The salivary glands of hard ticks consist of three types (type I, II, and III) of acini according to their functions and location. The type II and III acini play critical roles in tick salivation, which is likely controlled by a variety of neuropeptides or neurotransmitter via interaction with their receptor, G protein-coupled receptors (GPCRs). Orchestration of dopamine receptor (D1) and invertebrate specific D1-like dopamine receptor (InvD1L) located in type II and III acini precisely control tick salivary secretion via collection of primary saliva in the lumen and expulsion of collected saliva, respectively. The two dopamine receptors (D1 and InvD1L) in Haemaphysalis longicornis were identified as 1278 bp (426 aa) and 1362 bp (454 aa) in length, respectively. Both dopamine receptors were functionally analyzed through Ca2+ and cAMP assay using the heterologous expression system. The transcripts of D1 and InvD1L were profiled from synganglion and salivary glands of female ticks (unfed, 3/18/60/96 post blood meal and replete). D1 and InvD1L were significantly upregulated in the early phase of blood feeding from female H. longicornis. Salivary secretion induced by dopamine was significantly reduced by RNAi of D1 and InvD1L. Interestingly, RNAi of two dopamine receptors induced a significantly longer period of blood feeding in female ticks, which were significantly lighter after feeding than control. Taken together, it was suggested that D1 and InvD1L play critical roles in early and late phase of tick blood feeding for feeding capability.
Due to the concerns over their environmental and health impacts, there have been attempts for shift towards biorational pesticides from synthetic pesticides. Among them, plant essential oils have emerged as promising active ingredients. Due to the complex interactions among their constituents, the bioactivities of essential oils can vary depending on the compositions, which often undermine their stability in efficacy. Here, we present a model-based optimization approach to develop reliable rosemary oil-based biorational pesticide, against two-spotted spider mites, Tetranychus urticae Koch. The ecotoxicity against Daphnia magna and foliar phytotoxicity against Phaseolus vulgaris were also evaluated. Our quadratic models accurately predicted miticidal activity, ecotoxicity, and phytotoxicity. We aimed to maximize, minimize, and minimize these parameters, respectively. We employed seven multi-objective evolutionary algorithms in Matlab. Among them, the nondominated sorting genetic algorithm II with adaptive rotation based simulated binary crossover (NSGA-II-ARSBX) performed best. We experimentally determined the thresholds for miticidal activity and phytotoxicity, based on the current approval process for agricultural pesticide products in Korea. After applying the thresholds, we validated the obtained viable solutions. Our study offers a novel framework to enhance the reliable and responsible use of essential oils as biorational pesticides.
Silicon (Si) has the potential to improve plant growth and stress tolerance. The study aimed to explore Si-involving plant responses and molecular characterization of different Si-responsive genes in alfalfa. In this study, the exogenous supplementation of Si enhanced plant growth, and biomass yield. Si-acquisition in alfalfa root and shoot was higher in Si-supplemented compared to silicon deficient (-Si) plants, implying Si-acquisition has beneficial on alfalfa plants. As a consequence, the quantum efficiency of photosystem II (Fv/Fm) was significantly increased in silicon-sufficient (+Si) plants. The quantitative gene expression analysis exhibited a significant upregulation of the Lsi1, Lsi2, Lsi3, NIP5;1, and NIP6;1 genes in alfalfa roots, while BOR1, BOR4, NIP2, and NIP3 showed no significant variation in their expression. The MEME results further noticed the association of four motifs related to the major intrinsic protein (MIP). The interaction analysis revealed that NIP5;1 and Lsi1 showed a shared gene network with NIP2, BOR1, and BOR4, and Lsi2, Lsi3 and NIP3-1, respectively. These results suggest that members of the major intrinsic proteins (MIPs) family especially Lsi1, Lsi2, Lsi3, NIP5;1, and NIP6;1 genes helped to pass water and other neutral solutes through the cell membrane and those played significant roles in Si uptake and transport in plants. Together, these insights might be useful for alfalfa breeding and genome editing approaches for alfalfa improvement.
