Miracle-dz/UniFAR-FTUs huggingface dataset:
Theoretic optimisation of microfluidic and magnetic self-assembly of carbon nanotubes

In this reported work, a magnetic and fluidic analysis has been performed to theoretically analyse the self-assembly mechanism of carbon nanotubes (CNTs) and to characterise the assembling environments for the high-density integration of individual CNTs. In previous work by the present author, the residual iron (Fe) catalyst at one end of a CNT was magnetically captured and the captured CNT was aligned along the flow direction by fluid drag force, leading to precise individual integration of CNTs between electrodes. To advance the previous work and technique, theoretic characterisations were executed to optimise the assembling conditions which increased the number of attached CNTs with a high density of integration. For calculating the fluidic force applied to the individual CNT, the slender-body theory was adopted by modelling the CNT as a slender object. Moreover, magnetic simulation was performed to calculate the magnetic force applied to the residual Fe catalysis at one end of the CNT. These simulation results were combined and used to determine the critical height where the fluidic force was equal to the magnetic force. On the basis of these analyses, the array of CNT-assembled electrodes was implemented with a 2 m interval, whereas only a single CNT-assembled electrode was achieved in the previous work. A result of the present work, enables dense integration of the CNT circuit as a highly functional nanodevice.
American Call Options Under Jump‐Diffusion Processes – A Fourier Transform Approach

We consider the American option pricing problem in the case where the underlying asset follows a jump‐diffusion process. We apply the method of Jamshidian to transform the problem of solving a homogeneous integro‐partial differential equation (IPDE) on a region restricted by the early exercise (free) boundary to that of solving an inhomogeneous IPDE on an unrestricted region. We apply the Fourier transform technique to this inhomogeneous IPDE in the case of a call option on a dividend paying underlying to obtain the solution in the form of a pair of linked integral equations for the free boundary and the option price. We also derive new results concerning the limit for the free boundary at expiry. Finally, we present a numerical algorithm for the solution of the linked integral equation system for the American call price, its delta and the early exercise boundary. We use the numerical results to quantify the impact of jumps on American call prices and the early exercise boundary.
PROBING THE ACCRETION DISK AND CENTRAL ENGINE STRUCTURE OF NGC 4258 WITH SUZAKU AND XMM-NEWTON OBSERVATIONS

We present an X-ray study of the low-luminosity active galactic nucleus (AGN) in NGC 4258 using data from Suzaku, XMM-Newton, and the Swift/Burst Alert Telescope survey. We find that signatures of X-ray reprocessing by cold gas are very weak in the spectrum of this Seyfert-2 galaxy; a weak, narrow fluorescent Kα emission line of cold iron is robustly detected in both the Suzaku and XMM-Newton spectra but at a level much below that of most other Seyfert-2 galaxies. We conclude that the circumnuclear environment of this AGN is very “clean” and lacks the Compton-thick obscuring torus of unified Seyfert schemes. From the narrowness of the iron line, together with evidence of line flux variability between the Suzaku and XMM-Newton observations, we constrain the line emitting region to be between 3 × 103rg and 4 × 104rg from the black hole. We show that the observed properties of the iron line can be explained if the line originates from the surface layers of a warped accretion disk. In particular, we present explicit calculations of the expected iron line from a disk warped by Lens–Thirring precession from a misaligned central black hole. Finally, the Suzaku data reveal clear evidence of large amplitude 2–10 keV variability on timescales of 50 ksec and smaller amplitude flares on timescales as short as 5–10 ksec. If associated with accretion disk processes, such rapid variability requires an origin in the innermost regions of the disk (r ≈ 10rg or less). Analysis of the difference spectrum between a high- and low-flux states suggests that the variable component of the X-ray emission is steeper and more absorbed than the average AGN emission, suggesting that the primary X-ray source and absorbing screen have a spatial structure on comparable scales. We note the remarkable similarity between the circumnuclear environment of NGC 4258 and another well studied low-luminosity AGN, M81*.
On Bivariate Reversed Hazard Rates

