Miracle-dz/UniFAR-FTUs huggingface dataset:
Electronic transport in single-walled carbon nanotubes, and their application as scanning probe microscopy tips

Single-walled carbon nanotubes (SWNTs) are remarkable molecules composed of a graphite sheet rolled into a seamless cylinder. With nanometer diameter, and micrometer length, their physical properties are due to a mixture of quantum and classical effects. This work investigates the electrical transport properties of these molecules, and demonstrates their application as Atomic Force Microscopy (AFM) tips. SWNTs were grown by catalysed chemical vapour deposition (cCVD), and characterized using AFM, electron microscopy and Raman spectroscopy. Electronic devices were fabricated from SWNTs grown by cCVD on Si02. Electronic transport through the SWNT devices was studied using electric force microscopy (EFM) and scanned gate microscopy (SGM). SGM was used to study the effects of defects on transport through the devices. A novel form of SGM, based on the modulation of the tip-gating potential by the oscillating tip in dynamic mode AFM, was demonstrated and shown to massively enhance the signal to noise ratio. Using EFM we directly demonstrated the transition from ballistic transport in metallic SWNT at low source-drain voltages, to diffusive transport at high-source drain voltages. EFM was also used to image the charge injection induced around a SWNT at high gate voltages, and correlate it with the observed hysteresis in the transconductance of SWNT devices. Both of these results are of fundamental importance to the future applications of SWNT electronic devices. The high bias behaviour of metallic SWNT is crucial to their proposed use as interconnects in nanoscale devices. Hysteresis in the transconductance of semiconducting SWNT devices is limiting their application as chemical and biological sensors, where environmental effects are monitored by the change in conductance of the devices. SWNTs were mounted at the apex of AFM tips, and used as high resolution scanning probe tips. Electrical transport through the SWNT-AFM tips was investigated using both liquid (Hg) and solid contacts. An efficient technique for fabricating nanowire AFM tips, using SWNT-AFM tips as templates, was also invented. The resultant nanowire tips were shown to be robust, high aspect ratio, electrical probes. Using calibration samples fabricated from SWNTs, SWNT-AFM tips were quantitatively demonstrated to increase the resolution of EFM. Under optimal conditions identical features could be distinguished down to separations as low as 15 nm, comparable to the topographic resolution.
Active and Transfer Learning of Grasps by Sampling from Demonstration

We guess humans start acquiring grasping skills as early as at the infant stage by virtue of two key processes. First, infants attempt to learn grasps for known objects by imitating humans. Secondly, knowledge acquired during this process is reused in learning to grasp novel objects. We argue that these processes of active and transfer learning boil down to a random search of grasps on an object, suitably biased by prior experience. In this paper we introduce active learning of grasps for known objects as well as transfer learning of grasps for novel objects grounded on kernel adaptive, mode-hopping Markov Chain Monte Carlo. Our experiments show promising applicability of our proposed learning methods.
Different antivascular endothelial growth factor treatments and regimens and their outcomes in neovascular age-related macular degeneration: a literature review

Antivascular endothelial growth factor (anti-VEGF) therapy has revolutionised the treatment of wet age-related macular degeneration (wAMD). Recent research has focused on evaluating competing agents and alternative dosage regimens, providing evidence to help determine optimal treatment strategies. We therefore conducted a review of clinical research studies in wAMD published since 2008 that compared anti-VEGF dosing regimens and therapies; seven studies met our inclusion criteria. Data on baseline disease characteristics, disease outcomes, safety (ocular and systemic) and treatment burden (injection and visit frequencies) were extracted on patients treated with ranibizumab 0.5 mg, bevacizumab 1.25 mg or aflibercept 2.0 mg for up to 2 years. For ranibizumab and bevacizumab, visual and anatomical outcomes at 1 and 2 years were superior using scheduled monthly (or 4 weekly (q4w)) compared with as needed or scheduled quarterly dosing regimens. Treatment outcomes were generally better for both drugs when more aggressive retreatment criteria were used, which resulted in more frequent injections. Bevacizumab, however, was associated with a 30–35% elevated rate of serious systemic adverse events compared with ranibizumab, regardless of dosing interval; further study in larger patient populations will be required to determine the validity of this finding. Intravitreal aflibercept injection every 8 weeks was non-inferior to ranibizumab q4w on all visual and anatomical endpoints at week 52, had a similar safety profile and required five fewer anti-VEGF injections.
Bayesian Analysis: A Practical Approach to Interpret Clinical Trials and Create Clinical Practice Guidelines

