Secrecy Analysis of a Mu-MIMO LIS-Aided Communication Systems under Nakagami-m Fading Channels.

This study evaluates the performance of large intelligent surface (LIS) technology in the context of a multi-user MIMO mobile communication system (Mu-MIMO) proposed for the sixth generation (6G). LIS employs digitally controlled reflectors to enhance Signal-to-Interference plus Noise Ratio (SINR) and establish line of sight (LoS) connectivity in non-LoS environments, improving transmission security. Analytical expressions are derived to assess LIS performance metrics, including distribution parameters, bit error probability, and secrecy outage probability, considering the presence of eavesdroppers and environmental fading. The study highlights the potential of LIS technology to enhance the confidentiality and reliability of digital communication systems in next-generation networks.

Simultaneous Estimation of Azimuth and Elevation Angles Using a Decision Tree-Based Method.

This study addresses the problem of accurately predicting azimuth and elevation angles of signals impinging on an antenna array employing Machine Learning (ML). Using the information obtained at a receiving system when a transmitter's signal hits it, a Decision Tree (DT) model is trained to estimate azimuth and elevation angles simultaneously. Simulation results demonstrate the robustness of the proposed DT-based method, showcasing its ability to predict the Direction of Arrival (DOA) in diverse conditions beyond the ones present in the training dataset, i.e., the results display the model's generalization capability. Additionally, the comparative analysis reveals that DT-based DOA estimation outperforms the state-of-the-art MUltiple SIgnal Classification (MUSIC) algorithm. Our results demonstrate an average reduction of over 90% in the prediction error and 50% in the prediction time achieved by our proposal when compared to the MUSIC algorithm. These results establish DTs as competitive alternatives for DOA estimation in signal reception systems.

A Literature Survey on AI-Aided Beamforming and Beam Management for 5G and 6G Systems.

Modern wireless communication systems rely heavily on multiple antennas and their corresponding signal processing to achieve optimal performance. As 5G and 6G networks emerge, beamforming and beam management become increasingly complex due to factors such as user mobility, a higher number of antennas, and the adoption of elevated frequencies. Artificial intelligence, specifically machine learning, offers a valuable solution to mitigate this complexity and minimize the overhead associated with beam management and selection, all while maintaining system performance. Despite growing interest in AI-assisted beamforming, beam management, and selection, a comprehensive collection of datasets and benchmarks remains scarce. Furthermore, identifying the most-suitable algorithm for a given scenario remains an open question. This article aimed to provide an exhaustive survey of the subject, highlighting unresolved issues and potential directions for future developments. The discussion encompasses the architectural and signal processing aspects of contemporary beamforming, beam management, and selection. In addition, the article examines various communication challenges and their respective solutions, considering approaches such as centralized/decentralized, supervised/unsupervised, semi-supervised, active, federated, and reinforcement learning.

Emerging MIMO Technologies for 6G Networks.

The demand for wireless connectivity has grown exponentially over the last years. By 2030 there should be around 17 billion of mobile-connected devices, with monthly data traffic in the order of thousands of exabytes. Although the Fifth Generation (5G) communications systems present far more features than Fourth Generation (4G) systems, they will not be able to serve this growing demand and the requirements of innovative use cases. Therefore, Sixth Generation (6G) Networks are expected to support such massive connectivity and guarantee an increase in performance and quality of service for all users. To deal with such requirements, several technical issues need to be addressed, including novel multiple-antenna technologies. Then, this survey gives a concise review of the main emerging Multiple-Input Multiple-Output (MIMO) technologies for 6G Networks such as massive MIMO (mMIMO), extremely large MIMO (XL-MIMO), Intelligent Reflecting Surfaces (IRS), and Cell-Free mMIMO (CF-mMIMO). Moreover, we present a discussion on how some of the expected key performance indicators (KPIs) of some novel 6G Network use cases can be met with the development of each MIMO technology.

Preliminary results of a new surgical technique: bladder mucosal graft harvested with holmium:YAG (HO:YAG) laser. A new option in bulbar replacement urethroplasty?

