cssi/SciSciGPT-SciSciNet huggingface dataset:
DENNING ECOLOGY IN SYMPATRIC POPULATIONS OF SKUNKS (SPILOGALE GRACILIS AND MEPHITIS MEPHITIS) IN WEST-CENTRAL TEXAS

We examined den-site selection patterns for western spotted skunks (Spilogale gracilis) and striped skunks (Mephitis mephitis) co-occurring in mesquite brushland of Tom Green County, Texas. Sixteen S. gracilis and 14 M. mephitis were radiocollared to locate den sites from October 2001 through June 2003. Characteristics of dens were assessed using 23 habitat variables. S. gracilis favored den sites with dense mesquite (Prosopis glandulosa), shrubs, and cacti (Opuntia), whereas M. mephitis used these areas but also more open habitats. Den habitats of S. gracilis were more uniform than were those of M. mephitis, implying that S. gracilis is more specialized in den-site selection. Both species used multiple den sites, both above and below ground, rather than a primary den. Aboveground denning occurred year-round for both species. For S. gracilis, 56% (n = 60) of dens were above ground, but denning was more common above ground in the spring and summer. Aboveground denning was more common than belowground denning for M. mephitis in all seasons, representing 64% (n = 50) of all dens. Den habitat analysis suggests that S. gracilis, unlike M. mephitis, may be limited to areas with sufficient cover, including prickly pear cactus, for denning.
Dynamics of the QT interval during and after exercise in healthy children

The dynamics and homogeneity of the QT interval have been used as indicators of susceptibility to ventricular arrhythmias. We determined the relationship between QT intervals and heart rate during exercise testing and subsequent recovery in 18 healthy children. The QT intervals were measured to the apex (early QT), to the end (total QT), and from the apex to the end of the Twave (late QT) (inhomogeneity of repolarization) at heart rates from 60 by steps of 10 to 180 beats. min−1. Group mean total QT and early QT exhibited better linear correlations with heart rate (r 0.998 and 0.999) than with cardiac cycle length (r 0.954 and 0.959). The slope relating total QT to heart rate was − 1.30 during exercise and − 1.42 during recovery ( P 440 ms) in 12 children (67%) whereas linear correction gave values below 440 ms only. In conclusion, the relationship between QT and heart rate is linear and differs during exercise and recovery. Inhomogeneity of repolarization increases at high heart rates. Linear correction of total QT and early QT intervals improves the evaluation of repolarization duration in exercise testing in children.
Methodological aspects of a Marxian approach to development: An analysis of the modes of production school

Abstract This essay presents a methodological analysis of one Marxian approach to development, the so-called modes of production (MOP) school. The three basic positions encompassed by the MOP school are examined in terms of the specific issues of the constitution of theories, the process of concept formation, and the status of concepts within theory in general. The MOP school is criticized for two major problems associated with its use of the concept of mode of production: the problem of economic determinism and the use of a strict theory-fact dichotomy.
Redox equilibria in hydroxylamine oxidoreductase. Electrostatic control of electron redistribution in multielectron oxidative processes.

We report results of continuum electrostatics calculations of the cofactor redox potentials, and of the titratable group pK a values, in hydroxylamine oxidoreductase (HAO). A picture of a sophisticated multicomponent control of electron flow in the protein emerged from the studies. First, we found that neighboring heme cofactors strongly interact electrostatically, with energies of 50-100 mV. Thus, cofactor redox potentials depend on the oxidation state of other cofactors, and cofactor redox potentials in the active (partially oxidized) enzyme differ substantially from the values obtained in electrochemical redox titration experiments. We found that, together, solvent-exposed heme 1 (having a large negative redox potential) and heme 2 (having a large positive redox potential) form a lock for electrons generated during the oxidation reaction The attachment of HAO's physiological electron transfer partner cytochrome c 5 5 4 results in a positive shift in the redox potential of heme 1, and "opens the electron gate". Electrons generated as a result of hydroxylamine oxidation travel to heme 3 and heme 8, which have redox potentials close to 0 mV versus NHE (this result is in partial disagreement with an existing experimental redox potential assignment). The closeness of hemes 3 and 8 from different enzyme subunits allows redistribution of the four electrons generated as a result of hydroxylamine oxidation, among the three enzyme subunits. For the multielectron oxidation process to be maximally efficient, the redox potentials of the electron-accepting cofactors should be roughly equal, and electrostatic interactions between extra electrons on these cofactors should be minimal. The redox potential assignments presented in the paper satisfy this general rule.
Multi-channel random demodulation for hardware efficient compressive sensing

In this paper we propose and analyze the multichannel random demodulator, a compressive sensing system employing multiple random demodulation channels. This system fills the gap between a single channel system, the random demodulator, and an M channel system, which acquires one measurement per channel. The trade-off for changing the number of channels involves hardware efficiency and compactness. We provide an analysis of this trade-off and study the performance of the multi-channel random demodulator.
A new method for generating ceramic restorations: a CAD-CAM system

