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2007

University of Nebraska - Lincoln

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Articles 1 - 30 of 943

Full-Text Articles in Physical Sciences and Mathematics

Unresolved Issues With The Assessment Of Multidecadal Global Land Surface Temperature Trends, Roger A. Pielke Sr., Christopher A. Davey, Dev Niyogi, Souleymane Fall, Jesse Steinweg-Woods, Ken Hubbard, Xiaomao Lin, Ming Cai, Young-Kwon Lim, Hong Li, John Nielsen-Gammon, Kevin Gallo, Robert Hale, Rezaul Mahmood, Stuart Foster, Richard T. Mcnider, Peter Blanken Dec 2007

Unresolved Issues With The Assessment Of Multidecadal Global Land Surface Temperature Trends, Roger A. Pielke Sr., Christopher A. Davey, Dev Niyogi, Souleymane Fall, Jesse Steinweg-Woods, Ken Hubbard, Xiaomao Lin, Ming Cai, Young-Kwon Lim, Hong Li, John Nielsen-Gammon, Kevin Gallo, Robert Hale, Rezaul Mahmood, Stuart Foster, Richard T. Mcnider, Peter Blanken

School of Natural Resources: Faculty Publications

This paper documents various unresolved issues in using surface temperature trends as a metric for assessing global and regional climate change. A series of examples ranging from errors caused by temperature measurements at a monitoring station to the undocumented biases in the regionally and globally averaged time series are provided. The issues are poorly understood or documented and relate to micrometeorological impacts due to warm bias in nighttime minimum temperatures, poor siting of the instrumentation, effect of winds as well as surface atmospheric water vapor content on temperature trends, the quantification of uncertainties in the homogenization of surface temperature data, …

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Exploiting Self-Assembly For Ligand-Scaffold Optimization: Substrate-Tailored Ligands For Efficient Catalytic Asymmetric Hydroboration, Shin A. Moteki, James M. Takacs Dec 2007

Exploiting Self-Assembly For Ligand-Scaffold Optimization: Substrate-Tailored Ligands For Efficient Catalytic Asymmetric Hydroboration, Shin A. Moteki, James M. Takacs

James Takacs Publications

A self-assembled ligand library (SAL XY) affords a wide range of R/S ratios in Rh-catalyzed asymmetric hydroboration (nbd = 2,5norbornadiene, R* is a chiral substituent). Ligand-scaffold optimization reveals “substrate-tailored” ligands that afford high regio- and enantioselectivity for a variety of ortho-substituted styrene derivatives.

Includes article (4 pp.) and supporting information (106 pp.).

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Measurement Of The Pp̅ → Wz + X Cross Section At √S =1.96 Tev And Limits On Wwz Trilinear Gauge Couplings, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration Dec 2007

Measurement Of The Pp̅ → Wz + X Cross Section At √S =1.96 Tev And Limits On Wwz Trilinear Gauge Couplings, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration

Kenneth Bloom Publications

We present measurements of the process pp̅ → WZ + X → ℓ′νℓℓ&#; at √s = 1.96 TeV, where ℓ and ℓ′ are electrons or muons. Using 1 fb-1 of data from the D0 experiment, we observe 13 candidates with an expected background of 4.5 ± 0.6 events and measure a cross section σ(WZ) = 2.7-1.3+1.7 pb. From the number of observed events and the Z boson transverse momentum distribution, we limit the trilinear WWZ gauge couplings to -0.17 ≤ λZ ≤ 0.21(ΔκZ= 0) at the 95% C.L. for a form …

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Observation Of P-Wave Threshold Behavior In Electron Attachment To F2 Molecules, M. Braun, M.-W. Ruf, Ilya I. Fabrikant, H. Hotop Dec 2007

Observation Of P-Wave Threshold Behavior In Electron Attachment To F2 Molecules, M. Braun, M.-W. Ruf, Ilya I. Fabrikant, H. Hotop

Ilya Fabrikant Publications

Using the high resolution laser photoelectron attachment method, we demonstrate that the cross section for F- formation due to electron capture by F2 (X1Σg+) molecules at very low energies exhibits p-wave threshold behavior. This finding confirms the theoretical expectation that low-energy attachment to F2 proceeds through the F2-(2 Σu+) p-wave shape resonance in contrast with previous experimental claims for s-wave threshold behavior.

