cssi/SciSciGPT-SciSciNet huggingface dataset:
Modeling of Wake-vortex Aircraft Encounters

There are more people passing through the world's airports today than at any other time in history. With this increase in civil transport, airports are becoming capacity limited. In order to increase capacity and thus meet the demands of the flying public, the number of runways and number of flights per runway must be increased. In response to the demand, the National Aeronautics and Space Administration (NASA), in conjunction with the Federal Aviation Administration (FAA), airport operators, and the airline industry are taking steps to increase airport capacity without jeopardizing safety. Increasing the production per runway increases the likelihood that an aircraft will encounter the trailing wake-vortex of another aircraft. The hazard of a wake-vortex encounter is that heavy load aircraft can produce high intensity wake turbulence, through the development of its wing-tip vortices. A smaller aircraft following in the wake of the heavy load aircraft will experience redistribution of its aerodynamic load. This creates a safety hazard for the smaller aircraft. Understanding this load redistribution is of great importance, particularly during landing and take-off. In this research wake-vortex effects on an encountering 10% scale model of the B737-100 aircraft are modeled using both strip theory and vortex-lattice modeling methods. The models are then compared to wind tunnel data that was taken in the 30ft x 60ft wind tunnel at NASA Langley Research Center (LaRC). Comparisons are made to determine if the models will have acceptable accuracy when parts of the geometry are removed, such as the horizontal stabilizer and the vertical tail. A sensitivity analysis was also performed to observe how accurately the models could match the experimental data if there was a 10% error in the circulation strength. It was determined that both models show accurate results when the wing, horizontal stabilizer, and vertical tail were a part of the geometry. When the horizontal stabilizer and vertical tail were removed there were difficulties modeling the sideforce coefficient and pitching moment. With the removal of only the vertical tail unacceptable errors occurred when modeling the sideforce coefficient and yawing moment. Lift could not be modeled with either the full geometry or the reduced geometry attempts.
A realistic microcomputer exercise designed to teach geologic reasoning

A computer program we have developed simulates three-dimensional geology and permits beginning geology students to learn the thought processes used by geologists to develop regional histories. Designed to be a term project, the exercise shows students how scientific research supports analysis of geological problems. Given only the surface geology, students simulate drilling holes and staying within a fixed budget to unravel the subsurface geology. The computer handles budget details, provides a drill log at any desired location, offers multiple ways to visualize the drill-log data, and automates tedious work so students can concentrate on understanding concepts. By changing key variables, it is possible to create many different versions of the geology, so that each student's project is unique. The exercise integrates the topics covered in a first-semester physical-geology course, provides a challenge for students of all ability levels, and can be used to develop team skills.
MEMBRANE TRANSPORT PROCESSES IN AFFECTIVE ILLNESS

ABSTRACT Previous investigations have suggested that lithium transport, may be altered in erythrocytes (RBCs) from patients with bipolar affective disorder. The earliest studies measured the transmembrane distribution of lithium between RBCs and plasma during treatment with this agent, and the findings from different groups of investigators were contradictory. Subsequent studies showed that in vivo measurements of transmembrane lithium distribution are subject to several sources of experimental variability. To overcome these methodological difficulties, a number of investigators have studied transmembrane lithium distribution in vitro . Such in vitro investigations have provided some support for the idea that lithium transport by RBCs from bipolar patients may be altered as compared to control subjects. Such studies have also provided evidence of similar alterations in RBCs from the relatives of bipolar patients who themselves have a history of affective disorder. Only a limited number of studies have compared direct measurements of lithium efflux in various categories of subjects. These studies have generally found slightly lower mean lithium efflux rates in bipolar patients than in control subjects, although there is disagreement as to the statistical significance of this observation. Preliminary evidence from our laboratory suggests that simultaneous consideration of sodium influx in addition to lithium efflux substantially increases the significance of the difference between bipolar patients and control subjects. Our findings suggest that lithium and sodium transport by the Na+-Li+ countertransport system may be altered in a subgroup of patients with bipolar affective disorder. This chapter also briefly reviews the effects of lithium treatment on RBC membrane transport processes for lithium, sodium, and choline.
Roc Analysis of Mammography Alone and in Combination with Clinical Palpation for Breast Cancer Screening

Relative operating characteristic curves (ROCs) for mammography and clinical palpation individually and in combination are generated using screening data from Breast Cancer Detection Demonstration Project (BCDDP) No. 25. Comparative analysis of the ROCs illustrates the clear superiority of mammography over clinical palpation as an individual screening modality as well as the further superiority of the combined use of both modalities.
Super-Flexible Leadership: Aligning Knowledge Workers Through Peer-Peer Practices

How do business leaders keep knowledge workers emotionally engaged and intellectually focused? How do they set clear mandates, yet create room for entrepreneurial initiatives? How do they guide geo-distributed teams and provide a sense of community? Silicon Valley is an entrepreneurial ecosystem built on knowledge-based assets. A critical challenge is how to recruit, engage, motivate, develop, guide, and retain knowledge workers. This task presents a dilemma: On the one hand, knowledge workers do not want to be micro-managed; on the other hand, they have to be guided, coached, directed, and ultimately “aligned”.
Studies on the Gall Characteristics of Dryocosmus kuriphilus in Chestnut Genotypes in Yalova and Bursa Provinces of Turkey

