of the CNT x-ray source technology and will introduce the stationary digital breast tomosynthesis and microbeam radiation therapy systems currently under development at UNC.
Properties of bacteriophage PM2: A lipid-containing bacterial virus

Abstract Procedures are described for the isolation in pure form of the bacterial virus PM2. This virus isolated from seawater is shown to contain lipids by its sensitivity to ethyl ether and by chemical analysis of the purified virus. The virus has a buoyant density in CsCl of 1.28 g cm −3 and a sedimentation constant in 1 M NaCl of 230 S ; it contains 14% by weight of DNA and a minimum of 10% by weight of lipids. Phosphatidylethanolamine is the main lipid present in weight percent. The virus is disrupted in 0.05% Sarkosyl or sodium dodecyl sulfate. Analysis in acrylamide gel electrophoresis indicates the presence in the virus of at least two proteins, probably lipoproteins since they can be stained with Black Sudan. The virus appears to be a polyhedral object 60 mμ in diameter; the coat seems to have an unusual structure, in that an apparent double-layered wall can be observed in the electron microscope.
Characteristic function equations for the state of dynamic systems with Gaussian, Poisson, and Lévy white noise

The Ito formula for semimartingales is applied to develop equations for the characteristic function of the state of linear and non-linear dynamic systems with Gaussian, Poisson, and Levy white noise, viewed as the formal derivatives of Brownian, compound Poisson, and Levy processes, respectively. These equations can be obtained if the drift and diffusion coefficient of a dynamic system are polynomials of the system state and the driving noise is Gaussian or Poisson. It was not possible to derive equations for the characteristic function for the state of systems driven by Levy white noise. Numerical results are presented for dynamic systems with real-valued states driven by Gaussian, Poisson, and Levy white noise processes.
Analysis of long-distance vacation travel demand in the United States: a multiple discrete–continuous choice framework

This study analyzes the annual vacation destination choices and related time allocation patterns of American households. More specifically, an annual vacation destination choice and time allocation model is formulated to simultaneously predict the different vacation destinations that a household visits in a year, and the time (no. of days) it allocates to each of the visited destinations. The model takes the form of a multiple discrete–continuous extreme value (MDCEV) structure. Further, a variant of the MDCEV model is proposed to reduce the prediction of unrealistically small amounts of vacation time allocation to the chosen destinations. To do so, the continuously non-linear utility functional form in the MDCEV framework is replaced with a combination of a linear and non-linear form. The empirical analysis was performed using the 1995 American Travel Survey data, with the United States divided into 210 alternative destinations. The model estimation results provide several insights into the determinants of households’ vacation destination choice and time allocation patterns. Results suggest that travel times and travel costs to the destinations, and lodging costs, leisure activity opportunities (measured by employment in the leisure industry), length of coastline, and weather conditions at the destinations influence households’ destination choices for vacations. The annual vacation destination choice model developed in this study can be incorporated into a larger national travel modeling framework for predicting the national-level, origin–destination flows for vacation travel.
Nuclear matrix elements in the first-forbidden β-decays of 122Sb and 124Sb

Abstract Nuclear matrix elements in the 2−(1.41 MeV β−)2+ β-decay of 122Sb and the 3−(2.31 MeV β−)2+ β-decay of 124Sb have been extracted using the formalism of Buhring. In the 124Sb decay, the vector matrix element ratio ∫ ga /(∫ ir /R) was found to be significantly smaller than the conserved vector current (CVC) prediction based upon the assumption that the Coulomb Hamiltonian is diagonal. In the 122Sb decay, no quantitative CVC conclusions were possible. In both β-decays the ∫ iBij/R matrix element is dominant, while the tensor rank one matrix elements have values approximately one order of magnitude smaller. These results can be understood on the basis of the simple shell model with configuration mixing. However, there are two experimental results which are not easy to understand. The tensor rank zero matrix elements make a large contribution to the 122Sb decay, and the overall sizes of the 124Sb β-decay matrix elements are approximately two orders of magnitude smaller than their counterparts in the 122Sb decay.
A note on convex cones and constraint qualifications in infinite-dimensional vector spaces

