bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoemission into water adsorbed on metals: Probing dissociative electron transfer using theory
Authors: Zhang Yu , Whitten J. L.
Published: August 2009

The photoinduced dissociation of water adsorbed on a silver nanoparticle is explored using theory to probe reaction pathways that produce hydrogen. Ab initio configuration theory is used to describe the systems. A formulation that allows excited electronic states embedded in a near continuum of lower energy states to be calculated accurately is described. Electron attachment of a photoemitted electron to adsorbed water can lead to the formation of H2 at a very low energy barrier with oxygen remaining on the Ag surface. A large energy barrier to form H2 plus adsorbed O is found for the ground state. The excited state has a much smaller barrier to OH stretch; however, to dissociate, the system must cross over from the excited state to the ground state potential energy surface. The cross over point is near the transition state for a ground state process. A characteristic feature of the excited state potential curve is an increase in energy in the early stages of OH stretch as the charge transfer state evolves from a state with considerable Rydberg character to one that has a typical OH antibonding molecular orbital. Another pathway releases a H atom leaving OH on the surface. Effects due to doping of a Ag nanoparticle with a K electron donor atom are compared with those caused by a Fermi level shift due to an applied potential. Results are also reported for electron transfer to a solvated lithium ion, Li(H2O), near the surface of a silver particle. A steering mechanism is found that involves the interaction of a hydridic hydrogen formed after electron transfer with an acidic hydrogen of a second solvated water molecule. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Experimental determination of a Viviparus contectus thermometry equation
Authors: Bugler Melanie J. , Grimes Stephen T. , Leng Melanie J. , Rundle Simon D. , Price Gregory D. , Hooker Jerry J. , Collinson Margaret E.
Published: August 2009

Experimental measurements of the 18O/16O isotope fractionation between the biogenic aragonite of Viviparus contectus (Gastropoda) and its host freshwater were undertaken to generate a species‐specific thermometry equation. The temperature dependence of the fractionation factor and the relationship between Δδ18O (δ18Ocarb. – δ18Owater) and temperature were calculated from specimens maintained under laboratory and field (collection and cage) conditions. The field specimens were grown (Somerset, UK) between August 2007 and August 2008, with water samples and temperature measurements taken monthly. Specimens grown in the laboratory experiment were maintained under constant temperatures (15°C, 20°C and 25°C) with water samples collected weekly. Application of a linear regression to the datasets indicated that the gradients of all three experiments were within experimental error of each other (±2 times the standard error); therefore, a combined (laboratory and field data) correlation could be applied. The relationship between Δδ18O (δ18Ocarb. – δ18Owater) and temperature (T) for this combined dataset is given by:

(T is in °C, δ18Ocarb. is with respect to Vienna Pee Dee Belemnite (VPDB) and δ18Owater is with respect to Vienna Standard Mean Ocean Water (VSMOW). Quoted errors are 2 times standard error).

Comparisons made with existing aragonitic thermometry equations reveal that the linear regression for the combined Viviparus contectus equation is within 2 times the standard error of previously reported aragonitic thermometry equations. This suggests there are no species‐specific vital effects for Viviparus contectus. Seasonal δ18Ocarb. profiles from specimens retrieved from the field cage experiment indicate that during shell secretion the δ18Ocarb. of the shell carbonate is not influenced by size, sex or whether females contained eggs or juveniles. Copyright © 2009 John Wiley & Sons, Ltd.
Two‐injection workflow for a liquid chromatography/LTQ‐Orbitrap system to completein vivobiotransformation characterization: demonstration with buspirone metabolite identification
Authors: Li Austin C. , Ding Jie , Jiang Xiangyu , Denissen Jon
Published: August 2009

The relatively high background matrix inin vivosamples typically poses difficulties in drug metabolite identification, and causes repeated analytical runs on unit resolution liquid chromatography/mass spectrometry (LC/MS) systems before the completion of biotransformation characterization. Ballpark parameter settings for the LTQ‐Orbitrap are reported herein that enable completein vivometabolite identification within two HPLC/MS injections on the hybrid LTQ‐Orbitrap data collection system. By setting the FT survey full scan at 60K resolution to trigger five dependent LTQ MS2scans, and proper parameters of Repeat Duration, Exclusion Duration and Repeat Count for the first run (exploratory), the Orbitrap achieved the optimal parallel data acquisition capability and collected maximum number of product ion scans. Biotransformation knowledge based prediction played the key role in exact mass ion extraction and multiple mass defect filtration when the initial data was processed. Meanwhile, product ion extraction and neutral loss extraction of the initial dependent data provided additional bonus in identifying metabolites. With updated parent mass list and the data‐dependent setting to let only the ions on the parent mass list trigger dependent scans, the second run (confirmatory) ensures that all precursor ions of identified metabolites trigger not only dependent product ion scans, but also at or close to the highest concentration of the eluted metabolite peaks. This workflow has been developed for metabolite identification ofin vivoor ADME studies, of which the samples typically contain a high level of complex matrix. However, due to the proprietary nature of thein vivostudies, this workflow is presented herein within vitrobuspirone sample incubated with human liver microsomes (HLM). The major HLM‐mediated biotransformation on buspirone was identified as oxidation or hydroxylation since five mono‐ (+16 Da), seven di‐ (+32 Da) and at least three tri‐oxygenated (+48 Da) metabolites were identified. Besides the metabolites 1‐pyrimidinylpiperazine (1‐PP) and hydroxylated 1‐PP that formed by N‐dealkylation, a new metabolite M308 was identified as the result of a second N‐dealkylation of the pyrimidine unit. Two new metabolites containing the 8‐butyl‐8‐azaspiro[4,5]decane‐7,9‐dione partial structure, M240 and M254, were also identified that were formed apparently due to the first N‐dealkylation of the 1‐PP moiety. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of substrate surfaces in matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Togashi Hisashi , Kobayashi Yoshinori
Published: August 2009

