Bright Band Research Articles

Phonon-Driven Femtosecond Dynamics of Excitons in Crystalline Pentacene from First Principles.

Nonradiative exciton relaxation processes are critical for energy transduction and transport in optoelectronic materials, but how these processes are connected to the underlying crystal structure and the associated electron, exciton, and phonon band structures, as well as the interactions of all these particles, is challenging to understand. Here, we present a first-principles study of exciton-phonon relaxation pathways in pentacene, a paradigmatic molecular crystal and optoelectronic semiconductor. We compute the momentum- and band-resolved exciton-phonon interactions, and use them to analyze key scattering channels. We find that both exciton intraband scattering and interband scattering to parity-forbidden dark states occur on the same ∼100 fs timescale as a direct consequence of the longitudinal-transverse splitting of the bright exciton band. Consequently, exciton-phonon scattering exists as a dominant nonradiative relaxation channel in pentacene. We further show how the propagation of an exciton wave packet is connected with crystal anisotropy, which gives rise to the longitudinal-transverse exciton splitting and concomitant anisotropic exciton and phonon dispersions. Our results provide a framework for understanding the role of exciton-phonon interactions in exciton nonradiative lifetimes in molecular crystals and beyond.

Enhancing consistency of microphysical properties of precipitation across the melting layer in dual-frequency precipitation radar data

Abstract. Stratiform rain and the overlying ice play crucial roles in Earth's climate system. From a microphysics standpoint, water mass flux primarily depends on two variables: particles' concentration and their mass. The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement mission core satellite is a spaceborne instrument capable of estimating these two quantities through dual-wavelength measurements. In this study, we evaluate bulk statistics on the ice particle properties derived from dual-wavelength radar data in relation to the properties of rain underneath. Specifically, we focus on DPR observations over stratiform precipitation, characterized by columns exhibiting a prominent bright band, where the melting layer can be easily detected. Our analysis reveals a large increase in the retrieved mass flux as we transition from the ice to the rain phase in the official DPR product. This observation is in disagreement with our expectation that mass flux should remain relatively stable across the bright band in cold-rain conditions. To address these discrepancies, we propose an alternative retrieval algorithm that ensures a gradual transition of Dm (mean mass-weighted particle melted-equivalent diameter) and the precipitation rate across the melting zone. This approach also helps in estimating bulk ice density above the melting level. These findings demonstrate that DPR observations can not only quantify ice particle content and their size above stratiform rain regions but also estimate bulk density, provided uniform conditions that minimize uncertainties related to partial beam filling.

Chromene-chromene Schiff base as a fluorescent chemosensor for Th4+ and its application in bioimaging of Caenorhabditis elegans

The manuscript presents the synthesis of a new di-chromene Schiff base (COM-CH) by combining 7-(diethylamino)-2-oxo-2H-chromene-3-carbohydrazide and 4-oxo-4H-chromene-3-carbaldehyde, and its characterization using various analytical techniques. The probe COM-CH functional group contains a hard donor atom that selectively complexes with Th4+ ions. This report investigated COM-CH's sensing ability towards Th4+ chromogenic and fluorogenic methods in ACN: H2O (8:2, v/v) with Th4+ ions. The COM-CH-Th4+ complex was excited at 430 nm, resulting in a bright emission band at 475 nm with a 45 nm Stokes shift. The COM-CH probe demonstrated the highest performance at pH 4.0 to 8.0, with a sensitivity of 18.7 nM. The complex formation of COM-CH with Th4+ was investigated using NMR, FTIR spectrometry, and density functional theory calculations. The COM-CH and Th4+ are bound with 2:1 stoichiometry and an association constant of 1.92 × 108 M−2. The probe's performance enabled the analysis of monazite sand and water samples for Th4+ content. The probe successfully detected Th4+ content in Caenorhabditis elegans, marking the first Th4+ detection in animal models.