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Automated Refinement And Augmentation Of Web Service Description Files, Marc Fisher Ii, Sebastian Elbaum, Gregg Rothermel Dec 2007

Automated Refinement And Augmentation Of Web Service Description Files, Marc Fisher Ii, Sebastian Elbaum, Gregg Rothermel

CSE Technical Reports

Web Service Description Language (WSDL) is being increasingly used to specify web service interfaces. Specifications of this type, however, are often incomplete or imprecise. For example, cursory examination of the WSDL file for Amazon’s E-Commerce Web Service reveals that it often uses a less specific type where a more specific type is applicable, or declares that elements could be missing where other documentation indicates that they are required. Further, specifications reflecting the temporal relationships between operations are completely missing, which is not surprising since they are not supported by the current WSDL standard. These problems in WSDL specifications can cause …

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Ultrashort Intense-Field Optical Vortices Produced With Laser-Etched Mirrors, James Strohaber, Timothy D. Scarborough, Cornelis J. Uiterwaal Dec 2007

Ultrashort Intense-Field Optical Vortices Produced With Laser-Etched Mirrors, James Strohaber, Timothy D. Scarborough, Cornelis J. Uiterwaal

C.J.G.J. Uiterwaal Publications

We introduce a simple and practical method to create ultrashort intense optical vortices for applications involving high-intensity lasers. Our method utilizes femtosecond laser pulses to laser etch grating lines into laser-quality gold mirrors. These grating lines holographically encode an optical vortex. We derive mathematical equations for each individual grating line to be etched, for any desired (integer) topological charge. We investigate the smoothness of the etched grooves. We show that they are smooth enough to produce optical vortices with an intensity that is only a few percent lower than in the ideal case. We demonstrate that the etched gratings can …

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Post-Breeding Habitat Use By Adult Boreal Toads (Bufo Boreas) After Wildfire In Glacier National Park, Usa, C. Gregory Guscio, Blake R. Hossack, Lisa A. Eby, Paul Stephen Corn Dec 2007

Post-Breeding Habitat Use By Adult Boreal Toads (Bufo Boreas) After Wildfire In Glacier National Park, Usa, C. Gregory Guscio, Blake R. Hossack, Lisa A. Eby, Paul Stephen Corn

United States Geological Survey: Staff Publications

Effects of wildfire on amphibians are complex, and some species may benefit from the severe disturbance of stand-replacing fire. Boreal Toads (Bufo boreas boreas) in Glacier National Park, Montana, USA increased in occurrence after fires in 2001 and 2003. We used radio telemetry to track adult B. boreas in a mosaic of terrestrial habitats with different burn severities to better understand factors related to the post-fire pulse in breeding activity. Toads used severely burned habitats more than expected and partially burned habitats less than expected. No toads were relocated in unburned habitat, but little of the study area …

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Wildfire Effects On Water Temperature And Selection Of Breeding Sites By The Boreal Toad (Bufo Boreas) In Seasonal Wetlands, Blake R. Hossack, Paul Stephen Corn Dec 2007

Wildfire Effects On Water Temperature And Selection Of Breeding Sites By The Boreal Toad (Bufo Boreas) In Seasonal Wetlands, Blake R. Hossack, Paul Stephen Corn

United States Geological Survey: Staff Publications

Disturbances can significantly affect the thermal regime and community structure of wetlands. We investigated the effect of a wildfire on water temperature of seasonal, montane wetlands after documenting the colonization of recently burned wetlands by the Boreal Toad (Bufo boreas boreas). We compared the daily mean temperature, daily maximum temperature, and accumulated growing degree·days measured on the north shore of three classes of wetlands: unburned wetlands, burned wetlands that were colonized by breeding toads, and burned wetlands that were not colonized. We hypothesized that toads colonized burned wetlands because they were warmer than unburned wetlands and selected specific …

