Miracle-dz/UniFAR-FTUs huggingface dataset:
Optical Wireless Communications: Research Challenges for MAC Layer

Optical wireless communication (OWC) has emerged as a potential addition to current wireless technologies because of its high capacity, security, and unlicensed spectrum. In addition, owing to recent advancements in optoelectronic components and the industry’s globalization, OWC has become a promising solution for addressing upcoming bandwidth requirements and the “border mile bottleneck”. In 2018, the IEEEE 802.15. 7 (updated) standard was released, which proposes physical (PHY) and medium access layer (MAC) layers for OWC-based systems employing visible light (380nm and 780nm) for downstream and infrared spectrum for upstream. Significant research has already been undertaken on the PHY layer; however, the MAC layer must be tailored for application-specific demands. This paper presents a historical overview, summarizes recent works, and offers a broader perspective on OWC-based MAC layer issues, suggesting prospective future research areas. Furthermore, the document aims to provide an overview of the primary technologies necessary to comprehend OWC technology. The document investigates various MAC layer challenges in OWC, including hidden nodes, appropriate guaranteed time slot (GTS) resource allocation, network mobility, and fast link recovery. A comprehensive literature review is performed to identify these MAC layer challenges hindering the widespread implementation of green wireless communication technology. In contrast to previous assessments, this article provides a concise summary of relevant publications on the development of an application-specific OWC-MAC layer.
Estimation of image noise variance

A novel algorithm for estimating the noise variance of an image is presented. The image is assumed to be corrupted by Gaussian distributed noise. The algorithm estimates the noise variance in three steps. At first the noisy image is filtered by a horizontal and a vertical difference operator to suppress the influence of the (unknown) original image. In a second step a histogram of local signal variances is computed. Finally a statistical evaluation of the histogram provides the desired estimation value. For a comparison with several previously published estimation methods an ensemble of 128 natural and artificial test images is used. It is shown that with the novel algorithm more accurate results can be achieved.
Polymeric Nanoparticles for Drug Delivery in Osteoarthritis

Osteoarthritis (OA) is a degenerative musculoskeletal disorder affecting the whole synovial joint and globally impacts more than one in five individuals aged 40 and over, representing a huge socioeconomic burden. Drug penetration into and retention within the joints are major challenges in the development of regenerative therapies for OA. During the recent years, polymeric nanoparticles (PNPs) have emerged as promising drug carrier candidates due to their biodegradable properties, nanoscale structure, functional versatility, and reproducible manufacturing, which makes them particularly attractive for cartilage penetration and joint retention. In this review, we discuss the current development state of natural and synthetic PNPs for drug delivery and OA treatment. Evidence from in vitro and pre-clinical in vivo studies is used to show how disease pathology and key cellular pathways of joint inflammation are modulated by these nanoparticle-based therapies. Furthermore, we compare the biodegradability and surface modification of these nanocarriers in relation to the drug release profile and tissue targeting. Finally, the main challenges for nanoparticle delivery to the cartilage are discussed, as a function of disease state and physicochemical properties of PNPs such as size and surface charge.
Photosensitive Hydrogel-Based Embolic Agent Treatment of Wide-Necked Aneurysms: Preliminary Animal Results

