Centralized Light Access Network (C-LiAN): A Novel Paradigm for Next Generation Indoor VLC Networks

Visible light communication (VLC) builds upon the idea of using existing lighting infrastructure for wireless data transmission. In a conventional VLC network, each light fixture acts as an access point (AP) which are connected to each other through electrical grid as well as data backbone. These VLCenabled fixtures consist baseband unit (BBU) followed by the optical front-end (OFE). In this paper, we propose the so-called Centralized Light Access Network (C-LiAN) which aggregates all AP computational resources into a central pool that is managed by a centralized controller. Unlike the distributed architecture where each light fixture performs both baseband processing and optical transmission/reception, the centralized architecture employs “dummy” fixtures with a VLC OFE. Moving the baseband processing to a central pool reduces the associated cost and complexity of each VLC-enabled LED luminary. It further enables joint processing of signals from different APs making possible an efficient implementation of joint processing, offloading, handover, interference management, scheduling and resource management algorithms. As an example to demonstrate the virtues of C-LiAN, we further present the performance of Coordinated Multi-point Transmission (CoMP) and Enhanced ICIC (eICIC) with almost blank subframe (ABSF) techniques originally proposed for LTE-A in the context of indoor VLC networks

Hip Fracture Mortality: Is It Affected by Anesthesia Techniques?

We hypothesized that combined peripheral nerve block (CPNB) technique might reduce mortality in hip fracture patients with the advantage of preserved cardiovascular stability. We retrospectively analyzed 257 hip fracture patients for mortality rates and affecting factors according to general anesthesia (GA), neuraxial block (NB), and CPNB techniques. Patients' gender, age at admission, trauma date, ASA status, delay in surgery, followup period, and Barthel Activities of Daily Living Index were determined. There were no differences between three anesthesia groups regarding to sex, followup, delay in surgery, and Barthel score. NB patients was significantly younger and CPNB patients' ASA status were significantly worse than other groups. Mortality was lower for regional group (NB + CPNB) than GA group. Mortality was increased with age, delay in surgery, and ASA and decreased with CPNB choice; however, it was not correlated with NB choice. Since the patients' age and ASA status cannot be changed, they must be operated immediately. We recommend CPNB technique in high-risk patients to operate them earlier

Cooperative Visible Light Communications With Full-Duplex Relaying

In this paper, we investigate cooperative visible light communication (VLC) system where an intermediate light source acts as a relay terminal. We assume that relay terminal operates in full-duplex mode. In contrast to radio frequency counterparts, full-duplex VLC terminal is relatively easier to implement due to directive propagation characteristic of light. We first model VLC relay terminal taking into account loop interference channel based on ray tracing simulations. Then, we investigate error rate performance of the relay-assisted VLC system. Our performance evaluations demonstrate the superiority of full-duplex relaying over half-duplex counterpart especially for high modulation sizes

The relationship between burnout and emotional labour of the employees

Abstract Emotions of the employees of especially the sectors like banking, tourism, and health care, in which the interaction with the customers is at utmost importance, are expected by the businesses to be properly managed. While the display of emotions by the employees according to the demands of the organization in respect to the payments made has positive contributions to the businesses, i

Effect of Wiring and Cabling Topologies on the Performance of Distributed MIMO OFDM VLC Systems

Since most indoor spaces have multiple luminaires for illumination, for visible light communication (VLC) systems, multiple-input multiple-output (MIMO) communication emerges as a natural solution to improve the data rates and/or the link reliability. The existing works on MIMO VLC systems, however, overlook the characteristics of the lighting infrastructure and the luminaire design, which might have implications for the VLC system design. A luminaire typically consists of multiple LED chips. The wiring topology refers to how the LED chips are connected within the luminaire. The cabling topology, on the other hand, refers to how the luminaires are connected to the communication access point (AP). Based on the type and length of cabling and wiring, significant delays can be introduced, which should be taken into account in channel modeling. In this paper, we adopt the non-sequential ray tracing to model the distributed MIMO VLC channels for various practical wiring and cabling topologies. Based on the developed channel models, we provide a comparative performance analysis of repetition coding (RC), spatial multiplexing (SMUX), and spatial modulation (SMOD) MIMO modes. Our results quantify the effect of wiring/cabling delays and provide insights into the optimized design of lighting infrastructure and luminaires for the support of VLC as an add-on service...

