cssi/SciSciGPT-SciSciNet huggingface dataset:
Numerical investigation on conjugate heat transfer in octet-shape-based single unit cell thick metal foam

Abstract Present study reports flow and thermal transport characteristics of metal-foam based on Octet-shaped unit cell (porosity ~ 0.97) for electronic cooling application with water as the working fluid. Conjugate simulations were carried out on a single cell thick lattice frame comprising of four consecutive connected unit cells in the streamwise direction. Simulations were performed for flow velocity range of 2–8 cm/s with the substrate subjected to a heat flux of 10 W/cm2, for two different solid-phases corresponding to solid-to-fluid thermal conductivity ratios (ks/kf) of 37 and 288. A control-volume-based energy balance method was adopted for calculation of global and cell-based convective heat transfer coefficient in the conjugate simulations, where the global heat transfer coefficient was ~ 2900 W/m2K for ks/kf~288 and ~ 2100 W/m2K for ks/kf~37, both for flow velocity of 8 cm/s. The cell-based heat transfer coefficient showed a sharp declining trend typical of developing flow. The interfacial heat transfer coefficient (hsf) on the fibers and the substrate-endwall was also obtained through separate simulations imposing constant heat flux and constant temperature boundary conditions on the walls. The averaged hsf on fiber walls and substrate-endwall was ~ 8700 W/m2K and ~ 2000 W/m2K, respectively, corresponding to average flow velocity of 8 cm/s.
Effects of a carbon tax in the United States on agricultural markets and carbon emissions from land-use change

Abstract There is increased interest in a carbon tax in the United States (U.S.) and policy makers, farmers, and other stakeholders need to understand the various economic and environmental aspects of such a policy on agriculture. A global agricultural simulation model assesses changes in production, commodity prices, and trade resulting from a U.S. carbon tax. In addition, greenhouse gas (GHG) emissions from land-use change are quantified to evaluate the possible unintended consequence of increasing emissions in the rest of the world. Three U.S. carbon tax scenarios are evaluated ranging from $15–$144 per metric ton of carbon dioxide equivalent (t−1 CO2-e) and covering a 10-year projection period. The results show that the production cost for corn and soybeans increase by a maximum of 32.6% and 22.4%, respectively at a carbon tax of $144 t−1 CO2-e. The production cost increase is compensated in part by an increase in commodity prices. Hence, the decrease in net returns for corn, soybeans, and wheat is 11.4%, 8.7%, and 11.0%, respectively, in the scenario with the highest carbon price. U.S. exports decrease for major commodities such as corn (24.9%), sorghum (20.5%), and wheat (8.7%). Barley, soybeans, and sunflower see an increase in exports of 1.2–8.8%. These changes in trade patterns also result in a re-allocation of land-use in the rest of the world leading to a slight increase in global GHG emissions from land-use change representing 1.8% of total U.S. emissions in 2017. The increase in emissions is small compared to the overall projected reduction from the carbon tax. Policy makers need to be cognizant of leakage in terms of land-use change and that measures must be taken to avoid expansion into carbon rich native vegetation.
A review on semitransparent solar cells for agricultural application

Abstract Modern agriculture dramatically increases food production and continuously plays a critical role to remit the food crisis in the world. However, agricultural modernization also consumes more energy and land than the traditional small-scale peasant farming. The integration of photovoltaics into modern agriculture is a promising method to utilize the vast agricultural land efficiently and provide extra energy for crop production. Due to the tunable energy of the organic molecules, semitransparent organic solar cell serves as an ideal candidate. Rationally designed devices can allow sunlight with selected wavelengths to pass though and get absorbed by the plants for photosynthesis. Meanwhile, relatively high photovoltaic performances are also preferred for energy generation. In this article, important studies of semitransparent organic solar cells for agricultural applications are reviewed, and the design routes and strategies are summarized. The perspectives for the future research on agricultural photovoltaics are also presented.
SPECTRAL THEORY OF WATER WAVES

Spectral theory is applied to elemental water wave problems for a compressible liquid. Compressibility is introduced primarily to facilitate the spectral representation. Two basic representations are developed. The first (Havelock) expansion is derived from a vertical (z) spectral integration while the second modified Fourier form of Fourier-Bessel form comes from the lateral (x or r) spectrum. Both representations are interrelated by analytic continuation in the spectral space, and are shown to be consistent with existing results when compressibility is suppressed.
Improving random projections using marginal information

We present an improved version of random projections that takes advantage of marginal norms. Using a maximum likelihood estimator (MLE), margin-constrained random projections can improve estimation accuracy considerably. Theoretical properties of this estimator are analyzed in detail.
On chip circuit model for accurate mid-frequency simultaneous switching noise prediction

