134 research outputs found
The management of an ageing workforce: organisational policies in Germany and Britain
Demographic change as well as pressure from the European Union and national government are forcing organisations to change age-discriminatory Human Resource Management (HRM) approaches. Based on a qualitative analysis of eight British and German organisations, we found that commitment, scope, coverage and implementation of age management differ due to country-specific institutions, particularly government, in nudging employers and unions to preferred age practices. This confirms the path-dependency concept suggested by institutional theory. Nevertheless, we also found that industry-specific factors mediate the implementation of age management, leading to some convergence across countries. This indicates that organisations deviate from the institutional path to implement practices that they deem important
Modelling Robust Feedback Control Mechanisms That Ensure Reliable Coordination of Histone Gene Expression with DNA Replication
Funding: Andrea Christopher was supported by the University of Aberdeen through a Milner Studentship. Heike Hameister was supported by a Postgraduate Research Studentship of the University of Aberdeen. Oliver Ebenhöh was supported by the University of Aberdeen and the Deutsche Forschungsgemeinschaft [Cluster of Excellence on Plant Sciences, CEPLAS (EXC 1028)]. Berndt Müller was supported by the University of Aberdeen. Ekkehard Ullner was supported by the Scottish Universities Life Sciences Alliance (SULSA). The funders provided support in the form of salaries for authors but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section. Heike Hameister is currently employed by Merck Serono GmbH. Merck Serono GmbH did not provide any support for this work and did not have any role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. This does not alter our adherence to PLOS ONE policies on sharing data and materials.Peer reviewedPublisher PD
New aspects of electron transfer revealed by the crystal structure of a truncated bovine adrenodoxin, Adx(4–108)
AbstractBackground: Adrenodoxin (Adx) is a [2Fe–2S] ferredoxin involved in steroid hormone biosynthesis in the adrenal gland mitochondrial matrix of mammals. Adx is a small soluble protein that transfers electrons from adrenodoxin reductase (AR) to different cytochrome P450 isoforms where they are consumed in hydroxylation reactions. A crystallographic study of Adx is expected to reveal the structural basis for an important electron transfer reaction mediated by a vertebrate [2Fe–2S] ferredoxin.Results: The crystal structure of a truncated bovine adrenodoxin, Adx(4–108), was determined at 1.85 å resolution and refined to a crystallographic R value of 0.195. The structure was determined using multiple wavelength anomalous dispersion phasing techniques, making use of the iron atoms in the [2Fe–2S] cluster of the protein. The protein displays the compact (α+β) fold typical for [2Fe–2S] ferredoxins. The polypeptide chain is organized into a large core domain and a smaller interaction domain which comprises 35 residues, including all those previously determined to be involved in binding to AR and cytochrome P450. A small interdomain motion is observed as a structural difference between the two independent molecules in the asymmetric unit of the crystal. Charged residues of Adx(4–108) are clustered to yield a strikingly asymmetric electric potential of the protein molecule.Conclusions: The crystal structure of Adx(4–108) provides the first detailed description of a vertebrate [2Fe–2S] ferredoxin and serves to explain a large body of biochemical studies in terms of a three-dimensional structure. The structure suggests how a change in the redox state of the [2Fe–2S] cluster may be coupled to a domain motion of the protein. It seems likely that the clearly asymmetric charge distribution on the surface of Adx(4–108) and the resulting strong molecular dipole are involved in electrostatic steering of the interactions with AR and cytochrome P450
The extracellular N-terminal domain of G-protein coupled receptor 83 regulates signaling properties and is an intramolecular inverse agonist
Background
Recently, the orphan G-protein coupled receptor 83 (GPR83) was identified as a new participant in body weight regulation. This receptor is highly expressed in the hypothalamic arcuate nucleus and is regulated in response to nutrient availability. Gpr83 knock-out mice are protected from diet-induced obesity. Moreover, in a previous study, we designed and characterized several artificial constitutively activating mutations (CAMs) in GPR83. A particular CAM was located in the extracellular N-terminal domain (eNDo) that is highly conserved among GPR83 orthologs. This suggests the contribution of this receptor part into regulation of signaling, which needed a more detailed investigation.
Findings
In this present study, therefore, we further explored the role of the eNDo in regulating GPR83-signaling and demonstrate a proof-of-principle approach in that deletion mutants are characterized by a strong increase in basal Gq/11-mediated signaling, whilst none of the additionally characterized signaling pathways (Gs, Gi, G12/13) were activated by the N-terminal deletion variants. Of note, we detected basal GPR83 MAPK-activity of the wild type receptor, which was not increased in the deletion variants.
