cssi/SciSciGPT-SciSciNet huggingface dataset:
In situ electrochemical nuclear magnetic resonance spectroscopy for electrocatalysis: Challenges and prospects

Summary Development of in situ electrochemical nuclear magnetic resonance (EC-NMR) spectroscopy for studying electrocatalysts and associated electrocatalysis started in early 1990 s and aimed at harnessing many unique features that make NMR a ubiquitous spectroscopic method widely used in researches crisscrossing chemistry, physics and biology. Despite constant struggle with the NMR's Achilles’ heel, i.e., low intrinsic mass detection sensitivity, which is further exacerbated by the incompatibility between the electrical conduction of electrochemistry and the induction-based resonance circuitry for NMR detection, many progresses have been made in in situ EC-NMR for characterizing electrocatalysts and understanding associated electrocatalysis over the last two and a half decades. Even more exciting in the horizon is that the newly reinvigorated dynamic nuclear polarization (DPN) NMR and the fast-developing nitrogen-vacancy (NV) based, optically detected NMR, as will be discussed briefly in this Opinion, could have the transformative potential to revolutionize in situ EC-NMR to an unprecedented level.
Effect of beta, beta-diethylalanine on composition of rat livers.

SummaryThe effect of the administration of β, β-diethylalanine (DEA) upon the composition of rat livers has been studied. Feeding DEA to male rats resulted, at the higher of 2 levels, in lower liver lipide and higher liver water and protein content than in controls. Injections of massive doses of DEA were without significant effect. The implications of these results with respect to similar studies with ethionine are discussed.
Microalgae-Based Biorefineries as a Promising Approach to Biofuel Production

Microalgae are photosynthetic microorganisms that are capable of converting carbon dioxide, nutrients, and solar energy into biomass and oxygen. In addition, microalgae have high photosynthetic rates, do not require potable water and arable land for cultivation, and can use liquid and gaseous effluents as nutrients for growth. The biochemical composition of microalgae can be manipulated by changing the cultivation conditions and environmental stresses. Thus, these microorganisms can be induced to produce biomass that is rich in biocompounds of commercial importance. The microalgal biomass can be converted into biofuels and high value-added bioproducts. Thus, microalgae have potential uses as renewable raw materials and could provide promising materials for the development of biorefineries. In this context, this chapter examines microalgae within a biorefinery concept and describes the advantages of using microalgae, culture conditions, biocompounds from biomass and the potential for converting them into biofuel and bioproducts.
Institutions for managing global climate change: Compliance, fairness, and universal participation

Abstract Ensuring that treaties designed to manage global climate change are ‘implementable’ is an important negotiating challenge. Implementable agreements have a reasonable chance of being ratified by nation states that are the greatest contributors to the problem; are acceptable to parties with the resources to do something about it; and induce voluntary compliance. This article contends that, aside from domestic political characteristics, other factors contributing to effective implementation of international agreements are their structure, requirements, and expectations. Factors that optimize implementable agreements include: a sufficient number of relevant participants in negotiations to enhance their legitimacy; reliance on confidence-building to deter non-compliance; stating precisely the signatory obligations; and designing treaties to be renegotiable in the face of changing scientific, political, and economic conditions. Global environmental agreements most likely to obtain signatory compliance will avoid overly stringent standards; allow variable compliance and discretion in implementation; consult domestic interests at each stage of agreement ‘design’ and execution; permit transfers of resources and technology; and rely on ‘functional integration’ to build confidence.
Logistic Regression for Correlated Data: GEE

In this chapter, the logistic model is extended to handle outcome variables that have dichotomous correlated responses. The analytic approach presented for modeling this type of data is the generalized estimating equations (GEE) model, which takes into account the correlated nature of the responses. If such correlations are ignored in the modeling process, then incorrect inferences may result.
An efficient and fair reliable multicast protocol for 802.11-based wireless LANs

Many applications are inherently multicast in nature. Such applications can benefit tremendously from reliable multicast support at the MAC layer since addressing reliability at the MAC level is much less expensive than handling errors at the upper layers. However, the IEEE 802.11 MAC layer does not support reliable multicast. This void in the MAC layer is a limiting factor in the efficacy of multicast applications. In this work, we propose a Slot Reservation based Reliable Multicast protocol that adds a novel reliability component to the existing multicast protocol in the 802.11 MAC. Our protocol builds on the existing DCF support in the IEEE 802.11 MAC to seamlessly incorporate an efficient reliable multicast mechanism. Intelligent assignment of transmission slots, minimal control packet overhead and an efficient retransmission strategy form the basis of our protocol. We evaluate the performance of our protocol through extensive simulations. Our simulation results show that our protocol outperforms another reliable multicast protocol, Batch Mode Multicast MAC in terms of delivered throughput in various scenarios. We enhance our protocol to add a fairness component in the presence of parallel unicast and multicast flows and provide unicast friendly multicast operation. We then evaluate the performance of our Slot Reservation Based Reliable Multicast Protocol with Fairness through extensive simulations and see that the scheme ensures fairness among parallel unicast and multicast flows.
The Future of Corporate Governance Part I: The Problem of Twelve