An on chip circuit model for accurate mid-frequency simultaneous switching noise (SSN) prediction has been studied in this paper. Voltage controlled switching resistors, voltage controlled leakage resistors have been proposed to represent the switching activities and leakage of a chip. Empirical formulas are presented for the calculations of resistors. The on chip power grid impacts on mid-frequency SSN as well as the clock frequency noise have been analyzed. For mid-frequency SSN prediction, we don't have to include on chip power grid in the model except an accurate intrinsic capacitance extraction. However, for clock-frequency noise, we need the on chip power grid characteristics.
Quark form factors and leading double logarithms in QCD

Perturbative quantum chromodynamic corrections involving the emission of gluons that are both soft and collinear are discussed for both hadronic production of lepton pairs and e/sup +/e/sup -/ annihilation. The result is an exponential, double logarithmic quark form factor. The differences between previous analyses are clarified, and the possible experimental observation of the form factor is discussed and illustrated. 9 figures, 1 table.
Intramolecular Organization of Class I Molecules in Relation to Function

In the study of structure function relationships in class I molecules, several problems are being encountered: variable residues may create determinants indirectly by means of conformational effects; most alloantigens carry multiple differences; private specificities may map to two or more separate sites. However, as more sequence information becomes available and the question of direct or indirect recognition of altered residues is approached using exon shuffling [9], site-directed mutagenesis and synthetic peptide techniques, it should be possible to move fast towards the goal of assigning specific residues as being involved in alloantigenic and CTL determinants.
An Information-Gathering Approach to Copyright Policy

For over a century and with increasing frequency, major controversies have erupted between large distributors of copyrighted works (song publishers, movie studios, record labels, book publishers, etc.) and makers of new technologies for experiencing those works (player piano manufacturers, VCR manufacturers, the creators of file-sharing software, Google Books, etc.). Usually, the copyright owners and the technology firms reach a licensing deal — but not without some form of government intervention. Various institutions within the federal government have become involved in these disputes, using a variety of different mechanisms. This article is a theoretical investigation of government intervention in these content–technology copyright disputes. We analyze government institutions based on the relative ability of each one to gather information about the impact of new technology, the positive and negative consequences of using these institutions in combination, the most favorable time for each institution to intervene during the course of a dispute, and the track record of each institution’s success or failure in the copyright context. We argue that some government actions might be able to facilitate, hasten, or otherwise encourage a licensing deal, whereas other government actions might be counterproductive on those dimensions. We then apply our framework to disputes between copyright owners and four technologies as case studies to illustrate the theory: piano rolls, radio, VCRs, and webcasting. Each case study explains in detail the many government institutions that intervened in each dispute, describes the governmental and private actions chronologically, and reflects on the lessons learned from each set of government interventions. Some of the case studies are familiar, but many important details about the nature of various government institutions’ intervention have been underappreciated. The dispute over webcasting royalties is less familiar, motivating a comprehensive discussion of the complicated government role in webcasting. The ultimate goal of the article is to characterize what policy tools should be used to resolve content–technology disputes and when those tools should be deployed. We hope that our framework can be a guide to policymakers within the various governmental institutions currently involved in copyright policy.
Chromatographic separation and antigenic analysis of proteins of the oncornaviruses. III. Avian viral proteins with group-specific antigenicity.

Abstract Group-specific viral proteins, p27, p19, p15, and p12, have been purified from different strains of avian leukemia-sarcoma viruses, and their chemical and serological properties have been compared. Functionally homologous proteins from two different viral isolates had similar amino acid compositions. The major constituent of the viral ribonucleoprotein, p12, possesses the highest content of hydrophilic amino acids (53%), while the core shell protein, p27, has the lowest (42%). In isolates from six viral subgroups the equivalent proteins were serologically indistinguishable by immunodiffusion analyses with monospecific anti-sera. By contrast, for the four different proteins from the same viral isolate, no serological cross reactions were found, nor could structural homologies be demonstrated by amino acid and peptide analyses.
CouRse 1 Fundamental aspects of electron correlations and quantum transport in one-dimensional systems

Abstract Some aspects of physics on interacting fermions in 1D are discussed in a tutorial-like manner. We begin by showing that the non-analytic corrections to the Fermi-liquid forms of thermodynamic quantities result from essentially 1D collisions embedded into a higher-dimensional phase space. The role of these collisions increases progressively as dimensionality is reduced and, finally, they lead to a breakdown of the Fermi liquid in 1D. An exact solution of the Tomonaga-Luttinger model, based on exact Ward identities,. is reviewed in the fermionic language. Tunneling in a 1D interacting systems is discussed first in terms of the scattering theory for interacting fermions and then via bosonization. Universality of conductance quantization in disorder-free quantum wires is discussed along with the breakdown of this universality in the spin-incoherent case. A difference between charge (universal) and thermal (non-universal) conductances is explained in terms of Fabry-Perrot resonances of charge plasmos.
Screening Mammography Guidelines.

