149 research outputs found
EU Policy towards Ukraine: Entering Geopolitical Competition over European Order
Since 2004, competition between the European Union (EU) and Russia over the European political, economic and security order intensified sporadically, with a focal point in Ukraine. The EU’s main mitigation tactic in response to this competition used to be denial, but in 2022, following Russia’s full-scale invasion of Ukraine, this approach became untenable. As a result, the EU entered the competition as an emerging geopolitical actor in three important respects: engaging in a conflict over the European order; utilising its (still limited) hard power; and extending its geographical borders. Most importantly, the EU is actively trying to shape the future of the European order that was challenged by Russia’s war against Ukraine. While pursuing its goals predominantly through civilian means, the EU has also taken major steps to strengthen its hard power capabilities and contributed military assistance. Furthermore, by granting candidate country status to Ukraine, it took a clear stance on its future borders, while these were violently contested.</p
Treatment of rising damp in historical buildings: wall base ventilation
Intervention in older buildings increasingly requires extensive and objective knowledge of what one will be working with. The multifaceted aspect of work carried out on buildings tends to encompass a growing number of specialities, with marked emphasis on learning the causes of many of the problems that affect these buildings and the possible treatments that can solve them. Moisture transfer in walls of old buildings, which are in direct contact with the ground, leads to a migration of soluble salts responsible for many building pathologies.http://www.sciencedirect.com/science/article/B6V23-4H7T0H7-1/1/f5e8a4ec173c5dadf120770678facf4
Synthetic Biology Open Language (SBOL) Version 1.1.0
In this BioBricks Foundation Request for Comments (BBF RFC), we specify the Synthetic Biology
Open Language (SBOL) Version 1.1.0 to enable the electronic exchange of information
describing DNA components used in synthetic biology. We define:
1. the vocabulary, a set of preferred terms and
2. the core data model, a common computational representation
Effect of Double Substitution in Cationic Chitosan Derivatives on DNA Transfection Efficiency
Recently, much effort has been expended on the development of non-viral gene delivery systems based on polyplexes of nucleic acids with various cationic polymers. Natural polysaccharide derivatives are promising carriers due to their low toxicity. In this work, chitosan was chemically modified by a reaction with 4-formyl-n,n,n-trimethylanilinium iodide and pyridoxal hydrochloride and subsequent reduction of the imine bond with NaBH4. This reaction yielded three novel derivatives, n-[4-(n',n',n'-trimethylammonium)benzyl]chitosan chloride (TMAB-CS), n-[(3-hydroxy-5-(hydroxymethyl)-2-methyl-4-pyridine)methyl]chitosan chloride (Pyr-CS), and n-[4-(n',n',n''-trimethylammonium)benzyl]-n-[(3-hydroxy-5-(hydroxymethyl)-2-methyl-4-pyridine)methyl]chitosan chloride (PyrTMAB-CS). Their structures and degrees of substitution were established by H-1 NMR spectroscopy as DS1 = 0.22 for TMAB-CS, DS2 = 0.28 for Pyr-CS, and DS1 = 0.21, DS2 = 0.22 for PyrTMAB-CS. Dynamic light scattering measurements revealed that the new polymers formed stable polyplexes with plasmid DNA encoding the green fluorescent protein (pEGFP-N3) and that the particles had the smallest size (110-165 nm) when the polymer:DNA mass ratio was higher than 5:1. Transfection experiments carried out in the HEK293 cell line using the polymer:DNA polyplexes demonstrated that Pyr-CS was a rather poor transfection agent at polymer:DNA mass ratios less than 10:1, but it was still more effective than the TMAB-CS and PyrTMAB-CS derivatives that contained a quaternary ammonium group. By contrast, TMAB-CS and PyrTMAB-CS were substantially more effective than Pyr-CS at higher polymer:DNA mass ratios and showed a maximum efficiency at 200:1 (50%-70% transfected cells). Overall, the results show the possibility of combining substituent effects in a single carrier, thereby increasing its efficacy.Peer reviewe
Photosystem II core phosphorylation and photosynthetic acclimation require two different protein kinases
Illumination changes elicit modifications of thylakoid proteins
and reorganization of the photosynthetic machinery. This involves, in the short term, phosphorylation of photosystem II
(PSII) and light-harvesting (LHCII) proteins. PSII phosphorylation
is thought to be relevant for PSII turnover1,2, whereas LHCII
phosphorylation is associated with the relocation of LHCII and
the redistribution of excitation energy (state transitions) between
photosystems3,4. In the long term, imbalances in energy distribution
between photosystems are counteracted by adjusting
photosystem stoichiometry5,6. In the green alga Chlamydomonas
and the plant Arabidopsis, state transitions require the orthologous
protein kinases STT7 and STN7, respectively7,8. Here we
show that in Arabidopsis a second protein kinase, STN8, is
required for the quantitative phosphorylation of PSII core proteins.