For matrix‐assisted laser desorption/ionization (MALDI) mass spectra, undesirable ion contamination can occur due to the direct laser excitation of substrate materials (i.e., laser desorption/ionization (LDI)) if the samples do not completely cover the substrate surfaces. In this study, comparison is made of LDI processes on substrates of indium and silver, which easily emit their own ions upon laser irradiation, and conventional materials, stainless steel and gold. A simultaneous decrease of ion intensities with the number of laser pulses is observed as a common feature. By the application of an indium substrate to the MALDI mass spectrometry of alkali salts and alkylammonium salts mixed with matrices, 2,5‐dihydroxybenzoic acid (DHB) or N‐(4‐methoxybenzylidene)‐4‐butylaniline (MBBA), the mixing of LDI processes can be detected by the presence of indium ions in the mass spectra. This method has also been found to be useful for investigating the intrinsic properties of the MALDI matrices: DHB samples show an increase in the abundance of fragment ions of matrix molecules and cesium ions with the number of laser pulses irradiating the same sample spot; MBBA samples reveal a decrease in the level of background noise with an increase in the thickness of the sample layer. Copyright © 2009 John Wiley & Sons, Ltd.
Isotopologue enrichment factors of N2O reduction in soils
Authors: Well R. , Flessa H.
Published: August 2009

Isotopic signatures can be used to study sink and source processes of N2O, but the success of this approach is limited by insufficient knowledge on the isotope fractionation factors of the various reaction pathways. We investigated isotope enrichment factors of the N2O‐to‐N2 step of denitrification (ε) in two arable soils, a silt‐loam Haplic Luvisol and a sandy Gleyic Podzol. In addition to the ε of 18O (ε18O) and of average 15N (εbulk), the ε of the 15N site preference within the linear N2O molecule (εSP) was also determined. Soils were anaerobically incubated in gas‐tight bottles with N2O added to the headspace to induce N2O reduction. Pre‐treatment included the removal of NO to prevent N2O production. Gas samples were collected regularly to determine the dynamics of N2O reduction, the time course of the isotopic signatures of residual N2O, and the associated isotope enrichment factors. To vary reduction rates and associated fractionation factors, several treatments were established including two levels of initial N2O concentration and anaerobic pre‐incubation with or without addition of N2O. N2O reduction rates were affected by the soil type and initial N2O concentration. The ε18O and εbulk ranged between −13 and −20‰, and between −5 and −9‰, respectively. Both quantities were more negative in the Gleyic Podzol. The ε of the central N position (εα) was always larger than that of the peripheral N‐position (εβ), giving εSP of −4 to −8‰. The ranges and variation patterns of ε were comparable with those from previous static incubation studies with soils. Moreover, we found a relatively constant ratio between ε18O and εbulk which is close to the default ratio of 2.5 that had been previously suggested. The fact that different soils exhibited comparable ε under certain conditions suggests that these values could serve to identify N2O reduction from the isotopic fingerprints of N2O emitted from any soil. Copyright © 2009 John Wiley & Sons, Ltd.
Doublecortin and CaM Kinase-like-1 and Leucine-Rich-Repeat-Containing G-Protein-Coupled Receptor Mark Quiescent and Cycling Intestinal Stem Cells, Respectively
Authors: May Randal , Sureban Sripathi M. , Hoang Nguyet , Riehl Terrence E. , Lightfoot Stan A. , Ramanujam Rama , Wyche James H. , Anant Shrikant , Houchen Courtney W.
Published: August 2009

It is thought that small intestinal epithelia (IE) undergo continuous self-renewal primarily due to their population of undifferentiated stem cells. These stem cells give rise to transit amplifying (daughter/progenitor) cells, which can differentiate into all mature cell types required for normal gut function. Identification of stem cells in IE is paramount to fully understanding this renewal process. One major obstacle in gastrointestinal stem cell biology has been the lack of definitive markers that identify small intestinal stem cells (ISCs). Here we demonstrate that the novel putative ISC marker doublecortin and CaM kinase-like-1 (DCAMKL-1) is predominantly expressed in quiescent cells in the lower two-thirds of intestinal crypt epithelium and in occasional crypt-based columnar cells (CBCs). In contrast, the novel putative stem cell marker leucine-rich-repeat-containing G-protein-coupled receptor (LGR5) is observed in rapidly cycling CBCs and in occasional crypt epithelial cells. Furthermore, functionally quiescent DCAMKL-1+ crypt epithelial cells retain bromo-deoxyuridine in a modified label retention assay. Moreover, we demonstrate that DCAMKL-1 is a cell surface expressing protein; DCAMKL-1+ cells, isolated from the adult mouse small intestine by fluorescence activated cell sorting, self-renew and ultimately form spheroids in suspension culture. These spheroids formed glandular epithelial structures in the flanks of athymic nude mice, which expressed multiple markers of gut epithelial lineage. Thus, DCAMKL-1 is a marker of quiescent ISCs and can be distinguished from the cycling stem/progenitors (LGR5+). Moreover, DCAMKL-1 can be used to isolate normal small intestinal stem cells and represents a novel research tool for regenerative medicine and cancer therapy.
Purification and Characterization of a Radical Scavenging Peptide from Rapeseed Protein Hydrolysates
Authors: Zhang Shao Bing , Wang Zhang , Xu Shi Ying , Gao Xian Fu
Published: August 2009

