bluuebunny/crossref_metadata_2025 huggingface dataset:
Antimalarial activity of some plants traditionally used in Meru district of Kenya
Authors: Muthaura C. N. , Rukunga G. M. , Chhabra S. C. , Omar S. A. , Guantai A. N. , Gathirwa J. W. , Tolo F. M. , Mwitari P. G. , Keter L. K. , Kirira P. G. , Kimani C. W. , Mungai G. M. , Njagi E. N. M.
Published: May 2007

Ten plant extracts commonly used by the Meru community of Kenya were evaluated for thein vitroantiplasmodial,in vivoantimalarial, cytotoxicity and animal toxicity activities. The water and methanol extracts ofLudwigia erectaand the methanol extracts ofFuerstia africanaandSchkuhria pinnataexhibited high antiplasmodial activity (IC50< 5 µg/mL) against chloroquine sensitive (D6) and resistant (W2)Plasmodium falciparumclones. The cytotoxicity of these highly active extracts on Vero E6 cells were in the range 161.5–4650.0 µg/mL with a selectivity index (SI) of 124.2–3530.7.In vivostudies of these extracts showed less activity with chemosuppression of parasitaemia inPlasmodium bergheiinfected mice of 49.64–65.28%. The methanol extract ofClerodendrum eriophyllumwith a lowerin vitroactivity (IC509.51–10.56 µg/mL) exhibited the highest chemosuppression of 90.13%. The methanol and water extracts ofPittosporum viridiflorumwere toxic to mice but at a lower dose prolonged survival ofP. bergheiinfected mice (p< 0.05) with no overt signs of toxicity. However, the extracts were cytotoxic (SI, 0.96–2.51) on Vero E6 cells. These results suggest that there is potential to isolate active non‐toxic antimalarial principles from these plants. Copyright © 2007 John Wiley & Sons, Ltd.
Toki‐to protects dopaminergic neurons in the substantia nigra from neurotoxicity of MPTP in mice
Authors: Sakai Risa , Irie Yoshifumi , Murata Takeshi , Ishige Atsushi , Anjiki Naoko , Watanabe Kenji
Published: May 2007

Parkinson's disease (PD) is a neurodegenerative disease of the brain characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN). No clinically proven drugs that may halt or retard the progression of PD have been reported. This study examined the anti‐PD effect of a traditional Japanese/Chinese herbal remedy Toki‐to (TKT) using mice treated with a neurotoxin 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydroxypyridine (MPTP). TKT showed improvement of MPTP‐induced PD‐like symptoms (bradykinesia) in a behavioral test (pole test). Histological studies of SNs from these mice demonstrated that TKT had a protective effect on dopaminergic neurons against MPTP neurotoxicity. Real‐time RT‐PCR analyses of mRNA from SNs demonstrated that expression of tyrosine hydroxylase (TH) and dopamine transporter (DAT) genes were decreased by MPTP treatment and that these decreases were reversed by TKT administration prior to MPTP treatment. DNA microarray analyses indicated that TKT per se suppressed gene expression of serum‐ and glucocorticoid regulated kinase (SGK) that is believed to be a molecule that drives the pathogenesis of PD. Hence, it is suggested that TKT may inhibit the activation of SGK at the transcriptional level and thusmay participate in halting the progression of MPTP‐induced neurotoxicity. Copyright © 2007 John Wiley & Sons, Ltd.
The universal Hamiltonian of the exchange interaction for the system of particles with an arbitrary spin j
Authors: Orlenko Elena
Published: May 2007

On the basis of the arrangement symmetry for the system of identical particles the universal Hamiltonian of the exchange interaction in the spin representation is developed. For the case of spin‐1/2 particles the obtained Hamiltonian is equivalent to the Heisenberg form. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Identification and determination of fat‐soluble vitamins and metabolites in human serum by liquid chromatography/triple quadrupole mass spectrometry with multiple reaction monitoring
Authors: Priego Capote Feliciano , Jiménez José Ruiz , Granados José María Mata , de Castro María Dolores Luque
Published: May 2007

A method for determination of fat‐soluble vitamins K1, K3, A, D2, D3 and E (as α‐ and δ‐tocopherol) and metabolites 25‐hydroxyvitamin D2 and D3 and 1,25‐dihydroxyvitamin D3 in human serum by liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) in positive mode is proposed. Highly selective identification of the target compounds in serum was confirmed by the most representative transitions from precursor ion to product ion. Quantitative MS/MS analysis was carried out by multiple reaction monitoring optimizing the most sensitive transition for each analyte in order to achieve low detection limits (from 0.012 to 0.3 ng/mL estimated with serum). The analysis was performed with 1 mL of serum, which was subjected to protein precipitation, liquid–liquid extraction to an organic phase, evaporation to dryness and reconstitution with methanol. The precision of the overall method ranged from 3.17–6.76% as intra‐day variability and from 5.07–11.53% as inter‐day variability. The method, validated by the standard addition method, provides complete information on the fat‐soluble vitamins profile, which is of interest in clinical and metabolomics studies. Copyright © 2007 John Wiley & Sons, Ltd.
Study of the coupling reaction of pyridine in the gas phase
Authors: Yao Shengjun , Zhang Xiang , Zhang Lei , Wang Cuihong , Guo Yinlong
Published: May 2007

