Flash Duration Research Articles

Flickering flash signals and mate recognition in the Asian firefly, Aquatica lateralis

Nocturnal fireflies sometimes use intricate bioluminescent signal systems for sexual communication. In this study, we examined flash signals and mate recognition in the Asian firefly, Aquatica lateralis, under natural field conditions. We found that the flash pattern of females changes after copulation, from simple short flashes to flashes with longer duration and flickering. To understand the functions of flickering, we video-recorded and analyzed the flashes of sedentary males, receptive females, and mated females. The results showed that the flashes of these three adult phases can be discriminated from each other by two parameters, flash duration and flicker intensity, with little overlap. Male attraction experiments using an artificial LED device termed ‘e-firefly’ confirmed that flying and sedentary males are attracted to flashes with shorter durations and lower flicker intensities. The range of attraction success was much wider for flying males and narrower for sedentary males, and the latter was close to the range of receptive female’s flashes. These findings suggest that in addition to flash duration, flicker intensity is a flash signal parameter of mate recognition in A. lateralis males.

Effect of Fennel-Valerian Extract on Hot Flashes and Sleep Disorders in Postmenopausal Women: A Randomized Trial.

This study aims to evaluate the effect of a mixture of fennel and valerian extracts on hot flashes and sleep disorders of postmenopausal women in Iran. A randomized trial was conducted. A total of 76 postmenopausal women were randomly assigned to either of the two groups: fennel-valerian extract or control. One 500 mg fennel-valerian extract capsule was given twice, daily for 8 weeks. The 500 mg oral placebo capsule (starch) was given the same way. The mean duration of hot flashes increased in both the groups over time (P < 0.001). The mean frequency and severity of hot flashes in the intervention group were significantly lower than in the control group, in the first and second months after intervention (P < 0.050). Women in the fennel-valerian extract group had a significantly lower Pittsburgh Sleep Quality Index score than the control group 2 months after intervention (P = 0.030). This study found that fennel-valerian extract was effective for relieving sleep disorders as well as the severity and frequency of hot flashes compared with a placebo.

Flash Characterization of Smartphones Used in Point-of-Care Diagnostics.

Rapidly growing interest in smartphone cameras as the basis of point-of-need diagnostic and bioanalytical technologies increases the importance of quantitative characterization of phone optical performance under real-world operating conditions. In the context of our development of lateral-flow immunoassays based on phosphorescent nanoparticles, we have developed a suite of tools for characterizing the temporal and spectral profiles of smartphone torch and flash emissions, and their dependence on phone power state. In this work, these tools are described and documented to make them easily available to others, and demonstrated by application to characterization of Apple iPhone 5s, iPhone 6s, iPhone 8, iPhone XR, and Samsung Note8 flash performance as a function of time and wavelength, at a variety of power settings. Flash and torch intensity and duration vary with phone state and among phone models. Flash has high variability when the battery charge is below 10%, thus, smartphone-based Point-of-Care (POC) tests should only be performed at a battery level of at least 15%. Some output variations could substantially affect the results of assays that rely on the smartphone flash.

Symptom-Based Risk Factors for Retinal Tears and Detachments in Suspected Posterior Vitreous Detachment

