44 research outputs found
Low Molecular Weight Nucleoside Gelators: A Platform for Protein Aggregation Inhibition
© Copyright 2018 American Chemical Society. Low molecular weight nucleoside gelators hold great promise in drug delivery and particularly for the delivery of biologics because of their excellent biocompatibility. However, the influence of these gelators on protein aggregation inhibition has not yet been studied. Protein aggregation is the most significant cause of protein instability and can severely impact the biological activity of the protein, impairing the quality and safety of the formulation. Herein, we report the ability of a nucleoside-based gelator, N4-octanoyl-2âČ-deoxycytidine, to inhibit protein aggregation. Using turbidimetric, spectroscopic, and microscopic methods, we demonstrate that protein aggregation inhibition is dependent on gelator concentration. Moreover, we have found that the protein is still functionally active in the hydrogel
Local and landscape responses of biodiversity in calcareous grasslands
Across Europe, calcareous grasslands become increasingly fragmented and their quality deteriorates through abandonment and land use intensification, both affecting biodiversity. Here, we investigated local and landscape effects on diversity patterns of several taxonomic groups in a landscape of highly fragmented calcareous grassland remnants. We surveyed 31 grassland fragments near Göttingen, Germany, in spring and summer 2017 for vascular plants, butterflies and birds, with sampling effort adapted to fragment area. Through regression modelling, we tested relationships between species richness and fragment size (from 314 to 51,395 m2), successional stage, habitat connectivity and the per cent cover of arable land in the landscape at several radii. We detected 283 plant species, 53 butterfly species and 70 bird species. Of these, 59 plant species, 19 butterfly species and 9 bird species were grassland specialists. Larger fragments supported twice the species richness of plants than small ones, and hosted more species of butterflies, but not of birds. Larger grassland fragments contained more grassland specialist plants, but not butterfly or bird specialists. Increasing amounts of arable land in the landscape from 20 to 90% was related to the loss of a third of species of plants, and less so, of butterflies, but not of birds. Per cent cover of arable land negatively correlated to richness of grassland specialist plants and butterflies, but positively to grassland specialist birds. We found no effect by successional stages and habitat connectivity. Our multi-taxa approach highlights the need for conservation management at the local scale, complemented by measures at the landscape scale.</p
The Contribution of Halos with Different Mass Ratios to the Overall Growth of Cluster-Sized Halos
We provide a new observational test for a key prediction of the \Lambda CDM
cosmological model: the contributions of mergers with different
halo-to-main-cluster mass ratios to cluster-sized halo growth. We perform this
test by dynamically analyzing seven galaxy clusters, spanning the redshift
range and caustic mass range M, with an average of 293 spectroscopically-confirmed
bound galaxies to each cluster. The large radial coverage (a few virial radii),
which covers the whole infall region, with a high number of spectroscopically
identified galaxies enables this new study. For each cluster, we identify bound
galaxies. Out of these galaxies, we identify infalling and accreted halos and
estimate their masses and their dynamical states. Using the estimated masses,
we derive the contribution of different mass ratios to cluster-sized halo
growth. For mass ratios between ~0.2 and ~0.7, we find a ~1 agreement
with \Lambda CDM expectations based on the Millennium simulations I and II. At
low mass ratios, , our derived contribution is underestimated
since the detection efficiency decreases at low masses,
M. At large mass ratios, , we do not
detect halos probably because our sample, which was chosen to be quite X-ray
relaxed, is biased against large mass ratios. Therefore, at large mass ratios,
the derived contribution is also underestimated.Comment: 25 pages, 16 figures, 6 tables, 2 machine readable tables, accepted
for publication in ApJ, updated acknowledgements and data table format
modifications mad
CLASH: Mass Distribution in and around MACS J1206.2-0847 from a Full Cluster Lensing Analysis
We derive an accurate mass distribution of the galaxy cluster MACS
J1206.2-0847 (z=0.439) from a combined weak-lensing distortion, magnification,
and strong-lensing analysis of wide-field Subaru BVRIz' imaging and our recent
16-band Hubble Space Telescope observations taken as part of the Cluster
Lensing And Supernova survey with Hubble (CLASH) program. We find good
agreement in the regions of overlap between several weak and strong lensing
mass reconstructions using a wide variety of modeling methods, ensuring
consistency. The Subaru data reveal the presence of a surrounding large scale
structure with the major axis running approximately north-west south-east
(NW-SE), aligned with the cluster and its brightest galaxy shapes, showing
elongation with a \sim 2:1 axis ratio in the plane of the sky. Our full-lensing
mass profile exhibits a shallow profile slope dln\Sigma/dlnR\sim -1 at cluster
outskirts (R>1Mpc/h), whereas the mass distribution excluding the NW-SE excess
regions steepens further out, well described by the Navarro-Frenk-White form.
