Miracle-dz/UniFAR-FTUs huggingface dataset:
Comparison of phenology trends by land cover class : a case study in the Great Basin , USA

Direct impacts of human land use and indirect impacts of anthropogenic climate change may alter land cover and associated ecosystem function, affecting ecological goods and services. Considerable work has been done to identify long-term global trends in vegetation greenness, which is associated with primary productivity, using remote sensing. Trend analysis of satellite observations is subject to error, and ecosystem change can be confused with interannual variability. However, the relative trends of land cover classes may hold clues about differential ecosystem response to environmental forcing. Our aim was to identify phenological variability and 10-year trends for the major land cover classes in the Great Basin. This case study involved two steps: a regional, phenology-based land cover classification and an identification of phenological variability and 10-year trends stratified by land cover class. The analysis used a 10-year time series of Advanced Very High Resolution Radiometer satellite data to assess regional scale land cover variability and identify change. The phenology-based regional classification was more detailed and accurate than national or global products. Phenological variability over the 10-year period was high, with substantial shifts in timing of start of season of up to 9 weeks. The mean long-term trends of montane land cover classes were significantly different from valley land cover classes due to a poor response of montane shrubland and pinyon-juniper woodland to the early 1990s drought. The differential response during the 1990s suggests that valley ecosystems may be more resilient and montane ecosystems more susceptible to prolonged drought. This type of regional-scale land cover analysis is necessary to characterize current patterns of land cover phenology, distinguish between anthropogenically driven land cover change and interannual variability, and identify ecosystems potentially susceptible to regional and global change.
Implications of the WHO Child Growth Standards in rural Honduras

Abstract Objective The present study analysed the impact of using the 2006 WHO Child Growth Standards (‘the WHO standards’) compared with the 1977 National Center for Health Statistics (NCHS) international growth reference (‘the NCHS reference’) on the calculated prevalence of chronic malnutrition in children aged 6·0–59·9 months. Design Anthropometric data were collected as part of a cross-sectional study exploring the association between household environments and nutritional status of children. Z-scores were computed for height-for-age (HAZ), weight-for-age (WAZ) and weight-for-height (WHZ) using each reference/standard. Results were compared using Bland–Altman plots, percentage agreement, kappa statistics, line graphs and proportion of children in Z-score categories. Setting The study was conducted in thirteen rural villages within Honduras's department of Intibucá. Subjects Children aged 6·0–59·9 months were the focus of the analysis, and households with children in this age range served as the sampling unit for the study. Results The WHO standards yielded lower means for HAZ and higher means for WAZ and WHZ compared with the NCHS reference. The WHO standards and NCHS reference showed good agreement between Z-score categories, except for HAZ among males aged 24·0–35·9 months and WHZ among males aged >24·0 months. Using the WHO standards resulted in higher proportions of stunting (low HAZ) and overweight (high WHZ) and lower proportions of underweight (low WAZ). The degree of difference among these measures varied by age and gender. Conclusions The choice of growth reference/standard employed in nutritional surveys may have important methodological and policy implications. While ostensibly comparable, data on nutritional indicators derived with different growth references/standards must be interpreted cautiously.
Giant Solitary Anterior Cervical Canal Neurofibroma: Case Report and Surgical Technique

Giant solitary anterior cervical canal neurofibroma (GSACCN) is rarely reported in the literature. When the large lesion is ventrally located to the spinal cord, an anterolateral approach may not be ideal due to various technical challenges. In this report, we describe a case of intradural extramedullary GSACCN located at the cervical region extending from the axis to the sixth cervical vertebrae. Here we also describe a posterior technique successfully used to resect the tumour. Therefore, the posterior approach by En bloc decompressive laminectomy and laminoplasty might be used to adequately treat the lesion.
Amplitude variability or close frequencies in pulsating stars — the δ Scuti star FG Vir

The nature of the observed amplitude variability of several modes in the δ Scuti star FG Vir is examined. This is made possible by the extensive photometry obtained during 2002–04, as well as the long photometric time-base starting in 1992. In this star, three frequencies show strong amplitude and phase variations. In the power spectrum, these frequencies also show up as frequency doublets. However, since true amplitude variability of a single frequency can also lead to (false) frequency doublets in the power spectrum, a specific test examining in detail the observed amplitude and the phase variations of an assumed single frequency is applied. For the frequencies at 12.15 and 23.40 cycle d−1, it is shown that the amplitude variability of a single mode can be ruled out. In particular, an important property of beating between two modes is fulfilled: the amplitude and the phase vary synchronously with a phase shift close to 90°. The origin of the amplitude variability of a third mode, namely, near 19.86 cycle d−1, is not clear due to the long beat period of 20+ yr, for which the amplitude–phase test suffers from gaps in the coverage. However, even for this frequency, the amplitude variations can be expressed well by a mathematical two-mode model. If we examine these three close frequency pairs together with other (usually more widely separated) close frequencies in FG Vir, 18 pairs of frequencies with separations closer than 0.10 cycle d−1 have been detected. It is shown that the majority of the pairs occur near the theoretically expected frequencies of radial modes. Mode identifications are available for only a few modes: the only detected radial mode at 12.15 cycle d−1 is part of a close pair. It is shown that accidental agreements between the frequencies of excited modes can be ruled out because of the large number of detected close frequency doublets.
Modified Frame Reconstruction Algorithm for Compressive Sensing

