Multiplexed PCR to measure growth rates of uropathogenic during experimental urinary tract infection.

Measuring bacterial growth rates is routine, however, determining growth rates during infection in host has been more challenging. Peak-to-trough ratio (PTR) is a technique for studying microbial growth dynamics, calculated using the ratio of replication origin () copies to that of the terminus (), as originally defined by whole genome sequencing (WGS). WGS presents significant challenges in terms of expense and data analysis complexity due to the presence of host DNA in the samples.

Negative feedback of cyclic di-GMP levels optimizes switching between sessile and motile lifestyles in .

The signaling molecule cyclic di-GMP (cdG) controls the switch between bacterial motility and biofilm production, and fluctuations in cellular levels of cdG have been implicated in pathogenesis. Intracellular concentrations of cdG are controlled by the interplay of diguanylate cyclase (DGC) enzymes, which synthesize cdG to promote biofilms, and phosphodiesterase (PDE) enzymes, which hydrolyse cdG to drive motility. To track the complete regulatory logic of how responds to changing cdG levels, we followed a timecourse of overexpression of either the diguanylate cyclase QrgB or a variant of QrgB lacking catalytic activity (QrgB*).

Production and separation of Be for use in an ion source.

Beryllium-7 (Be) was created by proton irradiation of natural (B) and enriched (B) boron targets. The targets were dissolved in nitric acid, and the Be was separated from the bulk boron target material by cation-exchange chromatography. An average recovery of (99.

Activation of a CBASS anti-phage system by quorum sensing and folate depletion.

To counteract infection with phage, bacteria have evolved a myriad of molecular defense systems. Some of these systems initiate a process called abortive infection, in which the infected cell kills itself to prevent phage propagation. However, such systems must be inhibited in the absence of phage infection to prevent spurious death of the host.

Preparation of stable and long-lived source samples for the stand-alone beam program at the Facility for Rare Isotope Beams.

At the Facility for Rare Isotope Beams (FRIB), an oven-ion source combination was used to create rare isotope beams in support of the stand-alone user beam program of the ReAccelerator (ReA) facility. This ion source, called Batch-Mode Ion Source (BMIS), was loaded with enriched stable nuclides (Si, Cr, and Fe) and long-lived radionuclides (Al, Si). The introduced samples, herein designated as source samples, were thermally volatilized in the BMIS oven, and then ionization was used to generate the required beams.

Proof-of-concept studies of novel protocols for producing highly pure V from a Cr/V generator.

The quest to improve the quality of nuclear data, such as half-lives, transition yields, and reaction cross-sections, is a shared endeavor among various areas of nuclear science. V is a vanadium isotope for which experimental data on neutron reaction cross-sections is needed. However, traditional isotope production techniques cannot produce V with high enough isotopic purity for some of these measurements.

Harvesting Zr from heavy-ion beam irradiated tungsten at the National Superconducting Cyclotron Laboratory.

Tungsten is a commonly used material at many heavy-ion beam facilities, and it often becomes activated due to interactions with a beam. Many of the activation products are useful in basic and applied sciences if they can be recovered efficiently. In order to develop the radiochemistry for harvesting group (IV) elements from irradiated tungsten, a heavy-ion beam containing Zr was embedded into a stack of tungsten foils at the National Superconducting Cyclotron Laboratory and a separation methodology was devised to recover the Zr.

Solid-phase isotope harvesting of Zr from a radioactive ion beam facility.

During routine operation of the Facility for Rare Isotope Beams (FRIB), radionuclides will accumulate in both the aqueous beam dump and along the beamline in the process of beam purification. These byproduct radionuclides, many of which are far from stability, can be collected and purified for use in other scientific applications in a process called isotope harvesting. In this work, the viability of Zr harvesting from solid components was investigated at the National Superconducting Cyclotron Laboratory.

A Model for Radiolysis in a Flowing-Water Target during High-Intensity Proton Irradiation.

At the Facility for Rare Isotope Beams (FRIB), interactions between heavy-ion beams and beam-dump water will create a wide variety of radionuclides which can be accessed by a technique known as "isotope harvesting". However, irradiation of water is always accompanied by the creation of numerous radical, ionic, and molecular radiolysis products. Some of the radiolysis products have sufficiently long lifetimes to accumulate in the irradiated water and affect the harvesting chemistry.

Phage defence by deaminase-mediated depletion of deoxynucleotides in bacteria.

Vibrio cholerae biotype El Tor is perpetuating the longest cholera pandemic in recorded history. The genomic islands VSP-1 and VSP-2 distinguish El Tor from previous pandemic V. cholerae strains.

The ADP-Heptose Biosynthesis Enzyme GmhB is a Conserved Gram-Negative Bacteremia Fitness Factor.

Klebsiella pneumoniae is a leading cause of Gram-negative bacteremia, which is a major source of morbidity and mortality worldwide. Gram-negative bacteremia requires three major steps: primary site infection, dissemination to the blood, and bloodstream survival. Because K.

PET in vivo generators Ce and Nd on an internalizing monoclonal antibody probe.

