Miracle-dz/UniFAR-FTUs huggingface dataset:
A penny for your thoughts! patterns of fMRI activity reveal the content and the spatial topography of visual mental images

Visual mental imagery is a complex process that may be influenced by the content of mental images. Neuropsychological evidence from patients with hemineglect suggests that in the imagery domain environments and objects may be represented separately and may be selectively affected by brain lesions. In the present study, we used functional magnetic resonance imaging (fMRI) to assess the possibility of neural segregation among mental images depicting parts of an object, of an environment (imagined from a first‐person perspective), and of a geographical map, using both a mass univariate and a multivariate approach. Data show that different brain areas are involved in different types of mental images. Imagining an environment relies mainly on regions known to be involved in navigational skills, such as the retrosplenial complex and parahippocampal gyrus, whereas imagining a geographical map mainly requires activation of the left angular gyrus, known to be involved in the representation of categorical relations. Imagining a familiar object mainly requires activation of parietal areas involved in visual space analysis in both the imagery and the perceptual domain. We also found that the pattern of activity in most of these areas specifically codes for the spatial arrangement of the parts of the mental image. Our results clearly demonstrate a functional neural segregation for different contents of mental images and suggest that visuospatial information is coded by different patterns of activity in brain areas involved in visual mental imagery. Hum Brain Mapp 36:945–958, 2015. © 2014 Wiley Periodicals, Inc.
Robust Equilibria in Additively Coupled Games in Communications Networks

We obtain the robust Nash equilibrium (RNE) for a wide range of multi-user communications networks under uncertainty by utilizing the robust optimization theory for the worst-case uncertainties. To do so, we consider the uncertainty as a distance between the estimated and the actual values of the system parameters as a general norm function, and utilize the finite-dimensions variational inequalities (VI) to derive the conditions for existence and uniqueness of RNE. Two effects of uncertainty on the performance of the system are investigated: the difference between the achieved social utility at the RNE and the Nash equilibrium (NE) of the nominal game, and the distance between the deployed strategies of users at the RNE and at the NE. We quantify these two effects for the cases of unique NE and multiple NEs, and show that when the NE is unique, the achieved social utility at the RNE is always less than that of the NE. Interestingly, the worst-case robustness approach may lead to a higher social utility at the RNE in the multiple NEs scenario. Considering uncertainty at RNE introduces coupling between users, and hence, developing distributed algorithms for reaching RNE is more challenging as compared to the NE in the nominal game. However, for some special forms of utilities and norm functions, we propose simultaneous and sequential distributed algorithms; and investigate the performance of the robust game for power control in interference channels, and for flow control in Jackson networks.
Near-field/far-field azimuth and elevation angle estimation using a single vector hydrophone

This paper introduces a new underwater acoustic eigenstructure ESPRIT-based algorithm that yields closed-form direction-of-arrival (DOA) estimates using a single vector hydrophone. A vector hydrophone is composed of two or three spatially co-located but orthogonally oriented velocity hydrophones plus another optional co-located pressure hydrophone. This direction finding algorithm may (under most circumstances) resolve up to four uncorrelated monochromatic sources impinging from the near-field or the far-field, but it assumes that all signal frequencies are distinct. It requires no a priori knowledge of the signals' frequencies, suffers no frequency-DOA ambiguity, and pairs automatically the x-axis direction cosines with the y-axis direction cosines. It significantly outperforms an array of spatially displaced pressure hydrophones of comparable array-manifold size and computational load but may involve more complex hardware. This work also derives new Cramer-Rao bounds (CRBs) for various vector hydrophone constructions of arrival angle estimates for the incident uncorrelated sinusoidal signals corrupted by spatio-temporally correlated additive noise.
Class of cyclic-based estimators for frequency-offset estimation of OFDM systems

We present a new class of blind cyclic-based estimators for carrier frequency-offset and symbol-timing error estimation of orthogonal frequency-division multiplexing (OFDM) systems. The proposed approach exploits the properties of the cyclic prefix subset to reveal the synchronization parameters in the likelihood function of the received vector. A new likelihood function for the joint timing and frequency-offset estimation is derived, which globally characterizes the estimation problem. The resulting probabilistic measure is used to develop three classes of unbiased estimators, namely, maximum-likelihood, minimum variance unbiased, and moment estimator. In comparison to the previously proposed methods, the proposed estimators in this study are computationally and statistically efficient, which makes the estimators more attractive for real-time applications. The performance of the estimators is assessed by simulation for an OFDM system.
Structuring a gene network using a multiresolution independence test

In order to structure a gene network, a score-based approach is often used. A score-based approach, however, is problematic because by assuming a probability distribution, one is prevented from finding other dependent relationships with other genes. In this research, we structured a gene network from observed gene expression data using a multiresolution independence test and a conditional independence test, which is the non-parametric method proposed by Margaritis for learning the structure of Bayesian networks without making any probability distribution assumptions. The experimental results achieved an improvement in sensitivity of 0.05, and an improvement in specificity of 0.01.
Power, Social Influence, and Sense Making: Effects of Network Centrality and Proximity on Employee Perceptions.

