Migrant-led Organisations and their Communities: Participation

The purpose of this study is to examine the processes of participation of migrant-led organisations and migrant communities in the Irish ‘intercultural’ sector, and also the broader third sector. The rational behind this research is to gain an understanding of the types and levels of participation in order to ascertain if inequities exist between the involvement of migrant communities and indigenous Irish people. Participation is assessed in relation to the emergence of barriers to participation, and how involvement is supported and facilitated by the organisations and the intercultural sector in general. This qualitative research utilises a critical ethnography, which integrates aspects of ethnography and critical enquiry in order to identify relationships between power and culture. The conclusions of this report have determined that inequalities exist for migrant-led organisations and communities in terms of their ability to participate in the sector and in the broader third sector. The issues that arose include; funding issues, disparate levels of influence between Irish NGOs and migrant-led organisations, formal participation in networks, a lack of informal connections with indigenous Irish people in government and civil society, and localised conceptions of community. Problems with perceptions and trust permeated these issues. This report recommends a recognition by Pobail of ‘culture as community’, the implementation of the funding recommendations made by the Fitzpatrick Report, the participation of intercultural organisations on funding advisory committees and greater support from funding bodies with application processes

Multinational Enterprise (MNE) Supplier Networks: Organizational Innovation or Innovation Policy?

In the context of Brazil/Chile, this article examines ways in which innovation policy can enhance the competitiveness of developing countries while building on organizational innovations which benefit multinational enterprises (MNEs). After a survey of Brazilian/Chilean innovation policy, we conclude that it has failed to bring about linkages between firms. One exception is provided by a Brazilian supplier network programme - an initiative which helps generate links between large and small firms. However, there is no Brazilian or Chilean programme designed to create linkages between MNEs and local firms. We argue that if the supplier network were modified to do just this, increases in MNE and national competitiveness would ensue

‘I’ll Say the Bad Words I Have’: Anne Enright and Eimear McBride’s Subversive Modernisms

There has been an increasing tendency within literary critical discourse to refer to at least two developing trends, both in the context of Ireland and internationally. The first is an upsurge in the volume of quality work being produced by young Irish writers, and the second is a resurgence of novel-writing that re-engages modernist aesthetics, which can be seen in the fiction of writers such as Will Self, Tom McCarthy and Mike McCormack. It’s worth remarking on the centrality afforded to women’s writing in the articulation of both of these developing strands, such as Sara Baume, Claire-Louise Bennett, Joanna Walsh, Eimear McBride and Anne Enright. Brian Dillon, in his review of Bennett’s Pond (2015) in the London Review of Books, sounds a dissenting note, touching on the somewhat parochial overtones of this nascent discourse: She [Bennett] has somewhat misleadingly been set aside Eimear McBride as representative of a modernist turn among young writers in Ireland, especially women writers. Misleadingly, not because they don't share something — a commitment to voice, a syntax that is speedy, bristling and strange at first encounter — but because they sound so different…If there is a modernism of sorts at work in current fiction in Ireland, it’s less a return in the manner called for by authors such as Tom McCarthy, and more an acknowledgement of the variety of experimental traditions on which young writers now draw (Dillon, 2016, 37–38)

Single Molecule investigations of DNA Looping Using the Tethered Particle Method and Translocation by Acto-Myosin Using Polarized Total Internal Reflection Fluorescence Microscopy

