On the relaxed maximum-likelihood blind MIMO channel estimation for orthogonal space-time block codes

This paper concerns the maximum-likelihood channel estimation for MIMO systems with orthogonal space-time block codes when the finite alphabet constraint of the signal constellation is relaxed. We study the channel coefficients estimation subspace generated by this method. We provide an algebraic characterisation of this subspace which turns the optimization problem into a purely algebraic one and more importantly, leads to several interesting analytical proofs. We prove that with probability one, the dimension of the estimation subspace for the channel coefficients is deterministic and it decreases by increasing the number of receive antennas up to a certain critical number of receive antennas, after which the dimension remains constant. In fact, we show that beyond this critical number of receive antennas, the estimation subspace for the channel coefficients is isometric to a fixed deterministic invariant space which can be easily computed for every specific OSTB code

The possibility of sex identification in beluga (Huso huso) by using PCR-RAPD technique

The goal of this study was to find a sex-specific DNA sequences in the male and female genomes of beluga (Huso huso), by random amplified polymorphic DNA (RAPD) assays performed on pooled DNA samples. Of the 310 different primers was tested, 7 primers produced no band. The most likely possibility is that PCR conditions have not been suitable for these 7 primers. It is also possible that these RAPD primers did not find suitable binding position to generate fragments. A single band was produced by primer 295 (OPT -17) which was specific to the male DNA. Further analysis of individual male and female beluga demonstrated that this primer yielded a product that were in fact variable and reproducible, but were the result of variation in some individual males and females and not male-specific. Therefore, of the 4146 RAPDs scored, none were tightly linked to a sex-determining gene. The results support the idea that sex chromosomes are either not present or they weakly differentiated in the genome of beluga

The effect of metoclopramide addition to lidocaine on pain of patients with grades II and III post-episiotomy repair

Episiotomy is the most common procedure used for dilatation of the vaginal opening for giving birth. Although episiotomy is associated with benefits for the mother, it may lead to short term and long term disabilities, including postpartum perineal pain that is secondary to perineal tearing. Aim: The aim of this study was to investigate the effect of subcutaneous lidocaine compared with lidocaine and metoclopramide on pain after episiotomy. Materials and Methods: In this clinical trial study, the patients (83 for control group and 83 for case group) with episiotomy Grades II and III were enrolled and were asked to express their postpartum episiotomy pain as a number, from zero (no pain) to 10 (severest pain) Visual Analogue Scale (VAS score) at 0, 30 minute, 1 hour, 2 hour, 4 hour, 6 hour and 12 hour postpartum. Patients at the second stage of labour (crowning) were assigned to two groups: In the control group, 5 cc lidocaine 2% and in the case group, 5 cc lidocaine + 10 mg metoclopramide was injected for episiotomy. Then, the pain score was compared between the two groups. The data were analyzed by t-test and chi-square test with software SPSS version 20.0. Results: Mean age of the women was 23.19±0.46 years in the control group and 23.96±0.58 years in the case group with no significant difference between the two groups (p<0.05). The mean pain score in the control group was 3.54±0.71 and in the case group 2.93±0.91 at 30 minutes after the injection, with a statistically significant difference. At other intervals, postnatal pain scores in the case group was lower than those of the control group (p<0.05). Conclusion: Injection of metoclopramide with lidocaine is more effective than lidocaine alone for relieving the pain after episiotom

Energy Efficient Communications in RIS-assisted UAV Networks Based on Genetic Algorithm

This paper proposes a solution for energy-efficient communication in reconfigurable intelligent surface (RIS)-assisted unmanned aerial vehicle (UAV) networks. The limited battery life of UAVs is a major concern for their sustainable operation, and RIS has emerged as a promising solution to reducing the energy consumption of communication systems. The paper formulates the problem of maximizing the energy efficiency of the network as a mixed integer non-linear program, in which UAV placement, UAV beamforming, On-Off strategy of RIS elements, and phase shift of RIS elements are optimized. The proposed solution utilizes the block coordinate descent approach and a combination of continuous and binary genetic algorithms. Moreover, for optimizing the UAV placement, Adam optimizer is used. The simulation results show that the proposed solution outperforms the existing literature. Specifically, we compared the proposed method with the successive convex approximation (SCA) approach for optimizing the phase shift of RIS elements

Effectiveness of Reconfigurable Intelligent Surfaces to Enhance Connectivity in UAV Networks

