cssi/SciSciGPT-SciSciNet huggingface dataset:
Data assimilation optimization for the evaluation of inverse mixing and convection flows

A data assimilation approach is developed for evaluation of fluid-thermal systems wherein a complete specification of the boundary conditions is not known a priori and experimental diagnostics are restricted to a limited region of the flowfield. The methodology is applied to the configuration of a heated jet injected into a laminar boundary layer where the jet temperature and velocity are unknowns. The closed loop method selects the initial locations for the experimental measurements of mean temperature within the flowfield using diode laser absorbance. Diode laser absorption measurements near 761 nm of molecular oxygen are recorded to characterize the time varying temperature of the two dimensional jet. The Response Surface Models built using two-dimensional unsteady Navier–Stokes simulations are used to predict the jet exit temperature and velocity, and select the second set of locations for the experimental measurements. The two sets of experimental data are used to generate the final prediction for the jet exit temperature and velocity. The jet exit velocity is correctly predicted to within the experimental uncertainty; however, the jet exit temperature is over-estimated by 9% to 23%.
Controlling human utilization of shared resources via taxes

We study a general resource sharing game where overutilization by selfish decision makers leads to possible failure of the resource. Our goal is to understand the effectiveness of a taxation mechanism in reducing the utilization and fragility of the resource when players have behavioral risk preferences. In particular, we incorporate risk preferences drawn from prospect theory, an empirically validated behavioral model of human decision making. We first identify counter-intuitive behavior under prospect theory, where utilization (and hence fragility) can increase under taxation, depending on the resource characteristics. We then identify conditions under which taxation is effective in reducing the fragility of the resource. We also show that homogeneous sensitivities to taxes leads to smaller failure probability compared to the case where players have heterogeneous (player-specific) sensitivities to taxes.
Cümülön-D: data analytics in a dynamic spot market

We present a system called Cumulon-D for matrix-based data analysis in a spot market of a public cloud. Prices in such markets fluctuate over time: while users can acquire machines usually at a very low bid price, the cloud can terminate these machines as soon as the market price exceeds their bid price. The distinguishing features of Cumulon-D include its continuous, proactive adaptation to the changing market, and its ability to quantify and control the monetary risk involved in paying for a workflow execution. We solve the dynamic optimization problem in a principled manner with a Markov decision process, and account for practical details that are often ignored previously but nonetheless important to performance. We evaluate Cumulon-D's effectiveness and advantages over previous approaches with experiments on Amazon EC2.
Effects of cannabinoids on reproductive organs in the female Fischer rat.

Abstract We investigated the effects of Δ 9 -tetrahydrocannabinol (Δ 9 -THC) and crude marihuana extract (CME) given orally on the ovaries, uteri and adrenals in the Fischer rat. Dosages of 1, 5 and 25 mg/kg Δ 9 -THC and 3, 15 and 75 mg/kg CME were administered daily for 72 d. Both vehicle-intubated and untreated controls were included. Half the animals were continued another 30 d without treatment (recovery period). After 72 d treatment uterine and ovarian weights were considerably reduced in animals treated with the highest dose of either Δ 9 -THC or CME. In animals allowed to recover from treatment for 30 d uteri and ovaries had regained their weights to approximately 85–90% of that of the controls. Based on the above organ weights, on reproductive tract histology and on vaginal smear analysis, we conclude that Δ 9 -THC and CME prolong the diestrus stage of the cycle.
Spectral-Temporal Modulated Ripple Discrimination by Children With Cochlear Implants.

Objectives A postlingually implanted adult typically develops hearing with an intact auditory system, followed by periods of deafness (or near deafness) and adaptation to the implant. For an early implanted child whose brain is highly plastic, the auditory system matures with consistent input from a cochlear implant. It is likely that the auditory system of early implanted cochlear implant users is fundamentally different than postlingually implanted adults. The purpose of this study is to compare the basic psychophysical capabilities and limitations of these two populations on a spectral resolution task to determine potential effects of early deprivation and plasticity. Design Performance on a spectral resolution task (Spectral-temporally Modulated Ripple Test [SMRT]) was measured for 20 bilaterally implanted, prelingually deafened children (between 5 and 13 years of age) and 20 hearing children within the same age range. Additionally, 15 bilaterally implanted, postlingually deafened adults, and 10 hearing adults were tested on the same task. Cochlear implant users (adults and children) were tested bilaterally, and with each ear alone. Hearing listeners (adults and children) were tested with the unprocessed SMRT and with a vocoded version that simulates an 8-channel cochlear implant. Results For children with normal hearing, a positive correlation was found between age and SMRT score for both the unprocessed and vocoded versions. Older hearing children performed similarly to hearing adults in both the unprocessed and vocoded test conditions. However, for children with cochlear implants, no significant relationship was found between SMRT score and chronological age, age at implantation, or years of implant experience. Performance by children with cochlear implants was poorer than performance by cochlear implanted adults. It was also found that children implanted sequentially tended to have better scores with the first implant compared with the second implant. This difference was not observed for adults. An additional finding was that SMRT score was negatively correlated with age for adults with implants. Conclusions Results from this study suggest that basic psychophysical capabilities of early implanted children and postlingually implanted adults differ when assessed in the sound field using their personal implant processors. Because spectral resolution does not improve with age for early implanted children, it seems likely that the sparse representation of the signal provided by a cochlear implant limits spectral resolution development. These results are supported by the finding that postlingually implanted adults, whose auditory systems matured before the onset of hearing loss, perform significantly better than early implanted children on the spectral resolution test.
Evaluation of a deep learning architecture for MR imaging prediction of ATRX in glioma patients

