Miracle-dz/UniFAR-FTUs huggingface dataset:
An exploration of social identity: The geography and politics of news-sharing communities in twitter

The importance of collective social action in current events is manifest in the Arab Spring and Occupy movements. Electronic social media have become a pervasive channel for social interactions, and a basis of collective social response to information. The study of social media can reveal how individual actions combine to become the collective dynamics of society. Characterizing the groups that form spontaneously may reveal both how individuals self-identify and how they will act together. Here we map the social, political, and geographical properties of news-sharing communities on Twitter, a popular micro-blogging platform. We track user-generated messages that contain links to New York Times online articles and we label users according to the topic of the links they share, their geographic location, and their self-descriptive keywords. When users are clustered based on who follows whom in Twitter, we find social groups separate by whether they are interested in local (NY), national (US) or global (cosmopolitan) issues. The national group subdivides into liberal, conservative and other, the latter being a diverse but mostly business oriented group with sports, arts and other splinters. The national political groups are based across the US but are distinct from the national group that is broadly interested in a variety of topics. A person who is cosmopolitan associates with others who are cosmopolitan, and a US liberal / conservative associates with others who are US liberal / conservative, creating separated social groups with those identities. The existence of "citizens" of local, national and cosmopolitan communities is a basis for dialog and action at each of these levels of societal organization.
Quality Control Methods in Accelerometer Data Processing: Defining Minimum Wear Time

Background When using accelerometers to measure physical activity, researchers need to determine whether subjects have worn their device for a sufficient period to be included in analyses. We propose a minimum wear criterion using population-based accelerometer data, and explore the influence of gender and the purposeful inclusion of children with weekend data on reliability. Methods Accelerometer data obtained during the age seven sweep of the UK Millennium Cohort Study were analysed. Children were asked to wear an ActiGraph GT1M accelerometer for seven days. Reliability coefficients(r) of mean daily counts/minute were calculated using the Spearman-Brown formula based on the intraclass correlation coefficient. An r of 1.0 indicates that all the variation is between- rather than within-children and that measurement is 100% reliable. An r of 0.8 is often regarded as acceptable reliability. Analyses were repeated on data from children who met different minimum daily wear times (one to 10 hours) and wear days (one to seven days). Analyses were conducted for all children, separately for boys and girls, and separately for children with and without weekend data. Results At least one hour of wear time data was obtained from 7,704 singletons. Reliability increased as the minimum number of days and the daily wear time increased. A high reliability (r = 0.86) and sample size (n = 6,528) was achieved when children with ≥ two days lasting ≥10 hours/day were included in analyses. Reliability coefficients were similar for both genders. Purposeful sampling of children with weekend data resulted in comparable reliabilities to those calculated independent of weekend wear. Conclusion Quality control procedures should be undertaken before analysing accelerometer data in large-scale studies. Using data from children with ≥ two days lasting ≥10 hours/day should provide reliable estimates of physical activity. It’s unnecessary to include only children with accelerometer data collected during weekends in analyses.
Physical-Layer Security in Distributed Wireless Networks Using Matching Theory

We consider the use of physical-layer security in a wireless communication system where multiple jamming nodes assist multiple source-destination nodes in combating unwanted eavesdropping from a single eavesdropper. In particular, we propose a distributed algorithm that matches each source-destination pair with a particular jammer. Our algorithm caters for three channel state information (CSI) assumptions: global CSI, local CSI, and local CSI without the eavesdropper channel. We prove that our algorithm has many desirable properties. First, the outcome of the proposed algorithm results in a stable matching, which is important if the source and jamming nodes are selfish. Second, the secrecy rate of the proposed algorithm converges to the secrecy rate of a centralized optimal solution, if the price step-number is sufficiently small. Third, our algorithm converges only after a small number of iterations, and its overhead is relatively small. Fourth, our algorithm has a significantly lower complexity than a centralized optimal approach.
Patent Holdup and Royalty Stacking