In connection with mathematical programming in infinite-dimensional vector spaces, Zowe has studied the relationship between the Slater constraint qualification and a formally weaker qualification used by Kurcyusz. The attractive feature of the latter is that it involves only active constraints. Zowe has proved that, in barreled spaces, the two qualifications are equivalent and has asked whether the assumption of barreledness is superfluous. By studying cores and interiors of convex cones, we show that the two constraint qualifications are equivalent in a given topological vector spaceE iff every barrel inE is a neighborhood of the origin. Thus, whenE is locally convex, the two constraint qualifications are equivalent iffE is barreled. Other questions of Zowe are also answered.
Comparing exposure assessment methods for traffic-related air pollution in an adverse pregnancy outcome study

Background Previous studies reported adverse impacts of traffic-related air pollution exposure on pregnancy outcomes. Yet, little information exists on how effect estimates are impacted by the different exposure assessment methods employed in these studies.
Toward a poetics of divine languages

This review highlights three central issues in Yelle's book, namely the suggestion that an important component of religions is constituted of supposedly non-arbitrary languages and sign systems, and that such non-arbitrary sign systems are constructed through particular poetics (semiotic) strategies and have an essentially performative nature and function. Yelle also argues that Western modernity is characterized by a different regime of signs, one in which not only are signs no longer non-arbitrary, but non-arbitrariness itself is radically questioned and ultimately excluded from religion. The review points to the presence in religious discourses and practices of other dimensions that cannot be reduced to non-arbitrariness, but also to the possible existence of other discourses against non-arbitrariness in other cultures outside the modern West.
Isolation of the subunits of the coronavirus envelope glycoprotein E2 by hydroxyapatite high-performance liquid chromatography.

Abstract The coronavirus glycoprotein E2, which is responsible for virus attachment to cell receptors and virus-induced cell fusion, was purified by solubilization of virions with Triton X-114 and phase fractionation. Native E2 and tryptic subunits of the glycoprotein were separated by size-exclusion high-performance liquid chromatography (HPLC). Two distinct 90 kD E2 subunits, which had identified elecrophoretic mobilities when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, were separated by hydroxyapetite HPLC in the presence of sodium dodecyl sulfate.
A Solid Matrix Bioassay for Determining Chemical Feeding Stimulants

Abstract Attempts to manipulate the chemical composition of fish feeds and baits to increase their efficacy have required experimental studies to determine feeding preferences for species of interest. This article describes a generally useful assay method in which test stimuli are incorporated into a solid agar matrix. Agar disks are then presented to fish in a two-choice feeding assay. The agar disk assay is simple and inexpensive, requires only small quantities of test materials, and gives direct information about consumption and preference.
An in vitro method for demonstrating the effects of various cutting instruments on tooth structure

Abstract Results of this study indicate that alteration of the hard tissues of teeth can be induced by the cutting instruments commonly utilized in everyday operative procedures. Two hundred human teeth in groups of twenty were used to study the effects on the teeth when cavities were prepared with commonly used cutting instruments operated at different speeds. A fluorescent penetrating dye was utilized to reveal the extension of pre-existing defects or the initiation of additional defects. All of the instruments used in this study, with each of the different cutting tips, produced cracks in some teeth. Some instruments produced the effect with greater frequency than others. The frequency and severity of crazing in each group did appear to be influenced by the type of cutting tip used with the rotating instruments. However, the differences noted with various handpieces should not be interpreted as recommendations for the specific instrument. Rather, the investigation illustrates that a surface phenomenon is produced, the exact clinical significance of which is as yet unknown. In order to establish the clinical significance, further investigation along similar lines is necessary. The test method has been demonstrated, and its application to in vivo studies is suggested.
An Approach to Emissions Minimization in Power Dispatch

Abstract Pollution control strategies currently in use by electric power systems are reviewed and a new minimum emission dispatch (MED) method is developed. This new method minimizes overall emission levels at an increased cost in large-scale power systems while simultaneously accommodating local pollution level requirements, as well as economic constraints.
How to Obtain a National Heart, Lung, and Blood Institute-Sponsored K08 and K99/R00 Grant in the Current Funding Climate

