cssi/SciSciGPT-SciSciNet huggingface dataset:
Sedimentation and facies analysis of theGirvanella-constituted oncolitic shoals and associated lithofacies in the middle Ordovician Antelope Valley Limestone, central Nevada, USA

InGirvanella-constituted oncolitic packstone and grainstone lithofacies of the Antelope Valley Limestone, ellipsoidal- or well-rounded,Girvanella oncoids along with thick-shelled gastropods (Maclurites andPalliseria) are the primary sediments. These particles are cemented by columnar calcite marine cement within the normal-graded, thin- to medium beds. These bedforms overlie one another with a sharp contact and constitute the grain-supported basal part of thick, massive lenticular bedforms. The basal amalgamated units are overlain by the upper packstone to wackestone subunits, which consist of evenly parallel silty quartz-rich laminae. All of the indicated sedimentary structures and textures represent moderately high energy, storm-dominated subtidal oncoidal shoals. Progressively abating, multiple high-energy pulses or storm events in these shoals probably resulted in the normal-graded, multiple thin to medium bedforms.
Nonwords and generalization in children with phonological disorders.

Purpose To evaluate the effects of using nonword (NW) stimuli in treatment of children with phonological disorders relative to real words (RWs). Methods Production data from 60 children were examin...
Systems analysis of dual-purpose nuclear power and desalting plants part II. Sensitivity analysis

Abstract In Part I of this series, a dual purpose plant for production of power and water is analyzed and its performance is optimized for producing various levels of power and water demands. The plant consists of a nuclear reactor, a steam-turbine power generator, and two water plants (a multistage flash plant and a reverse osmosis plant). In this part an analysis is carried out to determine the sensitivity of the system to selected process parameters of such a plant designed and constructed to produce 150 million gallons of water and 50 megawatts of salable power per day at the optimal conditions.
Transfection of Lepidopteran insect cells with Baculovirus DNA

Several protocols are presented for preparation and transfection of Baculovirus and plasmid DNAs into Lepidopteran insect cells using the calcium-phosphate co-precipitation technique. Important parameters for optimum efficiency include the inherent susceptibility of the recipient cell line for transfection, and the method of preparation of viral and plasmid DNAs. The protocols presented provide reproducible high efficiencies for transfection of several Lepidopteran cell lines.
The 1994 Bolivia and Tonga events: Fundamentally different types of deep earthquakes?

The 1994 Bolivia and Tonga events show large differences in source and aftershock properties. The Bolivia earthquake, characterized by high stress drop, slow rupture propagation, and a weak aftershock sequence, appears similar to other large deep earthquakes that are isolated from active seismic zones, including the 1970 Colombia earthquake. In contrast, the 1994 Tonga event showed stress drop, rupture propagation velocities, and an aftershock sequence similar to that found for shallow earthquakes. The aftershock sequence of the 1994 Tonga event is many times stronger than has been observed for any other deep earthquake. A survey of deep earthquake aftershocks suggests that aftershock occurrence is correlated with the overall subduction zone magnitude-frequency relation (b-value). The largest deep events occur in isolated regions lacking smaller earthquakes, or in subduction zones characterized by anomalously low b-values. The 1994 Tonga event is an exception and is the largest deep earthquake to occur within an active subduction zone showing a large b-value, perhaps explaining the strong aftershock sequence. The Bolivia and Tonga events may represent end members of a population of deep earthquakes showing exceptional diversity in source properties, or they may represent two fundamentally different types of deep earthquakes, perhaps resulting from different physical mechanisms.
Large-N harmonic oscillator as a string theory

We propose a duality between the large-N gauged harmonic oscillator and a novel string theory in two dimensions.
The moral consequences of studying the vulnerable: Court mandated reporting and beyond.

Qualitative researchers studying children through the use of narratives face a particular set of ethical challenges as they relate to the need to report issues of abuse and neglect. These challenges are compounded by the lack of a court mandate to report abuse, for without such a mandate researchers are left to decide whether a case merits reporting and, if so, whether they are the ones responsible to do so. While researchers may be reluctant to support a mandate, citing issues of confidentiality, lack of training, harm to research outcomes, and social and political ramifications, it is argued herein that they have a moral imperative to report. Thus, to remain a silent bystander to suspected abuse ultimately results in complicity to the injustice. More generally, it is also argued that the role of the dispassionate researcher, committed to his or her data alone, must be suspended in order to protect vulnerable populations.
Can technology advance education

Abstract Because the enormous educational challenges that developing countries presently face are beyond the capacity of conventional school systems to handle, the author argues that careful reconsideration must be given to educational technologies—despite some unfortunate experiences with them in the past. To compare student learning outcomes, in wealthy countries the impact of some technologies has been minimal, whereas in developing countries that impact on student performance and on costs is often considerable. Furthermore, equipment is now both cheaper and sturdier, and people are more secure about using technology and more realistic about what it can accomplish. Interpreting ‘technology’ in its broadest sense, he then proposes a framework that permits a fine-grained reconsideration of the scarce evidence on the more fruitful areas of application relevant to developing countries: technologies to improve conventional schools; technologies for vocational education and training; and technologies to totally or partially replace schools, through distance education. The author concludes that these days it is no longer a question of whether to use technologies but why, where, and how they can be made cost-effective.
Self-reported frequency of sexual urges, fantasies, and masturbatory fantasies in heterosexual males and females

