cssi/SciSciGPT-SciSciNet huggingface dataset:
Comparison of experimental and theoretical thermal fatigue lives for five nickel-base alloys.

The alloys Nimonic 90, IN 100, coated IN 100, B 1900, coated B 1900, MAR M200, and MAR M200DS (directionally solidified) were studied. Maximum temperatures ranged from 770 C to 1120 C (1420 F to 2050 F). Specimen geometries included tapered disks, double-edged wedges, and cambered airfoils. The disks and wedges were heated and cooled in fluidized beds. The airfoil specimens were heated by a Mach 1 natural gas burner and rapid-air-cooled, with and without spanwise loading. Life calculations included two distinct failure modes: conventional low cycle fatigue and cyclic creep. Required material properties were limited to conventional thermal, tensile, and creep rupture data. The complete life calculation system included the calculation of transient temperature distributions, thermal strains, stresses, creep damage, fatigue damage, and cycles to first crack. Calculated lives were within a factor of two for 76 of the 86 data points analyzed. Cyclic creep accounted for 81% of all the calculated damage.
Glycolytic Control Mechanisms IV. KINETICS OF GLYCOLYTIC INTERMEDIATE CHANGES DURING ELECTRICAL DISCHARGE AND RECOVERY IN THE MAIN ORGAN OF ELECTROPHORUS ELECTRICUS

Abstract A detailed kinetic analysis of the changes of the glycolytic intermediates has been made in the main electric organ of Electrophorus electricus during periods of electrical discharge and recovery. Discharge of the organ was elicited by electrical stimulation and was associated with a transient increase in the levels of the glycolytic intermediates and the utilization of endogenous ATP and creatine phosphate. The high energy reserves were partially replenished during recovery by increased glycolytic activity. Principal sites of control in the glycolytic pathway were identified at phosphorylase and phosphofructokinase. Glycogen utilization was induced by a prompt increase in the active form of phosphorylase b kinase. Increases of phosphorylase a and glucose-1-P followed in turn after a brief delay. The increased rate of input of hexose phosphates to the glycolytic pathway was accommodated by concurrent activation of phosphofructokinase, and the levels of glucose-6-P and fructose-6-P either remained approximately constant or diminished while fructose-1,6-di-P levels increased greatly. The activated glycolytic flux was subsequently switched off by inhibition of phosphofructokinase, as evidenced by increases in the levels of glucose-6-P and fructose-6-P and a decrease in the level of fructose-1,6-di-P. Glycogenolysis was curtailed by the reconversion of phosphorylase a to phosphorylase b. The kinetics of the metabolic changes during different times of discharge indicate that phosphorylase and phosphofructokinase are regulated by separate mechanisms.
Accumulation of CD8+ T Cells in Advanced-Stage Tumors and Delay of Disease Progression following Secondary Immunization against an Immunorecessive Epitope

Self-reactive T cells that survive the process of positive and negative selection during thymocyte development represent potential effector cells against tumors that express these same self-Ags. We have previously shown that CD8 + T lymphocytes (T CD8 ) specific for an immunorecessive epitope, designated epitope V, from the SV40 large T Ag (Tag) escape thymic deletion in line SV11 Tag-transgenic mice. In contrast, these mice are tolerant to the three most dominant Tag epitopes. The majority of the residual epitope V-specific T CD8 have a low avidity for the target epitope, but a prime/boost regimen can expand higher avidity clones in vivo. Whether higher avidity T CD8 targeting this epitope are affected by Tag-expressing tumors in the periphery or can be recruited for control of tumor progression remains unknown. In the current study, we determined the fate of naive TCR-transgenic T CD8 specific for Tag epitope V (TCR-V cells) following transfer into SV11 mice bearing advanced-stage choroid plexus tumors. The results indicate that TCR-V cells are rapidly triggered by the endogenous Tag and acquire effector function, but fail to accumulate within the tumors. Primary immunization enhanced TCR-V cell frequency in the periphery and promoted entry into the brain, but a subsequent booster immunization caused a dramatic accumulation of TCR-V T cells within the tumors and inhibited tumor progression. These results indicate that epitope V provides a target for CD8 + T cells against spontaneous tumors in vivo, and suggests that epitopes with similar properties can be harnessed for tumor immunotherapy.
Predicting student help-request behavior in an intelligent tutor for reading

This paper describes our efforts at constructing a fine-grained student model in Project LISTEN's intelligent tutor for reading. Reading is different from most domains that have been studied in the intelligent tutoring community, and presents unique challenges. Constructing a model of the user from voice input and mouse clicks is difficult, as is constructing a model when there is not a well-defined domain model. We use a database describing student interactions with our tutor to train a classifier that predicts whether students will click on a particular word for help with 83.2% accuracy. We have augmented the classifier with features describing properties of the word's individual graphemes, and discuss how such knowledge can be used to assess student skills that cannot be directly measured.
Cross-immunity between strains explains the dynamical pattern of paramyxoviruses

