bluuebunny/crossref_metadata_2025 huggingface dataset:
Month of harvest and yield components of tea tree. I. Biomass
Authors: Murtagh GJ
Published: November 2004

The effect of month of harvest on the biomass production of coppice growth from tea tree plants (Melaleuca alternifolia) grown under plantation conditions and harvested annually was assessed in a field experiment on the north coast of New South Wales. Tea tree oil is obtained from leaves, and the yield of leaf is determined by the total plant yield, the proportion of twig in total yield, and the proportion of leaf in twig. Harvesting between July and October gave a significant increase in total plant yield over other months. This advantage appeared to come from synchronising the most efficient stage of growth (4-6 months after harvest) with the best growing conditions. Under the same environment conditions, the relative efficiencies of regrowth were 46, 100, and 71 during months 1-3, 4-6, and 7-12, respectively. District observations suggested that there would be little growth at mean monthly temperatures <16OC, and the data analysis showed a reduction in growth when the soil dried to <69% of the total available water capacity. The proportion of twig in total yield was affected by the total plant weight, and the proportion of leaf in twig responded to the air temperature. However, variation in both proportions had a relatively minor effect on leaf yield, and changes in total plant yield accounted for more than 90% of the variation in leaf yield.
Responses to feeding canola meal or lupin seed to pregnant, lactating, and dry ewes
Authors: Masters DG , Mata G
Published: November 2004

Responses in wool production, ewe liveweight, lamb birth weight, and growth were compared when the major source of protein in the diet was either lupin seed or canola meal. The diets were fed to ewes during the final 3 weeks of pregnancy and first 3 weeks of lactation, and for a similar period of time to a group of dry ewes. All ewes were fed to maintain conceptus-free liveweight. The diet containing canola meal increased (P < 0.001) wool growth in the reproducing ewes (50-63%) and the dry ewes (12.5-20%) during, and for 3 weeks after, the treatment period. Fibre diameter of wool grown during the treatment period was increased (P < 0.025) by 0.5-1.5 pm in the ewes fed canola meal compared with ewes fed lupins. The ewes fed canola meal gained slightly (P = 0.06) more weight during the experiment than the ewes fed lupins. Lambs from the ewes fed canola meal were lighter (P < 0.05) at birth (480 g) than lambs from ewes fed lupins. The reproducing ewes had lower fleece weights, average fibre diameters, and staple strengths and lengths than the dry ewes. These fleece characteristics were not significantly affected by diet. Canola meal is partially protected from rumen degradation and is less expensive than other sources of similar proteins and may therefore provide a practical option for commercial sheep producers.
Ionic Liquid Promoted Knoevenagel and Michael Reactions
Authors: Fan Xuesen , Hu Xueyuan , Zhang Xinying , Wang Jianji
Published: November 2004

The utilization of the ionic liquid [bmim][BF4] as both reaction medium and promoter for the Knoevenagel condensation and Michael addition reactions is described in this paper. Through these reactions, several useful electrophilic alkenes and chromene derivatives are obtained in high yields. The advantages of these two novel procedures include their environmentally benign nature, atom economy, simple operation process, and mild reaction conditions.
Bandshape Parameters' Dependence on Solvent in Raman Excitation Profiles, and Absorption Spectra of Violaxanthin and Lutein
Authors: Maisuradze Gia G.
Published: November 2004

The experimental results of resonance Raman excitation profiles (RREPs) for the Ω1, Ω2, and Ω3 vibrations of violaxanthin and lutein in acetone, toluene, and carbon disulfide have been interpreted in terms of an improved vibronic interaction theory. The bandshape parameters from RREPs have been employed for the calculation of absorption spectra. Excellent agreement between calculated and observed RREPs and absorption spectra was found. However, the results obtained for RREPs of lutein in carbon disulfide deviate considerably from experiment. The results indicate that the major broadening mechanism is homogeneous in carbon disulfide, whereas the broadening in acetone and toluene includes contributions from both homogeneous and inhomogeneous mechanisms.
Slowly divergent geodesics in moduli space
Authors: Cheung Yitwah
Published: November 2004

Slowly divergent Teichmüller geodesics in the moduli space of Riemann surfaces of genus

g
≥
2

g\geq 2

are constructed via cyclic branched covers of the torus. Nonergodic examples (i.e. geodesics whose defining quadratic differential has nonergodic vertical foliation) diverging to infinity at sublinear rates are constructed using a Diophantine condition. Examples with an arbitrarily slow prescribed rate of divergence are also exhibited.
New Carboniferous brachiopods from the eastern Great Basin, Nevada, USA: implications for loop ontogeny and evolution in Late Palaeozoic terebratuloids
Authors: Pérez‐Huerta Alberto
Published: November 2004

Terebratuloid brachiopods from two localities in the eastern Great Basin, Nevada, USA, include the new taxa Cryptacanthia savagei sp. nov., Fletcherithyris infrequens sp. nov., Cryptonella simplex sp. nov., and Albelenina alvarezi gen. et sp. nov. The faunas are considered to be mid Desmoinesian (late Moscovian) in age. The brachiopods were found associated in clusters, and many of the specimens are well preserved. Records of Pennsylvanian terebratuloid brachiopods are uncommon, and these faunas have enabled an understanding of internal features previously unknown or poorly understood. Systematic analyses of the faunas have generated some new concepts on the ontogeny and evolution of the loop in Late Palaeozoic terebratuloids. From ontogenetic analyses, it is inferred that the stage of loop development may be the most important aspect in taxonomic classification. Analyses of loop evolution suggest the possibility of a transition from a teloform stage to long‐flanged deltiform and deltiform stages. These transitions may be possible through reduction in length of the descending lamellae of the crura by resorption of calcium carbonate or posteroventral folding of flanges. Subsequently, these changes in loop morphology are retained by paedomorphosis within long‐term evolutionary processes.
Gap characteristics and regeneration in Bwindi Impenetrable National Park, Uganda
Authors: Babaasa Dennis , Eilu Gerald , Kasangaki Aventino , Bitariho Robert , McNeilage Alastair
Published: November 2004

