cssi/SciSciGPT-SciSciNet huggingface dataset:
Charting the Universe with Stars

The physics of stars has turned out to be surprisingly important for cosmology. If we understand how stars work, we can use their observed properties to infer their intrinsic luminosities, and combine those with measured fluxes to determine distances. Finding stars at different distances then allows us to map the geometry of the universe. Two types of stars have come to play vital roles in cosmology: pulsating stars called Cepheids, and exploding white dwarfs called type Ia supernovae.
Ataxia, head tilt, nystagmus: vestibular diseases

Diseases affecting the vestibular system cause ataxia, characterized by head tilt, circling, falling, and rolling to the side of the lesion. Nystagmus occurs initially but may resolve. These clinical signs occur regardless of whether the lesion affects the peripheral or central portion of the vestibular system. Peripheral and central vestibular disorders are distinguished based on additional signs of brain stem involvement in the latter, as discussed in The Neurologic Examination and Lesion Localization on page 309. This distinction is critical in establishing both a differential diagnosis and prognosis in affected cats.
The effects of variations in tissue microstructure from postmortem rat brain on the asymmetry of the water proton resonance

PURPOSE This work was performed to investigate the effects of tissue microstructure from postmortem rat brain on the shape of the water proton spectrum. METHODS Perfusion-fixed, resected rat brains (N = 4) were imaged at 9.4T. 3D DTI and 3D echo-planar spectroscopic imaging (EPSI) data were acquired with 150 μm isotropic resolution. DTI data were acquired over 60 directions with b = 3000 s/mm2 . Water spectra were produced from EPSI data acquired over 128 echoes, with 2.9 Hz spectral resolution. A voxel-wise metric reflecting spectral asymmetry about the peak of the resonance was computed and compared with orientation estimates from DTI data by fitting data with the susceptibility anisotropy model. RESULTS Asymmetric broadening of the water resonance was computed for mixed populations of grey and/or white matter as determined by thresholding the fractional anisotropy. Asymmetry was shown to be differentially affected by tract orientation relative to B0 in high FA voxels, whereas low FA voxels exhibited little sensitivity. Anatomic structures in the hippocampus were also found to produce distinct changes in the water resonance. CONCLUSION Present results demonstrate that structural variations in tissue architecture cause characteristic, reproducible changes in the water resonance shape. This suggests that water spectra are sensitive to cytoarchitectural variations in brain tissue.
Abstract 2533: Regulation of proliferation and metastasis gene expression by DAX-1 (NR0B1) in human breast cancer cells

The orphan nuclear receptor DAX-1 (Dosage Sensitive Sex Reversal, Adrenal Hypoplasia Congenita, critical region on the X chromosome, gene 1) is known to serve an important role early on in mammalian sex determination as well as in the regulation of expression of steroid hormones. While it is unclear whether DAX-1 functions independently, DAX-1 has been demonstrated to act as a repressor of many nuclear hormone receptors, including ER, AR, PR, LRH-1 and SF-1. DAX-1 plays a role in select adult tissues, including gonadal tissue. However, it has also been shown to play a role in several types of cancer, though its specific function is not well understood. For example, in some types of cancer DAX-1 expression is upregulated, while in other cancers it is highly downregulated or completely absent. In an effort to better understand DAX-1 function both in normal and disease states, we examined the actions of DAX-1 in MCF7 breast cancer cells, which do not express the DAX-1 gene. We probed three different PCR arrays (breast cancer genes, proliferation genes and metastatic genes) to determine which genes were influenced by DAX-1 expression. With the introduction of DAX-1 in ERα positive breast cancer cells (MCF-7), we find that DAX-1 inhibits cell proliferation and blocks estradiol activation of key cell cycle regulatory genes, such as cyclin D1, as well as important metastatic genes. We show that DAX-1 binds directly to ERα and the ERα-DAX-1 complex binds to the cyclin D1 promoter. The outcome of DAX-1 expression in MCF7 cells is cell cycle arrest through the repression of key cell cycle regulatory genes. These results demonstrate that DAX-1 functions as a corepressor of ERα in MCF7 breast cancer cells by preventing the activation of growth-promoting genes and decreasing cell proliferation in response to estrogens. These findings could have significant implications for future drug development strategies specifically aimed at ER-interacting proteins such as DAX-1. Citation Format: Christina Tzagarakis-Foster. Regulation of proliferation and metastasis gene expression by DAX-1 (NR0B1) in human breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2533.
Lewis and Taylor as Partners in Sin

David Lewis’s analysis of “can” in “The Paradoxes of Time Travel” (Lewis, American Philosophical Quarterly, 13, 145–52, 1976) has been widely accepted both as a definitive analysis of “can” and as a successful resolution of the Grandfather Paradox for time travel. I argue that the central feature of his analysis puts it on all fours with a fallacy frequently imputed to fatalists such as Richard Taylor. I go on to consider two moves that might be made to avoid the fallacy, arguing that one of them leads to the unavailability of an all-things-considered “can” and the other to a new primitive modality, not analyzable in Lewis’s way.
Buccal bone thickness adjacent to virtual dental implants following guided bone regeneration.