Introduction: The aim of this study was to determine symptom-level risk factors for retinal tear/retinal detachment (RT/RD) in our patients presenting with symptoms of posterior vitreous detachment (PVD). Methods: We conducted a prospective cohort study of patients presenting to outpatient ophthalmology clinics at a single academic institution with complaint(s) of flashes, floaters, and/or subjective field loss (SFL). Patients received a standardized questionnaire regarding past ocular history and symptom characteristics including number, duration, and timing of flashes and floaters, prior to dilated ocular examination. Final diagnosis was categorized as RT/RD, PVD, ocular migraine, vitreous syneresis, or “other.” Simple and multivariate logistic regressions were used to identify symptoms predictive of various pathologies. Results: We recruited 237 patients (age 20–93 years) from March 2018 to March 2019. The most common diagnosis was PVD (141, 59.5%), followed by vitreous syneresis (38, 16.0%) and RT/RD (34, 14.3%). Of those with RT/RD, 16 (47.1%) had retinal tear and 15 (44.1%) had RD. Significant differences in demographic and examination-based factors were observed between these groups. Symptom-based predictive factors for RT/RD were the presence of subjective visual reduction (SVR; OR 2.77, p = 0.03) or SFL (OR 2.47, p = 0.04), and the absence of either floaters (OR 4.26, p = 0.04) or flashes (OR 2.95, p = 0.009). The number, duration, and timing of flashes and floaters did not predict the presence of RT/RD in our cohort. Within the RT/RD group, patients with RT were more likely to report floaters (100% vs. 66.7%, p = 0.018) and less likely to report SFL (0% vs. 86.7%, p < 0.001) compared to those with RD. Conclusion: While well-known demographic and exam-based risk factors for RT/RD exist in patients with PVD symptoms, the relative importance of symptom characteristics is less clear. We found that the presence of SVR and SFL, as well as the absence of either flashes or floaters, predicts RT/RD in patients with PVD symptoms. However, the number, duration, and timing of flashes and floaters may be less relevant in the triage of these patients.

Effects of Low Mental Energy from Long Periods of Work on Brain-Computer Interfaces.

Brain-computer interfaces (BCIs) provide novel hands-free interaction strategies. However, the performance of BCIs is affected by the user’s mental energy to some extent. In this study, we aimed to analyze the combined effects of decreased mental energy and lack of sleep on BCI performance and how to reduce these effects. We defined the low-mental-energy (LME) condition as a combined condition of decreased mental energy and lack of sleep. We used a long period of work (>=18 h) to induce the LME condition, and then P300- and SSVEP-based BCI tasks were conducted in LME or normal conditions. Ten subjects were recruited in this study. Each subject participated in the LME- and normal-condition experiments within one week. For the P300-based BCI, we used two decoding algorithms: stepwise linear discriminant (SWLDA) and least square regression (LSR). For the SSVEP-based BCI, we used two decoding algorithms: canonical correlation analysis (CCA) and filter bank canonical correlation analysis (FBCCA). Accuracy and information transfer rate (ITR) were used as performance metrics. The experimental results showed that for the P300-based BCI, the average accuracy was reduced by approximately 35% (with a SWLDA classifier) and approximately 40% (with a LSR classifier); the average ITR was reduced by approximately 6 bits/min (with a SWLDA classifier) and approximately 7 bits/min (with an LSR classifier). For the SSVEP-based BCI, the average accuracy was reduced by approximately 40% (with a CCA classifier) and approximately 40% (with a FBCCA classifier); the average ITR was reduced by approximately 20 bits/min (with a CCA classifier) and approximately 19 bits/min (with a FBCCA classifier). Additionally, the amplitude and signal-to-noise ratio of the evoked electroencephalogram signals were lower in the LME condition, while the degree of fatigue and the task load of each subject were higher. Further experiments suggested that increasing stimulus size, flash duration, and flash number could improve BCI performance in LME conditions to some extent. Our experiments showed that the LME condition reduced BCI performance, the effects of LME on BCI did not rely on specific BCI types and specific decoding algorithms, and optimizing BCI parameters (e.g., stimulus size) can reduce these effects.

Impact of lifetime lactation on the risk and duration of frequent vasomotor symptoms: A longitudinal dose-response analysis.

