1,784 research outputs found
The Application of Multi-dimensional Fluorescence Imaging to Microfluidic Systems
This thesis describes the application of multidimensional fluorescence imaging to microfluidic
systems. The work focuses on time- and polarisation-resolved fluorescence microscopy to
extract information from microchannel environments. The methods are applied to polymerase
chain reaction (PCR) and a DNA repair enzyme, uracil DNA glycosylase (UDG).
The fluorescence lifetimes Rhodamine B are calibrated over a thermal gradient using time
correlated single photon counting. The dye is then introduced in solution into a novel
microfluidic PCR device. Fluorescence lifetime imaging microscopy (FLIM) is then performed,
and using the calibration curve, the temperature distributions are accurately determined. The
device is subsequently optimised for efficient DNA amplification.
A line-scanning FLIM microscope is used to characterise a rapid microfluidic mixer via a
fluorescence quenching experiment. Fluorescein and sodium iodide are mixed in a continuous flow
format and imaged in 3-D. The spatial distributions of the fluorescence lifetimes are
converted to the concentrations of sodium iodide to quantify mixing. Computational fluid
dynamic (CFD) simulations are validated by comparison to the quantitative concentrations
obtained experimentally.
The binding reaction between UDG and a hexachlorofluorescein (HEX) labelled DNA strand is
characterised spectrally. As well as an increase in fluorescence polarisation anisotropy, a 700 ps
increase in the fluorescence lifetime is measured. Confocal microscopy shows the same spectral
properties when the reaction is performed in both simple and rapid microfluidic mixers. In the
latter experiment, a concentration series allows the determination of kinetics, which agree with
conventional stopped-flow data.
A two-colour two-photon (2c2p) FLIM microscope is developed and applied to the UDG-DNA
system. An oligonucleotide containing 2-aminopurine, a reporter of DNA base flipping, and HEX
is mixed with UDG in a microfluidic Y-mixer. The 2c2p excitation allows FLIM of both
fluorophores and hence detection of binding and base flipping. Comparison to CFD with known
kinetic rate constants confirms the experimental observations
Scaling Recurrent Neural Network Language Models
This paper investigates the scaling properties of Recurrent Neural Network
Language Models (RNNLMs). We discuss how to train very large RNNs on GPUs and
address the questions of how RNNLMs scale with respect to model size,
training-set size, computational costs and memory. Our analysis shows that
despite being more costly to train, RNNLMs obtain much lower perplexities on
standard benchmarks than n-gram models. We train the largest known RNNs and
present relative word error rates gains of 18% on an ASR task. We also present
the new lowest perplexities on the recently released billion word language
modelling benchmark, 1 BLEU point gain on machine translation and a 17%
relative hit rate gain in word prediction
Betaalbaar wonen als ontwikkelingshulp
It was not by coincidence that the UN Economical and Social Council decided in 1948, only a few years after the actual foundation of the United Nations as an organization, to start a division on Housing and Town and Country Planning. This division was a central component in the larger so-called technical assistance programme that the United Nations developed to help countries that were in need – ranging from war-affected countries in Europe to newly independent nation-states in African and Asia. Among the members of the council, there was a clear understanding that affordable housing was a universal human right, as well as a main matter of concern and a prime field of intervention for the new international organization.
The Housing and Town and Country Planning (HTCP) division was from its inception until 1966 headed by a former member of the Congress Internationaux d’Architecture Moderne (CIAM), the Yugoslavian Ernest Weismann. The new division was defined first and foremost as a base of expertise: it was meant to gather worldwide knowledge on the matter of affordable housing that was generated in the different member countries. With this in mind, the HTCP managed to unite different professional camps of architects and urban planners, gathering public administrations and avant-garde groups, but also organizations that had previously been keen to establish an ideological distance such as the CIAM and the International Union of Architects (IUA).