Background Crestal bone thickness is a critical determinant of peri-implant tissue stability. This retrospective observational study sought to quantify the buccal bone thickness achieved adjacent to virtual dental implants following guided bone regeneration (GBR) surgery and evaluate the influence of patient- and procedure-related variables on buccal bone thickness. Methods Cone-beam computed tomography (CBCT) images acquired from patients who had undergone GBR surgery between July 1, 2012, and November 7, 2016, were used for this analysis. In all cases, the GBR procedure involved a dense polytetrafluoroethylene (dPTFE) barrier membrane and a mineralized cortical particulate freeze-dried bone allograft (FDBA). Eighty-four virtual dental implants were placed at planned locations using CBCT images from 84 patients, and the adjacent buccal bone thickness was measured at each site. The effects of sex, age, estimated baseline ridge width, number of missing teeth in site, site type (tooth-bounded versus terminal position in arch), dental arch (mandibular or maxillary), arch location (anterior or posterior), smoking status, titanium reinforcement in the membrane, membrane fixation, and tenting screw use were assessed. Results The mean post-GBR buccal bone thickness adjacent to virtual dental implants was 2.24 ± 1.01 mm. Fifty-nine of 84 virtual implants (70%) exhibited buccal bone thickness > 1.9 mm. GBR sites using membrane fixation produced significantly greater virtual implant buccal bone thickness than those without membrane fixation (2.31 ± 0.96 versus 1.15 ± 1.25 mm, P = 0.012). Virtual implant buccal bone thickness also exhibited moderate correlation with estimated initial ridge width (r = 0.43, P Conclusions Observations in this study suggest GBR procedures using dPTFE membranes and FDBA result in favorable ridge dimensions for dental implant placement in most cases. However, additional augmentation at implant surgery may be necessary at ≈ 30% of sites, if buccal bone thickness > 1.9 mm is intended.
Laplace Transform and Its Application in Circuits

Most of the circuits introduced so far have been analyzed in time domain. This means that the input to the circuit, the circuit variables, and the responses have been presented as a function of time. All the input functions such as unit step, ramp, impulse, exponential, sinusoidal, etc. have been introduced as a time-dependent variable, and their effects on circuits have been identified directly as a function of time. This required utilization of differential equations and solutions in time domain. However, high-order circuits result in high-order differential equations, which, considering the initial conditions, sometimes are hard to solve. In addition, for circuits which are exposed to a spectrum of frequencies such as filters, the time domain analysis is a limiting factor.
Irradiation and isolation of fission products from uranium metal–organic frameworks

Typical fission product formation experiments utilize metal or oxide target materials that must be dissolved prior to product separation. We report here a novel study using metal–organic frameworks for recovery of fission products into acidic media. We further show that the frameworks are largely preserved, such that this bulk target material could be retained for additional irradiations or characterizations. Through this approach, fission products can be separated from the actinide-based metal–organic framework using 0.01 M HNO3 without the need to dissolve the framework itself, reducing the amount of acidic waste. Extraction yields of four frameworks with varying pore sizes are compared. The results suggest that it may be possible to use porous frameworks as target materials for the extraction of select fission products.
Dynamic Spectrum Allocation with Carrier Aggregation for Aircraft-to-Ground Communication

Aeronautical communications are expected to increasingly demand spectrum in the next years. Given the endemic scarcity of spectrum, both the opportunistic use of licensed bands and carrier aggregation enable aeronautical systems to accommodate higher data rates and more aircrafts. We study dynamic spectrum allocation for air-to-ground (A2G) transmissions when carriers can be aggregated to form larger channels with complete and incomplete information: the aircrafts might not reveal their available channels for security reasons as it would expose their location. The single and multiple ground station scenarios are analyzed. Semi-distributed algorithms are proposed to deal with the incomplete information case for both scenarios, exhibiting a very good tradeoff between performance and complexity.
Patterns of Cocaine Use During Treatment: Associations With Baseline Characteristics and Follow-Up Functioning.

Objective:Abstinence outcomes are typically prioritized in the treatment of cocaine use disorder while ignoring patterns of low-frequency cocaine use. This study examined patterns of cocaine use fr...
Executive function developmental trajectories kindergarten to first grade: monolingual, bilingual and English language learners

Many studies examine how bilinguals and monolinguals differ in their executive function abilities at one time-point or cross-sectionally. Fewer examine how these groups of children may differ over ...
How the lack of consensus among stone researchers influences current guidelines.