Conclusions
Finally, the extracellular portion of GPR83 has a strong regulatory function on this receptor. A suppressive - inverse agonistic - effect of the eNDo on GPR83 signaling activity is demonstrated here, which also suggests a putative link between extracellular receptor activation and proteolytic cleavage. These new insights highlight important aspects of GPR83-regulation and might open options in the development of tools to modulate GPR83-signaling
Accelerated stem cell labeling with ferucarbotran and protamine
To develop and characterize a clinically applicable, fast and efficient method for stem cell labeling with ferucarbotran and protamine for depiction with clinical MRI.
The hydrodynamic diameter, zeta potential and relaxivities of ferucarbotran and varying concentrations of protamine were measured. Once the optimized ratio was found, human mesenchymal stem cells (MSCs) were labeled at varying incubation times (1–24 h). Viability was assessed via Trypan blue exclusion testing. 150,000 labeled cells in Ficoll solution were imaged with T1-, T2- and T2*-weighted sequences at 3 T, and relaxation rates were calculated.
Varying the concentrations of protamine allows for easy modification of the physicochemical properties. Simple incubation with ferucarbotran alone resulted in efficient labeling after 24 h of incubation while assisted labeling with protamine resulted in similar results after only 1 h. Cell viability remained unaffected. R2 and R2* relaxation rates were drastically increased. Electron microscopy confirmed intracellular iron oxide uptake in lysosomes. Relaxation times correlated with results from ICP-AES.
Our results show internalization of ferucarbotran can be accelerated in MSCs with protamine, an approved heparin antagonist and potentially clinically applicable uptake-enhancing agent
Identification of Hepatic Niche Harboring Human Acute Lymphoblastic Leukemic Cells via the SDF-1/CXCR4 Axis
In acute lymphoblastic leukemia (ALL) patients, the bone marrow niche is widely known to be an important element of treatment response and relapse. Furthermore, a characteristic liver pathology observed in ALL patients implies that the hepatic microenvironment provides an extramedullary niche for leukemic cells. However, it remains unclear whether the liver actually provides a specific niche. The mechanism underlying this pathology is also poorly understood. Here, to answer these questions, we reconstituted the histopathology of leukemic liver by using patients-derived primary ALL cells into NOD/SCID/Yc null mice. The liver pathology in this model was similar to that observed in the patients. By using this model, we clearly demonstrated that bile duct epithelial cells form a hepatic niche that supports infiltration and proliferation of ALL cells in the liver. Furthermore, we showed that functions of the niche are maintained by the SDF-1/CXCR4 axis, proposing a novel therapeutic approach targeting the extramedullary niche by inhibition of the SDF-1/CXCR4 axis. In conclusion, we demonstrated that the liver dissemination of leukemia is not due to nonselective infiltration, but rather systematic invasion and proliferation of leukemic cells in hepatic niche. Although the contribution of SDF-1/CXCR4 axis is reported in some cancer cells or leukemic niches such as bone marrow, we demonstrated that this axis works even in the extramedullary niche of leukemic cells. Our findings form the basis for therapeutic approaches that target the extramedullary niche by inhibiting the SDF-1/CXCR4 axis
Sulindac Sulfide Reverses Aberrant Self-Renewal of Progenitor Cells Induced by the AML-Associated Fusion Proteins PML/RARα and PLZF/RARα
Chromosomal translocations can lead to the formation of chimeric genes encoding fusion proteins such as PML/RARα, PLZF/RARα, and AML-1/ETO, which are able to induce and maintain acute myeloid leukemia (AML). One key mechanism in leukemogenesis is increased self renewal of leukemic stem cells via aberrant activation of the Wnt signaling pathway. Either X-RAR, PML/RARα and PLZF/RARα or AML-1/ETO activate Wnt signaling by upregulating γ-catenin and β-catenin. In a prospective study, a lower risk of leukemia was observed with aspirin use, which is consistent with numerous studies reporting an inverse association of aspirin with other cancers. Furthermore, a reduction in leukemia risk was associated with use of non-steroidal anti-inflammatory drug (NSAID), where the effects on AML risk was FAB subtype-specific. To better investigate whether NSAID treatment is effective, we used Sulindac Sulfide in X-RARα-positive progenitor cell models. Sulindac Sulfide (SSi) is a derivative of Sulindac, a NSAID known to inactivate Wnt signaling. We found that SSi downregulated both β-catenin and γ-catenin in X-RARα-expressing cells and reversed the leukemic phenotype by reducing stem cell capacity and increasing differentiation potential in X-RARα-positive HSCs. The data presented herein show that SSi inhibits the leukemic cell growth as well as hematopoietic progenitors cells (HPCs) expressing PML/RARα, and it indicates that Sulindac is a valid molecular therapeutic approach that should be further validated using in vivo leukemia models and in clinical settings
Purchasing and supply management (PSM) competencies: Current and future requirements