The Asian chestnut gall wasp Dryocosmus kuriphilus is a global pest of chestnut (Castanea spp.). It has been spreading in Turkey’s forests and orchards since 2014. This pest imposes a big threat to the Turkish chestnut industry, which is among the top producers in the world. Its gall morphology has been related to pest pressure and host cultivar, thus eventually modulating plant damage with heavy impact on growth and fruit production. We compared gall characters (position on plant organ, ratios, dimensions, volumes, number of larval chambers) in wild Castanea sativa, two local cultivars and a Euro Japanese hybrid. Overall, leaf galls were more common (55.36%), followed by the stem (19.6%) and leaf stipule galls (15.29%). The mean number of chamber and volume value of gall types were 1.52-5.93 and 0.43-2.15 cm3, respectively. The highest values were observed in ‘stem gall’. The more gall formation was observed in the wild chestnut trees and ‘Marigoule’ than the other local varieties.
Extended Length of Stay After Lumbar Spine Surgery: Sick Patients, Postoperative Complications, or Practice Style Differences Among Hospitals and Physicians?

Background The degree to which extended length of stay (LOS) after surgery represents patient illness or postoperative complications is unknown. The aim of this study was to investigate the influence of postoperative complications and patient comorbidities on variance in extended length of hospital stay after lumbar spine surgery. Methods Data from the American College of Surgeons National Surgical Quality Improvement Program were analyzed from January 1, 2008, through December 31, 2014. Study participants were 23,102 patients undergoing a 1-level or 2-level lumbar decompression and fusion procedure. Multivariable logistic regression analysis was used to determine the odds ratio for risk-adjusted extended length of hospital stay, defined as patients with a hospital stay greater than the 75th percentile (LOS >5 days) for the cohort. The primary outcome was the extent to which extended LOS represented preoperative patient illness or postoperative complications. Results Of 23,102 participants, 3794 (16.42%) had extended LOS. Most patients (2849 patients; 75.10%) with extended LOS did not have a documented postoperative complication. Only a minority of patients with extended LOS had a history of comorbidities known to influence outcomes in patients undergoing spine surgery, including diabetes (24%), chronic obstructive pulmonary disease (7%), congestive heart failure (0.69%), myocardial infarction (0.20%), acute renal failure (0.26%), and stroke (2.23%). Conclusions This study suggests that much of the variation in LOS after lumbar spine surgery is not attributable to baseline patient illness or complications and most likely represents differences in practice style or surgeon preference.
Case Studies in the Environment: an Analysis of Author, Editor, and Case Characteristics

Who and what academic journals publish reflects and affects the broader social context in which they are embedded. Case Studies in the Environment (CSE) is a new peer-reviewed journal developed by UC Press due to the growing interest in environmental studies and the increasing use of case studies in teaching at all levels. This paper examines the gender and geographic distribution of authors and editors during CSE’s first year of publication, the geographic distribution of the case studies, and attitudes of authors regarding the journal’s purpose, format, and use in teaching. While studies of many journals reveal a predominance of male authors, women authors slightly outnumber men in CSE. Large majorities of the authors and editors are based at United States institutions and >90% are located in industrialized countries. Approximately half of the published articles present case studies from the US and nearly 75% are from industrialized countries. Authors reported being generally pleased with the purpose, format, and publishing logistics of the new journal.
Exchange rate movements, export sophistication and direction of trade: the development channel and North–South trade flows

We study the effects of real exchange rate (RER) changes on trade flows considering the skill content and origin/destination of products in a North–South framework. The empirical analysis is based on bilateral trade flows in five product categories of technology-and-skill intensities between 172 countries during 1962–2012. Consistent with the development channel, we find that both the composition and direction of trade affect how exports respond to RER changes. We find that high-skill manufactures and primary goods are the least affected from RER depreciation and volatility. The strongest effects are found for medium-skill, low-skill and resource-intensive manufactures. We also show that these effects depend on the direction of trade. Southern exports are more sensitive to RER than Northern exports in all product categories except for primary goods. Regarding volatility, South–North exports are hurt the most while North–South the least. Also, South–South exports appear to be less sensitive to volatility in all product groups than South–North. Overall, this paper provides a synthesis of the recent neoclassical international trade literature with the heterodox development literature.
Relaxed controls in infinite dimensional systems

We consider a semilinear control system in a Banach space E. Relaxed (i.e. probability measure — valued) controls are introduced in a way that avoids special assumptions (such as compactness) on the control set, with a view to obtaining automatic existence theorems for optimal control problems. Relaxed trajectories are shown to be the same as those defined by differential inclusions. The set of relaxed trajectories is closed and results on optimal control of systems driven by ordinary controls are easily shown to generalize to the relaxed control setting.
Organizing Pneumonia Induced by Ablative Radioembolization for the Treatment of Hepatic Metastatic Renal Cell Carcinoma