In this paper we discuss various definitions of bivariate reversed hazard rate and their properties. An exponential representation of bivariate distribution using reversed hazard rates is given and we also develop a new family of bivariate distributions using bivariate reversed hazard rate. Finally we give a local dependence measure using bivariate reversed hazard rates and study its properties. Various applications of the models are pointed out.
Incumbents and Challengers on a Level Playing Field: Assessing the Impact of Campaign Finance in Brazil

This article assesses the impact of campaign spending on incumbent and challenger vote shares in elections to the Brazilian Chamber of Deputies. I argue that incumbents and challengers gain equally from campaign spending. This contrasts with the prominent argument about U.S. House elections that incumbents gain little from spending while challengers gain a great deal. In the U.S., incumbents gain little because being in office generates significant name recognition and additional spending suffers quickly from diminishing returns. In contrast, challengers gain a lot because they start the campaign from scratch. In Brazil, because incumbency provides fewer benefits than in the U.S., both incumbents and challengers must spend money to increase their name recognition and both benefit from spending. My findings imply that campaign spending limits in Brazil would encourage rather than restrict competition, and they point to the importance of assessing the relative advantages of incumbency when assessing the impact of campaign spending.
Inference on Breakdown Frontiers

Given a set of baseline assumptions, a breakdown frontier is the boundary between the set of assumptions which lead to a specific conclusion and those which do not. In a potential outcomes model with a binary treatment, we consider two conclusions: First, that ATE is at least a specific value (e.g., nonnegative) and second that the proportion of units who benefit from treatment is at least a specific value (e.g., at least 50%). For these conclusions, we derive the breakdown frontier for two kinds of assumptions: one which indexes relaxations of the baseline random assignment of treatment assumption, and one which indexes relaxations of the baseline rank invariance assumption. These classes of assumptions nest both the point identifying assumptions of random assignment and rank invariance and the opposite end of no constraints on treatment selection or the dependence structure between potential outcomes. This frontier provides a quantitative measure of the robustness of conclusions to relaxations of the baseline point identifying assumptions. We derive N ‐consistent sample analog estimators for these frontiers. We then provide two asymptotically valid bootstrap procedures for constructing lower uniform confidence bands for the breakdown frontier. As a measure of robustness, estimated breakdown frontiers and their corresponding confidence bands can be presented alongside traditional point estimates and confidence intervals obtained under point identifying assumptions. We illustrate this approach in an empirical application to the effect of child soldiering on wages. We find that sufficiently weak conclusions are robust to simultaneous failures of rank invariance and random assignment, while some stronger conclusions are fairly robust to failures of rank invariance but not necessarily to relaxations of random assignment.
Blind equalization of nonlinear channels from second order statistics using precoding and channel diversity

This paper considers the blind equalization problem for nonlinear Volterra type channels excited by real IID (independent and identically distributed) symbols. Previous work has shown that under the right conditions the equalizers can be found from the second order statistics of the channel output as long as the number of subchannels exceeds the number of kernels. In order to alleviate this requirement, we consider the use of a simple precoding device previous to transmission which provides a tradeoff between effective data rate and number of subchannels required. Necessary and sufficient conditions for blind equalizability under this scheme are given, and an algorithm for the computation of the equalizers is presented.
1H NMR determination of base-pair lifetimes in oligonucleotides containing single base mismatches.

Proton nuclear magnetic resonance (NMR) spectroscopy is employed to characterize the kinetics of base-pair opening in a series of 9mer duplexes containing different single base mismatches. The imino protons from the different mismatched, as well as fully matched, duplexes are assigned from the imino-imino region in the WATERGATE NOESY spectra. The exchange kinetics of the imino protons are measured from selective longitudinal relaxation times. In the limit of infinite exchange catalyst concentration, the exchange times of the mismatch imino protons extrapolate to much shorter lifetimes than are commonly observed for an isolated GC base pair. Different mismatches exhibit different orders of base-pair lifetimes, e.g. a TT mismatch has a shorter base-pair lifetime than a GG mismatch. The effect of the mismatch was observed up to a distance of two neighboring base pairs. This indicates that disruption in the duplex caused by the mismatch is quite localized. The overall order of base-pair lifetimes in the selected sequence context of the base pair is GC > GG > AA > CC > AT > TT. Interestingly, the fully matched AT base pair has a shorter base-pair lifetime relative to many of the mismatches. Thus, in any given base pair, the exchange lifetime can exhibit a strong dependence on sequence context. These findings may be relevant to the way mismatch recognition is accomplished by proteins and small molecules.
Social influences of competition on impulsive choices in domestic chicks

