In this work we approach the Schrödinger equation in quantum wells with arbitrary potentials, using the machine learning technique. Two neural networks with different architectures are proposed and ...trained using a set of potentials, energies, and wave functions previously generated with the classical finite element method. Three accuracy indicators have been proposed for testing the estimates given by the neural networks. The networks are trained by the gradient descent method and the training validation is done with respect to a large training data set. The two networks are then tested for two different potential data sets and the results are compared. Several cases with analytical potential have also been solved.
DNA and RNA nanotechnology has been used for the development of dynamic molecular devices. In particular, programmable enzyme-free nucleic acid circuits, such as catalytic hairpin assembly, have been ...demonstrated as useful tools for bioanalysis and to scale up system complexity to an extent beyond current cellular genetic circuits. However, the intracellular functions of most synthetic nucleic acid circuits have been hindered by challenges in the biological delivery and degradation. On the other hand, genetically encoded and transcribed RNA circuits emerge as alternative powerful tools for long-term embedded cellular analysis and regulation. Herein, we reported a genetically encoded RNA-based catalytic hairpin assembly circuit for sensitive RNA imaging inside living cells. The split version of Broccoli, a fluorogenic RNA aptamer, was used as the reporter. One target RNA can catalytically trigger the fluorescence from tens-to-hundreds of Broccoli. As a result, target RNAs can be sensitively detected. We have further engineered our circuit to allow easy programming to image various target RNA sequences. This design principle opens the arena for developing a large variety of genetically encoded RNA circuits for cellular applications.
Abstract
The effects of confinement potentials of the first and second materials, core size and first shell thickness on the confinement of electron, electron-donor atom, and exciton in cylindrical ...core/shell/shell quantum dot (CSSQD) are studied taking into account the finite confinement potential model. The confinement of charge carriers in CSSQD with two finite confinement potentials models of the barrier materials are studied. Within the effective mass and parabolic band approximation, the 3D time-independent Schrödinger equation has been resolved. To obtain the ground state quasiparticles energies, we have used the variational technique. Our results show that the donor atom and exciton binding energy, as well as the electron energy, strongly depend on the core radius, first shell thickness, confinement potentials of the barrier materials, and their structures (A and B). Moreover, the confinement potential effect of the first material on the energies is more pronounced when their thickness is large and the core radius is small. So, the external potential effect is more significant when the first shell thickness and potential are small. Also, The binding energy of an on-center (off-center) donor atom is greater (weaker) than that of the exciton, whatever the structure of the confinement potential. In addition, the transition from a type-A to a type-B confinement system has been observed. The findings might be used to modify the electronic and excitonic properties in nanomaterials science.
•We addressed the scheduling and routing of a repair crew after a disaster.•We present a dynamic programming model that solves small/mid-sized problems.•We develop a IGRCP procedure to solve large ...problem instances efficiently.•Our work has societal impact as it helps to efficiently repair a network damaged by a disaster.•Considering the routing of the repair crew makes the problem more realistic.
Every year, hundreds of thousands of people are affected by natural disasters. The number of casualties is usually increased by lack of clean water, food, shelter, and adequate medical care during the aftermath. One of the main problems influencing relief distribution is the state of the post-disaster road network. In this paper, we consider the problem of scheduling the emergency repair of a rural road network that has been damaged by the occurrence of a natural disaster. This problem, which we call the Network Repair Crew Scheduling and Routing Problem addresses the scheduling and routing of a repair crew optimizing accessibility to the towns and villages that demand humanitarian relief by repairing roads. We develop both an exact dynamic programming (DP) algorithm and an iterated greedy-randomized constructive procedure to solve the problem and compare the performance of both approaches on small- to medium-scale instances. Our numerical analysis of the solution structure validates the optimization model and provides managerial insights into the problem and its solutions.
Heart failure (HF) is a complex clinical syndrome with multiple interactions between the failing myocardium and cerebral (dys‐)functions. Bi‐directional feedback interactions between the heart and ...the brain are inherent in the pathophysiology of HF: (i) the impaired cardiac function affects cerebral structure and functional capacity, and (ii) neuronal signals impact on the cardiovascular continuum. These interactions contribute to the symptomatic presentation of HF patients and affect many co‐morbidities of HF. Moreover, neuro‐cardiac feedback signals significantly promote aggravation and further progression of HF and are causal in the poor prognosis of HF. The diversity and complexity of heart and brain interactions make it difficult to develop a comprehensive overview. In this paper a systematic approach is proposed to develop a comprehensive atlas of related conditions, signals and disease mechanisms of the interactions between the heart and the brain in HF. The proposed taxonomy is based on pathophysiological principles. Impaired perfusion of the brain may represent one major category, with acute (cardio‐embolic) or chronic (haemodynamic failure) low perfusion being sub‐categories with mostly different consequences (i.e. ischaemic stroke or cognitive impairment, respectively). Further categories include impairment of higher cortical function (mood, cognition), of brain stem function (sympathetic over‐activation, neuro‐cardiac reflexes). Treatment‐related interactions could be categorized as medical, interventional and device‐related interactions. Also interactions due to specific diseases are categorized. A methodical approach to categorize the interdependency of heart and brain may help to integrate individual research areas into an overall picture.
