cssi/SciSciGPT-SciSciNet huggingface dataset:
On random walk models for simulation of particle-laden turbulent flows

Abstract In this investigation, the accuracy of the discrete and continuous random walk (DRW, CRW) stochastic models for simulation of fluid (material) point particle, as well as inertial and Brownian particles, was studied. The corresponding dispersion, concentration, and deposition of suspended micro- and nano-particles in turbulent flows were analyzed. First, the DRW model used in the ANSYS-Fluent commercial CFD code for generating instantaneous flow fluctuations in inhomogeneous turbulent flows was evaluated. For this purpose, turbulent flows in a channel were simulated using a Reynolds-averaged Navier–Stokes (RANS) approach in conjunction with the Reynolds Stress Transport turbulence model (RSTM). Then spherical particles with diameters in the range of 30 µm to 10 nm were introduced uniformly in the channel. Under the assumption of one-way coupling, ensembles of particle trajectories for different sizes were generated by solving the particle equation of motion, including the drag and Brownian forces. The DRW stochastic turbulence model of the software was used to include the effects of instantaneous velocity fluctuations on particle motion, and the steady state concentration distribution and deposition velocity of particles of various sizes were evaluated. In addition, the improved CRW model based on the normalized Langevin equation was used in an in-house Matlab code. Comparisons of the predicted results of the DRW model of ANSYS-Fluent with the available experimental data and the DNS simulation results and empirical predictions showed that this model is not able to accurately predict the flow fluctuations seen by the particles in that it leads to unreasonable concentration profiles and time-varying deposition velocities. However, the predictions of the improved CRW model were in good agreement with the experimental data and the DNS results. Possible reasons causing the discrepancies between the DRW predictions and the experimental data were discussed. The improved CRW model was also implemented through user-defined functions into the ANSYS-Fluent code, which resulted in accurate concentration distribution and deposition velocity for different size particles.
Motivating Students on a Time Budget: Pedagogical Frames and Lesson Plans for In-person and Online Information Literacy Instruction. Sarah Steiner and Miriam Rigby, eds., for the Association of College and Research Libraries. Chicago, IL: American Library Association, 2019. 322p. $64.00 (ISBN 978-083898949-4).

Any instruction or subject librarian will know the anxiety felt when working to prepare an information literacy session for students in a one-shot session. Librarians must incorporate the faculty member’s, sometimes numerous, desires for class as well as ensure the session is relevant and engaging for students, all within a usually short, one-off class period. The editors of this work are familiar with these seemingly constraining variables and seek to flip librarians’ idea that these factors are constraining or a burden but rather “a gift: because we have only a short period of time with our students, we can exist outside the world of performance…and position ourselves as fellow curious explorers” (2). This volume of work is aimed at moving from the more motivation-related instruction topics, such as active learning, and expanding examination to a broader look at motivation theory to foster intrinsic motivation in students. The editors of this book hope that this presentation of broader motivational theory will inspire readers to meet students where they are, both intellectually and emotionally, and help students to cross threshold concepts critical to information literacy.
Securing the software defined perimeter with evolutionary co-optimization

We investigate the robustness of a network defense isolation technique called Software Defined Perimeter (SDP). SDP tries to limit security risk by isolating users access based on user accounts, rules and resources. We show how a competitive co-evolutionary framework can be used to evaluate different SDP configurations. It employs a simulation to test the strength of different SDP configurations against different attackers. It uses a co-evolutionary algorithm to search through the action spaces of SDP configurations and possible attackers. These results enable the comparison of different SDP configurations based on the objective of minimizing the number of potentially compromised high-value resources.
Duration of Androgen Deprivation Therapy Influences Outcomes for Patients Receiving Radiation Therapy Following Radical Prostatectomy

Abstract Background Limited data exist to guide the use of androgen deprivation therapy (ADT) for men treated with radiation therapy (RT) after radical prostatectomy (RP). The optimal duration of ADT in this setting is unknown. Objective To determine if the duration of ADT influences clinical outcomes for men receiving post-RP RT. Design, setting, and participants A total of 680 men who received adjuvant radiation therapy ( n =105) or salvage radiation therapy ( n =575) between 1986 and 2010 at a single tertiary care institution were reviewed retrospectively. Median follow-up post-RT was 57.8 mo. Intervention RT was delivered using three-dimensional conformal or intensity-modulated RT in 1.8-Gy fractions. For patients treated with ADT, >80% were treated with a gonadotropin-releasing hormone agonist with or without a nonsteroidal antiandrogen. Outcome measurements and statistical analysis Biochemical failure (BF), distant metastasis (DM), prostate cancer–specific mortality (PCSM), and overall mortality were assessed using Kaplan-Meier analysis and propensity score analysis. Results and limitations Overall, 144 patients (21%) received ADT with post-RP RT, most of whom had high-risk disease features such as Gleason score 8–10, seminal vesicle invasion, or pre-RT prostate-specific antigen >1 ng/ml. Median ADT duration was 12 mo (interquartile range: 6.0–23.7). Patients who received p =0.003) and DM (HR: 2.48; p =0.03) compared with patients receiving ≥12 mo of ADT. The 5-yr rates of DM were 6.0% and 23% for ≥12 and p =0.0004), DM (HR: 0.88; p =0.0004), and PCSM (HR: 0.90; p =0.037). These findings are limited by the retrospective nature of our analysis. Conclusions For men with high-risk disease features receiving ADT with post-RP RT, the duration of ADT is associated with clinical outcomes. Our findings suggest that for these men an extended course of ADT ≥12 mo may be preferable. Validation of our findings is needed. Patient summary We evaluated outcomes for men with high-risk disease features treated with androgen deprivation therapy (ADT) and radiotherapy after radical prostatectomy. Longer durations of ADT resulted in improved patient outcomes.
Duplicity and the Depraved Uncanny in Mediations of Ted Bundy

