During the last decade, the exponential growth of mobile devices and wireless services created a huge demand for radio frequency-based technologies. Meanwhile, the lighting industry has been ...revolutionized due to the popularization of LED light bulbs, which are more economical and efficient. In that context, visible light communication (VLC) is a disruptive technology based on LEDs that offers a free spectrum and high data rate, which can potentially serve as a complementary technology to the current radio frequency standards. In this paper, we present a comprehensive state-of-the-art survey of VLC, as well as the main concepts and challenges related to this emergent area. We overview VLC technology, from its physical aspects and communication architecture to its main applications and research challenges. Finally, we present the main research platforms available today, along with a deep analysis of the system design and future directions in the field.
In the regime of deep strong light-matter coupling, the coupling strength exceeds the transition energies of the material
, fundamentally changing its properties
; for example, the ground state of ...the system contains virtual photons and the internal electromagnetic field gets redistributed by photon self-interaction
. So far, no electronic excitation of a material has shown such strong coupling to free-space photons. Here we show that three-dimensional crystals of plasmonic nanoparticles can realize deep strong coupling under ambient conditions, if the particles are ten times larger than the interparticle gaps. The experimental Rabi frequencies (1.9 to 3.3 electronvolts) of face-centred cubic crystals of gold nanoparticles with diameters between 25 and 60 nanometres exceed their plasmon energy by up to 180 per cent. We show that the continuum of photons and plasmons hybridizes into polaritons that violate the rotating-wave approximation. The coupling leads to a breakdown of the Purcell effect-the increase of radiative damping through light-matter coupling-and increases the radiative polariton lifetime. The results indicate that metallic and semiconducting nanoparticles can be used as building blocks for an entire class of materials with extreme light-matter interaction, which will find application in nonlinear optics, the search for cooperative effects and ground states, polariton chemistry and quantum technology
.
An innovative treatment for congested urban road networks is the split intersection. Here, a congested two-way–two-way traffic light-controlled intersection is transformed into two lighter ...intersections. By reducing conflict points and improving travel time, it facilitates smoother flow with less driver delay. We propose a visible light communication system based on Vehicle-to-Vehicle (V2V), Vehicle-to-Infrastructure (V2I) and Infrastructure-to-Vehicle (I2V) communications able to safely manage vehicles crossing through an intersection, leveraging Edge of Things (EoT) facilities. Headlights, street lamps, and traffic signals are used by connected vehicles to communicate with one another and with infrastructure. Through internally installed Driver Agents, an Intersection Manager coordinates traffic flow and interacts with vehicles. For the safe passage of vehicles across intersections, request/response mechanisms and time and space relative pose concepts are used. A virtual scenario is proposed, and a “mesh/cellular” hybrid architecture used. Light signals are emitted by transmitters by encoding, modulating, and converting data. Optical sensors with light-filtering properties are used as receivers and decoders. The VLC request/response concept uplink and downlink communication between the infrastructure and the vehicles is tested. Based on the results, the short-range mesh network provides a secure communication path between street lamp controllers and edge computers through neighbor traffic light controllers that have active cellular connections, as well as peer-to-peer communication, allowing V-VLC ready cars to exchange information.
The carcinogenicity of perfluorooctanoic acid (PFOA) has been reviewed previously by several different regulatory agencies and researchers, with contradictory conclusions-especially regarding ...epidemiological findings on kidney cancer and testicular cancer. In addition, previous dose-response assessments have focused primarily on evidence from animal studies. This critical review summarizes peer reviewed epidemiological studies on PFOA and cancers of the kidneys and testes, using modified Hill's criteria to assess the evidence for causation. We converted exposures to a common scale based on serum PFOA concentrations and applied meta-analysis to estimate the average increase in cancer risk reported by the studies with sufficient information to estimate serum PFOA. Using random effects meta-analysis, we found that the average relative increase in cancer risk per 10 ng/mL increase in serum PFOA for these studies is 16% (95% CI: 3%, 30%) for kidney cancer and 3% (95% CI: 2%, 4%) for testicular cancer. These associations are most likely causal, but results are limited by the small number of studies for testicular cancer, the overlapping study populations for several studies, and the lack of measured or modeled serum PFOA concentrations for several studies.