Viral respiratory tract diseases pose serious public health problems. Our ability to predict and thus, be able to prepare for outbreaks is strained by the complex factors driving the prevalence and severity of these diseases. The abundance of diseases and transmission dynamics of strains are not only affected by external factors, such as weather, but also driven by interactions among viruses mediated by human behavior and immunity. To untangle the complex out-of-phase annual and biennial pattern of three common paramyxoviruses, Respiratory Syncytial Virus (RSV), Human Parainfluenza Virus (HPIV), and Human Metapneumovirus (hMPV), we adopt a theoretical approach that integrates ecological and immunological mechanisms of disease interactions. By estimating parameters from multiyear time series of laboratory-confirmed cases from the intermountain west region of the United States and using statistical inference, we show that models of immune-mediated interactions better explain the data than those based on ecological competition by convalescence. The strength of cross-protective immunity among viruses is correlated with their genetic distance in the phylogenetic tree of the paramyxovirus family.
Clinical Trial Modeling and Simulation—Work in Progress

Suboptimal clinical trials and data management are critical concerns to the pharmaceutical industry, where there is increasing pressure to contain costs, drive profits, and expedite drug development. Using data from three completed trials of a central nervous system drug, a collaborative effort between Zeneca Pharmaceuticals and the Center for Drug Development Science at Georgetown University Medical Center is being made to develop computer-assisted simulation models that predict outcomes measures of clinical trials. The objectives for this project are to more fully understand computer-assisted modeling and simulation techniques (including steps and assumptions made), their application in the design of clinical trials, and their potential impact on the drug development process. Using mixed-effects pharmacokinetic/pharmacodynamic modeling and Bayesian techniques, models were built showing a relationship between predicted and measured drug concentrations and between predicted and measured Brief Psychiatric Rating Scale scores. Although the work is ongoing, it has yielded valuable insight into how clinical trial modeling and simulation may contribute to more efficient drug development.
Pharmacogenomics in the clinic

After decades of discovery, inherited variations have been identified in approximately 20 genes that affect about 80 medications and are actionable in the clinic. And some somatically acquired genetic variants direct the choice of 'targeted' anticancer drugs for individual patients. Current efforts that focus on the processes required to appropriately act on pharmacogenomic variability in the clinic are moving away from discovery and towards implementation of an evidenced-based strategy for improving the use of medications, thereby providing a cornerstone for precision medicine.
On the cost and benefit of cooperation

In cooperative communication, network nodes that would otherwise act independently instead coordinate their efforts with the aim of improving communication performance. To better understand cooperation, we consider communication over a multiple access channel using a “cooperation facilitator”, a node that receives rate-limited message descriptions from the transmitters and sends rate-limited message descriptions back. This model includes the conferencing encoders model and a prior model from the current authors as special cases. We characterize a class of multiple access channels for which there is no gain in sum-capacity under current or prior cooperation models. We then show that for all other multiple access channels, the gain in sum-capacity can be far greater than the capacity of the cooperation facilitator's output links. These channels violate the edge removal property. The Gaussian multiple access channel is an important special case for which we explicitly characterize the sum-rate cooperation gain.
Mitochondrial morphology in yeast with and without mitochondrial DNA.

The morphology of yeast mitochondria in Schizosaccharomyces pombe and a petite and wild-type strain of Saccharomyces cerevisiae were examined using gentle fixation procedures. The major objective was to determine the effect of the complete loss of mitochondrial DNA on the morphology of mitochondria in the strains of S. cerevisiae . The fission yeast was used as a test organism for developing a fixation procedure that would yield well-defined cristae. Optimal results were obtained when protoplasts were fixed with glutaraldehyde alone. In thin sections of wild-type S. cerevisiae which contained a full complement of mitochondrial DNA, cristae were readily discernible, while in the petite mutant strain completely lacking mitochondrial DNA, normal cristae were totally absent despite the appearance of a well-preserved innermost and outermost surface membrane. One interpretation is that the cristae membranes are different from the innermost surface membranes.
Chemical ionization mass spectra of macrolide antibiotics

Chemical ionization mass spectrometry is shown to be a valuable tool for structural analysis of certain macrolide antibiotics.
Effects of food and shelter on aggressive activity in the crayfish Orconectes rusticus (Girard)

ABSTRACT In a simplified laboratory environment, aggressive activity (threats, strikes, fights) of Orconectesrusticus declined with increasing availability of both shelter and food. Shelter and food interacted to determine overall aggressive activity; however, in general, shelter reduced aggressive activity more than did food over the 42 h duration of our treatments. Preferred food (fish pieces) reduced activity more than did less preferred food (Tetramin). Individual crayfish varied substantially in amount of aggressive activity. Overall, threats accounted for 16% of aggressive interactions, strikes for 46%, and fights for 38%; proportions were relatively constant among most treatments and between day and night.
Differential requirement for ptf1a in endocrine and exocrine lineages of developing zebrafish pancreas

