Physical Sciences and Mathematics Commons^™

Co2 Levels And Climate Change During Early Eocene Hyperthermals, Ying Cui

Ying Cui

Early Eocene (56 to 33.9 million years ago) is punctuated by a series of rapid and extreme global warming events, known as the ‘hyperthermals’, triggered by massive release of carbon dioxide. Despite the carbon emission rate might have been ten times smaller than the current emission from burning fossil fuels and cement production, the early Eocene hyperthermals are considered one of the best analogues for CO2 concentration projected into the future. The temperature records are well established from deep sea sediments during these hyperthermals, but the CO2 levels in the atmosphere remain poorly known, partly due to the lack of …

Marine Sediment Record From The East Antarctic Margin Reveals Dynamics Of Ice Sheet Recession, Amy Leventer, Eugene Domack, Jennifer Pike, Catherine Stickley, Eleanor Maddison, Stefanie A. Brachfeld, Patricia Manley, Charlie Mcclennen

Stefanie Brachfeld

The Antarctic shelf is traversed by large-scale troughs developed by glacial erosion. Swath bathymetric, lithologic, and chronologic data from jumbo piston cores from four sites along the East Antarctic margin (Iceberg Alley, the Nielsen Basin, the Svenner Channel, and the Mertz-Ninnis Trough) are used to demonstrate that these cross-shelf features controlled development of calving bay reentrants in the Antarctic ice sheet during deglaciation. At all sites except the Mertz-Ninnis Trough, the transition between the Last Glacial Maximum and the Holocene is characterized by varved couplets deposited during a short interval of extremely high primary productivity in a fjordlike setting. Nearly …

Properties Of New York/New Jersey Harbor Sediments, K. W. Jones, Huan Feng, E. A. Stren, U. Neuhäusler, J. Osán, N. Marinkovic, Z. Song

Huan Feng

Sediments found in waterways around the world may contain toxic compounds of anthropogeilic origin that can harm the environment and human health. As a result, it is often necessary to remove them and find disposal methods that are environmentally and economically acceptable. Here, we report on results obtained in an experimental program to characterize the nature of the sediment contamination. The objective was to gain a better understanding of the properties of the sediments to develop better methods for understanding the fate and transport of the contaminants and for improving methods for their removal from the sediments. Our investigations made …

Urban Environmental Pollution 2010: Trace Metal Dispersion In Soil From Auto-Mechanic Village To Urban Residential Areas In Owerri, Nigeria, Michael A. Nwachukwu, Huan Feng, Jude Alinnor

Huan Feng

Due to poor waste management in mechanic villages (MVs), average metal concentration (mgkg-1) is Pb 1162±572; Mn 864±531; Cu 385±202; Fe 49259±4770; Cd 20±13; Zn 824±190; and Ni 40±35, causing ecological and public health risks in parts of Nigeria. Average metal dispersion (mgkg-1/m) from MVs to residential areas was estimated at 9.2 for Pb; 6.7 for Mn; 6.1 for Zn; 1.5 for Cu; 197 for Fe; 0.3 for Ni; and 0.04 for Cd. This represents a mobility order of Fe>Pb>Mn>Zn>Cu>Ni>Cd, and a pollution order of Pb>Ni>Mn>Zn>Fe>Cu>Cd. MV advantages …

Magnetic Mineral Diagenesis In The River‐Dominated Inner Shelf Of The East China Sea, China, Can Ge, Weiguo Zhang, Chenyin Dong, Yan Dong, Jinyan Liu, Nguyen Thi Thu Hien, Huan Feng, Lizhong Yu

Huan Feng

The inner shelf of the East China Sea is a river-dominated margin characterized by fine-grained mud deposits and a rapid sedimentation rate. Three short sediment cores (similar to 2.7m in length) were examined to characterize spatial variations in magnetic mineral diagenesis. The sediment cores were analyzed for sedimentation rates, magnetic properties, particle size distribution, organic carbon, and total sulfur content. The two more proximal cores with higher sedimentation rates (similar to 2.2cm/yr and similar to 0.96cm/yr) do not exhibit obvious effects of reductive dissolution of magnetite with increasing depth, which is consistent with their lower total sulfur content. The offshore …