We previously reported that crude rapeseed peptides (CRPs) and peptide fractions (RP25 and RP55) prepared from aqueous enzymatic extraction of rapeseed exhibited marked antioxidant activities, among which RP55 showed the most potent effects. In the present study, RP55 was further purified using consecutive chromatographic methods for identification of antioxidant peptides. The α,α‐diphenyl‐β‐picrylhydrazyl (DPPH) radical scavenging effects of peptides were measured at each purification step to evaluate the antioxidant activities. RP55 was first fractionated by anion‐exchange chromatography, and three fractions (E1, E2, and E3) were obtained. All of them showed significantly lower scavenging activities compared to RP55, which was very probably due to the remarkable loss of tannin during the separation. Next, the active fraction E2 with higher protein content was sequentially purified by gel filtration chromatography (GFC) and reversed‐phase high performance liquid chromatography (RP‐HPLC). The purified peptide, of which the median effective dose (ED50) value for DPPH radical scavenging was 0.063 mg/mL, was identified to be Pro‐Ala‐Gly‐Pro‐Phe (487 Da) using electrospray ionization (ESI) mass spectrometry. The unique amino acid composition and sequence in the peptide might play an important role in expression of its antioxidant activity.
Impact of chronic inflammation on the pharmacokinetic–pharmacodynamic relationship of naproxen
Authors: Huntjens Dymphy R.H. , Spalding David J.M. , Danhof Meindert , Del la Pasqua Oscar E.
Published: August 2009

ObjectivesThe use of biomarkers for predicting the clinical doses of analgesic drugs relies on the understanding of the relationship between drug exposure and response under disease conditions. In this study, we demonstrate the relevance of such a relationship for COX‐inhibitors by modelling the effect of naproxen on prostaglandin E2and thromboxane B2in a chronic inflammation model in rats.

Methods:Rats were treated with Freund's complete adjuvant (FCA) by intraplantar injection. On post‐inoculation days (PID) 7–21, animals received single or chronic (qd until day 21) doses of naproxen (10 mg/kg). Blood samples were collected at various intervals after dosing to characterise naproxen pharmacokinetics and its effects onandproduction. PK‐PD modelling was performed using nonlinear mixed effects in NONMEM.

Results:The inhibition ofandcould be described by a sigmoidmodel. A decrease in the potency estimates of both biomarkers was observed under chronic inflammation, as compared to healthy animals.values forinhibition showed a shift fromto, whilstvalues forinhibition increased fromtoin healthy and FCA‐inoculated animals, respectively.

Conclusions:Our results show that chronic inflammation causes a significant change in the potency estimates for COX‐inhibition. These findings illustrate the implications of pathophysiological processes on pharmacodynamics and consequently on the required exposure levels for achieving response during chronic treatment.
Comparison of plasma clearance of exogenous creatinine, exo-iohexol, and endo-iohexol over a range of glomerular filtration rates expected in cats
Authors: van Hoek Ingrid M. , Lefebvre Hervé P. , Paepe Dominique , Croubels Siska , Biourge Vincent , Daminet Sylvie
Published: August 2009

The study investigated plasma clearance of exogenous creatinine (PECCT), exo-iohexol (PexICT) and endo-iohexol (PenICT) in six healthy cats, four cats with chronic kidney disease (CKD) and six hyperthyroid (HT) cats to assess potential differences in glomerular filtration rate (GFR) measurement over a wide range of GFR values. The PECCT, PexICT and PenICT were performed in a combined protocol. There was a significant difference between PexICT and PenICT and PECCT in healthy cats. Differences between clearance techniques are suggested to be correlated to range in GFRs and should be taken into account when GFR is measured.
Partisanship and Economic Behavior: Do Partisan Differences in Economic Forecasts Predict Real Economic Behavior?
Authors: GERBER ALAN S. , HUBER GREGORY A.
Published: August 2009

Survey data regularly show that assessments of current and expected future economic performance are more positive when a respondent's partisanship matches that of the president. To determine if this is a survey artifact or something deeper, we investigate whether partisanship is associated with behavioral differences in economic decisions. We construct a new data set of county-level quarterly taxable sales to examine the effect of partisanship on consumption. Consumption change following a presidential election is correlated with a county's partisan complexion, a result consistent with partisans acting outside the domain of politics in accordance with the opinions they express in surveys. These results support an expansive view of the role of partisanship in mass politics and help validate surveys as a method for studying political behavior.
STABILITY OF HALF-LINEAR NEUTRAL STOCHASTIC DIFFERENTIAL EQUATIONS WITH DELAYS
Authors: WU MENG , HUANG NAN-JING , ZHAO CHANG-WEN
Published: August 2009

