bluuebunny/crossref_metadata_2025 huggingface dataset:
Gonadal and hormonal phenology in free-living male rufous whistlers, Pachycephala rufiventris (Passeriformes : Pachycephalidae)
Authors: McDonald P. G. , Astheimer L. B. , Buttemer W. A.
Published: September 2002

The hormonal and gonadal profiles of the few Australian old endemic passerine
species studied to date have exhibited less annual variation in gonad size,
reduced amplitude in testosterone (T) and luteinising hormone (LH) levels in
comparison with those exhibited by many predominantly migratory species from
the north temperate zone. Because none of the Australian endemics studied to
date were migratory species, we studied a migratory population of rufous
whistlers in central western New South Wales to determine whether differences
in life history might be associated with different gonadal and hormonal
profiles. Breeding stages were classified into five functional categories:
territory/pair establishment, nest building, incubation, feeding
nestlings/fledglings and post-breeding. We captured adult males at all
breeding stages, examined their gonadal status through unilateral laparotomy,
collected a blood sample and assessed this for plasma T and LH content using
radioimmunoassay. Both hormones peaked early in the breeding season: LH levels
during territory/pair establishment at 2.8 ng/mL 1.7 (s.d.) and T
levels during nest building at 1.8 ng/mL 1.6 (s.d.). Following incubation
LH and T (in particular) levels decreased substantially with the onset of
parental duties – whilst feeding nestlings/fledglings T was 0.1
ng/mL 0.1 (s.d.), and LH was 1.6 ng/mL 1.2 (s.d.). This temporal
variation in hormone secretion and an observed synchronous peak in gonad size
at nest-building is reminiscent of migratory species from the north temperate
zone displaying biparental care. Peak concentrations of both plasma T and LH
in whistlers were intermediate between those reported for passerines from the
north temperate zone with a similar life history and sedentary Australian old
endemic passerines examined to date. This possibly reflects differences in
life-history traits, the functional use of T in this species and/or
possible phyletic effects.
Metabolic response to feeding and fasting in the water python (Liasis fuscus)
Authors: Bedford Gavin S. , Christian Keith A.
Published: September 2002

Compared with other reptiles, pythons have a relatively low standard metabolic
rate (SMR) when post-absorptive, but metabolism increases substantially after
feeding. This study examined the effects of feeding and fasting on adult and
hatchling water pythons (Liasis fuscus). We compared
ratios of peak digestive metabolic rate (PDMR) after feeding with the
metabolic rate of both post-absorptive (SMR) and fasted water pythons. If
metabolic rate of a fasting snake is taken as ‘SMR’, then the
ratio PDMR/SMR becomes increasingly exaggerated as fasting continues.
After 56 days of fasting in adults, or after 45 days in hatchlings, the
metabolic rate of water pythons was significantly lower than that of
post-absorptive animals. Peak digestive metabolic rate of post-absorptive
adult water pythons was only 6.3–12.0 times SMR, but the ratio was twice
that if fasted (metabolically depressed) animals were used to determine the
‘SMR’ denominator. Thus, this ratio should be used with caution.
Peak digestive metabolic rate after feeding increased with increasing meal
size for meals less than 20% of body mass, but PDMR did not increase
for meals between 20% and 39% of body mass for adult water
pythons. Similarly, the PDMR did not increase signif icantly between
25% and 50% meal sizes for hatchlings. The digestive physiology
of water pythons is apparently better suited to frequent meals of relatively
small prey compared with the digestive physiology of some other pythons.
The response of captive silvereyes (Zosterops lateralis) to the colour and size of fruit
Authors: Stanley M. C. , Smallwood E. , Lill A.
Published: September 2002

Birds are important consumers and dispersers of the seeds of fleshy fruit and some have been shown to be selective in their choice of fruit. However, our knowledge of how birds respond to a variety of fruit characteristics is poor. Some birds are known to avoid green fruit or consume them less than fruit of other colours. The fruit of many plant species are green when they are unripe and contain low concentrations of sugars and high concentrations of secondary compounds. In this study, captive silvereyes (Zosterops lateralis) were presented with a choice of red, white and green artificial fruit. Half of them were given these fruit with equal sugar concentrations (15%) and the other half were given the choice but with the green fruit having a sugar concentration twice that of the other two colours (30%). Green fruit were not strongly avoided by silvereyes and were actually preferred when they had a higher sugar concentration than the other two fruit types (red and white). Sugar concentration was therefore a more important determinant of fruit choice than colour. Fruit size is also known to affect fruit choice in some bird species. Small fruit are easier to consume than larger fruit, but contain less pulp. To maximise energy gain, birds should consume fruit that are large, but not large enough to incur high handling costs. Silvereyes in this study were presented with a choice between 20 artificial fruit 4 mm in diameter (large fruit) and 20 artificial fruit 2 mm in diameter (small fruit), both of which they are able to consume. In this experiment, silvereyes exhibited a strong preference for large fruit over small fruit. In general, larger fruit contain more pulp and therefore more energy than smaller fruit. However, other fruit traits, such as seed load, are likely to influence fruit choice by silvereyes in the wild and result in a trait hierarchy.
Polymorphism, mate choice and sexual selection in the Gouldian finch (Erythrura gouldiae)
Authors: Fox S. , Johnson C. N. , Brooks R. , Lewis M. J.
Published: September 2002

