Miracle-dz/UniFAR-FTUs huggingface dataset:
Development of the Modes of Collaboration framework

Group work is becoming increasingly common in introductory physics classrooms. Understanding how students engage in these group learning environments is important for designing and facilitating productive learning opportunities for students. We conducted a study in which we collected video of groups of students working on conceptual electricity and magnetism problems in an introductory physics course. In this setting, students needed to negotiate a common understanding and coordinate group decisions in order to complete the activity successfully. We observed students interacting in several distinct ways while solving these problems. Analysis of these observations focused on identifying the different ways students interacted and articulating what defines and distinguishes them, resulting in the development of the Modes of Collaboration framework. The Modes of Collaboration framework defines student interactions along three dimensions: social, discursive, and disciplinary content. This multi-dimensional approach offers a unique lens through which to consider group work and provides a flexibility that could allow the framework to be adapted for a variety of contexts. We present the framework and several examples of its application here.
Carbon cations and silicon atoms in the ISM: modelling their charge exchange reaction

The time-dependent rate coefficients for the charge exchange reaction C + + Si ! C + Si + for doublet and quartet states have been determined with ab initio quantum calculations coupled with a non-adiabatic transition model based on a simple LandauZener picture. This reaction plays a key role in determining the abundances of C, Si, and their ions, in the ISM since these abundances affect the fine structure cooling and hence the star formation rates. We also provide additional calculations to evaluate the differences between the gas evolution as obtained by using the empirical rate estimates found in the current literature and the calculations presented in this work which are based on our more realistic evaluation of such rates from ab initio transition probabilities. We shall thus show here that the new rates yield important differences for metal-rich environments where T < 10 4 K and the UV flux is very small, while
SUZAKU OBSERVATIONS OF THE HMXB 1A 1118−61

We present broadband analysis of the Be/X-ray transient 1A 1118−61 by Suzaku at the peak of its third observed outburst in 2009 January and two weeks later when the source flux had decayed by an order of magnitude. The continuum was modeled with a cutoffpl model as well as a compTT model, with both cases requiring an additional blackbody component at lower energies. We confirm the detection of a cyclotron line at ∼55 keV and discuss the possibility of a first harmonic at ∼110 keV. Pulse profile comparisons show a change in the profile structure at lower energies, an indication for possible changes in the accretion geometry. Phase-resolved spectroscopy in the outburst data shows a change in the continuum throughout the pulse period. The decrease in the cyclotron resonance scattering feature centroid energy also indicates that the viewing angle on the accretion column is changing throughout the pulse period.
Lithium adsorption on zigzag graphene nanoribbons

We have studied the adsorption of Li atoms at the hollow sites of graphene nanoribbons (zigzag and armchair), graphene, and fullerenes by means of density functional theory calculations including local and semilocal functionals. The binding energy of a Li atom on armchair nanoribbons [of about 1.70 eV for local spin density approximation (LSDA) and 1.20 eV for Perdew–Burke–Ernzerhof (PBE)] is comparable to the corresponding value in graphene (1.55 and 1.04 eV for LSDA and PBE, respectively). Notably, the interaction between Li and zigzag nanoribbons is much stronger. The binding energy of Li at the edges of zigzag nanoribbons is about 50% stronger than in graphene for the functionals studied here. While the charge transfer between the Li adatom and the zigzag nanoribbon significantly affects the magnetic properties of the latter providing an additional interaction mechanism that is not present in a two-dimensional graphene or armchair nanoribbons, we find that the morphology of the edges, rather than magn.
Prospects for high-precision pulsar timing

Timing pulses of pulsars has been proved to be the most powerful technique useful to a host of research areas in astronomy and physics. Importantly, the precision of this timing is not only affected by radiometer noise, but also by intrinsic pulse shape changes, interstellar medium (ISM) evolution, instrumental distortions, etc. In this paper we review the known causes of pulse shape variations and assess their effect on the precision and accuracy of a single measurement of pulse arrival time with current instrumentation. Throughout this analysis we use the brightest and most precisely timed millisecond pulsar (MSP), PSR J0437−4715, as a case study, and develop a set of diagnostic tools to evaluate profile stability in timing observations. We conclude that most causes of distortion can be either corrected by state-of-the-art techniques or taken into account in the estimation of time-of-arrival (TOA) uncertainties. The advent of a new generation of radio telescopes (e.g. the Square Kilometre Array, SKA) and their increase in collecting area have sparked speculation about the timing precision achievable through increases in gain. Based on our analysis of current data, we predict that for normal brightness MSPs a TOA precision of between 80 and 230 ns can be achieved at 1.4 GHz with 10 min integrations by the SKA. The actual rms timing residuals for each pulsar will be approximately at the same level only if all the other influences on timing precision (e.g. ISM, spin noise) are either corrected, modelled or negligible.
An Updated Edln Equation for the Refractive Index of Air

