bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of ASR-gels in concretes against accelerated mortar bar test samples
Authors: Gavrilenko E. , García del Amo D. , Calvo Pérez B. , García García E.
Published: July 2007

Through scanning electron microscopy and local chemical analysis by energy-dispersive X-ray spectroscopy, alkali–silica reaction (ASR) products in two Spanish dam concretes and accelerated mortar bar test samples (UNE 146508:1999) were compared. In chemical composition, gels formed in the accelerated test revealed marked differences to gels formed in concrete. Higher sodium and lower calcium and potassium contents were especially noteworthy in mortar bar test samples. Further, very marked, contrary tendencies in the evolution of chemical composition between gels formed in concrete and those formed in the accelerated mortar bar test were observed. In mortar samples, enrichment in sodium and impoverishment in calcium, among later gel generations, related to progressive ASR development, is characteristic. Real concretes show a contrary tendency; later phases of gel become markedly enriched in calcium. The differences observed may lead to variations in aggregate behaviour in accelerated test and in field performance in concretes.
Behaviour and strut-and-tie predictions of high-strength concrete deep beams with trapezoidal web openings
Authors: Hu O. E. , Tan K. H. , Liu X. H.
Published: July 2007

The present paper investigates the effects of the size of trapezoidal web openings and shear span-to-overall-height a/h ratio on the behaviour and shear strength of high-strength concrete deep beams. A total of six deep beams with compressive strengths in the range 84 MPa ≤ f′c ≤ 103 MPa (12 200 psi ≤ f′c ≤ 15 000 psi) were tested to failure under two-point symmetric top loading to determine their failure modes, diagonal cracking, mid-span deflection and ultimate shear strengths. All six beams were reinforced with 2·61% longitudinal main steel to prevent flexural failure at mid-span. They had an overall depth of 1000 mm and a web thickness of 150 mm with an a/h ratio of 0·5, 1·0 and 1·5. Trapezoidal web openings with different sizes were located in the middle interior of the beams. Test results indicate that the ultimate strength of a deep beam with a web opening is comparable with that of a solid beam, if the web opening does not interpose the force path—that is, does not reduce the strut width between the load point and the support. Otherwise, the ultimate strength will decrease significantly. A strut-and-tie approach is also proposed to analyse the shear strength of a deep beam with this kind of web opening.
EUROPEAN STARLINGS ARE CAPABLE OF DISCRIMINATING SUBTLE SIZE ASYMMETRIES IN PAIRED STIMULI
Authors: Swaddle John P. , Johnson Charles W.
Published: July 2007

Small deviations from bilateral symmetry (fluctuating asymmetries) are cues to fitness differences in some animals. Therefore, researchers have considered whether animals use these small asymmetries as visual cues to determine appropriate behavioral responses (e.g., mate preferences). However, there have been few systematic studies of animals' abilities to visually discriminate such minor asymmetries. If the asymmetries cannot be discriminated, fluctuating asymmetry can not be a visual cue. Here, we report an investigation of European starlings' (Sturnus vulgaris) abilities to discriminate small size asymmetries. We trained starlings, through operant conditioning in a free‐flight aviary, to discriminate achromatic, symmetric paired stimuli from size‐matched asymmetric stimuli. By starting the learning process with a large asymmetry and progressing through sequential trials of decreasing asymmetry, we elucidated a behavioral limit to asymmetry discrimination. We found that starlings are capable of discriminating a 10% size asymmetry. There was weaker evidence for discrimination of 5% asymmetry but no evidence for signal discrimination at 2.5% size asymmetry. This level of asymmetry discrimination suggests that many size asymmetry cues in nature can be discriminated by birds. At each level of asymmetry discrimination, we also tested whether starlings could generalize their learned symmetry preference to unreinforced novel images. Consistent with previous findings, we found that starlings could generalize their symmetry preferences.
CONDITIONAL RELATIONS WITH COMPOUND ABSTRACT STIMULI USING A GO/NO‐GO PROCEDURE
Authors: Debert Paula , Matos Maria Amelia , McIlvane William
Published: July 2007

The aim of this study was to evaluate whether emergent conditional relations could be established with a go/no‐go procedure using compound abstract stimuli. The procedure was conducted with 6 adult humans. During training, responses emitted in the presence of certain stimulus compounds (A1B1, A2B2, A3B3, B1C1, B2C2, and B3C3) were followed by reinforcing consequences (points); responses emitted in the presence of other compounds (A1B2, A1B3, A2B1, A2B3, A3B1, A3B2, B1C2, B1C3, B2C1, B2C3, B3C1 and B3C2) were not (i.e., extinction). During subsequent tests of emergent relations, new configurations (BA, CB, AC, and CA relations) were presented, formed by the recombination of training stimuli and structurally resembling tests usually employed in stimulus equivalence studies. Results showed that all 6 participants displayed immediate emergence of relations consistent with symmetry. Four participants exhibited emergent relations consistent with both transitivity and equivalence. These results indicate that a go/no‐go procedure with compound stimuli can establish emergent conditional relations, thus providing a procedural alternative to the matching‐to‐sample procedures commonly used in studies of stimulus equivalence.
RESURGENCE OF INTEGRATED BEHAVIORAL UNITS
Authors: Bachá‐Méndez Gustavo , Reid Alliston K. , Mendoza‐Soylovna Adela
Published: July 2007

