Dependence of Irradiated High-Power Electromagnetic Waves on the Failure Threshold Time of Semiconductors Using a Closed Waveguide

The failure threshold time of semiconductors caused by the impact of irradiated high-power electromagnetic waves (HPEM) is experimentally studied. A SN7442 integrated circuit (IC) is placed in an emulator with a WR430 closed waveguide and is irradiated by HPEM generated from a magnetron oscillator. The state of the SN7442 component is observed by a light-emitting diode (LED) detector and the voltage measured in the SN7442 component. As the magnitude of the electric field in the HPEM is varied from 24 kV/m to 36 kV/m, the failure threshold time falls from 195 s to 17 s with dependence of the irradiated electric field (E) on the failure threshold time (T) from T~E−12 to a T~E−6.

Enhancement of Recombinase-Aided Amplification (Raa) Assay by Betaine and Pullulan

In this research, nucleic acid amplification enhancers suitable for recombinase-aided amplification (RAA) assay were studied for the first time, and amplification of a long-fragment (509 bp) by the RAA assay was initially explored. Using recombinant plasmids and clinical samples, RAA fluorescence and basic methods were used to evaluate the efficacy. The fluorescence method was evaluated by threshold time (TT) and fluorescence value, and the basic method was interpreted by 2% agarose gel electrophoresis. Taking a previously established RAA assay for HPV18 as an example, we demonstrated that the addition of 0.2, 0.4, and 0.6 M betaine and 10% pullulan could enhance RAA. The new RAA assays with betaine and pullulan were called B-RAA and P-RAA, respectively. In the B-RAA and P-RAA fluorescence methods, TT values could be shortened by 1.72–2.32 and 2.60 minutes, respectively, and fluorescence values could be enhanced by 8847.25–9094.37 and 5250 mv, respectively. In the basic method, sensitivity could be increased by 10-fold. We successfully amplified a long-fragment of 509 bp in a P-RAA assay with a sensitivity of 102 copies/μL (compared with 103 copies/μL in the RAA assay). We thus conclude that betaine and pullulan are effective additives to enhance RAA assays.

A simple model for how the risk of pandemics from different virus families depends on viral and human traits

Different virus families, like influenza or corona viruses, exhibit characteristic traits such as typical modes of transmission and replication as well as specific animal reservoirs in which each family of viruses circulate. These traits of genetically related groups of viruses influence how easily an animal virus can adapt to infect humans, how well novel human variants can spread in the population, and the risk of causing a global pandemic. Relating the traits of virus families to their risk of causing future pandemics, and identification of the key time scales within which public health interventions can control the spread of a new virus that could cause a pandemic, are obviously significant. We address these issues using a minimal model whose parameters are related to characteristic traits of different virus families. A key trait of viruses that “spillover” from animal reservoirs to infect humans is their ability to propagate infection through the human population (fitness). We find that the risk of pandemics emerging from virus families characterized by a wide distribution of the fitness of spillover strains is much higher than if such strains were characterized by narrow fitness distributions around the same mean. The dependences of the risk of a pandemic on various model parameters exhibit inflection points. We find that these inflection points define informative thresholds. For example, the inflection point in variation of pandemic risk with time after the spillover represents a threshold time beyond which global interventions would likely be too late to prevent a pandemic.

Clustering of Fast Coronal Mass Ejections during Solar Cycles 23 and 24 and Implications for CME–CME Interactions

<p>Coronal Mass Ejections (CMEs) and their interplanetary counterparts (ICMEs) are the major sources for strong space weather disturbances. We present a study of statistical properties of fast CMEs (v≥1000 km/s) that occurred during solar cycles 23 and 24. We apply the Max Spectrum and the declustering threshold time methods. The Max Spectrum can detect the predominant clusters, and the declustering threshold time method provides details on the typical clustering properties and timescales. Our analysis shows that during the different phases of solar cycles 23 and 24, fast CMEs preferentially occur as isolated events and in clusters with, on average, two members. However, clusters with more members appear, particularly during the maximum phases of the solar cycles. During different solar cycle phases, the typical declustering timescales of fast CMEs are τ<sub>c</sub> =28-32 hrs, irrespective of the very different occurrence frequencies of CMEs during a solar minimum and maximum. These findings suggest that  τ<sub>c</sub>   for extreme events may reflect the characteristic energy build-up time for large flare and CME-prolific active regions. Statistically associating the clustering properties of fast CMEs with the disturbance storm time index at Earth suggests that fast CMEs occurring in clusters tend to produce larger geomagnetic storms than isolated fast CMEs. Our results highlight the importance of CME-CME interaction and their impact on Space Weather.</p>

Robust Emergency Relief Supply Planning for Foreseen Disasters Under Evacuation-Side Uncertainty