The knowledge that was gathered was made available to the member countries in different ways: through the publication of manuals and a bulletin, through the installation of a library and by curating a mediatheque with movies on different forms of housing worldwide. Besides this function as a base of expertise, the HTCP section also focussed on more concrete sorts of intervention. It would commission urban and regional planners, architects, engineers and technicians to go on missions to regions, countries or cities that were in need. In the decades after 1948 the HTCP would initiate hundreds of missions, organize trainings, make regional and urban plans and even design buildings for a variety of contexts and places. The numerous urban plans, neighbourhoods and buildings that resulted from these ‘development aid’ initiatives have for a long time been the no-go zones of architectural criticism and historiography. Plans and projects have often been considered as too instrumental and too technical in character to carry any cultural significance.Het was geen toeval dat de Economische en Sociale Raad van de Verenigde Naties (ECOSOC) in 1948, enkele jaren na de oprichting van de Verenigde Naties als organisatie, besloot een afdeling Housing and Town and Country Planning op te zetten. Deze afdeling was een centraal onderdeel van het grotere zogenaamde ‘programma voor technische ondersteuning’ dat de Verenigde Naties had ontwikkeld om landen in nood te helpen – uiteenlopend van Europese landen in de nasleep van de Tweede Wereldoorlog tot nieuwe, onafhankelijke natiestaten in Afrika en Azië. De leden van de Raad waren het erover eens dat betaalbare huisvesting zowel tot de universele rechten van de mens behoorde als een van de belangrijkste punten van zorg was van de nieuwe organisatie. Interventies op dit terrein zouden tot haar fundamentele taken gaan behoren.
De afdeling Housing and Town and Country Planning (HTCP) werd vanaf haar oprichting tot 1966 geleid door een voormalig lid van de Congrès Internationaux d’Architecture Moderne (CIAM), de Joegoslaaf Ernest Weismann. De nieuwe afdeling werd in de eerste plaats gedefinieerd als een expertiseplatform: overal ter wereld zouden de diverse lidstaten kennis over betaalbare huisvesting verzamelen. Op basis van dit perspectief wist HTCP uiteenlopende professionele kampen van architecten en stedenbouwkundigen te verenigen, en bracht ze overheidsdiensten en avant-gardistische groepen bij elkaar. Ook organisaties die elkaar eerder op ideologische gronden maar al te graag op afstand hadden gehouden, zoals de CIAM en de International Union of Architects (IUA).
De verzamelde kennis werd op verschillende manieren beschikbaar gesteld aan de lidstaten: via de publicatie van handboeken en een bulletin, door het openen van een bibliotheek en het beheren van een mediatheek met films over verschillende vormen van huisvesting wereldwijd. Naast haar functie als expertiseplatform richtte HTCP zich ook op concrete interventies. Zij stuurde stedenbouwkundigen, architecten, ingenieurs en technici erop uit om regio’s, landen of steden die in nood zaten te hulp te schieten. In de decennia na 1948 zou de afdeling HTCP honderden missies initiëren, trainingen organiseren, plannen opstellen voor regio’s en steden, en zelfs gebouwen ontwerpen voor allerlei contexten en locaties. De talrijke stedenbouwkundige plannen, wijken en gebouwen die uit deze ‘ontwikkelingshulp’ resulteerden, waren binnen de architectuurkritiek en architectuurgeschiedenis lange tijd onbespreekbaar. Men vond de plannen en projecten vaak te instrumenteel en te technisch om van enig cultureel belang te zijn
Blackpool Opportunity Area Evaluation Strand 2: Executive Summary:Report for Blackpool Council
Date of Snowmelt at High Latitudes as Determined from Visible Satellite Data and Relationship with the Arctic Oscillation
Spring snow cover across Arctic lands has, on average, retreated approximately five days earlier since the late 1980s compared to the previous twenty years. However, it appears that since about 1990, the date the snowline first retreats north during the spring has remained nearly unchanged--in the last twenty years, the date of snow disappearance has not been occurring noticeably earlier. Snowmelt changes observed in the 1980s was step-like in nature, unlike a more continuous downward trend seen in Arctic sea ice extent. At latitude 70 deg N, several latitudinal segments (of 10 degrees) show significant (negative) trends. However, only two latitudinal segments at 60 deg N show significant trends, one positive and one negative. These variations appear to be related to variations in the Arctic Oscillation (AO). Additional observations and modeling investigations are needed to better explain past and present spring melt characteristics and peculiarities
Non-explosive actuation for the ORBCOMM (TM) satellite
Spool-based non-explosive actuator (NEA) devices are used for three important holddown and release functions during the establishment of the ORBCOMM (TM) constellation. Non-explosive separation nuts are used to restrain and release the 26 individual satellites into low earth orbit. Cable release mechanisms based on the same technology are used to release the solar arrays and antenna boom
Why do People Blog: A Q Analysis of Perceptions for Blogging
The purpose of this article is to understand user perceptions of new media formats, in this case blogging. While much of the blog research identifies blogging in terms of blog types, this research identifies user perceptions of why they like to blog. By applying Q-methodology to the blogging process, this research asked bloggers to rank subjective statements of blogging. Factor analyses were then applied to the rankings, which provided three main user factors (perspectives) of blogging motivations: Memorians, Bonders, and Soap Boxers. These perspectives provide an alternative to traditional views of social media use and categories of subjective media experience
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