Mate choice can result in both assortative mating and directional sexual selection, but few studies have addressed both processes simultaneously. Here we test several hypotheses regarding the possible role of female mate choice in maintaining the face-colour polymorphism of, and affecting directional sexual selection in, the Gouldian finch. These endangered Australian finches are highly sexually dimorphic and are genetically polymorphic for face colour: there are black-, red- and gold-faced individuals. First we showed that Gouldian finches tend to pair positive-assortatively by face colour morph in aviaries. In a laboratory experiment, we tested whether female mate choice is assortative by face colour. Overall, females neither preferred males of the same or of different face colour morphs as themselves. We found weak evidence for positive assortative female choice at one of the two loci involved in determining face colour. Next, we tested whether females showed frequency-dependent mate choice, and found that they preferred neither rare nor common male morphs. In order to test for directional sexual selection on males by female mate choice, we examined the correlations between male morphological traits and attractiveness to females. We found that tail pin length and bill size are correlated with male attractiveness, and may be under sexual selection. Thus, whilst female mate choice may be an important process in determining the evolution of male morphology, and potentially sexual dimorphism, it does not appear to be the primary force behind the assortative mating pattern among the face colour morphs.
Chromosome morphology in Gilbert's potoroo, Potorous gilbertii (Marsupialia : Potoroidae)
Authors: Sinclair E. A. , Murch A. R. , Di Renzo M. , Palermo M.
Published: September 2002

Chromosome morphology was examined for male and female Gilbert’s
potoroo, Potorous gilbertii, to infer taxonomic and
evolutionary relationships among the extant taxa within the genus
Potorous. P. gilbertii has the same number of
chromosomes as P. tridactylus, 2n
= 12,13. Giemsa-banding patterns were very similar in
P. gilbertii and P. tridactylus;
however, differences were noted between the sex chromosomes. Given that the
relationships among extant Potorous are unresolved, we
mapped karyotypes onto two alternative phylogenies to suggest methods of
karyotype evolution within this group. Karyotypes and molecular-based
information from the now ‘presumed extinct’
P. platyops or sequencing of multiple gene regions for
phylogenetic analysis within the Potoroidae would provide valuable information
for resolving the issue of rooting, and hence drawing conclusions on the
evolution of karyotypes within this group.
DEDD regulates degradation of intermediate filaments during apoptosis
Authors: Lee Justine C. , Schickling Olaf , Stegh Alexander H. , Oshima Robert G. , Dinsdale David , Cohen Gerald M. , Peter Marcus E.
Published: September 2002

Apoptosis depends critically on regulated cytoskeletal reorganization events in a cell. We demonstrate that death effector domain containing DNA binding protein (DEDD), a highly conserved and ubiquitous death effector domain containing protein, exists predominantly as mono- or diubiquitinated, and that diubiquitinated DEDD interacts with both the K8/18 intermediate filament network and pro–caspase-3. Early in apoptosis, both cytosolic DEDD and its close homologue DEDD2 formed filaments that colocalized with and depended on K8/18 and active caspase-3. Subsequently, these filamentous structures collapsed into intracellular inclusions that migrated into cytoplasmic blebs and contained DEDD, DEDD2, active caspase-3, and caspase-3–cleaved K18 late in apoptosis. Biochemical studies further confirmed that DEDD coimmunoprecipitated with both K18 and pro–caspase-3, and kinetic analyses placed apoptotic DEDD staining prior to caspase-3 activation and K18 cleavage. In addition, both caspase-3 activation and K18 cleavage was inhibited by expression of DEDDΔNLS1-3, a cytosolic form of DEDD that cannot be ubiquitinated. Finally, siRNA mediated DEDD knockdown cells exhibited inhibition of staurosporine-induced DNA degradation. Our data suggest that DEDD represents a novel scaffold protein that directs the effector caspase-3 to certain substrates facilitating their ordered degradation during apoptosis.
Inhibition of Type 1 Cytokine–mediated Inflammation by a Soluble CD30 Homologue Encoded by Ectromelia (Mousepox) Virus
Authors: Saraiva Margarida , Smith Philip , Fallon Padraic G. , Alcami Antonio
Published: September 2002

CD30 is up-regulated in several human diseases and viral infections but its role in immune regulation is poorly understood. Here, we report the expression of a functional soluble CD30 homologue, viral CD30 (vCD30), encoded by ectromelia (mousepox) virus, a poxvirus that causes a severe disease related to human smallpox. We show that vCD30 is a 12-kD secreted protein that not only binds CD30L with high affinity and prevents its interaction with CD30, but it also induces reverse signaling in cells expressing CD30L. vCD30 blocked the generation of interferon γ–producing cells in vitro and was a potent inhibitor of T helper cell (Th)1- but not Th2-mediated inflammation in vivo. The finding of a CD30 homologue encoded by ectromelia virus suggests a role for CD30 in antiviral defense. Characterization of the immunological properties of vCD30 has uncovered a role of CD30–CD30L interactions in the generation of inflammatory responses.
Proteolytic cleavage of the THR subunit during anaphase limits Drosophila separase function
Authors: Herzig Alf , Lehner Christian F. , Heidmann Stefan
Published: September 2002