Three ongoing mega-trends are reshaping corporate governance: indexing, private equity, and globalization. These trends threaten to permanently entangle business with the state and create organizations controlled by a small number of individuals with unsurpassed power. The essay focuses on indexation. After providing background, the essay describes the rise of and reasons for indexation, noting that “passive” indexed investing takes a variety of forms. Data on indexation are presented — with the bottom line that indexation has progressed farther than most realize, because foreign ownership, institutional indexation, and “closet” indexation are often neglected by observers. Index providers’ incentives, resources, and methods are reviewed, with an emphasis on the how such providers have greater practical importance than simpler analytical approaches might suggest. The essay ends with an outline of policy options, and preliminary analyses of which seem likely to address the “Problem of Twelve” — the likelihood that in the near future roughly twelve individuals will have practical power over the majority of U.S. public companies.
Abstract TMP38: Comorbidities Drive Chronic Post-Stroke Fatigue

Introduction: Post-stroke fatigue (PSF) is a debilitating part of stroke recovery with long-term effects. Risk factors contributing to PSF, whether they are modifiable, and if they change over time...
Emotion regulation moderates the association between parent and child hair cortisol concentrations

Successful emotion regulation facilitates children's coping with everyday stress. It develops rapidly in the early preschool period. However, no work has been done to investigate the potential buffering role of emotion regulation from cumulative physiological effects of stress. In this study, we examined hair cortisol concentration (HCC), an early marker of chronic physiological stress, socioeconomic status (SES), parental sensitivity, and emotion regulation and reactivity in a sample of 3.5-year-old children (N = 86). Emotion regulation and emotional reactivity were independent of child HCC. However, emotion regulation moderated the relationship between parent and child HCC. For children with better emotion regulation, there was no association between parent and child HCC, suggesting that emotion regulation skills buffered the transgenerational effects of chronic physiological stress. Emotional reactivity moderated the relationship between SES and child HCC, and attenuated the association between parental sensitivity and child HCC. Taken together, these findings demonstrate that children who were less emotionally reactive were less susceptible to their environments. Results provide support that child emotion regulation and emotional reactivity can reduce or strengthen the relationship between established risk factors and levels of chronic physiological stress in early childhood.
Nature and impact of stripe freezing in La 1.67 Sr 0.33 NiO 4

${\mathrm{La}}_{1.67}{\mathrm{Sr}}_{0.33}{\mathrm{NiO}}_{4}$ develops charge and spin stripe orders at temperatures of roughly 200 K, with modulation wave vectors that are temperature independent. Various probes of spin and charge response have provided independent evidence for some sort of change below $\ensuremath{\sim}50$ K. In combination with a new set of neutron scattering measurements, we propose a unified interpretation of all of these observations in terms of a freezing of Ni-centered charges stripes, together with a glassy ordering of the spin stripes that shows up in neutron scattering as a slight rotation of the average spin direction.
Stabilization of metal(II)oxides on the nanoscale

ABSTRACTIncreasing surface-to-volume ratios for nanoscale materials may cause metal(II)oxides phases to be thermodynamically unstable compared to their bulk counterparts. For instance, previous stu...
Transient analysis of mode locking

Current theories of mode locking have proved useful in analyzing the steady-state behavior of mode-locked lasers. The Kuizenga-Siegman-Haus theory, for example, examines the round-trip change in the pulse and then finds the steady-state solution by demanding that the pulse shape and phase remain constant after each round trip.
Interventional Stroke Management in a Patient With COVID-19

In patients with COVID-19, acute stroke management may need to be limited to patients with viable outcomes, perhaps younger population with fewer comorbidities, and patients without respiratory failure requiring mechanical ventilation. Protecting healthcare professionals must be kept at the forefront if aggressive stroke treatment is used.
Visual Correspondence, the Lambert-Ambient Shape Space and the Systematic Design of Feature Descriptors

In this expository article, we justify the use of sparse local descriptors for correspondence, and illustrate a systematic method for their design. Correspondence is the process that allows using image data to infer properties of the “scene,” where the scene can refer to a specific object or landscape, or can be abstracted into a category label to take into account intra-class variability. As the generality increases, the complexity of nuisance factors does too, so global pixel-level correspondence is not viable, and one has to settle instead for sparse descriptors. These should be co-designed with the classifier, and for a given classifier family, one can design the descriptors to be invariant to uninformative nuisances that are explicitly modeled, insensitive to other nuisances that are not explicitly modeled, and maximally discriminative, relative to the chosen family of classifiers. Existing descriptors are interpreted in this framework, where their limitations are illustrated, together with pointers on how to improve them.
House of Prototyping Guidelines: A Framework to Develop Theoretical Prototyping Strategies for Human-Centered Design

