3D printing has emerged as a rapid and cost-efficient manufacturing technique to enable the fabrication of bespoke, complex prototypes. If the technology is to have a significant impact in biomedical ...applications, such as drug discovery and molecular diagnostics, the devices produced must be biologically compatible to enable their use with established reference assays and protocols. In this work we demonstrate that we can adapt the Fish Embryo Test (FET) as a new method to quantify the toxicity of 3D printed microfluidic devices. We assessed the biocompatibility of four commercially available 3D printing polymers (VisiJetCrystal EX200, Watershed 11122XC, Fototec SLA 7150 Clear and ABSplus P-430), through the observation of key developmental markers in the developing zebrafish embryos. Results show all of the photopolymers to be highly toxic to the embryos, resulting in fatality, although we do demonstrate that post-printing treatment of Fototec 7150 makes it suitable for zebrafish culture within the FET.
Using a sample of four galaxy clusters at 1.35 < z < 1.65 and 10 galaxy clusters at 0.85 < z < 1.35, we measure the environmental quenching timescale, tQ, corresponding to the time required after a ...galaxy is accreted by a cluster for it to fully cease star formation. Cluster members are selected by a photometric-redshift criterion, and categorized as star-forming, quiescent, or intermediate according to their dust-corrected rest-frame colors and magnitudes. We employ a "delayed-then-rapid" quenching model that relates a simulated cluster mass accretion rate to the observed numbers of each type of galaxy in the cluster to constrain tQ. For galaxies of mass M* 1010.5 M , we find a quenching timescale of tQ = Gyr in the z ∼ 1.5 cluster sample, and Gyr at z ∼ 1. Using values drawn from the literature, we compare the redshift evolution of tQ to timescales predicted for different physical quenching mechanisms. We find tQ to depend on host halo mass such that quenching occurs over faster timescales in clusters relative to groups, suggesting that properties of the host halo are responsible for quenching high-mass galaxies. Between z = 0 and z = 1.5, we find that tQ evolves faster than the molecular gas depletion timescale and slower than an estimated star formation rate-outflow timescale, but is consistent with the evolution of the dynamical time. This suggests that environmental quenching in these galaxies is driven by the motion of satellites relative to the cluster environment, although due to uncertainties in the atomic gas budget at high redshift, we cannot rule out quenching due to simple gas depletion.
Abstract
Subterranean habitats are generally very stable environments, and as such evolutionary transitions of organisms from surface to subterranean lifestyles may cause considerable shifts in ...physiology, particularly with respect to thermal tolerance. In this study we compared responses to heat shock at the molecular level in a geographically widespread, surface-dwelling water beetle to a congeneric subterranean species restricted to a single aquifer (Dytiscidae: Hydroporinae). The obligate subterranean beetle
Paroster macrosturtensis
is known to have a lower thermal tolerance compared to surface lineages (CT
max
38 °C cf. 42–46 °C), but the genetic basis of this physiological difference has not been characterized. We experimentally manipulated the thermal environment of 24 individuals to demonstrate that both species can mount a heat shock response at high temperatures (35 °C), as determined by comparative transcriptomics. However, genes involved in these responses differ between species and a far greater number were differentially expressed in the surface taxon, suggesting it can mount a more robust heat shock response; these data may underpin its higher thermal tolerance compared to subterranean relatives. In contrast, the subterranean species examined not only differentially expressed fewer genes in response to increasing temperatures, but also in the presence of the experimental setup employed here alone. Our results suggest
P. macrosturtensis
may be comparatively poorly equipped to respond to both thermally induced stress and environmental disturbances more broadly. The molecular findings presented here have conservation implications for
P. macrosturtensis
and contribute to a growing narrative concerning weakened thermal tolerances in obligate subterranean organisms at the molecular level.
