492 research outputs found

    Welfare, Due Process, and Brutal Need : The Requirement of a Prior Hearing in State-Wide Benefit Reductions

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    This Note examines the right of welfare recipients to request a prior hearing in the context of state-wide, across-the-board benefit reductions by a state. After reviewing the due process requirement of a pretermination hearing articulated by the Supreme Court in Goldberg v. Kelly, the Note examines the standard for reductions established by the HHS regulations. The Note also considers the various approaches taken by the courts in attempting to determine the constitutional and statutory requirements of a prior hearing in a state-wide reduction. The Note argues that the standard delineated by the HHS regulations and by some courts fails to provide the full procedural protection necessary to safeguard the benefits of impoverished individuals from wrongful reduction. Observing that the Supreme Court has declined to recognize a substantive due process right to welfare, the Note points out that recipients must depend upon the requirements of procedural due process to protect their very means of economic survival. The Note contends that Goldberg dictates that states be extremely cautious in reducing benefits and that consequently, because a wrongful reduction would subject recipients to a condition of brutal need, due process requires that states provide the opportunity for a fair hearing even when the intended reduction is due to a policy of whole-sale cutbacks. Because the regulations have in fact encouraged blanket denials of requests for prior hearings in across-the-board reductions, the Note concludes that, in order to reconcile the statutory requirements for prior hearings with the constitutional imperatives, HHS must either rewrite or eliminate the provision of the federal regulations concerning automatic, state-wide reductions

    SLIDES: Climate Change Action in Arizona & the West

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    Presenter: Stephen A. Owens, Director, Arizona Department of Environmental Quality. 24 slides

    Thick-film piezoelectric bimorph actuators for MEMS devices

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    Active ow control can be used to improve the aerodynamic e ciency of passenger aircraft, road tra c and wind turbines amongst other applications. This work describes the fabrication of an ultra-compact microvalve that has been designed as part of an active aerodynamic ow control system that generates airjets of a scale and velocity that have been shown to have desirable e ects on the macroscopic air ow. The design of the microvalve is based on criteria speci ed by the requirements of active ow control and the piezoelectric bimorph actuator which opens and closes the valve outlet. Cont/d.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Regulation of Nonribosomal Peptide Synthesis: bis-Thiomethylation Attenuates Gliotoxin Biosynthesis in Aspergillus fumigatus

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    Gliotoxin is a redox-active nonribosomal peptide produced by Aspergillus fumigatus. Like many other disulfide-containing epipolythiodioxopiperazines, a bis-thiomethylated form is also produced. In the case of gliotoxin, bisdethiobis(methylthio)gliotoxin (BmGT) is formed for unknown reasons by a cryptic enzyme. Here, we identify the S-adenosylmethionine- dependent gliotoxin bis-thiomethyltransferase (GtmA), which converts dithiogliotoxin to BmGT. This activity, which is induced by exogenous gliotoxin, is only detectable in protein lysates of A. fumigatus deficient in the gliotoxin oxidoreductase, gliT. Thus, GtmA is capable of substrate bis-thiomethylation. Deletion of gtmA completely abrogates BmGT formation and we now propose that the purpose of BmGT formation is primarily to attenuate gliotoxin biosynthesis. Phylogenetic analysis reveals 124 GtmA homologs within the Ascomycota phylum. GtmA is encoded outside the gliotoxin biosynthetic cluster and primarily serves to negatively regulate gliotoxin biosynthesis. This mechanism of postbiosynthetic regulation of nonribosomal peptide synthesis appears to be quite unusual

    Whole genome sequencing of experimental hybrids supports meiosis-like sexual recombination in Leishmania

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    Hybrid genotypes have been repeatedly described among natural isolates of Leishmania, and the recovery of experimental hybrids from sand flies co-infected with different strains or species of Leishmania has formally demonstrated that members of the genus possess the machinery for genetic exchange. As neither gamete stages nor cell fusion events have been directly observed during parasite development in the vector, we have relied on a classical genetic analysis to determine if Leishmania has a true sexual cycle. Here, we used whole genome sequencing to follow the chromosomal inheritance patterns of experimental hybrids generated within and between different strains of L. major and L. infantum. We also generated and sequenced the first experimental hybrids in L. tropica. We found that in each case the parental somy and allele contributions matched the inheritance patterns expected under meiosis 97–99% of the time. The hybrids were equivalent to F1 progeny, heterozygous throughout most of the genome for the markers that were homozygous and different between the parents. Rare, non-Mendelian patterns of chromosomal inheritance were observed, including a gain or loss of somy, and loss of heterozygosity, that likely arose during meiosis or during mitotic divisions of the progeny clones in the fly or culture. While the interspecies hybrids appeared to be sterile, the intraspecies hybrids were able to produce backcross and outcross progeny. Analysis of 5 backcross and outcross progeny clones generated from an L. major F1 hybrid, as well as 17 progeny clones generated from backcrosses involving a natural hybrid of L. tropica, revealed genome wide patterns of recombination, demonstrating that classical crossing over occurs at meiosis, and allowed us to construct the first physical and genetic maps in Leishmania. Altogether, the findings provide strong evidence for meiosis-like sexual recombination in Leishmania, presenting clear opportunities for forward genetic analysis and positional cloning of important genes.</div

    Decorin protein core affects the global gene expression profile of the tumor microenvironment in a triple-negative orthotopic breast carcinoma xenograft model