Prototyping is one of the most critical and costly steps in the product development process. However, the existing literature lacks in prototyping strategies that are comprehensive and widely accepted. Current prototyping strategies mostly focus on the hands-on activity of building the prototype by relying on the designer’s experience. Another limitation is that prototyping strategies often do not address human factors for prototyping human-centered products. This paper introduces a House of Prototyping Guidelines (HOPG) framework, which integrates the existing prototyping guidelines and human factor engineering principles for better prototyping outcomes. The methodology contains four steps. The first step pertains to the state-of-the-art prototyping literature review. The second step consists of filtering the prototyping findings and summarizing the key prototyping findings from Step 1. The third step presents the HOPG conceptual map, which is loosely based on the House of Quality (HOQ) approach. HOPG contains the Prototyping Categories and Prototyping Dimensions, which are similar to Customer Requirement and Engineering Requirement of HOQ, respectively. In the HOPG framework, designers go through the Prototyping Categories to understand the prototyping requirements and then identifies the Prototyping Dimensions to create the prototypes that fit human-centered design needs.
Homologous Recombination in Clostridioides difficile Mediates Diversification of Cell Surface Features and Transport Systems.

ABSTRACT Illness caused by the pathogen Clostridioides difficile is widespread and can range in severity from mild diarrhea to sepsis and death. Strains of C. difficile isolated from human infections exhibit great genetic diversity, leading to the hypothesis that the genetic background of the infecting strain at least partially determines a patient’s clinical course. However, although certain strains of C. difficile have been suggested to be associated with increased severity, strain typing alone has proved insufficient to explain infection severity. The limited explanatory power of strain typing has been hypothesized to be due to genetic variation within strain types, as well as genetic elements shared between strain types. Homologous recombination is an evolutionary mechanism that can result in large genetic differences between two otherwise clonal isolates, and also lead to convergent genotypes in distantly related strains. More than 400 C. difficile genomes were analyzed here to assess the effect of homologous recombination within and between C. difficile clades. Almost three-quarters of single nucleotide variants in the C. difficile phylogeny are predicted to be due to homologous recombination events. Furthermore, recombination events were enriched in genes previously reported to be important to virulence and host-pathogen interactions, such as flagella, cell wall proteins, and sugar transport and metabolism. Thus, by exploring the landscape of homologous recombination in C. difficile, we identified genetic loci whose elevated rates of recombination mediated diversification, making them strong candidates for being mediators of host-pathogen interaction in diverse strains of C. difficile. IMPORTANCE Infections with C. difficile result in up to half a million illnesses and tens of thousands of deaths annually in the United States. The severity of C. difficile illness is dependent on both host and bacterial factors. Studying the evolutionary history of C. difficile pathogens is important for understanding the variation in pathogenicity of these bacteria. This study examines the extent and targets of homologous recombination, a mechanism by which distant strains of bacteria can share genetic material, in hundreds of C. difficile strains and identifies hot spots of realized recombination events. The results of this analysis reveal the importance of homologous recombination in the diversification of genetic loci in C. difficile that are significant in its pathogenicity and host interactions, such as flagellar construction, cell wall proteins, and sugar transport and metabolism.
First-Principles Modeling of Sodium Ion and Water Intercalation into Titanium Disulfide Interlayers for Water Desalination

Recent experiments revealed the possibility of using titanium disulfide (TiS2) as the cathode material in capacitive deionization (CDI) devices for water desalination. Although it performed stably ...
The mediating effects of alcohol use and parental monitoring on dating violence victimization among multiracial and monoracial youth

The population of multiracial children is growing significantly in the United States as multiracial births are occurring at a faster rate than monoracial births. Though a cadre of all youth experie...
Homelessness Countering the Destruction of Home: A Return to Sensuous Communication

Heidegger’s description of dwelling shows a kind of being home wherein the constituents of home interact through relations characterized by sensuous communication: “blossoming and fruiting, spreading out in rock and water … the wandering glitter of the stars, the year’s seasons and their changes, the light and dusk of day” all unfolding in sensuous array. In this sensuous communication the constituents care for one another and thereby comprise a community. However, a dampening occurs where the constituents of home become objects of utility. Home becomes a factory instead of a dwelling place. One way to counter this destruction of the home is through voluntary homeless journeys, pilgrimages wherein the healing of the home takes place. When one is homeless, one ceases to be master. This essay will explore the interrelationships between home and homelessness, home and factory, sensuous communication and the dampening of that communication, and the journey of building a virtuous home.
A Behavioral Contract Theory Perspective on Retirement Savings

The primary motivation for retirement savings policy is the view that many of us, if left to our own devices, will not save enough for retirement. Special tax subsidies for employer-sponsored retirement plans — a principal component of the federal policy scheme — have made such plans the predominant vehicle for private savings for retirement. A growing body of evidence shows that the details of plan design can have large effects on savings outcomes. The design of the “choice architecture” of these plans, however, is delegated to employers. We analyze the incentives for employer plan design produced by the labor market. Employers offer retirement plans to attract workers. If those workers make systematic mistakes in their retirement savings decisions, then the labor market will produce incentives for plan designs that generally fail to effectively address the problems. Indeed, the presence of workers who undersave due to myopia results in equilibrium employer plan designs that exploit the myopic by lowering their total compensation. Our analytic framework provides novel explanations for a range of features of plan design, including the high prevalence of matching contributions, the use of low default contribution rates in automatic enrollment plans, the shift away from annuities toward lump sum distributions, and the offering of investment options with excessive fees. The regulation of these plans should be reformed to address the problems with employer incentives that we identify. More fundamentally, our analysis calls for a rethinking of the current scheme’s special subsidies for employer-sponsored plans.
A nonpharmacological intervention to improve sleep in nursing home patients : Results of a controlled clinical trial

