cssi/SciSciGPT-SciSciNet huggingface dataset:
INFLUENCE OF AN ELECTRIC FIELD ON DIAPHRAGM STABILITY AND VIBRATION IN A CONDENSER MICROPHONE

Abstract The electric field due to the constant bias voltage between the diaphragm and the base plate of a condenser microphone introduces a deflection load intensity on the diaphragm. Since this load intensity increases with deflection, the electric field has a destabilizing influence on the plate vibration. Considering the diaphragm as a clamped circular plate, the dependence of the steady deflection and the natural vibration of the plate on the strength of the electric field is investigated. The analysis shows that as the field strength increases, the steady deflection also increases and reaches a neutral equilibrium state corresponding to a critical value of the field strength. Any further increase in the field strength buckles the diaphragm on to the base plate. The electric field decreases the fundamental natural frequency of vibration which approaches zero as the field strength reaches its critical value.
Using multiscale preconditioning to accelerate the convergence of iterative molecular calculations

Iterative procedures for optimizing properties of molecular models often converge slowly owing to the computational cost of accurately representing features of interest. Here, we introduce a preconditioning scheme that allows one to use a less expensive model to guide exploration of the energy landscape of a more expensive model and thus speed the discovery of locally stable states of the latter. We illustrate our approach in the contexts of energy minimization and the string method for finding transition pathways. The relation of the method to other multilevel simulation techniques and possible extensions are discussed.
Primary sternal plating in high-risk patients prevents mediastinitis.

Objective Sternal wound infection leading to post-operative mediastinitis is a devastating complication of cardiac surgery carrying nearly a 15% mortality rate despite current treatment methods. Instability of bone fragments pre-disposes a patient to have non-union, mal-union and can subsequently lead to deep sternal wound infections progressing to mediastinitis. Rigid plate fixation has been utilized for acquired and surgically created fractures of virtually every bone in the body to prevent instability. However, the current standard for sternotomy closure remains the method of wire-circlage. Application of rigid plate fixation for sternal osteotomies affords greater stability of the sternum. We report on our preliminary experience with this technique in high-risk patients. Methods From July of 2000 to December 2001, rigid plate fixation was applied to 45 patients designated as having high risk for sternal dehiscence and subsequent mediastinitis. High risk was defined as patients having 3 or more established historical risk factors, including: COPD, Re-Operative Surgery, Renal Failure, Diabetes, Chronic Steroid Use, Morbid Obesity, Concurrent Infection and Acquired or Iatrogenic Immunosuppression. Intra-operative risk factors included off-midline sternotomy, osteoporosis, long cardio-pulmonary bypass runs (>2 h), transverse fractures of the sternum. Rigid plate fixation was performed using a combination of plates secured by bi-cortical screws, after the cardiac surgical procedure was complete and hemostasis was secured. Results Rigid plate fixation was performed on 26 males and 19 females. The average age of patients was 63 (43-88) years. The average follow-up was 15 weeks (range 8-41 weeks). While there were 4 peri-operative deaths unrelated to sternal closure: one from aspiration pneumonia (post-operative day 9), one from a pulmonary embolus (post-operative day 29), one from overwhelming sepsis from pre-existing endocarditis (post-operative day 15), and one for primary respiratory failure (post-operative day 12). All others healed successfully. One patient who had a sterile dehiscence subsequently underwent successful re-operative rigid fixation. Comparing the cohort of patients who received rigid plate fixation to a matched population of high-risk patients during a similar time period who received wire closure, revealed a significant difference in the incidence of post-operative mediastinitis. The wire closed group (n = 207) had 18 deaths unrelated to sternal closure and had 28 patients who developed mediastinitis (14.8%). The rigid plate fixation group had no mediastinitis (Fisher's exact test, P = 0.006). The total incidence of post-operative mediastinitis during the designated study period was 4.2%. Conclusion Patients who benefited from sternal closure with rigid plate fixation showed a significant decrease in the incidence of post-operative mediastinitis when compared to similar population of patients whose sterna were closed with wire.
Research-centric project-based learning of optomechanical design

In the Spring Semester of 2011, Univ. of Central Florida's CREOL introduced an elective course in Optomechanical Design. In addition to homework assignments and exams, one component of the course grade was a design project. Rather than the traditional "assigned" project, the instructor experimented with a novel research-centric approach. Specifically, students were asked to select a project directly applicable to their graduate research. While challenging for the instructor to grade, student motivation and performance remained exceptionally high throughout the semester. This paper summarizes the background, projects, and pedagogical benefits of such a research-centric approach to project-based learning.
Process semantics: universal axioms compositional rules, and applications

