bluuebunny/crossref_metadata_2025 huggingface dataset:
The curx of the water water power issue
Authors: Hurlburt Walter C.
Published: June 2007

Under existing court decisions can the public protect itself against exploitation if valuable water rights are transferred to private hands?
Iv. the virginia cities
Authors: bradford Ernest S.
Published: June 2007

It is in the medium‐sized cities that manager government has had its fullest trial and the results are most clearly evident‐cities such as Petersburg, Portsmouth and Lynchburg, Virginia, all ranging from thirty thousand to sixty thousand population. These three cities are here considered along with teh larger city of Norfolk, and Staunton, the first city to adopt the manger plan
Woman suffrage and the French municipal elections
Authors: Gooch R. K.
Published: June 2007

Because of the part played by municipal councils in the selection of senators, local elections in France involve the suffrage issue.
Government for the St. Louis metropolis
Authors: Loeb Isidor
Published: June 2007

The city and county of St. Louis, divorced for more than a half century, are interested in the possibility of a new union. Thus far, however, they have been unable to agree on the marriage settlement.
Los Angeles votes extension of water supply system
Authors: Ford Thomas F.
Published: June 2007

Citizens approve $38,800,000 bond issue for normal expansion of water system until Colorado River project is finished.
The Iowa county budget law
Authors: Manning John W.
Published: June 2007

The new budget law for Polk County is good as far as it goes and will undoubtedly improve financial practice. It illustrates, however, the limitations which the prevailing forms of county government impose upon any attempt to apply thoroughgoing budget principles to an antiquated organization.
San Francisco completes bernal cut
Authors: O'Shaughnessy M. M.
Published: June 2007

The Bernal Cut is one of those ingenious highway projects which are making over OUT cities.
Manager cities in action VI. The conclusions of an observer
Authors: Bradford Ernest S.
Published: June 2007

This article summarizes and concludes Dr. Bradford's series on the manager cities he has visited.
Signs of progress in county government national municipal league model law will aid spread of manager plan
Authors: Wager Paul W. , Jones Howard P.
Published: June 2007

Where given fair trial in North Carolina and Virginia, the county manager plan has cut governmental costs and improved public service. This article is a companion piece to the Model County Manager Law published as a supplement to this issue.
Ohio revives its municipal league
Authors: Aumann F. R.
Published: June 2007

The resuscitated Ohio League will hold its annual convention in cooperation with the National Municipal League and affiliated associations in Cleveland, November 10‐12.
What the manager plan has meant to cleveland
Authors: Marshall John D.
Published: June 2007

Despite efforts to abandon it the manager plan still stands. Cleveland has advanced under it.
The citizens' league of cleveland. Thirty‐four years of continuous public service
Authors: Vilas Malcolm B.
Published: June 2007

Because of its long life and the independence and effectiveness of its work, the Citizens' League of Cleveland commands an enviable reputation throughout the whole United States.
Cleveland's miles of respectability
Authors: Morris Warren L.
Published: June 2007

Cleveland is famous for the high character of its residential areas. Single‐family homes dominate. Real estate developers have shown courage and judgment.
The taxless city
Authors: Babson Roger W.
Published: June 2007

Municipal administration is primarily a business matter. Why shouldn't a city make a profit. There is nothing sacred in its being run at a loss.
Quaint electric rates
Authors: Cooke Morris Llewellyn
Published: June 2007

A lesson drawn from existing electric rates on the Island of Nantucket
American city government as seen by a German expert
Authors: Berthold Franz
Published: June 2007

Many readers of the REVIEW will recall Dr. Berthold's engaging personality and the almost incredible range and speed of his questions regarding all phases of our municipal life.
Dallas joins ranks of manager cities
Authors: Head Louis P.
Published: June 2007

Success marks a three‐year campaign of attrition. Usual ballyhoo of political contests conspicuous by its absence.
London's progress in slum abatement. I. The governmental and economic backgrounds
Authors: Dence E. M.
Published: June 2007

London's radical attack upon the Slum evil may have a lesson for Americans who have been experimenting with milder palliatives.
Comparative tax rates of 185 cities, 1930
Authors: Rightor C. E.
Published: June 2007

Mr. Rightor presents his annual comparison of municipal tax rates.
Between spin and reality: examining disclosure practices in three African countries
Authors: Larbi George A.
Published: June 2007

The declaration of assets and liabilities represents a growing trend in the avoidance and resolution of conflict of interest and has become a part of an integrated strategy to control corruption. This article reviews practices in Ghana, Tanzania and Uganda by addressing questions of who must declare, what must be declared, where to declare and how often to declare. It argues that like all the other mechanisms for controlling corruption, its efficacy depends on enforcement and compliance. The three cases reviewed suggest that there is a significant gap between the rhetoric of declaration and the reality of effective monitoring and compliance to make the system work to ensure transparency and public trust. Copyright © 2007 John Wiley & Sons, Ltd.
Civic education for combating corruption: lessons from Hong Kong and the US for donor‐funded programmes in poor countries
Authors: Marquette Heather
Published: June 2007

