bluuebunny/crossref_metadata_2025 huggingface dataset:
Synaptic scaffolding molecule (S‐SCAM) membrane‐associated guanylate kinase with inverted organization (MAGI)‐2 is associated with cell adhesion molecules at inhibitory synapses in rat hippocampal neurons
Authors: Sumita Kazutaka , Sato Yuji , Iida Junko , Kawata Akira , Hamano Mamiko , Hirabayashi Susumu , Ohno Kikuo , Peles Elior , Hata Yutaka
Published: October 2006

Synaptic scaffolding molecule (S‐SCAM) is a synaptic protein, which harbors five or six PSD‐95/Discs large/ZO‐1 (PDZ), a guanylate kinase and two WW domains. It interacts with NMDA receptor subunits, neuroligin and β‐catenin, and is involved in the accumulation of neuroligin at excitatory synapses. In this study, we have demonstrated S‐SCAM is localized at inhibitory synapses in rat primary cultured hippocampal neurons. We have identified β‐dystroglycan (β‐DG) as a binding partner for S‐SCAM at inhibitory synapses. WW domains of S‐SCAM bind to three sequences of β‐DG. We have also revealed that S‐SCAM can interact with neuroligin 2, which is known to be exclusively localized at inhibitory synapses. The WW domains and the second PDZ domain of S‐SCAM are involved in the interaction with neuroligin 2. β‐DG, neuroligin 2 and S‐SCAM form a tripartite complex in vitro. Neuroligin 2 is detected in the immunoprecipitates by anti‐β‐DG antibody from rat brain. S‐SCAM, β‐DG and neuroligin 2 are partially co‐localized in rat hippocampal neurons. These data suggest that S‐SCAM is associated with β‐DG and neuroligin 2 at inhibitory synapses, and functions as a linker between the dystrophin glycoprotein complex and the neurexin–neuroligin complex.
Development of microsatellite markers in a clonal perennial herb, Convallaria keiskei
Authors: ARAKI K. , LIAN C. L. , SHIMATANI K. , OHARA M.
Published: October 2006

We developed eight polymorphic microsatellite simple sequence repeat (SSR) loci from genomic DNA of a clonal perennial herb, Convallaria keiskei, using a dual‐suppression‐polymerase chain reaction (PCR) technique and an improved technique. These markers with four to 10 alleles per locus identified 29 genotypes in 82 samples collected from a population in Hokkaido, Japan. The observed and expected heterozygosities ranged from 0.241 to 0.862 and from 0.639 to 0.825, respectively. These SSR markers will be available to identify genets and evaluate genetic diversity of C. keiskei.
How to deal with multiple endpoints in clinical trials
Authors: Neuhäuser Markus
Published: October 2006

Multiple endpoints are common in clinical trials. This article discusses statistical methods that can be applied to control the rate of false positive conclusions at an acceptable level. The considered methods include the Bonferroni adjustment and related methods, the intersection‐union test, ordered hypotheses and gatekeeper procedures, composite endpoints and global assessment measures, closed testing procedures, and combinations of different approaches.
Ultrastructural clues for the potent therapeutic effect of melatonin on aging skin in pinealectomized rats
Authors: Eşrefoğlu Mukaddes , Gül Mehmet , Seyhan Muammer , Parlakpınar Hakan
Published: October 2006

Recently we have reported a significant reduction in the thickness of epidermis and epidermis + dermis in the back, abdominal and thoracic skin of the long‐term pinealectomized rats and the potent therapeutic effect of melatonin on the pinealectomy‐induced morphometric changes. The present study was aimed to determine the fine structure of the abdominal and thoracic skin in pinealectomized rats and the effect of melatonin on skin ultrastructure. Rats were pinealectomized or sham operated (control) for 6 months. Half of the pinealectomized rats were treated with 4 mg/kg melatonin during the last month of the experiment. Pinealectomy resulted in prominent ultrastructural changes in the skin. Epidermal atrophy, disorganization and cytological atypia were obvious. Tonofilament distribution was not uniform, and intercellular space was narrow. Nuclear irregularity and heterochromatin condensation were detected. Many mitochondria were irregular and edematous with increased translucence of the matrix, either partial or total destruction of crests and frequently the presence of vacuoles, myelin figures and dense bodies. Microprojections of basal cells into the dermis were observed. The dermis was thin, and collagenous fibers were loosely arranged. The epidermis in melatonin administered pinealectomized rats was obviously thicker than that of pinealectomized rats. The cells of each layers had characteristic morphological and ultrastructural features. Nuclear irregularity and heterochromatin condensation were not seen. Mitochondria were generally normal in ultrastructural appearance but rarely vacuoles and myelin figures were observed. The dermis was thick, and collagenous fibers were closely packaged. This paper provides an additional ultrastructural evidence that the damage to mitochondria is the major contributory factor to skin aging and that melatonin has potent therapeutic effects in reducing age‐related changes via protecting fine structure of the skin.
Self‐expression and the negotiation of identity in a foreign language1
Authors: Riley Philip
Published: October 2006

This article sets out an approach to the architecture, perception and negotiation of personal identity in relation to a number of issues in the fields of social interaction, communication and language teaching. In part one, particular attention is paid to the concept of ethos, a collaborative construct resulting from mutually influencing communcative behaviours: a speaker's projected self‐image as assessed and perceived by hearers. In part two a variety of communicative practices involved in the negotiation of identity are exemplified and analysed, including membershipping, anecdote and pragmatic failure, and their relevance to applied linguistics is discussed.
Tawny Owls Strix aluco with reliable food supply produce male‐biased broods
Authors: DESFOR KASI B. , BOOMSMA JACOBUS J. , SUNDE PETER
Published: October 2006

