cssi/SciSciGPT-SciSciNet huggingface dataset:
Structure and regulation of expression of the acetylcholinesterase gene

Acetylcholinesterase, an enzyme essential for the termination of the action of acetylcholine, is encoded by a single gene. Alternative mRNA processing gives rise to the expression of enzyme forms with three distinct carboxyl-termini. These structural differences govern the cellular disposition of the expressed enzyme but do not influence catalytic activity. Alternative polyadenylation signals give rise to distinct 3' non-coding regions which are likely to affect mRNA stability. Alternative splicing also occurs at the 5' end of the gene where two promoter regions can be identified. Hence, regulation of expression of the gene occurs at 3 levels, transcriptional through alternative promoters, translational by affecting mRNA stability and processing of distinct mRNAs and post-translationally by giving rise to distinct peptide chains which are processed differently. Recombinant DNA studies have also been extended to modifying protein structure through site-specific mutagenesis and studying the function of the mutant enzymes.
A survey of practices in infectious diseases by obstetrician-gynecologists.

Objective To survey current practices among obstetricians and gynecologists concerning a wide range of infectious diseases to guide future efforts in continuing medical education. Methods A survey questionnaire of multiple-choice questions was mailed to 2500 physicians, under age 65, randomly selected from the American Medical Association specialty list of obstetrician-gynecologists. The first 500 returns constituted the data set and were analyzed by computer. Results We found many clinical areas in which practice patterns were deemed appropriate, including antibiotic selection, universal screening for hepatitis B, and follow-up of urinary tract infection in pregnancy. In other areas, marked by controversy among "experts," practice patterns varied widely. These areas included management of premature rupture of the membranes and premature labor, and universal screening for group B streptococci. Areas in need of further continuing medical education efforts include management of perinatal viral infections and diagnosis and treatment of sexually transmitted diseases. Conclusions Although this survey indicated that practice patterns of American obstetricians and gynecologists are appropriate in many clinical areas relevant to infectious diseases, there are other clinical conditions requiring future efforts in continuing medical education.
Matching Biochemical Reaction Kinetics to the Timescales of Life: Structural Determinants That Influence the Autodephosphorylation Rate of Response Regulator Proteins.

In two-component regulatory systems, covalent phosphorylation typically activates the response regulator signaling protein, and hydrolysis of the phosphoryl group reestablishes the inactive state. Despite highly conserved three-dimensional structures and active-site features, the rates of catalytic autodephosphorylation for different response regulators vary by a factor of almost 10(6). Previous studies identified two variable active-site residues, corresponding to Escherichia coli CheY residues 59 and 89, that modulate response regulator autodephosphorylation rates about 100-fold. Here, a set of five CheY mutants, which match other "model" response regulators (ArcA, CusR, DctD, FixJ, PhoB, or Spo0F) at variable active-site positions corresponding to CheY residues 14, 59, and 89, were characterized functionally and structurally in an attempt to identify mechanisms that modulate autodephosphorylation rate. As expected, the autodephosphorylation rates of the CheY mutants were reduced 6- to 40-fold relative to wild-type CheY, but all still autodephosphorylated 12- to 80-fold faster than their respective model response regulators. Comparison of X-ray crystal structures of the five CheY mutants (complexed with the phosphoryl group analogue BeF(3)(-)) to wild-type CheY or corresponding model response regulator structures gave strong evidence for steric obstruction of the phosphoryl group from the attacking water molecule as one mechanism to enhance phosphoryl group stability. Structural data also suggested that impeding the change of a response regulator from the active to the inactive conformation might retard the autodephosphorylation reaction if the two processes are coupled, and that the residue at position '58' may contribute to rate modulation. A given combination of amino acids at positions '14', '59', and '89' adopted similar conformations regardless of protein context (CheY or model response regulator), suggesting that knowledge of residue identity may be sufficient to predict autodephosphorylation rate, and hence the kinetics of the signaling response, in the response regulator family of proteins.
A non-bile duct origin for intestinal crypt-like ducts with periductular fibrosis induced in livers of F344 rats by chloroform inhalation

To evaluate the toxic effects of prolonged exposure to chloroform vapors, female and male F344 rats were exposed to 0, 2, 10, 30, 90 and 300 p.p.m. chloroform by inhalation for 7 or 5 days/week for up to 13 weeks. The purpose of this study was to characterize a lesion that occurred in the livers of rats in the 300 p.p.m. exposure groups. Atypical glandular structures lined by intestinal-like epithelium and surrounded by dense connective tissue occurred in the livers of rats exposed to strongly hepatotoxic atmospheric concentrations of chloroform. Bile duct bromodeoxyuridine labeling indices as well as observations of the locations of the early lesions at the 3 and 6 week time points indicate that these lesions arose from a population of cells remote from the bile ducts. We refer to these lesions as intestinal crypt-like ducts with periductular fibrosis to distinguish them from true cholangiofibrosis. Here, intestinal crypt-like ducts with periductular fibrosis were seen only in rats exposed to 300 p.p.m. chloroform, and the multiplicity and severity of the lesions were greater in the right liver lobe. The lesion only occurred in association with liver necrosis and dramatic increases in hepatocyte labeling indices, while labeling indices in bile ducts in the same animals were not significantly different from controls. There was a treatment-related increase of transforming growth factor-alpha immunoreactivity in hepatocytes, bile duct epithelium, bile canaliculi and oval cells, and an increase in transforming growth factor-beta immunoreactivity in hepatocytes, bile duct epithelium and intestinal crypt-like ducts. Thus, intestinal crypt-like ducts with periductular fibrosis appeared to develop from a population of cells unrelated to bile ducts. Also, they occurred only in animals exposed to chloroform concentrations that induced significant hepatocyte necrosis and regenerative cell proliferation and were associated with increased growth factor expression or uptake.
Dry Etching of Magnetic Materials