A new computer-aided design and computer-aided manufacturing (CAD-CAM) system described in this article can fabricate a ceramic restoration in less than20 minutes. A major breakthrough in restorative dentistry, this technique should be available in the United States by late 1989. A number of computer-aided design and computer-aided manufacturing (CAD-CAM) systems are being generated for electronically designing and milling dental restorations. Such systems eliminate the need for impressions, temporary prostheses, and laboratory assistance. Furthermore, the entire procedure can be completed in one appointment. Although the dental literature described some of these developments in moderate detail, little or no information is available regarding one of the newest systems. A heady available in Europe, this new CAD-CAM device is capable of fabricating a ceramic restoration in less than 20 minutes. This paper describes the operation procedures of this new system as it relates to clinical practice.
The inherent dynamics of a molecular liquid: geodesic pathways through the potential energy landscape of a liquid of linear molecules.

Because the geodesic pathways that a liquid follows through its potential energy landscape govern its slow, diffusive motion, we suggest that these pathways are logical candidates for the title of a liquid's “inherent dynamics.” Like their namesake “inherent structures,” these objects are simply features of the system's potential energy surface and thus provide views of the system's structural evolution unobstructed by thermal kinetic energy. This paper shows how these geodesic pathways can be computed for a liquid of linear molecules, allowing us to see precisely how such molecular liquids mix rotational and translational degrees of freedom into their dynamics. The ratio of translational to rotational components of the geodesic path lengths, for example, is significantly larger than would be expected on equipartition grounds, with a value that scales with the molecular aspect ratio. These and other features of the geodesics are consistent with a picture in which molecular reorientation adiabatically foll...
Nonlinear Reynolds stress models and the renormalization group

The renormalization group is applied to derive a nonlinear algebraic Reynolds stress model of anisotropic turbulence in which the Reynolds stresses are quadratic functions of the mean velocity gradients. The model results from a perturbation expansion that is truncated systematically at second order with subsequent terms contributing no further information. The resulting turbulence model applied to both low and high Reynolds number flows without requiring wall functions or ad hoc modifications of the equations. All constants are derived from the renormalization group procedure; no adjustable constants arise. The model permits inequality of the Reynolds normal stresses, a necessary condition for calculating turbulence-driven secondary flows in noncircular ducts.
Dialectic tension, double reflexivity and the everyday accounting researcher: On using qualitative methods☆

Abstract Qualitative, naturalistic research methods have been suggested as being useful in studying the symbolic roles of accounting in organizations and society. The purposes of this article are to reflect on the authors' use of various interpretative research approaches in conducting a series of field studies and to discuss the interdependencies that exist among the research questions being addressed, the research approaches employed, the organizations and actions studied, and the researchers. The importance of a dialectic tension and double reflexivity to conducting interpretive fieldwork are also condsidered. Several implications for future research are explored.
Human immunodeficiency virus-1 transgene expression increases pulmonary vascular resistance and exacerbates hypoxia-induced pulmonary hypertension development

AbstractPulmonary arterial hypertension (PAH) is a progressive disease characterized by increased pulmonary arterial resistance and vessel remodeling. Patients living with human immunodeficiency virus-1 (HIV-1) have an increased susceptibility to develop severe pulmonary hypertension (PH) irrespective of their CD4+ lymphocyte counts. While the underlying cause of HIV-PAH remains unknown, the interaction of HIV-1 proteins with the vascular endothelium may play a critical role in HIV-PAH development. Hypoxia promotes PH in experimental models and in humans, but the impact of HIV-1 proteins on hypoxia-induced pulmonary vascular dysfunction and PAH has not been examined. Therefore, we hypothesize that the presence of HIV-1 proteins and hypoxia synergistically augment the development of pulmonary vascular dysfunction and PH. We examined the effect of HIV-1 proteins on pulmonary vascular resistance by measuring pressure-volume relationships in isolated lungs from wild-type (WT) and HIV-1 Transgenic (Tg) rats. W...
ac conductivity and ac photoconductivity in amorphous and crystalline insulators

Measurements of ac conductivity and ac photoconductivity are reported on representative amorphous and crystalline insulators. Low-frequency measurements have been argmented by photomicrowave experiments. In the dark some of these materials exhibit the familiar ${\ensuremath{\omega}}^{s}$ frequency dependence but under illumination all materials studied exhibit frequency-independent ac conductivity in the range 20 Hz-100 kHz. The amorphous chalcogenides studied do not exhibit photomicrowave response; however, strong response is observed in these films following crystallization in situ. Frequency-independent ac conductivity is usually associated with transport in extended states. In ${\mathrm{As}}_{2}$${\mathrm{Se}}_{3}$, however, transient measurements are interpreted most easily in terms of hopping transport. A phenomenological model which reconciles these observations is presented. Aspects of the relationship of steady-state ac to dc electrical measurements and the relationship of ac measurements to the time-of-flight technique are analyzed.
Government, Business and Finance in Korean Industrial Development