I thank Dr Meyer for his kind remarks. One would think that time would resolve most scientific controversies, even those that have endured for decades. However, no amount of historic retrospection will probably fully answer the questions raised by screening mammography. Future diagnostic and therapeutic advances, as well as the trend toward screening guidelines based on more sophisticated risk assessment and patient preference, will hopefully render mute much of the current debate. As with most controversies, future medical historians will probably look back at screening mammography and conclude that the correct answer lay somewhere between the extreme views. That middle-oftheroad approach is what I hope my editorial conveyed. I would take exception to one comment by Dr Meyer. I believe tomosynthesis is a game-changing better mousetrap that will replace traditional mammography, much as digital is replacing analog breast imaging. Virtually every publication on screening mammography using tomosynthesis has shown a statistically significant reduction in recall rates. The major reasons that breast cancer screening guidelines in the United States differ from those practiced in almost all other comparable counties, each based on assessment of the same published data, relate to our higher recall rates, our concern regarding costs, and our differing medicolegal climate. I hope and believe that all of these factors will gradually change in the future.
Yes, But Are They Happy? Effects of Trait Self‐Control on Affective Well‐Being and Life Satisfaction

Does trait self-control (TSC) predict affective well-being and life satisfaction—positively, negatively, or not? We conducted three studies (Study 1: N = 414, 64% female, Mage = 35.0 years; Study 2: N = 208, 66% female, Mage = 25.24 years; Study 3: N = 234, 61% female, Mage = 34.53 years). The key predictor was TSC, with affective well-being and life satisfaction ratings as key outcomes. Potential explanatory constructs including goal conflict, goal balancing, and emotional distress also were investigated. TSC is positively related to affective well-being and life satisfaction, and managing goal conflict is a key as to why. All studies, moreover, showed that the effect of TSC on life satisfaction is at least partially mediated by affect. Study 1's correlational study established the effect. Study 2's experience sampling approach demonstrated that compared to those low in TSC, those high in TSC experience higher levels of momentary affect even as they experience desire, an effect partially mediated through experiencing lower conflict and emotional distress. Study 3 found evidence for the proposed mechanism—that TSC may boost well-being by helping people avoid frequent conflict and balance vice-virtue conflicts by favoring virtues. Self-control positively contributes to happiness through avoiding and dealing with motivational conflict.
Kinetic Gelation Modeling of Controlled Radical Polymerizations

A kinetic gelation model has been developed that incorporates the kinetics of a living/controlled radical polymerization. Specifically, the kinetics of an iniferter polymerization were implemented in the model to determine the effect of the kinetics on the polymer structure. In particular, the replacement of the termination step with a reversible termination was examined. The model predicts the formation of more monodisperse linear polymers in the presence of an iniferter and a reversible termination reaction. When termination by combination is allowed to occur, the polydispersity increases. For cross-linking reactions, it was concluded that the iniferter only had an effect on reactions with small amounts of cross-linking agent, resulting in a delay in the gel point and a more heterogeneous structure. When the amount of cross-linking agent is increased, there is no difference in the network structure obtained by a cross-linking reaction with an iniferter versus a cross-linking reaction with the classical ...
Asymmetry in Dual Language Practice

The capacity for dual-language programs to deliver specific benefits to students with different primary and secondary language skills continues to be debated. Individuals favoring dual language assert that as it relies upon a reciprocal approach, dual language students acquire dual language proficiency without the need for teachers to translate from one language to another. By utilizing and conserving the language skills that students bring, dual language students also gain cross-cultural understandings and an expanded opportunity to realize academic success in the future. Research that explores whether these programs meet the needs of monolingual and bilingual students is limited. The intent of this study is not to criticize dual language practice. Instead, it is to describe a newly implemented dual language immersion program that exists and operates in Phoenix, Arizona. In particular, this study examines the practices of dual language teachers at Leigh Elementary School and the challenges encountered as school personnel worked to provide students with different primary and secondary language skills increased opportunities to learn.
Traumatic posterior urethral injury and early primary endoscopic realignment: evaluation of long-term follow-up.

Abstract Objectives. The management of complete or partial posterior urethral disruption is controversial and much debate continues regarding immediate versus delayed definitive therapy. We further analyze our experience and long-term results using early endoscopic realignment. Methods. Between April 1991 and June 1995, 8 men with posterior urethral avulsion, either complete or partial and secondary to blunt trauma and pelvic fractures, presented to our institution. A variety of endourologic techniques were employed to achieve urethral continuity while attempting to minimize stricture formation, incontinence, and impotence. Results. After a mean of 50.4 months (range 35 to 85) of follow-up, 7 men (87.5%) are continent, with 2 of those requiring intermittent self-dilation ranging from once every 7 days to once a month. One patient required conversion to an open perineal urethroplasty. Of the 8 patients, 5 (62.5%) are potent, and 2 others achieve adequate erections for intercourse using intracorporeal injections. Four of the 8 have required subsequent internal urethrotomies with eventual voiding stabilization over the course of 12 months. Average time to realignment was 9.5 days (range 0 to 19). Conclusions. Primary endoscopic realignment offers an effective method for treating traumatic urethral injuries. Our long-term follow-up provides further support for use of this technique by demonstrating that urethral continuity can be established without increased incidence of impotence, stricture formation, or incontinence. By achieving early and minimally invasive realignment, we seem to lessen the severity of stricture disease that almost uniformly afflicts those patients who undergo delayed repair. If a minimally invasive technique should fail, it does not seem to delay nor does it preclude further management using open techniques.
Quantification of Uncertainty in Reactivity Adjustment Factors from Reformulated Gasolines and Methanol Fuels

