bluuebunny/crossref_metadata_2025_split huggingface dataset:
Composition control of ZnSSeO quaternary alloys grown on GaP
Authors: Nabetani Y. , Ito Y. , Kamisawa K. , Kato T. , Matsumoto T. , Hirai T. 
Published: March 2006

AbstractZnSSeO quaternary alloys were grown on GaP substrates by molecular beam epitaxy and the group VI compositions were controlled. Reductions of the supply amounts of Se and S both increase the O concentration. S concentration were decreased by the decrease of S supply and increased by the decrease of Se supply. ZnSSeO alloys lattice‐matched to GaP were obtained with high O and S concentrations. Dominant peaks were observed at the near band edge in the photoluminescence spectra. The band gap energies were shifted according to the group VI compositions. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence spectroscopy of single crystalline ZnO‐nanoparticles from the gas phase
Authors: Schneider L. , Halm S. , Bacher G. , Roy A. , Kruis F. E. 
Published: March 2006

AbstractPhotoluminescence (PL) measurements on ZnO nanoparticles synthesized by chemical vapour synthesis (CVS) are presented. We show that the green defect related emission band can be almost completely suppressed by the right choice of processing parameters, like oxygen concentration and sintering temperature. Using temperature dependent time integrated and time resolved PL measurements we obtained information about the excitonic structure of the nanoparticles. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Determination of crystallographic polarity of ZnO bulk crystals and epilayers
Authors: Tampo H. , Fons P. , Yamada A. , Kim K.‐K. , Shibata H. , Matsubara K. , Yoshikawa H. , Kanie H. , Niki S. 
Published: March 2006

AbstractThe crystallographic polarity of ZnO bulk crystals and epilayers were determined by X‐ray diffraction (XRD) using anomalous dispersion near the Zn K‐edge. The method is not destructive and is straightforward to carry out using a typical XRD measurement system. The polarity difference between the Zn (0001) and O (000$ \bar 1 $) surfaces could be easily determined using a {0002} diffraction peak and the Bremstrahlung radiation from a Cu rotating anode source. By using the normalized pre and post‐Zn K‐edge diffraction intensity ratios of the {0002} diffraction peak, Zn polar and O polar ZnO layers could always be distinguished but, the absolute value of the ratio was found to change with layer thickness. Acid etching results confirmed the veracity of the polarity determination of the XRD measurement. To test the technique, Zn and O polar ZnO layers were grown by radical source molecular beam epitaxy on MgO buffer layers on c‐sapphire substrate and O polar ZnO layers were grown on a‐plane substrates and measured using the X‐ray technique with excellent agreement. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Percolation model for long wave phonons in random zincblende alloys: from II‐VI's to III‐V's
Authors: Chafi A. , Pagès O. , Fristot D. , Postnikov A. V. , Tite T. , Laurenti J. P. , Bormann D. , Maksimov O. , Tamargo M. C. 
Published: March 2006

AbstractWe propose a simplified version of our 1‐bond → 2‐mode percolation model initially developed for the q ∼ 0 phonon properties of the stiff Be‐VI bond in (Zn,Be)‐chalcogenides, which open the class of random mixed crystals with contrast in the bond stiffness. The simplified version applies to the ‘usual’ alloys, i.e. made of soft‐like bonds only. It is derived from detailed comparison of the Raman responses from the stiff Be‐Te bond and the soft Zn‐Te one in the pioneer (Zn,Be)Te system. The simplified version is eventually tested on (Ga,In)As whose 1‐bond → 2‐mode behavior in the Ga‐As range of the Raman spectra remains a much debated issue. Further, we lay the foundations for a comprehensive re‐examination of the puzzling phonon behavior' of the similar (Ga,In)P alloy, by analogy with (Ga,In)As. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence recombination centers in ZnO
Authors: Shibata H. , Tampo H. , Sakai M. , Yamada A. , Matsubara K. , Sakurai K. , Ishizuka S. , Kim K. , Fons P. , Iwata K. , Niki S. , Tamura K. , Nakahara K. , Takasu H. , Maeda K. , Niikura I. 
Published: March 2006