Two experiments with rats examined the dynamics of well‐learned response sequences when reinforcement contingencies were changed. Both experiments contained four phases, each of which reinforced a 2‐response sequence of lever presses until responding was stable. The contingencies then were shifted to a new reinforced sequence until responding was again stable. Extinction‐induced resurgence of previously reinforced, and then extinguished, heterogeneous response sequences was observed in all subjects in both experiments. These sequences were demonstrated to be integrated behavioral units, controlled by processes acting at the level of the entire sequence. Response‐level processes were also simultaneously operative. Errors in sequence production were strongly influenced by the terminal, not the initial, response in the currently reinforced sequence, but not by the previously reinforced sequence. These studies demonstrate that sequence‐level and response‐level processes can operate simultaneously in integrated behavioral units. Resurgence and the development of integrated behavioral units may be dissociated; thus the observation of one does not necessarily imply the other.
Chromosomal Locations of Genes for Stem Rust Resistance in Monogenic Lines Derived from Tetraploid Wheat Accession ST464
Authors: Klindworth Daryl L. , Miller James D. , Jin Yue , Xu Steven S.
Published: July 2007

The genetics of resistance to stem rust (caused by Puccinia graminis Pers.:Pers. f. sp. tritici Eriks. and Henn.) in durum (Triticum turgidum L. ssp. durum) is not as well understood as for bread wheat (T. aestivum L.). Our objective was to determine the chromosomal location of genes for stem rust resistance in four monogenic lines derived from the Ethiopian tetraploid landrace ST464. The four monogenic lines were crossed to a set of stem rust susceptible aneuploids based on the tetraploid line 47‐1. We observed chromosome pairing in the hybrids and made testcrosses to ‘Rusty’ durum. Monogenic lines ST464‐A1 and ST464‐A2 were observed to carry a 2A/4B translocation, and subsequent crosses proved that the translocation was derived from ST464. Testcross F2 seedlings were inoculated with one of three stem rust pathotypes and classified for segregation for resistance to identify the critical chromosome for each monogenic line. The stem rust resistance genes in monogenic lines ST464‐A1, ST464‐A2, and ST464‐C1 were located to chromosomes 6A, 2B, and 6A, respectively. The gene in ST464‐B1 may be located to chromosome 4A, because it appeared it was not located on any of the other 13 chromosomes. The four ST464 monogenic lines and hexaploid lines carrying Sr9e and Sr13 were then tested with eight stem rust pathotypes with the objective of postulating the genes present in the monogenic lines. The genes in ST464‐A2 and ST464‐C1 were postulated to be Sr9e and Sr13, respectively.
Potential Use of Spectral Reflectance Indices as a Selection Tool for Grain Yield in Winter Wheat under Great Plains Conditions
Authors: Prasad B. , Carver B. F. , Stone M. L. , Babar M. A. , Raun W. R. , Klatt A. R.
Published: July 2007

Selection criteria that would facilitate increased genetic gain for grain yield would be considered advantageous in plant breeding programs. We evaluated the potential of spectral reflectance indices (SRI) for assessing grain yield variability in winter wheat (Triticum aestivum L.) genotypes under Great Plains conditions. One experiment was conducted at two locations on the Oklahoma State University research farms for 1 yr, and two experiments were conducted for 2 yr at a single location. The first experiment included 25 winter wheat cultivars from the Great Plains, and the other two experiments contained two groups of 25 F4:6 and F4:7 recombinant inbred lines. Six reported SRI (red and green normalized difference vegetation index, RNDVI, GNDVI; simple ratio, SR; water index, WI; normalized water indices 1 and 2, NWI‐1 and NWI‐2), and two new normalized water indices (NWI‐3 and NWI‐4) were calculated at booting, heading, and early grain‐filling stages using a FieldSpec UV/VNIR spectroradiometer. Significant genotypic variation was observed for SRI and growth stages, though the booting stage was least associated with grain yield. The relationships of grain yield with WI and NWI were stronger than with the RNDVI and SR. The WI and the NWI performed better in identifying superior genotypes, either at any individual growth stage or in a combination of growth stages. Our study clearly demonstrated the potential of using SRI as a selection tool for grain yield in a winter wheat breeding program.
Elevated Carbon Dioxide and Ozone Effects on Peanut: II. Seed Yield and Quality
Authors: Burkey Kent O. , Booker Fitzgerald L. , Pursley Walter A. , Heagle Allen S.
Published: July 2007

Many adverse effects of tropospheric O3 on C3 crop plants are ameliorated by elevated concentrations of atmospheric CO2, but the extent of the interaction can vary, depending on the species, gas concentrations, and other experimental conditions. A 2‐yr open‐top field chamber experiment was conducted to examine this interaction in peanut (Arachis hypogaea L.) by testing the effects of O3 and CO2 mixtures on yield and seed quality. Treatments were ambient CO2 (375 μmol mol−1) and CO2 additions of approximately 173 and 355 μmol mol−1 in combination with charcoal‐filtered (CF) air (22 nmol O3 mol−1), nonfiltered (NF) air (46 nmol O3 mol−1), and NF air plus O3 (75 nmol O3 mol−1). At ambient CO2, pod number was suppressed 16% in NF air and 44% in elevated O3 Pod and seed mass were not significantly affected in NF air but were lowered 33 to 37% in elevated O3 Elevated CO2 increased yield parameters 7 to 17% for plants grown in CF air and restored yield in NF air and elevated O3 treatments to control or higher levels. Gas treatment effects on peanut market grade characteristics were small. No treatment effects were observed on the protein and oil contents of seeds, but there were changes in fatty acid composition. Overall results indicate that increasing concentrations of tropospheric O3 will suppress yield of O3–sensitive peanut cultivars, while elevated CO2 will moderate this response. Elevated O3 and CO2 are not expected to have major effects on peanut seed composition and quality.
Genetic Improvement of Seedling Emergence of Soybean Lines with Low Phytate
Authors: Spear Jordan D. , Fehr Walter R.
Published: July 2007