Juno’s JunoCam Images of Europa

On 2022 September 29 the Juno spacecraft passed Europa at 355 km, the first close pass since the Galileo flyby in 2000. Juno’s visible-light imager, JunoCam, collected four images, enabling cartographic, topographic, and surface geology analysis. The topography along the terminator is consistent with previously reported features that may indicate true polar wander. A bright band was discovered, and indicates global symmetry in the stress field that forms bright bands on Europa. The named feature Gwern is shown not to be an impact crater. Surface change detection shows no changes in 22 yr, although this is a difficult task considering differences between the JunoCam and Galileo imagers and very different viewing geometries. No active eruptions were detected.

Development and Testing of Species-Specific Primers for Detecting the Presence of the Northern Pacific Sea Star (Asterias amurensis) from Environmental DNA.

The starfish Asterias amurensis, a well-known predator of molluscan species in intertidal ecosystems, has caused substantial ecological and economic losses in North China such as offshore Qingdao. Effective monitoring and prevention measures are urged to minimize its negative impacts. Compared with traditional biomonitoring methods, environmental DNA technology has emerged as a powerful and cost-efficient tool for inferring species' presence and abundance. In this study, we developed a pair of species-specific primers (i.e., Ast-F and Ast-R) for the A. amurensis mitochondrial COI gene and tested its utility in amplifying and quantifying the DNA fragments from environmental samples under both laboratory and field conditions. The results of controlled water tank experiments demonstrated that the amount of eDNA released by A. amurensis was positively related to its biomass; after the removal of the starfish, the eDNA degraded significantly in 24h and remained detectable for 8days. The number of eDNA copies enriched tended to increase with smaller pore size of filter membrane and larger volume of filtered water. For field tests, we confirmed the validation of our approach in six locations in Qingdao by filtering 1000ml water per sample with a 0.45-µm pore size filtration. All the amplification products generated a single and bright band via gel electrophoresis, and the quantitative PCR results unveiled significant differences in eDNA copies. This study provided an eDNA-based approach for investigating the distribution and biomass of A. amurensis, which may help to formulate early warning and management strategies in coastal Qingdao and other regions.

Large‐Scale Room‐Temperature Synthesis of the First Sb3+‐Doped Organic Ge(IV)‐Based Metal Halides with Efficient Yellow Emission for Solid‐State Lighting and Latent Fingerprint Detection

Organic–inorganic hybrid Ge(II)‐based metal halides have garnered significant interest due to their intriguing photophysical properties and environmentally friendly characteristics. However, challenges such as poor stability, low emission intensity, and a complex synthesis process have hindered their widespread application. In addressing these issues, a breakthrough in the large‐scale production of Sb3+‐doped Ge(IV)‐based metal halide (C13H14N3)2GeCl6 phosphors at room temperature through a straightforward solution method is presented. The synthesized compound exhibits a remarkable bright broad yellow emission band at 590 nm, boasting a photoluminescence quantum efficiency of 99.53 ± 0.06% the highest among Ge(IV)‐based metal halides. Notably, the introduction of Sb3+ induces the formation of Jahn–Teller‐like self‐trapped excitons in [SbCl6]3− species, attributable to lattice distortion and strong electron–phonon coupling. Consequently, Sb3+‐doped (C13H14N3)2GeCl6 demonstrates a large Stokes shift (221 nm) and a prolonged decay lifetime (3.06 μs). Furthermore, the Sb3+‐doped compound exhibits commendable chemical‐ and photostability, prompting exploration in applications such as white light‐emitting diodes and latent fingerprint detection. This work not only provides a practical approach for designing economically viable, environmentally friendly, and highly efficient emission phosphors but also paves the way for novel directions in their expanded application.