Tawny Owls Strix aluco have been reported to skew the sex ratio of their offspring towards males when facing food shortage during the nestling period (and vice versa), because female fitness is more compromised by food shortage during development than male fitness. To test the generality of these results we used a DNA marker technique to determine the sex ratio in broods of Tawny Owls in Danish deciduous woodland during two years of ample food supply (rodent population outbreak) and two years of poor food supply. Of 268 nestlings, 59% were males (95% CI: 53–65%). This proportion was higher than previously reported for the species (49% in Northumberland, UK, and 52% in Hungary), but consistent with Fisherian sex allocation, which predicts a male bias of c. 57% based on inferred differences in energy requirements of male and female chicks. Contrary to previous results, brood sex ratios were not correlated with the resource abundance during the breeding seasons, despite considerable variation in breeding frequency, brood size or hatching date across years. Brood sex ratios were unaffected by brood reduction prior to DNA sampling, and nestling mortality rates after DNA sampling were not related to gender. The inconsistency between the sex ratio allocation patterns in our study and previous investigations suggests that adaptive sex allocation strategies differ across populations. These differences may relate to reproductive constraints in our population, where reproductive decisions seem primarily to concern whether to lay eggs at all, rather than adjust the sex ratio to differences in starvation risk of nestlings.
Crystallographic Relationships of the {111} Growth Twins in Tetragonal Barium Titanate Determined by Electron‐Backscatter Diffraction
Authors: Cheng Shun‐Yu , Ho New‐Jin , Lu Hong‐Yang
Published: October 2006

The {111} growth twins are often found in sintered BaTiO3 ceramics with non‐stoichiometric TiO2‐excess compositions. The twin crystallographic orientation relationships studied in the past using transmission electron microscopy combined with the selected area diffraction patterns have now been determined directly from polished and etched samples using electron‐backscatter diffraction equipped with a scanning electron microscope. This technique is an effective way of determining orientation relationships for growth twins as well as transformation twins. The crystal poles of the Kikuchi patterns were determined automatically using a commercial electron‐backscatter diffraction system, INCACrystal™, supplied by Oxford Instruments. The automatic indexing, however, requires modification in order to ensure that the twin plane is consistent with previous findings by transmission electron microscopy and is of an identical index. The crystallographic relationships thus derived are in complete accord with those reported before.
Fabrication of Hydroxyapatite–Zirconia Composites for Orthopedic Applications
Authors: Zhang Jingxian , Iwasa Mikio , Kotobuki Noriko , Tanaka Toshi , Hirose Motohiro , Ohgushi Hajime , Jiang Dongliang
Published: October 2006

Dense hydroxyapatite–zirconia (HAp–ZrO2) composites are expected to have desired mechanical and biological properties for orthopedic applications. However, due to some processing problems, to date, this material can only be prepared by special techniques. In this paper, we report for the first time a facile route to prepare HAp–ZrO2 composites. Initially, HAp and ZrO2 powders were dispersed in aqueous media with polyacrylic acid and glutamic acid as the dispersants. The slurries exhibited a well‐stabilized state at a high solid content (>50 vol%) and therefore green samples with high density (>60%) can be obtained after slip casting. These HAp–ZrO2 green samples can be easily densified by pressureless sintering at 1450°C with 2 h holding. After sintering, only hydroxyoxyapatite Ca10(PO4)6Ox (OH)2(1−x) (HOA), ZrO2, and trace amounts of α‐tricalcium phosphate phases were detected. No obvious reactions between HAp and ZrO2 phase were observed. The HAp–ZrO2 samples showed excellent mechanical and biological properties. For 40 vol% HAp–60 vol% ZrO2 samples sintered at 1450°C, the flexural strength and toughness were 220 MPa and 4.37 MPa·m1/2, respectively. In addition, we observed the attachment, spreading, and proliferation of mesenchymal stem cells on the HAp–ZrO2 samples' surface. The results showed that the proposed colloidal processing and pressureless sintering process is feasible for preparing HAp–ZrO2 composites with high mechanical properties and promising bioactivity for orthopedic applications.
Low Temperature Sintering of Zn3Nb2O8 Ceramics from Fine Powders
Authors: Shlyakhtin Oleg A. , Oh Young‐Jei
Published: October 2006

A possibility to produce microwave (MW) dielectric materials by liquid‐phase sintering of fine particles was investigated. Zn3Nb2O8 powders with a grain size 50–300 nm were obtained by the thermal decomposition of freeze‐dried Zn–Nb hydroxides or frozen oxalate solutions. The crystallization of Zn3Nb2O8 from amorphous decomposition products was often accompanied by the simultaneous formation of ZnNb2O6. Maximum sintering activity was observed for single‐phase crystalline Zn3Nb2O8 powders obtained at the lowest temperature. The sintering of as‐obtained powders with CuO–V2O5 sintering aids results in producing MW dielectric ceramics with a density 93%–97% of the theoretical, and a Q×f product up to 36 000 GHz at sintering temperature (Ts)≥680°C. The high level of MW dielectric properties of ceramics was ensured by intensive grain growth during the densification and the thermal processing of ceramics.
Crystalline Transition from H2Ti3O7 Nanotubes to Anatase Nanocrystallines Under Low‐Temperature Hydrothermal Conditions
Authors: Wang Ning , Lin Hong , Li Jianbao , Zhang Luozheng , Lin Chunfu , Li Xin
Published: October 2006

