Investigation of Un8-Mediated Barley Loose Smut Resistance

Barley loose smut, caused by the basidiomycete pathogen Ustilago nuda (Jens.) Rostr. (U. nuda), is a common fungal disease throughout Canadian barley growing regions and can be effectively controlled by the Un8 resistance gene. The first study (Chapter 3) was designed to isolate the Un8 gene by map-based cloning. The Un8 gene was delimited to a 0.108 cM interval on chromosome arm 1HL and a minimal tiling path consisting of two overlapping bacterial artificial chromosomes was identified. Sequence analysis identified a Un8 candidate gene predicted to be a putative protein kinase with two kinase domains. Twenty-six cultivated and eight wild barley accessions with diverse genetic backgrounds were collected for the second study (Chapter 4) and sequence alignment revealed that all resistant accessions from Canada shared the same amino acid sequence with the landrace accession, CN91953, which was reported as the donor of Un8 to North American barley breeding programs. The remaining three studies focused on elucidating the mechanisms underlying Un8-mediated loose smut resistance. In Chapter 5, a simple and reliable diagnostic method was developed to examine the infection processes of U. nuda within barley seeds and it was found that the early seedling stage might be the most important time point for Un8-conditioned loose smut resistance. Seedling mortality was also observed in resistant and susceptible lines which led to questions as to whether this was a function of the high inoculum concentration used to evaluate disease response. To further investigate this resistance, the commonly used inoculation method was improved by reducing the inoculum concentration (Chapter 6). During this study a large fitness cost (i.e. seedling mortality) previously observed was associated only with resistant lines carrying the Un8 gene. In the final study (Chapter 7), expression analysis was undertaken to better understand Un8-mediated resistance and seedling mortality observed. Two barley genes involved in cytokinin regulation, CKX1 and CKX2.1, which encode cytokinin oxidase/dehydrogenase (CKX) enzymes to irreversibly degrade cytokinins, were significantly up-regulated at time points that coincided with early seed germination. This indicated that the cytokinin pathway may be involved in the loose smut resistance conditioned by the Un8 gene. Taken together, this study has provided deeper insight into the long-lived Un8 loose smut resistance gene, including a possible role for cytokinins in barley loose smut resistance

Diaqua­(5-carb­oxy­benzene-1,3-dicarboxyl­ato-κ2 O 1,O 1′)(6,6′-dimethyl-2,2′-bipyridine-κ2 N,N′)nickel(II) hepta­hydrate

In the title compound, [Ni(C9H4O6)(C12H12N2)(H2O)2]·7H2O, the NiII atom is six-coordinated by two O atoms from a chelating carboxyl­ate group of a 5-carb­oxy­benzene-1,3-dicarboxyl­ate ligand, two O atoms of two water mol­ecules and two N atoms from a 6,6′-dimethyl-2,2′-bipyridine ligand in a distorted octa­hedral geometry. The compound exhibits a three-dimensional supra­molecular structure composed of the complex mol­ecules and lattice water mol­ecules, which are linked together by inter­molecular O—H⋯O hydrogen bonds and partly overlapping π–π inter­actions between the pyridine and benzene rings [centroid–centroid distances = 3.922 (2) and 3.921 (2) Å]. One of the lattice water mol­ecules is disordered over two positions in an occupancy ratio of 0.521 (6):0.479 (6)

Diaqua­(5-carb­oxy­benzene-1,3-di­carboxyl­ato-κO 1)(4,4′-dimethyl-2,2′-bipyridine-κ2 N,N′)zinc

In the title compound, [Zn(C9H4O6)(C12H12N2)(H2O)2], the ZnII atom is five-coordinated by two N atoms from a 4,4′-dimethyl-2,2′-bipyridine ligand, one O atom from a 5-carb­oxy­benzene-1,3-dicarboxyl­ate ligand and two water mol­ecules in a distorted trigonal–bipyramidal geometry. The complex mol­ecules are linked by inter­molecular O—H⋯O hydrogen bonds and partly overlapping π–π inter­actions [centroid–centroid distance = 4.017 (2) Å] into a three-dimensional supra­molecular network

Poly[[hexa­aqua­bis­(μ3-benzene-1,3,5-tricarboxyl­ato-κ3 O 1:O 3:O 5)bis­(5,5′-dimethyl-2,2′-bipyridine-κ2 N,N′)trizinc] hexa­hydrate]

In the title compound, {[Zn3(C9H3O6)2(C12H12N2)2(H2O)6]·6H2O}n, one ZnII atom, lying on an inversion center, is six-coordinated by two O atoms from two benzene-1,3,5-tricarboxyl­ate (btc) ligands and four water mol­ecules in a distorted octa­hedral geometry. The other ZnII atom is five-coordinated by two N atoms from a 5,5′-dimethyl-2,2′-bipyridine (dmbpy) ligand, two O atoms from two btc ligands and one water mol­ecule in a distorted trigonal–bipyramidal geometry. The compound features a one-dimensional ladder structure, with windows of ca 10.245 (1) × 15.446 (2) Å. The ladders are linked together by inter­molecular O—H⋯O hydrogen bonds and π–π inter­actions between the benzene rings and between the pyridine rings [centroid-to-centroid distances 3.858 (2) and 3.911 (3) Å, respectively] to form a three-dimensional supra­molecular structure. One of the lattice water molecules is disordered over two positions in a 0.592:0.408 ratio

