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2010

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Articles 2011 - 2040 of 8620

Full-Text Articles in Physical Sciences and Mathematics

New Cyclic Peptides Via Ring-Closing Metathesis Reactions And Their Anti-Bacterial Activities, Timothy P. Boyle, John B. Bremner, Jonathan Coates, John Deadman, Paul A. Keller, Stephen G. Pyne, David I. Rhodes Aug 2010

New Cyclic Peptides Via Ring-Closing Metathesis Reactions And Their Anti-Bacterial Activities, Timothy P. Boyle, John B. Bremner, Jonathan Coates, John Deadman, Paul A. Keller, Stephen G. Pyne, David I. Rhodes

Paul Keller

As part of a program investigating cyclic peptides with an internal aromatic hydrophobic scaffold as potential novel anti-bacterial agents, we explored the synthesis of simple tyrosine-based systems. These were prepared via key intermediates containing internal allylglycine and allyltyrosine residues for subsequent ring closing metathesis reactions. Although the resulting anti-bacterial activity against Staphylococcus aureus was modest, this represents a novel and simple route to this class of compounds. One intermediate acyclic dipeptide precursor showed good activity against S. aureus with an MIC of 7.8 µg/mL.


Regioselective Synthesis Of Novel E-Edge-[60]Fullerenylmethanodihydropyrroles And 1,2-Dihydromethano[60]Fullerenes, Leila Chaker, Graham E. Ball, James R. Williams, Glenn A. Burley, Bill C. Hawkins, Paul A. Keller, Stephen G. Pyne Aug 2010

Regioselective Synthesis Of Novel E-Edge-[60]Fullerenylmethanodihydropyrroles And 1,2-Dihydromethano[60]Fullerenes, Leila Chaker, Graham E. Ball, James R. Williams, Glenn A. Burley, Bill C. Hawkins, Paul A. Keller, Stephen G. Pyne

Paul Keller

Treatment of a tethered N-(diphenylmethylene)glycinate-malonate derivative with [60]fullerene under Bingel conditions yielded an e-edge-[60]fullerenylmethanodihydropyrrole adduct in a regioselective manner. The regiochemical outcome was independent of the order of addition of either the N-(diphenylmethylene)glycinate or the malonate moieties. This new bis-adduct was also prepared in 13C enriched form allowing for its unequivocal structural characterization by 2D INADEQUATE NMR experiments. Ring-opening of the dihydropyrrole functionality of the bisadducts under reductive conditions gave exclusively novel dihydromethano[60]fullerene derivatives.


The Role Of The Hpa Axis In Psychiatric Disorders And Crf Antagonists As Potential Treatments, Paul A. Keller, A. Mccluskey, J. Morgan, S. M. O'Connor Aug 2010

The Role Of The Hpa Axis In Psychiatric Disorders And Crf Antagonists As Potential Treatments, Paul A. Keller, A. Mccluskey, J. Morgan, S. M. O'Connor

Paul Keller

An overview of the links between the Hypothalamic-Pituitary-Adrenal (HPA) axis and psychiatric disorders is presented. The current treatments are outlined, indicating that they are insufficient to meet the needs of those that suffer from these affective disorders. Therefore, there is an urgent need for the generation of new therapeutics, in particular, against new targets. The association of the corticotrophin releasing factor (CRF) and the HPA axis indicates that CRF antagonists should be beneficial as potential therapeutics.


A Convenient And Efficient Synthesis Of (S)-Lysine And (S)-Arginine Homologues Via Olefin Cross-Metathesis, Timothy P. Boyle, John B. Bremner, Jonathan A. Coates, Paul A. Keller, Stephen G. Pyne Aug 2010

A Convenient And Efficient Synthesis Of (S)-Lysine And (S)-Arginine Homologues Via Olefin Cross-Metathesis, Timothy P. Boyle, John B. Bremner, Jonathan A. Coates, Paul A. Keller, Stephen G. Pyne

Paul Keller

A convenient five step synthesis of (S)-homolysine, incorporating a key olefin cross-metathesis step in the chain extension methodology, has been developed, together with a six step related synthesis of a new homologue of arginine, (S)-bishomoarginine.