Site-specific PCR identification of animal species and formula particles of Scorpio

Scorpio, a commonly used animal medicine in China, is derived from Buthus martensii as recorded in the Chinese Pharmacopoeia. China harbors rich species of Scorpionida and adulterants exist in the raw medicinal material and deep-processed products of Scorpio. The microscopic characteristics of the deep-processed products may be incomplete or lost during processing, which makes the identification difficult. In this study, the maximum likelihood(ML) tree was constructed based on the morphology and cytochrome C oxidase subunit I(COⅠ) to identify the species of Scorpio products. The results showed that the main adulterant of Scorpio was Lychas mucronatus. According to the specific SNP sites in the COⅠ sequence of B. martensii, the stable primers were designed for the identification of the medicinal material and formula granules of Scorpio. The polymerase chain reaction(PCR) at the annealing temperature of 61 ℃ and 30 cycles produced bright specific bands at about 150 bp for both B. martensii and its formula particles and no band for adulterants. The adaptability of the method was investigated, which showed that the bands at about 150 bp were produced for Scorpio medicinal material, lyophilized powder, and formula granules, and commercially available formula granules. The results showed that the established method could be used to identify the adulterants of Scorpio and its formula granules, which could help to improve the quality control system and ensure the safe clinical application of Scorpio formula granules.

Statistical characteristics of convective and stratiform precipitation during the rainy season over South China based on GPM-DPR observations

South China is one of the wettest regions in the world, and is prone to precipitation-related disasters. The GPM-DPR product is utilized in this study to investigate the vertical structure and drop size distribution (DSD) characteristics of different precipitation types, i.e., stratiform precipitation (SP) and convective precipitation (CP) in South China. The precipitation frequency and accumulation in South China are dominated by SP and deep CP, respectively. Shallow CP has comparable occurrence ratio to deep CP, but the mean intensity is much lower. As such, it contributes <5% to the total rainfall. Vertical features differ among precipitation types and intensities. Higher storm top altitude (STA) is roughly related to more intense precipitation, especially for CPs. As surface PR increases in deep CP, the contribution of increase of PR (ΔPR) in liquid-phase region to total PR also increases, from approximately 10% for 4 mm/h to 55% for 100 mm/h. The intensity of shallow CP is generally low, but ΔPR in the liquid-phase region is significant. For SP and shallow CP, higher precipitation intensity is often caused by higher hydrometer concentration. Differently, for deep CP with PR >15 mm/h, both the increases in hydrometer size and concentration contribute to the increase in PR. The collision-coalescence process is dominant in the low-level layers in SP without bright band and CP, and approximately four fifth of shallow CP samples are influenced by collision-coalescence process. Compared with inland mountainous region, collision-coalescence process plays more important role in intense precipitation in coastal region. The results of this study indicate that it is important to consider the vertical evolution and DSD characteristics of different precipitation types for improving the accuracy of near surface quantitative precipitation estimate.

Quantitative Precipitation Estimation using X-Band Radar for Orographic Rainfall in the San Francisco Bay Area

In the San Francisco Bay Area, precipitation occurs in the wintertime, mostly as rain. Wintertime rainfall can be further classified into cold or stratiform rain with a typical radar bright band signature and warm orographic rain with absence of a radar bright band. Vertical Pointing S-Band profiler radar and disdrometer measurements from two of NOAA’s Hydrometeorology Testbed (HMT) sites in California are used to study the differences in microphysical properties between these two types of rain and their implications in radar rainfall estimation. A methodology has been developed to discriminate non bright band (NBB) rainfall from bright band (BB) rainfall using reflectivity (Z) and differential reflectivity (Z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DR</sub> ) computed from disdrometer data. Delineating the two rainfall types in this way allowed for an algorithm to be applied to the radar scans to identify rainfall types and apply appropriate reflectivity based and specific differential phase (K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DP</sub> ) based rainfall estimators. Recently, a gap-filling X-Band weather radar with dual-polarization capabilities was deployed in the San Francisco Bay Area in Santa Rosa to aid in weather monitoring and provide high resolution Quantitative Precipitation Estimation (QPE) products. When applied to real radar observations, this method shows great potential for improving the QPE compared to traditional operational products which more often tend to underestimate rainfall in the California coastal region.

Radiofrequency interference in magnetic resonance imaging: Identification and rectification.