Purchasing & Supply Management (PSM) competencies are the individual-level foundations of organisational PSM performance. In light of recent developments in the workplace and the external environment, the question of what PSM competencies are needed now, as well as in the future, becomes one of increasing importance. Analysing qualitative data from 46 interviews from 16 companies, this paper identifies what current and future competencies are required by PSM professionals, categorizes PSM competencies according to the framework established by Tassabehji and Moorhouse (2008) and establishes how these competency requirements have changed over the last ten years. The most important current competencies required by PSM professionals are negotiation, communication and relationship management (e.g. ‘Interpersonal communication’), strategy and analytics (e.g. ‘Strategic thinking’), as well as professional knowledge requirements (e.g. ‘Basic knowledge on PSM role & processes’). When looking at future requirements, competencies in the areas of sustainability and digitisation were identified as becoming increasingly important. Overall, 17 competencies in addition to those shown in Tassabehji and Moorhouse (2008) were identified. The most prominent new competency areas are related to digitisation (e.g. ‘eProcurement Technology’, ‘Automation’), innovation (e.g. ‘Innovative sourcing’) and sustainability. The interviewees also identified 11 new competencies within the interpersonal skills cluster, most of them at the intersection between competencies and traits (e.g. ‘Deal with Ambiguity’, ‘Curiosity’, ‘Passion’)
Current Wildland Fire Patterns and Challenges in Europe : A Synthesis of National Perspectives
Changes in climate, land use, and land management impact the occurrence and severity of wildland fires in many parts of the world. This is particularly evident in Europe, where ongoing changes in land use have strongly modified fire patterns over the last decades. Although satellite data by the European Forest Fire Information System provide large-scale wildland fire statistics across European countries, there is still a crucial need to collect and summarize in-depth local analysis and understanding of the wildland fire condition and associated challenges across Europe. This article aims to provide a general overview of the current wildland fire patterns and challenges as perceived by national representatives, supplemented by national fire statistics (2009-2018) across Europe. For each of the 31 countries included, we present a perspective authored by scientists or practitioners from each respective country, representing a wide range of disciplines and cultural backgrounds. The authors were selected from members of the COST Action "Fire and the Earth System: Science & Society" funded by the European Commission with the aim to share knowledge and improve communication about wildland fire. Where relevant, a brief overview of key studies, particular wildland fire challenges a country is facing, and an overview of notable recent fire events are also presented. Key perceived challenges included (1) the lack of consistent and detailed records for wildland fire events, within and across countries, (2) an increase in wildland fires that pose a risk to properties and human life due to high population densities and sprawl into forested regions, and (3) the view that, irrespective of changes in management, climate change is likely to increase the frequency and impact of wildland fires in the coming decades. Addressing challenge (1) will not only be valuable in advancing national and pan-European wildland fire management strategies, but also in evaluating perceptions (2) and (3) against more robust quantitative evidence.Peer reviewe
In situ guided tissue regeneration in musculoskeletal diseases and aging: Implementing pathology into tailored tissue engineering strategies
In situ guided tissue regeneration, also addressed as in situ tissue engineering or endogenous regeneration, has a great potential for population-wide “minimal invasive” applications. During the last two decades, tissue engineering has been developed with remarkable in vitro and preclinical success but still the number of applications in clinical routine is extremely small. Moreover, the vision of population-wide applications of ex vivo tissue engineered constructs based on cells, growth and differentiation factors and scaffolds, must probably be deemed unrealistic for economic and regulation-related issues. Hence, the progress made in this respect will be mostly applicable to a fraction of post-traumatic or post-surgery situations such as big tissue defects due to tumor manifestation. Minimally invasive procedures would probably qualify for a broader application and ideally would only require off the shelf standardized products without cells. Such products should mimic the microenvironment of regenerating tissues and make use of the endogenous tissue regeneration capacities. Functionally, the chemotaxis of regenerative cells, their amplification as a transient amplifying pool and their concerted differentiation and remodeling should be addressed. This is especially important because the main target populations for such applications are the elderly and diseased. The quality of regenerative cells is impaired in such organisms and high levels of inhibitors also interfere with regeneration and healing. In metabolic bone diseases like osteoporosis, it is already known that antagonists for inhibitors such as activin and sclerostin enhance bone formation. Implementing such strategies into applications for in situ guided tissue regeneration should greatly enhance the efficacy of tailored procedures in the future
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