Antimalarial Activity Of 2,4-Diaminopyrimidines, J. Morgan, R. Haritakul, Paul A. Keller Aug 2010

Antimalarial Activity Of 2,4-Diaminopyrimidines, J. Morgan, R. Haritakul, Paul A. Keller

Paul Keller

A series of 2,4- and 4,6-diaminopyrimidines were prepared and evaluated for their in vitro antimalarial activity. Of the 12 compounds tested 7 showed reasonable activity with 1 having a sub-micromolar IC50.


Aryl Nitro Reduction With Iron Powder Or Stannous Chloride Under Ultrasonic Irradiation, A. B. Gamble, James A. Garner, Christopher Gordon, S. M. J. O'Conner, Paul A. Keller Aug 2010

Aryl Nitro Reduction With Iron Powder Or Stannous Chloride Under Ultrasonic Irradiation, A. B. Gamble, James A. Garner, Christopher Gordon, S. M. J. O'Conner, Paul A. Keller

Paul Keller

The selective reduction of aryl nitro compounds in the presence of sensitive functionalities, including halide, carbonyl, nitrile and ester substituents under ultrasonic irradiation at 35 kHz is reported in yields of 39-98%. Iron powder proved superior to stannous chloride with high tolerance of sensitive functional groups and high yields of the desired aryl amines in relatively short reaction times. Simple experimental procedure and purification also make the iron reduction of aryl nitro compounds advantageous over other methods of reduction.


Control Of Hiv Through The Inhibition Of Hiv-1 Integrase: A Medicinal Chemistry Perspective, Christopher Gordon, R. Griffith, Paul A. Keller Aug 2010

Control Of Hiv Through The Inhibition Of Hiv-1 Integrase: A Medicinal Chemistry Perspective, Christopher Gordon, R. Griffith, Paul A. Keller

Paul Keller

This article reviews the current status of classes of HIV-1 integrase enzyme inhibitors. These classes include peptide-based inhibitors, natural products, polyhydroxylated aromatics, diketo acids, naphthyridines, and sulfonated compounds including sulfonic acids. Discussions of structure activity relationships are presented and include the current overview of the structure-based model, suitable for the further design and development. To date, the advances in the medicinal chemistry of HIV-1 integrase inhibitors have relied mostly on ligand-based designs leading to most displaying similar binding interactions within the active site or at the dimer interface. This paves the way for single enzyme mutations rendering entire compound classes …


The Prevention Of Preterm Labour – Corticotropin Releasing Hormone Type 1 Receptors As A Target For Drug Design And Development, Paul A. Keller, K. Kirkwood, J. Morgan, S. Westcott, A. Mccluskey Aug 2010

The Prevention Of Preterm Labour – Corticotropin Releasing Hormone Type 1 Receptors As A Target For Drug Design And Development, Paul A. Keller, K. Kirkwood, J. Morgan, S. Westcott, A. Mccluskey

Paul Keller

The role of the corticotropin releasing hormone in the onset of labour and the subsequent medicinal chemistry implications of CRH antagonists for the prevention of premature birth, and identification of the CRH type 1 receptor as the target for this drug design, are reviewed here.


A New Methodology For The Simulation Of Flexible Protein – Ligand Interactions, James A. Garner, John Deadman, David I. Rhodes, Renate Griffith, Paul A. Keller Aug 2010

A New Methodology For The Simulation Of Flexible Protein – Ligand Interactions, James A. Garner, John Deadman, David I. Rhodes, Renate Griffith, Paul A. Keller

Paul Keller

A methodology has been developed for the simulation of induced fit between a ligand and its target protein. It utilizes constrained molecular dynamics where atoms determined to be immobile from difference distance matrix studies are fixed. Application of this methodology to HIV-1 reverse transcriptase (RT) as the example target protein has demonstrated its robustness. Short simulation times are sufficient to achieve good refinement of docking poses resulting from exchange of structurally dissimilar inhibitors between crystal structures.