In this paper, we study the mean square asymptotic stability of a generalized half-linear neutral stochastic differential equation with variable delays applying fixed point theory. An asymptotic mean square stability theorem with a necessary and sufficient condition is proved, which improves and generalizes some results due to Burton, Zhang and Luo. Two examples are given to illustrate our results.
RATIONAL MAPS ADMITTING MEROMORPHIC INVARIANT LINE FIELDS
Authors: WANG XIAOGUANG
Published: August 2009

It is shown that a rational map of degree at least 2 admits a meromorphic invariant line field if and only if it is conformally conjugate to either an integral Lattès map, a power map, or a Chebyshev polynomial.
COMBINATORIAL REES–SUSHKEVICH VARIETIES THAT ARE CROSS, FINITELY GENERATED, OR SMALL
Authors: LEE EDMOND W. H.
Published: August 2009

A variety is said to be a Rees–Sushkevich variety if it is contained in a periodic variety generated by 0-simple semigroups. Recently, all combinatorial Rees–Sushkevich varieties have been shown to be finitely based. The present paper continues the investigation of these varieties by describing those that are Cross, finitely generated, or small. It is shown that within the lattice of combinatorial Rees–Sushkevich varieties, the set ℱ of finitely generated varieties constitutes an incomplete sublattice and the set 𝒮 of small varieties constitutes a strict incomplete sublattice of ℱ. Consequently, a combinatorial Rees–Sushkevich variety is small if and only if it is Cross. An algorithm is also presented that decides if an arbitrarily given finite set Σ of identities defines, within the largest combinatorial Rees–Sushkevich variety, a subvariety that is finitely generated or small. This algorithm has complexity 𝒪(nk) where n is the number of identities in Σ and k is the length of the longest word in Σ.
Hamburger high in total, saturated andtrans-fatty acids decreases HDL cholesterol and LDL particle diameter, and increases TAG, in mildly hypercholesterolaemic men
Authors: Adams Thaddeus H. , Walzem Rosemary L. , Smith Dana R. , Tseng Stephen , Smith Stephen B.
Published: August 2009

The consumption of high-fat hamburger enriched with SFA andtrans-fatty acids may increase risk factors for coronary vascular disease, whereas hamburger enriched with MUFA may have the opposite effect. Ten mildly hypercholesterolaemic men consumed five, 114 g hamburger patties per week for two consecutive phases. Participants consumed high-SFA hamburger (MUFA:SFA = 0·95; produced from pasture-fed cattle) for 5 weeks, consumed their habitual diets for 3 weeks and then consumed high-MUFA hamburger (MUFA:SFA = 1·31; produced from grain-fed cattle) for 5 weeks. These MUFA:SFA ratios were typical of ranges observed for retail ground beef. Relative to habitual levels and levels during the high-MUFA phase, the high-SFA hamburger: increased plasma palmitic acid, palmitoleic acid and TAG (P < 0·01); decreased HDL cholesterol (HDL-C) and LDL particle diameter percentile distributions (P < 0·05); and had no effect on LDL cholesterol or plasma glucose (P>0·10). Plasma palmitoleic acid was positively correlated with TAG (r0·90), VLDL cholesterol (r0·73) and the LDL:HDL ratio (r0·45), and was negatively correlated with plasma HDL-C (r− 0·58), whereas plasma palmitic, stearic and oleic acids were negatively correlated with LDL particle diameter (allP ≤ 0·05). Because plasma palmitoleic acid was derived from Δ9 desaturation of palmitic acid in liver, we conclude that alterations in hepatic stearoyl-CoA desaturase activity may have been responsible the variation in HDL-C and TAG caused by the high-SFA and high-MUFA hamburgers.
Early introduction of oats associated with decreased risk of persistent asthma and early introduction of fish with decreased risk of allergic rhinitis
Authors: Virtanen Suvi M. , Kaila Minna , Pekkanen Juha , Kenward Michael G. , Uusitalo Ulla , Pietinen Pirjo , Kronberg-Kippilä Carina , Hakulinen Timo , Simell Olli , Ilonen Jorma , Veijola Riitta , Knip Mikael
Published: August 2009

The evidence of the effect of the age at introduction of new foods during infancy on the development of asthma and allergic rhinitis is inconsistent and scarce. We set out to study these associations. A prospective birth cohort of infants with increased HLA-DQB1-conferred risk for type 1 diabetes was recruited in 1996–2000. The families completed at home a record on the age at introduction of new foods. Persistent asthma and allergic rhinitis were assessed at the age of 5 years with an International Study of Asthma and Allergies in Childhood-type questionnaire. The Cox proportional hazards regression analyses were adjusted for parental asthma and allergic diseases, and several perinatal and sociodemographical factors. Out of the 1293 children, 77 (6·0 %) developed persistent asthma; and out of the 1288 children, 185 (14·4 %) developed allergic rhinitis by the age of 5 years. Early age at introduction of oats was associated with a reduced risk of persistent asthma (hazard ratio (HR; 95 % CI) for the first and mid-tertiles compared with the latest tertile was 0·36 (0·15, 0·85) and 0·37 (0·22, 0·62), respectively,P < 0·001). Early age at introduction of fish was dose dependently associated with a decreased risk of allergic rhinitis (HR (95 % CI) for the first and mid-tertiles compared with the latest tertile was 0·34 (0·22, 0·54) and 0·45 (0·28, 0·70), respectively,P < 0·001). The present finding that age at introduction of oats is inversely and independently associated with development of persistent asthma is novel. We confirmed the earlier observation that the age at introduction of fish is inversely related to the risk of allergic rhinitis. Clinical implications remain to be determined.
Iterated extensions
Authors: Ellis Robert , Glasner Shmuel
Published: August 2009