The disposal of organic pollutants is one of the important research topics. Some of the studies in this field are based on the degradation of organic pollutants with a catalytic agent. The cobalt tetraoxide/peroxymonosulfate system is an important catalytic system used for the radical degradation of organic pollutants. To increase the catalytic efficiency of such reactions, graphitization of activated carbon used as a support solid and nitrogen doping to the carbon structure are commonly used methods. In this study, cobalt tetraoxide production, N-doping and graphitization were carried out in a single step by heat treatment of activated carbon doped with the phthlocyanine cobalt (II) complex. The catalytic performance of the catalyst/ peroxymonosulfate system was investigated by changing the pH, catalyst, and PMS concentration parameters on rhodamine B and 1,3,5 trichlorophenol, which were used as models. It was seen that the catalysts had 97% activity on rhodamine B in 16 min and 100% on 1,3,5 trichlorophenol in 6 min. It was observed that the catalysts continued to show high catalytic activity for five cycles in reusability studies and had a very low cobalt leaching rate. These results are in good agreement with previously published studies. In line with these results, the synthesized N-doped graphitic carbon/Co3O4 catalyst can be used as an effective catalyst for wastewater treatments.
본 연구는 전라북도 남원시, 장수군과 경상남도 함양군의 경계에 위치한 백두대간 봉화산의 관속식물상을 파악하여, 생물다 양성 보존 및 외래식물의 확산 방지를 위한 기초자료로 활용하기 위하여 조사를 실시하였다. 국립수목원 산림생물표본관에 소장된 봉화산 표본 검토와 함께, 2020년 4월부터 2023년 7월까지 총 15회에 걸쳐 현지조사를 수행하였다. 그 결과, 본 조사 지역의 관속식물은 97과 279속 409종 16아종 32변종 9품종의 총 466분류군으로 조사되었다. 이 중 특산식물은 8분류군, 적색목록 중 취약(VU)에 속하는 종은 1분류군으로 확인되었다. 식물구계학적 특정식물종은 총 57분류군으로 Ⅴ등급에 1분류 군, Ⅲ등급에 9분류군, Ⅱ등급에 14분류군, Ⅰ등급에 33분류군이 각각 발견되었으며, 외래식물은 24분류군, 그리고 생태계교 란야생종은 1분류군이었다. 분류군의 유용성 조사에서 식용 353분류군, 섬유용 3분류군, 약용 71분류군, 관상용 21분류군, 목초용 108분류군, 공업용 2분류군, 잡용 7분류군, 용재용 11분류군으로 나타났다.
1996년 고성산불지역의 복원유형별 식생구조와 종다양도 변화를 파악하여 생태적 관점에서 복원의 효과를 정략적으로 평가하고자 자연복원지와 인공복원지로 구분한 영구조사지를 대상으로 매목조사와 군집분류를 수행하였다. 조사구 26개소를 대상으로 이원지표종분석(TWINSPAN)과 DCA분석을 통해 분류한 결과, 군집 I (신갈나무-굴참나무 군집), 군집 II (소나무군집) 2개의 군집으로 분류되었다. 군집 별 상대우점치 분석 결과, 군집 I은 굴참나무와 신갈나무가 우세한 가운데 졸참나무의 출현으로 참나무류 간의 경쟁이 예상된다. 군집 II는 소나무가 우점하는 가운데 잣나무가 출현하는 군집으로 소나무 군집이 유지될 것이나 향후 아교목층의 참나무류와의 경쟁이 예상된다. 군집 간 유사도지수는 32.31%로 나타났다. 종다양도지수는 군집Ⅱ에서 1.3940으로 군집Ⅰ의 1.0768보다 높은 것으로 나타났다. 자연복원지는 활엽수 중심으로 맹아 재생이 일어나 군집 I과 같은 참나무림으로 천이가 진행되었다. 인공복원지는 지속적인 관리로 인해 개체수는 줄었으나 생육공간 확보로 자연복원지보다 원활한 직경생장을 보이며 초기 식재종 중심의 군집으로 천이가 진행되고 있음을 확인하였다.
Firms are increasingly using social media influencers to promote their products. We develop a two-period model to investigate a firm’s strategy for introducing a product via an influencer, where there is uncertainty in the influencer-product match. In the second period, the influencer exerts an effort to promote the product to her followers, who can spread the product information to non-followers via word-of-mouth (WOM). In the second period, the firm sells to the non-followers. We show that the firm’s pricing, production, and commission contract decisions depend on the influencer’s incentive-independent excess payoff from the promotion and on the difference between the WOM effect of followers who do or do not make a purchase rather than the WOM effect of each group. As the influencer’s incentive-independent payoff increase, the firm will increase (decrease) commissison rate and commission rate when the followers’ sensitivity to product price is relatively low (high) compared with that to the influencer’s effort. As the marginal WOM benefit of the first-period sales increases, the firm tends to reduce his unit net profit from sales. The influencer with a medium-sized follower base receives the highest commission rate and exerts the largest promotion effort. While the followers of influencers with a medium-sized follower base may pay the highest price. We also show that (i) there exists a threshold for the probability of match, above which the firm faces zero demand in the first period if an influencer-product mismatch occurs; and (ii) the firm may charge followers a lower price than non-followers, even though followers are less sensitive to price than non-followers. Finally, regarding influencer selection, we find that the firm may not be better off employing an influencer with a larger follower base.
