Fast radio bursts and their gamma-ray or radio afterglows as Kerr-Newman black hole binaries

Fast radio bursts (FRBs) are radio transients lasting only about a few milliseconds. They seem to occur at cosmological distances. We propose that these events can be originated in the collapse of the magnetosphere of Kerr-Newman black holes (KNBHs). We show that the closed orbits of charged particles in the magnetosphere of these objects are unstable. After examining the dependencies on the specific charge of the particle and the spin and charge of the KNBH, we conclude that the resulting timescale and radiation mechanism fit well with the extant observations of FRBs. Furthermore, we argue that the merger of a KNBH binary is one of the plausible central engines for potential gamma-ray or radio afterglow following a certain FRBs, and can also account for gravitational wave (GW) events like GW 150914. Our model leads to predictions that can be tested by combined multi-wavelength electromagnetic and GW observations.Comment: 6 pages, 4 figures, accepted for publication in Ap

Optimizing Energy Prediction in Smart Home Area Networks and Buildings Using Artificial Neural Networks and Machine Learning Techniques

Smart home area networks (HANs) and buildings have become increasingly popular in recent years, with the integration of various smart devices into these networks. However, managing energy consumption in these networks is a major challenge. In this paper, we propose a hybrid artificial neural network-based energy prediction model to predict energy consumption of smart devices in HANs and smart buildings. Our proposed model utilizes a combination of artificial neural networks (ANNs) and machine learning (ML) techniques to predict energy consumption in smart HANs and buildings. The ANN component of the model is used to model the complex relationships between different variables, while the ML component is used to improve the accuracy of the predictions. To evaluate the performance of our proposed model, we collected data from a smart building and a smart HAN. Our results show that the proposed model outperforms traditional prediction methods, with an average prediction error of less than 3%. The proposed model can be used to optimize energy consumption in smart HANs and buildings, by providing accurate predictions of energy consumption. This can help to reduce energy costs and improve the overall energy efficiency of these networks. Additionally, the proposed model can be easily adapted to other types of smart networks, such as smart cities and industrial networks

Predicting Students Performance Based on Their Reading Behaviors

E-learning systems can support students in the on-line classroom environment by providing different learning materials. However, recent studies find that students may misuse such systems with a variety of strategies. One particular misused strategy, gaming the system, has repeatedly been found to negatively affect the students’ learning results. Unfortunately, methods to quantitatively capture such behavior are poorly developed, making it difficult to predict students learning outcomes. In this work, we tackle this problem based on a study of the 567,193 records of the 71 students’ reading behaviors from two classes in the academic year 2016. We first quantify the extent to which students misused the system and then predict their class performance based on the quantified results. Our results demonstrated that such misbehavior in the E-learning system can be quantified as a probability and then further used as a significant factor to predict students class learning outcomes with high accuracy

Elevated Baseline Serum Fibrinogen: Effect on 2-Year Major Adverse Cardiovascular Events Following Percutaneous Coronary Intervention.

BackgroundElevated fibrinogen is associated with short-term major adverse cardiovascular events (MACE) after percutaneous coronary intervention, but the relation with late MACE is unknown.Methods and resultsBaseline demographics and 2-year MACE were recorded among subjects undergoing nonemergent percutaneous coronary intervention. A total of 332 subjects (66.6±19.5 years, 69.9% male, 25.3% acute coronary syndrome) were enrolled. Two-year MACE (periprocedural myocardial infarction 9.0%, rehospitalization 6.3%, revascularization 12.7%, non-periprocedural myocardial infarction 4.5%, stent thrombosis 0.9%, stroke 1.8%, and death 0.6%) were associated with higher fibrinogen (352.8±123.4 mg/dL versus 301.6±110.8 mg/dL; P<0.001), longer total stent length (40.1±25.3 mm versus 32.1±19.3 mm; P=0.004), acute coronary syndrome indication (38.7% versus 17.8%; P<0.001), number of bare-metal stents (0.5±1.1 versus 0.2±0.5; P=0.002), and stent diameter ≤2.5 mm (55.8% versus 38.4%, P=0.003). No relation between platelet reactivity and 2-year MACE was observed. Fibrinogen ≥280 mg/dL (odds ratio [OR] 3.0, confidence interval [CI], 1.6-5.4, P<0.001), total stent length ≥32 mm (OR 2.2, CI, 1.3-3.8, P<0.001), acute coronary syndrome indication (OR 4.1, CI, 2.3-7.5, P<0.001), any bare-metal stents (OR 3.2, CI, 1.6-6.1, P<0.001), and stent diameter ≤2.5 mm (OR 2.0, CI, 1.2-3.5, P=0.010) were independently associated with 2-year MACE. Following a landmark analysis excluding periprocedural myocardial infarction, fibrinogen ≥280 mg/dL remained strongly associated with 2-year MACE (37.0% versus 17.4%, log-rank P<0.001).ConclusionsElevated baseline fibrinogen level is associated with 2-year MACE after percutaneous coronary intervention. Acute coronary syndrome indication for percutaneous coronary intervention, total stent length implanted, and use of bare-metal stents or smaller-diameter stents are also independently associated with 2-year MACE, while measures of on-thienopyridine platelet reactivity are not

Regulation of vaccine immunity : from myeloid cell functions to antibody responses

The generation of vaccine-induced protection against infections relies on a well-coordinated network of innate immune responses, adaptive cellular responses, and humoral responses. Sufficient stimulation of the innate immune system by vaccination is critical to subsequently induce effective pathogen-specific T cell and B cell responses. The magnitude, characteristics and functions of the T cell and B cell response will further determine the protective effect of the vaccines. This thesis has investigated aspects of both the early innate immune response as well as the adaptive T cell and B cell response after vaccination. Specifically, the first part focuses on the functions of different innate myeloid cell subsets in regulating vaccine responses. The second part focuses on the antibody responses induced by a new live pertussis vaccine compared to the currently used acellular pertussis vaccine (aPV). Neutrophils are the major circulating myeloid cells. Heterogeneity and plasticity of neutrophils have received much attention during the past years. In Paper I, we show that neutrophils can present antigens to antigen-specific memory CD4+ T cells. This is dependent on the upregulation of MHC-II and costimulatory molecules on neutrophils which can occur in the presence of antigens and autologous antigen-specific memory CD4+ T cells. Furthermore, we found that neutrophils isolated from lymph nodes draining vaccine injection sites of rhesus macaques can present vaccine antigens to antigen-specific CD4+ T cells. Neutrophils may therefore play a role in the induction and regulation of vaccine-specific T cell responses through antigen presentation. There have been efforts trying to understand how vaccines induce immune responses but much less is known about immune suppressive regulation. In Paper II, we demonstrate that myeloid- derived suppressor cells (MDSCs), which is a unique population of myeloid cells with suppressive functions particularly on T cells, accumulate transiently after vaccination. We found that monocytic (M)-MDSCs and polymorphonuclear (PMN)-MDSCs are present in rhesus blood and possess inherent suppressive effects on T cells. The frequency of M-MDSCs rapidly and transiently increased in the blood, and these cells infiltrated the injection sites after vaccination. We speculate that MDSCs contribute with an immune-balancing role to prevent excessive immune activation and inflammation upon vaccine exposure. In Paper III, we evaluated the immune responses in humans receiving the live attenuated Bordetella pertussis vaccine BPZE1 in a clinical trial. A single intranasal immunization of BPZE1 induced well-detectable plasmablasts, activated circulating T follicular helper cells, vaccine-specific Th1-polarized CD4+ T cells, memory B cells and antibodies. In contrast to the antibodies induced by the currently used aPV, BPZE1-induced antibodies showed substantially broader specificities to several B. pertussis antigens, many of which were identified for the first time. The BPZE1-induced antibodies were also more potent in mediating bacterial opsonization to stimulate reactive oxygen species production in neutrophils, which further led to enhanced bactericidal function. Collectively, these studies help in the understanding of how myeloid cells dictate immune responses and how the quality and specificities of antibody responses can be influenced by different pertussis vaccine platforms. This information will ultimately aid in the development of better future vaccines