Digital Commons Network^™

Extending And Measuring The Quality Of Fresh-Cut Fruit And Vegetables: A Review, Ana Belen Martin-Diana, Daniel Rico, Gary Henehan, Jesus Maria Frias, J. Barat

Articles

The market sales of ready - to - use vegetables have grown rapidly in recent decades as a result of changes in consumer attitudes especially consumption of fresh-cut lettuce and carrot due to their use in prepared salads. Chlorine solutions have been widely used to sanitise fruit and vegetables in the fresh-cut industry. However, the association of chlorine with the possible formation of carcinogenic chlorinated compounds in water has called into question the use of chlorine in food processing. There is a real need to find alternatives for preservation of fresh-cut fruit and vegetables in order to improve the efficacy …

Torsion-Free Groups And Modules With The Involution Property, Brendan Goldsmith, C. Meehan, S.L. Wallutis

Articles

An Abelian group or module is said to have the involution property if every endomorphism is the sum of two automorphisms, one of which is an involution. We investigate this property for completely decomposable torsion-free Abelian groups and modules over the ring of -adic integers.

Use Of The Mitsunobu Reaction In The Synthesis Of Orthogonally Protected A,B-Diaminopropionic Acids, Fintan Kelleher, Keith Ó Proinsias

Articles

Orthogonally protected a,b-diaminopropionic acids have been synthesised in good yields by the reaction of N-trityl L-serine esters with N-substituted sulfonamides under Mitsunobu reaction conditions (DEAD, PPh₃, THF). The best isolated yields were obtained when N-Boc p-toluenesulfonamide was used as the nitrogen nucleophile precursor in the Mitsunobu reaction. Subsequently, the N-trityl group was efficiently replaced with the more stable allyloxycarbonyl (alloc) group.

A Novel Processing Route For The Production Of Nanoparticulate Zinc Oxide Using An Isophthalate Precursor, Grainne Duffy, Declan Mccormack, Suresh Pillai

Articles

Zinc oxide nanoparticles have been processed from a novel isophthalate precursor. In contrast to those processed from an oxalate precursor, this material exhibits three-dimensional, non-directional aggregation behaviour.

Such non-directional aggregation of uniaxial crystallites may allow for the production of structures with a higher proportion of catalytically active surfaces than can be prepared through conventional sol–gel methods. XRD,

FTIR, TEM and SEM were used to characterize the synthesized materials.

Zinc oxide particles synthesized by using isophthalic acid (C6H4-1,3-(COOH)2) are found to be slightly smaller than the previously reported materials prepared through chelation with oxalic acid (H2C2O2・2H2O).

Phenomenographic Study Of Students’ Problem Solving Approaches In Physics, Laura Walsh, Robert Howard, Brian Bowe

Articles

This paper describes ongoing research investigating student approaches to quantitative and qualitative problem solving in physics. This empirical study was conducted using a phenomenographic approach to analyze data from individual semistructured problem solving interviews with 22 introductory college physics students. The main result of the study is a hierarchical set of categories that describe the students’ problem solving approaches in the context of introductory physics.

The Complexity Of Computing The Size Of An Interval, Lane A. Hemaspaandra, Christopher M. Homan, Sven Kosub, Klaus W. Wagner

Articles

Given a p-order A over a universe of strings (i.e., a transitive, reflexive, antisymmetric relation such that if (x, y) ∈ A then |x| is polynomially bounded by |y|), an interval size function of A returns, for each string x in the universe, the number of strings in the interval between strings b(x) and t(x) (with respect to A), where b(x) and t(x) are functions that are polynomial-time computable in the length of x. By choosing sets of interval size functions based on feasibility requirements for their underlying p-orders, we obtain new characterizations of complexity classes. We prove that the …