Predicting mutation/loss of alpha-thalassemia/mental retardation syndrome X-linked (ATRX) gene utilizing MR imaging is of high importance since it is a predictor of response and prognosis in brain tumors. In this study, we compare a deep neural network approach based on a residual deep neural network (ResNet) architecture and one based on a classical machine learning approach and evaluate their ability in predicting ATRX mutation status without the need for a distinct tumor segmentation step. We found that the ResNet50 (50 layers) architecture, pre trained on ImageNet data was the best performing model, achieving an accuracy of 0.91 for the test set (classification of a slice as no tumor, ATRX mutated, or mutated) in terms of f1 score in a test set of 35 cases. The SVM classifier achieved 0.63 for differentiating the Flair signal abnormality regions from the test patients based on their mutation status. We report a method that alleviates the need for extensive preprocessing and acts as a proof of concept that deep neural network architectures can be used to predict molecular biomarkers from routine medical images.
A Learning-Based Method for Generating Synthetic Power Grids

Analysis and improvement of power grids resilience and efficiency requires the topologies and geographical coordinates of the real transmission networks. However, due to security reasons, such topologies and particularly the locations of the substations and lines are usually not publicly available. In this work, we thoroughly study the structural properties of the U.S. Western Interconnection grid (WI) and, based on the results, present the network imitating method based on learning (NIMBLE) for generating synthetic spatially embedded networks with similar properties to a given grid. We apply NIMBLE to the WI and show that it can generate networks with similar structural and spatial properties as well the same level of robustness to failures to the WI, without revealing the real locations of the lines and substations. To the best of our knowledge, this is the first attempt to consider the spatial distributions of the buses (nodes) and lines and their importance in generating synthetic grids. Moreover, this is the first time that the power flows and vulnerability against failures are considered in evaluating a synthetic power grid.
College Writing and Campus Values: The Nixon Library Debate at UC Irvine

This article examines a debate from the early 1980s about siting the Nixon Presidential Library at UC Irvine. I analyze the debate as it unfolds across the pages of the campus newspaper, exploring the interplay between literacy and geography to document how the newspaper provides a venue for inhabitants of the campus and the surrounding area to wrangle over the academic, civic, and regional responsibilities of UCI. The ideological fault lines that emerge are evidence that campus values are, much like the campus itself, an evolving construction to which college writing has much to contribute. I conclude by calling upon teacher-scholars to sustain and diversify the array of literacy practices associated with college campuses by using newspapers and other campus publications for research, pedagogy, and other curricular and cocurricular ends.
The Shapes of the Radiation Dose-Mutation Response Curves in Drosophila: Mechanisms and Implications

The major thesis we wish to make in this presentation is that radiation induced mutations, namely sex-linked recessive lethals in Drosophila and forward mutations at specific loci in Drosophila, mammals and lower eucaryotes, are the result of two sub-lesions or hits, induced by either single ionization tracks or by the interaction of two independent tracks for low LET radiations, when the dose is delivered in an acute fashion. This statement formally reduces to the well recognized linear quadratic expression: Y = C + αD + βD2 where C is the spontaneous frequency of events scored and α and β represent the coefficients of the dose. In practice, the curve is more complex because saturation occurs at high doses. This linear-quadratic relationship is most often applied to the yield of gross chromosome aberrations in plant and animal systems and was first demonstrated by Sax (1940). Lea (1955) and subsequently Neary (1965) and Kellerer and Rossi (1972) have developed the biophysical and microdosimetric framework for the empirically derived dose-response relationship.
Targeting the PI3K/AKT/mTOR Pathway in Prostate Cancer

The PI3K/AKT/mTOR pathway is one of the most frequently altered pathways in human cancers. Although the loss of function of PTEN in prostate cancer increases the activity of the PI3K/AKT/mTOR pathway, clinical studies thus far have been disappointing. Studies of the mammalian target of rapamycin (mTOR) inhibitors rapamycin, everolimus, and temsirolimus when used as single-agents failed to demonstrate significant clinical activity in metastatic castration-resistant prostate cancer (CRPC) patients. Novel inhibitors of this pathway such as dual inhibitors of the phosphatidylinositol 3-kinase (PI3K) and mTOR pathway are now in clinical development. The most promising future use of these agents will likely be in combination with other agents such as potent AR pathway inhibitors.
Clinical Update: Transgender HIV Prevention: A Model Education Workshop