Seedling emergence of low‐phytate (LP) soybean [Glycine max (L.) Merr.] lines has been reported to be lower than that of normal‐phytate (NP) lines. One objective of this study was to evaluate if backcrossing the LP trait into a NP line would result in LP progeny with normal emergence. The LP line CX1834‐1‐6 (CX1834) was crossed to B01769B019 (B019), a NP line with reduced palmitate content, and three backcrosses were made to B019. A total of 36 BC3F4–derived LP lines from the population were evaluated at five locations in 2005 in comparison with CX1834, B019, and an NP cultivar IA3023. The mean phytate P and inorganic P content of all the backcross lines was not significantly different from CX1834. There were 18 backcross lines that had a mean field emergence that was significantly greater than CX1834 and not significantly different from B019. The results indicated that backcrossing seemed to be successful for developing LP lines with normal field emergence. A second objective of the study was to determine the effectiveness of warm germination, cold vigor, and accelerated aging tests for predicting field emergence of LP lines. Fifteen of the backcross lines were evaluated in the three tests that represented the range of field emergence that had been observed. The tests were useful for identifying lines with inferior field emergence but were not reliable enough to replace field tests for identifying the best emerging lines.
Combining Maize Base Germplasm for Cold Tolerance Breeding
Authors: Rodríguez V. M. , Butrón A. , Sandoya G. , Ordás A. , Revilla P.
Published: July 2007

Early planting can contribute to increased grain yield of maize (Zea mays L.), but it requires cold tolerance. A limited number of cold‐tolerant maize genotypes have been reported. The objectives of this study were to test a new strategy to improve cold tolerance in maize searching for broad × narrow genetic combinations that may be useful as base populations for breeding programs, to compare genotype performance under cold‐controlled and field conditions, and to establish the major genetic effects involved in crosses between cold‐tolerant inbred lines and populations. Nine cold‐tolerant populations were crossed to five inbred lines and evaluated in a cold chamber and in the field. Most inbred line × population crosses performed better than populations per se or hybrids used as checks, both in the cold chamber and in the field, suggesting that broad × narrow genetic combination could be a suitable start point for further breeding programs for cold tolerance. The crosses between the inbred line EP80 and northwestern Spanish populations are the most promising base germplasm. In particular, EP80 × Puenteareas showed the greatest yield and good performance at the first stages of development under cold conditions. In addition, EP80 and Puenteareas showed favorable general combining ability for most traits. Early vigor rating would be the most suitable trait to select maize genotypes with superior cold tolerance during emergence and postemergence stages, because it was the only trait for which differences among genotypes were observed in both the cold chamber and the field. Although evaluation under controlled conditions is essential to test cold tolerance, field evaluations are complementary because no association was found between traits evaluated in both conditions.
Photoperiod and E‐genes Influence the Duration of the Reproductive Phase in Soybean
Authors: Kumudini Saratha V. , Pallikonda Praveen K. , Steele C.
Published: July 2007

Duration of the reproductive phase (DRP) is critical for soybean [Glycine max (L.) Merr.] yield. Manipulation of this phase may benefit breeding for higher yield. The soybean E‐gene series control time to flowering and maturity through a photoperiod‐mediated response. It is possible that E‐genes and photoperiod may control the DRP. Two 2‐yr studies were conducted with the objective to assess whether the DRP is influenced by either or both E‐gene alleles and post‐flowering photoperiod. In a planting‐date experiment, the main plots were two planting dates, and sub plots were 15 E‐gene near‐isogenic lines (NILs) in two genetic backgrounds. In a daylength‐extension experiment, seven E‐gene NILs were planted to synchronize flowering date. Two photoperiods treatments were imposed after flowering: (i) ambient and (ii) ambient plus 3‐h incandescent daylength extension. Early planting and daylength extension exposed plants to a longer post‐flowering photoperiod, and resulted in an increase in the DRP. When exposed to the same post‐flowering photoperiod, the DRP was positively related to the number of dominant E‐gene alleles. Both E‐genes and post‐flowering photoperiod controlled the DRP and this was in addition to the known impact of E‐genes on time to flowering. Hence, E‐genes control time to maturity through both their effect on time to flowering and through their effect on the DRP. The results of this study underline the importance of time of flowering for determination of the DRP.
Identification and Mapping of Lr3 and a Linked Leaf Rust Resistance Gene in Durum Wheat
Authors: Herrera‐Foessel Sybil A. , Singh Ravi P. , Huerta‐Espino Julio , William Manilal , Rosewarne Garry , Djurle Annika , Yuen Jonathan
Published: July 2007