We present the public release of the stellar mass catalogs for the GOODS-S and UDS fields obtained using some of the deepest near-IR images available, achieved as part of the Cosmic Assembly ...Near-infrared Deep Extragalactic Legacy Survey project. We combine the effort from 10 different teams, who computed the stellar masses using the same photometry and the same redshifts. Each team adopted their preferred fitting code, assumptions, priors, and parameter grid. The combination of results using the same underlying stellar isochrones reduces the systematics associated with the fitting code and other choices. Thanks to the availability of different estimates, we can test the effect of some specific parameters and assumptions on the stellar mass estimate. The choice of the stellar isochrone library turns out to have the largest effect on the galaxy stellar mass estimates, resulting in the largest distributions around the median value (with a semi interquartile range larger than 0.1 dex). On the other hand, for most galaxies, the stellar mass estimates are relatively insensitive to the different parameterizations of the star formation history. The inclusion of nebular emission in the model spectra does not have a significant impact for the majority of galaxies (less than a factor of 2 for ~80% of the sample). Nevertheless, the stellar mass for the subsample of young galaxies (age <100 Myr), especially in particular redshift ranges (e.g., 2.2 < z < 2.4, 3.2 < z < 3.6, and 5.5 < z < 6.5), can be seriously overestimated (by up to a factor of 10 for <20 Myr sources) if nebular contribution is ignored.
Fundamental research questions in subterranean biology Mammola, Stefano; Amorim, Isabel R.; Bichuette, Maria E. ...
Biological reviews of the Cambridge Philosophical Society,
December 2020, Letnik:
95, Številka:
6
Journal Article
Recenzirano
Odprti dostop
ABSTRACT
Five decades ago, a landmark paper in Science titled The Cave Environment heralded caves as ideal natural experimental laboratories in which to develop and address general questions in ...geology, ecology, biogeography, and evolutionary biology. Although the ‘caves as laboratory’ paradigm has since been advocated by subterranean biologists, there are few examples of studies that successfully translated their results into general principles. The contemporary era of big data, modelling tools, and revolutionary advances in genetics and (meta)genomics provides an opportunity to revisit unresolved questions and challenges, as well as examine promising new avenues of research in subterranean biology. Accordingly, we have developed a roadmap to guide future research endeavours in subterranean biology by adapting a well‐established methodology of ‘horizon scanning’ to identify the highest priority research questions across six subject areas. Based on the expert opinion of 30 scientists from around the globe with complementary expertise and of different academic ages, we assembled an initial list of 258 fundamental questions concentrating on macroecology and microbial ecology, adaptation, evolution, and conservation. Subsequently, through online surveys, 130 subterranean biologists with various backgrounds assisted us in reducing our list to 50 top‐priority questions. These research questions are broad in scope and ready to be addressed in the next decade. We believe this exercise will stimulate research towards a deeper understanding of subterranean biology and foster hypothesis‐driven studies likely to resonate broadly from the traditional boundaries of this field.
We have been conducting the Giant Metrewave Radio Telescope High Resolution Southern Sky (GHRSS) survey for the last four years and have discovered 18 pulsars to date. The GHRSS survey is an ...off-Galactic-plane survey at 322 MHz in a region of the sky (decl. range −40° to −54°) complementary to other ongoing low-frequency surveys. In this paper we report the discovery of three pulsars (PSRs), J1239−48, J1516−43, and J1726−52. We also present timing solutions for three pulsars previously discovered with the GHRSS survey: PSR J2144−5237, a millisecond pulsar with a period P = 5 ms in a 10 days orbit around a ≤0.18 M companion; PSR J1516−43, a mildly recycled P = 36 ms pulsar in a 228 days orbit with a companion of mass ∼0.4 M ; and the P = 320 ms PSR J0514−4408, which we show is a source of pulsed γ-ray emission. We also report radio polarimetric observations of three of the GHRSS discoveries, PSRs J0418−4154, J0514−4408, and J2144−5237.
Aims/hypothesis
Enhanced vascular inflammation, immune cell infiltration and elevated production of reactive oxygen species (ROS) contribute significantly to pro-atherogenic responses in diabetes. We ...assessed the immunomodulatory role of NADPH oxidase (NOX)-derived ROS in diabetes-accelerated atherosclerosis.