The frequency of sexual imagery outside of sexual behavior was assessed. In addition, an attempt was made to determine the viability of a distinction between internally generated sexual thoughts (fantasy) and externally provoked sexual thoughts (urge). After a 3-day practice period, 49 male and 47 female heterosexual undergraduates self-monitored the frequency of fantasies, urges, and masturbatory fantasies for 7 consecutive days. The most significant finding was that men reported a significantly greater frequency of sexual urges and masturbatory fantasies than women. No gender differences emerged with respect to fantasies. These findings suggest that a distinction between internally and externally generated sexual imagery is viable and may be useful in future studies examining the frequency, functions, and determinants of sexual imagery.
Capillary permeability in the isolated rabbit heart as measured by local tissue clearance

Abstract The relatively simple method of local tissue clearance was used to measure capillary permeability-surface area products (PS) in the isolated, Ringer-perfused rabbit heart. Ten microliters of a mixture of [3H]inulin and [14C]sucrose was injected at a depth of 2 mm into the left ventricular myocardium and clearance rate constants (k in min−1) were determined by analyzing the draining perfusion fluid. PS (ml/min per 100 ml) for each solute was calculated by the following equation: PS = −F ln (1 − λk F ) , where F is perfusate flow (ml/min per 100 ml) and λ is the equilibrium tissue/Ringer partition coefficient. At a perfusion pressure of 40 mm Hg, F = 133 ± 9.7 (mean ± SEM), PSsucrose = 77 ± 8.0, and PSinulin = 13.9 ± 0.7. These PS products are within the range of values previously reported by others using several different techniques. The mean inulin/sucrose permeability ratio was 0.189 ± 0.018 which is significantly less than the separately measured free diffusion coefficient ratio (= 0.41 ± 0.005), thus indicating that sucrose and inulin crossed myocardial capillary walls by restricted diffusion. The reasons why some investigators did not find similar evidence of restricted diffusion are discussed.
HYDRODYNAMIC ANALYSIS OF VARIABLE DRAFT SPIRAL WAVEMAKER

Abstract An eigenfunction expansion technique is utilized to investigate the linear wave field produced by a spiral wavemaker consisting of an eccentrically-mounted, right circular cylinder rotating at a constant angular velocity in a basin of arbitrary uniform depth. In the present study the effect of a finite gap which exists between the underside of the wavemaker and the floor of the basin is included in a mathematially consistent manner. Numerical results are presented which illustrate the influence of this gap on the generated waves and on the hydrodynamic loads experienced by the wavemaker.
Late Holocene advance of the Müller Ice Shelf, Antarctic Peninsula: sedimentological, geochemical and palaeontological evidence

Marine sediment cores were obtained from in front of the Muller Ice Shelfin Lallemand Fjord, Antarctic Peninsula in the austral summer of 199&91. Sedimentological and geochemical data from these cores document a warm period that preceded the advance of the Miiller Ice Shelf into Lallemand Fjord. The advance of the ice shelf is inferred from a reduction in the total organiccarboncontent and an increase in well-sorted, aeolian, sand in cores proximal to the present calving line. This sedimentological change is paralleled by a change in the foraminifera1 assemblages within the cores. Advance of the ice shelf is indicated by a shift from assemblages dominated by calcareous benthic and planktonic forms to those dominated by agglutinated forms. A I4C chronology for the cores indicates that the advance of the Miiller Ice Shelf took place c. 400 years ago, coincident with glacier advances in other high southern latitude sites during the onset of the Little Ice Age. Ice core evidence, however, documents this period as one of warmer temperatures for the Antarctic Peninsula. We suggest that the ice shelf advance was linked to the exclusion of circumpolar deep water from the fjord. This contributed to increased mass balance of the ice shelf system by preventing the rapid undermelt that is today associated with warm circumpolar deep water within the fjord. We also document the recent retreat of the calving line of the Miiller Ice Shelf that is apparently in response to a recent (four decade long) warming trend along the western side of the Antarctic Peninsula.
WE-G-BRCD-03: Improvement in Robustness and Delivery Efficiency of Intensity-Modulated Proton Therapy Using Single-Field Optimization with Energy Absorber.