Leaf rust, caused by Puccinia triticina Eriks., is an important disease of durum wheat (Triticum turgidum ssp. durum) worldwide and can be controlled through the use of genetic resistance. Two leaf rust resistance genes in durum wheat lines ‘Camayo’ and ‘Storlom’ were mapped to chromosome 6BL via amplified fragment length polymorphism (AFLP) with bulked segregant analysis. The leaf rust resistance gene in Storlom was identified to be Lr3 using a previously known co‐segregating marker, Xmwg798 We validated a sequence tagged site version of this marker and identified three AFLP markers that were associated with the resistance gene in Camayo. The lack of recombination between the two genes in Storlom and Camayo, and comparison of the phenotypic and molecular characteristics of Camayo and the common wheat (T. aestivum) near‐isogenic ‘Thatcher’ lines carrying Lr3a, Lr3ka, and Lr3bg, indicated that the resistance in Camayo is conferred by a previously unknown gene adjacent to the Lr3 locus. The two closely linked genes confer resistance to P. triticina race BBG/BN prevalent on durum wheat in Northwestern Mexico and should be deployed in combination with other resistance genes, to prolong their effectiveness.
Alfalfa Leaf Protein and Stem Cell Wall Polysaccharide Yields under Hay and Biomass Management Systems
Authors: Lamb JoAnn F. S. , Jung Hans‐Joachim G. , Sheaffer Craig C. , Samac Deborah A.
Published: July 2007

Alfalfa (Medicago sativa L.) has been proposed as a biofuel feedstock in which the stems would be processed to produce ethanol and the leaves sold separately as a livestock feed. Our objectives were to evaluate the effects of management strategy on leaf crude protein (CP), and stem carbohydrate concentrations and yields of alfalfa germplasms differing in genetic background. Two hay‐type and two biomass‐type alfalfas were established at 450 plants m−2 and harvested at early bud (hay management system) and at 180 plants m−2 and harvested at green pod (biomass management system) in three environments. The biomass‐type alfalfas under the biomass management had lower leaf CP, higher stem cell wall polysaccharide, and higher stem lignin concentrations, comparable leaf CP yield, and 37% greater stem cell wall polysaccharide yields compared to the hay‐type alfalfas under the hay management treatment. The impact of altered stem cell wall composition and increased stem dry matter yield of a biomass‐type alfalfa under the biomass system compared to a hay‐type alfalfa under the hay system increased the theoretical potential ethanol yield by 99%.
Sucrose‐Phosphate Synthase, a Biochemical Marker of High Sucrose Accumulation in Sugarcane
Authors: Grof Christopher P. L. , Albertson Peter L. , Bursle Johanna , Perroux Jai M. , Bonnett Graham D. , Manners John M.
Published: July 2007

Increasing sucrose content is a major objective of sugarcane breeding programs. One approach employed by breeders is to introgress new genes from genotypes of Saccharum officinarum L. not previously used in breeding. The activity of a suite of key sucrose metabolizing enzymes was measured in progeny of an introgression program to find biochemical markers associated with high sucrose content, measured as commercial cane sugar (CCS). The enzymes sucrose‐phosphate synthase (SPS), three isoforms of invertase, and sucrose synthase were measured in four high and four low CCS clones from an initial cross between a S. officinarum and the commercial cultivar Q165. Subsequently, SPS and the two soluble isoforms of invertase were measured in clones derived from a backcross of one of the progeny to another commercial cultivar Mida. Enzyme activities were measured in tissue from internodes taken from four different positions down the stem profile. Of particular significance was the finding that the activity of a key enzyme involved in sucrose synthesis, SPS, was significantly higher in the upper internodes (one to three) of high CCS clones as compared with low CCS clones in both populations, suggesting that this enzyme may have a key role in establishing metabolic and developmental processes necessary for high sugar accumulation during stem growth and maturation.
Estimating water demand for domestic use in rural South Africa in the absence of price information
Authors: Banda B. M. , Farolfi S. , Hassan R. M.
Published: July 2007

The paper applies the travel cost method (TCM) to estimate the value that rural households in the Steelpoort sub-basin of South Africa place on river and collective tap water. While the TCM calculations are based on the opportunity cost of the time household members spend on water collection, the resulting welfare values are close in magnitude to the estimates obtained using a contingent valuation method (CVM) on the same sample. The paper shows that in the absence of price data, the TCM provides satisfactory estimates of benefits where direct estimation of demand elasticity would otherwise be impossible. According to both methods, households consuming river water attribute higher value to the resource than collective tap users. The income elasticity of the trip generating function is much higher than that of the opportunity cost of time (price), implying that household's water use behaviour would be more responsive to factors affecting household income than to price incentives. Comparing the estimated values with actual operating and maintenance cost of water provision in the study area suggests that policies promoting cost-covering water tariffs have a potential to succeed.
A girl with duplication 9q34 syndrome
Authors: Gawlik‐Kuklinska Katarzyna , Iliszko Mariola , Wozniak Agnieszka , Debiec‐Rychter Maria , Kardas Iwona , Wierzba Jolanta , Limon Janusz
Published: July 2007

We report on a 17‐year‐old female with numerous developmental abnormalities associated with 46,XX,dup(9)(q33.3q34.1), where the duplication occurred de novo. The patient presented with dysmorphic features and notable psychomotor delays, manifestations similar to those described in other reported cases of duplication of 9q34‐qter. Due to late presentation and diagnosis, our patient was not evaluated and characterized until adolescence, when particular attention was paid to the development of secondary sexual characteristics, secondary amenorrhea and obesity. © 2007 Wiley‐Liss, Inc.
A previously undescribed form of congenital disorder of glycosylation with variable presentation in siblings: Early fetal loss with hydrops fetalis, and infant death with hypoproteinemia
Authors: McKenzie F.A. , Fietz M. , Fletcher J. , Smith R.L.L. , Wright I.M.R. , Jaeken J.
Published: July 2007