Organizing pneumonia is a recognized complication after external beam radiotherapy of breast and lung cancer but has not been described after radioembolization. A 67-year-old female who underwent ablative trans-arterial radioembolization for the treatment of hepatic metastatic renal cell carcinoma adjacent to the diaphragm presented with computed tomography findings of asymptomatic organizing pneumonia in the lower lobes. A follow-up computed tomography 8 months after conservative management demonstrated near-total resolution of the previous pulmonary parenchymal disease. The patient continues to remain asymptomatic and shows no evidence of residual tumor 10 months after radioembolization.
Market Shifts in the Sharing Economy: The Impact of Airbnb on Housing Rentals

This paper examines the impact of Airbnb on the local rental housing market. Airbnb provides landlords an alternative opportunity to rent to short-term tourists, potentially leading some landlords to switch from long-term rentals, thereby affecting rental housing supply and affordability. Despite recent government regulations to address this concern, it remains unclear how many and what types of properties are switching. Combining Airbnb and American Housing Survey data, we estimate a structural model of property owners' decisions and conduct counterfactual analyses to evaluate various regulations. We find that Airbnb mildly cannibalizes the long-term rental supply. Cities where Airbnb is more popular experience a larger rental supply reduction, but they do not necessarily have a larger percentage of switchers. Affordable units are the major sources of both the negative and positive impacts of Airbnb: they cause a larger rental supply reduction, which harms local renters; they also create a larger market expansion effect, which benefits local hosts who own affordable units and may be economically disadvantaged. Policy makers need to strike a balance between local renters' affordable housing concerns and local hosts' income source needs. We also find that imposing a linear tax is more desirable than limiting the number of days a property can be listed. We propose a new convex tax that imposes a higher tax on expensive units and show that it can outperform existing policies in terms of reducing cannibalization and alleviating social inequality. Finally, Airbnb and rent control can exacerbate each other's negative impacts.
Is it a subspace or not? Making sense of subspaces of vector spaces in a technology-assisted learning environment

The purpose of this research study was to understand how linear algebra students in a university in the United States make sense of subspaces of vector spaces in a series of in-depth qualitative interviews in a technology-assisted learning environment. Fourteen mathematics majors came up with a diversity of innovative and creative ways in which they coordinated visual and analytic approaches in the exploration of subspaces of a number of vector spaces such as $${\mathbb{R}}^n ,{\mathbb{R}}^{n \times n} ,{\mathbb{P}}_n$$ and $$C\left( {\mathbb{R}} \right)$$. In the demonstration of the closure property, the research participants embraced three different approaches in expressing the linear combination of $${\mathbf{u}}$$ and $${\mathbf{v}}$$: (i) $${\mathbf{u}} + {\mathbf{v}}$$ [type I notation]; (ii) $$c{\mathbf{u}} + {\mathbf{v}}$$ [type II notation]; and (iii) $$c{\mathbf{u}} + d{\mathbf{v}}$$ [type III notation]. Although the majority of the students embraced type I notation at the beginning; there was a considerable shift towards type II notation towards the end of the study. Although students’ visualizations on the DGS appeared at times to be in agreement with the vector sum notation analytically embraced, students still most of the time utilized the type I notation in their visualizations. The role of the zero vector manifested itself in three main categories: (i) to show nonemptiness of a subspace; (ii) to show the failure of closure property of a nonsubspace [e.g., $${\mathbf{u}},{\mathbf{v}} \in W,{\text{but}}\,{\mathbf{u}} + {\mathbf{v}} = {\mathbf{0}} \notin W$$]; (iii) to show nonsubspaceness by showing that $$0 \notin W$$. The zero vector seemed to be emphasized both within the visual approach and the analytic approach. Moreover, the visual approach did not prove necessary except for the nonsubspace explorations of certain cases. The paper concludes by offering pedagogical implications along with implications for the mathematics teaching profession and recommendations for further research.
Endobronchial high-intensity ultrasound for thermal therapy of pulmonary malignancies: simulations with patient-specific lung models.

AbstractObjective: This study investigates the feasibility of endobronchial ultrasound applicators for thermal ablation of lung tumors using acoustic and biothermal simulations.Methods: Endobronchi...
Platform Stabilization of Floating Offshore Wind Turbines by Artificial Muscle Based Active Mooring Line Force Control

The floating offshore wind turbine (FOWT) presents underactuation challenge for controls in terms of platform stability, power regulation, and increased structural loads, which demands for simple, low-cost, low-power, and high-bandwidth actuation concepts. In this article, an active mooring line force control (AMLFC) strategy is proposed based on a novel thermally actuated fishing line artificial muscle (FLAM) actuator. The proposed FLAM actuator consists of multiple bundles of twisted nylon fishing lines, which is added to the junction between the mooring lines and platform bars of FOWT with tensioned-leg platform (TLP). A simulation model of the FLAM actuator is developed in Simulink, along with an interface to the mooring line model of TLP-FOWT in NREL's FAST. The dynamic model of the FLAM actuator is obtained with ANSYS simulation, and a control-oriented model is obtained for the FOWT platform motion. A linear quadratic regulator is implemented for the FLAM-based AMLFC. Simulations are performed on the 5-MW WindPACT model for one Region-2 and one Region-3 scenarios. Simulation results show that, with mild power consumption, the proposed strategy can significantly reduce the platform roll motion and the tower-base side–side bending loads without little impact on the rotor speed and power output.
Existence of structured perfect Bayesian equilibrium in dynamic games of asymmetric information.