Purpose: Intensity‐modulated proton therapy (IMPT) using multi‐field optimization (MFO) could generate highly conformal dose distributions but it is more sensitive to setup and proton range uncertainties than IMPT using single‐field optimization (SFO). This work evaluates the effectiveness of SFO treatment plans with the use of energy absorbers (EAs) to improve the robustness and delivery efficiency of IMPT for head and neck cancers.Methods: IMPT treatment plans were generated using 2‐field SFO with an EA in each field (EA‐SFO) for four patients with head and neck cancers. We compared the plan quality, robustness, and delivery efficiency of the EA‐ SFO plan with a 3‐field MFO plan that was used to treat the patient. Robustness analysis of each plan was performed to generate two dose distributions, consisting of the highest and the lowest possible doses from spatial and range perturbations at every voxel. Dosimetric indices and the numbers of energy layers required in the EA‐SFO and MFO plans were compared. Results: All the nominal EA‐SFO plans are clinically acceptable. They achieved similar levels of target coverage compared to the MFO plans; the differences in D95 of the GTV and CTVs between the two plans were within 3.5%. Although some of the OARs received higher dose in the EA‐ SFO plan, they were all within tolerance. The EA‐SFO plans yielded an average of 38.5% reduction of plan sensitivity to uncertainties in the targets and 18.5% overall. The EA‐SFO plans used an average of 79 (46%) fewer energy layers than the MFO plans, which corresponds to nearly 3 minutes shorter delivery time. Conclusions: The use of energy absorber greatly facilitated the design of clinically acceptable SFO treatment plans. Compared to MFO, EA‐SFO not only improved the robustness to setup and range uncertainties, but also reduced the time required for delivery and patient QA.
Structure of the E. coli DNA Glycosylase AlkA Bound to the Ends of Duplex DNA: A System for the Structure Determination of Lesion-Containing DNA.

The constant attack on DNA by endogenous and exogenous agents gives rise to nucleobase modifications that cause mutations, which can lead to cancer. Visualizing the effects of these lesions on the structure of duplex DNA is key to understanding their biologic consequences. The most definitive method of obtaining such structures, X-ray crystallography, is troublesome to employ owing to the difficulty of obtaining diffraction-quality crystals of DNA. Here, we present a crystallization system that uses a protein, the DNA glycosylase AlkA, as a scaffold to mediate the crystallization of lesion-containing duplex DNA. We demonstrate the use of this system to facilitate the rapid structure determination of DNA containing the lesion 8-oxoguanine in several different sequence contexts, and also deoxyinosine and 1,N6-ethenoadenine, each stabilized as the corresponding 2′-flouro analog. The structures of 8-oxoguanine provide a correct atomic-level view of this important endogenous lesion in DNA.
Automated Generation of Tissue-Specific Finite Element Models Containing Ellipsoidal Cellular Inclusions

Microstructural cellular finite element (FE) models provide a means of describing tissue micromechanics and cell mechanobiology. For the cartilage, for example, the mechanical environment of chondrocytes has been explored with models such as those from the pioneering work of Guilak and Mow [1]. However, most cellular FE models typically include a single cell. These models do not provide the capacity to explore mechanobiological function and micromechanical effects caused by intercellular interactions. Therefore, it is desirable to develop models that more closely represent cell distribution and shape within the tissue of interest.Copyright © 2012 by ASME
Identification of genes required for hydrogenase activity in Chlamydomonas reinhardtii

The eukaryotic green alga, Chlamydomonas reinhardtii, produces H(2) under anaerobic conditions, in a reaction catalysed by an [FeFe]-hydrogenase. To identify genes that influence H(2) production in C. reinhardtii, a library of 6000 colonies on agar plates was screened with sensitive chemochromic H(2)-sensor films for clones defective in H(2) production. Two mutants of particular interest were fully characterized. One mutant, hydEF-1, is unable to assemble an active [FeFe]-hydrogenase. This is the first reported C. reinhardtii mutant that is not capable of producing any H(2). The second mutant, sta7-10, is not able to accumulate insoluble starch and has significantly lowered H(2)-photoproduction rates in comparison with the wild-type. In hydEF-1, anaerobiosis induces transcription of the two reported C. reinhardtii hydrogenase genes, HydA1 and HydA2, indicating a normal transcriptional response to anaerobiosis. In contrast, the transcription of both hydrogenase genes in sta7-10 is significantly attenuated.
Targeting hepatocellular carcinoma with aptamer-functionalized PLGA/PLA-PEG nanoparticles

ABSTRACT Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwid e, particularly in regions where chronic Hepatitis B and C infections are common. Nanopar ticle assemblies that incorporate high-affinity aptamers which specifically bind malignant hepatocellular carcinoma cells could be useful for targeted drug delivery or enhancing contrast with existing ablation therapies. The in vitro interactions of a tumor-specific aptamer, TLS11a, were characterized in a hepatoma cell line via live-cell fluorescence imaging, SDS- PAGE and Western Blotting techniques. Cell surface binding of the aptamer-AlexaFluor ® 546 conjugate was found to occur within 20 minutes of initial exposure, followed by internalization and localization to late endosomes or lysosomes using a pH-sensitive LysoSensor  Green dye and confocal microscopy. Aptamer-functionalized polymer nanoparticles containing poly(lactic-co-glycolic acid) (PLGA) and poly(lactide)-b-poly(ethylene glycol) (PLA-PEG) were then prepared by nanoprecipitation and passively loaded with the chemotherapeu tic agent, doxorubicin, yielding spherical nanoparticles approximately 50 nm in diameter. Targeted drug delivery and cytotoxicity was assessed using live/dead fluorescent dyes and a MTT colorimetric viability assay with elevated levels of cell deat h found in cultures treated with either the aptamer-coated and uncoated polymer nanoparticles. Identification and characterization of the cell surface protein epitope(s) recognized by the TLS11a aptamer are ongoing along with nanoparticle optimization, but these preliminary studies support continued investigation of this aptamer and functionalized nanoparticle conjugates for targeted labeling and drug delivery within malignant hepatocellular carcinomas. Keywords: cancer, hepatocellular carcinoma, ap tamer, nanoparticle, drug delivery
Effect of the antiviral drug, cytosine arabinoside, on the developing nervous system.