We present two siblings with a previously undescribed congenital disorder of glycosylation (CDG). The first child died in utero with severe hydrops fetalis and the second presented following preterm delivery with respiratory insufficiency, generalised edema and a protein‐losing enteropathy. Both had a similar pattern of facial dysmorphism and joint contractures. The diagnosis of CDG‐I was made following the birth of the second child based on the serum transferrin isoform pattern. CDG‐Ia and ‐Ib were excluded by specific enzyme analysis. Joint contractures are a relatively uncommon finding in CDG, although fetal hydrops (CDG‐Ia) and protein‐losing enteropathy (CDG‐Ib) are well recognized. CDG must be considered in the differential diagnosis of hydrops fetalis, congenital hypoproteinemia and death in early infancy, particularly when associated with dysmorphic features. © 2007 Wiley‐Liss, Inc.
Enantiomerenangereicherte Cyclopropene: vielseitige Bausteine in der asymmetrischen Synthese
Authors: Marek Ilan , Simaan Samah , Masarwa Ahmad
Published: July 2007

Enantiomerenangereicherte Cyclopropenderivate, die kleinstmöglichen ungesättigten Carbocyclen, sind von großem Interesse für die Synthese, da sie als vielseitige reaktive Bausteine eingesetzt werden können. Die Reaktivität rührt von der Ringspannung her, die durch Umsetzungen gemildert wird. Die Cyclopropenderivate können zu komplexeren chiralen Strukturen umgesetzt werden, wobei in diesem Aufsatz besonders die Herstellung von enantiomerenangereicherten Methylen‐ und Alkylidencyclopropanderivaten herausgehoben wird. Die einfache Verfügbarkeit chiraler Bausteine dieser Art bildet eine ausgezeichnete Grundlage für die Entdeckung neuartiger Reaktionen, die das Repertoire der organischen Synthese bereichern können.
Surface modification of quarry stone by hexamethyldisiloxane plasma treatment
Authors: López‐Barrera Jose A. , Avila‐Ortega Alejandro , Morales Juan , Cervantes Jorge , Olayo Roberto
Published: July 2007

The surface of quarry stone was modified by continuous plasma polymerization of hexamethyldisiloxane. The hydrophilic surface of the quarry stone was made hydrophobic and impermeable to water. Three different reaction times were analyzed. All of them resulted in the formation of a homogenous layer on the quarry stone surface. Contact angle and FT‐IR analyses show that the hydrophobic character of the surface is due to methyl groups on the surface. The change in the contact angle with temperature and the wetting temperature (Tw) are also discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Experimental research and characteristics analysis of alumina‐supported copper oxide sorbent for flue gas desulfurization
Authors: Xiang Jun , Zhao Qingsen , Hu Song , Sun Lushi , Su Sheng , Fu Peng , Zhang Anchao , Qiu Jianrong , Chen Hanping , Xu Minghou
Published: July 2007

The dry regenerative sorption process using the γ‐alumina‐supported copper oxide sorbent is considered an alternative to the conventional once‐through limestone scrubbing process for flue gas desulfurization. To define the characteristics of the γ‐alumina‐supported copper oxide sorbent in the sulfation and regeneration reactions, the wet‐impregnation method was applied to prepare γ‐alumina‐supported copper oxide sorbent, and cycles of sulfation‐regeneration reactions were carried out in a quartz tube reactor. The effects of the physical properties of the used supports and the concentration of the impregnation solution on the SO2sorption capacity of the sorbent, as well as the dispersed form of the copper oxide on the support and the stability of the sorbent were determined by means of Brunauer, Emmett and Teller (BET), X‐Ray Diffraction (XRD), electron probe microanalyser (EPMA) and scanning electron microscope (SEM) techniques. The results show that the γ‐alumina used for the sorbent should have both a large surface area and an ideal pore size. As the supports were impregnated with 2 mol/l Cu(NO3)2solution, the loading amount of the active copper oxide coated on the sorbent was optimum and the copper oxide was dispersed in the desired form. The prepared γ‐alumina (DS)‐supported copper oxide sorbent exhibited high SO2sorption capacity and the desired sulfation‐regeneration properties. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.
Selection of controls in case‐control studies on maternal medication use and risk of birth defects
Authors: Bakker Marian K. , de Walle Hermien E.K. , Dequito Aileen , van den Berg Paul B. , de Jong‐van den Berg Lolkje T.W.
Published: July 2007

BACKGROUND:

In case‐control studies on teratogenic risks of maternal drug use during pregnancy, the use of normal or malformed controls may lead to recall‐bias or selection bias. This can be avoided by using controls with a genetic disorder. However, researchers are hesitant to use these as controls because it is unknown whether their selection is independent of exposure status. The aim of this study is to investigate whether first trimester drug use among mothers of children with genetic disorders is representative for the “general pregnant population”.

METHODS:

From a birth defects registry 565 mothers of infants with a genetic disorder born between 1998–2004 were selected (the “genetic population”). The first trimester exposure rate was calculated for prescription‐only drugs as the number of exposed women per 100. By calculating the rate ratio (RR) and 95% CI, the exposure rates in the genetic population were compared with those in the “source population” obtained from a population‐based prescription database and consisting of 10,870 mothers who gave birth to a child between 1998–2004.

RESULTS:

The mean age at birth was 32.1 for the genetic population and 29.6 for the source population (p = .000). In the genetic population, a higher use was found for antimigraine medication (RR = 2.7, 95% CI = 1.0–7.8) and for ovulation stimulants (RR = 1.6, 95% CI = 1.0–2.6). After adjustment for maternal age, the difference in use of ovulation stimulants disappeared.