In~[1],authors considered a general finite horizon model of dynamic game of asymmetric information, where N players have types evolving as independent Markovian process, where each player observes its own type perfectly and actions of all players. The authors present a sequential decomposition algorithm to find all structured perfect Bayesian equilibria of the game. The algorithm consists of solving a class of fixed-point of equations for each time $t,\pi_t$, whose existence was left as an open question. In this paper, we prove existence of these fixed-point equations for compact metric spaces.
Exploring the Effects of Different Online Syllabus Formats on Student Engagement and Course-Taking Intentions

This study explores how different online syllabus formats affect students’ engagement and their course-taking intentions. Using a 2 (format: online learning management system vs. instructor’s websi...
In vivo Characterization of Four 18F-Labeled S1PR1 Tracers for Neuroinflammation.

The sphingosine-1-phosphate receptor 1 (S1PR1) is an important biomarker for imaging inflammation in the central nervous system (CNS). Herein, we report our recent evaluation of four 18F-labeled S1PR1 tracers (18F-TZ43113, 18F-TZ35104, 18F-TZ4877, and 18F-TZ4881) in a rat model of multiple sclerosis (MS). MicroPET studies of each tracer’s uptake and kinetics were performed in an experimental autoimmune encephalomyelitis (EAE) rat model of MS to quantify upregulated S1PR1 expression in the lumbar spinal cord of EAE rats. Western blot analysis was conducted to confirm the differences in the expression of S1PR1 protein level between EAE and sham rats. Radiometabolite analysis was performed for the most promising candidate in rats. All four S1PR1 tracers detected increased S1PR1 levels in response to neuroinflammation in the lumbar spinal cord of EAE rats, which was supported by western blot results. The ranked order of tracer uptake in rat spinal cord was 18F-TZ4877 > 18F-TZ4881 > 18F-TZ35104 > 18F-TZ43113. 18F-TZ4877 had the highest uptake of the four tracers and showed good kinetic modeling fits in rat spinal cord using an image-based method of arterial blood input function. Radiometabolite analysis of 18F-TZ4877 showed good in vivo stability with no major radiometabolite accumulation in the rat brain. Among these four new PET tracers, 18F-TZ4877 showed the most favorable profile for assessing S1PR1 expression in the EAE rat model of MS. Further characterization of these radiotracers in other models of neuroinflammation is warranted to identify a promising 18F-labeled tracer for imaging S1PR1 in vivo.
The basics of molecular pathology

Abstract Knowledge of the structure of the basic units of DNA, RNA, and proteins is invaluable for understanding the key concepts of in situ hybridization and immunohistochemistry. The reason is that, at its most basic, in situ hybridization and immunohistochemistry are simply biochemical reactions that occur in the aqueous environment of fixed cells and tissues. Indeed, in situ hybridization and immunohistochemistry are each basically high-throughput platforms in which each cell serves as the equivalent of an Eppendorf tube, meaning that in each experiment, you are doing hundreds of thousands of “mini-experiments.” This basic understanding will allow you to visualize the different forces that tend to affect annealing and denaturation of key reagents during in situ hybridization and immunohistochemistry. In this regard, it is very useful to also appreciate the three-dimensional macromolecule cross-linked network that is created when the cells and tissue are fixed in 10% buffered formalin. A key thread that goes throughout this book is that an appreciation of the role that the three-dimensional macromolecule cross-linked network plays during immunohistochemistry and in situ hybridization will greatly assist you in optimizing your in situ-based molecular pathology data.
Regulation of eIF6 through multisite and sequential phosphorylation by GSK3β

Abstract Eukaryotic translation initiation factor 6 is essential for the synthesis of 60S ribosomal subunits and for regulating the association of 60S and 40S subunits. A mechanistic understanding of how eIF6 modulates translation in response to stress, specifically starvation-induced stress, is lacking. Our studies have uncovered a novel mode of eIF6 regulation by GSK3 that is predominantly active in response to serum starvation. Human eIF6 is phosphorylated by GSK3β at a multisite motif in the C-terminus. Sequential phosphorylation by GSK3β requires phosphorylation at a priming site. In response to serum starvation, eIF6 accumulates in the cytoplasm and this altered localization is dependent on GSK3. Expression of the phosphodead mutant increases free 60S levels along with an enhanced inhibition of translation and cell growth in response to starvation. These results suggest that eIF6 regulation by GSK3β contributes to the attenuation of global protein synthesis that is critical for adaptation to starvation-induced stress.
Fourier Analysis of India's Implied Volatility Index