Technology for the treatment of stone disease has rapidly advanced, but a common nomenclature to communicate research and high-quality studies to assess treatment outcomes are lacking. Thus, guidelines are based on low-grade evidence and cannot make definitive recommendations in many scenarios. To improve clinical practice and patient outcomes, the endourology community must unite to address these inadequacies.
Fair Housing Enforcement in the Age of Digital Advertising: A Closer Look at Facebook’s Marketing Algorithms

The increasing use of social media platforms to advertise rental opportunities creates new challenges for fair housing enforcement. The Fair Housing Act, 42 U.S.C. §§ 3601-19 (“FHA”) makes it unlawful to discriminate in the sale or rental of housing on the basis of race, color, religion, sex, familial status, national origin, and disability (“protected classes”). The FHA also prohibits discriminatory advertising, including distributing advertisements in a way that denies people information about housing opportunities based on their membership in a protected class. Accordingly, advertisers and digital platforms that intentionally or unintentionally cause housing advertisements to be delivered to users based on their membership in a protected class may be liable for violating the FHA. In March 2018, in response to what they perceived to be discriminatory advertising on Facebook, the National Fair Housing Alliance (“NFHA”) and several housing organizations filed suit in federal court in New York City. The lawsuit alleged that Facebook’s advertising platform enabled landlords and real estate brokers to prevent protected classes from receiving housing ads. Facebook settled the suit on March 19, 2019. As part of the settlement, Facebook agreed to make a number of changes to its advertising portal so that housing advertisers can no longer choose to target users based on protected characteristics such as age, sex, race, or zip code. Facebook also committed to allow experts to study its advertising platform for algorithmic bias. It remains to be seen whether this agreement goes far enough in curtailing discriminatory advertising practices, as Facebook is confronting further enforcement action from a government watchdog in respect to similar issues. Moreover, a recent research study found that Facebook’s digital advertising platform may still lead to discriminatory outcomes despite changes already made. On August 13, 2018, the Assistant Secretary for Fair Housing and Equal Opportunity filed a complaint with the Department of Housing and Urban Development (“HUD”) alleging that Facebook is in violation of the FHA. The Office of Fair Housing and Equal Opportunity determined in March, 2019 (the same time as the settlement agreement with NFHA) that reasonable cause exists and issued an official Charge against Facebook. Notwithstanding these suits and administrative actions, it remains that, for fair housing claims to survive in court against media giants like Facebook, HUD and future plaintiffs must first successfully argue that Facebook is not protected by the Communications Decency Act (“CDA”).
DISTEMA: distance map-based estimation of single protein model accuracy with attentive 2D convolutional neural network

Abstract Background Estimation of the accuracy (quality) of protein structural models is important for both prediction and use of protein structural models. Deep learning methods have been used to integrate protein structure features to predict the quality of protein models. Inter-residue distances are key information for predicting protein’s tertiary structures and therefore have good potentials to predict the quality of protein structural models. However, few methods have been developed to fully take advantage of predicted inter-residue distance maps to estimate the accuracy of a single protein structural model. Result We developed an attentive 2D convolutional neural network (CNN) with channel-wise attention to take only a raw difference map between the inter-residue distance map calculated from a single protein model and the distance map predicted from the protein sequence as input to predict the quality of the model. The network comprises multiple convolutional layers, batch normalization layers, dense layers, and Squeeze-and-Excitation blocks with attention to automatically extract features relevant to protein model quality from the raw input without using any expert-curated features. We evaluated DISTEMA’s capability of selecting the best models for CASP13 targets in terms of ranking loss of GDT-TS score. The ranking loss of DISTEMA is 0.079, lower than several state-of-the-art single-model quality assessment methods. The work demonstrates that using raw inter-residue distance information alone with deep learning can predict the quality of protein structural models reasonably well.
Genetic basis of a spontaneous mutation’s expressivity

Genetic background often influences the phenotypic consequences of mutations, resulting in variable expressivity. How standing genetic variants collectively cause this phenomenon is not fully understood. Here, we comprehensively identify loci in a budding yeast cross that impact the growth of individuals carrying a spontaneous missense mutation in the nuclear-encoded mitochondrial ribosomal gene MRP20. Initial results suggested that a single large effect locus influences the mutation′s expressivity, with one allele causing inviability in mutants. However, further experiments revealed this simplicity was an illusion. In fact, many additional loci shape the mutation′s expressivity, collectively leading to a wide spectrum of mutational responses. These results exemplify how complex combinations of alleles can produce a diversity of qualitative and quantitative responses to the same mutation.
Helmet-Cam: tool for assessing miners’ respirable dust exposure

Video technology coupled with datalogging exposure monitors have been used to evaluate worker exposure to different types of contaminants. However, previous application of this technology used a stationary video camera to record the worker's activity while the worker wore some type of contaminant monitor. These techniques are not applicable to mobile workers in the mining industry because of their need to move around the operation while performing their duties. The Helmet-Cam is a recently developed exposure assessment tool that integrates a person-wearable video recorder with a datalogging dust monitor. These are worn by the miner in a backpack, safety belt or safety vest to identify areas or job tasks of elevated exposure. After a miner performs his or her job while wearing the unit, the video and dust exposure data files are downloaded to a computer and then merged together through a NIOSH-developed computer software program called Enhanced Video Analysis of Dust Exposure (EVADE). By providing synchronized playback of the merged video footage and dust exposure data, the EVADE software allows for the assessment and identification of key work areas and processes, as well as work tasks that significantly impact a worker's personal respirable dust exposure. The Helmet-Cam technology has been tested at a number of metal/nonmetal mining operations and has proven to be a valuable assessment tool. Mining companies wishing to use this technique can purchase a commercially available video camera and an instantaneous dust monitor to obtain the necessary data, and the NIOSH-developed EVADE software will be available for download at no cost on the NIOSH website.
Dropwise condensation on gold