Before Bwindi Impenetrable forest, Uganda, became a national park in 1991, there was a high level of human activity in much of the forest, especially cutting of large trees for timber by pitsawyers. This created extensive gaps in this tropical Afromontane rain forest. We quantified and compared tree regeneration in three sites that were logged at different intensities. Gap sizes in Bwindi, even under fairly natural conditions are very large (mean =4460.1 m2). Logging further enlarged the gap sizes and had a negative impact on tree regeneration. The study shows the strong role of logging disturbance in promoting an alternative successional pathway, where the large gaps created by logging are in a low‐canopy state dominated by a dense tangle of herbs, shrubs, and herbaceous or semi‐woody climbers. We recommend periodic monitoring of gap size and tree regeneration in the gaps to ascertain the trend of recovery from past logging disturbance.
The nuclear genes Lhcb and HEMA1 are differentially sensitive to plastid signals and suggest distinct roles for the GUN1 and GUN5 plastid‐signalling pathways during de‐etiolation
Authors: McCormac Alex C. , Terry Matthew J.
Published: November 2004

Feedback mechanisms are critical to the regulation of chloroplast development and signals from functional plastids are required to maintain nuclear gene expression of chloroplast proteins. To understand the role of these signals in de‐etiolating Arabidopsis thaliana L. seedlings, we followed the expression of three nuclear genes, Lhcb, HEMA1 and GSA, under a variety of treatments (Norflurazon, lincomycin and a far‐red light pre‐treatment) leading to plastid damage in white light and in a range of genetic backgrounds known to modulate plastid signalling: the genomes uncoupled mutants, gun1, gun4, gun5 and the gun1,5 double mutant, and in a transgenic line over‐expressing NADPH:protochlorophyllide oxidoreductase. The three nuclear genes were differentially sensitive to changes in plastid signalling, with Lhcb the most strongly repressed and GSA insensitive to all but the most severe treatments. Analysis of plastid morphology in seedlings grown under identical conditions demonstrated that these responses corresponded closely to the degree of plastid damage. Furthermore, although Lhcb and HEMA1 were responsive to both GUN1 and GUN5 signals, the relative inputs from these pathways differed for each transcript with GUN1 being dominant for HEMA1 regulation. Further analysis of HEMA1 expression in gun1 seedlings under non‐photobleaching conditions indicates that GUN1 is an important suppressor of HEMA1 expression in the dark and under saturating white light. These results are consistent with plastid signals functioning in a feedback regulatory mechanism during chloroplast biogenesis, and suggest a key role for GUN1 during the early stages of chloroplast development.
Short Communication: Observations on false positive reactions in the rapid NOW® Filariasis card test
Authors: Simonsen Paul E. , Magesa Stephen M.
Published: November 2004

The NOW® Filariasis card test is a useful tool for rapid field diagnosis of Wuchereria bancrofti infection, based on detection of specific circulating filarial antigen (CFA) in the patients’ blood. Concern has been raised that a high proportion of infection negative individuals develop false positive reactions in these tests when the test cards are left for a prolonged period before being examined. We carried out a survey in an endemic Tanzanian village to investigate this phenomenon. Individuals who were positive in the NOW® Filariasis test at 10 min after specimen application were also positive in the TropBio ELISA for CFA, and thus appeared to be truly positive. Many of the test cards that were negative at 10 min developed a positive line later, but these lines appeared to be falsely positive when the TropBio test was used as the gold standard. Close examination revealed that true and false positivity lines could be distinguished on their shape and colour. The study thus reaffirmed that test cards should be read after 10 min to avoid false positives, but it also indicated that experienced test card users should be able to make a correct diagnosis even at a later time.
Melioidosis epidemiology and risk factors from a prospective whole‐population study in northern Australia
Authors: Currie Bart J. , Jacups Susan P. , Cheng Allen C. , Fisher Dale A. , Anstey Nicholas M. , Huffam Sarah E. , Krause Vicki L.
Published: November 2004

Objectives  The aims of this study were to describe the epidemiology of melioidosis in tropical northern Australia and to assess the importance of defined risk factors.

Methods  The data were taken from a 14‐year prospective study of 364 cases of melioidosis in the ‘Top End’ of the Northern Territory. A whole‐population logistic regression model was used to estimate the crude and adjusted relative risk (RR) for the defined risk factors.

Results  The mean age of the study population was 46.8 years, 264 (72.5%) were male, 178 (49%) were aboriginal Australians and 59 (16.2%) died from melioidosis. Average annual incidence was 19.6 cases per 100 000 population, with an estimated rate of 260 cases per 100 000 diabetics per year. Using a whole‐population logistic regression model, the estimated crude and adjusted RR [95% confidence intervals (CI)] for melioidosis were 6.3 (5.1–7.8) and 4.0 (3.2–5.1) for those aged  ≥ 45 years, 2.3 (1.8–2.9) and 2.4 (1.9–3.0) for males, 2.9 (2.3–3.5) and 3.0 (2.3–4.0) for aboriginal Australians, 21.2 (17.1–26.3) and 13.1 (9.4–18.1) for diabetics, 2.7 (2.2–3.4) and 2.1 (1.6–2.6) for those with excess alcohol consumption, 6.8 (5.4–8.6) and 4.3 (3.4–5.5) for chronic lung disease and 6.7 (4.7–9.6) and 3.2 (2.2–4.8) for chronic renal disease, respectively.

