bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrothermal Synthesis and Structure of a New Three‐Dimensional Inorganic‐Organic Hybrid Polyoxomolybdate Based on Keggin Cluster Units
Authors: Chen Qi , Cai Chunxiu , Zhou Guangpeng , Xu Yan , Zhu Dunru , Zheng Xuefang
Published: May 2008

A new 3‐D inorganic‐organic hybrid compound {[Cu(4,4′‐bipy)]3(4,4′‐bipy)}[PMo12O40]·2H2O (1) was hydrothermally synthesized and characterized by IR, TG and X‐ray diffraction analysis. Single crystal X‐ray diffraction confirms that this compound crystallizes in the triclinic crystal system, space group P‐1 with a = 10.9180(11), b = 12.3759(13), c = 13.0264(13) Å, α = 113.3560(10)°, β = 93.8730(10)°, γ = 99.0300(10)°. V = 1579.4(3) Å3, Z = 1. Structural analysis indicates that compound 1 exhibits a three‐dimensional structure, in which Keggin anions [PMo12O40]3− are linked by infinite [Cu(4,4′‐bipy)]+n chains through Cu‐O, and come into being a 3‐D inorganic‐organic hybrid open framework. The guest 4,4′‐bipy molecules and water molecules are filled in the channel formed by Keggin anions [PMo12O40]3− and [Cu(4,4′‐bipy)]+n chains.
Some Alkynyl‐Ruthenium Complexes Containing Di‐Imine and Tertiary Phosphine Ligands
Authors: Bruce Michael I. , Hall Benjamin C. , Skelton Brian W. , White Allan H.
Published: May 2008

Reactions between $\rm [RuCl_{2}(PPh_{3})_{2}(Bu^{t}_{2}bpy)]$, (1), and terminal alkynes in the presence of Tl[PF6], followed by chromatography on alumina, have given the mono‐alkynyl complexes $\rm [RuCl(C{\equiv}CR)(PPh_{3})_{2}(Bu^{t}_{2}bpy)]$ (R = Ph 2, C6H4NO2−4 3, CO2Me 4, Fc 5, CPh2(OH) 6), of which the single‐crystal XRD molecular structures of 3, 4 and 5 are reported.
Ag4I2SeO4 and Ag3ITeO4 – Two New Silver Solid Electrolytes
Authors: Pitzschke Dragan , Curda Jan , Cakmak Güliz , Jansen Martin
Published: May 2008

Two new silver solid electrolytes, Ag4I2SeO4 and Ag3ITeO4, have been synthesized by solid state reactions starting from stoichiometric mixtures of Ag2O and AgI with SeO2, or TeO2, respectively, at elevated oxygen pressures. The new materials have been characterized using powder X‐ray diffraction, differential scanning calorimetry, ionic conductivity measurements and single crystal structure determination. Both compounds, Ag4I2SeO4 and Ag3ITeO4, show an abrupt increase in the ionic conductivity in the temperature range of 50 to 70 °C and 90 to 130 °C, respectively. Ag4I2SeO4 has a silver ion conductivity of 1.6 × 10−3 at 30 °C with an activation energy of 0.22 eV, between 30 and 51 °C. It crystallizes as green crystals in Pna21 with a = 9.3514(1) Å, b = 13.1552(4) Å, c = 7.0886(4) Å, V = 871.80(6) Å3 and Z = 4. The crystal structure consists of isolated SeO4 tetrahedra separated by Ag+ and I− ions. Ag3ITeO4 crystallizes in P21/c with a = 19.6597(2) Å, b = 7.1240(4) Å, c = 13.3598(3) Å, β = 97.795(2)°, V = 1853.83(11) Å3 and Z = 12. The structure consists of $^{1}_{\infty}\rm [TeO_{4/2}O_{2/1}]^{2-}\}$ isopolyanions, extending along the b‐axis. The chains are separated by Ag+ and I− ions. Ag3ITeO4 has a silver ion conductivity of 7.4 × 10−5 Ω−1 cm−1 at 30 °C, with an activation energy of 0.27 eV between 25 and 100 °C.
Comparative Investigation of the Crystal Structure of LnCuSe2 Compounds (Ln = Tb, Dy, Ho, Er, Tm, Yb and Lu)
Authors: Daszkiewicz M. , Gulay L. D. , Shemet V. Ya. , Pietraszko A.
Published: May 2008

LnCuSe2 compounds crystallize either in the monoclinic LaCuS2 (space group P21/c) or the trigonal CaLi2Si2 (space group $P{\bar 3}m{\rm 1}$) type of structure. The first group is formed by the light rare‐earth elements (Ln = La, Ce, Pr, Nd, Sm, Gd and Tb), the second by the heavier rare‐earth elements (Ln = Tb, Dy, Ho, Er, Tm, Yb, Lu). Accordingly, the formation of the structure type critically depends on the ionic radius of Ln. This dependence is clearly reflected by the spatial separation of the two structure types in a plot Vat(r) listing the average atomic volume versus the ionic radius of the rare earth element in its trivalent state. The crystal structures presented here exhibit trigonal symmetry. Seven crystal structures were determined by means of the single crystal X‐ray diffraction. The Se atoms form a hexagonal closest packing of spheres with AB stacking sequence of the atomic layers. The Ln atoms occupy 1/2 of the octahedral interstices. In each of the seven trigonal structures the Cu atoms are statistically distributed over 1/2 of the tetrahedral interstices with 50 % occupation probability.
The correlation of aflatoxin and norsolorinic acid production
Authors: Bennett Joan W. , Lee Louise S. , Vinnett Carolyn
Published: May 2008