Sister-chromatid separation in mitosis requires proteolytic cleavage of a cohesin subunit. Separase, the corresponding protease, is activated at the metaphase-to-anaphase transition. Activation involves proteolysis of an inhibitory subunit, securin, following ubiquitination mediated by the anaphase-promoting complex/cyclosome. In Drosophila, the securin PIM associates not only with separase (SSE), but also with an additional protein, THR. Here we show that THR is cleaved after the metaphase-to-anaphase transition. THR cleavage only occurs in functional SSE complexes and in a region that matches the separase cleavage-site consensus. Mutations in this region abolish mitotic THR cleavage. These results indicate that THR is cleaved by SSE. Expression of noncleavable THR variants results in cold-sensitive maternal-effect lethality. This lethality can be suppressed by a reduction of catalytically active SSE levels, indicating that THR cleavage inactivates SSE complexes. THR cleavage is particularly important during the process of cellularization, which follows completion of the last syncytial mitosis of early embryogenesis, suggesting that Drosophila separase has other targets in addition to cohesin subunits.
Biochemical and Genetic Characterization of the
vanC-2
Vancomycin Resistance Gene Cluster of
Enterococcus casseliflavus
ATCC 25788
Authors: Dutta Ireena , Reynolds Peter E.
Published: September 2002

The
vanC-2
cluster of
Enterococcus casseliflavus
ATCC 25788 consisted of five genes (
vanC-2
,

vanXY
C-2

,

vanT
C-2

,

vanR
C-2

, and

vanS
C-2

) and shared the same organization as the
vanC
cluster of
E. gallinarum
BM4174. The proteins encoded by these genes displayed a high degree of amino acid identity to the proteins encoded within the
vanC
gene cluster. The putative
d
,
d
-dipeptidase-
d
,
d
-carboxypeptidase, VanXY
C-2
, exhibited 81% amino acid identity to VanXY
C
, and VanT
C-2
displayed 65% amino acid identity to the serine racemase, VanT. VanR
C-2
and VanS
C-2
displayed high degrees of identity to VanR
C
and VanS
C
, respectively, and contained the conserved residues identified as important to their function as a response regulator and histidine kinase, respectively. Resistance to vancomycin was expressed inducibly in
E. casseliflavus
ATCC 25788 and required an extended period of induction. Analysis of peptidoglycan precursors revealed that UDP-
N
-acetylmuramyl-
l
-Ala-δ-
d
-Glu-
l
-Lys-
d
-Ala-
d
-Ser could not be detected until several hours after the addition of vancomycin, and its appearance coincided with the resumption of growth. The introduction of additional copies of the

vanT
C-2

gene, encoding a putative serine racemase, and the presence of supplementary
d
-serine in the growth medium both significantly reduced the period before growth resumed after addition of vancomycin. This suggested that the availability of
d
-serine plays an important role in the induction process.
Effect of Prolonged Fluconazole Treatment on
Candida albicans
in Diffusion Chambers Implanted into Mice
Authors: Sohnle Peter G. , Hahn Beth L.
Published: September 2002

Fluconazole is an azole agent with primarily fungistatic activity in standard in vitro susceptibility tests. The present study was undertaken to develop a diffusion chamber model system in mice in order to study the in vivo effects of prolonged fluconazole treatment on
Candida albicans
. Chambers containing 100
C. albicans
yeast cells were implanted subcutaneously on the flanks of C57BL/6 mice and were then retrieved 6 or 14 weeks later (after fluconazole treatment for 4 or 12 weeks, respectively). Leukocyte counts demonstrated that implantation of the chambers did elicit an inflammatory response but that only small numbers of inflammatory cells were able to enter the chamber interior. Treatment with fluconazole at 10 mg/kg of body weight/day for 12 weeks not only reduced the numbers of viable organisms within the chambers compared to those in untreated mice (mean ± standard deviation of log
10
CFU of 0.7 ± 1.2 versus 2.3 ± 2.0;
P
< 0.001 by the Bonferroni test) but also increased the numbers of chambers that became sterile over the treatment period (14 of 16 versus 6 of 19;
P
= 0.0009 by the chi-square test). However, treatment for only 4 weeks had minimal effects on the numbers of chamber CFU, and none of the chambers became sterile during this period. Distribution of retrieved organisms between interior fluid and the chamber filters was approximately equal in all the treatment groups. This model system appears to be useful for evaluating the effects of antifungal drugs over prolonged periods in vivo. Its use in the present study demonstrates that fluconazole can increase the rate of sterilization of
C. albicans
foci that are protected from the host's inflammatory response.
Bactericidal Effect and Pharmacodynamics of Cethromycin (ABT-773) in a Murine Pneumococcal Pneumonia Model
Authors: Kim Myo-Kyoung , Zhou Wen , Tessier Pamela R. , Xuan Dawei , Ye Min , Nightingale Charles H. , Nicolau David P.
Published: September 2002

