A rigid donor–acceptor daisy chain dimer

Cao, Dennis,Wang, Cheng,Giesener, Marc A.,Liu, Zhichang,Stoddart, J. Fraser The Royal Society of Chemistry 2012 Chemical communications Vol.48 No.54

<P>A functionalised cyclobis(paraquat-<I>p</I>-phenylene) attached by a rigid linker to a tetrathiafulvalene unit, which is incapable of self-complexation, forms preferentially a [<I>c</I>2]daisy chain which undergoes rapid disassociation and reassociation on the <SUP>1</SUP>H NMR time-scale above room temperature.</P> <P>Graphic Abstract</P><P>A functionalised cyclobis(paraquat-<I>p</I>-phenylene) attached by a rigid linker to a tetrathiafulvalene unit, which is incapable of self-complexation, forms preferentially a [<I>c</I>2]daisy chain which undergoes rapid disassociation and reassociation on the <SUP>1</SUP>H NMR time-scale above room temperature. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2cc32499g'> </P>

A self-complexing and self-assembling pillar[5]arene

Strutt, Nathan L.,Zhang, Huacheng,Giesener, Marc A.,Lei, Juying,Stoddart, J. Fraser The Royal Society of Chemistry 2012 Chemical communications Vol.48 No.11

<P>A monofunctionalised pillar[5]arene derivative carrying a viologen side chain which exhibits self-complexation in dilute dichloromethane solutions forms supramolecular daisy chain polymers and eventually organogels as its concentration is increased three-fold over the range from 0.1 to 100 mM.</P> <P>Graphic Abstract</P><P>A viologen-functionalized pillar[5]arene exhibits self-complexation in dilute solutions and forms supramolecular daisy chain polymers and organogels at high concentrations. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2cc16030g'> </P>

A Radically Configurable Six-State Compound

Barnes, J. C.,Fahrenbach, A. C.,Cao, D.,Dyar, S. M.,Frasconi, M.,Giesener, M. A.,Benitez, D.,Tkatchouk, E.,Chernyashevskyy, O.,Shin, W. H.,Li, H.,Sampath, S.,Stern, C. L.,Sarjeant, A. A.,Hartlieb, K. American Association for the Advancement of Scienc 2013 Science Vol.339 No.6118

<P>Most organic radicals possess short lifetimes and quickly undergo dimerization or oxidation. Here, we report on the synthesis by radical templation of a class of air- and water-stable organic radicals, trapped within a homo[2]catenane composed of two rigid and fixed cyclobis(paraquat-p-phenylene) rings. The highly energetic octacationic homo[2]catenane, which is capable of accepting up to eight electrons, can be configured reversibly, both chemically and electrochemically, between each one of six experimentally accessible redox states (0, 2+, 4+, 6+, 7+, and 8+) from within the total of nine states evaluated by quantum mechanical methods. All six of the observable redox states have been identified by electrochemical techniques, three (4+, 6+, and 7+) have been characterized by x-ray crystallography, four (4+, 6+, 7+, and 8+) by electron paramagnetic resonance spectroscopy, one (7+) by superconducting quantum interference device magnetometry, and one (8+) by nuclear magnetic resonance spectroscopy.</P>

Sex Discrimination in Germany

Dieter Giesen 한국법학원 1977 저스티스 Vol.14 No.1

의사(醫師)의 민사법상의 책임 : 특히 새로운 치료방법이나 실험적 치료방법을 원용한 경우의 책임을 중심으로

양승두,디터기젠 연세대학교 사회과학연구소 1979 社會科學論集 Vol.10 No.-

A Pair of Pharyngeal Gustatory Receptor Neurons Regulates Caffeine-Dependent Ingestion in <i>Drosophila</i> Larvae

Choi, Jaekyun,van Giesen, Lena,Choi, Min Sung,Kang, KyeongJin,Sprecher, Simon G.,Kwon, Jae Young Frontiers Media S.A. 2016 Frontiers in cellular neuroscience Vol.10 No.-

<P>The sense of taste is an essential chemosensory modality that enables animals to identify appropriate food sources and control feeding behavior. In particular, the recognition of bitter taste prevents animals from feeding on harmful substances. Feeding is a complex behavior comprised of multiple steps, and food quality is continuously assessed. We here examined the role of pharyngeal gustatory organs in ingestion behavior. As a first step, we constructed a gustatory receptor-to-neuron map of the larval pharyngeal sense organs, and examined corresponding gustatory receptor neuron (GRN) projections in the larval brain. Out of 22 candidate bitter compounds, we found 14 bitter compounds that elicit inhibition of ingestion in a dose-dependent manner. We provide evidence that certain pharyngeal GRNs are necessary and sufficient for the ingestion response of larvae to caffeine. Additionally, we show that a specific pair of pharyngeal GRNs, DP1, responds to caffeine by calcium imaging. In this study we show that a specific pair of GRNs in the pharyngeal sense organs coordinates caffeine sensing with regulation of behavioral responses such as ingestion. Our results indicate that in <I>Drosophila</I> larvae, the pharyngeal GRNs have a major role in sensing food palatability to regulate ingestion behavior. The pharyngeal sense organs are prime candidates to influence ingestion due to their position in the pharynx, and they may act as first level sensors of ingested food.</P>