A university-based human sexuality program collaborated with transgender and HIV/AIDS community organizations to develop one of the first HIV prevention programs targeting the transgender community. Based on focus group data outlining specific intervention needs, we designed, implemented, and evaluated a model prevention education workshop. The 4-hour workshop included large- and small-group meetings with presentations, discussions, role playing, and exercises based on the Health Belief Model, the Eroticizing Safer Sex approach to HIV prevention, and principles of personal and community empowerment. Transgender-sensitive audiovisual materials were developed; sexually explicit materials were incorporated. Transgender peer educators facilitated the workshop. This clinical update reviews the empirical and theoretical background of the workshop and discusses its development and implementation.
Up to a Limit?: Privacy Concerns of Bystanders and Their Willingness to Share Additional Information with Visually Impaired Users of Assistive Technologies

The emergence of augmented reality and computer vision based tools offer new opportunities to visually impaired persons (VIPs). Solutions that help VIPs in social interactions by providing information (age, gender, attire, expressions etc.) about people in the vicinity are becoming available. Although such assistive technologies are already collecting and sharing such information with VIPs, the views, perceptions, and preferences of sighted bystanders about such information sharing remain unexplored. Although bystanders may be willing to share more information for assistive uses it remains to be explored to what degree bystanders are willing to share various kinds of information and what might encourage additional sharing of information based on the contextual needs of VIPs. In this paper we describe the first empirical study of information sharing preferences of sighted bystanders of assistive devices. We conducted a survey based study using a contextual method of inquiry with 62 participants followed by nine semi-structured interviews to shed more insight on our key quantitative findings. We find that bystanders are more willing to share some kinds of personal information with VIPs and are willing to share additional information if higher security assurances can be made by improving their control over how their information is shared.
Eosinophilic Gastrointestinal Disorders

Eosinophilic gastrointestinal disorders (EGID) are a group of disorders characterized by pathologic eosinophilic infiltration of the esophagus, stomach, small intestine, or colon leading to organ dysfunction and clinical symptoms (J Pediatr Gastroenterol Nutr; Spergel et al., 52: 300-306, 2011). These disorders include eosinophilic esophagitis (EoE), eosinophilic gastritis (EG), eosinophilic gastroenteritis (EGE), eosinophilic enteritis (EE), and eosinophilic colitis (EC). Symptoms are dependent not only on the location (organ) as well as extent (layer invasion of the bowel wall). Common symptoms of EoE include dysphagia and food impaction in adults and heartburn, abdominal pain, and vomiting in children. Common symptoms of the other EGIDs include abdominal pain, nausea, vomiting, early satiety, diarrhea, and weight loss. These disorders are considered immune-mediated chronic inflammatory disorders with strong links to food allergen triggers. Treatment strategies focus on either medical or dietary therapy. These options include not only controlling symptoms and bowel inflammation but also on identifying potential food triggers. This chapter will focus on the clinical presentation, pathophysiology, and treatment of these increasingly recognized disorders.
The Possible Effects of Emotional Stress on Cancer Mediated through the Immune System

The complex pathological changes which we collectively call cancer present a series of complicated interactions within the interrelated systems of the body. It is not unreasonable, therefore, that consideration should be given to the possible ways in which the malignant process and the higher centers of the nervous system interact. Although a good deal of attention has been given to the consequences of malignancy on the central nervous system apart from the mechanical effects of metastasis, there is a growing awareness that the areas of the brain collectively concerned with emotions may in turn modify the development and progression of cancer. It is this latter aspect which will be considered in this paper.
Mothers’ adverse childhood experiences, depressive symptoms, parenting, and attachment as predictors of young children’s problems

Given that young children of mothers with adverse childhood experiences (ACEs) exhibit increased risk for maladaptive outcomes (including being maltreated by their caregivers), this study investiga...
The Effects of Funding Change and Reorganization on Patterns of Emergency Response in a Local Health Agency

Indicators for Stress Adaptation Analytics (ISAAC) is a protocol to measure the emergency response behavior of organizations within local public health systems. We used ISAAC measurements to analyze how funding and structural changes may have affected the emergency response capacity of a local health agency. We developed ISAAC profiles for an agency's consecutive fiscal years 2013 and 2014, during which funding cuts and organizational restructuring had occurred. ISAAC uses descriptive and categorical response data to obtain a function stress score and a weighted contribution score to the agency's total response. In the absence of an emergency, we simulated one by assuming that each function was stressed at an equal rate for each of the two years and then we compared the differences between the two years. The simulations revealed that seemingly minor personnel or budget changes in health departments can mask considerable variation in change at the internal function level.
Highly Sensitive Fiber Optic Pressure Sensor Based on Silica Diaphragm Fabricated by MEMS