Social factors involved in the control of impulsiveness were examined in domestic chicks. In binary choices between a large/long-delay option (LL) and a small/short-delay alternative (SS), chicks that had been competitively trained in groups of three individuals showed fewer choices of LL than did those trained in isolation (experiment 1), suggesting that competition causes impulsive choice. In experiment 2, in order to identify the critical factor involved, we tested the effects of perceived competition (coincident feeding without interruption) and scrounging (gaining food without pecking bead) separately. To examine the effects of risk/noise that individual chicks experienced in competition, the food amount varied randomly in trials according to a binomial distribution around the expected mean. Perceived competition primarily contributed to the influence on the impulsive choice, whereas the contribution of scrounging was weaker. Collection risk did not explain the social influences since the perceived competition was not accompanied by actual interruption of the delayed food reward. The risk owing to variable food per se did not cause impulsive choices. Coincident foraging during competition is thought to play a critical role.
Analysis of cerebrospinal fluid from chronic fatigue syndrome patients for multiple human ubiquitous viruses and xenotropic murine leukemia‐related virus

Recent reports showed many patients with chronic fatigue syndrome (CFS) harbor a retrovirus, xenotropic murine leukemia‐related virus (XMRV), in blood; other studies could not replicate this finding. A useful next step would be to examine cerebrospinal fluid, because in some patients CFS is thought to be a brain disorder. Finding a microbe in the central nervous system would have greater significance than in blood because of the integrity of the blood–brain barrier. We examined cerebrospinal fluid from 43 CFS patients using polymerase chain reaction techniques, but did not find XMRV or multiple other common viruses, suggesting that exploration of other causes or pathogenetic mechanisms is warranted. Ann Neurol 2011;
Regulation of sympathetic tone and arterial pressure by rostral ventrolateral medulla after depletion of C1 cells in rat

1 In this study we examined whether the rostral ventrolateral medulla (RVLM) maintains resting sympathetic vasomotor tone and activates sympathetic nerve activity (SNA) after the depletion of bulbospinal C1 adrenergic neurones. 2 Bulbospinal C1 cells were destroyed (≈84% loss) by bilateral microinjections (spinal segments T2‐T3) of an anti‐dopamine‐β‐hydroxylase antibody conjugated to the ribosomal toxin saporin (anti‐DβH‐SAP). 3 Extracellular recording and juxtacellular labelling of bulbospinal barosensitive neurones in the RVLM revealed that treatment with anti‐DβH‐SAP spared the lightly myelinated neurones with no tyrosine hydroxylase immunoreactivity. 4 In rats treated with anti‐DβH‐SAP, inhibition of RVLM neurones by bilateral microinjection of muscimol eliminated splanchnic SNA and produced the same degree of hypotension as in control rats. 5 Following treatment with anti‐DβH‐SAP the sympathoexcitatory (splanchnic nerve) and pressor responses to electrical stimulation of the RVLM were reduced. 6 Treatment with anti‐DβH‐SAP also eliminated the majority of A5 noradrenergic neurones. However, rats with selective lesion of A5 cells by microinjection of 6‐hydroxydopamine into the pons showed no deficits to stimulation of the RVLM. 7 In summary, the loss of 84% of bulbospinal adrenergic neurones does not alter the ability of RVLM to maintain SNA and arterial pressure at rest in anaesthetized rats, but this loss reduces the sympathoexcitatory and pressor responses evoked by RVLM stimulation. The data suggest sympathoexcitatory roles for both the C1 cells and non‐C1 cells of the RVLM and further suggest the C1 cells are critical for the full expression of sympathoexcitatory responses generated by the RVLM.
Association of Microvascular Function and Endothelial Biomarkers With Clinical Outcome in Dengue: An Observational Study