This paper reassesses the roles of government, business and finance in South Korea's economic growth and development. It argues that these extra-market mechanisms were each important, in their own ways, for solving coordination problems that would have otherwise posed obstacles to industrial growth. But what were solutions in the early stages of modern economic growth proved to be impediments later, as the problems that had to be solved changed but the institutions did not.
The Interregional Incidence of Energy-Production Taxes

A general equilibrium model of international trade with pure intermediate goods is adapted to analyze the interregional incidence of a severance tax. The effects of a small increase in a production tax on an intermediate good are not a priori predictable. In fact, outputs of final goods, factor rewards, and the commodity price ratio can move in either direction. An empirical illustration of the model indicates that energy-producing states may benefit from severance tax increases, but the nation suffers a net loss due to the tax-induced curtailment of energy production.
Oscillatory flows in a porous thermoelastic matrix due to earth tides

Abstract Vertical motions of a viscous fluid in a permeable elastic or rigid matrix due to a periodic fluctuation in gravity are examined. Isothermal solutions for a deforming matrix, and non-isothermal solutions for a rigid matrix, are obtained for periods over the range of earth tides and for a wide range of physical parameters. It is shown that the fluid pressure variation in each solution has no greater magnitude than the corresponding change due to the same gravity increment in a static situation.
On the Generation of ULF Magnetic Variations by Conductivity Fluctuations in a Fault Zone

— Prior to the October 18, 1989 Loma Prieta M s 7.1 earthquake, Fraser-Smith et al. (1990) recorded a 10–100 fold increase in ultra-low frequency (ULF) magnetic fields near the earthquake epicenter. Several mechanisms for generation of these ULF fields by fluid flow in the earth have been advanced, but all appear to require unrealistic fluid velocities or hydraulic permeabilities to match the observations. As an alternative explanation, Merzer and Klemperer (1998) proposed that the increase in ULF magnetic fields could result from induced electric currents flowing in a fault-zone made temporarily much more electrically conductive by stress-induced reorganization of pore geometry. Using a numerical model we show that while this mechanism could produce a significant increase in ULF variations, mutual induction between the fault zone and the surrounding crust would probably limit the amplitude increase to levels well below those observed at Loma Prieta. We consider a variant on this quasi-static conductive fault zone model in which low frequency telluric currents are modulated by small higher frequency variations of bulk fault zone conductivity. We show that because the spectrum of natural EM variations is red, substantially larger relative increases in ULF magnetic fields could be produced by this mechanism with even small conductivity fluctuations at these frequencies. These variations would be easy to detect with a well-designed experiment, if they occurred. In principle this mechanism could explain the Loma Prieta ULF observations, however the magnitude of conductivity fluctuations that would be required to match the very large reported amplification factors still appears to be too large to be physically plausible.
Highly enantioselective amide ligation by prior thiol capture

Abstract The mixed disulfides from (R,S)-l-(Cbz-L-alanyloxy)-9-mercapto-phenoxatiin-10-sulfoxide and H-L-Cys-OMe undergo O,N-acyl transfer in DMSO at 23°C with rate constants of 7.0 h−1 and 0.048 h−1, and a rate ratio of 146; EM values of 0.2 M and 0.0015 M .
The proliferative activity of neurilemomas.

Abstract Twenty-one patients with neurilemomas (15 intracranial and 6 intraspinal) received a 1-hour intravenous infusion of 5-bromodeoxyuridine (BrdU), 200 mg/m 2 before tumor removal, to label S-phase tumor cells. Excised tumor specimens were stained by the indirect immunoperoxidase method with anti-BrdU monoclonal antibodies to determine the BrdU labeling index, or percentage of Sphase cells. The BrdU labeling index ranged from 0.1% to 3.1% (mean, 0.9%). The BrdU labeling index was >1.5% in four of the 21 tumors (three trigeminal and one spinal). One acoustic tumor in a patient with neurofibromatosis type 1 had a labeling index of 1.3%, which was the highest among the acoustic tumors. The BrdU labeling indices did not correlate with the patient's age, tumor size, or the duration of signs and symptoms. There was no significant difference between the BrdU labeling indices of Antoni type A and Antoni type B tissue. The low BrdU labeling index of most of the intracranial neurilemomas coincides well with the slow growth of these tumors. As the BrdU labeling index may reflect growth potential of individual tumors, it could be used to guide the follow-up of patients with incompletely resected tumor.
YB-1 translational control of epithelial-mesenchyme transition.