Production of aflatoxins and norsolorinic acid by a mutant strain ofAspergillus parasiticus follows a similar course. Both substances are completely or partially inhibited when the mutant is grown in a chemically defined medium while illuminated continuously, at 37 C, in medium lacking zinc, and in the presence of para‐aminobenzoic acid. Higher yields of both compounds are obtained when the mold is grown in an enriched medium.
Low pressure hydrogenation of castor oil
Authors: Trivedi R. K. , Vasishtha A. K.
Published: May 2008

Castor Oil was hydrogenated at low pressure (2.0–2.5 kg/cm2) and low temperature (125–135 C) using nickel catalyst to obtain a saturated waxy product rich in hydroxy stearic acid. High catalyst concentration was required to obtain good results. However, the catalyst could be recycled. The final product had iodine value below 3.0, hydroxyl value 155, and slip point of 84 C.
Subclassification of soybean Bowman‐Birk isoinhibitors
Authors: Tan‐Wilson Anna L.
Published: May 2008

Trypsin inhibitors are proteins in the soybean which inhibit vertebrate pancreatic proteinases. Multiple forms of the two inhibitor classes, the Kunitz and the Bowman Birk inhibitors, are found in the soybean. The three Kunitz isoinhibitors are well characterized with regard to amino acid sequence, genetic inheritance and affinity for trypsin. Enough Bowman‐Birk trypsin inhibitors have been purified and characterized that identities can be established and inhibitors classified into subgroups. The first subgroup includes the classical doubleheaded inhibitor of bovine trypsin and chymotrypsin, BBSTI‐E; its proteolytic derivative, BBSTI‐D, and BBSTI‐E. Subgroup II has the double‐headed weak trypsin inhibitors, BBSTI‐C′, C and A″, related by proteolysis at the amino terminus. Subgroup III has the even weaker trypsin inhibitor BBSTI‐B′ and its apparent proteolytic derivative, BBSTI‐B. Subgroup I, II and III inhibitors have 70–80 residues with high half‐cystine and low glycine content. Subgroup IV consists of the strong trypsin inhibitor BBSTI‐A and its apparent proteolytic derivative BBSTI‐A′. These have about 200 residues, only two half‐cystine residues per molecule and 25 residue percent glycine. They crossreact better than do Subgroup III inhibitors with anti BBSTI‐E antibodies. While the cystine‐rich BBSTI‐E and BBSTI‐C are predominant in the cotyledon, the storage organ of the plant, the glycine‐rich trypsin inhibitors are predominant in the vegetative tissues of the seedling.
Antimicrobial properties of boric acid esters of alcohols
Authors: Watanabe S. , Fujita T. , Sakamoto M.
Published: May 2008

A variety of boric acid esters of various alcohols were prepared and screened for antimicrobial activity in spent coolants of water‐based cutting fluids. Boric acid esters of triethylene glycol, dipropylene glycol, geranic acid monodiethylene glycol and some hydroxy amines, such as 5‐aminopentanol, showed good antimicrobial activity.
Computer modeling ofα‐ toβ′‐ form phase transitions using theoretical triglyceride structures
Authors: Hagemann James W. , Rothfus John A.
Published: May 2008

Intermolecular energy calculations were performed on theoretical triarachidinα‐form structures as selected bond rotations converted them intoβ′‐forms with a chain‐tilt change in the glycerol region. Interactions across the methyl gaps amounted to only 2‐3% of the total energy in initialα‐ and finalβ′‐forms, but computer generated energy profiles duringα‐ toβ′‐phase transitions revealed highly repulsive regions due to the close approach of methyl groups. This methyl gap interaction, plus additional repulsive interactions in the lateral packing of molecules during rigid chain rotations, necessitated modification of certain chain movements during phase transition to reduce excessive repulsive energy. These results suggest that phase transitions proceed in a particular sequence of events that either distribute energy to promote further phase excitation or that lead to collapse into the stable polymorphic form. Phase transition energy curves also reveal that secondaryα‐ andβ′‐forms are possible and are dependent on the startingα‐forms, the direction of chain rotation and the subcell arrangement.
Sulphurization of jojoba oil for application as extreme pressure additive
Authors: Bhatia V. K. , Chaudhry A. , Masohan A. , Bisht R. P. S. , Sivasankaran G. A.
Published: May 2008

In order to develop jojoba oil‐based extreme pressure (E P) additives, a number of sulphurized jojoba oils have been prepared by varying the reaction conditions. The products differ in their amount of sulphur and in their structure. An attempt to predict their performance based on their structure reveals that it is not a simple addition of sulphur which is required; a certain level of cross linking and polymerization also are desirable to have a product which is effective as an E P additive.
Microbial transesterification of sugar‐corynomycolates
Authors: Göbbert Uwe , Schmeichel Armin , Lang Siegmund , Wagner Fritz
Published: May 2008

Growing cells ofArthrobacter sp. DSM 2567 and of the bacterium M9b were able to synthesize cell‐bound glycolipids. The carbon source determined the type of sugar moiety, whereas the α‐branched‐β‐hydroxy‐fatty acid remained constant. The incubation of resting cells of both bacteria in a simple buffer medium with various carbohydrates, including oligosaccharides and derivatives, led to the corresponding carbohydrate‐corynomycolates. Predominantly an enzymatic transesterification step seems to be responsible for the formation of new glycolipids; this was established by analytical data and 14C‐labeling studies. Concerning the substrate specifity, the transesterification reaction is characterized by a regioselective manner: (i) only the primary hydroxy‐groups at C‐6 (mono‐ and disaccharide) or C‐6′ (disaccharide) were acylated; (ii) 1‐β‐ or 4‐β‐substituents (including hydroxy groups) prevented the esterification; (iii) as for disaccharides with only one nonreducing moiety, the C‐6‐ and C‐6′‐positions were esterified one after another. In the presence of two nonreducing molecular ends with two possible C‐6‐esterification positions, both positions were substituted simultaneously.

