Miracle-dz/UniFAR-FTUs huggingface dataset:
Integration of Active Vision and Reaching From a Developmental Robotics Perspective

Inspired by child development and brain research, we introduce a computational framework which integrates robotic active vision and reaching. Essential elements of this framework are sensorimotor mappings that link three different computational domains relating to visual data, gaze control, and reaching. The domain of gaze control is the central computational substrate that provides, first, a systematic visual search and, second, the transformation of visual data into coordinates for potential reach actions. In this respect, the representation of object locations emerges from the combination of sensorimotor mappings. The framework is tested in the form of two different architectures that perform visually guided reaching. Systematic experiments demonstrate how visual search influences reaching accuracy. The results of these experiments are discussed with respect to providing a reference architecture for developmental learning in humanoid robot systems.
A life course perspective on social protection among the working poor of Egypt

Researchers and practitioners have increasingly been turning to the social protection framework as an approach to poverty alleviation in the Global South. Moving beyond the concept of the social safety net that accompanied structural adjustment programs in the 1990s, social protection encompasses a more integrated approach to poverty alleviation that focuses on reducing risk and vulnerability (Kabeer 2009). The social protection framework has thus developed along with increasing interest in the study of poverty dynamics, as well as non-monetary dimensions of poverty, including exclusion and insecurity (Norton et al. 2002; Barrientos et al. 2005; Barrientos and Hulme 2009).
Roles of Oxidative Stress and AT1 Receptors in Renal Hemodynamics and Oxygenation in the Postclipped 2K,1C Kidney

Abstract—The spontaneously hypertensive rat (SHR) exhibits angiotensin II (Ang II)–dependent oxidative stress and reduced efficiency of renal oxygen usage (QO2) for tubular sodium transport (TNa). We tested the hypothesis that oxidative stress determines the reduced TNa:QO2 ratio in the clipped kidney of the early 2-kidney, 1-clip (2K,1C) Ang II–dependent model. One week after sham operation (Sham) or clip placement, 2K,1C rats received for 2 weeks either a vehicle, the superoxide dismutase mimetic tempol (Temp), or candesartan (Cand). Oxidative stress was assessed from excretion of 8-isoprostaglandin F2&agr; (PGF2&agr;) and malondialdehyde (MDA) and renal oxygenation from pO2 in the renal cortex and from the ratio of calculated TNa and QO2 values. The mean arterial pressure (MAP) of Sham (113±6 mm Hg) was increased in 2K,1C vehicle-treated rats (148±4 mm Hg), but both Temp and Cand restored MAP to Sham levels. The excretions of 8-iso-PGF2&agr; and MDA were higher in 2K,1C vehicle-treated rats compared with Sham and were normalized by Temp. The pO2 of Sham (42±2 mm Hg) was lower in 2K,1C vehicle-treated animals (28±2 mm Hg). This was restored to Sham values by Temp (36±3 mm Hg) but not by Cand (28±2 mm Hg). The TNa:QO2 of Sham (12.9±1.6) was reduced in 2K,1C vehicle-treated rats (9.7±2.8) and was restored to Sham values by Temp (13.7±2.5) but not by Cand (7.5±1.6). We conclude that the correction of oxidative stress in the 2K,1C model partially corrects renal cortical hypoxia and inefficient utilization of O2 for Na+ transport, independent of the fall in blood pressure.
Host-to-Parasite Gene Transfer in Flowering Plants: Phylogenetic Evidence from Malpighiales

Horizontal gene transfer (HGT) between sexually unrelated species has recently been documented for higher plants, but mechanistic explanations for HGTs have remained speculative. We show that a parasitic relationship may facilitate HGT between flowering plants. The endophytic parasites Rafflesiaceae are placed in the diverse order Malpighiales. Our multigene phylogenetic analyses of Malpighiales show that mitochrodrial (matR) and nuclear loci (18S ribosomal DNA and PHYC) place Rafflesiaceae in Malpighiales, perhaps near Ochnaceae/Clusiaceae. Mitochondrial nad1B-C, however, groups them within Vitaceae, near their obligate host Tetrastigma. These discordant phylogenetic hypotheses strongly suggest that part of the mitochondrial genome in Rafflesiaceae was acquired via HGT from their hosts.
Customer Driven Establishment Dynamics and Allocative Efficiency