In this paper, we first reported the crystalline transition from H2Ti3O7 nanotubes to anatase TiO2 nanocrystallines under low‐temperature hydrothermal conditions (∼140°C). A newly proposed mechanism for the crystalline transition from H2Ti3O7 nanotubes to anatase TiO2 nanocrystallines under low‐temperature conditions is discussed in detail, which is supported by X‐ray diffraction, high‐resolution transmission electronic microscope, selected‐area electron diffraction, and crystal structure models.
Phase‐Transformation‐Induced Anti‐Phase Boundary Domains in Barium Cerate Perovskite
Authors: Cheng Shun‐Yu , Ho New‐Jin , Lu Hong‐Yang
Published: October 2006

Anti‐phase boundary (APB) domains resulting from the orthorhombic (o1, Ibmm (No. 74)) to orthorhombic (o2, Pbnm (No. 62)) phase transformation at ∼290°C in pressureless‐sintered barium cerate (BaCeO3) ceramics have been investigated by transmission electron microscopy and large‐angle convergent beam electron diffraction (LACBED). APB exhibiting symmetric π‐fringe patterns in both bright‐field and dark‐field images, lying in {011) with the fault vector R=1/2〈111〉, were determined adopting the invisibility criteria of 2πg·R=0 or 2nπ. The curved boundaries due to symmetry change can be related to the low symmetry phase by a pure translation upon phase transition. The displacement vector, R, relating the domains is the translational symmetry element from the origin to the lattice point that was lost upon transition. The formation of such domains induced by the o1→o2 phase transition is discussed in terms of change in the Bravais lattice and loss of lattice point upon the transition. The identification has also confirmed the existence of a higher symmetry orthorhombic o1 phase along the transition sequence of R3c→Ibmm→Pbnm. The increased spatial frequency of APB domains is attributed to A‐site ordering due to vacancies created by BaO loss and/or disordering of the B‐site substitutional defects generated extrinsically when doped with either a Y3+‐acceptor or a Nb5+‐donor.
Piezoelectric Film Response Studied with Finite Element Method
Authors: Sato Harumichi , Akedo Jun
Published: October 2006

It is difficult to measure accurately the piezoelectric constant, d33, of either a thin or thick film on a substrate, because piezoelectric deformation of a film is small. The measured value of d33 for the film is often smaller than the value of d33 for the bulk material. This is partly because of bending of the sample and side clamping of the film. However, we used finite element method (FEM) to simulate common experimental conditions and show that inner local deformation was more significant than either bending or side clamping. Using our FEM results, we propose optimum conditions for making unbiased d33 measurements.
Plate‐Like Na0.5Bi0.5TiO3 Template Synthesized by a Topochemical Method
Authors: Zeng J. T. , Kwok K. W. , Tam W. K. , Tian H. Y. , Jiang X. P. , Chan H. L. W.
Published: October 2006

Large plate‐like Na0.5Bi0.5TiO3 (NBT) templates have been successfully synthesized from bismuth layer‐structured ferroelectric Na0.5Bi4.5Ti4O15 (NBIT) particles by the topochemical method. Because of the highly anisotropic structure, plate‐like NBIT particles were first synthesized by the molten‐salt process. After the topochemical reaction with the complementary reactants (Na2CO3, and TiO2) in NaCl flux, the layer‐structured NBIT particles were transformed to the perovskite NBT templates. The resulting NBT templates are large and of plate‐like shape. Our results also reveal that they are more effective in inducing grain orientation in the BNKT‐BT ceramics as compared with BIT templates. For a BNKT‐BT ceramic textured with 20 wt% of NBT templates, it exhibits a very high degree of grain orientation and gives a large Lotgering factor of 0.89.
Preparation of Ceramic Well Plates for Combinatorial Methods Using the Morphogenic Effects of Droplet Drying
Authors: Zhang Yong , Chen Lifeng , Yang Shoufeng , Evans Julian R. G.
Published: October 2006

When droplets of a ceramic suspension dry on a non‐wetting substrate, powder migrates to the periphery and builds there a wall of powder. This intriguing phenomenon, which is a nuisance in some processes, can be used to make arrays of ceramic wells on a ceramic substrate. These wells can, after sintering, be used to hold ceramic samples made from powder by controlled mixing of ceramic inks or could be made from ceramics that act as heterogeneous catalysts and used to hold reactants. The well plates can even be made from electrically conducting ceramics so that electrical property measurements can be made with a ground electrode.
Effects of Bi2O3 and Na2O on the Thermal and Dielectric Properties of Zinc Borosilicate Glass for Plasma Display Panels
Authors: An Jae‐sul , Park Jong‐Sung , Kim Jeong‐Ryeol , Hong Kug Sun , Shin Hyunho
Published: October 2006

An approach to select appropriate network modifiers to tailor the thermal and dielectric properties of zinc borosilicate (ZBS) glass has been explored to apply the glass composition to a dielectric layer of plasma display panels. Based on ionic field strength of the modifiers and the ionic polarizability of the corresponding crystalline form, Bi2O3 and Na2O modifiers have been selected to modify the thermal and dielectric properties of the glass toward the required properties for the application (440<Tg<460°C, 7.5 × 10−6<CTE<8.5 × 10−6/K, and 10<K<15). Bi2O3 addition to ZBS could meet all the required properties simultaneously at a given addition range (8.5–14 mol%), while the addition of Na2O could not meet all the properties at a single composition range.
Effect of Cation Substitution and Non‐Stoichiometry on the Microwave Dielectric Properties of Sr(B′0.5Ta0.5)O3 [B′=Lanthanides] Perovskites
Authors: Khalam L. Abdul , Sebastian M. T.
Published: October 2006