CONCLUSIONS:

Except for antimigraine medication, first trimester drug use among mothers of infants with genetic disorders is representative for the general pregnant population. Birth Defects Research (Part A) 2007. © 2007 Wiley‐Liss, Inc.
Analysis of polyamines as carbamoyl derivatives in urine and serum by liquid chromatography–tandem mass spectrometry
Authors: Byun Jeong Ah , Lee Sang Hee , Jung Byung Hwa , Choi Man Ho , Moon Myeong Hee , Chung Bong Chul
Published: July 2007

A quantitative analysis of polyamines in urine and serum by liquid chromatography–tandem mass spectrometry (LC‐MS/MS) is described. The polyamines were carbamylated with isobutyl chloroformate, extracted with diethyl ether under pH 9.0, and analyzed by LC‐MS/MS with single reaction monitoring mode. The limit of quantification was 1 ng/mL based on a signal‐to‐noise ratio >3, and the correlation coefficient (r2) for the calibration curves was >0.99 for both urine and serum samples. The present method was applied to urine and serum samples from 30 breast cancer patients and 30 normal female controls. There was no significant difference in the urinary polyamine levels between breast cancer patients and controls. However, 1,3‐diaminopropane, putrescine, spermine and N‐acetylspermidine levels in serum increased in breast cancer patients. These four serum polyamines may be a good index to study both production and metabolism of polyamines, and a useful tool in assessment of the polyamine status of breast cancer patients. Copyright © 2007 John Wiley & Sons, Ltd.
Prediction of binding affinities of thrombin and trypsin inhibitors by chemometric modeling
Authors: Župerl Š. , Mlinsek G. , Solmajer T. , Zupan J. , Novič M.
Published: July 2007

Thrombin plays a central role in thrombosis and hemostasis. Inhibition of thrombin is a prime target for therapeutic intervention of thrombosis. A considerable number of experimental structures of both thrombin and trypsin complexes with their non‐covalently bound inhibitors is available and they offer an excellent database for development of chemometric models for prediction of inhibitors binding affinities towards thrombin and trypsin. Counter‐propagation artificial neural network (CP‐ANN) was applied as a modeling method. As input we have used molecular electrostatic potentials (MEP) of inhibitor–enzyme complexes computed at the contact surface of ligand and protein. The variable selection was performed with the implementation of a genetic algorithm (GA) and the original number of variables (points in which the MEP was computed) have been reduced by more than 70%. In order to assess the influence of non‐covalent interactions of inhibitors with protein environment a second model based on molecular descriptors (MD) for the isolated inhibitors was developed as well and the predictive ability of this approach was compared with the former. All optimized models were validated with compounds from the external validation set. A significantly improved predictive ability in comparison with our previous work was achieved with an RMS error of 0.83 and 0.34 log units for prediction of binding affinity pKi for thrombin and trypsin, respectively, in the external validation compound set. Copyright © 2007 John Wiley & Sons, Ltd.
Precise Synthesis of Poly(macromonomer)s Containing Sugars by Repetitive ROMP and Their Attachments to Poly(ethylene glycol): Synthesis, TEM Analysis and Their Properties as Amphiphilic Block Fragments
Authors: Murphy James J. , Furusho Hirotoshi , Paton R. Michael , Nomura Kotohiro
Published: July 2007

Various poly(macromonomer)s (PMMs) have been prepared by a repeating ring opening metathesis polymerization (ROMP) technique using the well‐defined molybdenum initiators of the type, [Mo(CHCMe2Ph)(NAr)(OR)2] with OR=OCMe3, OCMeC(CF3)2; Ar=2,6‐iPr2C6H3, 2,6‐Me2C6H3. The synthetic strategy is based on the polymerization of norbornene and its derivatives affording di‐ and triblock side chains bearing sugars (mannose, galactose, glucose etc.), linked via O‐ (ester), and glycosidase resistant C‐ (isoxazoline) glycosides. The efficient placement of norbornene units on the side chain termini and their conversion into PMMs, facilitated by the Mo alkylidenes, proceeded in a living manner with the quantitative initiation. The methodology was applied to prepare poly(macromonomer)‐graft‐PEG [PEG: poly(ethylene glycol)], by the attachment of a pseudo phenol terminus on the PMM main chain to PEG‐Ms2 [MsO(CH2CH2O)nMs, Ms=MeSO2] using a “grafting to” approach. Removal of the acetal protecting groups from the sugar coating of a variety of supramolecular structures including PMMs, linear amphiphilic block copolymers (ABC) and a PMM‐graft‐PEGby using trifluroacetic acid/water (9:1), and suspension in water, prompted the spontaneous formation of spherical architectures by self‐assembly of the amphiphilic PMMs as observed by transmission electron microscopy (TEM). The ability to uptake the hydrophobic dye (Nile Red) into the micellar cores of a variety of amphiphilic polymeric fragments is a significant step towards the production of sugar‐coated nanospheres for cell‐targeting biomimetic applications.
Refining basal insulin therapy: what have we learned in the age of analogues?
Authors: DeVries J. H. , Nattrass M. , Pieber T. R.
Published: July 2007

Background

The basal insulin analogues glargine and detemir have been subject to a series of trials comparing their clinical profiles to the conventional preparation, neutral protamine Hagedorn (NPH). Careful review of these trials provides opportunities to learn clinically useful lessons about these insulins.

Methods

MedLine‐indexed trials comparing glargine or detemir to NPH were scrutinized for control, tolerability and dose data. Separate considerations were made for types 1 and 2 diabetes, and for basal–bolus and basal plus oral glucose‐lowering drugs (OGLD) therapy. Attention was paid to dosing schedules and 24‐h glycaemic profiles.