The Edlen equation for the refractive index of air, published in 1966, is still widely used. Subsequent to its formulation, however, improved data have become available on the density of air and the refractivity of water vapour. The practical temperature scale has also been revised and the carbon dioxide content of normal laboratory air has increased. These effects result in a discrepancy of typically 1 × 10-7. The consequent revision of the equation brings the agreement between calculation and experiment within an experimental uncertainty of ± 3 × 10-8.
Microwave induced zero-conductance state in a Corbino geometry two-dimensional electron gas with capacitive contacts

Microwave induced photoconductivity of a two-dimensional electron gas in selectively doped GaAs/AlAs heterostructures has been studied using the Corbino geometry with capacitive contacts at a temperature T=1.6 K and magnetic field B up to 0.5 T. Zero-conductance states have been observed in the samples under study subject to microwave radiation, similarly to the samples with Ohmic contacts. It has been shown that Ohmic contacts do not play a significant role for observation of zero-conductance states induced by microwave radiation.
BIOINFORMATICS A fast, lock-free approach for efﬁcient parallel counting of occurrences of k -mers

Motivation: Counting the number of occurrences of every k -mer (substring of length k ) in a long string is a central subproblem in many applications, including genome assembly, error correction of sequencing reads, fast multiple sequence alignment and repeat detection. Recently, the deep sequence coverage generated by next-generation sequencing technologies has caused the amount of sequence to be processed during a genome project to grow rapidly, and has rendered current k -mer counting tools too slow and memory intensive. At the same time, large multicore computers have become commonplace in research facilities allowing for a new parallel computational paradigm. Results: We propose a new k -mer counting algorithm and associated implementation, called Jellyﬁsh, which is fast and memory efﬁcient. It is based on a multithreaded, lock-free hash table optimized for counting k -mers up to 31 bases in length. Due to their ﬂexibility, sufﬁx arrays have been the data structure of choice for solving many string problems. For the task of k -mer counting, important in many biological applications, Jellyﬁsh offers a much faster and more memory-efﬁcient solution. Availability: The Jellyﬁsh software is written in C++ and is GPL licensed. It is available for download at http://www.cbcb. umd.edu/ software/jellyﬁsh. are available at online.
A New 4-DOF Lower-Limb Rehabilitation Robot Based on Natural Motions of Knee and Ankle-Foot Complex: Simulation and Experiment

—Stationary robotic trainers are lower limb rehab robots which often incorporate an exoskeleton attached to a stationary base. The aim is to recover range of motion, increase muscles strength and reduce joint stiffness. The issue observed in the stationery trainers which involve knee and ankle-foot complex joints simultaneously is that they restrict the natural motion of ankle-foot in rehab trainings due to the insufficient Degrees of Freedom (DOFs) of these trainers. This restriction makes the joints deviate from their natural motion patterns, exerting potentially harmful forces and strain the joints. In this work, we propose a new stationary knee-ankle-foot rehab robot with all necessary DOFs including knee flexion/extension in addition to ankle plantarflexion/dorsiflexion, ankle-foot abduction-adduction and foot supination/pronation. Axes of motions are determined based on the kinematics of the joints. A typical rehab training exercise has been considered to evaluate the system performance. The chosen training (i.e., passive assistance) was first implemented in simulation to synthesize the control loop and to extract the parameters required for selecting the robot’s components. The robot was then fabricated and tested on a healthy subject. Results showed that all natural motions of the ankle-foot complex were generated during the training. Therefore, the proposed system fulfils the desired aim properly, so that it can be utilized in the design of rehab robots.
Solar-like Oscillations: An Observational Perspective

Solar-like oscillations are excited stochastically by convection. They occur in stars with an outer convection zone, which includes the Sun and other stars on the lower main sequence, as well as cool subgiants and red giants. This chapter reviews the basic properties of solar-like oscillations and summarises some of the main observational results. Mixed modes in subgiants and red giants are discussed in some detail, including an introduction to the so-called p-g diagram for avoided crossings.
Statistical properties of GARCH processes