Extract: Cytosine arabinoside (which is used to treat congenital viral infections) produced neurologic and retinal damage in infant mice. Station and gait abnormalities could be related to hypoplasia and marked microscopic changes in the cerebellum of treated animals. These, as well as microscopic changes in the retina, appeared to be irreversible. The damage produced appeared to result from destruction of primordial cells during a critical period of differentiation. Speculation: The potential for producing neurologic and other damage by treatment with DNA inhibitors during this period of rapid growth must be considered when contemplating the use of these DNA inhibitors for treatment of congenital virus infections.
Abstract: Semiparametric Bayesian Modeling With Application in Growth Curve Analysis

Traditional growth curve models (GCMs) often assume a known parametric form of growth patterns as well as normally distributed random effects and measurement errors. Tong and Zhang (2012) allowed r...
Communication about sex and birth control between mothers and their adolescent children

This paper explores the extent of communication about sex and birth control between mothers and two of their children between the ages of ten and eighteen. Results indicate that mothers are more likely to discuss these issues with their older and female children. Variations in patterns of communication are also examined by mother's education, race, and family income. Since many of the questions were asked of both mothers and children, comparisons are made of mother and child reports of discussions about sexual relations and birth control. Mothers' attitudes toward premarital sex and use of birth control, as well as her own behaviors in these areas are examined for their relationships to whether she communicates with her children about these topics. The relationship between presence of communication and children's knowledge about birth control is also discussed.
Black Nationalism and Rap Music

To take part in the African revolution it is not enough to write a revolutionary song; you must fashion the revolution with the people. And if you fashion it with the people, the songs will come by themselves, and of themselves.... In order to achieve real action, you must yourself be a living part of Africa and of her thought; you must be an element of that popular energy which is entirely called for the freeing, the progress, and the happiness of Africa. There is no place outside that fight for the artist or for the intellectual who is not himself concerned with and completely at one with the people in the great battle of Africa and of all suffering humanity.
Developmental control elements in the promoter of a Drosophila vitelline membrane gene.

Abstract DNA fragments from the 5′ flanking region of Drosophila melanogaster vitelline membrane gene VM26A1 were fused to hsp/lacZ reporter genes, reintroduced via P-element-mediated germ line transformation, and functionally assayed by histological staining for β-galactosidase activity. A developmental control element capable of promoting the basic vitelline membrane (VM) expression pattern was found within a 176-bp region. Additional multiple genetic control elements were found to be involved in modifying the level and spatial pattern of reporter gene expression but these required the 176-bp element in order to function. Unexpectedly, in isolation this 176-bp core element also promotes abnormal expression of the reporter gene in border cells of stage 8 and 9 egg chambers. This abnormal border cell expression is apparently suppressed in the native gene by an adjacent negative control element.
Inhibition of dopa decarboxylase synthesis by 20-hydroxyecdysone during the last larval moult of Manduca sexta

During the last third of fourth/fifth larval instar moult of the tobacco hornworm Manduca sexta, the level of epidermal dopa decarboxylase (DDC) activity increased four- or seven-fold, depending on whether the epidermis was taken from intact or allatectomized larvae, respectively. This increase in activity was prevented by infusion of 1.2 μg/hr 20-hydroxyecdysone for 24 hr from the time of head capsule slippage, which maintained an ecdysteroid titre of about 6 μg/ml 20-OH-ecdysone equivalents, but not by infusion of 0.15 μg 20-OH-ecdysone/hr. In the absence of ecdysteroid, the epidermal DDC activity steadily increased in vitro for 15 hr to a maximal level approx. three-fold higher than the maximum attained in vivo. Incubation with α-fluoromethyldopa, an irreversible inhibitor of DDC, for 7 hr eliminated DDC activity which could be restored by incubation in inhibitor-free medium for 17 hr. The presence of 1 μg/ml 20-OH-ecdysone or of actinomycin D, α-amanitin or cycloheximide (ED50 of 0.8, 1.2 and 3.8 μg/ml respectively) during this 17 hr period prevented the reappearance of DDC activity. Thus, the decline in ecdysteroid titre at the end of a larval moult is necessary to allow the onset of synthesis of DDC.
Fluorescent nucleotide triphosphate substrates for snake venom phosphodiesterase.

