On the geometric nature of characteristic classes of surface bundles

Each Morita--Mumford--Miller (MMM) class e_n assigns to each genus g >= 2 surface bundle S_g -> E^{2n+2} -> M^{2n} an integer e_n^#(E -> M) := in Z. We prove that when n is odd the number e_n^#(E -> M) depends only on the diffeomorphism type of E, not on g, M, or the map E -> M. More generally, we prove that e_n^#(E -> M) depends only on the cobordism class of E. Recent work of Hatcher implies that this stronger statement is false when n is even. If E -> M is a holomorphic fibering of complex manifolds, we show that for every n the number e_n^#(E -> M) only depends on the complex cobordism type of E. We give a general procedure to construct manifolds fibering as surface bundles in multiple ways, providing infinitely many examples to which our theorems apply. As an application of our results we give a new proof of the rational case of a recent theorem of Giansiracusa--Tillmann that the odd MMM classes e_{2i-1} vanish for any surface bundle which bounds a handlebody bundle. We show how the MMM classes can be seen as obstructions to low-genus fiberings. Finally, we discuss a number of open questions that arise from this work.Comment: 26 pages. v2: added examples to final section; v3: improved main theorem for complex fiberings; v4: final version, to appear in Journal of Topolog

Itera- tive Reconstruction Framework for High-Resolution X-ray CT Data

Small animal medical imaging has become an important tool for researchers as it allows noninvasively screening animal models for pathologies as well as monitoring dis- ease progression and therapy response. Currently, clinical CT scanners typically use a Filtered Backprojection (FBP) based method for image reconstruction. This algorithm is fast and generally produces acceptable results, but has several drawbacks. Firstly, it is based upon line integrals, which do not accurately describe the process of X-ray attenuation. Secondly, noise in the projection data is not properly modeled with FBP. On the other hand, iterative algorithms allow the integration of more complicated sys- tem models as well as robust scatter and noise correction techniques. Unfortunately, the iterative algorithms also have much greater computational demands than their FBP counterparts. In this thesis, we develop a framework to support iterative reconstruc- tions of high-resolution X-ray CT data. This includes exploring various system models and algorithms as well as developing techniques to manage the significant computa- tional and system storage requirements of the iterative algorithms. Issues related to the development of this framework as well as preliminary results are presented

Iterative Reconstruction of Cone-Beam Micro-CT Data

The use of x-ray computed tomography (CT) scanners has become widespread in both clinical and preclinical contexts. CT scanners can be used to noninvasively test for anatom- ical anomalies as well as to diagnose and monitor disease progression. However, the data acquired by a CT scanner must be reconstructed prior to use and interpretation. A recon- struction algorithm processes the data and outputs a three dimensional image representing the x-ray attenuation properties of the scanned object. The algorithms in most widespread use today are based on filtered backprojection (FBP) methods. These algorithms are rela- tively fast and work well on high quality data, but cannot easily handle data with missing projections or considerable amounts of noise. On the other hand, iterative reconstruction algorithms may offer benefits in such cases, but the computational burden associated with iterative reconstructions is prohibitive. In this work, we address this computational burden and present methods that make iterative reconstruction of high-resolution CT data possible in a reasonable amount of time. Our proposed techniques include parallelization, ordered subsets, reconstruction region restriction, and a modified version of the SIRT algorithm that reduces the overall run-time. When combining all of these techniques, we can reconstruct a 512 × 512 × 1022 image from acquired micro-CT data in less than thirty minutes

The Raja of Mahmudabad Palace Library Project

Over the course of the last year the Hill Museum and Manuscript Library (HMML) and the Roshan Institute for Persian Studies at the University of Maryland, College Park (Roshan Institute-UMD) have begun collaborating with the Raja of Mahmudabad family on the preservation of their important manuscript collection. The project will help protect the collection through both physical and digital preservation efforts and expand access to it through improved cataloging and digital display in HMML’s online manuscript reading room, vHMML. Funding for the various elements of this broader plan has generously been provided by the British Library’s Endangered Archives Programme (EAP), HMML, Roshan Institute-UMD, and the Islamic Manuscript Association