To examine the association between lifetime lactation and risk and duration of frequent vasomotor symptoms (VMS). Prospective cohort. USA, 1995-2008. 2356 parous midlife women in the Study of Women's Health Across the Nation. Lifetime lactation was defined as the duration of breastfeeding across all births in months. We used generalised estimating equations to analyse risk of frequent VMS and Cox regression to analyse duration of frequent VMS in years. Frequent VMS (hot flashes and night sweats) were measured annually for 10 years, defined as occurring ≥6 days in the past 2 weeks. Overall, 57.1% of women reported hot flashes and 43.0% reported night sweats during follow-up. Lifetime lactation was inversely associated with hot flashes plateauing at 12 months of breastfeeding (6months: adjusted odds ratio [AOR] 0.85, 95% confidence interval (CI) 0.75-0.96; 12 months: AOR 0.78, 95% CI 0.65-0.93) and was inversely associated with night sweats in a downward linear fashion (6months: AOR 0.93, 95% CI 0.81-1.08; 18 months: AOR 0.82, 95% CI 0.67-1.02; 30 months: AOR 0.73, 95% CI 0.56-0.97). Lifetime lactation was associated with shorter duration of hot flashes and night sweats in a quadratic (bell-shaped) fashion. The association was strongest at 12-18 months of breastfeeding and significant for hot flashes (6months: adjusted hazard ratio [AHR] 1.35, 95% CI 1.11-1.65; 18 months: AHR 1.54, 95% CI 1.16-2.03; 30 months: AHR 1.18, 95% CI 0.83-1.68). Longer lifetime lactation is associated with decreased risk and duration of frequent VMS.

A Light-curve Analysis of the X-Ray Flash First Observed in Classical Novae

An X-ray flash, expected in a very early phase of a nova outburst, was at last detected with the SRG/eROSITA in the classical nova YZ Reticuli 2020. The observed flash timescale, luminosity, and blackbody temperature substantially constrain the nova model. We present light-curve models of the X-ray flash for various white dwarf (WD) masses and mass-accretion rates. We have found the WD mass in YZ Ret to be as massive as M WD ∼ 1.3 M ☉ with mass-accretion rates of yr−1, including the case where the mass-accretion rate is changing between them, consistent with the SRG/eROSITA observation. The X-ray observation confirms the luminosity to be close to the Eddington limit at the X-ray flash. The occurrence of optically thick winds, with the photospheric radius exceeding ∼0.1 R ☉, terminated the X-ray flash of YZ Ret by strong absorption. This sets a constrain on the starting time of wind mass loss. A slight contamination of the hydrogen-rich envelope by the core material seems to be preferred to explain the very short duration of the X-ray flash.

Present-day model of lunar meteoroids and their impact flashes for LUMIO mission

The Lunar Meteoroid Impacts Observer (LUMIO) is a CubeSat mission to observe, quantify, and characterize the meteoroid impacts by detecting their flashes on the lunar farside. It complements lunar nearside observations performed by ground-based observatories to yield global information synthesis on the lunar meteoroid environment. Predicting LUMIO’s scientific outcome involves devising a methodology to model the meteoroid environment. We propose a method where numerous known meteoroid streams, as well as sporadic collisions with the lunar surface, are modeled. Impacts are generated with a stochastic approach based on experimental observations of fireballs, impact flashes, and meteors. A catalog collecting data of both meteoroid streams and sporadic background is made available to the community. Sample scenarios are reproduced to show the capabilities of our method. A synthesis of the statistical analysis performed on the collision dynamics is presented. Results show that a typical scenario counts almost 2 million impacts with impact kinetic energy larger than 10−7 kton TNT Equivalent, out of which approximately 200.000 fall in the energy range of interest for the LUMIO mission. For that subset, the equivalent black body temperature is estimated to range in 1510-2290K, the average impact flash duration is expected to be approximately 15ms, and the average plume area is predicted to be roughly 70m2.

