Apoptosis of bovine neutrophils following diapedesis through a monolayer of endothelial and mammary epithelial cells.

In a two-chamber system, isolated blood polymorphonuclear neutrophil leukocytes (PMN) were allowed to migrate (5 h, 37 C) in response to bovine complement component C5a across calfskin and rat-tail type I collagen-coated micropore membranes, arterial endothelial, or mammary epithelial cell monolayer on calfskin and rat-tail collagen-coated membranes, respectively. Migration through calfskin collagen-coated membranes resulted in 14.5% +/- 3.4% apoptotic PMN, which was significantly higher than 6.6% +/- 1.2% apoptotic nonmigrated C5a-treated PMN. The addition of an endothelial or epithelial cell monolayer to collagen-coated membranes prevented apoptosis of migrated PMN. After removing the membranes, nonmigrated (untreated and C5a treated) and migrated PMN were incubated for an additional 20 h. At this time point, 69.1% +/- 4.5% and 47% +/- 4.5% of PMN that have migrated through a calfskin-coated membrane and an endothelial monolayer, respectively, were apoptotic, compared with 28.2% +/- 3.0% and 21.1% +/- 4.5% apoptotic untreated and C5a-treated PMN, respectively; 46.9% +/- 4.8% of PMN that have migrated through rat-tail-coated membranes were apoptotic compared with 14.7% +/- 2.3% and 9.3% +/- 1.2% apoptotic untreated and C5a-treated PMN, respectively. Migration across rat-tail collagen-coated membranes with a monolayer of epithelial cells did not affect apoptosis of migrated PMN, even after 20 h of incubation. In conclusion, migration of PMN across collagen-coated membranes (either calfskin or rat-tail collagen) induced an apoptotic response, which was downregulated by a monolayer of endothelial cells and was negated by an epithelial cell monolayer

Drop on a Bent Fibre

Inspired by the huge droplets attached on cypress tree leaf tips after rain, we find that a bent fibre can hold significantly more water in the corner than a horizontally placed fibre (typically up to three times or more). The maximum volume of the liquid that can be trapped is remarkably affected by the bending angle of the fibre and surface tension of the liquid. We experimentally find the optimal included angle ($\sim {36}{^\circ}$) that holds the most water. Analytical and semi-empirical models are developed to explain these counter-intuitive experimental observations and predict the optimal angle. The data and models could be useful for designing microfluidic and fog harvesting devices

ERNST: Demonstrating Advanced Infrared Detection from a 12U CubeSat

The ERNST mission will demonstrate complex infrared detection capabilities using a 12U CubeSat platform. ERNST’s main payload is an advanced cryogenically-cooled infrared imager that implicates demanding requirements in terms of power demand, heat dissipation, and vibration response for a nanosatellite. The optical bench that integrates optics, a filter-wheel for switching between spectral bands, and the detector-cooler system has been additively designed and manufactured, giving it a bionic appearance and combined with a highly efficient radiator. An onboard radiation monitor and a COTS camera complete the mission payloads. The ERNST 12U platform is based on high-performance CubeSat subsystems for avionics, UHF, and X-band communication, attitude control, and power management. The commercial components are made compatible through a backplane solution. In-house developments include a fast DPU and an autonomous de-orbit dragsail. The platform provides 30 Watt (OAP) and \u3e6U payload volume. After comprehensive environmental and functional testing of the Engineering Model, the Flight Model is currently being integrated. Starting operations in February 2023, ERNST will verify early warning concepts and technology

Phylogenetic Signal Variation in the Genomes of Medicago (Fabaceae)

Genome-scale data offer the opportunity to clarify phylogenetic relationships that are difficult to resolve with few loci, but they can also identify genomic regions with evolutionary history distinct from that of the species history. We collected whole-genome sequence data from 29 taxa in the legume genus Medicago, then aligned these sequences to the Medicago truncatula reference genome to confidently identify 87 596 variable homologous sites. We used this data set to estimate phylogenetic relationships among Medicago species, to investigate the number of sites needed to provide robust phylogenetic estimates and to identify specific genomic regions supporting topologies in conflict with the genome-wide phylogeny. Our full genomic data set resolves relationships within the genus that were previously intractable. Subsampling the data reveals considerable variation in phylogenetic signal and power in smaller subsets of the data. Even when sampling 5000 sites, no random sample of the data supports a topology identical to that of the genome-wide phylogeny. Phylogenetic relationships estimated from 500-site sliding windows revealed genome regions supporting several alternative species relationships among recently diverged taxa, consistent with the expected effects of deep coalescence or introgression in the recent history of Medicago. [Medicago; phylogenomics; whole-genome resequencing.

Genome assembly and annotation ofArabidopsis halleri, a model for heavy metal hyperaccumulation and evolutionary ecology

The self-incompatible species Arabidopsis halleri is a close relative of the self-compatible model plant Arabidopsis thaliana. The broad European and Asian distribution and heavy metal hyperaccumulation ability makes A. halleri a useful model for ecological genomics studies.We used long-insert mate-pair libraries to improve the genome assembly of the A. halleri ssp.gemmifera Tada mine genotype (W302) collected from a site with high contamination by heavy metals in Japan. After five rounds of forced selfing, heterozygosity was reduced to 0.04%, which facilitated subsequent genome assembly. Our assembly now covers 196 Mb or 78% of the estimated genome size and achieved scaffold N50 length of 712 kb. To validate assembly and annotation, we used synteny of A. halleri Tada mine with a previously published high quality reference assembly of a closely related species, Arabidopsis lyrata. Further validation of the assembly quality comes from synteny and phylogenetic analysis of the HEAVY METAL ATPASE4 (HMA4) and METAL TOLERANCE PROTEIN1 (MTP1) regions using published sequences from European A. halleri for comparison. Three tandemly duplicated copies of HMA4, key gene involved in cadmium and zinc hyperaccumulation, were assembled on a single scaffold.The assembly will enhance the genome-wide studies of A. halleri as well as the allopolyploid Arabidopsis kamchatica derived from A. lyrata and A. halleri