Corticotropin Releasing Hormone - A Gpcr Drug Target, C. Hemley, A. Mccluskey, Paul A. Keller Aug 2010

Corticotropin Releasing Hormone - A Gpcr Drug Target, C. Hemley, A. Mccluskey, Paul A. Keller

Paul Keller

Corticotrophin Releasing Hormone (CRH) is a primary hormone in the fight or flight response targeting a membrane bound G-protein coupled receptor (GPCR). Many people worldwide stand to benefit by the development of CRH agonists and antagonists for the treatment of anxiety and depression, with additional therapeutic targets including Alzheimer’s, pain and the prevention of premature birth: so why the delay in development? In this review, we will discuss not only CRH, related proteins, receptors and ligands, but some of the obstacles that have arisen, as well as strategies being pursued to overcome these problems in the pursuit of this GPCR …


Combining Structure-Based Drug Design And Pharmacophores, Renate Griffith, T. T. T. Luu, James A. Garner, Paul A. Keller Aug 2010

Combining Structure-Based Drug Design And Pharmacophores, Renate Griffith, T. T. T. Luu, James A. Garner, Paul A. Keller

Paul Keller

Development towards integrated computer-aided drug design methodologies is presented by utilising crystal structure complexes to produce structure-based pharmacophores. These novel pharmacophores represent the ligand features that are involved in interactions with the target protein, as well as the space around the ligand occupied by the protein. The protein-ligand complexes can also yield information about all interactions that ligands could potentially form with the binding site, as well as about the size of the binding cavity. Together, these describe a 'superligand', which can also be viewed as a pharmacophore. Various types of novel pharmacophores are discussed and compared, using HIV-1 Reverse …


Estimating Self-Sustainability In Peer-To-Peer Swarming Systems, Daniel S. Menasché, Antonio A. A. Rocha, Edmundo A. De Souza E Silva, Rosa M. Leāo, Don Towsley, Arun Venkataramani Aug 2010

Estimating Self-Sustainability In Peer-To-Peer Swarming Systems, Daniel S. Menasché, Antonio A. A. Rocha, Edmundo A. De Souza E Silva, Rosa M. Leāo, Don Towsley, Arun Venkataramani

Arun Venkataramani

Peer-to-peer swarming is one of the \emph{de facto} solutions for distributed content dissemination in today's Internet. By leveraging resources provided by clients, swarming systems reduce the load on and costs to publishers. However, there is a limit to how much cost savings can be gained from swarming; for example, for unpopular content peers will always depend on the publisher in order to complete their downloads. In this paper, we investigate this dependence. For this purpose, we propose a new metric, namely \emph{swarm self-sustainability}. A swarm is referred to as self-sustaining if all its blocks are collectively held by peers; the …


Emergent Design Dissertation Errata, Kent D. Palmer Aug 2010

Emergent Design Dissertation Errata, Kent D. Palmer

Kent D. Palmer

Errors found in final dissertation


Web 2.0 Technologies Within A Higher Education Online Database Practicum Supporting A New Collaborated Methodology, Sandra Blackman Aug 2010

Web 2.0 Technologies Within A Higher Education Online Database Practicum Supporting A New Collaborated Methodology, Sandra Blackman

Regis University Student Publications (comprehensive collection)

Since the introduction of Web 2.0 technologies in 2004, computer based communication has evolved adding a new dimension to formal and informal knowledge sharing. Focusing on Web 2.0 technologies Facebook and Twitter, this case study researches the use of these tools to enhance a higher education online database practicum environment. This paper presents practical methodologies that can be used to incorporate Web 2.0 technologies to support knowledge sharing in a distance learning database practicum.


Jual Blue Wizard Di Nganjuk 085742304955, Yanto Sanjaya Yanto Aug 2010

Jual Blue Wizard Di Nganjuk 085742304955, Yanto Sanjaya Yanto

Yanto sanjaya Yanto


Adalah Obat Perangsang Cair Alami Yang Berasal Dari Jerman, Sangat Manjur Untuk Mengatasi Kaum Wanita Yang Kurang Bergairah Dalam Hubungan Intim ( Seksual ) . Obat Perangsang Cair Wanita Perangsang Blue Wizard Dapat Membangkitkan Rangsangan Sex Secara Spontans Dan Instan . Blue Wizard Cair Obat Perangsang Wanita Merupakan Cairan Perangsang Yang Tidak Berbau, Tidak Berwarna, Dan Tidak Berasa.