Mammalian studies have implicated important roles for the basic helix-loop-helix transcription factor Ptf1a-p48 in the development of both exocrine and endocrine pancreas. We have cloned the Ptf1a-p48 ortholog in Danio rerio. Early zebrafish ptf1a expression is observed in developing hindbrain and in endodermal pancreatic precursors. Analysis of ptf1a and insulin expression reveals a population of exocrine precursors that, throughout early development, are temporally and spatially segregated from endocrine elements. Morpholino-mediated knockdown of ptf1a confirms early divergence of these endocrine and exocrine lineages. Ptf1a morphants lack differentiated exocrine pancreas, but maintain normal differentiation and organization of the principal islet. In addition to the exocrine phenotype, ptf1a knockdown also reduces the prevalence of a small population of anterior endocrine cells normally found outside the principal islet. Together, these findings suggest the presence of distinct ptf1a-dependent and ptf1a-independent precursor populations in developing zebrafish pancreas.
Structural behavior of solid rocket motor field joints

Structural analysis studies conducted on three concepts for the Space Shuttle Solid Rocket Motor field joints are summarized. Deflections and stresses in the Challenger clevis-tang joint are compared with a proposed capture-tang replacement joint and with an alternate bolted joint design. Results indicate deflections and stresses are subsequently reduced in both the capture-tang and bolted joint concepts. The capture-tang and bolted joint designs are respectively 24 and 70 percent heavier than the baseline clevis-tang joint.
Transactions section: Preprint of corresponding pages from the current annual AIEE transactions volume: Analysis of arc-welding reactors

It is the purpose of this paper to examine the need and design of arc-welding reactors for d-c arc-welding sets. The inductance useful in stabilizing welding arcs is defined, and methods for calculating and measuring this quantity are suggested. Further, criteria for designs which make most effective use of material are established. Finally, a recent development in reactor design is described.
Osteosclerotic prostate cancer metastasis to murine bone are enhanced with increased bone formation

Spontaneous development of osteoblastic lesions of prostate cancer (PCa) in mice is modeled by orthotopic (intraprostatic) deposition of neoplastic cells followed by an extremely long latency associated with low incidence of spontaneous bone metastasis. Intracardial injection results in overt bone metastases only with osteoclastic PCa cells (i.e., PC-3). Herein, we report that androgen independent osteoblastic PCa cells readily colonize bone when in a high remodeling state. SCID/Beige mice were subjected to periods of intermittent human parathyroid hormone 1–34 (hPTH) exposure, followed by an intracardiac infusion of osteoblastic C4-2 PCa cells. At the time of PCa infusion, analysis of bone turnover markers from mice treated with hPTH revealed significant increases in osteocalcin (55.06 ± 7.5 vs. 74.01 ± 18.5 ng/ml) and TRAcP-5b (3.3 ± 0.6 vs. 4.81 ± 0.8 U/l), but no change in type I collagen C-terminal teleopeptide levels relative to control mice. Analysis of femoral cancellous bone architecture revealed significant increases in bone mineral density, trabecular thickness (0.056 ± 0.002 vs. 0.062 ± 0.001 mm) and porosity, but significant decreases in connectivity density and trabecular number in hPTH treated mice relative to controls. By 8 weeks post-infusion, 70% of mice pre-treated with hPTH demonstrated detectable serum prostate specific antigen (PSAs) ranging between 2 and 18.8 ng/ml. Immuno-histochemical labeling of femurs for PSA and pan-Cytokeratin revealed the presence of significant tumor cell nests in marrow and trabecular spaces. These results suggest that: (1) local bone physiology is an important factor for developing osteoblastic/sclerotic PCa bone metastases in murine hosts; (2) the establishment of osteosclerotic PCa bone metastases in mice is enhanced by alterations that drive bone formation.
The Unintended Effects of Penal Reform African American Presence, Incarceration, and the Abolition of Discretionary Parole in the United States

The authors use a pooled-time series design to examine the interplay between state incarceration rates, determinate sentencing, and the size of the African American population between 1978 and 2004. Consistent with prior research, findings show that larger Black populations are associated with higher incarceration rates but that this association has weakened over time. Results also indicate that determinate sentencing is associated with lower imprisonment rates. The interaction between a higher proportion of African American residents and determinate sentencing, however, is associated with higher incarceration rates, suggesting that in states with greater minority presence the abolition of discretionary parole amplifies the impact of punitive responses linked to racial threat. It is argued that this unintended effect reflects the fact that formal constraints on release decision making reduce the ability of justice systems to administer greater punishments to specific subpopulations.
The Coupling between the Hydration and Double Layer Interactions

The electric potential and the polarization between two charged, flat surfaces immersed in water are calculated without the usual assumption that the polarization is proportional to the electric fi...
Intracellular distribution of palmitoyl-CoA synthetase in rat liver