In computer and data processing systems the main form of data storage and retrieval is based on magnetic recording systems, either magnetic disks or tape drives [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]. Information is written and stored as magnetization patterns on a recording media, and can be transferred back and forth using a magnetic sense head. In addition, magnetic random access memories (MRAM) are used for storage and processing of very high bit densities. These devices offer the advantage over semiconductor memories of being radiation-hard and infinitely rewritable. Finally, there are magnetic sensors, transducers and actuators which are used in automobiles, aircraft, hydraulic equipment and defense applications (mine detection, perimeter defense) [8,9]. In all of these structures there is a need to pattern the magnetic layers [13], generally thin films of materials such as NiFe, NiFeCo, which are often incorporated into multilayers comprising magnetic and nonmagnetic materials.
Bimodal Orientation Defects in Main-Chain Thermotropic Liquid Crystalline Polymer Fibers

The molecular orientation in as-spun fibers of main-chain thermotropic liquid crystalline polymers (TLCP) has been investigated using electron diffraction at high spatial resolution. Although a lar...
Spatial 1/f spectra in open dynamical systems

A new mechanism for spatial 1/f power spectra is proposed for a type of open dynamical system. This mechanism has two competing ingredients. One tends to preserve the long-range correlations while the other tends to destroy it. A specific model with this mechanism based on a class of extremely simple context-free grammars is analyzed. In this model replication and transposition are repeated applied to a string of discrete elements. Computer experiments show that for a wide range of parameter values, the model yields spatial power spectra of the form 1/fα with α close to 1. The frequency range spanned by the 1/fα form as well as the exponent α depend on the probability with which replication and transposition operations are applied.
Thermomechanical coupling effect on the stability of nonconservative elastic continuous systems

Abstract In order to have a more realistic approach toward the study of the stability phenomena of elastic continuous systems subjected to nonconservative forces, the effect of thermomechanical coupling must be included in the analysis. Through the coupling effect, thermal damping is introduced and the flutter load is reduced considerably. A general formulation of local stability analysis of thermoelastic continuous systems subjected to nonconservative forces is established in this paper. Although the local stability analysis is based on a linearized theory, since the effect of thermal damping is included, it can be used to predict the result of nonlinear theory. An illustrative example is given in the stability analysis of an elastic cantilever column under a tangential follower force applied at its free end. The numerical solutions of the flutter load in the column problem are presented.
Dynamics of electron wave propagation in photoionization microscopy. II. Quantum-mechanical formulation

Complementary to the semiclassical method developed in the preceding paper, here we develop a quantum-mechanical approach to characterize propagation of electron waves to large distances in photoionization microscopy of hydrogen atoms in uniform external electric fields. A formula for outgoing electron waves from the atomic source produced in photoionization has been derived. Spatial distributions of electron probability densities can be determined using the obtained formula. The electron waves that propagate to a large distance due to photoionization from the $n=2$ initial state of hydrogen atoms in electric fields has been calculated and the resulting probability densities are presented. Comparison with semiclassical results is made, and they are found to be in good agreement. A detailed analysis is given of strong quantum tunneling effects found in our calculations.
Formal risk adjustment by private employers.

This paper explores explanations for why few private employers have adopted formal risk adjustment. The lack of data, challenges of using highly imperfect signals, and absence of market power are not compelling explanations. Alternative strategies that reduce selection problems are clearly important. The central argument is that U.S. health markets are not in equilibrium, but rather are changing rapidly. Since many agents-consumers, employers, health plans, and providers--do not currently demand formal risk adjustment, it is not surprising that adoption has been slow. Recent changes in health plan markets may change the demand and accelerate future adoption.
2D SMARTCyp reactivity-based site of metabolism prediction for major drug-metabolizing cytochrome P450 enzymes