The objective of this study was to analyze and model periodic behavior observed in India's Nifty Implied Volatility (VIX) Index and to seek the origins of these previously unreported calendar variations. Implied volatility and its variations are important to understand as the pricing of many financial assets and derivatives depend upon this variable. A novel modeling approach to this task uses Fourier analysis for the first time in the literature of implied volatility and calendar effect modeling. For this purpose, daily closing levels for the Nifty VIX Index were gathered covering trading days from 2010 through January 2014. Time series of VIX levels after removing a trend line were tested for normality, stationarity, and autocorrelation. Nifty index and Nifty VIX data were also tested for two-way Granger causality. Detrended Nifty VIX levels were Fourier analyzed to determine primary Fourier frequencies contributing to VIX periodic behavior. A Fourier model of VIX movements was constructed using four primary frequencies from the Fourier power spectrum. This model showed surprising accuracy in identifying the temporal location of VIX peaks and troughs. The probable origin of one recurring VIX calendar frequency was traced to India's earnings release cycle.
Race and in-hospital mortality after spontaneous intracerebral hemorrhage in the Stroke Belt: Secondary analysis of a case-control study.

Background and Purpose: Intracerebral hemorrhage (ICH) accounts for around 10% of stroke, but carries 50% of stroke mortality. ICH characteristics and prognostic factors specific to the Stroke Belt are not well defined by race. Methods: Records of patients admitted to the University of Alabama Hospital with ICH from 2017 to 2019 were reviewed. We examined the association of demographics; clinical and radiographic features including stroke severity, hematoma volume, and ICH score; and transfer status with in-hospital mortality and discharge functional status for a biracial population including Black and White patients. Independent predictors of in-hospital mortality and functional outcome were examined using logistic regression. Results: Among the 275 ICH cases included in this biracial analysis, Black patients (n = 114) compared to White patients (n = 161) were younger (60.6 vs. 71.4 years, P < 0.0001), more often urban (81% vs. 64%, P < 0.01), more likely to have a history of hypertension (87% vs. 71%, P < 0.01), less often transferred (44% vs. 74%, P < 0.01), and had smaller median initial hematoma volumes (9.1 vs. 12.6 mL, P = 0.041). On multivariable analysis, Glasgow Coma Scale (GCS) for White patients (OR 13.0, P < 0.0001), hyperlipidemia for Black patients (OR 13.9, P = 0.019), and ICH volume for either race (Black patients: OR 1.05, P = 0.03 and White patients: OR 1.04, P < 0.01) were independent predictors of in-hospital mortality. Conclusions: Hypertension is more prevalent among Black ICH patients in the Stroke Belt. The addition of hyperlipidemia to the ICH score model improved the prediction of mortality for Black ICH patients. No differences in in-hospital mortality or poor functional outcome were observed by race.
Should explanation be a guide to ground

Grounding and explanation are said to be intimately connected. Some even maintain that grounding just is a form of explanation. But grounding and explanation also seem importantly different—on the face of it, the former is ‘worldy’ or ‘objective’ while the latter isn’t. In this paper, we develop and respond to an argument to the effect that there is no way to fruitfully address this tension that retains orthodox views about grounding and explanation but doesn’t undermine a central piece of methodology, namely that explanation is a guide to ground.
Cardiotoxic safety communications after FDA approval of novel cancer therapies.

e18629Background: Proliferation of novel anticancer therapies has dramatically improved survival. However, in practice, cardiovascular disease (CVD) events have become an increasing concern. Post-m...
Obsolescence, Forgotten: “Survivor Holograms”, Virtual Reality, and the Future of Holocaust Commemoration

“Survivor holograms” and a VR rendition of the Majdanek concentration camp are two recent examples of the urgent effort to preserve the experience of Holocaust survivors in the “post-witness era.” These innovations, however, deny the tension between the premise of immortality associated with immersive technologies and their inherent planned obsolescence. By closely studying the USC Shoah Foundation’s Dimensions in Testimony, this essay explores how 3D digital projections and room-scale VR construct new regimes of mediation and immersion. This is achieved by developing an understanding of obsolescence as physical (the fragile body of the survivor), technological (non-compatible hardware, software, and algorithms), and narratological (turning testimonies into fragmented soundbites). Taken together, these categories demonstrate that technological solutionism cannot prevent embodied testimonies from sinking into oblivion, and force us to ask what form of memorialization might resist entropy.
Antimicrobial copper alloy surfaces are effective against vegetative but not sporulated cells of gram-positive Bacillus subtilis