I write this editorial in an attempt to help applicants and their mentors as they prepare their National Heart, Lung, and Blood Institute (NHLBI)-supported K08 or K99/R00 applications. In my view, these programs are critical for the future of cardiovascular research in the United States because they support talented new investigators at a particularly vulnerable period in their careers. In this issue, Circulation Research has published an article from the NHLBI that details critical aspects of these programs.1 Cardiovascular disease is still the number 1 cause of death in the United States.2 There is an obvious need to develop novel therapies to prevent or reverse the consequences of these diseases. New therapies should reduce the morbidity and mortality of cardiovascular disease, lower associated costs of health care, and improve the lives and productivity of affected patients. Basic, translational, and clinical research is the foundation on which these new therapies will be developed. High-impact discoveries that lead to medical advances are usually made by well-trained biomedical scientists, and many of these investigators have started their careers with support from NHLBI K08 (Mentored Clinical Scientist) and K99/R00 (Pathway to Independence) awards. These grants support training of young scientists in premier laboratories to prepare them for careers in what has been, in my view, the best biomedical science environment in the world, the United States. This “pipeline” of young talent is challenged by the current funding environment. In my view, the current lack of support for the biomedical research puts our leadership position in this field at risk. I digress. I have spent >25 years reviewing different types of grants for the NHLBI, and I have had significant experience both mentoring K08 awardees and reviewing K08 and K99/R00 applications. In this editorial, I give my personal views on who would make …
Design and synthesis of biomimetic hydrogel scaffolds with controlled organization of cyclic RGD peptides.

We report on the rational design and synthesis of a new type of bioactive poly(ethylene glycol) diacrylate (PEGDA) macromers, cyclic Arg-Gly-Asp (cRGD)-PEGDA, to mimic the cell-adhesive properties of extracellular matrix (ECM), aiming to create biomimetic scaffolds with controlled spatial organization of ligands and enhanced cell binding affinity for tissue engineering. To attach the cRGD peptide in the middle of PEGDA chain, a tailed cRGD peptide, c[RGDfE(SSSKK-NH2)] (1), was synthesized with c(RGDfE) linked to a tail of SSSKK. The tail consists of a spacer with three serine residues and a linker with two lysine residues for conjugating with acryloyl-PEG-NHS (5) to create cRGD-PEGDA (6). cRGD-PEGDA possesses good photopolymerization ability to fabricate hydrogel scaffolds under UV radiation. Surface morphology and composition analysis demonstrates that cRGD-PEGDA hydrogels were well-constructed with porous three-dimensional (3D) structures and uniform distribution of cRGD ligands. Our results show that c...
Evolution of Total Atmospheric Ozone from 1900 to 2100 Estimated with Statistical Models

AbstractStatistical models that account for the separate influences on total atmospheric ozone of ozone-depleting substances, anthropogenic greenhouse gases, and natural processes are formulated from the Merged Ozone Data (MOD V8 and V8.6) and used to explore scenarios for ozone’s evolution from 1900 to 2100. The statistical models based on MOD V8 project larger growth in total ozone during the twenty-first century than do coupled chemistry–climate models globally and in the tropics where the chemistry–climate models indicate persistent ozone depletion. The statistical models based on MOD V8.6 suggest, instead, that total ozone everywhere never (or barely) recovers to 1980 levels. Since the decline in ozone-depleting substances and the increase in greenhouse gas concentrations are both expected to increase ozone in the twenty-first century, these results suggest that downward instrumental drifts may be present in MOD V8.6. Instrumental drifts, of opposite sign, may also be present in MOD V8 since it is po...
Observing abyssal motions by tracking Swallow floats in the SOFAR channel

Abstract An observational program, currently in progress, to study abyssal water motions in the western Sargasso Sea by tracking Swallow floats in the SOFAR Channel is described. The pertinent properties of the SOFAR Channel, such as the vertical trapping and the low rate of attenuation of acoustic energy, are discussed briefly. In particular it is shown that useful acoustic ranges in excess of 1000 km are possible for tracking Swallow floats. Two floats have been built and the details of these, which were designed for 9–12 months operation, are given. The signals from the float, which must be received at at least two hydrophones, are detected in 1 Hz wide bandpass filters and the output is recorded continuously in digital form. The time of arrival of the signals is determined from a visual display of the data. The first two experiments have clearly shown that transmission over these distances is feasible. The abrupt failure of both floats after only a few days is unexplained. Concern is raised about the possibility of biological attack on the floats.
Changes in red blood cell transfusion practice during the past quarter century: A retrospective analysis of pediatric patients undergoing elective scoliosis surgery using the Mayo database