This article attends to the role of duplicity in managing serial killer Ted Bundy’s uncanniness. Texts such as Joe Berlinger’s Conversations with a Killer: The Ted Bundy Tapes (2019) and Extremely ...
Multimodality imaging of the extrapleural space lesions

Abstract Extrapleural space (EPS) is a potential space between the outer layer of the parietal pleura and the inner layer of the chest wall and the diaphragm. Many different pathologies including chronic inflammatory conditions, infections, trauma, neoplastic disease (both benign and malignant) as well as many infiltrative disorders can involve the EPS. It is one of the frequently overlooked entity on imaging due to relative lack of understanding of the anatomy and the imaging appearances of the diseases localized to this space. The knowledge of the EPS is essential for the radiologists as the pathologies which involve the EPS may require different treatment approach compared to pleural or parenchymal lung disease. Additionally, the EPS involvement may influence the staging and treatment planning for chest malignancies. In this review, we give an overview of the anatomy and various pathologies involving EPS, utility of different imaging modalities in the evaluation of EPS lesions with emphasis on cross sectional imaging and emerging technologies like spectral CT and its role in recognizing the imaging features which enable specific diagnosis of various pathologies.
Concordance measures and time-dependent ROC methods

The receiver operating characteristic (ROC) curve displays sensitivity versus 1-specificity over a set of thresholds. The area under the ROC curve (AUC) is a global scalar summary of this curve. In...
UL25 Capsid Binding Facilitates Mechanical Maturation of the Herpesvirus Capsid and Allows Retention of Pressurized DNA.

The maturation process that occurs in most viruses is evolutionarily driven as it resolves several conflicting virion assembly requirements. During herpesvirus assembly in a host cell nucleus, micron-long double-stranded herpes DNA is packaged into a nanometer-sized procapsid. This leads to strong confinement of the viral genome with resulting tens of atmospheres of intra-capsid DNA pressure. Yet, the procapsid is unstable due to weak, reversible interactions between its protein subunits, which ensures free energy minimization and reduces assembly errors. In this work we show that herpesviruses resolve these contradictory capsid requirements through a mechanical capsid maturation process facilitated by multi-functional auxiliary protein UL25. Through mechanical interrogation of herpes simplex virus type 1 (HSV-1) capsid with atomic force microscopy nano-indentation, we show that UL25 binding at capsid vertices post-assembly provides the critical capsid reinforcement required for stable DNA encapsidation; the absence of UL25 binding leads to capsid rupture. Furthermore, we demonstrate that gradual capsid reinforcement is a feasible maturation mechanism facilitated by progressive UL25 capsid binding, which is likely correlated with DNA packaging progression. This work provides insight into elegantly programmed viral assembly machinery where targeting of capsid assembly mechanics presents a new antiviral strategy that is resilient to development of drug resistance. Importance: Most viruses undergo a maturation process from a weakly assembled particle to a stable virion. Herpesvirus capsid undergoes mechanical maturation to withstand tens of atmospheres of DNA pressure. We demonstrate that this mechanical capsid maturation is mainly facilitated through binding of auxiliary protein UL25 in HSV-1 capsid vertices. We show that UL25 binding provides the critical capsid reinforcement required for stable DNA encapsidation. Our data also suggests that gradual capsid reinforcement by progressive UL25 binding is a feasible capsid maturation mechanism, correlated with DNA packaging progression.
Redifferentiation of BRAF V600E-Mutated Radioiodine Refractory Metastatic Papillary Thyroid Cancer After Treatment With Dabrafenib and Trametinib.