This paper presents the fabrication procedure of a 1.2-μm thick silica diaphragm with high uniformity using microelectromechanical systems (MEMS) technique. The diaphragm fabrication started from a commercially available double-polished 300-μm silicon wafer with a silica layer on its bottom. The silica diaphragm was released from the wafer by photolithography, wet etching and inductively coupled plasma (ICP) etching. A fiber optic Fabry-Perot (FP) pressure sensor was made by thermally bonding the diaphragm to the end face of an etched fiber with an outside diameter of 125 μm. The obtained sensor has a static pressure sensitivity of 12.4 nm/kPa (85.3 nm/psi). It has a great potential to work in medical applications where miniature size and high sensitivity are essential.
Synovial fluid lubricin and hyaluronan are altered in equine osteochondral fragmentation, cartilage impact injury, and full-thickness cartilage defect models.

The objectives of this study were to evaluate temporal changes in lubricin, hyaluronan (HA), and HA molecular weight (MW) distributions in three distinct models of equine joint injury affecting the carpal (wrist), tarsal (ankle), and femoropatellar (knee) joints. To establish ranges for lubricin, HA, and HA MW distributions across multiple joints, we first evaluated clinically healthy, high-motion equine joints. Synovial fluid was collected from high-motion joints in horses without clinical signs of joint disease (n = 11 horses, 102 joints) and from research horses undergoing carpal osteochondral fragmentation (n = 8), talar cartilage impact injury (n = 7), and femoral trochlear ridge full-thickness cartilage injury (n = 22) prior to and following arthroscopically induced joint injury. Lubricin and HA concentrations were measured via enzyme-linked immunosorbent assays, and gel electrophoresis was performed to evaluate HA MW distributions. Synovial fluid parameters were analyzed via linear regression models, revealing that lubricin and HA concentrations were conserved across healthy, high-motion joints. Lubricin concentrations increased post-injury in all osteoarthritis models (carpal fragmentation P = .001; talar impact P < .001; femoral trochlear ridge cartilage defect P = .03). Sustained loss of HA was noted post-arthroscopy following carpal osteochondral fragmentation (P < .0001) and talar impact injury (P < .001). Lubricin may be elevated to compensate for the loss of HA and to protect cartilage post-injury. Further investigation into the mechanisms regulating lubricin and HA following joint injury and their effects on joint homeostasis is warranted, including whether lubricin has value as a biomarker for post-traumatic osteoarthritis.
Informal multimedia biodiversity awareness event as a digital ecology for promoting culture of science

Using self-determination theory, this study investigated the influence of a multimedia-enhanced informal biodiversity awareness event on the evolving culture of science and internal and external motivation to take environmental action among the members of a small community in Southeastern US. The event was hosted by a local life and science museum and featured three main components: a) opening session by experts in biodiversity; b) animated video about biodiversity; and c) follow-up conversation with scientists. Motivation for Environmental Action survey was used to examine public’s motivation to take action to protect biodiversity prior to and upon finishing the event. Semi-structured interviews were employed to investigate public’s evolving culture of science. Ordinal regression analysis suggested that public’s internal motivation was positively associated with a greater number of actions taken to protect biodiversity. University students were less likely to take actions to protect biodiversity than other members of the public. Interestingly, the increase in internal motivation was larger for students than for non-students, suggesting that even a relatively short informal biodiversity awareness event can impact community’s motivation, especially among those who were not particularly motivated to take actions to protect biodiversity prior to the event.
The effect of Medicaid expansion on use of opioid agonist treatment and the role of provider capacity constraints

Objective To determine the effect of Medicaid expansion on the use of opioid agonist treatment for opioid use disorder (OUD) and to examine heterogeneous effects by provider supply and Medicaid acceptance rates. Data sources Yearly state-level data on methadone dispensed from opioid treatment programs (OTPs), buprenorphine dispensed from OTPs and pharmacies, number of OTPs and buprenorphine-waivered providers, and percent of OTPs and physicians accepting Medicaid. Study design This study used difference-in-differences models to examine the effect of Medicaid expansion on the amount of methadone and buprenorphine dispensed in states between 2006 and 2017. Interaction terms were used to estimate heterogeneous effects. Sensitivity analyses included testing the association of outcomes with Medicaid enrollment and state insurance rates. Principal findings The estimated effects of Medicaid expansion on buprenorphine and methadone dispensed were positive but imprecise, meaning we could not rule out negative or null effects of expansion. The estimated associations between state insurance rates and dispensed methadone and buprenorphine were centered near zero, suggesting that improvements in health coverage may not have increased OUD treatment use. The effect of Medicaid expansion was larger in the states with the most waivered providers compared to states with the fewest waivered providers. In the states with the most waivered providers, the average estimated effect of expansion on buprenorphine dispensed was 12 kg/y, enough to treat about 7500 individuals. We did not find evidence that the effect of expansion was consistently modified by OTP concentration, OTP Medicaid acceptance, or physician Medicaid acceptance. Conclusions Gains in health coverage may not be sufficient to increase OUD treatment, even in the context of high treatment need. Provider capacity likely limited Medicaid expansion's effect on buprenorphine dispensed. Policies to increase buprenorphine providers, such as ending the waiver requirement, may be needed to ensure coverage gains translate to treatment access.
Chapter 17 – Optical transmission