Abstract Background context Previous studies have demonstrated significant changes in red blood cell (RBC) transfusion practice over several decades. Purpose The purpose of the present study was to ascertain changes in transfusion practice during a 25-year study epoch and determine whether these changes had any impact on the frequency of perioperative morbidity and mortality in pediatric patients undergoing major spine surgery. Study design Retrospective chart review. Patient sample Pediatric patients undergoing elective scoliosis surgery. Outcome measures Impact of RBC transfusion on perioperative morbidity and mortality. Methods Pediatric patients undergoing elective scoliosis surgery were stratified into one of two transfusion-related groups: 1975 to 1985 (ie, pre–human immunodeficiency virus screening, early practice group, n=177) or 1990 to 2000 (ie, recent practice group, n=192). Transfusion and perioperative outcome data were obtained from medical records. Red blood cell use was analyzed as a continuous variable and compared between groups using the Wilcoxon rank sum test, as were preoperative, postoperative, and discharge hemoglobin concentration. Age-adjusted data were compared between groups using chi-square or Fisher exact tests. Results Patients in the recent practice group had significantly worse comorbid disease and more complex procedures compared with those in the early practice group. The percentage of patients in the recent practice group receiving allogeneic RBC transfusions was significantly less than the early group (37.5% vs. 89.8%, p Conclusions In this retrospective review, we report a significant change in blood management strategies in pediatric patients undergoing elective scoliosis surgery. We demonstrated a shift from utilization of allogeneic RBC transfusion toward preoperative donation and intraoperative autotransfusion. Although transfusion triggers were significantly lower in the recent practice group, we were unable to demonstrate a difference in major morbidity or mortality. Utilization of autologous RBC transfusion was safe and effective in reducing allogeneic RBC transfusions in this study. The advantages of autologous blood transfusion may be in preserving a relatively scarce resource (ie, allogeneic blood), rather than mitigating transfusion-related complications.
Defects in pulmonary vasculature and perinatal lung hemorrhage in mice heterozygous null for the Forkhead Box f1 transcription factor.

Abstract Decreased pulmonary expression of Forkhead Box f1 (Foxf1) transcription factor was associated with lethal alveolar hemorrhage in 55% of the Foxf1 +/− newborn mice. The severity of the pulmonary abnormalities correlates with the levels of Foxf1 mRNA. Defects in alveolarization and vasculogenesis were observed in subsets of the Foxf1 +/− mice with relatively low levels of expression from the normal Foxf1 allele. Lung hemorrhage was coincident with disruption of the mesenchymal–epithelial cell interfaces in the alveolar and bronchiolar regions of the lung parenchyma and was associated with increased apoptosis and reduced surfactant protein B (SP-B) expression. Finally, the lung defect associated with the Foxf1 +/− mutation was accompanied by reduced expression of vascular endothelial growth factor (VEGF), the VEGF receptor 2 (Flk-1), bone morphogenetic protein 4 (Bmp-4), and the transcription factors of the Brachyury T-Box family (Tbx2–Tbx5) and Lung Kruppel-like Factor. Reduction in the level of Foxf1 caused neonatal pulmonary hemorrhage and abnormalities in alveologenesis, implicating this transcription factor in the regulation of mesenchyme–epithelial interaction critical for lung morphogenesis.
Evaluation of DNA extraction from granulocytes discarded in the separation medium after isolation of peripheral blood mononuclear cells and plasma from whole blood

Background: Whole blood is generally processed for plasma and peripheral blood mononuclear cells (PBMCs) from granulocytes/erythrocytes using gradient centrifugation of blood with Histopaue-Ficoll. After separation of plasma and PBMCs, the residual erythrocytes/granulocytes, a rich source of DNA, is often discarded along with the separation medium. In order to isolate DNA from the granulocytes, current methods require the removal of the separation medium and subsequent purification of granulocytes. This report provides a method for extracting DNA using the PAXgene Blood DNA kit from granulocytes without purifying them from the separation medium. Findings: Based on 719 erythrocyte/granulocyte samples stored frozen for approximately 10 years in Ficoll-Hypaque separation medium, the mean yield of DNA was 395 μg (median = 281 μg; range = 1.36 to 2077.2 μg), with mean A260/A280 ratio of 1.84 (median = 1.84; range = 1.17 to 2.23). The quality of isolated DNA was sufficient for use as a template for restriction enzyme digestion, real-time PCR, pyrosequencing, and gel based variable number tandem repeats (VNTR) genotyping. Conclusions: By demonstrating the extraction of substantial amounts of high quality granulocytes DNA without purifying them from the separation medium, this method offers laboratories and biobanks a flexible and cost-effective approach to obtain plasma, PBMCs, and large amounts of DNA from a single blood collection for a variety of molecular genetics/epidemiologic studies.
MMPI Performance of Central American Refugees and Mexican Immigrants