We study several interconnected problems that arise under the current U.S. patent system when a patent covers one component or feature of a complex product. This situation is common in the information technology sector of the economy. Our analysis applies to cases involving reasonable royalties, but not lost profits. First, we show using bargaining theory that the threat to obtain a permanent injunction greatly enhances the patent holder’s negotiating power, leading to royalty rates that exceed a natural benchmark range based on the value of the patented technology and the strength of the patent. Such royalty overcharges are especially great for weak patents covering a minor feature of a product with a sizeable price/cost margin, including products sold by firms that themselves have made substantial R&D investments. These royalty overcharges do not disappear even if the allegedly infringing firm is fully aware of the patent when it initially designs its product. However, the hold-up problems caused by the threat of injunctions are reduced if courts regularly grant stays to permanent injunctions to give defendants time to redesign their products to avoid infringement when this is possible. Second, we show how hold-up problems are magnified in the presence of royalty stacking, i.e., when multiple patents read on a single product. Third, using third-generation cellular telephones and Wi-Fi as leading examples, we illustrate that royalty stacking can become a very serious problem, especially in the standard-setting context where hundreds or even thousands of patents can read on a single product standard. Fourth, we discuss the use of “reasonable royalties” to award damages in patent infringement cases. We report empirical results regarding the measurement of “reasonable royalties” by the courts and identify various practical problems that tend to lead courts to over-estimate “reasonable royalties” in the presence of royalty stacking. Finally, we make suggestions for patent reform based on our theoretical and empirical findings.
Towards self-calibrating inertial body motion capture

This paper presents a novel online capable method for simultaneous estimation of human motion in terms of segment orientations and positions along with sensor-to-segment calibration parameters from inertial sensors attached to the body. In order to solve this ill-posed estimation problem, state-of-the-art motion, measurement and biomechanical models are combined with new stochastic equations and priors. These are based on the kinematics of multi-body systems, anatomical and body shape information, as well as, parameter properties for regularisation. This leads to a constrained weighted least squares problem that is solved in a sliding window fashion. Magnetometer information is currently only used for initialisation, while the estimation itself works without magnetometers. The method was tested on simulated, as well as, on real data, captured from a lower body configuration.
Homogeneous Contracts for Heterogeneous Agents: Aligning Sales Force Composition and Compensation

Observed contracts in the real world are often very simple, which partly reflects the constraints faced by contracting firms in making the contracts more complex. In this article, the authors focus on one such rigidity: the constraints faced by firms in fine-tuning contracts to the full distribution of heterogeneity of their employees. The authors explore the implication of these constraints for the provision of incentives within the firm. The study's application is to sales force compensation, wherein a firm maintains a sales force to market its products. Consistent with ubiquitous real-world business practice, the study assumes that a firm is restricted to fully or partially set uniform commissions across its agent pool. The authors show that this restriction implies an interaction between the composition of agent types in the contract and the compensation policy used to motivate them, leading to a “contractual externality” in the firm and generating gains to sorting. This article explains how this contractual externality arises; discusses a practical approach to endogenizing agents and incentives at a firm in its presence; and presents an empirical application to sales force compensation contracts at a U.S. Fortune 500 company that explores these considerations and assesses the gains from a sales force architecture that sorts agents into divisions to balance firmwide incentives. Empirically, the authors find that the restriction to homogeneous plans significantly reduces a firm's payoff, relative to a fully heterogeneous plan, when the firm is unable to optimize the composition of its agents. However, a firm's payoff under a homogeneous plan comes very close to that under a fully heterogeneous plan when the firm can optimize both composition and compensation. Thus, in the empirical setting of this study, the ability to choose agents mitigates the loss in incentives from the restriction to uniform contracts. The authors conjecture this result may hold more broadly.
The internal cranial morphology of an armoured dinosaur Euoplocephalus corroborated by X‐ray computed tomographic reconstruction

