cssi/SciSciGPT-SciSciNet huggingface dataset:
Duality, Dirty Paper Coding, and Capacity for Multiuser Wireless Channels

We determine a duality between broadcast and multiple access channels that can be used to obtain the capacity region and optimal transmission strategy for one channel based on the capacity-achieving transmission strategy and region for the dual channel. This duality result in applicable to additive Gaussian noise and fading channels for several different notions of fading channel capacity, including ergodic capacity, outage capacity, and minimum rate capacity. We show that duality can be used to obtain any of these capacities for the fading broadcast channel from the same capacity on the dual MAC channel, and vice versa. We then apply this general result to obtain the minimum rate capacity of the fading multiple access channel, which also yields the ergodic and outage capacity as special cases. Next we turn our attention to broadcast channels with multiple antennas at the transmitter and receiver (the MIMO channel). Since this channel is in general non-degraded, its capacity region remains an unsolved problem. We establish a duality between the achievable region of the MIMO broadcast channel using Costa’s “dirty-paper” coding and the capacity region of the MIMO multiple-access channel, which is easy to compute. We also show that the dirty paper achievable region yields the sum-rate capacity of the MIMO broadcast channel.
Essential Assembly Factor Rpf2 Forms Novel Interactions within the 5S RNP in Trypanosoma brucei.

ABSTRACT Ribosome biogenesis is a highly complex and conserved cellular process that is responsible for making ribosomes. During this process, there are several assembly steps that function as regulators to ensure proper ribosome formation. One of these steps is the assembly of the 5S ribonucleoprotein particle (5S RNP) in the central protuberance of the 60S ribosomal subunit. In eukaryotes, the 5S RNP is composed of 5S rRNA, ribosomal proteins L5 and L11, and assembly factors Rpf2 and Rrs1. Our laboratory previously showed that in Trypanosoma brucei, the 5S RNP is composed of 5S rRNA, L5, and trypanosome-specific RNA binding proteins P34 and P37. In this study, we characterize an additional component of the 5S RNP, the T. brucei homolog of Rpf2. This is the first study to functionally characterize interactions mediated by Rpf2 in an organism other than fungi. T. brucei Rpf2 (TbRpf2) was identified from tandem affinity purification using extracts prepared from protein A-tobacco etch virus (TEV)-protein C (PTP)-tagged L5, P34, and P37 cell lines, followed by mass spectrometry analysis. We characterized the binding interactions between TbRpf2 and the previously characterized members of the T. brucei 5S RNP. Our studies show that TbRpf2 mediates conserved binding interactions with 5S rRNA and L5 and that TbRpf2 also interacts with trypanosome-specific proteins P34 and P37. We performed RNA interference (RNAi) knockdown of TbRpf2 and showed that this protein is essential for the survival of the parasites and is critical for proper ribosome formation. These studies provide new insights into a critical checkpoint in the ribosome biogenesis pathway in T. brucei. IMPORTANCETrypanosoma brucei is the parasitic protozoan that causes African sleeping sickness. Ribosome assembly is essential for the survival of this parasite through the different host environments it encounters during its life cycle. The assembly of the 5S ribonucleoprotein particle (5S RNP) functions as one of the regulatory checkpoints during ribosome biogenesis. We have previously characterized the 5S RNP in T. brucei and showed that trypanosome-specific proteins P34 and P37 are part of this complex. In this study, we characterize for the first time the interactions of the homolog of the assembly factor Rpf2 with members of the 5S RNP in another organism besides fungi. Our studies show that Rpf2 is essential in T. brucei and that it forms unique interactions within the 5S RNP, particularly with P34 and P37. These studies have identified parasite-specific interactions that can potentially function as new therapeutic targets against sleeping sickness.
Determinants of Unemployment

This chapter develops and tests a model which finds that Okun’s law of the negative relationship of GDP to unemployment holds remarkably well and that inflation and several shocks (oil prices in 1973, Hurricane Katrina in 2005, and the fiscal crisis in 2008) explained considerable fluctuation in unemployment as well.
The Bhopalator —A Molecular Model of the Living Cell; New Developments

The states of matter in nature can be divided into the living and the non-living states. It is useful to view the living cell as the simplest unit of the living state of matter. Therefore, the goal of understanding the phenomena of life and non-life may best be realized through a careful study of the properties of living cells
A Statistical Analysis of the Frequency of United States and Eastern North Pacific Hurricanes Related to Solar Activity

In this chapter, we examine the statistical relationship between the frequency of United States and eastern North Pacific (ENP) hurricanes and the solar cycle. First, a relationship between the probability of a hurricane and sunspot numbers is shown that is conditional on ocean temperature. For years of above normal ocean temperatures, the probability of three or more hurricanes in the United States decreases from 40% to 20% as sunspot numbers increase. Second, a solar index that tracks intraseasonal variability in sunspot numbers is constructed and correlated with hurricane activity. The index is inversely related to the total sunspot numbers (SSN) and is significantly correlated with the probability of hurricanes and major hurricanes affecting the United States. The chances of at least one U.S. hurricane in the lowest and highest SSN anomaly season are 25% and 64%, respectively. The solar index is then used as a predictor of major hurricane frequency over the ENP where it is found that the chance of at least six major ENP hurricanes increases from about 1% when the solar index lowest to 28% when the index is highest.
Physical Examination of the Cervical Spine