Radiofrequency (RF) interference artifact is a common type of magnetic resonance imaging (MRI) artifacts caused by the presence of unwanted RF field inside the scanner room. The artifact has the appearance of parallel bright lines or bands that resemble zippers, which can mimic pathology, obstruct the viewing of underlining tissues, and lower image signal-to-noise ratio, affecting the diagnostic evaluation of the image and sometimes even rendering it non-diagnostic. Due to the presence of multiple possible sources of RF interference in MRI and potential nonrelated MRI artifacts that resemble RF interference artifact, it may be difficult to effectively and timely resolve the artifact problem. The objective of this paper is to provide a review of RF interference in MRI and to offer guidance in the prompt and correct identification of the associated image artifacts as well as efficient approaches to resolve and prevent RF interference problems. This article should serve as a useful educational reference to magnetic resonance (MR) technologists and radiologists in dealing with MR image artifacts that may be caused by RF interference.

A novel methodology in fabricating dielectric reflectors for the desired wavelength spectrum using sol-gel spin coating technique

The use of passive photonic devices such as dielectric reflectors in electronics to replace semiconductor technology is being extensively researched. Dielectric reflectors with the required stop band are in high demand as smart windows, visual light communication boosters, and UV radiation defenders. The determination of a single approach for the envisioned wavelength spectrum of a dielectric reflector is unique and original. We offer a unique approach for synthesizing and developing dielectric reflectors in the required wavelength domain. The constructed reflectors were examined using XRD, which indicated the anatase phase of TiO2 in the multilayer structure. Cross-sectional FE-SEM examination revealed periodic bright (TiO2) and dark (SiO2) bands, and thickness analysis demonstrated that increasing the spin rate can lower the film thickness of the produced films. In addition, reflectance analysis on the structures using a UV-VIS-NIR spectrophotometer demonstrated that increasing the film thickness of the multilayer structure can move the reflectance band towards higher wavelengths.

DNA barcoding of Burgo chicken from Bengkulu, Indonesia, based on the cytochrome oxidase gene sub unit I mitochondria DNA

Abstract. Utama AF, Jarulis, Sipriyadi, Jannah IM. 2023. DNA barcoding of Burgo chicken from Bengkulu, Indonesia, based on the cytochrome oxidase gene sub unit I mitochondria DNA. Biodiversitas 24: 6268-6275. The Burgo chicken provides a genetic source of one crossbreed chicken in Bengkulu Province. However, genetic information on Burgo chickens is not yet available, while the population of this chicken continues to decline. Research on DNA barcoding using the cytochrome oxidase subunit I mtDNA gene was conducted to obtain DNA barcodes and the relationship between Burgo chickens and other chicken species based on the COI mtDNA gene. Blood samples were obtained from Burgo chickens belonging to the Bengkulu Burgo chicken hobbyist community. Collected blood was isolated following the dneasy® blood and tissue kit protocol based on the spin-column protocol procedure, Qiagen. Amplification of genomic DNA using Polymerase Chain Reaction. The product was electrophoresed on a 1.2% agarose gel and visualized under UV light using Gel Documentation System, Axygen. Samples with bright DNA bands proceeded to the sequencing process. Sequencing results were analyzed using MEGA 11.0 software. The results showed that the target length of the Burgo chicken band was in accordance with the primer design used (752pb). SNPs were obtained at 10 specific sites in Burgo chickens and had a species barcode at site 746. The intraspecies genetic distance was 0.6%, interspecies 1.2%, and with the outgroup 14.5%, there were 12 haplotypes from all samples (n=15). Based on the result, we can conclude that the Burgo chicken is closely related to the red jungle fowl compared to other chicken species.