Funding for this study was generously supplied by the Organizational Behavior Department of Yale University and the Harvard Business School Division of Research. Earlier versions of this paper were presented at the Sunbelt International Social Network Conference, San Diego, 1990 and the Academy of Management Annual Meetings, Miami, 1991. The authors are grateful to Paul DiMaggio, David Krackhardt, Peter Marsden, and Ron Rice for helpful suggestions. We also profited greatly from comments provided by Marshall Meyer and this journal's reviewers. This paper explores the hypothesis that network interaction patterns affect employee perceptions through two conceptually and empirically distinguishable mechanisms: localized social influence based on network proximity and systemic power based on network centrality. The study explores the relative contributions of individual attributes, formal organizational positions, network centrality, and network proximity in explaining individual variation in perceptions of work-related conditions in an advertising firm. Results suggest that network factors shape job-related perceptions, over and above the effects of individual attributes and formal positions. Both advice network centrality and friendship network proximity evidenced significant effects, although they were stronger for centrality than for proximity. '
Efficient schemes for reducing imperfect collective decoherences

We propose schemes that are efficient when each pair of qubits undergoes some imperfect collective decoherence with different baths. In the proposed scheme, each pair of qubits is first encoded in a decoherence-free subspace composed of two qubits. Leakage out of the encoding space generated by the imperfection is reduced by the quantum Zeno effect. Phase errors in the encoded bits generated by the imperfection are reduced by concatenation of the decoherence-free subspace with either a three-qubit quantum error correcting code that corrects only phase errors or a two-qubit quantum error detecting code that detects only phase errors, connected with the quantum Zeno effect again.
Perceived Acute Human Resource Management Problems in Small and Medium Firms: An Empirical Examination

The main objective of this study was to introduce and empirically test a novel and useful framework from which to study human resource management (HRM) problems in small– and medium–sized enterprises (SMEs). Specifically, the “perceived acute HRM problems framework” introduced in this study was an attempt to advance the literature by moving beyond simply studying when HRM problems may exist in SMEs, to instead studying when SME owners and managers perceive that HRM problems are the firm's most significant concern. Recent literature suggests that SME owners and managers do not conceptualize specific HRM problems on a spectrum. Rather, they are more likely to perceive only “people problems” in the aggregate and then only when severe. Thus, the acute problems framework may be a more appropriate angle from which to study HRM problems in SMEs. We employ binary logistic regression on a sample of 1,693 SMEs to analyze the effect of owner/manager characteristics and firm characteristics on the likelihood of perceiving acute HRM problems. Our results indicate that SME owners and managers who were running higher–performing firms were less likely to perceive acute HRM problems. Conversely, SME owners and managers who were more experienced, who were more educated, and who were running larger SMEs were more likely to perceive acute HRM problems. Finally, gender, owner age, firm age, and firm growth showed no significant relationship with likelihood of SME owners and managers perceiving acute HRM problems.
The Floral Regulator LEAFY Evolves by Substitutions in the DNA Binding Domain

The plant-specific transcription factor LEAFY controls general aspects of the life cycle in a basal plant, the moss Physcomitrella patens. In contrast, LEAFY has more specialized functions in angiosperms, where it specifically induces floral fate during the reproductive phase. This raises the question of a concomitant change in the biochemical function of LEAFY during the evolution of land plants. We report that the DNA binding domain of LEAFY, although largely conserved, has diverged in activity. On the contrary, other, more rapidly evolving portions of the protein have few effects on LEAFY activity.
Disparate substrates for head gaze following and face perception in the monkey superior temporal sulcus