Abstract Background: The endovascular treatment of cerebral aneurysms has become widespread but may still be limited by recurrence rates or complications. The discovery of novel embolic strategies may help mitigate these concerns. Methods: We formulated a Photosensitive Hydrogel Polymer (PHP) embolic agent which is low-viscosity, shear-thinning, and radio-opaque. After the filling of an aneurysm with PHP with balloon assistance, we utilized photopolymerization to induce solidification. Different methods of light delivery for photopolymerization were assessed in silicone models of aneurysms and in four acute animal trials with venous anastomosis aneurysms in pigs. Then, balloon-assisted embolization with PHP and photopolymerization was performed in three aneurysms in pigs with a one-month follow-up. Filling volume, recurrence rates, and complications were recorded. Results: The PHP was found to be suitable for the intravascular delivery and treatment of cerebral aneurysms. It was found that light delivery through the balloon catheter, as opposed to light delivery through the injection microcatheter, led to higher rates of filling in the 3D model and acute animal model for cerebral aneurysms. Using the balloon-assisted embolization and light delivery strategy, three wide-necked aneurysms were treated without complication. One-month follow-up showed no recurrence or neck remnants. Conclusions: We demonstrated a novel method of balloon-assisted photosensitive hydrogel polymer embolization and photopolymerization, leading to complete aneurysm filling with no recurrence at 1 month in three wide-necked aneurysms in pigs. This promising methodology will be investigated further with longer-term comparative animal trials.
Application of nested multigrid finite elements to two‐dimensional electromagnetic scattering

Nested multigrid techniques are combined with the finite‐element method for the fast numerical solution of two‐dimensional electromagnetic scattering problems. The finite‐element modeling is performed on nested meshes of the same computational domain. The conjugate‐gradient method is used to solve the resultant finite‐element matrix for the finest mesh, while the multigrid method acts as the preconditioner of the iterative solver. Numerical experiments are used to demonstrate the efficiency as well as the limits of the proposed methodology. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 97–101, 2001.
We implicitly empathize with virtual agents: the effect of motor simulation

Interacting with virtual agents (VAs) is becoming a quite common experience in our modern society. Therefore, it is important to explore the psychological mechanisms underlying the “hybrid” virtual-human social interaction. To this end, here we test whether motor simulation mechanisms affect localization in near or far space even when involving a virtual agent. In an Immersive Virtual Reality scenario, either VA or participants could have their arms blocked (motor interference) and could stand at a close (i.e., reachable) or far (i.e., unreachable) distance from each other. Participants had to perform a task that implicitly prompted them to consider each other’s space, that is, they had to judge whether a glass was closer to themselves (thus pointing to their own space) or to a VA (thus pointing to the other’s space). The results showed that when VAs and participants were at a near distance, VAs were blocked and the glass was closer to them, spatial judgments were slower than other conditions. This shows a strong effect of perceived motor interference in the VA. In contrast, when the participants and VAs were far apart, judgments were slower with the VA blocked only when the object was closer to the participant, i.e., within the participant’s reach. The slowdown in perceiving the blocked virtual agent may reflect a mechanism of identification and motor simulation that individuals implicitly activate, especially if virtual agents are near them.
An Improved Binary Owl Feature Selection in the Context of Android Malware Detection

Recently, the proliferation of smartphones, tablets, and smartwatches has raised security concerns from researchers. Android-based mobile devices are considered a dominant operating system. The open-source nature of this platform makes it a good target for malware attacks that result in both data exfiltration and property loss. To handle the security issues of mobile malware attacks, researchers proposed novel algorithms and detection approaches. However, there is no standard dataset used by researchers to make a fair evaluation. Most of the research datasets were collected from the Play Store or collected randomly from public datasets such as the DREBIN dataset. In this paper, a wrapper-based approach for Android malware detection has been proposed. The proposed wrapper consists of a newly modified binary Owl optimizer and a random forest classifier. The proposed approach was evaluated using standard data splits given by the DREBIN dataset in terms of accuracy, precision, recall, false-positive rate, and F1-score. The proposed approach reaches 98.84% and 86.34% for accuracy and F-score, respectively. Furthermore, it outperforms several related approaches from the literature in terms of accuracy, precision, and recall.
The Effectiveness of Stingless Bees on Pollination of Bitter Melon Plants Momordica charantia L. (Cucurbitaceae)

