Miracle-dz/UniFAR-FTUs huggingface dataset:
Experience versus talent shapes the structure of the Web

We use sequential large-scale crawl data to empirically investigate and validate the dynamics that underlie the evolution of the structure of the web. We find that the overall structure of the web is defined by an intricate interplay between experience or entitlement of the pages (as measured by the number of inbound hyperlinks a page already has), inherent talent or fitness of the pages (as measured by the likelihood that someone visiting the page would give a hyperlink to it), and the continual high rates of birth and death of pages on the web. We find that the web is conservative in judging talent and the overall fitness distribution is exponential, showing low variability. The small variance in talent, however, is enough to lead to experience distributions with high variance: The preferential attachment mechanism amplifies these small biases and leads to heavy-tailed power-law (PL) inbound degree distributions over all pages, as well as over pages that are of the same age. The balancing act between experience and talent on the web allows newly introduced pages with novel and interesting content to grow quickly and surpass older pages. In this regard, it is much like what we observe in high-mobility and meritocratic societies: People with entitlement continue to have access to the best resources, but there is just enough screening for fitness that allows for talented winners to emerge and join the ranks of the leaders. Finally, we show that the fitness estimates have potential practical applications in ranking query results.
Optimal path planning and coverage control for multi-robot persistent coverage in environments with obstacles

Persistent coverage aims to maintain a certain coverage level over time in an environment where such level deteriorates. This level can be associated to temperature, dust or sensor information. We propose an algorithmic solution in which each robot locally finds the best paths and coverage actions to keep the desired coverage level over the whole environment. Using Fast Marching Methods, optimal paths are computed in terms of coverage quality, while keeping a safety distance to obstacles. Additionally, our solution enables a computationally efficient evaluation of a list of potential trajectories, allowing us to choose the one that mostly improves the coverage along the whole path. The combination of this algorithm with a Dynamic Window navigation makes our approach competitive in terms of flexibility and robustness in changing environments with existing solutions. Finally, we also propose a coverage action controller, locally computed and optimal, that makes the robots maintain the coverage level of the environment significantly close to the objective. Simulations and real experiments validate the whole approach.
New analytical results on fiber parametric gain and its effects on ASE noise

Parametric gain (PG) in optical fibers may substantially enhance ASE noise, especially in long-haul amplified systems. We present new closed-form analytical results that permit to accurately characterize the effects of PG on ASE noise, as well as the interplay of PG and ASE noise with fiber dispersion in both the anomalous and normal dispersion regions. We introduce the concept of a PG transfer matrix that allows the easy analytical evaluation of ASE noise enhancement over chains of amplified fiber spans.
Phase Equilibria Constraints on the Chemical and Physical Evolution of the Campanian Ignimbrite

The Campanian Ignimbrite is a 4200 km trachyte^phonolite pyroclastic deposit that erupted at 39 3 0 1ka within the Campi Flegrei west of Naples, Italy. Here we test the hypothesis that Campanian Ignimbrite magma was derived by isobaric crystal fractionation of a parental basaltic trachyandesitic melt that reacted and came into local equilibrium with small amounts (5^10 wt%) of crustal rock (skarns and foid-syenites) during crystallization. Comparison of observed crystal and magma compositions with results of phase equilibria assimilation^fractionation simulations (MELTS) is generally very good. Oxygen fugacity was approximately buffered along QFMþ1 (where QFM is the quartz^ fayalite^magnetite buffer) during isobaric fractionation at 0 15 GPa ( 6 km depth). The parental melt, reconstructed from melt inclusion and host clinopyroxene compositions, is found to be basaltic trachyandesite liquid (51 1 wt% SiO2, 9 3 wt% MgO, 3 wt% H2O). A significant feature of phase equilibria simulations is the existence of a pseudo-invariant temperature, 883 8C, at which the fraction of melt remaining in the system decreases abruptly from 0 5 to50 1. Crystallization at the pseudo-invariant point leads to abrupt changes in the composition, properties (density, dissolved water content), and physical state (viscosity, volume fraction fluid) of melt and magma. A dramatic decrease in melt viscosity (from 1700 Pa s to 200 Pa s), coupled with a change in the volume fraction of water in magma (from 0 1 to 0 8) and a dramatic decrease in melt and magma density acted as a destabilizing eruption trigger. Thermal models suggest a timescale of 200 kyr from the beginning of fractionation until eruption, leading to an apparent rate of evolved magma generation of about 10 3 km/year. In situ crystallization and crystal settling in density-stratified regions, as well as in convectively mixed, less evolved subjacent magma, operate rapidly enough to match this apparent volumetric rate of evolved magma production.
Bridging a Temporary High Risk of Sudden Arrhythmic Death. Experience with the Wearable Cardioverter Defibrillator (WCD)