This study compared the MMPI scores of Central American refugees from Guatemala and El Salvador to those of Mexican immigrants. It was expected that subjects from Guatemala and El Salvador would obtain higher scores on the F, D, Pa, and Sc scales because these subjects came from "war-torn" countries. A multivariate analysis of variance yielded no significant differences between the three groups on any of the validity and clinical scales including F, D, Pa, and Sc. Recommendations for cross-national research are noted especially in light of the new version, or MMPI-2.
The Electrostatic Interaction of Rigid, Globular Proteins with Arbitrary Charge Distributions.

Abstract We use the linearized Poisson–Boltzmann equation to construct an analytical estimate of the electrostatic interaction energy for two rigid, globular proteins with arbitrary charge distributions represented by spherical multipole moments. Our analysis avoids invoking the superposition approximation and therefore is not limited to weakly interacting double layers. The interaction energy is a function of the protein properties (radii, multipole moments, and dielectric constant); the geometry (protein separation and orientations); and the solution properties (Debye screening length and dielectric constant). The proteins may be different. This is an extension of previous treatments for constant surface charge or for constant surface potential particles that are more applicable to isotropic colloids. We give example calculations for the interactions of Ribonuclease A molecules interacting in an electrolyte. These results suggest that electrostatic effects may be largely responsible for attractions between proteins, even if they are like charged. A set of routines using MATHEMATICA is available for performing the interaction energy and electrostatic potential calculations.
Low Molecular Weight Proteins and the Kidney: Physiologic and Pathologic Considerations

Low molecular weight proteins are normally, essentially, entirely catabolized by the proximal tubules. Physiological and pathological aspects of the renal interactions of three of these proteins: light chains, B-2 microglobulin, and myoglobin share similarities, but are also unique in certain ways. In pathological conditions, some may produce glomerular, proximal or distal nephron and/or vascular alterations.
When what you see is not what you hear.

Different facial movements are better predictors of speech sounds than others. A new study investigates the neural processes that use this predictive signal and what happens to brain rhythms when it goes awry.
Triggered Star Formation in a Massive Galaxy at z = 3.8: 4C 41.17

We present deep spectropolarimetric observations obtained with the W. M. Keck Telescope of the very high redshift (z=3.79786{plus_minus}0.0024) radio galaxy 4C 41.17. We find that the bright, spatially extended rest-frame UV continuum emission from this galaxy, which is aligned with the radio axis, is unpolarized (P{sub 2{sigma}}{lt}2.4{percent}). This implies that scattered AGN light, which is generally the dominant contributor to the rest-frame UV emission in z{approximately}1 radio galaxies, is unlikely to be a major component of the UV flux from 4C 41.17. The resulting total light spectrum shows absorption lines and P Cygni-like features that are similar to those detected in the spectra of the recently discovered population of star forming galaxies at slightly lower (z{approximately}2{endash}3) redshifts. It may be possible for a galactic outflow to contribute partially to the absorption line profiles of the low ionization species; however, it is unlikely that the high-velocity wings of the high ionization lines are dominated by a galactic wind since the outflow mass implied by the absorption line strengths is very large. The detection of the SV {lambda}1502 stellar photospheric absorption line, the shape of the blue wing of the SiIV profile, the unpolarized continuum emission, the inability of any AGN-related processesmore » to account for the UV continuum flux, and the overall similarity of the UV continuum spectra of 4C 41.17 and the nearby star-forming region NGC 1741B1 strongly suggest that the UV light from 4C 41.17 is dominated by young, hot stars. If all of the UV emission is due to starlight from a young population, the implied star formation rate is roughly 140{endash}1100h{sub 50}{sup {minus}2}M{sub {circle_dot}}yr{sup {minus}1}. The deep spectroscopy presented here combined with the morphology of the system at radio and optical wavelengths and the possibly comparable ages for the radio source structure and the UV stellar population suggest that star formation in 4C 41.17 was triggered by the expansion of the radio source into the ambient medium. Our current observations are consistent with the hypothesis that 4C 41.17 is undergoing its major epoch of star formation at z{approximately}4, and that by z{approximately}1 it will have evolved to have spectral and morphological properties similar to those observed in known z{approximately}1 powerful radio galaxies. {copyright} {ital 1997} {ital The American Astronomical Society}« less
Structure of barium in three phases under pressure