We present a set of global axioms and compositional rules for describing the semantics of concurrent processes. In our semantic model, a process is defined by a set of partially-ordered traces on ports. The global axioms serve to rule out pathological processes. The compositional rules are used to derive semantics of composite processes from the semantics of their component processes. We prove that the global axioms are preserved by the compositional rules. A sound and complete proof system for our semantics is given. Finally, we apply the semantic model to give a formal definition of a concurrent language with dynamic process creation and dynamic port bindings.
Familial aggregation of left main coronary artery disease and future risk of coronary events in asymptomatic siblings of affected patients

We thank Dr Patel et al. for their kind interest in our manuscript. Indeed, we agree with the authors that manifestation of atherosclerosis is anatomically diffuse and as such modulated by several, including heritable, risk factors. Also, their notion that left main disease (LMD) is rarely an isolated phenomenon but rather occurs in addition to disease manifestation at other branches of the coronary tree is concordant with our results. Based on their clinical observations, Dr Patel et al. argue that the heritability of LMD is a surrogate of heritability of severe coronary artery disease (CAD) rather than a result from distinct heritable predisposition. They further conclude that coincidence of …
Computational aspects of mining maximal frequent patterns

In this paper we study the complexity-theoretic aspects of mining maximal frequent patterns, from the perspective of counting the number of all distinct solutions. We present the first formal proof that the problem of counting the number of maximal frequent itemsets in a database of transactions, given an arbitrary support threshold, is #P-complete, thereby providing theoretical evidence that the problem of mining maximal frequent itemsets is NP-hard. We also extend our complexity analysis to other similar data mining problems that deal with complex data structures, such as sequences, trees, and graphs. We investigate several variants of these mining problems in which the patterns of interest are subsequences, subtrees, or subgraphs, and show that the associated problems of counting the number of maximal frequent patterns are all either #P-complete or #P-hard.
Kinetochores capture astral microtubules during chromosome attachment to the mitotic spindle: direct visualization in live newt lung cells.

When viewed by light microscopy the mitotic spindle in newt pneumocytes assembles in an optically clear area of cytoplasm, virtually devoid of mitochondria and other organelles, which can be much larger than the forming spindle. This unique optical property has allowed us to examine the behavior of individual microtubules, at the periphery of asters in highly flattened living prometaphase cells, by video-enhanced differential interference-contrast light microscopy and digital image processing. As in interphase newt pneumocytes (Cassimeris, L., N. K. Pryer, and E. D. Salmon. 1988. J. Cell Biol. 107:2223-2231), centrosomal (i.e., astral) microtubules in prometaphase cells appear to exhibit dynamic instability, elongating at a mean rate of 14.3 +/- 5.1 microns/min (N = 19) and shortening at approximately 16 microns/min. Under favorable conditions the initial interaction between a kinetochore and the forming spindle can be directly observed. During this process the unattached chromosome is repeatedly probed by microtubules projecting from one of the polar regions. When one of these microtubules contacts the primary constriction the chromosome rapidly undergoes poleward translocation. Our observations on living mitotic cells directly demonstrate, for the first time, that chromosome attachment results from an interaction between astral microtubules and the kinetochore.
A Close Association of RyRs with Highly Dense Clusters of Ca2+-activated Cl− Channels Underlies the Activation of STICs by Ca2+ Sparks in Mouse Airway Smooth Muscle

Ca2+ sparks are highly localized, transient releases of Ca2+ from sarcoplasmic reticulum through ryanodine receptors (RyRs). In smooth muscle, Ca2+ sparks trigger spontaneous transient outward currents (STOCs) by opening nearby clusters of large-conductance Ca2+-activated K+ channels, and also gate Ca2+-activated Cl− (Cl(Ca)) channels to induce spontaneous transient inward currents (STICs). While the molecular mechanisms underlying the activation of STOCs by Ca2+ sparks is well understood, little information is available on how Ca2+ sparks activate STICs. In the present study, we investigated the spatial organization of RyRs and Cl(Ca) channels in spark sites in airway myocytes from mouse. Ca2+ sparks and STICs were simultaneously recorded, respectively, with high-speed, widefield digital microscopy and whole-cell patch-clamp. An image-based approach was applied to measure the Ca2+ current underlying a Ca2+ spark (ICa(spark)), with an appropriate correction for endogenous fixed Ca2+ buffer, which was characterized by flash photolysis of NPEGTA. We found that ICa(spark) rises to a peak in 9 ms and decays with a single exponential with a time constant of 12 ms, suggesting that Ca2+ sparks result from the nonsimultaneous opening and closure of multiple RyRs. The onset of the STIC lags the onset of the ICa(spark) by less than 3 ms, and its rising phase matches the duration of the ICa(spark). We further determined that Cl(Ca) channels on average are exposed to a [Ca2+] of 2.4 μM or greater during Ca2+ sparks. The area of the plasma membrane reaching this level is <600 nm in radius, as revealed by the spatiotemporal profile of [Ca2+] produced by a reaction-diffusion simulation with measured ICa(spark). Finally we estimated that the number of Cl(Ca) channels localized in Ca2+ spark sites could account for all the Cl(Ca) channels in the entire cell. Taken together these results lead us to propose a model in which RyRs and Cl(Ca) channels in Ca2+ spark sites localize near to each other, and, moreover, Cl(Ca) channels concentrate in an area with a radius of ∼600 nm, where their density reaches as high as 300 channels/μm2. This model reveals that Cl(Ca) channels are tightly controlled by Ca2+ sparks via local Ca2+ signaling.
Comparison of two ventricular assist device dressing change protocols.

