1,984 research outputs found
The politicisation of evaluation: constructing and contesting EU policy performance
Although systematic policy evaluation has been conducted for decades and has been growing strongly within the European Union (EU) institutions and in the member states, it remains largely underexplored in political science literatures. Extant work in political science and public policy typically focuses on elements such as agenda setting, policy shaping, decision making, or implementation rather than evaluation. Although individual pieces of research on evaluation in the EU have started to emerge, most often regarding policy “effectiveness” (one criterion among many in evaluation), a more structured approach is currently missing. This special issue aims to address this gap in political science by focusing on four key focal points: evaluation institutions (including rules and cultures), evaluation actors and interests (including competencies, power, roles and tasks), evaluation design (including research methods and theories, and their impact on policy design and legislation), and finally, evaluation purpose and use (including the relationships between discourse and scientific evidence, political attitudes and strategic use). The special issue considers how each of these elements contributes to an evolving governance system in the EU, where evaluation is playing an increasingly important role in decision making
Transcriptional analysis of cell growth and morphogenesis in the unicellular green alga Micrasterias (Streptophyta), with emphasis on the role of expansin
<p>Abstract</p> <p>Background</p> <p>Streptophyte green algae share several characteristics of cell growth and cell wall formation with their relatives, the embryophytic land plants. The multilobed cell wall of <it>Micrasterias denticulata </it>that rebuilds symmetrically after cell division and consists of pectin and cellulose, makes this unicellular streptophyte alga an interesting model system to study the molecular controls on cell shape and cell wall formation in green plants.</p> <p>Results</p> <p>Genome-wide transcript expression profiling of synchronously growing cells identified 107 genes of which the expression correlated with the growth phase. Four transcripts showed high similarity to expansins that had not been examined previously in green algae. Phylogenetic analysis suggests that these genes are most closely related to the plant EXPANSIN A family, although their domain organization is very divergent. A GFP-tagged version of the expansin-resembling protein MdEXP2 localized to the cell wall and in Golgi-derived vesicles. Overexpression phenotypes ranged from lobe elongation to loss of growth polarity and planarity. These results indicate that MdEXP2 can alter the cell wall structure and, thus, might have a function related to that of land plant expansins during cell morphogenesis.</p> <p>Conclusions</p> <p>Our study demonstrates the potential of <it>M. denticulata </it>as a unicellular model system, in which cell growth mechanisms have been discovered similar to those in land plants. Additionally, evidence is provided that the evolutionary origins of many cell wall components and regulatory genes in embryophytes precede the colonization of land.</p
Smart Swarms of Bacteria-Inspired Agents with Performance Adaptable Interactions
Collective navigation and swarming have been studied in animal groups, such as fish schools, bird flocks, bacteria, and slime molds. Computer modeling has shown that collective behavior of simple agents can result from simple interactions between the agents, which include short range repulsion, intermediate range alignment, and long range attraction. Here we study collective navigation of bacteria-inspired smart agents in complex terrains, with adaptive interactions that depend on performance. More specifically, each agent adjusts its interactions with the other agents according to its local environment – by decreasing the peers' influence while navigating in a beneficial direction, and increasing it otherwise. We show that inclusion of such performance dependent adaptable interactions significantly improves the collective swarming performance, leading to highly efficient navigation, especially in complex terrains. Notably, to afford such adaptable interactions, each modeled agent requires only simple computational capabilities with short-term memory, which can easily be implemented in simple swarming robots
Asthma control cost-utility randomized trial evaluation (ACCURATE): the goals of asthma treatment
Contains fulltext :
97659.pdf (publisher's version ) (Open Access)ABSTRACT: BACKGROUND: Despite the availability of effective therapies, asthma
remains a source of significant morbidity and use of health care resources. The
central research question of the ACCURATE trial is whether maximal doses of
(combination) therapy should be used for long periods in an attempt to achieve
complete control of all features of asthma. An additional question is whether
patients and society value the potential incremental benefit, if any,
sufficiently to concur with such a treatment approach. We assessed patient
preferences and cost-effectiveness of three treatment strategies aimed at
achieving different levels of clinical control: 1. sufficiently controlled asthma
2. strictly controlled asthma 3. strictly controlled asthma based on exhaled
nitric oxide as an additional disease marker DESIGN: 720 Patients with mild to
moderate persistent asthma from general practices with a practice nurse, age
18-50 yr, daily treatment with inhaled corticosteroids (more then 3 months usage
of inhaled corticosteroids in the previous year), will be identified via patient
registries of general practices in the Leiden, Nijmegen, and Amsterdam areas in
The Netherlands. The design is a 12-month cluster-randomised parallel trial with
40 general practices in each of the three arms. The patients will visit the
general practice at baseline, 3, 6, 9, and 12 months. At each planned and
unplanned visit to the general practice treatment will be adjusted with support
of an internet-based asthma monitoring system supervised by a central
coordinating specialist nurse. Patient preferences and utilities will be assessed
by questionnaire and interview. Data on asthma control, treatment step, adherence
to treatment, utilities and costs will be obtained every 3 months and at each
unplanned visit. Differences in societal costs (medication, other (health) care
and productivity) will be compared to differences in the number of limited
activity days and in quality adjusted life years (Dutch EQ5D, SF6D, e-TTO, VAS).