A common result from models of misallocation is that allocative efficiency is reflected in the correlation between size and productivity. But establishments start small which raises the question: how does the distribution of size have to evolve over the lifecycle to achieve allocative efficiency? Simply put, it must be that more productive establishments grow faster at the expense of less productive establishments. As evidence of this selection mechanism, I use establishment level data to construct cohorts of entrants and show that the spread of growth between fast and slow growing establishments is positively associated with higher exit rates. But unlike typical models that feature selection, I show that neither increases in input costs nor greater volatility are the force behind selection. To reconcile these facts, I present a model where the degree to which customers are willing to match with establishments who produce low quality goods introduces a new margin that affects selection. In the model, 60 per cent of changes in the intensity of selection come from changes in demand side behavior. To assess this new margin of selection, I recalibrate a parameter which controls the degree to which establishments can crowd out others for customers to match the slower fanning out in the evolution of the size distribution in Chile relative to the US. The model suggests that going from the US to Chile in this dimension would result in a 44 per cent loss in welfare.
Fundamental differences between Dropout and Weight Decay in Deep Networks

We analyze dropout in deep networks with rectified linear units and the quadratic loss. Our results expose surprising differences between the behavior of dropout and more traditional regularizers like weight decay. For example, on some simple data sets dropout training produces negative weights even though the output is the sum of the inputs. This provides a counterpoint to the suggestion that dropout discourages co-adaptation of weights. We also show that the dropout penalty can grow exponentially in the depth of the network while the weight-decay penalty remains essentially linear, and that dropout is insensitive to various re-scalings of the input features, outputs, and network weights. This last insensitivity implies that there are no isolated local minima of the dropout training criterion. Our work uncovers new properties of dropout, extends our understanding of why dropout succeeds, and lays the foundation for further progress.
Visualizing Time-Varying Phenomena In Numerical Simulations Of Unsteady Flows

Streamlines, contour lines, vector plots, and volume slices (cutting planes) are commonly used for flow visualization. These techniques are sometimes referred to as instantaneous flow visualization techniques because calculations are based on an instant of the flow field in time. Although instantaneous flow visualization techniques are effective for depicting phenomena in steady flows, they sometimes do not adequately depict time-varying phenomena in unsteady flows. Streaklines and timelines are effective visualization techniques for depicting vortex shedding, vortex breakdown, and shock waves in unsteady flows. These techniques are examples of time-dependent flow visualization techniques, which are based on many instants of the flow fields in time. This paper describes the algorithms for computing streaklines and timelines. Using numerically simulated unsteady flows, streaklines and timelines are compared with streamlines, contour lines, and vector plots. It is shown that streaklines and timelines reveal vortex shedding and vortex breakdown more clearly than instantaneous flow visualization techniques.
Parallel Selection on TRPV6 in Human Populations

We identified and examined a candidate gene for local directional selection in Europeans, TRPV6, and conclude that selection has acted on standing genetic variation at this locus, creating parallel soft sweep events in humans. A novel modification of the extended haplotype homozygosity (EHH) test was utilized, which compares EHH for a single allele across populations, to investigate the signature of selection at TRPV6 and neighboring linked loci in published data sets for Europeans, Asians and African-Americans, as well as in newly-obtained sequence data for additional populations. We find that all non-African populations carry a signature of selection on the same haplotype at the TRPV6 locus. The selective footprints, however, are significantly differentiated between non-African populations and estimated to be younger than an ancestral population of non-Africans. The possibility of a single selection event occurring in an ancestral population of non-Africans was tested by simulations and rejected. The putatively-selected TRPV6 haplotype contains three candidate sites for functional differences, namely derived non-synonymous substitutions C157R, M378V and M681T. Potential functional differences between the ancestral and derived TRPV6 proteins were investigated by cloning the ancestral and derived forms, transfecting cell lines, and carrying out electrophysiology experiments via patch clamp analysis. No statistically-significant differences in biophysical channel function were found, although one property of the protein, namely Ca2+ dependent inactivation, may show functionally relevant differences between the ancestral and derived forms. Although the reason for selection on this locus remains elusive, this is the first demonstration of a widespread parallel selection event acting on standing genetic variation in humans, and highlights the utility of between population EHH statistics.
Exploring determinants in deploying mobile commerce technology: Amman stock exchange