The notion of an iterated extension of a flow is introduced and studied. In particular it is shown how eigenfunctions occur in a natural way. This is then exploited to produce an example of a weakly mixing minimal set with a non-weakly mixing quasi-factor.
Dynamical properties of quasihyperbolic toral automorphisms
Authors: Lind D. A.
Published: August 2009

We study the dynamical properties of ergodic toral autmorphisms that have some eigenvalues of modulus one. For such automorphisms, all sufficiently fine smooth partitions generate measurably, but never topologically, and are never weak Bernoulli. The points of period k become uniformly distributed exponentially fast, and Lipschitz functions mix exponentially fast. Every reasonably smooth compact null set has the property that there is a dense set of periodic points whose entire orbit misses the set, but this is false for general compact null sets. Katznelson's property of almost weak Bernoulli can be strengthened to a certain exponential rate of independence, but breaks down at a critical number. Finally, open sets have return times that decay exponentially fast.
Geodesics on modular surfaces and continued fractions
Authors: Moeckel R.
Published: August 2009

A connection between the symbolic description of the geodesic flows on certain modular surfaces and the theory of continued fractions is developed. The well-known properties of these dynamical systems then lead to some new results about continued fractions.
A mixing Markov chain with exponentially decaying return times is finitarily Bernoulli
Authors: Rudolph Daniel J.
Published: August 2009

We here show that the necessary condition of exponentially decaying first return times to a cylinder set is also sufficient for a countable state Markov chain to be almost continuously isomorphic to a Bernoulli shift.
Repellers for real analytic maps
Authors: Ruelle David
Published: August 2009

The purpose of this note is to prove a conjecture of D. Sullivan that when the Julia set J of a rational function f is hyperbolic, the Hausdorff dimension of J depends real analytically on f. We shall obtain this as corollary of a general result on repellers of real analytic maps (see corollary 5).
POWER PROPERTIES OF INVARIANT TESTS FOR SPATIAL AUTOCORRELATION IN LINEAR REGRESSION
Authors: Martellosio Federico
Published: August 2009

This paper derives some exact power properties of tests for spatial autocorrelation in the context of a linear regression model. In particular, we characterize the circumstances in which the power vanishes as the autocorrelation increases, thus extending the work of Krämer (2005). More generally, the analysis in the paper sheds new light on how the power of tests for spatial autocorrelation is affected by the matrix of regressors and by the spatial structure. We mainly focus on the problem of residual spatial autocorrelation, in which case it is appropriate to restrict attention to the class of invariant tests, but we also consider the case when the autocorrelation is due to the presence of a spatially lagged dependent variable among the regressors. A numerical study aimed at assessing the practical relevance of the theoretical results is included.
Mid-term results, and therapeutic management, for patients suffering hypertension after surgical repair of aortic coarctation
Authors: Giordano Ugo , Cifra Barbara , Giannico Salvatore , Turchetta Attilio , Calzolari Armando
Published: August 2009

We designed our study to investigate the efficacy of a new therapeutic approach to late onset hypertension in patients after surgical repair of aortic coarctation. Several studies have shown a higher incidence of hypertension during daily activities, and during exercise, in patients after surgical correction of coarctation. To the best of our knowledge, however, no data exists concerning haemodynamics, the response of arterial pressures, and the effects of medications for lowering blood pressure during exercise or during daily activities.

We studied 128 patients, aged 15.6 ± 4.3 years, to determine the response of blood pressure as we administered treatment in the attempt to achieve a normotensive state. We excluded patient with associated cardiac abnormalities, apart from those with bicuspid aortic valves. We evaluated blood pressure at rest in both the right arm and leg to establish presence of any gradient, as well as the blood pressure in the arm during exercise testing, and by 24-hour ambulatory monitoring.

Atenolol was prescribed for those with elevated values of blood pressure but with a normal increment of heart rate during exercise. We prescribed Candesartan for those with elevated levels of blood pressure but with reduced increments of heart rate, specifically maximal heart rates of less than 85% of their predicted value. Both drugs were used when one alone was not effective. We found that, in young patients, candesartan provided better control of blood pressure with no side-effects, especially as demonstrated using 24-hour ambulatory monitoring, while atenolol was less effective, with more side-effects. Our experience suggests that both drugs should be used in patients who are non-responsive to monotherapy.
Genetic screening of 104 patients with congenitally malformed hearts revealed a fresh mutation of GATA4 in those with atrial septal defects
Authors: Hamanoue Haruka , Rahayuningsih Sri Endah , Hirahara Yuya , Itoh Junko , Yokoyama Utako , Mizuguchi Takeshi , Saitsu Hirotomo , Miyake Noriko , Hirahara Fumiki , Matsumoto Naomichi
Published: August 2009