OBJECTIVES: To improve nighttime sleep in nursing home patients. DESIGN: Controlled clinical trial. SETTING: Eight community nursing homes enrolled two at a time. PARTICIPANTS: Of 1,077 patients assessed in the eight nursing homes, 638 (59%) were eligible, and consent was obtained for 273 (43% of those eligible). Of the 230 who underwent baseline assessments, 173 completed the immediate-intervention phase of the trial (77 in the intervention group and 96 in the control group). A total of 160 subjects completed the intervention (77 in the immediate-intervention group and 83 in the delayed-intervention phase). INTERVENTION: Trained research staff provided the intervention, which included daytime physical activity and attempts to keep subjects out of bed, evening bright light exposure, a consistent bedtime routine, nighttime care routines designed to minimize sleep disruption, and strategies to reduce nighttime noise. Subjects from one nursing home received the intervention (Group 1), whereas subjects in the second nursing home served as a control group (Group 2); then Group 2 received the intervention. MEASUREMENTS: Primary outcomes included measures of sleep recorded using wrist actigraphy in all subjects and polysomnography in a subgroup of subjects. Secondary measures included assessments of mood and behavior using the Neuropsychiatric Inventory, the Geriatric Depression Scale, and behavioral observations. RESULTS: There were no significant differences in any of the primary actigraphic sleep outcome measures between the intervention and control group after the immediate-intervention phase of the trial. In the 160 subjects who completed the intervention, there were no significant changes in any actigraphic measure of nighttime sleep, nor were there any significant changes in measures of sleep in the 45 subjects who had baseline and intervention polysomnography. CONCLUSION: This multicomponent, nonpharmacological intervention conducted by trained research staff had no effect on nighttime sleep in this sample of nursing home patients. Enhanced nonpharmacological interventions should be developed and tested and combined with environmental interventions to mitigate noise when feasible. Adjunctive drug therapy may be needed to improve sleep in a substantial proportion of this population and should be tested in addition to nonpharmacological interventions in rigorous clinical trials.
A subset of non-histone nuclear proteins reversibly stabilized by the sulfhydryl cross-linking reagent tetrathionate: Polypeptides of the internal nuclear matrix

Abstract When rat liver nuclei are isolated in the presence of the irreversible sulfhydryl-blocking reagent iodoacetamide, digested with DNase I and RNase A, and extracted with 1.6 M NaCl, nuclear envelope (NE) spheres depleted of intranuclear material, as analysed by thin-section electron microscopy, are obtained. Two-dimensional isoelectric focusing (IEF)/SDS-PAGE and non-equilibrium pH gradient electrophoresis (NEPHGE)/ SDS-PAGE reveal that the predominant polypeptides are lamins A, B and C. Nuclei isolated in the absence of sulfhydryl blocking reagents yield salt- and nuclease-resistant structures which contain sparse but demonstrable intranuclear material. A number of non-histone polypeptides are seen in addition to the lamins. Nuclei treated with the sulfhydryl cross-linking reagent sodium tetrathionate (NaTT) yield, after exposure to nucleases and 1.6 M NaCl, nuclear matrix-like structures containing an extensive intranuclear network and components of the nucleolus in addition to the NE. Increased amounts of the non-lamin, non-histone polypeptides are recovered with these structures. Subsequent treatment of these NaTT-cross-linked structures with reducing agents in 1.0 M NaCl selectively solubilizes the intranuclear components but leaves the nuclear envelope apparently intact. The lamins remain sedimentable and are virtually absent from the soluble (intranuclear) material. Instead, the major solubilized polypeptides are ( a ) 68 and 63 kD polypeptides which migrate in the vicinity of lamins B and C, respectively, but are distinguishable from the lamins by immunoblotting and by uni-dimensional peptide mapping; ( b ) a series of basic 60–70 kD polypeptides (pI > 8.0) which are not recognized by anti-lamin antisera; ( c ) an acidic (pI 5.3) 38 kD polypeptide; and ( d ) a number of high molecular mass (> 100 kD) polypeptides. These observations not only suggest a convenient method for fractionating matrix structures from rat liver nuclei into biochemically and morphologically discrete components, but also identify a subset of major non-lamin, non-histone nuclear polypeptides (comprising approx. 20% of the total nuclear protein) whose intermolecular interactions can be reversibly stabilized apparently by intermolecular disulfide bond formation by NaTT.
Nicotinic Acetylcholine Receptors Containing α7 Subunits Are Required for Reliable Synaptic Transmission In Situ