CARA PEMAKAIAN BLUE WIZARD CAIR OBAT PERANGSANG WANITA :
Satu Botol Blue Wizard Germany Bisa Dipakai Untuk 3 Kali, Karena Isi Lebih Banyak Dibandingkan Dengan Perangsang Wanita Cair Lainnya, Cukup 5 – 10 TetesPerangsang Wanita …


Cox Model Analysis With The Dependently Left Truncated Data, Ji Li Aug 2010

Cox Model Analysis With The Dependently Left Truncated Data, Ji Li

Mathematics Theses

A truncated sample consists of realizations of a pair of random variables (L, T) subject to the constraint that L ≤T. The major study interest with a truncated sample is to find the marginal distributions of L and T. Many studies have been done with the assumption that L and T are independent. We introduce a new way to specify a Cox model for a truncated sample, assuming that the truncation time is a predictor of T, and this causes the dependence between L and T. We develop an algorithm to obtain the adjusted risk sets and use the Kaplan-Meier …


Expert System For Online Diagnosis Of Red-Eye Diseases, Dr. Muhammad Zubair Asghar, Muhammad Junaid Asghar Aug 2010

Expert System For Online Diagnosis Of Red-Eye Diseases, Dr. Muhammad Zubair Asghar, Muhammad Junaid Asghar

Dr. Muhammad Zubair Asghar

This paper describes Expert System (ES) for online diagnosis and prescription of red-eye diseases. The types of eye diseases that can be diagnosed with this system are called Red-eye diseases i.e. disease in which red-eye is the common symptom. It is rule based web-supported expert system, assisting ophthalmologists, medical students doing specialization in ophthalmology, researchers as well as eye patients having computer know-how. System was designed and programmed with Java Technology. The expert rules were developed on the symptoms of each type of Red-eye disease, and they were presented using tree-graph and inferred using forward-chaining with depth-first search method. User …


Africa In The World Trade Network, Luca De Benedictis Aug 2010

Africa In The World Trade Network, Luca De Benedictis

Luca De Benedictis

This paper contributes to the analysis of the effect of the global financial crisis (Claessens et al., 2010) on African coutries (IMF, 2009) inspecting the effect of the crises on bilateral trade flows. The empirical analysis makes intensive use of network analysis techniques, describing the international trade of SSA countries as part of the world trade network. The paper analyzes the change in the topology of the trade network during the crisis. Single SSA countries participation to the network is reported in terms of link strength and centrality, showing if some specific countries were more radically disconnected from the giant …


In Memoriam Aug 2010

In Memoriam

Studia UBB Geologia

No abstract provided.


New Observations On Permocalculus Gosaviensis Schlagintweit, 1991 (Calcareous Alga) From The Upper Cretaceous Of The Northern Calcareous Alps (Gosau Group, Austria), Felix Schlagintweit Aug 2010

New Observations On Permocalculus Gosaviensis Schlagintweit, 1991 (Calcareous Alga) From The Upper Cretaceous Of The Northern Calcareous Alps (Gosau Group, Austria), Felix Schlagintweit

Studia UBB Geologia

New thin-sections from the Upper Cretaceous Gosau Group of Brandenberg, Tyrol, Austria, yielded well-preserved specimens of the calcareous alga Permocalculus gosaviensis Schlagintweit. Microfacies are foraminiferal-algal wackestones; stratigraphy is Upper Turonian (?Lower Coniacian). It is shown that the original description was based on oblique sections leading to the incorrect assumption of a piriform segment morphology. Instead, P. gosaviensis is a representative of Permocalculus of the group with constrictions/swellings along the segments (waxing-and-waning type). Permocalculus nikolapantici Radoičić from the Upper Turonian of Serbia is considered a junior synonym of Permocalculus gosaviensis Schlagintweit.