The cervical spine is formed by seven vertebrae which are naturally aligned in lordosis. Their main function is to provide support to the cranium and to serve as a bridge connecting it with the remaining spinal segments. Simultaneously, it provides protection for vital neural structures.
A new argument for the phenomenal approach to personal persistence

When it comes to personal identity, two approaches have long ruled the roost. The first is the psychological approach, which has it that our persistence through time consists in the continuance of certain of our psychological traits, such as our memories, beliefs, desires, or personality. The second is the biological approach, according to which personal persistence consists in continuity in our physical or biological makeup. Amid the bipartite reign of these approaches, a third contender has emerged: the phenomenal approach. On this approach, personal persistence consists in continuity in phenomenal consciousness or the capacity for phenomenal consciousness. In this paper I will introduce and defend a new argument for the phenomenal approach. In the process, I will argue against the psychological and biological approaches. I will also address some lingering questions and outline further ways to develop the phenomenal approach.
A Frequency Selective Surface With Miniaturized Elements for Chemical Sensing

In this paper, a bandpass miniaturized frequency selective surface made up of wire grid and loop element is employed for sensing. With a material under test between periodic arrays of wire grid and loop elements, the sensing capability of this structure to detect air, ethanol, and methanol in X band is demonstrated through numerical simulation. The structure can sense e′ and e″ variations as small as 0.4 and 0.55, respectively. Moreover, the maximum detectable e′ and e″ are 21.2 and 16.1, respectively.
Standardization of Diagnostic Immunohistochemistry

Standardization of every step in pre-analytic, analytic and post-analytic phases is crucial to achieve reproducible and reliable immunohistochemistry test results. This chapter delineates some critical points in pre-analytic, analytic and post-analytic phases, reiterates some important questions which may or may not have a consensus at this time, and updates the newly proposed guidelines on antibody validation from the College of American Pathologists Pathology and Laboratory Quality Center. Additionally, the chapter shares Geisinger’s experience with 1) testing/optimizing a new antibody and troubleshooting; 2) interpreting and reporting immunohistochemistry assay results; 3) improving and implementing a total immunohistochemistry quality management program; and 4) developing the concept of best practices in immunohistochemistry.
70. Anterior column realignment (ACR) performed at L2-3 achieves suboptimal lumbo-pelvic realignment compared with L2 pedicle subtraction osteotomy (PSO)

BACKGROUND CONTEXT The anterior column realignment (ACR) technique is increasingly becoming popular for treating patients with flatback deformity. The degreed of correction achieved with ACR performed at L2-3 disc has not been well studied. PURPOSE The purpose of this study was to compare the degree of deformity correction and perioperative outcomes between ACR and PSO being performed at L2 for iatrogenic flatback deformity. STUDY DESIGN/SETTING Retrospective review. PATIENT SAMPLE N = 27 patients, 9 ACR and 18 PSO. The patients were matched 1:2 (ACR:PSO) based on preoperative deformity parameters. OUTCOME MEASURES Primary outcome: Lumbo-pelvic parameters (LL-PI mismatch, SVA, PT). Secondary outcomes: estimated blood loss, transfusion requirement, length of hospital stay, operative time, postoperative complication, and hospital readmission rates. METHODS Patients were identified between 2012 and 2016 who underwent revision surgery using either the PSO or ACR technique at the L2-3 level to correct sagittal deformity. Patients who underwent ACR were matched to PSO patients in a 1:2 fashion based on preoperative lumbar lordosis (LL) and lumbar lordosis pelvis incidence (LL-PI) mismatch. Patient demographics, surgical variables, pre- and postoperative radiographic parameters, and perioperative characteristics were compared between the treatment groups using t-tests, chi-square tests, and multivariable regression models. RESULTS The cohort included 27 patients; 9 ACR patients matched to 18 PSO patients. The PSO group achieved a greater degree of lumbar lordosis compared to the ACR group (31° vs 14.23°, p CONCLUSIONS PSO surgery resulted in significantly improved lumbar lordosis and sagittal alignment correction compared to the ACR group. While ACR resulted in some improvement of lumbar lordosis, it resulted in residual lumbo-pelvic mismatch compared with patients treated with PSO. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.
Implementation of an Artificial Immune System to Mitigate Cybersecurity Threats in Unmanned Aerial Systems

This project aims to use an artificial immune system to detect cyber-attacks on the dynamics of a minidrone. Using linear transfer functions, a zero-dynamics attack was designed to be injected into the system. To further explore how zero-dynamics translates from linear to non-linear systems, a similar attack was made using a random value rather than an unstable zero of the system. These attacks were then injected via the ground station computer. An offline artificial immune system was created and used to test the effectiveness of detecting the attacks. The immune system uses a discrete, binary, non-self recognition algorithm to create detectors and find disturbances in the data.
Is There More Than One Way to Talk About Sex? A Longitudinal Growth Mixture Model of Parent-Adolescent Sex Communication.