Assuming a spherical halo, we obtain a virial mass M_{vir}=(1.1\pm 0.2\pm
0.1)\times 10^{15} M_{sun}/h and a halo concentration c_{vir} = 6.9\pm 1.0\pm
1.2 (\sim 5.7 when the central 50kpc/h is excluded), which falls in the range
4 <7 of average c(M,z) predictions for relaxed clusters from recent Lambda
cold dark matter simulations. Our full lensing results are found to be in
agreement with X-ray mass measurements where the data overlap, and when
combined with Chandra gas mass measurements, yield a cumulative gas mass
fraction of 13.7^{+4.5}_{-3.0}% at 0.7Mpc/h (\approx 1.7r_{2500}), a typical
value observed for high mass clusters.Comment: Accepted by ApJ (30 pages, 17 figures), one new figure (Figure 10)
added, minor text changes; a version with high resolution figures available
at http://www.asiaa.sinica.edu.tw/~keiichi/upfiles/MACS1206/ms_highreso.pd
CLASH: Precise New Constraints on the Mass Profile of Abell 2261
We precisely constrain the inner mass profile of Abell 2261 (z=0.225) for the
first time and determine this cluster is not "over-concentrated" as found
previously, implying a formation time in agreement with {\Lambda}CDM
expectations. These results are based on strong lensing analyses of new 16-band
HST imaging obtained as part of the Cluster Lensing and Supernova survey with
Hubble (CLASH). Combining this with revised weak lensing analyses of Subaru
wide field imaging with 5-band Subaru + KPNO photometry, we place tight new
constraints on the halo virial mass M_vir = 2.2\pm0.2\times10^15 M\odot/h70
(within r \approx 3 Mpc/h70) and concentration c = 6.2 \pm 0.3 when assuming a
spherical halo. This agrees broadly with average c(M,z) predictions from recent
{\Lambda}CDM simulations which span 5 <~ 8. Our most significant
systematic uncertainty is halo elongation along the line of sight. To estimate
this, we also derive a mass profile based on archival Chandra X-ray
observations and find it to be ~35% lower than our lensing-derived profile at
r2500 ~ 600 kpc. Agreement can be achieved by a halo elongated with a ~2:1 axis
ratio along our line of sight. For this elongated halo model, we find M_vir =
1.7\pm0.2\times10^15 M\odot/h70 and c_vir = 4.6\pm0.2, placing rough lower
limits on these values. The need for halo elongation can be partially obviated
by non-thermal pressure support and, perhaps entirely, by systematic errors in
the X-ray mass measurements. We estimate the effect of background structures
based on MMT/Hectospec spectroscopic redshifts and find these tend to lower
Mvir further by ~7% and increase cvir by ~5%.Comment: Submitted to the Astrophysical Journal. 19 pages, 14 figure
Metabolic biomarkers assessed with PET/CT predict sex-specific longitudinal outcomes in patients with diffuse large B-cell lymphoma
In many cancers, including lymphoma, males have higher incidence and mortality than females. Emerging evidence demonstrates that one mechanism underlying this phenomenon is sex differences in metabolism, both with respect to tumor nutrient consumption and systemic alterations in metabolism, i.e., obesity. We wanted to determine if visceral fat and tumor glucose uptake with fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) could predict sex-dependent outcomes in patients with diffuse large B-cell lymphoma (DLBCL). We conducted a retrospective analysis of 160 patients (84 males; 76 females) with DLBCL who had imaging at initial staging and after completion of therapy. CT-based relative visceral fat area (rVFA), PET-based SUVmax normalized to lean body mass (SULmax), and end-of-treatment FDG-PET 5PS score were calculated. Increased rVFA at initial staging was an independent predictor of poor OS only in females. At the end of therapy, increase in visceral fat was a significant predictor of poor survival only in females. Combining the change in rVFA and 5PS scores identified a subgroup of females with visceral fat gain and high 5PS with exceptionally poor outcomes. These data suggest that visceral fat and tumor FDG uptake can predict outcomes in DLBCL patients in a sex-specific fashion