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Study Of The Decay BS0 → DS(*)DS(*), V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration Dec 2007

Study Of The Decay BS0 → DS(*)DS(*), V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration

Kenneth Bloom Publications

We report a study of the decay Bs0 → Ds(*)Ds(*) using a data sample corresponding to 1.3 fb-1 of integrated luminosity collected by the D0 experiment in 2002–2006 during run II of the Fermilab Tevatron collider. One Ds(*) meson was partially reconstructed in the decay Ds→ φμν, and the other Ds(*) meson was identified using the decay Ds→ φπ where no attempt was made to distinguish Ds and Ds(*) states. For the branching fraction Br(Bs0 → Ds …

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Summary Of Trapping Regulations For Fur Harvesting In The United States, Gordon Batcheller, Furbearer Conservation Technical Work Group Dec 2007

Summary Of Trapping Regulations For Fur Harvesting In The United States, Gordon Batcheller, Furbearer Conservation Technical Work Group

Other Publications in Wildlife Management

A “Summary of Trapping Regulations for Fur Harvesting in the United States and Canada” was originally conducted by the International Association of Fish and Wildlife Agencies Fur Resources Technical Subcommittee in 1995. Over the last decade trapping devices and methods, as well as the regulations that guide them have undergone changes. The summary data of furbearer trapping regulations contained in this report were gathered during the summer/fall of 2007 in an effort to capture those regulation changes and report the current conditions and restrictions within existing laws for the harvest of 26 species of furbearers by regulated trapping throughout the …

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Identification Of The Possible Defect States In Poly(3-Hexylthiophene) Thin Films, D.-Q. Feng, A. N. Caruso, Yaroslav B. Losovyj, D. L. Schulz, Peter A. Dowben Dec 2007

Identification Of The Possible Defect States In Poly(3-Hexylthiophene) Thin Films, D.-Q. Feng, A. N. Caruso, Yaroslav B. Losovyj, D. L. Schulz, Peter A. Dowben

Peter Dowben Publications

The possible origins of a low density of defect states within the highest occupied molecular orbital to lowest unoccupied molecular orbital gap are suggested for regioregular poly(3- hexylthiophene). A number of chemical defects, impurities, and structural defects could contribute to features in photoemission for regioregular poly(3-hexylthiophene), observed within the highest occupied molecular orbital to lowest unoccupied molecular orbital gap of regioregular poly(3-hexylthiophene).

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Characterization Of Metalferroelectric-Insulator-Semiconductor Structures Based On Ferroelectric Langmuir-Blodgett Polyvinylidene Fluoride Copolymer Films For Nondestructive Random Access Memory Applications, Timothy J. Reece Dec 2007

Characterization Of Metalferroelectric-Insulator-Semiconductor Structures Based On Ferroelectric Langmuir-Blodgett Polyvinylidene Fluoride Copolymer Films For Nondestructive Random Access Memory Applications, Timothy J. Reece

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Ferroelectric field effect transistors (FeFETs) have attracted much attention recently because of their ability to combine high speed, low power consumption, and fast nondestructive readout with the potential for high density nonvolatile memory. The polarization of the ferroelectric is used to switch the channel at the silicon surface between states of high and low conductance.

Among the ferroelectric thin films used in FET devices; the ferroelectric copolymer of Polyvinylidene fluoride, PVDF (C2H2F2), with trifluoroethylene, TrFE (C2HF3), has distinct advantages, including low dielectric constant, low processing temperature, low cost and compatibility …

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Fabrication Of Pillar-Structured Thermal Neutron Detectors, Rebecca J. Nikolić, Adam M. Conway, Catherine E. Reinhardt, Robert T. Graff, Tzu Fang Wang, Nirmalendu Deo, Chin Li Cheung Dec 2007

Fabrication Of Pillar-Structured Thermal Neutron Detectors, Rebecca J. Nikolić, Adam M. Conway, Catherine E. Reinhardt, Robert T. Graff, Tzu Fang Wang, Nirmalendu Deo, Chin Li Cheung