Radioactive iodine-refractory metastatic differentiated thyroid cancer (RAIR) is associated with a poor prognosis. Multikinase inhibitors have demonstrated improvement in progression-free but not overall survival in such patients, but usage is limited by significant adverse effects and the development of resistance. Clinical research has demonstrated improvement in progression-free survival with the combined use of the BRAF/MEK inhibitor in patients with metastatic melanoma and anaplastic thyroid cancer with the BRAFV600E mutation and has shown promise in redifferentiation of BRAF-positive RAIR differentiated thyroid cancer. A 58-year-old woman went to her primary care physician for a growing mass on the left side of her neck. CT imaging noted a 6 x 8 x 6 cm mixed cystic and solid mass and lymphadenopathy. Core biopsy subsequently showed metastatic papillary thyroid cancer (Stage III, PT4a/PN1b), and she underwent a total thyroidectomy with left neck dissection. She then received 204mCi 131I post-total thyroidectomy. Unfortunately, her thyroglobulin continued to increase post-radioactive iodine (RAI) treatment, indicating persistent and/or recurrent thyroid cancer. An RAI-131 whole-body scan on the thyrogen protocol showed no significant RAI uptake. A fluorodeoxyglucose (FDG)-positron emission tomography (PET) CT scan was then performed, which showed recurrent metastatic disease with hypermetabolism noted in the left thyroid bed and FDG-avid bilateral cervical lymph nodes and pulmonary nodules. Given these findings, her cancer was classified as radioactive iodine refractory (RAIR). Molecular testing indicated the BRAFV600E mutation. After a discussion with the patient, it was decided to initiate therapy with a BRAF inhibitor (dabrafenib 150 mg twice a day) and MEK inhibitor (trametinib 2 mg once a day) in an attempt to redifferentiate RAIR. Repeat RAI-131 thyrogen whole body scan one month after initiation of therapy demonstrated left level 2 cervical lymphadenopathy radioiodine uptake. The patient subsequently received 216 mCi 131I treatment given evidence of redifferentiation. Her post-treatment scan indicated additional uptake in a left lower lobe pulmonary nodule as well as a left paratracheal mass indicating successful RAI-131 uptake by metastases. Her thyroglobulin level, six months post-RAI, decreased to 4.0 indicating an encouraging response. Further surveillance, including imaging studies, is planned. This case illustrates the re-differential potential for dabrafenib and trametinib treatment in patients with BRAFV600E-mutated RAIR differentiated thyroid cancer. This therapy has been shown to be successful in small series of patients and could potentially be offered to RAIR patients with the BRAFV600E mutation as an alternative to multikinase treatment given its favorable side-effect profile.
The effect of pressure upon the solubility of oxygen in water: Implications of the deviation from the ideal gas law upon measurements of fluorescence quenching

Abstract The effect of pressure upon the solubility of oxygen in water compressed up to 500 atmospheres (atm) was directly measured. Pressurized aqueous solutions were allowed to equilibrate with a low pressure atmosphere (air, total pressure, 1 atm; oxygen partial pressure, 0.2 atm) across a gas-permeable, pressure-resistant Teflon membrane, and the equilibrium molar concentration of oxygen determined chemically. The solubility of oxygen in water decreased exponentially with pressure up to approximately 200 atm. At higher pressures, decreases in the molar volume of oxygen in solution resulted in a slight deviation from this initial trend. Implications of these results upon measurements of fluorescence quenching by oxygen under conditions of elevated pressure, a probe for studying the structure of macromolecules, are discussed.
Object recognition can drive motion perception

When two spatially separated spots of light are flashed in rapid succession, apparent motion is seen between them1,2,3. We extended this phenomenon by photographing a face and producing from it a fragmented ‘puzzle picture’ or ‘Mooney face’ in which the face is not initially visible (Fig. 1, left; frame 1) but is seen after 15 to 60 seconds4. Another photograph of the same face seen in profile was used to produce a second Mooney face (Fig. 1, right; frame 2). When the two images were alternated, naive subjects at first saw random, incoherent, two-dimensional (2D) motion between the fragments. But once the face was recognized, it was perceived to rotate unambiguously in three dimensions. We conclude that complex image tokens set up by perceptual learning can drive perception of apparent motion.
Aberrant Asociality: How Individual Differences in Social Anhedonia Illuminate the Need to Belong

The need to belong, a fundamental concept in psychology, organizes a wide range of findings in the study of interpersonal relationships. We suggest that human belongingness needs can be illuminated by examining when they go awry. We review research on social anhedonia, a trait that involves a marked disinterest in interpersonal contact. Social anhedonia has a long history in clinical psychology, particularly in the study of schizotypy and schizophrenia-spectrum disorders, but it is just starting to get attention from social and personality psychologists. Three lines of research—cross-sectional studies of individual differences, longitudinal studies of risk for psychopathology, and experience-sampling studies of interpersonal behavior—suggest that (1) social anhedonia represents genuine social disinterest, not merely shyness, introversion, or social anxiety, and (2) people high in social anhedonia have consistently poorer functioning, including a higher risk for developing schizophrenia-spectrum disorders. Just as satisfied relatedness needs promote flourishing, dysfunctional social needs promote psychopathology.
Mechanisms of impurity diffusion in rutile

Tracer diffusion of 46Sc, 5lCr, 54Mn, 59Fe, 60Co, 63Ni, and 95Zr, was measured as functions of crystal orientation, temperature, and oxygen partial pressure in rutile single crystals using the radioactive tracer sectioning technique. Compared to cation self-diffusion, divalent impurities (e.g., Co and Ni) diffuse extremely rapidly in TiO2 and exhibit a large anisotropy in the diffusion behavior; divalent-impurity diffusion parallel to the c-axis is much larger than it is perpendicular to the c-axis. The diffusion of trivalent impurity ions (Sc and Cr) and tetravalent impurity ions (Zr) is similar to cation self-diffusion, as a function of temperature and of oxygen partial pressure. The divalent impurity ions Co and Ni apparently diffuse as interstitial ions along open channels parallel to the c-axis. The results suggest that Sc, Cr, and Zr ions diffuse by an interstitialcy mechanism involving the simultaneous and cooperative migration of tetravalent interstitial titanium ions and the tracer-impurity ions. Iron ions diffused both as divalent and as trivalent ions.
A New Solution to the Hidden Copy Problem