Polito- A New Open-Source, Platform Independent Software For Generating High-Quality Lithostratigraphic Columns, Ciprian C. Stremtan, Alexandru Tudor Aug 2010

Polito- A New Open-Source, Platform Independent Software For Generating High-Quality Lithostratigraphic Columns, Ciprian C. Stremtan, Alexandru Tudor

Studia UBB Geologia

POLITO is a free, open-source, and platform-independent software which can automatically generate lithostratigraphic columns from field data. Its simple and easy to use interface allows users to manipulate large datasets and create high-quality graphical outputs, either in editable vector or raster format, or as PDF files. POLITO uses USGS standard lithology patterns and can be downloaded from its Sourceforge project page (http://sourceforge.net/projects/polito/).


Mineralogy Of Speleothems From Four Caves In The Purcăreţ - Boiu Mare Plateau And The Baia Mare Depression (Nw Romania), Tudor Tamas, Razvan Ungureanu Aug 2010

Mineralogy Of Speleothems From Four Caves In The Purcăreţ - Boiu Mare Plateau And The Baia Mare Depression (Nw Romania), Tudor Tamas, Razvan Ungureanu

Studia UBB Geologia

The Purcăreţ - Boiu Mare Plateau and the southern edge of the Baia Mare Depression, in Sălaj and Maramureş Counties, NW Romania, host over 200 caves located in limestones ranging in age from Upper Eocene to Badenian. The carbonate rocks are interposed with non-karst rocks consisting of shales, sandstones and marls. Four caves hosted by limestones of different lithologies have been investigated for secondary minerals in the composition of their speleothems. Calcite, gypsum, goethite, jarosite, brushite, hydroxylapatite and taranakite were found in the composition of crusts, crystals, aggregates and earthy masses. The mineral association was characterized by means of X-ray …


Past Surface Conditions And Speleogenesis As Inferred From Cave Sediments In The Great Cave Of Șălitrari Mountain (Sw Romania), Cristina M. Pușcaș, Ciprian C. Stremtan, Ferenc Kristály Aug 2010

Past Surface Conditions And Speleogenesis As Inferred From Cave Sediments In The Great Cave Of Șălitrari Mountain (Sw Romania), Cristina M. Pușcaș, Ciprian C. Stremtan, Ferenc Kristály

Studia UBB Geologia

Abstract In one of the passages in the Great Cave of Șălitrari Mountain the floor is completely covered by an alluvial deposit at least 6 m in thickness, ranging from boulders, and cobbles, to sand and clay, topped by a layer of dry bat guano. Sediment and mineral samples collected from six profiles underwent broad analyses to determine their petrological and mineralogical makeup, grain-size distribution, and paleoclimatic significance. The complicated facies alternation suggests frequent changes in the former stream’s hydrological parameters, with frequent flooding, leading to the hypothesis that the climate was somewhat wetter than today. Both the mineralogical composition …


New Data On Facies Development And Micropaleontology Of The Eastern Margin Of The Getic Carbonate Platform (South Carpathians, Romania): Case Study Of Mateiaş Limestone, Ioan I. Bucur, Daniela Beles, Emanoil Sasaran, Constantin Balica Aug 2010

New Data On Facies Development And Micropaleontology Of The Eastern Margin Of The Getic Carbonate Platform (South Carpathians, Romania): Case Study Of Mateiaş Limestone, Ioan I. Bucur, Daniela Beles, Emanoil Sasaran, Constantin Balica

Studia UBB Geologia

Mateiaş Limestone represents a lithostratigraphic unit included in the Braşov Series, which is a component of the eastern end of the Getic Nappes’ cover (the Getic carbonate platform). The study of the Mateiaş Limestone in Hulei-Mateiaş-Măgura area has evidenced three main facies, and five microfacies types. The Kimmeridgian (possibly also Early Tithonian) age of the Mateiaş Limestone has been assigned based on a microfossil association identified in thin sections. The regional framework, as well as their sedimentological and micropaleontological features point to the deposition of these limestones on shelf margin and slope environments; the succession in the studied area corresponds …