Cethromycin (ABT-773), a new ketolide, possesses potent in vitro activity againstStreptococcus pneumoniae. The objective of this study was to investigate the in vivo bactericidal activity of cethromycin against macrolide-susceptible and -resistantS. pneumoniaein a murine pneumonia model and to describe the pharmacodynamic (PD) profile of cethromycin. Eight (two macrolide susceptible, six macrolide resistant) clinical isolates ofS. pneumoniaewere investigated. Cyclophosphamide administration rendered ICR mice transiently neutropenic prior to intratracheal inoculation with 0.05 ml of anS. pneumoniaesuspension containing 107to 108CFU/ml. Oral cethromycin was initiated 12 to 14 h postinoculation over a dosage range of 0.1 to 800 mg/kg of body weight/day. Lungs from seven to eight mice per treatment and control groups were collected at 0 and 24 h posttherapy to assess bacterial density. The cumulative mortality (n= 12 to 13) was assessed at 120 h (end of therapy) and at 192 h (3 days posttherapy). Recovery of pneumococci from the lungs of infected animals prior to the initiation of therapy ranged from 4.6 to 7.2 log10CFU. Growth in untreated control animals over a 24-h study period increased 0.3 to 2.7 log10CFU. Cethromycin demonstrated a substantial bactericidal effect, regardless of macrolide susceptibility. Correlation between changes in bacterial density (24 h) and survival over both 120 and 192 h were statistically significant. All three PD parameters demonstrated a significant correlation with changes in log10CFU/lung (Spearman's correlation coefficient,P< 0.001); however, the goodness of fit as assessed with the maximum effect (Emax) model revealed that the maximum concentration of free drug in serum (Cmax free)/MIC and the area under the free drug concentration-time curve (AUCfree)/MIC best explained the relationship between drug exposure and reductions in viable bacterial counts. These data reveal that an approximate cethromycin AUCfree/MIC of 50 orCmax free/MIC of 1 results in bacteriostatic effects, while higher values (twofold) maximize survival.
Ligands of the Peripheral Benzodiazepine Receptor Are Potent Inhibitors of
Plasmodium falciparum
and
Toxoplasma gondii
In Vitro
Authors: Dzierszinski Florence , Coppin Alexandra , Mortuaire Marlene , Dewailly Etienne , Slomianny Christian , Ameisen Jean-Claude , DeBels Frederic , Tomavo Stanislas
Published: September 2002

The increase in resistance of the malaria parasite
Plasmodium falciparum
to currently available drugs demands the development of new antimalarial agents. In this quest, we have found that ligands to the peripheral benzodiazepine receptor such as flurazepam, an agonist of the benzodiazepine family, and PK11195, an antagonist derived from isoquinoline, were active against
Plasmodium falciparum.
These two compounds effectively and rapidly inhibited parasite growth in vitro, irrespective of parasite resistance to chloroquine and mefloquine. Treatment with both drugs induced a sharp and consistent decline in parasitemia, a complete inhibition of parasite replication, and the destruction of parasites within the host red blood cells. Using electron microscopy, we showed that dramatic morphological changes, involving swollen endoplasmic reticulum and the reduction of hemozoin, were consistent with parasite death. The potent activities of flurazepam and PK11195 were also evaluated for antagonist or synergistic effects with currently used antimalarial drugs such as chloroquine and mefloquine. Moreover, flurazepam was found to be active against
Toxoplasma gondii
, another member of the phylum Apicomplexa. Taken together, our results indicated that benzodiazepines could be considered promising candidates in the treatment of both malaria and toxoplasmosis.
Comparative Evaluation of a New Fluorescent Carboxyfluorescein Diacetate-Modified Microdilution Method for Antifungal Susceptibility Testing of
Candida albicans
Isolates
Authors: Liao Robert S. , Rennie Robert P. , Talbot James A.
Published: September 2002

This report presents a fluorescent carboxyfluorescein diacetate (CFDA)-modified microdilution method used for the susceptibility testing of
Candida albicans
to amphotericin B, fluconazole, ketoconazole, itraconazole, voriconazole, and flucytosine. Four different broth microdilution susceptibility testing methods were simultaneously evaluated at 24 and 48 h. The MICs determined using the CFDA-modified method (MIC
cfda
) were compared to those obtained by the standard broth microdilution method (MIC
visual
) and a procedure employing the indicator Alamar blue (MIC
alamar
). The reference MIC was determined visually as recommended by the NCCLS M27-A protocol, and then quantified spectrophotometrically following agitation (MIC
spec)
. The CFDA-modified microdilution method was demonstrated to effectively determine the MICs for all the antifungal drugs tested at both 24 and 48 h. The results from both the MIC
spec
and MIC
cfda
methods yielded >80% agreement within ±1 dilution and >90% agreement within ±2 dilutions at 24 h in comparison to the reference MIC
visual
method, respectively. The trailing growth phenomenon that occurs with azole antifungal drugs and many strains of
C. albicans
did not inhibit the effectiveness of the MIC
spec
and MIC
cfda
methods. The MIC
spec
and MIC
cfda
methods shared 92.8% agreement within ±1 dilution at 24 h and 87.6% agreement within ±1 dilution at 48 h.
DNA Sequence Analysis of DNA Gyrase and DNA Topoisomerase IV Quinolone Resistance-Determining Regions of
Salmonella enterica
Serovar Typhi and Serovar Paratyphi A
Authors: Hirose Kenji , Hashimoto Ai , Tamura Kazumichi , Kawamura Yoshiaki , Ezaki Takayuki , Sagara Hiroko , Watanabe Haruo
Published: September 2002

The mutations that are responsible for fluoroquinolone resistance in the
gyrA
,
gyrB
,
parC
, and
parE
genes of
Salmonella enterica
serovar Typhi and serovar Paratyphi A were investigated. The sequences of the quinolone resistance-determining region of the
gyrA
gene in clinical isolates which showed decreased susceptibilities to fluoroquinolones had a single mutation at either the Ser-83 or the Asp-87 codon, and no mutations were found in the
gyrB
,
parC
, and
parE
genes.
In Vitro Activity of the New Oxazolidinone AZD2563 against Enterococci
Authors: Eliopoulos G. M. , Wennersten C. B. , Moellering R. C.
Published: September 2002