We consider the well-known problem of avoiding unnecessary costly copying that arises in languages with copy/value semantics and large aggregate structures such as arrays, sets, or files. The origins of many recent studies focusing on avoiding copies of flat arrays in functional languages may be traced back to SETL copy optimization [Schwartz 75]. The problem is hard, and progress is slow, but a successful solution is crucial to achieving a pointer-free style of programming envisioned by [Hoare 75]. We give a new solution to copy optimization that uses dynamic reference counts and lazy copying to implement updates efficiently in an imperative language with arbitrarily nested finite sets and maps (which can easily model arrays, records and other aggregate datatypes). Big step operational semantics and abstract interpretations are used to prove the soundness of the analysis and the correctness of the transformation. An efficient algorithm to implement the analysis is presented. The approach is supported by realistic empirical evidence. Our solution anticipates the introduction of arbitrarily nested polymorphic sets and maps into JAVA. It may also provide a new efficient strategy for implementing object cloning in Java and object assigment in C++. We illustrate how our methods might improve the recent approach of [Wand and Clinger 98] to avoid copies of flat arrays in a language of first-order recursion equations.
Market structures, price-cost margins, and unionism: An empirical note

Abstract Empirical results show the existence of a non-linear relationship between concentration and price—cost margins. A non-linear specification provides substantial evidence that unions reduce profits, especially in more oligopolistic industries.
Freedom of Cropping and the Good Life: Political Philosophy and the Conflict Between the Organic Movement and the Biotech Industry Over Cross-Contamination

This paper begins by describing recent controversies over cross-contamination of crops in the United States and European Union. The EU and US are both applying the principle of freedom of cropping to resolve these conflicts, which is based on an individualistic philosophy. However, despite the EU and the US starting with the principle of freedom of cropping they have very dissimilar regulatory regimes for coexistence. These contradictory policies based upon the same principle are creating different sets of winners and losers. In the US the organic industry claims the system of coexistence is unfair and in the EU the biotech industry claims the system is unfair. It seems that states, despites claims to neutrality and freedom of choice, are prejudicing one system of agriculture over another in resolutions to the conflict over cross contamination. In this paper I will argue that if states cannot remain neutral in coexistence policies, there are conditional reasons for favoring the organic industry over the biotech industry in coexistence policies based in communitarian moral philosophy.
A Review of “Cataloging and Classification: An Introduction”

For continuity purposes, the title and much of the text are the same as the second edition, but a noticeable change has been made in the labels for the six parts, portending great changes in the fi...
On the orbits of infalling satellite haloes

The orbital properties of infalling satellite haloes set the initial conditions which control the subsequent evolution of subhaloes and the galaxies that they host, with implications for mass stripping, star formation quenching and merging. Using a high-resolution cosmological N-body simulation, we examine the orbital parameters of satellite haloes as they merge with larger host haloes, focusing primarily on orbital circularity and pericentre. We explore in detail how these orbital parameters depend on mass and redshift. Satellite orbits become more radial and plunge deeper into their host halo at higher host halo mass, but they do not significantly depend on satellite halo mass. Additionally, satellite orbits become more radial and plunge deeper into their host haloes at higher redshift. We also examine satellite velocities, finding that most satellites infall with less specific angular momentum than the host halo virial value, but that satellites are ‘hotter’ than the host virial velocity. We discuss the implications of these results to the processes of galaxy formation and evolution, and we provide fitting formulae to the mass and redshift dependence of satellite orbital circularity and pericentre.
Career satisfaction and professional accomplishments.

Medical Education 2010: 44: 969–976 Context Research on doctor career satisfaction has often focused on factors such as income, specialty, gender, work hours, autonomy, patient load, lifestyle preferences, work environment, and insurance regulations. Other educational, personal and professional factors have not received sufficient empirical attention. Objective This study was designed to test the following five hypotheses that doctors’ career satisfaction is associated with: (i) Higher satisfaction with their undergraduate medical education; (ii) Greater academic and clinical competence; (iii) More involvement in teaching and research activities; (iv) Higher orientation toward lifelong learning; and (v) Increased professional accomplishments. Methods A survey was mailed in 2006 to a national sample of 5349 doctors in the United States who graduated from Jefferson Medical College between 1975 and 2000; 3170 (59%) returned completed surveys. Based on responses to a career satisfaction question, doctors were classified into three groups: Highly satisfied (top third, n = 1078); moderately satisfied (middle third, n = 1031); and least satisfied (bottom third, n = 1061). These groups were compared on a number of variables. Results All five research hypotheses were confirmed. Additionally, no significant association was observed between career satisfaction, age, years in practice, gender, or ethnicity; however, career satisfaction was associated with doctors’ specialties. Conclusions The findings suggest that factors such as satisfaction with medical education, medical school class rank, assessments of clinical competence, teaching, and research activities, orientation toward lifelong learning, and professional accomplishments should be considered for a more comprehensive understanding of doctors’ career satisfaction.
Optimization criteria and biological process enrichment in homologous multiprotein modules