With regard to the studies on localization of the esterase after cell disruption, we found the enzymatic activity bound to the cell debris. In transesterification reactions comparable to resting whole cell experiments, the cell particles also were able to produce disaccharidecorynomycolates.
Determination of nitrogen content of fats and oils by the method of combustion/ion chromatography
Authors: Wijesundera R. C. , Ackman R. G.
Published: May 2008

A method of combustion/ion chromatography (C/IC), initially developed for the determination of sulfur, has been extended to determination of total nitrogen in fats and oils. It is shown that nitrogen gas dissolved in the sample interferes with the determination, and that it is necessary to degas the sample before analysis. Moreover, there is a procedural blank for the nitrogen in the cylinder oxygen employed. Despite these drawbacks, the method has advantages over conventional methods, in that (i) measurements can be carried out with standard laboratory equipment, and (ii) nitrogen and sulfur, and possibly halogens and selenium, can be determined simultaneously.
Economic Forces, Structural Discrimination and Black Family Instability
Authors: Hill Robert B.
Published: May 2008

The social and economic gains achieved by black families during the 1960s were severely eroded during the seventies and eighties. Unemployment, poverty, single-parent families, out-of-wedlock births, and adolescent pregnancies soared to alarming levels. According to the thesis of the declining significance of race, this crisis is mainly concentrated among the black “underclass” and it is broad societal trends, not racism, that is mainly responsible for their increased deprivation. We contend that this thesis fails to assess the role of institutionalized racism as it is manifested in “unintended” or “structural” discrimination, i.e., the disproportionate adverse effects of economic trends and policies on the functioning of low-income and middle-income black families. Moreover, we argue that social forces or policies that have racially disparate adverse effects are “discriminatory” by result, whether intended or not. The major economic trends that affected black families adversely during the seventies and eighties were: back-to-back recessions, double-digit inflation, and industrial and population shifts. The key economic policies that undermined black family stability have been: anti-inflation fiscal and monetary policies, trade policies, plant closings, social welfare, block grants, and federal per capita formulas for allocating funds to states and local areas that have not been corrected for the census undercount.
The Employed Black: The Dynamics of Work-Family Tension
Authors: Johnson Leanor Boulin
Published: May 2008

The interrelationship of job stressors, job strain, and marital strain among black police officers is examined using a “Work-Family Tension Model.” Perceived job stressors, such as differential treatment based on racial status, tended to affect job strain. Furthermore, job stressors (direct/indirect) and job strain tended to influence the level of marital interaction and potential for separation and divorce. The implications these findings have for work organizations are discussed.
Volatile components from trilinolenin heated in air1
Authors: Selke E. , Rohwedder W. K.
Published: May 2008

Headspace volatiles derived from trilinolenin heated to 192 C in air were collected, separated and identified using a microroom/GC‐MS/ computer system. Data from four analyses indicated more than 80 volatiles were present. Of these volatiles, 38 have been identified, and their combined GC peak areas represent 90% of the total integrated Chromatographic area. Dominant volatiles identified included: ethanal (2%), 2‐pentene (3%), ethanol (0.5%), 2‐propenal (20%), propanal (7%), ethyl furan (13%), 2‐butenal (4%), 2‐pentenal (4%), 2,4‐heptadienal (21%), 4,5‐epoxy‐2‐heptenal (3%) and 2,4,7‐decatrienal (2%). Most of the dominant and some of the minor volatiles are the predicted decomposition products of the four linolenin monohydroperoxides. However, the ratios of the predicted volatiles do not correspond to the monohydroperoxide ratios observed from autoxidized linolenate. Other primary and minor volatiles are present that are not predicted from the classical hydroperoxide decomposition hypothesis, which suggests that trilinolenin and some of the volatile compounds undergo further oxidation.
Factors affecting the desolventization of canola meal
Authors: Grant D. R. , Eager R. L. , Pepper J. M. , Mathews J. F.
Published: May 2008

Factors affecting the level of residual solvent in hexane‐extracted canola meal included the moisture content of the crushed seed and the temperature of the hexane at the time of extraction, the duration of the extraction process and the severity of the cooking procedure prior to extraction. Low moisture, low temperature extraction, short exposure to excess hexane and mild cooking procedures all contribute to minimizing the levels of sorbed hexane after desolventization was complete. Dry heat could drive off only part of the residual hexane. Moist heat, as steam, was more effective.
The use of the polarograph to distinguish between the peroxide structures in oxidized fats
Authors: Lewis W. R. , Quackenbush F. W.
Published: May 2008

A polarographic method for the determination of peroxides has been applied to fats and related esters. The data presented show that at least three different peroxide structures are present in early stages of oxidation and persist during extensive autoxidation. The peroxides of lard, methyl oleate, and methyl linoleate cannot be distinguished by the polarographic method used in this investigation. Autoxidation of lard at 100°C. is shown to give reduction curves which are much different from those obtained when lard is autoxidized at 45°C. Preliminary work has indicated that the chromatographic technique of Dugan et al. does not separate the peroxide structures which are determined polarographically.
International chemical union
Authors: Hoffpauir C. L.
Published: May 2008

This translation gives the minutes of the meeting in London during July 1947, incorporating the decisions made on the unified international methods and the plans for collaborative work to be done before the next meeting of the Commission. Methods under discussion included those for the sampling and analysis for moisture and oil specified for several oil‐bearing seeds. They also included those for alkalis and rosin in soaps and those for soluble and insoluble volatile acids and sterols in fats and oil, also for the determination of thiocyanogen and peroxide numbers in fats and oil. The organization of and the representation on the present International Commission on Fats and Oils are also given.
The application of the polybromide yield in the estimation of methyl arachidonate in methyl ester mixtures
Authors: White Mary F. , Orians Betty M. , Brown J. B.
Published: May 2008

The preparation of and analytical data on three specimens of methyl arachidonate are described; these data include determinations of thiocyanogen number.