We analysed the GATA binding protein 4 gene, or GATA4, along with the NK2 transcription factor related, locus 5 gene, or NKX2.5, to determine their genetic contribution to 104 sporadic patients in Indonesia with congenitally malformed hearts, 76 cases having atrial septal defect and 28 tetralogy of Fallot. We found only 1 novel mutation of GATA4 in those with atrial septal defecst. Analysis of the genetic background of the parents of the patient showed for the first time that a new mutation of GATA4 can cause sporadic atrial septal defects. We failed to discover any other mutations of either the GATA4 or NKX2-5 genes, supporting the marked genetic heterogeneity of human congenital cardiac defects.
Catheter closure of an atrial septal defect in anatomically corrected malposition with left juxtaposition of atrial appendages
Authors: Sivakumar Kothandam
Published: August 2009

Anatomically corrected malposition is characterized by concordant atrioventricular and ventriculoarterial connection and parallel arrangement of arterial trunks. Left juxtaposition of the atrial appendages, a frequent association of this anomaly, alters the atrial septal plane. In this report, I describe the insertion of a device to close an atrial septal defect, as guided by transoesophageal echocardiography.
Totally anomalous pulmonary venous connection to superior caval vein after an intracytoplasmic injection of sperm
Authors: Pérez-Lescure Picarzo Javier , Crespo Marcos David
Published: August 2009

We report the occurrence of non-obstructive totally anomalous pulmonary venous connection to the superior caval vein in a child conceived by intracytoplasmic injection of sperm, a type of assisted reproductive technology. Totally anomalous pulmonary venous connection is an uncommon congenital anomaly, in which all the pulmonary veins connect to the morphologically right atrium, or one of its tributaries. To our knowledge, this malformation has not been previously described in a child conceived on the basis of assisted reproductive technology.
An intrathoracic arteriovenous malformation discovered as an extremely uncommon reason of neonatal congestive cardiac failure
Authors: Hofmann Sigrun R. , Weise Matthias , Nitzsche Katharina I.
Published: August 2009

Congenital arteriovenous malformations are rare causes of congestive cardiac failure in neonates. The most common sites are in the head and liver, but other sites include the thorax, the abdomen and the limbs. The onset of failure is usually not in the immediate neonatal period, but later on in life, albeit that lesions such as the arteriovenous malformation of the vein of Galen, and other arteriovenous malformations in different locations which produce high flow can present early. We describe here the first case, to the best of our knowledge, of prenatal detection of an intrathoracic arteriovenous malformation producing neonatal cardiac failure, which was successfully treated by surgery postnatally.
Low-affinity Fcγ receptors, autoimmunity and infection
Authors: Willcocks Lisa C. , Smith Kenneth G.C. , Clatworthy Menna R.
Published: August 2009

Low-affinity Fcγ receptors (FcγRs) mediate the effects of immunoglobulin G (IgG) antibodies on leukocytes, including recruitment to inflammatory lesions, phagocytosis, antibody-dependent cellular cytotoxicity, release of inflammatory mediators and regulation of B cell activation. These functions are an important part of the mammalian response to infection, but if deployed inappropriately can cause autoimmune disease. Although most FcγRs are activatory, there is also an inhibitory FcγR that, when bound to IgG immune complexes, is able to downregulate the effects of both the activatory FcγRs and the B cell receptor. This review discusses the role of the low-affinity FcγRs in a balanced immune response and how perturbations in FcγR function result in susceptibility to infection or autoimmunity.
Glutamatergic cerebellar granule neurons synthesize and secrete reelin in vitro
Authors: Sinagra Mélanie , Gonzalez Campo Cecilia , Verrier Danièle , Moustié Olivier , Manzoni Olivier J. , Chavis Pascale
Published: August 2009

In the postnatal forebrain, the extracellular matrix protein reelin is expressed and secreted by subsets of GABAergic neurons, whereas in the cerebellum reelin is detected in glutamatergic cells of the granule cell layer. Thus, various regions of the postnatal brain present different patterns of reelin expression, whose significance remains unknown. We combined immunocytochemical and pharmacological approaches to characterize the phenotypic and temporal profiles of reelin expression in dissociated cultures of cerebellar granule neurons. A single type of reelin immunoreactivity, identified by a punctate labelling, was present in the somata of the majority of neurons. This immunoreactivity was observed throughout maturation and was exclusively present in glutamatergic neurons expressing the vesicular glutamate transporter 1. Neurons containing the reelin receptors apolipoprotein E receptor 2 (Apoer2) and very low-density lipoprotein receptor (Vldlr) represented about 80% of cerebellar neurons. The vast majority of reelin-positive neurons coexpressed Apoer2, suggesting that reelin immunoreactivity resulted in part from receptor-bound reelin. Inhibition of protein synthesis with cycloheximide completely abolished reelin immunoreactivity. In contrast, blocking protein secretion with brefeldin A did not affect the proportion of punctate neurons but revealed a subpopulation of neurons characterized by a solid reelin staining. These data show for the first time that a homogeneous population of glutamatergic neurons can synthesize and secrete reelin in cerebellar granule cells in vitro.
THEMIS observations of duskside compressional Pc5 waves
Authors: Constantinescu O. D. , Glassmeier K.‐H. , Plaschke F. , Auster U. , Angelopoulos V. , Baumjohann W. , Fornaçon K.‐H. , Georgescu E. , Larson D. , Magnes W. , McFadden J. P. , Nakamura R. , Narita Y.
Published: August 2009