Despite the decreased infection rate with contemporary, continuous-flow ventricular assist devices (VADs), driveline infections remain problematic. Daily dressing changes have been postulated to be an important factor in minimizing the rate of infections but pose a substantial burden to patients and caregivers. A novel technique featuring dressing changes every third day has been described by the Utah Artificial Heart Program, Intermountain Healthcare (permission was obtained from Utah Artificial Heart Program), but the two methods have not been directly compared within a single program. A pilot project testing the Utah protocol was performed and we subsequently performed a retrospec-
99mTc Pertechnetate Scans of Posterior Fossa Tumors in Children Some Examples of Its Practical Utility

99mTechnetium as pertechnetate has proven to be safe, rapid and reliable in our experience in posterior fossa scanning. Even in relatively avascular cysts or cystic tumors there can be visualization. The relative uptake of 99mTc provides an in dication of vascularity and, indirectly, of relative malignancy.
The False Lock Performance of Costas Loops with Hard-Limited In-Phase Channel

The ability of a Costas loop to false lock on a data sideband is a problem which must be dealt with in the design of suppressedcarrier receivers which employ such loops for carrier reconstruction. For conventional Costas loops wherein the error signal is formed from the product of two analog signals, the false lock problem has recently been investigated by the author and others and is now well understood. For implementation reasons associated with the reduction of dc offsets, it is often desirable to hard limit the output of the in-phase channel and replace the analog multiplier which forms the above product with a chopper-type device. The false lock behavior of such a Costas loop with hard-limited in-phase channel is quite different from that of the conventional Costas loop and is the subject of investigation in this paper. Results are also presented for a modified version of the Costas loop wherein the quadrature arm filter is removed. This configuration has recently been suggested as a means of improving the false lock performance of the Costas loop with hard-limited in-phase channel.
Export composition and growth of selected low-income African countries: evidence from time-series data

This paper examines the hypothesis that economic growth is linked to export composition with the use of time-series data for some low-income African countries. On the basis of the regression results, the study supports the hypothesis of a positive linkage between the growth of non-fuel primary exports and growth. However, the results cast some doubt on the significance of the positive contribution of the manufactured exports sector to the growth process of the low-income African countries.
A Simple Sensor for Potentiometric Titrations

Abstract A sensor for potentiometric titrations was prepared by coating a spectroscopic graphite rod with a solution of poly(vinyl chloride) and dioctylphthalate in tetrahydrofuran. The reference was a Ag/AgCl single-junction electrode. The sensor was used in the following potentiometric titrations: 1. precipitation titrations 2. acid-base titrations, 3. compleximetric titrations, and 4. redox titrations. A survey of its use in such titrations is presented. Preparation of the coated-graphite sensor is simple and rapid. Moreover, it is quite inexpensive. A limitation is its applicability in aqueous media only, because organic solvents will dissolve the membrane.
Interdisciplinary Chronic Pain Management Programs

The clinical literature has shown that no single health care specialty is able to meet the needs of the majority of patients who suffer from chronic pain. American society and government are increasingly asking that health professionals address the needs of patients and are placing more emphasis on the management of pain. However, they are also challenging us to document the effectiveness of our efforts and to provide care in a cost-effective manner. In 1979 the American Society of Anesthesiology developed a classification system of pain centers: the major comprehensive pain center, comprehensive pain center, syndrome-oriented pain center, and the modality-oriented pain center. Each type of pain center has different resources available to meet patient needs. Pain centers have been documented in some studies to provide effective management of chronic pain problems. However, many studies suffer from defects including limited patient information, a lack of control groups, the weaknesses of the pain measureme...
Familial hypercholesterolemia in children and adolescents: A clinical perspective.