By a standard procedure polybromide yields are reported on five specimens of methyl arachidonate over a wide range of amounts of arachidonate brominated.

The empirical nature of the polybromide yield is demonstrated.

It is proposed to estimate methyl arachidonate in methyl ester mixtures by the interpolation from a standard curve which is drawn from bromide‐arachidonate data over a wide range of values.

The use of the proposed method along with the spectroscopic procedure is discussed.
Unusual Fatty Acid Isomers of Triacylglycerols and Polar Lipids in Female Limpet Gonads of Cellana grata
Authors: Kawashima Hideki , Ohnishi Masao , Ogawa Satoshi , Matsui Kenji
Published: May 2008

To investigate the occurrence of positional isomers of unsaturated fatty acids (FA) in triacylglycerols (TAG) and polar lipids (PL) in the female gonads of a dominant limpet, Cellana grata, fatty acid methyl esters (FAME) were fractionated according to the degree of their unsaturation by argentation thin‐layer chromatography. Their structures were elucidated by gas chromatography–mass spectrometry of a combination of their FAME and picolinyl esters. A total of 125 different FA ranging from 12 to 24 carbon atoms were identified, and 105 unsaturated FA, including 34 nonmethylene‐interrupted FA as minor components, were recognized. Although the major FA 16:0 and 18:1n‐7, which accounted for more than 20 and 10%, respectively, of total FA, were present in TAG and PL, higher amounts of 20:4n‐6 and 20:5n‐3 were present in PL. Unsaturated FA consisting of more than five different positional isomers were 17:1, 19:1, 18:2, 19:2, 20:2, 21:2, 22:2, 20:3, and 22:3, most of which were present in TAG. Furthermore, a larger variety of nonmethylene‐interrupted FA was found in TAG than in PL. This limpet gonad had a diverse assortment of unsaturated FA that comprised a wide range of unusual positional isomers with one to five double bonds.
Synthesis and Structural Analysis of Branched‐Chain Derivatives of Methyl Oleate
Authors: Dailey Oliver D. , Prevost Nicolette T. , Strahan Gary D.
Published: May 2008

As part of a project to develop new value‐added industrial applications for cottonseed oil (such as biodiesel, fuel additives, and lubricants), studies were conducted on the synthetic conversion of oleic acid to branched‐chain fatty acid esters. In these studies, methyl oleate was brominated in the allylic position and subsequently treated with organocuprate reagents to produce novel branched‐chain derivatives (methyl, n‐butyl, phenyl). Original reaction conditions afforded only the branched methyl derivatives as major products. Modification of reaction conditions (lower temperature, less organocuprate reagent) afforded predominantly the desired n‐butyl and phenyl derivatives and minimized products resulting from attack on the ester functionality. Details of the syntheses, characterization (especially by NMR), and the properties of the products (with emphasis on low‐temperature properties) are discussed.
Protein Subunit Composition Effects on the Thermal Denaturation at Different Stages During the Soy Protein Isolate Processing and Gelation Profiles of Soy Protein Isolates
Authors: Bainy Eduarda M. , Tosh Susan M. , Corredig Milena , Woodrow Lorna , Poysa Vaino
Published: May 2008

This study focussed on the evaluation of thermal denaturation at three different stages during soy protein isolation and the effect of subunit composition on the formation of heat‐induced soy protein gels. Soy protein isolates (SPI) were prepared from 12 high protein lines, Harovinton variety and 11 derived null‐lines which lacked specific glycinin (11S) and β‐conglycinin (7S) protein subunits. Protein denaturation during SPI processing was monitored by differential scanning calorimetry (DSC). The results showed that hexane extraction of oil from soybean flours at 23 °C or 105 °C did cause changes in protein conformation. Rheological measurements showed that lines with different subunit compositions and 11S:7S ratio had distinctive gelation temperatures and resulted in gels with different network structures. All lines formed particulate gels at 11% protein. The 11S:7S ratio was not correlated to final stiffness, measured as the storage modulus G′, of SPI gels. Lower gelation temperatures were usually observed for 7S‐rich lines. The absence of A3 and the combination of A1, A2 and A4 subunits of 11S fraction may suggest the formation of stiffer gels. A more detailed study of the frequency dependence of G′ for the various networks formed also indicated that differences in subunit composition influenced the network structures.
The Consensus on Defense and Weimar Prussia's Civil Service
Authors: Bergien Rüdiger
Published: May 2008

The impact of the Reichswehr's program of clandestine armament on Weimar Germany's civil society is a phenomenon largely overlooked by post-war historiography. Not only did it fail to identify the wide support enjoyed by the illegal preparations for a general mobilization on the national and local levels, but it also failed to address the question why the officials collaborated with the Reichswehr under the aegis of “national defense” at all. The reasons for both omissions are easy to find. While the role played by civilians within the militarization of society has been largely ignored (due to the historiographical dominance of the interpretation model of the army as an autonomous “state within the state”), the few authors who recognized its importance considered a more detailed analysis of civilian dispositions to be dispensable in view of the well-known nationwide anti-Versailles sentiment.
From Memory to Research: German Popular Genealogy in the Early Twentieth Century
Authors: Tebbe Jason
Published: May 2008