Speciated data for motor vehicle exhaust emissions of volatile organic compounds (VOCs) have been combined with estimates of uncertainty in the calculated photochemical reactivities of the VOCs to evaluate the resulting uncertainty in the overall reactivity of the exhaust. Mean reactivity adjustment factor (RAF) values for exhaust emissions from reformulated gasolines relative to conventional gasoline ranged from 0.85 to 0.93, with uncertainties of about 10% at the 1{rho} level. The mean RAF value for M85 (85% methanol, 15% gasoline) in variable/flexible-fueled vehicles relative to emissions from gasoline in conventional vehicles was 0. 42, with an uncertainty of 17%. For the gasoline-based fuels, the variability of the exhaust composition data was a major contributor to the uncertainty in the RAFs. For M85, rate constant uncertainties in the reactivities of the VOCs in the exhaust contributed almost two-thirds of the total uncertainty in the RAF values. 43 refs., 4 figs., 2 tabs.
Multimodal Percutaneous Intervention for Critical Venous Occlusive Disease

Critical deep venous thrombosis and occlusion constitutes a small percentage of patients with venous disease, who exhibit severe symptomatology. This study examined the results of multimodal percutaneous therapy for the treatment of complex critical venous thrombotic and occlusive disease. Twenty-five patients presented with critical venous thromboses or occlusions (11 with debilitating unilateral lower extremity edema causing ambulatory impairment, 2 with debilitating bilateral lower extremity edema, 3 with phlegmasia cerulea dolens, 2 with venous claudication, 2 with superior vena cava (SVS) syndrome with respiratory compromise, 4 with debilitating upper extremity edema, and 1 with renal insufficiency). Therapeutic modalities including thrombolysis, mechanical thrombectomy, percutaneous venoplasty and stent placement, temporary inferior vena cava filtration, and ultrasound guidance were used in all cases in conjunction with long-term systemic anticoagulation. The venous access site was determined by the anatomic location of the lesion and included popliteal, femoral, brachial, and lesser saphenous. Patients were followed with clinical exam and duplex surveillance. Resolution of symptoms was achieved in 18 of 25 patients (72%) and partial resolution occurred in 4 of 25 (16%). Failure of treatment identified as both lack of clinical response and evidence of continued venous thrombosis occurred 3 of 25 patients (12%). Restoration of arterial pulses and limb salvage was achieved in the three patients with phlegmasia cerulea dolens and acute limb-threatening ischemia. Both patients with SVC syndrome experienced resolution of respiratory compromise and facial edema. The mean length of follow-up was 11 ± 2.7 months. Complications included transfusion requirement (2), hematuria (2), retroperitoneal hematoma (1), and cellulitis (1). Acute critical venous thrombotic and occlusive disease is responsive to multimodal percutaneous treatment. The relief of pain and resolution of acutely life and limb-threatening conditions in this most severely symptomatic subset of patients represents the immediate goal of treatment.
Specification testing in censored regression models: Parametric and semiparametric methods

We define a hierarchy of parametric and semiparametric specifications for censored regression models that is ordered according to the strength of the assumptions that are made. We review the estimation techniques and specification tests that are available at each level of the hierarchy. The estimation and testing procedures are illustrated by applying them to a model of strike duration. Several tests (some graphical) are able to detect errors in standard parametric specifications even in the presence of fairly heavy censoring, but two distinct semiparametric specifications leading to different substantive inferences cannot be rejected. In addition, the conditional mean as a prediction of the dependent variable is highly sensitive to specification errors, whereas the conditional median is not.
Oakeshott on the theory-practice problem: a reply to Terry Nardin

This is a reply to:Nardin, Terry. 2015. “Oakeshott on theory and practice.” Global Discourse. 5 (2): 310–322. http://dx.doi.org/10.1080/23269995.2014.976921.
Beyond Li Fraumeni Syndrome: Clinical Characteristics of Families With p53 Germline Mutations