The purpose of this research is to explore the critical determinants that affect the intention of the users to deploy mobile commerce technology in Amman Stock Exchange. This research applied TAM model using the following variables: perceived trust, perceived usefulness, perceived ease of use, social and cultural values, and economic issues. The result of the distributed 210 questionnaires to mobile commerce users in Amman Stock Exchange (Brokers and Investors), and 179 were returned correct and studied, reveal that perceived trust, perceived usefulness, perceived ease of use, social and cultural values have significant association with intention to deploy mobile commerce technology while economical issue is not significant. The results of the research indicate that TAM have capability in exploring critical determinants that affecting the intention to deploy mobile commerce technology in Jordanian marketplace, therefore, further studies are recommended to explore the critical determinants of deploying mobile commerce technology in other economic sectors.
Role of a Relay in Bursty Multiple Access Channels

We investigate the role of a relay in multiple access channels (MACs) with bursty user traffic, where intermittent data traffic restricts the users to bursty transmissions. As our main result, we characterize the degrees of freedom (DoF) region of a K-user bursty multi-input multi-output (MIMO) Gaussian MAC with a relay, where Bernoulli random states are introduced to govern bursty user transmissions. To that end, we extend the noisy network coding scheme to achieve the cut-set bound. Our main contribution is in exploring the role of a relay from various perspectives. First, we show that a relay can provide a DoF gain in bursty channels, unlike in conventional non-bursty channels. Interestingly, we find that the relaying gain can scale with additional antennas at the relay to some extent. Moreover, observing that a relay can help achieve collision-free performances, we establish the necessary and sufficient condition for attaining collision-free DoF. Lastly, we consider scenarios in which some physical perturbation shared around the users may generate data traffic simultaneously, causing transmission patterns across them to be correlated. We demonstrate that for most cases in such scenarios, the relaying gain is greater when the users’ transmission patterns are more correlated, hence when more severe collisions take place. Our results have practical implications in various scenarios of wireless networks such as device-to-device systems and random media access control protocols.
Multiple and Opposing Roles of Cholinergic Transmission in the Main Olfactory Bulb

The main olfactory bulb is a critical relay step between the olfactory epithelium and the olfactory cortex. A marked feature of the bulb is its massive innervation by cholinergic inputs from the basal forebrain. In this study, we addressed the functional interaction between cholinergic inputs and intrinsic bulbar circuitry. Determining the roles of acetylcholine (ACh) requires the characterization of cholinergic effects on both neural excitability and synaptic transmission. For this purpose, we used electrophysiological techniques to localize and characterize the diverse roles of ACh in mouse olfactory bulb slices. We found that cholinergic inputs have a surprising number of target receptor populations that are expressed on three different neuronal types in the bulb. Specifically, nicotinic acetylcholine receptors excite both the output neurons of the bulb, i.e., the mitral cells, as well as interneurons located in the periglomerular regions. These nicotine-induced responses in interneurons are short lasting, whereas responses in mitral cells are long lasting. In contrast, muscarinic receptors have an inhibitory effect on the firing rate of interneurons from a deeper layer, granule cells, while at the same time they increase the degree of activity-independent transmitter release from these cells onto mitral cells. Cholinergic signaling thus was found to have multiple and opposing roles in the olfactory bulb. These dual cholinergic effects on mitral cells and interneurons may be important in modulating olfactory bulb output to central structures required for driven behaviors and may be relevant to understanding mechanisms underlying the perturbations of cholinergic inputs to cortex that occur in Alzheimer's disease.
A Generalized Winner ' s Curse : An Experimental Investigation of Complexity and Adverse Selection