Bayesian analysis is firmly grounded in the science of probability and has been increasingly supplementing or replacing traditional approaches based on P values. In this review, we present gradually more complex examples, along with programming code and data sets, to show how Bayesian analysis takes evidence from randomized clinical trials to update what is already known about specific treatments in cardiovascular medicine. In the example of revascularization choices for diabetic patients who have multivessel coronary artery disease, we combine the results of the FREEDOM trial (Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease) with prior probability distributions to show how strongly we should believe in the new Class I recommendation (“should be done”) for a preference of bypass surgery over percutaneous coronary intervention. In the debate about the duration of dual antiplatelet therapy after drug-eluting stent implantation, we avoid a common pitfall in traditional meta-analysis and create a network of randomized clinical trials to compare outcomes after specific treatment durations. Although we find no credible increase in mortality, we affirm the tradeoff between increased bleeding and reduced myocardial infarctions with prolonged dual antiplatelet therapy, findings that support the new Class IIb recommendation (“may be considered”) to extend dual antiplatelet therapy after drug-eluting stent implantation. In the decision between culprit artery-only and multivessel percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction, we use hierarchical meta-analysis to analyze evidence from observational studies and randomized clinical trials and find that the probability of all-cause mortality at longest follow-up is similar after both strategies, a finding that challenges the older ban against noninfarct-artery intervention during primary percutaneous coronary intervention. These examples illustrate how Bayesian analysis integrates new trial information with existing knowledge to reduce uncertainty and change attitudes about treatments in cardiovascular medicine.
Lower Bounds for Las Vegas Automata by Information Theory

We show that the size of a Las Vegas automaton and the size of a complete, minimal deterministic automaton accepting a regular language are polynomially related. More precisely, we show that if a regular language L is accepted by a Las Vegas automaton having r states such that the probability for a definite answer to occur is at least p , then r ≥ np , where n is the number of the states of the minimal deterministic automaton accepting L . Earlier this result has been obtained in [2] by using a reduction to one-way Las Vegas communication protocols , but here we give a direct proof based on information theory.
Processing and reliability of corner bonded CSPs

Chip scale packages (CSPs) are now widely used for many electronic applications including portable electronics, telecommunications, and automotive assemblies. Assemblers of these types of devices are looking for solutions that both decrease cost and increase reliability. Underfilling CSPs is known to increase the reliability of these devices. This process can be costly in materials, capital equipment, and process time. This paper presents an alternate solution, bonding the CSP at the corners and edges. This process is used to increase the reliability of CSP devices with respect to shock and vibration. The corner bonding material examined in this study can be dispensed prior to reflow along side the solder paste onto the substrate and cured during the reflow process. This paper will discuss the processing aspects and the reliability of the bonded device. Processing parameters to be discussed are the maximum displacement that allows self-alignment, the optimum placement of the corner bond material on packages with corner bumps will be presented, and dot diameter and heights. The second half of the paper discusses the reliability performance of the material in comparison with several traditional underfill materials. Reliability testing included performing drop testing and thermal cycling (-55/spl deg/C to +125/spl deg/C) on test vehicles. These studies were conducted are several sizes of components from a 35 mm/spl times/35 mm, 1.27 mm pitch, PBGA down to a 6 mm/spl times/8 mm, 0.75 mm microBGA.
Programming languages for mobile code