Towards Measuring Microlensing Event Rate in the Galactic Center: I. Events Detection from the UKIRT Microlensing Survey Data

To overcome the high optical extinction, near-infrared observations are needed for probing the microlensing events toward the Galactic center. The 2015-2019 UKIRT microlensing survey toward the Galactic center is the first dedicated precursor near-infrared (NIR) survey for the Nancy Grace Roman Space Telescope. We here analyze the online data from the UKIRT microlensing survey, reaching $l=b=0^\circ$. Using the event-finder algorithm of KMTNet with the $\Delta \chi^2$ threshold of 250, we find 522 clear events, 436 possible events, and 27 possible anomalous events. We fit a point-source point-lens (PSPL) model to all the clear events and derive the PSPL parameters with uncertainties using a Markov chain Monte Carlo method. Assuming perfect detection efficiency, we compute the uncorrected event rates, which should serve as the lower limits on the true event rate. We find that the uncorrected NIR event rates are likely rising toward the Galactic center and higher than the optical event rates.Comment: 16 pages, Accepted for publication at ApJ

On Fractional Quantum Hall Solitons in ABJM-like Theory

Using D-brane physics, we study fractional quantum Hall solitons (FQHS) in ABJM-like theory in terms of type IIA dual geometries. In particular, we discuss a class of Chern-Simons (CS) quivers describing FQHS sytems at low energy. These CS quivers come from R-R gauge fields interacting with D6-branes wrapped on 4-cycles, which reside within a blown up CP^3 projective space. Based on the CS quiver method and mimicking the construction of del Pezzo surfaces in terms of CP^2, we first give a model which corresponds to a single layer model of FQHS system, then we propose a multi-layer system generalizing the doubled CS field theory, which is used in the study of topological defect in graphene.Comment: 10 pages, Late

9,9-Dimethyl-12-phenyl-8,9-dihydro-12H-benzo[a]xanthen-11(10H)-one

The title compound, C25H22O2, was synthesized via the three-component coupling of benzaldehyde, 2-naphthol and 5,5-dimethyl­cyclo­hexane-1,3-dione. In the crystal structure, centrosymmetrically related mol­ecules are linked into dimers by pairs of inter­molecular C—H⋯O hydrogen bonds. The dimers are further connected into a three-dimensional network by π–π aromatic stacking inter­actions involving the naphthalene ring system, with centroid–centroid separations of 3.695 (7) Å

A new transient field balancing method of a rotor system based on empirical mode decomposition

Effective reduction of the vibration in rotor and stator at critical speed is important for steady operation of rotor systems. A new transient field balancing method is proposed in this paper. The empirical mode decomposition (EMD) method coupled with holospectral technique is used to extract rotating frequency information including precise frequency, amplitude and phase nearby the critical speed from the run-up vibration signals. Reasonable trial weights are selected through estimating the unbalance masses and position. Moreover, the correction masses and position are obtained by holo-balancing method. Compared with the traditional dynamic balancing method, this method does not need obtain steady-state vibration signals, and the rotor can pass through the critical speed smoothly. The principle and detailed procedures of this method are described in this paper, and the effectiveness of the new method was validated by field balancing of rotor kit system

AMPK exerts dual regulatory effects on the PI3K pathway

BACKGROUND AMP-activated protein kinase (AMPK) is a fuel-sensing enzyme that is activated when cells experience energy deficiency and conversely suppressed in surfeit of energy supply. AMPK activation improves insulin sensitivity via multiple mechanisms, among which AMPK suppresses mTOR/S6K-mediated negative feedback regulation of insulin signaling. RESULTS In the present study we further investigated the mechanism of AMPK-regulated insulin signaling. Our results showed that 5-aminoimidazole-4-carboxamide-1 ribonucleoside (AICAR) greatly enhanced the ability of insulin to stimulate the insulin receptor substrate-1 (IRS1)-associated PI3K activity in differentiated 3T3-F442a adipocytes, leading to increased Akt phosphorylation at S473, whereas insulin-stimulated activation of mTOR was diminished. In 3T3-F442a preadipocytes, these effects were attenuated by expression of a dominant negative mutant of AMPK α1 subunit. The enhancing effect of ACIAR on Akt phosphorylation was also observed when the cells were treated with EGF, suggesting that it is regulated at a step beyond IR/IRS1. Indeed, when the cells were chronically treated with AICAR in the absence of insulin, Akt phosphorylation was progressively increased. This event was associated with an increase in levels of phosphatidylinositol -3,4,5-trisphosphate (PIP3) and blocked by Wortmannin. We then expressed the dominant negative mutant of PTEN (C124S) and found that the inhibition of endogenous PTEN per se did not affect phosphorylation of Akt at basal levels or upon treatment with AICAR or insulin. Thus, this result suggests that AMPK activation of Akt is not mediated by regulating phosphatase and tensin homologue (PTEN). CONCLUSION Our present study demonstrates that AMPK exerts dual effects on the PI3K pathway, stimulating PI3K/Akt and inhibiting mTOR/S6K.National Institutes of Health (CA118918, GM057959