The implantable cardioverter defibrillator (ICD) is able to reduce sudden arrhythmic death in patients who are considered to be at high risk. However, the arrhythmic risk may be increased only temporarily as long as the proarrhythmic conditions persist, left ventricular ejection fraction remains low, or heart failure prevails. The wearable cardioverter defibrillator (WCD) represents an alternative approach to prevent sudden arrhythmic death until either ICD implantation is clearly indicated or the arrhythmic risk is considered significantly lower or even absent. The WCD is also indicated for interrupted protection by an already implanted ICD, temporary inability to implant an ICD, and lastly refusal of an indicated ICD by the patient. The WCD is not an alternative to the ICD, but a device that may contribute to better selection of patients for ICD therapy. The WCD has the characteristics of an ICD, but does not need to be implanted, and it has similarities with an external defibrillator, but does not require a bystander to apply lifesaving shocks when necessary.
Transmission of Population-Coded Information

Abstract As neural activity is transmitted through the nervous system, neuronal noise degrades the encoded information and limits performance. It is therefore important to know how information loss can be prevented. We study this question in the context of neural population codes. Using Fisher information, we show how information loss in a layered network depends on the connectivity between the layers. We introduce an algorithm, reminiscent of the water filling algorithm for Shannon information that minimizes the loss. The optimal connection profile has a center-surround structure with a spatial extent closely matching the neurons’ tuning curves. In addition, we show how the optimal connectivity depends on the correlation structure of the trial-to-trial variability in the neuronal responses. Our results explain how optimal communication of population codes requires the center-surround architectures found in the nervous system and provide explicit predictions on the connectivity parameters.
Probabilistic Trees and Automata for Application Behavior Modeling

We describe methods for inferring and using probabilistic m odels that capture characteristic pattern structures that may ex ist in symbolic data sequences. Our emphasis is on modeling the sequen ce of system calls made during the execution of a software applica tion. To obtain learning data, sequences of predetermined system calls are intercepted and mapped into simple symbolic descriptio ns f r a number of runs of the application being modeled. We then con struct a probabilistic suffix tree (PST) that represents the probability of each system call given a finite-length sequence of prev iously observed system calls. Ultimately, we translate the PST int o a analogous probabilistic suffix automaton (PSA) which is a pa rsimonious, variable-order Markov chain. Either model can subse quently be used for real-time data monitoring by means of a matching a lgorithm. New contributions include an algorithm for compar ing two PSTs. We also outline how to extract important Markovian statistics from a PSA and discuss their possible use. Prelim inary experimental results are presented based on Visual Basic ma cros embedded in Microsoft Excel worksheets.
Paranoid Parenting: Why Ignoring the Experts May Be Best for Your Child

Introduction 1. Making Sense of Parental Paranoia 2. The Myth of the Vulnerable Child 3. Parents as Gods 4. Parenting on Demand: a New Concept in Child Rearing 5. Parenting Turned into an Ordeal 6. The Problem of Holding the Line 7. Unclear Rules 8. Professional Power and the Erosion of Parental Authority 9. The Politicisation of Parenting.
Reactivation of FMR1 by CRISPR/Cas9-Mediated Deletion of the Expanded CGG-Repeat of the Fragile X Chromosome