Shock Breakout in Three-dimensional Red Supergiant Envelopes

Using Athena++, we perform 3D radiation-hydrodynamic calculations of the radiative breakout of the shock wave in the outer envelope of a red supergiant (RSG) that has suffered core collapse and will become a Type IIP supernova. The intrinsically 3D structure of the fully convective RSG envelope yields key differences in the brightness and duration of the shock breakout (SBO) from that predicted in a 1D stellar model. First, the lower-density “halo” of material outside of the traditional photosphere in 3D models leads to a shock breakout at lower densities than 1D models. This would prolong the duration of the shock breakout flash at any given location on the surface to ≈1–2 hr. However, we find that the even larger impact is the intrinsically 3D effect associated with large-scale fluctuations in density that cause the shock to break out at different radii at different times. This substantially prolongs the SBO duration to ≈3–6 hr and implies a diversity of radiative temperatures, as different patches across the stellar surface are at different stages of their radiative breakout and cooling at any given time. These predicted durations are in better agreement with existing observations of SBO. The longer durations lower the predicted luminosities by a factor of 3–10 (L bol ∼ 1044 erg s−1), and we derive the new scalings of brightness and duration with explosion energies and stellar properties. These intrinsically 3D properties eliminate the possibility of using observed rise times to measure the stellar radius via light-travel time effects.

우리나라에서 최근(1982 ~ 2020) 발생한 여름철 급성가뭄의 특성 및 변화에 대한 연구

A flash drought is a rapidly evolving drought, unlike general meteorological droughts that develop over months to years due to persistent precipitation deficits. This study investigated the characteristics of summertime flash droughts in South Korea for the period of 1982 ~ 2020. Flash droughts can be classified into heatwave flash droughts and precipitation deficit flash droughts, with the former occurring most frequently in South Korea. Both the occurrence and duration of flash droughts increased during the analysis period, especially heatwave flash droughts. Composite analysis results of reanalysis dataset and land surface model simulation revealed that large-scale anticyclonic atmospheric circulation and positive temperature anomalies contribute to increased evapotranspiration and reduced soil moisture, which lead to flash droughts in South Korea. In the summer of 2016 and 2018, when flash droughts occurred most frequently with record-breaking heatwaves, these characteristics were prevalent. Land-atmosphere interactions associated with the anticyclonic circulation might influence the development of summer heatwave flash droughts in South Korea.

Soft X-ray radiography for measurements of a dense metal plasma created by intense relativistic electron beam on a tantalum target

A radiographic diagnostic has been developed to quantify the plume of erosion products after the interaction between a target and a relativistic electron beam. The diagnostic is based on a point Z-pinch (PZ-pinch) with a metallic plasma jet. It creates an X-ray source with a typical size of 10 μm, a photon energy of up to 3 keV and a flash duration of 3 ns. The X-ray visualization system is based on a thin scintillator and a CCD camera. The spatial resolution of the diagnostic was evaluated experimentally. The spatial frequency limit was found to be about 1.5 line pairs per millimeter. The diagnostic was tested in an experiment performed using an LIA-5 linear induction accelerator. An electron beam with a current of 400 A, an energy of 3.5 MeV and a pulse duration of 80 ns was focused on a plane tantalum target 1 mm in thickness. The FWHM of the focal spot was ∼ 2 mm. Radiographs of the plume were taken with different delays after different accelerator pulses. According to our data, the plume most commonly propagates toward the beam. After 70 μs its length was about 70 mm, i.e. the plume expansion rate was about 1 km/s. The area density of the semi-transparent regions of the plume was estimated as lying in the range 3 · 10-16–2 · 1017 cm-2.

Global flash clustering and infrared radiance characteristics: Analysis of TRMM/LIS data

Lightning activities are usually related to climate change and meteorological disasters. We investigated the spatiotemporal distribution of global lightning activities and infrared radiance characteristics of lightning flashes. Based on the Lightning Imaging Sensor (LIS) data product from 1998 to 2014, the spatiotemporal distributions of flash duration, length, footprint, and radiance were analyzed. K-means was used to perform cluster analysis on global lightning data. Finally, based on LIS event data, the lightning radiance in a single detection was processed statistically, and the probability density of the flash radiance was fitted. The results indicated that the flash density had significant spatiotemporal distribution characteristics, which were primarily affected by the climates of different geographical locations and seasons. According to the K-means clustering algorithm, lightning was geographically divided into six categories. The flash density in the area with the strongest lightning activities was 62.9280 fl·km−2·a-1 and the mean annual radiance was 1.1371 J·m−2·sr-1·μm−1·a-1, primarily distributed in North America, southern South America, central and southern Africa, southern Asia, and northwest and southeast Australia. The strength of lightning activities was mainly affected by the climate. Offshore waters, low latitude areas, and the barrier of mountain ranges cause strong convective activity in the atmosphere, which leads to strong lightning activity. Additionally, human activities, such as high-temperature exhaust gas and aerosols emitted by factories, will also affect atmospheric convection activities and cloud formation, consequently affecting lightning activities. The probability density functions of lightning flash radiance obtained by single detection had almost the same form in the radiance range of 0–0.6 J·m−2·sr-1·μm−1 regardless of the geographic location. This may be related to the inherent discharge properties of lightning at low radiance. When the radiance was greater than 0.6 J·m−2·sr-1·μm−1, the difference between the probability density functions of the radiance of the six categories was subtle. The lightning clustering result and the probability density function radiance obtained by single detection are helpful for the identification and prediction of lightning flash radiation characteristics.