Abstract The fluorophore 1-aminonaphthalene-5-sulfonate has been coupled to the γ-phosphorus of dTTP, CTP, UTP, ATP, GTP, dCTP, and dGTP via a phosphoramidate linkage. The synthetic reaction was monitored by chromatography on an analytical μBonadpak HPLC column. Changes in the fluorescence of these nucleotide analogs upon cleavage of the α-β phosphodiester bond provide a sensitive and convenient steady-state assay of enzymes which act upon this bond and are active within the pH range of 4 to 10. For pyrimidine derivatives this cleavage increases fluorescence above 350 nm 2- to 6-fold while for purines it quenches it 1.2- to 1.4-fold. The kinetic constants determined by initial rate measurements and from integrated Michaelis-Menten equations indicate that these fluorescent nucleotides are excellent substrates of snake venom phosphodiesterase from C. adamanteus . The fluorophoric group does not interfere with binding or catalysis. This is consistent with product inhibition studies that demonstrate that most of the substrate binding strength resides in the nucleotide monophosphate moiety. The substrates bind tightly with K m 's ranging from 5 to 30 μ m and are hydrolyzed rapidly. Values of k cat range from 200 to 600 s −1 at pH 8.0 and 20°C. A wide variety of fluorophores are therefore possible without greatly affecting the catalysis of the substrate by snake venom phosphodiesterase.
A field investigation of the effects of expert systems use on the information processing capacity of the organization

In the past few years interest in creating expert systems (ESs) for businesses has dramatically increased. Although the number of publicized, commercial successes is small, the potential for augmenting human expertise with ESs is noteworthy. Vendors and computer science researchers have chronicled technical issues, but the organizational and management complexities of ES use have yet to be explored. The research questions are: "How does use of an ES affect the task it is designed to support?" Or more specifically, "How does ES use change the process of the task, the product which is created, and the roles of the individuals involved in the process?"
Women's personality in middle age: Gender, history, and midcourse corrections.

This article examines several key features of the course of adult development in the cohort of women born during the baby boom. By focusing on the women in this group and comparing their experience with that of older cohorts and research on men, the authors demonstrate the need for models of aging that take account of the inter-sections of history, gender, and individual development. Concepts proposed as universal features of middle age (midlife crisis, generativity, aging), as well as those proposed as specific to women (empty nest, menopause) are examined. Perhaps most important, certain features not commonly viewed as particularly important in women's middle aging (midlife review, identity, confident power) are shown to be central. The need for further research examining these same processes among men and different groups of women is underscored.
A pilot study of research methods for determining the impact of pictorial cigarette warning labels among smokers

Background Science to determine the impact of pictorial cigarette warning labels can inform decisions about warning label implementation and adjustments to their contents to maximize impact. This pilot study builds from earlier research on plain cigarette packaging to examine the feasibility of a method for determining the impact of pictorial warnings among smokers.
High-Power 2.2- $\mu$ m Diode Lasers With Heavily Strained Active Region

High-power 2.2-μm diode lasers and their arrays were designed and fabricated. Laser heterostructures were grown using solid-source molecular beam epitaxy on GaSb substrates. The device active regions contained two 1.5% compressively strained GaInAsSb quantum wells. Heavy compressive strain in the active region ensured strong carrier confinement and high differential gain. A broadened waveguide design approach was utilized to obtain an internal optical loss below 4 cm-1 and a threshold current density below 100 A/cm2. Individual high-power lasers produced 1.6 W of continuous-wave (CW) multimode power at room temperature from a single 100-μm-wide aperture. Linear laser arrays generated more than 25 W of quasi-continuous wave output power. The device power conversion efficiencies were better than 20% in peak and above 10% at maximum output power level.
A scalable, distributed algorithm for efficient task allocation

We present a distributed algorithm for task allocation in multi-agent systems for settings in which agents and tasks are geographically dispersed in two-dimensional space. We describe a method that enables agents to determine individually how to move so that they are, as a group, efficiently assigned to tasks. The method comprises two algorithms and is especially useful in environments with very large numbers of agent and task nodes. One algorithm adapts computational geometry techniques to determine adjacency information for the agent nodes given the geographical positions of agents and tasks. This adjacency information is used to determine the visible nodes that are most relevant to an agent's decision making process and to eliminate those that it should not consider. The second algorithm uses local heuristics based solely on an agent's adjacent nodes to determine its course of action. This method yields improved task allocations compared to previous algorithms proposed for similar environments. We also present a modification to the second algorithm that improves performance in environments in which multiple agents are required to complete a single task.
The Management of Strategic Time Horizons within Biotechnology Firms The Impact of Cognitive Complexity on Time Horizon Diversity

Strategic time horizons are an important but neglected area of research in the strategic management literature. Using inductive methods, the authors attempted to explore and develop the concept of ...
Prevalence of pathologies in systems of systems