Compressive sensing is a technique to sample signals well below the Nyquist rate using linear measurement operators. In this paper we present an algorithm for signal reconstruction given such a set of measurements. This algorithm generalises and extends previous iterative hard thresholding algorithms and we give sufficient conditions for successful reconstruction of the original data signal. In addition we show that by underestimating the sparsity of the data signal we can increase the success rate of the algorithm. We also present a number of modifications to this algorithm: the incorporation of a least squares step, polynomial acceleration and an adaptive method for choosing the step-length. These modified algorithms converge to the correct solution under similar conditions to the original un-modified algorithm. Empirical evidence show that these modifications dramatically increase both the success rate and the rate of convergence, and can outperform other algorithms previously used for signal reconstruction in compressive sensing.
Factor Models for Binary Financial Data

Researchers are often interested in modeling binary decisions made by firms (e.g., the yes or no decisions to split the shares, initiate a dividend, or acquire another firm) as functions of economy-wide variables (common factors). Although factor models for continuous dependent variables are used widely, the toolkit of a financial researcher does not contain a generally accepted methodology that allows estimating factor models for binary dependent variables. In this paper, we study such a methodology. Using simulations, we identify data characteristics that allow for reliable estimates of factor parameters and conclude that the methodology is appropriate for the panel datasets of the type often used in finance. As an illustration, we use the methodology to address a currently debated issue of common factors in firms’ decisions to split their shares.
Control For Neutral Systems Via Dynamic Output Feedback

This paper deals with the design problem for dynamic output feedback robust H∞ control problem for a class of uncertain linear neutral systems in delay dependent case. Sufficient conditions for the existence of H∞ controller is derived based on the delay dependent Bounded Real Lemma (BRL) in terms of linear matrix inequalities (LMIs) with inverse constraints which is obtained without resorting to any model transformations. A convex optimization algorithm is used to satisfy these constraints. A numerical example is given to illustrate the effectiveness of the proposed results.
Kinematic and Excitation Structure of the NGC 1068 Narrow-Line Region

We investigated the kinematic and excitation structure of the NGC 1068 narrow-line region (NLR). We obtained profiles of several emission lines, [OIII]$\lambda$5007, H$\beta$, [OI]$\lambda$6300 and [FeVII]$\lambda$6087 at high-velocity resolution (R ~ 7500 - 11000), and confirmed that they showed different profiles. These profiles are useful for understanding the NLR structure, as they cover a wide ionization potential range. By comparing the results with a photoionization model, we found that 1) blueshifted components at the center are very dense, 2) those in the northeast region have slightly lower densities than those in the center, and 3) ionization parameters of the blueshifted components increase with increasing velocity with respect to the systemic velocity. We investigated the NLR structure in NGC 1068 based on these results. We show that both the observed velocity dependence of the ionization parameter and the gradually increasing velocity field can be reproduced by varying the ionizing continuum attenuation, assuming a hollowed biconical geometry and varying the column densities of outflowing clouds.
Ballbot : A Low-Cost Robot for Tennis Ball Retrieval

This paper presents a robotic platform which is targeted to perform the task of a tennis ball boy. This platform is self-contained with on-board sensing and computation, uses only cost-effective off-the-shelf components, and was designed to perform robustly and repeatably in semistructured real-world environments. In particular, this paper presents a particle-filter implementation that allows the robot to localize itself and navigate on a tennis court. Along with navigation and tennis ball detection, this will enable it to pick up tennis balls on a real tennis court. This paper describes our system, presents our initial experimental results, and discusses some of the challenges faced.
Distributed size estimation in anonymous networks