Beaver-Dredged Canals and their Spacial Relationship to Beaver-Cut Stumps

Castor canadensis Kuhl (North American beavers) are central place foragers whocollect woody plants and building materials from their surroundings and return to a main body of water containing a lodge or food cache. It has been suggested that beavers dredge water-filled canals to extend access to foraging areas; however, the possibility that these engineered transportation routes function as extensions to the beavers\u27 central place has yet to be considered. Our objective in this study was to gain a better understanding of the formation and utilization of canals by beavers and thus further elucidate the complex foraging behavior of these ecosystem engineers. During 2004–2011, we mapped beaver ponds, canals, and cut stumps in eight groundwater-fed wetlands, from at least four separate colonies, in Indianapolis, IN. We found that the mean length, depth, and width of the beaver-dredged canals were 604.3 6 493.1 m, 28.0 6 22.2 cm, and 107.7 6 107.1 cm respectively. Two of the canal systems were mapped for multiple years and their length, depth, and width increased over time and supported the prediction that beavers continuously engineer these canal systems to extend their foraging area into new locations. In addition, and in contrast to previous studies, we found that the number of beaver-cut stumps was negatively related to distance from canals, but not from the body of water containing their lodges. We recommend that studies of optimal foraging in beavers take canals into account, where applicable, when relating foraging to distance from the central place

Characterization of MKIDs for CMB observation at 220 GHz with the South Pole Telescope

We present an updated design of the 220 GHz microwave kinetic inductance detector (MKID) pixel for SPT-3G+, the next-generation camera for the South Pole Telescope. We show results of the dark testing of a 63-pixel array with mean inductor quality factor $Q_i = 4.8 \times 10^5$, aluminum inductor transition temperature $T_c = 1.19$ K, and kinetic inductance fraction $\alpha_k = 0.32$. We optically characterize both the microstrip-coupled and CPW-coupled resonators, and find both have a spectral response close to prediction with an optical efficiency of $\eta \sim 70\%$. However, we find slightly lower optical response on the lower edge of the band than predicted, with neighboring dark detectors showing more response in this region, though at level consistent with less than 5\% frequency shift relative to the optical detectors. The detectors show polarized response consistent with expectations, with a cross-polar response of $\sim 10\%$ for both detector orientations.Comment: 6 pages, 5 figures, ASC 2022 proceeding

The Lantern Vol. 68, No. 1, Fall 2000

• In Attempting to Imitate J. Agard (III) • Headstones • Calligraphy Grace • Fifty Years • Morning • The Millstone • Quick Stop-Off • Jesus Wept (SuperBuick Bodybag) • Just a God • Amy • Silver Doubloons • Ogbanje • Left Behind • Asymmetrical Smile • Sundays • Pie in the Sky • No Surprises • Bill Gooden\u27s Son • Downcast Eyes Meet Tablecloth • Wetlands • Desperate Actions • Receiving End • A Pack of Matches • Coffeehttps://digitalcommons.ursinus.edu/lantern/1157/thumbnail.jp

The Lantern Vol. 68, No. 1, Fall 2000

• In Attempting to Imitate J. Agard (III) • Headstones • Calligraphy Grace • Fifty Years • Morning • The Millstone • Quick Stop-Off • Jesus Wept (SuperBuick Bodybag) • Just a God • Amy • Silver Doubloons • Ogbanje • Left Behind • Asymmetrical Smile • Sundays • Pie in the Sky • No Surprises • Bill Gooden\u27s Son • Downcast Eyes Meet Tablecloth • Wetlands • Desperate Actions • Receiving End • A Pack of Matches • Coffeehttps://digitalcommons.ursinus.edu/lantern/1157/thumbnail.jp

Strong signature of natural selection within an FHIT intron implicated in prostate cancer risk

Previously, a candidate gene linkage approach on brother pairs affected with prostate cancer identified a locus of prostate cancer susceptibility at D3S1234 within the fragile histidine triad gene (FHIT), a tumor suppressor that induces apoptosis. Subsequent association tests on 16 SNPs spanning approximately 381 kb surrounding D3S1234 in Americans of European descent revealed significant evidence of association for a single SNP within intron 5 of FHIT. In the current study, resequencing and genotyping within a 28.5 kb region surrounding this SNP further delineated the association with prostate cancer risk to a 15 kb region. Multiple SNPs in sequences under evolutionary constraint within intron 5 of FHIT defined several related haplotypes with an increased risk of prostate cancer in European-Americans. Strong associations were detected for a risk haplotype defined by SNPs 138543, 142413, and 152494 in all cases (Pearson's χ2 = 12.34, df 1, P = 0.00045) and for the homozygous risk haplotype defined by SNPs 144716, 142413, and 148444 in cases that shared 2 alleles identical by descent with their affected brothers (Pearson's χ2 = 11.50, df 1, P = 0.00070). In addition to highly conserved sequences encompassing SNPs 148444 and 152413, population studies revealed strong signatures of natural selection for a 1 kb window covering the SNP 144716 in two human populations, the European American (π = 0.0072, Tajima's D= 3.31, 14 SNPs) and the Japanese (π = 0.0049, Fay & Wu's H = 8.05, 14 SNPs), as well as in chimpanzees (Fay & Wu's H = 8.62, 12 SNPs). These results strongly support the involvement of the FHIT intronic region in an increased risk of prostate cancer. © 2008 Ding et al