OBJECTIVE: To describe the technique of transurethral harvesting of bladder mucosal graft using the Holmium:YAG (Ho-YAG) laser and describe the preliminary results from 7 cases where this graft was used for urethroplasty. MATERIALS AND METHODS: We performed a single-stage dorsal onlay urethroplasty using bladder mucosal graft in 7 patients with anterior urethral stricture. Transurethral harvesting was performed with the Ho-YAG laser. We performed a prospective and descriptive analysis with uroflowmetry performed at 30, 90 and 180 days after surgery and applied the PROM translated into Portuguese before and 6 months after urethroplasty. RESULTS: Seven patients were included, 2 (28.5%) with penile urethral stricture, and 5 (71.5%) with bulbar urethral stricture. Mean stricture length was 50mm (range 35-60mm). Stricture etiology was trauma in 3 (42.9%) patients, iatrogenic in 1 (14.3%) patient, and idiopathic in 3 (42.9%) patients. Two patients (28.6%) had previously undergone ventral buccal mucosa urethroplasty. Mean bladder mucosal graft length was 52.86mm (± 13.801), and mean harvest time was 46.43min (± 14.639). Dorsal onlay urethroplasty using bladder mucosa was successfully completed in 5 patients (71.4%). Two patients (28.6%) couldn't have the procedure completed using bladder mucosa, one due to thermal damage of the graft during harvesting, and one due to insufficient graft length. In both cases the procedure was completed using buccal mucosa. Two patients (28.6%) experienced minor hematuria between the twelfth and eighteenth postoperative day, but neither required hospitalization and/or additional procedures. All patients achieved normalization of peak flow, and this was maintained throughout the follow-up period. Mean peak flow was 17.8 ml/s (± 3.271) at 30 days, 20.6 ml/s (± 5.413) at 90 days, and 19.6 ml/s (± 8.019) 180 days. Mean IPSS score decreased from 19.3 to 5.4. Similar improvements were also seen in the ICIQ-MLUTS Score (a mean drop from 3.8 to 2.0) and Peeling's Voiding Picture Score (a mean drop from 4.0 to 2.2). Quality of Life improved post urethroplasty, with increases in EQ-5D (from 0.6371 to 0.7285) and EQ-VAS (from 58.0 to 84.0). CONCLUSION: Transurethral harvesting of bladder mucosa using the Holmium laser (Ho-YAG) is feasible and reproducible. Our preliminary experience suggests that bladder mucosa grafts achieve comparable results to other grafts when used for dorsal onlay urethroplasty. Further research is needed to confirm these results.

Spatial Analysis in Areas with High Occurrence of Accidents Caused by Tityus serrulatus and Tityus bahiensis (Scorpiones: Buthidae) in Brazil.

INTRODUCTION: In Brazil, scorpion stings are recorded in high numbers with an increasing epidemiological situation in most municipalities. In the present study, data between 1998 and 2018 in Americana, São Paulo, were analyzed. METHODS: In total, 4122 records on scorpion stings were georeferenced using a Garmin eTREX 30X global positioning system device, with WGS84 datum projection and Universal Transverse Mercator zone 23S. Multiple Poisson regression was used to explore the relationship between the incidence rates of stings and urban planning areas (UPAs). Eight quantitative variables were used to establish the environmental and anthropic characterization of UPAs associated or not associated with scorpionism. A spatial analysis was performed for geoprocessing maps of Americana using spatial statistics tools (optimized hotspot analysis and kernel density function) from cartographic clusters in the ArcMap software, version 10.5. RESULTS: The optimized hotspot analysis tool identified spatial clusters with high values of the incidence of scorpion stings in the surroundings of all UPAs in the municipality. The estimation of the kernel function of event intensity showed a wide distribution of stings across the area of the entire municipal territory, with UPA-02 and UPA-06 exhibiting the highest occurrence of scorpion stings. Six significant hotspots were established as highest-event-density areas (with occurrences of 160-270) and were contiguous to 4 environmental protection areas, located in more peripheral regions, and to 2 municipal cemeteries, which were located in urban central areas. CONCLUSIONS: This analysis showed that the risk of scorpion stings in different Americana's UPAs has increased occurrence and incidence intensity.