Donors are increasingly funding projects and programmes that fit under the general rubric of ‘civic education’. These tend to address both targeted problems within a country and wider institutional reforms, including, for example, projects aimed at voter education for first time elections within a country, or human rights education in countries coming out of a non‐democratic system. More recently, donors are funding civic education for both adults and children to help fight corruption. This article looks at lessons from two well‐known models for civic education, one of which targets corruption specifically and one which targets wider civic values: the Hong Kong Independent Commission Against Corruption's (ICAC) community relations programme, and the US civic education, including programmes funded by USAID in other countries. It argues that both the Hong Kong and US experiences of civic education demonstrate how unlikely it is that donors will produce similar results with a fraction of the budget and in environments characterised by weak institutions, widespread illiteracy, crumbling or non‐existent schools and inadequate training for teachers. It also explores how, in fact in both cases, corruption forms only a very small part of much wider civic education curricula based on citizenship, not corruption, and discusses the implications of this for donors. Copyright © 2007 John Wiley & Sons, Ltd.
Geometry‐based analysis of azulene and azulene‐like systems with H‐ or Li‐bonding
Authors: Krygowski Tadeusz M. , Zachara‐Horeglad Joanna E.
Published: June 2007

B3LYP/6–311+G** optimization was carried out for azulene and its analogs, in which CHCHCH fragment was replaced with O···X···O (X = H or Li). π‐electron delocalization in four possible derivatives with H‐bonding and three possible derivatives with Li‐bonding was described by the use of HOMA index. All derivatives with Li‐bonding exhibit high π‐electron delocalization similar to that found for azulene. Among four H‐bonded systems, two exhibit lower π‐electron delocalization (HOMA < 0.39) and higher total electron energy than the other two derivatives. Copyright © 2007 John Wiley & Sons, Ltd.
Theoretical study of optical and electronic properties of the bis‐dipolar diphenylamino‐endcapped oligoarylfluorenes as promising light emitting materials
Authors: Liu Yan‐Ling , Feng Ji‐Kang , Ren Ai‐Min
Published: June 2007

We present a detailed study of the structural, electronic, and optical properties of the bis‐dipolar emissive oligoarylfluorenes, OF(2)Ar‐NPhs. The aim of our quantum‐chemical calculations is to investigate the role of the transition and the influence of the optical properties of the various central aryl cores in the oligoarylfluorenes. Geometry optimizations were performed for the ground‐state and for the first electronically excited‐state. The absorption and emission spectra were calculated using time‐dependent density functional theory (TD‐DFT). The results show that the HOMO, LUMO, energy gap, ionization potentials (IP), electron affinities (EA) and reorganization energy (λ) of the oligoarylfluorenes are significantly affected by the electronic withdrawing property and the conjugated length of the central aryl core. Consistently, the stronger the electron withdrawing strength, the lower the LUMO energy is. This thus improves the electron‐accepting and transporting properties by the low LUMO energy levels. The absorption and emission spectra of this series of bis‐dipolar molecules exhibit red shifts to some extent by the electronic nature of the electron affinitive central core in the oligoarylfluorenes. All the calculated results show that the oligoarylfluorenes are promising as useful light emitting materials for OLEDs. Copyright © 2007 John Wiley & Sons, Ltd.
Specificity of helix packing in transmembrane dimer of the cell death factor BNIP3: A molecular modeling study
Authors: Vereshaga Yana A. , Volynsky Pavel E. , Pustovalova Julia E. , Nolde Dmitry E. , Arseniev Alexander S. , Efremov Roman G.
Published: June 2007

BNIP3 is a mitochondrial 19‐kDa proapoptotic protein, a member of the Bcl‐2 family. It has a single COOH‐terminal transmembrane (TM) α‐helical domain, which is required for membrane targeting, proapoptotic activity, hetero‐ and homo‐dimerization in membrane. The role and the molecular details of association of TM helices of BNIP3 are yet to be established. Here, we present a molecular modeling study of helix interactions in its membrane domain. The approach combines Monte Carlo conformational search in an implicit hydrophobic slab followed by molecular dynamics simulations in a hydrated full‐atom lipid bilayer. The former technique was used for exhaustive sampling of the peptides' conformational space and for generation of putative “native‐like” structures of the dimer. The latter ones were taken as realistic starting points to assess stability and dynamic behavior of the complex in explicit lipid–water surrounding. As a result, several groups of tightly packed right‐handed structures of the dimer were proposed. They have almost similar helix–helix interface, which includes the motif A176xxxG180xxxG184and agrees well with previous mutagenesis data and preliminary NMR analysis. Molecular dynamics simulations of these structures reveal perfect adaptation of most of them to heterogeneous membrane environment. A remarkable feature of the predicted dimeric structures is the occurrence of a cluster of H‐bonded histidine 173 and serines 168 and 172 on the helix interface, near the N‐terminus. Because of specific polar interactions between the monomers, this part of the dimer has no such dense packing as the C‐terminal one, thus allowing penetration of water from the extramembrane side into the membrane interior. We propose that the ionization state of His173can mediate structural and dynamic properties of the dimer. This, in turn, may be related to pH‐dependent proapoptotic activity of BNIP3, which is triggering on by acidosis appearing under hypoxic conditions. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Possible formation mechanisms for surface defects observed in heteroepitaxially grown 3C‐SiC
Authors: Speer K. M. , Neudeck P. G. , Crimp M. A. , Burda C. , Pirouz P.
Published: June 2007