Methods
Diabetes was induced in male
Apoe
−/−
mice with five daily doses of streptozotocin (55 mg kg
−1
day
−1
). Atherosclerotic plaque size, markers of ROS and immune cell accumulation were assessed in addition to flow cytometric analyses of cells isolated from the adjacent mediastinal lymph nodes (meLNs). The role of NOX-derived ROS was investigated using the NOX inhibitor, GKT137831 (60 mg/kg per day; gavage) administered to diabetic and non-diabetic
Apoe
−/−
mice for 10 weeks.
Results
Diabetes increased atherosclerotic plaque development in the aortic sinus and this correlated with increased lesional accumulation of T cells and CD11c
+
cells and altered T cell activation in the adjacent meLNs. Diabetic
Apoe
−/−
mice demonstrated an elevation in vascular ROS production and expression of the proinflammatory markers monocyte chemoattractant protein 1, vascular adhesion molecule 1 and IFNγ. Blockade of NOX-derived ROS using GKT137831 prevented the diabetes-mediated increase in atherosclerotic plaque area and associated vascular T cell infiltration and also significantly reduced vascular ROS as well as markers of inflammation and plaque necrotic core area.
Conclusions/interpretation
Diabetes promotes pro-inflammatory immune responses in the aortic sinus and its associated lymphoid tissue. These changes are associated with increased ROS production by NOX. Blockade of NOX-derived ROS using the NOX inhibitor GKT137831 is associated with attenuation of these changes in the immune response and reduces the diabetes-accelerated development of atherosclerotic plaques in
Apoe
−/−
mice.
Spin-Dependent WIMP Limits from a Bubble Chamber Behnke, E; Collar, J.I; Cooper, P.S ...
Science (American Association for the Advancement of Science),
02/2008, Letnik:
319, Številka:
5865
Journal Article
Recenzirano
Odprti dostop
Bubble chambers were the dominant technology used for particle detection in accelerator experiments for several decades, eventually falling into disuse with the advent of other techniques. We report ...here on a new application for these devices. We operated an ultraclean, room-temperature bubble chamber containing 1.5 kilograms of superheated CF₃I, a target maximally sensitive to spin-dependent and -independent weakly interacting massive particle (WIMP) couplings. An extreme intrinsic insensitivity to the backgrounds that commonly limit direct searches for dark matter was measured in this device under operating conditions leading to the detection of low-energy nuclear recoils like those expected from WIMPs. Improved limits on the spin-dependent WIMP-proton scattering cross section were extracted during our experiments, excluding this type of coupling as a possible explanation for a recent claim of particle dark-matter detection.
The aim of this study was to determine the stability and purity of a phage cocktail to be delivered by nebulization. A cocktail of three phages active against Pseudomonas aeruginosa isolates from ...cystic fibrosis patients was developed for a potential nebulized formulation. The individual phages were examined for their retention of activity over time, while the phage cocktail was analysed for bacterial contaminant and endotoxin level according to regulatory requirements for nebulized products. The phage cocktail was nebulized using a Porta‐neb nebulizer connected to an Anderson cascade impactor. The three phages retained activity over a period of 180 days storage at room temperature and at 4°C. Nebulized phages were recovered in the lower stages of the cascade impactor indicative of potential delivery deep into the lungs. The phage cocktail met bacterial limits but the endotoxin levels measured with the Limulus amoebocyte lysate (LAL) test remained considerably in excess of acceptable levels even following purification. These findings suggest that nebulization of phage is a viable delivery option; although, there is a need for appropriate depyrogenation strategies to remove bacterial endotoxins from phage‐based preparations to meet regulatory requirements. SIGNIFICANCE AND IMPACT OF THE STUDY: With increasing reports of bacterial resistance to antibiotics and the lack of new antibiotics being produced, bacteriophage therapy is becoming an attractive alternative. There has been no published report on the quality assurance of bacteriophage product to date. This is the first study on the quality assurance of a Pseudomonas aeruginosa phage cocktail following pharmacopoeial requirements. The presence of bacterial endotoxin was found to be the key stumbling block for meeting regulatory criteria.
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