This study explores the role of membrane phospholipid peroxidation in the copper alloy mediated contact killing of Bacillus subtilis, a spore-forming gram-positive bacterial species. We found that B. subtilis endospores exhibited significant resistance to copper alloy surface killing but vegetative cells were highly sensitive to copper surface exposure. Cell death and lipid peroxidation occurred in B. subtilis upon copper alloy surface exposure. In a sporulation-defective strain carrying a deletion of almost the entire SpoIIA operon, lipid peroxidation directly correlated with cell death. Moreover, killing and lipid peroxidation initiated immediately and at a constant rate upon exposure to the copper surface without the delay observed previously in E. coli. These findings support the hypothesis that membrane lipid peroxidation is the initiating event causing copper surface induced cell death of B. subtilis vegetative cells. The findings suggest that the observed differences in the kinetics of copper-induced killing compared to E. coli result from differences in cell envelop structure. As demonstrated in E. coli, DNA degradation was shown to be a secondary effect of copper exposure in a B. subtilis sporulation-defective strain.
Student Loan Debt Does Not Predict Female Physicians’ Choice of Primary Care Specialty

OBJECTIVE: There has never been a conclusive test of whether there is a relation between ultimately choosing to be a primary care physician and one’s amount of student loan debt at medical school graduation.
Inhibition of PI3K contributes to nanoparticle-mediated exaggeration of endotoxin-induced leukocyte procoagulant activity (INC6P.340)

Nanoparticles are increasingly used in biomedical applications due to their ability to change biodistribution, increase safety and improve efficacy of drugs. However, application of engineered nanomaterials in medicine is often halted by safety concerns. Endotoxin contamination is very common in nanomaterials and there is an increasing number of studies reporting that certain nanoparticles can exaggerate endotoxin-mediated inflammation. We studied the relationship between physicochemical properties of polyamidoamine (PAMAM) dendrimers and their ability to exaggerate LPS-induced procoagulant activity (PCA) of human leukocytes in vitro. The PCA is phospholipid-protein complex composed of tissue factor (TF) and phosphotidylserine (PS). We found that cationic but not anionic or neutral PAMAM dendrimers, increase LPS-induced leukocyte PCA. Cationic PAMAM dendrimers enhanced both LPS-induced TF expression and PS exposure on the cell surface. The mechanism of LPS-induced PCA exaggeration by PAMAM dendrimers is not mediated by the electrostatic interaction between cationic dendrimers and anionic LPS, calcium influx and secondary messengers released by dendrimer activated platelets. We hypothesize that dendrimers exaggerate LPS-mediated PCA through the inhibition of negative regulation of inflammation. Specifically, we demonstrate that cationic PAMAM dendrimers inhibit phosphoinositol-3-kinase (PI3K), a negative regulator of TF expression in response to endotoxin.
Palaeoclimatic variation, adaptation and biogeography of inversion polymorphisms in natural populations of Drosophila robusta

Studies of natural and sexual selection in wild populations of Drosophila have historically provided strong inference for the maintenance of inversion polymorphism. Analysis of geographical variation in the Drosophila robusta chromosomal data collected over more than 50 years from 133 natural populations across eastern North America has confirmed several north–south and east–west clines in the frequencies of some gene arrangements and linked arrangement combinations. Patterns of geographical variation, including several north–south clines, revealed by regression and spatial autocorrelation analyses are concordant with palaeoclimatic shifts, Pleistocene glaciations and historical changes in the composition of North American forest communities. Because D. robusta is a sap-breeder, using the microbe-infested sap exudates of a number of deciduous tree species in which they carry out their life cycle, shifts in climate and palaeovegetation types since the formation of the eastern deciduous forests in the Miocene are hypothesized to be major factors influencing patterns of inversion polymorphisms across the range of this drosophilid species. In areas where sharp deviations in frequencies have been observed, particularly in the mid-western and western portions of the range, these divisions parallel historical geographical disjunctions in the species range that have yet to promote divergence and species formation despite the long history of D. robusta in North America. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 81, 395–411.
Stage B heart failure: is it more common than we think?

The American College of Cardiology/American Heart Association endorse a scheme embracing the progressive nature of heart failure (HF), which exists as a continuum from asymptomatic, at-risk individuals to those with progressively more symptomatic disease [(1)][1]. Patients with HF risk factors such
Viewpoint On public service and computer science

Members of the computer science community should become more involved in public service by becoming program managers at federal agencies, the opportunities and benefits of which are outlined here.
Epitaxial Multiferroic BiFeO3 Thin Films: Progress and Future Directions

We write this article in honor of Professor Vitaly L. Ginzburg, truly the father of the field of ferroelectricity. This article serves as a review of the current state of research pertaining to multiferroic BiFeO 3 thin films. In this review we will delve into details of the growth of BiFeO 3 thin films and the use of piezoforce microscopy and x-ray reciprocal space mapping to characterize the crystal structure and domain structure of BiFeO 3 . We will also discuss the use of vicinal and asymmetric substrates to simplify the domain structure in BiFeO 3 . By simplifying the domain structure we can, in turn, control the ferroelectric switching mechanisms in BiFeO 3 . Finally we describe the basic ferroelectric properties of BFO films and discuss the critical issues needed to be solved in BiFeO 3 films including leakage, complex domain structure, coercivity, and reliability. Such results are promising for continued exploration for detailed multiferroic-coupling studies in the magnetoelectric BiFeO 3 system a...
Nonlinear absorption and refraction in CuCl at 532 nm