AbstractWe have studied the effects of (i) impurity doping, (ii) rapid thermal annealing, and (iii) crystal polarity control on photoluminescence spectra in the band‐edge emission region of high quality ZnO. As a result, we have discussed the possible lattice defects responsible for some photoluminescence emission peaks, namely (i) peak I 8 appears at 3.3596 eV, (ii) peak I 9 appears at 3.3565 eV and (iii) peak G appears at 3.3327 eV. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence properties of ZnO single crystals with polar and non‐polar faces
Authors: Sasaki H. , Kato H. , Izumida F. , Endo H. , Maeda K. , Ikeda M. , Kashiwaba Y. , Niikura I. , Kashiwaba Y. 
Published: March 2006

AbstractPhotoluminescence (PL) was circumstantially measured for ZnO single crystals with polar and non‐polar faces. PL spectra of ZnO single crystals depended on the sector and polarity of ZnO single crystals. Emissions due to excitons from c ‐plane substrates sliced from the +c sector were strong, and FWHMs of the emissions were smaller than those from substrates sliced from the –c sector. An emission due to neutral‐donor‐bound exicitons (D0X) at 3.361 eV was dominantly observed on all surfaces of ZnO single crystals, and an emission due to ionized‐donor‐bound excitons (D+X) around 3.366 eV was observed on the O‐face but not on the Zn‐face at 4.2 K. It is thought that surface state densities due to oxygen caused this difference in PL emission for polarity of ZnO. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A high‐resolution electron microscopy study of MgxZn1–xO films grown on MgO/c‐sapphire
Authors: Vashaei Z. , Minegishi T. , Suzuki H. , Cho M.W. , Yao T. 
Published: March 2006

AbstractWe report on the microstructure of MgxZn1–xO films grown on MgO/c‐sapphire by P‐MBE. Cross sectional specimens of three layers with rock salt, wurtzite, and mixed crystal structure were studied by high‐resolution transmission electron microscopy (HRTEM). Selected area diffraction pattern (SADP) and fast fourier transform (FFT) were also employed to analyze the samples. The results indicate the growth of cubic‐MgZnO along the [111] direction accompanied by twinning. HRTEM micrograph of wurtzite‐MgZnO confirmed that initial stage of the growth starts with a cubic structure and then changes to the wurtzite phase. Our results demonstrate that by introducing a thin MgO buffer layer, growth of cubic‐MgZnO with low Mg content is feasible. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Regulation of cardiolipin synthase levels in Saccharomyces cerevisiae
Authors: Su Xuefeng , Dowhan William 
Published: March 2006

AbstractThe Saccharomyces cerevisiae cardiolipin (CL) synthase encoded by the CRD1 gene catalyses the synthesis of CL, which is localized to the inner mitochondrial membrane and plays an important role in mitochondrial function. To investigate how CRD1 expression is regulated, a lacZ reporter gene was placed under control of the CRD1 promoter and the 5′‐untranslated region of its mRNA (PCRD1‐lacZ). PCRD1‐lacZ expression was 2.5 times higher in early stationary phase than in logarithmic phase for glucose grown cells. Non‐fermentable growth resulted in a two‐fold elevation in expression relative to glucose grown cells. A shift from glycerol to glucose rapidly repressed expression, whereas a shift from glucose to glycerol had the opposite effect. The derepression of PCRD1‐lacZ expression by non‐fermentable carbon sources was dependent on mitochondrial respiration. These results support a tight coordination between translation and transcription of the CRD1 gene, since similar effects by the above factors on CRD1 mRNA levels have been reported. In glucose‐grown cells, PCRD1‐lacZ expression was repressed 70% in a pgs1Δ strain (lacks phosphatidylglycerol and CL) compared with wild‐type and rho− cells and elevated 2.5‐fold in crd1Δ cells, which have increased phosphatidylglycerol levels, suggesting a role for phosphatidylglycerol in regulating CRD1 expression. Addition of inositol to the growth medium had no effect on expression. However, expression was elevated in an ino4Δ mutant but not in ino2Δ cells, suggesting multiple and separate functions for the inositol‐responsive INO2/INO4 gene products, which normally function as a dimer in regulating gene function. Copyright © 2006 John Wiley & Sons, Ltd.
The budding yeast rRNA and ribosome biosynthesis (RRB) regulon contains over 200 genes
Authors: Wade Christopher H. , Umbarger Mark A. , McAlear Michael A. 
Published: March 2006