Biological process enrichment is a widely used metric for evaluating the quality of multiprotein modules. In this study, we examine possible optimization criteria for detecting homologous multiprotein modules and quantify their effects on biological process enrichment. We find that modularity, linear density, and module size are the most important criteria considered, complementary to each other, and that graph theoretical attributes account for 36% of the variance in biological process enrichment. Variations in protein interaction similarity within module pairs have only minor effects on biological process enrichment. As random modules increase in size, both biological process enrichment and modularity tend to improve, although modularity does not show this upward trend in modules with size at most 50 proteins. To adjust for these trends, we recommend a size correction based on random sampling of modules when using biological process enrichment or other attributes to evaluate module boundaries. Characteristics of homologous multiprotein modules optimized for each of the optimization criteria are examined.
Dispersion of Air in the Near-Infrared*

Methods of computation are described for determination of the refractivity of air from measurements made with a corner-reflector Michelson interferometer. Results are given for eleven vacuum wavelengths from 7034 to 20 587 A. These results support Svensson’s conclusion that Edlen’s dispersion formula may be increased in precision by raising it slightly in the near-infrared. They indicate however an increase of 0.12×10−8×(3.35 μ−2−σ2) over Svensson’s formula. A question is raised as to the existence of appreciable variations, perhaps seasonal in nature, in the refractivity of outdoor air.
Understanding Sleep in Persons With Diabetes

Restorative sleep is as essential for well-being as proper diet or exercise in persons with type 2 diabetes. However, sleep disorders such as insomnia, restless leg syndrome/ periodic leg movements, and obstructive sleep apnea increase in prevalence with age and are very common in persons with type 2 diabetes. Disrupted sleep may result in weight gain, increased insulin resistance, and decreased daytime functioning. Although sleep disturbances have a major influence on health and quality of life, diagnosis and treatment can reduce their negative effects. Diabetes educators are pivotal in patient assessment, management, teaching, and collaborating with the primary health care provider to deliver holistic management of the patient with diabetes. This article will provide diabetes educators with various strategies for assessing sleep, including an easy 8-item questionnaire that can be used in the clinical setting. In addition, interventions to improve sleep hygiene that can be easily implemented by diabetes ...
Hugo von Hofmannsthals Weltgeheimnis: Ein Spiel mit dem Unaussprechlichen

Meine Arbeit versucht zu zeigen, das die syntaktisch-semantische Polyvalenz von Hugo von Hofmannsthals Gedicht Weltgeheimnis sich weder mittels einer hermeneutischen Methodik auf Eindeutigkeit reduzieren last, noch das Zustandekommen einer Textaussage etwa ganzlich verhindert. Vielmehr, so mochte ich argumentieren, verdankt sich eben diese Polyvalenz den Gesetzlichkeiten des “Geheimnisses” selbst, so das sie letztlich zur Gesetzlichkeit des Textes werden mus. Der Text hat kein “Geheimnis”, das durch ihn hindurch oder hinter ihm freigelegt werden konnte, sondern der Text ist sein eigenes “Geheimnis”, und zwar insofern, als er sich nie vollig preisgibt, weil er sich nie vollig preisgeben kann, da das Spiel seiner Zeichen potentiell unendlich ist. Das “Geheimnis” Text liegt offen an der vom Text selbst konstituierten und komponierten Oberflache zu Tage, aber es kann sich nie vollends mitteilen, da es nicht “fest”-steht, sondern bestandig neue Verweisstrukturen in sich entstehen last. Das “Geheimnis” Text mus unterschieden werden von einem etwa auserhalb des Textes vermuteten Geheimnis - der Text kann nur das immer schon Andere dessen sein, was auserhalb seiner selbst liegt. Der imaginierte Verlust eines Wissens um ein Geheimnis auserhalb des Textes bringt ein Geheimnis anderer Art hervor, namlich das aus Sprache sich zusammensetzende Gedicht.
A new concept of ballasting mechanisms of microwave power transistors in class C operation

Emitter ballasting in class C microwave power transistors is shown to cause a sacrifice of output power and collector efficiency. The use of base impedance balasting resulted in the development of an experimental 4 GHz microwave power transistor which is capable of providing 3 watts of output power with a 6.4 dB power gain and a 65% collector efficiency. The experimental data on the collector current dependence of the power gain, and the spatial temperature distribution of the device working in class C and class A operations are presented. General guidelines for designing class C microwave transistors for optimum performance are given.
Colorectal carcinomas: Diagnostic implications of their changing frequency and anatomic distribution