Conclusions  Diabetes, excess alcohol intake, chronic renal disease and chronic lung disease are each independent risk factors for melioidosis. In tropical northern Australia, male sex, aboriginal ethnicity and age of ≥45 years are also independent predictors for melioidosis. Impaired polymorph function may be critical in the predisposition to melioidosis.
Evolution of floral dimorphism in a cleistogamous annual,Impatiens noli‐tangereL. occurring under different environmental conditions
Authors: MASUDA Michiko , YAHARA Tetsukazu , MAKI Masayuki
Published: November 2004

The resource allocation models for the evolution of a mixed production of cleistogamous and chasmogamous flowers were tested in four natural populations ofImpatiens noli‐tangereL. When we incorporated the estimated parameter values into our basic model, under the assumption that the environmental conditions did not change through the reproductive season, the model predicted the obligate chasmogamy in all four populations. However, including the fluctuation of the fertility of chasmogamous flowers in the model, the seasonal switching of chasmogamous and cleistogamous flower production becomes an evolutionary stable strategy, which explains the reproductive behavior of the individuals in two populations. Only after the relationship between the geitonogamy of chasmogamous flowers and the number of chasmogamous flower production was considered in the model did the simultaneous production of both of the dimorphic flowers become an evolutionary stable strategy. Further, the complete model clarifies the reproductive behavior of the individuals in the other two populations.
Regeneration failure of lakeshore plants under an artificially altered water regime
Authors: NISHIHIRO Jun , MIYAWAKI Shigenari , FUJIWARA Nobuo , WASHITANI Izumi
Published: November 2004

To reveal the effects of artificial alteration of water level regime on the regeneration of lakeshore plants from seeds, we examined the factors causing regeneration failure in Lake Kasumigaura, Japan. A survey of microtopography within and around a remnant fragment of lakeshore vegetation revealed that, over a large range, the habitat is frequently inundated in spring under the current water regime, although it was rarely inundated under past water regimes. Analysis of the patterns of seedling emergence and establishment at microsites at various elevations revealed a significant negative correlation between number of inundation days and abundance or species‐richness of seedlings that emerged in the spring. Most seedling deaths occurred when the study site was inundated. We suggest that regeneration failure caused by the artificial raising of the lake's water level is one of the principal mechanisms of the recent vegetational decline in the lake.
Asian weaver ants,Oecophylla smaragdina,and their repelling of pollinators
Authors: TSUJI Kazuki , HASYIM Ahsol , Harlion  , NAKAMURA Koji
Published: November 2004

The Asian weaver ant,Oecophylla smaragdina,is known to have outstanding predatory power. This ant can protect the host plants from attacks of phytophagous insects and therefore has been used for biological control in the tropics. We present evidence for a possible negative effect ofOecophyllaon the performance of host plants. Our observation in a fruit orchard of rambutan in Sumatra suggested that the presence ofOecohyllanests on the trees statistically significantly lowered the flower‐visiting rate of flying insects, involving the major pollinatorTrigona minangkabau. The visiting rate ofOecophyllaworkers to each flower shoot of rambutan significantly negatively correlated with the visiting rate of flying insects. Empirical evidence of such an inhibitory effect on flower‐visiting of pollinators cased by aggressive ants has been scarce so far.
Laparoscopic resection for rectal cancer in patients with previous abdominal surgery: A comparative study
Authors: Kwok Shek‐Yuen , Chung Cliff Chi‐Chiu , Tsang Wilson Wen‐Chieng , Li Michael Ka‐Wah
Published: November 2004

Objective:  In laparoscopic colorectal procedures, the presence of peritoneal adhesions caused by previous surgery is one of the most common reasons for conversion and is often associated with increased postoperative morbidity. However, improvements in laparoscopic technique and instruments might, to some extent, help to overcome the adverse effects of peritoneal adhesions. Therefore, the present study was designed to compare and evaluate laparoscopic rectal cancer excision in patients who had had and who had not had previous abdominal surgery.

Methods:  The present study was a non‐randomized comparison of patients who have had and have not had previous abdominal surgery. Data were extracted from a prospective cohort of patients who had undergone laparoscopic anterior resection for rectal cancer in one particular unit between January 1996 and May 2000. For the purpose of standardization, data on laparoscopic low anterior resection and laparoscopic abdomino‐perineal resection were not used for analysis. The measured outcomes included operation time, blood loss and length of hospital stay as well as complications and conversions.

Results:  Of the 91 patients recruited for analysis, 26 patients had had previous abdominal surgery (study group), whereas 65 patients had not had previous abdominal surgery (control group). The two groups had a similar age and gender distribution as well as tumour staging. The median operating times of the study group and control group (115 vs 123 min, P = 0.34), their blood loss (122 vs 144 mL, P = 0.30) and lengths of hospital stay (10 vs 11 days, P = 0.66) were similar. The complication rates (23 vs 23%, P = 0.79) and conversion rates (15.4 vs 7.7%, P = 0.55) were also similar between the two groups.

Conclusion:  Laparoscopic resection for rectal cancer in patients who have had previous abdominal surgery is technically safe and produces similar results to those who have not had previous abdominal surgery.
Peritoneal mesothelial cells produce inflammatory related cytokines
Authors: Yao Veronica , Platell Cameron , Hall John C.
Published: November 2004

Background:  Peritonitis involves cascading interactions between cytokines that initiate robust signalling processes via the interferon‐g and nuclear factor kappa B pathways. The present study evaluates the interplay between various putative inducers of peritonitis and a battery of inflammation‐related cytokines.

