• ALGAE
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• 제25권4호
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• pp.217-227
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• 2010

During feeding on algal cytoplasm, some sacoglossans are known to keep the chloroplasts photosynthetically active for days to months in their digestive cells. Korean sacoglossan mollusks containing functional chloroplasts were screened using an in vivo chlorophyll fluorescence measuring system (pulse amplitude modulation, PAM). We collected six sacoglossans feeding on siphonous and siphonocladous green algae (Elysia atroviridis, E. nigrocapitata, E. ornata, Ercolania boodleae, Placida dendritica, Stiliger sp.) and one feeding on ceramiaceaen algae (Stiliger berghi) and performed feeding experiments using 37 algal species. Three species of Elysia showed strong photosynthetic activity for months. However, P. dendritica maintained functional chloroplasts only for several hours after feeding. E. boodleae, S. berghi, and Stiliger sp. showed no photosynthetic activity in any circumstances. Among all species, E. nigrocapitata was capable to tolerate the longest period of starvation for over 4 months. Four 'solar powered' sacoglossans bonded avidly to their specific algal food. Each species attached to and consumed only one algal species when several algae were given together. While they occasionally consumed other algae after prolonged starvation, they always reverted to their specific algae when available.

• Molecules and Cells
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• 제40권10호
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• pp.787-795
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• 2017

Avoiding ingestion of excessively salty food is essential for cation homeostasis that underlies various physiological processes in organisms. The molecular and cellular basis of the aversive salt taste, however, remains elusive. Through a behavioral reverse genetic screening, we discover that feeding suppression by $Na^+$-rich food requires Ionotropic Receptor 76b (Ir76b) in Drosophila labellar gustatory receptor neurons (GRNs). Concentrated sodium solutions with various anions caused feeding suppression dependent on Ir76b. Feeding aversion to caffeine and high concentrations of divalent cations and sorbitol was unimpaired in Ir76b-deficient animals, indicating sensory specificity of Ir76b-dependent $Na^+$ detection and the irrelevance of hyperosmolarity-driven mechanosensation to Ir76b-mediated feeding aversion. Ir76b-dependent $Na^+$-sensing GRNs in both L- and s-bristles are required for repulsion as opposed to the previous report where the L-bristle GRNs direct only low-$Na^+$ attraction. Our work extends the physiological implications of Ir76b from low-$Na^+$ attraction to high-$Na^+$ aversion, prompting further investigation of the physiological mechanisms that modulate two competing components of $Na^+$-evoked gustation coded in heterogeneous Ir76b-positive GRNs.

• Journal of Photoscience
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• 제9권2호
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• pp.90-93
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• 2002

Phytochrome A (phyA) and phytochrome B (phyB) perceive light and adapt to fluctuating circumstances by different manners in terms of effective wavelengths, required fluence and photoreversibility. Action spectra for induction of seed germination and inhibition of hypocotyl elongation using phytochrome mutants of Arabidopsis showed major difference. PhyA is the principal photoreceptor for the very low fluence responses and the far-red light-induced high irradiance responses, while phyB controls low fluence response in a red/far-red reversible mode. The structural requirement of their bilin chromophores for photosensory specificity of phyA and phyB was investigated by reconstituting holophytochromes through feeding various synthetic bilins to the following chromophore-deficient mutants: hy1, hyl/phyA and hyl/phyB mutants of Arabidopsis. We found that the vinyl side-chain of the D-ring in phytochromobilin interacts with phyA apoprotein. This interaction plays a direct role in mediating the specific photosensory function of phyA. The ethyl side-chain of the D-ring in phycocyanobilin fails to interact with phyA apoprotein, therefore, phyA specific photosensory function is not observed. In contrast, both phytochromobilin and phycocyanobilin interact with phyB apoprotein and induce phyB specific photosensory functions. Structural requirements of the apoproteins and the chromophores for the specific photoperception of phyA and phyB are discussed.