Today genealogy enjoys a wide range of enthusiastic practitioners, and almost every extended family has a self-appointed family historian. Along with professional historians, genealogists are ubiquitous at archives both in Germany and the United States. Of course this was not always so; until about one hundred years ago genealogy was the almost exclusive purview of nobles and aristocrats who had rather immediate concerns driving their inquiries into their families' pasts. That changed around 1900 in Germany, when in the words of a “how-to” guide for amateur researchers written in 1920, genealogy underwent a transformation from a “nobleman's sport” to a bourgeois “science.” This meant that, “today the middle class constitutes four fifths, nay nine tenths, of the biggest genealogical societies.” According to the growing corpus of genealogical literature, the middle class had marked family research with superior values and a greater dedication to truth and knowledge. Beyond the rhetoric, the bourgeois acceptance of genealogy altered the ways that middle-class families saw and remembered the past.
A brief background on the U.S. Department of Agriculture Agricultural Research Service Walnut Gulch Experimental Watershed
Authors: Renard K. G. , Nichols M. H. , Woolhiser D. A. , Osborn H. B.
Published: May 2008

Watershed research is critical for quantifying the unique characteristics of hydrologic processes worldwide and especially in semiarid regions. In 1953, the United States Department of Agriculture established the Walnut Gulch Experimental Watershed (WGEW) near Tombstone, Arizona, to conduct hydrologic and erosion research. This manuscript (1) provides a historical context summarizing the evolution of the Southwest Watershed Research Center research program, (2) describes significant contributions to instrumentation development and contributions to science, and (3) describes the current WGEW data collection program in the context of contemporary research questions. The development of specialized flumes for streamflow measurement and the establishment of the core monitoring networks are described. WGEW data have been used to quantify semiarid rainfall, runoff, infiltration, and transmission losses; to develop and validate simulation models; and to support broader, regional, basin‐scale research. Currently, rainfall, runoff, sediment, meteorology, and flux data collection continue at the WGEW, but the monitoring network has been expanded, and data use has evolved to support several multiple government agencies, universities, and international research programs.
Long‐term precipitation database, Walnut Gulch Experimental Watershed, Arizona, United States
Authors: Goodrich David C. , Keefer Timothy O. , Unkrich Carl L. , Nichols Mary H. , Osborn Herbert B. , Stone Jeff J. , Smith John R.
Published: May 2008

An extensive precipitation database at the ∼149 km2 Walnut Gulch Experimental Watershed (WGEW) has been developed over the past 53 years with the first records starting in August 1953 and continuing to the present. The WGEW is a tributary of the San Pedro River, is located in southeastern Arizona, and surrounds the town of Tombstone. Average annual precipitation for the period of 1956–2005, as measured with six gauges, is roughly 312 mm, with approximately 60% falling during the summer monsoon. From a historical high of 95 rain gauges, a current network of 88 gauges is operational. This constitutes one of the densest rain gauge networks in the world (∼0.6 gauges/km2) for watersheds greater than 10 km2. Through 1999, the network consisted of analog recording weighing rain gauges. In 2000, a newly designed digital gauge with telemetry was placed adjacent (∼1 m) to the analog gauges. Both the analog and digital networks of gauges were in operation from 2000 to 2005 to enable a comparative analysis of the two systems. The analog data were digitized from paper charts and were stored in breakpoint format. The digital data consist of rainfall depths at 1‐min intervals during periods of rainfall. All these data can be obtained in a variety of formats and were accumulated over various time intervals (daily, monthly, and annual) via a web interface at http://www.tucson.ars.ag.gov/dap/.
A magnetic null geometry reconstructed from Cluster spacecraft observations
Authors: He J.‐S. , Tu C.‐Y. , Tian H. , Xiao C.‐J. , Wang X.‐G. , Pu Z.‐Y. , Ma Z.‐W. , Dunlop M. W. , Zhao H. , Zhou G.‐P. , Wang J.‐X. , Fu S.‐Y. , Liu Z.‐X. , Zong Q.‐G. , Glassmeier K.‐H. , Reme H. , Dandouras I. , Escoubet C. P.
Published: May 2008

This paper reports for the first time the identification of a magnetic structure around a magnetic null in a magnetic reconnection region in the magnetotail. Magnetic reconnection is one of the fundamental processes in astrophysical and solar‐terrestrial plasmas. Though the concept of reconnection has been studied for many years, the process that really occurs has not been fully revealed by direct measurements. In particular, the lack of a description of three‐dimensional (3‐D) reconnecting magnetic field from observations makes the task more difficult. The Cluster spacecraft array provide an opportunity to reconstruct the 3‐D magnetic reconnection structure based on magnetic field vectors simultaneously measured at four positions. The identification of this structure comes from a new method of analysis of in situ measurements proposed here. Applying a fitting model of 10 spherical harmonic functions and a Harris current sheet function, plus a constant field, we reconstruct a 3‐D magnetic field configuration around the magnetic null in an reconnection event observed by Cluster in the geo‐magnetotail.
A model for heat flow in deep borehole disposals of high‐level nuclear waste
Authors: Gibb Fergus G. F. , Travis Karl P. , McTaggart Neil A. , Burley David
Published: May 2008