Methods:  Cultures of peritoneal mesothelial cells were isolated from omenta harvested from male Wistar rats. These cultures were exposed to tumour necrosis factor (TNF)‐α, lipopolysaccharide, zymosan, myeloperoxidase, peritoneal fluid from rats with zymosan‐induced peritonitis, and peritoneal fluid from control animals. The production of TNF‐α, interleukin (IL)‐1β, IL‐6, and IL‐10 was assessed after 4, 12 and 24 h.

Results:  Lipopolysaccharide and zymosan stimulated TNF‐α, IL‐1β, and IL‐10 production; and peritoneal fluids from both control animals and animals with zymosan‐induced peritonitis stimulated the production of TNF‐α, IL‐1RII, and IL‐6. Expression and secretion of TNF‐α occurred in a constitutive manner and was regulation at the protein level. The decoy molecule IL‐1 receptor type II (IL‐1RII) was produced at the same time as IL‐1β and production of the anti‐inflammatory cytokine IL‐10 was evident within 4 h. IL‐6 was constitutively expressed and regulated at the transcriptional level as indicated by a marked discontinuity between the amount of IL‐6 produced and the extent IL‐6 messenger ribonucleic acid (mRNA) expression.

Conclusions:  Tumour necrosis factor‐α might not be the sole primary mediator of peritonitis. The anti‐inflammatory molecules IL‐1RII and IL‐10 are induced at the same time as the pro‐inflammatory cytokines TNF‐α, IL‐1β, and IL‐6. This suggests that complex control systems are set in place by the factors that stimulate peritoneal mesothelial cells and might have the potential to cause peritonitis.
Use of Foley's catheter to gain access for retroperitoneoscopy
Authors: Shah Amar , Chandran Harish
Published: November 2004

With the increasing popularity of laparoscopic urologic surgery, many different methods have been used to dissect the extraperitoneal space and gain access to the kidney and ureter. We present our initial experience using a Foley catheter to gain retroperitoneal access. This technique was successfully used in 30 children. We have not encountered any major complications and recommend its use in children.
Daily versus intermittent iron supplementation in pregnant women: Hematological and pregnancy outcome
Authors: Mukhopadhyay Asima , Bhatla Neerja , Kriplani Alka , Pandey Ravindra M. , Saxena Renu
Published: November 2004

Aim:  To compare the hematological parameters and pregnancy outcome in women receiving daily versus weekly iron supplements during pregnancy.

Methods:  A prospective randomized controlled study was carried out at the Department of Obstetrics and Gynaecology of the All India Institute of Medical Sciences, New Delhi, India, during which 111 women were randomized to receive either 100 mg elemental iron daily (n = 55) or 200 mg elemental iron weekly (n = 56). Hemogram and serum ferritin level estimation were carried out at the beginning of pregnancy and within the 32–34‐week period of gestation. Side‐effects, compliance and the number of tablets consumed were noted for each group. The mean birth weight, period of gestation at delivery and mode of delivery were also compared between the two intervention groups.

Results:  There was no significant difference in the mean hemoglobin levels between the two intervention groups at the end of an average 17 weeks of iron supplementation. However, among anemic women who received daily supplementation, there was a greater rise in hemoglobin compared with those receiving supplementation weekly. The serum ferritin level was lower in the weekly supplemented group compared with that in the daily. There was no difference in the mean birth weight, period of gestation and mode of delivery between the two groups. Side‐effects and non‐compliance were significantly higher (P < 0.001) in the daily supplemented group.

Conclusions:  Weekly iron supplementation is an effective option for prophylaxis in non‐anemic pregnant women, but has less than optimal benefit in anemic women.
Relationship between the timing of hysterosalpingography before gamete intrafallopian transfer and the subsequent fertility outcome
Authors: Kaya Hakan , Karci Mehmet , Ozkaya Okan , Sezik Mekin
Published: November 2004

Aim:  To investigate the prognostic significance of hysterosalpingography carried out before one‐sided gamete intrafallopian transfer for unexplained infertility.

Methods:  Fifty‐nine first gamete intrafallopian transfer cycles in 59 couples with unexplained infertility were evaluated in two groups: 30 women with a hysterosalpingogram carried out 1–6 months prior to gamete intrafallopian transfer procedure combined with diagnostic laparoscopy, and 29 women with a hysterosalpingogram carried out during any other interval up to 2 years. The outcome measures were biochemical pregnancy, clinical pregnancy, miscarriage, preterm delivery, and term delivery. Groups were compared using Student's t‐test and chi‐squared tests. Logistic regression was used to predict the effects of hysterosalpingography on subsequent fertility outcomes.

Results:  Univariate analysis yielded no significant differences across groups regarding the baseline characteristics and outcome measures. When confounding factors were controlled, carrying out hysterosalpingography at some time before 6 months of gamete intrafallopian transfer was associated with 5.2‐ and 3.4‐fold increased clinical pregnancy and term delivery rates, respectively.