Transitions between epithelial and mesenchmal phenotypes play critical roles in normal development and cancer progression. In this issue of Cancer Cell , Evdokimova et al. demonstrate that YB-1 regulates epithelial-mesenchyme transition (EMT) by inducing cap-independent translation of mRNAs encoding EMT-promoting factors and suppressing cap-dependent translation of mRNAs encoding growth-promoting factors.
Assessing Atrial Mechanical Remodeling and Its Consequences

The principal function of the left atrium is to modulate left ventricular (LV) filling and cardiovascular performance through reservoir, conduit, and booster pump functions; the latter is often (mistakenly) regarded synonymously with atrial function, and in contrast to the reservoir and conduit phases, has been studied extensively. Typically, the importance of atrial contraction has been estimated by measurements of cardiac output and end-diastolic volumes both with and without effective atrial systole, by relative LV filling using Doppler transmitral velocimetry (E/A ratios) or radionuclide angiography, or by atrial shortening using 2D echocardiography, angiography, and sonomicrometry. Despite considerable investigation, the magnitude and relative importance of the atrial contribution to LV filling and cardiac output remain controversial and provide motivation for a more complete evaluation of the atrial cycle. In this regard, nearly half of the LV stroke volume and its associated energy is stored in the left atrium during ventricular systole, which acts as a ventricular restoring force during the ensuing ventricular diastole.1 This reservoir function of the left atrium is governed by atrial compliance, which is most rigorously measured by mathematically fitting atrial pressure and volume data during ventricular systole. A number of studies have shown, however, that the proportion of left atrial inflow during ventricular systole with Doppler pulmonary venous flow (ie, S/D ratios) can estimate relative reservoir function. Thus, we showed that an isolated change in left atrial compliance alters predictably reservoir function and the pattern of pulmonary venous flow.2 Decreased atrial compliance is associated with greater phasic atrial pressures but a lower mean level of atrial pressure during ventricular filling, and as a result, a smaller end-diastolic volume and decreased venous return.3 In contrast, increased atrial compliance increases early LV filling and atrial systolic shortening.4 See p 387 Pressure-strain analysis in the intact dog …
Extracellular ATP and ADP Activate Transcription Factor NF-κB and Induce Endothelial Cell Apoptosis

Abstract Inflammation within the vasculature is associated with endothelial cell (EC) perturbation, loss of vascular ATP-diphosphohydrolase activity, and platelet microthrombus formation with release of ATP and ADP into the micro-environment. The nature and effects of purinergic stimulation of EC under these circumstances remain largely undetermined. ATP and ADP activated EC transcribed mRNA from certain transcription factor NF-κB target genes and expressed E-selectin protein on cell membranes. Band shift analysis and reporter assays confirmed the activation of NF-κB in response to both ATP and ADP. Apoptosis was shown to occur in response to purinergic signaling, potentially through the activation of P2z/P2x7 receptors. Induction of EC activation responses and apoptosis in response to stimulation with ATP and ADP is associated with activation of NF-κB.
Independent predictors of failure of nonoperative management of spinal epidural abscesses

Abstract Background context The notion that all patients with spinal epidural abscess (SEA) require surgical decompression has been recently challenged by reports of successful medical management of select patients with SEA. Purpose The purpose of this study was to identify the independent variables that determine success or failure of medical management of SEA. Study design/setting This was a retrospective, case-control study. Patient sample Patients 18 years or older with diagnosis of SEA admitted to our institution during the study period were included in the sample. Outcome measures The outcome measure was successful management of SEA by eradication of the infection without worsening of neurologic deficits. Methods All patients admitted to our health-care system with a diagnosis of SEA from 1993 to 2011 were identified and the data were retrospectively collected. Patients 18 years or older diagnosed with SEA were included. Excluded were those with postsurgical SEA or phlegmon without an abscess and those with a complete spinal cord injury from SEA for longer than 48 hours. Results A total of 355 patients with average age of 60 years met our inclusion criteria. Of the patients who initially underwent nonoperative treatment, 54 patients failed medical management and 73 patients were successfully treated without surgery. Univariate and multivariate analysis identified incomplete or complete spinal cord deficits as the most significant risk factor for failure of medical management. Age older than 65 years, diabetes, and methicillin-resistant Staphylococcus aureus (MRSA) were also independent risk factors for failure. An algorithm for probability of failed antibiotic management of spinal epidural abscess predicted 99% probability of failure for patients with all four of these risk factors. Conclusions SEA treated with medical management alone has a very high risk for failure if the patient is older than 65 years with diabetes, MRSA infection, or neurologic compromise. In the absence of these risk factors, nonoperative management of spinal epidural abscess may be considered as the initial line of treatment with close monitoring.
Mechanistic issues concerning cancer prevention by tea catechins

The cancer preventive activities of tea (Camellia sinensis, Theaceae) have been demonstrated in animal models for cancers at different organ sites and suggested by some epidemiological studies. Many mechanisms for cancer prevention have been proposed based on studies in cell lines, which demonstrated the modulation of signal transduction and metabolic pathways by (-)-epigallocatechin-3-gallate (EGCG), the most abundant and active polyphenol in green tea. These molecular events may result in cellular changes, such as enhancement of apoptosis, suppression of cell proliferation, and inhibition of angiogenesis. Nevertheless, it is not known whether these are the molecular mechanisms of inhibition of carcinogenesis in animals and humans. This article discusses the key issues involved in extrapolating results from cell line studies to mechanistic information in vivo and in translating animal studies to human cancer prevention.
Influence of Physical Grain Characteristics on Optimal Rotor Speed During Impact Dehulling of Oats

