cssi/SciSciGPT-SciSciNet huggingface dataset:
Functional redundancy of type II BMP receptor and type IIB activin receptor in BMP2-induced osteoblast differentiation

Signaling pathways for bone morphogenetic proteins (BMPs) are important in osteoblast differentiation. Although the precise function of type I BMP receptors in mediating BMP signaling for osteoblast differentiation and bone formation has been characterized previously, the role of type II BMP receptors in osteoblasts is to be well clarified. In this study, we investigated the role of type II BMP receptor (BMPR-II) and type IIB activin receptor (ActR-IIB) in BMP2-induced osteoblast differentiation. While osteoblastic 2T3 cells expressed BMPR-II and ActR-IIB, loss-of-function studies, using dominant negative receptors and siRNAs, showed that BMPR-II and ActR-IIB compensated each other functionally in mediating BMP2 signaling and BMP2-induced osteoblast differentiation. This was evidenced by two findings. First, unless there was loss of function of both type II receptors, isolated disruption of either BMPR-II or ActR-IIB did not remove BMP2 activity. Second, in cells with loss of function of both receptors, restoration of function of either BMPR-II or ActR-IIB by transfection of the wild-type forms, restored BMP2 activity. These findings suggest a functional redundancy between BMPR-II and ActR-IIB in osteoblast differentiation. Results from experiments to test the effects of transforming growth factor β (TGF-β), activin, and fibroblast growth factor (FGF) on osteoblast proliferation and differentiation suggest that inhibition of receptor signaling by double-blockage of BMPR-II and ActR-IIB is BMP-signaling specific. The observed functional redundancy of type II BMP receptors in osteoblasts is novel information about the BMP signaling pathway essential for initiating osteoblast differentiation.
Numerical Verification of Scaling Laws for Shock-Boundary Layer Interactions in Arbitrary Gases

The steady, two-dimensional interaction of an oblique shock with a laminar flat-plate boundary layer has been examined through use of the Beam-Warming implicit scheme. A wide range of fluids is considered as are freestream pressures corresponding to dense gases, i.e., gases at pressures which are so large that the ideal gas law is no longer accurate. The results, when combined with the triple-deck theory of Kluwick, provides strong support for the idea that the classical scaling laws can be extended to dense gases.
Stability criteria for a general class of finite difference schemes

The von Neumann stabllity analysis is performed on a generalized class of two-level space-centered finite difference schemes known as Lerat-Peyret schemes. In the present study, these schemes are used to solve the convection-diffusion equation in an effort to obtain a better assessment of the accuracy of such schemes. Exact stability criteria are derived for each of five different schemes applied to the Burgers equation. Exact results for the amplification factor and phase error are plotted for several values of Courant number and diffusion parameter for each scheme. These exact results, which are presented here for the flat time, are extremely valuable in assessing the dissipation and dispersion characteristics of each scheme
Chinese hamster cells expressing antisense to metallothionein become spontaneous mutators

Abstract The functions of metallothioneins (MTs) have been debated for at least a decade. Because it seems unlikely that they evolved only to protect cells against exogenous heavy metals, it has been suggested that MTs have roles in scavenging reactive intermediates, controlling zinc and copper homeostasis, and controlling transfer of zinc to transcription factors and other proteins. Previously, we demonstrated that Chinese hamster G12 cells which overexpress MT have greatly reduced spontaneous mutation rates, suggesting that MT evolved to prevent spontaneous mutagenesis induced by free nuclear zinc ions. We have now isolated G12 transfectants which express antisense RNA to MT. Immunofluorescent staining reveals MT protein in both the nucleus and the cytoplasm in parental cells. A clone expressing high levels of antisense RNA (AMT30) shows reduced basal and induced levels of MT protein. AMT30 cells are hypersensitive to cadmium, zinc, copper and mercury chlorides as well as to menadione. Glutathione levels in AMT30 and G12 cells do not differ. AMT30 cells are spontaneous mutators, showing a spontaneous mutation rate 5–10 times that of G12 cells or G12 cells transfected with vector alone. Only transfectants which show a high level of MT antisense expression (i.e., AMT30) had greatly elevated spontaneous mutation rates. These results support our hypothesis that a major role of MT is to act as an endogenous antimutagen probably via scavenging of reactive intermediates in the nucleus. AMT30 cells should be useful in delineating the sources of spontaneous mutagenesis.
Analytical Studies on the Prediction of Photosensitive/Phototoxic Potential of Pharmaceutical Substances

