Long-lived heteronuclear spin-singlet states

We report observation of long-lived spin-singlet states in a 13C-1H spin pair at zero magnetic field. In 13C-labeled formic acid, we observe spin-singlet lifetimes as long as 37 seconds, about a factor of three longer than the T1 lifetime of dipole polarization in the triplet state. We also observe that the lifetime of the singlet-triplet coherence, T2, is longer than T1. Moreover, we demonstrate that this singlet states formed by spins of a heteronucleus and a 1H nucleus, can exhibit longer lifetimes than the respective triplet states in systems consisting of more than two nuclear spins. Although long-lived homonuclear spin-singlet states have been extensively studied, this is the first experimental observation of analogous spin-singlets consisting of a heteronucleus and a proton.Comment: 5 pages, 4 figure

Suppression of electron spin decoherence of the diamond NV center by a transverse magnetic field

We demonstrate that the spin decoherence of nitrogen vacancy (NV) centers in diamond can be suppressed by a transverse magnetic field if the electron spin bath is the primary decoherence source. The NV spin coherence, created in "a decoherence-free subspace" is protected by the transverse component of the zero-field splitting, increasing the spin-coherence time about twofold. The decoherence due to the electron spin bath is also suppressed at magnetic fields stronger than ~25 gauss when applied parallel to the NV symmetry axis. Our method can be used to extend the spin-coherence time of similar spin systems for applications in quantum computing, field sensing, and other metrologies.Comment: 20 pages, 4 figure

RELATIONSHIP BETWEEN LOBLOLLY PINE SMALL CLEAR SPECIMENS AND DIMENSION LUMBER TESTED IN STATIC BENDING

Prior to the 1980s the allowable stresses for lumber in North America were derived from testing of small clear specimens but the procedures changed because these models were found to be inaccurate.  Nevertheless, small clear testing continues to be used around the world for allowable stress determinations and in studies that examine forest management impacts on wood quality.  Using small clears and nondestructive technologies is advantageous because of the ease of obtaining and testing small clear specimens compared to lumber.  The objective of this study was to compare the mechanical properties in bending of small clear specimens with lumber specimens for loblolly pine.  Eight hundred and forty-one pieces of lumber in the No. 1 to No. 3 grades and 2×4 to 2×10 sizes were collected from a forest-thru-mill study and tested in static bending.  A small clear specimen (25 x 25 x 410 mm) was prepared from each piece of lumber and tested in static bending.  The effect of growth ring orientation was explored and overall samples tested on the radial or rift face did a better job of explaining the variation in lumber than samples tested on the tangential face; however, the relationships were generally poor for the modulus of elasticity (MOE) (R2 = 0.22) and modulus of rupture (MOR) (R2 = 0.11) pooled data.  A lumber-based multiple regression model explained 44% and 37% of the variability for MOE and MOR, respectively; whereas a stand-based multiple regression model explained 41% and 29% of the variability for MOE and MOR, respectively

Do cladistic and morphometric data capture common patterns of morphological disparity?

The distinctly non-random diversity of organismal form manifests itself in discrete clusters of taxa that share a common body plan. As a result, analyses of disparity require a scalable comparative framework. The difficulties of applying geometric morphometrics to disparity analyses of groups with vastly divergent body plans are overcome partly by the use of cladistic characters. Character-based disparity analyses have become increasingly popular, but it is not clear how they are affected by character coding strategies or revisions of primary homology statements. Indeed, whether cladistic and morphometric data capture similar patterns of morphological variation remains a moot point. To address this issue, we employ both cladistic and geometric morphometric data in an exploratory study of disparity focussing on caecilian amphibians. Our results show no impact on relative intertaxon distances when different coding strategies for cladistic characters were used or when revised concepts of homology were considered. In all instances, we found no statistically significant difference between pairwise Euclidean and Procrustes distances, although the strength of the correlation among distance matrices varied. This suggests that cladistic and geometric morphometric data appear to summarize morphological variation in comparable ways. Our results support the use of cladistic data for characterizing organismal disparity