The five Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft offer new possibilities to analyze ULF waves in the magnetosphere by means of multipoint measurements. During the coast phase, THEMIS observed many compressional oscillations with periods in the Pc5 range and longer. The observed events occur inside a well‐defined spatial domain in the outer equatorial duskside magnetosphere. We analyze these waves using the unique string‐of‐pearls configuration of the THEMIS constellation to evaluate their phase speed and propagation direction. We find that the waves are propagating sunward (westward) and radially outward, orthogonal to the mean magnetic field, with phase speeds around 30 km/s and higher in the spacecraft frame. In the plasma frame the propagation direction is still sunward, with lower speeds (up to 30 km/s for most events). The oscillations exhibit a strong anticorrelation between the magnetic field and the plasma density. On the basis of this, as well as their low propagation speed, orthogonal to the mean magnetic field propagation direction and almost parallel to the magnetic field maximum variance direction, we conclude that the most likely source of these waves is the drift mirror instability.
Structure and composition of a strongly stratified, tidally pulsed river plume
Authors: Nash Jonathan D. , Kilcher Levi F. , Moum James N.
Published: August 2009

The initial composition of a river plume depends on the cumulative turbulent entrainment within the estuary and how this dilutes the supplied freshwater. Here we examine the relative roles of turbulence and freshwater input using observations from the Columbia River estuary and plume during two periods with contrasting river flow. Within the estuary, intense turbulence observed on flood and ebb stages is controlled by the bottom stress and scales with tidally dominated near‐bottom velocity as utidal3. Shear associated with the estuarine circulation is found to have a much weaker influence on turbulence dissipation rates. On the basis of these observations, we suggest that properties of the Columbia River tidal plume should be controlled by the ratio of horizontal advection to turbulent mixing within the estuary. This ratio depends on the magnitude of freshwater river input (characterized by its volumetric flow rate Qf) as compared to turbulent fluxes due to tidal mixing. This is summarized in terms of the estuary Richardson number RiE, a nondimensional ratio between Qf and utidal3. From 17 tidally resolving offshore surveys during spring/neap tides and low/high river flows, we find that the plume's median salinity, thickness, and turbulent mixing are each predicted through RiE. It is hoped that these simple formulations will provide guidance in assessing critical properties of river plumes and their influence on coastal circulation.
Overestimation of CO2 respiration fluxes by the closed chamber method in low‐turbulence nighttime conditions
Authors: Schneider J. , Kutzbach L. , Schulz S. , Wilmking M.
Published: August 2009

Knowledge about ecosystem respiration is required for accurate estimates of daily, seasonal and annual carbon exchange between ecosystems and the atmosphere. Measurements by the closed chamber technique were often used to calculate nighttime respiration fluxes during low‐turbulence nighttime conditions when the eddy covariance method is problematic. The goal of this study is to investigate if the closed chamber measurements could also be biased during low‐turbulence atmospheric conditions. We applied the closed chamber technique for measurements of CO2 flux at flark, lawn and hummock microsites at a boreal peatland (n = 602). The friction velocity (u*) was used for screening data into either well developed or low‐turbulence conditions (u* ≤ 0.1 m s−1). During chamber experiments in low‐turbulence nighttime conditions, the CO2 concentrations within the chamber headspace were observed to increase extremely fast and nonlinearly at the start of the chamber deployment period. The possible reason is the abrupt disturbance of the natural concentration gradients in the soils, plants and the near‐surface atmosphere. This artifact leads to an overestimation of CO2 fluxes and occurs at all microsite types. However, the strongest overestimation occurs at hummocks. Consequently, we recommend that nighttime chamber measurements have to be carefully checked with respect to prevailing turbulence conditions. Under low‐turbulence conditions their results can be overestimated. Since the bias is difficult to correct, chambers are probably not suitable to replace eddy covariance measurements under low‐turbulence nighttime conditions, since both measurements tend to be biased.
Integrating collocated auxiliary parameters in geostatistical simulations using joint probability distributions and probability aggregation
Authors: Mariethoz Grégoire , Renard Philippe , Froidevaux Roland
Published: August 2009

We propose a new cosimulation algorithm for simulating a primary attribute using one or several secondary attributes known exhaustively on the domain. This problem is frequently encountered in surface and groundwater hydrology when a variable of interest is measured only at a discrete number of locations and when the secondary variable is mapped by indirect techniques such as geophysics or remote sensing. In the proposed approach, the correlation between the two variables is modeled by a joint probability distribution function. A technique to construct such relation using underlying variables and physical laws is proposed when field data are insufficient. The simulation algorithm proceeds sequentially. At each location of the domain, two conditional probability distribution functions (cpdf) are inferred. The cpdf of the main attribute is inferred in a classical way from the neighboring data and a model of spatial variability. The second cpdf is inferred directly from the joint probability distribution function of the two attributes and the value of the secondary attribute at the location to be simulated. The two distribution functions are combined by probability aggregation to obtain the local cpdf from which a value for the primary attribute is randomly drawn. Various examples using synthetic and remote sensing data demonstrate that the method is more accurate than the classical collocated cosimulation technique when a complex relation relates the two attributes.
A state‐space Bayesian framework for estimating biogeochemical transformations using time‐lapse geophysical data
Authors: Chen Jinsong , Hubbard Susan S. , Williams Kenneth H. , Pride Steve , Li Li , Steefel Carl , Slater Lee
Published: August 2009