Background. The hallmark of severe dengue is increased microvascular permeability, but alterations in the microcirculation and their evolution over the course of dengue are unknown. Methods. We conducted a prospective observational study to evaluate the sublingual microcirculation using side-stream dark-field imaging in patients presenting early (<72 hours after fever onset) and patients hospitalized with warning signs or severe dengue in Vietnam. Clinical findings, microvascular function, global hemodynamics assessed with echocardiography, and serological markers of endothelial activation were determined at 4 time points. Results. A total of 165 patients were enrolled. No difference was found between the microcirculatory parameters comparing dengue with other febrile illnesses. The proportion of perfused vessels (PPV) and the mean flow index (MFI) were lower in patients with dengue with plasma than those without leakage (PPV, 88.1% vs 90.6% [P = .01]; MFI, 2.1 vs 2.4 [P = .007]), most markedly during the critical phase. PPV and MFI were correlated with the endothelial activation markers vascular cell adhesion molecule 1 (P < .001 for both) and angiopoietin 2 (P < .001 for both), negatively correlated. Conclusions. Modest microcirculatory alterations occur in dengue, are associated with plasma leakage, and are correlate with molecules of endothelial activation, angiopoietin 2 and vascular cell adhesion molecule 1.
Penetration and differentiation of cephalic neural crest‐derived cells in the developing mouse telencephalon

Neural crest (NC) cells originate from the neural folds and migrate into the various embryonic regions where they differentiate into multiple cell types. A population of cephalic neural crest‐derived cells (NCDCs) penetrates back into the developing forebrain to differentiate into microvascular pericytes, but little is known about when and how cephalic NCDCs invade the telencephalon and differentiate into pericytes. Using a transgenic mouse line in which NCDCs are genetically labeled with enhanced green fluorescent protein (EGFP), we observed that NCDCs started to invade the telencephalon together with endothelial cells from embryonic day (E) 9.5. A majority of NCDCs located in the telencephalon expressed pericyte markers, that is, PDGFRβ and NG2, and differentiated into pericytes around E11.5. Surprisingly, many of the NC‐derived pericytes express p75, an undifferentiated NCDC marker at E11.5, as well as NCDCs in the mesenchyme. At the same time, a minor population of NCDCs that located separately from blood vessels in the telencephalon were NG2‐negative and some of these NCDCs also expressed p75. Proliferation and differentiation of pericytes appeared to occur in a specific mesenchymal region where blood vessels penetrated into the telencephalon. These results indicate that (i) NCDCs penetrate back into the telencephalon in parallel with angiogenesis, (ii) many NC‐derived pericytes may be still in pre‐mature states even though after differentiation into pericytes in the early developing stages, (iii) a small minority of NCDCs may retain undifferentiated states in the developing telencephalon, and (iv) a majority of NCDCs proliferate and differentiate into pericytes in the mesenchyme around the telencephalon.
Dynamics of epigenetic regulation at the single-cell level