The Sr(B′0.5Ta0.5)O3 ceramics where B′=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Er, and Yb have been prepared by the conventional solid‐state ceramic route and their microwave dielectric properties have been investigated. The structure and microstructure of the ceramics have been characterized by X‐ray diffraction and scanning electron microscope techniques. The relative permittiviy (ɛr) varies linearly with B′‐site ionic radii, except for La, and the temperature coefficient of resonant frequency (τf) varies linearly with the tolerance factor. The Sr(B′0.5Ta0.5)O3 ceramics have ɛr in the range 25.9–32, Qu×f=4500–54 300 GHz, and τf=−79 to −42 ppm/°C. A slight deviation from stoichiometry affects the dielectric properties of these double perovskites. Partial substitution of Ba for Sr could tune the dielectric properties. Addition of rutile (TiO2) lowered the sintering temperature and improved the dielectric properties of Sr(B′0.5Ta0.5)O3 ceramics.
Thermodynamic Analysis of ZrB2–SiC Oxidation: Formation of a SiC‐Depleted Region
Authors: Fahrenholtz William G.
Published: October 2006

A thermodynamic model was developed to explain the formation of a SiC‐depleted layer during ZrB2–SiC oxidation in air at 1500°C. The proposed model suggests that a structure consisting of (1) a silica‐rich layer, (2) a Zr‐rich oxidized layer, and (3) a SiC‐depleted zirconium diboride layer is thermodynamically stable. The SiC‐depleted layer developed due to active oxidation of SiC. The oxygen partial pressure in the SiC‐depleted layer was calculated to lie between 4.0 × 10−14 and 1.8 × 10−11 Pa. Even though SiC underwent active oxidation, the overall process was consistent with passive oxidation and the formation of a protective surface layer.
Formation of 0.65 Pb(Mg1/3Nb2/3)O3–0.35 PbTiO3 Using a High‐Energy Milling Process
Authors: Kuscer Danjela , Holc Janez , Kosec Marija
Published: October 2006

We have investigated the synthesis of lead‐magnesium‐niobate–lead‐titanate perovskite powder using high‐energy milling of the constituent oxides. The compositions of the crystalline and amorphous phases as a function of milling time were determined with X‐ray powder diffraction using a Rietveld refinement. The perovskite can be formed by two reaction routes. In the initial stage of milling, it is formed directly from the highly activated nano‐sized constituent oxides, and after a certain milling time it is mainly formed from a pyrochlore phase. The obtained as‐milled powder consists of crystalline perovskite and an amorphous phase that crystallizes into the perovskite after heating at 800°C.
A comparison of root surface instrumentation using two piezoelectric ultrasonic scalers and a hand scaler in vivo
Authors: Kawashima H. , Sato S. , Kishida M. , Ito K.
Published: October 2006

Background and Objective:  This study compared the effectiveness of two piezoelectric ultrasonic scalers and a hand scaler for subgingival scaling and root planing in vivo.

Material and Methods:  Fifteen patients with advanced periodontal disease and with teeth scheduled for extraction were selected for this study. Three experimental groups of 10 teeth each were treated with one of two piezoelectric ultrasonic scalers [Vector™ scaler and Enac® scaler] or with a hand scaler. Instrumentation was continued until the root surface felt hard and smooth to an explorer tip. The root surface characteristics after instrumentation were examined using scanning electron microscopy, and the amount of remaining calculus, roughness and loss of tooth substance were estimated using the remaining calculus index and roughness loss of tooth substance index.

Results:  The remaining calculus index did not differ significantly among the three groups. The roughness loss of tooth substance index was significantly lower for the Vector™ scaler and Enac® scaler groups than for the hand scaler group and also differed significantly between the Vector™ scaler and Enac® scaler groups.

Conclusion:  This study suggests that the Vector™ scaler produces a smooth root surface with minimal loss of tooth substance. It is a reasonable choice for gentle periodontal maintenance treatment.
Physico‐chemical properties of molten dimer ascorbate oxidase
Authors: Nicolai Eleonora , Di Venere Almerinda , Rosato Nicola , Rossi Antonello , Finazzi Agro' Alessandro , Mei Giampiero
Published: October 2006

The possible presence of dimeric unfolding intermediates might offer a clue to understanding the relationship between tertiary and quaternary structure formation in dimers. Ascorbate oxidase is a large dimeric enzyme that displays such an intermediate along its unfolding pathway. In this study the combined effect of high pressure and denaturing agents gave new insight on this intermediate and on the mechanism of its formation. The transition from native dimer to the dimeric intermediate is characterized by the release of copper ions forming the tri‐nuclear copper center located at the interface between domain 2 and 3 of each subunit. This transition, which is pH‐dependent, is accompanied by a decrease in volume, probably associated to electrostriction due to the loosening of intra‐subunit electrostatic interactions. The dimeric species is present even at 3 × 108 Pa, providing evidence that mechanically or chemically induced unfolding lead to a similar intermediate state. Instead, dissociation occurs with an extremely large and negative volume change (ΔV ≈ −200 mL·mol−1) by pressurization in the presence of moderate amounts of denaturant. This volume change can be ascribed to the elimination of voids at the subunit interface. Furthermore, the combination of guanidine and high pressure uncovers the presence of a marginally stable (ΔG ≈ 2 kcal·mol−1) monomeric species (which was not observed in previous equilibrium unfolding measurements) that might be populated in the early folding steps of ascorbate oxidase. These findings provide new aspects of the protein folding pathway, further supporting the important role of quaternary interactions in the folding strategy of large dimeric enzymes.
Where are the carers in healthcare law and ethics?
Authors: Herring Jonathan
Published: October 2006