We report two-photon absorption in CuCl and its polarization dependence to give all three χ(3) tensor elements at 532 nm. We also report bound electronic n2 and free-carrier refraction in CuCl. The values obtained are each approximately one half the corresponding values for ZnSe. Previously, with ZnSe, the large two-photon absorption (2PA) and negative bound-electronic nonlinear refraction were combined with defocusing from 2PA-generated free carriers to provide effective optical limiting for visible picosecond input pulses. For nanosecond pulses thermal refraction is a problem because it leads to self focusing, and thus damage in ZnSe and most other semiconductors studied. However, the thermal refraction in CuCl is reported to be self-defocusing. Thus one might expect the self-protection properties of CuCl to be better than those of ZnSe for optical-limiting applications for nanosecond input pulses.
Effect of pressure on metal-die heat transfer coefficient during solidification

Abstract A combined theoretical and experimental program was carried out to study the effect of applied pressure and die coatings on the heat transfer coefficient at the metal-die interface during solidification of AlSi eutectic alloy against an H-13 die. The castings were unidirectionally solidified in a commercial hydraulic press modified to accept a controlled temperature die set. The die thermal behavior was experimentally determined from thermocouples located at different distances from the metal-die interface. A one-dimensional computer heat flow program was used to correlate measured and simulated die temperatures and hence to deduce the heat transfer coefficients. It was found that application of a pressure of 19.6 × 107 Pa increases the heat transfer coefficient from about 3.4 × 103 to 5.25 × 104 W m−2 K−1. The effects of different die coatings on the heat transfer coefficient were also determined.
Oxytocin, prostaglandins E and F, estradiol, progesterone, sodium, and potassium in preovulatory bovine follicles either developed normally or stimulated by follicle stimulating hormone☆

Abstract To determine the differences between stimulation by follicle stimulating hormone (FSH) and normal development of follicles in heifers and the endocrinologic events associated with ovulatory development of follicles in heifers, follicular fluid was aspirated from follicles (n = 627) at 24, 48, and 72 h after estrus synchronization (via prostaglandin F2α (PGF2α)) from control animals (n = 10/time period) and a treatment group (n = 10/time period) that received FSH. No endocrinologic or ionic differences were noted between follicles harvested from control or FSH-stimulated animals within follicular size or time (24, 48, or 72 h). No interaction of treatment (FSH stimulation vs controls) by time was detected; thus the effect and timing of the LH surge was similar between treatments. At 48 h after PGF2α administration, sodium from follicular fluid decreased and potassium increased, signifying a considerable physiologic change in the follicle. Follicular prostaglandins E and F increased ten-fold by 72 h, and these changes were primarily found in the estrogen-inactive follicles at 72 h. Though progesterone concentrations within follicular fluid tended to increase throughout the three periods and increased with enlargement of follicular size, a major increase was detected 72 h after PGF2α injection. Estradiol concentrations tended to increase with enlargement of follicular size within a time period, but estradiol concentrations in the follicles greater than 10 mm in diameter decreased with time (24, 48, and 72 h) after PGF2α. Concentrations of oxytocin increased with increases in follicular diameter, and the time trends were similar to changes in follicular progesterone. By 72 h after PGF2α administration, follicular estradiol) was decreasing in concentration and progesterone and oxytocin were increasing, thus signifying a change in the secretory role of the granulosa cells.
RENT DISSIPATION AND THE SOCIAL COST OF PRICE POLICY

This paper uses a general equilibrium-based exchange economy model to examine rent seeking for a price policy. Opposing interests spend resources to influence the government's choice of a price vector. Rents, the willingness to pay for the policy, are determined endogenously from the Nash equilibirum of a non-cooperative game. Numerical simulations explore the degree to which rents are dissipated by wasteful rent seeking. It is found that dissipation, measured as the ratio of rent-seeking costs to rents garnered, can grow without limit, and is greatest when opponents are evenly matched. Dissipation is smallest with widely disparate groups, a result that might help explain the underdissipation that seems to occur in many industries.
A Universal Aerosol Sampling Probe for High Efficiency Particle sampling from flowing gas streams

An aerosol sampling inlet has been developed to collect representative samples from the flowing gas stream. The inlet is referred to as the “Universal Aerosol Sampling Probe” because it is capable of efficient sampling over a wide range of free stream velocity without the need to change either the probe tip or sampling flow rate. It is a multi-nozzle device consisting of one or more outer nozzles to extract a sample isokinetically and decelerate it from the relatively high stream velocity to a relatively low velocity. An inner nozzle is then used to extract a representative particle sample for delivery to the impactor or other particle collectors placed downstream. The approach enables a representative particle sample to be extracted at a fixed flow rate, irrespective of the velocity of the gas stream in which the probe is placed. The theoretical considerations leading to the design of such a universal probe are described. It is followed by the description of an experimental evalution of a prototype device. Good agreement was found between the experimental results and the theoretical prediction.
Transgressions and Transformations: Initiation Rites among Urban Portuguese Boys