Purpose A clinical testing cohort was used to gain a broader understanding of the spectrum of tumors associated with germline p53 mutations to aid clinicians in identifying high-risk families. Patients and Methods Full sequencing of the coding exons (2 to 11) and associated splice junctions of the p53 gene was performed on 525 consecutive patients whose blood samples were submitted for diagnostic testing. Clinical features of p53 germline carriers in this cohort were characterized, clinical referral schemes based on reported p53-associated family phenotypes were evaluated, and practical mutation prevalence tables were generated. Results Mutations were identified in 91 (17%) of 525 patients submitted for testing. All families with a p53 mutation had at least one family member with a sarcoma, breast, brain, or adrenocortical carcinoma (ACC). Every individual with a choroid plexus tumor (eight of eight) and 14 of 21 individuals with a childhood ACC had a mutation regardless of family history. Based on report...
CDF Scheduling Methods for Finite Rate Multiuser Systems With Limited Feedback

In this work, simple and practical CDF scheduling methods are developed that preserve the virtues of CDF scheduling, namely fairness and effective use of multiuser diversity. They are the accelerated extended CDF scheduling (AeCS), modified non-parametric CDF scheduling (modified NPCS), and the CDF scheduling with optimized Quantizers (CSwQ) methods. The developed methods do not need a priori knowledge of the channel distribution and can work effectively in systems that support discrete number of transmission rates and are constrained by limited feedback resources. They exploit the limited feedback resource for their scheduling decisions and transmission rate selections and learn the distribution of channel quality information of each user, as needed, to best exploit multiuser diversity. The CSwQ method is shown to have desirable properties in terms of both system throughput and power savings. Analytical results for the system throughput and power savings of the CSwQ method are developed that are valid for a finite number of observation samples. Then, through numerical simulations, the developed methods are shown to effectively save transmit power and achieve high system throughput. In addition, they converge rapidly with the number of data samples to the ideal case wherein perfect knowledge of the channel CDF is assumed.
Alcohol, racial segregation and popular politics in northern rhodesia

Historians who have studied the rise of African opposition to colonialism in Northern Rhodesia have concentrated largely on the development of political parties and their campaigns for political rights. This paper explores some of the social and cultural elements of the popular movement against British rule through an examination of challenges to restrictions on the production and consumption of alcoholic beverages. In Northern Rhodesia as in much of British-ruled east, central and southern Africa, the colonial government banned the consumption by Africans of all European-type alcoholic drinks and placed tight restrictions on the brewing and sale of grain beers. In the immediate postwar period racially discriminatory alcohol regulations emerged as a highly emotional issue and remained so despite liberalization of the restrictions on beer and wine. But the focus of popular anger was the municipal grain beer monopolies and attempts on the part of the authorities to stamp out an illegal beer trade conducted by women brewers. Beginning in the mid-1950s this anger erupted in a series of protests and boycotts directed against municipal beerhalls. The protesters, many of whom were women, opposed the exclusion of Africans from a potentially lucrative sector of trade as well as the supposedly immoral and degrading characteristics of the beerhalls. Examination of the struggle over the beerhalls illuminates some of the diverse and contradictory sources and objectives of popular political expression during this period and in particular sheds light on the interplay among issues of race, class and gender in the nationalist movement.
Thruster and fpso hull interaction

A hybrid method which couples a Vortex-Lattice Method (VLM) solver and a Reynolds-Averaged Navier-Stokes (RANS) solver is applied to simulate the interaction between a Dynamic Positioning (DP) thruster and an FPSO hull. The hybrid method could significantly reduce the number of cells to fifth of that in a full blown RANS simulation and thus greatly enhance the computational efficiency. The numerical results are first validated with available experimental data, and then used to assess the significance of the thruster/hull interaction in DP systems.Copyright © 2014 by ASME
Ultrafast singlet excited-state polarization in electronically asymmetric ethyne-bridged bis[(porphinato)zinc(II)] complexes.

The excited-state dynamics of two conjugated bis[(porphinato)zinc(II)] (bis[PZn]) species, bis[(5,5‘-10,20-bis[3,5-bis(3,3-dimethyl-1-butyloxy)phenyl]porphinato)zinc(II)]ethyne (DD) and [(5,-10,20-bis[3,5-bis(3,3-dimethyl-1-butyloxy)phenyl]porphinato)zinc(II)]-[(5‘,-15‘-ethynyl-10‘,20‘-bis(heptafluoropropyl)porphinato)zinc(II)]ethyne (DA), were studied by pump-probe transient absorption spectroscopy and hole burning techniques. Both of these meso-to-meso ethyne-bridged bis[PZn] compounds display intense near-infrared (NIR) transient S1→Sn absorptions and fast relaxation of their initially prepared, electronically excited Q states. Solvational and conformational relaxation play key roles in both DD and DA ground- and excited-state dynamics; in addition to these processes that drive spectral diffusion, electronically excited DA manifests a 3-fold diminution of S1→S0 oscillator strength on a 2−20 ps time scale. Both DD and DA display ground-state and time-dependent excited-state conformational heterogeneity;...
How and why parents select profit-making day care programs: A study of two southeastern college communities

