58 research outputs found

    The behaviour of dark matter associated with 4 bright cluster galaxies in the 10kpc core of Abell 3827

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    Galaxy cluster Abell 3827 hosts the stellar remnants of four almost equally bright elliptical galaxies within a core of radius 10kpc. Such corrugation of the stellar distribution is very rare, and suggests recent formation by several simultaneous mergers. We map the distribution of associated dark matter, using new Hubble Space Telescope imaging and VLT/MUSE integral field spectroscopy of a gravitationally lensed system threaded through the cluster core. We find that each of the central galaxies retains a dark matter halo, but that (at least) one of these is spatially offset from its stars. The best-constrained offset is 1.62+/-0.48kpc, where the 68% confidence limit includes both statistical error and systematic biases in mass modelling. Such offsets are not seen in field galaxies, but are predicted during the long infall to a cluster, if dark matter self-interactions generate an extra drag force. With such a small physical separation, it is difficult to definitively rule out astrophysical effects operating exclusively in dense cluster core environments - but if interpreted solely as evidence for self-interacting dark matter, this offset implies a cross-section sigma/m=(1.7+/-0.7)x10^{-4}cm^2/g x (t/10^9yrs)^{-2}, where t is the infall duration.Comment: 15 pages, 9 figure

    The behaviour of dark matter associated with four bright cluster galaxies in the 10kpc core of Abell 3827

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    Galaxy cluster Abell 3827 hosts the stellar remnants of four almost equally bright elliptical galaxies within a core of radius 10kpc. Such corrugation of the stellar distribution is very rare, and suggests recent formation by several simultaneous mergers. We map the distribution of associated dark matter, using new Hubble Space Telescope imaging andVery Large Telescope/Multi-Unit Spectroscopic Explorer integral field spectroscopy of a gravitationally lensed system threaded through the cluster core. We find that each of the central galaxies retains a dark matter halo, but that (at least) one of these is spatially offset from its stars. The best-constrained offset is 1.620.49+0.471.62^{+0.47}_{-0.49}kpc, where the 68 per cent confidence limit includes both statistical error and systematic biases in mass modelling. Such offsets are not seen in field galaxies, but are predicted during the long infall to a cluster, if dark matter self-interactions generate an extra drag force. With such a small physical separation, it is difficult to definitively rule out astrophysical effects operating exclusively in dense cluster core environments - but if interpreted solely as evidence for self-interacting dark matter, this offset implies a cross-section σDM/m∼(1.7±0.7)×10−4cm2g−1×(tinfall/109 yr)−2, where tinfall is the infall duratio

    Development and functionality analysis of lipoplex-loaded polysaccharide-based surface coatings for local nucleic acid delivery

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    Although therapeutic nucleic acids reached the clinical application for a decade, the success of these new drugs is dependent on their delivery strategies, which are still a challenge. In particular, local delivery of nucleic acids is a promising approach to develop therapies with a spatially controlled site of action. However, compared to techniques for systemic administration, local nucleic acid delivery systems are still rarely described. In this study, we present a promising approach to fill this gap by the design of surface coatings based on polysaccharides for local delivery of nucleic acids. An automatized Layer-by-Layer deposition approach was applied using hyaluronic acid and chitosan to form polyelectrolyte multilayer systems, into which lipid nanoparticles, more specific lipoplexes, were embedded as nucleic acid carriers. Different manufacturing parameters, in particular the number of deposited polyelectrolyte layers and the preparation buffer, were varied. The multilayer film characteristics were investigated systematically regarding their physical properties, with a focus on thickness and topology as well as lipoplex deposition, to identify a system with efficient transfection properties. The multilayer systems prepared in acetate buffer were characterized by a good lipoplex embedding with a more uniform distribution and lower tendency for formation of large lipoplex aggregates in the polyelectrolyte film. Additionally, we were able to demonstrate the functionality of the developed system for nucleic acid delivery. The nucleic acids were successfully transferred into cells in a contact-triggered manner. Furthermore, we could demonstrate the enzymatic degradation-based release of nucleic acid cargo from the delivery system caused by hyaluronidase, followed by successful in vitro transfection

    Outcomes of a new slowly resorbable biosynthetic mesh (Phasix (TM)) in potentially contaminated incisional hernias : a prospective, multi-center, single-arm trial