Barry Chin Li Cheung Publications

Pillar detector is an innovative solid state device structure that leverages advanced semiconductor fabrication technology to produce a device for thermal neutron detection. State-of-the-art thermal neutron detectors have shortcomings in achieving simultaneously high efficiency, low operating voltage while maintaining adequate fieldability performance. By using a 3-dimensional silicon PIN diode pillar array filled with isotopic boron 10, (10B) a high efficiency device is theoretically possible. The fabricated pillar structures reported in this work are composed of 2 μm diameter silicon pillars with a 4 μm pitch and pillar heights of 6 and 12 μm. The pillar detector with a …

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2007 Annual Report Dec 2007

2007 Annual Report

Nebraska Game and Parks Commission: Publications

Contents:
Letter to Governor Heineman . . . . . . . . . . . . . . . . . 2
Commissioners and Administrators . . . . . . . . . . . 2
Financial Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Recreation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . …

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Tris(Dialkylamino)Aluminums: Syntheses, Characterization, Volatility Comparison, And Atomic Layer Deposition Of Alumina Thin Films, Casey R. Wade, Carter Silvernail, Chiranjib Banerjee, Axel Soulet, James Mcandrew, John A. Belot Jr. Dec 2007

Tris(Dialkylamino)Aluminums: Syntheses, Characterization, Volatility Comparison, And Atomic Layer Deposition Of Alumina Thin Films, Casey R. Wade, Carter Silvernail, Chiranjib Banerjee, Axel Soulet, James Mcandrew, John A. Belot Jr.

Chemistry Department: Faculty Publications

The syntheses and characterization of both tris(diethylamino)aluminum and tris(diisopropylamino)aluminum are presented in this letter. Characterization includes vapor pressure measurements and comparison of the two non-pyrophoric precursors showing them to be viable alternatives to trimethylaluminum. Ultimately, tris(diisopropyl)aluminum was successful in the atomic layer deposition of alumina thin films.

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Occurrence And Biological Effect Of Exogenous Steroids In The Elkhorn River, Nebraska, Usa, Alan S. Kolok, Daniel D. Snow, Satomi Kohno, Marlo K. Sellin, Louis J. Guillette Jr. Dec 2007

Occurrence And Biological Effect Of Exogenous Steroids In The Elkhorn River, Nebraska, Usa, Alan S. Kolok, Daniel D. Snow, Satomi Kohno, Marlo K. Sellin, Louis J. Guillette Jr.

Nebraska Water Center: Faculty Publications

Recent studies of surface waters in North America, Japan, and Europe have reported the presence of steroidogenic agents as contaminants. The current study has three objectives: 1) to determine if steroidogenic compounds are present in the Elkhorn River, 2) to determine if sediments collected from the Elkhorn River can act as a source of steroidogenic compounds to aquatic organisms, and 3) to determine if site-specific biological effects are apparent in the hepatic gene expression of fathead minnows. Evidence was obtained using three approaches: 1) deployment of polar organic chemical integrative samplers (POCIS), 2) deployment of caged fathead minnows, and 3) …

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Western Gray Whales Off Sakhalin Island, Russia: A Joint Russia-U.S. Scientific Investigation July-September 2007, David W. Weller, Amanda L. Bradford, Aimée R. Lang, Hyun Woo Kim, Maxim Sidorenko, Grigory A. Tsidulko, Alexander M. Burdin, Robert L. Brownell Jr. Dec 2007

Western Gray Whales Off Sakhalin Island, Russia: A Joint Russia-U.S. Scientific Investigation July-September 2007, David W. Weller, Amanda L. Bradford, Aimée R. Lang, Hyun Woo Kim, Maxim Sidorenko, Grigory A. Tsidulko, Alexander M. Burdin, Robert L. Brownell Jr.

