cssi/SciSciGPT-SciSciNet huggingface dataset:
Sea Beam Mapping Systems

The introduction to the oceanographic community of deep ocean, multibeam mapping systems such as Sea Beam has had a profound effect both on the way we view the sea floor and on the way in which sea floor surveys are conducted, particularly with regard to open ocean navigation. These systems provide more than a hundred-fold increase in survey resolution as well as practical potential for complete survey coverage with deep water resolution of 100–200m. Thus they have not only placed severe demands on shipboard navigation but have also by themselves permitted highly accurate terrain-following navigation in areas previously surveyed. Map production from these systems generally relies on topographic matching for final adjustment of ship navigation, even when extremely accurate navigation, such as GPS, is available. There are now a dozen Sea Beam installations worldwide (5 in the U.S.) with each system contributing on the order of 1/2 gigabyte of sea floor survey data each year. This paper will detail some of the history of multibeam sea floor mapping as well as some of the promises and problems of these systems. The systems installed and operated aboard the R/V’s CONRAD and ATLANTIS II by the URI/NECOR Sea Beam Facility will be described. The CONRAD is a well-equipped geophysical research ship with multichannel and precision gravity capabilities. Its navigation equipment includes Loran-C, two-axis doppler speed log, SATNAV and GPS with atomic clock. The ATLANTIS II is the support ship for the submersible ALVIN, and is equipped for acoustic transponders and range/bearing navigation in addition to speed log, Loran-C, SATNAV and GPS.
Sol-gel processing and sintering of yttrium aluminum garnet (YAG) powders

Gels of yttrium aluminum garnet (YAG) with the stoichiometric composition 3Y2O3·5AI2O3, were prepared by a sol-gel technique and dried by supercritical extraction with CO2. Powders were produced by lightly grinding the dried gels. Crystallization of the powder occurred at ≈900°C and within the limits of detection, the X-ray diffraction pattern of the crystallized material was identical to that of the stoichiometric composition. Powder compacts with a green density of ≈0.50 of the theoretical were sintered to nearly full density in O2 during constant heating rate sintering at 5 °C min−1 to 1600 °C. This is better than the density obtained with powders from a similar gel dried conventionally (by evaporation of the liquid) and considerably better than that obtained with powders prepared by solid state reaction. The room temperature flexural strength and fracture toughness of the material fabricated from the supercritically dried gels were 190 MPa and 2.2 MPa.m1/2, respectively. These strength and fracture toughness values are higher than those reported in other studies for YAG produced by the sintering route.
What's Stalling Learning? Using a Formative Assessment Tool to Address Critical Incidents in Class

We report on the use of Brookfield’s (1995) formative assessment tool, the “Critical Incident Questionnaire” (CIQ) to help students and teachers identify and discuss key factors affecting learning. We offer insight into two major areas: 1) testing and adapting the existing tool to improve teaching and learning and 2) identifying moments of potentially productive tension between the learner and the learning process—moments that, once named, we can address more directly. We call these moments stasis points. Our research questions were: “Based on insights emerging from regular use of the CIQ, how might the tool be better worded to encourage productive student reflection?” and “What common stasis points do students identify when they reflect on their learning in the weekly CIQ?” This research was conducted within the context of a longitudinal, cross-institutional study of reflective practices in writing courses. Responses indicated a tendency to report challenges related to the pedagogical approaches of the class more than challenges concerning the understanding of course content. The study yields insights into the use of the CIQ itself, as well as into the kinds of “critical incidents” students considered most noteworthy.
“A Soldier Intoxicated is Far Worse than No Soldier at All”: Intoxication and the American Civil War

AbstractThis article examines the prevalence and role of alcoholic intoxication in the American Civil War, 1861–65. Using an array of sources, including letters, diaries, memoirs, newspaper account...
Muddy-booted, disingenuous revolution in personal jurisdiction

Although the Supreme Court claims that its six personal jurisdictions in the last seven years have been unremarkable applications of existing law, the Court is dissembling. In fact, the Court has severely constricted plaintiff forum choice, often leaving U.S. plaintiffs injured in the U.S. with no U.S. forum, or no rational one. Although commentators refer to this sea change as a "stealth" revolution, in fact the vast change is the law is obvious to any commentator paying close attention. This article argues that a central difficulty is that the Supreme Court does not have any clear rationale for employing the Due Process Clause to closely regulate personal jurisdiction, leading to vacillating results and untenable decisions.
Compact Error-Resilient Self-Assembly of Recursively Defined Patterns