The coupling reaction of pyridine in the gas phase to form bipyridyl and terpyridyl has been studied by electron ionization using an ion trap mass spectrometer. In contrast to the difficulty in carrying out electrophilic substitutions at carbon atoms in the pyridine ring under highly acidic solvent conditions, reactions in the gas phase overcame the conjugate acidification of pyridine in the solvent phase, thus decreasing the hardness of this electrophilic coupling. Through product ion mass spectra of the ion at m/z 157, we have shown that this ion was protonated bipyridyl rather than the ion/molecule adduct. A computational study of the heat of formation surface also supported the formation of polypyridyls through the electrophilic substitution of pyridine. We have confirmed the reaction through a study of pyridine‐d5 coupling in the gas phase. Copyright © 2007 John Wiley & Sons, Ltd.
Highly sensitive assay for tiotropium, a quaternary ammonium, in human plasma by high‐performance liquid chromatography/tandem mass spectrometry
Authors: Wang Jiang , Jiang Yao , Wang Yingwu , Li Hao , Fawcett J. Paul , Gu Jingkai
Published: May 2007

Tiotropium bromide, a long‐acting inhaled bronchodilator analogous to ipratropium bromide, is currently undergoing development for the treatment of chronic obstructive pulmonary disease. To evaluate its systemic absorption in humans, we have developed a rapid and sensitive method for its determination in human plasma based on high‐performance liquid chromatography with tandem mass spectrometric detection (HPLC/MS/MS). Reversed‐phase chromatography of tiotropium and the internal standard clenbuterol was carried out using acetonitrile/10 mM ammonium acetate (1% formic acid) 40:60 as mobile phase in a run time of 3.0 min. The sample preparation involved deproteination with acetonitrile, extraction into dichloromethane and back‐extraction into hydrochloric acid. The assay was linear over the concentration range 0.500–50.0 pg/mL with intra‐ and inter‐day precision (as relative standard deviation) both ≤7.34%. The method was successfully applied to a pharmacokinetic study of systemic absorption in healthy male volunteers given a single 18 µg inhaled dose. Copyright © 2007 John Wiley & Sons, Ltd.
Deuterium and oxygen‐18 determination of microliter quantities of a water sample using an automated equilibrator
Authors: Uemura Ryu , Matsui Yohei , Motoyama Hideaki , Yoshida Naohiro
Published: May 2007

We describe a modified version of the equilibration method and a correction algorithm for isotope ratio measurements of small quantities of water samples. The δD and the δ18O of the same water sample can both be analyzed using an automated equilibrator with sample sizes as small as 50 µL. Conventional equilibration techniques generally require water samples of several µL. That limitation is attributable mainly to changes in the isotope ratio (18O/16O or D/H) of water samples during isotopic exchange between the equilibration gas (CO2 or H2) and water, and therefore the technique for µL quantities of water requires mass‐balance correction using the water/gas (CO2 or H2) mole ratio to correct this isotopic effect. We quantitatively evaluate factors controlling the variability of the isotopic effect due to sample size. Theoretical consideration shows that a simple linear equation corrects for the effects without determining parameters such as isotope fractionation factors and water/gas mole ratios. Precisions (1‐sigma) of 50‐µL meteoric water samples whose isotopic compositions of −1.4 to −396.2‰ for δD are ±0.5 to ±0.6‰, and of −0.37 to −51.37‰ for δ18O are ±0.01 to ±0.11‰. Copyright © 2007 John Wiley & Sons, Ltd.
Water–polysaccharide macromolecules: competitive interaction on glass microspheres
Authors: Piccirilli P. , Caracciolo N. , Enrich C. , Boeykens S. , Vázquez C. , Rosen M.
Published: May 2007

The equilibrium properties of a polymer solution in the vicinity of a solid–liquid interface are locally altered relative to those in bulk. Discrepancies between porous media and conventional rheology appear when the pore wall is either attractive or repulsive for the polymer adsorption. These local alterations become evident in practical situations, such as filtration, dissolution, purification, chromatography of polymers and various membrane permeation situations, as well as in many industrial applications.

In the present paper we study the adsorption of scleroglucan on a glass surface. In order to understand polymer adsorption at a liquid–solid interface, it is necessary to consider the competitive interaction that takes place between the macromolecules and the solvent molecules on the solid surface and the structural transformations of the system as a whole. The experiments were performed with aqueous scleroglucan solutions of concentrations up to 0.1% on 400–600 µm glass microspheres. The polymer had been previously labeled with iodine in a chemical reaction. The iodine concentration was detected by total reflection x‐ray fluorescence spectrometry (TXRF). The adsorbed polymer films were evaluated as given by the concentration measurements. Copyright © 2007 John Wiley & Sons, Ltd.
Diffraction enhanced imaging and x‐ray fluorescence microtomography for analyzing biological samples
Authors: Rocha H. S. , Pereira G. R. , Anjos M. J. , Faria P. , Kellermann G. , Pérez C. A. , Tirao G. , Mazzaro I. , Giles C. , Lopes R. T.
Published: May 2007

In this work, breast tissue samples were investigated in order to verify the distribution of certain elements by x‐ray fluorescence computed tomography (XRFCT) correlated with the characteristics and pathology of each tissue observed by diffraction enhanced imaging (DEI).