CLASH: Complete Lensing Analysis of the Largest Cosmic Lens MACS J0717.5+3745 and Surrounding Structures
The galaxy cluster MACS J0717.5+3745 (z=0.55) is the largest known cosmic
lens, with complex internal structures seen in deep X-ray, Sunyaev-Zel'dovich
effect and dynamical observations. We perform a combined weak and strong
lensing analysis with wide-field BVRi'z' Subaru/Suprime-Cam observations and
16-band Hubble Space Telescope observations taken as part of the Cluster
Lensing And Supernova survey with Hubble (CLASH). We find consistent weak
distortion and magnification measurements of background galaxies, and combine
these signals to construct an optimally estimated radial mass profile of the
cluster and its surrounding large-scale structure out to 5 Mpc/h. We find
consistency between strong-lensing and weak-lensing in the region where these
independent data overlap, <500 kpc/h. The two-dimensional weak-lensing map
reveals a clear filamentary structure traced by distinct mass halos. We model
the lensing shear field with 9 halos, including the main cluster, corresponding
to mass peaks detected above 2.5\sigma_\kappa. The total mass of the cluster as
determined by the different methods is M_{vir}=(2.8\pm0.4) \times 10^15 M_sun.
Although this is the most massive cluster known at z>0.5, in terms of extreme
value statistics we conclude that the mass of MACS J0717.5+3745 by itself is
not in serious tension with LambdaCDM, representing only a ~2{\sigma} departure
above the maximum simulated halo mass at this redshift.Comment: 24 pages, 16 pages, 6 tables; matches version accepted for
publication in Ap
BIOFRAG: A new database for analysing BIOdiversity responses to forest FRAGmentation
Habitat fragmentation studies are producing inconsistent and complex results across which it is nearly impossible to synthesise. Consistent analytical techniques can be applied to primary datasets, if stored in a flexible database that allows simple data retrieval for subsequent analyses. Method: We developed a relational database linking data collected in the field to taxonomic nomenclature, spatial and temporal plot attributes and further environmental variables (e.g. information on biogeographic region. Typical field assessments include measures of biological variables (e.g. presence, abundance, ground cover) of one species or a set of species linked to a set of plots in fragments of a forested landscape. Conclusion: The database currently holds records of 5792 unique species sampled in 52 landscapes in six of eight biogeographic regions: mammals 173, birds 1101, herpetofauna 284, insects 2317, other arthropods: 48, plants 1804, snails 65. Most species are found in one or two landscapes, but some are found in four. Using the huge amount of primary data on biodiversity response to fragmentation becomes increasingly important as anthropogenic pressures from high population growth and land demands are increasing. This database can be queried to extract data for subsequent analyses of the biological response to forest fragmentation with new metrics that can integrate across the components of fragmented landscapes. Meta-analyses of findings based on consistent methods and metrics will be able to generalise over studies allowing inter-comparisons for unified answers. The database can thus help researchers in providing findings for analyses of trade-offs