Sun's announcement of the programming language Java more that anything popularized the notion of mobile code, that is, programs traveling on a heterogeneous network and automatically executing upon arrival at the destination. We describe several classes of mobile code and extract their common characteristics, where security proves to be one of the major concerns. With these characteristics as reference points, we examine six representative languages proposed for mobile code. The conclusion of this study leads to our recommendations for future work, illustrated by examples of ongoing research.
The changing X-ray light curves of the intermediate polar FO Aquarii

Comparison of five X-ray observations of the intermediate polar FO Aqr reveals that the morphology of the X-ray light curve changes considerably with time. In particular, power spectra of the 1988 Ginga and 1993 ASCA data reveal strong sideband and orbital variations, whereas the 1990 Ginga observation does not. This suggests that the amount of stream-fed accretion varies with epoch, and the system was accreting predominantly from a disc in 1990. In contrast to other intermediate polars, the X-ray spin-pulse profiles show significant variations between observations, ranging from relatively sinusoidal to sawtooth-shaped at medium energies. During the 1988 and 1990 observations a notch is visible at spin phase zero, due to the presence of an interpulse at phase 0.85, which is absent during the other observations. At lower energies a narrow pulse of emission is seen at spin phase 0.2. We interpret the pulse profile from the 1990 Ginga observation using a model for accretion from a disc on to a dipolar magnetic field, the axis of which is offset from the white dwarf centre by ~ 0.15 white dwarf radii. In order to account for the later occurrence of the hardness-ratio maximum in 1988 and 1993, we suggest that the accretion-rate profile changes so that accretion is favoured along the field lines which trail the magnetic pole. This also accounts for the disappearance of the interpulse and notch in 1993.
Pension Benets & Retirement Decisions: Income vs. Price Elasticities

We separately identify the income and price elasticities in individualsretirement decisions. We develop a dynamic model of retirement decisions that establishes a precise relationship between a structural parameter and these elasticities. Next, we estimate these elasticities in a proportional hazard speci cation that is independent of any assumptions of the dynamic model. The elasticities are identi ed and estimated using policy variation from pension reforms in Austria and administrative data from the Austrian Social Security Database. We then use these elasticities to estimate the dynamic model and examine the labor supply and welfare consequences of potential social security reforms. We thank Tajendra Singh and Shao-Ching Huang for excellent computing assistance. We are also grateful for helpful comments from Alan Auerbach, Sandy Black, David Blau, Leah Boustan, Moshe Buchinsky, Raj Chetty, Julie Cullen, Alan Gustman, Justine Hastings, Michael Hurd, Pierre-Carl Michaud, Emmanuel Saez and numerous seminar participants. yCorresponding author. E-mail: dsmanoli@econ.ucla. edu. Phone: (310) 794-6617.
Is routine follow-up useful after combined-modality therapy for advanced head and neck cancer?

OBJECTIVE To evaluate the usefulness of routine follow-up in a selected group of patients with head and neck cancer. DESIGN Retrospective cohort study with follow-up of 5 years for all patients. PATIENTS Three hundred two patients with advanced (stage II or IV) squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, and larynx were treated with curative intent with surgery and postoperative radiation therapy between January 1, 1970, and December 31, 1990. MAIN OUTCOME MEASURE Survival after recurrence of the index tumor or the development of a second head and neck primary tumor. RESULTS Overall actuarial 5-year survival was 56%. Relapse occurred in 119 patients, and salvage therapy was attempted in 49 patients. Only 2 patients survived to 5 years after relapse. CONCLUSION In patients with advanced head and neck squamous cell carcinoma, routine follow-up is more important for evaluation of treatment results and emotional support than of benefit in improving patient survival.
Physical activity, physical fitness, and insulin and glucose concentrations in an isolated Native Canadian population experiencing rapid lifestyle change.