Cytochrome P450 (CYP) 3A4, 2D6, 2C9, 2C19, and 1A2 are the most important drug-metabolizing enzymes in the human liver. Knowledge of which parts of a drug molecule are subject to metabolic reactions catalyzed by these enzymes is crucial for rational drug design to mitigate ADME/toxicity issues. SMARTCyp, a recently developed 2D ligand structure-based method, is able to predict site-specific metabolic reactivity of CYP3A4 and CYP2D6 substrates with an accuracy that rivals the best and more computationally demanding 3D structure-based methods. In this article, the SMARTCyp approach was extended to predict the metabolic hotspots for CYP2C9, CYP2C19, and CYP1A2 substrates. This was accomplished by taking into account the impact of a key substrate-receptor recognition feature of each enzyme as a correction term to the SMARTCyp reactivity. The corrected reactivity was then used to rank order the likely sites of CYP-mediated metabolic reactions. For 60 CYP1A2 substrates, the observed major sites of CYP1A2 catalyzed metabolic reactions were among the top-ranked 1, 2, and 3 positions in 67%, 80%, and 83% of the cases, respectively. The results were similar to those obtained by MetaSite and the reactivity + docking approach. For 70 CYP2C9 substrates, the observed sites of CYP2C9 metabolism were among the top-ranked 1, 2, and 3 positions in 66%, 86%, and 87% of the cases, respectively. These results were better than the corresponding results of StarDrop version 5.0, which were 61%, 73%, and 77%, respectively. For 36 compounds metabolized by CYP2C19, the observed sites of metabolism were found to be among the top-ranked 1, 2, and 3 sites in 78%, 89%, and 94% of the cases, respectively. The computational procedure was implemented as an extension to the program SMARTCyp 2.0. With the extension, the program can now predict the site of metabolism for all five major drug-metabolizing enzymes with an accuracy similar to or better than that achieved by the best 3D structure-based methods. Both the Java source code and the binary executable of the program are freely available to interested users.
Head position affects intracranial pressure in newborn infants.

We studied the effects of six different head positions on intracranial pressure and cerebral blood flow velocity in six infants with a recent history of asphyxia and eight without. ICP was measured nominvasively using a transfontanel pressure transducer, and CBF was assessed using the continuus-wave Doppler method. We found that ICP was lowest with the head elevated and in the midline ( P P P
Anomalous Muscle Bundle of the Right Ventricle Hemodynamic Consequences and Surgical Considerations

Seven examples of anomalous muscle bundles of the right ventricle have been presented. In one patient having an associated ventricular septal defect, spaces between the anomalous muscle were confused surgically with the ventricular septal defect. In the remaining six cases, the anomalous muscle bundle caused obstruction within the right ventricular cavity. Five of these patients had associated ventricular septal defect, with a clinical picture resembling that of the cyanotic or acyanotic tetralogy of Fallot. The cases served to demonstrate that the surgeon who exposes the right ventricle to relieve an obstructive lesion in the right ventricular infundibulum or in the pulmonary valve, may find no such lesions in these locations but instead may be dealing with an obstruction more proximal than these areas. Relief of the obstruction within the right ventricle may be attained by resecting the anomalous muscle mass. In one patient having intact ventricular septum and pulmonary valvular stenosis, an anomalous m...
Spout voidage distribution, stability and particle circulation rates in spouted beds of coarse particles—I. Theory

Abstract Mass and momentum balance equations are used with a derived expression for the interaction force between the fluid and particle phases to calculate the axial spout voidage distribution and particle circulation rate in a spouted bed of coarse particles. The voidage profiles above minimum spouting are found to follow a similarity relationship and an explicit equation for the circulation rate is developed using that relationship and the calculated voidage at the top of the spout. Criteria for stability and spouting regime identification are discussed.
A microcosm of musical expression. I. Quantitative analysis of pianists' timing in the initial measures of Chopin's Etude in E major

Patterns of expressive timing were measured in bars 1–5 of 115 commercially recorded performances of Chopin’s Etude in E major, op. 10, No. 3. These patterns were subjected to principal components analysis, which suggested at least four independent “timing strategies”: (1) major ritards at the ends of melodic gestures; (2) acceleration within some of these gestures, without final ritards; (3) extreme lengthening of the initial downbeat; and (4) ritards between as well as within melodic gestures. Strategies 1 and 4 respond in different ways to the melodic-rhythmic grouping structure of the music, and strategy 3 merely represents a local emphasis. Strategy 2 is the one most difficult to rationalize; it does not seem to represent an alternative structural interpretation of the music but rather an alternative gestural shaping. Each individual pianist’s timing pattern could be described as a weighted combination of these four strategies plus idiosyncratic variation. A wide variety of combinations was represented, and no two individual patterns were exactly the same. In addition, there was a wide range of basic tempi and of degrees of tempo modulation. There were no strong relationships between any of these variables and sociocultural characteristics of the artists, although some weak trends were observed.
Correlation between time- and depth-resolved simulated lidar signals

Abstract In this letter, the results from the analysis of the recent runs of SALMON code are presented. One important result is that the effective attenuation coefficient at excitation wavelength shows a maximum correlation between depth-and time-resolved signals for variable field of view and variable chlorophyll concentration. Under the situation considered here the effective attenuation coefficients are related as cz,l ≅ 2ct,l. It is also found that the effective velocity of Raman photons decreases as the chlorophyll concentration increases. The incremental Raman normalized fluorescence signal as a function of depth lags behind the one as a function of time.
Mechano- and Chemoreceptor Modulation of Renal Sympathetic Nerve Activity(RSNA) at Birth in Term Lambs † 1126