Deep borehole disposal (DBD) is emerging as a viable alternative to mined repositories for many forms of highly radioactive waste. It is geologically safer, more secure, less environmentally disruptive and potentially more cost‐effective. All high‐level wastes generate heat leading to elevated temperatures in and around the disposal. In some versions of DBD this heat is an essential part of the disposal while in others it affects the performances of materials and waste forms and can threaten the success of the disposal. Different versions of DBD are outlined, for all of which it is essential to predict the distribution of temperature with time. A generic physical model is established and a mathematical model set up involving the transient conductive heat flow differential equation for a cylindrical source term with realistic decay. This equation is solved using the method of Finite Differences. A Fortran computer code (GRANITE) has been developed for the model in the context of DBD and validated against theoretical and other benchmarks. The limitations of the model, code, input parameters and data used are discussed and it is concluded that the model provides a satisfactory basis for predicting temperatures in DBD. Examples of applications to some DBD scenarios are given and it is shown that the results are essential to the design strategy of the DBD versions, geometric details and choice of materials used. Without such modeling it would be impossible to progress DBD of nuclear wastes; something that is now being given serious consideration in several countries.
Hydrological cycle in the Danube basin in present‐day and XXII century simulations by IPCCAR4 global climate models
Authors: Lucarini Valerio , Danihlik Robert , Kriegerova Ida , Speranza Antonio
Published: May 2008

We present an intercomparison and verification analysis of 20 GCMs (Global Circulation Models) included in the 4th IPCC assessment report regarding their representation of the hydrological cycle on the Danube river basin for 1961–2000 and for the 2161–2200 SRESA1B scenario runs. The basin‐scale properties of the hydrological cycle are computed by spatially integrating the precipitation, evaporation, and runoff fields using the Voronoi‐Thiessen tessellation formalism. The span of the model‐ simulated mean annual water balances is of the same order of magnitude of the observed Danube discharge of the Delta; the true value is within the range simulated by the models. Some land components seem to have deficiencies since there are cases of violation of water conservation when annual means are considered. The overall performance and the degree of agreement of the GCMs are comparable to those of the RCMs (Regional Climate Models) analyzed in a previous work, in spite of the much higher resolution and common nesting of the RCMs. The reanalyses are shown to feature several inconsistencies and cannot be used as a verification benchmark for the hydrological cycle in the Danubian region. In the scenario runs, for basically all models the water balance decreases, whereas its interannual variability increases. Changes in the strength of the hydrological cycle are not consistent among models: it is confirmed that capturing the impact of climate change on the hydrological cycle is not an easy task over land areas. Moreover, in several cases we find that qualitatively different behaviors emerge among the models: the ensemble mean does not represent any sort of average model, and often it falls between the models' clusters.
Sensitivity of a model projection of near‐surface permafrost degradation to soil column depth and representation of soil organic matter
Authors: Lawrence David M. , Slater Andrew G. , Romanovsky Vladimir E. , Nicolsky Dmitry J.
Published: May 2008

The sensitivity of a global land‐surface model projection of near‐surface permafrost degradation is assessed with respect to explicit accounting of the thermal and hydrologic properties of soil organic matter and to a deepening of the soil column from 3.5 to 50 or more m. Together these modifications result in substantial improvements in the simulation of near‐surface soil temperature in the Community Land Model (CLM). When forced off‐line with archived data from a fully coupled Community Climate System Model (CCSM3) simulation of 20th century climate, the revised version of CLM produces a near‐surface permafrost extent of 10.7 × 106 km2 (north of 45°N). This extent represents an improvement over the 8.5 × 106 km2 simulated in the standard model and compares reasonably with observed estimates for continuous and discontinuous permafrost area (11.2–13.5 × 106 km2). The total extent in the new model remains lower than observed because of biases in CCSM3 air temperature and/or snow depth. The rate of near‐surface permafrost degradation, in response to strong simulated Arctic warming (∼ +7.5°C over Arctic land from 1900 to 2100, A1B greenhouse gas emissions scenario), is slower inthe improved version of CLM, particularly during the early 21st century (81,000 versus 111,000 km2 a−1, where a is years). Even at the depressed rate, however, the warming is enough to drive near‐surface permafrost extent sharply down by 2100. Experiments with a deep soil column exhibit a larger increase in ground heat flux than those without because of stronger near‐surface vertical soil temperature gradients. This appears to lessen the sensitivity of soil temperature change to model soil depth.
Diffraction by a right‐angled impedance wedge
Authors: Osipov Andrey V. , Senior Thomas B. A.
Published: May 2008

A plane electromagnetic wave is incident at an oblique (skew) angle on a wedge of open angle 3π/2 with scalar face impedances, the same on both faces. When the theory previously developed for wedges of arbitrary angle with tensor face impedances is specialized to this case, the analysis simplifies, and the resulting expressions for the geometrical optics, surface wave and diffracted fields are presented. Because of the practical importance of this geometry, a large set of figures is included showing the behavior of the diffracted field for a variety of face impedances.
Mechanical erosion of xenoliths by magmatic shear flow
Authors: Del Gaudio Piero , Ventura Guido
Published: May 2008

We focus on the role of mechanical erosion by magmatic shear flow in the formation of xenoliths occurring in lava flows. The process is analyzed by combining the physics of fragmentation and erosion to the concept of rock mass. The conditions for the country rock fragmentation are analyzed as a function of the magma viscosity, strain rate and tensile strength of the rock mass. In reservoirs, mechanical processes play a subordinate role and thermal erosion processes prevail. In conduits, intermediate and silicic magmas may erode and, eventually, fragment good to poor quality country rock masses. Basalts may erode poor quality country rocks. A crystal‐rich magma has more chance to break up the conduit walls with respect to a vesiculated melt. The variety of xenoliths of a lava reflects a set of wall‐rocks with similar mechanical properties and may not mirror the stratigraphy of the substratum of a volcanic area.
Hydrogen peroxide‐induced translocation of glycolipid‐anchored (c)AMP‐hydrolases to lipid droplets mediates inhibition of lipolysis in rat adipocytes
Authors: Müller G , Wied S , Jung C , Over S
Published: May 2008