Abstract Purpose Parents can be effective and consistent sex educators of their children, but research suggests that most parents only engage in a one-time talk about sex with their children. That being said, we know little about the potential variability in trajectories of parent–child sex communication over time. Thus, the present study took a person-centered approach to parent–child sex communication about sexual risk and explored predictors and outcomes of varying trajectories. Methods Participants included 468 adolescents and their parents who took part in a longitudinal study every year from ages 14–18 years (52% female, 67% white, and 33% single parents). Results Growth mixture modeling suggested four different trajectories of parent–child sex communication using child reports and two different trajectories using mother and father reports, with the majority of parents displaying low and stable levels of communication over time. Predictors and outcomes suggested that varying trajectories were in part a function of child behaviors (i.e., early sexual debut and externalizing behaviors), and mothers who reported trajectories of moderate-stable levels of communication had children who reported safer sex practices at age 21 years. Conclusions The discussion focused on the benefits of longitudinal, person-centered approaches at identifying variability in parenting and the implications of findings for those concerned about the need for parental education on the importance of sex communication across adolescence.
Context, structure, and informativeness judgments: An extensive empirical investigation

We explored the nature of human informativeness judgments: namely, people’s judgments about the quantity of information that object stimuli convey about the category of objects to which they belong. Informativeness judgments play a key role in everyday decision-making situations involving the selection of items from groups that best represent the “group as a whole.” They also provide insight into the nature of prototype formation. We investigated informativeness judgments with an experiment involving 41 category structures – the most comprehensive and rigorous examination thus far. We assess the robustness and generalizability of the results from this experiment by examining the relationship between group-level and individual-level performance. In addition, we show that in most cases (and especially in those involving relatively lower dimensionality structures), these judgments are predicted more accurately and explained more satisfactorily by Representational Information Theory (Vigo in Information Sciences 181: 4847–4859, 2011 and in Information 4(1):1–30, 2012) and its simplest core model than by standard models of prototypicality. Finally, we argue that prototypicality models are special cases of the more general “representational information” framework.
Harvesting the skeletonized internal mammary artery

Abstract Since the landmark paper from Loop et al. in 1986, the use of the left internal mammary artery (LIMA) for revascularization of the left anterior descending (LAD) artery is the standard of care in coronary artery disease. As such, the successful harvest of the LIMA is critical to the outcome of coronary artery bypass grafting. Described is the approach to harvesting a skeletonized LIMA; the decision between skeletonized and pedicled mammary harvest is beyond the scope of this technical chapter, but a surgeon should never hesitate to use either technique depending on their level of comfort or expertise. Skeletonized is associated with reduced incidence of sternal wound complications and medastinitis and is the preferred approach for patients undergoing bilateral internal mammary artery grafting.
Language, Cognition, and Script Effects

This chapter begins with the discussions of what language is and the relationship between spoken language and written language, along with the early view of language-is-speech in linguistics as well as a written-language bias. A series of questions are posed and answered, covering whether we think differently according to the language we speak, whether language affects thinking or thinking affects language, and what the impact of literacy is. These questions are closely related to the linguistic relativity hypothesis. Based on empirical evidence for linguistic relativity, script relativity is proposed as an extension. Fundamental challenges in research into both linguistic relativity and script relativity are identified. The chapter ends with the introduction to this book, including the scope of the volume, terminology used throughout the book, and intended audiences.
Access to care and health insurance coverage for workers with disabilities: Outcomes by state-level responses to the ACA.

Abstract Background States had flexibility in their implementation of the Patient Protection and Affordable Care Act (ACA) Medicaid expansions, which may have led to variation in coverage and changes in access to care for workers with disabilities. Objective/hypothesis To examine differential trends in health insurance coverage and access to care among workers with disabilities by states’ decisions about expanding Medicaid under the ACA. Methods We aggregated data from the National Health Interview Survey into groups by time period relative to ACA implementation: pre-ACA (2006–2009), early ACA (2010–2013), and later ACA (2014–2017). We produced health insurance and access statistics for each time period, by state-level Medicaid expansion status. Results Uninsurance rates decreased after 2014 in all states, regardless of the state’s decision whether to expand Medicaid. There was a substantial increase after 2014 in the share of workers with disabilities covered by Medicaid in states that expanded in that year; in other states, workers with disabilities experienced larger increases in privately purchased coverage. At the same time, the share of workers with disabilities reporting cost-related barriers to care declined markedly in 2014 Medicaid expansion states, but it increased slightly in the non-expansion states. Structural barriers to accessing care increased in all states, with the smallest increase in 2014 expansion states. Conclusions Medicaid coverage and cost-related access to care improved significantly among workers with disabilities in 2014 Medicaid expansion states, both overall and relative to workers with disabilities in non-expansion states.
Reflections on a Half-Century of Foodborne Botulism

My personal interest in foodbome botulism dates from the first course in food microbiology that I took 55 years ago. The thing that impressed me most, then as well as now, was the spectacular potency of the toxin. It is hard to believe that so little of anything can do so much damage.
Crystal structure of cis-2-(2-carb-oxy-cyclo-prop-yl)glycine (CCG-III) monohydrate.

