981 research outputs found
Log Fano varieties over function fields of curves
Consider a smooth log Fano variety over the function field of a curve.
Suppose that the boundary has positive normal bundle. Choose an integral model
over the curve. Then integral points are Zariski dense, after removing an
explicit finite set of points on the base curve.Comment: 18 page
Geometric invariant theory of syzygies, with applications to moduli spaces
We define syzygy points of projective schemes, and introduce a program of
studying their GIT stability. Then we describe two cases where we have managed
to make some progress in this program, that of polarized K3 surfaces of odd
genus, and of genus six canonical curves. Applications of our results include
effectivity statements for divisor classes on the moduli space of odd genus K3
surfaces, and a new construction in the Hassett-Keel program for the moduli
space of genus six curves.Comment: v1: 23 pages, submitted to the Proceedings of the Abel Symposium
2017, v2: final version, corrects a sign error and resulting divisor class
calculations on the moduli space of K3 surfaces in Section 5, other minor
changes, In: Christophersen J., Ranestad K. (eds) Geometry of Moduli.
Abelsymposium 2017. Abel Symposia, vol 14. Springer, Cha
Antimicrobial Susceptibility Trends Observed in Urinary Pathogens Obtained From New York State
International guidelines recommend using local susceptibility data to direct empiric therapy for acute uncomplicated cystitis. We evaluated outpatient urinary isolate susceptibility trends in New York State. Nitrofurantoin had the lowest resistance prevalence whereas trimethoprim-sulfamethoxazole and fluoroquinolones had higher prevalences. This study highlights the need for local outpatient antimicrobial stewardship programs
Face Processing in Humans and New World Monkeys: the Influence of Experiential and Ecological Factors. Animal Cognition
This study tests whether the face-processing sys- tem of humans and a nonhuman primate species share char- acteristics that would allow for early and quick processing of socially salient stimuli: a sensitivity toward conspecific faces, a sensitivity toward highly practiced face stimuli, and an ability to generalize changes in the face that do not sug- gest a new identity, such as a face differently oriented. The look rates by adult tamarins and humans toward conspecific and other primate faces were examined to determine if these characteristics are shared. A visual paired comparison (VPC) task presented subjects with either a human face, chimpanzee face, tamarin face, or an object as a sample, and then a pair containing the previous stimulus and a novel stimulus was presented. The stimuli were either presented all in an upright orientation, or all in an inverted orientation. The novel stim- ulus in the pair was either an orientation change of the same face/object or a new example of the same type of face/object, and the stimuli were shown either in an upright orientation or in an inverted orientation. Preference to novelty scores re- vealed that humans attended most to novel individual human faces, and this effect decreased significantly if the stimuli were inverted. Tamarins showed preferential looking toward novel orientations of previously seen tamarin faces in the up- right orientation, but not in an inverted orientation. Similarly, their preference to look longer at novel tamarin and human faces within the pair was reduced significantly with inverted stimuli. The results confirmed prior findings in humans that novel human faces generate more attention in the upright than in the inverted orientation
recA and catalase in H2O2-mediated toxicity in Neisseria gonorrhoeae.
Neisseria gonorrhoeae cells defective in the biosynthesis of the recA gene product are no more sensitive to hydrogen peroxide than wild-type cells. Although gonococci possess nearly 100-fold-greater catalase levels than Escherichia coli, they are more susceptible to hydrogen peroxide than this organism. The natural niche of gonococci undoubtedly results in exposure to oxidant stress; however, they do not demonstrate particularly efficient antioxidant defense systems
Fibrations on four-folds with trivial canonical bundles
Four-folds with trivial canonical bundles are divided into six classes
according to their holonomy group. We consider examples that are fibred by
abelian surfaces over the projective plane. We construct such fibrations in
five of the six classes, and prove that there is no such fibration in the sixth
class. We classify all such fibrations whose generic fibre is the Jacobian of a
genus two curve.Comment: 28 page
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Characterization of a fluidized-bed combustion ash to determine potential for environmental impact. Final report
A 440-megawatt, circulating fluidized-bed combustion (CFBC), lignite-fired power plant is planned for construction in Choctaw County north of Ackerman, Mississippi. This power plant will utilize Mississippi lignite from the first lignite mine in that state. Malcolm Pirnie, Inc., is working with the power plant developer in the current planning and permitting efforts for this proposed construction project. In order to accommodate Mississippi state regulatory agencies and meet appropriate permit requirements, Malcolm Pirnie needed to provide an indication of the characteristics of the by-products anticipated to be produced at the proposed plant. Since the Mississippi lignite is from a newly tapped mine and the CFBC technology is relatively new, Malcolm Pirnie contacted with the Energy and Environmental Research Center (EERC) to develop and perform a test plan for the production and characterization of ash similar to ash that will be eventually produced at the proposed power plant. The work performed at the EERC included two primary phases: production of by-products in a bench-scale CFBC unit using lignite provided by Malcolm Pirnie with test conditions delineated by Malcolm Pirnie to represent expected operating conditions for the full-scale plant; and an extensive characterization of the by-products produced, focusing on Mississippi regulatory requirements for leachability, with the understanding that return of the by-product to the mine site was an anticipated by-product management plan. The overall focus of this project was the environmental assessment of the by-product expected to be produced at the proposed power plant. Emphasis was placed on the leachability of potentially problematic trace elements in the by-products. The leaching research documented in this report was performed to determine trends of leachability of trace elements under leaching conditions appropriate for evaluating land disposal in monofills, such as returning the by-products to the mine site
An extremal effective survey about extremal effective cycles in moduli spaces of curves
We survey recent developments and open problems about extremal effective
divisors and higher codimension cycles in moduli spaces of curves.Comment: Submitted to the Proceedings of the Abel Symposium 2017. Comments are
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Stability conditions and positivity of invariants of fibrations
We study three methods that prove the positivity of a natural numerical
invariant associated to parameter families of polarized varieties. All
these methods involve different stability conditions. In dimension 2 we prove
that there is a natural connection between them, related to a yet another
stability condition, the linear stability. Finally we make some speculations
and prove new results in higher dimension.Comment: Final version, to appear in the Springer volume dedicated to Klaus
Hulek on the occasion of his 60-th birthda
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