Phototoxic responses after administration of photosensitive pharmaceutics have been recognized as undesirable side effects, and predicting potential hazardous side effects is gaining importance as new drugs are introduced to the market. In this work, we characterize the photochemical/photobiological properties of model compounds to develop an effective screening method for the prediction of phototoxic/photosensitive potential. Twenty-one known photosensitive/phototoxic compounds and five weak/nonphototoxic compounds were subjected to ultraviolet (UV) spectral analyses and photochemical evaluation including the determination of produced reactive oxygen species (ROS) and photostability study. The photooxidation of linoleic acid was also monitored in the presence of tested compounds, guided on the formation of thiobarbituric acid reactive substances. Most photosensitive/phototoxic drugs tested, even weak UV absorbers, at a concentration of 200 μM showed significant production of ROS under 18 h light exposure (30,000 lx). On the other hand, ROS generated from weak/nonphototoxic compounds, including strong UV absorber benzocaine, were low or negligible. Although exposure of quinine to light resulted in significant degradation (half-life, t 1/2 = 6.4 h), it was dramatically attenuated by the addition of ROS scavengers, especially sodium azide (t 1/2 = 122.6 h). Furthermore, concomitant exposure of photosensitive/phototoxic compounds (200 μM) and linoleic acid (1 mM) for 18 h led to the marked formation of lipoperoxide. Results indicated that known photosensitive/phototoxic compounds tested have the ability to generate ROS under light exposure, and this photochemical reaction could be associated with their photoinstability and/or phototoxic responses. Based on these findings, determination of ROS, generated from photoirradiated compounds, may be an effective predictive model in recognizing their photosensitive/phototoxic potential.
The effect of an external electric field on the scavenging of aerosol particles by cloud drops and small rain drops

Abstract A theoretical model is described which determines the efficiency E with which aerosol particles of radius r ≲ 0.5 μm are collected by water drops of radius a due to the combined action of convective Brownian diffusion, thermo- and diffusiophoresis, and electric forces caused by the presence of an external electric field and electric charges on drops and aerosol particles, but in the absence of inertial impaction effects. The results of this model are combined with the results of our earlier model which determines the collection efficiency of drops for particles of r > 0.5 μ m due to the combined action of inertial impaction, thermo- and diffusiophoresis, and electric forces due to the presence of an external electric field and electric charges on drops and aerosol particles, but in the absence of convective Brownian diffusion. Both models combined are able to quantitatively predict E vs r for 0.001 ≲ r ≲ 10 μ m and 8.6 ≲ a ≲ 438 μ m, for relative humidities in the ambient air up to 100%, and for external electric fields and electric charges on drops and aerosol particles of a magnitude up to those found in thunderstorms. Our results show that external electric fields act to significantly enhance the efficiency with which drops collide with aerosol particles of radii 0.01 ≲ r ≲ 1.0 μ m, the size range in which E experiences a minimum. External electric fields have negligible effects on the scavenging of aerosol particles of r μ m and of r > 1.0 μ m.
Regions of Backprojection and Comet Tail Artifacts for $\pi$-Line Reconstruction Formulas in Tomography

We explore two characteristic features of x-ray computed tomography inversion formulas in two and three dimensions that are dependent on $\pi$-lines. In such formulas the data from a given source position contribute only to the reconstruction of $f(\mathbf{x})$ for $\mathbf{x}$ in a certain region, called the region of backprojection. The second characteristic is a certain small artifact in the reconstruction called a comet tail artifact. We propose that the comet tail artifact is closely related to the boundary of the region of backprojection and make this relationship precise, developing a general theory of the region of backprojection, its boundary, and the location of the artifact in helical and fan-beam tomography. This theory is applied to a number of specific examples and confirmed by numerical experiments. Furthermore it is demonstrated that a strong comet tail artifact appears in numerical reconstructions from misaligned fan-beam data. A numerical method for using the artifact to find the correct...
Design of a ruthenium-labeled cytochrome c derivative to study electron transfer with the cytochrome bc1 complex.

A new ruthenium-cytochrome c derivative was designed to study electron transfer from cytochrome bc 1 to cytochrome c (Cc). The single sulfhydryl on yeast H39C;C102T iso-1-Cc was labeled with Ru(2,2'-bipyrazine)2(4-bromomethyl-4'-methyl-2,2'-bipyridine) to form Ru z -39-Cc. The Ru z -39-Cc derivative has the same steady-state activity with yeast cytochrome bc 1 as wild-type yeast iso-1-Cc, indicating that the ruthenium complex does not interfere in the binding interaction. Laser excitation of reduced Ru z -39-Cc results in electron transfer from heme c to the excited state of ruthenium with a rate constant of 1.5 x 10 6 s - 1 . The resulting Ru(I) is rapidly oxidized by atmospheric oxygen in the buffer. The yield of photooxidized heme c is 20% in a single flash. Flash photolysis of a 1: 1 complex between reduced yeast cytochrome bc 1 and Ru z -39-Cc at low ionic strength leads to rapid photooxidation of heme c, followed by intracomplex electron transfer from cytochrome c 1 to heme c with a rate constant of 1.4 x 10 4 s - 1 . As the ionic strength is raised above 100 mM, the intracomplex phase disappears, and a new phase appears due to the bimolecular reaction between solution Ru-39-Cc and cytochrome bc 1 . The interaction of yeast Ru-39-Cc with yeast cytochrome bc 1 is stronger than that of horse Ru-39-Cc with bovine cytochrome bc 1 , suggesting that nonpolar interactions are stronger in the yeast system.
Distribution of laminin, type IV collagen, and fibronectin in the cell columns and trophoblastic shell of early macaque placentas.