Abstract 1. 1. The intracellular localization of rat-liver long-chain fatty acyl-CoA synthetase (acid: CoA ligase (AMP), EC 6.2.1.3; trivial name: palmitoyl-CoA synthetase) has been studied. Our results fail to confirm a previousl report that the plasma memberane fraction is richest in palmitoyl-CoA synthetase 1 . In agreement with Farstad et al. 2 we found most of the activity in the microsomes, some activity in the mitochondria, and only traces in the nuclear- plus -cell-debris fraction, which contained the plasma membrane plus contaminants from other fractions. 2. 2. The cell debris was separated from the nuclei and fractionated on a sucrose gradient. Each of the fractions was characterized by enzyme markers; DNA and protein content; and palmitoyl-CoA synthetase activity. The specific activity of palmitoyl-CoA synthetase was highest in those gradient fractions which had a high specific activity of the microsomal or mitochondrial marker enzymes. The specific activity of palmitoyl-CoA synthetase in plasma membranes isolated by two different methods was only 25% of the corresponding microsomal specific activity.
The Contribution of Mother‐Child and Father‐Child Relationships to the Quality of Sibling Interaction: A Longitudinal Study

Although several studies have now examined the relations between mother-child and sibling interaction, the role of fathers in the development of sibling relationships is noticeably absent. The present study included assessments of both mother-child and father-child interaction in order to examine the correlates of sibling conflict and cooperation. Home observations of parent-child and sibling interaction and reports of differential parental treatment were obtained for 30 families with 2 preschool children when the firstborns were approximately 6 years old. Earlier assessments of infant-mother and infant-father attachments when firstborns were 12 and 13 months old, respectively, were also available, as were prior laboratory assessments of mothering and fathering when the oldest child was 3 years of age. Results suggested that sibling conflict and aggression were related to high levels of conflict between the mother and the 2 children at 6 years, intrusive and overcontrolling mothering at 3 years, and an insecure infant-mother attachment. Facilitative and affectionate fathering, on the other hand, was associated with prosocial sibling interaction. Early relationship experiences between parents and their firstborn children had an enduring effect on the quality of sibling relationships and interacted with differential parental treatment in predicting sibling relationship outcomes.
Electric vehicle production and advanced-transportation systems: prospects for the development of an industrial district in Southern California

In this paper I question the likely development trajectory of electric vehicle (EV) manufacture and related advanced-transportation systems in Southern California. The large base of labor skills, technical expertise, and research and development organizations that are found in the region in the aerospace, electronics, and metalworking industries provide a solid foundation for the EV industry. These sectors also provide a legacy of industrial organization that is oriented more towards flexible production than mass production. The technological immaturity of the EV and the uncertain market it faces, combined with the existing industrial atmosphere in Southern California, suggest that early production of EVs will be organized flexibly in an industrial district uniting firms and technologies in the production of components for an advanced ground-transportation industry.
Natural disasters online

Wildfires, severe storms, floods, volcanic eruptions, and major air pollution events are types of major natural hazards that NASA will track on a new Web site unveiled on 16 January. The site, part of the agency's Earth Observatory, will track these hazards in near-real time with imagery acquired from NASA's Earth Science Enterprise and Earth Observing System satellite missions, along with related descriptive information.
Introduction to CCE-LTER: Responses of the California Current Ecosystem to climate forcing

Abstract The California Current Ecosystem Long Term Ecological Research (CCE-LTER) site has been in existence since 2004. One of its primary objectives is to understand the response of the southern California Current ecosystem to climate forcing. The CCE-LTER site cooperates with the California Cooperative Oceanic Fisheries Investigations (CalCOFI) program and complements CalCOFI׳s work through more extensive observations, process studies, and a modeling program. This special issue is focused on the long-term observations made by the CCE-LTER and CalCOFI programs, describing and understanding long-term changes in the physical, chemical, and biotic environment in the region. The papers in this issue highlight the climatological conditions during recent years and employ modeling to diagnose the principal forcing of meridional currents and eddy transport, both of which affect biotic responses. Changes in source waters in the region, and altered flushing of the Santa Barbara Basin, are considered. Temporal variations in inherent optical properties and in higher trophic levels, including seabirds and marine mammals, are presented. Key methodological developments presented include the incorporation of subsurface phytoplankton and light distributions in order to improve remotely sensed measures of primary production, and the validation of multi-frequency acoustic estimates of mesopelagic fish biomass. Results also highlight significant spatial differences across the CCE-LTER region, including cross-shore trends in microbial assemblages, and glider-resolved frontal features and zones of mixing associated with abrupt topography. Alterations to the spatial structure of the pelagic ecosystem must also be considered when evaluating future climate-related changes.
Stroke Research in Issues of Prevention and Health Care

The stroke mortality rate has continued to decline steadily since 1950. This has been paralleled by a decline in the stroke incidence rate. However, in recent years, the stroke incidence rate has leveled and may be increasing. As a result of cerebrovascular and related research, improved methods of primary prevention are now available through control of identified risk factors. In addition, several variables are under investigation which may control the consequences of stroke and improve the quality of life of those afflicted. The direct and indirect economic costs of stroke are very high and there is a high probability they will increase. This is particularly true in populations in which incidence remains high but mortality decreases. (Hypertens Res 1994; 17 Suppl. I: S109-S113)
Relationships between structures and mutagenic potencies of 16 heterocyclic nitrogen mustards (ICR compounds) in Salmonella typhimurium