In this study, we investigated the exciton binding energy and interband transition between the electron and heavy-hole for the single and double quantum wells which have different hyperbolic-type ...potential functions subject to electric, magnetic, and non-resonant intense laser fields. The results obtained show that the geometric shapes of the structure and the applied external fields are very effective on the electronic and optical properties. In the absence of the external fields, the exciton binding energy is a decreasing function of increasing well sizes except for the strong confinement regime. Therefore, for all applied external fields, the increase in the well widths produces a red-shift at the absorption peak positions. The magnetic field causes an increase in the exciton binding energy and provides a blue-shift of the absorption peak positions corresponding to interband transitions. The effect of the electric field is quite pronounced in the weak confinement regime, it causes localization in opposite directions of the quantum wells of the electron and hole, thereby weakening the Coulomb interaction between them, causing a decrease in exciton binding energy, and a red-shift of the peak positions corresponding to the interband transitions. Generally, an intense laser field causes a decrease in the exciton binding energy and produces a red-shift of the peak positions corresponding to interband transitions.
Using the concept of appropriation, the initial act of social metabolism, and other land use transition perspectives, this paper examines the land use transitions and landscape appropriation in the ...Colombian South Pacific region (CSP) across three historical periods: the Colonial period (16th–18th centuries), the opening of the liberal economy (19th century), and globalization (20th–21st centuries). Historical information on land uses and economic exchange in the CSP were synthesized in material flow models. Landscape appropriation increased in each period due to an increase in productive and extractive practices and the exchange of matter and energy. These processes were primarily driven by i) shifting environmental ideologies associated with different political regimes, ii) shifting labor relations, iii) population growth and new settlement patterns, iv) improvements in transportation and communication technologies, and v) the increase of the number and diversity of circulated goods.
•Presents historical landscape appropriation and land use transitions in the Colombian South Pacific•Applies a flows model of appropriation to examine patterns of resource extraction and exchange•The intensity and diversity of extraction increased in response to shifting political regimes, labor relations, settlement patterns, and improvements in transportation•Pressure on nature tends to grow due to increasing productive and extractive practices, despite more recent conservation efforts
•We studied a home care planning problem faced by Landelijke Thuiszorg, a non-profit organisation that provides home care services in several provinces of Belgium.•A set partitioning formulation of ...the bi-objective problem is proposed.•We propose a two-phase approach that allows to analyse the trade-off between the prioritised objectives.•Our solution strategy is flexible in the sense that it can be easily adapted to tackle additional and complicating constraints.•The solution strategy is simple and easy to understand which facilitates the communication and the acceptance of our algorithm within the organisation.•Our two-phase algorithm will be the core optimisation component of a decision support system.
Landelijke Thuiszorg is a “social profit” organisation that provides home care services in several Belgian regions. In this paper, the core optimisation component of a decision support system to support the planning of the organisations’ home care service is described. Underlying this decision support system is an optimisation problem that aims to maximise the service level and to minimise the distance travelled by the caregivers of the organisation. This problem is formulated as a bi-objective mathematical program, based on a set partitioning problem formulation. A flexible two-stage solution strategy is designed to efficiently tackle the problem. Computational tests, as well as extensive pilot runs performed by the organisation’s personnel, show that this approach achieves excellent performance, both in terms of the service level and total travelled distance. Moreover, computational times are small, allowing for the weekly planning to be largely automated. The organisation is currently in the process of implementing our solution approach in collaboration with an external software company.
Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects people from birth, whose symptoms are found in the early developmental period. The ASD diagnosis is usually performed ...through several sessions of behavioral observation, exhaustive screening, and manual coding behavior. The early detection of ASD signs in naturalistic behavioral observation may be improved through Child-Robot Interaction (CRI) and technological-based tools for automated behavior assessment. Robot-assisted tools using CRI theories have been of interest in intervention for children with Autism Spectrum Disorder (CwASD), elucidating faster and more significant gains from the diagnosis and therapeutic intervention when compared to classical methods. Additionally, using computer vision to analyze child’s behaviors and automated video coding to summarize the responses would help clinicians to reduce the delay of ASD diagnosis. In this article, a CRI to enhance the traditional tools for ASD diagnosis is proposed. The system relies on computer vision and an unstructured and scalable network of RGBD sensors built upon Robot Operating System (ROS) and machine learning algorithms for automated face analysis. Also, a proof of concept is presented, with participation of three typically developing (TD) children and three children in risk of suffering from ASD.
Two types of graphene nanoribbons: (a) potassium-split graphene nanoribbons (GNRs), and (b) oxidative unzipped and chemically converted graphene nanoribbons (CCGNRs) were investigated for their ...magnetic properties using the combination of static magnetization and electron spin resonance measurements. The two types of ribbons possess remarkably different magnetic properties. While a low-temperature ferromagnet-like feature is observed in both types of ribbons, such room-temperature feature persists only in potassium-split ribbons. The GNRs show negative exchange bias, but the CCGNRs exhibit a “positive exchange bias”. Electron spin resonance measurements suggest that the carbon-related defects may be responsible for the observed magnetic behavior in both types of ribbons. Furthermore, information on the proton hyperfine coupling strength has been obtained from hyperfine sublevel correlation experiments performed on the GNRs. Electron spin resonance finds no evidence for the presence of potassium (cluster) related signals, pointing to the intrinsic magnetic nature of the ribbons. Our combined experimental results may indicate the coexistence of ferromagnetic clusters with antiferromagnetic regions leading to disordered magnetic phase. We discuss the possible origin of the observed contrast in the magnetic behaviors of the two types of ribbons studied.
PDF