This retrospective review included 1,694 consecutive cases of colorectal carcinoma diagnosed at the University of Chicago Medical Center during a 25-year period (1960 through 1984). The number and percentage of tumors occurring within 7 anatomic segments of the large bowel were determined. The statistical data for a recent 5-year interval were then compared with those of the 2 preceding decades. There was a 10.2% increase in the frequency of cancers originating in the cecum or ascending colon, while rectal and rectosigmoid carcinomas declined by 15.8% during the same study period. These data provide further evidence for a progressive left-to-right shift in cancer distribution within the colon during the past quarter century. Currently, the most proximal and distal 20–25 cm segments of the large bowel (cecum or ascending colon versus rectum and rectosigmoid) each harbor approximately 25% of the tumors. Therefore, the classic medical teaching that over 50% of colorectal cancers would be detectable by digital examination and/or proctosigmoidoscopy is no longer accurate. This documented increase in proximal colon cancers and redistribution of lesions within various large bowel segments indicate the growing importance of barium enema and colonoscopy as the optimal techniques for detection of colorectal neoplasms.
Insulin-Like Growth Factors are Mitogenic for Human Keratinocytes and a Squamous Cell Carcinoma

Normal adult human keratinocytes in monolayer culture and SCL-1, a skin-derived squamous-cell carcinoma cell line, were investigated for the expression of receptors for insulin- like growth factors (IGF) and insulin. As demonstrated by affinity crosslinking, radiolabeled IGF-1, IGF-2, and insulin bound specifically to both cell types. Each cell expressed type I IGF receptors, with affinity for IGF-1 > IGF-2 >> insulin. Insulin receptors, with highest affinity for insulin, were also present on both cells. However, keratinocytes and SCL-1 cells differed in 125I-IGF-2 binding. 1251-JGF-2-bound to both type I and type II IGF receptors in normal keratinocytes, but bound predominantly to membrane-associated IGF binding proteins in SCL-1. IGF-1 was slightly more potent than IGF-2 in stimulating growth of both keratinocytes and SCL-1 cells. In keratinocytes, concentrations of IGF-1 ranging from 5–100 ng/ml, and of IGF-2 from 50–100 ng/ml, resulted in a significant increase in cell number. At the maximum dose of 100 ng/ml, either IGF-1 or IGF-2 caused a 2.3-times increase in cell number. In SCL-1 cells, IGF-1 was more potent than IGF-2 or insulin at lower concentrations, but either IGF-1 or IGF-2 at the maximal concentration of 333 ng/ml stimulated a 4.7-times increase in thymidine incorporation. The stimulatory effect of insulin in SCL-1 was 10–50 times less potent than that of the IGF. The effect of either IGF on SCL-1 was completely inhibited by the type I IGF receptor antibody alphaIR-3, suggesting that both IGFs are mitogenic through the type I IGF receptor. Insulin action was partially blocked by alphalR-3, suggesting that insulin can act through both the insulin and type I IGF receptors. It thus appears that IGF-1 and IGF-2 are mitogens for normal and transformed human keratinocytes and that their actions are primarily mediated through the type I IGF receptor, whereas insulin is a mitogen through both the IGF-1 receptor and the insulin receptor.
Reentrant formation of magnetic polarons in quantum dots

We propose a model of magnetic polaron formation in semiconductor quantum dots doped with magnetic ions. A wetting layer serves as a reservoir of photo-generated holes, which can be trapped by the adjacent quantum dots. For certain hole densities, the temperature dependence of the magnetization induced by the trapped holes is reentrant: it disappears for some temperature range and reappears at higher temperatures. We demonstrate that this peculiar effect is not an artifact of the mean field approximation and persists after statistical spin fluctuations are accounted for. We predict fingerprints of reentrant magnetic polarons in photoluminescence spectra.
Working, reflected and detrimental active powers

The active power P is one of the best established power quantities, commonly regarded as the useful power. There is awareness in the electrical engineering community, however, that some components of this power in systems with non-sinusoidal and asymmetrical voltages and currents are not useful for customers. Owing to an increase in cost of energy, increase in expectations towards the supply reliability and security, electrical power system technology faces a need of extensive changes. Even the best established concepts can be challenged and revised. Therefore the concept of the active power is revised in this study. It is shown that the active power P can be decomposed into three components of different usefulness, referred to as working, reflected and detrimental active powers. It is shown, that energy accounts based on the working, instead of the active energy, might create economic incentives for reducing harmonics and asymmetry both on the energy provider and the customer sides. This idea challenges deeply rooted standards; therefore the study can be regarded only as an initiation of a debate on the very sensitive issue of rationalisation of energy accounts in systems with non-sinusoidal and asymmetrical voltages and currents.
Programs and resources in distance education

Distance education programs are offered by both commercial and traditional educational institutions. Some programs offer complete degrees while others only provide courses geared toward professional development or personal enrichment. This article presents short profiles of several distance education programs, a list of World Wide Web sites, and a bibliography about distance learning. The number of institutions offering some flavor ofdistance education is constantly increasing (see Roberts. 1996). The content and method of delivery of these programs ranges from correspondence courses on children’s writing to on-demand digital video on the latest developments in information systems technology sent directly to a student’s home. While the short profiles of some of the programs described here attempt to give the reader a representative sampling of the current state of distance education, it is by no means a comprehensive review of the field. Figure I summarizes the methods the programs in this article use to provide instructional delivery and faculty-student interaction. The Uniform Resource Locators ( URLs) for Web sites and the bibliography that follows provide more breadth and depth on the nature and scope of distance education programs.
Wavefront engineering from 500- to 100-nm CD