Continuation for thin film hydrodynamics and related scalar problems

This chapter illustrates how to apply continuation techniques in the analysis of a particular class of nonlinear kinetic equations that describe the time evolution through transport equations for a single scalar field like a densities or interface profiles of various types. We first systematically introduce these equations as gradient dynamics combining mass-conserving and nonmass-conserving fluxes followed by a discussion of nonvariational amendmends and a brief introduction to their analysis by numerical continuation. The approach is first applied to a number of common examples of variational equations, namely, Allen-Cahn- and Cahn-Hilliard-type equations including certain thin-film equations for partially wetting liquids on homogeneous and heterogeneous substrates as well as Swift-Hohenberg and Phase-Field-Crystal equations. Second we consider nonvariational examples as the Kuramoto-Sivashinsky equation, convective Allen-Cahn and Cahn-Hilliard equations and thin-film equations describing stationary sliding drops and a transversal front instability in a dip-coating. Through the different examples we illustrate how to employ the numerical tools provided by the packages auto07p and pde2path to determine steady, stationary and time-periodic solutions in one and two dimensions and the resulting bifurcation diagrams. The incorporation of boundary conditions and integral side conditions is also discussed as well as problem-specific implementation issues

Using a Non-Image-Based Medium-Throughput Assay for Screening Compounds Targeting N-myristoylation in Intracellular Leishmania Amastigotes

We have refined a medium-throughput assay to screen hit compounds for activity against N-myristoylation in intracellular amastigotes of Leishmania donovani. Using clinically-relevant stages of wild type parasites and an Alamar blue-based detection method, parasite survival following drug treatment of infected macrophages is monitored after macrophage lysis and transformation of freed amastigotes into replicative extracellular promastigotes. The latter transformation step is essential to amplify the signal for determination of parasite burden, a factor dependent on equivalent proliferation rate between samples. Validation of the assay has been achieved using the anti-leishmanial gold standard drugs, amphotericin B and miltefosine, with EC50 values correlating well with published values. This assay has been used, in parallel with enzyme activity data and direct assay on isolated extracellular amastigotes, to test lead-like and hit-like inhibitors of Leishmania Nmyristoyl transferase (NMT). These were derived both from validated in vivo inhibitors of Trypanosoma brucei NMT and a recent high-throughput screen against L. donovani NMT. Despite being a potent inhibitor of L. donovani NMT, the activity of the lead T. brucei NMT inhibitor (DDD85646) against L. donovani amastigotes is relatively poor. Encouragingly, analogues of DDD85646 show improved translation of enzyme to cellular activity. In testing the high-throughput L. donovani hits, we observed macrophage cytotoxicity with compounds from two of the four NMT-selective series identified, while all four series displayed low enzyme to cellular translation, also seen here with the T. brucei NMT inhibitors. Improvements in potency and physicochemical properties will be required to deliver attractive lead-like Leishmania NMT inhibitors

Patterns of polymorphism and selection in the subgenomes of the allopolyploid Arabidopsis kamchatica

Genome duplication is widespread in wild and crop plants. However, little is known about genome-wide selection in polyploids due to the complexity of duplicated genomes. In polyploids, the patterns of purifying selection and adaptive substitutions may be affected by masking owing to duplicated genes or homeologs as well as effective population size. Here, we resequence 25 accessions of the allotetraploid Arabidopsis kamchatica, which is derived from the diploid species A. halleri and A. lyrata. We observe a reduction in purifying selection compared with the parental species. Interestingly, proportions of adaptive non-synonymous substitutions are significantly positive in contrast to most plant species. A recurrent pattern observed in both frequency and divergence–diversity neutrality tests is that the genome-wide distributions of both subgenomes are similar, but the correlation between homeologous pairs is low. This may increase the opportunity of different evolutionary trajectories such as in the HMA4 gene involved in heavy metal hyperaccumulation

Rapid Accumulation of Polymorphonuclear Neutrophils in the Corpus luteum during Prostaglandin F2α-Induced Luteolysis in the Cow

Prostaglandin F2α (PGF2α) induces luteolysis within a few days in cows, and immune cells increase in number in the regressing corpus luteum (CL), implying that luteolysis is an inflammatory-like immune response. We investigated the rapid change in polymorphonuclear neutrophil (PMN) numbers in response to PGF2α administration as the first cells recruited to inflammatory sites, together with mRNA of interleukin-8 (IL-8: neutrophil chemoattractant) and P-selectin (leukocyte adhesion molecule) in the bovine CL. CLs were collected by ovariectomy at various times after PGF2α injection. The number of PMNs was increased at 5 min after PGF2α administration, whereas IL-8 and P-selectin mRNA increased at 30 min and 2 h, respectively. PGF2α directly stimulated P-selectin protein expression at 5–30 min in luteal endothelial cells (LECs). Moreover, PGF2α enhanced PMN adhesion to LECs, and this enhancement by PGF2α was inhibited by anti-P-selectin antibody, suggesting that P-selectin expression by PGF2α is crucial in PMN migration. In conclusion, PGF2α rapidly induces the accumulation of PMNs into the bovine CL at 5 min and enhances PMN adhesion via P-selectin expression in LECs. It is suggested that luteolytic cascade by PGF2α may involve an acute inflammatory-like response due to rapidly infiltrated PMNs