Quantitative analysis of epigenetic memory To explore quantitative and dynamic properties of transcriptional regulation by epigenetic modifications, Bintu et al. monitored a transcriptional reporter gene carried on a human artificial chromosome in Chinese hamster ovary cells (see the Perspective by Keung and Khalil). They measured effects of DNA methylation and histone modifications by methylation or deacetylation in single cells using time-lapse microscopy. Silencing was an all-or-none, stochastic event, so graded adjustments to transcription occurred from changes in the proportion of cells that responded. Furthermore, the duration of recruitment of the chromatin regulators determined the fraction of cells that were silenced. Thus, distinct modifiers can produce different characteristics of epigenetic memory. Science, this issue p. 720; see also p. 661 Quantitative, single-cell measurements reveal characteristics of epigenetic control of transcription. [Also see Perspective by Keung and Khalil] Chromatin regulators play a major role in establishing and maintaining gene expression states. Yet how they control gene expression in single cells, quantitatively and over time, remains unclear. We used time-lapse microscopy to analyze the dynamic effects of four silencers associated with diverse modifications: DNA methylation, histone deacetylation, and histone methylation. For all regulators, silencing and reactivation occurred in all-or-none events, enabling the regulators to modulate the fraction of cells silenced rather than the amount of gene expression. These dynamics could be described by a three-state model involving stochastic transitions between active, reversibly silent, and irreversibly silent states. Through their individual transition rates, these regulators operate over different time scales and generate distinct types of epigenetic memory. Our results provide a framework for understanding and engineering mammalian chromatin regulation and epigenetic memory.
Polynomial time algorithms for some evacuation problems

Evacuation problems can be modeled as flow problems on dynamic networks. A dvnamic network is defined by a graph with capacities and integral transit times on its edges. The maximum dvnamic flow oroblem is to send a maximum amount of flow from a source to a sink within a given time bound T; conversely, the quickest flow problem is to send a given flow amount v from the source to the sink in the shortest possible time. These dynamic flow problems have been studied previously and can be solved via simple minimum cost flow computations. More complicated dynamic flow problems have numerous applications and have been studied extensively. There are no polynomial time algorithms known for many of these nroblems. includine the auickest flow problem with iust two sources, each with-a flow amount that must reacha single sink. The general multiple source quickest flow problem is commonly used as a model for building evacuation; we also call it the evacuation problem. In this paper we consider three problems related to the evacuation problem. We give a polynomial time algorithm for the evacuation problem with a fixed number of sources and sinks. We give a polynomial time algorithm for the lexicographic maximum dynamic flow problem with any number of sources: in this problem we seek a dynamic flow that lexicographically maximizes the amounts-of flow leavine the sources in a soecified order. Our algorithm for the evzcuation problem follows as an application. We also consider the earliest arrival flow problem. Given a source, sink, and time bound T, an earliest arrival flow maximizes the amount of flow reaching the sink at every time step up to and including T. The existence of such a flow is well known, but there are no polynomial time algorithms known even to approximate it. We give a polynomial time algorithm that for any fixed c > 0 approximates an earliest arrival flow within a factor of 1 +c. ‘Research was done while the authors were visiting the Department of Computer Science at Princeton University. tDepartment of Computer Science, Cornell University, Ithaca, NY 14853. Research supported by a National Science Foundation Graduate Research Fellowship. tSchoo1 of Operations Research & Industrial Engineering, Cornell University, Ithaca, NY 14853. Research supported in part by a Packard FeIIowship, an NSF PYI award, and by the National Science Foundation, the Air Force Office of Scientific Research, and the Office of Naval Research, through NSF grant DMS-8920550. Iha Tardost
Fluctuations for a conservative interface model on a wall

We consider an effective interface model on a hard wall in (1+1) di- mensions, with conservation of the area between the interface and the wall. We prove that the equilibrium fluctuations of the height variable converge in law to the solution of a SPDE with reflection and conservation of the space average. The proof is based on recent results obtained with L. Ambrosio and G. Savare on stability properties of Markov processes with log-concave invariant measures.
Conditioned stable Lévy processes and the Lamperti representation

By variously killing a stable Lévy process when it leaves the positive half-line, conditioning it to stay positive, and conditioning it to hit 0 continuously, we obtain three different, positive, self-similar Markov processes which illustrate the three classes described by Lamperti (1972). For each of these processes, we explicitly compute the infinitesimal generator and from this deduce the characteristics of the underlying Lévy process in the Lamperti representation. The proof of this result bears on the behaviour at time 0 of stable Lévy processes before their first passage time across level 0, which we describe here. As an application, for a certain class of Lévy processes we give the law of the minimum before an independent exponential time. This provides the explicit form of the spatial Wiener-Hopf factor at a particular point and the value of the ruin probability for this class of Lévy processes.