We investigate experimentally a possible Winner’s Curse in a generalized environment with pure common values. In our design, participants are given examples in which parameters lead to prize values (using an undisclosed and typically complex formula). They are then asked to estimate the prize value with a final set of parameter values and then bid for this prize value in a second-price auction. Unlike previous studies, two main ingredients ‘responsible’ for the creation of the winner’s curse are absent: 1) there is no presumption of common knowledge of a joint distribution, and 2) all signals are identical and public. Thus, it is difficult to discuss or compute a Bayes-Nash Equilibrium, let alone to measure individual departures from it. It is unclear what ought to be the behavioral norm, how to compute it and/or measure individual departures from it. It is also difficult, if not impossible, to talk about a posterior distribution conditional on winning as we don’t induce any priors. Assuming common knowledge in this context is patently implausible. In this generalized environment, we find strong evidence of the winner’s curse that is entirely consistent with previous findings from standard environments. We also find that the winner’s curse results from both dispersion in the estimates made and poorly-chosen bid-strategies. Finally, the nearest-neighbors method explains well how participants make estimates of the (common) value.
Bivalve Grazing Can Shape Phytoplankton Communities

The ability of bivalve filter feeders to limit phytoplankton biomass in shallow waters is well-documented, but the role of bivalves in shaping phytoplankton communities is not. The coupled effect of bivalve grazing at the sediment-water interface and sinking of phytoplankton cells to that bottom filtration zone could influence the relative biomass of sinking (diatoms) and non-sinking phytoplankton. Simulations with a pseudo-2D numerical model showed that benthic filter feeding can interact with sinking to alter diatom:non-diatom ratios. Cases with the smallest proportion of diatom biomass were those with the fastest sinking speeds and strongest bivalve grazing rates. Hydrodynamics modulated the coupled sinking-grazing influence on phytoplankton communities. For example, in simulations with persistent stratification, the non-sinking forms accumulated in the surface layer away from bottom grazers while the sinking forms dropped out of the surface layer toward bottom grazers. Tidal-scale stratification also influenced vertical gradients of the two groups in opposite ways. The model was applied to Suisun Bay, a low-salinity habitat of the San Francisco Bay system that was transformed by the introduction of the exotic clam Potamocorbula amurensis. Simulation results for this Bay were similar to (but more muted than) those for generic habitats, indicating that P. amurensis grazing could have caused a disproportionate loss of diatoms after its introduction. Our model simulations suggest bivalve grazing affects both phytoplankton biomass and community composition in shallow waters. We view these results as hypotheses to be tested with experiments and more complex modeling approaches.
Do Item Writing Best Practices Improve Multiple Choice Questions for University Students?

We conduct a randomized experiment using a series of three finance exams sat by over 1,000 students at an Australian university, to determine the extent to which multiple-choice questions (MCQs) are improved by item writing best practices. We identify deviations from best practices (i.e. “flaws”) in MCQs, correct these flaws in a random sample of MCQs and re-administer the exams. Regardless of question difficulty, editing the MCQs according to best practices provides greater clarity for students and increases the proportion of correct responses. We also observe a substantial improvement in MCQ performance related to the effective removal of non-performing distractors. The effect of MCQ editing is larger on those items that students find more difficult. The discriminatory power of MCQs edited according to best practices declines on average, but it increases among students with the lowest scores.
Necessity Never Made a Good Bargain : External Conditions , Entrepreneurial Motives , and Startup Outcomes January 29 , 2018