The DEI system can show details in low attenuation tissues. It is based on the contrast imaging obtained by extinction, diffraction and refraction characteristics and can improve reduction in false positive and false negative diagnoses. XRFCT allows mapping of all elements within the sample, since even a minute fluorescence signal can be detected. DEI imaging techniques revealed the complex structure of the disease, confirmed by the histological section, and showed microstructures in all planes of the sample. The XRFCT showed the distribution of Zn, Cu and Fe at higher concentration. Copyright © 2007 John Wiley & Sons, Ltd.
Fractional vacuum distillation of herring oil methyl esters
Authors: Ackman R. G. , Ke P. J. , Jangaard P. M.
Published: May 2007

Methyl esters of a Canadian Atlantic herring oil containing 62% monoethylenic fatty acids were subjected to batch fractional distillation under vacuum on a pilot plant scale, to study the feasibility of fractionating fatty acid esters of marine oils of low iodine value into monounsaturated fractions with increased commercial value for industrial chemical uses. A total of 64 methyl ester fractions were collected and analyzed by gas liquid chromatography. Recoveries of the major saturated and monounsaturated acids were close to 100%, and some fractions contained over 90% of the desired 22:1 long chain monounsaturated acids. The short chain polyunsaturated acids were recovered in good yields, but the long chain highly unsaturated acids were recovered in yields of 60% or less due to oxidative and thermal decomposition in the particular apparatus employed. If small amounts of unsaturated acids are acceptable, fractional distillation of low iodine value marine oils could inexpensively supply fractions with high concentrations of methyl esters of longer chain (C20 and C22) monounsaturated and shorter chain (C14) saturated acid or (C16) saturated‐monounsaturated acid mixture.
Hydrogenation and deuteration of conjugated isomers of linoleate and linolenate with palladium, platinum, nickel and lindlar catalysts
Authors: Koritala Asmbasivarao , Scholfield C. R. , Selke E. , Dutton H. J.
Published: May 2007

Conjugated isomers of methyl linoleate and linolenate were reduced with palladium, platinum, nickel and Lindlar catalysts at atmospheric hydrogen or deuterium pressure. After the products were separated, positions of their double bonds were determined by ozonolysis. Palladium and platinum catalysts reduced β‐eleostearate directly to monoene. Nickel reduced β‐eleostearate to dienes chiefly by 1,2‐addition and to a lesser extent by 1,4‐ and 1,6‐addition, whereas Lindlar catalyst reduced by 1,2‐and 1,6‐addition only. All catalysts reduced conjugated linoleate isomers by both 1,2‐ and 1,4‐addition, with nickel being somewhat preferential for 1,2‐addition. Selectivity for the catalytic reduction of dienes to monoenes decreased in the order: nickel, palladium and platinum. Lindlar catalyst did not isomerize or reduce monoenes that formed during reduction. Palladium and platinum did not isomerize conjugated dienes and trienes during their reduction, whereas nickel and Lindlar catalysts isomerized them slightly. Some deuterium was found in unreacted conjugated diene and triene with nickel and Lindlar catalysts, but none with palladium or platinum. Deuterated products contained a wide range of isotopic isomers with some products having up to 31 deuterium atoms. This wide deuterium distribution resulted from (a) exchange followed by addition, (b) addition followed by exchange and (c) exchange‐addition‐exchange reactions.
Concentrations of some aliphatic aldehydes and ketones found in raw and roasted spanish and runner peanuts
Authors: Brown David F. , Senn Vincent J. , Dollear F. G. , Goldblatt L. A.
Published: May 2007

Carbonyl compounds in oil cold‐pressed from raw and roasted peanuts were isolated and quantitated as their 2,4‐dinitrophenylhydrazones. Quantitative data were obtained for more than 40 compounds and compared to the flavor threshold values of the compounds in oil. In general, concentrations of aldehydes and ketones in Spanish peanuts were higher than in runner peanuts. Hexanal and octanal and possibly nonanal, 2‐octenal and 2‐nonenal may contribute to the “green‐beany” flavor of raw peanuts. Concentrations of 2‐methylpropanal, 2‐methylbutanal and 3‐methylbutanal vastly exceeded their flavor thresholds and probably contribute significantly to the harsh note of freshly roasted peanuts. Other compounds that could contribute to the flavor and aroma of roasted peanuts are: hexanal, heptanal, octanal, nonanal, dodecanal, 2‐heptenal, 2‐octenal, 2‐nonenal, 2‐decenal and 2,4‐decadienal.
Liquid‐liquid extraction of BHT from vegetable oils
Authors: Phipps A. M.
Published: May 2007

Partition behavior of the antioxidants BHT and BHA has been investigated betweenn‐heptane and the polar phases; DMSO, DMF, acetonitrile and 80% methanol‐water v/v. The distribution of four vegetable oils in these solvent pairs was also examined, as well as the influence of the oil on the partition of the antioxidants. Consideration has been given to requirements for quantitative extraction in the more promising cases.
The presence of volatile, nonpolar bromo organic compounds synthesized by marine organisms
Authors: Lunde Gulbrand
Published: May 2007

The presence of volatile, nonpolar bromine‐containing compounds in marine organisms is demonstrated. These compounds represent, especially in tissue containing a high fat content, ca. 0.1–1.0% of the total amount of bromo organic compounds present in marine oils. In tissue with a low fat content, a higher concentration of bromo organic compounds is found. It is concluded that these compounds are probably synthesized in one or more stages in the marine food chain. These compounds may follow and disturb the analyses when isolating and determining chlorinated hydrocarbons originating from industrial and other sources of pollution.
The analysis of organically bound elements (As, Se, Br) and phosphorus in raw, refined, bleached and hydrogenated marine oils produced from fish of different quality
Authors: Lunde Gulbrand
Published: May 2007