Conclusions:  An additional hysterosalpingography at most 6 months prior to gamete intrafallopian transfer procedure might improve fertility prospects. This effect could be attributed to proper selection of the fallopian tube for cannulation during transfer or some therapeutic effect of hysterosalpingography.
Relationship between noradrenaline and nonlinear indexes of blood pressure dynamics in normotensive and spontaneously hypertensive rats
Authors: Dabiré Hubert
Published: November 2004

Recent studies in normotensive Wistar–Kyoto (WKY) and spontaneously hypertensive (SHR) rats show that some nonlinear indexes derived from the recurrence plot method may be better markers of sympathetic activity than the spectral powers of blood pressure (BP). We herein investigated the relationships between nonlinear indexes and plasma noradrenaline concentration in conscious WKY rats and SHRs. Blood pressure was recorded for 30 min after intravenous injection of saline (0.9% NaCl, 100 μL/kg), hexamethonium (20 mg/kg), atropine (0.5 mg/kg), atenolol (1 mg/kg) or prazosin (1 mg/kg). Spectral power in the low‐frequency (LF) band and the nonlinear index (Lmax), calculated on diastolic (DBP) and systolic blood pressures (SBP), were used to analyse the BP signal. Noradrenaline concentration was determined by radioenzymatic technique. A robust stepwise regression analysis – using noradrenaline concentration as dependent variable, and LF, Lmax and treatment, as independent variables –shows that treatment is the main variable explaining the variance of noradrenaline level in WKY rats, excluding the use of the pooled data to explore the relationship between noradrenaline concentration and LF or Lmax. In contrast, in SHRs, treatment has no effect on the variance of noradrenaline concentration and the pooled data were then used. In this group, no correlation was observed between noradrenaline concentration and LF. In contrast, very high positive correlation was observed between noradrenaline level and Lmax‐DBP (r = 0.59; P = 0.0005) or Lmax‐SBP (r = 0.53; P < 0.002). The results strengthen our previous suggestion that nonlinear indexes may be better tools than spectral powers to investigate the sympathetic nervous system.
Executive Prerogative and the “Good Officer” in Thomas Jefferson's Letter to John B. Colvin
Authors: BAILEY JEREMY DAVID
Published: November 2004

Thomas Jefferson's clearest statement on executive prerogative can be found in his letter to John B. Colvin. Although this letter has been cited often, few scholars have considered its argument in its entirety, and no scholar has yet considered its context. By reexamining the letter, this article presents Jefferson's understanding of the prerogative power, which argues that the president must act outside the law when self‐preservation or the public good requires but must then declare his action to Congress or the people. Because Jefferson's understanding both expands and demarcates prerogative, it can contribute to the scholarly debate on prerogative.
DILATIONS AND COMMUTANT LIFTING FOR SUBALGEBRAS OF GROUPOID C*-ALGEBRAS
Authors: MUHLY PAUL S. , SOLEL BARUCH
Published: November 2004

Let B be a nuclear C*-algebra that has a diagonal subalgebra D in the sense of Kumjian and let A be a closed, not necessarily self-adjoint subalgebra of B that contains D such that A + A* is dense in B. We show that every contractive representation of A has an essentially unique minimal dilation to a C*-representation of B and that the commutant of the representation of A can be lifted to the commutant of the dilation without increasing norms.
EXTREMAL RAYS AND NULL GEODESICS ON A COMPLEX CONFORMAL MANIFOLD
Authors: YE YUN-GANG
Published: November 2004

A holomorphic conformal structure on a complex manifold X is an everywhere non-degenerate section [Formula: see text] for some line bundle N. In this paper, we show that if X is a projective complex n-dimensional manifold with non-numerically effective Kx and admits a holomorphic conformal structure, then X ≅ ℚn. This in particular answers affirmatively a question of Kobayashi and Ochiai. They asked if the same holds assuming c1 (X) > 0. As a consequence, we also show that any projective conformal manifold with an immersed rational null geodesic is necessarily a smooth hyperquadric ℚn.
DIMENSION GROUPS AND EMBEDDINGS OF GRAPH ALGEBRAS
Authors: EVANS DAVID E. , GOULD JEREMY D.
Published: November 2004

If Γ is a graph, with distinguished vertex *, let A(Γ) denote the non-commutative path algebra on the space [Formula: see text] of semi-infinite paths in Γ beginning at *. We discuss embeddings A(Γ1) → A(Γ2) of AF algebras associated with graphs Γ1 and Γ2 from a dimension group point of view. For certain infinite T-shaped graphs, we have K0(A(Γ)) ≅ ℤ [t], with positive cone identified with {0}∪ {P ∈ ℤ [t]: P (λ) > 0, λ ∈ (0, γ]}, where γ = γ (Γ) =||Γ||−2 < 1/4. Hence for certain graphs there exists a unital homomorphism A(Γ1) → A(Γ2) if ||Γ1|| ≤ ||Γ2||. For certain finite T-shaped graphs K0 (A(Γ)) ≅ ℤ [t]/ where  denotes the ideal generated by a polynomial Q=Q(Γ) which is essentially the characteristic polynomial of the graph Γ and positive cone identified with {0}∪ {f + : f(γ) > 0} where γ = γ(Γ) = ||Γ||-2. Hence there exists a unital homomorphism A(Γ1) → A(Γ2) if ||Γ1|| = ||Γ2||, and Q(Γ2) divides Q(Γ1). The structure of K0(A(Γ)) as an ordered ring is related to the fusion rules of rational conformal field theory.
ORBIFOLD CONSTRUCTION FOR NON-AFD SUBFACTORS
Authors: GOTO SATOSHI
Published: November 2004

We extend the orbifold construction to arbitrary (not necessarily AFD) subfactors. That is, we construct subfactors with principal graphs D2n from those with principal graphs A4n−3 by taking simultaneous Z2-crossed products with non-strongly outer actions. Our result can be applied to Popa's universal subfactors with principal graphs A4n−3, for example.
CLUSTER VS. SINGLE-SPIN ALGORITHMS—WHICH ARE MORE EFFICIENT?
Authors: ITO N. , KOHRING G.A.
Published: November 2004

A comparison between single-cluster and single-spin algorithms is made for the Ising model in 2 and 3 dimensions. We compare the amount of computer time needed to achieve a given level of statistical accuracy, rather than the speed in terms of site updates per second or the dynamical critical exponents. Our main result is that the cluster algorithms become more efficient when the system size, Ld, exceeds, L~70–300 for d=2 and l~80–200 for d=3. The exact value of the crossover is dependent upon the computer being used. The lower end of the crossover range is typical of workstations while the higher end is typical of vector computers. Hence, even for workstations, the system sizes needed for efficient use of the cluster algorithm is relatively large.
HIGHER ORDER UNITARY INTEGRATORS FOR THE SCHRÖDINGER EQUATION
Authors: FRAUENKRON HELGE , GRASSBERGER PETER
Published: November 2004

For classical Hamiltonian dynamics, much progress has recently been made in manifestly symplectic integrators. In this work some of these integrators will be generalized to the Schrödinger equation. There they correspond to algorithms which preserve unitarity and time reversal invariance exactly. In particular, we apply them to the one-dimensional harmonic and anharmonic oscillators. The accuracies of the three different algorithms are compared.
COMPUTATION OF TWO-DIMENSIONAL INCOMPRESSIBLE TURBULENT BOUNDARY LAYER FLOWS WITH EQUILIBRIUM AND NONEQUILIBRIUM TURBULENCE MODELS
Authors: Wong Daniel , Ahmed Salahuddin
Published: November 2004

Two-dimensional incompressible turbulent boundary layer flows over a flat plate were predicted using turbulent boundary layer equations. Reynolds stresses were calculated using Cebeci-Smith, Baldwin-Lomax, and Johnson-King eddy viscosity models. Computational results of mean-flow properties based on Cebeci-Smith model and Baldwin-Lomax model are in excellent agreement with experimental data, and, those based on Johnson-King model are not as accurate as the other two models.
ACCURATE CALCULATION OF THE HIGH TEMPERATURE THERMOPHYSICAL PROPERTIES OF GASES
Authors: BIOLSI LOUIS , HOLLAND PAUL M.
Published: November 2004

The kinetic theory of gases can be used to accurately calculate the transport properties of gases based on knowledge of the intermolecular potential between the interacting atoms, molecules or ions. This approach has been especially useful at high temperatures where experimental transport data are either sparse or unavailable. In recent years, increasingly accurate potentials for atom-atom and atom-ion interactions have become available for such calculations, and approaches for applying these potentials to calculate the high temperature thermophysical properties of gases are described.
SOME PARAMETER STUDIES ON HYPERSONIC COUETTE FLOW
Authors: SARMA G.S.R.
Published: November 2004

Parametric studies using the plane Couette flow as a simple model for shear flows to test different physico-chemical aspects of the very complex high-temperature chemically reacting flows occurring in hypersonic flow configurations are under way. Some typical results on the dissociation/recombination reactions of diatomic gases as to the effects of the choice of transport coefficient modelling and reaction rate coefficient data on the practically relevant quantitites such as heat transfer and skin friction at the solid walls are discussed.
SPIN GLASS GROUNDSTATE INVESTIGATION BY MULTICANONICAL ENSEMBLE
Authors: HANSMANN ULRICH H.E. , BERG BERND A.
Published: November 2004

We study the 3d Edwards-Anderson Ising spin glass on finite lattices by multicanonical ensemble. Performing simulations of this ensemble enables to generate large numbers of groundstate configurations in thermal equilibrium.
A MULTICANONICAL STUDY OF THE PROTEIN FOLDING PROBLEM
Authors: HANSMANN ULRICH H.E. , OKAMOTO YUKO
Published: November 2004

Applications of the multicanonical ensemble for the protein folding problem are presented. Performing simulations of this ensemble alleviates the multiple-minima problem and allows to calculate thermodynamical quantities at any temperature from only one Monte Carlo run.
An Economy of Molecular Dynamics Simulations of Non-equilibrium Phenomena in Physics
Authors: Zhu H. , Averback R.S.
Published: November 2004

A method to reduce the CPU time required for molecular dynamics computer simulations of nonequilibrium phenomena in physics has been developed. At each time step in the simulation of a solid system, a force calculation is performed on only those atoms that satisfy at least one of three criteria: (i) its distance moved, (ii) its acceleration, (iii) its change in acceleration. A fourth criteria on the time interval since the forces on all atoms were updated is also employed. For a gas system, forces of the atoms which fly freely in a certain time interval are not updated until these atoms move in a distance that is greater than a predetermined value. A savings in CPU time greater than a factor of two is obtained with negligible loss in accuracy.
Calculating Fundamental Vibrational Frequencies of Rutile by Combining Ab Initio Method with GF Matrix Method
Authors: Libin Lin , Xiangyin Zheng
Published: November 2004

Based on cluster model, we have calculated the fundamental vibrational frequencies of rutile by combining ab initio method and Wilson’s GF-matrix method. In the calculation, we have introduced the concept of environment factor α to correct the force field of the cluster model. The results of calculation are in good agreement to the experimental data and the normal modes give us clear physical picture of the crystal vibration.
BASIC ELEMENTS OF BIOLOGICAL COMPUTATIONAL SYSTEMS
Authors: ANDERSON CHARLES H.
Published: November 2004

This paper explores some basic representational and implementation issues arising from the premise that cortical circuits operate on probability density functions to reason about analog quantities. Some insight is provided into why neurobiological systems can appear messy, while at the same time provide a rich and robust computational environment.
FERMION NUMBER VIOLATION AND A TWO-DIMENSIONAL HIGGS MODEL
Authors: MONTVAY I.
Published: November 2004