16 heterocyclic nitrogen mustards (ICR compounds), which were synthesized for use as possible antitumor agents by Creech and coworkers, were tested for mutagenicity in Salmonella typhimurium strains TA1535, TA1536, TA1537, TA1538, TA98 and TA100. The compounds were incorporated into the top agar at 5 doses: 0.5, 1, 2.5, 5 and 10 micrograms/plate. All of the compounds were negative in TA1535 except ICR 449, which was positive in all 6 strains. The other 15 compounds were positive in the remaining strains with the following exceptions: ICR 371 and 355 were negative in TA100; ICR 445 was negative in TA98 and TA100; and ICR 360 was negative in TA1537, TA1538, TA98 and TA100. Good qualitative agreement was observed between the mutagenic and antitumor activities of the 16 compounds, and between the mutagenic and carcinogenic activities of the 5 compounds that have been tested for carcinogenicity by Peck and coworkers. However, no significant correlation was found between mutagenic potency in Salmonella and antitumor potency in mice for the 16 compounds. Also, for the 5 compounds that have been tested for carcinogenicity, no significant correlation was found between their mutagenic potency in Salmonella and their carcinogenic potency in mice. In Salmonella, the secondary (2 degrees) amines generally were more mutagenic than their tertiary (3 degrees) amine homologs, although the opposite result has been reported in certain eukaryotes. Relationships between structures and potencies for the different nuclei of the 16 ICR compounds are discussed, as are similarities and differences in strain sensitivities. We conclude that the Salmonella his reversion test is not a good predictor of the antitumor and carcinogenic potencies of these ICR compounds.
Bilateral Simultaneous Spontaneous Pneumothorax

Bilateral simultaneous spontaneous pneumothorax, although rare, may constitute a grave emergency when it does occur. Early diagnosis and institution of prompt therapeutic measures may be essential for survival. The great majority of cases of spontaneous pneumothorax involve one lung only and are readily treated by simple aspiration of the air, or by intercostal catheter and water seal drainage. In general, thoracotomy is reserved for those cases which may be classified as chronic or recurrent pneumothorax. On the other hand, a recent experience with a case of bilateral simultaneous pneumothorax has demonstrated that in such a circumstance, early thoracotomy is justified and desirable in order to avoid a subsequent and possibly fatal recurrence.
Radioiodinated styrylbenzene derivatives as potential SPECT imaging agents for amyloid plaque detection in Alzheimer's disease.

Development of probes for beta-amyloid (A beta) plaques, a critical factor associated with Alzheimer's disease (AD), provides important tools for studying their role in AD. Previously, we reported [125I]IMSB and [125I]ISB as excellent probes for A beta plaque labeling. Despite their exquisite in vitro binding characteristics, low brain uptakes (likely due to two ionizable carboxylic acid groups) limited their potential as in vivo imaging agents. To improve brain penetration, we have successfully prepared a neutral radioiodinated probe [125I]3. The improved probe displayed good binding affinity for A beta aggregates (Ki = 2.0 +/- 0.2 using A beta40 aggregates). In addition, the brominated counterpart displayed fluorescent-staining properties of A beta plaques in postmortem AD brain sections similar to BSB, a fluoroscent probe reported previously. [125I]3 gave excellent plaque labeling by film autoradiography of AD brain sections. Unlike [125I]IMSB (which preferentially detects A beta40 plaques), the improved radioioinated probe, [125I]3, can readily detect plaques containing aggregates of both A beta40 and A beta42. The initial brain uptake of [125I]3 in normal mice at 2 min p.i. was moderate (0.18% ID) and displayed a very slow washout from the brain (0.11%.ID at 4 h p.i). Taken together, these data suggest that [125I]3 is useful for in vitro plaque detection, it may not be suitable for in vivo monitoring of A beta progression and deposition.
Impurity-driven structural deformations in 2D- and 3D-ordered gold nanowires

Abstract Density functional theory is used to explore the adsorption of light impurities (O, O2 and CO) on the ordered atomic structures that self organize during the late stages of tensile deformation of gold nanowires. Because such ordering precedes the formation of the single atom chain, adsorption at this stage may critically alter the formation and/or the properties of the single atom chain itself. Two particular structures are investigated: the 3-dimensional “Triangular110” and the 2-dimensional “ZigZag”. The absorbed molecules produce significant changes in the structure of the nanowires and exhibit a wide range of adsorption energies.
Modeling Liquid Association