Mechano- and Chemoreceptor Modulation of Renal Sympathetic Nerve Activity(RSNA) at Birth in Term Lambs † 1126
Sequential computer algorithms for printed circuit board inspection

Surface mounted technology (SMT) in automated assembly facilities requires the use of automatic surface-mount-device (SMD) placement machines. One of the problems involved in the electronic printed circuit board (PCB) assembly process is the verification of the SMD placement operation within tight tolerances. The high throughput of modern manufacturing lines along with the required accuracy demand the use of automatic inspection systems to verify SMD placement. Image complexity of the board makes the use of machine vision for the inspection process a difficult task. This is complicated by the fact that misclassification errors should be kept to a minimum. Additionally, it is desirable that the inspection results provide enough information to be used for statistical process control (SPC). The strategy adopted to solve this problem was to simplify the complexity of the image by means of special illumination devices. The simplified image was then suitable for analysis by simple processing, segmentation, and detection algorithms that, sequentially applied to the image, met the required repeatability and accuracy specifications for the inspection system. The scope of this paper is to describe the techniques explored by the authors to solve the SMD inspection problem in order to develop a working industrial SMD inspection system.
Simulation Model Development Environments: A Research Prototype

The objectives of this paper are to: (1) describe the current state of research on simulation support environments, (2) use the Simulation Model Development Environment (SMDE) research prototype as an example for describing concepts and principles employed, experiences gained, and guidelines (potential principles) derived in the design and creation of the prototype, and (3) identify and speculate on future directions.
Growth of oriented chains in dipolar colloids

Abstract We investigate the dynamics of the irreversible aggregation of linear rigid chains oriented along a preferred direction. We propose a Monte Carlo model, whose key ingredient is a logarithmically corrected anisotropic diffusivity of the clusters. A simple heuristic argument suggests that these logarithmic corrections should also emerge at a macroscopic scale.
A Consideration of Some Problems of Content Identification in Scaling

It is possible that something other than the intended attitudinal content may be measured in cumulative scaling. This paper includes an empirical demonstration of how cumulative content can be "built" into a scale, and how the simple Guttman scale is in this case improved by the H-technique. The authors demonstrate that even in a high reproducibility scale the factor loadings of questions differ somewhat with the cutting points used, and that the factor loadings on items may vary substantially with the frequency of positive response to the question when cutting points are held constant. Andrew F. Henry is Associate Professor of Sociology at Vanderbilt University and Edgar F. Borgatta is Professor of Sociology at New York University and Associate Social Psychologist at the Russell Sage Foundation. O NE of the unique and attractive features of cumulative scaling is that, if conditions which are defined statistically are satisfied, the researcher may have confidence in the internal validity or "unidimensionality" of his scale.1 By definition, if the Guttman scale is "perfect" (i.e., the distribution of responses is determined completely by one set of parameters, in this case marginal frequencies of responses), the scale is unidimensional. "Perfect" scales, however, do not occur frequently and are difficult to manufacture even with trite content definitions. Most operations with cumulative scales, therefore, concentrate on what Guttman has called quasi-scales, in which the definition of unidimensionality is either not satisfied by virtue of insufficiently good sampling of the universe of content or the impossibility of getting "pure" or error-free questions. Rigorous and arbitrary criteria for acceptability of "almost" scales may be set, and reasonable confidence in the unidimensionality of the scales maintained. (We introduce the concept "almost" scale to distinguish Guttman's particular conditions for the existence of a quasi-scale from any arbitrary set of conditions.) These criteria may be met by (1) improvement of questions, (2) improvement of how questions are asked, or (3) as has been suggested with the H-technique, by utilizing statistical tech* This research, carried out at the Harvard Laboratory of Social Relations, was supported in
Soil Organic Carbon Pools After 12 Years in No-Till Dryland Agroecosystems

the slow pool, with decadal turnover times, while 5% oftheSOCisfound intherapidlycyclingactivefraction, Previous studies of no-till management in the Great Plains have with turnover times ranging from hours to months (Fol- shown that increased cropping intensity increased soil organic carbon matter C; POM-C) increased as cropping intensity increased, depen- dent on PET. Passive C (mineral associated organic C (MAOC)) was namics of SOM with C losses due to cultivation increas- strongly influenced by a site-by-slope position interaction but not by ing with precipitation and decreasing with soil clay con- cropping system. Toeslope soils had 35% higher POM-C compared tent(Burkeetal.,1989). PredictedGreatPlainsregional with summits and sideslopes. All C pools were strongly correlated patterns in SOC show higher levels in the cooler North- with total SOC, with the variability decreasing as C pool turnover ern Great Plains and lower in the warmer Southeast time increased. Carbon pool sizes in cropping systems relative to Great Plains (Burke et al., 1989, 1995). Analysis of cli- levels found in G were independently influenced by cropping system. matic and textural controls on SOC by Parton et al. The highest were found in the CC system, which had 91, 78, and 90% (1987) indicate that temperature is a direct control on of the amounts of C found in the perennial G system in the active, SOC decomposition, while soil texture controls both the slow, and passive C pools, respectively. formation and decomposition rates of the active and slow SOC pools. Hook and Burke (2000) suggest that soil texture has a major impact over the biogeochemical
A fine-structural analysis of larval salivary gland function in Chironomus thummi (diptera)