A first-principles calculation of the structure of barium under pressure was done with a procedure which finds the equilibrium structure by minimizing the Gibbs free energy at zero temperature with respect to structure at each pressure. The calculated structures agree with measurements at the 1% level in three phases, Ba I (body-centered cubic), Ba II and V (hexagonal close-packed), over a range of pressure from 0 to 900 kbar. The fit to experiment is closer than that of two previous calculations, one of which used molecular dynamics under an applied stress to find equilibrium structure, and the other minimized the energy at constant volume. Hexagonal close-packed barium is shown to be metastable in the pressure range of the incommensurate Ba IV phase.
Regulation of LEF-1/TCF transcription factors by Wnt and other signals

LEF-1/TCF transcription factors mediate a nuclear response to Wnt signals by interacting with beta-catenin. Wnt signaling and other cellular events that increase the stability of beta-catenin result in transcriptional activation by LEF-1/TCF proteins in association with beta-catenin. In the absence of Wnt signaling, LEF-1/TCF proteins repress transcription in association with Groucho and CBP. The LEF-1/TCF transcription factors can also interact with other cofactors and play an architectural role in the assembly of multiprotein enhancer complexes, which may allow for the integration of multiple signaling pathways.
Knockdown of Zebrafish Fancd2 Causes Developmental Abnormalities via p53-Dependent Apoptosis

Mechanisms underlying the multiple developmental defects observed in Fanconi anemia (FA) patients are not well defined. We have identified the zebrafish homolog of human FANCD2, which encodes a nuclear effector protein that is monoubiquitinated in response to DNA damage, targeting it to nuclear foci where it preserves chromosomal integrity. Fancd2-deficient zebrafish embryos develop defects similar to those found in children with FA, including shortened body length, microcephaly, and microophthalmia, which are due to extensive cellular apoptosis. Developmental defects and increased apoptosis in Fancd2-deficient zebrafish were corrected by injection of human FANCD2 or zebrafish bcl2 mRNA, or by knockdown of p53, indicating that in the absence of Fancd2, developing tissues spontaneously undergo p53-dependent apoptosis. Thus, Fancd2 is essential during embryogenesis to prevent inappropriate apoptosis in neural cells and other tissues undergoing high levels of proliferative expansion, implicating this mechanism in the congenital abnormalities observed in human infants with FA.
Hydroxyl radical-mediated advanced oxidation processes for textile dyes: a comparison of the radiolytic and sonolytic degradation of the monoazo dye Acid Orange 7

Acid Orange 7, a textile azo dye, has been partially mineralized and degraded using γ-radiolysis and sonolysis. These two different advanced oxidation processes (AOP) are effective in producing ⋅OH radicals and cause complete destruction of the chromophore. The reaction mechanism of dye degradation has been probed by analyzing the reaction products with HPLC. In both cases, the final end products of degradation are oxalate and formate ions. The intermediates observed are all similar. While hydroxybenzenesulfonic acid is the major observed reaction intermediate in the oxidation processes, the pulse radiolysis studies indicate that the OH radical initiated pathway for attack occurs via the initial formation of 1,2-naphthaquinone and subsequent breakdown into oxalic acid.
Nodule Nitrate Reductase as a Source of Reduced Nitrogen in Soybean, Glycine max

Hydroponically grown soybeans were fed 15N-enriched NaNO3 at nine reproductive stages of development. The stem exudates contained excess 15N in the fully reduced nitrogen fraction. The soybean nodules had high nitrate reductase activity, whereas the roots had no detectable nitrate reductase activity. Based on these results, we concluded that the nodule nitrate reductase system has the potential of contributing significantly to the nitrogen economy of the plant.
Prenatal ethanol exposure alters immune capacity and noradrenergic synaptic transmission in lymphoid organs of the adult mouse