In 2002, Ker-Chau Li introduced the liquid association measure to characterize three-way interactions between genes, and developed a computationally efficient estimator that can be used to screen gene expression microarray data for such interactions. That study, and others published since then, have established the biological validity of the method, and clearly demonstrated it to be a useful tool for the analysis of genomic data sets. To build on this work, we have sought a parametric family of multivariate distributions with the flexibility to model the full range of trivariate dependencies encompassed by liquid association. Such a model could situate liquid association within a formal inferential theory. In this article, we describe such a family of distributions, a trivariate, conditional normal model having Gaussian univariate marginal distributions, and in fact including the trivariate Gaussian family as a special case. Perhaps the most interesting feature of the distribution is that the parameterization naturally parses the three-way dependence structure into a number of distinct, interpretable components. One of these components is very closely aligned to liquid association, and is developed as a measure we call modified liquid association. We develop two methods for estimating this quantity, and propose statistical tests for the existence of this type of dependence. We evaluate these inferential methods in a set of simulations and illustrate their use in the analysis of publicly available experimental data.
Modified ‘Joyce model’ of opioid dependence/withdrawal

By comprehensive and detailed measurement of the time course of withdrawal signs in rats, Joyce et al. (J. Theo. Biol. 240:531–537, 2006) recently provided a creative quantitative model of onset of drug-dependence based on the requirement of protein synthesis. Because the initial model fit the data imperfectly over the full time course, the authors postulated that additional features would be needed. We report excellent fit of the data (R2 = 0.96) by adding: (1) a transient early phase, and (2) a delay in the buildup of protein.
Overexpression of human keratin 16 produces a distinct skin phenotype in transgenic mouse skin

Human cytokeratin 16 (K16; 48 kDa) is constitutively expressed in postmitotic keratinocytes in a variety of stratified epithelial tissues, but it is best known for the marked enhancement of its expression in stratified squamous epithelia showing hyperproliferation or abnormal differentiation. Of particular interest to us, K16 is strongly induced at the wound edge after injury to the epidermis, and its accumulation correlates spatially and temporally with the onset of reepithelialization. To examine the properties of K16 in its natural cellular context, we introduced a wild-type human K16 gene into the germ line of transgenic mice. Several transgenic lines were established and characterized. Under most conditions, the human K16 transgene is regulated tissue specifically in the skin of transgenic mice. Animals that feature low levels of transgene expression are indistinguishable from controls during the first 6-8 months of life. In contrast, transgenic animals expressing the transgene at higher levels develop skin lesions at 1 week after birth, coinciding with the emergence of fur. At a cellular level, alterations begin with the reorganization of keratin filaments and are first seen at the level of the hair follicle outer root sheath (ORS), where K16 expression is known to occur constitutively. The lesions then progressively spread to involve the proximal epidermis, with which the ORS is contiguous. Elevated transgene expression is associated with a marked thickening of these two epithelia, along with altered keratinocyte cytoarchitecture and aberrant keratinization but no keratinocyte lysis. The implications of this phenotype for epithelial differentiation, human genodermatoses, and wound healing in skin are discussed.
Effects of Classical Resonances on the Chaotic Microwave Ionization of Highly Excited Hydrogen Atoms

Experimental measurements of the microwave ionization of highly excited hydrogen atoms with principal quantum numbers ranging from n = 32 to 90 are well described by a classical treatment of the nonlinear electron dynamics. In particular, the measurements of the threshold field for the onset of significant ionization exhibits a curious dependence on the microwave frequency with distinct peaks at rational values of the scaled frequency, n3Ω = 1, 2/3, 1/2, 2/5, 1/3, 1/4, 1/5, which is in excellent agreement with the predictions for the onset of classical chaos in a one-dimensional model of the experiment. In the classical theory this frequency dependence of the threshold fields is due to the stabilizing effect of nonlinear resonances ("islands") in the classical phase space which is greatly enhanced when the microwave perturbation is turned on slowly (adiabatically) as in the experiments. Quantum calculations for this one-dimensional model also exhibits this stabilizing effect due to the preferential excitation of localized quasi-energy states.
Is bone a Cosserat solid

In a viscoelastic composite material including bone, acoustic waves undergo both geometric and viscoelastic dispersions as they propagate through the medium. The viscoelastic dispersion is characterized by an increase in phase velocity with increase in frequency, while the geometric dispersion is well-known. By comparing the dispersion data on these and other types of materials, it has been noted that the increases in the ultrasonic velocities for bones are much larger than those for simple viscoelastic solids and composites, suggesting an additional dispersion mechanism. This additional dispersion can be explained by Mindlin's theory on the Cosserat continuum with microstructure.
Automatic parameterization of rational curves and surfaces IV: algebraic space curves

For an irreducible algebraic space curve C that is implicitly defined as the intersection of two algebraic surfaces, f (x, y, z) = 0 and g (x, y, z) = 0, there always exists a birational correspondence between the points of C and the points of an irreducible plane curve P, whose genus is the same as that of C. Thus C is rational if the genus of P is zero. Given an irreducible space curve C = (f ∩ g), with f and g not tangent along C, we present a method of obtaining a projected irreducible plane curve P together with birational maps between the points of P and C. Together with [4], this method yields an algorithm to compute the genus of C, and if the genus is zero, the rational parametric equations for C. As a biproduct, this method also yields the implicit and parametric equations of a rational surface S containing the space curve C.The birational mappings of implicitly defined space curves find numerous applications in geometric modeling and computer graphics since they provide an efficient way of manipulating curves in space by processing curves in the plane. Additionally, having rational surfaces containing C yields a simple way of generating related families of rational space curves.
The immunity dilemma: Are state colleges and universities still liable for copyright infringements?