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    Background: Resorbable biomaterials have been developed to reduce the amount of foreign material remaining in the body after hernia repair over the long-term. However, on the short-term, these resorbable materials should render acceptable results with regard to complications, infections, and reoperations to be considered for repair. Additionally, the rate of resorption should not be any faster than collagen deposition and maturation; leading to early hernia recurrence. Therefore, the objective of this study was to collect data on the short-term performance of a new resorbable biosynthetic mesh (Phasix (TM)) in patients requiring Ventral Hernia Working Group (VHWG) Grade 3 midline incisional hernia repair. Materials and methods: A prospective, multi-center, single-arm trial was conducted at surgical departments in 15 hospitals across Europe. Patients aged >= 18, scheduled to undergo elective Ventral Hernia Working Group Grade 3 hernia repair of a hernia larger than 10 cm(2) were included. Hernia repair was performed with Phasix (TM) Mesh in sublay position when achievable. The primary outcome was the rate of surgical site occurrence (SSO), including infections, that required intervention until 3 months after repair. Results: In total, 84 patients were treated with Phasix (TM) Mesh. Twenty-two patients (26.2%) developed 32 surgical site occurrences. These included 11 surgical site infections, 9 wound dehiscences, 7 seromas, 2 hematomas, 2 skin necroses, and 1 fistula. No significant differences in surgical site occurrence development were found between groups repaired with or without component separation technique, and between clean-contaminated or contaminated wound sites. At three months, there were no hernia recurrences. Conclusion: Phasix (TM) Mesh demonstrated acceptable postoperative surgical site occurrence rates in patients with a Ventral Hernia Working Group Grade 3 hernia. Longer follow-up is needed to evaluate the recurrence rate and the effects on quality of life. This study is ongoing through 24 months of follow-up

    A post-market, prospective, multi-center, single-arm clinical investigation of Phasix™ mesh for VHWG grade 3 midline incisional hernia repair

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    BACKGROUND: Incisional heia is a frequent complication of midline laparotomy. The use of mesh in hernia repair has been reported to lead to fewer recurrences compared to primary repair. However, in Ventral Hernia Working Group (VHWG) Grade 3 hernia patients, whose hernia is potentially contaminated, synthetic mesh is prone to infection. There is a strong preference for resorbable biological mesh in contaminated fields, since it is more able to resist infection, and because it is fully resorbed, the chance of a foreign body reaction is reduced. However, when not crosslinked, biological resorbable mesh products tend to degrade too quickly to facilitate native cellular ingrowth. Phasix™ Mesh is a biosynthetic mesh with both the biocompatibility and resorbability of a biological mesh and the mechanical strength of a synthetic mesh. This multi-center single-arm study aims to collect data on safety and performance of Phasix™ Mesh in Grade 3 hernia patients. METHODS: A total of 85 VHWG Grade 3 hernia patients will be treated with Phasix™ Mesh in 15 sites across Europe. The primary outcome is Surgical Site Occurrence (SSO) including hematoma, seroma, infection, dehiscence and fistula formation (requiring intervention) through 3 months. Secondary outcomes include recurrence, infection and quality of life related outcomes after 24 months. Follow-up visits will be at drain removal (if drains were not placed, then on discharge or staple removal instead) and in the 1st, 3rd, 6th, 12th, 18th and 24th month after surgery. CONCLUSION: Based on evidence from this clinical study Depending on the results this clinical study will yield, Phasix™ Mesh may become a preferred treatment option in VHWG Grade 3 patients. TRIAL REGISTRATION: The trial was registered on March 25, 2016 on clinicaltrials.gov: NCT02720042

