28 research outputs found
Analogues of Neuropeptide Y Containing β-Aminocyclopropane-carboxylic Acids are the Shortest Linear Peptides Selective for the Y₁-Receptor
No full textKoglin N, Zorn C, Beumer R, et al. Analogues of neuropeptide Y containing beta-aminocyclopropane carboxylic acids are the shortest linear peptides that are selective for the Y-1 receptor. Angewandte Chemie International Edition. 2003;42(2):202-205
Application sharing services design and performance
No full textDigital information is becoming increasingly integrated in our daily life. We can communicate with each other via e-mail and exchange documents, photographs and video fragments and use webcams during a telephone call ("nice for the kids"). Digital information is used in education to communicate with other students and teachers and it is used for commercial purposes and for public services: delivering information direct to citizens at home without visiting an office at any time a citizen wishes to obtain such information. This readily available digital information is causing new problems. Problems occur, for instance, because specific information can not be found on a website or on a digital form. Problems may also occur when filling in a digital form. Moreover, technical problems can occur, such as computer or program crashes, problems with the server or with printing the information needed. A new technology service concept called Audio Supported Application Sharing (ASAS) services can be used to solve these problems at a distance. When using ASAS technology the present forms of support and training face-to-face or via the telephone, are replaced by a new service to help clients. This service combines audio support, i.e. telephonic support, with application sharing, i.e. distance access to another's computer screen.Technology, Policy and Managemen
ChemInform Abstract: β‐Aminocyclopropanecarboxylic Acids with α‐Amino Acid Side Chain Functionality.
No full text
Fine Pointing Assembly for Optical Ground Station: Tip-Tilt removal through feedback control
No full textThe mini optical ground station (MISO), on top of the Aerospace Engineering faculty, serves the purpose of demonstrating Free Space Optical Communication technology. A downlink from low earth orbit imposes pointing requirements beyond what can be achieved by the telescope mount. A Fine Pointing Assembly (FPA), the topic of this thesis, aims to reduce residual pointing error to facilitate coupling into a single-mode fiber architecture. This thesis addresses the design, implementation, and characterization of FPA to fulfill this job in a lab environment. The FPA was built as a feedback control system actuating a fine steering mirror to counteract tip-tilt with feedback from a SWIR camera and the center of the gravity tracking algorithm. The bandwidth of this system is limited by latency from software implementations of the interfaces. The developed FPA removes 76% of the Tip-Tilt disturbance energy and can be improved by mitigation efforts toward latency reduction.Aerospace Engineerin
Energy Efficiency Valuation: Estimating the increase in expected transaction price due to improved energy efficiency in the Dutch housing market
No full textRecent advancements in causal inference and machine learning research have brought forward methods to estimate effects of interventions from observational data. The augmented inverse probability weighted (AIPW) estimator is such a method, which can be used to obtain estimates of potential outcomes. Potential outcomes are defined as a hypothetical outcome pair {Y(1),Y(0)}, of which only one outcome is observed in the data. Estimation of intervention effects boils down to effectively estimating these potential outcomes.Using the AIPW estimator, we aim to evaluate the average effect of increasing the energy efficiency of houses in the Netherlands on their expected transaction price. Moreover, we investigate how this expected effect changes when we condition on a certain subset of the data.Given that our assumptions hold, we find that on average, the estimated expected increase in transaction price is positive when improving the energy efficiency of a house. Improving an energy inefficient house to moderately energy efficient is expected to increase the transaction price by approximately €97.70,- per m2, while the improvement from moderately energy efficient to energy efficient increases the expected transaction price by approximately €20.96 per m2. In general, older, smaller and more energy inefficient houses increase most in expected transaction price per m2 when their energy efficiency is improved.Applied Mathematic
β-Aminocyclopropanecarboxylic Acids with α-Amino Acid Side Chain Functionality
No full textThe synthesis of conformationally restricted trans-beta -aminocyclopropanecarboxylic acids (beta -ACCs) having alpha -amino acid side chain functionality of asparagine, arginine, cysteine, or serine is described. (C) 2001 Elsevier Science Ltd. All rights reserved
Aanbevelingen voor beheersmaatregelen bij herinrichting van uiterwaarden en beekdalen