Marine oils have been produced in pilot plant by boiling, pressing and separation of the press liquor from raw material (mackerel and herring) of different levels of spoilage. The difference in quality is obtained by varying the period of storage. Some of the oil samples have been refined and hydrogenated. In samples taken both from the raw oils and from oils at the different steps in the processing, organic bound arsenic, selenium, bromine and phosphorus are analyzed. When the raw material deteriorates during storage, an increase in the selenium and phosphorus content in the oils produced from these materials is observed, whereas the bromine and the arsenic content is nearly constant. During the refining the arsenic and phosphorus disappear almost completely from the oils, whereas the selenium content is reduced to about two‐thirds and the bromine content is nearly unaffected. In the hydrogenation step the selenium disappears relatively fast and the bromine more slowly.
Determination of tin salts in fats
Authors: Lowry Robert R. , Tinsley Ian J.
Published: May 2007

Tin compounds in both the oxidation states of II and IV can be determined directly in the fat or oil, using a solution of pyrocatechol violet in ethyl acetate and methanol. This method provides a rapid estimation of tin in the range of 5–54 µg/g of fat with either solid or liquid samples. The stability of the color with respect to both oxidation states and the effects of fat and free fatty acid levels are discussed.
Influence of solvent on degree of acylation in the formation of sucrose esters
Authors: Weiss T. J. , Brown Mona , Zeringue H. J. , Feuge R. O.
Published: May 2007

Sucrose palmitates were prepared by the interesterification of sucrose and methyl palmitate in different solvents. The ratio of methyl palmitate to sucrose in dimethylformamide (DMF) solution was varied so that the effect on yield and ester composition could be evaluated. When sucrose esters were prepared in DMF, the palmitoyl groups approximated a random distribution when only penta‐ and lower esters were formed. When the proportion of palmitoyl groups was increased, hexa‐ through octaesters were formed, but the yield was less than that calculated for a random distribution. The interesterification of sucrose and methyl palmitate in solvents other than DMF, but under otherwise identical reaction conditions, yielded different reaction products. Only traces of sucrose esters were produced in hexamethylphosphoramide and formylmorpholine. Reactions in dimethylsulfoxide and N‐methyl‐2‐pyrrolidinone yielded larger percentages of higher esters than were obtained in DMF. However the distribution was far from random.
Selective hydrogenation catalyzed by polymeric palladium and platinum complexes
Authors: Bruner Harold S. , Bailar John C.
Published: May 2007

An organic polymer containing a diphenylbenzyl‐phosphine functional group, combined with PtCl2 or PdCl2, gives a heterogeneous hydrogenation catalyst which is analogous to the homogeneous catalysts PtCl2(Pø3)2 and PdCl2(Pø3)2. In the hydrogenation of soybean methyl ester, this catalyst is highly selective, the products being monoene and diene, with almost no increase in the content of saturated ester.
Alkali isomerization of linoleate isomers: Characterization of products
Authors: Koritala Sambasivarao
Published: May 2007

Geometrical isomers of methyl linoleate were reacted with alakli, and the resulting conjugated isomers were separated intotrans,trans;cis,trans; andcis,cis fractions. The position of double bonds in the various fractions was determined by reductive ozonolysis.trans‐9,trans‐12‐Isomer of linoleate formedtrans,trans‐ andcis,trans‐conjugated dienes, whereascis‐9,trans‐12‐ andtrans‐9,cis‐12‐isomers in addition formedcis,cis‐conjugated dienes. The formation of the products is in accordance with the theoretical predictions. During conjugationtrans double bonds shifted to form atrans bond preferentially. During conjugation ofcis‐9,trans‐12‐ andtrans‐9,cis‐12‐linoleate isomers, thecis double bond shifted preferentially over thetrans double bond. A small amount of diene not conjugated was probably a geometrical and positional isomer of the starting material.
Thickening action of hydroxystearates in peanut butter
Authors: Elliger Carl A. , Guadagni D. G. , Dunlap C. E.
Published: May 2007

When 0.5–1% of 12‐hydroxystearic acid or the corresponding triglyceride is incorporated into unhardened peanut butter, the resulting product has stiff creamy consistency, and no oil separation takes place upon standing. Sensory evaluation of this peanut butter indicated that it was indistinguishable from typical commercial material in flavor and texture.
Hearing loss in a family affected by Fabry disease
Authors: Sergi Bruno , Conti Guido
Published: May 2007

Fabry disease is an inborn error of metabolism due to deficient activity of the lysosomal enzyme α‐galactosidase A. The enzyme defect leads to the systemic accumulation of neutral glycosphingolipids in tissues. Otological manifestations consist of hearing loss and mild vestibular disorders. In this report we describe a family of five members affected by Fabry disease with four subjects showing inner ear involvement.
Switching to the bingeing/purging subtype of anorexia nervosa is frequently associated with suicidal attempts
Authors: Foulon C. , Guelfi J.D. , Kipman A. , Adès J. , Romo L. , Houdeyer K. , Marquez S. , Mouren M.C. , Rouillon F. , Gorwood P.
Published: May 2007

Objective

Anorexia nervosa has the highest suicide mortality ratio of psychiatric disorders, suicide being associated with many factors. We assessed the first lifetime occurrence of these factors taking into account their possible overlap.

Method

Three hundred and four in- and out-patients with anorexia nervosa (DSM-IV) were systematically recruited in three hospitals of Paris suburbs, between December 1999 and January 2003. Patients were assessed by a face-to-face interview (DIGS). Current eating disorder dimensions were measured, and patients interviewed by a trained clinician to assess minimal BMI and, retrospectively, the age at which anorexia nervosa, major depressive disorder, anxiety disorders and switch to bingeing/purging type occurred for the first time, if applicable.