The title compound, C6H9NO4·H2O [systematic name: (αR,1R,2S)-rel-α-amino-2-carb­oxy­cyclo­propane­acetic acid monohydrate], crystallizes with two organic mol­ecules and two water mol­ecules in the asymmetric unit. The space group is P21 and the organic mol­ecules are enanti­omers, thus this is an example of a `false conglomerate' with two mol­ecules of opposite handedness in the asymmetric unit (r.m.s. overlay fit = 0.056 A for one mol­ecule and its inverted partner). Each mol­ecule exists as a zwitterion, with proton transfer from the amino acid carb­oxy­lic acid group to the amine group. In the crystal, the components are linked by N—H⋯O and O—H⋯O hydrogen bonds, generating (100) sheets. Conformationally restricted glutamate analogs are of inter­est due to their selective activation of different glutamate receptors, and the naturally occurring (+)-CCG-III is an inhibitor of glutamate uptake and the key geometrical parameters are discussed.
Chemical reactions in solution under high pressure

Some recent aspects of the effects of pressure on chemical equilibria and kinetics, primarily in dilute solutions, are reviewed. Chemical equilibria are represented mainly by polymerization reactions, and the concept of a polymerization pressure is discussed. Some contributions to volumes of activation and of reaction are reviewed, and an example of the use of volumes of activation to determine mechanism is given. The final section is concerned with the use of energies and entropies of activation at constant volume to characterize chemical rate processes. Es wird ein Uberblick uber einige neue Aspekte der Wirkungen hoher Drucke auf chemische Gleichgewichte und Kinetik, speziell in verdunnten Losungen, gegeben. Chemische Gleichgewichte werden vorwiegend durch Polymerisationsreaktionen vertreten; die Einfuhrung eines Polymerisationsdrucks wird diskutiert. Einige Beitrage zu Fragen der Aktivierungsvolumina und der Reaktionsvolumina werden wiedergegeben, und ein Beispiel fur die Bestimmung eines Mechanismus mit Hilfe der Aktivierungsvolumina wird gegeben. Der abschliesende Abschnitt befast sich mit der Verwendung von Aktivierungsenergien und -entropien bei konstantem Volumen zur Charakterisierung der Geschwindigkeit chemischer Reaktionen.
A Review of “Bhutto and the Breakup of Pakistan”

Mohammed Yunus's short memoir on how Pakistan lost the 1971 war with India over what became Bangladesh provides a behind-the-scenes look at “what happened to the idyllic country of Pakistan” (vii)....
Hot Money and External Adjustment

This paper studies the behavior of international capital flows driven by the portfolio reallocation decisions of international investors; so-called hot money. I develop an open economy model with endowment and preference shocks that can account for the empirical behavior of real exchange rates, interest rates and consumption in the U.S. and Europe. The model includes financial frictions that impede international risk-sharing and hot money flows driven by optimal portfolio reallocations. My analysis reveals that hot money flows are an economically insignificant part of the international adjustment process following standard (temporary) endowment shocks. In contrast, preference shocks that change investors’ risk aversion produce sizable hot money flows. These shocks also produce sizable variations in the expected return differentials on foreign assets and liabilities that allow for external adjustment via the valuation channel. Consistent with the model’s predictions, I show that forecasts of future return differentials contributed most to the volatility of the U.S. net foreign asset position in the post Bretton-Woods era. Together, these findings indicate that hot money flows are an integral and empirically important part of the external adjustment process.
Theories of Performance: Organizational and Service Improvement in the Public Domain, by Colin Talbot

Los Angeles, CaliforniaColin Talbot, Professor of Public Policy and Management at the University of Manchester, is well known to the readers of this journal as he is its current editor. Those who h...
Free Fatty Acid Effects on the Atrial Myocardium: Membrane Ionic Currents Are Remodeled by the Disruption of T-Tubular Architecture.