The work of carers is too often unvalued and unrecognised. This paper seeks to demonstrate some of the ways in which law and traditional medical ethics overlook the interests of carers and the importance of their work. It argues that this is, in part, due to the individualistic ethic that has come to dominate legal and ethical discourse about medicine. It recommends an approach based on an ethic of care that seeks to promote and protect just relationships of care, rather than an individualised model of rights.
Differences in litter mass change mite assemblage structure on a deciduous forest floor
Authors: H. R. Osler Graham , Korycinska Anastasia , Cole Lisa
Published: October 2006

Few mechanisms that determine the assemblage structure of mites have been identified. Whilst the relative abundance of soil fauna is known to change with humus form, the degree to which the quantity of litter inputs play a part in these changes has not been investigated. We tested the response of oribatid and mesostigmatid mites in litter and soil layers to increasing levels of birchBetula pubescenslitter to test whether litter mass could affect the mite assemblage. Six litter treatments (1, 2, 4, 8 and 12×natural litter mass and complete litter removal) were established in November 2004 and the soil and litter communities sampled in October 2005. Species composition of oribatids was distinct for the soil and litter. There was no apparent effect of increasing litter mass on the soil mite assemblage. In the litter layer, the number of oribatids g−1of litter showed a strong negative relationship with increasing litter mass whilst the number of mesostigmatids g−1of litter was unresponsive to litter mass. Hence, the relative abundance of these two groups altered with increasing litter mass. The response of the oribatid groups Oppiidae and Poronota followed this negative relationship with litter mass but Phthiracaridae appeared less affected. Consequently, there was a subtle shift in the relative abundance of these groups with increasing litter mass. Our results demonstrate that oribatids as a whole and within groups respond in a predictable manner to increases in litter mass whilst mesostigmatids are unresponsive. Whilst there are undoubtedly biological and physical aspects that vary with litter mass, litter mass itself, is able to explain some patterns in the assemblage of oribatid mites.
Spatial structure in the diet of imperial eaglesAquila heliacain Kazakhstan
Authors: Katzner Todd E. , Bragin Evgeny A. , Knick Steven T. , Smith Andrew T.
Published: October 2006

We evaluated the relationship between spatial variability in prey and food habits of eastern imperial eaglesAquila heliacaat a 90,000 ha national nature reserve in north‐central Kazakhstan. Eagle diet varied greatly within the population and the spatial structure of eagle diet within the population varied according to the scale of measurement. Patterns in dietary response were inconsistent with expectations if either ontogenetic imprinting or competition determined diet choice, but they met expectations if functional response determined diet. Eagles nesting near a high‐density prey resource used that resource almost exclusively. In contrast, in locations with no single high‐density prey species, eagles' diet was more diverse. Our results demonstrate that spatial structuring of diet of vertebrate predators can provide important insight into the mechanisms that drive dietary decisions.
Extra‐pair fertilization and effective population size in the song sparrowMelospiza melodia
Authors: D. O'Connor Kathleen , B. Marr Amy , Arcese Peter , F. Keller Lukas , J. Jeffery Kathryn , W. Bruford Michael
Published: October 2006

The concept of effective population size (Ne) is used widely by conservation and evolutionary biologists as an indicator of the genetic state of populations, but its precision and relation to the census population size is often uncertain. Extra‐pair fertilizations have the potential to bias estimates of Newhen they affect the number of breeders or their estimated reproductive success tallied from social pedigrees. We tested if the occurrence of extra‐pair fertilizations influenced estimates of Nein a resident population of song sparrowsMelospiza melodiausing four years of detailed behavioural and genetic data. Estimates of Nebased on social and genetic data were nearly identical and averaged c. 65% of the census population size over four years, despite that 28% of 471 independent young were sired outside of social pairs. Variance in male reproductive success also did not differ between estimates based on social and genetic data, indicating that extra‐pair mating had little effect on the distribution of reproductive success in our study population. Our results show that the genetic assignment will not always be necessary to estimate Neprecisely.
More colourful eggs induce a higher relative paternal investment in the pied flycatcher Ficedula hypoleuca: a cross‐fostering experiment
Authors: Moreno Juan , Morales Judith , Lobato Elisa , Merino Santiago , Tomás Gustavo , Martínez‐de la Puente Josué
Published: October 2006