Nicotinic acetylcholine receptors containing alpha7 subunits are widely expressed in the nervous system. The receptors are cation-selective, relatively permeable to calcium, and avid binders of alpha-bungarotoxin. Although the receptors can act both pre- and postsynaptically, their physiological significance is unclear. Using whole-cell patch-clamp analysis of chick ciliary ganglion neurons in situ, we show that the receptors are required for reliable synaptic transmission early in development. Stimulation of the presynaptic nerve root elicited a biphasic synaptic current, including a large rapidly decaying component generated by alpha7-containing receptors. Selective blockade of alpha7-containing receptors by perfusing the ganglion with alpha-bungarotoxin induced failures in synaptic transmission. One-half of the ciliary neurons that were tested failed when stimulated synaptically at 1 Hz, and two-thirds failed at 25 Hz. Failing cells missed, on average, 80% of the trials during a test train of stimuli. The ability to fire synaptically evoked action potentials after toxin treatment was correlated positively with the amplitude of the remaining synaptic current, suggesting that alpha7-containing receptors were needed to augment synaptic responses. Consistent with patch-clamp analysis, toxin blockade reduced the amplitude of the synaptically evoked compound action potential in the postganglionic nerve; it also desynchronized the firing of the remaining units. Methyllycaconitine, another antagonist of alpha7-containing receptors, mimicked alpha-bungarotoxin blockade. Toxin blockade had less impact on transmission in ganglia at the end of embryogenesis. The ability of the receptors to synchronize and sustain population firing, together with their ability to deliver calcium, may influence early developmental events such as target innervation and neuronal survival.
NEIGHBORHOOD REVITALIZATION AND THE COMMUNITY QUESTION

This study addressed the question of whether the community exists as a meaningful social entity in modern urban society by examining neighborhood participation patterns and degrees of neighborhood attachment in a revitalized neighborhood. The research examined the effects of informal networks and participation in local organizations on resident's neighborhood attachments. Differences were found between longterm residents and newcomers, and renovators and non-renovators. Long-term residents were integrated into the social network of the neighborhood. Long-term residents who were renovators were also active in neighborhood organizations. Newcomers, whether renovators or not, were not integrated into the local network but newcomer renovators were highly active in local organizations.
Burke's Dialogic Theory: An Epistemology of Interpretive Practice for Poetry Therapy

Emergent from the Pre-Raphaelite and Symbolist Movements in painting and poetry, Kenneth Burke's epistemology for interpretive practice contributed to the aesthetics of oral interpretation of literature. In this historical study, the author summarizes Burke's dialogic theories and exemplifies how they describe not only Edward Burne-Jones's interpretations of his paintings, but also his painted interpretations of poetry. The author then discusses how Burke's epistemology of interpretive practice contributes to the discipline of poetry therapy.
Cytochemical and biochemical observations on the digestive tracts of digenetic trematodes. 8. Acid phosphatase activity in Schistosoma mansoni and Schistosomatium douthitti.

Abstract At the light microscope level, nonspecific acid phosphatase (AcPase) (EC 3.1.3.2) and N-acetyl glucosaminidase (NAGase) (EC 3.2.1.29) activities are in the esophageal gland cells of Schistosoma mansoni and Schistosomatium douthitti and in the gastrodermis of S. mansoni. The gastrodermis of S. douthitti is negative for these two enzymes. At the electron microscope level, AcPase activity in the esophageal gland cells of both species is observed in cytoplasmic vesicles. In S. mansoni, AcPase activity is also observed associated with the infoldings of the basal plasma membranes of the esophagus and the gastrodermis. It is hypothesized that this enzyme(s) is involved with membrane transport. AcPase activity is also associated with “droplets” and vesicles in the gastrodermis of S. mansoni. It is believed that the digestion of foodstuffs in both species occurs extracellularly.
Tradition, Society, The Figure of The Poet

(1980). Tradition, Society, The Figure of The Poet. Caribbean Quarterly: Vol. 26, Braithwaite Walcott, pp. 1-12.
The influence of grain size and stress on the morphology of a 300-grade maraging steel

The effects of austenite grain size and externally applied stress on the morphology of martensite formation for a 300-grade maraging steel were investigated. Austenite grain sizes ranging from ASTM 14 to 5 were examined. The growth pattern of the martensite was revealed by a selective aging treatment that involved heating to 815° C (austenitizing), cooling to 184° C (about 50 pct transformation to martensite), reheating to 400° C (partial aging of the martensite), and finally, cooling to room temperature (balance of austenite transforms). Blocky martensite formed in the fine-grain austenite, whereas for the coarse-grain size, a stringer-like structure developed. Electron transmission studies showed that the individual martensite units (laths or platelets) were similar in size for both types of morphologies. In both cases, the length of these units corresponded closely to the spacing between the twin boundaries or grain boundaries of the fine-grain specimens. Differences in morphology for different grain sizes are explained in terms of the relative ratios between the size of the martensite unit and the distance between boundaries intersecting the path of growing platelets. The application of an external stress to a coarse-grain specimen results in the delineation of the austenite annealing twins that normally cannot be readily detected. It is proposed that the application of a stress causes a preferential acceleration of the transformation in one of the two differently oriented, twin-related regions of an austenite grain. This argument is based on the differences in the maximum resolved shear stress for the most favorable orientation of the (112) {111} shear variants in each of the various possible twin-related austenite crystal orientations. Hardness and tensile data were also obtained. The absence of any significant variation in these properties for the different grain sizes is attributed to the similarity in size of the martensite units.
Dispersive instability and its minimization in time-domain computation of steady-state responses of cochlear models