The in vivo-generator radionuclides Nd (t = 3.4 d) and Ce (t = 3.2 d) were used to trace a urokinase-type plasminogen activator (uPA)-targeting mouse monoclonal antibody, ATN-291, in U87 MG xenograft tumor-bearing mice.

Harvesting krypton isotopes from the off-gas of an irradiated water target to generate Br and Br.

A flowing-water target was irradiated with a 150 MeV/nucleon beam of Kr at the National Superconducting Cyclotron Laboratory to produce Kr and Kr. Real-time gamma-imaging measurements revealed the mass transport of the krypton radioisotopes through the target-water processing, or "isotope harvesting", system. The production rates were determined to be 2.

Branching ratios for the three most intense gamma rays in the decay of Ca.

A sample of Ca produced through isotope harvesting at the National Superconducting Cyclotron Laboratory was used to measure branching ratios of 7.17(5)%, 7.11(5)%, and 75.

Shigella flexneri Diguanylate Cyclases Regulate Virulence.

Shigella flexneri is an intracellular human pathogen that invades colonic cells and causes bloody diarrhea. S. flexneri evolved from commensal Escherichia coli, and genome comparisons reveal that S.

Production, Collection, and Purification of Ca for the Generation of Sc through Isotope Harvesting at the National Superconducting Cyclotron Laboratory.

An experiment was performed at the National Superconducting Cyclotron Laboratory using a 140 MeV/nucleon Ca beam and a flowing-water target to produce Ca for the first time with this production route. A production rate of 0.020 ± 0.

Surface sensing stimulates cellular differentiation in .

Cellular differentiation is a fundamental strategy used by cells to generate specialized functions at specific stages of development. The bacterium employs a specialized dimorphic life cycle consisting of two differentiated cell types. How environmental cues, including mechanical inputs such as contact with a surface, regulate this cell cycle remain unclear.

Cs-131 as an experimental tool for the investigation and quantification of the radiotoxicity of intracellular Auger decays in vitro.

Purpose: In this work, we set out to provide an experimental setup, using Cs-131, with associated dosimetry for studying relative biological effectiveness (RBE) of Auger emitters.

Material And Methods: Cs-131 decays by 100% electron capture producing K- (9%) and L- (80%) Auger electrons with mean energies of 26 keV and 3.5 keV, respectively, plus ≈ 9.

Radiolysis and radionuclide production in a flowing-water target during fast Ca irradiation.

A flowing-water target was irradiated with a 140 MeV/u, 8 nA 40Ca20+ beam to test the feasibility of isotope harvesting at the upcoming Facility for Rare Isotope Beams. Among other radionuclides, 2.6(2)E-6 48Cr and 5.

Harvesting V at the National Superconducting Cyclotron Laboratory.

As part of an effort to develop aqueous isotope harvesting techniques at radioactive beam facilities, V and a cocktail of primary- and secondary-beam ions created by the fragmentation reaction of a 160 MeV/nucleon Ni beam were stopped in an aqueous target cell. After collection, V was separated from the mixture of beam ions using cation-exchange chromatography. The extraction efficiency from the aqueous solution was (47.

A solid support generator of the Auger electron emitter rhodium-103m from [Pd]palladium.

Auger electron therapy is an attractive modality for targeting microscopic tumors. Rhodium-103 m (Rh, T = 56.1 min) is a promising Auger electron emitter that can be obtained as the decay product of palladium-103 (Pd, T = 16.

Tricarboxylic Acid (TCA) Cycle Enzymes and Intermediates Modulate Intracellular Cyclic di-GMP Levels and the Production of Plant Cell Wall-Degrading Enzymes in Soft Rot Pathogen .

is a plant-pathogenic bacterium that causes soft-rot in a wide range of plants. Although we have previously demonstrated that cyclic bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP), a bacterial secondary messenger, plays a central role in virulence regulation in , the upstream signals that modulate c-di-GMP remain enigmatic. Using a genome-wide transposon mutagenesis approach of a Δ mutant strain that has high c-di-GMP and reduced motility, we uncovered transposon mutants that recovered the c-di-GMP-mediated repression on swimming motility.

Under Elevated c-di-GMP in Escherichia coli, YcgR Alters Flagellar Motor Bias and Speed Sequentially, with Additional Negative Control of the Flagellar Regulon via the Adaptor Protein RssB.

In and , the c-di-GMP effector YcgR inhibits flagellar motility by interacting directly with the motor to alter both its bias and speed. Here, we demonstrate that in both of these bacteria, YcgR acts sequentially, altering motor bias first and then decreasing motor speed. We show that when c-di-GMP levels are high, deletion of restores wild-type motor behavior in , indicating that YcgR is the only motor effector in this bacterium.

The Vc2 Cyclic di-GMP-Dependent Riboswitch of Vibrio cholerae Regulates Expression of an Upstream Putative Small RNA by Controlling RNA Stability.

Cyclic di-GMP (c-di-GMP) is a bacterial second messenger molecule that is important in the biology of , but the molecular mechanisms by which this molecule regulates downstream phenotypes have not been fully characterized. We have previously shown that the Vc2 c-di-GMP-binding riboswitch, encoded upstream of the gene , functions as an off switch in response to c-di-GMP. However, the mechanism by which c-di-GMP controls expression of has not been fully elucidated.