'Wavefront engineering' is the discipline of producing an exposure pattern, adequate for delineating resist at high yield, in spite of the limitations of the imaging technology. Although this discipline relies on century-old optical insights and despite decade-past experiments demonstrating dramatic improvements in resolution and process-window, this field has languished in comparison to traditional approaches, such as exposing with shorter wavelength radiation or larger numerical apertures. Further progress in NA and (lambda) will soon be limited by physical and materials considerations, necessitating other schemes for decreasing the critical dimensions of volume-production devices. Today, with 193 nm systems delayed and non-optical approaches confronting infrastructure and economic barriers, the semiconductor industry is trying to adopt such wavefront engineering techniques as off-axis illumination, optical proximity correction and phase-shifting masks. CAD/CAM methods similar to those applied to optimize lenses and chips now are being applied to optimize the exposure-dose pattern itself.
A Novel Technique for Hybrid Aortic Arch Reconstruction: The Deployment Cuff Technique

Extensive thoracic aortic aneurysmal disease involving the arch and descending aorta has been a difficult problem. The "frozen elephant trunk" single-stage procedure combining open arch repair under circulatory arrest with a deployment of a stented thoracic endograft has shown good results in recent reports, but it can be technically challenging to deploy the endovascular device in the exact location. In patients with aortic dissection, back bleeding through the false lumen necessitates obliteration of the false lumen proximally. We describe a technique that allows for precise deployment and obliteration of false lumen flow at the proximal end of the stent graft.
The varying time courses of attentional and affective modulation of the startle eyeblink reflex

In previous research on modulation of the startle eyeblink reflex, emotional effects have been demonstrated only at late probe positions, whereas attentional effects have been found at both early and late positions but only when the prepulses were affectively neutral. In Experiment 1, participants viewed emotionally valenced pictures and were instructed to attend to the duration of half of the slides. Affective modulation of the startle eyeblink occurred at long lead intervals, but attentional modulation also occurred late. In Experiment 2, participants viewed the same slides used in Experiment 1 but were instructed to attend to the duration of only the positive or the negative slides. Affective modulation occurred at both early and late probe positions, whereas attentional effects occurred only following slide offset. Early (250 ms) affective modification of startle eyeblink has not been previously reported. These results suggest that the time courses of emotional and attentional modulation of startle are variable and can occur at both early and late startle probe positions, depending on task requirements.
Investigation of clinical methodology for sample collection and processing prior to the reversed-phase liquid chromatographic determination of UV-absorbing plasma constituents.

The study of the purine and pyrimidine levels in the blood fluids of normal and diseased individuals has gained considerable importance over the last few years. The analysis of plasma, unlike that of serum, does not preclude the recovery of intact blood cells and their use for further investigations. The examination of various plasma chromatograms following blood collection in tubes with heparin, acid-citrate-dextrose or EDTA reveals that only the heparin anticoagulant does not interfere with the uv absorbance of plasma constituents. However, whereas the acid-citrate-dextrose blood remains stable for a period of 7 h at 25°C, both the heparinized plasma and red blood cell lysates exhibit an increase in hypoxanthine and xanthine. These elevations correlate with the erythrocyte decomposition of the nucleotides into their bases, followed by the purine base transfer across the cell membrane and into the plasma. The same phenomena occur to an even greater extent in serum. Thus, heparinized plasma can only be used for the quantification of endogenous nucleoside and base levels if separated from the blood cells immediately after collection and centrifugation.
Feature reduction methods for hyperspectral data

Hyperspectral (HS) data contains spectral response information that provides detailed chemical, moisture, and other descriptions of constituent parts of an item. These new sensor data are useful in USDA product inspection and in automatic target recognition (ATR) applications. However, such data introduces problems such as the curse of dimensionality, the need to reduce the number of features used to accommodate realistic small training set sizes, and the need to employ discriminatory features and still achieve good generalization (comparable training and test set performance). HS produces high-dimensional data; this is characterized by a training set size (Ni) per class that is less than the number of input features (HS (lambda) bands). A new high-dimensional generalized discriminant (HDGD) feature extraction algorithm and a new high-dimensional branch and bound (HDBB) feature selection are described and compared to other feature reduction methods for two HS product inspection application. Cross-validation methods, not using the test set, select algorithm parameters.
Effective spread and timecourse of neural inactivation caused by lidocaine injection in monkey cerebral cortex.