As system of systems engineering (SoSE) continues to mature and evolve as a field, there is a natural search for transcending themes and perspectives. The confluence of these themes and perspectives will serve to both distinguish as well as integrate the field. The purpose of this paper is to suggest advancement of the SoSE field by offering an emerging set of common systems-based pathologies that may be prevalent in systems of systems. These pathologies are explored as deviations from the healthy functioning of an effective system of systems, potentially constraining performance, wasting resources, and reducing the level of system viability (sustaining existence). Upon recognising these pathologies, implications for utilising systems theory-based principles to aid in understanding their manifestation, systemic assessment, and strategies for system redesign to address the pathologies are explored. This paper concludes with implications and further development of research and practice related to pathologies in the developing SoSE field.
Biomedical MEMS research at the University of Minnesota

Microelectromechanical systems (MEMS) technology has often been characterized as an enabling technology. As MEMS technology expands with improved designs, refined processes, and extension to materials beyond standard silicon substrates, opportunities for applications in new research areas are growing rapidly. Beyond the pressure sensors, there are many possibilities in research fields such as biology, agriculture, and veterinary and human medicine. Over the past two years, the Microtechnology Laboratory at the University of Minnesota has been cultivating a research program based on applying MEMS to biomedical and medical situations. The program was motivated by a fruitful series of discussions between MEMS researchers from the engineering disciplines and faculty from medical school departments such as Urology, Surgery and Laboratory Medicine and Pathology. These discussions brought forth several possible applications of traditional MEMS technology to problems faced by these researchers, such as specialized small surgical tools. The process of implementing a program of bringing these possible applications to reality has been a difficult and rewarding one. In this talk we will give a historical view of development of the program. Some of the topics that will be discussed include: the unique problems faced by researchers from such disparate disciplines working collaboratively, funding, organization and management, and interaction with industry.
Outcomes of coverage of the left subclavian artery during endovascular repair of the thoracic aorta

Abstract Purpose To report outcomes of coverage of the left subclavian artery (LSCA) during thoracic endovascular aortic repair (TEVAR). Materials and Methods A retrospective review was performed of 285 patients (160 male) with a mean age of 62 years (range, 13–91 y) who underwent TEVAR at a single institution between March 2005 and May 2013. The LSCA was covered to obtain an adequate proximal landing zone, and a selective LSCA revascularization and embolization strategy was employed. All patient outcomes were recorded including neurologic complications, left arm claudication, endoleak rates, and repeat procedures. Results The origin of the LSCA was covered in 98/285 (34%) patients. Median follow-up was 533 days (range, 2–2,895 d). Cerebrovascular accident (CVA) rates for covered LSCA and noncovered groups were 11/98 (11%) and 5/188 (3%), respectively ( P = .005). LSCA was revascularized at time of initial TEVAR in 44/98 (45%) patients. Of the remaining 54 patients, 10 (19%) required subsequent revascularization for claudication. LSCA embolization was done to prevent or treat endoleak in 41/98 (42%) patients, with 33/98 (34%) patients undergoing LSCA embolization at the time of LSCA coverage and 8 of the remaining 65 (12%) patients requiring subsequent embolization for persistent endoleak. Conclusions Coverage of the LSCA during TEVAR is feasible with low complication rates, although it carries an increased risk of CVA. The selective LSCA revascularization and embolization strategy was well tolerated. A more liberal strategy may be required to decrease the rate of delayed revascularization and embolization procedures to treat arm claudication and endoleaks, respectively.
Bistability and correlation with arrhythmogenesis in a model of the right atrium.

Rapid pacing is an important tool for understanding cardiac arrhythmias. A recent experiment involving rapid pacing of sheep atria indicated that the initiation of atrial arrhythmias may be related to the 1:1/2:1 bistability. To elucidate the mechanism of this relation, this study applied the pacing protocol from the sheep study to an idealized model of the right atrium. The model included all major anatomical features, the sino-atrial node, and the regional differences in the action potential duration (APD). A pacing protocol was applied, in which the basic cycle length (BCL) was decreased in steps of 10 ms until the response switched to 2:1, then BCL was increased. The 1:1-to-2:1 transitions occurred at shorter BCLs than the 2:1-to-1:1 transitions yielding a global bistability window of 60 ms. As in the sheep study, idiopathic waves were observed at BCLs within or near the bistability window. The model was used to quantify the types, prevalence, and persistence of idiopatic waves, study their initiation and termination, and relate them to the model components. The results demonstrate that idiopatic waveforms move with the shift of the bistability window and that they disappear when bistability is eliminated. Thus, this modeling study supports causal relationship between the 1:1/2:1 bistability and the initiation of arrhythmias.
Inductively coupled power transfer for continuously powered electric vehicles