Evidence For Exocellular Arsenic In Fronds Of Pteris Vittata, Rupali Datta, Padmini Das, Ryan Tappero, Pravin Punamiya, Evert Elzinga, Shivendra Sahi, Huan Feng, Jeffrey Kiiskila, Dibyendu Sarkar

Huan Feng

The arsenic (As) hyperaccumulating fern species Pteris vittata (PV) is capable of accumulating large quantities of As in its aboveground tissues. Transformation to AsIII and vacuolar sequestration is believed to be the As detoxification mechanism in PV. Here we present evidence for a preponderance of exocellular As in fronds of Pteris vittata despite numerous reports of a tolerance mechanism involving intracellular compartmentalization. Results of an extraction experiment show that 43–71% of the As extruded out of the fronds of PV grown in 0.67, 3.3 and 6.7mM AsV. SEM-EDX analysis showed that As was localized largely on the lower pinna surface, …

Enhancing Digestibility And Ethanol Yield Of Populus Wood Via Expression Of An Engineered Monolignol 4-O-Methyltransferase, Yuanheng Cai, Kewei Zhang, Hoon Kim, Guichuan Hou, Xuebin Zhang, Huijun Yang, Huan Feng, Lisa Miller, John Ralph, Chang-Jun Liu

Huan Feng

Producing cellulosic biofuels and bio-based chemicals from woody biomass is impeded by the presence of lignin polymer in the plant cell wall. Manipulating the monolignol biosynthetic pathway offers a promising approach to improved processability, but often impairs plant growth and development. Here, we show that expressing an engineered 4-O-methyltransferase that chemically modifies the phenolic moiety of lignin monomeric precursors, thus preventing their incorporation into the lignin polymer, substantially alters hybrid aspens’ lignin content and structure. Woody biomass derived from the transgenic aspens shows a 62% increase in the release of simple sugars and up to a 49% increase in the …

Viscosity Of Bacterial Suspensions: Hydrodynamic Interactions And Self-Induced Noise, Shawn D. Ryan, Brian M. Haines, Leonid Berlyand, Falko Ziebert, Igor S. Aranson

Shawn Ryan

The viscosity of a suspension of swimming bacteria is investigated analytically and numerically. We propose a simple model that allows for efficient computation for a large number of bacteria. Our calculations show that long-range hydrodynamic interactions, intrinsic to self-locomoting objects in a viscous fluid, result in a dramatic reduction of the effective viscosity. In agreement with experiments on suspensions of Bacillus subtilis, we show that the viscosity reduction is related to the onset of large-scale collective motion due to interactions between the swimmers. The simulations reveal that the viscosity reduction occurs only for relatively low concentrations of swimmers: Further …

An Elastica Model Of The Buckling Of A Nanoscale Sheet Perpendicular To A Rigid Substrate, Shawn D. Ryan, Dmitry Golovaty, Patrick Wilber

Shawn Ryan

We study a variation on the classical problem of the buckling of an elastica. The elastica models a nanoscale sheet that interacts with a rigid substrate by intermolecular forces. We formulate a buckling problem in which the sheet is perpendicular to the substrate and a load is applied to the edge of the sheet further from the substrate. Our study is motivated by problems in nanomechanics such as the bending of a graphene sheet interacting with a rigid substrate by van der Waals forces. After identifying a trivial branch, we combine computation and analysis to determine the stability and bifurcations …

A Kinetic Model For Semidilute Bacterial Suspensions, Shawn D. Ryan, Leonid Berlyand, Brian M. Haines, D. A. Karpeev

Shawn Ryan

Suspensions of self-propelled microscopic particles, such as swimming bacteria, exhibit collective motion leading to remarkable experimentally observable macroscopic properties. Rigorous mathematical analysis of this emergent behavior can provide significant insight into the mechanisms behind these experimental observations; however, there are many theoretical questions remaining unanswered. In this paper, we study a coupled PDE/ODE system first introduced in the physics literature and used to investigate numerically the effective viscosity of a bacterial suspension. We then examine the kinetic theory associated with the coupled system, which is designed to capture the long-time behavior of a Stokesian suspension of point force dipoles (infinitesimal …

Population Fragmentation Leads To Morpho-Functional Variation In British Red Squirrels (Sciurus Vulgaris), Philip G. Cox, Philip J.R. Morris, Andrew C. Kitchener