United States Department of Commerce: Staff Publications

A collaborative Russia-U.S. research program on western gray whales (Eschrichtius robustus) summering off northeastern Sakhalin Island, Russia, has been ongoing since 1995 and has produced important new information on the present day conservation status of this critically endangered population. This interim report reviews preliminary findings from 2007 research activities and combines such with data from previous years, in some cases ranging back to 1994. Photo-identification research conducted off Sakhalin Island in 2007 resulted in the identification of 83 whales, including nine calves and two previously unidentified non-calves. When combined with data from 1994-2006, a catalog of 169 photo-identified …

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Molecules That Target Beta-Amyloid, Cliff I. Stains, Kalyani Mondal, Indraneel Ghosh Dec 2007

Molecules That Target Beta-Amyloid, Cliff I. Stains, Kalyani Mondal, Indraneel Ghosh

Cliff Stains Publications

The devastating effects of Alzheimer’s and related amyloidogenic diseases have inspired the synthesis and evaluation of numerous ligands to understand the molecular mechanism of the aggregation of the beta-amyloid peptide. Our review focuses on the current knowledge in this field with respect to molecules that have been demonstrated to interact with either oligomeric or fibrillar forms of the beta-amyloid peptide. We describe natural proteins, peptides, peptidomimetics, and small molecules that have been found to interfere with beta-amyloid aggregation. We also detail recent efforts in selecting molecules that target beta-amyloid isolated from antibody, protein, and peptide libraries. These new molecules will …

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Evaluation Of Remote Trap Monitors Dec 2007

Evaluation Of Remote Trap Monitors

USDA Wildlife Services: Staff Publications

Can trap monitors save Wildlife Services (WS) specialists time and money by increasing the efficiency of trap checks? To find out, WS scientists and field specialists evaluated the use of remote trap monitors. In 2006, WS personnel evaluated the effectiveness of two remote monitoring devices to alert wildlife specialists when an animal is captured in a trap. The devices, which can be used with any type of trap, consist of small radio transmitters that emit unique pulse rates when an animal is captured. WS personnel tested the device on a variety of wildlife species using several different types of traps …

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Diagnosis Of The July 6, 2002 Ogallala, Nebraska Flash Flood, David B. Radell, Mark R. Anderson, John W. Stoppkotte, James R. Mccormick Dec 2007

Diagnosis Of The July 6, 2002 Ogallala, Nebraska Flash Flood, David B. Radell, Mark R. Anderson, John W. Stoppkotte, James R. Mccormick

Department of Earth and Atmospheric Sciences: Faculty Publications

During the early morning hours of 6 July 2002, a mesoscale convective system (MCS) traversed southwestern Nebraska and produced more than 40 cm of precipitation, resulting in a flash flood that closed Interstate 80 and caused one fatality near Ogallala, Nebraska. Regional climatology yields that this flash flood ranked first in precipitation amount for a 24 hour period over the past one hundred years. Synoptic and mesoscale features similar to other flash flooding events and conducive to extremely heavy precipitation were in place over the Central Plains, including a weak upper level ridge, high precipitable water values (180% of normal), …

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Reinterpreting The Pollen Data From Dos Cabezas, Karl J. Reinhard, Vaughn M. Bryant, Sheila D. Vinton Dec 2007

Reinterpreting The Pollen Data From Dos Cabezas, Karl J. Reinhard, Vaughn M. Bryant, Sheila D. Vinton

School of Natural Resources: Faculty Publications

The published pollen analysis of the Dos Cabezas giants, Geyer et al. (2003), lists variety of purported dietary pollen types. The paper also hypothesises that the giants were poisoned with plant toxins. We have severe reservations about the pollen evidence of diet and poisoning. We suggest that the analysts made several errors in their interpretation. Firstly, some of the discovered pollen types are not prehistoric endemics to the Dos Cabezas region of coastal Peru. These include the pollen of fava beans (cultivated in the Old World), and specified species of agave and sage. We believe that some or all of …

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Nebraska Record Fish Nov 2007

Nebraska Record Fish

Nebraska Game and Parks Commission: Publications

Nebraska Record Fish:
Rod and Reel
Bow and Arrow
Underwater Powered Spearing
Surface Spearfishing