Salivary glands of Chironomus thummi larvae were examined with the light and electron microscopes to obtain information on the structure and function of the gland cells. The large gland cells (those containing giant polytene chromosomes) display a cytoplasm rich in granular endoplasmic reticulum and Golgi complexes, and an apical brush border. Dense “secretory” granules and “coated” vesicles are concentrated in the apical cytoplasm. The fine structure of these cells suggests that they are active in the synthesis of secretory proteins. These same cells possess an elaborate system of basal membrane infoldings with numerous associated mitochondria; this surface specialization is implicated in the uptake of hemal materials for transport to the saliva. Multivesicular bodies and larger inclusion bodies are numerous; inclusions resembling autophagic vacuoles are especially prevalent in the basal cytoplasm of the “special” lobe (SZ) cells. Additional cells, which form thin layers on the two flattened faces of the gland, appear to contribute a distinctive type of secretory material to the saliva.
How one TSH receptor antibody induces thyrocyte proliferation while another induces apoptosis

Thyroid stimulating hormone (TSH) activates two major G-protein arms, Gsα and Gq leading to initiation of down-stream signaling cascades for survival, proliferation and production of thyroid hormones. Antibodies to the TSH receptor (TSHR-Abs), found in patients with Graves' disease, may have stimulating, blocking, or neutral actions on the thyroid cell. We have shown previously that such TSHR-Abs are distinct signaling imprints after binding to the TSHR and that such events can have variable functional consequences for the cell. In particular, there is a great contrast between stimulating (S) TSHR-Abs, which induce thyroid hormone synthesis and secretion as well as thyroid cell proliferation, compared to so called "neutral" (N) TSHR-Abs which may induce thyroid cell apoptosis via reactive oxygen species (ROS) generation. In the present study, using a rat thyrocyte (FRTL-5) ex vivo model system, our hypothesis was that while N-TSHR-Abs can induce apoptosis via activation of mitochondrial ROS (mROS), the S-TSHR-Abs are able to stimulate cell survival and avoid apoptosis by actively suppressing mROS. Using fluorescent microscopy, fluorometry, live cell imaging, immunohistochemistry and immunoblot assays, we have observed that S-TSHR-Abs do indeed suppress mROS and cellular stress and this suppression is exerted via activation of the PKA/CREB and AKT/mTOR/S6K signaling cascades. Activation of these signaling cascades, with the suppression of mROS, initiated cell proliferation. In sharp contrast, a failure to activate these signaling cascades with increased activation of mROS induced by N-TSHR-Abs resulted in thyroid cell apoptosis. Our current findings indicated that signaling diversity induced by different TSHR-Abs regulated thyroid cell fate. While S-TSHR-Abs may rescue cells from apoptosis and induce thyrocyte proliferation, N-TSHR-Abs aggravate the local inflammatory infiltrate within the thyroid gland, or in the retro-orbit, by inducing cellular apoptosis; a phenomenon known to activate innate and by-stander immune-reactivity via DNA release from the apoptotic cells.
Oral Hydralazine Therapy for Acute Pulmonary Embolism and Low Output State

Shortly after pelvic surgery, massive bilateral pulmonary emboli and shock developed in an elderly woman. Despite fluids, dopamine hydrochloride, and heparin sodium, her condition steadily deteriorated. Two trials of hydralazine hydrochloride were given and each was associated with pronounced clinical and hemodynamic improvements. Ninety minutes and 24 hours after the first trial, her pulmonary vascular resistance decreased 44% and 67%, respectively, and cardiac index increased 40% and 90%, respectively. There were insignificant changes in heart rate and blood pressure. The hemodynamic improvements reversed when the hydralazine therapy was stopped but improved again during the second trial. Hydralazine may be of substantial benefit to patients with hemodynamic compromise secondary to pulmonary embolism. ( Arch Intern Med 1981;141:1537-1538)
Knee loading dynamically alters intramedullary pressure in mouse femora

Dynamic mechanical loads have been known to stimulate bone formation. Many biophysical factors such as number of daily loading cycles, bone strain, strain-induced interstitial fluid flow, molecular transport, and modulation of intramedullary pressure have been considered as potential mediators in mechanotransduction of bone. Using a knee loading modality that enhances anabolic responses in mouse hindlimb, we addressed a question: Do oscillatory loads applied to the knee induce dynamic alteration of intramedullary pressure in the femoral medullary cavity? To answer this question, mechanical loads were applied to the knee with a custom-made piezoelectric loader and intramedullary pressure in the femoral medullary cavity was measured with a fiber optic pressure sensor. We observed that in response to sinusoidal forces of 0.5 Hz and 10 Hz, pressure amplitude increased up to 4-N loads and reached a plateau at 130 Pa. This amplitude significantly decreased with a loading frequency above 20 Hz. To confirm alteration of intramedullary pressure, real-time motion of microparticles in a glass tube inserted to the femoral medullary cavity ex vivo was visualized. Taken together, these data reveal that knee loading dynamically alters intramedullary pressure as a function of loading intensities and frequencies.
Lifted Tableaux Inequalities for 0--1 Mixed-Integer Programs: A Computational Study