Philip Morris

It is well-known that population fragmentation and isolation can lead to rapid morphological and functional divergence, with the effect being particularly well-documented in rodents. Here, we investigated whether such a phenomenon could be identified in the Eurasian red squirrel (Sciurus vulgaris), which was once widespread across the majority of Great Britain, but suffered a severe population decline across the 20^th century, leaving a highly fragmented distribution. The aim was to test for morphological and biomechanical variation of the mandible between the remaining British red squirrel populations. Linear and geometric morphometric methods were used to analyse shape in …

Convergent Evolution In The Euarchontoglires, Philip J.R. Morris, Samuel N.F. Cobb, Philip G. Cox

Philip Morris

Convergence—the independent evolution of similar phenotypes in distantly related clades—is a widespread and much-studied phenomenon. An often-cited, but hitherto untested, case of morphological convergence is that between the aye-aye and squirrels. The aye-aye (Daubentonia madagascariensis) is a highly unusual lemuriform primate that has evolved a dentition similar to that of rodents: it possesses large, ever-growing incisors which it uses to strip the bark from trees in order to feed on wood-boring beetle larvae. Indeed, such is the similarity that some of the earliest classifications of the aye-aye placed it in the squirrel genus Sciurus. Here, we aimed …

Mechanical Significance Of Morphological Variation In Diprotodont Incisors, Philip J.R. Morris, Philip G. Cox, Samuel N. Cobb

Philip Morris

All rodents possess a single pair of enlarged incisors that grow throughout life. This condition (diprotodonty) is characteristic of Rodentia, but is also found in other mammals such as lagomorphs, hyraxes, the aye-aye and common wombat. This study surveyed lower incisor morphology across extant diprotodonts to examine shape variation within and between rodents and other diprotodonts, and to determine if tooth shape varies in a manner predictable from mechanics. Six linear and area variables were recorded from microCT scans of the mandibles of 33 diprotodont mammals. The curvature of the rodent lower incisors, as measured by the proportion of a …

A Socio-Demographic Analysis Of Responses To Terrorism, Gabriel Rubin, Christopher Salvatore

Christopher Salvatore

Extensive research has found that there are differences in reported levels of fear of crime and associated protective actions influenced by socio-demographic characteristics such as race and gender. Further studies, the majority of which focused on violent and property crime, have found that specific demographic characteristics influence fear of crime and protective behaviors. However, little research has focused on the influence of socio-demographic characteristics on perceptions, and protective actions in response to the threat of terrorism. Using data from the General Social Survey, this study compared individual-level protective actions and perceptions of the effectiveness of protective responses to the 9/11 …

Nonsupereulerian Graphs With Large Size, Paul A. Catlin, Zhi-Hong Chen

Zhi-Hong Chen

No abstract provided.

On The Edge Arboricity Of A Random Graph, P. A. Catlin, Zhi-Hong Chen, E. M. Palmer

Zhi-Hong Chen

No abstract provided.

On Hamiltonian Line Graphs, Zhi-Hong Chen

Zhi-Hong Chen

No abstract provided.

Supereuleriaun Graphs And The Petersen Graph, Zhi-Hong Chen

Zhi-Hong Chen

Using a contraction method, we find some best-possible sufficient condi­tions for 3-edge-connected simple graphs such that either the graphs have spanning eulerian subgraphs or the graphs are contractible to the Petersen graph.

Potential Economic Impacts Of Allocating More Land For Bioenergy Biomass Production In Virginia, Thomas O. Ochuodho, Janaki R. R. Alavalapati, Pankaj Lal, Domena A. Agyeman, Bernabas Wolde, Pralhad Burli

Pankaj Lal

The growing attention to renewable energy and rural development has created greater demand for production of biomass feedstock for bioenergy. However, forest growth rates and the amount of land in most existing forests may not be sufficient to sustainably supply the forest biomass required to support existing forest products industries and the expanding bioenergy industry. Additionally, concerns about agricultural land use competition have dampened expansion of biomass production on agricultural land base. One of the ways to meet the growing forest biomass feedstock demand for bioenergy production is by allocating currently marginal non-forested land for growing bioenergy feedstocks. In Virginia, …

Transparent Solar Windows From Labs To Industry, Towards Smart Cities - Encyclopedia- Oct 2019.Pdf, Mohammad Nur-E-Alam, Mikhail Vasiliev, Kamal Alameh

Mikhail Vasiliev

An Optimal Upper Bound On The Tail Probability For Sums Of Random Variables, Iosif Pinelis

Iosif Pinelis

No abstract provided.