This is the first study to assess patient preferences and cost-effectiveness of
asthma treatment strategies driven by different target levels of asthma control.
Trial registration: Netherlands Trial Registration NTR1756
Search algorithms as a framework for the optimization of drug combinations
Combination therapies are often needed for effective clinical outcomes in the
management of complex diseases, but presently they are generally based on
empirical clinical experience. Here we suggest a novel application of search
algorithms, originally developed for digital communication, modified to
optimize combinations of therapeutic interventions. In biological experiments
measuring the restoration of the decline with age in heart function and
exercise capacity in Drosophila melanogaster, we found that search algorithms
correctly identified optimal combinations of four drugs with only one third of
the tests performed in a fully factorial search. In experiments identifying
combinations of three doses of up to six drugs for selective killing of human
cancer cells, search algorithms resulted in a highly significant enrichment of
selective combinations compared with random searches. In simulations using a
network model of cell death, we found that the search algorithms identified the
optimal combinations of 6-9 interventions in 80-90% of tests, compared with
15-30% for an equivalent random search. These findings suggest that modified
search algorithms from information theory have the potential to enhance the
discovery of novel therapeutic drug combinations. This report also helps to
frame a biomedical problem that will benefit from an interdisciplinary effort
and suggests a general strategy for its solution.Comment: 36 pages, 10 figures, revised versio
The structure of the PapD-PapGII pilin complex reveals an open and flexible P5 pocket
P pili are hairlike polymeric structures that mediate binding of uropathogenic Escherichia coli to the surface of the kidney via the PapG adhesin at their tips. PapG is composed of two domains: a lectin domain at the tip of the pilus followed by a pilin domain that comprises the initial polymerizing subunit of the 1,000-plus-subunit heteropolymeric pilus fiber. Prior to assembly, periplasmic pilin domains bind to a chaperone, PapD. PapD mediates donor strand complementation, in which a beta strand of PapD temporarily completes the pilin domain's fold, preventing premature, nonproductive interactions with other pilin subunits and facilitating subunit folding. Chaperone-subunit complexes are delivered to the outer membrane usher where donor strand exchange (DSE) replaces PapD's donated beta strand with an amino-terminal extension on the next incoming pilin subunit. This occurs via a zip-in-zip-out mechanism that initiates at a relatively accessible hydrophobic space termed the P5 pocket on the terminally incorporated pilus subunit. Here, we solve the structure of PapD in complex with the pilin domain of isoform II of PapG (PapGIIp). Our data revealed that PapGIIp adopts an immunoglobulin fold with a missing seventh strand, complemented in parallel by the G1 PapD strand, typical of pilin subunits. Comparisons with other chaperone-pilin complexes indicated that the interactive surfaces are highly conserved. Interestingly, the PapGIIp P5 pocket was in an open conformation, which, as molecular dynamics simulations revealed, switches between an open and a closed conformation due to the flexibility of the surrounding loops. Our study reveals the structural details of the DSE mechanism
Influence of Matrix Polarity on the Properties of Ethylene Vinyl Acetate–Carbon Nanofiller Nanocomposites
A series of ethylene vinyl acetate (EVA) nanocomposites using four kinds of EVA with 40, 50, 60, and 70 wt% vinyl acetate (VA) contents and three different carbon-based nanofillers—expanded graphite (EG), multi-walled carbon nanotube (MWCNT), and carbon nanofiber (CNF) have been prepared via solution blending. The influence of the matrix polarity and the nature of nanofillers on the morphology and properties of EVA nanocomposites have been investigated. It is observed that the sample with lowest vinyl acetate content exhibits highest mechanical properties. However, the enhancement in mechanical properties with the incorporation of various nanofillers is the highest for EVA with high VA content. This trend has been followed in both dynamic mechanical properties and thermal conductivity of the nanocomposites. EVA copolymer undergoes a transition from partial to complete amorphousness between 40 and 50 wt% VA content, and this changes the dispersion of the nanofillers. The high VA-containing polymers show more affinity toward fillers due to the large free volume available and allow easy dispersion of nanofillers in the amorphous rubbery phase, as confirmed from the morphological studies. The thermal stability of the nanocomposites is also influenced by the type of nanofiller
- …