Results

Collectively, the trials demonstrated an improved balance between glycaemic control and tolerability for both analogues compared to NPH, regardless of regimen and diabetes type. Neither once‐daily glargine nor detemir reliably provides 24‐h basal insulin replacement in all patients with type 1 diabetes; a waning of effect frequently obliges twice‐daily administration. When added to OGLDs in type 2 diabetes, goal‐titrated once‐daily basal insulin generally lowered HbA1c by ∼1.5%, whereas twice‐daily administration tended to increase insulin dose disproportionately to improvement in control. Hence, adding bolus insulin may be a preferable intensification method to dividing the basal dose. Varying injection time or dividing the basal insulin dose predictably affects the pattern of hypoglycaemia and bolus dose requirements. Morning administration tends to require higher dosing than evening administration.

Conclusions

Scrutiny of trials involving glargine and detemir has increased our understanding of how best to dose basal insulins. An individualized approach is still necessary however, and several questions remain that require further research. Copyright © 2007 John Wiley & Sons, Ltd.
Palladium(II) and Nickel(II) Complexes Bearing N,N,O‐Chelate Ligands: Syntheses, Characterization and Catalysis in Heck and Kumada Coupling Reactions
Authors: Wang Zhong‐Xia , Chai Zuo‐Yun
Published: July 2007

Two new anionic ligands, namely [2‐{OC(Ph)2CH2}‐6‐(3,5‐Me2C3HN2)C5H3N]– (L1–) and [2‐{OC(Ph)=CH}‐6‐(3,5‐Me2C3HN2)C5H3N]– (L2–), and their palladium and nickel complexes, were synthesized and characterized. 6‐(3,5‐Dimethyl‐1H‐pyrazol‐1‐yl)‐2‐methylpyridine was lithiated with nBuLi and the lithiated product treated with benzophenone to give Li(L1) (2), whereas treatment of 2‐[6‐(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)pyridin‐2‐yl]‐1‐phenylethanone with NaH afforded Na(L2) (6). The palladium and nickel complexes [(L1)PdCl] (3), [(L1)NiAr] [Ar = o‐MeC6H4 (4a), 1‐C10H7 (4b)], [(L2)PdCl] (7) and [(L2)NiAr] [Ar = o‐MeC6H4 (8a), 1‐C10H7 (8b)] were obtained by ligand‐transfer reactions between Li(L1) or Na(L2) and [PdCl2(PhCN)2] or [(Ph3P)2Ni(Ar)Cl] (Ar = o‐MeC6H4 and 1‐C10H7, respectively). These complexes are diamagnetic and were characterized by NMR spectroscopy and elemental analyses. The structures of complexes 4b and 8a were determined by single‐crystal X‐ray diffraction techniques. The catalytic activity of the nickel and palladium complexes in the Heck and Kumada cross‐coupling reactions were investigated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
The Tuning Effect of 2‐Amino‐4,6‐dipyridylpyrimidine Isomers on the Structural Dimensionalities and Motifs of Copper(I) Cyanide Complexes
Authors: Chi Ying‐Nan , Cui Feng‐Yun , Xu Yan‐Qing , Hu Chang‐Wen
Published: July 2007

Four novel copper(I) cyanide complexes of three isomeric oligopyridine ligands, namely 2‐amino‐4,6‐bis(2‐pyridyl)pyrimidine (L1), 2‐amino‐4‐(2‐pyridyl)‐6‐(4‐pyridyl)pyrimidine (L2), 2‐amino‐4‐(2‐pyridyl)‐6‐(3‐pyridyl)pyrimidine (L3) have been hydrothermally synthesized. These complexes have one‐ and two‐dimensional structures, as determined by single‐crystal X‐ray diffraction. The structural dimensionalities and motifs of complexes 1–4 are directed by the coordination modes of the ligands. Thus, L1 acts as a bis‐chelating ligand in complex 1 to join the adjacent 1D {CuCN}n chains into a two‐dimensional corrugated layer. Complexes 2 and 4 both consist of one‐dimensional zigzag chains where the ligands (L2 for complex 2 and L3 for complex 4) occupy the terminal positions and N···NH2 hydrogen bonds play an important role in the assembly of the supramolecular network. Complex 3 (another product isolated from the L3‐Cu‐CN reaction system) is a two‐dimensional network in which L3 acts as a bridging ligand and the cyanide groups exhibit both μ2 and μ3 linking modes. Further investigation shows that the thermal stability of complexes 1–4 is in the order 1 > 3 > 2 > 4. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Displacement of Neutral Nitrogen Donors by Chloride in AuCl3(am) (am = Pyridines and Amines): Kinetics and DFT Calculations Show the Effects of Basicity and π‐Acceptor Ability
Authors: Pitteri Bruno , Bortoluzzi Marco
Published: July 2007

The kinetics of the process AuCl3(am) + Cl– → AuCl4– + am (am = sp2 N‐donor isosteric pyridines with different π systems and sp3 amines; they cover a wide range of basicity) have been studied in methanol at 25 °C. The reactions obey the usual two‐term rate law observed in substitutions on square‐planar complexes. The second‐order rate constants, k2, are very sensitive to the nature of the leaving group, and plots of log k2 against the pKa of the conjugate acids are linear, with the same slope, –0.68, for both “normal” pyridines and pyridines with a more extended π system, such as 4‐cyanopyridine, isonicotinic acid, methyl isonicotinate and 4‐acetylpyridine. The reactivity of the considered N‐donors is different and follows the order sp3 N‐donors > “normal” pyridines > “π‐extended” pyridines. This result, with the support of ground‐state DFT calculations on the AuCl3(am) derivatives, is explained on the basis of an Au–N bond enforcement due to an increased π‐back‐donation contribution.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Revisit of Joule heating in CE: The contribution of surface conductance
Authors: Xuan Xiangchun
Published: July 2007