Familial hypercholesterolemia (FH) is an autosomal dominant disorder of low-density lipoprotein (LDL) metabolism leading to high LDL cholesterol (LDL-C) and accelerated atherosclerosis. The rare homozygous form is associated with physical examination findings and coronary heart disease during childhood. The more common heterozygous form (hetFH) is asymptomatic until adulthood, when those affected develop premature cardiovascular disease (CVD) events, often in early adulthood. Identification of hetFH is key because of the relatively high prevalence, 1 in 200 to 500, and the opportunity to lower LDL-C and reduce CVD outcomes. Selective screening based on family history can identify affected individuals, but many with hetFH are missed by relying on this strategy and go undiagnosed during childhood, leading to the recommendation by the National Heart, Lung, and Blood Institute Expert Panel for universal lipid screening between ages 9 and 11 y and again at ages 17 to 21 y. Diagnosis should lead to treatment with lifestyle modification and pharmacotherapy when appropriate because lowering LDL-C in youth has beneficial effects on subclinical atherosclerosis and likely reduces premature CVD events. This article reviews what is known about the epidemiology and pathophysiology of FH as it relates to the care of children and adolescents. Approaches to identification and treatment of FH during childhood are presented, including both recommendations from published guidelines and clinical experience. A clinical case is used to illustrate various points.
Building competitive advantage through information systems: the organizational information quotient

Information systems (IS) have significant potential for making quantum leaps in productivity, increasing the ability to compete, and maintaining sustainable competitive advantage. However, much of that potential remains to be achieved.This paper uses dynamic case analysis and survey data to identify the critical success elements found in effective use of IS. These foundational elements are then integrated into a framework for innovatively deploying IS for sustainable competitive advantage. Common pitfalls are examined. Finally, a measure of the effective implementation of IS, information quotient (IQ), is proposed.Results of this analysis are five fundamental mandates that form the basis for effective and innovative IS deployment for sustainable competitive advantage through advancement of organizational IQ. The IS of the future as prescribed here will promote both environmental responsiveness and strategic cohesiveness by providing internal and external intelligence to information processing.
Homoclinic orbits and chaos in a second-harmonic generating optical cavity

Abstract We present two large families of Silnikov-type homoclinic orbits in a two-mode model that describes second-harmonic generation in a passive optical cavity. These families of homoclinic orbits give rise to chaotic dynamics in the model.
Rescue of volume-regulated anion current by bestrophin mutants with altered charge selectivity.

Mutations in human bestrophin-1 are linked to various kinds of retinal degeneration. Although it has been proposed that bestrophins are Ca2+-activated Cl− channels, definitive proof is lacking partly because mice with the bestrophin-1 gene deleted have normal Ca2+-activated Cl− currents. Here, we provide compelling evidence to support the idea that bestrophin-1 is the pore-forming subunit of a cell volume-regulated anion channel (VRAC) in Drosophila S2 cells. VRAC was abolished by treatment with RNAi to Drosophila bestrophin-1. VRAC was rescued by overexpressing bestrophin-1 mutants with altered biophysical properties and responsiveness to sulfhydryl reagents. In particular, the ionic selectivity of the F81C mutant changed from anionic to cationic when the channel was treated with the sulfhydryl reagent, sodium (2-sulfonatoethyl) methanethiosulfonate (MTSES−) (PCs/PCl = 0.25 for native and 2.38 for F81C). The F81E mutant was 1.3 times more permeable to Cs+ than Cl−. The finding that VRAC was rescued by F81C and F81E mutants with different biophysical properties shows that bestrophin-1 is a VRAC in S2 cells and not simply a regulator or an auxiliary subunit. F81C overexpressed in HEK293 cells also exhibits a shift of ionic selectivity after MTSES− treatment, although the effect is quantitatively smaller than in S2 cells. To test whether bestrophins are VRACs in mammalian cells, we compared VRACs in peritoneal macrophages from wild-type mice and mice with both bestrophin-1 and bestrophin-2 disrupted (best1−/−/best2−/−). VRACs were identical in wild-type and best1−/−/best2−/− mice, showing that bestrophins are unlikely to be the classical VRAC in mammalian cells.
Evolution and influence of military adult education

This chapter reviews the historical relationship between adult education and the military and continuing efforts by the military to emphasize adult learning principles in training and education.
Heritable variation in courtship patterns in Drosophila melanogaster.

Little is known about the genetic basis of naturally occurring variation for sexually selected behavioral traits. Drosophila melanogaster, with its rich repertoire of courtship behavior and genomic and genetic resources, is an excellent model organism for addressing this question. We assayed a genetically diverse panel of lines with full genome sequences, the Drosophila Genetic Reference Panel, to assess the heritability of variation in courtship behavior and mating progression. We subsequently used these data to quantify natural variation in transition probabilities between courtship behaviors. We found heritable variation along the expected trajectory for courtship behaviors, including the tendency to initiate courtship and rate of progression through courtship, suggesting a genetic basis to male modulation of courtship behavior based on feedback from unrelated, outbred, and genetically identical females. We assessed the genetic basis of variation of the transition with the greatest heritability—from copulation to no engagement with the female—and identified variants in Serrate and Furin 1 as well as many other polymorphisms on the chromosome 3R associated with this transition. Our findings suggest that courtship is a highly dynamic behavior with both social and genetic inputs, and that males may play an important role in courtship initiation and duration.
Modeling the Effects of Capillary Property of Porous Media on the Performance of the Cathode of a PEMFC