In this chapter, we address optical communications as a subject separate from other transmission systems because of their interdependence with optical technology and inherent differences due to the extremely high carrier frequencies. We present an overview of the devices necessary for this type of communication and then address design options and the applications they are best suited to. Our goal is not to present a complete description of optical communications; rather, we focus on the differences between RF and optical, hoping to provide classical communications engineers enough information to begin to explore this highly applicable huge-capacity communication medium.
Impact of dispersant on crude oil content of airborne fine particulate matter emitted from seawater after an oil spill.

Abstract Inhalation of PM2.5, particles with an aerodynamic diameter The highest PM2.5 concentration (20.83 ± 5.21 μg/m3) was released from a slick of DOR 1:25, 8.83× greater than the case with pure crude oil. The average ratio of crude oil content from the slick of DOR 1:25 to the case with pure crude oil was 2.37 (1.83 vs 0.77 μg/m3) that decreased to 1.17 (0.90 vs 0.77 μg/m3) at DOR 1:100. For particles
Sexually selected traits as bioindicators: exposure to mercury affects carotenoid-based male bill color in zebra finches

To examine whether sexually selected traits are particularly sensitive bioindicators of environmental toxicants, we assessed the effects of exposure to environmentally relevant dietary concentrations of the pollutant methylmercury on pigment coloration in zebra finches (Taeniopygia guttata). First, we tested whether effects of methylmercury on coloration were influenced by timing of exposure. Birds were either exposed developmentally (up to 114 days after hatching), as adults (after reaching sexual maturity), or for their entire life. Bill coloration, which is a carotenoid-based, sexually selected trait, was less red in males with lifetime exposure to methylmercury, compared to controls. Neither adult, nor developmental exposure influenced bill color in adult males, with the possible exception of early exposure of nestlings. Among females, where bill color is not under strong sexual selection, neither lifetime nor adult exposure to methylmercury affected bill color. For males and females, there was no effect of either lifetime or adult methylmercury exposure on coloration of back feathers, which is a non-sexually-dimorphic, melanin-based trait that is not likely the result of sexual selection. This study is a comprehensive experimental test of the proposal that sexually selected traits may be particularly useful bioindicators of the stress imposed by environmental toxins such as methylmercury.
The Quest for Covert Consciousness: Bringing Neuroethics to the Bedside.

Plato, in his Allegory of the Cave, contemplates a group of people who have lived their entire lives facing a wall of a cave and whose impressions of the world are constrained to perceptual experiences of shadows cast on the wall by entities that are never directly observed. Since time immemorial, conscious states of others have been like Platonic shadows, inferred only imperfectly and indirectly through close observation of behaviors. Although for centuries philosophers and neuroscientists have sought to bring us closer to understanding consciousness, an influx of neurotechnologies now enables clinicians and researchers to potentially improve detection of consciousness and prediction of its recovery.1 Innovations in neuroimaging and electrophysiologic techniques now may permit detection of states of consciousness not readily discernible by bedside examination, known as covert consciousness or cognitive motor dissociation.2 The discovery of covert consciousness raises distinctive issues surrounding both the diagnosis and prognosis of persons with disorders of consciousness (DoC), highlighting the need for caution during the acute phase of neuroprognostication and exposing gaps in knowledge about the epidemiology and phenomenology of covert consciousness. These innovations represent a possible step forward from philosophical and scientific traditions that relied on behavioral observations to detect consciousness. In turn, these breakthroughs prompt reconsideration of standard approaches to the evaluation of persons with DoC and necessitate appraisal of how clinicians should communicate results of novel techniques with indeterminate meanings to surrogates. Proactive integration of neuroethical insights in clarifying responsible ends to which these technologies should be directed is essential for addressing these timely challenges. This article proposes an ethical framework to help the clinical and research community consider how to use these emerging neurotechnologies responsibly, calls for careful consideration of the consequences of searching for covert consciousness in practice, and highlights critical avenues for further study of how the finding of covert consciousness might help predict goal-concordant functional recovery.
"'Til Death Do Them Part?": Assessing the Permanence of Goodridge