Full-visible-spectrum LED lighting by using a near-UV-excitable broadband blue-emitting Ca2LuHf2GaAl2O12:Ce3+ garnet phosphor

Highly efficient broadband blue-emitting phosphors are urgently needed for full-visible-spectrum white light-emitting diodes (WLEDs). Herein, we report a new highly luminescent garnet-type Ca2LuHf2GaAl2O12:Ce3+ (abbreviated as: CLHGAO:Ce3+) blue phosphor enabling full-visible-spectrum LED lighting. These CLHGAO:Ce3+ phosphors doped with different Ce3+ concentrations have been prepared by using a high-temperature solid-state reaction approach, and their phase purity, crystal structure, luminescent properties, CIE color coordinates, and quantum efficiency have been systematically studied. Importantly, CLHGAO:Ce3+ blue phosphors show a broadband excitation spectrum in the 300–450 nm spectral range peaking around 398 nm, matching well with the emission wavelengths of commercial near-ultraviolet LED chips (380–420 nm). Upon 398 nm excitation, the optimal CLHGAO:2%Ce3+ phosphor sample generates a bright broad blue emission band (emission peak: 472 nm; bandwidth: 84 nm) with high internal quantum efficiency of 79.2% and external quantum efficiency of 55.3%. Notably, the emission intensity of CLHGAO:2%Ce3+ phosphor is about 1.87 times higher compared to the commercial BaMgAl10O17:Eu2+ blue phosphor (emission peak: 451 nm; bandwidth: 53 nm). Finally, a white LED device is fabricated with a 395 nm near-UV LED chip with CLHGAO:2%Ce3+ blue phosphor and commercial (Ba,Sr)2SiO4:Eu2+ green phosphor as well as commercial CaAlSiN3:Eu2+ red phosphor, and the device demonstrates bright warm-white emission with an ultrahigh color rendering index (Ra = 95.1, R9 = 97.8, R12 = 88.4) and low correlated color temperature of 3540 K. These results show that as-developed blue-emitting CLHGAO:Ce3+ garnet phosphors with superior photoluminescence properties can potentially be used in phosphor-converted full-visible-spectrum WLEDs.

The function of red and banded patterns in snakes: a review of hypotheses and evidence

Abstract The functions of bright bands in coral and other snakes have long been a puzzle. The most common opinion is that coral snakes display aposematic marks and that other red and black banded snakes in the Americas are mimics of coral snakes. Although supported by some evidence, the notion comes with unresolved difficulties. Here, I review the proposed functions of the colour of coral snakes and similar-coloured snakes, taking a more comprehensive view than usual, from the plausibility of aposematism in coral snakes to the apparent existence of a selective force for red and black banded patterns across the world. Theoretical models of the maintenance of aposematic signals do not seem applicable, hence aposematism has a low a priori plausibility in coral snakes. Evidence of avoidance is weak, field studies rely on unsettled methods and do not reproduce well, and two laboratory studies reporting strong innate fear are questioned. Coral snakes predict the geography and richness of ‘mimics’ in the Americas, but not in line with expectations. Conversely, polymorphism and evidence of local selection and of a worldwide selective force for patterns similar to coral snakes, including complex banded patterns, contradicts aposematism and mimicry and points to an undefined alternative. In summary, aposematism and mimicry fail on too many fronts to be sustained, existing alternatives also fail to be supported sufficiently, and hypotheses need to be formulated to account for the widespread selection for red and black bands and for complex banded patterns in snakes.

The function of red and banded patterns in snakes: the ophiophagy hypothesis

Abstract The functions of bright bands in coral and other snakes have long been a puzzle. The most common opinion is that coral snakes display aposematic marks and that other red and black banded snakes in the Americas are mimics of coral snakes. I previously found that this prevailing opinion is weakly supported and unlikely, that red and bands had probably evolved independently or conjointly many times, and that a present selection for bands and red seems to exist in a significant fraction of the world. Here, I review the potential selective forces for red and bands in snakes. I find that snakes as predators are a priori plausible selective agents. I find that ophiophagy appears to be an exceptionally high risk in snakes that are themselves ophiophagous. Testing the working hypothesis that bands and red are protective against snake predators via their association with ophiophagy, as ophiophagous snakes are at higher risk, I find that the consumption of elongate vertebrates predicts band and red coloration with a very high level of confidence: red and bands are probably defensive against snake predators. Noting an apparent correlation of coloration with specific defensive behaviours and ontogenetic colour changes, I review both and find that ophiophagous snakes are remarkable for using stereotypical defences and not being aggressive, while ontogenetic colour changes seem to affect red and bands in snakes disproportionately. Defence against ophidian predators may be an unexpected natural selection shaping the appearance and behaviours of many snakes.