Preterm birth and postpartum depression within 6 months after childbirth in a Brazilian cohort.

Preterm birth (PTB) and postpartum depression (PPD) are important public health issues, and although literature mainly supports the association between them, some reviews have highlighted methodological limitations in the studies in this field, restricting the interpretation of such finding. This study aimed at assessing the association between PTB and PPD, by comparing groups of preterm and full-term mothers in two Brazilian cities with contrasting sociodemographic indicators. This prospective convenience cohort study assessed 1421 women during pregnancy, at childbirth, and in the postpartum period. The Edinburgh Postnatal Depression Scale (EPDS) was administrated to assess PPD within 6 months after delivery and women were considered probably depressed if scores were EDPS ≥ 12. PTB was defined as the delivery before 37 completed weeks of pregnancy. A multivariate Poisson regression was used to estimate relative risk for PPD in mothers of preterm infants, and the final analysis models were adjusted for psychosocial variables, selected according to the directed acyclic graph (DAG) approach. Frequencies of PPD were not significantly different in mothers of preterm and full-term infants, in neither city. In the final adjusted model, PTB was not associated with PPD. The association between PTB and PPD was not confirmed in two large samples from two Brazilian cities with contrasting socioeconomic profile. However, maternal health during pregnancy plays an important role in predicting PPD. Prenatal care should promote maternal mental health as an effort towards decreasing unfavored outcomes for mothers, infants, and families.

Smart Strawberry Farming Using Edge Computing and IoT.

Strawberries are sensitive fruits that are afflicted by various pests and diseases. Therefore, there is an intense use of agrochemicals and pesticides during production. Due to their sensitivity, temperatures or humidity at extreme levels can cause various damages to the plantation and to the quality of the fruit. To mitigate the problem, this study developed an edge technology capable of handling the collection, analysis, prediction, and detection of heterogeneous data in strawberry farming. The proposed IoT platform integrates various monitoring services into one common platform for digital farming. The system connects and manages Internet of Things (IoT) devices to analyze environmental and crop information. In addition, a computer vision model using Yolo v5 architecture searches for seven of the most common strawberry diseases in real time. This model supports efficient disease detection with 92% accuracy. Moreover, the system supports LoRa communication for transmitting data between the nodes at long distances. In addition, the IoT platform integrates machine learning capabilities for capturing outliers in collected data, ensuring reliable information for the user. All these technologies are unified to mitigate the disease problem and the environmental damage on the plantation. The proposed system is verified through implementation and tested on a strawberry farm, where the capabilities were analyzed and assessed.

Optimization of Magnetoplasmonic ε-Near-Zero Nanostructures Using a Genetic Algorithm.

Magnetoplasmonic permittivity-near-zero (ε-near-zero) nanostructures hold promise for novel highly integrated (bio)sensing devices. These platforms merge the high-resolution sensing from the magnetoplasmonic approach with the ε-near-zero-based light-to-plasmon coupling (instead of conventional gratings or bulky prism couplers), providing a way for sensing devices with higher miniaturization levels. However, the applications are mostly hindered by tedious and time-consuming numerical analyses, due to the lack of an analytical relation for the phase-matching condition. There is, therefore, a need to develop mechanisms that enable the exploitation of magnetoplasmonic ε-near-zero nanostructures' capabilities. In this work, we developed a genetic algorithm (GA) for the rapid design (in a few minutes) of magnetoplasmonic nanostructures with optimized TMOKE (transverse magneto-optical Kerr effect) signals and magnetoplasmonic sensing. Importantly, to illustrate the power and simplicity of our approach, we designed a magnetoplasmonic ε-near-zero sensing platform with a sensitivity higher than 56∘/RIU and a figure of merit in the order of 102. These last results, higher than any previous magnetoplasmonic ε-near-zero sensing approach, were obtained by the GA intelligent program in times ranging from 2 to 5 min (using a simple inexpensive dual-core CPU computer).

Literature Review on Ship Localization, Classification, and Detection Methods Based on Optical Sensors and Neural Networks.