The signalling hypothesis of eggshell colouration in birds posits that females of species with blue‐green eggs signal their phenotypic quality or the quality of their eggs to their mates through deposition of the antioxidant biliverdin as pigment. Males respond by investing more in the offspring. Through a cross‐fostering experiment where we have exchanged whole clutches between pairs of pied flycatcher Ficedula hypoleuca nests, we managed to break potential associations between female quality and clutch chromaticity. We show that males respond to incubated clutches with more variable and higher peak values in blue‐green chroma through a higher proportional investment in nestling provisioning on day 4 of the nestling period, when males invest more heavily than females in provisioning. More variable clutches show higher peak chroma values. We also show that egg colour during the two‐week incubation period has a significant effect, which is not found for the colour of eggs during the laying period. Finally, the proportion of male provisioning visits affects negatively female brooding effort and nestling mortality, and thereby has positive effects on female fitness. Blue‐green chroma in the pied flycatcher functions as a signal of female or clutch quality to males which respond by adjusting their relative investment with respect to total pair effort.
DFT Study on 3-Substituted Tetrahydropyran-2-yl Radicals
Authors: Kozmon Stanislav , Tvaroška Igor
Published: October 2006

A series of tetrahydropyran-2-yl radical (1) analogs was studied using density functional theory (DFT) to model conformational behavior of glycopyranosyl radicals. Calculations of the structure and stability of the 4C1, 1C4, B2,5, O,3B, and 4H3 ring conformers for tetrahydropyran-2-yl radical (1) and for 3-fluoro- (2, 7), 3-hydroxy- (3, 8), 3-methoxy- (4, 9), 3-acetoxy- (5, 10), and 3-(benzyloxy)tetrahydropyran-2-yl (6, 11) derivatives showed that conformational behavior of the 3-substituted radicals depends on both the electronic character and orientation of the C3 substituent. The calculations show that radical 1 is slightly pyramidal and exists as an equilibrium mixture of the 4C1 and 1C4 conformers. Substituents at the C3 position force 2-11 radicals to adopt a chair conformation with the substituent in the axial orientation. Thus radicals 2-6 prefer the 1C4 conformer though there are several ring conformers in equilibrium whereas for radicals 7-11 the 4C1 conformer predominates. The calculated preferences are consistent with available ESR data. These results provide further support for the importance of quasi-homoanomeric interactions on stability of anomeric radicals.
Structural analysis of the Miniss River and related faults, western Superior Province: post-collisional displacement initiated at terrane boundaries
Authors: Bethune K M , Helmstaedt H H , McNicoll V J
Published: October 2006

Mountain building in the western part of the Archean Superior Province culminated with the formation of regional strike-slip faults. This paper reports on the kinematics and timing of several major faults at the juncture between the Uchi, English River, Winnipeg River, and western Wabigoon subprovinces. Sinistral-oblique mylonitization along the northeast-striking Miniss River fault occurred at 2681 [Formula: see text] Ma. This involved ~40 km of sinistral offset and a scissor-like motion whereby vertical displacement increased southwestward toward a restraining bend near Sioux Lookout. To the north, the Miniss River fault is intersected by the east-striking, dextral strike-slip Sydney Lake – Lake St. Joseph fault; the latter merges along strike with the Pashkokogan fault. Restoration of respective displacements indicates that the faults formed sequentially, not simultaneously in response to tectonic indentation. Dextral strike-slip motion along the Sydney Lake – Lake St. Joseph (– Pashkokogan) fault was instigated at ≤2670 Ma and drove greenschist-grade, dextral reactivation of the southwest segment of the Miniss River fault. U–Pb geochronology suggests that the latter coincides with an older terrane-boundary fault that juxtaposed ca. 2735 Ma juvenile, western Wabigoon arc complexes against ca. 3.05 Ga granitoid rocks of the Winnipeg River terrane. The Sydney Lake – Lake St. Joseph (– Pashkokogan) fault similarly demarcates a fundamental boundary between Uchian volcanoplutonic rocks and the English River accretionary prism. Strike-slip faults in this region therefore initiated at terrane boundaries and in some cases evolved so as to transect and displace these boundaries to accommodate further shortening during final stages of Archean orogenesis.
Pickle Lake revisited: New structural, geochronological and geochemical constraints on greenstone belt assembly, western Superior Province, Canada
Authors: Young M D , McNicoll V , Helmstaedt H , Skulski T , Percival J A
Published: October 2006

New field work, U–Pb ages, geochemical data, and Sm–Nd isotopic analyses have established the timing and determined the nature of volcanism, deformation, and tectonic assembly of the Pickle Lake greenstone belt in the Uchi subprovince of the western Superior Province of the Canadian Shield. The >2860 Ma Pickle Crow assemblage has been redefined to include the former Northern Pickle assemblage on the basis of stratigraphic continuity and similar volcanic geochemistry between the two units across a previously inferred fault contact. The Pickle Crow assemblage consists of tholeiitic basalt with thin, but laterally extensive, oxide-facies iron formation overlain by alkalic basalts and minor calc-alkaline andesites to dacites with primitive Nd isotopic compositions (εNd2.89 Ga = +2.1 to +2.4) suggestive of deposition in a sediment-starved oceanic basin. The ~2 km thick ~2836 Ma Kaminiskag assemblage (former Woman assemblage) consists of tholeiitic basalt interbedded with intermediate and rare felsic pyroclastic flows with primitive Nd isotopic compositions (εNd2.836 Ga = +2.4). Two samples of intermediate volcanic rocks interbedded with southeast-younging pillowed basalt, previously inferred to be part of the Pickle Crow assemblage, yielded U–Pb zircon ages of 2744 [Formula: see text] Ma and 2729 ± 3 Ma. These rocks are thus part of the younger Confederation assemblage, which consists of intercalated basalt and dacite (εNd2.74 Ga = +0.1 to +0.8) exhibiting diverse compositions probably reflecting eruption in a continental margin arc to back-arc setting. The contact between the Confederation and Kaminiskag assemblages is assumed to be a fault. The greenstone belt is intruded by late syn- to posttectonic plutons including the composite quartz dioritic to gabbroic July Falls stock with a new U–Pb zircon age of 2749 [Formula: see text] Ma, and the ~2741 to 2740 Ma trondhjemitic to granodioritic Ochig Lake pluton and Pickle Lake stock, as well as the ~2697 to 2716 Ma Hooker–Burkoski stock. The earliest recognized deformation (D1) is recorded by a local bedding-parallel foliation in the Pickle Crow assemblage. This foliation is truncated by the ~2735 Ma Albany quartz–feldspar porphyry dyke and is not recognized in the volcanic rocks of the Confederation assemblage. The early deformation event is attributed to overturning of the Pickle Crow assemblage prior to deposition of the ~2744 to 2729 Ma Confederation assemblage. Subsequent deformation and development of a regionally penetrative planar fabric (S2) postdates ~2729 Ma volcanism, pre-dates the intrusion of the ca. <2716 Ma Hooker–Burkoski stock and is host to gold mineralization.
Strike-slip juxtaposition of ca. 2.72 Ga juvenile arc and >2.98 Ga continent margin sequences and its implications for Archean terrane accretion, western Superior Province, Canada
Authors: Percival J A , McNicoll V , Bailes A H
Published: October 2006