However, PSII activity under high-intensity light is affected
only slightly in stn8 mutants, and D1 turnover is indistinguishable
from the wild type, implying that reversible protein phosphorylation
is not essential for PSII repair. Acclimation to changes in
light quality is defective in stn7 but not in stn8 mutants, indicating
that short-term and long-term photosynthetic adaptations are
coupled. Therefore the phosphorylation of LHCII, or of an
unknown substrate of STN7, is also crucial for the control of
photosynthetic gene expressio
Screening mammography beliefs and recommendations: a web-based survey of primary care physicians
<p>Abstract</p> <p>Background</p> <p>The appropriateness and cost-effectiveness of screening mammography (SM) for women younger than 50 and older than 74 years is debated in the clinical research community, among health care providers, and by the American public. This study explored primary care physicians' (PCPs) perceptions of the influence of clinical practice guidelines for SM; the recommendations for SM in response to hypothetical case scenarios; and the factors associated with perceived SM effectiveness and recommendations in the US from June to December 2009 before the United States Preventive Services Task Force (USPSTF) recently revised guidelines.</p> <p>Methods</p> <p>A nationally representative sample of 11,922 PCPs was surveyed using a web-based questionnaire. The response rate was 5.7% (684); (41%) 271 family physicians (FP), (36%) 232 general internal medicine physicians (IM), (23%) 150 obstetrician-gynaecologists (OBG), and (0.2%) 31 others. Cross-sectional analysis examined PCPs perceived effectiveness of SM, and recommendation for SM in response to hypothetical case scenarios. PCPs responses were measured using 4-5 point adjectival scales. Differences in perceived effectiveness and recommendations for SM were examined after adjusting for PCPs specialty, race/ethnicity, and the US region.</p> <p>Results</p> <p>Compared to IM and FP, OBG considered SM more effective in reducing breast cancer mortality among women aged 40-49 years (<it>p </it>= 0.003). Physicians consistently recommended mammography to women aged 50-69 years with no differences by specialty (<it>p </it>= 0.11). However, 94% of OBG "always recommended" SM to younger and 86% of older women compared to 81% and 67% for IM and 84% and 59% for FP respectively (<it>p = </it>< .001). In ordinal regression analysis, OBG specialty was a significant predictor for perceived higher SM effectiveness and recommendations for younger and older women. In evaluating hypothetical scenarios, overall PCPs would recommend SM for the 80 year woman with CHF with a significant variation by specialty (38% of OBG, 18% of FP, 17% of IM; <it>p </it>= < .001).</p> <p>Conclusions</p> <p>A majority of physicians, especially OBG, favour aggressive breast cancer screening for women from 40 through 79 years of age, including women with short life expectancy. Policy interventions should focus on educating providers to provide tailored recommendations for mammography based on individualized cancer risk, health status, and preferences.</p
Building blocks for protein interaction devices
Here, we propose a framework for the design of synthetic protein networks from modular protein–protein or protein–peptide interactions and provide a starter toolkit of protein building blocks. Our proof of concept experiments outline a general work flow for part–based protein systems engineering. We streamlined the iterative BioBrick cloning protocol and assembled 25 synthetic multidomain proteins each from seven standardized DNA fragments. A systematic screen revealed two main factors controlling protein expression in Escherichia coli: obstruction of translation initiation by mRNA secondary structure or toxicity of individual domains. Eventually, 13 proteins were purified for further characterization. Starting from well-established biotechnological tools, two general–purpose interaction input and two readout devices were built and characterized in vitro. Constitutive interaction input was achieved with a pair of synthetic leucine zippers. The second interaction was drug-controlled utilizing the rapamycin-induced binding of FRB(T2098L) to FKBP12. The interaction kinetics of both devices were analyzed by surface plasmon resonance. Readout was based on Förster resonance energy transfer between fluorescent proteins and was quantified for various combinations of input and output devices. Our results demonstrate the feasibility of parts-based protein synthetic biology. Additionally, we identify future challenges and limitations of modular design along with approaches to address them
Aβ Mediated Diminution of MTT Reduction—An Artefact of Single Cell Culture?