A limitation to molecular implementations of tile-based self-assembly systems is the high rate of mismatch errors which has been observed to be between 1% and 10%. Controlling the physical conditions of the system to reduce this intrinsic error rate $\epsilon$ prohibitively slows the growth rate of the system. This has motivated the development of techniques to redundantly encode information in the tiles of a system in such a way that the rate of mismatch errors in the final assembly is reduced even without a reduction in $\epsilon$. Winfree and Bekbolatov, and Chen and Goel, introduced such error-resilient systems that reduce the mismatch error rate to $\epsilon^k$ by replacing each tile in an error-prone system with a $k \times k$ block of tiles in the error-resilient system, but this increases the number of tile types used by a factor of $k^2$, and the scale of the pattern produced by a factor of $k$. Reif, Sahu and Yin, and Sahu and Reif, introduced compact error-resilient systems for the self-assembly of Boolean arrays that reduce the mismatch error rate to $\epsilon^2$ without increasing the scale of the pattern produced. In this paper, we give a technique to design compact error-resilient systems for the self-assembly of the recursively defined patterns introduced by Kautz and Lathrop. We show that our compact error-resilient systems reduce the mismatch error rate to $\epsilon^2$ by using the independent error model introduced by Sahu and Reif. Surprisingly, our error-resilient systems use the same number of tile types as the error-prone system from which they are constructed.
Exploring User Opinions of Fairness in Recommender Systems.

Algorithmic fairness for artificial intelligence has become increasingly relevant as these systems become more pervasive in society. One realm of AI, recommender systems, presents unique challenges for fairness due to trade offs between optimizing accuracy for users and fairness to providers. But what is fair in the context of recommendation--particularly when there are multiple stakeholders? In an initial exploration of this problem, we ask users what their ideas of fair treatment in recommendation might be, and why. We analyze what might cause discrepancies or changes between user's opinions towards fairness to eventually help inform the design of fairer and more transparent recommendation algorithms.
The impact of hempseed dehulling on chemical composition, structure properties and aromatic profile of hemp protein isolate

Abstract Hempseed protein has attracted increasing attention in both scientific and industrial field because of its high nutritional value. In the current study, the influence of dehulling process on the chemical composition, structure and functional properties of hempseed protein isolate (HPI) was determined by using SDS-PAGE, SEC-HPLC-UV/RI/MALS, CD spectroscopy and DSC. The result demonstrated that dehulling process significantly increased the extraction and protein recovery yields of HPI. Meanwhile, dehulled HPI also exhibited a higher protein purity and Arg/Lys ratio with improved color. No significant impact on protein composition and structure was observed upon seed dehulling, but HPI extracted from the dehulled seeds showed a reduced thermal stability as compared to non-dehulled HPI. The aromatic profile of HPI was determined by HS-SPME-GC-MS, and the data suggested that dehulled HPI accumulated more terpenes and less lipid oxidation volatiles than non-dehulled HPI. These findings indicated that dehulling process greatly enhances the extraction yield with higher protein content and more characteristic aroma of HPI. The current study for the first time provides valuable information about the influence of dehulling processing on the properties of HPI, which will facilitate further research and application of hempseed and its valued added ingredients in both academic and industry field.
Deep Neural Network Mapping and Performance Analysis on Tiled RRAM Architecture

Representative deep neural networks (DNNs) have been successfully mapped on an RRAM-based tiled in-memory computing (IMC) architecture. Effects of finite array size and quantized partial products (PPs) due to ADC precision constraints have been analyzed. Methods were developed to solve these challenges and preserve DNN accuracies and IMC performance gains in the tiled architecture. Popular models VGG-16, MobileNet, and RNN/LSTM have been successfully implemented and tested on ImageNet dataset and text classification tasks, respectively.
Resurgence, operator product expansion, and remarks on renormalons in supersymmetric Yang-Mills theory

We discuss similarities and differences between the resurgence program in quantum mechanics and the operator product expansion in strongly coupled Yang-Mills theories. In N = 1 super-Yang-Mills theories, renormalons are peculiar and are not quite similar to renormalons in QCD.
Impact of OER in Teacher Education

The purpose of this research study, which employed a quantitative research design, was to determine if there was a difference in the grades achieved by students who were enrolled in an entry-level Foundations of Education course using Open Educational Resources (OER) versus the grades achieved by students who used textbooks in other course sections. The goal was to find out whether OER was of the same or higher quality as textbooks in our minority-serving higher education institution. The outcomes revealed that there was no significant difference in grades for course sections that used OER when compared to course sections that used textbooks. Thus, it can be concluded that OER were as good as the textbook usage. The study was conducted at Hostos Community College (HCC), a two-year college of City University of New York (CUNY). CUNY is comprised of 25 campuses across the five boroughs in New York City, USA.
Abstract PO007: Role of PI3K pathway in reprogramming the tumor niche of angiosarcoma

Angiosarcoma (AS) is a highly aggressive, rare soft-tissue sarcoma that forms malignant blood vessels. Approximately half of patients have metastatic or unresectable disease with a median overall survival of less than 6 months, and tumor-related mortality is high. Inflamed tissue is frequently seen in angiosarcomas, and immune cells are key components that contribute to the landscape of the tumor microenvironment. Hemangiosarcoma (HSA) occurs commonly in companion dogs, and it shares clinical and morphological features with human AS. Recurrent mutations in TP53 and genes involved in PI3K pathway such as PIK3CA, and PIK3R1 were observed in both human AS and canine HSA, and the mutational landscape was associated with distinct molecular tumor subtypes; in particular, differing immunophenotypes. Recently, we have shown that human AS and canine HSA establish convergent transcriptional programs driven by angiogenic fusion genes and TP53 mutation. However, these vascular tumors are genomically complex, and molecular mechanisms that establish the tumor microenvironment are incompletely known. In this study, we analyzed RNA-seq transcriptomic data generated from human AS tissues (n=13) and canine HSA tissues (n=76) and HSA cell lines (n=11). The data showed that the tumors of both species enriched gene signatures associated with maintenance of hematopoietic stem cells. Then, we found that canine HSA cells supported expansion and differentiation of human CD34+ umbilical cord blood cells using long-term culture-initiating cell and colony-forming unit assays. We also developed xenograft models of canine HSA that facilitate myelopoiesis and macrophage infiltration in the tumor tissue. Our data showed that gene signatures of monocytes and naive macrophages were detectable in canine HSA cells. In human ASs, macrophage-associated genes, in particular M2 macrophage signatures were significantly enriched, compared to normal tissues. Collectively, our data suggest that human AS and canine HSA have cell-autonomous capacity to govern hematopoietic progenitors and immune cells, potentially establishing the tumor immune niche. We engineered HSA cells to induce homozygous H1047R mutations in PIK3CA gene using CRISPR-Cas9 system. Our ongoing work is to determine if regulating PI3K pathway in the tumor cells contributes to the molecular programs that create the tumor niche of the vascular malignancy. Citation Format: Sophia Wenthe, Ashley J. Schulte, Mathew G. Angelos, Dan S. Kaufman, Jaime F. Modiano, Jong Hyuk Kim. Role of PI3K pathway in reprogramming the tumor niche of angiosarcoma [abstract]. In: Proceedings of the AACR Virtual Special Conference on the Evolving Tumor Microenvironment in Cancer Progression: Mechanisms and Emerging Therapeutic Opportunities; in association with the Tumor Microenvironment (TME) Working Group; 2021 Jan 11-12. Philadelphia (PA): AACR; Cancer Res 2021;81(5 Suppl):Abstract nr PO007.
The Early Screening for Autism and Communication Disorders: Field-testing an autism-specific screening tool for children 12 to 36 months of age.

There is a critical need for validated screening tools for autism spectrum disorder in very young children so families can access tailored intervention services as early as possible. Few screeners ...
Multiview Virtual Confocal Microscopy Through A Multimode Fiber

Confocal microscopy is a powerful imaging tool to obtain high-contrast images of thin sections within bulk tissue. However, tissue scattering limits its utility to only superficial depths. The use of multimode fibers as ultra-thin endoscopes is promising as a deep-tissue minimally invasive imaging tool. Here, we present a method to perform high signal-to-noise ratio (SNR) virtual confocal microscopy through a multimode fiber, by filtering the backscattered light through multiple coplanar virtual pinholes. The use of multiple pinholes helps generate multi-view perspectives of the object, which can be shift corrected and combined to boost the SNR levels. The improved SNR also allows exploiting the potential of confocal imaging for gain in resolution.
A Quantum-Dash Dual-Wavelength DFB Laser for Optical Millimeter-Wave Radio-over-Fiber Systems

We experimentally demonstrate an optical-heterodyne millimeter-wave radio-over-fiber system with broadband wireless links through 25.22 km standard-single-mode fiber featuring a high bitrate of 24-Gb/s (64QAM × 4GBaud) using a highly correlated InAs/InP quantum-dash dual-wavelength DFB laser.
Programs for Networking Research and Testbed Activities in the U.S.

The last several years have witnessed a rapid increase in the investments made by the U.S. Government and by U.S. industry in networking research. A new phenomenon that has accompanied this increase: a substantial fraction of the investments have been devoted to the construction and operation of experimental networks, called testbeds, to be used to test in vivo the novel ideas and technologies proposed by the participating researchers.
HDAC4 Shuttling Promotes Neuronal Remodeling After Stroke (I10-1C)

OBJECTIVE: In this study, we tested whether stroke induces nuclear shuttling of histone deacetylase 4 (HDAC4) in cortical excitatory and inhibitory neurons during stroke recovery and whether shuttling of HDAC4 is associated with neuronal remodeling after stroke. BACKGROUND: HDAC4 can shuttle from the cytoplasm to the nucleus where it can deacetylate histone proteins and regulate gene expression. DESIGN/METHODS: Adult male Wistar rats (n=6/group) were subjected to middle cerebral artery occlusion (MCAo) and sacrificed at 2 or 14 days after MCAo. Sham operated rats were used as a control. Double immunohistochemistry was performed with antibodies against HDAC4 along with microtubule-associated protein 2 (MAP2, neurons), parvalbumin (PV, interneurons), Ctip2 (pyramidal neurons), APC (oligodendrocytes), GFAP (astrocytes), phosphorylated neurofilament heavy chain (pNFH, axons) and myelin basic protein (MBP, myelination). RESULTS: Stroke significantly (p<0.05) increased the percentage of neurons with nuclear HDAC4 immunoreactivity in the peri-infarct cortex at 2 (55 ± 2[percnt]) and 14 (76 ± 2[percnt]) days after MCAo compared to sham (27 ± 3[percnt]). Stroke-induced nuclear shuttling of HDAC4 is specific to neurons, since HDAC4 was not detected in nuclei of GFAP+ astrocytes or APC+ oligodendrocytes. Furthermore, stroke significantly (p<0.05) increased nuclear HDAC4 expression in the peri-infarct cortex at 2 and 14 days, in pyramidal neurons (Ctip2, 57[percnt] & 73[percnt]) and interneurons (PV, 66[percnt] & 74[percnt]) as compared to sham control (Ctip2 33[percnt], PV 12[percnt]). Additionally, nuclear HDAC4 shuttling was positively and significantly correlated with increased axonal density and myelination as determined by pNFH (r = 0.84, p<0.05) and MBP (r = 0.76, p<0.05), respectively. CONCLUSIONS: Stroke induces nuclear shuttling of HDAC4 in excitatory and inhibitory neurons of the peri-infarct cortex which is strongly correlated with enhanced axonal density and myelination, suggesting a role for HDAC4 in promoting neuronal remodeling after stroke. Study Supported by: RO1 AG037506 and NS075156 and AHA Grant 10SDG2790012. Disclosure: Dr. Shehadah has nothing to disclose. Dr. Kassis has nothing to disclose. Dr. Chopp has received personal compensation for activities with EVER Pharmaceutical and Johnson & Johnson. Dr. Roberts has nothing to disclose. Dr. Zhang has nothing to disclose.
Overview of Cerebrovascular Disease

Stroke is the third leading cause of death in industrialized nations, with an annual incidence of about 700,000 stroke events. Ischemic strokes constitute 80–86% of all strokes. It has been estimated that ≥50% carotid stenosis may be responsible for up to 25% of all ischemic strokes. This chapter highlights the basic anatomy and pathophysiology of the extracranial carotid system. The common carotid bifurcation and the proximal internal carotid artery account for 50% of the lesions. The most common cause of cerebral ischemic events is embolic phenomena, primarily arterial in origin (carotid) and secondary to cardiac sources. The work-up of patients presenting with asymptomatic carotid bruits or TIAs should include initial carotid duplex scanning. Duplex scanning of the carotid bifurcation provides a highly accurate method of identifying significant lesions of the internal carotid artery as well as of separating lesions into general pathologic categories. Carotid CTA/MRA may be added to the work-up of these patients, particularly if the carotid duplex ultrasound is inadequate, and conventional arteriography is usually reserved for use prior to CAS. Management of these patients includes medical treatment alone or CEA/CAS with medical treatment.
Differences in the survival of patients with recurrent versus de novo metastatic KRAS‐mutant and EGFR‐mutant lung adenocarcinomas

BACKGROUND Prognostic variables are independently associated with survival and are fundamental to clinical trial design. In the current study, the authors evaluated the impact of stage of disease at the time of the initial diagnosis on overall survival (OS) in 2 independent, oncogene-defined cohorts. METHODS All patients with epidermal growth factor receptor (EGFR)-mutant and KRAS-mutant metastatic lung adenocarcinomas were identified through routine molecular testing from January 2005 through January 2011. Clinical characteristics were obtained. OS from the date of diagnosis of recurrent or de novo metastatic disease was estimated using the Kaplan-Meier method. RESULTS A total of 635 patients with KRAS-mutant and 496 patients with EGFR-mutant metastatic lung adenocarcinomas were identified. Among patients with KRAS-mutant lung adenocarcinomas, those with de novo metastatic disease were found to have a shorter median OS compared with those with recurrent metastatic disease (13 months vs 18 months; P = .003). In a multivariable analysis of patients with KRAS-mutant lung adenocarcinomas, de novo metastatic disease at the time of diagnosis (TNM stage IV vs stage I-III: hazard ratio, 1.5 [95% confidence interval, 1.2-1.8]; P<.001) was independently associated with shorter OS. In patients with EGFR-mutant lung adenocarcinomas, after controlling for age and Karnofsky performance status, de novo metastatic disease at the time of diagnosis (stage IV vs stage I-III: hazard ratio, 1.3 [95% confidence interval, 1.0-1.7]; P = .03) was found to be independently associated with shorter OS. CONCLUSIONS Among patients with KRAS-mutant lung adenocarcinomas, stage of disease at diagnosis was associated with OS from the time of diagnosis of recurrent/metastatic disease. In multivariable analyses, in both patients with EGFR-mutant and KRAS-mutant lung adenocarcinomas, advanced stage at the time of diagnosis was found to be independently associated with shorter survival. Stage at diagnosis is a prognostic variable that should be accounted for in prospective studies in patients with metastatic lung adenocarcinomas. Cancer 2015;121:2078–2082. © 2015 American Cancer Society.
A learning automaton approach to trajectory learning and control system design using dynamic recurrent neural networks

A new approach based on the theory of learning automata is presented for training neural networks with recurrent connections and dynamical processing elements. This approach does not require gradient computations and hence affords a simple implementation. Both linear and nonlinear reinforcement actions are suggested which result in specific training algorithms. Applications of the method to two specific problems, viz. learning of continuous-time trajectories and control system design to stabilize a nonlinear dynamical plant, are outlined. >
A speaker-stress resistant HMM isolated word recognizer

Most current speech recognition systems are sensitive to variations in speaker style, the following is the result of an effort to make a Hidden Markov Model (HMM) Isolated Word Recognizer (IWR) tolerant to such speech changes caused by speaker stress. More than an order-of-magnitude reduction of the error rate was achieved for a 105 word simulated stress database and a 0% error rate was achieved for the TI 20 isolated word database.
Sensitivity analysis when model outputs are functions

When outputs of computational models are time series or functions of other continuous variables like distance, angle, etc., it can be that primary interest is in the general pattern or structure of the curve. In these cases, model sensitivity and uncertainty analysis focuses on the effect of model input choices and uncertainties in the overall shapes of such curves. We explore methods for characterizing a set of functions generated by a series of model runs for the purpose of exploring relationships between these functions and the model inputs.
Asking Spatial Questions to Identify GIS Functionality

Current desktop-GIS software cannot answer users' spatial questions directly. The GIS functionality is hard to identify and use without specific training of GIS skills because of the complex hierarchical organization and the gap between users' spatial thinking and systems' implement descriptions. In order to bridge this gap, we propose a semantic framework for designing a question-based user interface that integrates different levels of ontologies (spatial concept ontology, domain ontology and task ontology) to guide the process of extracting the core spatial concepts and translating them into a set of equivalent computational or operational GIS tasks. We also list some typical spatial questions that might be posed for spatial analysis and computation. The principle introduced in this paper could be applied not only to desktop-GIS software but also to web map services. The semantic framework would be useful to enhance the ability of spatial reasoning in web search engines (e.g. Google semantic search) and answering questions in location-based services as well (e.g. iPhone Siri assistant).
Biomedical Engineering, a Cornucopia of Challenging Engineering Tasks-all of Direct Human Significance

My introduction tobiomedical engineering wasconcurrent withmy computer-aided design experience. First, together withcolleagues andstudents, we instructed thedigital computer totranslate English intocontracted braille code, "BIOMEDICAL" modifies engineering-one of many andthendeveloped hardware toproduce palpable braille [4]. arenasinwhichengineering knowledge, methodology Awarenessoftheneedsofblindandvisually impaired andtechnology address humanneeds. Whatdistinguishes persons ledquickly toexplorations into theuseofultrasound biomedical engineering fromtraditional engineering fieldstosimplify their travel, together witha rangeofother (civil, mechanical, electrical, etc.), andfromother application communication, mobility, recreational, andvocational proareas(transportation, computer, sanitary) isthat"biomedi- jects [51-all conducted withandthrough students aspart of cal"denotes theapplication ofengineering research and/ortheir engineering education. Theneedtounderstand the design practice toquestions intrinsically humane.Itthus problems ofvision-impaired persons inorderto define approexactsthebestinengineering while being motivated bythe priate research, aswellastheresulting needtodemonstrate highest ofhumanaspirations. Nowonderitexcites students, theutility ofresearch findings intheeveryday worldofthe encourages faculty, enjoys visibility incareer planning, and blind person, ledtomy involvement inlocal rehabilitation intrigues andinspires thepublic! service organizations andpertinent national councils.
Impotence and Incontinence After Immediate Realignment of Posterior Urethral Trauma: Result of Injury or Management?

AbstractPurpose: We examined further whether the injury or method of management is responsible for impotence and incontinence after immediate realignment of prostato-membranous urethral disruptions.Materials and Methods: A total of 20 patients with complete urethral disruptions treated with immediate realignment (group 1) was compared to 12 with partial or complete injuries treated with retrograde catheterization alone (group 2). Followup status was obtained by patient questionnaire or telephone interview.Results: Of the patients 83 percent in group 1 and 80 percent in group 2 are continent, and 76 percent and 70 percent, respectively, regained erections suitable for sexual intercourse.Conclusions: The results suggest that impotence and incontinence in this setting are the result of the injury and not of attempts at immediate surgical management.
Understanding the link between perfectionism and adjustment in college students: Examining the role of maximizing

Abstract The present study examined the relations between perfectionism, maximizing, and psychosocial adjustment in a sample of 331 college students. Consistent with past research, perfectionism was found to be associated with adjustment (viz., life satisfaction, emotional exhaustion, depersonalization, & low personal accomplishment). Results of regression analyses indicated that even after controlling for maximizing, perfectionism continued to account for a significant amount of additional unique variance in each adjustment measure. Implications of the present findings for future research are discussed.
Interaction of seismic waves with a viscous liquid layer

abstract The interaction of seismic waves with a layer filled with a viscous fluid is studied. This study is intended to provide the basis for designing active seismic experiments to detect the existence of hydraulically induced fractures in a Hot Dry Rock Geothermal energy system. We compute transmission and reflection coefficients for P , SV , and SH waves incident at arbitrary angles onto a fluid layer embedded between two homogeneous half-spaces. We find that coefficients for SH waves at normal incidence can be written in terms of two dimensionless parameters. One of these parameters, I , is the ratio of acoustic impedance of the fluid to the acoustic impedance of the solid. The other dimensionless parameter, γd , is a measure of the amount of energy the SH wave loses during one pass through the fluid layer. We find that the amplitude of the SH wave transmitted through the fluid layer is equal to the amplitude of the incident SH wave if I is nearly 1 and γd is small. As γd increases, energy is lost due to viscous dissipation in the fluid and transmitted wave amplitude diminishes. If I is not nearly 1, some energy is reflected by the fluid layer. Three dimensionless parameters are required for solution for the case of P waves normally incident on the fluid layer. One parameter, R , is the ratio of the bulk modulus to effective shear modulus of the fluid. The second parameter is the ratio of elastic impedance of the solid to the shear impedance of the fluid and the third is γd . We find that the value of R is a good measure of the importance of fluid viscosity on the propagation of P waves through the fluid. Detailed studies of the effects of fluid and solid physical properties on the amplitudes of transmitted and reflected waves when waves are normally incident provide valuable insight into the importance of physical properties in the calculations for non-normal incidence. Finally, reflection and transmission coefficients are computed for P and SV waves incident at arbitrary angle on a viscous fluid layer. Physical properties of fluid and rock are chosen to be those thought appropriate for the Los Alamos National Laboratory Hot Dry Rock Geothermal test site located at Fenton Hill, New Mexico.
Surface morphology and electric conductivity of epitaxial Cu(100) films grown on H-terminated Si(100)

We have investigated the crystal structure, surface morphology, and electrical conductance of Cu films grown on H‐terminated Si(100). The films were grown by thermal evaporation at 10−8 Torr, at deposition rates from 0.1 to 3.5 nm/s and at substrate temperatures from room temperature up to 200 °C. Typical film thicknesses were ∼100 nm. Epitaxial growth was verified by x‐ray diffraction for films grown near room temperature at rates up to 2 nm/s. The root‐mean‐square surface roughness was measured to be 1–2 nm using atomic force microscopy (AFM). Higher growth rates or deposition temperatures above 100 °C produced poor quality, nonepitaxial films. Postdeposition annealing at temperatures up to 175 °C did not improve the surface roughness, and at higher annealing temperatures rapid silicide formation destroyed the Cu film. In situ electrical resistance measurements and AFM images suggest that for about the first 6 nm of growth the film consists of disconnected islands. X‐ray‐diffraction data show that the i...
DutyCon: A dynamic duty-cycle control approach to end-to-end delay guarantees in wireless sensor networks

It is well known that periodically putting nodes into sleep can effectively save energy in wireless sensor networks at the cost of increased communication delays. However, most existing work mainly focuses on the static sleep scheduling, which cannot guarantee the desired delay when the network conditions change dynamically. In many applications with user-specified end-to-end delay requirements, the duty cycle of every node should be tuned individually at runtime based on the network conditions to achieve the desired end-to-end delay guarantees and energy efficiency. In this article, we propose DutyCon, a control theory-based dynamic duty-cycle control approach. DutyCon decomposes the end-to-end delay guarantee problem into a set of single-hop delay guarantee problems along each data flow in the network. We then formulate the single-hop delay guarantee problem as a dynamic feedback control problem and design the controller rigorously, based on feedback control theory, for analytic assurance of control accuracy and system stability. DutyCon also features a queuing delay adaptation scheme that adapts the duty cycle of each node to unpredictable incoming packet rates, as well as a novel energy-balancing approach that extends the network lifetime by dynamically adjusting the delay requirement allocated to each hop. Our empirical results on a hardware testbed demonstrate that DutyCon can effectively achieve the desired trade-off between end-to-end delay and energy conservation. Extensive simulation results also show that DutyCon outperforms two baseline sleep scheduling protocols by having more energy savings while meeting the end-to-end delay requirements.
Marginality and vulnerability

Abstract The philosophical and methodological bases of urban disaster vulnerability analyses are presently underdeveloped. Few such analyses incorporate social data, partly because urban disaster managers and other potential user groups do not fully appreciate the value of this information, and partly because techniques for including it in existing vulnerability analyses have not been worked out. This paper explores the value of adding data on social marginality to Japanese models of earthquake impact and of incorporating marginal groups into the disaster planning process. The growing phenomenon of homelessness in Tokyo is used as a test case. It is argued that data on homelessness would improve the performance of systems designed to increase personal and social protection, whereas the incorporation of marginal urban groups would tap new knowledge of coping mechanisms and enrich the entire planning process.
Statistical properties of chaotic dynamical systems which exhibit strange attractors