In this study, 86 parents whose children attended six profit-making day care centers rated as average or above-average in two southeastern college communities were interviewed to determine how and why they selected their children's day care programs. Our results indicated that these parents typically got initial information about day care through second-hand sources (e.g., theYellow Pages, over the phone, through friends and neighbors) and then visited one center—the one they ultimately enrolled their child in. Little information-seeking about day care by first-hand observations of several centers was reported. However, these parents said they selected their center because it (a) provided an educational program and (b) had a competent staff. Next most important on their list of reasons were that the center (c) was close to home, (d) charged relatively low fees, and (e) provided nutritious meals and snacks.
Morphological and optical properties of InGaN laser diodes on laterally overgrown GaN

Abstract The morphological evolution of InGaN laser diodes on laterally overgrown GaN on sapphire was investigated to understand the effect of threading dislocations (TDs) on the morphology and subsequent device performance. Screw-component TDs were found to strongly influence the surface morphology and growth mechanism of InGaN-based laser diodes. Spiral growth about mixed character TDs (Burgers vector=a+c) resulted in growth hillocks for laser structures grown directly on sapphire as well as laser structures grown on lateral epitaxially overgrown (LEO) GaN on sapphire. The dislocation distribution dominated the size of growth hillocks. Small spirals, with typical heights of 15 A and diameters of 1.5 μm, were formed on laser structures grown on sapphire due to the uniformly distributed mixed character TDs, but large spiral hillocks, with heights of 65 A and diameters up to 30 μm, developed on the LEO GaN due to the larger spacing between mixed character TDs. The spirals exhibited steps oriented in crystallographic directions, showing the six-fold symmetry of the hexagonal crystal. Spirals that formed during the growth of the active region did not diminish with subsequent high-temperature growth. Even with larger spirals, the lasers on LEO GaN exhibited reduced threshold current densities as compared to lasers grown on sapphire.
Photocatalytic hydrogen production from water on Pt-free SrTiO 3 in alkali hydroxide solutions

Semiconductor surfaces can act as photosensitizers for small molecules which on their own do not absorb solar photons. Such sensitizers can be used for the photoassisted decomposition of water to hydrogen and oxygen. Most previous work on this process has concentrated on photoelectrochemical ceils using oxide semiconductor photoanodes for oxygen evolution and platinum cathodes for the evolution of hydrogen1–3. We report here the sustained photogeneration of hydrogen on SrTiO3 single crystal surfaces by a different mechanism, when no platinum coating or platinum counterelectrode is present. Hydrogen yields far exceed the monolayer amounts (∼1015 molecules cm−2) expected from a surface stoichiometric reaction. The reaction takes place on illumination of the crystal with band gap radiation (hv ≧ 3.2eV) in aqueous alkaline solution. The rate of hydrogen evolution increased with increasing hydroxide concentration in the solution. We also report the use of water vapour as a reactant through saturation of a layer of a basic deliquescent compound, such as NaOH, which coated the crystal. The photocatalytic generation of hydrogen on the illuminated surface of metal-free SrTiO3 crystals shows that strongly reductive as well as oxidative reactions can be carried out and sustained on illuminated oxide semiconductors. A wide range of photocatalytic reactions may possibly be carried out in conditions not amenable to the operation of photoelectrochemical cells by using this new mechanism.
Preparation, thermal, spectral and microscopic studies of calcium silicate hydrate-poly(acrylic acid) nanocomposite materials

A series of calcium silicate hydrate (C–S–H)-polymer nanocomposite (C–S–HPN) materials were prepared by incorporating poly(acrylic acid) (PAA) into the inorganic layers of C–S–H during precipitation of quasicrystalline C–S–H from aqueous solution. The as-synthesized C–S–HPN materials were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The XRD analysis of C–S–HPN materials suggest the intermediate organizations presenting intercalation of PAA within C–S–H and exfoliation of C–S–H. The SEM micrographs of C–S–H, PAA and C–S–HPN materials with different PAA contents exhibit the significant differences in their morphologies. The effect of the material’s composition on the thermal stability of a series of C–S–HPN materials along with PAA and C–S–H were studied by TG, DTA and DSC. Three significant decomposition temperature ranges were observed on the TG curves of all C–S–HPN materials.
Axoplasmic Flow in Cerebellar Mossy and Climbing Fibers

Tritiated leucine was injected unilaterally into pontine, inferior olivary, or reticular nuclei of cat brainstem to establish sources of cerebellar mossy and climbing terminals. Allowing 24 to 72 hours for label uptake and active transport by axoplasmic flow to cerebellar cortex, autoradiographs were prepared with the use of parasagittal sections from both sides. Larger volumes (1μI to 5μI) were injected initially to facilitate identification of labeled terminals. Thereafter, smaller volumes were used to obtain more discrete and reliable results. Several types of control eliminated alternative routes of transport. Both inferior olive and pontine nuclei were shown to be sources of contralaterally labeled mossy and climbing terminals, the former somewhat more numerous in pontine injections, the latter significantly so in olivary ones. Reticular sites prinicipally showed climbing terminals. Labeled terminals were also seen homolaterally to the injection, but much less frequently than contralaterally.
Energy Status Parameters, Hypoxia Fraction and Radiocurability Across Tumor Types