Abstract We studied the effective spread of lidocaine to inactivate neural tissue in the frontal cortex of the rhesus monkey. Injections of 2% lidocaine at 4 μl/min were made while units were recorded 1 or 2 mm away. To inactivate units 1 mm away from the injection site 100% of the time, 7 μl of lidocaine had to be injected. To inactivate units 2 mm away from the injection site 100% of the time, 30 μl of lidocaine were required. Units were maximally inactivated around 8 min after the start of a lidocaine injection, and they gradually recovered, regaining most of their initial activity by around 30 min after the start of an injection. The volume of lidocaine required to inactivate neurons ≥90% of the time could be estimated by the spherical volume equation, V=4/3 pi (r)3. To prolong the inactivation, a slower infusion of lidocaine subsequent to an initial bolus was effective. Saline control injections had no effect. These results allow both a prediction of the timecourse of neural inactivation and an estimate of the spread of neural inactivation following injection of lidocaine into the monkey cerebral cortex.
An information processing model of knowledge systems

To date, knowledge-based systems ( KBS's) have been developed on an ad-hoc basis, without the benefit of quantitative tools for analysis and synthesis. If we are to approach the field of knowledge engineering systematically, we must develop performance measures to characterize the effectiveness and efficiency of knowledge systems, and thereby serve to highlight directions for improvement. When KBS's are applied to control tasks, real-time performance becomes critical. Consequently, the internal processes of knowledge-based control systems ( KBCS) must be optimized to fulfill real-time requirements. This article derives relationships between information attributes and system performance. The performance measures are applied to a knowledge-based design system ( KBDS) for the synthesis of KBCS. The performance measures reflect intuitively satisfying properties of the KBDS and provide insights into the system not possible through a straight orward inspection of the program code. This type of system can be use...
Martingale conditions for the optimal control of continuous time stochastic systems

Abstract A martingale condition is shown to be sufficient for optimality in a generally formulated continuous time control problem. Under the additional assumption that the class of admissible control laws has an ϵ-lattice property, the same martingale property is shown also to be necessary for optimality. The method makes use of the P -ess inf of a class of measurable functions used by Rishel [4] in a less general formulation. The general result of the paper is applied to more specific Markov and stochastic differential equation models to obtain conditions for optimality for these models.
Mechanistic Studies on Histone Catalyzed Cleavage of Apyrimidinic/Apurinic Sites in Nucleosome Core Particles

Duplex DNA containing an apurinic/apyrimidinic (AP) lesion undergoes cleavage significantly more rapidly in nucleosome core particles (NCPs) than it does when free. The mechanism of AP cleavage within NCPs was studied through independently generating lesions within them. AP mediated DNA cleavage within NCPs is initiated by DNA–protein cross-link (DPCun) formation followed by β-elimination to give DPCs containing cleaved DNA (DPCcl). Hydrolysis of DPCcl produces a DNA single strand break (SSB). C2-dideuteration of AP showed that deprotonation from this position is involved in the rate-determining step. Experiments utilizing NCPs containing mutated histone H4 proteins indicated that lysine residues in the amino terminal tail are involved in both DPC formation and β-elimination steps. Lysines 16 and 20 seem to play a greater role in reacting with AP at superhelical location 1.5, but other amino acids (e.g., lysines 5, 8, and 12) compensate in their absence. The mechanism of rapid double strand breaks in bist...
Contrasting stratified plutons exposed in tilt blocks, Eldorado Mountains, Colorado River Rift, NV, USA

Abstract Roof-to-floor exposures of mid-Miocene plutons in tilt blocks south of Las Vegas, NV, reveal distinct but strongly contrasting magma chamber statigraphy. The Searchlight and Aztec Wash plutons are well-exposed, stratified intrusions that show a similar broad range in composition from ∼45–75 wt.% SiO 2 . Homogeneous granites that comprise about one-third of each intrusion are virtually identical in texture and elemental and isotopic chemistry. Mafic rocks that are present in both plutons document basaltic input into felsic magma chambers. Isotopic compositions suggest that mafic magmas were derived from enriched lithospheric mantle with minor crustal contamination, whereas more felsic rocks are hybrids that are either juvenile basaltic magma+crustal melt mixtures or products of anatexis of ancient crust+young (Mesozoic or Miocene?) mafic intraplate. Despite general similarities, the two plutons differ markedly in dimensions and lithologic stratigraphy. The Searchlight pluton is much thicker (∼10 vs. 3 km) and has thick quartz monzonite zones at its roof and floor that are absent in the Aztec Wash pluton. Isotopic and elemental data from Searchlight pluton suggest that the upper and lower zones are cogenetic with the granite; we interpret the finer grained, slightly more felsic upper zone to represent a downward migrating solidification front and the lower zone to be cumulate. In contrast, the upper part of the Aztec Wash pluton is granite, and a heterogeneous, mafic-rich injection zone with distinct isotopic chemistry forms the lower two-thirds of the intrusion. Similar mafic rocks are relatively sparse in Searchlight pluton and do not appear to have played a central role in construction of the pluton. Large felsic and composite dikes that attest to repeated recharging and intrachamber magma transfer are common in the Aztec Wash pluton but absent in the Searchlight pluton. Thus, although both intrusions were filled by similar magmas and both developed internal stratification, the two intrusions evolved very differently. The distinctions may be attributable to scale and resulting longevity and/or to subtle differences in tectonic setting.