Abstract Clinical and experimental evidence indicates that exposure to alcohol in utero is associated with altered immune capacity. The mechanisms underlying such abnormalities are not clear. However, the suggestion that reciprocal interactions between the immune and the nervous systems are necessary for a competent immune response may be relevant. This work examined the consequences of prenatal ethanol exposure on cellular immune responses and noradrenergic synaptic transmission in lymphoid organs of the adult C57B1/6 mouse. Pregnant mice were fed a liquid diet containing 25% of the calories as ethanol (4.8% w/v) or pair-fed an isocaloric equivalent of this diet throughout gestation, followed by foster-nursing the neonates on normal dams. As young adults, mice exposed to ethanol prenatally displayed immunologie and selective neurochemical changes: (1) depressed ability to produce cellular immune responses, including contact hypersensitivity and a local graft-vs-host response, and (2) altered noradrenergic synaptic transmission, including enhanced norepinephrine turnover, and a reduction in norepinephrine levels and β-adrenoceptor density in the thymus and spleen, but not the heart. However, both the integrity and compartmentation of noradrenergic nerve fibres in the spleen were intact. It is suggested that altered noradrenergic synaptic transmission selectively in lymphoid organs may contribute to the impaired immune capacity associated with fetal alcohol exposure.
On nonlinear effects in fracture mechanics

Linear elastic treatment of fracture is considered applicable for net section stress up to about 0.8 the uniaxial tensile yield stress. Crack front plastic yield is still small enough to be viewed and treated as a small perturbation to the local crack front elastic stress field. Assuming these same circumstances and adopting the same point of view, an approach is presented for incorporating the nonlinear effects of small scale crack front plastic yield and slow crack extension in determination of the energy release rate and fracture toughness. Deviation from linearity of the load-displacement record in a fracture toughness test offers a quantifiable measure of these effects and is used to calculate the energy release rate. Fracture toughness values for one-eight inch thick 7075-T6 center cracked aluminum sheet are compared with uncorrected values and with values obtained by the Irwin method of plasticity correction.
The Origin of New Adaptive Characters

THE author of the article in NATURE of July 15 entitled “The Material Basis of Evolution” has misunderstood some of the chief bearings of my address entitled “Origin of Single Characters as Observed in Fossil and Living Animals”1, and I would regret to have certain passages in this well-intentioned review quoted as expressing my opinions. My address was based on researches carried on continuously since 1889 on the actual modes of origin of single specific and generic characters as observed in several lines of mammalian descent (horses, rhinoceroses, and titanotheres) in which such characters can be traced from their beginnings to their final development without any break. The term numerical was used as a convenient designation for all characters which may be expressed in numbers and formulae, while the term proportional was used for such characters as may be expressed in indices and ratios.2 There is a clear genetic distinction between these two kinds of characters, for while changes of proportion, such as the reduction of the lateral digits of the feet of horses, gradually lead into changes which may be expressed numerically, such reduction-changes fall under laws which govern quantitative changes in general rather than laws which govern the origin of new characters.
The Anodic Behavior of Zinc Electrodes in Potassium Hydroxide Electrolytes

The electrochemical oxidation of zinc anodes in potassium hydroxide solutions of 0.5–5.0M has been studied under stationary and hydrodynamic conditions. Linear sweep voltammetry and rotating ring‐disk electrode techniques were employed to elucidate the different processes involved in the electrode reaction. Two different surface films are formed on zinc anodes. The first of these causes a small retardation in the rate of dissolution of the electrode in the active region while the second causes passivation. Measurements with rotating ring‐disk arrangements indicate that the "dissolution‐precipitation" model for the formation of these films may not be correct. The majority of the current passed in those regions where the surface is covered by a film is utilized in direct electrochemical oxidation of the zinc to soluble products and not in processes associated with thickening of the surface layer.
The garden as collage: rupture and continuity in the landscape projects of Peter and Anneliese Latz

Abstract The experience of collage begins on an edge: as a rupture or cut in presumed categories and normative traditions. Picasso described it as an act of defiance, of ‘throwing a little dust in the eyes of our horrible canvas’, as he put it in a 1912 letter to Braque.2 Yet for all its disjunctions, its odd and sometimes shocking juxtapositions, a collage can also summon in us a very different awareness of the harmony of its elements. The wooden office chair juxtaposed to a traditionally stretched canvas in Robert Rauschenberg's 1960 Pilgrim (figure 1) may be startling and even seem a preposterous intrusion. But as we look closer we may be equally surprised by the many formal qualities linking chair to painting: for instance, by the canvas's rhythmic stripes that echo the chair's vertical back slats, or the way the two merge in a unified sweep of colors. As the aesthetic gap between Rauschenberg's chair and canvas diminishes, the divide between the concepts they represent begins to lose its strict meani...
Feasibility, safety, acceptability, and yield of office-based, screening transnasal esophagoscopy (with video).