We describe families of inequalities for 0--1 mixed-integer programming problems that are obtained by lifting cover and packing inequalities. We show that these inequalities can be separated from single rows of the simplex tableaux of their linear programming relaxations. We present the results of a computational study comparing their performance with that of Gomory mixed-integer cuts on a collection of MIPLIB and randomly generated 0--1 mixed-integer programs. The computational study shows that these cuts yield better results than Gomory mixed-integer cuts.
Comparison of clients' and nonclients' expectations of counseling.

Sumwry.-The Expectations About Counseling Questionnaire was used to measure subjects' expectations about a counselor's characteristics and the counseling relationship. Subjects were compared based on their previous experience in a counseling relationship, high and low Trait anxiety, and gender. The interpersonal influence model (6) considers the effect of interpersonal variables such as clients' initial expectations about counseling and about the counselors' characteristics on the ultimate effectiveness of counseling (2, 3, 4, 8). A review of several studies (1) showed that initial perceptions of counselors' characteristics were zhe most powerful predictors of counseling outcome; cliencs with higher expectations obtained more satisfactory counseling outcomes. However, little is known about how those who have not previously had counseling (nonclients) differ in their expectations from those who have previousIy been clients. It is also conceivable that gender and anxiecy might moderate perceptions. This study examined the correspondence between these clients' characteristics and their expectations about counseling. The Expectations About Counseling Questionnaire, Brief Form (7), was used to identify clients' expectations about counseling on three dimensions consisting of 1.1 scales: -Dimension 1 describes clients' attitudes and behaviors, scales include motivation and openness; Dimension 2 describes counselors' aai.tudes and behaviors, scales include acceptance, empathy, genuineness, nur.turance, and self-disclosure; and Dimension 3 describes counselors' characteristics, scales include attractiveness, expertise, tolerance, and trustworthiness. Internal consistency estimates for each of the 11 scales range from .71 to .89. No other reliability or validity data exists on these scales. METHOD Subjects (N = 85) were undergraduates drawn from the introductory classes in the college of education at a large midwestern university. The collection of data was conducted in two phases. The first phase consisted of collecting the pretests for the State Trait Anxiety Inventory (5) according to which students were split at the median into high vs low anxiety groups. Subjects were asked to indicate if they had ever been in a counseling relationship for a personal problem. At a later dace they were administered the questionnaire on expectations.
The relationship between mobile and fixed-line communications: A survey

Abstract The dramatic worldwide increase in mobile communication that has led to more than 4 billion users has over the last few years been accompanied in wealthy countries by a significant decline in fixed network subscriptions. Such fixed-to-mobile substitution (FMS) is at the center of this literature survey. Theoretical models explaining FMS are scarce and are inconclusive regarding the balance between substitution and complementarity of the fixed and mobile sectors. Empirical explanations hinge on the interaction of positive cross-elasticities of demand and reductions in mobile relative to fixed communications prices. FMS is also supported by relative declines in mobile network costs, network effects in demand and quality improvements of mobile services. The policy consequences of FMS stem from the potential reductions in market power of operators in fixed-line markets and from the ability of mobile operators to enable universal service. The survey reveals ample opportunity for further empirical and theoretical research in the area of FMS.
Combat guilt and its relationship to PTSD symptoms

Guilt regarding combat experiences is often considered an associated symptom of PTSD in military veterans. Little is known, however, about the role combat guilt plays in the development and maintenance of PTSD. Inadequate measurement of combat-related guilt may be one reason for this deficiency in the literature. In the present study, 40 veterans with PTSD completed a novel measure of combat guilt. Items on the scale assessed various types of guilt and shame concerning combat experiences (i.e., survival guilt, guilt over acts of omission and acts of commission, guilt about thoughts/feelings). Guilt was quite prevalent within this sample, and severity of guilt regarding combat was positively correlated with the reexperiencing and avoidance symptoms of PTSD and a general measure of PTSD severity. Implications of these findings and recommendations for the development of measures for combat-related guilt are discussed.
High-precision positioning stages for micro- and nanolithography

Low scanning speed as well as hysteresis nonlinearities have been fundamental limitations of scanning probe based micro/nano-fabrication techniques. Scanning speeds are typically limited to about 1/10th the fundamental vibrational mode of the piezo-positioning system while hysteresis nonlinearities cause significant errors in large- range positioning applications. This paper presents a method to achieve higher scan rates by using inversion of the piezo-actuator dynamics as well as by compensating for the hysteresis nonlinearities. The approach decouples the inversion into (a) inversion of the hysteresis nonlinearities and (b) inversion of the structural dynamics, to find an input voltage profile that achieves precision tracking of a desired scan trajectory. The results show that an order of magnitude increase in scanning speed is achieved, while maintaining precision tracking of the desired scan path.
Bioassessment of silvicultural impacts in streams and wetlands of the eastern United States