This dissertation contains five chapters. An introduction and a summary of the research are given in Chapter 1. The other four chapters present theoretical results on the moment structure of GARCH processes. Some chapters also contain empirical examples in order to illustrate applications of the theory. The focus, however, is mainly on statistical theory. Chapter 2 considers the moments of a family of first-order GARCH processes. First, a general condition of the existence of any integer moment of the absolute values of the observations is given. Second, a general expression of this moments as a function of lower-order moments is derived. Third, the kurtosis and the autocorrelation function of the squared and absolute-valued observations are derived. The results apply to a host of different GARCH parameterizations. Finally, the existence, or the lack of it, of the theoretical counterpart to the so-called Taylor effect for some members of this GARCH family is discussed. The asymmetric power ARCH model is a recent addition to time series models that may be used for predicting volatility. Its performance is compared with that of standard models of conditional heteroskedasticity such as GARCH. This has previously been done empirically. In Chapter 3 the same issue is studied theoretically using unconditional fractional moments for the A-PARCH model that are derived for the purpose. The role of the heteroskedasticity parameter of the A-PARCH process is highlighted and compared with corresponding empirical results involving autocorrelation functions of power-transformed absolute-valued return series.In Chapter 4, a necessary and sufficient condition for the existence of the unconditional fourth moment of the GARCH(p,q) process is given as well as an expression for the moment itself. Furthermore, the autocorrelation function of the centred and squared observations of this process is derived. The statistical theory is further illustrated by a few special cases such as the GARCH(2,2) process and the ARCH(q) process.Nonnegativity constraints on the parameters of the GARCH(p,q) model may be relaxed without giving up the requirement of the conditional variance remaining nonnegative with probability one. Chapter 5 looks into the consequences of adopting these less severe constraints in the GARCH(2,2) case and its two second-order special cases, GARCH(2,1) and GARCH(1,2). This is done by comparing the autocorrelation function of squared observations under these two sets of constraints. The less severe constraints allow more flexibility in the shape of the autocorrelation function than the constraints restricting the parameters to be nonnegative. The theory is illustrated by an empirical example.
Gene Co-Expression Network Modular Analysis Reveals Altered Immune Mechanisms in HIV-HAND

Although the introduction of HAART has completely changed the natural course of HIV infection, the number of chronic forms of HIV-associated neurocognitive disorder (HAND) has risen. It is estimated that up to half of subjects undergoing HAART therapy exhibit mild cognitive impairments. In the current study, we apply the gene co-expression network modular analysis, a well-established system biology approach, to the gene expression profiles of cases from the National NeuroAIDS Tissue Consortium (NNTC). We observed a negative enrichment for genes associated with the control of immune responses and putatively regulated by the transcription factors IRF8 and SPI1 and by both type I and II interferons. Our study provides evidence of altered immune responses, which are likely associated with the occurrence of HAND in the absence of HIV encephalitis (HIVE).
Labeling on a Chip of Cellular Fibronectin and Matrix Metallopeptidase-9 in Human Serum

We present a microfluidic chip for protein labeling in the human serum-based matrix. Serum is a complex sample matrix that contains a variety of proteins, and a matrix is used in many clinical tests. In this study, the device performance was tested using commercial serum samples from healthy donors spiked with the following target proteins: cellular fibronectin (c-Fn) and matrix metallopeptidase 9 (MMP9). The microfluidic molds were fabricated using micro milling on acrylic and using stereolithography (SLA) three-dimensional (3D) printing for an alternative method and comparison. A simple quality control was performed for both fabrication mold methods to inspect the channel height of the chip that plays a critical role in the labeling process. The fabricated microfluidic chip shows a good reproducibility and repeatability of the performance for the optimized channel height of 150 µm. The spiked proteins of c-Fn and MMP9 in the human serum-based matrix, were successfully labeled by the functionalized magnetic nanoparticles (MNPs). The biomarker labeling occurring in the serum was compared using a simple matrix sample: phosphate buffer. The measured signals obtained by using a magnetoresistive (MR) biochip platform showed that the labeling using the proposed microfluidic chip is in good agreement for both matrixes, i.e., the analytical performance (sensitivity) obtained with the serum, near the relevant cutoff values, is within the uncertainty of the measurements obtained with a simple and more controlled matrix: phosphate buffer. This finding is promising for stroke patient stratification where these biomarkers are found at high concentrations in the serum.
Barriers to accessing mother, new-born and services in urban Gambia during COVID-19: An interview-based qualitative study.