    Globally invariant metabolism but density-diversity mismatch in springtails

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    DATA AVAILABILITY : The data that support the findings of this study have been deposited in the Figshare database64 under CC-BY 4.0 license and accession code: https://doi.org/10.6084/m9.figshare.16850419; high-resolutionmaps85 can be accessed at https://doi.org/10.6084/m9.figshare. 16850446. Source data are provided with this paper.CODE AVAILABILITY : Programming code for the path analysis and the geospatial modelling is available under CC-BY 4.0 from Figshare64: https://doi.org/10.6084/ m9.figshare.16850419.Soil life supports the functioning and biodiversity of terrestrial ecosystems. Springtails (Collembola) are among the most abundant soil arthropods regulating soil fertility and flow of energy through above- and belowground food webs. However, the global distribution of springtail diversity and density, and how these relate to energy fluxes remains unknown. Here, using a global dataset representing 2470 sites, we estimate the total soil springtail biomass at 27.5 megatons carbon, which is threefold higher than wild terrestrial vertebrates, and record peak densities up to 2 million individuals per square meter in the tundra.Despite a 20-fold biomass difference between the tundra and the tropics, springtail energy use (community metabolism) remains similar across the latitudinal gradient, owing to the changes in temperature with latitude. Neither springtail density nor community metabolism is predicted by local species richness, which is high in the tropics, but comparably high in some temperate forests and even tundra. Changes in springtail activity may emerge from latitudinal gradients in temperature, predation and resource limitation in soil communities. Contrasting relationships of biomass, diversity and activity of springtail communities with temperature suggest that climate warming will alter fundamental soil biodiversity metrics in different directions, potentially restructuring terrestrial food webs and affecting soil functioning.FUNDING : Open Access funding enabled and organized by Projekt DEAL.The article is an outcome of the #GlobalCollembola community initiative that is voluntarily supported by researchers around the world. Data collection and analysis was supported by the Russian Science Foundation and by Deutsche Forschungsgemeinschaft. We acknowledge support by the Open Access Publication Funds of the Göttingen University. The following funding bodies provided support for individual contributors: ARC SRIEAS Securing Antarctica’s Environmental Future., Slovak Scientific Grant Agency, RFBR 19-516- 60002 to N.A.K., Carl Tryggers Stiftelse för Vetenskaplig Forskning and Qatar Petroleum to J.M.A., BIO 27 (2013-2014)-MAGyP and PICTO 2084 (2012)-ANPCyT to V.B., DAAD-19-10 and MSM200962001 to T.C., grant TE, PN-III-P1-1.1-TE-2019-0358 to C.F., NWO grant 821.01.015 to O.F., National Natural Sciences Foundation of China No 41471037 and 41871042 to M.G., BIO 27 (2013-2014), MAGyP; PICT 2084 (2012), FONCyT to D.F.G., NRF South African National Antarctic Programme grant 110734 to M.G., Natural Resources Canada (NRCan), EcoEnergy Innovation Initiative under the Office of Energy Research and Development, and the Natural Sciences and Engineering Research Council of Canada (NSERC) to I.T.H., L.A.V. and L.R., Independent Research Fund Denmark grant no. DFF-4002-00384 to M.H., Estonian Science Foundation G9145 to M.I., SA-France bilateral grant to C.J., SA (NRF)/Russia (RFBR) Joint Science and Technology Research Collaboration project no. 19-516-60002 (FRBR) and no. 118904 (NRF) to M.P. and C.J., European Research Council (ERC), European Union’s Horizon 2020 research and innovation programme (grant agreement no. 677232; to N.E.); iDiv, German Research Foundation (DFG–FZT 118, 202548816) to M.J. and N.E., French National Agency of Research (ANR) (JASSUR research project; ANR-12-VBDU- 0011), «Ministère de l’Agriculture et de la Pêche» and «Ministère de l’Education Nationale de la Recherche et de la Technologie» (ACTA programme), «Ministère de l’Aménagement du Territoire et de l’Environnement » (Pnetox programme), EU-funded project, ECOGEN QLK5-CT-2002-01666 (www.ecogen.dk), “Agence de l’Environnement et de la Maîtrise de l'Énergie” (BIOINDICATEUR 2, BIOTECHNOSOL), ANDRA and GISFI (www.gisfi.fr) to S.J., GRR SERBIODIV (Région Normandie, France) to MCha, ESF9258, B02 to A.K., Fundamental Research Funds for the Central Universities (grant no. 2018CDXYCH0014) to D.L., DFG 316045089 to J.L., Massey University Research Fund grant to M.A.M., DFG SCHE 376/38-2 to M.M.P., grant fromthe Austria Academy of Science: Heritage_2020-043_Modeling- Museum to P.Q., Slovak Scientific Grant Agency: VEGA Nos. 1/0441/ 03 and 1/3267/06 to N.R., Higher Education Commission of Pakistan to M.I.R., RSF 21-74-00126 to R.A.S., Austrian Federal Government and European Union (Rural Development 2014-2020) to J.S., АААА- А17-122040600025-2 to A.A.T., Brazilian Council for Scientific and Technological Development—CNPq (grant no. 152717/2016-1) to B.R.W., 309030/2018-8 to D.Z. and 305426/2018-4 to B.C.B., National Natural Science Foundation of China (31970434, 31772491) to N.N.G., Research and Innovation Support Foundation of Santa Catarina (FAPESC) (6.309/2011-6/FAPESC) and the CNPq (563251/2010-7/ CNPq) to L.C.I.O.F., O.K.-F., the Latvian Council of Science Grants no. 90.108, 93.140, 96.0110, 01.0344 to E.J., CNPq for the Research Productivity Grant (305939/2018-1) to D.B., FPI-MICINN grant in the project INTERCAPA (CGL2014-56739-R) to P.H, the Natural Sciences and Engineering Research Council of Canada (NSERC) to Z.L., Ministry of Innovation and Technology of Hungary TKP2021-NKTA-43 to D.W.https://www.nature.com/ncomms/am2024Plant Production and Soil ScienceSDG-13:Climate actionSDG-15:Life on lan

    Privatización de los derechos de propiedad y disolución del ejido. Redes privadas y organización comunitaria en el noroeste del estado de Tlaxcala, México, 1940-2018

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    El presente artículo propone analizar las recomposiciones que han afectado las estructuras de propiedad dentro de una comunidad ejidal del altiplano central mexicano, a partir de las reformas de 1992 a la Ley agraria y los cambios estructurales inducidos por el Tratado de Libre Comercio con Estados Unidos y Canadá. Examina en particular las incidencias de la apertura del mercado de tierras ejidales y de la posibilidad de adoptar el régimen de propiedad privada. Estas dinámicas son analizadas en referencia a los procesos históricos de compenetración entre agricultura campesina y agricultura empresarial, diversificación económica de los hogares rurales y cambio generacional, y permiten aproximarse a los procesos de disolución de una institución que fue pilar del régimen de regulación agraria y política en el México rural durante el siglo XX.</jats:p
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