Primates use gaze cues to follow peer gaze to an object of joint attention. Gaze following of monkeys is largely determined by head or face orientation. We used fMRI in rhesus monkeys to identify brain regions underlying head gaze following and to assess their relationship to the ‘face patch’ system, the latter being the likely source of information on face orientation. We trained monkeys to locate targets by either following head gaze or using a learned association of face identity with the same targets. Head gaze following activated a distinct region in the posterior STS, close to-albeit not overlapping with-the medial face patch delineated by passive viewing of faces. This ‘gaze following patch’ may be the substrate of the geometrical calculations needed to translate information on head orientation from the face patches into precise shifts of attention, taking the spatial relationship of the two interacting agents into account. DOI: http://dx.doi. org/10.7554/eLife.03222. 001
A Stochastic Formulation of the Dynamic Assignment Problem, with an Application to Truckload Motor Carriers

The dynamic assignment problem arises in a number of application areas in transportation and logistics. Taxi drivers have to be assigned to pick up passengers, police have to be assigned to emergencies, and truck drivers have to pick up and carry loads of freight. All of these problems are characterized by demands that arrive continuously and randomly throughout the day, and require a dispatcher to assign a driver to handle a specific demand. We use as our motivating application the load matching problem that arises in long-haul truckload trucking, where we have to assign drivers to loads on a real-time basis. A hybrid model is presented that handles the detailed assignment of drivers to loads, as well as handling forecasts of future loads. Numerical experiments demonstrate that our stochastic, dynamic model outperforms standard myopic models that are widely used in practice.
Doxorubicin-loaded redox-responsive micelles based on dextran and indomethacin for resistant breast cancer

Multidrug resistance (MDR) against chemotherapeutic agents has become one of the major obstacles to successful cancer therapy and MDR-associated proteins (MRPs)-mediated drug efflux is the key factor for MDR. In this study, a redox-responsive polymer based on dextran (DEX) and indomethacin (IND), which could reduce MRPs-mediated efflux of chemotherapeutics, was synthesized, and the obtained polymer could spontaneously form stable micelles with well-defined core-shell structure and a uniform size distribution with an average diameter of 50 nm and effectively encapsulate doxorubicin (DOX); the micelles contain a disulfide bridge (cystamine, SS) between IND and DEX (DEX-SS-IND). In vitro drug release results indicated that DEX-SS-IND/DOX micelles could maintain good stability in a stimulated normal physiological environment and promptly depolymerized and released DOX in a reducing environment. After incubating DEX-SS-IND/DOX micelles with drug-resistant tumor (MCF-7/ADR) cells, the intracellular accumulation and retention of DOX were significantly increased under the synergistic effects of redox-responsive delivery and the inhibitory effect of IND on MRPs. In vitro cytotoxicity showed that DEX-SS-IND/DOX micelles exhibited higher cytotoxicity against MCF-7/ADR cells. Moreover, DEX-SS-IND/DOX micelles showed significantly enhanced inhibition of tumor in BALB/c nude mice bearing MCF-7/ADR tumors and reduced systemic toxicity. Overall, the cumulative evidence indicates that DEX-SS-IND/DOX micelles hold significant promise for overcoming MDR for cancer therapy.
Framing skilful performance to enact organizational knowledge: (a proposal for the integration of data-driven and user-driven approaches to cognitive computing)

Whereas we know a great deal about what characterizes organizational knowledge and what forms it can -- or even should -- take, we know significantly less about how that knowledge is -- and should be -- enacted or built up in skilful performance in and by organizations. This research is based on the extension of classical approaches to formal semantics especially into situation semantics in the LIR (Language -- Information -- Reality) model-theoretic systemic framework of analysis. The purpose of this research is to methodologically identify and describe the enactment of knowledge in skilful performance in and by organizations to support the integration both of data-driven and user-driven approaches to cognitive computing.
Walking pattern design and feedback control for humanoid robot

This paper proposes a smooth cooperated walking pattern design and feedback control based on tilt senor for biped humanoid robot. In this research, the smoothness and stability problem is the key work of the motion planning. We make the robot walk stably and naturally like a human using static Zero Moment Point (ZMP) theory and the inclination feedback control. Its basic idea is as follows: firstly, through the geometry and static ZMP analysis, we get separate smooth rotation trajectories of all joints of robot. Then a smooth cooperation action of all joints of robot will be calculated by interpolate breakpoints which are selected in each rotation trajectory. Lastly, using tilt feedback control, we can get a smooth and stable walking of humanoid robot. To make robot walk corporately, we use three methods of interpolation to get all trajectories of 18 joints. The design of walking contains single-support phase planning and double-support phase planning. The effectiveness of our proposed method was confirmed by Matlab simulation and walk experiments of an actual 18 DOF humanoid robot.
Recent trends and important developments in propolis research