Introduction: Evidence is being consolidated that shows that the utilisation of mother, newborn, and child health (MNCH) services has declined in low-income countries (LICs) during the COVID-19 pandemic. Very little is known about the effects of the pandemic on MNCH service utilisation in the Gambia. We set out to explore the COVID-19-related factors affecting the utilisation of antenatal and immunisation services in the Gambia. Methods: A qualitative methodology was used to explore patients’ and providers’ experiences of MNCH services during the pandemic in two Local Government Areas (LGAs) in the Gambia. Thirty-one study participants were recruited from four health facilities, applying a theory-driven sampling framework, including health workers as well as female patients. Qualitative evidence was collected through theory-driven semi-structured interviews, and was recorded, translated into English, transcribed, and analysed thematically, applying a social-ecological framework. Results: In our interviews, we identified five main themes, ranging from individual factors to interpersonal, community, institutional and policy factors. Individual factors revolved around patients’ fear of being infected in the facilities, and of being quarantined, and their anxiety about passing on infections to family members. Interpersonal factors involved the reluctance of partners and family members, as well as perceived negligence and disrespect by health workers. Community factors included misinformation within the community and mistrust of vaccines. Institutional factors included the shortage of health workers, closures of health facilities, and the lack of personal protective equipment (PPEs) and essential medicines. Finally, policy factors revolved around the consequences of COVID-19 prevention measures, particularly the shortage of transport options and mandatory wearing of face masks. Conclusions: Our findings suggest that patients’ fears of contagion, perceptions of poor treatment in the health system, and a general anxiety around the imposing of prevention measures, undermined the uptake of MNCH services. In future emergencies, the government in the Gambia, and governments in other LICs, will need to consider the unintended consequences of epidemic control measures on the uptake of MNCH services. CC-BY 4.0 International license It is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted October 7, 2022. ; https://doi.org/10.1101/2022.10. 06.22280770 doi: medRxiv preprint NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice.
Design of Integrated Energy System Based on IEC 61499 and OPC UA

Integrated Energy System (IES) is a key component of energy internet, which has made great progress in multi-energy supplementation, energy conservation and emission reduction. IEC 61499 standard and OPC UA communication are powerful cyber-physical system technologies for dynamic reconfiguration, interoperability, and integrability. In this paper, we propose a modular design and development approach for IES, based on the reconfiguration-supporting distributed architecture of IEC 61499. For data integration and transmission, we use OPC UA on the communication level to support multiple devices and communication protocols. The program design is implemented on an IEC 61499 compliant software platform. We build a photovoltaic simulation system with real-time electric meter data acquisition through an OPC UA gateway device. Experimental and simulation results show that the proposed approach is effective in realizing a unified, robust and efficient integrated energy control system.
Enhancing Stress Prediction Models for Rice with Ambient and Field Data in Rabi 2019-20

Every crop needs optimum environment conditions to grow and provide good yield. Similarly, pests and diseases for a given crop require conducive ambient conditions to start proliferating thereby interfering with the yield and increasing management costs for the crop. For farmers to timely respond to crop damage, precisely predicting the likelihood of pest and disease stress conditions for a given region of interest is paramount to take early action. Rice is major crop in India grown over Kharif and Rabi seasons. For a key state Andhra Pradesh and associated major stress conditions in Rabi 2019-20, we present localised prediction models that use ambient micro-climatic conditions and ground reported data to forecast trends for major pests and diseases such as Stem Borer, Leaf Folder, Leaf Blast, and Bacterial Blight. For effective localisation, images reported from the fields for these conditions are validated with AI based detection models before getting processed further. A major contribution of the work is to realise an integrated system that continuously adapts to pest and disease stress conditions on the ground and offers precise risk prediction advisory to the farmer ecosystem for effective management. The approach has been demonstrated to work well with in-season farm surveillance activities at scale.
Researches on Non-standard Optics for Advanced Gravitational Waves Interferometers

This thesis presents a collection of different researches on non-standard optics in view of enhancing the performances of the Advanced Gravitational waves interferometric detectors, where the thermal noise of the test masses is expected to be a limiting factor for their sensitivity. We provide a quantitative analysis of the impact of non-Gaussian beams on different kinds of thermal noises. We developed the theory of mesa beam, in view of a future implementation in advanced GW interferometers of the mesa beam idea, focusing on the analytical derivation of the quantities (i.e. beam width, divergence, propagation factor), which are chosen as ISO standard reference parameters for the characterization of an optical beam. We also analytically proved a new duality relation between optical cavities with non-spherical mirrors. The interest of the GW community in this new beam technology led us to the construction and testing of a prototype mesa beam Fabry-Perot cavity with Mexican-hat mirror. Part of the work of this thesis was devoted to the development of new simulation programs of optical systems. These programs provided the theoretical expected behaviour of our experiment, in particular cavity modes structure and misalignments sensitivity to be confronted with the experimental results. We also explored another complementary way of reducing the mirror thermal noise, beside the beam shaping, that is the multi-layered coating thickness optimization. We show it to be effective in reducing the coating noise and explore the possible implications for GW interferometers in terms of sensitivity. During this analysis we developed an independent model for the coating effective elastic parameters, which is based on the well understood subject of homogenization theory.