Discerning the role of IP3R1 activation by Gq/G11 signaling in murine lymphatic collecting vessel pacemaking

Collecting lymphatic vessels (cLVs) exhibit spontaneous contractions with a pressure‐dependent frequency that increases with elevations in intraluminal pressure. Our recent work posits a putative role for lymphatic muscle cells (LMCs) as the pacemaker cell that regulates this pressure‐dependent phenomenon through activation of the Ca2+‐activated chloride channel anoctamin 1 (Ano1) in an IP3R1‐dependent process. However, the specific mechanisms underlying IP3R1 activation and SR Ca2+ release in lymphatic muscle cells is unknown. We tested the hypothesis that cLV pressure‐dependent pacemaking by the IP3R1‐Ano1 axis is downstream of the canonical Gq/G11‐PLC‐β signaling pathway. To this end, we crossed mice with the smooth muscle‐specific tamoxifen‐inducible Cre, MYH11CreERT2, to the fluorescent reporter ROSAmT/mG and sorted GFP+ LMCs from an isolated murine inguinal‐axillary (IngAx) lymphatic cLVs. Murine lymphatic muscle cell expression of Gq and G11 were assessed via RT‐PCR. We crossed MYH11CreERT2 mice with IP3R1fl/fl or G11KO/KO‐Gqfl/fl mice to achieve IP3R1ismKO (MYH11CreERT2‐IP3R1fl/fl) and double G11KO‐GqismKO (MYH11CreERT2‐ G11KO/KO‐Gqfl/fl) mice. We tested the function of the IngAx cLVs isolated from these mice, as well as their respective heterozygous WT/KO and fl/fl controls, using isolated vessel isobaric myography. Ca2+ imaging using IP3R1ismKO‐GCaMP6f mice, and membrane potential recordings using sharp electrodes. IngAx cLVs from G11KO‐GqismKO mice displayed a significant reduction in contraction frequency and vessel tone, however a pressure‐dependent increase in frequency was observed. Similarly, IngAx cLVs isolated from IP3R1ismKO mice had significantly lower vessel tone, a significant reduction in contraction frequency at all pressures tested, and a significantly higher contraction amplitude. Critically, contraction frequency in IngAx cLVs isolated from IP3R1ismKO mice did not increase with pressure in contrast to IngAx cLVs isolated from G11KO‐GqismKO mice and wildtype mice. In wildtype (WT) MYH11CreERT2‐GCaMP6f controls, Ca2+ puffs and/or Ca2+ waves were observed in the majority of LMCs during the diastolic period, intervening the bright global Ca2+ flashes indicative of Ca2+ entry through L‐type Ca2+ channels during the LMC action potential (AP). These local diastolic Ca2+ transients (CaTs) persisted in the presence of nifedipine, and the frequency and spatial spread of CaTs increased with pressure. Diastolic CaTs were largely absent in LMCs of IP3R1ismKO mice, and their diastolic depolarization recapitulated the lower rate observed in previous studies of Ano1smKO cLVs. However, APs recorded in IP3R1ismKO significantly increased AP plateau duration that corresponds with an increased Ca2+ flash duration. We conclude that the Gq/G11 dependent signaling is involved in pressure‐dependent pacemaking in murine cLVs, particularly at low pressure, but their deletion is insufficient to reproduce the IP3R1ismKO phenotype.

