Molecular Communications at the Macroscale: A Novel Framework for Modeling Epidemic Spreading and Mitigation

Using the notion of effective distance proposed by Brockmann and Helbing, complex spatiotemporal processes of epidemic spreading can be reduced to circular wave propagation patterns with well-defined wavefronts. This hidden homogeneity of contagion phenomena enables the mapping of virtual mobility networks to physical propagation channels. Subsequently, we propose a novel communications-inspired model of epidemic spreading and mitigation by establishing the one-to-one correspondence between the essential components comprising information and disease transmissions. The epidemic processes can be regarded as macroscale molecular communications, in which individuals are macroscale information molecules carrying messages (epidemiological states). We then present the notions of normalized ensemble-average prevalence (NEAP) and prevalence delay profile (PDP) to characterize the relative impact and time difference of all the spreading paths, which are analogous to the classical description methods of path loss and power delay profile in communications. Furthermore, we introduce the metric of root mean square (RMS) delay spread to measure the distortion of early contagion dynamics caused by multiple infection transmission routes. In addition, we show how social and medical interventions can be understood from the perspectives of various communication modules. The proposed framework provides an intuitive, coherent, and efficient approach for characterization of the disease outbreaks by applying the deep-rooted communications theories as the analytical lens.Comment: 16 pages, 5 figure

A locally-induced increase in intracellular Ca2+ propagates cell-to-cell in the presence of plasma membrane Ca2+ ATPase inhibitors in non-excitable cells

AbstractIntercellular Ca2+ waves are commonly observed in many cell types. In non-excitable cells, intercellular Ca2+ waves are mediated by gap junctional diffusion of a Ca2+ mobilizing messenger such as IP3. Since Ca2+ is heavily buffered in the cytosolic environment, it has been hypothesized that the contribution of the diffusion of Ca2+ to intercellular Ca2+ waves is limited. Here, we report that in the presence of plasma membrane Ca2+ ATPase inhibitors, locally-released Ca2+ from the flash-photolysis of caged-Ca2+ appeared to induce further Ca2+ release and were propagated from one cell to another, indicating that Ca2+ was self-amplified to mediate intercellular Ca2+ waves. Our findings support the notion that non-excitable cells can establish a highly excitable medium to communicate local responses with distant cells

Characterization of hydrogen peroxide removal reaction by hemoglobin in the presence of reduced pyridine nucleotides

AbstractHydrogen peroxide removal rates by hemoglobin were enhanced in the presence of reduced pyridine nucleotides. The species which had the activity to oxidize pyridine nucleotides was purified from human blood and identified as hemoglobin A. Hydrogen peroxide removal rates by hemoglobin A without reduced pyridine nucleotides at 0.2 mM hydrogen peroxide were 0.87±0.11 μmol/s/g hemoglobin, and the removal rates using 0.2 mM NADH and NADPH were 2.02±0.20 and 1.96±0.31 μmol/s/g hemoglobin, respectively. We deduced that the removal reaction by hemoglobin included formations of methemoglobin and the ferryl radical and reduction of the latter with pyridine nucleotides. The hydrogen peroxide removal ability by hemoglobin was less than that by catalase but was larger than that by glutathione peroxidase-glutathione reductase system at 0.2 mM hydrogen peroxide. Under acatalasemic conditions, it was suggested that NAD(P)H were important factors to prevent the oxidative degradation of hemoglobin

A Case Report of Primordial Odontogenic Tumor That Required Distinction from a Dentigerous Cyst

Primordial odontogenic tumor (POT) is a rare odontogenic tumor characterized by a variably cellular loose fibrous tissue with areas similar to the dental papilla and covered by cuboidal to columnar epithelium. We herein report a case of POT in a 14-year-old boy. Computed tomography (CT) exhibited a round cavity with a defined cortical border circumscribing the tooth of the second molar. However, the gross finding was a solid mass, not a cyst. Histologically, the tumor consisted of dental papillalike myxoid connective tissue covered by columnar epithelium. Therefore, although the clinical diagnosis was dentigerous cyst (DC), we diagnosed POT based on histologic findings. Clinical findings of POT resemble DC, but the clinical behavior of POT is different to DC, such as cortical expansion and root resorption of teeth. Therefore, histological differentiation of POT from DC is critical for accurate diagnosis

Structure of carbohydrate chain of a thrombin-like protease from the venom of Agkistrodon halys brevicaudus stejneger snake

The structure of the carbohydrate chain of kangshuanmei, a thrombin-like serine protease isolated from Agkistrodon halys brevicaudus stejneger snake venom, was determined. The carbohydrate content of the kangshuanmei was 18%. The sugar composition was analyzed by the acid hydrolysis followed by aminobenzoic ethyl ester labeling. Galactose, N-acetylglucosamin, mannose, and fucose were detected, indicating that the binding carbohydrate chain is asparagine-linked type oligosaccharides. N-Acetylneuraminic acid located at non-reduced terminal of the carbohydrate chain was identified by neuraminidase digestion. The carbohydrate chain moiety was separated from kangshuanmei by hydrazynolysis treatment followed by aminobenzoic octyl ester (ABOE) labeling. The isolated ABOEmodified carbohydrate chain was compared to the asparagine-linked type standard oligosaccharides. The carbohydrate chains were consisted of sialylated bi(39.4%)-, tri(50.4%)- and tetra(10.2%)- antennary lactosamins complex containing fucose. The structure of the conjugated carbohydrate chain of kangshuanmei was significantly different from that of thrombin, which has a bisected antennary structure of oligosaccharide

The electric field changes and UHF radiations caused by the triggered lightning in Japan

In the rocket triggered lightning experiment of fiscal 1989, researchers observed electromagnetic field changes and UHF electromagnetic radiation accompanying rocket triggered lightning. It was found that no rapid changes corresponding to the return stroke of natural lightning were observed in the electric field changes accompanying rocket triggered lightning. However, continuous currents were present. In the case of rocket triggered lightning to the tower, electromagnetic field changes corresponding to the initiation of triggered lightning showed a bipolar pulse of a relatively large amplitude. In contrast, the rocket triggered lightning to the ground did not have such a bipolar pulse. The UHF radiation accompanying the rocket triggered lightning preceded the waveform portions corresponding to the first changes in electromagnetic fields. The number of isolated pulses in the UHF radiation showed a correlation with the time duration from rocket launching up to triggered lightning. The time interval between consecutive isolated pulses tended to get shorter with the passage of time, just like the stepped leaders of natural lightning