p–n diodes were fabricated from 3C‐SiC films heteroepitaxially grown atop on‐axis, Si‐face (0001) 4H‐SiC mesa substrate arrays [P. G. Neudeck et al., Mater. Sci. Forum 433–436, 213 (2003); 527–529, 1335 (2006)]. Images taken by electroluminescence‐based optical emission microscopy (ELOEM) and electron channelling contrast imaging (ECCI) revealed immobile linear features aligned along 〈110〉 directions; defects were expected on these particular devices, as the 3C films were grown on stepped 4H mesas. To explain the formation of these defects, we have used a procedure by which surface energies are calculated for terraces on a stepped 4H, Si‐face surface to investigate their comparative stability; subsequently, we use energetic calculations to confirm the formation – and determine the orientation – of 3C nuclei on the more stable 4H terraces and to evaluate the nature of the coalescence of nuclei from neighbouring terraces. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Signatures of distinct structures related to rod‐like defects in silicon detected by various measurement methods
Authors: Mchedlidze T. , Arguirov T. , Jia G. , Kittler M.
Published: June 2007

Silicon samples containing rod‐like defects (RLD) and pre‐characterized by the electric‐dipole spin resonance (EDSR) method were investigated by photoluminescence (PL) and deep level transient spectroscopy (DLTS) methods. Employing previously reported strict correlation between the EDSR signatures of various RLD structures and their structural models developed from microscopy (TEM) investigations it became possible to associate PL and DLTS features with these defects. The results suggest that at low measurement temperatures, i.e. at 10 K, sharp PL emission peak detected at 1405 nm is related to line‐interstitial defects (LID), that detected at 1372 nm to plane defects (PD) and two peaks detected at 1426 nm and 1515 nm to dislocation dipoles (DD). Two energy bands related to LIDs are positioned at 0.2 eV and 0.25 eV from the conduction band of Si. Band‐like stated associated with PD are positioned at ∼0.5 eV and those related to DDs at 0.32–0.36 eV below the conduction band. Properties of DLTS signatures and temperature dependencies for the PL peaks are reported. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Out‐diffusion of nitrogen from float‐zone silicon measured by dislocation locking
Authors: Alpass C. R. , Murphy J. D. , Giannattasio A. , Senkader S. , Falster R. J. , Wilshaw P. R.
Published: June 2007

A measurement of nitrogen out‐diffusion from nitrogen‐doped float‐zone silicon made using a dislocation locking technique is presented. Specimens containing a well‐defined array of dislocation half‐loops are subjected to identical anneals at 750 °C, during which nitrogen diffuses both to the surface and to the dislocations. The specimens are then chemically etched so as to remove different thicknesses of material from the surface. The stress required to move the dislocations away from the nitrogen is then measured. The variation in this unlocking stress with thickness of material removed allows some measure of nitrogen diffusivity to be deduced. The result obtained is consistent with an extrapolation of SIMS out‐diffusion measurements previously performed at higher temperatures, but indicates a different activation energy for out‐diffusion to that associated with dislocation locking by nitrogen. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cathodoluminescence investigation of stacking faults extension in 4H‐SiC
Authors: Juillaguet S. , Albrecht M. , Camassel J. , Chassagne T.
Published: June 2007

We report the results of a cathodoluminescence (CL) investigation performed on as‐grown stacking faults in a thick, undoped, 4H‐SiC epitaxial layer grown by CVD. To investigate the size and optical signature of the defects we used, first, room‐temperature (RTCL) and then low‐temperature (LTCL) spectroscopy. From RTCL we find that all defects have identical optical properties, with a maximum emission wavelength centered at 480 nm at 300 K. We find also that the defects have a triangular shape, with large extension in the basal plane. This makes them intermediate between the usual (semi‐infinite) quantum wells (QWs) and pure (zero‐dimensional) quantum dots. From a comparison of the LTCL results with a simple computation, we determine the QW thickness and find that all SFs are made of 4 bilayers of 3C‐SiC polytype embedded in the 4H‐SiC matrix. Scanning across one single (isolated) triangular defect, we then find that the maximum signal wavelength shifts, depending on the excitation spot position over the defect. To the best of our knowledge, this is one of the few experimental evidences of a screening of the built‐in electric field when increasing the carrier concentration in a fault. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Airborne observations of the impact of a convective system on the planetary boundary layer thermodynamics and aerosol distribution in the inter‐tropical discontinuity region of the West African Monsoon
Authors: Flamant C. , Chaboureau J.‐P. , Parker D. J. , Taylor C. M. , Cammas J.‐P. , Bock O. , Timouk F. , Pelon J.
Published: June 2007