Reconfigurable intelligent surfaces (RISs) are expected to make future 6G networks more connected and resilient against node failures, due to their ability to introduce controllable phase-shifts onto impinging electromagnetic waves and impose link redundancy. Meanwhile, unmanned aerial vehicles (UAVs) are prone to failure due to limited energy, random failures, or targeted failures, which causes network disintegration that results in information delivery loss. In this paper, we show that the integration between UAVs and RISs for improving network connectivity is crucial. We utilize RISs to provide path diversity and alternative connectivity options for information flow from user equipments (UEs) to less critical UAVs by adding more links to the network, thereby making the network more resilient and connected. To that end, we first define the criticality of UAV nodes, which reflects the importance of some nodes over other nodes. We then employ the algebraic connectivity metric, which is adjusted by the reflected links of the RISs and their criticality weights, to formulate the problem of maximizing the network connectivity. Such problem is a computationally expensive combinatorial optimization. To tackle this problem, we propose a relaxation method such that the discrete scheduling constraint of the problem is relaxed and becomes continuous. Leveraging this, we propose two efficient solutions, namely semi-definite programming (SDP) optimization and perturbation heuristic, which both solve the problem in polynomial time. For the perturbation heuristic, we derive the lower and upper bounds of the algebraic connectivity obtained by adding new links to the network. Finally, we corroborate the effectiveness of the proposed solutions through extensive simulation experiments.Comment: 14 pages, 8 figures, journal paper. arXiv admin note: text overlap with arXiv:2308.0467

Clinicopathologic Characteristics of Multifocal Gastric Adenocarcinoma

BACKGROUNDANDOBJECTIVE: Gastric cancer is the fifth prevalent cancer in worldwide. Among of this, adenocarcinoma is more than 95% of all case and most prevalent. According to gastric adenocarcinoma is resistant to adjuvant therapy, surgical resection is the cardinal strategies of treatment. One of the problems with treating adenocarcinoma of the stomach is that its main causes are malignant or pre-malignant changes in the residual gastric tissue that may be neglected during resection. By recognizing these lesions and resection, they can be expected to reduce the malignancy. Therefore, this study was conducted to investigate the characteristics of non-tumoral gastric tissue in terms of malignant or pre-malignant changes. METHODS: In this retrospective cross-sectional study, 112 patients who had undergone total gastrectomy in the hospitals affiliated to Babol University of Medical Sciences during the period of 2013-2017 were examined and analyzed for age, sex, type and location of tumor. FINDINGS: Of 112 cases that studied,72 cases (64.3%) were male and 40 cases (35.7%) were female. The mean of ages was 64.7±8.6 year. Poorly differentiated pathology in 60.7% and well differentiated pathology in 39.3% of patients were seen. In 64 patients (57%), there was synchronous lesions in addition to primary pathology. These synchronous lesions were related statistically significant to pathology, cancer stage and gender. CONCLUSION: Based on the results of this study, it can be concluded that resection should be accompanied by considering simultaneous lesions in addition to primary pathology, which can be a reason for total gastrectomy as a standard treatment for gastric cancer

A novel multiplex assay combining autoantibodies plus PSA has potential implications for classification of prostate cancer from non-malignant cases

<p>Abstract</p> <p>Background</p> <p>The lack of sufficient specificity and sensitivity among conventional cancer biomarkers, such as prostate specific antigen (PSA) for prostate cancer has been widely recognized after several decades of clinical implications. Autoantibodies (autoAb) among others are being extensively investigated as potential substitute markers, but remain elusive. One major obstacle is the lack of a sensitive and multiplex approach for quantifying autoAb against a large panel of clinically relevant tumor-associated antigens (TAA).</p> <p>Methods</p> <p>To circumvent preparation of phage lysates and purification of recombinant proteins, we identified B cell epitopes from a number of previously defined prostate cancer-associated antigens (PCAA). Peptide epitopes from cancer/testis antigen NY-ESO-1, XAGE-1b, SSX-2,4, as well as prostate cancer overexpressed antigen AMACR, p90 autoantigen, and LEDGF were then conjugated with seroMAP microspheres to allow multiplex measurement of autoAb present in serum samples. Moreover, simultaneous quantification of autoAb plus total PSA was achieved in one reaction, and termed the "A+PSA" assay.</p> <p>Results</p> <p>Peptide epitopes from the above 6 PCAA were identified and confirmed that autoAb against these peptide epitopes reacted specifically with the full-length protein. A pilot study was conducted with the A+PSA assay using pre-surgery sera from 131 biopsy-confirmed prostate cancer patients and 121 benign prostatic hyperplasia and/or prostatitis patients. A logistic regression-based A+PSA index was found to enhance sensitivities and specificities over PSA alone in distinguishing prostate cancer from nonmalignant cases. The A+PSA index also reduced false positive rate and improved the area under a receiver operating characteristic curve.</p> <p>Conclusions</p> <p>The A+PSA assay represents a novel platform that integrates autoAb signatures with a conventional cancer biomarker, which may aid in the diagnosis and prognosis of prostate cancer and others.</p