Recent court rulings have created the most extraordinary result of appearing to leave state agencies—and, hence, state universities—immune from copyright infringement liabilities. These decisions are based on constitutional principles that protect states from liability in federal courts; meanwhile, copyright infringement cases are required to be filed only in federal courts. These developments might lead some members of the academic community to conclude that state institutions are sheltered from any threat of legal liability; therefore, they need not concern themselves with subtleties and responsibilities associated with copyright and fair use. Leaping to that conclusion would be a serious error for many reasons. Despite some protection from legal liabilities, that protection is hardly complete and is far from certain.
Carbohydrate moieties of the basal lamina: their role in attachment and spreading of basal corneal epithelial cells.

Three lectins, Wheat germ agglutinin, succinyl Concanavalin A and Ricinus communis agglutinin were used to block specific sugar moieties in the basal lamina. Corneal epithelial basal cells were plated onto freshly denuded basal lamina. Attachment was studied by quantifying the adherence of prelabeled cells and by examining attachment sites using transmission electron microscopy. Spreading was examined using scanning electron microscopy. Attachment of the cells occurred within 15 min and spreading was apparent after 45 min. Both Wheat germ agglutinin and β-N-acetylglucosaminidase inhibited cellular attachment. Succinyl Concanavalin A and Ricinus Communis agglutinin permitted attachment, but inhibited extensive cellular spreading. The results indicate that the attachment of basal cells is dependent on N-acetylglucosamine residues, and spreading is mediated by alpha methylmannoside, glucose, and galactose residues.
Identification of cryptic lox sites in the yeast genome by selection for Cre-mediated chromosome translocations that confer multiple drug resistance.

Abstract The Cre recombinase efficiently causes site-specific DNA recombination at loxP sites placed into the eukaryotic genome. Since the loxP site of phage P1 is 34 base-pairs in size, the natural occurrence of this exact sequence is unlikely in any eukaryotic genome. However, related sequences may exist in eukaryotic genomes that could recombine at low efficiency with an authentic loxP site. This work identifies such cryptic lox sites in the yeast genome using a positive selection procedure that allows the detection of events occurring at a frequency of −7 . The selection is based on the disruption/reconstruction of the yeast gene YGL022 . Disruption of YGL022 confers multiple drug sensitivity. Recombination events at a loxP site 5′ to the structural gene restore expression of YGL022 and result in a multiple drug resistant phenotype. These drug resistant mutants all display chromosomal rearrangements resulting from low-frequency Cre-mediated recombination with an endogenous cryptic lox site. Ten such sites have been found and they have been mapped physically to a number of different yeast chromosomes. Although the efficiency of Cre-mediated recombination between loxP and such endogenous sites is quite low, it may be possible to redesign recombination substrates to improve recombination efficiency. Because of the greater complexity of the human and mouse genomes compared with yeast, an analogous situation is likely to exist in these organisms. The availability of such sites would be quite useful in the development of alternative strategies for gene therapy and in the generation of transgenic animals.
Leptospirosis in the Tropics and in Travelers

Leptospirosis, caused by spirochetes of the genus Leptospira, has increasingly been recognized to affect travelers and residents in tropical settings. A zoonotic disease, leptospirosis is transmitted to humans through environmental surface waters contaminated by the urine of chronically infected mammals. Outcome of infection varies, ranging from acute febrile illness (including selfresolving undifferentiated fever) to aseptic meningitis to a fulminant syndrome of jaundice, oliguric renal failure, pulmonary hemorrhage, and refractory shock. Hospitalized cases have mortality rates as high as 25%. A recent clinical trial showed that third-generation cephalosporin is as effective as doxycycline and penicillin in the treatment of acute disease. Doxycycline is effective in preventing leptospirosis in travelers. No protective vaccine is currently available.
Defining features of natural kinds and artifacts

Two experiments investigated the role of three types of features (physical characteristics, functions, and chromosomal/molecular structure) in determining membership in natural kind and artifact categories. In the first, subjects decided if an object “X” would still be an “X” if it were different in one type of feature. A significant interaction was found between word type and change type, with the effects of chromosomal/molecular changes significantly greater for natural kinds than for artifacts, and the effects of functional changes significantly greater for artifacts than natural kinds. In the second experiment, subjects judged whether something would be an “X” if it were unlike instances of “X” in two of the above types of features, but like instances of “X” in one. There was again a significant interaction, with the effects of chromosomal/molecular features significantly greater for natural kinds than for artifacts, and the effects of functional changes significantly greater for artifacts than for natural kinds. These results suggest that chromosomal/molecular features define membership in natural kind categories and functional features define membership in artifact categories. The implications of these findings for the meaning of “defining features” are also discussed.
On the controllability and observability of Cartesian product networks