Fragile X syndrome (FXS) is a common cause of intellectual disability that is most often due to a CGG-repeat expansion mutation in the FMR1 gene that triggers epigenetic gene silencing. Epigenetic modifying drugs can only transiently and modestly induce FMR1 reactivation in the presence of the elongated CGG repeat. As a proof-of-principle, we excised the expanded CGG-repeat in both somatic cell hybrids containing the human fragile X chromosome and human FXS iPS cells using the CRISPR/Cas9 genome editing. We observed transcriptional reactivation in approximately 67% of the CRISPR cut hybrid colonies and in 20% of isolated human FXS iPSC colonies. The reactivated cells produced FMRP and exhibited a decline in DNA methylation at the FMR1 locus. These data demonstrate the excision of the expanded CGG-repeat from the fragile X chromosome can result in FMR1 reactivation.
Editosome Accessory Factors KREPB9 and KREPB10 in Trypanosoma brucei

ABSTRACT Multiprotein complexes, called editosomes, catalyze the uridine insertion and deletion RNA editing that forms translatable mitochondrial mRNAs in kinetoplastid parasites. We have identified here two new U1-like zinc finger proteins that associate with editosomes and have shown that they are related to KREPB6, KREPB7, and KREPB8, and thus we have named them Kinetoplastid RNA Editing Proteins, KREPB9 and KREPB10. They are conserved and syntenic in trypanosomatids although KREPB10 is absent in Trypanosoma vivax and both are absent in Leishmania. Tandem affinity purification (TAP)-tagged KREPB9 and KREPB10 incorporate into ∼20S editosomes and/or subcomplexes thereof and preferentially associate with deletion subcomplexes, as do KREPB6, KREPB7, and KREPB8. KREPB10 also associates with editosomes that are isolated via a chimeric endonuclease, KREN1 in KREPB8 RNA interference (RNAi) cells, or MEAT1. The purified complexes have precleaved editing activities and endonuclease cleavage activity that appears to leave a 5′ OH on the 3′ product. RNAi knockdowns did not affect growth but resulted in relative reductions of both edited and unedited mitochondrial mRNAs. The similarity of KREPB9 and KREPB10 to KREPB6, KREPB7, and KREPB8 suggests they may be accessory factors that affect editing endonuclease activity and as a consequence may affect mitochondrial mRNA stability. KREPB9 and KREPB10, along with KREPB6, KREPB7, and KREPB8, may enable the endonucleases to discriminate among and accurately cleave hundreds of different editing sites and may be involved in the control of differential editing during the life cycle of T. brucei.
Genetically encoding a light switch in an ionotropic glutamate receptor reveals subunit-specific interfaces

Significance The design of protein receptors responsive to light stimuli has wide-ranging applications in structure–function studies and optogenetics. We present here the design of a light-sensitive NMDA receptor by introducing through genetic-code expansion a photoreactive moiety carried by a single unnatural amino acid. NMDA receptors form glutamate-gated ion channels that are essential mediators of synaptic plasticity associated with learning and memory. By exploring the molecular mechanisms and subunit dependence of the light-induced receptor inactivation, we find that the two major NMDA receptor subtypes, GluN1/GluN2A and GluN1/GluN2B, differ in their ectodomain-subunit interactions. Besides providing important new information about NMDA receptor molecular structure, our work opens the possibility of using engineered light-sensitive NMDA receptors to explore native receptor function. Reprogramming receptors to artificially respond to light has strong potential for molecular studies and interrogation of biological functions. Here, we design a light-controlled ionotropic glutamate receptor by genetically encoding a photoreactive unnatural amino acid (UAA). The photo–cross-linker p-azido-l-phenylalanine (AzF) was encoded in NMDA receptors (NMDARs), a class of glutamate-gated ion channels that play key roles in neuronal development and plasticity. AzF incorporation in the obligatory GluN1 subunit at the GluN1/GluN2B N-terminal domain (NTD) upper lobe dimer interface leads to an irreversible allosteric inhibition of channel activity upon UV illumination. In contrast, when pairing the UAA-containing GluN1 subunit with the GluN2A subunit, light-dependent inactivation is completely absent. By combining electrophysiological and biochemical analyses, we identify subunit-specific structural determinants at the GluN1/GluN2 NTD dimer interfaces that critically dictate UV-controlled inactivation. Our work reveals that the two major NMDAR subtypes differ in their ectodomain-subunit interactions, in particular their electrostatic contacts, resulting in GluN1 NTD coupling more tightly to the GluN2B NTD than to the GluN2A NTD. It also paves the way for engineering light-sensitive ligand-gated ion channels with subtype specificity through the genetic code expansion.
Rural Schools Positioned to Promote the High Achievement of Students with Disabilities