Background Epicardial adiposity and plasma levels of free fatty acids (FFAs) are elevated in atrial fibrillation, heart failure and obesity, with potentially detrimental effects on myocardial function. As major components of epicardial fat, FFAs may be abnormally regulated, with a potential to detrimentally modulate electro-mechanical function. The cellular mechanisms underlying such effects of FFAs are unknown.
Summa contra ontologiam

This paper is a critical analysis of the concept of ontology thus as it is used in contemporary computing science. It identifies three main problems with such a concept, two of which are intrinsic to it and one of which is extrinsic, so to speak, being related to the use that of ontology is made in applications. The first problem with ontology is that the only accepted definition of its main artifact is teleological rather than structural as it would be proper in computing science. The second problem is that claiming that ontology is in any way a semantic discipline requires such a limited and outdated notion of semantic to be to all practical purposes useless. The third and final problem is that the limitations and misconceptions of ontology might make it a limiting factor, rather than a help, for many of the applications for which it is sought. The article concludes that a profound reconsideration of the relation between computers and semantics might be overdue.
Treatment of hydrogen bonding within CNDO/2 and MINDO/3: CNDO/2H and MINDO/3H

A formalism has been developed to treat hydrogen-bonded A—H…B systems within the CNDO/2 and the MINDO/3 methodologies. In this formalism the interactions are divided into three distinct classes; those between (a) two hydrogen-bonded atoms, (b) one hydrogen-bonded and non-hydrogen-bonded atom, and (c) two non-hydrogen-bonded atoms. The last class of interactions is treated solely by the existing CNDO/2 or MINDO/3 method. For A –H…B systems, the core resonance integrals are individually parametrized depending upon the class of the interaction. Three types of A—H…B systems have been thus far parametrized. Nine hydrogen-bonded dimers have been studied using the new formalism and the current CNDO/2 and the MINDO/3 methods. MINDO/3 predicts very large interatomic (A –B) distances for the equilibrium geometry, and relatively small stabilization values for the hydrogen-bond energies. CNDO/2 predicts the reverse. The new formalism for both CNDO/2 and MINDO/3 predicts accurate geometries as well as energies for all nine dimers. The new formalisms are called CNDO/2H and MINDO/3H. A general discussion of the nature of hydrogen bonding as exhibited by CNDO/2H and MINDO/3H is presented.
Soap opera viewing motivations and the cultivation process

Previous research of possible cultivation effects of television viewing has ignored television viewing motivations as possible variables in the construction of a “television world view.” Results of the present survey of 265 college student soap opera viewers revealed that the interaction of soap opera exposure and viewing motivations better explains cultivation effects based on soap opera content. Viewers who frequently and ritualistically select soap operas as an undemanding activity may be most vulnerable to the genre's messages.
ASHP guidelines on emergency medicine pharmacist services.

Emergency medicine (EM) is an ever-changing, rapidly evolving practice specialty. The formal emergency department (ED) has its roots in the 1950s, when full-time emergency services were established in the United States.[1][1] Since then, the rate of mortality from accidental and traumatic injuries
Non-cell-autonomous stimulation of stem cell proliferation following ablation of Tcf3

Abstract A combination of cell intrinsic factors and extracellular signals determine whether mouse embryonic stem cells (ESC) divide, self-renew, and differentiate. Here, we report a new interaction between cell intrinsic aspects of the canonical Wnt/Tcf/β-catenin signaling pathway and extracellular Lif/Jak/Stat3 stimulation that combines to promote self-renewal and proliferation of ESC. Mutant ESC lacking the Tcf3 transcriptional repressor continue to self-renew in the absence of exogenous Lif and through pharmacological inhibition of Lif/Jak/Stat3 signaling; however, proliferation rates of TCF3−/− ESC were significantly decreased by inhibiting Jak/Stat3 activity. Cell mixing experiments showed that stimulation of Stat3 phosphorylation in TCF3−/− ESC was mediated through secretion of paracrine acting factors, but did not involve elevated Lif or LifR transcription. The new interaction between Wnt and Lif/Jak/Stat3 signaling pathways has potential for new insights into the growth of tumors caused by aberrant activity of Wnt/Tcf/β-catenin signaling.
The Crosspoint-Queued switches with virtual crosspoint queueing

Scalable high speed routers and switches implemented with distributed units introduced a large RTT latency between the line cards and switch fabric, making the crosspoint buffer requirement impractical to provide 100% throughput for unbalanced traffic on combined input and crosspoint queued (CICQ) switches. Crosspoint Queued (CQ)-only switches remove this RTT latency by completely eliminating the need of flow control between the line cards and switch fabrics. This study shows that the CQ-only switches are prone to frequent packet loss in unbalanced traffic common to realistic Internet traffic. CQ switches with virtual crosspoint queues (VCQs) is proposed and investigated to minimize this problem. Each of VCQs unit associated with a set of CPs with the same upstream link functions as a dynamically sharable buffer that can maximize the use of its limited memory space inside the switch fabric. Furthermore, the all memory units in the proposed switch operate at the line rate, making the implementation practical. Unlike the CICQ switch, the CQ switches with VCQs do not require flow control between the line card and switch fabric. Simulation results show that the CQ switch with VCQs can achieve high throughput for unbalanced traffic and significantly reduce packet loss pertinent to the CQ-only switch.
Metastasis development at the site of cervical spine arthrodesis.