Economic and environmental issues are main motivation for developing efficient and sustainable electrical vehicle for urban transportation. Electrical vehicles (EV) have two main advantages compared to hybrid and gasoline vehicle: eliminated tailpipe emissions and simplified drive-train. However, electric vehicles have a limited range between recharges when fitted with the current state-of-the-art energy storage. To mitigate the limitations of the energy storage technology, we propose to use inductively coupled power transfer (ICPT) to supply power to the vehicle while it is moving. ICPT is an efficient technique for transferring power with no physical connection between the source and the load. In this paper we investigate the ICPT requirements for two types of vehicles operating in combination with ICPT system. The first vehicle makes use of a battery as primary and ICPT as secondary energy source for electric vehicle supplying. The goal is to achieve 300 miles range of covering. The second uses electrochemical capacitors (Ultracapacitors) as the power source and ICPT as the energy source. The goal is to provide unlimited range for the vehicle. The result is system analysis of feasibility of battery-ICPT and ultracapacitor-ICPT combinations for different driving conditions and vehicles as well as rough evaluation of expected length and optimal positions of ICPT track for specified driving cycles.
MRE11/RAD50 Cleaves DNA in the AID/UNG-Dependent Pathway of Immunoglobulin Gene Diversification

MRE11/RAD50/NBS1 (MRN) is a ubiquitous complex that participates in the response to DNA damage and in immunoglobulin (Ig) gene diversification. Ig gene diversification is initiated by deamination of cytosine to uracil, followed by removal of uracil to create an abasic (AP) site. We find that MRE11 associates specifically with rearranged Ig genes in hypermutating B cells, whereas APE1, the major AP-endonuclease in faithful base excision repair, does not. We show that purified, recombinant MRE11/RAD50 can cleave DNA at AP sites and that this AP-lyase activity is conserved from humans to Archaea. MRE11/RAD50 cleaves at AP sites within single-stranded regions of DNA, suggesting that at transcribed Ig genes, cleavage may be coordinated with deamination by AID and deglycosylation by UNG2 to produce single-strand breaks (SSBs) that undergo subsequent mutagenic repair and recombination. These results identify MRN with DNA cleavage in the AID-initiated pathway of Ig gene diversification.
Standoff raman spectroscopy system for remote chemical detection.

We have developed a class of aperture coding schemes for Remote Raman Spectrometers (RRS) that remove the traditional trade-off between throughput and spectral resolution. As a result, the size of the remote interrogation region can be driven by operational, rather than optical considerations. In this paper we present the design of our coded-aperture standoff spectroscopy system as well as experimental data collected while making remote measurements.
A formalism for monitoring real-time constraints at run-time

A formalism is presented for specification and analysis of real-time constraints of systems at run time. Real-time logic (RTL) is employed to illustrate how timing properties can be specified elegantly in the form of annotation added to a program (or to a design specification). The algorithms for detecting a violation of a timing property at runtime, expressed in RTL, are presented. >
A heuristic approach to the development of frequency response characteristics in the design of feedback amplifiers

One of the most significant benefits in the application of feedback in the design of electronic amplifiers is an increase in the midband frequency bandwidth. Because of the complexity of the mathematics involved in modeling feedback amplifier performance characteristics, several simplifying techniques are typically introduced. Among these in the frequency domain are single-pole approximations and the concept of dominant poles. While these techniques can reasonably approximate many amplifiers, they fail to adequately address some of the significant phenomena invoked when feedback is applied. In addition, it is often difficult for the typical student of electronics to understand the fundamental reasoning behind each approximation and its realm of validity. A unique approach to understanding feedback amplifier frequency response through the use of simple graphical heuristics is introduced. Primary among these is a display of pole migration using a plot of the pole polynomial as a function of the amount of feedback. General pole migration and the formation of pole pairs can easily be seen using this technique. The graphical nature of the approach brings particular significance to understanding pole dominance throughout the possible range of feedback. It can also be seen that the two-pole approximation to multipole feedback amplifiers has a significant region of validity while the validity of single-pole approximations is questionable.
Educational audiologists: their access, benefit, and collaborative assistance to speech-language pathologists in schools

Purpose The main goals of this study were to determine if school-based speech-language pathologists (SLPs) have access to the services of an audiologist and if those SLPs felt they obtained benefit...
Hybrid Reynolds-Averaged and Large-Eddy Simulations of a Supersonic Cavity Flameholder

Simulation results are presented for non-reacting flow within a supersonic cavity flameholder. The freestream is air at Mach 2. A case is simulated with no fuel injection, and two cases are simulated with different rates of ethylene fuel injected through holes located on the back face of the cavity. The simulations correspond to a series of experiments for which particle image velocimetry measurements of two velocity components were made within the cavity. Reynolds-averaged Navier-Stokes simulations are used to examine the influence of the finite-width, low-angled slot used to seed the flow for the particle image velocimetry. The simulations indicate that the seeder has little influence on the flow within the cavity, allowing for the seeder to be neglected in the remainder of the simulations. The flow within the cavity is simulated using steady-state Reynolds-averaged Navier-Stokes simulations, as well as unsteady hybrid Reynolds-averaged Navier-Stokes and large-eddy simulations. A thorough grid resolution study is presented in which the resolution required to resolve the flow within the cavity is determined. The results of the simulations on the final grids are compared to the velocity measurements from the experiments and the hybrid Reynolds-averaged Navier-Stokes and large-eddy simulation results are found to provide improved agreement with certain aspects of the flow. The simulation results are then used to investigate the mixing within the cavity, which was not measured in the experiments. The mixing information from the simulations provides further insight into the physics of the cavity flameholder flowfield.
Self-heating Parameter Extraction of Power Metal-oxide-silicon Field Effect Transistor Based on Transient Drain Current Measurement