A two-phase model was developed to study the impact of the capillary property of the gas diffusion (GDL) and catalyst layers (CL) and the saturation-level jump condition at the interface between these two dissimilar materials on the liquid water transport rate and the liquid water saturation levels in these porous layers and the performance of the cathode of a proton exchange membrane fuel cell (PEMFC). The study involves adjusting various aspects of the capillary curves of these porous layers and studying how these changes affect the cathode electrochemical performance to identify the most sensitive aspects. The simulated results show that fuel cell performance and the liquid water saturation levels in the CL and GDL depend on both the individual two-phase properties of these components and their interactions at the GDL/CL interface. The boundary condition at the GDL/ channel interface for saturated air operation constrains the transport phenomenon in the GDL and CL to the hydrophobic regions of the capillary pressure curves. It was also found that capillary properties of the GDL had a more significant effect on the fuel cell performance than those of the CL, and better fuel cell performance was obtained with GDL and CL with high capillary diffusion capability and low hydrophilic porosity.
The Potential Role of Spirituality in Conducting Field Research: Examination of a Model and a Process

The Cognitive-Experiential Tri-Circle is a model developed by the author to explain the relationship between conducting field research and reflecting on beliefs, including spiritual beliefs. His sample included graduate students, faculty, and friends of the university who participated in field research trips to Cuba through Loyola University Chicago. The basic assumption of the model is that "self," "beliefs," and "experience" are related in such a way that "depth" applies to each equally in a field research experience. Depth of experience for the self leads to depth of belief for the self. Reflection tools that encourage depth of belief for the self lead to depth of experience for the self. The author designed a particular method for processing or "reflection" which he used with participants on these trips. He also discusses at length the philosophical issues involved in this topic. The paper concludes that the processing method was effective and that the model is applicable to field research experiences.
Phase-contrast serial time-encoded amplified microscopy

Real-time multi-dimensional optical imaging is of paramount value for observation of fast non-repetitive dynamic processes such as shockwaves and fluid dynamics. They also have important biomedical applications such as flow cytometry [1], neural networks, and cell signaling [2]. Unfortunately, conventional CCD or CMOS cameras are incapable of observing fast dynamics with high sensitivity and resolution. This is due to a technological limitation - it takes time to read out the data from sensor arrays, as well as the fundamental trade-off between sensitivity and frame rate - a predicament that affects all imaging systems. The latter is simply due to the fact that at high frame rates, fewer photons are collected during each frame leading to loss of signal-to-noise ratio.
Utilizing home node prediction to improve the performance of software distributed shared memory

Summary form only given. Many researchers use a home-based lazy release consistent protocol (HLRC) to provide a simple, effective, and scalable way to build software distributed shared memory (DSM) systems. However, the performance of HLRC is notoriously sensitive to the initial page distribution among home nodes. We propose an adaptive HLRC protocol in which the home page designation is able to change according to the observed application sharing pattern. Our system differs from HLRC and other adaptive derivatives in the following respects. First, the number of home nodes for each shared page can be varied, as opposed to having only a single home node. Second, we use prediction in a novel way to dynamically change the the location of home nodes according to different memory access patterns. The home node of each shared page is able to propagate, perish, and migrate. An online home predictor determine whether or not the current node should remain a home node or drop from the current set of home nodes for a given page. Finally, all decisions concerning home node group membership are made locally, eliminating the costly global decision-making communication present in many other systems. Performance evaluations using six well-known DSM benchmarks show that our adaptive protocol outperforms conventional HLRC by up to 60%.
Boolean division and factorization using binary decision diagrams

A method for performing Boolean division and factorization using a new cofactor operation, the interval cofactor, is proposed. This method Is efficiently implemented using BDD's and allows for the use of external and internal don't care sets. As well as generating a normal factored form, the method also generates an extended factored form that allows for the use of the exclusive-OR function in the expression. Using this extended form, much better factorizations may sometimes be found. The method was implemented in Catamount, a logic synthesis system currently under development. The method compares favorably to existing algebraic methods. >
Cancer Stem Cells in Glioblastoma

Glioblastoma multiforme (GBM) is the most common adult malignant brain tumor and is comprised of a heterogeneous population of cells. Despite advanced surgical and medical therapies, the 2-year survival rate for patients with GBM remain only 10–25%. Recently, increasing evidence suggest that the progression of GBM is driven by a small subpopulation of tumor cells, termed cancer stem cells. These cancer stem cells have capability of self-renewal, proliferation, and differentiation into the phenotypically diverse populations of cells similar to those present in the original GBM. Furthermore, these cancer stem cells are able to form tumors and generate both neuron-like and glial-like progenies after implantation into the brains of SCID mice. Here, we summarize the methods of isolating cancer stem cells from GMB, and discuss the implications of the cancer stem cell hypothesis for understanding the origin and growth of GBM and development of new therapeutic strategies for the treatment of brain tumors.
Synergistic effects of LTC4 and TxA2 on coronary flow and myocardial function