In America’s Struggle for Same-Sex Marriage, Daniel Pinello explores the social and political underpinnings of the controversy surrounding socalled “gay” marriage. Pinello’s analysis is directed toward using the struggle for marriage equality as an empirical basis for achieving a better understanding of how public policy derives from the interactions of citizens, interest groups, and government entities. This Book Review argues the importance to policy formation of a force Pinello tends to underemphasize: the counter-majoritarian influence of constitutional law and judicial review. The significance of this factor is considered primarily in relation to state constitutional amendments that purport to “define” marriage as being strictly between one man and one woman. This Book Review concludes that such amendments, by their nature, violate the Federal Equal Protection Clause. Separate consideration is given to the particular illegitimacy and vulnerability of such an amendment in Massachusetts, where state constitutional jurisprudence requires equal marriage rights for same-
Quantitative analysis of immunofluorescent retinal images

We present a novel method to quantitatively analyze confocal microscope images of retinas. We automatically detect nuclei within the outer nuclear layer (ONL) in a retinal image. Based on nuclei detection results, we also automatically measure the thickness of the ONL and the local cell density within the ONL. These measurements provide the first thorough quantitative analysis of retinal images. Our results not only verify previous conclusions about retinal restructuring during detachment, but also provide biologists with significant information about the regional responses in the ONL.
Molecular Biology and Cytokines

The proliferation and differentiation of hematopoietic cells is regulated by the interaction of multiple genes, transcription factors, and proteins.
New Algorithms and Approaches for 1-Dimensional Layout Compaction

We consider the 1-dimensional compaction problem when the layout area contains forbidden regions and the layout components are allowed to move across these regions. Assume we are given a feasible layout containing k forbidden regions and n layout components, where the i-th layout component is a rectilinear polygon consisting of v i vertical edges, v=∑ i=1 n vv. We present an algorithm that determines the positions of the layout components resulting in minimum area in O(σlogσ+σnlogn) time with an O((v+k)log k+(v+ σ)log v) preprocessing time. The quantity σ measures the interaction between the layout components and the forbidden regions, σ ≤ vk. We also describe variants of this algorithms that make the running time problem-dependent. Our algorithms make use of an elegant characterization of a layout of minimum area.
Utility of percutaneous renal biopsy in chronic kidney disease.

Background: We tested the hypothesis that patterns of serum creatinine concentrations (S-cr) prior to percutaneous renal biopsy (PRB) predict the utility of PRB in safely making renal diagnoses, revealing treatable disease, and altering therapy in chronic kidney disease patients. Methods: PRB specimens (170 patients) were assigned to 1 of 5 groups: S-cr never greater than 0.11 mM for at least 6 months prior to PRB (Group 1); S-cr greater than 0.11 mM but less than 0.18 mM during the 6 months prior to PRB (Groups 2); S-cr less than 0.18 mM during the 6 months prior to PRB but greater than 0.18 mM prior to these 6 months (Group 3); S-cr greater than 0.18 mM for less than 6 months prior to PRB (Group 4); S-cr greater than 0.18 mM for more than 6 months prior to PRB (Group 5). Results: Histopathology chronicity score (0–9) increased with increasing group number: 2.1 (Group 1); 4.4 (Group 2); 4.5 (Group 3); 5.4 (Group 4); 7.0 (Group 5). Post-PRB bleeding was more common with increasing group number. New therapy was instituted after PRB most frequently in Group 4 (62%) and least frequently in Group 5 (24%). Conclusion: After more prolonged elevations of S-cr, PRB may be less safe and less likely to reveal treatable disease and opportunities for therapy.
Security and Privacy in a Sensor-Based Search and Rescue System

With the emergence of small devices equipped with wireless communication, several sophisticated systems for search and rescue have been proposed and developed. However, a key obstacle in large deployment of these systems is vulnerability to users’ security and privacy. On one hand, search and rescue systems need to collect as much information about a user’s location and movement as possible to locate that user in a timely manner. On the other hand, this very capability can be misused by adversaries to stalk a person, which in turn drives users away from using such a system. This paper describes the design, implementation and performance of a security and privacy framework for SenSearch, which is a sensor-based search and rescue system for people in emergency situation in wilderness areas. This framework has been carefully built by employing a combination of symmetric and asymmetric key cryptography to meet the constraints of resource-limited devices and short time intervals during which most security operations have to be performed.
Modeling proton intensity gradients and radiation dose equivalents in the inner heliosphere using EMMREM: May 2003 solar events