Under full nutrient in vitro conditions, the cellular adenylate energy charge of six different rodent and human tumor cell types was identical, i.e., 0.94 +/- 0.01, suggesting the potential utility of this parameter as a cell (and tissue) independent marker of nutrient deprivation and hypoxia, across tumor types. The adenylate energy charge values of tumors, arising from these cells, was reduced and variable ranging from 0.72 to 0.91 for the various tumor types. However, neither the tumor adenylate energy charge, NTP/Pi, nor PCr/Pi ratios correlated with the radiobiologic hypoxic cell fractions across tumor types. The reduced adenylate energy charge in vivo suggests varying degrees of nutrient deprivation in the different tumor types, however, factors other than or in addition to hypoxia likely contribute to tumor energy status.
Media content management on the DTV platform

Digital TV offers many advantages over analog TV. The obvious advantages are higher picture resolution and superior quality, more programs for the same channel bandwidth, and potential for mixed video and data broadcasting. In addition, the reception of video, audio, and data in digital form, offer new opportunities for better filtering, management and organization of the content, during and after the broadcast. The platform on which these media content management operations are performed is similar to the computing platform, with which we are familiar. Hence, the goals are to process incoming bits of data and to generate output for users' reception and/or interactivity. In this paper, we present our vision and summarize our research activities in media content management on the DTV platform. In particular, we will focus on three key areas, namely, channel surfing, digital video recording, and content filtering. We will also demonstrate how media content management can offer new and better viewing experiences in the era of DTV.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Making predictions in an eternally inflating universe.

Eternally inflating universes can contain large thermalized regions with different values of the constants of nature and with different density fluctuation spectra. To find the probability for a ``typical'' observer to detect a certain set of constants, or a certain fluctuation spectrum, one needs to compare the volumes occupied by different types of regions. If the volumes are taken on an equal-time hypersurface, the results of such a comparison are extremely sensitive to the choice of the time variable t. Here, I propose a method of comparing the volumes which is rather insensitive to the choice of t. The method is then applied to evaluate the relative probability of different minima of the inflaton potential and the probability distribution for the density fluctuation spectra.
The tyrosyl-DNA phosphodiesterase Tdp1 is a member of the phospholipase D superfamily

The phospholipase D (PLD) superfamily is a diverse group of proteins that includes enzymes involved in phospholipid metabolism, a bacterial toxin, poxvirus envelope proteins, and bacterial nucleases. Based on sequence comparisons, we show here that the tyrosyl-DNA phosphodiesterase (Tdp1) that has been implicated in the repair of topoisomerase I covalent complexes with DNA contains two unusual HKD signature motifs that place the enzyme in a distinct class within the PLD superfamily. Mutagenesis studies with the human enzyme in which the invariant histidines and lysines of the HKD motifs are changed confirm that these highly conserved residues are essential for Tdp1 activity. Furthermore, we show that, like other members of the family for which it has been examined, the reaction involves the formation of an intermediate in which the cleaved substrate is covalently linked to the enzyme. These results reveal that the hydrolytic reaction catalyzed by Tdp1 occurs by the phosphoryl transfer chemistry that is common to all members of the PLD superfamily.
Ketamine-Induced NMDA Receptor Hypofunction as a Model of Memory Impairment and Psychosis

N-methyl-D-aspartate (NMDA) glutamate receptor antagonists are reported to induce schizophrenia-like symptoms in humans, including cognitive impairments. Shortcomings of most previous investigations include failure to maintain steady-state infusion conditions, test multiple doses and/or measure antagonist plasma concentrations. This double-blind, placebo-controlled, randomized, within-subjects comparison of three fixed subanesthetic, steady-state doses of intravenous ketamine in healthy males (n = 15) demonstrated dose-dependent increases in Brief Psychiatric Rating Scale positive (F[3,42] = 21.84; p < 0.0001) and negative symptoms (F[3,42] = 2.89; p = 0.047), and Scale for the Assessment of Negative Symptoms (SANS) total scores (F[3,42] = 10.55; p < 0.0001). Ketamine also produced a robust dose-dependent decrease in verbal declarative memory performance (F[3,41] = 5.11; p = 0.004), and preliminary evidence for a similar dose-dependent decrease in nonverbal declarative memory, occurring at or below plasma concentrations producing other symptoms. Increasing NMDA receptor hypofunction is associated with early occurring memory impairments followed by other schizophrenia-like symptoms.
Neuronal morphology of the rabbit cochlear nucleus