Abstract A path integral method is developed for the calculation of teh statistical properties of turbulent dynamical systems. The method is applicable to conservative systems which exhibit a transition to stochasticity as well as dissipative systems which exhibit strange attractors. A specific dissipative mapping is considered in detail which models the dynamics of a Brownian particle in a wave field with a broad frequency spectrum. Results are presented for the low order statistical moments for three turbulent regimes which exhibit strange attractors corresponding to strong, intermediate, and weak collisional dumping. In the dissipationless limit this map is equivalent to the conservative Chrikov- Taylor mapping. The turbulent behavior of the Chirikov-Taylor mapping is shown to be diffusive due to the intrinsic stochasticity; and the stochastic diffusion coefficient derived by Rechester and White is recovered. The statistical dynamics are significantly altered by the inclusion of damping which restricts the chaotic motion to a strange attractor which is bounded in phase space. Specifically, for weak and intermediate damping the long-time dynamics are no longer diffusive; and the corrections to the random phase results for the low order moments decay away for long times. In addition the “accelerator modes”, which are exhibited by the Chirikov-Taylor mapping, are destroyed by the drug. These results provide a new description of the effects of collisional damping on the stochastic heating of plasmas by electrostatic waves.
Multiwavelength bioaerosol sensor performance modeling

This paper describes work in modeling the performance of multiwavelength bioaerosol sensors. In particular, results are presented on modeling the performance of the Biological Agent Sensor Testbed (BAST), which employs LED UV sources at 280 and 340 nm. A previously developed catalog of Excitation/Emission Matrix (EEM) data for bioagents and interferents is used to determine fluorescence scattering for a specified particle mixture. These particle mixtures were applied to the model in order to assess discrimination performance. An initial comparison of simulated and measured BAST data is presented. This work was sponsored by DARPA under the Semiconductor Ultraviolet Optical Sources (SUVOS) program.
A half-million-year record of paleoclimate from the Lake Manix Core, Mojave Desert, California

Abstract Pluvial lakes in the southwestern U.S. responded sensitively to past climate through effects on rainfall, runoff, and evaporation. Although most studies agree that pluvial lakes in the southwestern U.S. reached their highest levels coeval with glacial stages, the specific timing of increased effective moisture and lake-level rise is debated, particularly for the southwesternmost lakes. We obtained a 45-m core of lacustrine sediment from Lake Manix, the former terminus of the Mojave River prior to about 25 ka, and supplemented data from the core with outcrop studies. These sediments provide a robust record of Mojave River discharge over the last half-million years. Lake Manix persisted from OIS 12 through early OIS 2, including during interstadial OIS 3 and interglacials OIS 5, 7, and 9. The ostracode faunal record displays a shift from an unexpectedly warm, summer-dominated lake hydrology during OIS 12 to predominantly colder, winter-dominated conditions afterwards. The ostracode-based stable isotope record displays a large degree of intra-sample variability and does not mimic other well-known isotopic records of climate change. Evaporation likely buffered the Manix δ18O record from most of the expected isotopic differences between interglacial and glacial-interval discharge. Isotopically depleted and stable lakes occurred only four to six times, most notably during OIS 7 and OIS 9. Internal drainage-basin changes also affected the isotopic record. Persistence of lakes in the Manix basin during interglacials requires atmospheric or oceanic circulation controls on the mean position of the Pacific storm track other than large ice sheets. We propose that the relative strength and sign of the Northern Annular Mode (NAM) and its influence on atmospheric river-derived precipitation is a potential explanation.
Energy Transport and Thermal Stress Formation in Hybrid Laser-MIG Welding

This study is focusing on understanding the thermal stress formation in hybrid laser-MIG welding which has been gaining a lot of interests due to its many advantages over laser welding. Thermal stress formation is tightly associated with heat and mass transfer in hybrid laser welding, so accurate analysis of heat transfer process in the welding process is critical to correctly predict thermal stress information and residual stress in hybrid laser welds. In this study, a comprehensive heat and mass transfer model analyzing the energy, mass, and momentum transport processes in hybrid laser-MIG welding is successfully integrated with a mechanical model to study thermal stress formation in hybrid laser-MIG welding and residual stress in final welds as well. High compressive stress is found to exist on the top surface of the weld which might cause irregular welds topology and high tensile residual stresses were found in some locations in the final weld. This proposed study can be used as a foundation to further understand the thermal stress formation mechanisms in welding and to provide an efficient way to optimize the hybrid laser-arc welding process.Copyright © 2013 by ASME
Maps in the Mining Industry

This paper analyses the problems and procedures of using maps for prospecting and developing ore deposits. It discusses some of the problems associated with mining maps, their compilation, publicat...
On the influence of tribo-induced superheating on protective layer formation in dry sliding of metallic pairs

This paper studies the effects of the heat diffusion ability of a rubbing material on wear resistance at high temperatures. These effects are studied with a special focus on the dilution of thermal energy in sliding. The results suggest a correlation between wear transition and the change in the heat transfer limit of a rubbing material. The nature of change in the thermal properties before and after the transition influences the thermal environment within the contacting layers. This controls the kinetics of oxide formation and thereby controls wear. Thermal dilution is a super position of three functions which represent the competing effects of the room temperature thermal properties and their respective variation with temperature. Hence, the change in the thermal properties bears on dilution. The possible relation between thermal dilution and protective oxide formation is studied by examining fretting wear data for two alloys: a Ni-based alloy and a Co-based alloy. Results indicate a strong correlation between the formation of protective oxides and the change in the dilution of thermal energy of the examined alloys with temperature. Moreover, examination of the wear data suggests that a critical ratio between the effects of the conductivity and those of the diffusivity has to be established for favorable wear resistance. This ratio reflects on the intrinsic ability of the material to sustain an oxidative reaction of a controlled rate in which protective glaze oxide layers are formed in a rate that is approximately equal to the rate of oxide layer break down. Therefore, continuous compensation for the removed oxide layer (self-repairing oxides) is established in such a case.
Temperature-based extrinsic reproductive isolation in two species of Drosophila.