Next Generation Very Large Array Memo No. 6, Science Working Group 1: The Cradle of Life

This paper discusses compelling science cases for a future long-baseline interferometer operating at millimeter and centimeter wavelengths, like the proposed Next Generation Vary Large Array (ngVLA). We report on the activities of the Cradle of Life science working group, which focused on the formation of low- and high-mass stars, the formation of planets and evolution of protoplanetary disks, the physical and compositional study of Solar System bodies, and the possible detection of radio signals from extraterrestrial civilizations. We propose 19 scientific projects based on the current specification of the ngVLA. Five of them are highlighted as possible Key Science Projects: (1) Resolving the density structure and dynamics of the youngest HII regions and high-mass protostellar jets, (2) Unveiling binary/multiple protostars at higher resolution, (3) Mapping planet formation regions in nearby disks on scales down to 1 AU, (4) Studying the formation of complex molecules, and (5) Deep atmospheric mapping of giant planets in the Solar System. For each of these projects, we discuss the scientific importance and feasibility. The results presented here should be considered as the beginning of a more in-depth analysis of the science enabled by such a facility, and are by no means complete or exhaustive.Comment: 51 pages, 12 figures, 1 table. For more information visit https://science.nrao.edu/futures/ngvl

Room Temperature Operation of a Radiofrequency Diamond Magnetometer near the Shot Noise Limit

We operate a nitrogen vacancy (NV-) diamond magnetometer at ambient temperatures and study the dependence of its bandwidth on experimental parameters including optical and microwave excitation powers. We introduce an analytical theory that yields an explicit formula for the response of an ensemble of NV- spins to an oscillating magnetic field, such as in NMR applications. We measure a detection bandwidth of 1.6 MHz and a sensitivity of 4.6 nT/Hz^(1/2), unprecedented in a detector with this active volume and close to the photon shot noise limit of our experiment.Comment: 4 pages; 4 figures; supporting informatio

Prospectus, December 16, 1981

CHRISTMAS GREETINGS; Parkland offers workshop on real estate Jan. 16; Student bids farewell to Parkland; Attention Accounting students; Students should let state know feelings; News In Brief; Cleaning holiday messes; Bookstores having a prosperous gift season; W.I.R.E. celebrates fifth year; Spring semester classes begin Jan. 18; Greetings from the President...; Don\u27t want to complain, but...: Mother wants to avoid hassles; She enjoys atmosphere; Second annual video competition is underway; Students help with layout; Sistercelebration plans winter ritual; Uni High could get aid; Area offerings; 3 sides involved in radio issue; County eligible for grant; Com Club donates money; Stay on diet with sensible foods; \u27Sugar Babies\u27 rescheduled; Poinsettia: sign of season; Tree trimming becomes an art; Christmas cards start in England; He shares a gift of love; Christmas signifies something for everyone; Gift of jewelry never grows old; Boar\u27s head: traditional feast; Day after: throw nuts; Tiny candy shop tempts with treats; Age-old customs make lovely Christmas; Collectibles make memorable Christmas; Joyous carols fill December air; Norwegian Christmas same, yet different from other countries; Christmas garden takes place of tree; Ski club selling candy bars; Good food, drink is large part of Christmas tradition; Sweep bad luck out of house; Spread holiday cheer with goodies from Great Britain; Drive carefully on icy winter days; \u27Tis the season; Santa puts a smile on everyone\u27s face; \u27Buddy Buddy\u27 funny, \u27Rollover\u27 does better; \u27Pennies from Heaven\u27 is touching; Cablevision announces service changes; A tribute to Lennon; Two new books make good Christmas presents; Max? He\u27s a sweetheart; Christmas lives on through years; Burnham offers counsel; LRC adds two new librarians; Movie theatres offer good holiday viewing; Crazy Ozzy coming soon; Santa chooses rug over outdated reindeer; Keep holidays safe, hazard-free; Albums, 45\u27s make great music gifts; Disease killing off pine trees in Illinois; U of I receives 3 grants; Computer model acts like storm; Artificial tree puts a crimp in her tradition; Christmas celebrated in spring?; Guest speaker featured; Students do same things on break as during class; For those who love to skate: Ice arena offers fun for all ages; Parkland\u27s 1981-82 women\u27s basketball; Classifieds; Christmas personals; Post offices keep busy with holiday season; Survey explains degree days; Final Exam Schedule -- Fall \u2781; Prospectus Christmas Hide-A-Word; 1981-1982 College bowl calendar; Women face stern test with Cougars; Women play with balanced attack; B-ballers raise to 5-0; Plenty of upcoming action for football fans; Last Fast Freddy is on Bowls; Fast Freddy Contest; Cobras meet DuPage 19th; Fall semester in reviewhttps://spark.parkland.edu/prospectus_1981/1000/thumbnail.jp