ABSTRACTCentral to commercial oat (Avena sativa L.) processing is impact dehulling. During impact dehulling, oats are fed into a spinning rotor that expels the grains against an impact ring. The impact frees the groat from the hulls. To optimize dehulling protocols, we examined the effects of physical grain characteristics and rotor speed on oat dehulling using an impact dehuller. We separated grain of three cultivars (Gem, CDC Dancer, Ronald) according to size by sieve fractionation (separation by width), disk fractionation (separation by length), and by gravity table (separation by density). Grains were characterized by mass, digital image analysis, and bulk density. Samples (50 g) were adjusted to 9% moisture and dehulled at four different rotor speeds. Groat percentage, dehulling efficiency, and groat breakage were measured after dehulling. In general, oats with higher bulk density dehulled more efficiently at slower rotor speeds, regardless of grain mass. Groat breakage increased with rotor speed and...
Airway Smooth Muscle Mechanics, Remodeling and Proliferation: Effects of Aicar and Metformin

Obesity is a risk factor for asthma. The purpose of this study was to determine whether metformin, an agent used in the treatment of another obesity-related condition, type II diabetes, might have therapeutic potential for airway smooth muscle (ASM) function in obesity.
Partial-state estimation using an adaptive disturbance rejection algorithm

This paper develops an adaptive disturbance rejection framework to achieve partial state estimation. The cost of covariance propagation in the Kalman filter and the spatially local Kalman filter is prohibitive if the order of the system is large. Alternatively, the order of the adaptive controller can be chosen manually and the adaptive disturbance rejection algorithm yields better estimates in the presence of large uncertainty in the plant inputs. The state estimation using the adaptive disturbance rejection technique was demonstrated on a serially interconnected mass spring damper simulation example and its performance compared with the Kalman filter. The adaptive disturbance rejection estimator that uses the state dependent Markov parameters was then used for data assimilation in a one dimensional hydrodynamic flow example.
Continuation of a catalog of explicit, closed-form symbolic expressions for the dual-kernel, matric convolution integral for some simple generic examples in Discrete/Continuous Control Theory

D/C Control Theory is a recently developed generalized-version of modern MIMO discrete-time control in which the inter-sample behavior of the control signal is allowed to vary with time, according to “smart” real-time selections of user-chosen basis functions, at each sample-time. This paper is a continuation of a paper published in the 41st Southeastern Symposium on System Theory in which a Table of the exact, closed-form, explicit, analytical expressions for the generalized matric convolution-integral BH(T) that arises in Discrete/Continuous (D/C) Control Theory was developed using symbolic calculation software.
Synthesis of random copolymer based pH-responsive nanoparticles as drug carriers for cancer therapeutics†

We report the design and synthesis of pH-responsive vesicular nanoparticles (NPs) based on amphiphilic random copolymers as novel drug carriers for chemotherapy. The random copolymers were photopolymerized from acryloyl chloride, followed by assembly in acetone. The resulting vesicular PAC NPs with an acrylate-functionalized shell were hydrolyzed in aqueous solution to form NPs with a carboxylated shell, which were further modified with branched poly(ethyleneimine) (PEI) to obtain positively charged PEI NPs. The resulting NPs maintained their structures and were pH-sensitive. The effects of molecular weight and concentration of PEI on the grafting efficiency, surface charge, and pH-sensitivity of PEI NPs were investigated by Fourier transform infrared (FT-IR) spectroscopy, electron microscopy, dynamic light scattering and zeta-potential measurements, respectively. We examined two packaging strategies to load the anticancer drug molecule, doxorubicin hydrochloride (Dox), into the NPs by encapsulating Dox inside the cavity of NPs during the assembly of the PAC NPs and by coupling Dox to the shell of PEI modified NPs. The first showed ∼30 wt% Dox loading efficiency, which was 15 times more than the latter, likely due to the larger loading capacity of both within the cavity and on the NP shell. We then tested in vitro delivery of Dox using cavity and surface loaded PEI NPs to HEK 293T cells. At the optimal concentration of NPs (9 μg mL−1), approximately 10 times more Dox were delivered compared to the naked Dox with a low level of cytotoxicity (over 90% relative cell viability).
Site-specific protein immobilization through N-terminal oxime linkages

Immobilizing proteins in specific orientations is important for diagnostic protein arrays, biomaterials, and other applications where retention of bioactivity is essential. We report an approach for protein micropatterning that exploits a chemoselective reaction to conjugate proteins at the N-terminus to polymer films. A copolymer from 2-hydroxyethyl methacrylate and a Boc-protected aminooxy tetra(ethylene glycol) methacrylate was synthesized by radical polymerization. Boc groups were locally deprotected using photoacid generator-based photolithography. Micropatterns were verified by fluorescence microscopy utilizing green fluorescent aldehyde microspheres. Streptavidin that was subjected to a transamination reaction to install an α-ketoamide group at the N-terminus was conjugated to the patterns by oxime bond formation. Since the majority of proteins may be modified to contain a reactive carbonyl group, this methodology should be applicable to pattern a wide variety of proteins specifically through the N-terminus.
The Evolution of Human Genetic and Phenotypic Variation in Africa