Climate warming outweighs vegetation greening in intensifying flash droughts over China

The increasing occurrence of flash droughts with rapid onsets poses a great threat to food security and ecosystem productivity. While temporal trends in flash droughts have been extensively studied, the contributions of climate warming, vegetation greening, and the physiological effect of rising CO2 to trends in flash drought characteristics remain unclear. Here we show there are significant increasing trends in flash drought frequency, duration, and intensity for most of China during 1961–2016. Warmer temperatures and vegetation greening increase evapotranspiration and decrease soil moisture, and explain 89% and 54% of the increasing frequency of flash drought respectively. Rising CO2 concentrations reduce stomatal conductance, which acts to decelerate the increasing drought frequency trend by 18%, whereas the physiological effects of rising CO2 on flash drought duration and intensity are smaller. Warming also outweighs vegetation greening for the increasing trends of flash drought duration and intensity over most of China, except North China. Our study highlights the role of climate warming in increasing the risk of flash droughts.

Response of vegetation ecosystems to flash drought with solar-induced chlorophyll fluorescence over the Hai River Basin, China during 2001–2019

With global climate change, frequent flash droughts have critically impacted vegetation productivity. Based on the new definition on flash drought onset and duration, the temporal and spatial evolution patterns of the flash drought over the Hai River Basin (HRB) was analysed. Among the events, the flash drought in 2019 lasted for 40 days, from the day of the year (DOY) 120 to DOY160, which was the strongest and mainly concentrated in the south-eastern part of the basin. Solar-induced chlorophyll fluorescence (SIF) and vegetation indices were used to explore the responses of different vegetation types to this flash drought. Compared to forest and grassland, the SIF and SIFyield (SIF normalized by the absorbed photosynthetically active radiation (APAR)) values of cropland were more sensitive to water losses and replenishment. By analysing different radiation conditions which would affect SIF and photosynthesis, low radiation was found altering the linear relationship between fluorescence and photosynthesis. The flash drought event caused gross primary productivity (GPP) losses in 40% of the basin and the maximum loss reached 0.16 kg C m−2, indicating that the impact of this flash drought on vegetation productivity was quite serious. The results obtained in this work can be used to understand the mechanisms with which the vegetation photosynthetic capacity responds to flash droughts and to evaluate the impact of flash droughts on terrestrial ecosystems.

New WMO Certified Megaflash Lightning Extremes for Flash Distance and Duration Recorded from Space

New WMO Certified Megaflash Lightning Extremes for Flash Distance and Duration Recorded from Space

Duration invariance and intensity dependence of the human circadian system phase shifting response to brief light flashes.

The melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs) are characterized by a delayed off-time following the cessation of light stimulation. Here, we exploited this unusual physiologic property to characterize the exquisite sensitivity of the human circadian system to flashed light. In a 34 h in-laboratory between-subjects design, we examined phase shifting in response to variable-intensity (3–9500 photopic lux) flashes at fixed duration (2 ms; n = 28 participants) and variable-duration (10 µs–10 s) flashes at fixed intensity (2000 photopic lux; n = 31 participants). Acute melatonin suppression, objective alertness and subjective sleepiness during the flash sequence were also assessed. We find a dose–response relationship between flash intensity and circadian phase shift, with an indication of a possible threshold-like behaviour. We find a slight parametric relationship between flash duration and circadian phase shift. Consistent with prior studies, we observe no dose–response relationship to either flash intensity or duration and the acute impact of light on melatonin suppression, objective alertness or subjective sleepiness. Our findings are consistent with circadian responses to a sequence of flashes being mediated by rod or cone photoreceptors via ipRGC integration.