The cytoarchitecture of the cochlear nucleus in young adult albino rabbits (Cuniculus oryctolagus) has been examined in Nissl- and Golgi-impregnated material to compare rabbit cochlear nucleus with other mammalian species. Cochlear nucleus was subdivided into anteroventral (AVCN), posteroventral (PVCN), and dorsal (DCN) regions, as in other mammals. AVCN was characterized by bushy cells and stellate cells. The "bushy" dendritic trees of adjacent bushy cells often overlapped. PVCN was characterized by octopus, elongate, and stellate cells. The dendritic trees of adjacent octopus cells extended in a parallel array across the auditory nerve fibers. DCN had molecular, fusiform and polymorphic layers. The fusiform cell layer was especially prominent, with the fusiform cells appearing visually to be the organizing elements in DCN. The large cells in DCN were the fusiform and giant neurons; the medium cells were the stellate and elongate neurons; the small cells were the cartwheel, small stellate, and granule cells. The cochlear nucleus of rabbit is essentially similar in cytoarchitectural organization to other mammalian species which have been studied. The detailed morphology of the various cell types seen in Golgi preparations is quite similar to that of cat (Brawer et al., '74), although some differences do exist.
Ultrathin (∼2nm) HfO x as the fundamental resistive switching element: Thickness scaling limit, stack engineering and 3D integration

This paper addresses the thickness scaling limit of HfO x -based RRAM through a combination of theoretical calculations of electron transport and experimental demonstration of 2nm-HfO x devices. The comparison of 2nm devices with thicker references and bilayer stacks confirm the switching thickness is less than 2nm. The 3D integration of 2nm-HfO x devices enables much larger array size and leads to superior performances compared to planar devices.
Biological application of the statistical concepts used in the Second Law.

Abstract The idea that living things violate the Second Law has been suggested many times. We point out that any mathematical formalism can be applied to a variety of physical processes; here to all molecules on the one hand (Boltzmann) and to messages of the genetic code on the other. The latter is an application of what is known as Shannon's law of communications theory. One application can be valid without the other, in particular if we suspect Shannon's law, this does not imply a breakdown of the molecular law leading to thermodynamics. To avoid a defect of Shannon's law, a widening of the representative “space” of the genome is proposed; the new space, called here the “polymeric space” is found to have properties that make it particularly suitable as a vehicle of biological description. We find that in this manner an apparent violation of Shannon's law can be accounted for.
Advantages Of Hexagonal Detectors And Variable Focus For Point-Source Sensors

Analytical results are presented showing improved detection and location performance of point sources in a staring sensor using a hexagonal detector array or having the capability to adjust the size of its blur spot (variable focus). Square and hexagonal detector arrays are compared for detection probability versus focus, for location accuracy versus focus and signal-to-noise ratio, and for location accuracy versus blur size and detector array fill factor. We find that hexagonal detectors provide better detection probability when the point source lies near a corner of the detector, but otherwise the two detector types give comparable performance. Hexagonal detectors generally give better location accuracy than square detectors. Variable focus is shown to be advantageous for maximizing performance for both detection and location of point sources.
Life Cycle and Mesoscale Frontal Structure of an Intermountain Cyclone

Abstract High-resolution analyses and MesoWest surface observations are used to examine the life cycle and mesoscale frontal structure of the “Tax Day Storm,” an intermountain cyclone that produced the second lowest sea level pressure observed in Utah during the instrumented period and the strongest cold frontal passage at the Salt Lake City International Airport in the past 25 years. A key mesoscale surface feature contributing to the cyclone’s evolution is a confluence zone that extends downstream from the Sierra Nevada across the Great Basin. Strong contraction (i.e., deformation and convergence) within this Great Basin confluence zone (GBCZ) forms an airstream boundary that is initially nonfrontal but becomes the locus for surface frontogenesis as it collects and concentrates baroclinicity from the northern Great Basin, including that accompanying an approaching baroclinic trough. Evaporative and sublimational cooling from postfrontal precipitation, as well as cross-front contrasts in surface sensible...
Antijam Capability of Frequency-Hop Spread-Spectrum with Reed-Solomon Coding

This paper is concerned with increasing the antijam (AJ) capability of frequency-hop spread-spectrum through the use of diversity transmission, Reed-Solomon coding, and a parallel errors and erasures decoding algorithm. The goals are twofold. First it is desirable to increase the jamming margin against a partial-band noise jammer by use of coding and diversity with an efficient error-correction algorithm. Second, it is necessary to totally eliminate the threat of a narrowband jammer (regardless of the jammer's power level) in order to have an effective AJ system. Through an analysis of the effects of partial-band jamming on a frequency-hop spread-spectrum system with diversity, it is shown that the use of Reed-Solomon coding with a parallel errors and erasures decoding algorithm accomplishes these goals. The paper also investigates the accuracy of the Chernoff bound as an approximation to the true performance of a frequency-hop spread-spectrum communication system with diversity, side information, and Reed-Solomon coding. The performance results presented in the paper are exact results based on analysis and computer evaluation and approximate results based on the Chernoff bound. It is shown that the Chernoff bound gives a very poor approximation for many cases of interest.