This article presents case studies of two rural districts—both confronting economic and demographic challenges—that were making significant strides toward closing achievement gaps between students with and without disabilities. The districts accomplished this work by using six practices, common to both but implemented differently in each: (a) using data well, (b) establishing and maintaining focus, (c) selecting and implementing shared instructional practices, (d) implementing deeply, (e) monitoring and providing feedback and support, and (f) inquiring and learning. These findings illustrate that, contrary to popular stereotypes, some rural districts serving low income and diverse families are able to increase the achievement levels of students with disabilities.
The distributional consequences of a fiscal food policy: evidence from the UK

The literature on fiscal food policies focuses on their effectiveness in altering diets and improving health, while this paper focuses on their welfare costs. A formal welfare economics framework is developed to calculate the combined individualistic and distributional impacts of a tax-subsidy. Distributional characteristics of foods targeted by a tax tend to be concentrated in lower-income households. Further, consumption of fruit and vegetables tends to be concentrated in higher-income households; therefore, a subsidy on such foods increases regressivity. Aggregate welfare changes that result from a fiscal food policy are found to range from an increase of 1.41 per cent to a reduction of 2.06 per cent according to whether a subsidy is included, the degree of inequality aversion, and whether substitution among foods is allowed.
Generation of random sequences by human subjects: A critical survey of literature.

The subjective concept of randomness is used in many areas of psychological research to explain a variety of experimental results. One method to study randomness is to have subjects generate random series. Unfortunately, few results of the experiments that used this method lend themselves to comparison and synthesis because the investigators employed such a variety of experimental conditions and definitions of mathematical randomness. Some suggestions for future research are made.
Full Serotype- and Group-Specific NS1 Capture Enzyme-Linked Immunosorbent Assay for Rapid Differential Diagnosis of Dengue Virus Infection

ABSTRACT Dengue virus (DENV), a member of the Flavivirus family, has four distinct serotypes (DENV serotype 1 [DENV1], DENV2, DENV3, and DENV4) that require differentiation for the effective prevention of morbid disease. Early and rapid differentiation between flaviviruses remains challenging. Full assays combining four individual, serotype-specific and one group-specific nonstructural protein 1 (NS1) antigen capture enzyme-linked immunosorbent assays (ELISAs) based on monoclonal antibodies (MAbs) against DENV NS1 were developed and validated. The sensitivities and specificities of the full NS1 ELISAs were evaluated with viral cultures and dengue acute-phase sera. Four serotype-specific NS1 ELISAs displayed high specificities for the detection and differentiation of appropriate serotypes. The group-specific NS1 ELISA was broadly reactive with the four dengue virus serotypes. None of the NS1 ELISAs displayed cross-reactivity with the other flaviviruses or samples from febrile patients with non-dengue virus infections. The full serotype- and group-specific MAb-based NS1 capture ELISAs may provide tools for the early detection and typing of dengue infection, which is preferable to reverse transcriptase PCR (RT-PCR) for the rapid differential diagnosis of dengue virus infection in the field.
Distilling Free-Form Natural Laws from Experimental Data

For centuries, scientists have attempted to identify and document analytical laws that underlie physical phenomena in nature. Despite the prevalence of computing power, the process of finding natural laws and their corresponding equations has resisted automation. A key challenge to finding analytic relations automatically is defining algorithmically what makes a correlation in observed data important and insightful. We propose a principle for the identification of nontriviality. We demonstrated this approach by automatically searching motion-tracking data captured from various physical systems, ranging from simple harmonic oscillators to chaotic double-pendula. Without any prior knowledge about physics, kinematics, or geometry, the algorithm discovered Hamiltonians, Lagrangians, and other laws of geometric and momentum conservation. The discovery rate accelerated as laws found for simpler systems were used to bootstrap explanations for more complex systems, gradually uncovering the “alphabet” used to describe those systems.
Spatial Distortion Correction and Crystal Identification for MRI-Compatible Position-Sensitive Avalanche Photodiode-Based PET Scanners