AbstractThe ribosome biogenesis pathway constitutes one of the major metabolic obligations for a dividing yeast cell and it depends upon the activity of hundreds of gene products to produce the necessary rRNA and ribosomal protein components. Previously, we reported that a set of 65 S. cerevisiae genes that function in the rRNA biosynthesis pathway are transcriptionally co‐regulated as cells pass through a variety of physiological transitions. By analysing multiple microarray‐based transcriptional datasets, we have extended that study and now suggest that the ribosomal and rRNA biosynthesis regulon contains over 200 genes. This regulon is distinct from the set of ribosomal protein genes, and the promoters of the expanded RRB gene set are highly enriched for the PAC and RRPE motifs. Since a similar pattern of organization and gene regulation can be recognized in C. albicans, the RRB regulon appears to be a conserved, extensive, and metabolically important group of genes. Copyright © 2006 John Wiley & Sons, Ltd.
Biotransformation of malachite green by Saccharomyces cerevisiae MTCC 463
Authors: Jadhav J. P. , Govindwar S. P. 
Published: March 2006

AbstractIn recent years, use of microbial biomass for decolourization of textile industry wastewater is becoming a promising alternative in which some bacteria and fungi are used to replace present treatment processes. Saccharomyces cerevisiae MTCC 463 decolourized the triphenylmethane dyes (malachite green, cotton blue, methyl violet and crystal violet) by biosorption, showing different decolourization patterns. However, malachite green decolourized by biosorption at the initial stage and further biodegradation occurred, about 85% in plain distilled water within 7 h, and about 95.5% in 5% glucose medium within 4 h, under aerobic conditions and at room temperature. Decolourization of malachite green depends on various conditions, such as concentration of dye, concentration of cells, composition of medium and agitation. HPLC, UV‐VIS, FTIR and TLC analysis of samples extracted with ethyl acetate from decolourized culture flasks confirmed the biodegradation of malachite green into several metabolites. A study of the enzymes responsible for the biodegradation of malachite green in the control and cells obtained after decolourization showed the activities of laccase, lignin peroxidase, NADH‐DCIP reductase, malachite green reductase and aminopyrine N‐demethylase in control cells. A significant increase in the activities of NADH‐DCIP reductase and MG reductase was observed in the cells obtained after decolourization, indicating a major involvement of reductases in malachite green degradation. Copyright © 2006 John Wiley & Sons, Ltd.
Density, biomass, and guild structure of arboreal arthropods as related to their inhabited tree size in a Cryptomeria japonica plantation
Authors: Hijii Naoki 
Published: March 2006

AbstractArboreal arthropods in a 15‐year‐old plantation of Cryptomeria japonica were surveyed using the smoking method under open conditions and also in the enclosed condition in which the whole above‐ground part of a tree was covered by a cloth bag. Per tree, the number of individuals collected was 8200–14000, with a biomass of 340–1700 mg d.wt. Collembola and Acarina were major components in number, while Diplopoda, Collembola, and Araneae occupied the larger part of the biomass. About 60–70% of total numbers of individuals dropped within two hours after the open fumigation. Clear power‐form regressions between total numbers of individuals and biomasses of all animals and their host tree size (stem diameter at clear length, DB) showed they were approximately proportional to DB2. The guilds of scavengers and tourists demonstrated the most significant correlations between their numbers and biomasses and the tree size. Numbers and biomasses of Collembola, Diptera, and Araneae revealed remarkable dependence on the tree size. From these regressions, numbers of individuals and biomasses per unit ground area were estimated for all arthropods to be 3755/m2 and 165.87 mg d.wt./m2, respectively. Power‐form regressions were observed between numbers and biomasses of prey and predators. The number‐and biomass ratios of all predators to all prey tended to decrease with increasing tree size. A similar trend was observed in the corresponding ratios of parasitic Hymenoptera to lepidopteran larvae, while those of Araneae to Collembola were almost constant, irrespective of tree size.
A simple generalized model of attack by predators and parasites
Authors: Fujii Koichi , Holling C. S. , Mace P. M. 
Published: March 2006

AbstractA generalized descriptive equation for the effect of prey density on the instantaneous rate of attack was proposed; urn:x-wiley:09123814:ere0141:equation:ere0141-math-0001 where A(No) is the number of attacks per predator during time Tt, No is the prey density, Tt is the total time the prey was exposed, Th is the handling time per prey, a′ is the rate of successful search, and c is the facilitation coefficient. The proposed equation can describe all types of the functional response curves; with c=a′ th (pseudo Type I), with c=0 (Type II), with c>a′ th (Type III), and with c<0 (Type IV). The applicability of the equation was tested against the results of a simulation model and available laboratory and field data on predation. The equation described these data very well and in many cases yielded biologically interesting insights, although the equation was proposed primarily for descriptive purposes.
Size‐sex relationship and sexual dimorphism in Japanese Arisaema (Araceae)
Authors: Kinoshita Eiichiro 
Published: March 2006