Results

Major depressive disorder (p < 0.001) and subtype switch from the restrictive to the bingeing/purging type (p < 0.001) were the two factors significantly more frequently occurring before suicidal attempts, and remained involved when a multivariate analysis is performed, whether syndromic or dimensional measures are being used. Taking into account lifetime occurrence with a survival analysis, the switch to bingeing/purging type of anorexia appears as a major predictive factor, with a large increase of the frequency of suicidal attempts (OR = 15) when compared to patients with neither major depressive disorder nor bingeing/purging type.

Conclusions

Bingeing/purging type of anorexia nervosa is largely associated with suicidal attempts, and may deserve specific attention. If confirmed on a prospectively designed study, these results would argue for early detection and/or more intensive and specific therapeutic intervention on this aspect of bingeing and purging behaviors.
Negative Soziale Unterstützung bei der Bewältigung von Lebensbelastungen
Authors: Laireiter Anton-Rupert , Fuchs Miriam , Pichler Maria-Elisabeth
Published: May 2007

Zusammenfassung. Neben unterstützendem Verhalten müssen durch Lebensereignisse Belastete immer auch mit belastenden Reaktionen aus ihrer Umwelt rechnen. Die vorliegende Studie ist einer konzeptuellen und empirischen Analyse dieses Phänomens und seiner Effekte gewidmet. Dabei wird über eine retrospektive Lebensereignisstudie berichtet (N = 224), bei der u.a. negative und positive Unterstützungsformen erhoben wurden. Explorative Hauptkomponentenanalysen erbrachten vier gut interpretierbare und mit den konzeptuellen Analysen übereinstimmende Faktoren negativer Unterstützung (Kritik und Abwertung, Diskriminierung und Feindseligkeit, Enttäuschung und nicht ernst nehmen, Einmischung und übertriebene Sorge), wobei übertriebene und mangelnde Unterstützung (Einmischung/übertrieben Sorge, Enttäuschung/nicht ernst nehmen) häufiger vorkommen als die beiden aggressiveren Formen (Kritik und Abwertung, Diskriminierung und Feindseligkeit). Dennoch sind diese aber mit schlechterem Bewältigungserfolg, geringerem Selbstwert und schlechterem Befinden am Ende des Lebensereignisses assoziiert. Mediator- und Moderatoranalysen zeigen, dass diese Effekte zum Teil durch die initiale Reaktion auf das belastende Ereignis vermittelt werden, insofern solche Personen ein hohes Maß an Negativunterstützung erleben, die initial intensiv und eher negativ auf das Ereignis reagieren. Das Ausmaß erhaltener positiver Unterstützung kann diese Effekte puffern. Die Ergebnisse sprechen dafür, negativer Unterstützung bei präventiven Maßnahmen vermehrte Aufmerksamkeit zu schenken.
Seasonal and interannual variations in CO and BC emissions from open biomass burning in Southern Africa during 1998–2005
Authors: Ito Akinori , Ito Akihiko , Akimoto Hajime
Published: May 2007

We estimate the emissions of carbon monoxide (CO) and black carbon (BC) from open vegetation fires in the Southern Hemisphere Africa from 1998 to 2005 using satellite information in conjunction with a biogeochemical model. Monthly burned areas at a 0.5‐degree resolution are estimated from the Visible InfraRed Scanner (VIRS) fire count product and the MODerate resolution Imaging Spectroradiometer (MODIS) burned area data set associated with the MODIS tree cover imagery in grasslands and woodlands. The monthly fuel load distributions are derived from a 0.5‐degree terrestrial carbon cycle model in conjunction with satellite data. The monthly maps of combustion factors and emission factors are estimated using empirical models that predict the effects of fuel conditions on these factors in grasslands and woodlands. Our annually averaged effective CO and BC emissions per area burned are 27 g CO m−2 and 0.17 g BC m−2 which are consistent with the products of fuel consumption and emission factors typically measured in southern Africa. The CO and BC emissions from open vegetation burning in southern Africa range from 45 Tg CO yr−1 and 0.26 Tg BC yr−1 for 2002 to 75 Tg CO yr−1 and 0.42 Tg BC yr−1 for 1998. The monthly averaged burned areas from VIRS fire counts peak earlier than modeled CO emissions. This characteristic delay between burned areas and emissions is mainly explained by significant changes in combustion factors for woodlands in our model. Consequently, the peaks in CO and BC emissions from our bottom‐up approach are identical to those from previous top‐down estimates using the Measurement Of the Pollution In The Troposphere (MOPITT) and the Total Ozone Mapping Spectrometer (TOMS) Aerosol Index (AI) data.
Multiscale analysis of precipitable water vapor over Africa from GPS data and ECMWF analyses
Authors: Bock O. , Guichard F. , Janicot S. , Lafore J. P. , Bouin M.‐N. , Sultan B.
Published: May 2007

This is the first climatological analysis of precipitable water vapor (PWV) from GPS data over Africa. The data reveal significant modulations and variability in PWV over a broad range of temporal scales. GPS PWV estimates are compared to ECMWF reanalysis ERA40. Both datasets show good agreement at the larger scales (seasonal cycle and inter‐annual variability), driven by large scale moisture transport. At intra‐seasonal (15–40 days) and synoptic (3–10 days) scales, strong PWV modulations are observed from GPS, consistently with ECMWF analysis. They are shown to be correlated with convection and the passage of equatorial waves and African Easterly waves. The high‐frequency GPS observations also reveal a significant diurnal cycle in PWV, which magnitude and spectral content depends strongly on geographic location and shows a seasonal modulation. The diurnal cycle of PWV is poorly represented in ERA40 reflecting weaknesses in the water cycle of global circulation models at this timescale.
Magnetospheric seismology using multiharmonic toroidal waves observed at geosynchronous orbit
Authors: Takahashi Kazue , Denton Richard E.
Published: May 2007