A bibliometric analysis, spanning five decades of knowledge is employed with the aim of: (i) assessing core intellectual knowledge of international services research; (ii) examining the contribution of international services marketing to broader research disciplines; and, (iii) estimating forecasting trends for the most promising international services research directions.
Sponsored product reviews have emerged as an important tool in influencer marketing. In particular, non-monetary sponsorships, where brands give influencers a product as a gift for a free trial, are widely used in influencer marketing. Yet, there is little understanding of i) the impact of non-monetary sponsorship on consumers’ downstream behaviors, such as social media engagement, ii) the moderating effect of influencer type, and iii) the underlying mechanisms through consumer perceptions of the brand (i.e., brand trust) and product (i.e., perceived product quality). To fill this gap, we first empirically examined the impact of non-monetary sponsorship on customer engagement using an Instagram dataset through regression analyses. In this analysis, the propensity score matching (PSM) method was employed to match non-monetary sponsored posts with other similar posts, which controls unobserved confounding variables and resolves the endogeneity problem. The empirical analysis shows that non-monetary sponsorship increases social media engagement, and the positive impact is stronger when a micro-influencer generates a non-monetary sponsored post. Next, using a lab experiment, we provide evidence for a causal link between non-monetary sponsorship and consumers’ downstream behavior (i.e., social media engagement, purchase intention, and brand attitude) and support the mediation through higher perceived product quality and brand trust. We contribute to the literature on influencer marketing by documenting the positive impact of non-monetary sponsorship on social media engagement, examining the moderating role of influencer type, and providing novel mechanisms underlying the effect of non-monetary sponsorship. The findings also highlight the changes in consumer perception of sponsorship and offer insights into the design of influencer marketing campaigns for marketing practitioners.
We investigated an emerging magnetic loop dynamically formed on the Sun, which has the effective footpoint heating source that may play a key role in heating a solar atmosphere with free magnetic energy in it. It is suggested that the heating source could be related to local compression of a plasma in the emerging loop by means of Lorentz force, which converts the magnetic energy to the internal energy of the plasma that is used to reaccelerate a decelerated downflow along the loop, eventually generating the source when the kinetic energy of the downflow is thermalized. By analyzing very high-cadense data obtained from a magnetohydrodynamic simulation, we demonstrate how the local compression is activated to trigger the generation of the heating source. This reveals a characteristic of the emerging loop that experiences a dynamic loop-loop interaction, which causes the local compression and makes the plasma gain the internal energy converted from the magnetic energy in the atmosphere. What determines the characteristic that could distinguish an illuminated emerging loop from a nonilluminated one is discussed.
지구과학 II 및 한국지리 교과서는 ‘한반도의 지질’과 관련된 내용을 공통적으로 중요하게 다루고 있다. 이 연구 는 지구과학 II 및 한국지리 교과서에 제시된 ‘한반도의 지질’ 관련 내용의 차이를 분석하고, 차이가 있다면 최신 과학 지식과의 일치 여부를 비교하기 위한 것이다. 이를 위하여 2015 개정 교육과정에서 발간된 교과서 7종(지구과학 II 4종, 한국지리 3종)을 분석 대상으로 선정하고, 한반도의 지체구조, 지질 연대 자료 및 지질시대별 지질학적 특성의 설명 텍 스트에 대한 차이를 비교하였다. 분석 결과, 한반도의 지체구조와 관련된 용어, 명칭, 분포 범위에서 교과서 간에 불일 치 사례가 발견되었다. 한반도의 지질 연대 자료도 불일치 사례를 보였는데, 한국지리 교과서의 경우 오래된 자료를 인 용하여 최신 과학 지식과의 차이를 보였다. 또한, ‘한반도의 암석 분포’, ‘평안누층군의 특징’, ‘고생대의 대결층’에 대한 설명 텍스트에서 불일치 사례가 발견되었다. 지구과학 및 지리 교과는 중복되는 내용 요소가 많기 때문에 교과 간의 내용 차이를 최소화하는 노력이 필요하며, 이를 위해서는 최신의 과학 지식을 반영한 적절한 내용을 선정하여 교과에 관계없이 일관성 있게 제시하는 것이 중요하다.