between land use benefits and impacts on biodiversity and to track performance of management for biodiversity conservation in human-modified landscapes.Fil: Pfeifer, Marion. Imperial College London; Reino UnidoFil: Lefebvre, Veronique. Imperial College London; Reino UnidoFil: Gardner, Toby A.. Stockholm Environment Institute; SueciaFil: Arroyo RodrĂguez, VĂctor. Universidad Nacional AutĂłnoma de MĂ©xico; MĂ©xicoFil: Baeten, Lander. University of Ghent; BĂ©lgicaFil: Banks Leite, Cristina. Imperial College London; Reino UnidoFil: Barlow, Jos. Lancaster University; Reino UnidoFil: Betts, Matthew G.. State University of Oregon; Estados UnidosFil: Brunet, Joerg. Swedish University of Agricultural Sciences; SueciaFil: Cerezo BlandĂłn, Alexis Mauricio. Universidad de Buenos Aires. Facultad de AgronomĂa. Departamento de MĂ©todos Cuantitativos y Sistemas de InformaciĂłn; ArgentinaFil: Cisneros, Laura M.. University of Connecticut; Estados UnidosFil: Collard, Stuart. Nature Conservation Society of South Australia; AustraliaFil: DÂŽCruze, Neil. The World Society for the Protection of Animals; Reino UnidoFil: Da Silva Motta, Catarina. MinistĂ©rio da CiĂȘncia, Tecnologia, InovaçÔes. Instituto Nacional de Pesquisas da AmazĂŽnia; BrasilFil: Duguay, Stephanie. Carleton University; CanadĂĄFil: Eggermont, Hilde. University of Ghent; BĂ©lgicaFil: Eigenbrod, FĂ©lix. University of Southampton; Reino UnidoFil: Hadley, Adam S.. State University of Oregon; Estados UnidosFil: Hanson, Thor R.. No especifĂca;Fil: Hawes, Joseph E.. University of East Anglia; Reino UnidoFil: Heartsill Scalley, Tamara. United State Department of Agriculture. Forestry Service; Puerto RicoFil: Klingbeil, Brian T.. University of Connecticut; Estados UnidosFil: Kolb, Annette. Universitat Bremen; AlemaniaFil: Kormann, Urs. UniversitĂ€t Göttingen; AlemaniaFil: Kumar, Sunil. State University of Colorado - Fort Collins; Estados UnidosFil: Lachat, Thibault. Swiss Federal Institute for Forest; SuizaFil: Lakeman Fraser, Poppy. Imperial College London; Reino UnidoFil: Lantschner, MarĂa Victoria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca; Argentina. Instituto Nacional de TecnologĂa Agropecuaria. Centro Regional Patagonia Norte. EstaciĂłn Experimental Agropecuaria San Carlos de Bariloche; ArgentinaFil: Laurance, William F.. James Cook University; AustraliaFil: Leal, Inara R.. Universidade Federal de Pernambuco; BrasilFil: Lens, Luc. University of Ghent; BĂ©lgicaFil: Marsh, Charles J.. University of Leeds; Reino UnidoFil: Medina Rangel, Guido F.. Universidad Nacional de Colombia; ColombiaFil: Melles, Stephanie. University of Toronto; CanadĂĄFil: Mezger, Dirk. Field Museum of Natural History; Estados UnidosFil: Oldekop, Johan A.. University of Sheffield; Reino UnidoFil: Overal , Williams L.. Museu Paraense EmĂlio Goeldi. Departamento de Entomologia; BrasilFil: Owen, Charlotte. Imperial College London; Reino UnidoFil: Peres, Carlos A.. University of East Anglia; Reino UnidoFil: Phalan, Ben. University of Southampton; Reino UnidoFil: Pidgeon, Anna Michle. University of Wisconsin; Estados UnidosFil: Pilia, Oriana. Imperial College London; Reino UnidoFil: Possingham, Hugh P.. Imperial College London; Reino Unido. The University Of Queensland; AustraliaFil: Possingham, Max L.. No especifĂca;Fil: Raheem, Dinarzarde C.. Royal Belgian Institute of Natural Sciences; BĂ©lgica. Natural History Museum; Reino UnidoFil: Ribeiro, Danilo B.. Universidade Federal do Mato Grosso do Sul; BrasilFil: Ribeiro Neto, Jose D.. Universidade Federal de Pernambuco; BrasilFil: Robinson, Douglas W.. State University of Oregon; Estados UnidosFil: Robinson, Richard. Manjimup Research Centre; AustraliaFil: Rytwinski, Trina. Carleton University; CanadĂĄFil: Scherber, Christoph. UniversitĂ€t Göttingen; AlemaniaFil: Slade, Eleanor M.. University of Oxford; Reino UnidoFil: Somarriba, Eduardo. Centro AgronĂłmico Tropical de InvestigaciĂłn y Enseñanza; Costa RicaFil: Stouffer, Philip C.. State University of Louisiana; Estados UnidosFil: Struebig, Matthew J.. University of Kent; Reino UnidoFil: Tylianakis, Jason M.. University College London; Estados Unidos. Imperial College London; Reino UnidoFil: Teja, Tscharntke. UniversitĂ€t Göttingen; AlemaniaFil: Tyre, Andrew J.. Universidad de Nebraska - Lincoln; Estados UnidosFil: Urbina Cardona, Jose N.. Pontificia Universidad Javeriana; ColombiaFil: Vasconcelos, Heraldo L.. Universidade Federal de Uberlandia; BrasilFil: Wearn, Oliver. Imperial College London; Reino Unido. The Zoological Society of London; Reino UnidoFil: Wells, Konstans. University of Adelaide; AustraliaFil: Willig, Michael R.. University of Connecticut; Estados UnidosFil: Wood, Eric. University of Wisconsin; Estados UnidosFil: Young, Richard P.. Durrell Wildlife Conservation Trust; Reino UnidoFil: Bradley, Andrew V.. Imperial College London; Reino UnidoFil: Ewers, Robert M.. Imperial College London; Reino Unid
Cluster Lensing And Supernova survey with Hubble (CLASH): An Overview
The Cluster Lensing And Supernova survey with Hubble (CLASH) is a 524-orbit
multi-cycle treasury program to use the gravitational lensing properties of 25
galaxy clusters to accurately constrain their mass distributions. The survey,
described in detail in this paper, will definitively establish the degree of
concentration of dark matter in the cluster cores, a key prediction of CDM. The
CLASH cluster sample is larger and less biased than current samples of
space-based imaging studies of clusters to similar depth, as we have minimized
lensing-based selection that favors systems with overly dense cores.
Specifically, twenty CLASH clusters are solely X-ray selected. The X-ray
selected clusters are massive (kT > 5 keV; 5 - 30 x 10^14 M_solar) and, in most
cases, dynamically relaxed. Five additional clusters are included for their
lensing strength (Einstein radii > 35 arcsec at z_source = 2) to further
quantify the lensing bias on concentration, to yield high resolution dark
matter maps, and to optimize the likelihood of finding highly magnified
high-redshift (z > 7) galaxies. The high magnification, in some cases, provides
angular resolutions unobtainable with any current UVOIR facility and can yield
z > 7 candidates bright enough for spectroscopic follow-up. A total of 16
broadband filters, spanning the near-UV to near-IR, are employed for each
20-orbit campaign on each cluster. These data are used to measure precise
(sigma_phz < 0.02(1+z)) photometric redshifts for dozens of newly discovered
multiply-lensed images per cluster. Observations of each cluster are spread
over 8 epochs to enable a search, primarily in the parallel fields, for Type Ia
supernovae at z > 1 to improve constraints on the time dependence of the dark
energy equation of state and the evolution of such supernovae in an epoch when
the universe is matter dominated.Comment: Accepted for publication in the Astrophysical Journal Supplements, 22
pages, 16 figures. Updated Tables 3,4,8 and figures 6 and 8 to reflect
replacement of Abell 963 with Abell 1423 in CLASH survey. A963 cannot be
observed with WFC3 due to the lack of usable guide star
TRY plant trait database â enhanced coverage and open access
Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of traitâbased plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for âplant growth formâ. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and traitâenvironmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives