bluuebunny/crossref_metadata_2025_split huggingface dataset:
Messy simulated annealing
Authors: Kvasnička V. , Pospíchal J. 
Published: May 2005

AbstractThe method of simulated annealing is modified so that the concept of messy chromosomes is applied. Constituent genes of messy chromosomes are specified by their respective names (indices) and values (alleles) simultaneously. Unlike simple chromosomes (binary vectors), messy chromosomes may be either under‐ or overspecified with respect to the problem being solved. The messy simulated annealing algorithm is a very robust and efficient stochastic optimization method which is able to find correct minima of deceptive or highly multimodal objective functions. This is shown by way of a number of simulations.
Univariate regression models with errors in both axes
Authors: Riu J. , Rius F. X. 
Published: May 2005

AbstractCalibration is a fundamental step in the calculation of the unknown concentration of analyte in most analytical methods. It is known that for certain methodologies, if only the errors in the independent variable are taken into account, there may be considerable errors in the estimation of the value of the regression coefficients, the derived statistical parameters and in some cases the sought for response and concentration values. This paper reviews the calibration methods including some references to procedures for the detection of outliers and robust regression when there are errors in both axes. The advantages and limitations of the different approaches are discussed and a comparative study is made of the approaches of several techniques for which computer programmes have been developed based on the algorithms put forward by the different authors. Finally, some trends of future development in this field are envisaged.
Maximum sum of binary‐coded residuals (MASBR) regression as a robust procedure for treatment of spectral data
Authors: Wang Ji‐Hong , Xie Yu‐Long , Yu Ru‐Qin 
Published: May 2005

AbstractIn this paper, a novel robust regression method, the maximum sum of binary coded residuals (MASBR), is proposed. Instead of the sum of squared residuals used in least squares regression as the minimization criterion, MASBR regression maximizes the sum of binary coded residuals. MASBR regression is designed for cases where the conventional robust regression methods with breakdown points less than 50% fail. To circumvent the problem of being trapped in local optima, a stepwise‐varying acceptable error limit (SVAEL) algorithm is proposed. Both numerical simulation and treatment of real analytical data demonstrate the feasibility of MASBR regression in conjunction with the SVAEL algorithm.
Hydrogen in Cvd Diamond Films
Authors: Rutledge Karen Mcnamara , Gleason Karen K. 
Published: May 2005

AbstractUnderstanding of the incorporation of hydrogen and its role in determining the properties of CVD diamond is critical to the successful commercial production of these films. Hydrogen is usually the most abundant impurity in solid‐state CVD diamond and has been studied extensively by a variety of techniques, including nuclear magnetic resonance, infrared spectroscopy, and several others. This article reviews the application of a number of characterization methods to the study of hydrogen in CVD diamond, with particular attention toward understanding the incorporation of this impurity and its effect on properties of commercial significance.
Aerosol‐assisted chemical vapor deposition of CeO2‐doped Y2O3‐stabilized ZrO2 films on porous ceramic supports for membrane applications
Authors: Xia Changfeng , Ward Timothy L. , Schwartz Robert W. 
Published: May 2005

Dense stabilized zirconia has a number of important applications because of its oxygen ion conductivity and excellent thermal and chemical stability. Conventional multicomponent CVD has a number of problems, including low precursor delivery rates and premature decomposition. The results in this paper suggest that the novel use of aerosol‐assisted CVD can be used to overcome these problems. The Figure shows the cross section of a CeO2‐doped Y2O3‐stabilized ZrO2 film deposited by AACVD. magnified image
Conversion of tetraethoxysilane (TEOS) to silica film‐forming precursors in atomic oxygen‐induced chemical vapor deposition
Authors: Wróbel Aleksander M. , Walkiewicz‐Pietrzykowska Agnieszka , Stasiak Marek , Kulpiúski Józef 
Published: May 2005

AbstractThe gas phase reactions of tetraethoxysilane in atomic oxygen‐induced chemical vapor deposition were investigated. A high‐resolution gas chromatography/mass spectrometry examination of the reaction products, collected in a cold trap, revealed the presence of linear and cyclic siloxane oligomers containing the ‐(EtO)2SiO‐ repeating unit. The structure of the identified oligomers and mechanisms of TEOS reactions with atomic oxygen suggest that diethoxysilanone plays a predominant role in the silica film growth process.
Palladium Thin Films Grown by CVD from (1,1,1,5,5,5‐Hexafluoro‐2,4‐pentanedionato) Palladium(II)
Authors: Bhaskaran Vijay , Hampden‐Smith Mark J. , Kodas Toivo T. 
Published: May 2005

AbstractThe precursor (1,1,1,5,5,5‐hexafluoro‐2,4‐pentanedionato) palladium(II) [Pd(hfac)2] was used to deposit high‐purity, polycrystalline palladium films under low‐pressure CVD conditions at high growth rates (1000–4000 Å/min) over a substrate temperature range of 80–200°C in the presence of H2. Mixing of the precursor and H2 streams near the substrate was required to avoid reactions of the precursor with H2 at locations other than the substrate surface. Auger electron spectroscopy (AES) showed that the films were impurity free when sufficient H2 was used. Resistivity values of 20 μΩcm were obtained at the higher deposition temperatures (∼200 °C) while high values of 50 μΩ cm were observed at the lower deposition temperatures (∼ 90 °C). The deposition rate was feed‐rate limited even at the lowest deposition temperatures and highest precursor delivery rates, suggesting that even higher deposition rates could be obtained with higher feed rates. A high precursor conversion of 50–60 % was observed. The high surface reaction probability of Pd(hfac)2 in the presence of H2 was reflected qualitatively by trench fill studies which showed a greater film thickness on the top of sub‐micrometer trenches than in the bottom.
Microwave Plasma CVD in the System Si‐C‐H‐Ar: Effect of Process Parameters
Authors: Scordo Stephane , Ducarroir Michel , Berjoan René , Jauberteau Jean Louis 
Published: May 2005

AbstractSi‐C films were prepared on steel by the microwave (2.45 GHz) decomposition of tetramethylsilane (TMS) diluted in argon. The device used decouples the plasma power and the substrate temperature. The effects of various parameters (substrate position, temperature, gas flow rate, power, pressure) on composition and deposition rate were investigated. They are discussed in relation to electrostatic probe measurements. For all conditions, deposition rates are high (3–60 μm h−1). By using only TMS, the Si/C ratio in the films is restricted to values between 0.3 and 0.7. The variations in the process parameters do not induce significant changes in film compositions, however, they significantly change the deposition rates and the film hardness. In this field, the TMS dissociation process seems quite invariant with the conditions. With the introduction of SiH4 to the input gas phase (i.e., mixture SiH4 + TMS + Ar), silicon‐rich films were obtained. The composition range was extended to Si/C = 1.7 but the mechanical properties are strongly changed.
Quantum Modeling of the CVD of transition metal materials
Authors: Cundari Thomas R. , Sommerer Shaun O. 
Published: May 2005

AbstractQuantum mechanical studies of the decomposition pathways of model OMCVD precursors are analyzed, in particular kinetic trends as a function of OMCVD precursors components‐metal (M), element (E), ancillary ligands (Ln), element substituents (Z), transfer group (At) and leaving group (X), 1. Based on geometric and energetic effects it is possible to further subdivide these components into three groups: active site (M, E), participants (At, X), and spectators (Ln, Z). Considerable progress has been made over the past several years, although many challenges remain in quantum modeling of transition metal materials and reactions pertinent to their CVD from volatile organometallics. Computational improvements in methods and technology are briefly discussed in relation to quantum modeling of OMCVD precursor structure and reactivity. Future directions are considered in which to more closely integrate the results of quantum modeling of OMCVD reactions with other aspects in this diverse research area.
The Growth of Indium Selenide Thin Films from a Novel Asymmetric Dialkyldiselenocarbamate of Indium
Authors: O'Brien Paul , Otway David J. , Walsh John R. 
Published: May 2005

AbstractThin films of cubic In2Se3 have been grown by low‐pressure metal‐organic chemical vapor deposition (LP‐MOCVD) using the novel precursor In(Se2CNMe n‐hexyl)3. The precursor was prepared from carbon diselenide and a modified experimental procedure for the synthesis of CSe2 is described. Films were grown on glass and InP(111) between 450 and 500°C, and characterized by X‐ray diffraction and scanning electron microscopy.
Structural and Electrical Changes in Polycrystalline Silicon Thin Films That Are Heavily In Situ Boron‐Doped and Thermally Oxidized with Dry Oxygen
Authors: Boukezzata Messaoud , Birouk Boubekeur , Mansour Farida , Bielle‐Daspet Daniéle 
Published: May 2005

AbstractIn this paper, we investigate some particular aspects of changes in the thermal behavior polycrystalline silicon films deposited by low pressure CHEMICAL VAPOR DEPOSITION (LPCVD). The results will concern changes in both the structural and electrical properties of heavily (2 × 1020 cm−3) in situ boron‐doped thin films before and after thermal‐oxidation treatments. Secondary ion mass spectrometry (SIMS), transmission electron microscopy (TEM), and four‐point‐probe resistivity (FPPR) measurements were carried out on submicrometer layers (≈ 300 nm) deposited at two interesting temperatures Td = 520 °C and Td = 605 °C. The termal‐oxidation experiments are performed under dry O2 at three oxidation temperatures Tox = 840, 945, and 1050 °C for several durations. Remarkable changes in the behavior of doping profile, grain growth, and electrical conductivity were observed. While the kinetic‐oxidation analyses reveal the presence of a “differential oxidation rate (DOR)” between the two layers, recrystallization effects show a similar behavior, called “diferential growth mechanism (DGM)”, between the same layers. These observations seem to be characteristic of the in situ heavily boron‐doped films, consistent with results of a previous study.
The production of chimeric rats and their use in the analysis of the hooded pigmentation pattern
Authors: Yamamura Ken‐ichi , Markert Clement L. 
Published: May 2005

AbstractNew, improved media and procedures for making rat chimeric embryos and culturing them in vitro have been developed. We have produced 27 rat chimeras: 20 males and 7 females. This ratio of males to females is consistent with that seen in mouse chimeras, suggesting that rat sex chimeras develop as phenotypic males. By aggregating embryos containing appropriate genetic markers for pigment cell differentiation, it is possible to produce chimeras that elucidate the site of action of the hooded gene. The coat color patterns of black ↔ black hooded chimeras display a white belly spot. In black ↔ albino hooded chimeras, small patches of white hair appear on the head and a large white spot occurs on the belly. Black ↔ agouti hooded chimeras display both agouti and nonagouti pigmentation over the entire surface of the chimera. These animals are fully pigmented with no white spots. In black ↔ albino non‐hooded chimeras, rather small irregular patches of black and white hairs are distributed throughout the pelage. Histological examination of sections of hair follicles obtained from the white areas in the head of black ↔ albino hooded chimeras revealed amelanotic melanocytes. On the other hand, hair bulbs from the white belly spots do not contain any such melanocytes. Thus the white hairs of the head are due to the presence of albino melanocytes, but the white hairs of the belly are due to the total absence of melanocytes. All these observations are consistent with the conclusion that the hooded gene acts within melanoblasts, probably to retard their migration from the neural crest and/or to prevent their entrance into the hair follicles of the white areas of hooded rats.
Studies of fs(1)1621, a mutation producing ovarian tumors in Drosophila melanogaster
Authors: Gollin Susanne M. , King Robert C. 
Published: May 2005

AbstractThe ethyl methane sulfonate‐induced mutation, fs(1)1621, resides at 11.7 on the genetic map and within segment 4F1‐5A1 of the cytological map of the X chromosome. When homozygous, fs(1)1621 renders females semisterile but has no effect on their viability; nor does it affect the viability or fertility of hemizygous males. Heterozygous females are fertile and have cytologically normal ovaries. The ovaries of homozygous females first produce normal oocytes, which, if fertilized, can develop into adult males or females. After this period, ovarian chambers containing only pseudonurse cells are formed, and finally mutant germaria produce only tumors. These contain hundreds to thousands of cells that appear to be derived from germarial cystocytes, because they occasionally form clones of interconnected cells and also can differentiate into endopolyploid pseudonurse cells. Raising the temperature speeds the rate at which tumors form; lowering it increases the probability of pseudonurse cell differentiation. Df(1)C159 includes fs(1)1621. The pattern of ovarian chamber production is more temperature sensitive in hemizygous females than in homozygous ones. The morphology of hemizygous tumors and the number of dividing cells within them also differ from homozygotes. These observations support the hypothesis that fs(1)1621 is producing a product, that less is produced by one gene than by two, and that the product plays a role in the mitosis and cytokinesis of ovarian cystocytes.
Mating type differentiation in Tetrahymena thermophila: Strong influence of delayed refeeding of conjugating pairs
Authors: Orias Eduardo , Baum Mary P. 
Published: May 2005

AbstractMating type differentiation in Tetrahymena thermophila is known to regularly involve stable hereditary alterations at a single chromosomal locus in the somatic (macro)nucleus. This differentiation is directionally affected by the temperature at which new macronuclei develop after fertilization. We now report large and predictable effects of delayed refeeding of conjugating pairs upon mating type differentiation, particularly among mat‐2 homozygotes. The mating types whose frequency is affected the most are IV, VI, and VII, a set different from that most affected by temperature. We interpret our observations to reveal the existence of a second system which can participate in mating type differentiation, with different specificity from the system influenced by temperature under conditions of early refeeding of conjugating pairs. These observations enrich the phenomenology surrounding mating type differentiation in T thermophila and provide additional, easily controllable experimental conditions for the manipulation of mating type frequencies.
Age‐dependent behavior loss in adult Drosophila melanogaster
Authors: Leffelaar David , Grigliatti Thomas 
Published: May 2005

AbstractThe use of Drosophila as an organism in which to study aging has been limited by the fact that few biomarkers of aging exist in the adult. In this paper we examine behavior loss relative to longevity in wild‐type populations maintained at 22°C and 29°C to determine whether behavior loss—that is, loss of ability to perform certain innate behavioral responses within a defined test interval—can be used as biomarkers of aging. We find that under controlled conditions behavior loss can be used as a landmark of aging in populations maintained at either 22°C or 29°C. The ability to perform normal geotactic and phototactic responses is lost during the reproductive phase of the adult populations, whereas motor activity is not lost until well into the death phase. We feel that the use of behavior loss, together with other parameters of longevity in Drosophila, will allow comparisons to be made between different strains or between different environmental conditions to test their effect on aging. In the companion paper we demonstrate the use of behavior loss to identify a mutation which may accelerate the aging process.
Genetic control of cell interactions in chimeras
Authors: Markert Clement L. 
Published: May 2005

AbstractThe manufacture of mammalian chimeras by aggregating embryos of different genetic constitutions makes possible the study of the genetic control of cellular interactions during embryonic development. Several different chimeric combinations have been made to study the role of the sex‐reversed mutation in gonadogenesis and in gametogenesis. Sex reversed directs the gonad to become a testis and thus renders a SxrXX mouse sterile since gonocytes with two X chromosomes cannot complete gametogenesis in a testis. However, SxrXX gonocytes in the ovary of a female chimera become normal oocytes. The competitive interactions of genetically different melanoblasts in populating hair follicles and of primordial germ cells in populating the gonad have been revealed in chimeras. Chimeras have also been used to rescue inviable teraploid embryos and to permit teteraploid cells to display their differentiative capacities in normal tissue environments. We conclude that the genotype affects the capacity of cells to elaborate and to respond to inductive stimuli at each step in differentiation. The fine tuning of cellular interactions becomes apparent in chimeras made from embryos of different genotype.
Opportunities for natural selection on DNA and protein at the Adh locus in Drosophila melanogaster
Authors: Clarke Bryan , Whitehead Diane L. 
Published: May 2005

AbstractA study was made of environmental and genetic factors affecting the quantity and disposition of the alcohol dehydrogenase (ADH) protein in Drosophila melanogaster. It was found that the amount of enzyme per fly is greatly influenced by the environmental conditions in which it develops. A critical factor is the concentration of yeast in the medium. A high concentration of yeast can double the quantity of ADH. The yeast appears to act through the provision of protein, and the protein to act through the provision of threonine, which is already known to induce ADH in fungi.Various genetic factors affect the quantity of enzyme. Males have more ADH than females. Files homozygous for the Fast allele have more ADH than those homozygous for the slow allele, and the difference is greater in females than in males. One particular line (ve), homozygous for Slow, has approximately half the normal quantity of enzyme, and the quantity segregates with the electrophoretic allele. Lines differ in the relative amounts of ADH in the gut (including Malpighian tubules) and the fat body. In general it seems that slow lines have relatively more enzyme in the fat body. In a cross between ve and a line homozygous to Fast, the difference in tissue distribution segregated with the electrophoretic allele. It is argued, but not demonstrated, that the differences in quantity and tissue distribution are due to nucleotide substitutions in noncoding regions close to, or within, the structural gene.It seems likely that the observed environmental and genetic differences in the quantity and disposition of ADH will influence the relative selective values of the electrophoretic genotypes.
Allelic isozyme variants in the mexican axolotl (Ambystoma mexicanum) as potential markers for developmental experiments
Authors: Cooper Gillian M. , Armstrong John B. , Gottlob‐McHugh Sylvia 
Published: May 2005

AbstractFour isozyme systems were surveyed in our laboratory‐bred colony of axolotls (Ambystoma mexicanum) to determine whether there were elecrophoretic variants that could be used as markers in developmental experiments. For malate dehydrogenase (MDH), lactate dehydrogenase (LDH), and phosphoglucomutase (PGM), the best separations were obtained by isoelectric focussing on polyacrylamide slab gels, whereas for soluble esterases (Est), conventional polyacrylamide gel electrophoresis was used. The patterns for both MDH and LDH were consistent with two‐locus models, but no variation was obtained. The results for PGM support a single‐locus model with two alleles that are expressed codominantly in heterozygotes. There is also evidence for a third, null allele. The pgm gene maps approximately 24 map units from its centromere. The majority of the animals tested produced four esterase bands. We propose that each is controlled by a separate locus. One of the bands, Est‐3, is absent in some animals. The results of various crosses support the proposition that these animals are homozygous for a null allele. The est‐3 gene is distant from its centromere.
The role of cell death in the induction of pattern abnormalities in a cell‐lethal mutation of drosophila
Authors: Girton Jack R. , Kumor Anne L. 
Published: May 2005

AbstractThe effects of 48‐hr 29°C temperature treatments on the imaginal leg discs of Drosophila hemizygous for a temperature‐sensitive cell‐lethal mutation were examined to determine whether the induction of patches of cell death in the imaginal discs is a prerequisite for the induction of pattern triplications. In a statistical analysis, the frequency of induction of cell death was found to be highly correlated with the frequency of induction of triplications. In addition, individual discs in which cell death had been induced were cultured and found to triplicate at frequencies significantly greater than discs with no visible cell death, or unselected discs from the same larvae.