Africa is the birthplace of modern humans, and is the source of the geographic expansion of ancestral populations into other regions of the world. Indigenous Africans are characterized by high levels of genetic diversity within and between populations. The pattern of genetic variation in these populations has been shaped by demographic events occurring over the last 200,000 years. The dramatic variation in climate, diet, and exposure to infectious disease across the continent has also resulted in novel genetic and phenotypic adaptations in extant Africans. This review summarizes some recent advances in our understanding of the demographic history and selective pressures that have influenced levels and patterns of diversity in African populations.
Thermal conversion of PR Spring bitumen-derived heavy oil in the presence of Na/alumina

Abstract The thermal cracking of PR Spring bitumen-derived heavy oils in the presence of hydrogen was studied in a fixed-bed reactor as a function of process operating variables. The reactor was filled with a catalytically inert sodium exchanged alumina. The packing consisted of an alumina hydrodenitrogenation catalyst support which had been impregnated with 2 wt.% sodium to reduce the acidity of the alumina. Thermal reactions were investigated with regard to denitrogenation, desulfurization, demetallation, Conradson carbon residue (CCR) reduction and residuum conversion. The process operating variables investigated were temperature (642–683 K), and WHSV (0.25–0.74 h−1). The reactor pressure and hydrogen-to-oil ratio were fixed at 13.7 MPa and 890 m3/m3 (5000 scf H2/bbl); respectively, in all experiments. The product distributions and yields were also determined as a function of process operating variables. Residuum conversion over the sodium-impregnated catalyst support was greater in all cases relative to nitrogen and sulfur removal due to thermal cracking of the residuum. Only low levels of heteroatom conversion were possible via thermal reactions. The extent of nitrogen removal over the sodium-impregnated catalyst support was lower than that of all other classes of component-types. Significant levels of CCR conversion were obtained despite the absence of metal sulfides on the alumina and were attributed to hydrothermal conversion.
What Happens when a Candidate Doesn’t Bark? “Cursed” Voters and Their Impact on Campaign Discourse

Formal models of candidate and voter election behavior often assume that the voters are Bayesian learners who are able to draw inferences not only from the choices candidates make, but also from choices that the candidates did not make. Here, we introduce a formal model and experiment designed to test the extent of voter updating and how it affects campaign strategies. We find that voter behavior tends toward quite incomplete updating, which in turn leads candidates to increase their use of negative campaigning.
Material Properties of Si-Ge/Ge Quantum Wells

Germanium (Ge) and silicon-germanium (Si-Ge) have the potential to integrate optics with Si IC technology. The quantum-confined Stark effect, a strong electroabsorption mechanism often observed in III-V quantum wells (QWs), has been demonstrated in Si-Ge/Ge QWs, allowing optoelectronic modulators in such group IV materials. Here, based on photocurrent electroabsorption experiments on different samples and fitting of the resulting allowed and nominally forbidden transitions, we propose more accurate values for key parameters such as effective masses and band offsets that are required for device design. Tunneling resonance modeling including conduction band nonparabolicity was used to fit the results with good consistency between the experiments and the fitted transitions.
Alice in warningland: a large-scale field study of browser security warning effectiveness

We empirically assess whether browser security warnings are as ineffective as suggested by popular opinion and previous literature. We used Mozilla Firefox and Google Chrome's in-browser telemetry to observe over 25 million warning impressions in situ. During our field study, users continued through a tenth of Mozilla Firefox's malware and phishing warnings, a quarter of Google Chrome's malware and phishing warnings, and a third of Mozilla Firefox's SSL warnings. This demonstrates that security warnings can be effective in practice; security experts and system architects should not dismiss the goal of communicating security information to end users. We also find that user behavior varies across warnings. In contrast to the other warnings, users continued through 70.2% of Google Chrome's SSL warnings. This indicates that the user experience of a warning can have a significant impact on user behavior. Based on our findings, we make recommendations for warning designers and researchers.
CpG Oligodeoxynucleotides Can Reverse Th2-Associated Allergic Airway Responses and Alter the B7.1/B7.2 Expression in a Murine Model of Asthma

CpG oligodeoxynucleotides (CpG-ODN) administered during Ag sensitization or before Ag challenge can inhibit allergic pulmonary inflammation and airway hyperreactivity in murine models of asthma. In this study, we investigated whether CpG-ODN can reverse an ongoing allergic pulmonary reaction in a mouse model of asthma. AKR mice were sensitized with conalbumin followed by two intratracheal challenges at weekly intervals. CpG-ODN was administered 24 h after the first Ag challenge. CpG-ODN administration reduced Ag-specific IgE levels, bronchoalveolar lavage fluid eosinophils, mucus production, and airway hyperreactivity. We found that postchallenge CpG-ODN treatment significantly increased IFN-gamma concentrations and decreased IL-13, IL-4, and IL-5 concentrations in bronchoalveolar lavage fluids and spleen cell culture supernatants. Postchallenge CpG-ODN treatment also increased B7.1 mRNA expression and decreased B7.2 mRNA expression in lung tissues. These results suggest that CpG-ODN may have potential for treatment of allergic asthma by suppressing Th2 responses during IgE-dependent allergic airway reactions. The down-regulation of Th2 responses by CPG-ODN may be associated with regulation of the costimulatory factors B7.1 and B7.2.
BER of UCA in Rician fading channel