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Inconsistencies Between Pangean Reconstructions And Basic Climate Controls, Clinton Rowe, David B. Loope, Robert J. Oglesby, Rob Van Der Voo, Charles E. Broadwater Nov 2007

Inconsistencies Between Pangean Reconstructions And Basic Climate Controls, Clinton Rowe, David B. Loope, Robert J. Oglesby, Rob Van Der Voo, Charles E. Broadwater

Department of Earth and Atmospheric Sciences: Faculty Publications

The supercontinent Pangea dominated our planet from the Permian into the Jurassic. Paleomagnetic reconstructions have been used to estimate the latitudinal position of Pangea during this 100-million-year period. Atmospheric circulation, recorded by eolian sandstones in the southwestern United States, shows a broad sweep of northeasterly winds over their northernmost extent, curving to become northwesterly in the south. This evidence is consistent with paleomagnetic reconstructions of the region straddling the equator in the Early Permian but is at odds with its northward movement to about 20°N by the Early Jurassic. At least one of the following scenarios must be true: the …

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Persistent Near-Bottom Aggregations Of Mesopelagic Animals Along The North Carolina And Virginia Continental Slopes, John V. Gartner Jr., Kenneth J. Sulak, Steve W. Ross, Ann Marie Necaise Nov 2007

Persistent Near-Bottom Aggregations Of Mesopelagic Animals Along The North Carolina And Virginia Continental Slopes, John V. Gartner Jr., Kenneth J. Sulak, Steve W. Ross, Ann Marie Necaise

United States Geological Survey: Staff Publications

Submersible observations during four missions over the North Carolina and Virginia continental slopes (184–900 m) documented the occurrence of large aggregations of mesopelagic Wshes and macronektonic invertebrates near or on the bottom. Aggregated mesopelagics formed a layer up to tens of meters deep positioned from a few centimeters to 20 m, usually <10 >m, above the substrate. Aggregations were numerically dominated by microvores, notably the myctophid Wsh Ceratoscopelus maderensis and the penaeid shrimp Sergestes arcticus. Consistently present but in relatively lower numbers, were mesopelagic predators, including the paralepidids Notolepis rissoi and Lestidium atlanticum, the eel Nemichthys scolopaceus, the …

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Scalable And Adaptive Metadata Management In Ultra Large-Scale File Systems, Yu Hua, Yifeng Zhu, Hong Jiang Nov 2007

Scalable And Adaptive Metadata Management In Ultra Large-Scale File Systems, Yu Hua, Yifeng Zhu, Hong Jiang

CSE Technical Reports

This paper presents a scalable and adaptive decentralized metadata lookup scheme for ultra large-scale file systems (≥ Petabytes or even Exabytes). Our scheme logically organizes metadata servers (MDS) into a multi-layered query hierarchy and exploits grouped Bloom filters to efficiently route metadata requests to desired MDSs through the hierarchy. This metadata lookup scheme can be executed at the network or memory speed, without being bounded by the performance of slow disks. An effective workload balance algorithm is also developed in this paper for server reconfigurations. This scheme is evaluated through extensive trace-driven simulations and prototype implementation in Linux. Experimental results …

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Measurement Of The Tt̅ Production Cross Section In Pp̅ Collisions At √S = 1.96 Tev Using Kinematic Characteristics Of Lepton + Jets Events, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration Nov 2007

Measurement Of The Tt̅ Production Cross Section In Pp̅ Collisions At √S = 1.96 Tev Using Kinematic Characteristics Of Lepton + Jets Events, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration

Kenneth Bloom Publications

We present a measurement of the top quark pair production cross section in pp̅ collisions at √s = 1.96 TeV utilizing 425 pb-1 of data collected with the D0 detector at the Fermilab Tevatron Collider. We consider the final state of the top quark pair containing one high-pT electron or muon and at least four jets. We exploit specific kinematic features of tt̅ events to extract the cross section. For a top quark mass of 175 GeV, we measure σ tt̅ = 6.4-1.2+1.3(stat) ± 0.7(syst) ± 0.4(lum) pb, in good agreement with the …