The function of red and banded patterns in snakes: the eyes of the beholders—also, the function of bands in fish

Abstract The functions of bright bands in coral and other snakes have long been a puzzle. A common opinion is that coral snakes display aposematic marks and that other red and black banded snakes in the Americas are mimics of coral snakes. In two previous reviews, I challenged this prevailing opinion and showed that red and bands are probably defensive against snake predators. Here, I offer a plausible mechanisms through which red and bands could be protective against ophidian predators: the function of bands is to interfere with the focusing ability of snakes, which eyes, as in fish, rely on a ball lens that moves back and forth, a peculiarity among terrestrial vertebrates. Simulations show how the spherical aberrations created by ball lenses produce local maxima in contrast when out of focus, which would feel in focus. I conjecture that red targets specific visual receptors in snakes active in low light: these receptors would have a slow and saturating response. This conjecture is justified by the lability of vision in snakes and the overabundance of red light in dim light. Those conjectures allow precise and well-respected predictions and credibly explain a wide range of observations, such as the geographical repartition of tricolour snakes, the evolution of triadal patterns, the evolution of specific triadal-like patterns in some Erythrolamprus, and the repeated evolution of black and white banded snakes with a red dorsal line. Fish eyes have similar optics, and the function of the ubiquitous fish bands could likewise be to interfere with the vision of predators.

Overcoming the cyan gap for full‐spectrum lighting using cation‐substitution‐induced rigid Ca2YZr2Al3O12:Ce3+

AbstractMixing multicolor phosphors for simulating the full spectrum of sunlight illumination is a popular solution to obtain high‐quality white light. However, there is still a need to overcome the cyan gap in the emission spectrum. In this work, a series of garnet Ca2Y0.94–xLuxZr2–yHfyAl3O12:6%Ce3+ (abbreviated as CY0.94–xLuxZr2–yHfyA:Ce3+) cyan phosphors are designed and prepared by substituting Y3+ and Zr4+ in Ca2YZr2Al3O12:6%Ce3+ with Lu3+ and Hf4+ with smaller ionic radius and larger mass. Under 405 nm violet light excitation, the optimized Ca2Y0.88Lu0.06Hf2Al3O12:6%Ce3+ (CY0.88Lu0.06Hf2A:Ce3+) shows a bright cyan emission band in the range of 430–750 nm with the peak at 477 nm. Importantly, the emission intensity and thermal stability properties of CY0.88Lu0.06Hf2A:Ce3+ were significantly improved by 58% and 47% compared to those of pure Ca2YZr2Al3O12:Ce3+. Small and heavy cation substitution could induce highly stable rigid structure, thus enhancing emission intensity and stability. The color rendering index increases from 84.5 to 92.0 after supplementing CY0.88Lu0.06Hf2A:Ce3+ phosphor in white light‐emitting diode devices combining commercial red, green, and blue phosphors with a violet chip, indicating its practical application in full‐spectrum lighting. The present study provides promising strategies for the design and development of efficient cyan materials for high‐quality full visible spectrum light‐emitting diode lighting.

A contrastive analysis on the causes of two regional snowstorm processes influenced by the southern branch trough in Hunan in early 2022