A new and potentially large-scale use of gold is in coalings to cause steam to condense in the form of drops instead of in the usual form of continuous films. The consequent increase in heat transfer that could be achieved could lead to reductions in both the size and the cost of equipment for desalination and for power generation.
Touch-down angle control for spring-mass walking

In this paper we propose the fastest converging control policy (also known as deadbeat control) for walking with the bipedal spring-mass model, which serves as an abstraction of a robot on compliant legs. To fully leverage the passive dynamics of the system, the touchdown angle of the swing-leg is assigned as the only control input of the system. We show that two steps (or one stride) are necessary and sufficient to converge to target walking gaits. We first analyze the dynamics of the system to identify the limit cycles as well as the limitations of the control authority within the definition of walking. Then, we present the two-step deadbeat control policy that guarantees stability with the fastest possible convergence rate for the system. For each equilibrium gait, the basin of attraction in which this two-step control exists is a measure of the robustness of the system. The simulation results show that human-like walking gaits (double hump ground reaction force profile) have relatively large basins of attraction. Finally, we extend the policy to various energy levels to accommodate walking on uneven ground that has height changes. We show in simulation that the system indeed rejects various disturbances and converges to the desired equilibrium gait in two steps.
Immunization with Lentiviral Vector-Transduced Dendritic Cells Induces Strong and Long-Lasting T Cell Responses and Therapeutic Immunity

Dendritic cell (DC) therapies are currently being evaluated for the treatment of cancer. The majority of ongoing clinical trials use DCs loaded with defined antigenic peptides or proteins, or tumor-derived products, such as lysates or apoptotic cells, as sources of Ag. Although several theoretical considerations suggest that DCs expressing transgenic protein Ags may be more effective immunogens than protein-loaded cells, methods for efficiently transfecting DCs are only now being developed. In this study we directly compare the immunogenicity of peptide/protein-pulsed DCs with lentiviral vector-transduced DCs, and their comparative efficacy in tumor immunotherapy. Maturing, bone marrow-derived DCs can be efficiently transduced with lentiviral vectors, and transduction does not affect DC maturation, plasticity, or Ag presentation function. Transduced DCs efficiently process and present both MHC class I- and II-restricted epitopes from the expressed transgenic Ag OVA. Compared with peptide- or protein-pulsed DCs, lentiviral vector-transduced DCs elicit stronger and longer-lasting T cell responses in vivo, as measured by both in vivo killing assays and intracellular production of IFN-γ by Ag-specific T cells. In the B16-OVA tumor therapy model, the growth of established tumors was significantly inhibited by a single immunization using lentiviral vector-transduced DCs, resulting in significantly longer survival of immunized animals. These results suggest that compared with Ag-pulsed DCs, vaccination with lentiviral vector-transduced DCs may achieve more potent antitumor immunity. These data support the further development of lentiviral vectors to transduce DCs with genes encoding Ags or immunomodulatory adjuvants to generate and control systemic immune responses.
Galaxy Interactions and the Radio Galaxy Phenomenon

We have been studying powerful radio galaxies (which we define as having radio power at 178MHz, P 178 ≥ 5xl024 Watts/Hz for a cosmology of H o = 100 km sec-1 Mpc-1 and q o = 0) in order to determine their origins. There are two distinct classes of powerful radio galaxies (PRGs), the so called class A and B radio galaxies (Hine and Longair 1979; Heckman et al. 1986). The class A radio galaxies exhibit strong optical emission-lines (L H α > 1041erg/s), “edge-brightened” Fanaroff-Riley (1974) type II radio morphologies, dominate the radio luminosity function at L Radio > 1042 erg/s, and exhibit strong cosmological evolution. Two nearby examples are 3C 120 and NGC1275. The Class B radio galaxies typically have weak emission-lines or pure absorption line spectra, Fanaroff-Riley type I radio morphologies, dominate at L Radio ~1040-42 erg/s, and exhibit weak cosmological evolution. Some nearby prototypes are M84 and M87. If we hypothesize that these, like other active galaxies, may be the products of interactions or mergers we must account for their striking differences given their similar triggering mechanism. We have acquired (in collaboration with S. Baum, W. van Breugel, G. Illingworth, and G. Miley) a large body of data on roughly equal numbers of class A and B radio galaxies (in the redshift range 0.01 < z < 0.3) consisting of broad-band images (to study morphology, photometric structure, stellar content, dust, and the local environment), Narrow-band Hα images (to study the ISM), spectroscopy (to examine the stellar dynamics and the ISM), and radio maps. These data were principally acquired with the CTIO 4m, KPNO 4m, KPNO 2.1m telescopes, and the VLA.
Linear vein-based arteriovenous malformations in children.