The frequencies of the harmonics of standing Alfvén waves depend on the field line distribution of mass that sustains the waves. This fact is the basis of inversion techniques to estimate the plasma mass density variation along the magnetic field from the frequencies of observed ultra‐low‐frequency waves (normal mode magnetospheric seismology). However, the technique has not been used extensively because it is difficult to accurately determine the frequencies. Wave observations from geostationary satellites provide the best chance of a successful implementation of the technique because the satellites accumulate the spectral information of the harmonics with minimal variations in frequency. We have statistically studied the frequency of multiharmonic toroidal waves detected by the GOES 5 geostationary satellite. We quantify the relationships among the harmonics using the frequency ratio fn/f3, where fn is the frequency of the nth harmonic (n = 1 for the fundamental mode). The third harmonic is chosen for the reference frequency because it is the most ubiquitous mode at GOES 5. Using all data acquired in 1986, we find that f1/f3 changes from 0.25 in the early morning to 0.22 in the afternoon, whereas the other frequency ratios are more nearly constant: f2/f3, = 0.634–0.646, f4/f3 = 1.36–1.37, and f5/f3 = 1.73–1.74. The frequencies are in general inconsistent with the power law density model. When the frequencies are used in the density modeling technique developed by Denton et al. (2001, 2004), we find an equatorial mass density enhancement in the afternoon local time sector but not on the dawnside.
Global 30–240 keV proton precipitation in the 17–18 April 2002 geomagnetic storms: 2. Conductances and beam spreading
Authors: Fang Xiaohua , Liemohn Michael W. , Kozyra Janet U. , Evans David S.
Published: May 2007

We investigate the global Pedersen and Hall conductance distribution during the 17–18 April 2002 geomagnetic storms by combining NOAA/POES 30–240 keV proton precipitation measurements with three‐dimensional (3‐D) particle transport modeling. Significant conductances are generated due to energetic proton precipitation in the selected storms, with peak values up to ∼10 S in the dusk sector. The effect of horizontal beam spread on the conductances, which is a unique feature of ion precipitation, is first assessed in this paper. It is found that with the neglect of the beam spread, an overestimation (up to 10%) occurs at the center of the major proton precipitation region. At the edge (particularly at the equatorward edge), a severe underestimation (around −50% or worse) is induced. Moreover, 3‐D scattering extends the equatorward edge of the high conductance region down to around 55° magnetic latitude in the storms. A significance domain (up to 4.4°) exists equatorward of the peak proton precipitation region, in which significant conductances would be seriously underestimated without the beam spreading effect. It is also found that the beam spreading effect is more significant for the Pedersen conductances than for the Hall conductances because of the altitude dependence of both the conductivity profiles and the spreading. The findings emphasize the role of proton precipitation as well as its associated beam spreading, especially at the equatorward edge of the precipitation zone in the evening sector, where proton precipitation‐produced conductivity can influence storm‐time phenomena, such as subauroral polarization streams, ionospheric storm enhanced density structures, and inner magnetospheric plasma dynamics (i.e., the ring current and plasmasphere).
Variations of turbulent flow with river discharge in the Altamaha River Estuary, Georgia
Authors: Di Iorio Daniela , Kang Ki Ryong
Published: May 2007

Turbulent flow characteristics under two significantly different river discharge periods were studied in the Altamaha River Estuary, Georgia, using a variety of moored instrumentation, combined with detailed water column profiling from an anchored vessel. Estimates of the Reynolds stress, shear production (P), and dissipation rate (ɛ) were derived and compared for the two contrasting river conditions which essentially characterized the estuary as weakly stratified during low discharge (2001) and partially mixed during high discharge (2003). Wave effects were removed from the measurement of turbulent kinetic energy (TKE) using a linear filtration method and a −5/3 slope was fit for an indirect measurement of ɛ. We suggest two possible mechanisms for observed flood/ebb asymmetries in the shear production of energy: wave‐induced bottom roughness change or the competing effects of the barotropic and baroclinic pressure gradients. For 2001 the buoyancy flux was estimated by calculating the dissipation of temperature variance from rapidly sampled temperature time series over two different tidal cycles. The mixing efficiency Γ approached 0.25 but was on average 0.05. The mixing rate depended on the flow and stratification with highest values of 200 cm2/s during maximum flow and weakest stratification and lowest values of 0.1 cm2/s during low flow and greater stratification. A balance of production and dissipation of energy was achieved only during ebb tide in 2001, implying that turbulent transport of TKE maybe a consideration since buoyancy dissipation is too small for 2001 and would only enhance the imbalance further in 2003 because of strong stratification that exists during the flood and ebb tide.
Effects of atmospheric inorganic nitrogen deposition on ocean biogeochemistry
Authors: Krishnamurthy Aparna , Moore J. Keith , Zender Charles S. , Luo Chao
Published: May 2007