Object detection is a common application within the computer vision area. Its tasks include the classic challenges of object localization and classification. As a consequence, object detection is a challenging task. Furthermore, this technique is crucial for maritime applications since situational awareness can bring various benefits to surveillance systems. The literature presents various models to improve automatic target recognition and tracking capabilities that can be applied to and leverage maritime surveillance systems. Therefore, this paper reviews the available models focused on localization, classification, and detection. Moreover, it analyzes several works that apply the discussed models to the maritime surveillance scenario. Finally, it highlights the main opportunities and challenges, encouraging new research in this area.

Endoscopic Holmium Laser harvesting of bladder mucosal graft for substitution urethroplasty.

INTRODUCTION: Tissue transfer has been used in urethral reconstruction for decades, and several grafts have been described (1, 2). The ideal graft would have optimal tissue characteristics and lead to minimal morbidity at the donor site. Urethroplasty using bladder mucosa was first described by Memmelaar in 1947 (3). The main limitation in using bladder mucosal grafts has been the invasiveness of open harvesting (4). We describe an endoscopic technique using Holmium:YAG laser to harvest bladder mucosal graft for substitution urethroplasty. METHODOLOGY: A 33-year-old male with no history of urethral instrumentation, trauma, or infection presented with obstructive lower urinary tract symptoms. On retrograde urethrogram a 6cm bulbar urethral stricture was identified. Several options were discussed, and the patient opted for a one-sided onlay dorsal urethroplasty (5) using a bladder mucosal graft. Equipment used to harvest the graft included an 18.5Fr continuous flow laser endoscope with a Kuntz working element (RZ) and a 60W Holmium Laser (Quanta) with 550µm laser fiber. The procedure was started by making a perineal incision, urethral mobilization and incision of the stricture segment. The laser endoscope was then introduced via the perineum. Settings of 0.5J, 30 Hz, and long pulse were used and a 7 x 2.5cm graft was harvested from the posterior bladder wall. Hemostasis of the harvest site was performed. The bladder mucosal graft was thinned in similar fashion to a buccal mucosal graft and sutured as per previously described techniques. CONCLUSION: Endoscopic Holmium Laser harvesting of bladder mucosal graft is feasible and may allow this graft to become an alternative to buccal mucosa. Further studies are required to define its role in urethral reconstruction.

Sum-Rate Channel Capacity for Line-of-Sight Models.

This work considers a base station equipped with an M-antenna uniform linear array and L users under line-of-sight conditions. As a result, one can derive an exact series expansion necessary to calculate the mean sum-rate channel capacity. This scenario leads to a mathematical problem where the joint probability density function (JPDF) of the eigenvalues of a Vandermonde matrix WWH are necessary, where W is the channel matrix. However, differently from the channel Rayleigh distributed, this joint PDF is not known in the literature. To circumvent this problem, we employ Taylor's series expansion and present a result where the moments of mn are computed. To calculate this quantity, we resort to the integer partition theory and present an exact expression for mn. Furthermore, we also find an upper bound for the mean sum-rate capacity through Jensen's inequality. All the results were validated by Monte Carlo numerical simulation.

Secrecy Analysis and Error Probability of LIS-Aided Communication Systems under Nakagami-m Fading.

Large intelligent surfaces (LIS) are a new trend to achieve higher spectral efficiency and signal-to-noise ratio in mobile communications. For this reason, this paper proposes metrics to analyze the performance of systems with multiple antennas aided by LIS and derive the spectral efficiency, secrecy outage probability, and bit error probability in an environment with Nakagami-m distributed fading. In addition to an eavesdropper, there is a single-antenna user, an array of antennas at the transmitter side and the possibility of a direct link between transmitter and receiver. This study assumes that the LIS performs non-ideal phase cancellation leading to a residual phase error that follows a Von Mises distribution, and shows that the resulting channel can be accurately approximated by a Gamma distributed SNR whose parameters are analytically derived. From these formulas, it is possible to evaluate the effect of the strength of the line-of-sight link by varying the Nakagami parameter, m.

Holmium laser enucleation of the prostate: Problem-based evolution of the technique.