Bioassessment is a useful tool to determine the impact of logging practices on the biological integrity of streams and wetlands. Measuring biota directly has an intuitive appeal for impact assessment, and biota can be superior indicators to physical or chemical characteristics because they can reflect cumulative impacts over time. Logging can affect stream and wetland biota by increasing sedimentation rates, altering hydrologic, thermal, and chemical regimes, and changing the base of food webs. Biotic impacts of logging on streams compared to wetlands probably differ, and in this paper we review some of those differences. In streams, invertebrates, fishes, amphibians, algae, and macrophytes have been used as indicators of logging impacts. In wetlands, bioassessment is just beginning to be used, and plants and birds are the most promising indicator taxa. Various best management practices (BMPs) have been developed to reduce the impacts of logging on stream and wetland biota, and we review quantitative studies that have evaluated the efficacy of some of these techniques in streams and wetlands in the eastern United States. Remarkably few studies that address the overall efficacy of BMPs in limiting biotic changes in streams and wetlands after BMP implementation have been published in scientific journals, although some work exists in reports or is unpublished. We review these works, and compile conclusions about BMP efficacy for biota from this body of research.
A Two-Multiplet Tunneling Model

The tunneling model is extended to include two multiplets of energy levels. The inclusion of tunneling matrix elements between the multiplets is found to modify the ground state level considerably and also gives rise to allowed paraelectric transitions similar to the “backward” lines observed in KI:OH−. Das Tunnelmodell wird auf Ubergange zwischen zwei Multipletts von Energieniveaus erweitert. Die Berucksichtigung der entsprechenden Matrixelemente zwischen den Multipletts andert den Grundzustand betrachtlich; erlaubte paraelektrische Ubergange, ahnlich den in KJ:OH− beobachteten „Ruckwarts-Linien”, treten dadurch auf.
Natal and neonatal factors in prematureinfant mortality

Summary 1. An analysis of premature mortalityrates for a ten-year period has been presented. 2. In 20,331 live births there were1,373 living premature infants, that is, 6.8 per cent. 3. The over-all, uncorrected premature mortality rate was 22.4 per cent. If this figure is corrected by omission of premature infants under 1,000 grams, the rate drops to 15.9 per cent. 4. Breakdown into five-year groups gives mortality rates of 23.8 and 21.7 per cent, respectively, the latter figure covering the most recent period from Jan. 1, 1946, to Jan. 1, 1951. 5. There scems to be a preponderance of premature females. The female mortality rate was only 20 per cent as compared to 24.9 for males. 6. After the first forty-eight hours of life, our premature mortality was only 3.1 per cent. Expressed in another way, 86 per cent of our deaths occurred in the first forty-eight hours after birth. 7. The above factor indicates that further marked reduction in premature mortality rates will have to come from attacking the problems of this critical forty-eight-hour period of life. 8. In cases complicated by maternaland obstetric difficulties the mortality rate was 41.1 per cent as compared to 14.4 per cent in uncomplicated cases. 9. The use of episiotomy, low forceps, or both has a favorable effect on premature, mortality as shown by a death rate of 7 per cent where such procedures were employed; whereas cases not having these advantages had a higher rate of 34.1 per cent deaths. 10. In 157 cases of premature deliveries where conduction anesthesia was employed the mortality rate was 11.4 per cent. During this same period of time 593 cases receiving general or no anesthesia showed a mortality rate of 24.0 per cent.
Applying L2 Lexical Research Findings in ESL Teaching

& English language learners face a debilitating lexical gap between the words they know and the words they need to know. Although educated native speakers of English know approximately 20,000 word families (Nation, 2001), or roughly 70,000 words, one estimate of ELLs’ lexical needs is approximately 2,000 words to maintain conversations, 5,000 to read authentic texts, and perhaps 10,000 to comprehend challenging academic materials (Schmitt, 2000). Unfortunately, even well-educated ELLs may know less than a quarter of their native counterparts’ vocabulary (Laufer & Yano, 2001). Within the last 15 years, this lexical gap has prompted a number of useful studies addressing issues relevant to both learners and teachers. Though much of this work has investigated reading (e.g., Cobb, 2008), lexical knowledge impacts all skill areas, including writing (Engber, 1995; Ferris, 1994), listening (Chang, 2007), and speaking (Joe, 1998). The purpose of this short article is to present several teaching applications from the current body of L2 vocabulary research. This information focuses on four key pedagogical questions. (Readers interested in research details should see the timeline of influential L2 vocabulary studies of vocabulary acquisition presented by Laufer [2009], the review of extant research on vocabulary instruction by Schmitt [2008], and the extensive vocabulary bibliography by year or topic at the Vocabulary Acquisition Research Group Archive [2011] at http://www.lognostics.co.uk/varga/.)
Large-scale gyrokinetic particle simulation of microturbulence in magnetically confined fusion plasmas