The knowledge of the size of a network, i.e. of the number of nodes composing it, is important for maintenance and organization purposes. In networks where the identity of the nodes or is not unique or cannot be disclosed for privacy reasons, the size-estimation problem is particularly challenging since the exchanged messages cannot be uniquely associated with a specific node. In this work, we propose a totally distributed anonymous strategy based on statistical inference concepts. In our approach, each node starts generating a vector of independent random numbers from a known distribution. Then nodes compute a common function via some distributed consensus algorithms, and finally they compute the Maximum Likelihood (ML) estimate of the network size exploiting opportune statistical inferences. In this work we study the performance that can be obtained following this computational scheme when the consensus strategy is either the maximum or the average. In the max-consensus scenario, when data come from absolutely continuous distributions, we provide a complete characterization of the ML estimator. In particular, we show that the squared estimation error decreases as 1/M , where M is the amount of random numbers locally generated by each node, independently of the chosen probability distribution. Differently, in the average-consensus scenario, we show that if the locally generated data are independent Bernoulli trials, then the probability for the ML estimator to return a wrong answer decreases exponentially in M . Finally, we provide a discussion as how the numerical errors may affect the estimators performance under different scenarios. Index Terms Size estimation, sensor networks, distributed estimation, privacy-preservation, number of nodes, number of agents, anonymous networks, consensus.
XMM–Newton observations of high-luminosity radio-quiet quasi-stellar objects

XMM-Newton observations of five high-luminosity radio-quiet quasi-stellar objects (QSOs; Q 0144-3938, UM 269, PG 1634+706, SBS 0909+532 and PG 1247+267) are presented. Spectral energy distributions were calculated from the XMM-Newton European Photon Imaging Camera (EPIC) and Optical Monitor (OM) data, with bolometric luminosities estimated in the range from 7 x 10 45 to 2 × 10 48 erg s -1 for the sample, peaking in the ultraviolet. At least four of the QSOs show a similar soft excess, which can be well modelled by either one or two blackbody components, in addition to the hard X-ray power law. The temperatures of these blackbodies (∼100-500 eV) are too high to be direct thermal emission from the accretion disc, so Comptonization is suggested. Two populations of Comptonizing electrons, with different temperatures, are needed to model the broad-band spectrum. The hotter of these produces what is seen as the hard X-ray power law, while the cooler (∼0.25-0.5 keV) population models the spectral curvature at low energies. Only one of the QSOs shows evidence for an absorption component, while three of the five show neutral iron emission. Of these, PG 1247+267 seems to have a broad line (with an equivalent width of ∼250eV), with a strong, associated reflection component (R ∼ 2), measured out to 30 keV in the rest frame of the QSO. Finally, it is concluded that the X-ray continuum shape of active galactic nuclei remains essentially constant over a wide range of black hole mass and luminosity.
Inverse rendering in SUV space with a linear texture model

In this paper, we consider the problem of inverse rendering in the case where surface texture can be approximated by a linear basis. Assuming a dichromatic reflectance model, we show that spherical harmonic illumination coefficients and texture parameters can be estimated in a specular invariant colour subspace by solving a system of bilinear equations. We focus on the case of faces, where both shape and texture can be efficiently described by a linear statistical model. In this context, we are able to fit a 3D morphable model to a single colour image, accounting for both non-Lambertian specular reflectance and complex illumination of the same light source colour. We are able to recover statistical texture model parameters with an accuracy comparable to more computationally expensive analysis-by-synthesis approaches. Moreover, our approach requires only the solution of convex optimisation problems.
Impact of feedbacks on Chihuahuan desert grasslands: Transience and metastability

A simplistic model of grass‐shrub dynamics was used to investigate the role of grass demographic processes on grassland‐shrubland dynamics when grasses are in competitive advantage over shrubs. The model suggests that a feedback between grass biomass and soil erosion may cause an abrupt transition to a shrubland state. The model explains how a simple change in either grass recruitment or grass mortality, presumably linked to climate change or grazing, could produce changes in Holocene flora and the conversion of grasslands to shrublands, which has been observed throughout the southwestern U.S. in the past 150 years.
Option pricing with perturbation methods