This study aimed to measure the effectiveness of stingless bee Tetragonula cf. biroi pollination on the fruit formation of bitter melon Momordica charantia plants. We used hoods on the observed bitter melon plants. In the first hood, stingless bees are inserted to help pollinate 100 bitter melon plants, while in the other hoods, stingless bees are not inserted so that there is no assistance in pollinating the other 100 bitter melon plants. The method used is the focal sampling method for 25 days of observation. Based on the results of the study, stingless bee pollination assistance increased the percentage of the number of flowers that became fruit by 390%, the weight of seeds/fruit by 64%, number of seeds/fruit by 260%, fruit weight by 163%, fruit diameter by 91%, and fruit length by 86%. In addition to the size of the fruit, the shape of the bitter melon pollinated by bees is standard (long and straight). In contrast, the bitter melon that does not get pollination assistance grows with a bent shape resembling the letter "C. " Bitter melon is an agricultural commodity that needs pollinating agents such as stingless bees because of its monoecy.
Randomized Controlled Trial of Robot-Assisted Gait Training versus Therapist-Assisted Treadmill Gait Training as Add-on Therapy in Early Subacute Stroke Patients: The GAITFAST Study Protocol

The GAITFAST study (gait recovery in patients after acute ischemic stroke) aims to compare the effects of treadmill-based robot-assisted gait training (RTGT) and therapist-assisted treadmill gait training (TTGT) added to conventional physical therapy in first-ever ischemic stroke patients. GAITFAST (Clinicaltrials.gov identifier: NCT04824482) was designed as a single-blind single-center prospective randomized clinical trial with two parallel groups and a primary endpoint of gait speed recovery up to 6 months after ischemic stroke. A total of 120 eligible and enrolled participants will be randomly allocated (1:1) in TTGT or RTGT. All enrolled patients will undergo a 2-week intensive inpatient rehabilitation including TTGT or RTGT followed by four clinical assessments (at the beginning of inpatient rehabilitation 8–15 days after stroke onset, after 2 weeks, and 3 and 6 months after the first assessment). Every clinical assessment will include the assessment of gait speed and walking dependency, fMRI activation measures, neurological and sensorimotor impairments, and gait biomechanics. In a random selection (1:2) of the 120 enrolled patients, multimodal magnetic resonance imaging (MRI) data will be acquired and analyzed. This study will provide insight into the mechanisms behind poststroke gait behavioral changes resulting from intensive rehabilitation including assisted gait training (RTGT or TTGT) in early subacute IS patients.
Investigation of Anti-inflammatory and Anti-oxidative Activities of Lonicerae Flos, Citri Pericarpium and Violae Herba Complex (LCVC)

Objectives: The anti-inflammatory and anti-oxidative activities of LCVC (Lonicerae Flos, Citri Pericarpium and Violae Herba Complex) have not been fully elucidated. The purpose of this study was to investigate the mechanisms underlying these effects in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages.Methods: The evaluation of the anti-oxidative activity of LCVC was completed via DPPH and ABTS radical scavenging capacity, FRAP assay, measurement of polyphenol and flavonoid, assessment of ROS and NO levels in LPS-induced RAW 264.7 cells. The anti-inflammatory activity was defined by measuring the production of biomarkers (PGE2, IL-1B, IL-6 and TNF-α), proteins (ERK, JNK, P38, Nrf2, Keap1, HO-1 and NQO1) and expressions of genes (iNOS, COX-2, IL-1β, IL-6, TNF-α, Nrf2, Keap1, HO-1 and NQO1) in LPS-induced RAW 264.7 cells.Results: LCVC have polyphenol and flavonoid contents. The results of DPPH and ABTS free radical scavenging capacity and FRAP assay showed that the anti-oxidative activity was increased. Production of ROS, NO, IL-6, TNF-α, mRNA expressions of IL-1β, IL-6, TNF-α, Keap1, iNOS and COX-2 were decreased, and NQO1, Nrf2, and HO-1 were increased. In protein expression, JNK and Keap1 were decreased, NQO1, Nrf2 and HO-1 were increased, and no relationships were observed with the ERK and P38 by LCVC.Conclusions: These results suggest that LCVC may offer protective effects against LPS-induced inflammatory and oxidative responses through attenuating Nrf2/HO-1 pathway and MAPKs pathway. Therefore, we propose that LCVC has anti-inflammatory and anti-oxidative activities that have therapeutic potential in the treatment of inflammatory and oxidative disorders caused by the over-activation of macrophages.
Effect of Experimental Electrical and Biological Parameters on Gene Transfer by Electroporation: A Systematic Review and Meta-Analysis