The investigation of topological properties of the gauge field in a two-dimensional Higgs model can help in understanding anomalous fermion number violation.
HOW STRONG IS THE ELECTROWEAK PHASE TRANSITION ON THE LATTICE?
Authors: ILGENFRITZ E.-M. , SCHILLER A.
Published: November 2004

We discuss the strength of the first order thermal phase transition of the SU(2) Higgs model appearing in a lattice study. Based on block-spinning, an order parameter for Higgs condensation is proposed.
THE ELECTROWEAK PHASE TRANSITION ON THE LATTICE
Authors: FARAKOS K. , KAJANTIE K. , RUMMUKAINEN K. , SHAPOSHNIKOV M.
Published: November 2004

According to the electroweak baryogenesis scenario the matter-antimatter asymmetry of the Universe was created shortly after the Big Bang, during the electroweak phase transition. This process depends strongly on the detailed nature of the electroweak phase transition. For realistic Higgs particle masses, the standard perturbative analysis indicates that the transition is at most only weakly first order. We have studied the transition with non-perturbative lattice Monte Carlo simulations. We found large non-perturbative effects; in particular, the phase transition is a strongly first order one, at least up to Higgs mass of about 85 GeV. This makes electroweak baryogenesis a viable scenario with a Higgs mass not exceeding 85 GeV.
SIMULATED ANNEALING APPLIED TO OPTIMAL DCT QUANTIZATION
Authors: SHERLOCK BARRY G. , MONRO DONALD M.
Published: November 2004

We present a method for determining optimum quantization tables for use in image compression systems which conform to the ISO/CCITT standard for Image Compression, also known as the Joint Photographic Experts Group (JPEG) standard1. An algorithm based on simulated annealing2 compresses and decompresses any collection of 8 by 8 pixel blocks, while searching the space of 8 by 8 quantization tables for optimum fidelity according to some chosen measure. A composite cost function maintains a predefined compression ratio while minimizing the RMS error in the decoded image compared to the original. The process can be carried out on a raw image, or greater weight can be given to a selected range of DCT coefficients on the basis of psychophysical considerations3. The results of applying the methods to the intensity (y) components of three JPEG test images are presented. In all cases improved fidelity as measured by RMS error is obtained compared to the quantization table suggested in the JPEG standard. Significantly, the quantization tables obtained for one image most often provide smaller error when applied to other images than does the table suggested with the JPEG standard. An unexpected result when using pre-emphasized images suggests that the psychophysical assumptions underlying the suggested JPEG table may be oversimplified. By applying the method to blocks selected from a variety of images, improved quantization tables can be found for images in general, including color.
ANALYSIS OF NUMERICAL METHODS FOR USE IN MOLECULAR DYNAMICS CALCULATIONS APPLIED TO CRYSTALLINE LATTICES
Authors: MAZZONE A.M.
Published: November 2004

This work analyzes stability and accuracy of standard numerical methods applied to molecular dynamics simulations which generate configurations in the microcanonical and in the canonical ensembles. Numerical testing has been made on crystalline lattices of metallic and semiconducting type (Ag, Fe, and Si, respectively).
EXTERNAL ANCHORING FOR WIDE-AREA NETWORK SUPPORT: THE RHYTHM PROJECT
Authors: MAIOLI CESARE , SOLA STEFANO , VITALI FABIO
Published: November 2004

A major step in future hypertext systems, will be that of providing some of the interactivity characteristics of small scale centralised collaborative hypertext systems to larger scale, widely distributed ones such as WWW. Particularly important, as often asserted, is allowing free linking to all users, which may pose severe scale problems unless specific design decisions are taken. One design that is completely scalable is storing links’ anchors cxternally of the nodes they refer to and obtaining correctly updated information by relying on automatic versioning for all nodes. The RHYTHM hypertext system is a highly distributable hypertext system based on this premise. It provides free link, annotation, inclusion and customisation facilities to all users, creating an integrated environment for public and private document. Modularity and expandability in the services provided to the users is also an important part of the RHYTHM project, whose approach is based on allowing additional managers to be included in the client application in order to carry out specific tasks or handle specific data types.
ON-LINE HYPERMEDIA NEWSPAPERS: AN EXPERIMENT WITH “L’UNIONE SARDA”
Authors: RUGGIERO FRANCESCO , VAN KLEIJ REINIER
Published: November 2004

In this brief paper we present a prototype of a an On-line hypermedia newspaper, the first example of daily electronic publishing in Italy, based on the results of a collaboration between CRS4 and L’UNIONE SARDA. The on-line newspaper (text and picture) is created by automatic retrieval, compression, transmission and conversion of newspaper data. The prototype is under development and currently allows automatic hypertextual links, article retrieval facilities and a simple mechanism for creating a personal newspaper. Some HyperText Markup Language (HTML) pages, are shown to give an impression of the prototype.
TOPOLOGY DEPENDENCE IN LATTICE SIMULATIONS OF NON-LINEAR PDES ON A MIMD COMPUTER
Authors: VALIN P. , GOULARD B. , SANIELEVICI M.
Published: November 2004

We tested the parallelization of explicit schemes for the solution of non-linear classical field theories of complex scalar fields which are capable of simulating hadronic collisions. Our attention focused on collisions in a fractional model with a particularly rich inelastic spectrum of final states. Relativistic collisions of all types were performed by computer on large lattices (64 to 256 sites per dimension). The stability and accuracy of the objects were tested by the use of two other methods of solutions: Pseudo-spectral and semi-implicit. Parallelization of the Fortran code on a 64-transputer MIMD Volvox machine revealed, for certain topologies, communication deadlock and less-than-optimum routing strategies when the number of transputers used was less than the maximum. The observed speedup, for N transputers in an appropriate topology, is shown to scale approximately as N, but the overall gain in execution speed, for physically interesting problems, is a modest 2–3 when compared to state-of-the-art workstations.
RELAXATION OF HOT ELECTRONS.: A SIMPLE AND EFFICIENT QUANTUM MECHANICAL MOLECULAR DYNAMICS SIMULATION METHOD
Authors: MAZZONE A.M.
Published: November 2004