Background:

The insulin‐independent inhibition of lipolysis by palmitate, the anti‐diabetic sulphonylurea glimepiride and H2O2 in rat adipocytes involves stimulation of the glycosylphosphatidylinositol (GPI)‐specific phospholipase‐C (GPI‐PLC) and subsequent translocation of the GPI‐anchored membrane ectoproteins (GPI‐proteins), Gce1 and cluster of differentiation antigen (CD73), from specialized plasma membrane microdomains (DIGs) to cytosolic lipid droplets (LDs). This results in cAMP degradation at the LD surface and failure to activate hormone‐sensitive lipase. Reactive oxygen species (ROS) may trigger this sequence of events in response to palmitate and glimepiride.

Experimental approach:

The effects of various inhibitors of ROS production on the release of H2O2, GPI anchor cleavage and translocation of the photoaffinity‐labelled or metabolically labelled Gce1 and CD73 from DIGs to LD and inhibition of lipolysis by different fatty acids and sulphonylureas were studied with primary rat adipocytes.

Key results:

Glimepiride and palmitate induced the production of H2O2 via the plasma membrane NADPH oxidase and mitochondrial complexes I and III, respectively. Inhibition of ROS production was accompanied by the loss of (i) GPI‐PLC activation, (ii) Gce1 and CD73 translocation and (iii) lipolysis inhibition in response to palmitate and glimepiride. Non‐metabolizable fatty acids and the sulphonylurea drug tolbutamide were inactive. NADPH oxidase and GPI‐PLC activities colocalized at DIGs were stimulated by glimepiride but not tolbutamide.

Conclusions and implications:

The data suggest that ROS mediate GPI‐PLC activation at DIGs and subsequent GPI‐protein translocation from DIGs to LD in adipocytes which leads to inhibition of lipolysis by palmitate and glimepiride. This insulin‐independent anti‐lipolytic mechanism may be engaged by future anti‐diabetic drugs.

British Journal of Pharmacology (2008) 154, 901–913; doi:10.1038/bjp.2008.146; published online 5 May 2008
Characterization of a CNS penetrant, selective M1muscarinic receptor agonist, 77‐LH‐28‐1
Authors: Langmead C J , Austin N E , Branch C L , Brown J T , Buchanan K A , Davies C H , Forbes I T , Fry V A H , Hagan J J , Herdon H J , Jones G A , Jeggo R , Kew J N C , Mazzali A , Melarange R , Patel N , Pardoe J , Randall A D , Roberts C , Roopun A , Starr K R , Teriakidis A , Wood M D , Whittington M , Wu Z , Watson J
Published: May 2008

Background and purpose:

M1muscarinic ACh receptors (mAChRs) represent an attractive drug target for the treatment of cognitive deficits associated with diseases such as Alzheimer's disease and schizophrenia. However, the discovery of subtype‐selective mAChR agonists has been hampered by the high degree of conservation of the orthosteric ACh‐binding site among mAChR subtypes. The advent of functional screening assays has enabled the identification of agonists such as AC‐42 (4‐n‐butyl‐1‐[4‐(2‐methylphenyl)‐4‐oxo‐1‐butyl]‐piperidine), which bind to an allosteric site and selectively activate the M1mAChR subtype. However, studies with this compound have been limited to recombinantly expressed mAChRs.

Experimental approach:

In this study, we have compared the pharmacological profile of AC‐42 and a close structural analogue, 77‐LH‐28‐1 (1‐[3‐(4‐butyl‐1‐piperidinyl)propyl]‐3,4‐dihydro‐2(1H)‐quinolinone) at human recombinant, and rat native, mAChRs by calcium mobilization, inositol phosphate accumulation and bothin vitroandin vivoelectrophysiology.

Key results:

Calcium mobilization and inositol phosphate accumulation assays revealed that both AC‐42 and 77‐LH‐28‐1 display high selectivity to activate the M1mAChR over other mAChR subtypes. Furthermore, 77‐LH‐28‐1, but not AC‐42, acted as an agonist at rat hippocampal M1receptors, as demonstrated by its ability to increase cell firing and initiate gamma frequency network oscillations. Finally, 77‐LH‐28‐1 stimulated cell firing in the rat hippocampusin vivofollowing subcutaneous administration.

Conclusions and implications:

These data suggest that 77‐LH‐28‐1 is a potent, selective, bioavailable and brain‐penetrant agonist at the M1mAChR and therefore that it represents a better tool than AC‐42, with which to study the pharmacology of the M1mAChR.

British Journal of Pharmacology(2008)154, 1104–1115; doi:10.1038/bjp.2008.152; published online 5 May 2008
Evidence for the role of neurogenic inflammation components in trypsin‐elicited scratching behaviour in mice
Authors: Costa R , Marotta D M , Manjavachi M N , Fernandes E S , Lima‐Garcia J F , Paszcuk A F , Quintão N L M , Juliano L , Brain S D , Calixto J B
Published: May 2008

Background and purpose:

We investigated the mechanisms underlying the pruritogenic response induced by trypsin in mice, to assess the relevance of neurogenic inflammation components in this response.

Experimental approach:

Itching was induced by an intradermal injection of trypsin in the mouse neck. The animals were observed for 40 min and their scratching behaviour was quantified.