We perform a sensitivity study with the Biogeochemical Elemental Cycling (BEC) ocean model to understand the impact of atmospheric inorganic nitrogen deposition on marine biogeochemistry and air‐sea CO2 exchange. Simulations involved examining the response to three different atmospheric inorganic nitrogen deposition scenarios namely, Pre‐industrial (22 Tg N/year), 1990s (39 Tg N/year), and an Intergovernmental Panel on Climate Change (IPCC) prediction for 2100, IPCC‐A1FI (69 Tg N/year). Globally, the increasing N deposition had widespread, but modest effects on export production and air‐sea CO2 exchange. The maximum increase in N deposition was 47 Tg N/year since Pre‐industrial control for the IPCC‐A1FI case, which had an increase in primary production (0.98 Gt C/year or 2%), export production (0.16 Gt C/year or 3%) and a decrease in atmospheric pCO2 of 1.66 ppm (0.6%) relative to the Pre‐industrial control. In some regions, atmospheric N inputs supported >20% of the export production in the current era and >50% of the export production in the IPCC‐A1FI case. As nitrogen deposition increased, N fixation decreased because the diazotrophs were outcompeted by diatoms and small phytoplankton under more N‐replete conditions. This decrease in N fixation could partially counteract the ongoing increase in new nitrogen inputs via atmospheric N deposition.
Measuring surface water from space
Authors: Alsdorf Douglas E. , Rodríguez Ernesto , Lettenmaier Dennis P.
Published: May 2007

Surface fresh water is essential for life, yet we have surprisingly poor knowledge of the spatial and temporal dynamics of surface freshwater discharge and changes in storage globally. For example, we are unable to answer such basic questions as “What is the spatial and temporal variability of water stored on and near the surface of all continents?” Furthermore, key societal issues, such as the susceptibility of life to flood hazards, cannot be answered with the current global, in situ networks designed to observe river discharge at points but not flood events. The measurements required to answer these hydrologic questions are surface water area, the elevation of the water surface (h), its slope (∂h/∂x), and temporal change (∂h/∂t). Advances in remote sensing hydrology, particularly over the past 10 years and even more recently, have demonstrated that these hydraulic variables can be measured reliably from orbiting platforms. Measurements of inundated area have been used to varying degrees of accuracy as proxies for discharge but are successful only when in situ data are available for calibration; they fail to indicate the dynamic topography of water surfaces. Radar altimeters have a rich, multidecadal history of successfully measuring elevations of the ocean surface and are now also accepted as capable tools for measuring h along orbital profiles crossing freshwater bodies. However, altimeters are profiling tools, which, because of their orbital spacings, miss too many freshwater bodies to be useful hydrologically. High spatial resolution images of ∂h/∂t have been observed with interferometric synthetic aperture radar, but the method requires emergent vegetation to scatter radar pulses back to the receiving antenna. Essentially, existing spaceborne methods have been used to measure components of surface water hydraulics, but none of the technologies can singularly supply the water volume and hydraulic measurements that are needed to accurately model the water cycle and to guide water management practices. Instead, a combined imaging and elevation‐measuring approach is ideal as demonstrated by the Shuttle Radar Topography Mission (SRTM), which collected images of h at a high spatial resolution (∼90 m) thus permitting the calculation of ∂h/∂x. We suggest that a future satellite concept, the Water and Terrestrial Elevation Recovery mission, will improve upon the SRTM design to permit multitemporal mappings of h across the world's wetlands, floodplains, lakes, reservoirs, and rivers.
Fault strength drop due to phase transitions in the pore fluid
Authors: Mizoguchi Kazuo , Takahashi Miki , Masuda Koji , Fukuyama Eiichi
Published: May 2007

We conducted tri‐axial friction experiments for quartz gouge at hydrothermal conditions to examine the effect of phase transition of water. We observed a decrease of ∼0.05 in its coefficient of friction during the transition between liquid and vapor. This can be interpreted as a local pore pressure increase in the gouge‐filled layer during the phase transition, which is caused by the surface tension of bubbles created between the two different phases. The local pore pressure increase deduces effective normal stress in the gauge layer, which makes a decrease of the frictional strength. The transient friction drop on a fault can play an important role in triggering an earthquake not only in hydrothermal areas but also in typical seismically active areas in the crust where water often contains CO2 of various concentrations because the CO2 density in the binary system of H2O‐CO2 controls the pressure‐temperature condition of liquid/vapor phase equilibrium.
Nitric oxide homeostasis as a target for drug additives to cardioplegia
Authors: Podesser B K , Hallström S
Published: May 2007

The vascular endothelium of the coronary arteries has been identified as the important organ that locally regulates coronary perfusion and cardiac function by paracrine secretion of nitric oxide (NO) and vasoactive peptides. NO is constitutively produced in endothelial cells by endothelial nitric oxide synthase (eNOS). NO derived from this enzyme exerts important biological functions including vasodilatation, scavenging of superoxide and inhibition of platelet aggregation. Routine cardiac surgery or cardiologic interventions lead to a serious temporary or persistent disturbance in NO homeostasis. The clinical consequences are “endothelial dysfunction”, leading to “myocardial dysfunction”: no‐ or low‐reflow phenomenon and temporary reduction of myocardial pump function. Uncoupling of eNOS (one electron transfer to molecular oxygen, the second substrate of eNOS) during ischemia‐reperfusion due to diminished availability of L‐arginine and/or tetrahydrobiopterin is even discussed as one major source of superoxide formation. Therefore maintenance of normal NO homeostasis seems to be an important factor protecting from ischemia/reperfusion (I/R) injury. Both, the clinical situations of cardioplegic arrest as well as hypothermic cardioplegic storage are followed by reperfusion. However, the presently used cardioplegic solutions to arrest and/or store the heart, thereby reducing myocardial oxygen consumption and metabolism, are designed to preserve myocytes mainly and not endothelial cells. This review will focus on possible drug additives to cardioplegia, which may help to maintain normal NO homeostasis after I/R.