The paper presents an analysis framework for a class of dynamic composite networks. These networks are formed from smaller factor networks via graph Cartesian products. We provide a composition method for extending the controllability and observability of the factor networks to that of the composite network. We then delve into the effectiveness of designing control and estimation algorithms for the composite network via symmetry in the network. Examples and applications are provided throughout the paper to demonstrate the results including a distributed output feedback stabilizer and a social network application.
Out with the Sit-Up, in with the Curl-Up!

(1993). Out with the Sit-Up, in with the Curl-Up! Journal of Physical Education, Recreation & Dance: Vol. 64, No. 6, pp. 62-66.
Computational Prediction of Polycomb-Associated Long Non-Coding RNAs

Among thousands of long non-coding RNAs (lncRNAs) only a small subset is functionally characterized and the functional annotation of lncRNAs on the genomic scale remains inadequate. In this study we computationally characterized two functionally different parts of human lncRNAs transcriptome based on their ability to bind the polycomb repressive complex, PRC2. This classification is enabled by the fact that while all lncRNAs constitute a diverse set of sequences, the classes of PRC2-binding and PRC2 non-binding lncRNAs possess characteristic combinations of sequence-structure patterns and, therefore, can be separated within the feature space. Based on the specific combination of features, we built several machine-learning classifiers and identified the SVM-based classifier as the best performing. We further showed that the SVM-based classifier is able to generalize on the independent data sets. We observed that this classifier, trained on the human lncRNAs, can predict up to 59.4% of PRC2-binding lncRNAs in mice. This suggests that, despite the low degree of sequence conservation, many lncRNAs play functionally conserved biological roles.
Fireside Politics: Radio and Political Culture in the United States, 1920-1940

In Fireside Politics, Douglas B. Craig provides the first detailed and complete examination of radio's changing role in American political culture between 1920 and 1940-the medium's golden age, when it commanded huge national audiences without competition from television. Craig follows the evolution of radio into a commercialized, networked, and regulated industry, and ultimately into an essential tool for winning political campaigns and shaping American identity in the interwar period. Finally, he draws thoughtful comparisons of the American experience of radio broadcasting and political culture with those of Australia, Britain, and Canada.
Effect of solutes on the heterogeneous nucleation temperature of supercooled water: an experimental determination

We investigate the effect of solute concentration on the heterogeneous ice nucleation temperature (Thet) of aqueous solutions of both NaCl and D-glucose. An automatic lag time apparatus (ALTA) technique allows the dependence of Thet on solute concentration to be determined with statistical significance. Our results point to the solute-induced lowering of Thet being a factor of two times the equivalent melting point depression at any fixed concentration, the same factor reported for homogeneous nucleation experiments with small molecular weight solutes.
Improved Glottic Exposure With the Video Macintosh Laryngoscope in Adult Emergency Department Tracheal Intubations

Study objective Glottic visualization with video is superior to direct laryngoscopy in controlled operating room studies. However, glottic exposure with video laryngoscopy has not been evaluated in the emergency department (ED) setting, where blood, secretions, poor patient positioning, and physiologic derangement can complicate laryngoscopy. We measure the difference in glottic visualization with video versus direct laryngoscopy. Methods We prospectively studied a convenience sample of tracheal intubations at 2 academic EDs. We performed laryngoscopy with the Karl Storz Video Macintosh Laryngoscope, which can be used for conventional direct laryngoscopy, as well as video laryngoscopy. We rated glottic visualization with the Cormack-Lehane (C-L) Scale, defining "good" visualization as C-L I or II and "poor" visualization as C-L III or IV. We compared glottic exposure between direct and video laryngoscopy, determining the proportion of poor direct visualizations improved to good visualization with video laryngoscopy. We also determined the proportion of good direct visualizations worsened to poor visualization by video laryngoscopy. Results We report data on 198 patients, including 146 (74%) medical, 51 (26%) trauma, and 1 (0.51%) unknown indications. All were tracheally intubated by emergency physicians. Postgraduate year 3 or 4 residents performed 102 (52.3%) of the laryngoscopies, postgraduate year 2 residents performed 60 (30.8%), interns performed 20 (10.3%), attending physicians performed 9 (4.6%), and operator experience and specialty were not reported in 4. Overall, good visualization (C-L grade I or II) was attained in 158 direct (80%) versus 185 video laryngoscopies (93%; McNemar's P Conclusion Video laryngoscopy affords more grade I and II views than direct laryngoscopy and improves glottic exposure in most patients with poor direct glottic visualization. In a small proportion of cases, glottic exposure is worse with video than direct laryngoscopy.