The activity of a new oxazolidinone antimicrobial, AZD2563, was assessed against >500 clinical isolates of enterococci representing six species. All isolates, including those resistant to other antibiotic classes, were inhibited by AZD2563 at concentrations ≤2 μg/ml, except for four strains resistant to linezolid. In most cases, AZD2563 was twofold more active than linezolid against enterococci.
Inhibition of Human Immunodeficiency Virus Type 1 Isolates by the Integrase Inhibitor L-731,988, a Diketo Acid
Authors: Reinke Ryan , Lee Deborah J. , Robinson W. Edward
Published: September 2002

L-731,988 inhibits human immunodeficiency virus (HIV) replication through integrase. In this study, approximately 600 nM L-731,988 inhibited the replication of 12 HIV type 1 isolates from multiple clades, including primary isolates and cloned viruses. These data suggest that diketo acids or their derivatives may prove useful on a worldwide basis in treating HIV infection.
In Vitro Synergistic Interaction between Amphotericin B and Pentamidine against
Scedosporium prolificans
Authors: Afeltra Javier , Dannaoui Eric , Meis Jacques F. G. M. , Rodriguez-Tudela Juan L. , Verweij Paul E.
Published: September 2002

To develop new approaches for the treatment of invasive infections caused by
Scedosporium prolificans
, the in vitro interaction between amphotericin B and pentamidine against 30 clinical isolates was evaluated using a checkerboard microdilution method based on the National Committee for Clinical Laboratory Standards M38-P guidelines. The interaction between the drugs was analyzed using fractional inhibitory concentration index (FICI) analysis and response surface modeling. Amphotericin B alone was inactive against all the isolates. The geometric mean MIC for pentamidine was 57 μg/ml (range, 8 to 256 μg/ml; MIC at which 50% of the isolates tested were inhibited [MIC
50
], 64 μg/ml; MIC
90
, 128 μg/ml). The combination was synergistic against 28 of 30 isolates (93.3%) by FICI analysis and 30 of 30 (100%) by response surface modeling analysis. Antagonism was not observed.
DIFFUSIONAL ANALYSIS OF INTERMITTENT TWO-PHASE FLOW TRANSITIONS
Authors: GIONA MASSIMILIANO , PAGLIANTI ALESSANDRO , SOLDATI ALFREDO
Published: September 2002

Diffusional analysis is employed to characterize two-phase flow regime transitions in horizontal pipes. The scaling analysis of the mean square displacement [Formula: see text] associated with the diffusional process driven by density fluctuations proves to be an efficient method for two-phase regime identification. Intermittent flow regime transitions are discussed and compared with theoretical and semiempirical models.
AN ADVERSARIAL MODEL FOR DISTRIBUTED DYNAMIC LOAD BALANCING
Authors: MUTHUKRISHNAN S. , RAJARAMAN RAJMOHAN
Published: September 2002

We study the problem of balancing the load on processors in an arbitrary network. If jobs arrive or depart during the process of load balancing, we have the dynamic load balancing problem; otherwise, we have the static load balancing problem. While static load balancing on a number of different networks has been well-studied, analytical work on dynamic load balancing is limited. The difficulty lies in modeling the arrivals and departures of jobs in a clean manner.

In this paper, we introduce a new framework for dynamic load balancing in which the job traffic is modeled by an adversary. Our main result is that a simple local load balancing algorithm maintains the load of the network within a stable level against a powerful adversary. Our result holds for different models of traffic patterns and processor communication.
On S‐cluster sets and S‐closed spaces
Authors: Mukherjee M. N. , Debray Atasi
Published: September 2002

A new type of cluster sets, called S‐cluster sets, of functions
and multifunctions between topological spaces is introduced,
thereby providing a new technique for studying S‐closed spaces.
The deliberation includes an explicit expression of S‐cluster set
of a function. As an application, characterizations of Hausdorff
and S‐closed topological spaces are achieved via such cluster
sets.
A general existence principle for fixed point theorems in D‐metric spaces
Authors: Dhage B. C. , Pathan A. M. , Rhoades B. E.
Published: September 2002

We establish two general principles for fixed point theorems in
D‐metric spaces, and then show that several theorems in
D‐metric spaces follow as corollaries of these general
principles.
A representation theorem for the linear quasi‐differentialequation (py′)′+qy=0
Authors: O′Hara J. G.
Published: September 2002

We establish a representation for q in the second‐order linear
quasi‐differential equation . We give a
number of applications, including a simple proof of Sturm′s
comparison theorem.
Statistical limit point theorems
Authors: Zeager Jeff
Published: September 2002

It is known that given a regular matrix A and a bounded sequence
x there is a subsequence (respectively, rearrangement,
stretching) y of x such that the set of limit points of Ay includes the set of limit points of x. Using the notion of a
statistical limit point, we establish statistical convergence
analogues to these results by proving that every complex number
sequence x has a subsequence (respectively, rearrangement,
stretching) y such that every limit point of x is a statistical
limit point of y. We then extend our results to the more general
A‐statistical convergence, in which A is an arbitrary
nonnegative matrix.
Some results on maximal elements
Authors: Carbone Antonio
Published: September 2002