Single molecule biophysics aims to understand biological processes by studying them at the single molecule level in real time. The proteins and nucleic acids under investigation typically exist in an aqueous environment within approximately ten degrees of room temperature. These seemingly benign conditions are actually quite chaotic at the nanoscale, where single bio-molecules perform their function. As a result, sensitive experiments and statistical analyses are required to separate the weak single molecule signal from its background. Protein-DNA interactions were investigated by monitoring DNA looping events in tethered particle experiments. A new analysis technique, called the Diffusive hidden Markov method, was developed to extract kinetic rate constants from experimental data without any filtering of the raw data; a common step that improves the signal to noise ratio, but at the expense of lower time resolution. In the second system, translocation of the molecular motor myosin along its actin filament track was studied using polarized total internal reflection (polTIRF) microscopy, a technique that determines the orientation and wobble of a single fluorophore attached to the bio-molecule of interest. The range of resolvable angles was increased 4-fold to include a hemisphere of possible orientations. As a result, the handedness of actin filament twirling as it translocated along a myosin-coated surface was determined to be left-handed. The maximum time resolution of a polTIRF setup was increased 50-fold, in part by recording the arrival times and polarization state of single photons using a modified time-correlated single photon counting device. A new analysis, the Multiple Intensity Change Point algorithm, was developed to detect changes in molecular orientation and wobble using the raw time-stamped data with no user-defined bins or thresholds. The analysis objectively identified changes in the orientation of a bifunctional-rhodamine labeled calmodulin that was attached to a myosin V molecule translocating along an actin filament. Long intervals corresponding to stable positions between tilting motions of the lever arm during each step were routinely observed. Substeps in the cycle that preceded these long dwells were measured, but only occasionally most likely because of the low number of photons detected during these rapid events

Surfactant-mediated surface modification of microparticles for pressurised metered dose inhalation.

The necessary phase-out of CFC propellants and their replacement with HFA propellants has re-awakened an interest in the formulation science of pMDI suspension formulations, largely driven by the need to identify novel surfactants as a result of the altered physicochemical properties of HFA propellants with respect to CFCs. The aims of this thesis were to explore the validity of using surfactants with a low solubility in HFA propellants as stabilising agents in pMDI HFA suspension formulations, and in so doing to investigate the relationship between powder surface energy and suspension performance within these systems. Adsorption of a range of non-ionic surfactants to the surface of a model hydrophilic drug, terbutaline sulphate (TS), was achieved and the performance of corresponding pMDI suspension formulations was investigated. Surfactant adsorption was found to improve pMDI suspension stability by reducing phase separation and particle aggregation. The improvement in suspension performance was linked to a reduction in both the dispersive and acidic components of powder surface energy following surfactant adsorption. Similar adsorption experiments were carried out using a model hydrophobic drug, budesonide. While surfactant adsorption to the drug surface succeeded in reducing powder surface energy values, the anticipated improvement in pMDI suspension performance was not observed. Surfactant adsorption did however reduce the amount of suspended material adhered to the container wall. The effect of surfactant adsorption to both drugs on pMDI suspension formulations over extended storage periods was investigated. Adsorption of a hydrophobic poloxamer surfactant to the surface of TS was seen to confer a limited protective effect against water-induced instability in pMDI suspension systems. In the case of budesonide, reduced adhesion to the container wall was seen in all surfactant-containing formulations when compared with controls. Attempts to correlate surface energy with adhesion were complicated by the necessary use of two separate methods for surface energy determination. Work in this thesis has confirmed that surfactants with a low solubility in HFA propellants may be considered as potential stabilisers in pMDI suspension systems, and a greater understanding of the role played by surface energy in the performance of these systems has been achieved

First-principles calculation of DNA looping in tethered particle experiments

We calculate the probability of DNA loop formation mediated by regulatory proteins such as Lac repressor (LacI), using a mathematical model of DNA elasticity. Our model is adapted to calculating quantities directly observable in Tethered Particle Motion (TPM) experiments, and it accounts for all the entropic forces present in such experiments. Our model has no free parameters; it characterizes DNA elasticity using information obtained in other kinds of experiments. [...] We show how to compute both the "looping J factor" (or equivalently, the looping free energy) for various DNA construct geometries and LacI concentrations, as well as the detailed probability density function of bead excursions. We also show how to extract the same quantities from recent experimental data on tethered particle motion, and then compare to our model's predictions. [...] Our model successfully reproduces the detailed distributions of bead excursion, including their surprising three-peak structure, without any fit parameters and without invoking any alternative conformation of the LacI tetramer. Indeed, the model qualitatively reproduces the observed dependence of these distributions on tether length (e.g., phasing) and on LacI concentration (titration). However, for short DNA loops (around 95 basepairs) the experiments show more looping than is predicted by the harmonic-elasticity model, echoing other recent experimental results. Because the experiments we study are done in vitro, this anomalously high looping cannot be rationalized as resulting from the presence of DNA-bending proteins or other cellular machinery. We also show that it is unlikely to be the result of a hypothetical "open" conformation of the LacI tetramer.Comment: See the supplement at http://www.physics.upenn.edu/~pcn/Ms/TowlesEtalSuppl.pdf . This revised version accepted for publication at Physical Biolog