The cytotrophoblastic cell columns and trophoblastic shell of macaque placentas accumulate progressively greater amounts of intercellular material during early gestation. We studied the composition of this material in placentas collected from 22–34 days of gestation by using immunoperoxidase techniques directed to the extracellular matrix molecules fibronectin, type IV collagen, and laminin. These antigens co-localized within the intercellular deposits at all stages studied. At day 22 the proximal cell columns were composed of cells with narrow interstices and which lacked immunoreactivity for the 3 antigens. Distally the cells were vacuolated and the intercellular spaces increased in size and contained dense matrix deposits. The trophoblastic shell consisted of closely packed, non-vacuolated cytotrophoblast cells with only a delicate meshwork of matrix. By day 27 the matrix deposits of the distal cell columns increased markedly in size. The trophoblastic shell contained larger numbers of vacuolated cells and was occupied by accumulations of matrix. By 34 days the matrix deposits of the cell columns expanded substantially along the longitudinal axes of the columns. These deposits were often continuous with a matrix-dense, cell-deficient layer in the trophoblastic shell. This matrix-rich zone lay between a cellular layer adjacent to the intervilous space and a similar, but discontinuous, cell layer that formed the junctional zone with the endometrium.
Human immunodeficiency virus—associated myopathy: Analysis of 11 patients

Neuromuscular disorders reported in association with human immunodeficiency virus (HIV) infection include several forms of peripheral neuropathy and polymyositis. We report 11 patients with HIV-associated myopathy. Five patients with acquired immunodeficiency syndrome (AIDS), 2 with AIDS-related complex, and 4 otherwise asymptomatic HIV-infected patients developed progressive proximal muscle weakness. Serum creatine phosphokinase levels were elevated and electromyography revealed abnormal spontaneous activity and myopathy in most patients. All 8 muscle biopsy specimens showed fiber necrosis. Four had inflammatory infiltrates, and nemaline rod bodies were prominent in 3. Immunosuppressant therapy in 5 patients resulted in improvement. Attempts at viral localization in 4 muscle biopsy specimens were unsuccessful. These findings suggest a distinct association between HIV infection and myopathy with features atypical for polymyositis.
Data modeling in DELAB

As the size and complexity of processing and manufacturing systems increases, the need for Database Management Systems (DBMS) that meet the special needs of studies that experiment with such systems becomes more current. System analysts who study the performance of modern processing systems have to manipulate large amounts of data in order to profile the behavior of the system. They have to identify the relationship between the properties of a compound system and a wide spectrum of performance metrics. In a recent study in which we have analyzed a set of distributed concurrency control algorithms, we performed more than 1400 simulation experiments. Each experiment was characterized by more than 6000 input parameters and generated more than 400 output values. It is thus clear that powerful means for defining the structure and properties of complex systems are needed, as well as efficient tools to retrieve the data accumulated in the course of the study. We are currently engaged in an effort to develop and implement the DELAB simulation laboratory that aims to provide such means and tools for simulation studies.The goal of the first phase of this effort was to design and implement a simulation language. It ended in 1986 when the DENET (Discrete Event NETwork) simulation language became operational. The language is based on the concept of Discrete Event System Specifications (DEVS). It views the simulator as a collection of self contained objects that communicate via Discrete Event Connectors that provide a unified synchronization protocol In the past two years the language has been used in a number of real life studies. It was used to simulate distributed processing environments, communication protocols, and production lines Several tools have been developed around the language. All tools adhere to the same modeling methodology and thus create a cohesive simulation environment.In the second phase of the DELAB project we have been addressing the data management problem DENET has been interfaced to a special purpose relational DBMS that can store descriptions of simulation runs and provides access to the stored data Based on our experience with thus DBMS, we have reached the conclusion that system analysts need to be provided with a view of the data that differs from the way the DENET program views the data, and thus decided to develop a data model that meets their needs. The M
Thermographic Eye Temperature as an Index to Body Temperature in Ponies