The impact of a convective system downdraught and associated gravity current on the monsoon and harmattan flow structure as well as on aerosol vertical distribution over the Sahel and the Sahara is investigated using dropsondes and an airborne lidar. Complementary ground‐based and satellite observations, as well as European Centre for Medium‐range Weather Forecasts analyses are also used. The mission was conducted on 5 June 2006, in the framework of the African Monsoon Multidisciplinary Analysis Special Observing Period. The targeted area was the Saharan heat low region, and Mali in particular, over which the inter‐tropical discontinuity was strongly perturbed by the convective system. To the north, away from the influence of the gravity current, the atmosphere exhibited a two‐layer structure, with a well mixed 3 km deep internal boundary layer capped by a stable layer 2–2.5 km deep layer referred to as the Saharan aerosol layer (SAL). The aerosol loading in the internal boundary layer (as determined by lidar) was observed to be much less than in the SAL above. Plumes of dust generated by strong low‐level winds west of the Hoggar as observed in Spinning Enhanced Visible and Infra‐Red Imager (SEVIRI) images, and possibly injected in the upper SAL through orographic lifting, contributed to the dust loading of the elevated SAL over much of the domain observed by the lidar. In the northernmost part of the domain investigated, the depth of the SAL top was decreased as the result of subsidence enhanced by the presence of an elevated jet associated with the monsoon trough and/or related to the return circulation of plain‐mountain wind system involving the Atlas range. Associated with the gravity current passing over dust sources, a large aerosol plume was observed by means of lidar measurements and SEVIRI imagery. The plume was seen to reach heights of approximately 3 km above ground level a few tens of kilometres behind the leading edge. Lidar measurements suggest that a fraction of the dust lifted by the gravity current is mixed into the SAL, and in some instances injected above the SAL. Copyright © 2007 Royal Meteorological Society
A strategy for high‐throughput analysis of levosimendan and its metabolites in human plasma samples using sequential negative and positive ionization liquid chromatography/tandem mass spectrometric detection
Authors: Zhang Jun , Gage Eric M. , Ji Qin C. , El‐Shourbagy Tawakol A.
Published: June 2007

Levosimendan (Simdax®) is an approved drug in approximately 40 countries and currently in phase III clinical studies in the USA and Europe. An accurate, high‐throughput and rugged assay is critical to support these clinical trials. Due to the mechanism of drug metabolism, the drug and its active metabolites often have significant differences in their chemical properties. In order to achieve high assay throughput and low sample volumes, a single bioanalytical assay for the drug and its metabolites is preferred. However, this need may prevent the optimization of both high‐performance liquid chromatography (HPLC) and mass spectrometric ionization conditions. The chemical properties of levosimendan are significantly different from those of its two active metabolites, OR‐1855 and OR‐1896. Here, we present a novel strategy for high‐throughput analysis of levosimendan and its metabolites. A 96‐well liquid/liquid extraction procedure was developed for sample preparation. A single liquid chromatography/tandem mass spectrometry (LC/MS/MS) system with two separate mobile phases, shared backwash solvent and conditioning solvent, was developed to perform sequential LC separation for levosimendan and the metabolites. Levosimendan was eluted by 5 mM ammonium acetate in 33.3% acetonitrile and detected using negative ionization mode MS/MS monitoring. The metabolites were eluted by 5 mM ammonium acetate and 0.2% acetic acid in 20% acetonitrile and detected with positive ionization mode MS/MS monitoring. The method has been demonstrated to have excellent precision and accuracy, with high assay ruggedness during method validation and clinical sample analysis. The linear dynamic ranges were approximately 200–50 000 pg/mL for levosimendan and approximately 500–130 000 pg/mL for both metabolites. The coefficient of determination (r2) for all analytes was greater than 0.9985. The intra‐assay %CVs for QC samples were from 0.9% to 2.0% for levosimendan, 0.9% to 3.2% for OR‐1855, and 0.4% to 4.9% for OR‐1896. The inter‐assay %CVs for QC samples were from 1.2% to 1.8% for levosimendan, 1.3% to 2.7% for OR‐1855, and 1.4% to 3.4% for OR‐1896. The mean % biases for QC samples were from 1.5% to 5.5% for levosimendan, −1.4% to 2.6% for OR‐1855, and −0.3% to 4.5% for OR‐1896. By using a single extraction approach coupled with sequential LC/MS/MS analysis for levosimendan and its metabolites, the assay maintained high throughput and low sample volume usage. Copyright © 2007 John Wiley & Sons, Ltd.
Animal and Human Health Implications of Avian Influenza Infections
Authors: Capua Ilaria , Alexander Dennis J.
Published: June 2007

Avian influenza (AI) is a listed disease of the World Organisation for Animal Health (OIE) that has become a disease of great importance both for animal and human health. Until recent times, AI was considered a disease of birds with zoonotic implications of limited significance. The emergence and spread of the Asian lineage highly pathogenic AI (HPAI) H5N1 virus has dramatically changed this perspective; not only has it been responsible of the death or culling of millions of birds, but this virus has also been able to infect a variety of non-avian hosts including human beings. The implications of such a panzootic reflect themselves in animal health issues, notably in the reduction of a protein source for developing countries and in the management of the pandemic potential. Retrospective studies have shown that avian progenitors play an important role in the generation of pandemic viruses for humans, and therefore these infections in the avian reservoir should be subjected to control measures aiming at eradication of the Asian H5N1 virus from all sectors rather than just eliminating or reducing the impact of the disease in poultry.
l‐2‐Hydroxyglutaric aciduria, a defect of metabolite repair
Authors: Rzem R. , Vincent M.‐F. , Van Schaftingen E. , Veiga‐da‐Cunha M.
Published: June 2007