The North Caribou terrane of the western Superior Province attained continental thickness (~35 km) by 2997 Ma. It records a subsequent 300 million years history of continental fragmentation, arc magmatism, and terrane accretion. At Lake Winnipeg the ~2978 Ma Lewis–Storey quartzite–komatiite–iron formation assemblage marks Mesoarchean breakup. Unlike the relatively continuous 2980–2735 Ma stratigraphic record of the Red Lake and Birch–Uchi greenstone belts to the east, little of this interval is recorded at Lake Winnipeg. Rather, two belts of younger, juvenile rocks are tectonically juxtaposed: the Black Island assemblage of isotopically depleted, 2723 Ma basalt, and calc-alkaline andesite; and Rice Lake greenstone belt of basalt, calc-alkaline andesite, and dacite (2731–2729 Ma). Collectively these terranes represent a short-lived island-arc–back-arc system that docked with the southwestern North Caribou margin along a northwest-trending, dextral, transpressive, D1 suture. This zone is marked by the highly deformed coarse clastic Guano Island sequence (<2728 Ma) that contains detritus of North Caribou affinity and is interpreted as a strike-slip basin deposit. Younger clastic sequences, including the Hole River (<2708 Ma), San Antonio (<2705 Ma), and English River (<2704 Ma) assemblages, occur in east–west belts that may have been deposited during the terminal collision (D2, D3) between the North Caribou terrane and continental crust of the Winnipeg River terrane to the south. Several terrane docking events within a framework of north-dipping subduction and continental arc magmatism appear necessary to explain structural and stratigraphic relationships in the 2735–2700 Ma interval.
New high-precision U–Pb ages for the Island Lake greenstone belt, northwestern Superior Province: implications for regional stratigraphy and the extent of the North Caribou terrane
Authors: Parks Jen , Lin Shoufa , Davis Don , Corkery Tim
Published: October 2006

A combined U–Pb and field mapping study of the Island Lake greenstone belt has led to the recognition of three distinct supracrustal assemblages. These assemblages record magmatic episodes at 2897, 2852, and 2744 Ma. Voluminous plutonic rocks within the belt range in age from 2894 to 2730 Ma, with a concentration at 2744 Ma. U–Pb data also show that a regional fault that transects the belt, the Savage Island shear zone, is not a terrane-bounding structure. The youngest sedimentary group in the belt, the Island Lake Group, has an unconformable relationship with older plutons. Sedimentation in this group is bracketed between 2712 and 2699 Ma. This group, and others similar to it in the northwestern Superior Province, is akin to Timiskaming-type sedimentary groups found throughout the Superior Province and in other Archean cratons. These data confirm that this belt experienced a complex geological history that spanned at least 200 million years, which is typical of greenstone belts in this area. Age correlations between the Island Lake belt and other belts in the northwest Superior Province suggest the existence of a volcanic "megasequence". This evidence, in combination with Nd isotopic data, indicates that the Oxford–Stull domain, and the Munro Lake, Island Lake, and North Caribou terranes may have been part of a much larger reworked Mesoarchean crustal block, the North Caribou superterrane. It appears that the Superior Province was assembled by accretion of such large independent crustal blocks, whose individual histories involved extended periods of autochthonous development.
Tectonic evolution of the western Superior Province from NATMAP and Lithoprobe studies
Authors: Percival J A , Sanborn-Barrie M , Skulski T , Stott G M , Helmstaedt H , White D J
Published: October 2006