AbstractIn early 2022, there were four low‐temperature weather processes with rain and snow in Hunan Province, China. Two processes occurred on January 28–29 (referred to as the “0128” process) and February 6–7 (referred to as the “0206” process), and they have overlapping areas of heavy snowfall and high intensity of short‐term snowfall. Multi‐source observation data and the National Centers for Environmental Prediction (NCEP) reanalysis data are used to analyze the characteristics of circulation background and mesoscale. In addition, the causes of heavy snowfall processes under the influence of the southern branch trough are discussed based on the dual‐polarization radar products at Changsha station. The results show that two processes are characterized by the rapid phase transformation of rain and snow, concentrated snowfall periods, and heavy snowfall at night. The short‐term snowfall intensity of the “0206” process is greater than that of the “0128” process. The high‐latitude blocking high of the “0206” process is stronger than that of the “0128” process, and the water vapor transport of the southerly jet in low levels in the “0206” process is also stronger. The organized development of cold cloud clusters from the meso‐β scale to the meso‐α scale indicates that the snowfall intensifies, and the maximum blackbody temperature gradient corresponds well to the center of heavy snowfall. The propagation that is similar to the train effect is an important reason for the heavy snowfall process. The vertical variation of the ZH and the bright band of dual‐polarization parameters can determine the phase transformation between rain and snow. When the ZH and ZDR bright bands are 1–3 km away from the ground, the phase state is rain if the ZH near the ground is greater than 0 dBZ and the CC is close to 1; the phase state is the rain‐snow mixed phase if the CC is less than 0.95. When the bottom of the ZH bright band decreases, the CC/ZDR bright band disappears, the near‐surface CC is greater than 0.99 and the ZDR is less than 1 dB, the rain turns to snow. Compared with the “0128” process, the characteristics of the bright ring during the rainfall period of the “0206” process are more obvious, the precipitation intensity judged from the larger ZH and KDP is larger, and the phase transformation is faster due to more significant cooling effect caused by precipitation.

POLYMORPHISM Inter Simple Sequence Repeats (ISSR) PRIMERS FOR GENETIC DIVERSITY FOR POOTI PLANTS (Hopea gregaria)

Pooti (Hopea gregaria) is a medium size tree that can grow up to 35 m from the Dipterocarpaceae family. Since 1998, the International Union for Conservation of Nature (IUCN) has reported the pooti tree as endangered, and the species has a narrow distribution, found only in Southeast Sulawesi. One of the efforts to overcome the rarity of the Pooti plant is through a tree breeding program. However, this tree breeding program will only be successful with the support of genetic diversity information. The study of genetic diversity can be done using a molecular-based approach using Inter Simple Sequence Repeats (ISSR) markers. Samples of Pooti leaves used in the study were taken from Botanical Forest Park Nipa-Nipa (Tahura) and Protected Forest Nanga-Nanga, Kendari City, Southeast Sulawesi Province. A total of 50 samples were extracted using the CTAB (Cetyl Trimethyl Ammonium Bromide) method. Ten types of primers that have been carried out obtained seven primers that can produce bright polymorphic bands and can be continued for study genetic diversity, namely UBC 810, UBC 813, UBC 814, UBC 822, UBC 823, UBC 827, and UBC 830.

Vertical structure of North Indian Ocean tropical cyclones: A composite analysis using TRMM and GPM

The present study deals with the vertical structure of Tropical Cyclones (TC) from 2010 to 2020 over the North Indian Ocean (NIO) using the Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Measurement Mission (GPM). We analyzed 31 TC which were characterized as severe cyclonic storms, very severe cyclonic storms, and super cyclones out of which 18 occurred over the Bay of Bengal and 13 over the Arabian Sea. The normalized intensity difference method of brightness temperature is used to distinguish the regions of the TC into eyewall, inner rainband, outer rainband, and outer region after identifying the eye. The eye radius (Re) of the cyclone is used to define the annular regions. The vertical structure is explored using the reflectivity in each region of the cyclone and also with respect to convective precipitation, stratiform precipitation, and sea surface temperature. The intensity of the convection in the eyewall and the rainbands is strong and reaches up to an altitude of 14 km. The outer rainbands were more of stratiform nature and a distinct bimodal distribution is observed with a peak below and above the bright band. The outermost region exhibited the characteristics of both the convective and stratiform, however, the intensity is observed to be less. The convection is observed to be strong in the eyewall for high SST compared to the marginal, however, the vertical extent is large in the marginal SST. The vertical structure of the TC over the NIO contained a wider distribution of reflectivity and vertically extended compared to that of the cyclones in the other oceanic basins.