l‐2‐hydroxyglutaric aciduria is a metabolic disorder in which l‐2‐hydroxyglutarate accumulates as a result of a deficiency in FAD‐linked l‐2‐hydroxyglutarate dehydrogenase, a mitochondrial enzyme converting l‐2‐hydroxyglutarate to α‐ketoglutarate. The origin of the l‐2‐hydroxyglutarate, which accumulates in this disorder, is presently unknown. The oxidation–reduction potential of the 2‐hydroxyglutarate/α‐ketoglutarate couple is such that l‐2‐hydroxyglutarate could potentially be produced through the reduction of α‐ketoglutarate by a NAD‐ or NADP‐linked oxidoreductase. In fractions of rat liver cytosolic extracts that had been chromatographed on an anion exchanger we detected an enzyme reducing α‐ketoglutarate in the presence of NADH. This enzyme co‐purified with cytosolic l‐malate dehydrogenase (cMDH) upon further chromatography on Blue Sepharose. Mitochondrial fractions also contained an NADH‐linked, ‘α‐ketoglutarate reductase’ which similarly co‐purified with mitochondrial l‐malate dehydrogenase (mMDH). Purified mMDH catalysed the reduction of α‐ketoglutarate to l‐2‐hydroxyglutarate with a catalytic efficiency that was about 107‐fold lower than that observed with oxaloacetate. For the cytosolic enzyme, this ratio amounted to 108, indicating that this enzyme is more specific. Both cMDH and mMDH are highly active in tissues and α‐ketoglutarate is much more abundant than oxaloacetate and more concentrated in mitochondria than in the cytosol. As a result of this, the weak activity of mMDH on α‐ketoglutarate is sufficient to account for the amount of l‐2‐hydroxyglutarate that is excreted by patients deficient in FAD‐linked l‐2‐hydroxyglutarate dehydrogenase. The latter enzyme appears, therefore, to be responsible for a ‘metabolite repair’ phenomenon and to belong to the expanding class of ‘house‐cleaning’ enzymes.
Ball Lightning–Aerosol Electrochemical Power Source or A Cloud of Batteries
Authors: Meshcheryakov Oleg
Published: June 2007

Despite numerous attempts, an adequate theoretical and experimental simulation of ball lightning still remains incomplete. According to the model proposed here, the processes of electrochemical oxidation within separate aerosol particles are the basis for this phenomenon, and ball lightning is a cloud of composite nano or submicron particles, where each particle is a spontaneously formed nanobattery which is short-circuited by the surface discharge because it is of such a small size. As free discharge-shorted current loops, aerosol nanobatteries are exposed to a powerful mutual magnetic dipole–dipole attraction. The gaseous products and thermal energy produced by each nanobattery as a result of the intra-particle self-sustaining electrochemical reactions, cause a mutual repulsion of these particles over short distances and prevent their aggregation, while a collectivization of the current loops of separate particles, due to the electric arc overlapping between adjacent particles, weakens their mutual magnetic attraction over short distances. Discharge currents in the range of several amperes to several thousand amperes as well as the pre-explosive mega ampere currents, generated in the reduction–oxidation reactions and distributed between all the aerosol particles, explain both the magnetic attraction between the elements of the ball lightning substance and the impressive electromagnetic effects of ball lightning.
New Sphingolipids with a Previously Unreported 9‐Methyl‐C20‐sphingosine Moiety from a Marine Algous Endophytic Fungus Aspergillus niger EN‐13
Authors: Zhang Yi , Wang Song , Li Xiao‐Ming , Cui Chuan‐Ming , Feng Chao , Wang Bin‐Gui
Published: June 2007

Asperamides A (1) and B (2), a sphingolipid and their corresponding glycosphingolipid possessing a hitherto unreported 9‐methyl‐C20‐sphingosine moiety, were characterized from the culture extract of Aspergillus niger EN‐13, an endophytic fungus isolated from marine brown alga Colpomenia sinuosa. The structures were elucidated by spectroscopic and chemical methods as (2S,2′R,3R,3′E,4E,8E)‐N‐(2′‐hydroxy‐3′‐hexadecenoyl)‐9‐methyl‐4,8‐icosadien‐1,3‐diol (1) and 1‐O‐β‐d‐glucopyranosyl‐(2S,2′R,3R,3′E,4E,8E)‐N‐(2′‐hydroxy‐3′‐hexadecenoyl)‐9‐methyl‐4,8‐icosadien‐1,3‐diol (2). In the antifungal assay, asperamide A (1) displayed moderate activity against Candida albicans.
Synthesis of Long Chain Unsaturated‐α,ω‐Dicarboxylic Acids from Renewable Materials via Olefin Metathesis
Authors: Ngo Helen L. , Foglia Thomas A.
Published: June 2007

The self‐metathesis reaction of soy, rapeseed, tall, and linseed oil fatty acids was investigated for the synthesis of symmetrical long‐chain unsaturated‐α,ω‐dicarboxylic acids. The metathesis reactions were carried out in the presence of a Grubbs catalyst under solvent‐free condition at a catalyst loading of 0.01 mol% to fatty acid substrate at 50 °C. Under these conditions, the conversions of starting unsaturated acids to metathesis products were >80% and the isolated yields of unsaturated dicarboxylic acid products were >70% of theoretical. This approach represents an effective and efficient route for the synthesis of these potentially useful dicarboxylic acids since they can serve as important intermediates in the production of several materials such as biodegradable polymers.
Human WIPI‐1 puncta‐formation: A novel assay to assess mammalian autophagy
Authors: Proikas-Cezanne Tassula , Ruckerbauer Sabine , Stierhof York-Dieter , Berg Carolin , Nordheim Alfred
Published: June 2007