The modeling of wireless channels vary greatly in different propagation environments. For example, the line-of-sight (LoS) radio links and non-line-of-sight (NLoS) are two basic channel models in wireless communications, but they are totally different from each other. For a LoS channel, if the signals propagate in an additive white Gaussian noise (AWGN) environment, it is referred to as an AWGN channel. However, the AWGN channel is seldom available for wireless systems in urban areas. For a mobile wireless system inside a city, since there are many structures between the base station and the mobile station, the signals are transmitted in NLoS channels with strong influence from diffractions and scatterers (Stuber, 2001). Thus, the received signal may arrive from many different directions and different delays. This phenomenon is referred to as multipath propagation. The multipath signals may be constructive or destructive and thus many fading models are proposed to represent it, such as Rayleigh fading and Rician fading. Rician fading is observed when, in addition to multipath signals, a direct path between the transmitter and the receiver exists.
The Issue of Intent in the Genocide Convention and Its Effect on the Prevention and Punishment of the Crime of Genocide: Toward a Knowledge-Based Approach

Since the Genocide Convention was created in 1948, its effectiveness has been hindered by debates on what the definition actually means. It has been widely accepted that the meaning of “intent,” within the Genocide Convention, refers to specific or special intent, dolus specialis. However, as more trials have taken place, creating more understanding of the crime of genocide, the linking of dolus specialis with the intent definition, that was so easily accepted at the first genocide trial (Akayesu at the International Criminal Tribunal for Rwanda [ICTR]), has been repeatedly put into question. The new approach being put forward as the most appropriate interpretation of “intent” is the knowledge-based approach. The Vienna Convention on Treaties states that interpretations of laws should follow the treaty's original purpose and objective, and should do this by looking at the preparatory work and its circumstances. By looking at the Travaux Preparatoires of the Genocide Convention and Raphael Lemkin's origina...
On the Robustness of Coefficient Estimates to the Inclusion of Proxy Variables

This paper considers the most eective use of multiple proxy measures for the same unobserved variable. In doing so, we contrast the approach taken in the measurement error literature to that of the model speci…cation litera- ture. We extend the results of Lubotsky and Wittenberg (2006) to examine the impact of proxy variables on correctly measured variables, and …nd that including all proxy variables in the regression minimizes the bias on all other coe¢ cients in the regression. Unlike previous results, estimates of coe¢ cients on other regressors do not require a scaling assumption. We derive a set of bounds based on results from Klepper and Leamer (1984) and Bollinger (2003) for parameters in the model, and compare these results to extreme bounds analysis, as an illustrative example of the model speci…cation approach. We show through Monte Carlo simulations that our bounds perform better than extreme bounds in most circumstances, and may in fact overturn many of the results found through extreme bounds analysis. We conclude with an empir- ical example from the cross-country growth literature in which human capital is measured through three proxy variables: literacy rates, and enrollment in primary and secondary school, and show that our approach yields results that contrast sharply with extreme bounds analysis.
Maximizing rewards for real-time applications with energy constraints

New technologies have brought about a proliferation of embedded systems, which vary from control systems to sensor networks to personal digital assistants. Many of the portable embedded devices run several applications, which typically have three constraints that need to be addressed: energy, deadline, and reward. However, many of these portable devices do not have powerful enough CPUs and batteries to run all applications within their deadlines. An optimal scheme would allow the device to run the most applications, each using the most amount of CPU cycles possible, without depleting the energy source while still meeting all deadlines. In this paper we propose a solution to this problem; to our knowledge, this is the first solution that combines the three constraints mentioned above. We devise two algorithms, an optimal algorithm for homogeneous applications (with respect to power consumption) and a heuristic iterative algorithm that can also accommodate heterogeneous applications (i.e., those with different power consumption functions). We show by simulation that our iterative algorithm is fast and within 1p of the optimal.
External model-based disturbance rejection in tracking control of Euler-Lagrange systems

We consider the systematic design of tracking controllers for Euler-Lagrange systems which are affected by unmeasurable harmonic disturbances. The problem addressed the paper departs from the classic setup of the regulator problem and its solution based on the internal model principle in two aspects. First, the presence of an exogenous disturbance affecting the output channel as well as the input channel of the plant is taken into account. Second, we aim at designing a nominal tracking controller using standard techniques, independently of the device that is used to provide asymptotic rejection of the disturbance. This latter is then placed outside the stabilizing loop, in such a way that stability is preserved, and asymptotic cancellation of the disturbance is guaranteed under mild conditions. The device in question is referred to as an external model of the exogenous system, to emphasize the departure from the classic internal model-based design. The external model is endowed with an adaptation mechanism that allows to deal with uncertainties on the frequencies of the exogenous signals as well. To validate our approach, we provide experimental results for a 2-DOF helicopter model.
Protecting web services from remote exploit code: a static analysis approach