Application-Specific Oxide-Based And Metal–Dielectric Thin-Film Materials Prepared By Radio Frequency Magnetron Sputtering, Mohammad Nur-E-Alam, Wade Lonsdale, Mikhail Vasiliev, Kamal Alameh

Mikhail Vasiliev

Supereulerian Graphs And The Petersen Graph, Ii, Zhi-Hong Chen, Hong-Jian Lai

Zhi-Hong Chen

In this note, we verify two conjectures of Catlin in [J. Graph Theory 13 (1989) 465 - 483] for graphs with at most 11 vertices. These are used to prove the following theorem which improves prior results in [10] and [13]:

Let G be a 3-edge-connected simple graph with order n. If n is large and if for every edge 11.v E E(G), d(u) + d(v) 2 % - 2, then either G has a spanning eulerian subgraph or G can be contracted to the Petersen graph.

Fan-Type Conditions For Collapsible Graphs, Zhi-Hong Chen

Zhi-Hong Chen

No abstract provided.

Connectivity Of Cycle Matroids And Bicircular Matroids, Zhi-Hong Chen, Kuang Ying-Qiang, Hong-Jian Lai

Zhi-Hong Chen

A unified approach to prove former connectivity results of Tutte, Cunningham, Inukai and Weinberg, Oxley and Wagner.

The Economic Impacts Of Blackbird (Icteridae) Damage To Sunflower In The Usa, Karina Ernst, Julie Elser, George Linz, Hans Kandel, Jason Holderieath, Samantha Degroot, Steven Shwiff, Stephanie Shwiff

Jason Holderieath

BACKGROUND: Blackbird (Icteridae) damage to ripening sunflower (Helianthus annuus L.) has been a persistent economic issue in the USA for the last five decades. To quantify losses, we surveyed blackbird damage from 2001 to 2013 (excluding 2004) to physiologically mature sunflower in eight states: North Dakota, South Dakota, Texas, Nebraska, Minnesota, Colorado, Kansas, and Vermont.

RESULTS:We pooled data gathered during the most recent 5 years (2009 to 2013) of the survey and found losses averaged $US2.5 million and $US11.3 million for confectionery and oilseed hybrids, respectively. Three states, North Dakota, South Dakota, and Nebraska, had sufficient acreage and bird damage …

Reinforcing The Number Of Disjoint Spanning Trees, Damin Liu, Hong-Jian Lai, Zhi-Hong Chen

Zhi-Hong Chen

The spanning tree packing number of a connected graph G, denoted by _T(G), is the maximum number of edge-disjoint spanning trees of G. In this paper, we determine the minimum number of edges that must be added to G so that the resulting graph has spanning tree packing number at least k, for a given value of k.

Even Subgraphs Of A Graph, Hong-Jian Lai, Zhi-Hong Chen

Zhi-Hong Chen

No abstract provided.

A University-Based Forensics Training Center As A Regional Outreach, Education, And Research Activity, Rayford B. Vaughn, David A. Dampier

David Dampier

This paper describes a university-based Forensics Training Center (FTC) established by a Department of Justice grant for the purpose of improving the ability of state and local law enforcement in the Southeastern part of the United States to address the rising incidence of computer based crime. The FTC effort is described along with supporting evidence of its need. The program is not only a service activity, but also contributes to the Mississippi State University (MSU) security program pedagogy, and research effort.

In Situ Investigation Of Magnetism In Metastable Phases Of Levitated Fe83b17 During Solidification, D. G. Quirinale, D. Messina, G. E. Rustan, Andreas Kreyssig, Ruslan Prozorov, Alan I. Goldman

A. I. Goldman

In situ measurements of structure, density, and magnetization on samples of Fe83B17 using an electrostatic levitation furnace allow us to identify and correlate the magnetic and structural transitions in this system during its complex solidification process. In particular, we identify magnetic ordering in the metastable Fe23B6/ fcc Fe coherently grown structures and primitive tetragonal Fe3B metastable phase in addition to characterizing the equilibrium Fe2B phase. Our measurements demonstrate that the incorporation of a tunnel-diode oscillator circuit within an electrostatic levitation furnace enables investigations of the physical properties of high-temperature metastable structures.