Outflowing winds of multiphase plasma have been proposed to regulate the buildup of galaxies, but key aspects of these outflows have not been probed with observations. By using ultraviolet absorption ...spectroscopy, we show that "warm-hot" plasma at 10 5.5 kelvin contains 10 to 150 times more mass than the cold gas in a post-star burst galaxy wind. This wind extends to distances > 68 kiloparsecs, and at least some portion of it will escape. Moreover, the kinematical correlation of the cold and warm-hot phases indicates that the warm-hot plasma is related to the interaction of the cold matter with a hotter (unseen) phase at »10⁶ kelvin. Such multiphase winds can remove substantial masses and alter the evolution of post-star burst galaxies.
Eosinophils are effectors in immunity to tissue helminths but also induce allergic immunopathology. Mechanisms of eosinophilia in non-mucosal tissues during infection remain unresolved. Here we ...identify a pivotal function of tissue macrophages (Mϕ) in eosinophil anti-helminth immunity using a BALB/c mouse intra-peritoneal Brugia malayi filarial infection model. Eosinophilia, via C-C motif chemokine receptor (CCR)3, was necessary for immunity as CCR3 and eosinophil impairments rendered mice susceptible to chronic filarial infection. Post-infection, peritoneal Mϕ populations proliferated and became alternatively-activated (AAMϕ). Filarial AAMϕ development required adaptive immunity and interleukin-4 receptor-alpha. Depletion of Mϕ prior to infection suppressed eosinophilia and facilitated worm survival. Add back of filarial AAMϕ in Mϕ-depleted mice recapitulated a vigorous eosinophilia. Transfer of filarial AAMϕ into Severe-Combined Immune Deficient mice mediated immunological resistance in an eosinophil-dependent manner. Exogenous IL-4 delivery recapitulated tissue AAMϕ expansions, sustained eosinophilia and mediated immunological resistance in Mϕ-intact SCID mice. Co-culturing Brugia with filarial AAMϕ and/or filarial-recruited eosinophils confirmed eosinophils as the larvicidal cell type. Our data demonstrates that IL-4/IL-4Rα activated AAMϕ orchestrate eosinophil immunity to filarial tissue helminth infection.
Highly efficient phage-based Escherichia coli homologous recombination systems have recently been developed that enable genomic DNA in bacterial artificial chromosomes to be modified and subcloned, ...without the need for restriction enzymes or DNA ligases. This new form of chromosome engineering, termed recombinogenic engineering or recombineering, is efficient and greatly decreases the time it takes to create transgenic mouse models by traditional means. Recombineering also facilitates many kinds of genomic experiment that have otherwise been difficult to carry out, and should enhance functional genomic studies by providing better mouse models and a more refined genetic analysis of the mouse genome.
Recent advances in thin-film deposition techniques, such as molecular beam epitaxy and pulsed laser deposition, have allowed for the manufacture of heterostructures with nearly atomically abrupt ...interfaces. Although the bulk properties of the individual heterostructure components may be well-known, often the heterostructures exhibit novel and sometimes unexpected properties due to interface effects. At heterostructure interfaces, lattice structure, stoichiometry, interface electronic structure (bonding, interface states, etc.), and symmetry all conspire to produce behavior different from the bulk constituents. This review discusses why knowledge of the electronic structure and composition at the interfaces is pivotal to the understanding of the properties of heterostructures, particularly the (spin polarized) electronic transport in (magnetic) tunnel junctions.
Recently, a highly efficient recombination system for chromosome engineering in Escherichia coli was described that uses a defective λ prophage to supply functions that protect and recombine a linear ...DNA targeting cassette with its substrate sequence (Yu et al., 2000, Proc. Natl. Acad. Sci. USA 97, 5978–5983). Importantly, the recombination is proficient with DNA homologies as short as 30–50 bp, making it possible to use PCR-amplified fragments as the targeting cassette. Here, we adapt this prophage system for use in bacterial artificial chromosome (BAC) engineering by transferring it to DH10B cells, a BAC host strain. In addition, arabinose inducible cre and flpe genes are introduced into these cells to facilitate BAC modification using loxP and FRT sites. Next, we demonstrate the utility of this recombination system by using it to target cre to the 3′ end of the mouse neuron-specific enolase (Eno2) gene carried on a 250-kb BAC, which made it possible to generate BAC transgenic mice that specifically express Cre in all mature neurons. In addition, we show that fragments as large as 80 kb can be subcloned from BACs by gap repair using this recombination system, obviating the need for restriction enzymes or DNA ligases. Finally, we show that BACs can be modified with this recombination system in the absence of drug selection. The ability to modify or subclone large fragments of genomic DNA with precision should facilitate many kinds of genomic experiments that were difficult or impossible to perform previously and aid in studies of gene function in the postgenomic era.