Implications: Our review meta-analysis indicates an average increase in cancer risk per 10 ng/mL increase in serum PFOA for kidney and testicular cancers. These associations are most likely causal, but results are limited by the small number of studies for testicular cancer, the overlapping study populations for several studies, and the lack of measured or modeled serum PFOA concentrations for several studies. The weight of evidence could be even stronger with the addition of future studies conducted in large cohorts.
Perfluorooctanoic acid (PFOA) has been linked to cancer in occupational mortality studies and animal toxicologic research.
We investigated the relationship between PFOA exposure and cancer among ...residents living near the DuPont Teflon-manufacturing plant in Parkersburg, West Virginia (WV).
Our analyses included incident cases of 18 cancers diagnosed from 1996 through 2005 in five Ohio (OH) counties and eight WV counties. For analyses of each cancer outcome, controls comprised all other cancers in the study data set except kidney, pancreatic, testicular, and liver cancers, which have been associated with PFOA in animal or human studies. We applied logistic regression models to individual-level data to calculate adjusted odds ratios (AORs) and confidence intervals (CIs). For the combined analysis of OH and WV data, the exposure of interest was resident water district. Within OH, geocoded addresses were integrated with a PFOA exposure model to examine the relationship between cancer odds and categories of estimated PFOA serum.
Our final data set included 7,869 OH cases and 17,238 WV cases. There was a positive association between kidney cancer and the very high and high serum exposure categories AOR = 2.0 (95% CI: 1.0, 3.9) n = 9 and 2.0 (95% CI: 1.3, 3.2) n = 22, respectively and a null association with the other exposure categories compared with the unexposed. The largest AOR was for testicular cancer with the very high exposure category 2.8 (95% CI: 0.8, 9.2) n = 6, but there was an inverse association with the lower exposure groups, and all estimates were imprecise because of small case numbers.
Our results suggest that higher PFOA serum levels may be associated with testicular, kidney, prostate, and ovarian cancers and non-Hodgkin lymphoma. Strengths of this study include near-complete case ascertainment for state residents and well-characterized contrasts in predicted PFOA serum levels from six contaminated water supplies.
Celotno besedilo
Dostopno za:
CEKLJ, DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Increased adipose tissue lipogenesis is associated with enhanced insulin sensitivity. Mice overexpressing the Glut4 glucose transporter in adipocytes have elevated lipogenesis and increased glucose ...tolerance despite being obese with elevated circulating fatty acids. Lipidomic analysis of adipose tissue revealed the existence of branched fatty acid esters of hydroxy fatty acids (FAHFAs) that were elevated 16- to 18-fold in these mice. FAHFA isomers differ by the branched ester position on the hydroxy fatty acid (e.g., palmitic-acid-9-hydroxy-stearic-acid, 9-PAHSA). PAHSAs are synthesized in vivo and regulated by fasting and high-fat feeding. PAHSA levels correlate highly with insulin sensitivity and are reduced in adipose tissue and serum of insulin-resistant humans. PAHSA administration in mice lowers ambient glycemia and improves glucose tolerance while stimulating GLP-1 and insulin secretion. PAHSAs also reduce adipose tissue inflammation. In adipocytes, PAHSAs signal through GPR120 to enhance insulin-stimulated glucose uptake. Thus, FAHFAs are endogenous lipids with the potential to treat type 2 diabetes.
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•Lipidomics identifies bioactive fatty acid esters of hydroxyl-fatty acids (FAHFAs)•FAHFAs are low in insulin-resistant humans and correlate with insulin sensitivity•These lipids improve insulin secretion and glucose tolerance in mice•FAHFAs block inflammatory cytokine production and reduce adipose inflammation
A new class of lipids that are low in insulin-resistant humans promotes glucose tolerance and ameliorates inflammation associated with obesity in mouse models.