Late Jurassic–Early Cretaceous Foraminifera From Štramberk-Type Limestones, Polish Outer Carpathians, Daria Ivanova, Boguslaw Kolodziej Aug 2010

Late Jurassic–Early Cretaceous Foraminifera From Štramberk-Type Limestones, Polish Outer Carpathians, Daria Ivanova, Boguslaw Kolodziej

Studia UBB Geologia

Foraminifera studies were carried out on the Štramberk-type limestones which occur as pebbles to small boulders (exotics) within the uppermost Jurassic–Palaeogene flysch deposits of the Polish Outer Carpathians. The studies were focused on foraminifera from (1) reef and peri-reef facies, and (2) lagoonal algal-foraminiferal facies. The paper deals with 34 species (including 8 in open nomenclature) representing 30 genera, 22 families, 14 superfamilies, 11 suborders, and 7 orders. A more precise age determination has been obtained for 30 exotics, representing a Tithonian (mostly) to Valanginian age. Foraminiferal assemblages from at least two exotics suggest a Valanginian age as indicated by …


Interview With Farhad Ghafarzade, Green Drop Garage, 2010 (Audio), Farhad Ghafarzade Aug 2010

Interview With Farhad Ghafarzade, Green Drop Garage, 2010 (Audio), Farhad Ghafarzade

All Sustainability History Project Oral Histories

Interview of Farhad Ghafarzade by Jeff Howard in SE Portland, Oregon on August 6th, 2010.

The interview index is available for download.


Multiferroic Pb(Fe1/2Nb1/2)O3 Single Crystals: A Raman Scattering Study, A. F. García-Flores, Dmitri A. Tenne, W. J. Ren, X. X. Xi., S.-W. Cheong Aug 2010

Multiferroic Pb(Fe1/2Nb1/2)O3 Single Crystals: A Raman Scattering Study, A. F. García-Flores, Dmitri A. Tenne, W. J. Ren, X. X. Xi., S.-W. Cheong

Physics Faculty Publications and Presentations

No abstract provided.


A Spectral Approach To Protein Structure Alignment, Yosi Shibberu, Allen Holder Aug 2010

A Spectral Approach To Protein Structure Alignment, Yosi Shibberu, Allen Holder

Mathematical Sciences Technical Reports (MSTR)

We present two algorithms that use spectral methods to align protein folds. One of the algorithms is suitable for database searches, the other for difficult alignments. We present computational results for 780 pairwise alignments used to classify 40 proteins as well as results for a separate set of 36 protein alignments used for comparison to four other alignment algorithms. We also provide a mathematically rigorous development of the intrinsic geometry underlying our spectral approach.


Type-1.5 Superconducting State From An Intrinsic Proximity Effect In Two-Band Superconductors, Egor Babaev, Johan Carlstrom, Martin Speight Aug 2010

Type-1.5 Superconducting State From An Intrinsic Proximity Effect In Two-Band Superconductors, Egor Babaev, Johan Carlstrom, Martin Speight

Egor Babaev

We show that in multiband superconductors, even an extremely small interband proximity effect can lead to a qualitative change in the interaction potential between superconducting vortices by producing long-range intervortex attraction. This type of vortex interaction results in an unusual response to low magnetic fields leading to phase separation into domains of two-component Meissner states and vortex droplets.


Differential Cross Sections And Recoil Polarizations For The Reaction ΓpK+Σ0, B. Dey, Gerard P. Gilfoyle, Et. Al. Aug 2010

Differential Cross Sections And Recoil Polarizations For The Reaction Γp→K+Σ0, B. Dey, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

High-statistics measurements of differential cross sections and recoil polarizations for the reaction γpK+Σ0 have been obtained using the CLAS detector at Jefferson Lab. We cover center-of-mass energies ( √s) from 1.69 to 2.84 GeV, with an extensive coverage in the K+ production angle. Independent measurements were made using the K+(γ) and K+p(π, γ) final-state topologies, and were found to exhibit good agreement. Our differential cross sections show good agreement with earlier CLAS, SAPHIR, and LEPS results, while offering better …