Biologically, the site of arthrodesis provides a microenvironment replete of growth factors and active remodeling, which is propitious for bone regrowth. There is a theoretical possibility though that this microenvironment would also provide a fertile site for metastatic deposits to occur. Although spinal fusion with various types of instrumentation is commonly used to treat various disorders, development of tumors at the site of spinal arthrodesis has not been previously reported. We present the clinical, radiographic, and pathological features of a case of previously undiagnosed metastatic adenocarcinoma, occurring 1 year following anterior arthrodesis and fusion for cervical spondylotic myelopathy at the C3–C4 level. The patient’s initial radiologic presentation suggested an epidural abscess with osteomyelitic destruction of C3 and C4. Our report alerts surgeons to the possibility that metastasis may occur at the site of a previous spinal arthrodesis.
An environment for learning interactive programming

We describe a web-based programming environment designed to support teaching introductory programming for a massive open online class. We discuss some of the thought processes behind the design of this environment and then focus on two key innovations incorporated in our environment: a simplified GUI library for interactive Python programming and a browser-based tool for visualizing the execution of event-driven Python programs.
Time-constrained reasoning under uncertainty

Dynamic classification problems present unique challenges beyond those of more traditionalstatic knowledge-based systems. Uncertain and incomplete input data, unpredictable event sequences, and critical time and resource constraints require new approaches and techniques for automated reasoning. Our work toward addressing these complex requirements has concentrated on developing an integrated software architecture which supports the knowledge engineering process from development to deployment. The approach we are using to deal with real-time issues in the deployment environment involves the use of a fast knowledge representation scheme, efficient forward and backward chaining mechanisms, and a meta-controller which handles asynchronous inputs, prioritized task requests, and hard performance deadlines.
An algorithm for converting the boundary representation of a CAD model to its octree representation

Abstract Present CAD systems store the solid model of an object using a convenient representation. Boundary models and CSG (Constructive Solid Geometry) models are the most frequently used representations. Based on recent research findings, octree representation of an object presents a promising approach in solving problems in the areas of Computer Graphics, Manufacturing and Robotics. The most notable use of octree representations is in CAD-based robotic path planning problems. Octree models have also been used in fast rendering of 3-D solid models using ray tracing methods. This paper presents an algorithm for converting the boundary representation of polyhedral models to its octree representation. Such an algorithm would provide the link between an object generated using a solid modelling system and the application involving an octree representation of an object. The algorithm is demonstrated by converting a polyhedral boundary model of a sample object to its octree representation.
The surface compartment model: a theory of ion transport focused on ionic processes in the electrical double layers at membrane protein surfaces.

Abstract This paper is a review of the surface compartment model of ion flow across the channels of natural membranes. The model emphasizes the role of electrical double layers in ion transport and is derived from first principles. When the surface compartment model is applied to the membrane of an excitable cell, (e.g., the squid axon), one can calculate voltage clamp currents that are similar to those observed in the sodium and potassium channels of excitable membranes. The difference in the selectivity of the two types of ion channel appears to be determined by the differences in gating current, and is in line with measurements on the sodium and potassium channels of squid axon. These results indicate that there is a kinetic basis for the selectivity of voltage gated channels and suggest that other types of channels may operate by related mechanisms. The focus of the surface compartment model on charged surfaces has led to a description of the channel opening/closing process in terms of surface free energy, assuming an analogy to the aggregation/disaggregation reactions in oligomeric proteins. The opening of voltage gated oligomeric channels can be formulated in terms of variations in the surface free energy that are triggered by changes in the surface charge density. On this basis, it is possible to introduce gating phenomena into the surface compartment model and to couple the channel processes with charge movements.
First prize. Central motor excitability changes after spinal manipulation: A transcranial magnetic stimulation study

Abstract Background: The physiologic mechanism by which spinal manipulation may reduce pain and muscular spasm is not fully understood. One such mechanistic theory proposed is that spinal manipulation may intervene in the cycle of pain and spasm by affecting the resting excitability of the motoneuron pool in the spinal cord. Previous data from our laboratory indicate that spinal manipulation leads to attenuation of the excitability of the motor neuron pool when assessed by means of peripheral nerve Ia-afferent stimulation (Hoffmann reflex). Objective: The purpose of this study was to determine the effects of lumbar spinal manipulation on the excitability of the motor neuron pool as assessed by means of transcranial magnetic stimulation. Methods: Motor-evoked potentials were recorded subsequent to transcranial magnetic stimulation. The motor-evoked potential peak-to-peak amplitudes in the right gastrocnemius muscle of healthy voulunteers (n = 24) were measured before and after homolateral L5-S1 spinal manipulation (experimental group) or side-posture positioning with no manipulative thrust applied (control group). Immediately after the group-specific procedure, and again at 5 and 10 minutes after the procedure, 10 motor-evoked potential responses were measured at a rate of 0.05 Hz. An optical tracking system (OptoTRAK, Northern Digital Inc, Waterloo, Canada [
Frog pond: a codefirst learning environment on evolution and natural selection