The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide (MTT) reduction assay is a frequently used and easily reproducible method to measure beta-amyloid (Aβ) toxicity in different types of single cell culture. To our knowledge, the influence of Aβ on MTT reduction has never been tested in more complex tissue. Initially, we reproduced the disturbed MTT reduction in neuron and astroglia primary cell cultures from rats as well as in the BV2 microglia cell line, utilizing four different Aβ species, namely freshly dissolved Aβ (25-35), fibrillar Aβ (1-40), oligomeric Aβ (1-42) and oligomeric Aβ (1-40). In contrast to the findings in single cell cultures, none of these Aβ species altered MTT reduction in rat organotypic hippocampal slice cultures (OHC). Moreover, application of Aβ to acutely isolated hippocampal slices from adult rats and in vivo intracerebroventricular injection of Aβ also did not influence the MTT reduction in the respective tissue. Failure of Aβ penetration into the tissue cannot explain the differences between single cells and the more complex brain tissue. Thus electrophysiological investigations disclosed an impairment of long-term potentiation (LTP) in the CA1 region of hippocampal slices from rat by application of oligomeric Aβ (1-40), but not by freshly dissolved Aβ (25-35) or fibrillar Aβ (1-40). In conclusion, the experiments revealed a glaring discrepancy between single cell cultures and complex brain tissue regarding the effect of different Aβ species on MTT reduction. Particularly, the differential effect of oligomeric versus other Aβ forms on LTP was not reflected in the MTT reduction assay. This may indicate that the Aβ oligomer effect on synaptic function reflected by LTP impairment precedes changes in formazane formation rate or that cells embedded in a more natural environment in the tissue are less susceptible to damage by Aβ, raising cautions against the consideration of single cell MTT reduction activity as a reliable assay in Alzheimer's drug discovery studies
Gendered Risk Perceptions Associated with Human-Wildlife Conflict: Implications for Participatory Conservation
This research aims to foster discourse about the extent to which gender is important to consider within the context of participatory approaches for biological conservation. Our objectives are to: (1) gender-disaggregate data about stakeholders' risk perceptions associated with human-wildlife conflict (HWC) in a participatory conservation context, and (2) highlight insights from characterizing gendered similarities and differences in the way people think about HWC-related risks. Two communal conservancies in Caprivi, Namibia served as case study sites. We analyzed data from focus groups (n = 2) to create gendered concept maps about risks to wildlife and livelihoods and any associations of those risks with HWC, and semi-structured interviews (n = 76; men = 38, women = 38) to measure explicit risk attitudes associated with HWC. Concept maps indicated some divergent perceptions in how groups characterized risks to wildlife and livelihoods; however, not only were identified risks to wildlife (e.g., pollution, hunting) dissimilar in some instances, descriptions of risks varied as well. Study groups reported similar risk perceptions associated with HWC with the exception of worry associated with HWC effects on local livelihoods. Gendered differences in risk perceptions may signal different priorities or incentives to participate in efforts to resolve HWC-related risks. Thus, although shared goals and interests may seem to be an obvious reason for cooperative wildlife management, it is not always obvious that management goals are shared. Opportunity exists to move beyond thinking about gender as an explanatory variable for understanding how different groups think about participating in conservation activities
Paradigmatic or Critical? Resilience as a New Turn in EU Governance for the Neighbourhood
Rising from the margins of EU aid documents, resilience became a centrepiece of the 2016 EU Global Security Strategy, especially in relation to the neighbourhood. While new resilience-thinking may signify another paradigmatic shift in EU modus operandi, the question that emerges is whether it is critical enough to render EU governance a new turn, to make it sustainable? This article argues that in order for resilience-framed governance to become more effective, the EU needs not just engage with ‘the local’ by way of externally enabling their communal capacity. More crucially, the EU needs to understand resilience for what it is – a self-governing project – to allow ‘the local’ an opportunity to grow their own critical infrastructures and collective agency, in their pursuit of ‘good life’. Is the EU ready for this new thinking, and not just rhetorically or even methodologically when creating new instruments and subjectivities? The bigger question is whether the EU is prepared to critically turn the corner of its neoliberal agenda to accommodate emergent collective rationalities of self-governance as a key to make its peace-building project more successful
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