Fast Radio Bursts by High-frequency Synchrotron Maser Emission Generated at the Reverse Shock of a Powerful Magnetar Flare

Abstract We consider a magnetar flare model for fast radio bursts (FRBs). We show that millisecond bursts of sufficient power can be generated by synchrotron maser emission ignited at the reverse shock propagating through the weakly magnetized material that forms the magnetar flare. If the maser emission is generated in an anisotropic regime (due to the geometry of the production region or presence of an intense external source of stimulating photons), the duration of the maser flashes is similar to the magnetar flare duration even if the shock front radius is large. Our scenario allows for relaxing the requirements for several key parameters: the magnetic field strength at the production site, luminosity of the flare, and the production site bulk Lorentz factor. To check the feasibility of this model, we study the statistical relation between powerful magnetar flares and the rate of FRBs. The expected ratio is derived by convoluting the redshift-dependent magnetar density with its flare luminosity function above the energy limit determined by the FRB detection threshold. We obtain that only a small fraction, ∼10−5, of powerful magnetar flares trigger FRBs. This ratio agrees surprisingly well with our estimates: we obtained that 10% of magnetars should be in the evolutionary phase suitable for the production of FRBs, and only 10−4 of all flares are expected to be weakly magnetized, which is a necessary condition for the high-frequency maser emission.

Effect of pressure on the electrical resistance flash sintering of tungsten carbide

The application of external pressure during the Electrical Resistance Flash Sintering of tungsten carbide (WC), a “metallic ceramic” with positive temperature coefficient (PTC) for resistivity, results in a limited densification of the powder. In the present work, the effect of pressure on the ultrafast sintering of WC is analysed in detail. In particular, the application of pressure at different stages of flash sintering is studied by varying independently the processing parameters i.e., voltage, time and pressure. Microstructural characterization performed by FE-SEM and XRD identifies biphasic structures of WC and W2C, which compositions result almost unchanged for different sintering parameters. Increasing the external load from 4 up to 100 MPa leads to microporous materials, limiting the attainable final density. Pressure is demonstrated to control the flash phenomenon directly by affecting the flash duration and intensity, thus controlling the electrical energy dissipated during the power surge with respect to the overall process.

Species-Specific Flash Patterns Track the Nocturnal Behavior of Sympatric Taiwanese Fireflies.

Simple SummaryNocturnal fireflies are facing various challenges to their survival (e.g., artificial light pollution and extreme climate change). However, there are still no effective diagnostic tools to distinguish firefly species and monitor how their population size and nocturnal behavior change in the wild. Here, we demonstrated that flash interval (FI), a timing character of firefly flash signaling, can be a reliable species-specific luminescent marker for identifying three species (Abscondita cerata, Luciola kagiana, and Luciola curtithorax) in a wild sympatric population and evaluating their nightly behaviors in video-imagery analysis, as well as a traditional field specimen collection. Our studies provide key information and valuable references for future studies of (1) the behaviors of sympatric fireflies in the wild and (2) the development of automatic and rapid digital diagnostic tools for identifying firefly species and quantifying population size, especially for firefly conservation.It is highly challenging to evaluate the species’ content and behavior changes in wild fireflies, especially for a sympatric population. Here, the flash interval (FI) and flash duration (FD) of flying males from three sympatric species (Abscondita cerata, Luciola kagiana, and Luciola curtithorax) were investigated for their potentials in assessing species composition and nocturnal behaviors during the A. cerata mating season. Both FI and FD were quantified from the continuous flashes of adult fireflies (lasting 5–30 s) via spatiotemporal analyses of video recorded along the Genliao hiking trail in Taipei, Taiwan. Compared to FD patterns and flash colors, FI patterns exhibited the highest species specificity, making them a suitable reference for differentiating firefly species. Through the case study of a massive occurrence of A. cerata (21 April 2018), the species contents (~85% of the flying population) and active periods of a sympatric population comprising A. cerata and L. kagiana were successfully evaluated by FI pattern matching, as well as field specimen collections. Our study suggests that FI patterns may be a reliable species-specific luminous marker for monitoring the behavioral changes in a sympatric firefly population in the field, and has implication values for firefly conservation.