AbstractThe size‐sex relationship and sexual differences of six Arisaema species native to Japan were investigated. The size‐sex relationship showed almost the same pattern in all species. When the plant was small in size, the sex expression was male, and sex expression changed from male to female as the plant grew larger. Male ratios decreased rapidly around a critical size, but this critical size differed from one species to another.Sexual differences were detected in reproductive structures and behavior, although no difference was detected in vegetative structures. The stoutness, longevity and inner tissue of the scape showed remarkable differences between males and females, and this difference was represented most clearly as the size‐weight relationship. Earlier initiation of flowering in males was also observed.No difference was found in resource allocation to reproductive structures between male and female plants at the flowering stage. However, a broad variation in the amount of resource allocation to reproductive structures was found at the fruiting stage in female individuals, which was attributed to differences in the setting rate of mature fruits.
Evaluation of the light interception by non‐photosynthetic organs in a Larix leptolepis plantation
Authors: Kurachi Nahoko , Hagihara Akio , Hozumi Kazuo 
Published: March 2006

AbstractVertical changes in relative light intensity within the canopy of a 19‐year‐old (as of 1982) plantation of Japanese larch were investigated before and after defoliation. The relative light intensity at 1.3m above the ground was 6% before defoliation, while it was about 20% after defoliation. The leaf area index and the total longitudinal section area of such non‐photosynthetic organs as stems and branches were in the range 4.84 to 5.61 ha/ha and 0.788 to 0.798 ha/ha, respectively. An equation of I′(z)/I0=exp[‐(KFF(z)+KcC(z)], which gives a description of light attenuation within a canopy, was proposed on the assumption that the relative light intensity I′(z)/Io at a depth z from the canopy surface is affected by both the cumulative densities of leaf area F(z) and the longitudinal section area of non‐photosynthetic organs C(z) existing above that depth. The value of the extinction coefficient for the leaves KF was computed to be 0.31–0.36 ha/ha, while that for the non‐photosynthetic organs Kc was computed to be 1.4–1.7 ha/ha. The function C(z) was proportional to F(z), or C(z)=aF(z) where the constant a was 0.11–0.13. The proposed equation led to the formula, I′(z)/I0=exp[‐KF(z)]. The apparent extinction coefficient K was partitioned into two terms as follows, K=KF+aKc. The value of K was estimated to be 0.46–0.59 ha/ha, and was about 1.5 times larger than of KF.
Species numbers, area, and habitat diversity on the habitat‐islands of Mizorogaike pond, Japan
Authors: Shimizu Yoshikazu 
Published: March 2006

AbstractSpecies‐area relationships of flowering plants were analyzed on the habitat‐islands (hummocks on a floating bog) of Mizorogaike Pond, Japan. Three habitat units (Sphagnum cuspidatum unit, Sphagnum palustre unit, and fallen leaves unit) in which habitat conditions were homogeneous and a group of habitat‐specific species occurred were recognized on the hummocks. Six hummock types were determined according to various combinations of the three habitat units. The most fundamental species‐area relationships in which size itself affects the number of species were shown by hummocks with only one habitat unit. The species‐area relationships for hummocks with two or three habitat units included the effects of habitat diversity in addition to size. The speciesarea curve for all hummocks was an average of these relationships. It is concluded that area in species‐area relationships affects species numbers in two ways: number of habitat units and size of each habitat unit.
The effects of a typhoon on Japanese warm temperate rainforests
Authors: Bellingham P. J. , Kohyama Takashi , Aiba Shin‐ichiro 
Published: March 2006