We present in this short communication the true form of Joule heating in CE which considers the contribution of surface conductance. This increased conductivity of electrolyte solution within electrical double layer has never been discussed in previous studies. The resultant intensive heat generation near the capillary wall is demonstrated using numerical simulation to produce not a locally strong temperature rise, but an additional temperature elevation in the whole solution compared to the model neglecting surface conductance. The latter effect is, however, negligible in typicall CE while it might become significant in very small channels.
Yoctomole analysis of ganglioside metabolism in PC12 cellular homogenates
Authors: Whitmore Colin D. , Olsson Ulf , Larsson E. Andreas , Hindsgaul Ole , Palcic Monica M. , Dovichi Norman J.
Published: July 2007

We report an ultrasensitive method for the analysis of glycosphingolipid catabolism. The substrate GM1 and the set of seven metabolites into which it can be degraded (GA1, GM2, GA2, GM3, LacCer, GlcCer, and Cer) were labeled with the highly fluorescent dye tetramethylrhodamine. CE with LIF detection was used to assay these compounds with 150 ± 80 yoctomole mass (1 ymol = 10−24 mol = 0.6 copies) detection limits and 5 ± 3 pM concentration detection limits. An alignment algorithm based on migration of two components was employed to correct for drift in the separation. The within‐day and between‐day precision in peak height was 20%, in peak width 15%, and in adjusted migration time 0.03%. After normalization to total sample injected, the RSD in peak height reduced to 2–6%, which approaches the limit set by molecular shot noise in the number of molecules taken for analysis. PC12 cells were incubated with the labeled GM1. Fluorescent microscopy demonstrated uptake by the cells. CE was used to separate a cellular homogenate prepared from these cells. A set of peaks was observed, which were tentatively identified based on comigration with the standards. Roughly 120 pL of homogenate was injected, which contained a total of 150 zmol of labeled substrate and products. Metabolite that preserves the fluorescent label can be detected at the yoctomole level, which should allow characterization of this metabolic pathway in single cells.
Studies on the interactions between lactam analogs and the N‐terminal extracellular tail of CC chemokine receptor 4 by CZE
Authors: Sun Zhe , Ling Xiaomei , Sun Wei , Xiao Junhai , Yin Caihua , Wang Ying
Published: July 2007

CC chemokine receptor 4 (CCR4) is a kind of G‐protein‐coupled receptors with a characteristic seven‐transmembrane structure and selectively expressed on Th2‐type CD4+ T‐cells, which play a pivotal role in allergic inflammation. In this study, the interactions between 2‐(2‐(2,4‐dichloro‐phenyl)‐4‐{[(2‐methyl‐3‐chloro‐phenyl)‐1‐ylmethyl]‐carbamoyl}‐methyl)‐5‐oxo‐pyrrole‐1‐yl)‐N‐(3‐piperidinyl‐propyl)‐acetamide (compound A), a known CCR4 antagonist, and ML40 were studied by CZE for the first time. Both qualitative and quantitative characterizations of the drug–peptide binding were determined. The binding constant of the interaction between the trans‐diastereomer of compound A and ML40, calculated from the Scatchard plot by regression, was (1.06 ± 0.11)×105/M. Also, it was confirmed that the trans‐diastereomer was more potent affinity with CCR4 than its cis‐counterpart. The experimental results show that this reported method by CZE for the determination of the compound A and ML40 interactions is powerful, sensitive, and fast, requires less amounts of reagents, and further, it can be employed as one of the reliable screening methods to a series of lactam analogs in the drug discovery for allergic inflammation diseases.
Mild cognitive impairment: a risk indicator of later dementia, or a preclinical phase of the disease?
Authors: Guarch J. , Marcos T. , Salamero M. , Gastó C. , Blesa R.
Published: July 2007

Objectives

The proposals for classifying the transitional range between normal, ageing‐associated cognitive dysfunctions and those suggestive of evolution towards dementia do not clarify whether the profiles are risk indicators of later cognitive impairment or represent preclinical phases of dementia.

Methods

Retrospective study of the baseline neuropsychological performance of ten subjects with subjective complaints of memory loss which evolved to dementia within 2 years and who meet clinical and neurological diagnosis for Probable Alzheimer's Disease (Progression group). They were compared with 34 normal subjects (Normative group), 33 patients with subjective complaints of memory who in 2 year did not evolve towards dementia and presented a stable profile (Stable group), and 47 Alzheimer's patients (Alzheimer group). A broad neuropsychological battery was administered to assess a range of cognitive functions.

Results

The Progression group presented a globally poor baseline neuropsychological performance, except in Working Memory, with clear deficits in Episodic Memory and Visual Memory. In the logistic regression analysis, Delayed Verbal Memory was significant as prognostic value for 80 · 5% of cases.

Conclusion

Deficit on Episodic and Visual Memory at least 1.5 SD below T = 50 are preclinical manifestations of dementia in subjects with complain of memory loss. The use of broad neuropsychological batteries and the quantitative assessment of deficits is essential to identify and predict the risk of dementia. Copyright © 2007 John Wiley & Sons, Ltd.