Autophagy depends on the activity of phosphoinositide‐3 kinase class III to generate PI(3)P. We identified the human WIPI protein family of PI(3)P‐binding factors and showed that WIPI‐1 (Atg18) is linked to autophagy in human cells. Induction of autophagy by rapamycin, gleevec, thapsigargin and amino acid deprivation led to an accumulation of WIPI‐1 at LC3‐positive membrane structures (WIPI‐1 puncta‐formation), suggested to represent autophagosomal isolation membranes. WIPI‐1 puncta‐formation is inhibited by wortmannin and LY294002, and PI(3)P‐binding‐deficient WIPI‐1 is puncta‐formation‐incompetent. Quantification of WIPI‐1 puncta should be suitable to assay mammalian autophagy.
Clinical indicators for success of misoprostol treatment after early pregnancy failure
Authors: Robledo C. , Zhang J. , Troendle J. , Barnhart K. , Creinin M.D. , Westhoff C. , Huang X. , Frederick M.
Published: June 2007

Objective: To identify clinical indicators for success of misoprostol treatment after early pregnancy failure. Methods: A total of 473 women with early pregnancy failure received 800 μg of vaginal misoprostol on treatment day 1. At the follow‐up visit on day 3, a second dose was given if expulsion was incomplete. On day 8, vacuum aspiration was offered if expulsion had not occurred. Ultrasonography was used as gold standard for success. A Classification and Regression Tree analysis was undertaken to derive two decision trees for the success of misoprostol treatment on study days 3 and 8. Results: Heavy bleeding after the first dose and an open cervical os were identified as clinical indicators of treatment success on day 3. Treatment success occurred in 84% of women with either or both indicators. Reporting passage of tissue after a second misoprostol dose and old blood in the vagina were potential indicators of treatment success or failure on day 8. A woman with either of these indicators has a 65% chance of treatment success after the second dose. Conversely, a woman with neither indicator on day 8 has a 94% chance of treatment failure. Conclusion: Standard clinical findings may be useful as indicators for success or failure of medical management of early pregnancy failure in settings with limited or no access to ultrasonography. More research to identify even better indicators is warranted.
Magnetic hysteresis parameters and Day plot analysis to characterize diagenetic alteration in gas hydrate‐bearing sediments
Authors: Enkin Randolph J. , Baker Judith , Nourgaliev Danis , Iassonov Pavel , Hamilton Tark S.
Published: June 2007

The J meter coercivity spectrometer is a machine capable of rapid and simple measurement of magnetic hysteresis, isothermal remanence acquisition and magnetic viscosity of rocks and sediments. The J meter was used to study a suite of samples collected from strata in the gas hydrate‐bearing JAPEX/JNOC/GSC Mallik 5L‐38 well (69.5°N, 134.6°W) in the Mackenzie Delta of the northwestern Canadian Arctic. The Day plot of magnetic hysteresis ratios for these samples is exotic in that the points do not plot along a hyperbola as is usually observed. Rather, they plot as a scatter which is shown to contour into vertical slices using coercivity field (HC) or saturation magnetization (JS), and horizontal slices using the relative quantity of superparamagnetism (JSPM/JS). Optical microscopy reveals that the magnetic minerals are detrital magnetite and authigenic greigite. Greigite is dominant in sands which in situ had >70% gas hydrate saturation and in silts in which gas hydrate growth was blocked by insufficient porosity. We infer that the silts were the accumulation sites for solutes which had been excluded from the pore waters in neighboring coarser‐grained sediments during the course of gas hydrate formation. Consequently, we conclude that magnetic properties are related to gas hydrate‐related processes, and as such, may have potential as a method of remote sensing for gas hydrate deposits.
Modeling multivariable hydrological series: Principal component analysis or independent component analysis?
Authors: Westra Seth , Brown Casey , Lall Upmanu , Sharma Ashish
Published: June 2007

The generation of synthetic multivariate rainfall and/or streamflow time series that accurately simulate both the spatial and temporal dependence of the original multivariate series remains a challenging problem in hydrology and frequently requires either the estimation of a large number of model parameters or significant simplifying assumptions on the model structure. As an alternative, we propose a relatively parsimonious two‐step approach to generating synthetic multivariate time series at monthly or longer timescales, by first transforming the data to a set of statistically independent univariate time series and then applying a univariate time series model to the transformed data. The transformation is achieved through a technique known as independent component analysis (ICA), which uses an approximation of mutual information to maximize the independence between the transformed series. We compare this with principal component analysis (PCA), which merely removes the covariance (or spatial correlation) of the multivariate time series, without necessarily ensuring complete independence. Both methods are tested using a monthly multivariate data set of reservoir inflows from Colombia. We show that the discrepancy between the synthetically generated data and the original data, measured as the mean integrated squared bias, is reduced by 25% when using ICA compared with PCA for the full joint distribution and by 28% when considering marginal densities in isolation. These results suggest that there may be significant benefits to maximizing statistical independence, rather than merely removing correlation, when developing models for the synthetic generation of multivariate time series.
Two modes of accelerated glacier sliding related to water
Authors: Harper Joel T. , Humphrey Neil F. , Pfeffer W. Tad , Lazar Brian
Published: June 2007