Dispersive instability appears in time-domain solutions of classical cochlear models. In this letter, a derivation of optimal initial data is presented to minimize the effect of instability. A second-order accurate implicit boundary integral method is introduced. Numerical solutions of two-dimensional models show that the optimal initial conditions work successfully in time-domain steady-state computations for both the zero Neumann and zero Dirichlet fluid pressure boundary conditions at the helicotrema.
Controlling low rates of cell differentiation through noise and ultrahigh feedback

Mammalian tissue size is maintained by slow replacement of de-differentiating and dying cells. For adipocytes, key regulators of glucose and lipid metabolism, the renewal rate is only 10% per year. We used computational modeling, quantitative mass spectrometry, and single-cell microscopy to show that cell-to-cell variability, or noise, in protein abundance acts within a network of more than six positive feedbacks to permit pre-adipocytes to differentiate at very low rates. This reconciles two fundamental opposing requirements: High cell-to-cell signal variability is needed to generate very low differentiation rates, whereas low signal variability is needed to prevent differentiated cells from de-differentiating. Higher eukaryotes can thus control low rates of near irreversible cell fate decisions through a balancing act between noise and ultrahigh feedback connectivity.
Evaluation of cardiac cone-beam single photon emission computed tomography using observer performance experiments and receiver operating characteristic analysis.

RATIONALE AND OBJECTIVES Single photon emission computed tomography (SPECT) with a cone-beam collimator improves the trade-off between detection efficiency and spatial resolution for cardiac imaging. However, acquisitions using orbits where the focus remains in a plane do not provide sufficient data for exact reconstruction. In the current study the authors evaluate the clinical utility of planar-orbit cone-beam SPECT in detecting a simple myocardial defect. METHODS Observer performance experiments compared high-resolution cone-beam with same-resolution parallel-hole and fan-beam collimator designs in myocardial defect detection using a computer-simulated cardiac model. The uptake of Thallium-201 in the myocardium and other tissue organs was modeled by a mathematical three-dimensional upper torso phantom from which physically realistic projections were simulated. Eight observers viewed reconstructed transaxial images from the three collimator designs and indicated the certainty with which they detected a Gaussian-shaped defect at a specified location. RESULTS The area under the receiver operating characteristic curve indicated that the cone-beam design, regardless of slice position, was superior to the fan-beam, which in turn was superior to the parallel-hole design for the specified detection task. CONCLUSIONS The observer study demonstrated that reconstruction artifacts resulting from insufficient data sampling do not hinder obtaining improved diagnostic information from planar-orbit cone-beam cardiac SPECT images compared to conventional cardiac SPECT using parallel-hole and fan-beam collimators.
Biochemically functionalized silica nanoparticles

In this report, we demonstrate the biochemical modification of silica based nanoparticles. Both pure and dye-doped silica nanoparticles were prepared, and their surfaces were modified with enzymes and biocompatible chemical reagents that allow them to function as biosensors and biomarkers. The nanoparticles produced in this work are uniform in size with a 1.6% relative standard deviation. They have a pure silica surface and can thus be modified easily with many biomolecules for added biochemical functionality. Specifically, we have modified the nanoparticle surfaces with enzyme molecules (glutamate dehydrogenase (GDH) and lactate dehydrogenase (LDH)) and a biocompatible reagent for cell membrane staining. Experimental results show that the silica nanoparticles are a good biocompatible solid support for enzyme immobilization. The immobilized enzyme molecules on the nanoparticle surface have shown excellent enzymatic activity in their respective enzymatic reactions. The nanoparticle surface biochemical functionalization demonstrates the feasibility of using nanoparticles for biosensing and biomarking applications.
An Experimental Study of Entrainment Effects on the Heat Transfer From a Flat Surface to a Heated Circular Impinging Jet

This paper reports on a study to investigate the effect of ambient air entrainment into a heated impinging jet on the heat transfer from a flat surface. It provides a well-characterized jet by using a long circular pipe to obtain fully developed pipe flow for the jet and a uniform heat flux surface thermal boundary condition by electrically heating a vacuum-deposited gold coating. The surface temperature distribution is measured using a liquid crystal.
Interictal Sharp EEG Transients in Neonatal Seizures

This study describes the differences between several quantifiable variables that characterize interictal sharp EEG transients (SETS) recorded from neurologically ill neonates with proven electrographic seizures and a comparison group of apparently neurologically well babies with no known seizures. The abundance (number of sharp EEG transients per ten minutes), waveform morphology, repetitive behavior, and spatial distribution of SETS provide interpretive guidelines that help discriminate between these two patient populations (J Child Neurol 1989;4:30-38).
The oxidation of chromium(III) by hydroxyl radical in alkaline solution. A stopped-flow and pre-mix pulse radiolysis study