Key results:

Trypsin‐induced itching was blocked by the lima bean trypsin inhibitor, the selective proteinase‐activated receptor‐2 (PAR‐2) antagonist FSLLRY and PAR‐2 receptor desensitization. An important involvement of mast cells was observed, as chronic pretreatment with the mast cell degranulator compound 48/80 or the mast cell stabilizer disodium cromoglycate prevented scratching. Also, trypsin response was inhibited by the selective COX‐2 inhibitor celecoxib and by the selective kinin B2(FR173657) and B1(SSR240612) receptor antagonists. Moreover, an essential role for the mediators of neurogenic inflammation was established, as the selective NK1(FK888), NK3(SR142801) and calcitonin gene‐related peptide (CGRP8−37fragment) receptor antagonists inhibited trypsin‐induced itching. Similarly, blockade of transient receptor potential vanilloid 1 (TRPV1) receptors by the selective TRPV1 receptor antagonist SB366791, or by genetic deletion of TRPV1 receptor reduced this behaviour in mice. C‐fibre desensitization showed a very similar result.

Conclusions and implications:

Trypsin intradermal injection proved to be a reproducible model for the study of itching and the involvement of PAR‐2 receptors. Also, trypsin‐induced itching seems to be widely dependent on neurogenic inflammation, with a role for TRPV1 receptors. In addition, several other mediators located in the sensory nerves and skin also seem to contribute to this process.

British Journal of Pharmacology(2008)154, 1094–1103; doi:10.1038/bjp.2008.172; published online 5 May 2008
A constant entropy increase model for the selection of parallel tempering ensembles
Authors: Sabo Dubravko , Meuwly Markus , Freeman David L. , Doll J. D.
Published: May 2008

The present paper explores a simple approach to the question of parallel tempering temperature selection. We argue that to optimize the performance of parallel tempering it is reasonable to require that the increase in entropy between successive temperatures be uniform over the entire ensemble. An estimate of the system’s heat capacity, obtained either from experiment, a preliminary simulation, or a suitable physical model, thus provides a means for generating the desired tempering ensemble. Applications to the two-dimensional Ising problem indicate that the resulting method is effective, simple to implement, and robust with respect to its sensitivity to the quality of the underlying heat capacity model.
A stochastic model of coherent structures for particle deposition in turbulent flows
Authors: Guingo Mathieu , Minier Jean-Pierre
Published: May 2008

In this paper, we propose a new stochastic Lagrangian model that is used to compute particle deposition rate in turbulent flows. This one dimensional boundary-layer model of the velocity of the flow seen by a particle explicitly simulates the interaction of particles with the near-wall coherent phenomena governing the wall-normal transport of particles (the so-called sweep and ejections events). For this purpose, a Markovian jump process, driving other stochastic processes, is introduced to model the coherent events. This method is believed to be one of the first attempts to include relevant geometrical features of the near-wall region in a statistical Lagrangian description. The model is first validated by comparing results obtained in the fluid-particle limit to available statistics of the boundary layer and by ensuring that the well-mixed condition is satisfied. Then, the deposition velocity is computed, and good agreement with experimental data is obtained. Furthermore, the two deposition regimes (“free flight” and “diffusional”) recently identified by direct numerical simulations are qualitatively retrieved.
Bifurcations and symmetry breaking in the wake of axisymmetric bodies
Authors: Fabre David , Auguste Franck , Magnaudet Jacques
Published: May 2008

We consider the generic problem of wake instabilities past fixed axisymmetric bodies, and focus on the extreme cases of a sphere and a flat disk. Numerical results reveal that the wakes of these two bodies evolve differently as the Reynolds number is increased. Especially, two new vortex shedding modes are identified behind a disk. To interpret these results, we introduce a model based on the theory of mode interactions in presence of O(2) symmetry. This model, which was initially developed for the Taylor–Couette system, allows us to explain the structural differences observed in the evolution of the two types of wakes and to accurately predict the evolution of the lift force.
Unbiased computation of transition times by pathway recombination
Authors: Kuipers J. , Barkema G. T.
Published: May 2008

In many systems, the time scales of the microscopic dynamics and macroscopic dynamics of interest are separated by many orders of magnitude. Examples abound, for instance, nucleation, protein folding, and chemical reactions. For these systems, direct simulation of phase space trajectories does not efficiently determine most physical quantities of interest. The past decade has seen the advent of methods circumventing brute force simulation. For most dynamical quantities, these methods all share the drawback of systematical errors. We present a novel method for generating ensembles of phase space trajectories. By sampling small pieces of these trajectories in different phase space domains and piecing them together in a smart way using equilibrium properties, we obtain physical quantities such as transition times. This method does not have any systematical error and is very efficient; the computational effort to calculate the first passage time across a free energy barrier does not increase with the height of the barrier. The strength of the method is shown in the Ising model. Accurate measurements of nucleation times span almost ten orders of magnitude and reveal corrections to classical nucleation theory.
Dielectrophoretic particle dynamics in alternating-current electro-osmotic micropumps
Authors: Weiss Bernhard , Hilber Wolfgang , Holly Roman , Gittler Philipp , Jakoby Bernhard , Hingerl Kurt
Published: May 2008

This letter deals with the dynamics of dielectric microparticles in alternating-current electro-osmotic micropumps, which is based on the competitive interplay of inertial, dielectrophoretic, and viscous drag forces. The electric field and the electro-osmotic flow are modeled and computed by means of finite elements and particle trajectories are evaluated taking into account the forces above. Thereby, mean traveling height and velocity depend on driving voltage and frequency, which allows for an effective type of particle manipulation and separation. The obtained particle velocities show good agreement with measured velocities of hollow glass beads in a device realized in SU8/glass technology.