Position-sensitive avalanche photodiodes (PSAPDs) are gaining widespread acceptance in modern PET scanner designs, and owing to their relative insensitivity to magnetic fields, especially in those that are MRI-compatible. Flood histograms in PET scanners are used to determine the crystal of annihilation photon interaction and hence, for detector characterization and routine quality control. For PET detectors that use PSAPDs, flood histograms show a characteristic pincushion distortion when Anger logic is used for event positioning. A small rotation in the flood histogram is also observed when the detectors are placed in a magnetic field. We first present a general purpose automatic method for spatial distortion correction for flood histograms of PSAPD-based PET detectors when placed both inside and outside a MRI scanner. Analytical formulas derived for this scheme are based on a hybrid approach that combines desirable properties from two existing event positioning schemes. The rotation of the flood histogram due to the magnetic field is determined iteratively and is accounted for in the scheme. We then provide implementation details of a method for crystal identification we have previously proposed and evaluate it for cases when the PET detectors are both outside and in a magnetic field. In this scheme, Fourier analysis is used to generate a lower-order spatial approximation of the distortion-corrected PSAPD flood histogram, which we call the ldquotemplaterdquo. The template is then registered to the flood histogram using a diffeomorphic iterative intensity-based warping scheme. The calculated deformation field is then applied to the segmentation of the template to obtain a segmentation of the flood histogram. A manual correction tool is also developed for exceptional cases. We present a quantitative assessment of the proposed distortion correction scheme and crystal identification method against conventional methods. Our results indicate that our proposed methods lead to a large reduction in manual labor and indeed can routinely be used for calibration and characterization studies in MRI-compatible PET scanners based on PSAPDs.
Modeling of a Theoretical Construct in Inquiry-Based Science Education // Modelización de un constructo teórico sobre la percepción del alumnado en procesos de indagación en ciencias

El objetivo de este estudio es la modelizacion teorica de un constructo sobre la investigacion escolar en ciencias experimentales. El estudio se llevo a cabo con una muestra incidental de alumnado dentro un amplio rango de edades y diversos niveles educativos que participaban en un proyecto sobre el uso de trabajos practicos en ciencia y tecnologia. El instrumento consistia en un cuestionario tipo Likert que indagaba en cuestiones conceptuales, procedimientos cientificos, emision de hipotesis, realizacion de informes de investigacion y actitudes hacia la ciencia y tecnologia en un abanico muy amplio de problemas de investigacion escolar. Las variables de estudio inciden en estos aspectos de interes. Se estimo un modelo teorico con tres factores de primer orden (experiencial, conceptual y explicativo) y otro factor de tercer orden (factor integrador). El modelo disenado no se rechazo y puede proporcionar una base para comprender como percibe el alumnado los trabajos experimentales en ciencias y tecnologia.
Voices of Tribal Parents and Caregivers of Children with Special Needs

Educational reform presents a number of challenges for elders, tribal educational leaders, American Indian and Alaska Native (AI/AN) teachers and administrators, and families across the United States, including the pressing need to address parent or caregiver and community involvement in education. This study was conducted to (a) summarize major factors that impact special education service delivery for AI/AN children and young adults, (b) highlight legal and ethical issues by sharing six AI/AN parents' and caregivers' personal stories, and (c) discuss the implications of the issues raised for service delivery, policy development, and research. Qualitative methods were chosen to obtain an in-depth knowledge of individual participants' experiences, thoughts, and recommendations regarding serving AI/AN children with disabilities. Ethnographic interviews were conducted and several themes emerged from the data including AI/AN parents' and caregivers' responses regarding professional development, information sharing, assessments, individualized education program and individual family service plan implementation, and cultural concerns. The implications of shared individual issues within each theme are discussed.