Abstract The p K a for the equilibrium Cr III (H 2 O) 3 (OH) 3 ⇌Cr III (H 2 O) 2 (OH) − 4 + H + was determined to be 12.8 at 25°C. The dimerization of the two monomeric forms was studied in alkaline solutions using the stopped-flow method: k 2 [Cr III (H 2 O) 3 (OH) 3 + Cr III (H 2 O) 3 (OH) 3 ] = (2.5 ± 0.3) × 10 4 dm 3 mol −1 s −1 ; k 3 [Cr III (H 2 O) 3 (OH) 3 + Cr III (H 2 O) 2 (OH) − 4 ] = (3.8 ± 0.5) × 10 3 dm 3 mol −1 s −1 and k 4 [Cr III (H 2 O) 2 (OH) − 4 + Cr III (H 2 O) 2 (OH) − 4 ] = (1.2 ± 0.2) × 10 2 dm 3 mol −1 s −1 . The absorption spectra of the monomeric and dimeric species are also reported. The oxidation of chromium monomer Cr III and dimer (Cr) III,III 2 by hydroxyl radicals was studied by the pre-mix pulse radiolysis technique. The kinetic parameters were established for: (a) Cr IV monomer formation; (b) formation of (Cr) III,IV 2 dimer; (c) dissociation of (Cr) III,IV 2 dimer and (d) formation of polymers e.g. [Cr VI (O Cr III ) n ]. Furthermore, a second-order reaction between two Cr IV monomers to yield a species which may be either a (Cr) IV,IV 2 or a (Cr) III,V 2 mixed-valence dimer was observed. The corresponding spectra in both the UV and visible range were determined.
Data partition analyses for MPEG-2 decoders on a dual core embedded Platform

Three main roots devalue the performance of the multicore video decoder: data dependency, imbalanced workload, and resource contention. This paper strategically employs one frame partition and group of macroblock row (GMR) partitions, with different GMR sizes, for a dual core MPEG-2 decoder to reduce or remove the effect of data dependency and also to analyze how much deterioration those roots cause. Six MPEG-2 simple profile sequences are tested by the decoder software run in a PAC Duo Platform, a heterogeneous multicore SoC containing one ARM core and two PACDSP's (Parallel Architecture Core DSP). The experimental result indicates that the GMR partitions normally have better performance than frame partition does and the GMR partitions with smaller number of macroblock rows have faster decoding speed than the ones with larger number of macroblock rows.
Feasibility studies for a global wind measuring satellite system (Windsat): analysis of simulated performance.

A detailed computer simulation of the Windsat global wind measuring process has been developed and used to establish error limits as a function of design parameters. Studies were conducted for a Windsat research system in a 300- and an 800-km orbit. Wind measuring errors were <2 m sec−1 in the troposphere for the recommended set of parameters. Our study results indicate the feasibility of measuring global winds from a space platform using a coherent laser radar.
Estrogen receptor in hamster kidney during estrogen-induced renal tumorigenesis.

Abstract Specific binding of [ 3 H]-estradiol to isolated cytosol and to nuclei in tissue slices was determined in hamster kidney before and during estrogen-induced renal tumorigenesis and in the kidney of normal rats, a species which does not develop the tumor. At 10 −9 M [ 3 H]-estradiol, cytosol from normal hamster kidney bound 6.48 ± 0.3 × 10 −15 mol/mg protein, which was significantly less than the 15.8 ± 1.1 × 10 −15 mol/mg bound by the rat. The apparent dissociation constant for estradiol was not significantly different (0.50 ± 0.08 nM in hamster and 0.66 ± 0.14 nM in rat). Cytosol binding increased after hamsters were implanted with estrogen pellets for 6 months (9.23 ± 0.2 × 10 −15 mol/mg) or had developed tumors (13.7 ± 3.5 × 10 −15 mol/mg). In tissue slices, the amount of [ 3 H]-estradiol translocated to nuclei was greater in the rat (21.8 ± 0.8 × 10 −14 mol/mg nuclear protein) than in the normal hamster (3.28 ± 0.96 × 10 −14 mol/mg) and was greater in tumor-bearing hamsters (6.70 ± 0.86 × 10 −15 mol/mg DNA) than in normal hamsters (3.19 ± 0.63 × 10 −15 mol/mg DNA). We conclude: (1) the kidney of the tumor prone hamster does not contain an estrogen receptor of excessive quantity or unusual affinity and (2) the estrogen-receptor complex in estrogen-induced tumors can be translocated to cellular nuclei.
Proposal for the classification of critical points by order

Abstract Critical points of complex thermodynamic systems are classified by their order O , defined here for the first time. A convenient notation is developed for such points.
The effect of heat flux limiting on divertor fluid models