AbstractFor the use of circuit simulation model for power Metal-Oxide-Silicon Field Effect Transistors (MOSFETs), the extraction of self-heating parameters based on transient I-V measurements has been developed. A set of transient drain current was measured through a pulsed I-V setup. The thermal resistance and thermal capacitance are extracted from the set of transient current data. The self-heating-free drain current, which is required for MOSFET model extraction, is obtained by extrapolating the transient data to t=0. Since the measurements after a certain delay are analyzed in this method, a very short pulse measurement which tends to suffer from ringing noises and requires a complicated DUT design is not required. The accuracy of the method is demonstrated for a power MOS model using the BSIMSOI parameter set.
Detection of high-intensity focused ultrasound liver lesions using dynamic elastometry.

A novel ultrasound technique was developed for detecting the distribution of stiffness in biological tissue. The method, which we call ‘dynamic elastometry,’ involves applying a low-frequency vibration (≤5 Hz) to the tissue and measuring the resulting velocity pattern within the sample using Doppler spectral analysis. Based upon the velocity differences, an elastically stiff region can be differentiated from surrounding soft tissue. Dynamic elastometry was used to both detect and quantify lesions produced by high-intensity focused ultrasound (HIFU) in porcine livers. Measurements of the lesion position and length agreed well with independent geometric measurements. The mean and standard deviation of the differences between the two types of measurement were −0.01cm and 0.10 cm for lesion position, and −0.05 cm and 0.12 cm for lesion length, respectively. The relative stiffness between lesions and normal liver tissue was estimated by the velocity gradient ratio. Results were compared with the Young's modulu...
Civility in News Discourse: The Case of PBS’ Brooks and Shields

In a political environment viewed as containing much uncivil discourse, and in which opinion journalism is often blamed, Mark Shields and David Brooks give their disparate political views on the PBS NewsHour with exemplary civility. This conversation analysis of the Shields/Brooks weekly discussions during 2012 reveals ways each frames his position while maintaining civility. The study distinguishes between watchdog journalism, opinion journalism, and incivility and reviews relevant research on mediated political discourse and civility. Using the Brooks and Shields exchanges as a model, it suggests conditions under which opinion and partisan journalism could make useful contributions.
Acute Citrulline-Malate Supplementation Improves Maximal Strength and Anaerobic Power in Female, Masters Athletes Tennis Players

Citrulline-malate (CM) is a precursor to nitric-oxide (NO) in the NO synthase (NOS) pathway and is suggested to increase exercise performance in younger individuals. With age, NO production decreas...
Structure Integrity Analysis of Free Loading Solid Rocket Grain under Internal Pressure

There is definite gap between free loading solid rocket mix grain/inhibitor and case.During solid rocket motor works,internal surface of mix grain is acted on uniform pressure,but pressure inside gap is increasing to maximum at different rate.Based on linear viscoelasticity,the structure integrity analysis of mix grain was studied on two limit cases.Results show that max vonmises strain of mix grain considering pressure inside gap is greater than which without considering pressure inside gap.Because the pressurization process is unstable and difficult to simulate,pressure inside gap can be neglected on structure integrity analysis of free loading solid rocket grain,and the results are safer.
How Can We Look Anew at Strabismus

There is no more refreshing experience in medicine, and perhaps in all of science, than to look with fresh eyes at phenomena that have long since ceased to mystify us and to which we have become apathetic because we failed to understand their meaning. The mind “adapts” to what is mysterious in nature and in so doing trivializes it. Not because the phenomenon itself is trivial, but because our mind repeatedly fails to comprehend it and it therefore becomes an irritant around which we build an eschar to wall it off from our conscious thought processes. When, on the other hand, an explanation that suggests a rational basis for understanding arises, it is with a sense of joy and challenge that we look again at the once mysterious, then irritating, then trivial phenomenon. Let us do this with the phenomenology of strabismus in the clinic and examine the ways in which the new conception may enlighten us.
Shock and kill with caution

Antiretroviral therapy has made life-long suppression of human immunodeficiency virus (HIV) replication a possibility for some patients. But with the 2015 estimate of 36.7 million people infected worldwide, there is a great need to explore other ways to address this epidemic—from preventing new infections by treating uninfected high-risk individuals, to developing a vaccine, to targeting latent HIV that hides in immune cells and persists in patients. The idea of clearing latent infection has prompted strategies aimed at an HIV-1 cure. Although this approach should continue to be tested, other approaches, including those that seek to permanently suppress the latent virus, should also be explored. Different strategies may target different viral reservoirs, and may turn out to be complementary.