[1] Solar energetic particles (SEPs) provide a significant radiation hazard for manned and unmanned interplanetary (IP) space missions. In order to estimate these hazards, it is essential to quantify the gradients of SEP intensities in the IP medium. The Earth-Moon-Mars Radiation Exposure Module (EMMREM) is a new project aimed at characterizing the time-dependent radiation exposure in IP space. In this paper, we utilize EMMREM to study the radial dependence of proton peak intensities, event fluences, and radiation dose equivalents of 27–31 May 2003 SEP events at eight different locations between 1 and 4.91 AU at energies between ∼1.5 MeV and ∼130 MeV. We have modeled onset times and intensity profiles of the SEP events at Mars and Ulysses and found very good agreement at different energies. We report observations of energetic particles at locations with magnetic field line footprints that are separated by ∼90° in heliolongitude, possibly indicating very large coronal mass ejection sizes and/or high cross-field diffusion at large radial distances. Our results show that radial dependencies of proton peak intensities exhibit a broken power law between 1 to 2.5 AU and 2.5 to 4.91 AU, ranging between R−2.52 ± 0.42 and R−5.97 ± 0.32 for 25 MeV and between R−2.13 ± 0.36 and R−5.21 ± 0.29 for 52 MeV, where R is the radial distance from the Sun in units of AU. Event fluences exhibit a similar behavior but with a harder spectra. Radiation dose calculations show that these events did not pose a short-term radiation hazard to humans in the IP space.
What are Middle School Students Talking About During Clicker Questions? Characterizing Small-Group Conversations Mediated by Classroom Response Systems

There is a growing interest in using classroom response systems or clickers in science classrooms at both the university and K-12 levels. Typically, when instructors use this technology, students are asked to answer and discuss clicker questions with their peers. The existing literature on using clickers at the K-12 level has largely focused on the efficacy of clicker implementation, with few studies investigating collaboration and discourse among students. To expand on this work, we investigated the question: Does clicker use promote productive peer discussion among middle school science students? Specifically, we collected data from middle school students in a physical science course. Students were asked to answer a clicker question individually, discuss the question with their peers, answer the same question again, and then subsequently answer a new matched-pair question individually. We audio recorded the peer conversations to characterize the nature of the student discourse. To analyze these conversations, we used a grounded analysis approach and drew on literature about collaborative knowledge co-construction. The analysis of the conversations revealed that middle school students talked about science content and collaboratively discussed ideas. Furthermore, the majority of conversations, both ones that positively and negatively impacted student performance, contained evidence of collaborative knowledge co-construction.
Measuring Auditory Selective Attention using Frequency Tagging

Frequency tagging of sensory inputs (presenting stimuli that fluctuate periodically at rates to which the cortex can phase lock) has been used to study attentional modulation of neural responses to inputs in different sensory modalities. For visual inputs, the visual steady-state response (VSSR) at the frequency modulating an attended object is enhanced, while the VSSR to a distracting object is suppressed. In contrast, the effect of attention on the auditory steady-state response (ASSR) is inconsistent across studies. However, most auditory studies analyzed results at the sensor level or used only a small number of equivalent current dipoles to fit cortical responses. In addition, most studies of auditory spatial attention used dichotic stimuli (independent signals at the ears) rather than more natural, binaural stimuli. Here, we asked whether these methodological choices help explain discrepant results. Listeners attended to one of two competing speech streams, one simulated from the left and one from the right, that were modulated at different frequencies. Using distributed source modeling of magnetoencephalography results, we estimate how spatially directed attention modulates the ASSR in neural regions across the whole brain. Attention enhances the ASSR power at the frequency of the attended stream in contralateral auditory cortex. The attended-stream modulation frequency also drives phase-locked responses in the left (but not right) precentral sulcus (lPCS), a region implicated in control of eye gaze and visual spatial attention. Importantly, this region shows no phase locking to the distracting stream. Results suggest that the lPCS in engaged in an attention-specific manner. Modeling results that take account of the geometry and phases of the cortical sources phase locked to the two streams (including hemispheric asymmetry of lPCS activity) help to explain why past ASSR studies of auditory spatial attention yield seemingly contradictory results.
High temperature degradation of structural materials in environments encountered in the petroleum and petrochemical industries: Some mechanistic observations

This paper reviews some of the important processes underlying high temperature degradation of structural materials used in the petroleum and petrochemical industries. Particular emphasis is palced in degradation processes involving the interaction of structural metals and alloys with environments containing sulfidizing, carburizing, and halogenizing species. In addition the effect of gaseous hydrogen environments at elevated temperatures and pressures on the mechanical properties of steels will be discussed. The mechanism of attack and the effect of alloying elements in these phenomena will be described and discussed.
The isolation and properties of a glycoprotein from hamster submaxillary gland.