We propose STILL, a signature-free remote exploit binary code injection attack blocker to protect web servers and web applications. STILL is robust to almost all anti-signature, anti-static-analysis and anti-emulation obfuscation.
Impact of anxiety and depressive symptoms on perceptions of stigma in persons living with HIV disease in rural versus urban North Carolina

This analysis examined the relationships between HIV-related stigma, depression, and anxiety in rural and urban sites. Participants were HIV-positive urban (n = 100) and rural (n = 100) adult residents of a US southern state, drawn from a sample for a larger international study of self-esteem and self-compassion. Measures included demographic and health information, the HIV Stigma Scale, the Center for Epidemiology Studies Depression Scale (CES-D), and the Symptom Checklist 90 Revised (SCL-R-90) anxiety scale. Independent sample t-tests showed no significant differences between urban/rural groups on measures of HIV-related stigma, anxiety, or depression, except that rural participants reported greater disclosure concerns (t = 2.11, df = 196, p = .036). Both groups indicated high levels of depression and anxiety relative to published norms and clinically relevant cut-off scores. Hierarchical regression analyses were conducted for the HIV Stigma Scale including its four subscales and total stigma scores. Block 1 (control) contained health and demographic variables known to predict HIV-related stigma. Block 2 included the CES-D and the SCL-R-90, and Block 3 was urban/rural location. Mental health symptom scores contributed a significant amount to explained variance in total stigma scores (5.5%, FΔ = 6.020, p < .01), personalized stigma (4.8%, FΔ = 5.035, p < .01), negative self-image (9.7%, FΔ = 12.289, p < .001), and concern with public attitudes (4.9%, FΔ = 5.228, p < .01), but not disclosure concerns. Urban/rural location made significant additional contributions to the variance for total stigma (1.7%, FΔ = 3.899, p < .05), disclosure concerns (2.6%, FΔ = 5.446, p < .05), and concern with public attitudes (1.9%, FΔ = 4.169, p < .05) but not personalized stigma or negative self-image. Depression scores consistently and significantly predicted perceived stigma total and subscale scores. Findings suggest that mental health symptoms and urban/rural location play important roles in perceived stigma, and treatment implications are presented.
Design of Collusion-Resistant Fingerprinting Systems: Review and New Results

To protect the copyright of a media file, one idea is to develop a traitor tracing system that identifies its unauthorized distribution or usage by tracing fingerprints of illegal users (i.e., traitors). There exists a simple yet effective attack that can break a naive traitor tracing system easily known as the collusion attack. The design of a fingerprinting system that is robust against collusion attacks has been intensively studied in the last decade. A review of previous work in this field will be given. Most previous work deals with collusion attacks with equal weights or its variants (e.g., the cascade of several collusion attacks with equal weights). Consequently, the weight of each colluder is a constant throughout the collusion process. The collusion attack on continuous media such as audio and video with time-varying weights is simple to implement. However, we are not aware of any effective solution to this type of attacks. To address this problem, we first show that this can be formulated as a multi-user detection problem in a wireless communication system with a time-varying channel response. Being inspired by the multi-carrier code division multiaccess (MC-CDMA) technique, we propose a new fingerprinting system that consists of the following modules: 1) codeword generation with a multi-carrier approach, 2) colluder weight estimation, 3) advanced message symbol detection. We construct hiding codes with code spreading followed by multi-carrier modulation. For colluder weight estimation, we show that the colluder weight estimation is analogous to channel response estimation, which can be solved by inserting pilot signals in the embedded fingerprint. As to advanced message symbol detection, we replace the traditional correlation-based detector with the maximal ratio combining (MRC) detector and the parallel interference cancellation (PIC) multiuser detector. The superior performance of the proposed fingerprinting system in terms of user/colluder capacity and the bit error probability (BEP) of symbol detection is demonstrated by representative examples.
The Role of Forensic Factors and Potential Harm to the Child in the Decision Not to Act Among Men Sexually Attracted to Children

To date, sexual abuse prevention efforts have largely focused on tertiary prevention strategies designed to prevent recidivism among forensic samples of men with a history of sex offending behavior. The present study used mixed methodology to investigate the role of several forensic and related factors on the decision not to commit a sex offense among two groups of community men who self-reported a sexual attraction to children: those who reported a history of acting on their attractions (Acted, n = 29) and those who reported never acting on their attractions (Not Acted, n = 71). Participants from both groups described in their own words the factors that contributed to their decision not to act on their attractions. They also responded to quantitative and qualitative questions regarding the influence and role of the following factors on their decision not to act: (a) the possibility of jail or punishment, (b) mental health treatment, and (c) not wanting to hurt the child. Results were compared across groups, and across prompted and unprompted responses. Analyses highlighted harm to the child as a particularly salient factor in the decision not to act among men in the community at risk for sexually offending. The present study suggests that investigating potential protective factors may be an important direction for future research among samples of community men at risk for both first-time and repeat offenses against children.