We prove some results on maximal elements using the KKM‐map
principle.
The Kostant partition functions for twisted Kac‐Moody algebras
Authors: Chakrabarti Ranabir , Santhanam Thalanayar S.
Published: September 2002

Employing the method of generating functions and making use of some infinite product
identities like Euler, Jacobi′s triple product and pentagon identities we derive recursion
relations for Kostant′s partition functions for the twisted Kac‐Moody algebras.
On the decomposition of xd + aexe + ⋯+a1x + a0
Authors: Gomez-Calderon Javier
Published: September 2002

Let K denote a field. A polynomial f(x) ∈ K[x] is said to be
decomposable over K if f(x) = g(h(x)) for some
polynomials g(x) and h(x) ∈ K[x] with
1 < deg(h) < deg(f).
Otherwise f(x) is called indecomposable. If
f(x) = g(xm) with m > 1, then f(x) is said to be
trivially decomposable. In this paper, we show that xd + ax + b is
indecomposable and that if e denotes the largest proper divisor
of d, then xd + ad−e−1xd−e−1 + ⋯+a1x + a0 is either
indecomposable or trivially decomposable. We also show that if
gd(x, a) denotes the Dickson polynomial of degree d and
parameter a and gd(x, a) = f(h(x)), then
f(x) = gt(x − c, a) and h(x) = ge(x, a) + c.
Hyperinvariant subspaces for some operators on locally convex spaces
Authors: Kramar Edvard
Published: September 2002

Some results concerning hyperinvariant subspaces of
some operators on locally convex spaces are considered. Denseness
of a class of operators which have a hyperinvariant subspace in
the algebra of locally bounded operators is proved.
Generalization of the formula of Faa di Bruno for a composite function with a vector argument
Authors: Mishkov Rumen L.
Published: September 2002

The paper presents a new explicit formula for the nth total
derivative of a composite function with a vector argument. The
well‐known formula of Faa di Bruno gives an expression for the
nth derivative of a composite function with a scalar argument.
The formula proposed represents a straightforward generalization of
Faa di Bruno′s formula and gives an explicit expression for the
nth total derivative of a composite function when the argument is
a vector with an arbitrary number of components. In this sense, the
formula of Faa di Bruno is its special case. The mathematical tools
used include differential operators, polynomials, and Diophantine
equations. An example is shown for illustration.
On a new generalization of Alzer′s inequality
Authors: Qi Feng , Debnath Lokenath
Published: September 2002

Let be an increasing sequence of positive
real numbers. Under certain conditions of this sequence we use the
mathematical induction and the Cauchy mean‐value theorem to prove
the following inequality:

, where n and m are natural numbers and r is a positive number.
The lower bound is best possible. This inequality generalizes the
Alzer′s inequality (1993) in a new direction. It is shown that the
above inequality holds for a large class of positive, increasing
and logarithmically concave sequences.
Spatial numerical ranges of elements of subalgebras of C0(X)
Authors: Takahasi Sin-Ei
Published: September 2002

When A is a subalgebra of the commutative Banach algebra
C0(X) of all continuous complex‐valued functions on a locally
compact Hausdorff space X, the spatial numerical range of
element of A can be described in terms of positive measures.
Right simple subsemigroups and right subgroups of compact convergence semigroups
Authors: Ho Phoebe , So Shing S.
Published: September 2002

Clifford and Preston (1961) showed several important
characterizations of right groups. It was shown in Roy and So
(1998) that, among topological semigroups, compact right simple or
left cancellative semigroups are in fact right groups, and the
closure of a right simple subsemigroup of a compact semigroup is
always a right subgroup. In this paper, it is shown that such
results can be generalized in convergence semigroups. In the
discussion of maximal right simple subsemigroups and maximal right
subgroups of semigroups, generalization of the results that no two
maximal right simple subsemigroups and maximal right subgroups of a
convergence semigroup intersect, is also established.
The game of Double‐Silver on intervals
Authors: Heuer Gerald A.
Published: September 2002

Silverman′s game on intervals was analyzed in a special case by Evans, and later more extensively by Heuer and Leopold‐Wildburger, who found that optimal strategies exist (and gave them) quite generally when the intervals have no endpoints in common. They exist in about half the parameter plane when the intervals have a left endpoint or a right endpoint, but not both, in common, and (as Evans had earlier found) exist only on a set of measure zero in this plane if the intervals are identical. The game of Double‐Silver, where each player has its own threshold and penalty, is examined. There are several combinations of conditions on relative placement of the intervals, the thresholds and penalties under which optimal strategies exist and are found. The indications are that in the other cases no optimal strategies exist.
On the existence of solution of a two‐point boundary value problem in a cylindrical floating zone
Authors: Yongdong Shi , Liangsheng Du
Published: September 2002

Existence of one solution for a two‐point boundary value problem
with a positive parameter Q arising in the study of
surface‐tension‐induced flows of a liquid metal or semiconductor
is studied. On the basis of the upper‐lower solution method and
Schauder′s fixed point theorem, it is proved that the problem
admits a solution when 0 ≤ Q ≤ 12.683. This improves a recent result where 0 ≤ Q < 1.
Geometric properties of composition operators belonging to Schatten classes
Authors: Zhu Yongsheng
Published: September 2002