A molecular dynamics simulation method designed for the analysis of hot electrons-lattice interactions is presented. The physics is based on a simplified quantum mechanical approach and from the computational point of view the simulation has been designed for parallel computing. The results are in agreement with other theories and experimental trends.
ACCELERATING WILSON FERMION MATRIX INVERSIONS BY MEANS OF THE STABILIZED BICONJUGATE GRADIENT ALGORITHM
Authors: FROMMER ANDREAS , HANNEMANN VOLKER , NÖCKEL BERTOLD , LIPPERT THOMAS , SCHILLING KLAUS
Published: November 2004

The stabilized biconjugate gradient algorithm BiCGStab recently presented by van der Vorst is applied to the inversion of the lattice fermion operator in the Wilson formulation of lattice Quantum Chromodynamics. Its computational efficiency is tested in a comparative study against the conjugate gradient and minimal residual methods.

Both for quenched gauge configurations at β=6.0 and gauge configurations with dynamical fermions at β=5.4, we find BiCGStab to be superior to the other methods. BiCGStab turns out to be particularly useful in the chiral regime of small quark masses.
RELAXATION PROCESSES IN NEON AFTER GLOW PLASMA
Authors: EL-KORAMY R.A. , AMRY A.M.A. , ACHURBECOV N.A.
Published: November 2004

The nanosecond impulse discharge in Ne gas has been investigated by mass spectrometric, optical, and probe methods. It is shown that the dissociative recombination of [Formula: see text] plays an important role in the population of the excited levels 2p53sX in Ne after glow plasma.
NONLINEAR DYNAMIC EXCITATIONS AND PHONONS IN NANOSYSTEMS
Authors: SCHOMMERS W. , KLANN H. , POLITIS C. , PAPANIKOLAOU P. , ATHANASIOU N.
Published: November 2004

The phonon density of states for nanoclusters has been studied theoretically using molecular dynamics; in this way, anharmonic effects could be fully considered. Comparisons are made with results obtained from bulk calculations. The cluster properties have been studied for several particle numbers and temperatures.

It turned out that the properties of clusters are sensitive to small variations in the interactions between the particles. Therefore, in the calculation of cluster properties, the precise knowledge of the interaction is necessary. In our study, we have chosen krypton nanosystems because for this substance, a reliable interaction potential is available. First estimations have also been performed for metal (Al, Pb) systems.
EXACT RESULTS FOR 1D CONSERVED ORDER PARAMETER MODEL
Authors: PRIVMAN VLADIMIR
Published: November 2004

Recent exact results for a particle-exchange model on a linear lattice, with only irreversible moves reducing the local energy allowed, are reviewed. This model describes a zero-temperature Kawasaki-type phase-separation process which reaches a frozen, initial-condition-dependent state at large times.
INFORMATION-THEORETIC APPROACH TO THE DYNAMICAL EVOLUTION OF TWO-ATOM DICKE MODEL
Authors: JOSHI AMITABH
Published: November 2004

The two-atom Dicke model driven by a coherent field and interacting with a thermal reservoir is considered here. The evolution of density operator for this system is explicitly calculated using the maximum entropy principle.
STRUCTURAL DISORDER IN AMORPHOUS III–V COMPOUNDS
Authors: GRADO CAFFARO M.A. , GRADO CAFFARO M.
Published: November 2004

Some new results on structural disorder in amorphous III–V semiconductors are established. In particular, a relationship is obtained for the maximum frequency (in the far-infrared range) at which |µ(ω)|/ω is constant (µ(ω) is the dipole moment matrix element in the angular frequency domain). The mathematical behaviors of |µ(ω)| and its first derivative are discussed. Furthermore, absorption coefficient at very low frequencies is determined analytically and compared with the experiment.
SYNTHESIS AND STUDY OF Hg-Ba-Ca-Cu-O SUPERCONDUCTORS
Authors: SHENG Z.Z. , LI Y.F. , GORETTA K.C.
Published: November 2004

We have synthesized good-quality Hg-Ba-Ca-Cu-O samples using a precursor method. The samples are dominated by Hg-1212 phase HgBa 2 CaCu 2 O 6. Annealing in flowing oxygen or in a vacuumed glass tube increases its Tc by about 20 K to an onset temperature of 130 K and a zero-resistance temperature up to 126 K. The samples also contain a small amount of Hg-1223 phase HgBa 2 Ca 2 Cu 3 O 8, which, after annealing, exhibits an onset temperature of 135 K. Possible much higher temperature superconductivity may exist in the Hg-Ba-Ca-Cu-O system.
SOLITONS IN THE FCC ANTIFERROMAGNETIC CEX AND UX
Authors: LIU WU-MING , ZHOU BEN-LIAN
Published: November 2004

By introducing the coherent state ansatz and the time-dependent variation principle, we obtain two nonlinear partial differential equations of motion from the Hamiltonian. Employing the method of multiple scalar, we reduce these equations into the envelope function equations. In order to apply the perturbation theory, we force the amplitude function to satisfy a nonlinear Schrödinger equation and obtain the single, two-, and N-solitons in the antiferromagnetic CeX and UX.