Infrared thermography (IRT) is a passive, remote, and noninvasive method of measuring surface temperatures. Select surface locations, such as the eye, could indicate body temperature. To investigate whether thermographic eye temperatures were associated with body temperatures and could be used to detect febrile ponies, we measured IRT eye temperatures, rectal temperatures, and implanted thermal microchip temperatures from 24 male ponies daily for 3 consecutive days. Information regarding distance of the pony from the IRT device, presence of direct sunlight during the measurement period, and ambient temperature were also collected. A multivariate linear regression analysis indicated that 60.41% of the variance in IRT was accounted for by rectal temperature, sunlight, and distance between the camera and the pony, with rectal temperature being the major contributor to variance (46.23%). Using a rectal temperature of >38.6°C (101.5°F) as the indicator of febrile status, sensitivity and specificity of the IRT device used to detect the febrile ponies were found to be 74.6% and 92.3%, respectively, when using the maximum IRT eye temperature per pony per day. In conclusion, IRT eye temperature could be a preliminary screening tool to determine whether a more time-consuming, labor–intensive, and invasive method (e.g., rectal temperature) is warranted for fever validation.
Political Tolerance and Territorial Threat: A Cross‐National Study

The Steps-to-War theory of international conflict argues that territorial issues are more salient than other issues domestically. However, the evidence for this conclusion almost always rests with international conflict outcomes, assuming away the domestic political processes leading to greater salience. In the tolerance literature, several studies note that political attitudes, particularly toward unpopular groups, vary systematically across different states but provide few explanations that account for these differences. We believe these two observations are linked and argue that territorial threats serve as one factor conditioning individual political attitudes that privilege national unity over freedom of expression. Using World Values Survey data collected from 33 countries, and Hierarchical Linear Modeling (HLM) techniques, our paper confirms this. We find evidence that the type of external threat facing a country matters in moderating individual attitudes, even after controlling for economic and in...
Capacitance ratio estimation on a novel MEMS tactile sensor for elasticity measurement

This paper develops a real-time capacitance ratio estimation system for a novel MEMS tactile sensor that can provide elasticity measurement of a variety of target objects. The tactile sensor is developed by this team for in-vivo tissue elasticity measurements and can be installed on a hand-held probe or on minimally invasive surgical instruments. The sensor readout consists of two channels of capacitance values and the ratio of these capacitance values needs to be reliably estimated in real-time. The proposed estimation algorithm utilizes a recursive least squares method with adaptive forgetting factors, which provides reliable elasticity measurement of polymer specimens and quickly detects changes in elasticity. Extensive experimental results are presented.
Mechanistic insights into operational lithium–sulfur batteries by in situ X-ray diffraction and absorption spectroscopy

The lithium–sulfur battery is an extremely attractive system for electrical energy storage because of its exceptional theoretical capacity and energy density. However, the practical values typically obtained are much lower and inherently determined by the complex chemistry of reduced sulfur species. The lack of methods to probe sulfur species under realistic battery conditions has frustrated chemical understanding and control. We have employed in situ X-ray diffraction (XRD) and sulfur K-edge X-ray absorption near edge spectroscopy (XANES) to probe the sulfur intermediates and products formed in battery electrodes during operation of prototype lithium–sulfur batteries. Correlations between the X-ray and electrochemical data show that the reduction of sulfur to lithium sulfide is mediated through dissociation and disproportionation reactions of a few dominant sulfur species. Deliberate control of these chemical equilibria is essential to approach the theoretical capacity of the lithium–sulfur system.
Multidimensional Infrared Signatures of Intramolecular Hydrogen Bonding in Malonaldehyde

The sixth-order anharmonic force field of malonaldehyde along the two proton-transfer double-well coordinates and the four O-H and C=O stretching modes is constructed at the MP2/6-31G(d,p) level. The vibrational Hamiltonian is diagonalized using the Arnoldi method. Coherent infrared (IR) vibrational spectra are predicted using the vibrational eigenstates. The three pulse IR signals, calculated in all possible phase matching directions, show specific signatures of the intramolecular proton transfer.
Questions developers ask while diagnosing potential security vulnerabilities with static analysis

Security tools can help developers answer questions about potential vulnerabilities in their code. A better understanding of the types of questions asked by developers may help toolsmiths design more effective tools. In this paper, we describe how we collected and categorized these questions by conducting an exploratory study with novice and experienced software developers. We equipped them with Find Security Bugs, a security-oriented static analysis tool, and observed their interactions with security vulnerabilities in an open-source system that they had previously contributed to. We found that they asked questions not only about security vulnerabilities, associated attacks, and fixes, but also questions about the software itself, the social ecosystem that built the software, and related resources and tools. For example, when participants asked questions about the source of tainted data, their tools forced them to make imperfect tradeoffs between systematic and ad hoc program navigation strategies.
Sub parts-per-million mass measurement accuracy of intact proteins and product ions achieved using a dual electrospray ionization quadrupole fourier transform ion cyclotron resonance mass spectrometer