We investigate the connection between the geometry of the image domain of an analytic function mapping the unit disk into itself and the membership of the composition operator induced by this function in the Schatten classes. The purpose is to provide solutions to Lotto′s conjectures and show a new compact composition operator which is not in any of the Schatten classes.
On the projections of Laplacians under Riemannian submersions
Authors: Le Huiling
Published: September 2002

We give a condition on Riemannian submersions from a Riemannian
manifold M to a Riemannian manifold N which will ensure that it
induces a differential operator on N from the Laplace‐Beltrami
operator on M. Equivalently, this condition ensures that a
Riemannian submersion maps Brownian motion to a diffusion.
The prime filter theorem of lattice implication algebras
Authors: Jun Young Bae
Published: September 2002

Using a special set x−1F, we give an equivalent condition
for a filter to be prime, and applying this result, we
provide the prime filter theorem in lattice implication algebras
Common fixed point theorems for commuting k‐uniformly Lipschitzian mappings
Authors: Elamrani M. , Mbarki A. B. , Mehdaoui B.
Published: September 2002

We give a common fixed point existence theorem for any sequence of
commuting k‐uniformly Lipschitzian mappings (eventually, for
k = 1 for any sequence of commuting nonexpansive mappings) defined
on a bounded and complete metric space (X, d) with uniform normal
structure. After that we deduce, by using the Kulesza and Lim
(1996), that this result can be generalized to any family of
commuting k‐uniformly Lipschitzian mappings.
The wave equation approach to an inverse eigenvalue problem for an arbitrary multiply connected drum in ℝ2 with Robin boundary conditions
Authors: Zayed E. M. E. , Abdel-Halim I. H.
Published: September 2002

The spectral function , where are the eigenvalues of the two‐dimensional negative Laplacian, is studied
for small |t| for a variety of domains, where −∞ < t < ∞ and . The dependencies of on the connectivity of a domain and the Robin boundary
conditions are analyzed. Particular attention is given to an
arbitrary multiply‐connected drum in ℝ2 together with
Robin boundary conditions on its boundaries.
Some examples of nontrivial homotopy groups of modules
Authors: Su C. Joanna
Published: September 2002

The concept of the homotopy theory of modules was discovered by Peter Hilton as a result of his trip in 1955 to Warsaw, Poland, to work with Karol Borsuk, and to Zurich, Switzerland, to work with Beno Eckmann. The idea was to produce an analog of homotopy theory in topology. Yet, unlike homotopy theory in topology, there are two homotopy theories of modules, the injective theory, , and the projective theory, . They are dual, but not isomorphic.
In this paper, we deliver and carry out the precise calculation of
the first known nontrivial examples of absolute homotopy groups of
modules, namely, , and , where ℚ/ℤ and ℤ
are regarded as ℤCk‐modules with trivial action. One interesting phenomenon of the results is the periodicity
of these homotopy groups, just as for the Ext groups.
On S3‐equivariant homology
Authors: Elhamdadi Mohamed
Published: September 2002

We prove that the group S3 (norm 1 quaternions) cannot be a geometric realization of a crossed simplicial group and construct an exact sequence connecting S3‐equivariant homology of an S3‐space with its Pin(2)‐equivariant homology.
On ideals of implicative semigroups
Authors: Jun Young Bae , Kim Kyung Ho
Published: September 2002

We introduce the notion of ideals in implicative semigroups, and
then state the characterizations of the ideals.
On the number of zeros of iterated operators on analytic Legendre expansions
Authors: Prather Carl
Published: September 2002

Let L = (1 − z2)D2 − 2zD, D = d/dz and , with Pn being the nth Legendre polynomial
and f analytic in an ellipse with foci ±1. Set Lk = L(Lk−1), k ≥ 2. Then the number of zeros of Lkf(z) in this ellipse is O(klnk).
Integral mean estimates for polynomials whose zeros are within a circle
Authors: Dewan K. K. , Mir Abdullah , Yadav R. S.
Published: September 2002

Let p(z) be a polynomial of degree n having all its zeros in |z| ≤ k;   k ≤ 1, then for each r > 0, p > 1, q > 1 with p−1 + q−1 = 1, Aziz and Ahemad (1996) recently proved that . In this paper, we extend the above inequality to the class of polynomials having all its zeros in |z| ≤ k;   k ≤ 1 and obtain a generalization as well as a refinement of the above
result.
On the fixed points of affine nonexpansive mappings
Authors: Duru Hülya
Published: September 2002

Let K be a closed convex bounded subset of a Banach space X and let T : K → K be a continuous affine mapping. In this note, we show that (a) if T is nonexpansive then it has a fixed point, (b) if T has only one fixed point then the mapping A = (I + T)/2 is a focusing mapping; and (c) a continuous mapping S : K → K has a fixed point if and only if, for each x ∈ k, ‖(An∘S)(x) − (S∘An)(x)‖ → 0for some strictly nonexpansive affine mapping T.
On the Diophantine equation x3 = dy2 ± q6
Authors: Abu Muriefah Fadwa S.
Published: September 2002

Let q > 3 denote an odd prime and d a positive integer without any prime factor p ≡ 1(mod3). In this paper, we have proved that if (x, q) = 1, then x3 = dy2 ± q6 has exactly two solutions provided q≢±1(mod24).
On θ‐precontinuous functions
Authors: Noiri Takashi
Published: September 2002