OBJECTIVE Little is known about the relation of physical activity and physical fitness to insulin resistance and glucose intolerance in isolated subarctic Native Canadian populations. The purpose of this effort was to examine the relation between activity and fitness and obesity and glucose concentrations in such a unique population. RESEARCH DESIGN AND METHODS This study describes 530 men and women from the community of Sandy Lake, Ontario, located in the boreal forest region of central Canada. Fasting blood glucose and insulin concentrations were determined after an overnight fast. Past year physical activity levels were assessed using a modified version of an interviewer-administered questionnaire. Maximal oxygen uptake, a measure of cardiovascular fitness, was estimated using a submaximal step test. RESULTS Total (leisure and occupational) physical activity and physical fitness were significantly associated with fasting insulin concentrations after adjusting for age, BMI or percent body fat, waist circumference, and fasting glucose concentration in men but not in women. The relations between physical activity, fitness, and fasting glucose concentrations were not as strong or as consistent as they were when fasting insulin concentration was the dependent variable. CONCLUSIONS In this isolated Native Canadian community, both physical activity and fitness were independently associated with fasting insulin concentrations, suggesting a beneficial role of physical activity/fitness on insulin sensitivity that is separate from any influence of activity on body composition. The fact that this relation was found in men but not in women is most likely explained by issues related to the measurement of activity and fitness in this study and the fact that the women in this population appear to be less active than the men.
Ferroelectric and Multiferroic Tunnel Junctions

The phenomenon of electron tunneling has been known since the advent of quantum mechanics, but it continues to enrich our understanding of many fields of physics, as well as offering a route toward useful devices. A tunnel junction consists of two metal electrodes separated by a nanometer-thick insulating barrier layer, in which an electron is allowed to transverse a potential barrier exceeding the electron’s energy. The electron therefore has a finite probability of being found on the opposite side of the barrier. In the 1970’s, spin-dependent electron tunneling from ferromagnetic metal electrodes across an amorphous Al2O3 film was observed by Tedrow and Meservey(1)(2). Based on this discovery, Julliere proposed and demonstrated that in a magnetic tunnel junction tunnel current depends on the relativemagnetization orientation of the two ferromagnetic electrodes(3). Such a phenomenon nowadays is known as tunneling magnetoresistance(TMR)(4). Magnetic tunnel junctions may be very useful for various technological applications in spintronics devices such as magnetic field sensors and magnetic random access memories. Other insulators are also used for tunnel barriers. For example, epitaxial perovskite SrTiO3 barriers were studied by De Teresa et al. to demonstrate the importance of interfaces in spin-dependent tunneling(5). In tunnel junctions with MgO barriers, Ikeda et al. found large magnetoresitance as high as 604% at room temperature and 1144% at 5 K(6), which approaches the theoretical predictions of Butler et al.(7) and Mathon et al.(8). Despite the diversity of materials used as the barrier of the tunnel junctions, the common feature is that almost all the barriers are nonpolar dielectrics. On the other hand, magnetic insulators, i.e, EuO, EuS and EuSe, are used for tunnel barriers. Spin filtering has been observed in these junctions as were first discussed by Moodera et al.(9). in 1988. They observed that the tunneling current in Au/EuS/Al junction has a spin polarization with the magnitude as high as 80%. and attributed it to the electron tunneling across the spin-dependent barriers (Fig.1). Later, they reported that the tunneling current across Ag/EuSe/Al junctions has an enhanced spin-polarization reaching 97%(10). Recently, using EuO with a higher Curier temperature (69 K) than EuS (16.7 K) and EuSe (4.6 K), Santos et al. obtained 29% spin-polarized tunneling current(11). Naturally, if electrodes are not normal metals, but ferromagnetic materials, both TMR and spin filter effects can be observed(Fig.2)(12). Another important concept is the ferroelectric tunnel junction (FTJ)(13)(14)(15), which take advantage of a ferroelectric as the barrier material. Ferroelectrics possess a spontaneous 2
Dissolved organic carbon lability and stable isotope shifts during microbial decomposition in a tropical river system