Accumulation of leukocytes and platelets in the injured myocardium may influence coronary arteriolar resistance via release of peptidoleukotrienes and thromboxane A2 (TxA2). Although leukotriene C4 (LTC4) and TxA2 individually reduce coronary blood flow, the effects of their simultaneous administration are not known. Accordingly, the combined effects of intracoronary administration of synthetic LTC4 and thromboxane "mimic" U 46619 on coronary blood flow in patent and severely narrowed coronary arteries and myocardial segmental function were examined in eight anesthetized dogs. Administration of LTC4 and U 46619 (0.3-3 micrograms) showed concentration-dependent reductions in coronary blood flow and myocardial segment shortening. When these eicosanoids (3 micrograms each) were administered in close sequence, coronary blood flow decreased 33% in the patent artery and 47% in the narrowed artery. This reduction in coronary blood flow in the narrowed coronary artery produced a 26% decrease in myocardial segment shortening. Reductions in narrowed coronary artery blood flow and myocardial segment shortening were greater than the sum of changes caused by LTC4 and U 46619 administered separately (P less than 0.05). The histopathology of the narrowed coronary artery revealed endothelial disruption at the site of occlusion and an in vivo thrombus just distal to the site of occlusion. These data suggest marked synergism between the actions of LTC4 and TxA2, which may be released locally at the site of coronary thrombus, on blood flow in a severely narrowed coronary artery, and on segmental function in the region supplied by this vessel.
A Scanning Probe and Quartz Crystal Microbalance Study of C 60 on Mica and Silver(111) Surfaces

Experimental investigations of friction, lubrication, and adhesion at nanometer length scales have traditionally been performed by employing scanning probe microscopy (SPM), surface forces apparatus, (SFA), or quartz crystal microbalance (QCM) techniques. While collectively these techniques have yielded much useful information, their results have never been mutually cross-referenced. In order to perform such a study, we have investigated the changes in interfacial friction of toluene on single crystal substrates in both the presence and absence of C60 adsorbed layers.
Boeing (B): No Nerds, No Birds Company Loyalty

This series of six cases (labeled A through F, UVA-E-0233 through UVA-E-0238) presents the various dilemmas that arose in the spring of 2001 when engineers at the Seattle-based Boeing Company, unhappy with management decisions, contemplated and undertook a strike, the first "white-collar" work stoppage in the history of American business.
Review Articles: Corporate Real Estate and Sustainable Competitive Advantage

This paper extends the growing literature on the role of corporate real estate (CRE) within the corporate strategy context and addresses the need to identify the degree to which CRE can be classified, and ultimately more efficiently exploited, as a strategic enterprise resource. The themes covered include identifying the underlying goal of corporate strategy as producing and sustaining competitive advantages; defining resources as strategic when they create firm-level entry barriers through isolating mechanisms; and identifying the criteria for determining CRE as a strategic, rather than purely operational, enterprise resource.
Behavioral Biases and Investor Behavior: Predicting the Next Step of a Random Walk (Revisited)

A recent paper by Bloomfield and Hales (2002) reports results of laboratory experiments with MBA-student participants that support the existence of regime-shifting beliefs of the type theorized by Barberis, Shleifer, and Vishny (1998). Specifically, they find a strong tendency for subjects to expect reversals in performance after seeing historical sequences with many reversals and to expect trending after seeing historical sequences with fewer reversals. We argue that the Bloomfield and Hales experiment does not provide a useful test of BSV because the set of sequences shown to subjects are not from a random walk process, but instead are more consistent with what would be expected if the true underlying process was of a regime-shifting type. A simple chi-square goodness of fit test based on the frequency of reversals strongly rejects that the set of sequences used in the experiment were generated by a random walk process. Furthermore, consistent with an underlying regime shifting process, the Bloomfield and Hales sequences have far too many observations in the tails of the distribution of reversal rates. We contend that because of the particular set of performance sequences used, the Bloomfield and Hales experiment cannot distinguish whether subjects rationally conclude that the underlying process is of a regime-shifting type or whether the subjects' belief in regime-shifting arises from behavioral biases as suggested by BSV. When we modify the Bloomfield and Hales experiment to be consistent with the crucial BSV assumption that the underlying data-generating process is random, we find no evidence supportive of investor belief in regime-shifting. Subjects in our experiment are more likely to expect a reversal in performance, rather than trending, after observing sequences with fewer reversals. This finding is consistent with the well-documented gambler's fallacy effect, which is a form of representativeness bias that arises when individuals know the underlying return-generating process.
ON THE MAINTENANCE OF A SHELL PATTERN AND BEHAVIOR POLYMORPHISM IN ACMAEA DIGITALIS, A LIMPET.