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Retreating To Advance Women Geoscience Faculty, Suzanne O'Connell, Mary Anne Holmes Nov 2007

Retreating To Advance Women Geoscience Faculty, Suzanne O'Connell, Mary Anne Holmes

Department of Earth and Atmospheric Sciences: Faculty Publications

Seventeen women geoscientists from New England, New York, and New Jersey assembled for a writing retreat at Boston College's Connors Family Retreat and Conference Center, set on 80 pastoral acres on the outskirts of Boston. Funded through the National Science Foundation ADVANCE program, the retreat had two objectives: to facilitate writing and to develop a supportive community. It succeeded on both accounts. Although new to science, retreats of this sort have long been a highly sought after experience for writers in other disciplines. The potential benefits for scientists, in particular, women scientists, are great. Writing is a cornerstone of our …

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An Architectural Approach To Improving The Availability Of Parity-Based Raid Systems, Lei Tian, Hong Jiang, Dan Feng, Qin Xin, Sai Huang Nov 2007

An Architectural Approach To Improving The Availability Of Parity-Based Raid Systems, Lei Tian, Hong Jiang, Dan Feng, Qin Xin, Sai Huang

CSE Technical Reports

In this paper, we propose an architectural approach, Supplementary Partial Parity (SPP), to addressing the availability issue of parity encoded RAID systems. SPP exploits free storage space and idle time to generate and update a set of partial parity units that cover a subset of disks (or data stripe units) during failure-free and idle/lightly-loaded periods, thus supplementing the existing full parity units for improved availability. By applying the exclusive OR operations appropriately among partial parity, full parity and data units, SPP can reconstruct the data on the failed disks with a fraction of the original overhead that is proportional to …

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Amp: An Affinity-Based Metadata Prefetching Scheme In Large-Scale Distributed Storage Systems, Lin Li, Xuemin Li, Hong Jiang, Yifeng Zhu Nov 2007

Amp: An Affinity-Based Metadata Prefetching Scheme In Large-Scale Distributed Storage Systems, Lin Li, Xuemin Li, Hong Jiang, Yifeng Zhu

CSE Technical Reports

Prefetching is an effective technique for improving file access performance, which can reduce access latency for I/O systems. In distributed storage system, prefetching for metadata files is critical for the overall system performance. In this paper, an Affinity-based Metadata Prefetching (APM) scheme is proposed for metadata servers in large-scale distributed storage systems to provide aggressive metadata prefetching. Through mining useful information about metadata assesses from past history, AMP can discover metadata file affinities accurately and intelligently for prefetching. Compared with LRU and some of the latest file prefetching algorithms such as NEXUS and C-miner, trace-driven simulations show that AMP can …

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A Set Of Phosphatase-Inert “Molecular Rulers” To Probe For Bivalent Mannose 6-Phosphate Ligand-Receptor Interactions, Xiang Fei, Christopher M. Connelly, Richard G. Macdonald, David B. Berkowitz Nov 2007

A Set Of Phosphatase-Inert “Molecular Rulers” To Probe For Bivalent Mannose 6-Phosphate Ligand-Receptor Interactions, Xiang Fei, Christopher M. Connelly, Richard G. Macdonald, David B. Berkowitz

David Berkowitz Publications

A set of bivalent mannose 6-phosphonate “molecular rulers” has been synthesized to examine ligand binding to the M6P/IGF2R. The set is estimated to span a P-P distance range of 16-26 Å (MMFF energy minimization on the hydrated phosphonates). Key synthetic transformations include sugar triflate displacement for phosphonate installation and Grubbs I cross-metathesis to achieve bivalency. Relative binding affinities were tested by radioligand displacement assays versus PMP-BSA (pentamannose phosphate-bovine serum albumin). These compounds exhibit slightly higher binding affinities for the receptor (IC50’s = 3.7-5 &#;M) than the parent, monomeric mannose 6-phosphonate ligand and M6P itself (IC50 = 11.5 …

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