For foreseen natural disasters (e.g., hurricanes or floods), the uncertainties faced in relief logistics primarily stem from evacuation activities. We present a strategic planning problem to supply relief items by considering uncertainties in disaster location, intensity, duration, and evacuee compliance. To ensure time- and cost-effectiveness in relief distribution, we develop a robust optimization model to determine centralized supply locations, and supply quantities for different transportation modes in a five-tier network. In doing so, we consider the interaction between evacuation and supply-side activities and capture the inherent uncertainties using a combination of event and box uncertainty representations. Our model provides a decision maker with the flexibility of including or excluding the time dependency of evacuation-related uncertainties. Accordingly, it suggests a threshold time window for relief distribution, beyond which either the system cost increases or the benefits of early distribution diminish. Although the model primarily aids a policymaker in strategic preparedness, its tactical variant can aid the efficient distribution. We devise an enhanced Benders decomposition-based efficient solution method to solve realistic-size problems. In a case study using geographic information system data, we highlight the complex dynamics among various system components and discuss the resulting time-cost trade-offs that also influence the network structure.

Expression Pattern of Ethylene-Related Genes in Response to Preharvest Chemical Treatments during Development and Ripening of Mangosteen Fruit (Garcinia mangostana L.)

The expression of ethylene associated genes based on development stage from fruit set until harvest in mangosteen has not been studied yet in some previous studies. The objective of this study was to investigate the expression pattern of genes involved in ethylene biosynthesis, Gm-ACS, and Gm-ACO, and perception, Gm-ETR, from the stages of fruit set (Period I), fruit development (Period II), and maturation until ripening or harvesting (Period III). The results showed that ethylene biosynthetic genes on the Gm-ACO gene were correlated with ethylene production's climacteric pattern. Gm-ACO was up-regulated at the beginning of the fruit set and then decreased. Fruit at age 2 - 10 weeks after anthesis showed a decrease in the Gm-ACO gene's mRNA levels. Then, Gm-ACO expression re-appeared and increased at the fruitage 11 - 12 after the fruit set. At the harvest-stage, the fruit showed down-regulation at the lowest level of the Gm-ACO expression. Ethephon treatment at or beyond 24 h (threshold time) increased the mRNA levels of Gm-ACS, Gm-ACO, and Gm-ETR. In contrast, the 1-Methylcyclopropene (1-MCP) treatment under the threshold time resulted in undetectable expression in all ethylene-related genes. These data would be beneficial to elucidate the molecular mechanisms in the mangosteen fruit ripening process. In addition, preharvest application of ethephon or 1-MCP can induce or inhibit the gene expression of ethylene biosynthesis and perception.

Characterization of Heat Protective Aerogel-Enhanced Textile Packages

The aim of this study was to investigate the effects of aerogel application on the thermal properties of textile packages intended for use in protective clothing. The packages were prepared in the form of removable inserts filled with aerogel, differing in terms of fabric and design. The developed packages were tested for resistance to the three major types of heat: radiant, convective, and contact. The package variant with superior thermal performance was also evaluated for water vapor resistance. The package after incorporation of aerogel was found to approximately double radiant and convective heat resistance, with an approx. eightfold improvement for contact heat at the highest test temperature 250℃. Threshold time increased from (17.7±0.7) s to (139.9±4.9) s for the optimum aerogel-enhanced package variant with the greatest number of pouches, which met the criteria of the highest performance level. The thermal conductivity and thermal resistance of three fabrics selected for testing were tested in order to determine their basic thermal insulation properties. In general, packages containing a larger number of narrower pouches exhibited higher thermal protective performance. The results show that the developed textile packages with aerogel can be successfully used in thermal protective clothing.

Quantification of colorimetric isothermal amplification on the smartphone and its open-source app for point-of-care pathogen detection

The increasing risk of infectious pathogens, especially in the under-developed countries, is demanding the development of point-of-care (POC) nucleic acid testing in the low-resource setting conditions. Here, we describe a methodology for colorimetric quantitative analysis of nucleic acid using an easy-to-build smartphone-based platform, offering low-cost, portability, simplicity in operation, and user-friendliness. The whole system consists of a hand-held box equipped with a smartphone, a film heater, a white LED, a loop-mediated isothermal amplification (LAMP) chip, and a DC converter, and all the processes were powered by a portable battery of 5 V. Upon the amplification of the target gene by an Eriochrome Black T-mediated LAMP reaction, the color of the LAMP reaction was changed from violet to blue that was real-time recorded by a smartphone camera. To keep track of the progress of the color change, we developed a novel mobile app in which a hue value was accepted as an indicator for color transition and for determining the threshold time of the amplification reaction. A calibration curve could be generated by plotting the logarithm of the known concentration of the DNA templates versus the threshold time, and it can be used to predict the copy number of nucleic acids in the test samples. Thus, the proposed mobile platform can inform us of not only qualitative but also quantitative results of the pathogens. We believe that this advanced colorimetric approach and the mobile app can expand the potentials of the smartphone for the future POCT system in the bio-diagnostic fields.