The exact mechanisms of nucleic acid (NA) delivery with gene electrotransfer (GET) are still unknown, which represents a limitation for its broader use. Further, not knowing the effects that different experimental electrical and biological parameters have on GET additionally hinders GET optimization, resulting in the majority of research being performed using a trial-and-error approach. To explore the current state of knowledge, we conducted a systematic literature review of GET papers in in vitro conditions and performed meta-analyses of the reported GET efficiency. For now, there is no universal GET strategy that would be appropriate for all experimental aims. Apart from the availability of the required electroporation device and electrodes, the choice of an optimal GET approach depends on parameters such as the electroporation medium; type and origin of cells; and the size, concentration, promoter, and type of the NA to be transfected. Equally important are appropriate controls and the measurement or evaluation of the output pulses to allow a fair and unbiased evaluation of the experimental results. Since many experimental electrical and biological parameters can affect GET, it is important that all used parameters are adequately reported to enable the comparison of results, as well as potentially faster and more efficient experiment planning and optimization.
The Biological Effects of Compound Microwave Exposure with 2.8 GHz and 9.3 GHz on Immune System: Transcriptomic and Proteomic Analysis

It is well-known that microwaves produce both thermal and nonthermal effects. Microwave ablation can produce thermal effects to activate the body’s immune system and has been widely used in cancer therapy. However, the nonthermal effects of microwaves on the immune system are still largely unexplored. In the present study, we exposed rats to multifrequency microwaves of 2.8 GHz and 9.3 GHz with an average power density of 10 mW/cm2, which are widely used in our daily life, to investigate the biological effects on the immune system and its potential mechanisms. Both single-frequency microwaves and multifrequency microwaves caused obvious pathological alterations in the thymus and spleen at seven days after exposure, while multifrequency microwaves produced more pronounced injuries. Unexpectedly, multifrequency microwave exposure increased the number of both leukocytes and lymphocytes in the peripheral blood and upregulated the proportion of B lymphocytes among the total lymphocytes, indicating activation of the immune response. Our data also showed that the cytokines associated with the proliferation and activation of B lymphocytes, including interleukin (IL)-1α, IL-1β and IL-4, were elevated at six hours after exposure, which might contribute to the increase in B lymphocytes at seven days after exposure. Moreover, multifrequency microwave exposure upregulated the mRNA and protein expression of B cell activation-associated genes in peripheral blood. In addition to immune-associated genes, multifrequency microwaves mainly affected the expression of genes related to DNA duplication, cellular metabolism and signal transduction in the peripheral blood and spleen. In conclusion, multifrequency microwaves with 2.8 GHz and 9.3 GHz caused reversible injuries of the thymus and spleen but activated immune cells in the peripheral blood by upregulating mRNA and protein expression, as well as cytokine release. These results not only uncovered the biological effects of multifrequency microwave on the immune system, but also provide critical clues to explore the potential mechanisms.
Wakes of Four Complex Bodies of Revolution at Zero Angle of Attack

The wakes of four complex bodies of revolution were investigated experimentally with a constant-temperature hot-wire anemometer. All tests were performed at a low Mach number (Moo — 0.1) and zero angle of attack. Mean and turbulence velocity profiles were obtained along and across the wakes. The structure of the axisymmetric wake and the effects of the geometric differences of the models on their wakes were investigated.
Water-Air Interface Imaging: Recovering the Images Distorted by Surface Waves via an Efficient Registration Algorithm