Optimal Spatial Scale for Land Use Change Modelling : A Case Study in a Savanna Landscape in Northern Ghana

박수진(Soo Jin Park),닉반드기슨(Nick van de Giesen),폴플렉(Paul L. G. Vlek) 대한지리학회 2005 대한지리학회지 Vol.40 No.2

토지이용 및 지표피복변화 (Land Use and Land Cover Changes, LUCC)는 지구환경변화의 원인으로 중요한 연구대상이 되고 있다. LUCC는 복잡한 사회적, 경제적, 정치적 상호작용속에서 다양한 시·공간적 스케일에서 발생하게 된다. 따라서 LUCC를 모델화하기 위해서는 LUCC를 야기시키는 원인(driving forces)과 제한요인(constraints)들의 시·공간적인 다양성을 이해하는 작업이 선행되어야 한다. 특히, 특정 지역에서 나타나는 LUCC의 동인을 파악하기 위해서는 스케일에 따른 그 특성의 변화를 이해하는 것이 급선무이다. 이 연구는 가나(Ghana) 북부지역의 사바나 지역을 대상으로 지난 15년간 나타난 지표피복변화의 공간적인 다양성을 파악한 뒤, 공간적 스케일을 달리하면서 나타나는 LUCC의 원인을 분석하였다. 이 과정을 통해 사바나 지역에서 LUCC 과정을 모형화하기 위한 최적의 공간적인 스케일을 규명하고자 하였다. 연구지역은 지난 15년간 인구증가의 결과로 농업생산활동이 급격하게 증가한 지역이다. 연구지역에서 나타나는 지표피복변화의 정도는 LANDSAT 위성영상에서 추출한 NDVI들을 다변량 통계분석기법을 이용하여 정량화하였다. 그리고 지표피복변화의 원인을 스케일별로 파악하기 위한 도구로 다축척 계층분석기법(multi-scale hierarchical adaptive model)을 개발·제안하였다. 개발된 기법은 지표피복의 변화정도와 원인이 될 수 있는 공간변수들간의 상관성을 공간적인 스케일을 달리하면서 순차적으로 계산해낼 수 있는 기법이다. 이 연구에서 지표피복변화의 원인으로는‘도로에서부터의 거리’, ‘하천으로부터의 거리’, ‘지형특성’의 세가지 변수를 사용하였다. 지표피복 변화정도와 위의 세가지 변수들간의 상관관계는 공간적인 범위가 10×10km 이하인 경우에 높게 나타났다. 하지만 공간범위가 그 이상이 될 경우에는 그 내부에서 나타나는 다양성으로 인해 통계적인 상관성이 현격하게 낮아지는 것을 관찰할 수 있었다. 이러한 결과는 지역 및 국가 단위의 환경변화모델에서 모델의 공간적인 구성범위가 일정한 수준을 넘으면, 그 내부에서 발생하고 있는 다양성이 급격하게 증가하여 지표피복변화의 원인과 결과를 정확하게 파악하기 힘들게 된다는 것을 의미한다. 10×10km의 공간적인 범위는 농업생산이 위주가 되는 사바나 지역에서는 주로 개별 마을이 차지하고 있는 공간적인 범위와 대체적으로 일치한다. 따라서 사바나 지역에서 나타나는 지표피복변화의 다양성을 고려하면서 보다 정확하게 모형화하기 위해서는 마을단위에서 나타나는 지표피복변화과정이 최소의 모델단위가 되어야 함을 시사한다. Land Use and Land Cover Changes (LUCC) occur over a wide range of space and time scales, and involve complex natural, socio-economic, and institutional processes. Therefore, modelling and predicting LUCC demands an understanding of how various measured properties behave when considered at different scales. Understanding spatial and temporal variability of driving forces and constraints on LUCC is central to understanding the scaling issues. This paper aims to 1) assess the heterogeneity of land cover change processes over the landscape in northern Ghana, where intensification of agricultural activities has been the dominant land cover change process during the past 15 years, 2) characterise dominant land cover change mechanisms for various spatial scales, and 3) identify the optimal spatial scale for LUCC modelling in a savanna landscape. A multivariate statistical method was first applied to identify land cover change intensity (LCCI), using four time-sequenced NDVI images derived from LANDSAT scenes. Three proxy land use change predictors: distance from roads, distance from surface water bodies, and a terrain characterisation index, were regressed against the LCCI using a multi-scale hierarchical adaptive model to identify scale dependency and spatial heterogeneity of LUCC processes. High spatial associations between the LCCI and land use change predictors were mostly limited to moving windows smaller than 10×10km. With increasing window size, LUCC processes within the window tend to be too diverse to establish clear trends, because changes in one part of the window are compensated elsewhere. This results in a reduced correlation between LCCI and land use change predictors at a coarser spatial extent. The spatial coverage of 5-10km is incidentally equivalent to a village or community area in the study region. In order to reduce spatial variability of land use change processes for regional or national level LUCC modelling, we suggest that the village level is the optimal spatial investigation unit in this savanna landscape.