The classical plasma electron heat flux can greatly overestimate the physical heat flux when the electron mean-free-path becomes long compared to the electron temperature gradient scale length. For fluid modelling of plasmas, a common remedy is to apply an artificial flux limiter that keeps the heat flux at a physically reasonable value in this long mean-free-path regime. The ad-hoc limiter is not derived from first principles and it introduces a poorly understood free parameter into the model. We study the effect of this parameter in our divertor plasma models to understand how it influences the computed solution. We investigate regimes of both short and long mean-free-path and consistently find large parameter sensitivity. Thus, without additional experimental or theoretical guidance in the choice of flux-limit parameter, flux limiting does not appear to provide an acceptable basis for predictive plasma fluid modelling.
Mechanism for resistivity minimum in amorphous ferromagnets

Abstract A mechanism for electron spin flip scattering in amorphous ferromagnets is proposed and shown to give rise to the observed resistivity minimum in these materials.
Therapeutics for Circadian Rhythm Sleep Disorders

The sleep-wake cycle is regulated by the interaction of endogenous circadian and homeostatic processes. The circadian system provides timing information for most physiological rhythms, including the sleep and wake cycle. In addition, the central circadian clock located in the suprachiasmatic nucleus of the hypothalamus has been shown to promote alertness during the day. Circadian rhythm sleep disorders arise when there is a misalignment between the timing of the endogenous circadian rhythms and the external environment or when there is dysfunction of the circadian clock or its entrainment pathways. The primary synchronizing agents of the circadian system are light and melatonin. Light is the strongest entraining agent of circadian rhythms and timed exposure to bright light is often used in the treatment of circadian rhythm sleep disorders. In addition, timed administration of melatonin, either alone or in combination with light therapy has been shown to be useful in the treatment of the following circadian rhythm sleep disorders: delayed sleep phase, advanced sleep phase, free-running, irregular sleep wake, jet lag and shift work.
Space physics and undergraduate education: Sins of omission

Ask the average undergraduate if he or she has heard of the Van Allen Belt, the magnetosphere, or the solar wind and most likely you will get a blank stare. On the other hand, ask the same about black holes, pulsars, or the big bang theory. Chances are you will get a positive response; moreover, they'll have some idea of what at least one of these objects is and may be happy to start a conversation on the subject. Most students have heard of, or even seen, an aurora, but few have any idea of its source. This holds for most educated adults as well. At a beach party on the shore of Lake Superior last summer, I was besieged with questions about a bright aurora seen over the lake. I realized that there is no point in a traditional education where this aspect of nature is encountered.
Interface microcrack nucleation

Abstract The Zener-Stroh mechanism of microcrack nucleation by a dislocation pile-up or band impinging upon an interface has been believed to be one of the basic mechanisms of microcrack nucleation in polycrystalline materials. In the case of different elastic properties of composite constituents, this problem is accurately solved in the present paper. The minimum number of elementary dislocations in the band necessary to form a microcrack, as well as the interface microcrack length are found in terms of physical properties and the number of elementary dislocations in the band. A band bears a stronger singularity than a pile-up, and therefore the obtained solution can serve as an upper bound estimate of the solution for the pile-up. The results of the paper may be used for the direct measurement of the true interface surface energy by an experimental observation of the nucleation of an interface microcrack.
Effects of fiber roughness on interface sliding in composites

Abstract The presence of asperites at the fiber-matrix interface is noted experimentally as a load rise during the initial stages of push-out and as a reseating load drop during push-back. These effects are modelled by considering the elastic deformation of asperites at the interface. During fiber sliding, the decorrelation of initially matching fiber and matrix geometries results in an asperity pressure at the interface. Fractal models of interface roughness are incorporated into an equation of fiber sliding that is found to accurately reproduce experimental observations. Additionally, an asperity wear mechanism must be introduced to explain the effects of fatigue, the variation of fiber reseating with sliding distance, and the rapid decay in sliding stress during pristine fiber push-out.
Protein instability during HIC: Evidence of unfolding reversibility, and apparent adsorption strength of disulfide bond-reduced α-lactalbumin variants

A two-conformation, four-state model has been proposed to describe protein adsorption and unfolding behavior on hydrophobic interaction chromatography (HIC) resins. In this work, we build upon previous study and application of a four-state model to the effect of salt concentration on the adsorption and unfolding of the model protein α-lactalbumin in HIC. Contributions to the apparent adsorption strength of the wild-type protein from native and unfolded conformations, obtained using a deuterium labeling technique, reveal the free energy change and kinetics of unfolding on the resin, and demonstrate that surface unfolding is reversible. Additionally, variants of α-lactalbumin in which one of the disulfide bonds is reduced were synthesized to examine the effects of conformational stability on apparent retention. Below the melting temperatures of the wild-type protein and variants, reduction of a single disulfide bond significantly increases the apparent adsorption strength (∼6–8 kJ/mol) due to increased instability of the protein. Finally, the four-state model is used to accurately predict the apparent adsorption strength of a disulfide bond-reduced variant. Biotechnol. Bioeng. 2009;102: 1416–1427. © 2008 Wiley Periodicals, Inc.