Internal cranial anatomy is a challenging area to study in fossilized skulls because of small sample sizes and varied post‐mortem preservational alterations. This difficulty has led to the lack of correspondence between results obtained from direct osteological observation and from more indirect reconstruction methods. This paper presents corroborating evidence from direct osteological observation and from reconstruction based on computed X‐ray tomography (CT) on the internal cranial anatomy of the ankylosaurid dinosaur Euoplocephalus tutus. A remarkable specimen of Euoplocephalus preserves rarely observed internal cranial structures such as vascular impressions in the nasal cavity, olfactory turbinates and possible impressions of conchae. Comparison with fossils and CT models of other taxa and other Euoplocephalus specimens adds osteological evidence for the previously reconstructed nasal cavity in this dinosaur and revises the previously described braincase morphology. A new interpretation of the ethmoidal homology identifies a mesethmoid, sphenethmoid and ectethmoid. These ethmoidal ossifications are continuous with the mineralized walls of the nasal cavity. The location of the olfactory fenestra provides further evidence that the olfactory regions of the nasal cavity are pushed to the sides of the main airway. This implies that the function of the vascular impressions in the nasal cavity and the looping of the cavity are not related to olfaction. A byproduct of the elongate, looping airway is a dramatic increase in surface area of the nasal respiratory mucosa, which in extant species has been linked to heat and water balance. A role in vocalization as a resonating chamber is another possible function of the looping and elongation of the nasal cavity. Olfaction remains as a possible function for the enlarged olfactory region, suggesting that multiple functions account for different parts of the ankylosaurid nasal cavity that underwent substantial modification. Cranial endocasts show negligible variation within Euoplocephalus, which lends some confidence to interspecific comparisons of endocranial morphology.
Modeling the spontaneous reactivation of experience‐specific hippocampal cell assembles during sleep

During slow‐wave sleep (SWS) following periods of spatial activity, hippocampal place cells that were temporally correlated, by virtue of the overlap of their place fields, exhibit enhanced temporal correlations, even though the animal sleeps in a different location (Wilson and McNaughton [1994] Science 267:676–679). The discharge of cells with overlapped place fields is more correlated in subsequent sleep, particularly during sharp waves, than in sleep episodes prior to the behavior, or than cell pairs with non‐overlapped place fields. The reactivated correlated states appear during hippocampal sharp waves (SPWs), and are weak or absent in the inter‐SPW interval. A simple conceptual hypothesis for this phenomenon is developed, based on the idea that hippocampal place fields reflect a two‐dimensional distribution of continuously overlapping dynamic attractors in which each location is represented by the self‐sustaining activity of a small subset of neurons with overlapping place fields. A numerical simulation of this hypothesis, based on a simplified representation of the CA3 recurrent network, accounts qualitatively for the main observations, including SPW‐like dynamics. It is shown that, under conditions in which the connection patterns have been previously established, either associative or nonassociative mechanisms might underlie the reactivation of recently experienced states. These two alternatives appear, under at least some conditions (e.g., sparse coding), to be indistinguishable. © 1997 Wiley‐Liss, Inc.
Soluble RANKL and risk of nontraumatic fracture.

CONTEXT The receptor activator of nuclear factor kappaB ligand (RANKL) is essential for osteoclast and, possibly, osteoblast activation and may represent a key link between bone formation and resorption. OBJECTIVE To determine the relationship between serum level of RANKL and the risk of nontraumatic fracture. DESIGN, SETTING, AND PARTICIPANTS As part of a prospective population-based study conducted in Bruneck, Italy, we recorded all fractures that occurred between 1990 and 2000 in 906 participants and classified them as traumatic (n = 115) or nontraumatic (n = 31). Serum levels of RANKL and osteoprotegerin and characteristics of bone metabolism and lifestyle were assessed in 1990 and at follow-up in 1995 and 2000. MAIN OUTCOME MEASURE Incident nontraumatic fracture by levels of RANKL. RESULTS Levels of RANKL did not differ between sexes and were not related to age, menopausal status, lifestyle characteristics, or data from bone ultrasound at the heel. However, RANKL emerged as a significant predictor of nontraumatic fracture. In pooled logistic regression analysis, the relative risks of nontraumatic fracture in the lowest and middle vs highest tertile for RANKL were 10.0 (95% confidence interval [CI], 2.3-43.1) and 3.9 (95% CI, 0.8-19.0) (P<.001 for trend), respectively. Patients in the highest-tertile group had a low risk of fracture even in the presence of other predisposing factors, whereas women aged 60 years or older in the lowest tertile had a 5-year rate of nontraumatic fracture greater than 7%. CONCLUSIONS A low level of RANKL is an independent predictor of nontraumatic fracture. This finding is consistent with the hypothesis of an important role of RANKL in human bone turnover and if confirmed in future investigations may gain relevance for assessment of fracture risk.
A First-Order Axiomatization of the Surprise Birthday Present Problem ( Preliminary Report ) : Abbreviated Version