Drosophila santomea and D. yakuba are sister species that live on the African volcanic island of Sao Tome, where they are ecologically isolated: D. yakuba inhabits low-altitude open and semiopen habitats while D. santomea lives in higher-elevation rain and mist forest. To determine whether this spatial isolation reflected differential preference for and tolerance of temperature, we estimated fitness components of both species at different temperatures as well as their behavioral preference for certain temperatures. At higher temperatures, especially 28°C, D. santomea was markedly inferior to D. yakuba in larval survival, egg hatchability, and longevity. Moreover, D. santomea females, unlike those of D. yakuba, become almost completely sterile after exposure to a temperature of 28°C, and conspecific males become semisterile. Drosophila santomea adults prefer temperatures 2–3°C lower than do adults of D. yakuba. Drosophila santomea, then, is poorly adapted to high temperature, partially explaining its restriction to cool, high habitats, which leads to extrinsic premating isolation and immigrant inviability. Rudimentary genetic analysis of the interspecific difference in egg hatchability and larval survival showed that these differences are due largely to cytoplasmic effects and to autosomal genes, with sex chromosomes playing little or no role.
Adam Smith Goes to College: An Economist Becomes an Academic Administrator

The author asks whether it is useful to view universities in a utility-maximizing framework and shows that university organizing virtually guarantees that the utility-maximizing model is the incorrect approach. He then discusses resource allocation issues at Cornell and reflects upon how concepts that are obvious to economists helped or hindered decision making at Cornell. The author hopes to convey not that economic concepts are irrelevant in operating a university, but rather that it takes a long time to explain to all the actors in the system why these concepts should matter and even longer to actually make them matter.
Borate complexes of amphotericin B: Polymeric species and aggregates in aqueous solutions

Amphotericin B, a polyene macrolide antibiotic, exists in aqueous solution as a poorly soluble, high-molecular-weight aggregate. A borate complex of this polyene was prepared that has greater solubility and is less aggregated. In aqueous solution this borate complex exists as a mixture of several molecular species differing in borate content, molecular weight, and molecular conformation. The solubility varied with pH and was minimal at neutrality. Throughout the pH range it was one to two orders of magnitude higher than that of the parent compound. The molecular size distribution, as determined by differential ultrafiltration, showed a progressive increase in the weight fraction of aggregates going from acid to alkaline solutions. The sizes of aggregates ranged from under 25 to over 100 molecules. The borate content of the complexes increased with increasing pH. No borate was complexed in acid solutions. This indicated that amphotericin B and borate ions can complex to form copolymer chains of varying length in which these species alternate, since both are bifunctional. The complexation equilibrium is favored by high pH. Absorption and CD spectra indicated that the polyene molecules can stack reversibly to form dimers. Dimerization constants calculated from the spectra were highest in neutral solution and declined with increasing acidity or alkalinity. In alkaline solutions the polymer chains are long and extended, with minimal stacking. In neutral solution the chains are shorter and extensively stacked. In acid solutions no borate complexes are formed, and the polyenes are stacked to an intermediate degree. The very different effects of pH and concentration on the degree of complexation with borate and on the degree of dimerization of the polyenes shows that these equilibria are independent of each other.
The Bradyrhizobium japonicum frcB Gene Encodes a Diheme Ferric Reductase

Iron utilization by bacteria in aerobic environments involves uptake as a ferric chelate from the environment, followed by reduction to the ferrous form. Ferric iron reduction is poorly understood in most bacterial species. Here, we identified Bradyrhizobium japonicum frcB (bll3557) as a gene adjacent to, and coregulated with, the pyoR gene (blr3555) encoding the outer membrane receptor for transport of a ferric pyoverdine. FrcB is a membrane-bound, diheme protein, characteristic of eukaryotic ferric reductases. Heme was essential for FrcB stability, as were conserved histidine residues in the protein that likely coordinate the heme moieties. Expression of the frcB gene in Escherichia coli conferred ferric reductase activity on those cells. Furthermore, reduced heme in purified FrcB was oxidized by ferric iron in vitro. B. japonicum cells showed inducible ferric reductase activity in iron-limited cells that was diminished in an frcB mutant. Steady-state levels of frcB mRNA were strongly induced under iron-limiting conditions, but transcript levels were low and unresponsive to iron in an irr mutant lacking the global iron response transcriptional regulator Irr. Thus, Irr positively controls the frcB gene. FrcB belongs to a family of previously uncharacterized proteins found in many proteobacteria and some cyanobacteria. This suggests that membrane-bound, heme-containing ferric reductase proteins are not confined to eukaryotes but may be common in bacteria.