• Korean Journal of Radiology
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• 제23권8호
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• pp.794-802
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• 2022

Objective: To evaluate the feasibility of single-shot whole thoracic time-resolved MR angiography (TR-MRA) to identify the feeding arteries of pulmonary arteriovenous malformations (PAVMs) and reperfusion of the lesion after embolization in patients with multiple PAVMs. Materials and Methods: Nine patients (8 females and 1 male; age range, 23-65 years) with a total of 62 PAVMs who underwent percutaneous embolization for multiple PAVMs and were subsequently followed up using TR-MRA and CT obtained within 6 months from each other were retrospectively reviewed. All imaging analyses were performed by two independent readers blinded to clinical information. The visibility of the feeding arteries on maximum intensity projection (MIP) reconstruction and multiplanar reconstruction (MPR) TR-MRA images was evaluated by comparing them to CT as a reference. The accuracy of TR-MRA for diagnosing reperfusion of the PAVM after embolization was assessed in a subgroup with angiographic confirmation. The reliability between the readers in interpreting the TR-MRA results was analyzed using kappa (κ) statistics. Results: Feeding arteries were visible on the original MIP images of TR-MRA in 82.3% (51/62) and 85.5% (53/62) of readers 1 and 2, respectively. Using the MPR, the rates increased to 93.5% (58/62) and 95.2% (59/62), respectively (κ = 0.760 and 0.792, respectively). Factors for invisibility were the course of feeding arteries in the anteroposterior plane, proximity to large enhancing vessels, adjacency to the chest wall, pulsation of the heart, and small feeding arteries. Thirty-seven PAVMs in five patients had angiographic confirmation of reperfusion status after embolization (32 occlusions and 5 reperfusions). TR-MRA showed 100% (5/5) sensitivity and 100% (32/32, including three cases in which the feeding arteries were not visible on TR-MRA) specificity for both readers. Conclusion: Single-shot whole thoracic TR-MRA with MPR showed good visibility of the feeding arteries of PAVMs and high accuracy in diagnosing reperfusion after embolization. Single-shot whole thoracic TR-MRA may be a feasible method for the follow-up of patients with multiple PAVMs.

• 식물병연구
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• 제25권3호
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• pp.149-155
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• 2019

선충 포식성곰팡이는 유기물에서 번식하다가 양분이 부족해지면 특수 기관을 형성하여 선충을 포획하고 선충으로부터 양분을 섭취하기 때문에 토양 내 동물계와 먹이사슬을 이루며 생태계에서 중요한 부분을 차지한다. 본 연구에서는 끈끈이그물형 포식기관을 가진 3종, Arthrobotrys oligospora, A. sinensis, A. thaumasia과 수축성올가미형 포식기관을 가진 Drechslerella brochopaga 1종 등 4종의 선충 포식성곰팡이의 식세균성선충 9종, 식균성선충 1종, 식물기생성선충 2종 등 총 12종의 선충류에 대한 포식력을 검정하였다. 4종의 포식성곰팡이에 모두 감수성인 선충은 식물기생성선충 2종류(Meloidogyne incognita, Pratylenchus penetrans), Rhabditidae에 속하는 P. strongyloides, Mesorhabditis irregularis이었고 접종 4일 후부터 선충을 포식하였으며, 선충 내부로 곰팡이가 번식하여 15일째에는 거의 선충의 형태를 알아볼 수 없을 정도였다. 반면, Cephlobidae에 속하는 Acrobeloides spp., A. avenae는 4종의 포식성곰팡이에 모두 저항성을 보였으며 15일 후 관찰하였을 때, 접종배지 내에 선충 수가 초기접종 밀도와 같거나 오히려 2-3배 정도까지 번식되었다. 나머지 선충 종들은 포식성곰팡이 종류에 따라 감수성에 다소간 차이가 있었다. 본 연구결과, 선충 포식성곰팡이가 선충 종에 따라 특이적으로 반응하였으며 이러한 기주특이성을 이용하여 식물기생성선충의 친환경적 방제를 위한 하나의 수단으로 이용될 수 있다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제16권2호
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• pp.95-103
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• 2013