We develop a state‐space Bayesian framework to combine time‐lapse geophysical data with other types of information for quantitative estimation of biogeochemical parameters during bioremediation. We consider characteristics of end products of biogeochemical transformations as state vectors, which evolve under constraints of local environments through evolution equations, and consider time‐lapse geophysical data as available observations, which could be linked to the state vectors through petrophysical models. We estimate the state vectors and their associated unknown parameters over time using Markov chain Monte Carlo sampling methods. To demonstrate the use of the state‐space approach, we apply it to complex resistivity data collected during laboratory column biostimulation experiments that were poised to precipitate iron and zinc sulfides during sulfate reduction. We develop a petrophysical model based on sphere‐shaped cells to link the sulfide precipitate properties to the time‐lapse geophysical attributes and estimate volume fraction of the sulfide precipitates, fraction of the dispersed, sulfide‐encrusted cells, mean radius of the aggregated clusters, and permeability over the course of the experiments. Results of the case study suggest that the developed state‐space approach permits the use of geophysical data sets for providing quantitative estimates of end‐product characteristics and hydrological feedbacks associated with biogeochemical transformations. Although tested here on laboratory column experiment data sets, the developed framework provides the foundation needed for quantitative field‐scale estimation of biogeochemical parameters over space and time using direct, but often sparse wellbore data with indirect, but more spatially extensive geophysical data sets.
Helium isotopes as a tool for detecting concealed active faults
Authors: Umeda Koji , Ninomiya Atusi
Published: August 2009

A magnitude (Mj) 7.3 crustal earthquake occurred in the western Tottori area, southwest Japan, on 6 October 2000. However, there was no obvious prefaulting indication at surface of a fault corresponding to the western Tottori earthquake in 2000. This study was undertaken to elucidate the geographic distribution of 3He/4He ratios around the seismic source region using helium isotope data obtained from groundwater samples from drinking water wells. The maximum 3He/4He ratio observed was from the water well nearest to the epicenter of the main shock. In addition, there appears to be a clear trend of decreasing 3He/4He ratios with distance away from the main trace of the probable fault segments. The observations provide significant evidence that the source fault of the earthquake in 2000 is associated with leakage of mantle volatiles through the crust to the Earth's surface. We suggest that helium isotopes can be regarded as a tool for investigating and/or mapping concealed active faults with no surface expression.
Effective resolution and drift of Paroscientific pressure sensors derived from long‐term seafloor measurements
Authors: Polster André , Fabian Marcus , Villinger Heinrich
Published: August 2009

Starting with the installation of the NOAA tsunami early warning system DART in 1983, the Paroscientific Digiquarz® Broadband Depth Sensor has been deployed for long‐term ocean bottom pressure measurements in numerous marine investigations. The sensor turned out to be very reliable with a good signal repeatability within a broad measuring range and high resolution. However, up to now its long‐term drift, noise level, and effective resolution under in situ conditions at the seafloor are only known from a few published studies and for a few sensors. In this study we analyze 118 long‐term seafloor pressure time series (longer than 2 months and up to a maximum time period of 9 years) to investigate effective resolution and long‐term drift under in situ conditions. The data are from DART, IFM‐GEOMAR, LOLEM, and CORK stations. The noise level of the data and therefore the mean sensor resolution are lower than an upper threshold of 20.7 Pa (corresponding to 2.07 mm equivalent water level) for stations installed directly on the seafloor. The noise level of CORK sensors is much larger, with a median value of 127 Pa. Long‐term sensor drift is assumed to be composed of an initial exponential part and a subsequent linear drift. In situ mean drift is −0.88 ± 0.73 kPa/a, determined from all available data with a slight increase of drift with deployment depth. For the first time, we are able to quantify effective pressure resolution and drift of the widely used Paroscientific pressure gauges under in situ conditions. Our results provide important constrains for the interpretation of seafloor pressure records. However, in situ self‐calibration procedures for the Paroscientific sensors are still needed in order to benefit from high effective resolution and long‐term stability and also to increase accuracy especially for the monitoring of geodynamic processes at the seafloor.
Is the Martian water table hidden from radar view?
Authors: Farrell W. M. , Plaut J. J. , Cummer S. A. , Gurnett D. A. , Picardi G. , Watters T. R. , Safaeinili A.
Published: August 2009

Mars may possess a global sub‐surface groundwater table as an integral part of its current hydrological system. However, the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) onboard the Mars Express (MEx) spacecraft has yet to make a definitive detection of such a body of liquid water. In this work, we quantify the conditions that would allow a detection of a deep aquifer and demonstrate that the lack of radar detection does not uniquely rule out the presence of such a body. Specifically, if the overlying crustal material has a conductivity above ∼10−5 S/m (equivalent to a loss tanget of 0.008), a radar echo from an aquifer could be sufficiently attenuated by the intervening medium to prevent its detection by MARSIS. As such, the lack of direct detection by MARSIS–a “null result”–does not rule out the possibility of the water table's existence.