Imaging through the wavy water–air interface is challenging since the random fluctuations of water will cause complex geometric distortion and motion blur in the images, seriously affecting the effective identification of the monitored object. Considering the problems of image recovery accuracy and computational efficiency, an efficient reconstruction scheme that combines lucky-patch search and image registration technologies was proposed in this paper. Firstly, a high-quality reference frame is rebuilt using a lucky-patch search strategy. Then an iterative registration algorithm is employed to remove severe geometric distortions by registering warped frames to the reference frame. During the registration process, we integrate JADE and LBFGS algorithms as an optimization strategy to expedite the control parameter optimization process. Finally, the registered frames are refined using PCA and the lucky-patch search algorithm to remove residual distortions and random noise. Experimental results demonstrate that the proposed method significantly outperforms the state-of-the-art methods in terms of sharpness and contrast.
Efficient search scheme for very large image databases

Nearest Neighbor search is a fundamental task in many applications. At present state of the art, approaches to nearest neighbor search are not efficient in high dimensions. In this paper we present an efficient angle based balanced index structure called AB-tree, which uses heuristics to decide whether or not to access a node in the index tree based on the estimated angle and the weight of the node. We have presented the result of AB-tree for up to 64 dimensions, and have shown that the performance of the AB-tree algorithm does not deteriorate when processing nearest neighbor queries as dimension increases. However, it is no longer guaranteed that the entire true K nearest neighbors to a query point will be found. Extensive experiments on synthetic data and real data demonstrate that the search time is improved by a factor of up to 85 times over that of SS-tree in 64 dimension while maintaining 90 percent accuracy. Real data includes color histogram and corner like features in a heterogenous collection of natural images.
A Deep Learning pipeline for Network Anomaly Detection based on Autoencoders

During the last decade, we have witnessed an ever-increasing growth of inter-connected devices (e.g. IoT, Cloud) and the security assessment of such networks has become more and more essential. Identifying network anomalies represents a promising strategy to detect network intrusions, thefts to users privacy, system damage and fraudulent activities. Thanks to their ability to learn complex anomalies patterns in a complete data-driven fashion, deep neural networks have recently received an increasing attention. However, the application of such techniques is constrained by the peculiar characteristics of network traffic data, which is very sparse and noisy — due to the high number of devices generating data and Internet applications — and suffer from a high imbalance, i.e. anomalies typically occur 0.001-1% of the time. In this work, we handle the above-mentioned challenges with a simple pipeline: first, we identify samples with anomalous behavior by means of an autoencoder (AE); then, an attack classifier is used to assign anomalies to their attack type. We experiment our framework on a million-scale dataset of real-world network traffic data for anomaly detection, showing promising performance in terms of Precision, Recall and F1 scores.
Effect of AlN/GaN superlattice buffer on the strain state in GaN-on-Si(111) system

The effect of AlN/GaN superlattice (SL) buffer on the strain state in a GaN-on-Si(111) system was studied in detail by room-temperature micro-Raman scattering measurement. An abnormal satellite peak attached to a GaN E2 peak was observed, which was verified to stem from the compressively strained GaN in SLs. The results indicate that the strain-sensitive GaN E2 (high) peak in the GaN-on-Si system with AlN/GaN SLs splits into two peaks because the GaN stress state in the top GaN layer is different from that in SLs. The compressive stress in the GaN layer in SLs was introduced by the AlN layer in each SL period because of the lattice mismatch between GaN and AlN, which ultimately counterbalanced the tensile stress in the top GaN during cooling. Such a counterbalance interaction is strongly dependent on the stiffness coefficient of AlN/GaN SLs, which is proportional to the number of periods of SLs and the relative thickness of AlN in SLs. Such two E2 peaks from GaN enable us to monitor the strain state in the GaN-on-Si system with AlN/GaN SLs quantitatively.