Crypsis is a common phenomenon in many animal groups and, with its attendant selective pressures, has been the subject of considerable discussion. It has been studied intensively in the snails Cepaea nemoralis and C. hortensis (Lamotte, 1959; Carter, 1967; Clarke, 1962; Cain and Sheppard, 1950, 1952, 1961; Owen, 1965; Sheppard, 1951). Briefly, Cepaea exhibit several colors and patterns which often match the habitat of the animal. Sheppard (1951) found that the thrush, Turdus ericetorum, selectively preys on color morphs of the snail, and Owen (1965) and Clarke (1962) report that the selection is frequency dependent or apostatic. This type of selection allows a highly diverse polymorphism to be maintained. Moths such as Biston betularia are also selectively preyed on by birds (Kettlewell, 1955) and the moths appear to actively select a matching background, enhancing their effective crypsis (Kettlewell, 1955; Sargeant, 1966). Colton (1916) described a polymorphism in Thais lapillus, the dog whelk, correlated it subjectively with background, and invoked weak natural selection as being responsible for reducing natural variety to a complex of inconspicuous forms. Moore (1936) found that the color of these whelks is a function of pigment quality of their food. In the limpet, Acmaea digitalis, two form complexes exist. The one, subjectively, is characteristic of beds of the gooseneck barnacle, Pollicipes polymerus
Zhang Yimou’s Movies in the Candle Light of Female Consciousness

A strong female consciousness developed in Zhang Yimou’s special life story. And it is reflected in almost his movies. He broke trough the set patterns of movies and boldly embodied the instinctive desire of women, their tragic opposition and their living conditions. Thus particular aesthetic features are expressed in his movies.
Absence Epilepsy and Moyamoya Disease

The case of a 6-year-old girl with typical absence epilepsy associated with moyamoya disease (MMD) is reported from the Department of Neurosurgery, Kyoto University Graduate School of Medicine, Japan.
The benefits of local depletion: The centrosome as a scaffold for ubiquitin-proteasome-mediated degradation

The centrosome is the major microtubule-organizing center in animal cells but is dispensable for proper microtubule spindle formation in many biological contexts and is thus thought to fulfill additional functions. Recent observations suggest that the centrosome acts as a scaffold for proteasomal degradation in the cell to regulate a variety of biological processes including cell fate acquisition, cell cycle control, stress response, and cell morphogenesis. Here, we review the body of studies indicating a role for the centrosome in promoting proteasomal degradation of ubiquitin-proteasome substrates and explore the functional relevance of this system in different biological contexts. We discuss a potential role for the centrosome in coordinating local degradation of proteasomal substrates, allowing cells to achieve stringent spatiotemporal control over various signaling processes.
SPATIAL CLASSIFICATION ERROR RATES RELATED TO PIXEL SIZE

Publisher Summary This chapter reviews spatial classification error rates related to pixel size. The goal is to classify the central point of the square pixel at t. If one does not exploit any spatial structure and pretend that pixels are class homogeneous then the optimal classifier for t based on X(t) is the Fisher linear discriminant function appropriately modified by the prior probabilities Q and 1 - Q. Larger pixels will have the property that the residual or noise component of the observation, e(t), will have smaller variance but, at the same time, larger pixels are less likely to be class-homogeneous. These properties work oppositely with respect to classification error probabilities even with computational questions aside. For modest increases in pixel size it will turn out, for the most part, that larger pixels are better than smaller pixels.
Abstract 618: Dual PI3K/mTOR inhibition as a treatment strategy for PIK3CA and APC mutant colorectal cancers