We present the first glacier‐wide detailed measurement of basal effective pressure and related observations including bed separation to elucidate the role of water in sliding. The hard bedded glacier instrumented in our study exhibited two phases of accelerated sliding motion apparently driven by separate mechanisms. The first acceleration phase (up to 5 fold increase in speed) was closely tied to an increase in bed separation. The faster second phase (up to 9 fold increase in speed) was related to an unusually high level of connectivity of subglacial waters. We infer the first mode was related to cavity opening and the second mode was related to reduced ice contact with the bed. Glacier sliding over a hard bed is typically represented by sliding laws that include the effective basal pressure, but neither sliding phase was accompanied by a simultaneous decrease in local or regional effective pressure.
Dramatic impact of the South China Sea on the Indonesian Throughflow
Authors: Tozuka Tomoki , Qu Tangdong , Yamagata Toshio
Published: June 2007

Using OGCM experiments with and without the South China Sea throughflow, it is shown that this throughflow plays an important role in generating the subsurface maxima in the meridional velocity of the Makassar Strait throughflow. The maximum in the southward flow is located at subsurface around 110 m in the control run, whereas that exists near the surface without the South China Sea throughflow. This results in 0.18 PW difference in the southward heat transport by the Makassar Strait throughflow, suggesting that the South China Sea throughflow may play an important role in climate variability of the Indo‐Pacific region. Furthermore, the South China Sea throughflow, which undergoes a seasonal variation with a maximum in boreal winter, significantly influences the simulated seasonal variation in the Makassar Strait throughflow.
Is there a cost of virus resistance in marine cyanobacteria?
Authors: Lennon Jay T , Khatana Sameed Ahmed M , Marston Marcia F , Martiny Jennifer B H
Published: June 2007

Owing to their abundance and diversity, it is generally perceived that viruses are important for structuring microbial communities and regulating biogeochemical cycles. The ecological impact of viruses on microbial food webs, however, may be influenced by evolutionary processes, including the ability of bacteria to evolve resistance to viruses and the theoretical prediction that this resistance should be accompanied by a fitness cost. We conducted experiments using phylogenetically distinct strains of marine Synechococcus (Cyanobacteria) to test for a cost of resistance (COR) to viral isolates collected from Mount Hope Bay, Rhode Island. In addition, we examined whether fitness costs (1) increased proportionally with ‘total resistance’, the number of viruses for which a strain had evolved resistance, or (2) were determined more by ‘compositional resistance’, the identity of the viruses to which it evolved resistance. A COR was only found in half of our experiments, which may be attributed to compensatory mutations or the inability to detect a small COR. When detected, the COR resulted in a ∼20% reduction in relative fitness compared to ancestral strains. The COR was unaffected by total resistance, suggesting a pleiotropic fitness response. Under competitive conditions, however, the COR was dependent on compositional resistance, suggesting that fitness costs were associated with the identity of a few particular viruses. Our study provides the first evidence for a COR in marine bacteria, and suggests that Synechococcus production may be influenced by the composition of co-occurring viruses.
New checksum functions for Biopython
Authors: Bassi Sebastian , Gonzalez Virginia
Published: June 2007

Checksum algorithms are used in biological databases for integrity check and identification purposes. CRC64 is the only checksum algorithm already included in Biopython. This work proposes two new implementation of known algorithms (GCG Checksum and SEGUID). There is also an application based on SEGUID: Looking for redundancy between two FASTA files full of protein sequences based only in sequence information, by comparing the SEGUIDs of both files.The code is shown in the manuscript and may be available at Biopython.org.
Transport optimization on complex networks
Authors: Danila Bogdan , Yu Yong , Marsh John A. , Bassler Kevin E.
Published: June 2007

We present a comparative study of the application of a recently introduced heuristic algorithm to the optimization of transport on three major types of complex networks. The algorithm balances network traffic iteratively by minimizing the maximum node betweenness with as little path lengthening as possible. We show that by using this optimal routing, a network can sustain significantly higher traffic without jamming than in the case of shortest path routing. A formula is proved and tested with numerical simulation that allows quick computation of the average number of hops along the path and of the average travel times once the betweennesses of the nodes are computed. Using this formula, we show that routing optimization preserves the small-world character exhibited by networks under shortest path routing, and that it significantly reduces the average travel time on congested networks with only a negligible increase in the average travel time at low loads. Finally, we study the correlation between the weights of the links in the case of optimal routing and the betweennesses of the nodes connected by them.
Spatial updating, spatial transients, and regularities of a complex automaton with nonperiodic architecture
Authors: Freire Joana G. , Brison Owen J. , Gallas Jason A. C.
Published: June 2007

We study the dynamics of patterns exhibited by rule 52, a totalistic cellular automaton displaying intricate behaviors and wide regions of active/inactive synchronization patches. Systematic computer simulations involving 230 initial configurations reveal that all complexity in this automaton originates from random juxtaposition of a very small number of interfaces delimiting active/inactive patches. Such interfaces are studied with a sidewise spatial updating algorithm. This novel tool allows us to prove that the interfaces found empirically are the only interfaces possible for these periods, independently of the size of the automata. The spatial updating algorithm provides an alternative way to determine the dynamics of automata of arbitrary size, a way of taking into account the complexity of the connections in the lattice.
A box-covering algorithm for fractal scaling in scale-free networks
Authors: Kim J. S. , Goh K.-I. , Kahng B. , Kim D.
Published: June 2007