The newest developments in propolis pharmacological research are summarized. The problem regarding biological studies, caused by the chemical variability of propolis, is discussed. The most important trends and developments in recent propolis research are outlined: biological studies performed with chemically characterized samples, bioassay-guided studies of active principles and comparative biological studies of propolis of different origin and chemical composition. These types of studies are extremely valuable with respect to propolis standardization and practical applications in therapy. They will allow scientists to connect a particular chemical propolis type to a specific type of biological activity and formulate recommendations for practitioners.
Genomic Insights into the Evolution of the Nicotine Biosynthesis Pathway in Tobacco1[CC-BY]

A series of metabolic and transport genes involved in the nicotine pathway form a regulon under the control of jasmonate-responsive transcription factors in tobacco. In tobacco (Nicotiana tabacum), nicotine is the predominant alkaloid. It is produced in the roots and accumulated mainly in the leaves. Jasmonates play a central signaling role in damage-induced nicotine formation. The genome sequence of tobacco provides us an almost complete inventory of structural and regulatory genes involved in nicotine pathway. Phylogenetic and expression analyses revealed a series of structural genes of the nicotine pathway, forming a regulon, under the control of jasmonate-responsive ETHYLENE RESPONSE FACTOR (ERF) transcription factors. The duplication of NAD and polyamine metabolic pathways and the subsequent recruitment of duplicated primary metabolic genes into the nicotine biosynthesis regulon were suggested to be the drivers for pyridine and pyrrolidine ring formation steps early in the pathway. Transcriptional regulation by ERF and cooperatively acting MYC2 transcription factors are corroborated by the frequent occurrence of cognate cis-regulatory elements of the factors in the promoter regions of the downstream structural genes. The allotetraploid tobacco has homologous clusters of ERF genes on different chromosomes, which are possibly derived from two ancestral diploids and include either nicotine-controlling ERF189 or ERF199. A large chromosomal deletion was found within one allele of the nicotine-controlling NICOTINE2 locus, which is part of one of the ERF gene clusters, and which has been used to breed tobacco cultivars with a low-nicotine content.
Timing information in transient behavior of neuropopulations

A computational model of neuronal populations based on neurophysiological data is presented. The neuronal population consists of model neurons that simulate electrochemical processes in real neurons. Input and output of the population are defined in terms of the stochastic behavior of the single neurons. Analysis of the populational behavior shows that neuronal populations can approximately function as delay elements that transform step input to step output, and the delay intervals can specify timing information in the several-millisecond range, which is essential to high speed parallel computation. An example network composed of neuronal populations is simulated to show how the timing information can serve to achieve parallel processing in neural networks. >
Diagnostic performance and predictive value of rheumatoid factor, anti-citrullinated peptide antibodies, and the HLA shared epitope for diagnosis of rheumatoid arthritis.

Rheumatoid factor (RF) is currently the most accepted laboratory test for rheumatoid arthritis (RA) and is part of the revised American College of Rheumatology (ACR) classification criteria for RA (1). The specificity of RF is, however, often low (2)(3)(4)(5). A newer diagnostic marker for RA is anti-citrullinated peptide antibodies (ACPAs), which can be identified by tests such as a line immunoassay (LIA™) for the detection of anti-pepA and anti-pepB antibodies (6), the anti-cyclic citrullinated peptide ELISA (7), an ELISA using citrullinated recombinant rat filaggrin (8), and an ELISA using deiminated fibrinogen (9). ACPAs have excellent specificity (89–100%) for RA, with good sensitivity (41–80%) (3)(4)(5)(6)(7)(10)(11)(12)(13)(14)(15). Furthermore, the HLA shared epitope (SE) has been described, which is found more often in RA patients than in controls (16)(17)(18). Most studies of these newer tests have used control populations consisting of selected groups of patients with defined diseases and healthy controls. This does not represent real-life clinical practice because the composition of the control group does not reflect the natural prevalences of diseases in cases for which serologic markers for RA are requested. Data about specificity, positive predictive value (PPV), and negative predictive value (NPV) are thus hard to interpret. We designed the present study to reflect everyday rheumatology practice. In this prospective study, we included 1003 consecutive patients in three academic and nonacademic centers: the Department of Rheumatology, Ghent University Hospital (Ghent, Belgium); the Locomotor Center, Elisabeth Hospital (Sijsele, Belgium); and the Department of Rheumatology, St-Augustinus Hospital (Wilrijk, Belgium). Patients were entered in the study when they presented with a new diagnostic problem for which RA was included in the differential diagnosis. This …