Object The authors reviewed the experience of a single surgeon in the surgical treatment of arteriovenous malformations (AVMs) in children, with specific attention to the angioarchitectural appearance of these lesions. Methods The authors performed a retrospective review of pediatric cases of AVM treated at a single institution over a 15-year period. Inclusion criteria consisted of pediatric age at time of treatment and resection of a pial AVM. The AVMs were considered linear-based if they had a single, centrally located, dominant vein with a linear configuration rather than the typical central nidus. Results Sixty-seven patients, ranging in age from 6 months to 17 years, underwent surgical treatment of an AVM between January 1, 1990, and December 30, 2005. In these patients, 31 AVMs (46%) had a distinct linear configuration that was centered on a dominant draining vein (“vein-based”). These AVMs presented with hemorrhage (61%), incidental findings on imaging (16%), or seizures (13%). In 4 cases, AVM recu...
Using Protein Motion to Read, Write, and Erase Ubiquitin Signals

Eukaryotes use a tiny protein called ubiquitin to send a variety of signals, most often by post-translationally attaching ubiquitins to substrate proteins and to each other, thereby forming polyubiquitin chains. A combination of biophysical, biochemical, and biological studies has shown that complex macromolecular dynamics are central to many aspects of ubiquitin signaling. This review focuses on how equilibrium fluctuations and coordinated motions of ubiquitin itself, the ubiquitin conjugation machinery, and deubiquitinating enzymes enable activity and regulation on many levels, with implications for how such a tiny protein can send so many signals.
Photometric Standards for Raman Spectroscopy

Correction of Raman spectra for instrument response to produce a spectrum with reliable relative peak intensities is not commonly performed, in part because of experimental difficulty and lack of suitable standards. Procedures are described on the basis of white light sources and on luminescent samples with known output intensity profiles. In the latter case, the procedure is fast and automatic, with an intensity standard merely taking the place of an ordinary sample. In addition to simplicity, the method is more accurate than a white light source because the illumination geometry of the intensity standard is identical to that of the sample. Standards are currently available from National Institute of Standards and Technology (NIST) for several wavelengths, including 785, 532, and 514.5 nm. Spectra of several compounds are provided for determining the accuracy of intensity calibrations, and procedures for deducing the Raman cross section for target materials are described. Keywords: Raman calibration; instrument response function; Raman intensity correction
Advantage of the cranial-right anterior oblique view in diagnosing mid left anterior descending and distal right coronary artery disease

Abstract The value of the cranial-right anterior oblique view in uncovering or improving the arteriographic visualization of lesions in the mid left anterior descending coronary artery, the origin of its diagonal and septal branches and of the distal branches of the right coronary artery was analyzed in 300 consecutive patients. The cranial-right anterior oblique view was compared with standard and other angled views. In the mid left anterior descending artery the view provided improved visualization over the other views in 80 percent of cases and uncovered lesions in 7 percent. In the septal arteries, the view improved visualization in more than 90 percent of cases and uncovered lesions in 26 percent. In the diagonal branches, the view improved visualization in nearly 75 percent of cases. In the distal right coronary artery there was improved visualization of the posterior descending and posterolateral branch arteries in more than 80 percent of cases. The cranial-right anterior oblique view was also the most advantageous view from a technical standpoint, yielding satisfactory exposure factors in obese and extremely heavy patients.
Arthroscopic delivery systems used for thermally induced shoulder capsulorraphy

Abstract Surgeons recently used thermal energy to alter the molecular structure of the shoulder capsule to treat patients with shoulder instability The first reports of thermal treatment of the shoulder capsule used a Holmium:YAG laser set at nonablative settings. Radiofrequency devices have subsequently been developed to deliver thermal energy to the shoulder capsule. Several devices and delivery systems are in current use in North America. These devices share a common final pathway: the delivery of thermal energy to the collagen molecule to disrupt the triple helical structure of collagen. Although each device delivers energy to the capsule, the mechanism of action and the tissue response differs with each device. This article evaluates the current literature regarding these arthroscopic delivery systems, and the response of tissue to the delivery systems.
The world economic crisis and the children: A United States case study

Abstract This is a review of the United States experience with issues of child health and services, as they relate to changes in economic trends. No existing data systems are entirely adequate for reporting on the current health status of children, an important consideration for the monitoring of children's health in the United States is the focus on subgroups such as those who are disadvantaged for reasons of poverty, discrimination or geographic isolation. Ample evidence exists that children living in poverty suffer adverse health consequences and that the proportion of children living in poverty in the United States has increased steadily since 1975 and dramatically since 1981. Most measures of health status and health risks for children show steady improvements througout the 1970s. The exercise of public responsibility for financing and providing essential services and supports held constant or improved during this recession period, especially during the recession of 1974–1975. The health status and risks for children since 1981 appear to be adversely affected which must be attributed to a combination of circumstances that include serious recession, increased poverty rates for households with children and diminished health benefits and social support services. These findings suggest that when either local or widespread economic reversals are anticipated, health services and social supports for children need to be expanded rather than contracted.
Superpositions of chiral amplitudes