BACKGROUND: Colorectal cancer (CRC) is understood as a diverse group of cancers calling for the personalization of therapeutics to individual subtypes of CRC. Mutations in PIK3CA, which result in a constitutively active phosphoinositide-3-kinase protein (PI3K), are present in 20-30% of CRCs. Aberrations in the Adenomatous Polyposis Coli (APC) gene are found in 86% of PIK3CA mutant CRCs. The potential for treatment of tumors with this specific profile is of great interest. METHODS: Mice expressing a constitutively active PI3K and loss of APC were generated and spheroid cultures were derived from the resulting cancers. PIK3CA and APC mutant spheroids were treated with GDC0941 (GDC), a pan PI3K inhibitor, NVP-BYL719 (BYL), a PI3K alpha isomer specific inhibitor, or NVP-BEZ235 (BEZ), a dual mTOR/PI3K inhibitor. Proliferation was measured by changes in spheroid diameter over time. BEZ treatment of mice with PIK3CA and APC mutant CRCs was performed over 14 days. Tumor response was measured with serial murine colonoscopy and dual hybrid 18F-FDG PET/CT imaging. RESULTS: Persistent PIK3CA and APC mutant CRC spheroid growth was observed with BYL and GDC treatment, while BEZ treatment resulted in a significant reduction in spheroid size. Immunoblotting determined that this correlated with significant suppression of phosphorylated AKT, RPS6 and 4EBP1 in BEZ-treated spheroids and incomplete PI3K pathway inhibition following BYL and GDC treatment. BEZ treatment was then investigated in mice with PIK3CA and APC mutant CRCs. BEZ elicited a dramatic treatment response in these cancers on endoscopy, with a 53% decrease in median lumen occlusion compared to a 60% increase in controls over the 14 day treatment period. PET/CT imaging results confirmed these findings demonstrating a decrease in tumor size and avidity post BEZ treatment. BEZ resulted in inhibition of the PI3K pathway in these tumors. Reactivation of PI3K signaling was observed within 24 hours of the withdrawal of BEZ. BEZ was well-tolerated in these mice and associated with a decrease in the endoscopic anemia score. CONCLUSIONS: PIK3CA and APC mutant CRCs are a potentially targetable subtype of cancer. These cancers are resistant to proximal inhibition of the PI3K pathway, but are responsive to dual PI3K/mTOR inhibition. These results warrant further investigation in clinical studies. Citation Format: Susan Payne, Tyler Foley, Cheri Pasch, Alexander Yueh, Demetra Korkos, Dana Van De Hey, Linda Clipson, Dustin Deming. Dual PI3K/mTOR inhibition as a treatment strategy for PIK3CA and APC mutant colorectal cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 618.
Chapter 113 Men, Women and Risk Aversion: Experimental Evidence

Publisher Summary This chapter reviews the results from experimental measures of risk aversion for evidence of systematic differences in the behavior of men and women. In most studies, women are found to be more averse to risk than men. Studies with contextual frames show less consistent results. Whether men and women systematically differ in their responses to risk is an important economic question. If women are more sensitive to risk than men, this will be reﬂected in all aspects of their decision making, including choice of profession (and so earnings), investment decisions, and what products to buy. Several recent studies investigate this difference directly. Most experiments that investigate preferences over risky choices deal with the question of whether people make choices that are consistent with expected utility maximization.
Impaired Ribosome Maturation In Human Cells Depleted of Shwachman-Diamond Syndrome Protein SBDS

Abstract Abstract 2242 Background: Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder characterized by pancreatic exocrine dysfunction, neurocognitive and skeletal abnormalities, and bone marrow failure. Mutations in SBDS have been shown to cause SDS. From experiments on its yeast ortholog (Haematologica 2010. 95:57-64), SBDS has been implicated in maturation and function of the 60S ribosomal subunit. In particular, subunit maturation in the SDS yeast model was associated with delayed export and accumulation of 60S-like particles in the nucleoplasm. Methods and Results: To clarify its role in human cells, erythroleukemia TF-1 cells were transduced with lentiviral vectors expressing short hairpin RNA (shRNA) against SBDS. Immunoblot assays confirmed approximately 60% knockdown in individual TF-1 cell clones expressing different shRNAs. The growth and hematopoietic colony forming potential of TF-1 knockdown cells were markedly hindered when compared to cells stably transduced with shRNA against a scrambled SBDS sequence. Using Hoechst 33342/Pyronin Y staining and flow cytometry, we also found an increased percentage of knockdown cells retained at the G0/G1 cell cycle phase. To address whether near-complete knockdown of SBDS affected ribosome synthesis as it does in yeast cells, we silenced SBDS in A549 cells. Our data revealed a reduction in polysomes but in contrast to what was observed in yeast, there was no evidence of half-mer polysomes indicative of decreased 60S subunits participating in translation. The absence of half-mers is not unusual in mammalian systems, so to better analyze the effect of SBDS on 60S subunit maturation subunit localization was assessed by co-transfection with a vector expressing a fusion between human RPL29 and enhanced GFP. Preliminary studies indicated a higher percentage of SBDS-depleted cells with nuclear localization of 60S subunits, when compared with normal controls (Fig. 1). Conclusions: (1) Partial depletion of SBDS results in a significant growth and clonogenic defect in TF-1 hematopoietic cells. The growth abnormalities can be attributed in part to delayed cell cycle transit. (2) Near-complete knockdown of SBDS leads to growth inhibition and defects in ribosome maturation, suggesting a role for wild-type SBDS in nuclear export of pre-60S subunits. Download : Download high-res image (217KB) Download : Download full-size image Fig. 1 . At 72h, the SBDS knockdown clone (labeled #2-12) transfected with RPL29-GFP had more cells with nuclear/nucleolar localization than the scrambled control clone similarly transfected. For each experiment, a total of 200 cells were counted at 72h to determine the percentage of cells with localization of RPL29-GFP. Thus, the ordinate axis represents the number of cells staining in both nucleus and cytoplasm divided by the number staining in the cytoplasm only. Disclosures: No relevant conflicts of interest to declare.