Ozone Therapy and Hyperbaric Oxygen Treatment in Lung Injury in Septic Rats

Various therapeutic protocols were used for the management of sepsis including hyperbaric oxygen (HBO) therapy. It has been shown that ozone therapy (OT) reduced inflammation in several entities and exhibits some similarity with HBO in regard to mechanisms of action. We designed a study to evaluate the efficacy of OT in an experimental rat model of sepsis to compare with HBO. Male Wistar rats were divided into sham, sepsis+cefepime, sepsis+cefepime+HBO, and sepsis+cefepime+OT groups. Sepsis was induced by an intraperitoneal injection of Escherichia coli; HBO was administered twice daily; OT was set as intraperitoneal injections once a day. The treatments were continued for 5 days after the induction of sepsis. At the end of experiment, the lung tissues and blood samples were harvested for biochemical and histological analysis. Myeloperoxidase activities and oxidative stress parameters, and serum proinflammatory cytokine levels, IL-1β and TNF-α, were found to be ameliorated by the adjuvant use of HBO and OT in the lung tissue when compared with the antibiotherapy only group. Histologic evaluation of the lung tissue samples confirmed the biochemical outcome. Our data presented that both HBO and OT reduced inflammation and injury in the septic rats' lungs; a greater benefit was obtained for OT. The current study demonstrated that the administration of OT as well as HBO as adjuvant therapy may support antibiotherapy in protecting the lung against septic injury. HBO and OT reduced tissue oxidative stress, regulated the systemic inflammatory response, and abated cellular infiltration to the lung demonstrated by findings of MPO activity and histopathologic examination. These findings indicated that OT tended to be more effective than HBO, in particular regarding serum IL-1β, lung GSH-Px and histologic outcome

Analysis of intestinal and nasopharyngeal microbiota of children with meningococcemia in pediatric intensive care unit: INMACS-PICU study

This article belongs to the Special Issue Pediatric Diagnostic Microbiology.Microbiota composition might play a role in the pathophysiology and course of sepsis, and understanding its dynamics is of clinical interest. Invasive meningococcal disease (IMD) is an important cause of community-acquired serious infection, and there is no information regarding microbiota composition in children with meningococcemia. In this study, we aimed to evaluate the intestinal and nasopharyngeal microbiota composition of children with IMD.[Materials and Methods]: In this prospective, multi-center study, 10 children with meningococcemia and 10 age-matched healthy controls were included. Nasopharyngeal and fecal samples were obtained at admission to the intensive care unit and on the tenth day of their hospital stay. The V3 and V4 regions of the 16S rRNA gene were amplified following the 16S Metagenomic Sequencing Library Preparation.[Results]: Regarding the alpha diversity on the day of admission and on the tenth day at the PICU, the Shannon index was significantly lower in the IMD group compared to the control group (p = 0.002 at admission and p = 0.001, on the tenth day of PICU). A statistical difference in the stool samples was found between the IMD group at Day 0 vs. the controls in the results of the Bray–Curtis and Jaccard analyses (p = 0.005 and p = 0.001, respectively). There were differences in the intestinal microbiota composition between the children with IMD at admission and Day 10 and the healthy controls. Regarding the nasopharyngeal microbiota analysis, in the children with IMD at admission, at the genus level, Neisseria was significantly more abundant compared to the healthy children (p < 0.001). In the children with IMD at Day 10, genera Moraxella and Neisseria were decreased compared to the healthy children. In the children with IMD on Day 0, for paired samples, Moraxella, Neisseria, and Haemophilus were significantly more abundant compared to the children with IMD at Day 10. In the children with IMD at Day 10, the Moraxella and Neisseria genera were decreased, and 20 different genera were more abundant compared to Day 0.[Conclusions]: We first found alterations in the intestinal and nasopharyngeal microbiota composition in the children with IMD. The infection itself or the other care interventions also caused changes to the microbiota composition during the follow-up period. Understanding the interaction of microbiota with pathogens, e.g., N. meningitidis, could give us the opportunity to understand the disease’s dynamics.This study was supported by the Eskisehir Osmangazi University Scientific Research Grant (2018/11046).Peer reviewe