Holmium laser enucleation of the prostate (HoLEP) is a minimally invasive and size-independent treatment for benign prostatic hyperplasia with excellent long-term surgical outcome. Considered difficult to learn, different modifications of the technique have been proposed in the last 21 years to overcome the most common problems encountered during this procedure. We present a step-by-step technique including the reasons and advantages of each modification we have progressively adopted until we evolved into our totally en-bloc no-touch low-power HoLEP.

A global knowledge, attitudes and practices survey on anatomical endoscopic enucleation of prostate for benign prostatic hyperplasia among urologists.

There is an increasing use of the procedure, anatomical endoscopic enucleation of the prostate, as an alternative to conventional transurethral resection of prostate for surgical treatment of benign prostatic hyperplasia. However, barriers to adoption of this procedure remain and no prior studies explored this important aspect till date. The aim of this study is to identify the predictors and barriers of surgeon-related practices in this area. The study findings may also provide valuable insight into current practice trends worldwide. To achieve the objectives, we conducted an online, cross-sectional, questionnaire-based study between 1st September 2019 and 5th October 2019 to investigate the knowledge, attitudes and practices among urologists worldwide. Our findings showed that the main barriers for adoption of the procedure were lack of mentorship, a steep learning curve, and unavailability of morcellator, bipolar or laser energy sources. Fear of urinary incontinence, bleeding and bladder injury were not major hindrance to adoption of this technique. The results also demonstrated that there will be continued increase in utility of the procedure in the future.

Capacity Bounds for Dense Massive MIMO in a Line-of-Sight Propagation Environment.

The use of large-scale antenna arrays grants considerable benefits in energy and spectral efficiency to wireless systems due to spatial resolution and array gain techniques. By assuming a dominant line-of-sight environment in a massive multiple-input multiple-output scenario, we derive analytical expressions for the sum-capacity. Then, we show that convenient simplifications on the sum-capacity expressions are possible when working at low and high signal-to-noise ratio regimes. Furthermore, in the case of low and high signal-to-noise ratio regimes, it is demonstrated that the Gamma probability density function can approximate the probability density function of the instantaneous channel sum-capacity as the number of served devices and base station antennas grows, respectively. A second important demonstration presented in this work is that a Gamma probability density function can also be used to approximate the probability density function of the summation of the channel's singular values as the number of devices increases. Finally, it is important to highlight that the presented framework is useful for a massive number of Internet of Things devices as we show that the transmit power of each device can be made inversely proportional to the number of base station antennas.

A Baseband Wireless Spectrum Hypervisor for Multiplexing Concurrent OFDM Signals.

The next generation of wireless and mobile networks will have to handle a significant increase in traffic load compared to the current ones. This situation calls for novel ways to increase the spectral efficiency. Therefore, in this paper, we propose a wireless spectrum hypervisor architecture that abstracts a radio frequency (RF) front-end into a configurable number of virtual RF front ends. The proposed architecture has the ability to enable flexible spectrum access in existing wireless and mobile networks, which is a challenging task due to the limited spectrum programmability, i.e., the capability a system has to change the spectral properties of a given signal to fit an arbitrary frequency allocation. The proposed architecture is a non-intrusive and highly optimized wireless hypervisor that multiplexes the signals of several different and concurrent multi-carrier-based radio access technologies with numerologies that are multiple integers of one another, which are also referred in our work as radio access technologies with correlated numerology. For example, the proposed architecture can multiplex the signals of several Wi-Fi access points, several LTE base stations, several WiMAX base stations, etc. As it able to multiplex the signals of radio access technologies with correlated numerology, it can, for instance, multiplex the signals of LTE, 5G-NR and NB-IoT base stations. It abstracts a radio frequency front-end into a configurable number of virtual RF front ends, making it possible for such different technologies to share the same RF front-end and consequently reduce the costs and increasing the spectral efficiency by employing densification, once several networks share the same infrastructure or by dynamically accessing free chunks of spectrum. Therefore, the main goal of the proposed approach is to improve spectral efficiency by efficiently using vacant gaps in congested spectrum bandwidths or adopting network densification through infrastructure sharing. We demonstrate mathematically how our proposed approach works and present several simulation results proving its functionality and efficiency. Additionally, we designed and implemented an open-source and free proof of concept prototype of the proposed architecture, which can be used by researchers and developers to run experiments or extend the concept to other applications. We present several experimental results used to validate the proposed prototype. We demonstrate that the prototype can easily handle up to 12 concurrent physical layers.