High mass measurement accuracy (MMA) is demonstrated for intact proteins and subsequent collision-induced dissociation product ions using internal calibration. Internal calibration was accomplished using a dual electrospray ionization source coupled with a hybrid quadrupole Fourier transform ion cyclotron resonance (Q-FT-ICR) mass spectrometer. Initially, analyte ions generated via the first electrospray (ESI) emitter are isolated and dissociated in the external quadrupole. This event is followed by a simultaneous switch to the calibrant ion ESI emitter and a disablement of the isolation and activation of the external quadrupole such that a broad m/z range of calibrant ions are accumulated before injecting the analyte/calibrant ion mixture into the ICR cell. Two different internal calibrant solutions were utilized in these studies to evaluate this approach for the top-down characterization of melittin and ubiquitin. While external calibration of protein fragments resulted in absolute MMA greater than 16 ppm, internal standardization significantly improved upon the MMA of both the intact proteins and their products ions which ranged from −2.0 ppm to 1.1 ppm, with an average of −0.9 ppm. This method requires limited modification to ESI-FT-ICR mass spectrometers and is applicable for both positive and negative ionization modes.
A Primer on the Design, Conduct, and Interpretation of Clinical Trials

Clinical trials are an especially powerful study design that often guides health care policy and clinical practice. Indeed, well-designed and rigorously conducted trials can establish the etiologic relevance of modifiable risk factors and the benefits (and risks) of candidate therapies. Contemporary schema that classify evidence place results from randomized trials at the pinnacle of evidence. The primary objective of this article is to provide an overview of the design, conduct, and interpretation of trials with an emphasis on aspects that are relevant to nephrology.
The scavenger cell hypothesis of apoptosis: Apoptosis redefined as a process by which a cell in living tissue is destroyed by phagocytosis

Current literature on the definition and description of apoptosis is very confusing and erratic, due to voluminous studies in recent decades using cell culture technique. Apoptosis has evolved as a programmed mechanism of cell demise to get rid of the cells that are no longer needed by the body. The most important reason for a creature to use this mechanism to kill cells is to avoid inflammatory response that causes tissue damage and ensuing scar formation, as seen in necrosis. To reach this aim, the dying cell communicates, at early stages of the dying process, with macrophages or its neighboring cells that have phagocytotic ability, coined collectively as scavenger cells herein. The dying cell is swiftly engulfed by a scavenger cell without leaking any noxious cellular components into the intercellular space to provoke an inflammatory response. Thus, apoptosis is a process involving at least one other cell type and is actually a mechanism occurring in live tissue. Most studies of apoptosis in recent decades neglect this fundamental point and use cell culture system with a single cell type in the medium, in which avoidance of inflammatory response and tissue damage is no longer a reason. In culture, the dying cell has no way to signal scavenger cells to engulf itself and thus needs to demobilize a series of special mechanisms, which have no need in live tissue, to complete the suicidal process and clearance of its own corpse. These "otherwise-no-need" mechanisms seem to involve activation of executor caspases by cytochrome c, and the activated caspases mediate late processes of apoptosis in vitro. However, because the late processes of apoptosis in vivo actually occur in a phagosome of scavenger cell, it may be phagosomal enzymes, but not executor caspases of the apoptotic cell origin, that are really involved in apoptosis. Therefore, I propose a "scavenger cell hypothesis of apoptosis" to redefine apoptosis as an in vivo mechanism of cell death, and suggest that programmed cell death in culture in a third cell demise mechanism besides necrosis and apoptosis that should be defined using other nomenclatures.
OBSERVATIONS ON POLICE UNDERCOVER WORK

Law enforcement officers are dependent upon citizens to alert them to criminal violations of the law. When citizens do not willingly communicate information to the police or cannot be induced to do so, police officers themselves adopt fictitious identities of various types. This paper explores police undercover work, a form of covert law enforcement used to gather information about conduct external to the organization. Through interviews with supervisors and practitioners, the benefits and liabilities of the assignment for the officers and the organization are presented. The work enables the police to investigate citizens who are not suspected of criminal activity and therefore lends itself to abuse. The practice itself demands attention as the lack of operational guidelines, standardless selection of operatives, and loose supervision imperil the safety of officers and the rights of citizens.
Touch Preps of Products of Conception for Rule-Out Ectopic Pregnancy: A Viable Alternative to Frozen Section.

Objectives: Tissue confirmation of the intrauterine location of a pregnancy can be difficult grossly, necessitating a frozen section diagnosis. First-trimester tissue is often scant and can be exhausted by frozen section. We examined 39 endometrial curettings performed for rule-out ectopic pregnancy by touch prep to examine the utility of cytopathology in documenting trophoblast or chorionic villi (products of conception [POC]). Methods: First-trimester curettage specimens sent to the Massachusetts General Hospital Pathology Departmentreceived a gross examination followed by a touch prep of the area most suspicious for villi. Touch preps were reviewed blinded to the final diagnosis and then compared. Results: Thirty-three of the 39 touch preps and histology specimens were concordant, including all 11 negative histology specimens and 22 of the 28 positive histology specimens. Conclusions: POC can be diagnosed by touch prep and may offer confirmation of grossly identified villi. Positive predictive value is 100%. Negative touch preps should receive further evaluation.
Geographic differences and microevolutionary changes in thermal sensitivity of butterfly larvae in response to climate