Background Endoscopic screening for esophageal neoplasia can identify patients eligible for early intervention for precancerous lesions. Unsedated transnasal esophagoscopy may provide an efficient and accurate endoscopic assessment with fewer risks and less cost, compared with conventional upper endoscopy. Objective To assess the feasibility, safety, acceptability, and yield of unsedated transnasal esophagoscopy in a primary care population. Design Multicenter, prospective, cross-sectional study. Setting Two outpatient tertiary-care centers. Patients This study involved a general medical clinic population aged between 40 and 85 years. Intervention Unsedated, office-based transnasal esophagoscopy. Main Outcome Measurements Procedure yield; completeness of examination; procedure length; adverse events and complications; choking, gagging, pain, or anxiety during the examination; and overall tolerability. Results A total of 426 participants (mean [± standard deviation] age 55.8 ± 9.5 years; 43% male) enrolled in the study, and 422 (99%) completed the examination. Mean (± standard deviation) examination time was 3.7 ± 1.8 minutes. There were no serious adverse events, and 12 participants (2.8%) reported minor complications. Participants reported minimal choking, gagging, pain, or anxiety. The examination was well-tolerated by most participants. Overall, 38% of participants had an esophageal finding that changed management (34% erosive esophagitis, 4% Barrett's esophagus). Limitations Nonrandomized study, tertiary-care centers only, self-selected population with a large proportion reporting esophageal symptoms. Conclusion Unsedated transnasal esophagoscopy is a feasible, safe, and well-tolerated method to screen for esophageal disease in a primary care population. Endoscopic findings are common in this patient population.
Nonvitellogenic female sterile mutants and the regulation of vitellogenesis in Drosophila melanogaster.

Abstract The genetic and endocrine regulation of vitellogenesis was investigated by studying 18 female sterile mutations that disrupt the development of normal vitellogenic follicles. Applications of exogenous juvenile hormone analog and reciprocal ovarian transplants between flies of different genotypes were employed to accomplish our first two objectives: to find (1) whether the mutation blocked development of the ovary directly, and (2) whether the mutation altered the hormonal milieu. In 15 of the mutants the developmental defect was localized to the ovary, but in the other 3 the ovary was competent to respond to a permissive environment. The internal milieu of these three mutants (ap4, fs(3)A1, fs(2)A18) was unable to provoke normal development in wild-type ovaries, suggesting that these mutations cause endocrine defects. Our third objective was to find whether an endocrine organ was itself defective in any of these mutants. The corpus allatum from two of the mutants was unable to provoke vitellogenesis in isolated wild-type abdomens, but corpora allata from wild-type females or from other mutants were able to promote maturation of ovarian follicles in isolated abdomens. Our fourth objective was to find whether any of the mutants were able to produce yolk proteins. Immunoelectrophoresis of fly hemolymph demonstrated that in all mutants tested vitellogenins were found in the blood. These experiments permit four main conclusions. First, they identify the first Drosophila mutants in which an endocrine gland is shown to be intrinsically defective during adulthood. Second, they show that the production of morphologically normal late previtellogenic follicles is not required for the induction of vitellogenin synthesis and secretion. Third, they show that juvenile hormone can cause ovarian follicles to sequester yolk in mutant flies. And finally, they show that mutants with defective corpora allata still synthesize and secrete vitellogenin. Taken together, these conclusions suggest that in Drosophila melanogaster the uptake of vitellogenin into follicles depends upon the availability of juvenile hormone, but that the synthesis and secretion of vitellogenin are independent of both normal ovaries and totally normal corpora allata.
Textural Changes during Topochemical Decomposition of Nanocrystalline Mg(OH)2 to MgO

Transformation of nanocrystalline Mg(OH)2 to MgO under dynamic vacuum in a temperature range of 570−770 K was studied by TGA-GCMS, FTIR, HREM, XRD, helium pycnometry, and nitrogen adsorption at 77 K. Several processes are shown to occur during transformation including: (a) release of compounds chemisorbed during preparation of nanocrystalline Mg(OH)2 simultaneously with hydroxide−oxide transformation; (b) fragmentation of nanoparticles at temperatures lower than 670 K; and (c) re-crystallization and sintering of nanoparticles, whose mean size increases and relative number decreases rapidly with temperature above 670 K. A new phenomenon of decrease of the interlayer distance in MgO crystallites with increase of the nanoparticle size was observed.