Diffusive Hidden Markov Model Characterization of DNA Looping Dynamics in Tethered Particle Experiments

In many biochemical processes, proteins bound to DNA at distant sites are brought into close proximity by loops in the underlying DNA. For example, the function of some gene-regulatory proteins depends on such “DNA looping” interactions. We present a new technique for characterizing the kinetics of loop formation in vitro, as observed using the tethered particle method, and apply it to experimental data on looping induced by lambda repressor. Our method uses a modified (“diffusive”) hidden Markov analysis that directly incorporates the Brownian motion of the observed tethered bead. We compare looping lifetimes found with our method (which we find are consistent over a range of sampling frequencies) to those obtained via the traditional threshold-crossing analysis (which can vary depending on how the raw data are filtered in the time domain). Our method does not involve any time filtering and can detect sudden changes in looping behavior. For example, we show how our method can identify transitions between long-lived, kinetically distinct states that would otherwise be difficult to discern

Myosin VI Lever Arm Rotation: Fixed or Variable?

Two recent articles addressed the power-stroke of myosin VI molecules during stepping. Although both groups measured the angles of fluorescent probes attached on the myosin VI molecule lever arm using polarized fluorescence techniques, they differ about whether the myosin VI lever arm rotation is fixed1 or variable2. Here we discuss the causes of the discrepancy between the two studies and the implications for myosin VI processive motility

Concentration and Length Dependence of DNA Looping in Transcriptional Regulation

In many cases, transcriptional regulation involves the binding of transcription factors at sites on the DNA that are not immediately adjacent to the promoter of interest. This action at a distance is often mediated by the formation of DNA loops: Binding at two or more sites on the DNA results in the formation of a loop, which can bring the transcription factor into the immediate neighborhood of the relevant promoter. These processes are important in settings ranging from the historic bacterial examples (bacterial metabolism and the lytic-lysogeny decision in bacteriophage), to the modern concept of gene regulation to regulatory processes central to pattern formation during development of multicellular organisms. Though there have been a variety of insights into the combinatorial aspects of transcriptional control, the mechanism of DNA looping as an agent of combinatorial control in both prokaryotes and eukaryotes remains unclear. We use single-molecule techniques to dissect DNA looping in the lac operon. In particular, we measure the propensity for DNA looping by the Lac repressor as a function of the concentration of repressor protein and as a function of the distance between repressor binding sites. As with earlier single-molecule studies, we find (at least) two distinct looped states and demonstrate that the presence of these two states depends both upon the concentration of repressor protein and the distance between the two repressor binding sites. We find that loops form even at interoperator spacings considerably shorter than the DNA persistence length, without the intervention of any other proteins to prebend the DNA. The concentration measurements also permit us to use a simple statistical mechanical model of DNA loop formation to determine the free energy of DNA looping, or equivalently, the J-factor for looping

Elementary simulation of tethered Brownian motion

We describe a simple numerical simulation, suitable for an undergraduate project (or graduate problem set), of the Brownian motion of a particle in a Hooke-law potential well. Understanding this physical situation is a practical necessity in many experimental contexts, for instance in single molecule biophysics; and its simulation helps the student to appreciate the dynamical character of thermal equilibrium. We show that the simulation succeeds in capturing behavior seen in experimental data on tethered particle motion.Comment: Submitted to American Journal of Physic