Understanding processes of evolution and natural selection is both important and challenging for learners. We describe a "codefirst" learning environment called Frog Pond designed to introduce natural selection to elementary and middle school aged learners. Learners use NetTango, a blocksbased programming interface to NetLogo, to control frogs inhabiting a lily pond. Simple programs result in changes to the frog population over successive generations. Our approach foregrounds computational thinking as a bridge to understanding evolution as an emergent phenomenon.
Gastrointestinal Temperature Increases and Hypohydration Exists After Collegiate Men's Ice Hockey Participation

The cold environments in which ice hockey players participate are counterintuitive to the predisposing factors of heat- and hypohydration-related illnesses. This population has received little consideration in hypohydration-related illness risk assessments. Protective equipment, multiple clothing layers, and performance intensity may predispose these athletes to significant decreases in hydration and increases in core temperature. The purpose of this study was to measure hydration status and gastrointestinal temperature (TGI) in male ice hockey players during practice sessions that focused on preseason skill development and cardiovascular conditioning. The study used a repeated measures design. Data were collected in a collegiate ice hockey rink (ambient temperature = 6.03 ± 1.65° C; relative humidity = 40.4 ± 11.89%). Seventeen ice hockey players (age = 20.6 ± 1.1, height = 180 ± 5 cm, mass = 85.04 ± 7.9 kg) volunteered for this study. Urine-specific gravity (USG) and body weight were measured before and after two 110-minute practice sessions. Urine reagent strips measured USG. Calibrated CorTemp (HQ, Inc., Palmetto, FL, USA) radiofrequency telemetered thermometers collected TGI before, during, and after two 110-minute practice sessions. Individual participant sweat rates were calculated. Data from both sessions were pooled. TGI (p < 0.0001), and USG (p < 0.0001) increased over the 110-minute session. Post-exercise body weight (83.9 ± 7.6 kg) was statistically lower (p < 0.001) than the pre-exercise weight (85.0 ± 7.9 kg). Sweat rates were calculated to be 0.83 ± 0.50 L·h-1. These male ice hockey players become hypohydrated during participation potentially predisposing them to dehydration-related illnesses. This change in hydration status resulted in a gastrointestinal temperature increase and significant weight loss during activity. Prevention and rehydration strategies such as those developed by the American College of Sports Medicine and National Athletic Trainers' Association should be implemented to reduce the possibility of heat-related illness for this population.
Photoaffinity labelling of the Ah receptor.

A series of halodibenzo-p-dioxins bearing the arylazide photolabile functional group were synthesized and tested as photoaffinity labels for the Ah receptor. 2-Azido-3-iodo-7,8-dibromodibenzo-p-dioxin (Kd = 0.76 × 10−9m) was selected for radiosynthesis. Analysis of the 125I-photoaffinity-labelled proteins in mouse-liver cytosol by denaturing gel electrophoresis revealed two peptides which had apparent molecular masses of 95,000 and 70,000 daltons respectively, were labelled in an approximately 1:1 ratio and were selectively labelled at low concentrations of the photoaffinity ligand (0.05 Kd = 0.04 × 10−9m). In addition, their labelling was inhibited by co-incubation with an excess of unlabelled ligand. On chromatographic separation under non-denaturing conditions, these two peptides co-migrated. These studies suggest that the Ah receptor in mouse liver cytosol is a heterodimer composed of two non-covalently bound peptides (95 K and 70 K) which each have a ligand binding site.
Multiple-feed, pure-product separation system synthesis

Abstract The multiple-feed, pure-product separation system synthesis problem is identified as a distinct subproblem of process synthesis. The combinatorial structure of the problem is examined; analytic expressions are found for the resulting numbers of possible distinct intermediate streams and separators. The number of separators increases polynomially with the number of components, but exponentially with the number of feed streams. This limits exhaustive solution methods such as dynamic programming to small instances of this problem. A general approximate solution method is presented which is based on a pseudo-random search technique. The structure of the problem leads to a conceptually simple method of flowsheet selection. Very good flowsheets are found with a reasonable sample size. Due to the absence of shortcut methods for evaluating multiple-feed separators, we used a process simulator to find the cost of the candidate flowsheets.
Organizing: Structure and Methodology

This article surveys the nature and aspects of structuring organization in a Muslim environment. It presents several questions and provides preliminary answers from Islamic perspectives. The article reflects on the current literature on management and examines the evolution of organizing in the early centuries of Islam. The article asserts that, though structures may seem similar across cultures, each culture gives different meanings to structural arrangements. The article also presents four forms of organization that are prevalent in Muslim countries. It is argued that the concept and practice of ehsan and Islamic general assumptions on organization offer practical guidelines for structuring and designing organizations more responsive to national culture and changing market conditions.
Magnetic Sources of the Solar Irradiance Cycle