Summary Rapid evolution of physiological traits in response to novel thermal environments has rarely been demonstrated in natural populations. We studied the temperature dependence [thermal performance curves (TPCs)] of larval feeding rate for two populations each of Colias eurytheme and Colias eriphyle in North America that occur over a range of elevations and climates. Using historical data for two of the populations, we assessed changes over time in both air temperatures and TPCs for larval feeding. Populations at lower elevations with longer growing seasons had broader TPCs for larval feeding. In contrast, higher elevation populations with shorter growing seasons had higher optimal and maximal temperatures for feeding. Overall mean air temperatures during the growing season showed little change at the two sites, but the frequency of high air temperatures (>28 °C) has increased markedly at both sites over the past 40 years. This climatic shift was associated with increased rates of larval feeding at higher temperatures (>28 °C) in both populations. These results suggest that recent climate warming has led to physiological shifts in the TPCs for larval feeding in this system, indicating that thermal adaptation can occur rapidly in response to changing thermal conditions.
Completeness in the theory of types

The first order functional calculus was proved complete by Godel in 1930. Roughly speaking, this proof demonstrates that each formula of the calculus is a formal theorem which becomes a true sentence under every one of a certain intended class of interpretations of the formal system.For the functional calculus of second order, in which predicate variables may be bound, a very different kind of result is known: no matter what (recursive) set of axioms are chosen, the system will contain a formula which is valid but not a formal theorem. This follows from results of Godel concerning systems containing a theory of natural numbers, because a finite categorical set of axioms for the positive integers can be formulated within a second order calculus to which a functional constant has been added.By a valid formula of the second order calculus is meant one which expresses a true proposition whenever the individual variables are interpreted as ranging over an (arbitrary) domain of elements while the functional variables of degree n range over all sets of ordered n-tuples of individuals. Under this definition of validity, we must conclude from Godel's results that the calculus is essentially incomplete.It happens, however, that there is a wider class of models which furnish an interpretation for the symbolism of the calculus consistent with the usual axioms and formal rules of inference. Roughly, these models consist of an arbitrary domain of individuals, as before, but now an arbitrary class of sets of ordered n-tuples of individuals as the range for functional variables of degree n. If we redefine the notion of valid formula to mean one which expresses a true proposition with respect to every one of these models, we can then prove that the usual axiom system for the second order calculus is complete: a formula is valid if and only if it is a formal theorem.
Kinetics of Facultative Heterochromatin and Polycomb Group Protein Association with the Herpes Simplex Viral Genome during Establishment of Latent Infection

ABSTRACT The herpes simplex virus (HSV) genome is associated with heterochromatic histone modifications, including trimethylation of the lysine 27 residue of histone H3 (H3K27me3), during latent infection of neurons. Here we have examined the kinetics of general chromatin and H3K27me3 association with the viral genome during establishment of latent infection. Using both wild-type virus and a mutant virus that is unable to undergo replication in neurons, we found that histone H3 associates with viral gene promoters by 7 days postinfection (dpi). Levels of H3K27me3 were low at 7 dpi but increased dramatically by 14 dpi. Hence, general chromatin association and/or other factors may play a key role(s) in the initial silencing of lytic genes, and H3K27me3 may play a role in further suppression of the genome and/or the maintenance of latency. A component of Polycomb repressive complex 2 (PRC2), which mediates the addition of K27me3 to histone H3 (Suz12), was also recruited by 14 dpi. We have shown previously that the levels of H3K27me3 during latent infection are increased in the presence of the latency-associated transcript (LAT). However, the initial targeting of PRC2 was not found to be dependent on the LAT. We found that a component of the PRC1 complex (Bmi1), which binds to H3K27me3, was not enriched at promoters found previously to be enriched for H3K27me3. Our results are consistent with (i) chromatinization of viral DNA or other mechanisms causing the initial silencing of HSV lytic genes and (ii) facultative heterochromatin maintaining that silencing during latent infection of neurons. IMPORTANCE The human pathogen herpes simplex virus (HSV) hides for the lifetime of the host in peripheral neurons. The mechanism by which HSV is able to shut off its gene expression and persist in neurons is not known. Here we show that the HSV DNA first associates with histone H3, with later recruitment of Polycomb repressor complex 2 (PRC2) and trimethylation of the lysine 27 residue of histone H3 (H3K27me3), a modification associated with heterochromatin. This work indicates that the initial silencing of HSV gene expression is not correlated with enrichment of H3K27me3 and that PRC2 may be recruited to already-silenced genes to further silence gene expression and/or maintain gene silencing. We demonstrate that recruitment of PRC2 is not dependent upon expression of the noncoding HSV latency-associated transcripts, indicating the presence of unknown triggers for PRC2 recruitment during the establishment of latent infection.
Improved restoration of space object imagery

We examine methods for preprocessing a collection of atmospheric turbulence-degraded short-exposure imagery to improve the resolving power of estimation algorithms. We redefine the method known as frame selection in the context of optimizing estimation results. We compare several measures of image quality with idealized standards, demonstrating their relative ability to rank highly the least-degraded image frames. In particular, we find the Fisher information measure to be the most noise tolerant and robust frame-selection measure. We then examine the resolving implication of removing additive background noise resulting from the sky and telescope. Specifically, we show that background compensation acts as a de facto restoration of the compact object support and leads to furthering the resolving power of estimation methods. Results from simulated imaging scenarios demonstrate the improved ability of a multiframe maximum a posteriori estimator to restore the passband object distribution as well as to further recover the lost spectral content residing beyond the diffraction limit.
Two-dimensional optical filtering of 1-D signals.