The microtubule network is thought to be used for long-range transport of cellular components in animal cells whereas the actin network is proposed to be used for short-range transport, although the ...mechanism(s) by which this transport is coordinated is poorly understood. For example, in sea urchins long-range Ca2+-regulated transport of exocytotic vesicles requires a microtubule-based motor, whereas an actin-based motor is used for short-range transport. In neurons, microtubule-based kinesin motor proteins are used for long-range vesicular transport but microtubules do not extend into the neuronal termini, where actin filaments form the cytoskeletal framework, and kinesins are rapidly degraded upon their arrival in neuronal termini, indicating that vesicles may have to be transferred from microtubules to actin tracks to reach their final destination. Here we show that an actin-based vesicle-transport motor, MyoVA, can interact directly with a microtubule-based transport motor, KhcU. As would be expected if these complexes were functional, they also contain kinesin light chains and the localization of MyoVA and KhcU overlaps in the cell. These results indicate that cellular transport is, in part, coordinated through the direct interaction of different motor molecules.
We survey the highly ionized circumgalactic media (CGM) of 29 blindly selected galaxies at based on high signal-to-noise ratio ultraviolet spectra of z 1 quasi-stellar objects and the galaxy database ...from the COS Absorption Survey of Baryon Harbors (CASBaH). We detect the Ne viii doublet in nine of the galaxies, and for gas with N( ) ( ), we derive a covering fraction ( ) within impact parameters ≤ 200 kpc of M* = 109.5-11.5 M galaxies and ( ) within ≤ 1.5 virial radii. We estimate the mass in -traced gas to be , or 6%-20% of the expected baryonic mass if the absorbers have solar metallicity. Ionizing Ne vii to requires 207 eV, and photons with this energy are scarce in the CGM. However, for the median halo mass and redshift of our sample, the virial temperature is close to the peak temperature for the ion, and the -bearing gas is plausibly collisionally ionized near this temperature. Moreover, we find that photoionized requires cool and low-density clouds that would be highly underpressured (by approximately two orders of magnitude) relative to the putative, ambient virialized medium, complicating scenarios where such clouds could survive. Thus, more complex (e.g., nonequilibrium) models may be required; this first statistical sample of absorber/galaxy systems will provide stringent constraints for future CGM studies.
Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene cause late-onset, autosomal dominant familial Parkinson's disease (PD) and also contribute to idiopathic PD. LRRK2 mutations represent the ...most common cause of PD with clinical and neurochemical features that are largely indistinguishable from idiopathic disease. Currently, transgenic mice expressing wild-type or disease-causing mutants of LRRK2 have failed to produce overt neurodegeneration, although abnormalities in nigrostriatal dopaminergic neurotransmission have been observed. Here, we describe the development and characterization of transgenic mice expressing human LRRK2 bearing the familial PD mutations, R1441C and G2019S. Our study demonstrates that expression of G2019S mutant LRRK2 induces the degeneration of nigrostriatal pathway dopaminergic neurons in an age-dependent manner. In addition, we observe autophagic and mitochondrial abnormalities in the brains of aged G2019S LRRK2 mice and markedly reduced neurite complexity of cultured dopaminergic neurons. These new LRRK2 transgenic mice will provide important tools for understanding the mechanism(s) through which familial mutations precipitate neuronal degeneration and PD.
Tpl 2 knockout mice produce low levels of TNF-α when exposed to lipopolysaccharide (LPS) and they are resistant to LPS/D-Galactosamine-induced pathology. LPS stimulation of peritoneal macrophages ...from these mice did not activate MEK1, ERK1, and ERK2 but did activate JNK, p38 MAPK, and NF-κB. The block in ERK1 and ERK2 activation was causally linked to the defect in TNF-α induction by experiments showing that normal murine macrophages treated with the MEK inhibitor PD98059 exhibit a similar defect. Deletion of the AU-rich motif in the TNF-α mRNA minimized the effect of
Tpl2 inactivation on the induction of TNF-α. Subcellular fractionation of LPS-stimulated macrophages revealed that LPS signals transduced by Tpl2 specifically promote the transport of TNF-α mRNA from the nucleus to the cytoplasm.
is one of the most common causes of systemic candidiasis, often resistant to antifungal medications. To describe the genomic context of emerging resistance, we conducted a retrospective analysis of ...82 serially collected isolates from 33 patients from population-based candidemia surveillance in the United States. We used whole-genome sequencing to determine the genetic relationships between isolates obtained from the same patient. Phylogenetic analysis demonstrated that isolates from 29 patients were clustered by patient. The median SNPs between isolates from the same patient was 30 (range: 7-96 SNPs), while unrelated strains infected four patients. Twenty-one isolates were resistant to echinocandins, and 24 were resistant to fluconazole. All echinocandin-resistant isolates carried a mutation either in the
or
HS1 region. Of the 24 fluconazole-resistant isolates, 17 (71%) had non-synonymous polymorphisms in the
gene, which were absent in susceptible isolates. In 11 patients, a genetically related resistant isolate was collected after recovering susceptible isolates, indicating
acquisition of resistance. These findings allowed us to estimate the intra-host diversity of
and propose an upper boundary of 96 SNPs for defining genetically related isolates, which can be used to assess donor-to-host transmission, nosocomial transmission
or acquired resistance. IMPORTANCE In our study, mutations associated to azole resistance and echinocandin resistance were detected in
isolates using a whole-genome sequence.
is the second most common cause of candidemia in the United States, which rapidly acquires resistance to antifungals,
and
.
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