AbstractA powerful typhoon (Typhoon No. 13) affected stands of primary warm temperate rainforest in Yakushima, southern Japan, in 1993. Censuses in three sites 1–5 months after the typhoon showed low levels of mortality resulting from the typhoon (0.4–3.0% of stems). Stems killed by the typhoon were generally larger than surviving stems. Among surviving stems there were generally low levels of damage (e.g. 0.5–1.3% of surviving stems lost crowns) and not all damage was widespread (e.g. defoliation was apparent only in one of three sites). The sizes of uprooted stems, stems that lost crowns and relatively undamaged stems were not different. Different species appeared to be damaged in different ways at different sites. Damage was most evident in higher altitude seaward sites but gap formation was more frequent in lower altitude sites near valley floors. After the typhoon the resultant gap area occupied 9.4% of one site and 8.6% of another, which is greater than that before the typhoon. Fresh sprouts were found on 17.35% of 2161 stems after the typhoon, including many apparently undamaged stems as well as those that were damaged. Species which sprouted most frequently were those that regenerate by seed least frequently in these forests; these species may maintain their relative abundance in part by sprouting. Most tree species in these forests may be relatively resistant to typhoons and there may be more opportunities for their regeneration following gap formation caused by the typhoon.
Pollination of the orchidEpipactis thunbergiiby syrphid flies (Diptera: Syrphidae)
Authors: Sugiura Naoto 
Published: March 2006

AbstractThe behavior of visitors to the flowers of the orchidEpipactis thunbergiiwas studied, with special attention to the role of the epichile in the pollination process. Only four species of syrphid flies legitimately pollinated the flower, among whichSphaerophoria macrogasterwas regarded as the most effective pollinator. The movable epichile, possessing a furrow at its base, played a critical role in the pollination process: it threw the syrphid fly onto the stigmatic surface when both sides of the basal slanting surface of the furrow were presumably pressed in the direction of the hypochile by the fore (and middle) legs of the retreating syrphid fly. At this moment, the fly received a set of pollinia on the thorax.
Microdistribution of sulfate‐reducing bacteria in sediments of a hypertrophic lake and their response to the addition of organic matter
Authors: Fukui Manabu , Takii Susumu 
Published: March 2006

AbstractTo clarify the ecological significance of the association of sulfate‐reducing bacteria (SRB) with sediment particle size, SRB utilizing lactate (l‐SRB), propionate (p‐SRB) and acetate (a‐SRB) were examined with different sizes of sediment particles in a hypertrophic freshwater lake using the anaerobic plate count method. The numbers of l‐SRB and a‐SRB were 104–105 colony forming units (CFU) per ml in the 0–3 cm layer and 102–103 CFU ml−1 in the 10–13 cm layer while the numbers of p‐SRB were one or two orders lower than those of l‐SRB and a‐SRB. A sediment suspension was fractionated into four fractions (<1, 1–10, 10–94 and >94 μm). The highest proportions of l‐SRB and a‐SRB were found in the 10–94 μm fraction: 66–97% for l‐SRB and 53–98% for a‐SRB. The highest proportion of p‐SRB was found in the >94 μm fraction (70–74%). These results indicate that most SRB were associated with sediment particles. One isolate from an acetate‐utilizing enrichment culture was similar to Desulfotomaculum acetoxidans, a spore‐forming sulfate‐reducing bacterium. When lactate and sulfate were added to sediment samples, l‐SRB and a‐SRB in the <10 μm‐fraction grew more rapidly than those in whole sediment for the first 2 days. This result suggests that nutrients uptake by free‐living and small particle‐associated (<10 μm) SRB is higher than that by SRB associated with larger particles.
Changes in foliage distribution with relative irradiance and tree size: Differences between the saplings of Acer platanoides and Quercus robur
Authors: Niinemets Ülo 
Published: March 2006

AbstractDependencies of foliage arrangement and structure on relative irradiance and total height (TH) were studied in saplings of Acer platanoides and Quercus robur. The distribution of relative foliar area and dry weight (leaf area and weight in a crown layer per total tree leaf area and weight, respectively) were examined with respect to relative height (RH, height in the crown per TH) and characterized by the Weibull function. The distributions of relative area and weight were nearly identical, and the differences between them were attributable to a systematic decline in leaf dry weight per area with increasing crown depth. Foliage distribution was similarly altered by tree size in both species; RH at foliage maximum was lower and relative canopy size (RCS, length of live crown per TH) greater in taller trees. However, the distribution was more uniform in A. platanoides than in Q. robur. Apart from the size effects, relative irradiance also influenced canopy structure; RCS increased in Q. platanoides and decreased in Q. robur with increasing irradiance. As crown architecture was modified by irradiance, foliage distribution was shifted upwards with decreasing irradiance in A. platanoides, but it was independent of irradiance in Q. robur. Higher foliage maximum at lower irradiance in more shade‐tolerant A. platanoides is likely to contribute towards more efficient foliar display for light interception and increase the competitive ability of this species in light‐limited environments. Consequently, these differences in crown architecture and foliage distribution may partly explain the superior behavior of A. platanoides in understory.