This paper presents a solution in a first-order monotonic logic to a simplified version of the Surprise Birthday Present Problem, a challenge problem for the formal commonsense reasoning community. The problem concerns two siblings who wish to surprise their sister with a present for her birthday: the aim is to construct a theory that will support the desired inferences, not allow undesired inferences, and be sufficiently elaboration tolerant to support reasoning about problem variations. The theory presented in this paper includes the development of a possible-worlds analysis of the concept of surprise, and an extension to previous work on multiple-agent planning to handle joint planning and actions. We show that this theory can solve the original SBP as well as many of its variants.
Effectiveness of counselling patients on physical activity in general practice: cluster randomised controlled trial

Abstract Objective: To assess the long term effectiveness of the “green prescription” programme, a clinician based initiative in general practice that provides counselling on physical activity. Design: Cluster randomised controlled trial. Practices were randomised before systematic screening and recruitment of patients. Setting: 42 rural and urban general practices in one region of New Zealand. Subjects: All sedentary 40–79 year old patients visiting their general practitioner during the study's recruitment period. Intervention: General practitioners were prompted by the patient to give oral and written advice on physical activity during usual consultations. Exercise specialists continued support by telephone and post. Control patients received usual care. Main outcome measures: Change in physical activity, quality of life (as measured by the “short form 36” (SF-36) questionnaire), cardiovascular risk (Framingham and D'Agostino equations), and blood pressure over a 12 month period. Results: 74% (117/159) of general practitioners and 66% (878/1322) of screened eligible patients participated in the study. The follow up rate was 85% (750/878). Mean total energy expenditure increased by 9.4 kcal/kg/week (P=0.001) and leisure exercise by 2.7 kcal/kg/week (P=0.02) or 34 minutes/week more in the intervention group than in the control group (P=0.04). The proportion of the intervention group undertaking 2.5 hours/week of leisure exercise increased by 9.72% (P=0.003) more than in the control group (number needed to treat=10.3). SF-36 measures of self rated “general health,” “role physical,” “vitality,” and “bodily pain” improved significantly more in the intervention group (P<0.05). A trend towards decreasing blood pressure became apparent but no significant difference in four year risk of coronary heart disease. Conclusion: Counselling patients in general practice on exercise is effective in increasing physical activity and improving quality of life over 12 months. What is already known on this topic Counselling patients in general practice on exercise has resulted in gains in physical fitness and activity, but no health benefits have been found What this study adds Counselling patients in general practice on exercise is effective in increasing physical activity and improving quality of life over 12 months without evidence of adverse effects The intervention may reduce blood pressure by an average of 1–2 mm Hg over 12 months No changes in the risk of coronary heart disease were observed The intervention is sustainable in usual general practice Prompting practice staff to deliver the intervention may have increased its effectiveness
Gravitational Waves from Supermassive Black Hole Coalescence in a Hierarchical Galaxy Formation Model