Large Intelligent Surfaces Communicating Through Massive MIMO Rayleigh Fading Channels.

Large intelligent surfaces (LIS) promises not only to improve the signal to noise ratio, and spectral efficiency but also to reduce the energy consumption during the transmission. We consider a base station equipped with an antenna array using the maximum ratio transmission (MRT), and a large reflector array sending signals to a single user. Each subchannel is affected by the Rayleigh flat fading, and the reflecting elements perform non-perfect phase correction which introduces a Von Mises distributed phase error. Based on the central limit theorem (CLT), we conclude that the overall channel has an equivalent Gamma fading whose parameters are derived from the moments of the channel fading between the antenna array and LIS, and also from the LIS to the single user. Assuming that the equivalent channel can be modeled as a Gamma distribution, we propose very accurate closed-form expressions for the bit error probability and a very tight upper bound. For the case where the LIS is not able to perform perfect phase cancellation, that is, under phase errors, it is possible to analyze the system performance considering the analytical approximations and the simulated results obtained using the well known Monte Carlo method. The analytical expressions for the parameters of the Gamma distribution are very difficult to be obtained due to the complexity of the nonlinear transformations of random variables with non-zero mean and correlated terms. Even with perfect phase cancellation, all the fading coefficients are complex due to the link between the user and the base station that is not neglected in this paper.

Music genetics research: Association with musicality of a polymorphism in the AVPR1A gene.

Musicality is defined as a natural tendency, sensibility, knowledge, or talent to create, perceive, and play music. Musical abilities involve a great range of social and cognitive behaviors, which are influenced by both environmental and genetic factors. Although a number of studies have yielded insights into music genetics research, genes and biological pathways related to these traits are not fully understood. Our hypothesis in the current study is that genes associated with different behaviors could also influence the musical phenotype. Our aim was to investigate whether polymorphisms in six genes (AVPR1A, SLC6A4, ITGB3, COMT, DRD2 and DRD4) related to social and cognitive traits are associated with musicality in a sample of children. Musicality was assessed through an individualized music therapy assessment profile (IMTAP) which has been validated in Brazil to measure musical ability. We show here that the RS1 microsatellite of the AVPR1A gene is nominally associated with musicality, corroborating previous results linking AVPR1A with musical activity. This study is one of the first to investigate musicality in a comprehensive way, and it contributes to better understand the genetic basis underlying musical ability.

Postpartum depression screening by telephone: a good alternative for public health and research.

This study verified the reliability and validity of the Edinburg Postpartum Depression Scale (EPDS) administered by telephone interviews. In a cross-sectional study of a cohort from Brazil (BRISA), the EPDS was administered by telephone to 1,083 women within 12 months postpartum, and 257 (23.7 %) participants had an EPDS score ≥10. At 67 ± 48 days after their telephone interview, 199 (EPDS ≥10 = 96; EPDS <10 = 103) participants were interviewed face-to-face using the Structured Clinical Interview for DSM-IV (SCID) and completed the EPDS again by self-report. In 90 participants, the diagnosis of major depressive episode was confirmed by the SCID (EPDS ≥10 = 65; EPDS <10 = 25). The Cronbach's alpha coefficient was 0.861. The Spearman's correlation between the EPDS administered by telephone and the self-reported EPDS was 0.69 (p < 0.001). The receiver-operating characteristic (ROC) curve for the EPDS administered by telephone was 0.78 (95 % confidence interval (CI) = 0.72 to 0.84). Scores ≥10 showed a sensitivity of 72.2 %, a specificity of 71.6 %, and a positive predictive value of 67.7 %. The application of the EPDS by telephone is a suitable alternative for clinical practice and research and represents a method to optimize the diagnosis of postpartum depression.