We demonstrate longitudinal beam-steering with a 1×16 silicon optical phased array (OPA) using a monochromatic light source and thermo-optic control of the refractive index in the grating radiator region. The refractive index is controlled by forming a series of n-i-n heaters, placing i-regions in each radiator of the OPA. When the biased voltage in the heaters is increased, the refractive index of the radiator region is increased by the thermo-optic effect, and the longitudinal radiation angle is changed according to the Bragg condition. The transversal beam-steering is accomplished by phase control with the phase shifters, which are devised with a p-i-n diode using the electro-optic effect. With these electro-optic p-i-n phase shifters and n-i-n thermo-optic radiators, we achieve a relatively wide 2D beam-steering in a range of 10.0°/45.4° in the longitudinal/transversal directions with a 1.55 μm light source. The tuning efficiency is 0.016°/mW in the longitudinal beam-steering.
The western conifer seed bug (WCSB; Leptoglossus occidentalis) causes huge ecological and economic problems as an alien invasive species in forests. In this study, a species distribution model (SDM) was developed to evaluate the potential occurrence of the WCSBs and the effects of climate on WCSB distribution in South Korea. Based on WCSB occurrence and environmental data, including geographical and meteorological variables, SDMs were developed with maximum entropy (MaxEnt) and random forest (RF) algorithms, which are machine learning methods, and they showed good performance in predicting WCSB occurrence. On the potential distribution map of WCSBs developed by the model ensemble with integrated MaxEnt and RF models, the WCSB occurrence areas were mostly located at low altitudes, near roads, and in urban areas. Additionally, environmental factors associated with anthropogenic activities, such as roads and night lights, strongly influenced the occurrence and dispersal of WCSBs. Metropolitan cities and their vicinities in South Korea showed a high probability of WCSB occurrence. Furthermore, the occurrence of WCSBs in South Korea is predicted to intensify in the future owing to climate change.
Functional traits are the result of evolution and adaptation, providing important ecological insights into how organisms interact with their environment. Aquatic macroinvertebrates, in particular, have garnered attention as biomonitoring indicators for freshwater ecosystems. This study presents a functional trait database for benthic aquatic macroinvertebrates, comprising 440 genera from five phyla (Annelida, Arthropoda, Mollusca, Nematomorpha, and Platyhelmenthes), categorized into nine traits related to life history, morphology, and habit. To account for variation in available trait information, we assigned confidence levels to each taxon and functional trait based on the level of evidence using fuzzy coding. Our database provides a comprehensive resource for understanding the ecology of benthic macroinvertebrates, serving as a valuable baseline dataset for studying their biodiversity, conservation, and biomonitoring in freshwater ecosystems.
Abstract Functional traits are the result of evolution and adaptation, providing important ecological insights into how organisms interact with their environment. Benthic macroinvertebrates, in particular, have garnered attention as biomonitoring indicators for freshwater ecosystems. This study presents a functional trait dataset for benthic macroinvertebrates, comprising 447 taxa (393 at genus level, 53 at family level and one at class level) from five phyla (Annelida, Arthropoda, Mollusca, Nematomorpha, and Platyhelmenthes), categorized into nine traits related to life history, morphology, and habit. To account for variation in available trait information, we assigned confidence levels to each taxon and functional trait based on the level of evidence using fuzzy coding. Our dataset provides an important resource for understanding the ecology of benthic macroinvertebrates in South Korea, serving as a valuable baseline dataset for studying their biodiversity, conservation, and biomonitoring in freshwater ecosystems.