As the global energy economy makes the transition from fossil fuels toward cleaner alternatives, nuclear fusion becomes an attractive potential solution for satisfying growing needs. Fusion, the power source of the stars, has been the focus of active research since the early, 1950s. While progress has been impressive--especially for magnetically confined plasma devices called tokamaks--the design of a practical power plant remains an outstanding challenge. A key topic of current interest is microturbulence, which is believed to be responsible for the unacceptably large leakage of energy and particles out of the hot plasma core. Understanding and controlling this process is of utmost importance for operating current devices and designing future ones. In addressing such issues, the Gyrokinetic Toroidal Code (GTC) was developed to study the global influence of microturbulence on particle and energy confinement. It has been optimized on the IBM Blue Gene/L™ (BG/L) computer, achieving essentially linear scaling on more than 30,000 processors. A full simulation of unprecedented phase-space resolution was carried out with 32,768 processors on the BG/L supercomputer located at the IBM T. J. Watson Research Center, providing new insights on the influence of collisions on microturbulence.
Extraoral imaging for proximal caries detection: Bitewings vs scanogram

Objective The objective of this study was to compare the diagnostic accuracy of 3 extraoral imaging modalities with an intraoral bitewing radiograph for proximal caries detection. Study design Three modalities of Cranex TOME scanograms, x-ray film and DenOptix photostimulable phosphor plates with and without digital enhancement, were compared with Insight intraoral radiographs for proximal caries detection. Nine observers evaluated images of the proximal surfaces of 45 extracted posterior teeth. The presence or absence of caries was scored using a 5-point confidence scale. The ground truth was determined from histological sections. Responses were evaluated by repeated measures analysis of variance (ANOVA) for areas under receiver operating characteristic (ROC) curves (A z ). Results Repeated measures ANOVA (at α = 0.05) demonstrated significant differences among modalities ( P = .041). Paired t tests with Bonferroni correction demonstrated that Insight was superior to only unenhanced digital scanograms ( P = .003). Mean A z scores (±SD) were 0.73 (±0.08) for Insight, 0.65 (±0.06) for screen/film scanogram, 0.64 (±0.04) for unenhanced digital scanogram, and 0.66 (±0.07) for enhanced digital scanogram. Conclusions The performances of film-based and enhanced digital scanograms were not statistically different from Insight film for proximal caries detection. Unenhanced digital scanograms exhibited a statistically significant lower diagnostic accuracy than Insight film.
Effects of sleep deprivation on serotonergic neuronal activity in the dorsal raphe nucleus of the freely moving cat

Total sleep deprivation (TSD) for one or more nights produces a rapid antidepressant response in humans. Since most pharmacological treatments for depression increase brain serotonin neurotransmission, the purpose of the present study was to determine whether TSD increases the activity of serotonergic neurons in the dorsal raphe nucleus (DRN) in cats. Cats were prevented from sleeping by the experimenter, who monitored the behavioral state of each animal on a polygraph. Firing rates during quiet waking (QW) and active waking (AW) were obtained throughout a 24-h sleep deprivation period and subsequent 6-h recovery period. During the experiments, unit activity was also recorded during exposure to loud white noise, which elicited strong behavioral arousal. The inhibitory response of serotonergic DRN neurons to systemic administration of the selective 5-HT1A agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) was determined before and after TSD to assess possible changes in 5-HT1A autoreceptor sensitivity. TSD increased mean firing rates by as much as 18% during both AW and white noise exposure. Maximal effects were observed after 15 h of TSD for AW, and after 18 h for white noise. QW firing rates also tended to be elevated throughout TSD. Firing rates for all conditions during the recovery period were not significantly different from baseline. The neuronal inhibition produced by 8-OH-DPAT was significantly diminished after TSD. Overall, these results indicate that TSD increases the firing rate of serotonergic DRN neurons during AW and arousal. This effect may be attributable to a decrease in the sensitivity of 5-HT1A autoreceptors. These findings are consistent with the hypothesis that TSD exerts its antidepressant action, at least in part, through an activation of brain serotonergic neurons.
As You Sow So Shall You Reap: Public Investment Surges, Growth, and Debt Sustainability in Togo

This paper presents an analysis of the public investment scaling-up strategy for Togo using a dynamic macroeconomic model that explicitly analyzes the links between public investment, economic growth, and debt sustainability. In the model, public capital is productive and complementary to private capital, generating positive medium and long-run effects to increases in public investment. The model application indicates that a very large increase in public investment would have positive macroeconomic effects in the long-run, but would require unrealistic increases in the tax burden to cover recurrent costs and ensure debt sustainability. More modest increases in public investment would require more feasible increases in the tax burden, particularly if the efficiency of tax collection is improved. The model simulations also emphasize the importance of improvements in the efficiency of public investment to reap welfare gains. However, even if the macroeconomic implications of public investment scaling-up can be favorable in the long-run under certain assumptions on rates of return and efficiency of investment, the transition period is challenging and exposes the country to increased risk of unsustainable debt dynamics. The model was also used to assess the growth projections underlying the standard Excel-based debt sustainability analysis for Togo.