Cosmological Constraints From The Sdss Luminous Red Galaxies, Max Tegmark, Daniel J. Eisenstein, Michael Strauss, David H. Weinberg, Michael R. Blanton, Joshua A. Frieman, Masataka Fukugita, James E. Gunn, Andrew J. S. Hamilton, Gillian R. Knapp, Robert C. Nichol, Jeremiah P. Ostriker, Nikhil Padmanabhan, Will J. Percival, David J. Schlegel, Donald P. Schneider, Roman Scoccimarro, Uroš Seljak, Hee-Jong Seo, Molly Swanson, Alexander S. Szalay, Michael S. Vogeley, Jaiyul Yoo, Idit Zehavi, Kevork Abazajian, Scott F. Anderson, James Annis, Neta A. Bahcall, Bruce Bassett, Andreas Berlind, John Brinkman, Tamás Budavari, Francisco Castander, Andrew Connolly, Istvan Csabai, Mamoru Doi, Douglas P. Finkbeiner, Bruce Gillespie, Karl Glazebrook, Gregory S. Hennessy, David W. Hogg, Željko Ivezić, Bhuvnesh Jain, David Johnston, Stephen Kent, Donald Q. Lamb, Brian C. Lee, Huan Lin, Jon Loveday, Robert H. Lupton, Jeffrey A. Munn, Kaike Pan, Changbom Park, John Peoples, Jeffrey R. Pier, Adrian Pope, Michael Richmond, Constance Rockosi, Ryan Scranton, Ravi K. Sheth, Albert Stebbins, Christopher Stoughton, István Szapudi, Douglas L. Tucker, Daniel E. Vanden Berk, Brian Yanny, Donald G. York

Articles

We measure the large-scale real-space power spectrum P(k) using luminous red galaxies (LRGs) in the Sloan Digital Sky Survey (SDSS) and use this measurement to sharpen constraints on cosmological parameters from the Wilkinson Microwave Anisotropy Probe (WMAP). We employ a matrix-based power spectrum estimation method using Pseudo-Karhunen-Lo`eve eigenmodes, producing uncorrelated minimum-variance measurements in 20 k-bands of both the clustering power and its anisotropy due to redshift-space distortions, with narrow and well-behaved window functions in the range 0.01 h/Mpc < k < 0.2 h/Mpc. Results from the LRG and main galaxy samples are consistent, with the former providing higher signal-to-noise. Our results are robust to omitting angular and radial density fluctuations and are consistent between different parts of the sky. They provide a striking confirmation of the predicted large-scale CDM power spectrum. Combining only SDSS LRG and WMAP data places robust constraints on many cosmological parameters that complement prior analyses of multiple data sets. The LRGs provide independent cross-checks on m and the baryon fraction in good agreement with WMAP. Within the context of flat CDM models, our LRG measurements complementWMAP by sharpening the constraints on the matter density, the neutrino density and the tensor amplitude by about a factor of two, giving m = 0.24±0.02 (1 ), Pmν < 0.9 eV (95%) and r < 0.3 (95%). Baryon oscillations are clearly detected and provide a robust measurement of the comoving distance to the median survey redshift z = 0.35 independent of curvature and dark energy properties. Within the CDM framework, our power spectrum measurement improves the evidence for spatial flatness, sharpening the curvature constraint tot = 1.05±0.05 from WMAP alone to tot = 1.003±0.010. Assuming tot = 1, the equation of state parameter is constrained to w = −0.94±0.09, indicating the potential for more ambitious future LRG measurements to provide precision tests of the nature of dark energy. All these constraints are essentially independent of scales k > 0.1h/Mpc and associated nonlinear complications, yet agree well with more aggressive published analyses where nonlinear modeling is crucial.

Geometry Of Minimal Flows, William Basener

Articles

Our main result is that a minimal flow on a compact manifold is either topologically conjugate to a Riemannian flow or every parametrization of φ is nowhere equicontinuous, defined as follows. A flow is Riemannian if given any points x, y ∈ M , the value of d(φt (x), φt (y)) is independent of t ∈ R . A flow is nowhere equicontinuous if there exists an

There Is No 2-(22,8,4) Block Design, Richard Bilous, Clement W.H. Lam, Larry H. Thiel, Ben P.C. Li, G.H. John Van Rees, Stanislaw P. Radziszowski, Wolfgang H. Holzmann, Hadi Kharaghani

Articles

In this paper we show that a 2-(22, 8, 4) design does not exist. This result was obtained by a computer search.

The Law Of Other States, Eric A. Posner, Cass R. Sunstein

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The question of whether courts should consult the laws of "other states" has produced intense controversy. But in some ways, this practice is entirely routine; within the United States, state courts regularly consult the decisions of other state courts in deciding on the common law, the interpretation of statutory law, and even the meaning of state constitutions. A formal argument in defense of such consultation stems from the Condorcet Jury Theorem, which says that under certain conditions, a widespread belief accepted by a number of independent actors, is highly likely to be correct. It follows that if a large majority …

Icing Location Client, Seamus Rooney, Keith Gardiner, James Carswell

Articles

The ICiNG (Innovative Cities for Next Generation) project is researching a multi-modal, multi-access model of e-Government. It develops the concept of a “thin-skinned City” that will be sensitive to both the citizen and the environment through the use of mobile devices, universal access gateways, social software and environmental sensors. Intelligent infrastructure will enable a Public Administration Services layer and a Communities layer. Communities will interact with the infrastructure to avail of ICiNG services created by the administration, and will also create their own information-based services.