Abstract A simple and rapid method is described for the isolation and purification of submaxillary gland secretory glycoprotein from hamsters. The glycoprotein was isolated in an apparently homogeneous form. The purified glycoprotein had an apparent molecular weight of 6.6 × 105. It was composed of approximately one-third protein, one-third hexosamine and one-third sialic acid. Threonine and serine accounted for more than half of the amino acids. The sialic acid seemed to be exclusively N-acetylneuraminic acid; the N-acetylhexosamine was identified as 2-acetamido-2-deoxy- d -galactose. The linkage between the protein core and the oligosaccharide side-chains was shown to be mainly O-glycosyl.
Measurement of far field combustion noise from a turbofan engine using coherence functions

Coherence measurements between fluctuating pressure in the combustor of a YF-102 turbofan engine and far-field acoustic pressure were made. The results indicated that a coherent relationship between the combustor pressure and far-field existed only at frequencies below 250 Hz, with the peak occurring near 125 Hz. The coherence functions and the far-field spectra were used to compute the combustor-associated far-field noise in terms of spectra, directivity, and acoustic power, over a range of engine operating conditions. The acoustic results so measured were compared with results obtained by conventional methods, as well as with various semiempirical predictions schemes. Examination of the directivity patterns indicated a peak in the combustion noise near 120 deg (relative to the inlet axis).
Geostatistical analysis of gas potential in Devonian shales of West Virginia

Abstract The geologic processes that control the occurrence of gas in the Devonian shales of West Virginia are understood poorly. Locating a new Devonian shale well may depend upon proximity to known producing wells. Maps of initial potentials and probability of success can play an important role in exploration and development. Experimental semivariograms show large nugget effects for both variables. Contour maps of kriged estimates for these variables show northeast—southwest and northwest—southeast-trending linearities that may implicate natural fractures as controls on gas presence and production potential.
The structure and motion of the Crab nebula jet

A high-resolution [O III]λ5007 image of the northern «jet» feature of the Crab nebula shows it to be a delicate structure containing numerous knots and filaments. Comparison of this image with one taken five years earlier yields proper motions of 0. 19-0.34 arcsec yr −1 for 14 features located in the northern half of the jet. Adopting 0.26 arcsec yr −1 as a representative value, the motion of the jet corresponds to a transverse velocity of 2500x(d/2 kpc) km s −1 . This is consistent with an age and postsupernova acceleration comparable to the rest of the nebula, suggesting an origin coeval with the AD 1054 supernova event
Predicted resistivities of liquid silver-tin alloys☆

Abstract The three partial interference functions I ij (K) were determined for liquid silver-tin alloys from X-ray measurements assuming that I ij (K) are approximately independent of the atomic concentration of the elements. Then using the refined I ij (K) and pseudopotential elements as calculated by Animalu, electrical resistivities were evaluated with the Faber-Ziman equation. The predicted values agree well with the experimental values.
Measurement of contact angle relaxation during the deposition of Langmuir-Blodgett films of cadmium stearate and valinomycin

Abstract We studied the contact angle relaxation during the Langmuir-Blodgett deposition of cadmium stearate and valinomycin films. For cadmium, we found that the relaxation time of the receding contact angle depends strongly on the deposition type; the static value that the receding angle relaxes to depends on the concentration of Cd 2+ ions in the subphase. For 4.0 × 10 -2 M Cd 2+ subphase, the deposition begins and remains Y-type. However, at a lower concentration of 2.5 × 10 -3 M the deposition changes from Y- to X-type. Prior to this transition, the static receding angles for the two different Cd 2+ concentrations are different but the relaxation times are about the same. After the transition, the relaxation process is more than 20 times faster. For valinomycin, the deposition is predominantly Z-type.
Error catastrophe in and the evolution of the protein synthesizing machinery.

Abstract The theory of the propagation of errors in the system of enzymes translating genetic information proposed earlier is developed further. It is shown that if initially for some of these enzymes the normal molecules are more than, for some less than, and for some equal to the erroneous ones, the evolution of the system can lead to many asymptotic conditions including error catastrophe and complete recovery from errors.
The Cap Region of Topoisomerase I Binds to Sites near Both Ends of Simian Virus 40 T Antigen

Two independent binding sites on simian virus 40 (SV40) T antigen for topoisomerase I (topo I) were identified. One was mapped to the N-terminal domain (residues 83 to 160) by a combination of enzyme-linked immunosorbent assays (ELISAs) and glutathione S-transferase (GST) pull-down assays performed with various T antigen deletion mutants. The second was mapped to the C-terminal domain (residues 602 to 708). The region in human topo I that binds to both sites in T antigen was identified by ELISAs, GST pull-down assays, and double-hexamer binding assays with topo I deletion mutants. This region corresponds to a distinct domain on topo I known as the cap region that maps from residues 175 to 433. By combining these data with information about the structure of T-antigen double hexamers associated with origin DNA, we propose that the cap region of topo I associates specifically with both ends of the double hexamer bound to the SV40 origin to initiate DNA replication.
Electronic absorption spectra and protolytic equilibria of doxorubicin: Direct spectrophotometric determination of microconstants

The ground- and excited-state dissociation constants and the electronic absorption and fluorescence spectra of doxorubicin were investigated by spectrophotometry. A general method for the direct calculation of individual microscopic dissociation constants was derived using the spectrophotometric data obtained. It was concluded that the protonated amino sugar group is slightly more acidic than the phenolic group. The spectrophotometric data were analyzed, and the macro- and microconstants for the various equilibria are reported.