British Journal of Pharmacology (2007) 151, 930–940; doi:10.1038/sj.bjp.0707272
Chromatography and Capillary Electrophoresis in Food Analysis
Authors: Sorensen Hilmer , Sorensen Susanne , Bjergegaard Charlotte , Michaelsen Soren
Published: May 2007

In the rapidly developing field of analysis it is important to be aware of the newest methods within available techniques. Chromatography and Capillary Electrophoresis in Food Analysis describes chromatographic and electrophoretic principles and procedures for analyses of various amphiphilic and hydrophilic biomolecules, particularly for food analysis. Providing basic information, including general sample preparation, the book then goes on to describe individual analytical methods and exemplify the strategy and methodologies employed for the analyses. The theory necessary to understand the methods and interpretation of results is also included, as are numerous detailed instructions on experiments. Tables, figures and references are included to give a complete picture. Chromatography and Capillary Electrophoresis in Food Analysis will be especially valuable for students and more experienced researchers interested in analysis of natural products, both inside and outside the field of food chemistry.
Feedstock Recycling of Plastic Wastes
Authors: Aguado Jose , Serrano David P , Braithwaite M J , Hassur Steven M , Papenfuhs T
Published: May 2007

The use of plastic materials has seen a massive increase in recent years, and generation of plastic wastes has grown proportionately. Recycling of these wastes to reduce landfill disposal is problematic due to the wide variation in properties and chemical composition among the different types of plastics. Feedstock recycling is one of the alternatives available for consideration, and Feedstock Recycling of Plastic Wastes looks at the conversion of plastic wastes into valuable chemicals useful as fuels or raw materials. Looking at both scientific and technical aspects of the recycling developments, this book describes the alternatives available. Areas include chemical depolymerization, thermal processes, oxidation and hydrogenation. Besides conventional treatments, new technological approaches for the degradation of plastics, such as conversion under supercritical conditions and coprocessing with coal are discussed.

This book is essential reading for those involved in plastic recycling, whether from an academic or industrial perspective. Consultants and government agencies will also find it immensely useful.
Mass Spectrometry of Natural Substances in Foods
Authors: Mellon Fred , Startin Jim R , Self Ron
Published: May 2007

Introducing the principles, practice and applications of mass spectrometric techniques in the study of natural substances in foods, this book conveys the depth and breadth of modern mass spectrometry in relation to food analysis. It covers traditional techniques such as electron and chemical ionisation and newer soft ionisation techniques such as matrix-assisted laser desorption ionisation and electrospray. All of these techniques are especially relevant in food quality and safety studies and in biopolymer analysis. The ability to analyse biopolymers by mass spectrometry is having a major impact on the study of food structure components, food proteins, food pathogens and food components produced from genetically modified organisms. The principles and practice of mass spectrometry are covered in the early chapters and are followed by applications in flavour analysis and the determination of non-nutrient, biologically-active, natural substances in foods. The analysis and metabolic studies of amino acids, peptides, proteins, lipids, sugars, carbohydrates and vitamins is also discussed, with separate chapters on mineral and micronutrient metabolism and techniques of pyrolysis mass spectrometry. Mass Spectrometry of Natural Substances in Food will be a valuable resource for food scientists, food analysts and others working in food research, nutrition and safety.
Self-Assembly in Supramolecular Systems
Authors: Atkinson Ian M , Lindoy Len F
Published: May 2007

Molecular self-assembly is a widespread phenomenon in both chemistry and biochemistry. Yet it was not until the rise of supramolecular chemistry that attention has increasingly been given to the designed self-assembly of a variety of synthetic molecules and ions. To a large extent, success in this area has reflected knowledge gained from nature. However, an increased awareness of the latent steric and electronic information implanted in individual molecular components has also contributed to this success. Whilst not yet approaching the sophistication of biological assemblies, synthetic systems of increasing subtlety and considerable aesthetic appeal have been created. Self-Assembly in Supramolecular Systems surveys highlights of the progress made in the creation of discrete synthetic assemblies and provides a foundation for new workers in the area, as well as background reading for experienced supramolecular chemists.
Earlier Flowering Induced by Over‐Expression of CO Gene Does Not Accompany Increase of Artemisinin Biosynthesis in Artemisia annua
Authors: Wang H. , Liu Y. , Chong K. , Liu B. Y. , Ye H. C. , Li Z. Q. , Yan F. , Li G. F.
Published: May 2007

Abstract: The early flowering gene CONSTANS (CO) from Arabidopsis thaliana was transferred into Artemisia annua using the Agrobacterium tumefaciens‐mediated transformation system. The plant expression vector pBICO was constructed by inserting the CO gene into the binary vector pBI121 under the control of CaMV 35S promoter. Analyses of PCR, PCR Southern blot, and Southern blot revealed that the transgenic plants contained the foreign CO gene. The results of RT‐PCT and RT‐PCR Southern blot suggested that the foreign CO gene had expressed at the transcriptional level. Although the flowering time of the CO transgenic plant was about 2 weeks earlier than that of the non‐transgenic plant under short‐day conditions, no significant difference in artemisinin content was found between the flowering transgenic plant and the non‐flowering non‐transgenic plant. These results show that the usually observed increase of artemisinin content before plant flowering under natural conditions is not a direct consequence of flowering itself, perhaps there is even no direct linkage between flowering and artemisinin biosynthesis.