We investigate the expected gravitational wave emission from coalescing supermassive black hole (SMBH) binaries resulting from mergers of their host galaxies. When galaxies merge, the SMBHs in the host galaxies sink to the center of the new merged galaxy and form a binary system. We employ a semianalytic model of galaxy and quasar formation based on the hierarchical clustering scenario to estimate the amplitude of the expected stochastic gravitational wave background due to inspiraling SMBH binaries and bursts due to the SMBH binary coalescence events. We find that the characteristic strain amplitude of the background radiation is hc(f) ~ 10-16(f/1 μHz)-2/3 for f ≲ 1 μHz just below the detection limit from measurements of the pulsar timing provided that SMBHs coalesce simultaneously when host galaxies merge. The main contribution to the total strain amplitude of the background radiation comes from SMBH coalescence events at 0 < z < 1. We also find that a future space-based gravitational wave interferometer such as the planned Laser Interferometer Space Antenna might detect intense gravitational wave bursts associated with coalescence of SMBH binaries with total mass Mtot < 107 M☉ at z ≳ 2 at a rate ~1.0 yr-1. Our model predicts that burst signals with a larger amplitude hburst ~ 10-15 correspond to coalescence events of massive SMBH binary with total mass Mtot ~ 108 M☉ at low redshift (z ≲ 1) at a rate ~0.1 yr-1, whereas those with a smaller amplitude (hburst ~ 10-17) correspond to coalescence events of less massive SMBH binaries with total mass Mtot ~ 106 M☉ at high redshift (z ≳ 3).
Low level of low-density lipoprotein cholesterol increases hemorrhagic transformation in large artery atherothrombosis but not in cardioembolism.

BACKGROUND AND PURPOSE Low cholesterol level is known to be associated with increased cerebral hemorrhage. However, the associations of hemorrhagic transformation (HTf) after acute ischemic stroke and the low levels of total cholesterol (TC) or low-density lipoprotein cholesterol (LDLC) are largely undiscovered. METHODS Of the 1034 patients with acute ischemic stroke who were consecutively admitted to our hospital, 377 patients with stroke attributable to large artery atherothrombosis (LAA; n=210) or cardioembolism (n=167) were selected for this study. Demographic and clinical information was collected and HTf was evaluated through follow-up T2*-weighted gradient-echo MRI performed usually within 1 week after stroke. Measurement of lipid parameters included TC, LDLC, high-density lipoprotein cholesterol, and triglyceride. RESULTS Of the 377 patients, HTf was noted in 74 patients (19.6%). When patients were divided into 4 groups according to their TC and LDLC levels, the incidence of HTf was significantly elevated in the lowest quartile of each TC (P<0.01) and LDLC (P<0.01) level in LAA subgroup, but not in cardioembolism. After adjusting covariates, a low level of LDLC (OR, 0.46 per 1 mmol/L-increase; 95% CI, 0.22-0.98) was independently associated with HTf in LAA, but not in cardioembolism. There was no significant association between low levels of TC (OR, 0.63 per 1 mmol/L-increase; 95% CI, 0.35-1.15) and HTf in LAA. CONCLUSIONS Low levels of LDLC, and possibly TC, are associated with greater risk of hemorrhagic transformation after acute ischemic stroke attributable to LAA.
Pitch-verticality and pitch-size cross-modal interactions

Two studies were conducted on cross-modal matching between pitch and sound source localization on the vertical axis, and pitch and size. In the first study 100 Hz, 200 Hz, 600 Hz, and 800 Hz tones were emitted by a loudspeaker positioned 60 cm above or below to the participant’s ear level. Using a speeded classification task, 30 participants had to indicate the sound source in 160 trials. Both reaction times and errors were analyzed. The results showed that in the congruent condition of high-pitched tones emitted from the upper loudspeaker, reaction times were significantly faster and the number of errors was significantly lower. Pitch was mapped on the vertical axis for sound localization. A main effect for sound source direction was also found. Tones coming from the upper loudspeaker were recognized faster and more accurately. Males were faster than females in identifying sound source direction. In the second experiment, 20 participants had to match 21 tones varying in pitch with 9 circles differing in visual angle on 42 trials. The results showed a clear inverse linear association between log-spaced tone pitch and circle diameter.