This thesis discusses the use of perturbation theory in the context of financial mathematics, in particular on the use of matched asymptotic expansions in option pricing. Our methods are applied to the ordinary Black-Scholes model for illustration. In this simple example of the Black-Scholes model an exact solution is available, so it is in fact not neccessary to apply the method of asymptotic expansions on this model. However, in case we do apply the method, two artificial layers have to be constructed. Making smart choices for the local variables leads to a transformation of the equations into a heat equation, which can easily be solved. Finally, the results are compared to a Taylor expansion of the exact solution to see that this method is very accurate. After this first instructive model, the method of matched asymptotic expansions is applied to two more advanced models based on papers by Sam Howison and Patrick Hagan et al. Here, different choices for the scalings are made. The former discusses a fast mean-reverting stochastic volatility model that turns out to have many open ends. In Howison's paper quite a lot of assumptions and simplifications are made. Unfortunately, often the motivation for them is not explicitly given in the paper, and in some cases we even think these assumptions and simplifications are incorrect. The latter examines a new three-parameter stochastic volatility model that successfully prices back the volatility smile as observed in the market nowadays, and that is commonly used. The derivation of this model is the main focus of this thesis. The resulting expression for the implied volatility under the SABR model is obtained by considering the forward and backward Kol-mogorov equations per order in epsilon, making some smart choices for local variables and functions in order to transform them into an equation that looks like a heat equation, which is easier to solve. Recommendations for further investigation on these models would be to consider several different choices for the scalings and see which one works best.
Promoting Mindfulness in Psychotherapists in Training Influences the Treatment Results of Their Patients: A Randomized, Double-Blind, Controlled Study

Background: All therapists direct their attention in some manner during psychotherapy. A special form of directing attention, ‘mindfulness’, is recommended. This study aimed to examine whether, and to what extent, promoting mindfulness in psychotherapists in training (PiT) influences the treatment results of their patients. Methods: The therapeutic course and treatment results of 124 inpatients, who were treated for 9 weeks by 18 PiTs, were compared. The PiTs were randomly assigned to 1 of 2 groups: (i) those practicing Zen meditation (MED; n = 9 or (ii) control group, which did not perform meditation (noMED; n = 9). The results of treatment (according to the intent-to-treat principle) were examined using the Session Questionnaire for General and Differen-tial Individual Psychotherapy (STEP), the Questionnaire of Changes in Experience and Behavior (VEV) and the Symptom Checklist (SCL-90-R). Results: Compared to the noMED group (n = 61), the patients of PiTs from the MED group (n = 63) had significantly higher evaluations (according to the intent-to-treat principle) for individual therapy on 2 STEP scales, clarification and problem-solving perspectives. Their evaluations were also significantly higher for the entire therapeutic result on the VEV. Furthermore, the MED group showed greater symptom reduction than the noMED group on the Global Severity Index and 8 SCL-90-R scales, including Somatization, Insecurity in Social Contact, Obsessiveness, Anxiety, Anger/Hostility, Phobic Anxiety, Paranoid Thinking and Psychoticism. Conclusions: This study indicates that promoting mindfulness in PiTs could positively influence the therapeutic course and treatment results in their patients.
Numerical simulations of pinhole and single-mode fibre spatial filters for optical interferometers

ABSTRA C T We use a numerical simulation to investigate the effectiveness of pinhole spatial filters for optical/IR interferometers and to compare them with single-mode optical fibre spatial filters and interferometers without spatial filters. We show that fringe visibility measurements in interferometers containing spatial filters are much less affected by changing seeing conditions than equivalent measurements without spatial filters. This reduces visibility calibration uncertainties, and hence can reduce the need for frequent observations of separate astronomical sources for calibration of visibility measurements. We also show that spatial filters can increase the signal-to-noise ratios (SNRs) of visibility measurements and that pinhole filters give SNRs within 17 per cent of the values obtained with single-mode fibres for aperture diameters up to 3r0. Given the simplicity of the use of pinhole filters we suggest that it represents a competitive, if not optimal, technique for spatial filtering in many current and next generation interferometers.
Neurobiological Findings in Bipolar II Disorder Compared with Findings in Bipolar I Disorder

Objective: To determine there are consistent neurobiological differences between patients with bipolar I disorder (BD I) and those with bipolar II disorder (BD II). Method: We reviewed the literature in areas where the most consistent neurobiological findings have been reported for bipolar disorder, specifically, neuroimaging and brain metabolism. The imaging studies reviewed, examined structure, using magnetic resonance imaging (MRI), and function, using functional MRI, positron emission tomography, and single photon emission computed tomography. We used magnetic resonance spectroscopy to examine brain chemistry. We reviewed those metabolic studies that examined cell calcium, 3-methoxy-4-hydroxyphenylglycol, and protein kinase C. Results: Some genetic studies suggest that there may be differences between BD II and BD I patients. However, our review of the imaging and metabolic studies identified few studies directly comparing these 2 groups. In those studies, there were few differences, if any, and these were not consistent. Conclusions: While genetic data suggest there may be differences between BD II patients and BD I patients, the neurobiological findings to date do not provide support. However, this may be owing to the small number of studies directly comparing the 2 groups and also to the fact that those carried out have not been adequately powered to detect possible small true differences. This is an important issue because, if there are no neurobiological differences, it would be anticipated that similar treatments would be similarly effective in both groups. Given the importance of understanding whether there are neurochemical differences between these groups, further research in this area is clearly needed.