Five discrete accretionary events assembled fragments of continental and oceanic crust into a coherent Superior craton by 2.60 Ga. They exhibit similar sequences of events at ~10 million year intervals: cessation of arc magmatism, early deformation, synorogenic sedimentation, sanukitoid magmatism, bulk shortening, regional metamorphism, late transpression, orogenic gold localization, emplacement of crust-derived granites, and postorogenic cooling. The Northern Superior superterrane recorded 3.7–2.75 Ga events prior to 2.72 Ga collision with the 3.0 Ga North Caribou superterrane. Following 2.98 Ga rifting, the Uchi margin of the North Caribou superterrane evolved in an upper plate setting before 2.72–2.70 Ga collision of the <3.4 Ga Winnipeg River terrane, which trapped synorogenic English River turbidites in the collision zone. The Winnipeg River terrane was reworked in 2.75–2.68 Ga magmatic and tectonic events, including the central Superior orogeny (2.71–2.70 Ga) that marks accretion of the juvenile western Wabigoon terrane. In the south, the Wawa–Abitibi terrane evolved in a mainly oceanic setting until Shebandowanian collision with the composite Superior superterrane at 2.695 Ga. Synorogenic Quetico turbidites were trapped in the collision zone. The final accretionary event involved addition of the Minnesota River Valley terrane (MRVT) from the south, and deposition and metamorphism of synorogenic turbidites of the Pontiac terrane during the ~2.68 Ga Minnesotan orogeny. Seismic reflection and refraction images indicate north-dipping structures, interpreted as a stack of discrete 10–15 km thick terranes. A slab of high-velocity material, possibly representing subcreted oceanic lithosphere, as well as Moho offsets, support a model of progressive accretion through plate-tectonic-like processes.
Reduction of clinkerisation temperature by addition of salts containing fluorine
Authors: Kacimi Larbi , Simon-Masseron Angélique , Ghomari Abdelhamid , Derriche Zoubir
Published: October 2006

The influence of some salts containing fluorine (CaF2, NaF, and KF) on the reduction of burning temperature of Portland clinker from three Algerian cement factories (units of Zahana, Beni-Saf, Chlef) has been studied in this paper. X-Ray fluorescence, optical microscope technique, and powder X-ray diffraction were then used to characterize each clinker and its raw mixture in terms of chemical composition and clinker mineralogical composition. The effects of these mineralizers on structural and morphological properties of clinker minerals and on the presence of alite were investigated by scanning electron microscopy combined with microprobe analysis. Physical and mechanical properties (density, specific area, setting time, hydration heat, expansion, and mechanical strength) of some samples were studied. The results show that the presence of the mineralizers under study induced a decrease of the burning temperature. For example, NaF improved the crystallization of clinker minerals with high alite rate. These characteristics explain the improvement of physical and strength properties of the new clinkers.Key words: clinker, alite, structure, hydraulic activity, clinkerisation temperature, mineralizer.
Carpentry workers issues and efficiencies related to construction productivity in commercial construction projects in Alberta
Authors: Hewage Kasun N , Ruwanpura Janaka Y
Published: October 2006

For decades, many researchers have reported the decline in construction productivity, but it is impossible to generalize the productivity problems due to issues such as geographical differences, weather changes, skill level differences in the labour force, and workload demand. There are currently approximately 160 000 construction workers in Alberta, and the value of ongoing and future projects in the oil and gas sector alone is over Can$200 billion. Because of the high demand and necessity for a comprehensive research study for Alberta to improve construction productivity, a 2 year study commenced with the collaboration of four eminent contractors to investigate human, management, and external issues. Under human issues, 101 construction workers in the carpentry trade were observed, interviewed, and surveyed by questionnaire. This paper discusses the research method, results, and recommendations of the productivity research specific to the human issues. These recommendations were communicated to the contractors for improving the human issues by developing and analyzing a new expectancy model considering construction workers' effort and performance and the tool times observed to mitigate the reasons for non-tool time.Key words: construction productivity, worker motivation, expectancy theory, tool time, construction workers.
Cost management for concrete batch plant using stochastic mathematical models
Authors: Zayed Tarek M , Nosair Ibrahim A
Published: October 2006

Assessing productivity, cost, and delays are essential to manage any construction operation, particularly the concrete batch plant (CBP) operation. This paper focuses on assessing the above-mentioned items for the CBP using stochastic mathematical models. It aims at (i) identifying the potential sources of delay in the CBP operation; (ii) assessing their influence on production, efficiency, time, and cost; and (iii) determining each factor share in inflating the CBP concrete unit expense. Stochastic mathematical models were designed to accomplish the aforementioned objectives. Data were collected from five CBP sites in Indiana, USA, to implement and verify the designed models. Results show that delays due to management conditions have the highest probability of occurrence (0.43), expected value of delay percent (62.54% out of total delays), and relative delay percent. The expected value of efficiency for all plants is 86.53%; however, the average total expense is US$15.56/m3 (all currency are in US$). In addition, the expected value of effective expenses (EE) is $18.03/m3, resulting in extra expenses (XE) of $2.47/m3. This research is relevant to both industry practitioners and researchers. It develops models to determine the effect of delays on concrete unit cost. They are also beneficial to the CBP management.Key words: concrete batch plant, delays, management conditions, cost models, cost management, stochastic mathematical models.
Temporal variation of clear water scour at cylindrical bridge piers
Authors: Yanmaz A Melih
Published: October 2006

Computation of temporal variation of clear water scour is important for the design of bridge pier footings. Previous studies indicated that very long flow duration was needed to achieve equilibrium scouring situations. However, the corresponding durations in the prototype conditions may yield considerably larger values than time-to-peak of the design flood. Therefore, there is a need to estimate the temporal variation of scour depth. This study deals with the development of a new semiempirical method for temporal variation of clear water scour at cylindrical bridge piers using the sediment continuity approach. A recent sediment pickup function proposed for sloping beds is used to formulate the rate of sediment transport out of the scour hole. Results of the proposed method agree well with experimental results. The findings of the proposed method are also compared with some recent empirical methods.Key words: bridge, pier, scour, clear water, sediment pickup.