A recent analysis has suggested that a version of femtosecond pump-probe spectroscopy, in which both pulses are themselves optical phase-controlled pulse pairs, would be useful in preparing and measuring chiral coherences. These coherences are absent in a racemic mixture or an incoherent sum of left- and right-handed states. Here we discuss the preparation of chiral coherences and the observation of their degradation via interaction with a low temperature medium.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The relationship of clients’ social class to early therapeutic impressions

Using case vignettes that differed in the presentation of the client's social class, the influence of social class on therapeutic impressions was studied in the context of just-world beliefs. Results suggested that (1) participants with higher levels of belief in a just world saw poor and working-class clients as more unpleasant to work with and more dysfunctional and (2) working-class vignettes were associated with the lowest predictions of session depth and smoothness. The findings suggest that counselors may respond differently to clients based on their social class, and in a way that negatively predisposes them toward work with poor and working-class clients.
IR spectroscopy study of cyclic anhydride as intermediate for ester crosslinking of cotton cellulose by polycarboxylic acids. V. Comparison of 1,2,4‐butanetricarboxylic acid and 1,2,3‐propanetricarboxylic acid

In recent years extensive efforts have been made to use multifunctional carboxylic acids as formaldehyde-free crosslinking agents for cotton to replace the traditional formaldehyde-based N-methylol reagents. In our previous research we found that a polycarboxylic acid esterifies cellulose through the formation of a five-membered cyclic anhydride intermediate by dehydration of two adjacent carboxyl groups. In this research we used Fourier transform IR (FTIR) spectroscopy to study the formation of cyclic anhydride intermediates and crosslinking of cotton by 1,2,4-butanetricarboxylic acid (BTA) and 1,2,3-propanetricarboxylic acid (PCA). BTA and PCA form five-membered cyclic anhydrides in the same temperature range. Both acids form the anhydrides at lower temperatures when a catalyst is present. When an acid molecule is bonded to cotton through an ester linkage, only PCA is able to form a second anhydride intermediate. We found that PCA is a more effective crosslinking agent, and it imparts higher levels of wrinkle resistance to the cotton fabric than BTA. Therefore, the formation of a five-membered cyclic anhydride by a polycarboxylic acid accelerates the esterification of cotton by the acid. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2142–2150, 2001
New directions in adaptive designs

In any sequential medical experiment on a cohort of human beings, there is an ethical imperative to provide the best possible medical care for the individual patient. This ethical imperative may be compromised if a randomization scheme involving 50-50 allocation is used as accruing evidence begins to favor (albeit not yet conclusively) one experimental therapy over another. Adaptive designs have long been proposed to remedy this situation. An adaptive design seeks to skew assignment probabilities to favor the treatment performing best thus far in the study, proportionately to the magnitude of the treatment effect. Current researchers in adaptive designs are attempting to provide physicians with a wide choice of design options, and to address practical and ethical concerns within a rigorous mathematical framework. This paper focuses on several broad families of designs, including urn models, random walk rules and other rules. Numerous examples are given along with applications, dose-response studies, clinical trials for efficacy and combined toxicity-efficacy studies.
The production of metal fibres and wires directly from the melt

Abstract The basic problem associated with the production of fibres directly from low viscosity melts is summarised, and a simplified attempt at qualtifying the effects of the various physical parameters associated with stable liquid jet formation is presented. Experi- designed to observe the form of liquid jets issuing from a capillary tube over a range of velocities are described. The results of these experiments are correlated with the theoretical treatment. Finally, a brief description is given of recent attempts in which, by various means, an extruded jet of liquid metal has been succesfully stablished to produce a fibre or wire on solidification.
Measurement of the Atmospheric Spectral Radiance at 35 km in the Near Ultraviolet

The results of 900 spectral measurements taken at 35 km altitude in the 2800-A to 3600-A wavelength region with 100-A resolution are given and compared with previous work. The instrument was stepped in elevation from 45° below to 70° above the horizon and was rotated in azimuth. The sun varied in elevation angle from zero to 60°. The signal varied by two orders of magnitude with instrument elevation angle, the minimum occurring at +70° and the maximum at −15° (1.5 × 10−2 W/cm2 sr μ at 3600 A and the sun at 60° elevation). The radiance level below 3300 A dropped more rapidly with decreasing wavelength for down-looking than for up-looking instrument elevation angles. The radiance varied by a factor of two with azimuth angle, but with a different trend for downward-looking than for upward-looking instrument elevation angles.
Automated validation of a communications protocol: the CCITT X.21 recommendation

The call establishment procedure of the X.21 interface recommended by the International Telegraph and Telephone Consultative Committee (CCITT) has been validated as a test of a recently developed theory and of an implemented system for automated communications protocol validation. The test demonstrated the applicability of the validation technique and identified a number of points where the interface state diagram does not completely define the interface behavior.
The proximal promoter of the aldolase A gene remains active during myogenesis in vitro and muscle development in vivo