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    Decorin, a member of the small leucine-rich proteoglycan gene family, exists and functions wholly within the tumor microenvironment to suppress tumorigenesis by directly targeting and antagonizing multiple receptor tyrosine kinases, such as the EGFR and Met. This leads to potent and sustained signal attenuation, growth arrest, and angiostasis. We thus sought to evaluate the tumoricidal benefits of systemic decorin on a triple-negative orthotopic breast carcinoma xenograft model. To this end, we employed a novel high-density mixed expression array capable of differentiating and simultaneously measuring gene signatures of both Mus musculus (stromal) and Homo sapiens (epithelial) tissue origins. We found that decorin protein core modulated the differential expression of 374 genes within the stromal compartment of the tumor xenograft. Further, our top gene ontology classes strongly suggests an unexpected and preferential role for decorin protein core to inhibit genes necessary for immunomodulatory responses while simultaneously inducing expression of those possessing cellular adhesion and tumor suppressive gene properties. Rigorous verification of the top scoring candidates led to the discovery of three genes heretofore unlinked to malignant breast cancer that were reproducibly found to be induced in several models of tumor stroma. Collectively, our data provide highly novel and unexpected stromal gene signatures as a direct function of systemic administration of decorin protein core and reveals a fundamental basis of action for decorin to modulate the tumor stroma as a biological mechanism for the ascribed anti-tumorigenic properties

    Functional Investigation of Iron-Responsive Microsomal Proteins, including MirC, in Aspergillus fumigatus

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    The functionality of many microsome-associated proteins which exhibit altered abundance in response to iron limitation in Aspergillus fumigatus is unknown. Here, we generate and characterize eight gene deletion strains, and of most significance reveal that MirC (AFUA_2G05730) contributes to the maintenance of intracellular siderophore [ferricrocin (FC)] levels, augments conidiation, confers protection against oxidative stress, exhibits an intracellular localization and contributes to fungal virulence in the Galleria mellonella animal model system. FC levels were unaffected following deletion of all other genes encoding microsome-associated proteins. MirC does not appear to play a role in either siderophore export from, or uptake into, A. fumigatus. Label-free quantitative proteomic analysis unexpectedly revealed increased abundance of siderophore biosynthetic enzymes. In addition, increased expression of hapX (7.2 and 13.8-fold at 48 and 72 h, respectively; p < 0.001) was observed in ΔmirC compared to wild-type under iron-replete conditions by qRT-PCR. This was complemented by significantly elevated extracellular triacetylfusarinine C (TAFC; p < 0.01) and fusarinine C (FSC; p < 0.05) siderophore secretion. We conclude that MirC plays an important role in FC biosynthesis and contributes to the maintenance of iron homeostasis in A. fumigatus

    An RNA interference (RNAi) toolkit and its utility for functional genetic analysis of Leishmania (Viannia)

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    RNA interference (RNAi) is a powerful tool whose efficacy against a broad range of targets enables functional genetic tests individually or systematically. However, the RNAi pathway has been lost in evolution by a variety of eukaryotes including most Leishmania sp. RNAi was retained in species of th

    Off-Body Boundary-Layer Measurement Techniques Development for Supersonic Low-Disturbance Flows

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    Investigations were performed to develop accurate boundary-layer measurement techniques in a Mach 3.5 laminar boundary layer on a 7 half-angle cone at 0 angle of attack. A discussion of the measurement challenges is presented as well as how each was addressed. A computational study was performed to minimize the probe aerodynamic interference effects resulting in improved pitot and hot-wire probe designs. Probe calibration and positioning processes were also developed with the goal of reducing the measurement uncertainties from 10% levels to less than 5% levels. Efforts were made to define the experimental boundary conditions for the cone flow so comparisons could be made with a set of companion computational simulations. The development status of the mean and dynamic boundary-layer flow measurements for a nominally sharp cone in a low-disturbance supersonic flow is presented

    The Aspergillus fumigatus Protein GliK Protects against Oxidative Stress and Is Essential for Gliotoxin Biosynthesis

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    The function of a number of genes in the gliotoxin biosynthetic cluster (gli) in Aspergillus fumigatus remains unknown. Here, we demonstrate that gliK deletion from two strains of A. fumigatus completely abolished gliotoxin biosynthesis. Furthermore, exogenous H2O2 (1 mM), but not gliotoxin, significantly induced A. fumigatus gliK expression (P 0.0101). While both mutants exhibited significant sensitivity to both exogenous gliotoxin (P<0.001) and H2O2 (P<0.01), unexpectedly, exogenous gliotoxin relieved H2O2-induced growth inhibition in a dose-dependent manner (0 to 10 g/ml). Gliotoxin-containing organic extracts derived from A. fumigatus ATCC 26933 significantly inhibited (P<0.05) the growth of the gliK26933 deletion mutant. The A. fumigatus gliK26933 mutant secreted metabolites, devoid of disulfide linkages or free thiols, that were detectable by reverse- phase high-performance liquid chromatography and liquid chromatography-mass spectrometry with m/z 394 to 396. These metabolites (m/z 394 to 396) were present at significantly higher levels in the culture supernatants of the A. fumigatus gliK26933 mutant than in those of the wild type (P0.0024 [fold difference, 24] and P0.0003 [fold difference, 9.6], respectively) and were absent from A. fumigatus gliG. Significantly elevated levels of ergothioneine were present in aqueous mycelial extracts of the A. fumigatus gliK26933 mutant compared to the wild type (P<0.001). Determination of the gliotoxin uptake rate revealed a significant difference (P0.0045) between that of A. fumigatus ATCC 46645 (9.3 pg/mg mycelium/min) and the gliK46645 mutant (31.4 pg/mg mycelium/min), strongly suggesting that gliK absence and the presence of elevated ergothioneine levels impede exogenously added gliotoxin efflux. Our results confirm a role for gliK in gliotoxin biosynthesis and reveal new insights into gliotoxin functionality in A. fumigatus
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