In the absence of institutionalized, adult-guided initiation rites in the community of Ajuda in Lisbon, Portugal, nine-and ten-year old boys constructed their own rites in the peer group. These rites consisted of a combination of rampages throughout the community and narrative performances about those experiences in the peer group. Both the rampages and the narratives exhibit features traditionally associated with rites of passage. This article applies traditional concepts in novel ways that may prove promising in studying initiation rites in other contemporary, Western, urban societies.
Eddy diffusion transport of Arctic pollution from the mid-latitudes: A preliminary model☆

Abstract Arctic haze, which here refers to aerosol particles of submicron size permeating the atmosphere of the northern polar regions, is a phenomenon showing strong and annually repeatable seasonal variations, with maxima in winter and early spring and minima in summer. This paper describes an eddy diffusion model which was constructed to understand that part of the haze (apparently its largest part) due to pollution sources at the mid-latitudes. The model is applied to the transport of emitted anthropogenic sulfur. The modeling has tentatively identified Arctic cloudiness amount as the controlling factor which gives rise to the tenfold seasonal changes of Arctic air pollution; it also has provided, within a factor of 2, the correct magnitude of the aerosol mass loading in the arctic regions and has allowed a rough estimate to be made of the possible impact on Arctic air quality as industrialization moves northward. Future development of mining, petroleum extraction, smelting, refining, and manufacturing is expected to double every 15–20 years, and in another 50 years arctic haze may be serious enough to cause significant heating of the atmosphere of the northern polar regions.
Is Prudden's Unit Type of Anasazi Settlement Valid and Reliable?:

Validity and reliability assessments of established anthropological concepts are rare. In this paper we assess the soundness and dependability of one of the oldest concepts of Southwestern prehistory. T. Mitchell Prudden associated a distinctive kind of Anasazi settlement, the unit type, with a particular form of social organization in 1914. Since then, his idea has played a prominent role in Anasazi archaeological theories. These formulations are justifiable only if Prudden's idea is valid and reliable. Aspects of Anasazi architectural design and construction have been used as empirical indicators of the unit type of settlement. The relationship between Prudden's concept and its architectural indicators is examined with a sample of archaeological sites claimed to be of the unit type. Although they are reliable, we find that the architectural indicators are invalid because they measure concepts other than Prudden's. Moreover, we find that there is more than one unit type of settlement that must be conside...
Application of GPS in Traffic Management Systems

Integrated Traffic Management Systems (ITMS) need reliable, accurate, and real-time data. Travel time, speed, and delay are three of the most important factors used in ITMS for monitoring, quantifying, and controlling congestion. GPS has recently become available for civil applications. Because it provides real-time spatial and time measurements, it has an increasing use in conducting different transportation studies. This article presents the application of GPS in collecting travel time, speed, and delay information of 64 major roads in the state of Delaware. A comparative statistical analysis was performed on data collected by GPS, with data collected simultaneously by the conventional method. The GPS data proved to be at least as accurate as the data collected by the conventional method, and it was 50% more efficient in terms of manpower. Moreover, the sample-size requirement was determined to maintain 95% confidence level throughout the controlled test. Benefiting from the Geographic Information System's dynamic segmentation tool, our travel time, delay, and speed information were integrated with other relevant traffic data. This was presented graphically on the Internet for public use. Statistical trend analysis for the data collected in 1997, 1998, 1999, and 2000 are also presented and applications on the overall ITMS are discussed. © 2002 Wiley Periodicals, Inc.
Facial skeletal augmentation using hydroxyapatite cement.

• This study investigates the use of a new calcium phosphate cement, which sets to solid, microporous hydroxyapatite, for facial bone augmentation. In six dogs, the supraorbital ridges were augmented bilaterally with this hydroxyapatite cement. On one side, the hydroxyapatite cement was placed directly onto the bone within a subperiosteal pocket. On the opposite side, the cement was contained within a collagen membrane tubule and then inserted into a subperiosteal pocket. The use of collagen tubules facilitated easy, precise placement of the cement. All implants maintained their original augmented height throughout the duration of the study. They were well tolerated without extrusion or migration, and there was no significant sustained inflammatory response. Histologic studies, performed at 3, 6, and 9 months revealed that when the cement was placed directly onto bone, progressive replacement of the implant by bone (osseointegration of the hydroxyapatite with the underlying bone) without a loss of volume was observed. In contrast, when the cement-collagen tubule combination was inserted, primarily a fibrous union was noted. Despite such fibrous union, the hydroxyapatite-collagen implant solidly bonded to the underlying bone, and no implant resorption was observed. Hydroxyapatite cement can be used successfully for the experimental augmentation of the craniofacial skeleton and may be applicable for such uses in humans. (Arch Otolaryngol Head Neck Surg. 1993;119:185-190)
A new high pressure form of DyF3

Abstract A new high-pressure phase of DyF 3 has been formed at 11.6 kb at 265°C in a hexahedral pressure apparatus. The new form shows a characteristic principal x-ray reflection corresponding to d-spacing 3.35A, and is metastable at ambient conditions for short periods of time.