Newly Identified Vitamin K-Producing Bacteria Isolated From The Neonatal Faecal Flora, Gordon Cooke, John Behan, Mary Costello

Articles

Fat-soluble vitamin K is an essential component of the blood clotting process. Menaquinones are the naturally occurring form of vitamin K identified in bacteria. Lipid extracts were made from three bacteria originally isolated from the human neonatal gut and identified as Enterobacter agglomerans, Serratia marcescens and Enterococcus faecium. Following preparative thin layer chromatography (TLC), the lipid extracts were subjected to liquid chromatography-mass spectrometry (LC-MS) analysis. Peak analysis of the LC-MS data showed that the three bacteria produce various forms of menaquinone.

Small Ramsey Numbers, Stanislaw Radziszowski

Articles

We present data which, to the best of our knowledge, includes all known nontrivial values and bounds for specific graph, hypergraph and multicolor Ramsey numbers, where the avoided graphs are complete or complete without one edge. Many results pertaining to other more studied cases are also presented. We give references to all cited bounds and values, as well as to previous similar compilations. We do not attempt complete coverage of asymptotic behavior of Ramsey numbers, but concentrate on their specific values.

Transverse Disks, Symbolic Dynamics, Homology Direction Bectors, And Thurston-Nielson Theory, William Basener

Articles

We review some properties of transverse disks and use symbolic dynamics to determine rotation vectors from the return map to a transverse disk. We also prove connections between the symbolic dynamics and Nielson equivalence of orbits.

Implications Of Mass Education On Chemistry Higher Education, Christine O'Connor

Articles

The following paper discusses the implications of government policy for widening access and participation in third level institutes. The increase in ‘non-traditional’ students has been widely recognised on an international scale; however, some issues of inequality still exist. The ‘struggles’ associated with widening participation and the creation of a ‘new’ student type are discussed, with particular reference to chemistry education. A change is needed with regard to the pedagogical approach taken by staff in order to cater for a diverse student body comprising a broad range of learner types, and this must be supported both at departmental and institutional levels. …

Minimal Rankings And The A-Rank Number Of A Path, Victor Kostyuk, Darren Narayan, Victoria Shults

Articles

Given a graph G, a function f:V(G)→ {1,2,…,k} is a k-ranking of G if f(u)=f(v) implies every u-v path contains a vertex w such that f(w)>f(u). A k-ranking is minimal if the reduction of any label greater than 1 violates the described ranking property. The arank number of a graph, denoted ψr(G), is the largest k such that G has a minimal k-ranking. We present new results involving minimal k-rankings of paths. In particular, we determine ψr(Pn), a problem posed by Laskar and Pillone in 2000 (Refer to PDF file for exact formulas).

The Effect Of Physiological Cyclic Stretch On The Cell Morphology, Cell Orientation And Protein Expression Of Endothelial Cells, V. Barron, Claire Brougham, K. Coghlan, C. Stenson-Cox, D. O'Mahoney, P.E. Mchugh

Articles

In vivo, endothelial cells are constantly exposed to pulsatile shear and tensile stresses. The main aim of this study was to design and build a physiological simulator, which reproduced homogenous strain profiles of the tensile strain experienced in vivo, and to investigate the effect of this cyclic tensile strain on the cell morphology, cell orientation and protein expression of endothelial cells. The biological response of human umbilical vein endothelial cells to a uniaxial cyclic stretch, in this newly developed simulator, was examined experimentally using immunohistostaining and confocal imaging and it was

found that the cells elongated and oriented at 58.9± …

Note: Computation Of The Ramsey Number R(W5,K5), Stanislaw Radziszowski, Josh Stinehour, Kung-Kuen Tse

Articles

We determine the value of the Ramsey number R(W5;K5) to be 27, where W5 = K1 + C4 is the 4-spoked wheel of order 5. This solves one of the four remaining open cases in the tables given in 1989 by George R. T. Hendry, which included the Ramsey numbers R(G;H) for all pairs of graphs G and H having ve vertices, except seven entries. In addition, we show that there exists a unique up to isomorphism critical Ramsey graph for W5 versus K5. Our results are based on computer algorithms.