Serratamolide is a hemolytic factor produced by Serratia marcescens

Serratia marcescens is a common contaminant of contact lens cases and lenses. Hemolytic factors of S. marcescens contribute to the virulence of this opportunistic bacterial pathogen. We took advantage of an observed hyper-hemolytic phenotype of crp mutants to investigate mechanisms of hemolysis. A genetic screen revealed that swrW is necessary for the hyper-hemolysis phenotype of crp mutants. The swrW gene is required for biosynthesis of the biosurfactant serratamolide, previously shown to be a broad-spectrum antibiotic and to contribute to swarming motility. Multicopy expression of swrW or mutation of the hexS transcription factor gene, a known inhibitor of swrW expression, led to an increase in hemolysis. Surfactant zones and expression from an swrW-transcriptional reporter were elevated in a crp mutant compared to the wild type. Purified serratamolide was hemolytic to sheep and murine red blood cells and cytotoxic to human airway and corneal limbal epithelial cells in vitro. The swrW gene was found in the majority of contact lens isolates tested. Genetic and biochemical analysis implicate the biosurfactant serratamolide as a hemolysin. This novel hemolysin may contribute to irritation and infections associated with contact lens use. © 2012 Shanks et al

Variability and Multiwavelength Detected AGN in the GOODS Fields

We identify 85 variable galaxies in the GOODS North and South fields using 5 epochs of HST ACS V-band (F606W) images spanning 6 months. The variables are identified through significant flux changes in the galaxy's nucleus and represent ~2% of the survey galaxies. With the aim of studying the active galaxy population in the GOODS fields, we compare the variability-selected sample with X-ray and mid-IR AGN candidates. Forty-nine percent of the variables are associated with X-ray sources identified in the 2Ms Chandra surveys. Twenty-four percent of X-ray sources likely to be AGN are optical variables and this percentage increases with decreasing hardness ratio of the X-ray emission. Stacking of the non-X-ray detected variables reveals marginally significant soft X-ray emission. Forty-eight percent of mid-IR power-law sources are optical variables, all but one of which are also X-ray detected. Thus, about half of the optical variables are associated with either X-ray or mid-IR power-law emission. The slope of the power-law fit through the Spitzer IRAC bands indicates that two-thirds of the variables have BLAGN-like SEDs. Among those galaxies spectroscopically identified as AGN, we observe variability in 74% of broad-line AGNs and 15% of NLAGNs. The variables are found in galaxies extending to z~3.6. We compare the variable galaxy colors and magnitudes to the X-ray and mid-IR sample and find that the non-X-ray detected variable hosts extend to bluer colors and fainter intrinsic magnitudes. The variable AGN candidates have Eddington ratios similar to those of X-ray selected AGN.Comment: 36 pages, 12 figures, ApJ accepte