Certain individuals start companies pulled by opportunity, others are pushed by necessity. We propose a novel methodology identifying necessity entrepreneurs based on their ex-ante risk of being unemployed holding the opportunity motive constant. Using a rich dataset of startup founders in life sciences, we show that, as unemployment rate increases, the fraction of necessity entrepreneurs rises. This finding is driven by deteriorating employment conditions reducing expected returns from wage work and not by necessity entrepreneurs crowding-out opportunity entrepreneurs when unemployment is high. Additionally, startups entirely founded by necessity entrepreneurs show worse financial and innovative performance than startups founded by at least one opportunity entrepreneur. Finally, having necessity entrepreneurs as founders explains at least seven percent of the negative effect unemployment has on startups' performance. Necessity Never Made a Good Bargain: External Conditions, Entrepreneurial Motives, and Startup Outcomes
Systematic Compact Modeling of Correlated Noise in Bipolar Transistors

A systematic method for the integration of correlated shot-noise sources into compact models (CMs) is presented, which significantly improves the accuracy of predicted high-frequency noise in transistors. The developed method relies on a system theory approach, and hence, is not limited to specific CM or device type. In this paper, the method is applied to the CM HICUM, which serves a vehicle for verification purposes. The method and its implementation were verified for SiGe heterojunction bipolar transistors based on measured data for frequencies up to 50 GHz, as well as on device simulation data up to 500 GHz, obtained from simulations of both hydrodynamic and a Boltzmann transport model.
Optimal Sets of Frequency Hopping Sequences From Linear Cyclic Codes

In communication systems, frequency hopping spread spectrum and direct sequence spread spectrum are two main spread coding technologies. Frequency hopping sequences are used in FH-CDMA systems. In this paper, an earlier idea of constructing optimal sets of frequency hopping sequences is further investigated. New optimal parameters of sets of frequency hopping sequences are obtained with subcodes of the Reed-Solomon codes. Optimal sets of frequency hopping sequences are constructed with a class of irreducible cyclic codes. As a byproduct, the weight distribution of a subclass of irreducible cyclic codes is determined.
Self-timed nano-PLA

Emerging molecular based nanoelectronics is a promising alternatives for current CMOS technology to reduce manufacturing costs and achieve higher levels of integration. Extreme parameter variations resulted from nondeterministic nanofabrication can seriously affect the correct functionality and performance of circuits implemented in this technology. In this paper, we introduce modifications to nano-PLA, a major nano-architecture, to immune it against extreme variations by using self-timed local control signaling within the blocks instead of external global signals. Extensive Monte Carlo simulations for delay variations on a set of benchmarks confirms that the circuits implemented on the proposed architecture are 100% immune against delay variation, compared to only 37% for those circuits implemented on the original nano-PLA architecture. Moreover, the proposed architecture results in 47% reduction, in average, in critical path delay of mapped circuits.
Isothermal Titration Calorimetric Studies on the Interaction of the Major Bovine Seminal Plasma Protein, PDC-109 with Phospholipid Membranes

The interaction of the major bovine seminal plasma protein, PDC-109 with lipid membranes was investigated by isothermal titration calorimetry. Binding of the protein to model membranes made up of diacyl phospholipids was found to be endothermic, with positive values of binding enthalpy and entropy, and could be analyzed in terms of a single type of binding sites on the protein. Enthalpies and entropies for binding to diacylphosphatidylcholine membranes increased with increase in temperature, although a clear-cut linear dependence was not observed. The entropically driven binding process indicates that hydrophobic interactions play a major role in the overall binding process. Binding of PDC-109 with dimyristoylphosphatidylcholine membranes containing 25 mol% cholesterol showed an initial increase in the association constant as well as enthalpy and entropy of binding with increase in temperature, whereas the values decreased with further increase in temperature. The affinity of PDC-109 for phosphatidylcholine increased at higher pH, which is physiologically relevant in view of the basic nature of the seminal plasma. Binding of PDC-109 to Lyso-PC could be best analysed in terms of two types of binding interactions, a high affinity interaction with Lyso-PC micelles and a low-affinity interaction with the monomeric lipid. Enthalpy-entropy compensation was observed for the interaction of PDC-109 with phospholipid membranes, suggesting that water structure plays an important role in the binding process.