The gene for aldolase A in mouse has been shown to be regulated by alternative promoters with attendant alternative first exons. The distal promoter/exon M functions only in muscle while the proximal promoter/exon H is active in early muscle development and in most other tissues. We have analyzed the developmental expression of M and H promoters in mouse throughout myogenesis both in vitro and in vivo. In C2C12 cells RNase protection assays revealed the M promoter is induced within 24 hr of the onset of myogenic differentiation, and both M- and H-specific mRNAs accumulate over 5 days in culture. Nuclear run-on transcription and in situ hybridization with an exon-specific probe demonstrate that the H promoter remains transcriptionally active even in differentiated myotubes. The in vitro results were then compared to similar RNase protection studies of M and H expression during muscle development in vivo. These data show a marked similarity between promoter activation and steady-state transcript accumulation in vivo and in vitro, but within a limited developmental time frame (E15 to 1 week postnatal). In situ hybridizations suggest that simultaneous transcription from both promoters may also occur early in muscle development. Furthermore, the M promoter shows no fiber-type restriction until 1 to 3 weeks postnatally, coincident with muscle maturation, while the H promoter remains transcriptionally active at all stages of development and in all fiber types.
The preparation of tritiated tunicamycin

A relatively simple and inexpensive procedure was devised for the radiolabeling of the glycoprotein biosynthesis inhibitor, tunicamycin. The procedure is based on hydrogen exchange in alkaline solutions of tritiated water. It was noted that the antibiotic was much more alkali labile than model compounds such as uridine. The alkali stability of the inhibitor was studied to determine conditions for optimum labeling and yield. The effects of alkaline incubation on the inhibitory properties of the antibiotic were also investigated and it was found that the breakdown products are not effective inhibitors of the reaction that transfers N-acetylglucosamine-1-phosphate to dolichyl phosphate. The isolated radioactive tunicamycin homologs, however, retained all their inhibitory action. Incubation of tunicamycin in the presence of deuterated water and mass spectral analysis showed that under the conditions used for the tritiation of tunicamycin the major product exchanged six hydrogen atoms. The position of the tritium atoms in labeled tunicamycin was not determined. The radioactive label in these compounds was shown to be stable under physiological conditions and should be useful for investigations involving the action of these antibiotics.
Suitability of the retrograde tracer Dil for electrophysiological studies of brainstem neurons: Adverse ramifications for G-protein coupled receptor agonists

Despite the acknowledged advantages of studying identified populations of neurons, few studies have convincingly established that fluorescent retrograde tracers do not alter the passive membrane properties, action potential characteristics, or effects of drugs on the labeled neurons. Whole-cell patch clamp recordings were made from spinally-projecting serotonergic neurons in the rostral ventromedial medulla (RVM) and spinally-projecting noradrenergic neurons in the locus coeruleus (LC) that were retrogradely labeled with 1,1'-dioactadecyl-3,3,3',3'-tetramethylindocarbodyanine perchlorate (Dil). The passive membrane and the action potential properties of Dil-labeled (0.2%) and non-labeled serotonergic neurons in the RVM did not differ. Similarly, the passive membrane and action potential properties of non-labeled noradrenergic LC neurons did not differ from neurons labeled with 0.2% or 5% Dil. Although the mu opioid receptor agonist [D-Ala(2)-NMePhe(4)-Gly-ol(5)]enkephalin (DAMGO) produced equivalent outward currents in non-labeled noradrenergic LC neurons and those labeled with 0.2% Dil, significantly smaller currents were recorded in LC neurons labeled with 5% Dil. Baclofen, a gamma-aminobutryic acid(B) receptor agonist, also produced smaller currents in RVM neurons labeled with 5% Dil compared to 0.2% Dil. These results indicate that 0.2% Dil is suitable for retrograde labeling of brainstem neurons in vivo for subsequent in vitro electrophysiological study. However, 5% Dil is likely to confound studies of the postsynaptic actions of G-protein coupled receptor ligands.
Role of the grain-boundary phase on the elevated-temperature strength, toughness, fatigue and creep resistance of silicon carbide sintered with Al, B and C

The high-temperature mechanical properties, specifically strength, fracture toughness, cyclic fatigue-crack growth and creep behavior, of an in situ toughened silicon carbide, with Al, B and C sintering additives (ABC-SiC), have been examined at temperatures from ambient to 1500°C with the objective of characterizing the role of the grain-boundary film/phase. It was found that the high strength, cyclic fatigue resistance and particularly the fracture toughness displayed by ABC-SiC at ambient temperatures was not severely compromised at elevated temperatures; indeed, the fatigue-crack growth properties up to 1300°C were essentially identical to those at 25°C, whereas resistance to creep deformation was superior to published results on silicon nitride ceramics. Mechanistically, the damage and shielding mechanisms governing cyclic fatigue-crack advance were essentially unchanged between ∼25°C and 1300°C, involving a mutual competition between intergranular cracking ahead of the crack tip and interlocking grain bridging in the crack wake. Moreover, creep deformation was not apparent below ∼1400°C, and involved grain-boundary sliding accommodated by diffusion along the interfaces between the grain-boundary film and SiC grains, with little evidence of cavitation. Such unusually good high-temperature properties in ABC-SiC are attributed to crystallization of the grain-boundary amorphous phase, which can occur either in situ, due to the prolonged thermal exposure associated with high-temperature fatigue and creep tests, or by prior heat treatment. Moreover, the presence of the crystallized grain-boundary phase did not degrade subsequent ambient-temperature mechanical properties; in fact, the strength, toughness and fatigue properties at 25°C were increased slightly.
Polypeptide composition of the globin poly(A)-protein complex from rabbit reticulocytes.