One-dimensional signals have complementary attributes, their space and spatial frequency properties. Recently, another signal representation was introduced in optics, the Wigner distribution (WD) function, which allows the simultaneous display of the two attributes of a 1-D signal. In this paper optical implementation of a generalized space–spatial frequency (GSF) function is discussed. Special cases of the GSF representations are the WD, the radar ambiguity function (AF), the energy distribution function, the various pseudo-WD functions, the spectrogram, the local frequency and the local Doppler frequency spectrum. The GSF representation allows the simultaneous filtering of both the spatial and the spatial frequency content of a 1-D signal. The 2-D filtering of a 1-D signal allows sidelobe reduction of the WD and AF of quasi-periodic 1-D signals, display of the instantaneous spatial frequency content of a 1-D signal, space–spatial frequency excision of a desired portion of a 1-D signal as well as the usual matched filter detection. Experimental results using coherent space-integrating techniques for the realization of different GSF are presented.
Death Tax Repeal: Alternative Reform Proposals

Professor Vasek believes that permanent repeal of the estate tax in 2010 will be problematic. Alternatives to repeal include taxing unrealized gains at death, taxing inheritances as income to the recipient, and increasing the amount exempt from estate tax. Political realities, such as the government's need for revenues and the need to not increase tax burdens or compliance difficulties for small estates, will be important if not determinative factors in the ultimate choice of estate tax reform proposals.
An Analysis of student Persistence in Online Education

This study examines the relationship between instructional interaction and student persistence among adult students in online courses. A survey research methodology was used to examine the frequency and the method of instructional interaction in online courses, student attitudes regarding instructional interaction, and the reasons online students provide for persisting in, or withdrawing from, online courses. The results indicate that student perceptions regarding the contribution of asynchronous, discussion forum use combined with frequent use of asynchronous discussion account for 26% of the variance in course persistence rates. Consistent with the literature on adult student dropout, the findings identify additional situational and institutional barriers to persistence among students in online courses. The findings sug gest that strategies to facilitate student persistence in online courses should address online instructional techniques, faculty development, technology development, and program development.
Assessing the Potential for Condensation in Supersonic MicroNozzle Flows

In this study, a numerical model for characterization of the flow-fi eld in aM EMS-based supersonic nozzle is reported. The flow of decomposed hydrogen peroxide (H2O2) monopropellant is simulated and results are analyzed in order to assess potential for condensation of the water species. Owing to the large surface area to volume ratio and inherently low Reynolds numbers (Re<1,000) of a MEMS device, wall phenomena such as heat transfer and viscous forces play critical roles in shaping flow behavior and performance characteristics of the micronozzle. The initially cold nozzle substrate in a space environment facilitates high values of heat transfer from the flow into the surrounding substrate. This heat loss combined with rapid expansion in the diverging section of the nozzle can result in conditions that are ripe for water vapor condensation. The latent heat of condensation acts a heat source in the flow and it is expected that flow behavior with condensation is analogous to Rayleigh flow with heat addition. This in turn can influence nozzle performance characteristics. Simulation results indicate that both subsonic and supersonic condensation may occur in micronozzles; the former as a consequence of heat loss from the flow and the latter as a result of supersonic expansion. In some flow regimes, it is a combination of heat loss and expansion that allows for potential condensation to occur. From simulation data, the mass fraction of condensate is determined, the associated temperature rise is reported, and the influence on nozzle performance is discussed.
Updating the Reference Trajectory for the Cassini Solstice Mission

The Cassini-Huygens deep-space probe has successfully completed a four-year prime tour and a two-year extended tour of the Saturnian system. Now in a second extended phase called the Solstice Mission, the Cassini spacecraft will continue to gather data as directed by the reference trajectory until 2017. This paper will describe the process of how a reference trajectory update is prepared and delivered to the project by the navigation team during Solstice Mission flight operations. This paper will also document the timeline of products released and utilized, as well as the study to include an Enceladus occultation observation that occurs in 2016.
SEMANTIC DIFFERENTIAL MEASURES OF EFFECT OF PUPIL SIZE ON PERSON PERCEPTION