Purpose: Iron deficiency remains a very common nutritional problem despite the improvement in nutrition and increased understanding of methods for its prevention. Thus, we try to create a new method for screening iron nutrition through infant nutrition history. Methods: Among the children who visited Inha University Hospital from March 2006 to July 2012, 181 children with iron deficiency anemia (IDA) and 52 children without IDA ranging from 6 to 36 months of age were reviewed in this study. We used the age when they began to wean food, the type of sort weaning foods, the time required for successful weaning, iron content in weaning foods, and the duration of breastfeeding for scoring infant nutrition history based on a questionnaire. Results: The mean score of the IDA group was $7.8{\pm}2.6$ points, which was significantly higher than that of the control group ($5.6{\pm}2.1$) (p=0.000). If we set up the cutoff value at 6 points, this screening has 86.8% sensitivity and 36% specificity. In addition, as the IDA score increased, there was a falling trend of hemoglobin. Conclusion: The IDA score does not have high specificity or high sensitivity. However, this study conveys that those patients who record a high score have low hemoglobin. Therefore, we suggest this score system for screening more IDA patients via nonpainful techniques.

• 수산해양기술연구
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• 제35권3호
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• pp.243-249
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• 1999

Specificity of catches has been analyzed to japanese tuna purse seine A principle component analysis was used to improve the efficiency of fishing and increase sustainable production and productivity of Korean tuna purse seine.The result are as follows;From the principal component analysis of the fish catches, the first principal component(Z1) to promote principal component score was skipjack Kastsuwonus Pelamis, LINNAEUS and yellowfin tuna Thunnus Albacares, BONNATERRE (Small : smaller than 10kg) and proportion was 86.8% of total. The second principal component(Z2) to increase principal component score was yellowfin tuna (Large : larger than 10kg) and proportion was 9.5%.On the other hand, fish operating that have caught skipjack and yellowfin tuna (Small and Larger) was not so much. Fish catches for one species raised volume of the catches while catches for multi-species decreased it since principal composition score for one species and both species together has been increased.Fish school could be divided into three groups of schools each of which was associated with drift objects, payaho and ship, school associated with shark, whale and porpoise and school of breezing, feeding and jumping from proportion of principal component analysis for fish catches of school types. However, the biological pattern is different among school associated with ship, payaho and school associated with drift objects for analysis eigen vector. School associated with ship, payaho and school associated with drifting object associated is judged as school which be assembled to vessel and drifted log temporary.

• Molecules and Cells
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• 제44권2호
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• pp.63-67
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• 2021

The bed nucleus of the stria terminalis (BNST)-a key part of the extended amygdala-has been implicated in the regulation of diverse behavioral states, ranging from anxiety and reward processing to feeding behavior. Among the host of distinct types of neurons within the BNST, recent investigations employing cell type- and projection-specific circuit dissection techniques (such as optogenetics, chemogenetics, deep-brain calcium imaging, and the genetic and viral methods for targeting specific types of cells) have highlighted the key roles of glutamatergic and GABAergic neurons and their axonal projections. As anticipated from their primary roles in excitatory and inhibitory neurotransmission, these studies established that the glutamatergic and GABAergic subpopulations of the BNST oppositely regulate diverse behavioral states. At the same time, these studies have also revealed unexpected functional specificity and heterogeneity within each subpopulation. In this Minireview, we introduce the body of studies that investigated the function of glutamatergic and GABAergic BNST neurons and their circuits. We also discuss unresolved questions and future directions for a more complete understanding of the cellular diversity and functional heterogeneity within the BNST.