A random sequential box-covering algorithm recently introduced to measure the fractal dimension in scale-free (SF) networks is investigated. The algorithm contains Monte Carlo sequential steps of choosing the position of the center of each box; thereby, vertices in preassigned boxes can divide subsequent boxes into more than one piece, but divided boxes are counted once. We find that such box-split allowance in the algorithm is a crucial ingredient necessary to obtain the fractal scaling for fractal networks; however, it is inessential for regular lattice and conventional fractal objects embedded in the Euclidean space. Next, the algorithm is viewed from the cluster-growing perspective that boxes are allowed to overlap; thereby, vertices can belong to more than one box. The number of distinct boxes a vertex belongs to is, then, distributed in a heterogeneous manner for SF fractal networks, while it is of Poisson-type for the conventional fractal objects.
Balls-in-boxes condensation on networks
Authors: Bogacz L. , Burda Z. , Janke W. , Waclaw B.
Published: June 2007

We discuss two different regimes of condensate formation in zero-range processes on networks: on a q-regular network, where the condensate is formed as a result of a spontaneous symmetry breaking, and on an irregular network, where the symmetry of the partition function is explicitly broken. In the latter case we consider a minimal irregularity of the q-regular network introduced by a single Q node with degree Q>q. The statics and dynamics of the condensation depend on the parameter α=lnQ∕q, which controls the exponential falloff of the distribution of particles on regular nodes and the typical time scale for melting of the condensate on the Q node, which increases exponentially with the system size N. This behavior is different than that on a q-regular network, where α=0 and where the condensation results from the spontaneous symmetry breaking of the partition function, which is invariant under a permutation of particle occupation numbers on the q nodes of the network. In this case the typical time scale for condensate melting is known to increase typically as a power of the system size.
Propagation of external regulation and asynchronous dynamics in random Boolean networks
Authors: Mahmoudi H. , Pagnani A. , Weigt M. , Zecchina R.
Published: June 2007

Boolean networks and their dynamics are of great interest as abstract modeling schemes in various disciplines, ranging from biology to computer science. Whereas parallel update schemes have been studied extensively in past years, the level of understanding of asynchronous updates schemes is still very poor. In this paper we study the propagation of external information given by regulatory input variables into a random Boolean network. We compute both analytically and numerically the time evolution and the asymptotic behavior of this propagation of external regulation (PER). In particular, this allows us to identify variables that are completely determined by this external information. All those variables in the network that are not directly fixed by PER form a core which contains, in particular, all nontrivial feedback loops. We design a message-passing approach allowing to characterize the statistical properties of these cores in dependence of the Boolean network and the external condition. At the end we establish a link between PER dynamics and the full random asynchronous dynamics of a Boolean network.
Treatment of geometric singularities in implicit solvent models
Authors: Yu Sining , Geng Weihua , Wei G. W.
Published: June 2007

Geometric singularities, such as cusps and self-intersecting surfaces, are major obstacles to the accuracy, convergence, and stability of the numerical solution of the Poisson-Boltzmann (PB) equation. In earlier work, an interface technique based PB solver was developed using the matched interface and boundary (MIB) method, which explicitly enforces the flux jump condition at the solvent-solute interfaces and leads to highly accurate biomolecular electrostatics in continuum electric environments. However, such a PB solver, denoted as MIBPB-I, cannot maintain the designed second order convergence whenever there are geometric singularities, such as cusps and self-intersecting surfaces. Moreover, the matrix of the MIBPB-I is not optimally symmetrical, resulting in the convergence difficulty. The present work presents a new interface method based PB solver, denoted as MIBPB-II, to address the aforementioned problems. The present MIBPB-II solver is systematical and robust in treating geometric singularities and delivers second order convergence for arbitrarily complex molecular surfaces of proteins. A new procedure is introduced to make the MIBPB-II matrix optimally symmetrical and diagonally dominant. The MIBPB-II solver is extensively validated by the molecular surfaces of few-atom systems and a set of 24 proteins. Converged electrostatic potentials and solvation free energies are obtained at a coarse grid spacing of 0.5Å and are considerably more accurate than those obtained by the PBEQ and the APBS at finer grid spacings.
Effect of oscillating sheath on near-wall conductivity in Hall thrusters
Authors: Yu Daren , Li Hong , Wu Zhiwen , Mao Wei
Published: June 2007

The effect of an oscillating sheath on near-wall conductivity has been studied using a model of the incident electron motions with the characteristic parameters of the oscillating sheath quantified. The model predicted an increase in both the frequency of electron-wall collisions and the coefficient of secondary electron emission compared to the steady sheath regime. This effect indicates that near-wall conductivity is enhanced in the oscillating sheath regime.
Short wavelength electromagnetic propagation in magnetized quantum plasmas
Authors: Lundin J. , Zamanian J. , Marklund M. , Brodin G.
Published: June 2007

The quantum electrodynamical (QED) short wavelength correction on plasma wave propagation for a nonrelativistic quantum plasma is investigated. A general dispersion relation for a thermal multicomponent quantum plasma is derived. It is found that the classical dispersion relation for any wave mode can be modified to include quantum and short wavelength QED effects by simple substitutions of the thermal velocity and the plasma frequency. Furthermore, the dispersion relation has been modified to include QED effects of strong magnetic fields. It is found that strong magnetic fields together with the short wavelength QED correction will induce dispersion both in vacuum and in otherwise nondispersive plasma modes. Applications to laboratory and astrophysical systems are discussed.