To clarify the effects of pupil size on person perception, 60 males and 60 females enrolled in introductory psychology classes rated a drawing of either a male or a female face characterized by either large, medium, or small pupils on semantic differential scales measuring the dimensions of pleasure, arousal, and dominance (6). The drawings had neutral facial expressions. Subjects also completed a checklist of facial features, indicating specific characteristics which most influenced their ratings of the drawings. Additional space was provided for subjects to describe the drawings. An inspection of the results of 3 x 2 X 2 (pupil size X sex of drawing X sex of subject) factorial analyses of variance for rhe dimensions of pleasure, arousal, and dominance, respectively, indicated no significant effects for pupil size. A significant effect for sex of drawing on the dominance dimension (P = 49.75, df = 1/108, p < ,001) was obtained, however. Both male and female subjects perceived the male drawing as more dominant than the female drawing, regardless of pupil size. Data from the checklist indicated that the most frequently checked facial features were eyes (85% of subjects), pupils of eyes (77% of subjects), and eyebrows (75% of subjects). The subjects' written descriptions of the drawings showed no system;ltic differences, and only 7 of the 120 subjects explicitly stated that pupil size influenced their ratings. Although negative findings were obtained for pupil size, it is important to note that pupil size was studied in isolation, suggesting that future research concern the possibility that pupil size may function as a moderator variable in such a way as to accentuate or to diminish the effects of other factors known to influence person perception.
Poster Abstract: Scheduling Multi-Threaded Tasks to Reduce Intra-Task Cache Contention

Summary form only given. Research on hard real-time systems and their models has predominately focused upon single-threaded tasks. When multithreaded tasks are introduced to the classical real-time model the individual threads are treated as distinct tasks, one for each thread. These artificial tasks share the deadline, period, and worst case execution time of their parent task. In the presence of instruction and data caches this model is overly pessimistic, failing to account for the execution time benefit of cache hits when multiple threads of execution share a memory address space. This work takes a new perspective on instruction caches. Treating the cache as a benefit to schedulability for a single task with m threads. To realize the “inter-thread cache benefit” a new scheduling algorithm and accompanying worst-case execution time (WCET) calculation method are proposed. The scheduling algorithm permits threads to execute across conflict free regions, and blocks those threads that would create an unnecessary cache conflict. The WCET bound is determined for the entire set of m threads, rather than treating each thread as a distinct task. Both the scheduler and WCET method rely on the calculation of conflict free regions which are found by a static analysis method that relies on no external information from the system designer. By virtue of this perspective the system's total execution execution time is reduced and is reflected in a tighter WCET bound compared to the techniques applied to the classical model. Obtaining this tighter bound requires the integration of three typically independent areas: WCET, schedulability, and cache-related preemption delay analysis.
Time Course of Pulmonary Response of Rats to Inhalation of Crystalline Silica: Histological Results and Biochemical Indices of Damage, Lipidosis, and Fibrosis

Previous studies have determined that alpha-quartz (crystalline silica) can cause pulmonary inflammation, damage, and fibrosis. However, the temporal relationship between silica inhalation and pulmonary inflammation, damage, and fibrosis has not been fully examined. To address this gap in our knowledge of silica-induced pulmonary fibrosis, a chronic inhalation study using rats was designed. Specifically, rats were exposed to a silica aerosol (15 mg/m3 silica, 6 h/d, 5 d/wk, 116 d), and measurements of pulmonary inflammation, damage, and fibrosis were monitored throughout the study. We report (1) data demonstrating that the silica aerosol generation and exposure system produced a consistent silica aerosol of respirable size particles; (2) the time course of silica deposition in the lung; (3) calculations that demonstrate that the rats were not in pulmonary overload; (4) histopathological data demonstrating time-dependent enhancement of silica-induced alveolitis, epithelial hypertrophy and hyperplasia, alveolar lipoproteinosis, and pulmonary fibrosis in the absence of overload; and (5) biochemical data documenting the development of lipidosis, lung damage, and fibrosis.
Freshwater molluscan fauna from the Florissant Formation, Colorado: paleohydrologic reconstruction of a latest Eocene lake1

The freshwater molluscan assemblage from the uppermost Eocene Florissant Formation (34.07 ± 0.10 Ma), Colorado, USA, provides a reliable proxy in reconstructing past ecology and environmental chara...
Soft magnetic composites: recent advancements in the technology

Soft magnetic composites allow for revolutionized designs of electromagnetic devices to aid in improved efficiency and reduced weight and costs, without sacrificing magnetic performance. Electrically insulated core powder are formed into toroid shapes and tested for core loss and magnetic permeability, which are desired to be minimized and maximized, respectively. Ferromagnetic powder has shown the most potential as core materials, however nanocrystalline materials are highly resistive and amorphous materials have benefits of very low coercivities. Likewise, organic and inorganic coating materials have been explored for the reduction of eddy currents to improve overall core losses at higher frequencies. The balance between properties is of the utmost concern for SMC applications.