• 한국습지학회지
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• 제25권3호
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• pp.184-195
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• 2023

한국에서 생태계교란 식물인 단풍잎돼지풀의 효과적인 관리방안을 마련하고자, 초식자인 돼지풀잎벌레의 기주특이성, 연간 이동거리를 조사하여 생물학적 방제 수단으로의 활용 가능성과 이 곤충의 섭식이 단풍잎돼지풀의 활력에 미치는 영향을 연구하였다. 이를 위해서 돼지풀잎벌레의 기주선호도를 조사하였고, 돼지풀잎벌레가 확인된 지점을 기준으로 거리가 10m, 20m, 30m, 100m 떨어진 지점에 돼지풀잎벌레가 없는 단풍잎돼지풀군락을 선정하여 돼지풀잎벌레의 출현 여부 파악을 통해 이들의 이동 거리를 확인하였다. 그리고 돼지풀잎벌레의 섭식에 따른 단풍잎돼지풀의 생육, 번식 그리고 생리반응을 측정하였다. 그 결과 돼지풀잎벌레는 국화과의 3분류군만을 섭식하였고, 숙주로부터 반경 30m/yr 이내로 단거리 이동하였다. 초식자의 섭식은 단풍잎돼지풀의 생육, 번식 그리고 생리반응에 부정적인 영향을 주었고, 초식자가 있는 곳으로부터 거리가 멀어질수록 생육 및 번식이 양호하였다. 또한, 단풍잎돼지풀의 식피율이 50% 이하일 때 초식자를 도입하면 90% 이상의 단풍잎돼지풀을 제어할 수 있었지만, 식피율이 90% 이상에서는 제거의 효과가 감소했다. 결과적으로 돼지풀잎벌레는 단풍잎돼지풀의 생태학적 제어자로서 활용 가능성이 있고, 제어의 효과를 높이기 위해서는 단풍잎돼지풀의 식피율이 낮은 봄(5월)에 이 곤충을 도입하는 것이 유리하다.

• BMB Reports
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• 제30권5호
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• pp.370-377
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• 1997

A novel assay method is described for rapid quantitation of reaction rate of sterol ${\Delta}^7$-reductase (${\Delta}^7$-SR) which catalyzes reduction of the ${\Delta}^7$-double bond of sterols. Of six different organ tissues-liver, small intestine, brain, lung, kidney, and testis-. ${\Delta}^7$-SR activity was detected only in liver (2.30 nmol/min/mg protein) and testis (0.11 nmol/min/mg protein). Using a newly developed method which employs diet-induced enzyme proteins and ergosterol as substrate, we assessed both kinetics ($K_m=210\;{\mu}M$, $V_{max}=1.93\;nmol/min/mg$) and inhibition of the rat hepatic ${\Delta}^7$-SR against well-studied cholesterol lowering agents such as triparanol ($IC_{50}=16\;{\mu}M$). 3-$\beta$-[2-(diethylamino)ethoxy]androst-5-en-17-one (U18666A) ($IC_{50}=5.2\;{\mu}M$), and trans-1.4-bis(2-chlorobenzylaminomethyl)cyclohexane dihydrochloride (AY-9944) ($IC_{50}=0.25\;{\mu}M$). Of the three well-known AY-9944-sensitive cholesterogenic enzymes (i.e., ${\Delta}^7$-SR, sterol ${\Delta}^8$-isomerase, and sterol ${\Delta}^14$-reductase). ${\Delta}^7$-SR was found to be the most sensitive enzyme with a noncompetitive inhibition of this compound ($K_i=0.109\;{\mu}M$). Substrate specificity studies of the microsomal ${\Delta}^7$-SR indicate that the relative reaction rate for 7-dehydrocholesterol and ergosterol are 5.6-fold and 1.6-fold higher than that for lathosterol. ${\Delta}^7$-SR activity was also modulated by feeding rats a diet supplemented with 0.5% ergosterol (>2.6-fold) in addition to 5.0% cholestyramine plus 0.1% lovastatin ($\simeq$5.0-fold). Finally, microsomal ${\Delta}^7$-SR was solubilized by 1.5% 3-[3-(cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CHAPS) and enriched on PEG (0~10%) precipitation, which should be suitable for further purification of the enzyme.