Using recently processed Ca K filtergrams, recorded with a 1 A filter at the Big Bear Solar Observatory (BBSO), we quantitatively assess the component of solar irradiance variability attributable to bright magnetic features on the Sun's disk. The Ca K filtergrams, flattened by removing instrumental effects and center-to-limb variations, provide information about bright sources of irradiance variability associated with magnetic activity in both active regions and dispersed active region remnants broadly distributed in the supergranule network (termed collectively faculae). Procedures are developed to construct both total and UV spectral solar irradiance variations explicitly from the processed Ca K filtergrams, independently of direct irradiance observations. The disk-integrated bolometric and UV facular brightness signals determined from the filtergrams between late 1991 and mid-1995 are compared with concurrent solar irradiance measurements made by high-precision solar radiometers on the Upper Atmosphere Research Satellite (UARS). The comparisons suggest that active-region and active-network changes can account for the measured variations. This good agreement during a period covering most of the decline in solar activity from the cycle 22 maximum to the impending solar minimum directly implicates magnetic features as the sources of the 11 yr irradiance cycle, apparently obviating the need for an additional component other than spots or faculae.
Specific heat of solid deuterium in the region of the proposed rotational glass phase

Abstract The specific heat of solid deuterium of 33% paradeuterium concentration has been measured for 1 K > T > 0.115K by a thermal relaxation technique. No evidence of a phase transition was found in the samples in the temperature range associated with the molecular rotational glass phase. No thermal remanence effects were observed for characteristic measurements times greater than 30 seconds. Integration of the specific heat indicates that rotational entropy of the solid below 0.35 Kelvin equals about 10% of the free rotator entropy, in agreement with ∂P/∂T) V studies of solid H 2 .
Neutrino backgrounds to dark matter searches

Neutrino coherent scattering cross sections can be as large as ${10}^{\ensuremath{-}39}\text{ }\text{ }{\mathrm{cm}}^{2}$, while current dark matter experiments have sensitivities to WIMP coherent scattering cross sections 5 orders of magnitude smaller; future experiments plan to have sensitivities to cross sections as small as ${10}^{\ensuremath{-}48}\text{ }\text{ }{\mathrm{cm}}^{2}$. With large target masses and few keV recoil energy detection thresholds, neutral current coherent scattering of solar neutrinos becomes an irreducible background in dark matter searches. In the current zero-background analysis paradigm, neutrino coherent scattering will limit the achievable sensitivity to dark matter scattering cross sections, at the level of ${10}^{\ensuremath{-}46}\text{ }\text{ }{\mathrm{cm}}^{2}$.
Comparison of clinician judgment with digitized image analysis in the detection of induced optic disk change in monkey eyes.

Purpose To compare the ability of clinicians to detect change in the photographic appearance of the optic disk with the performance of a system for digitized image analysis. Methods In 11 monkey eyes, a Topcon Imagenet System was used to acquire eight digitized image pairs and four stereoscopic photographs at an intraocular pressure of 10 mm Hg, and then, again, 45 minutes after intraocular pressure was increased to 45 mm Hg. We recently reported detection of global (ten of 11 eyes) and regional (11 of 11 eyes) change in the digitized images of these eyes by using two new statistical strategies for optic disk analysis. For the current study, we evaluated the ability of three clinicians (the authors) to detect a change within the stereoscopic photographs of these 11 optic disks. For each eye, the eight stereoscopic photographs (four at intraocular pressure of 10 mm Hg and four at intraocular pressure of 45 mm Hg) were developed as stereoscopic slides and arranged into four pairs (10/10, 45/45, 10/45, and 45/10 mm Hg). Thus, two pairs represented no change in intraocular pressure (10/10 and 45/45 mm Hg) and the other two pairs represented either an increase or a decrease in intraocular pressure (10/45 and 45/10 mm Hg). The 44 pairs of stereoscopic slides (four pairs for each of 11 eyes) were masked then randomly mixed. On two separate occasions, each clinician evaluated each pair of stereoscopic slides for the presence or absence of optic disk change. Results Reproducibility between the two readings of each clinician ranged from .50 to .64 (kappa statistic). Clinicians correctly detected change (as detected by image analysis) within 45% to 64% of the 10/45 and 45/10 pairs of stereoscopic slides. Clinicians correctly identified no change within 86% to 100% of the 10/10- and 45/45-mm Hg pairs of stereoscopic slides. Clinicians correctly identified no change significantly more often than change (P 2 test). Change was not detected consistently by all three clinicians in any of the 11 eyes. Conclusion In a controlled experimental setting, digitized image acquisition with extensive secondary statistical analysis more sensitively detected small short-term changes in the surface of the optic disks of monkeys than did three masked clinicians.
Brain tissue potassium in normal and potassium depleted rats.

Abstract The potassium concentration of muscle, brainstem and diencephalon were studied in normal and potassium-depleted rats. With 13% depletion of muscle potassium there was a 2.1% and 2.8% decrease in brainstem and diencephalon tissue potassium respectively. With 34% depletion of muscle potassium there was a 1.9% and 4.0% decrease in brainstem and diencephalon tissue potassium. These small decreases in regional brain tissue potassium could be related to observed functional alterations in the potassium depleted rat, i.e., altered cerebrospinal fluid bicarbonate regulation and altered control of the pattern of breathing and of body temperature regulation.