Polypeptides associated with the rabbit reticulocyte poly(A)-protein complex, isolated by oligo (dT)-cellulose chromatography, were analyzed by SDS-polyacrylamide gel electrophoresis. The complex derived from EDTA released total polysomal mRNP and 20S globin mRNP by RNase treatment contained four polypeptides of molecular weight 58000, 67000, 71000 and 79000. A 79000 molecular weight polypeptide, which was also a major component of the reticulocyte low molecular weight cytoplasmic fraction, was shown to form tenacious associations with poly(A) in vitro.
Specificity of platinum-DNA adduct repair.

Cell lines with resistance to cisplatin and carboplatin often retain sensitivity to platinum complexes with different carrier ligands (e.g., oxaliplatin and JM216). HeLa cell extracts were shown to excise cisplatin, oxaliplatin, and JM216 adducts with equal efficiency, suggesting that nucleotide excision repair does not contribute to the carrier-ligand specificity of platinum resistance. We have shown previously that the extent of replicative bypass in vivo is influenced by the carrier ligand of the platinum adducts. The specificity of replicative bypass may be determined by the DNA polymerase complexes that catalyze translesion synthesis past Pt-DNA adducts, by the mismatch-repair system that removes newly synthesized DNA opposite Pt-DNA adducts, and/or by DNA damage-recognition proteins that bind to the Pt-DNA adducts and block translesion synthesis. Primer extension on DNA templates containing site-specifically placed cisplatin, oxaliplatin, or JM216 Pt-GG adducts revealed that the eukaryotic DNA polymerases beta, zeta, gamma and HIV-1 RT had a similar specificity for translesion synthesis past Pt-DNA adducts (oxaliplatin > or = cisplatin > JM216). In addition, defects in the mismatch-repair proteins hMSH6 and hMLH1 led to increased replicative bypass of cisplatin adducts, but not of oxaliplatin adducts. Finally, primer extension assays performed in the presence of HMG1, which is known to recognize cisplatin-damaged DNA, revealed that inhibition of translesion synthesis by HMG1 also depended on the carrier ligand of the Pt-DNA adduct (cisplatin > oxaliplatin = JM216). These studies show that DNA polymerases, the mismatch-repair system and damage-recognition proteins can all impart specificity to replicative bypass of Pt-DNA adducts. Replicative bypass, in turn, may influence the carrier-ligand specificity of resistance.
Backlash and hysteresis effects in automation systems

Non-linearities of backlash and of hysteresis type provide generally different types of stability limits in feedback control systems. These limits and the corresponding frequencies of oscillation may be expressed in terms of characteristic adimensional system parameters. Examples of application to second and third order systems are shown.
The efficacy and safety of once-daily nifedipine administered without food: the coat-core formulation compared with the gastrointestinal therapeutic system formulation in patients with mild-to-moderate hypertension

Abstract A parallel-group, randomized, double-blind, forced-titration, multicenter study was done to compare the efficacy and safety of once-daily nifedipine coat-core (NIF CC) and once-daily nifedipine gastrointestinal therapeutic system (NIF GITS) dosed in the fasting state in patients with mild-to-moderate essential hypertension. Both formulations have been shown to effectively and safely lower blood pressure in placebo-controlled trials. After a 4-week placebo run-in period, 228 patients were randomized to 4 weeks of treatment with either NIF CC 30 mg daily or NIF GITS 30 mg daily. This period was followed by a forced-titration period to nifedipine 60 mg daily for an additional 4 weeks of double-blind therapy. After the 30-mg treatment period (the primary time point), there were no statistically significant differences between treatment groups in mean change from baseline in trough supine diastolic blood pressure, the primary efficacy variable (NIF CC patients, −7.0 mm Hg; NIF GITS patients, −8.4 mm Hg; P = 0.139). Also, because the upper bound of the treatment difference confidence interval was P 3 mm Hg, equivalence cannot be claimed. No statistically significant differences were noted for the comparison of mean 24-hour ambulatory blood pressure monitoring changes. Both formulations were well tolerated.
The History of Surgically Placed Feeding Tubes

Although supplemental enteral nutrition may have first been delivered by enema, the modern era of surgically placed feeding tubes began in the mid to late 1800s. Early procedures were generally disastrous, however, techniques rapidly improved. The basic techniques of surgical enteral access have not changed significantly in the last century, although endoscopic, radiologic and laparoscopic modifications have been described and adopted in the last 25 years. This article reviews some of the landmark surgical highlights in the United States and European literature regarding surgical enteral access.