Photoinstrumentation On The Range: A Laboratory Simulation For Postsecondary Education, Andrew Davidhazy

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Students were involved first hand in a simulation of events patterned after those at the White Sands Missile Range during the launch and photography of a missile. A special, but simplified photographic apparatus was used to record flight data. The purpose of the project was to emphasize the important role that photography plays in the acquisition of data and to expose the students to a quantitive application of photography. Cooperation, trust in fellow students and teamwork were an integral part of the project. Career opportunities in the photoinstrumentation field were also discussed.

Trial And Error: The Supreme Court's Philosophy Of Science, Susan Haack

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No abstract provided.

Lossless Compression Of Color Palette Images With One-Dimensional Techniques, Ziya Arnavut, Ferat Sahin

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Palette images are widely used on the World Wide Web (WWW) and in game-cartridge applications. Many images used on the WWW are stored and transmitted after they are compressed losslessly with the standard graphics interchange format (GIF), or portable network graphics (PNG). Well-known 2-D compression schemes, such as JPEG-LS and JPEG-2000, fail to yield better compression than GIF or PNG due to the fact that the pixel values represent indices that point to color values in a look-up table. To improve the compression performance of JPEG-LS and JPEG-2000 techniques, several researchers have proposed various reindexing algorithms. We investigate various compression …

A Stackelberg Game Model Of Trade In Renewable Resources With Competitive Sellers, Amitrajeet A. Batabyal, Hamid Beladi

Articles

We model international trade in renewable resources between a single buyer and competitive sellers as a Stackelberg differential game. The buyer uses unit and ad valorem tariffs to indirectly encourage conservation of the renewable resource under study. First, we show that the efficacy of these trade policy instruments in promoting conservation depends fundamentally on whether harvesting costs are stock dependent or independent. When harvesting costs are stock independent, the optimal open loop tariffs are dynamically consistent. In contrast, when harvesting costs are stock dependent, the optimal open loop tariffs are dynamically inconsistent. Second, we point out that whether the terminal …

Medical Imaging And What Lies Ahead, María Helguera

Articles

Even though the discovery of X-rays by Roentgen happened in 1895, more than 100 years ago, it wasn’t until the early 1960s that computerized analysis of radiological images was possible. Although the mathematical foundation for computed tomography was derived by Radon in 1917, it was not until the early 1970s that computed tomography scanners were initially developed. Since then computers have become an integral part of medical imaging systems and hospitals, being utilized for data acquisition, image generation and display, and image analysis.

An Integer Programming Approach To The Construction Of Trend-Free Experimental Plans On Split-Plot Designs, Andres Carrano, Brian Thorn, Guillermo Lopez

Articles

In many experimental designs, the standard procedure involves randomization of the factor-level combination run order. There are cases, however, where it Is known that a time or position trend that can seriously compromise the results of the experiment may be present. These trends Include wear of tooling and equipment, leaming curves, change In temperatures, and so on, and the trends may show up as linear, quadratic, or even higher order trends. All previously published work has dealt with various methods of constructing trend-resistant run order plans on full and fractional factorial designs. These previous efforts have not addressed any additional …

Process Modeling For Simulation, John Ryan, Cathal Heavey

Articles

This paper discusses shortfalls in relation to the requirements gathering phases of simulation. While many developments have taken place around supporting the model coding task of simulation, there are few tools available to assist in the requirements gathering phase. This is surprising as it has been reported by several researchers that the requirements phase can absorb twice as much resources as the coding phase. There are numerous process modeling tools available (over 100) that can and have been used to support the requirements phase of simulation. This paper provides a selective review of some of the most important in relation …

A Dispatch From The Crypto Wars, A. Michael Froomkin

Articles

Matt Curtin's Brute Force is a primarily personal account of one early effort to harness the power of distributed computing. In 1997, Mr. Curtin and other members of the DESCHALL (DES Challenge) project built, distributed, and managed software that united thousands of computers, many of them ordinary personal computers, in the search for a single decryption key among 72 quadrillion possibilities. The DESCHALL project sought to demonstrate that DES, then the U.S. national standard encryption algorithm, was no longer as secure as advertised. While Brute Force also offers some background on encryption regulation, export control policy, and other aspect of …

Exclusionary Amenities In Residential Communities, Lior Strahilevitz

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No abstract provided.

Behavioral Economics: Human Errors And Market Corrections, Richard A. Epstein

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No abstract provided.

Chenery Ii And The Development Of Federal Administrative Law, Linda Jellum

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No abstract provided.

The Territorial Temptation: A Siren Song At Sea, Bernard H. Oxman

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No abstract provided.