Background: Polyfluoroalkyl chemicals (PFCs) have been widely used in consumer products. Exposures in the United States and in world populations are widespread. PFC exposures have been linked to ...various health impacts, and data in animals suggest that PFCs may be potential developmental neurotoxicants. Objectives: We evaluated the associations between exposures to four PFCs and parental report of diagnosis of attention deficit/hyperactivity disorder (ADHD). Methods: Data were obtained from the National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2003-2004 for children 12-15 years of age. Parental report of a previous diagnosis by a doctor or health care professional of ADHD in the child was the primary outcome measure. Perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS) levels were measured in serum samples from each child. Results: Parents reported that 48 of 571 children included in the analysis had been diagnosed with ADHD. The adjusted odds ratio (OR) for parentally reported ADHD in association with a 1-μg/L increase in serum PFOS (modeled as a continuous predictor) was 1.03 95% confidence interval (CI), 1.01-1.05. Adjusted ORs for 1-μg/L increases in PFOA and PFHxS were also statistically significant (PFOA: OR = 1.12; 95% CI, 1.01-1.23; PFHxS: OR = 1.06; 95% CI, 1.02-1.11), and we observed a nonsignificant positive association with PFNA (OR = 1.32; 95% CI, 0.86-2.02). Conclusions: Our results, using cross-sectional data, are consistent with increased odds of ADHD in children with higher serum PFC levels. Given the extremely prevalent exposure to PFCs, follow-up of these data with cohort studies is needed.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Schistosomiasis, caused by blood flukes of the genus Schistosoma, still imposes a considerable public health burden on large parts of the world. The control of this disease depends almost exclusively ...on the drug praziquantel, and there are no alternative drugs in sight. Natural compounds have recently attracted significant attention due to their relevance to parasitic infection and potential development into new therapeutic agents. Epiisopiloturine is an imidazole alkaloid isolated from the leaves of Pilocarpus microphyllus (Rutaceae), a native plant from Brazil. Here, we report the in vitro effect of this drug on the survival time of Schistosoma mansoni of different ages, such as 3 h old and 1, 3, 5, and 7 days old schistosomula, 49-day-old adults, and on egg output by adult worms. Epiisopiloturine at a concentration of 300 μg/mL caused the death of all schistosomula within 120 h. Extensive tegumental alterations and death were observed when adult schistosomes had been exposed to 150 μg/mL of the epiisopiloturine. At the highest sub-lethal dose of alkaloid (100 μg/mL), a 100% reduction in egg laying of paired adult worms was observed. Additionally, epiisopiloturine showed selective antischistosomal activity and exhibited no cytotoxicity to mammalian cells. This report provides the first evidence that epiisopiloturine is able to kill S. mansoni of different ages and inhibit worm egg laying.
There is growing evidence that the commensal bacteria in the gastrointestinal tract (the gut microbiota) influence the development of autoimmunity in rodent models. Since humans have co-evolved with ...commensals for millennia, it is likely that people, who are genetically predisposed to autoimmunity, harbor gut microbial communities that similarly influence the onset and/or severity of disease. Beyond the current efforts to identify such disease-promoting or -preventing commensals (“pathobionts” or “symbionts”), it will be important to determine what factors modulate them. Dietary changes are known to affect both the composition and function of the gut microbial communities, which in turn can alter the innate and adaptive immune system. In this review, we focus on the relationships between diet, microbiota, and autoimmune diseases. We hypothesize that the beneficial and life-prolonging effects of caloric restriction on a variety of autoimmune models including lupus might partly be mediated by its effects on the gut microbiome and associated virome, the collection of all viruses in the gut. We give recent examples of the immunomodulatory potential of select gut commensals and their products or diet-derived metabolites in murine models of arthritis, multiple sclerosis, and type 1 diabetes. Lastly, we summarize the published phenotypes of germ-free mouse models of lupus and speculate on any role of the diet-sensitive microbiome and virome in systemic lupus and the related antiphospholipid syndrome.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Fast Packet Processing with eBPF and XDP Vieira, Marcos A. M.; Castanho, Matheus S.; Pacífico, Racyus D. G. ...
ACM computing surveys,
02/2020, Letnik:
53, Številka:
1
Journal Article
Recenzirano
Extended Berkeley Packet Filter (eBPF) is an instruction set and an execution environment inside the Linux kernel. It enables modification, interaction, and kernel programmability at runtime. eBPF ...can be used to program the eXpress Data Path (XDP), a kernel network layer that processes packets closer to the NIC for fast packet processing. Developers can write programs in C or P4 languages and then compile to eBPF instructions, which can be processed by the kernel or by programmable devices (e.g., SmartNICs). Since its introduction in 2014, eBPF has been rapidly adopted by major companies such as Facebook, Cloudflare, and Netronome. Use cases include network monitoring, network traffic manipulation, load balancing, and system profiling. This work aims to present eBPF to an inexpert audience, covering the main theoretical and fundamental aspects of eBPF and XDP, as well as introducing the reader to simple examples to give insight into the general operation and use of both technologies.
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