Abstract. A significant amount of carbon is transported to the ocean as dissolved organic carbon (DOC) in rivers. During transport, it can be transformed through microbial consumption and photochemical oxidation. In dark incubation experiments with water from the Tana River, Kenya, we examined the consumption of DOC through microbial decomposition and the associated change in its carbon stable isotope composition (δ13C). In 15 of the 18 incubations, DOC concentrations decreased significantly by 10 to 60 %, with most of the decomposition taking place within the first 24–48 h. After 8 days, the remaining DOC was up to 3 ‰ more depleted in 13C compared with the initial pool, and the change in δ13C correlated strongly with the fraction of DOC remaining. We hypothesize that the shift in δ13C is consistent with greater microbial lability of DOC originating from herbaceous C4 vegetation than DOC derived from woody C3 vegetation in the semi-arid lower Tana. The results complement earlier findings that the stable isotope concentration of riverine DOC does not necessarily reflect the proportion of C3 and C4-derived DOC in the catchment: besides spatial distribution patterns of different vegetation types, processing within the river can further influence the δ13C of riverine OC.
Environmental Exposure Conditions for Teflon® Fluorinated Ethylene Propylene on the Hubble Space Telescope

The outer layer of Teflon® fluorinated ethylene propylene (FEP) multi-layer insulation (MLI) on the Hubble Space Telescope (HST) was observed to be significantly cracked at the time of the Second HST Servicing Mission (SM2), 6.8 years after HST was launched into low Earth orbit (LEO). Comparatively minor embrittlement and cracking were also observed in the FEP materials retrieved from solar-facing surfaces on the HST at the time of the First Servicing Mission (3.6 years exposure). After SM2, a failure review board was convened to address the problem of degradation of MLI on the HST. In order for this board to determine possible degradation mechanisms, it was necessary to consider all environmental constituents to which the FEP MLI surfaces were exposed. Based on measurements and various models, the environmental exposure conditions for the FEP surfaces on the HST were estimated, including: the number and temperature ranges of thermal cycles; equivalent sun hours; fluence and absorbed radiation dose of x-rays, trapped protons and electrons and plasma electrons and protons; and atomic oxygen (AO) fluence. This paper presents the environmental exposure conditions for FEP on the HST, briefly describing the possible roles of the environmental factors in the observed FEP embrittlement and providing references to the published works which describe in detail testing and analysis related to FEP degradation on the HST.
Bimodal Distribution and Co-Bursting in Review Spam Detection

Online reviews play a crucial role in helping consumers evaluate and compare products and services. This critical importance of reviews also incentivizes fraudsters (or spammers) to write fake or spam reviews to secretly promote or demote some target products and services. Existing approaches to detecting spam reviews and reviewers employed review contents, reviewer behaviors, star rating patterns, and reviewer-product networks for detection. In this research, we further discovered that reviewers' posting rates (number of reviews written in a period of time) also follow an interesting distribution pattern, which has not been reported before. That is, their posting rates are bimodal. Multiple spammers also tend to collectively and actively post reviews to the same set of products within a short time frame, which we call co-bursting. Furthermore, we found some other interesting patterns in individual reviewers' temporal dynamics and their co-bursting behaviors with other reviewers. Inspired by these findings, we first propose a two-mode Labeled Hidden Markov Model to model spamming using only individual reviewers' review posting times. We then extend it to the Coupled Hidden Markov Model to capture both reviewer posting behaviors and co-bursting signals. Our experiments show that the proposed model significantly outperforms state-of-the-art baselines in identifying individual spammers. Furthermore, we propose a co-bursting network based on co-bursting relations, which helps detect groups of spammers more effectively than existing approaches.
Ensembl 2009

The Ensembl project (http://www.ensembl.org) is a comprehensive genome information system featuring an integrated set of genome annotation, databases, and other information for chordate, selected model organism and disease vector genomes. As of release 51 (November 2008), Ensembl fully supports 45 species, and three additional species have preliminary support. New species in the past year include orangutan and six additional low coverage mammalian genomes. Major additions and improvements to Ensembl since our previous report include a major redesign of our website; generation of multiple genome alignments and ancestral sequences using the new Enredo-Pecan-Ortheus pipeline and development of our software infrastructure, particularly to support the Ensembl Genomes project (http://www.ensemblgenomes.org/).