No full textKlimaatverandering - hetzij natuurlijk, hetzij door menselijke activiteiten veroorzaakt – leidt tot effecten op zowel de waterkwantiteit als de waterkwaliteit in riviersystemen. Om deze systemen aan te passen aan de te verwachten ontwikkelingen zijn en worden er diverse (her)inrichtingsmaatregelen uitgevoerd in grote rivieren en in beeksystemen. De meeste zijn gericht op het garanderen van een voldoende afvoercapaciteit of op het vergroten van het waterbergend vermogen. Ook natuurontwikkeling speelt een belangrijke rol. Na een beschrijving van deze maatregelen geeft dit rapport de volgende aanbevelingen voor deze beheermaatregelen: Inrichten met oog voor verontreinigingen Gebruik kwantitatieve modellen om een schatting te maken van veranderingen in locale condities (redoxovergangen) ten gevolge van de (her)inrichting. Grondverzet Houd rekening met de aanwezigheid van historisch verontreinigde lagen en de risico’s die mogelijk door de maatregelen worden verhoogd. Ga na of de nieuwe situatie na verwijdering van de toplaag past bij de beoogde vegetatieontwikkeling. Maak bij het bergen van materiaal onder water onderscheid tussen sediment van aquatische oorsprong en terrestrische uiterwaardgrond. Stofbalansen en beschikbaarheid Bouw inzicht op in de metalenbalans (het netto resultaat tussen vastlegging door bijvoorbeeld sulfiden en vrijmaking door het reduceren van ijzer) na uitvoering van de maatregel; Houd rekening met veranderingen in de nutriëntenhuishouding, in de vegetatiesamenstelling en in het nagestreefde natuurdoeltype ten gevolge van veranderingen in hydrologische regimes. Effecten op ecosysteemniveau Houd in de risicobeoordeling van verontreinigingen rekening met de ecologische draagkracht. Deze komt tot uiting in (1) doorvergiftiging en ophoping in de voedselketen, (2) de samenstelling van vegetatie en dientengevolge het voorkomen van specifieke diersoorten en (3) aantasting van de algehele vitaliteit van een ecotoop. Spuiregime Bouw voldoende kennis op van slibtransportprocessen in de riviersystemen met kunstwerken en andere elementen die het slibtransport beïnvloeden, zodat bij het spuiregime rekening kan worden gehouden met de voorspelde effecten
Superdutch - Eine Kopfgeburt der Medien
No full textStatement on contemporary Dutch architecture for a special issue of the German weekly Baunetzwoche devoted to Dutch architecture.ArchitectureArchitecture and The Built Environmen
Icones Plantarum Malabaricarum: early 18th century botanical drawings of medicinal plants from colonial Ceylon
No full textEthnopharmacological relevanceFrom 1640–1796, the Dutch East India Company (VOC) occupied the island of Ceylon (now Sri Lanka). Several VOC officers had a keen interest in the medicinal application of the local flora. The Leiden University Library holds a two-piece codexentitled: Icones Plantarum Malabaricarum, adscriptis nominibus et viribus, Vol. I. & II. (Illustrations of Plants from the Malabar, assigned names and strength). This manuscript contains 262 watercolour drawings of medicinal plants from Sri Lanka, with handwritten descriptions of local names, habitus, medicinal properties and therapeutic applications. This anonymous document had never been studied previously.Aim of the studyTo identify all depicted plant specimens, decipher the text, trace the author, and analyse the scientific relevance of this manuscript as well as its importance for Sri Lankan ethnobotany.Materials and methodsWe digitised the entire manuscript, transcribed and translated the handwritten Dutch texts and identified the depicted species using historic and modern literature, herbarium vouchers, online databases on Sri Lankan herbal medicine and 41 botanical drawings by the same artist in the Artis library, Amsterdam. We traced the origin of the manuscript by means of watermark analysis and historical literature. We compared the historic Sinhalese and Tamil names in the manuscript to recent plant names in ethnobotanical references from Sri Lanka and southern India. We published the entire manuscript online with translations and identifications.ResultsThe watermarks indicate that the paper was made between 1694 and 1718. The handwriting is of a VOC scribe. In total, ca. 252 taxa are depicted, of which we could identify 221 to species level. The drawings represent mainly native species, including Sri Lankan endemics, but also introduced medicinal and ornamental plants. Lamiaceae, Zingiberaceae and Leguminosae were the best-represented families. Frequently mentioned applications were to purify the blood and to treat gastro-intestinal problems, fever and snakebites. Many plants are characterised by their humoral properties, of which ‘warming’ is the most prevalent. Plant species were mostly used for their roots (28%), bark (16%) or leaves (11%). More Tamil names (260) were documented than Sinhalese (208). More than half of the Tamil names and 36% of the Sinhalese names are still used today. The author was probably a VOC surgeon based in northern Sri Lanka, who travelled around the island to document medicinal plant use. Less than half of the species were previously documented from Ceylon by the famous VOC doctor and botanist Paul Hermann in the 1670s. Further archival research is needed to identify the maker of this manuscript.ConclusionsAlthough the maker of this early 18th century manuscript remains unknown, the detailed, 300-year-old information on medicinal plant use in the Icones Plantarum Malabaricarum represents an important ethnobotanical treasure for Sri Lanka, which offers ample opportunities to study changes and continuation of medicinal plant names and practices over time.Plant science