We introduce a new class of functions called
θ‐precontinuous functions which is contained in the class
of weakly precontinuous (or almost weakly continuous) functions
and contains the class of almost precontinuous functions. It is
shown that the θ‐precontinuous image of a p‐closed space
is quasi H‐closed.
Blaschke inductive limits of uniform algebras
Authors: Grigoryan S. A. , Tonev T. V.
Published: September 2002

We consider and study Blaschke inductive limit algebrasA(b), defined as inductive limits of disc algebras A(D) linked by a sequence of finite Blaschke products. It is well known that big G‐disc algebras AG over compact abelian groups G with ordered duals can be expressed as Blaschke inductive limit algebras. Any Blaschke inductive limit
algebra A(b) is a maximal and Dirichlet uniform algebra. Its
Shilov boundary ∂A(b) is a compact abelian group with dual group that is a subgroup of ℚ. It is shown that a big G‐disc algebra AG over a group G with ordered dual is a Blaschke inductive limit algebra if and only if . The local structure of the maximal ideal space and the set of one‐point
Gleason parts of a Blaschke inductive limit algebra differ
drastically from the ones of a big G‐disc algebra. These differences are utilized to construct examples of Blaschke
inductive limit algebras that are not big G‐disc algebras. A
necessary and sufficient condition for a Blaschke inductive limit
algebra to be isometrically isomorphic to a big G‐disc algebra
is found. We consider also inductive limits H∞(I) of algebras H∞, linked by a sequence of inner functions, and prove a version of the corona theorem with estimates for it. The algebra H∞(I) generalizes the algebra of bounded hyper‐analytic functions on an open big G‐disc, introduced previously by Tonev.
On stochastic comparisons of energy functions with applications
Authors: Oluyede Broderick O.
Published: September 2002

We develop simple methods for the stochastic comparisons of informational energy functions. We introduce modified informational energy functions and uncertainty of parameter functions are introduced for models with realistic parameter
spaces. We present inequalities, comparisons, and applications including test procedures for testing the equality of informational energy functions. Some illustrative examples are also presented.
On characterizations of fixed points
Authors: Liu Zeqing , Zhang Lili , Kang Shin Min
Published: September 2002

We give some necessary and sufficient conditions for the existence
of fixed points of a family of self mappings of a metric space and we establish an equivalent condition for the existence of fixed points of a continuous compact mapping of a metric space.
An extension of a theorem of Sahab, Khan, and Sessa
Authors: Khan A. R. , Hussain N.
Published: September 2002

A fixed point theorem of Fisher and Sessa is generalized to locally convex spaces and the new result is applied to extend a recent theorem on invariant approximation of Sahab, Khan, and
Sessa.
Orderability of topological spaces by continuous preferences
Authors: Rodríguez Alcantud José Carlos
Published: September 2002

We extend van Dalen and Wattel′s (1973) characterization of orderable spaces and their subspaces by obtaining analogous results for two larger classes of topological spaces. This type of spaces are defined by considering preferences instead of linear orders in the former definitions, and possess topological properties similar to those of (totally) orderable spaces (cf.
Alcantud, 1999). Our study provides particular consequences of relevance in mathematical economics; in particular, a condition equivalent to the existence of a continuous preference on a
topological space is obtained.
Products of protopological groups
Authors: Jones Julie C.
Published: September 2002

Montgomery and Zippin saied that a group is approximated by Lie
groups if every neighborhood of the identity contains an
invariant subgroup H such that G/H is topologically
isomorphic to a Lie group. Bagley, Wu, and Yang gave a similar
definition, which they called a pro‐Lie group. Covington extended
this concept to a protopological group. Covington showed that
protopological groups possess many of the characteristics of
topological groups. In particular, Covington showed that in a
special case, the product of protopological groups is a
protopological group. In this note, we give a
characterization theorem for protopological groups and use it to
generalize her result about products to the category of all
protopological groups.
A Regularization of Fredholm type singular integral equations
Authors: Aliev N. , Hosseini S. Mohammad
Published: September 2002

We present a method to regularize first and second kind integral equations of Fredholm type with singular kernel. By appropriate application of the Poincaré‐Bertrand formula we change such integral equations into a second kind Fredholm′s integral equation
with at most weakly singular kernel.
The method of averaging and functional differential equations with delay
Authors: Lakrib Mustapha
Published: September 2002

We present a natural extension of the method of averaging to fast oscillating functional differential equations with delay. Unlike the usual approach where the analysis is kept in an infinite‐dimensional Banach space, our analysis is achieved in ℝn. Our results are formulated in classical mathematics. They are proved within Internal Set Theory which is an axiomatic description of nonstandard analysis.
On an infinite sequence of invariant measures for the cubic nonlinear Schrödinger equation
Authors: Zhidkov Peter E.
Published: September 2002

We consider the Cauchy problem periodic in the spatial variable
for the usual cubic nonlinear Schrödinger equation
and construct an infinite sequence of invariant
measures associated with higher conservation laws for dynamical
systems generated by this problem on appropriate phase spaces.
In addition, we obtain sufficient conditions for the boundedness
of the measures constructed.
On the Bohr transform of almost‐periodic solutions for some differential equations in abstract spaces
Authors: Zaidman Samuel
Published: September 2002

We consider abstract differential equations of the form u′(t) = Au(t) + f(t) or u″(t) = Au(t) + f(t) in Banach spaces X, where f(⋅), ℝ → X is almost‐periodic, while A is a linear operator, 𝒟(A) ⊂ X → X. If the solution u(⋅) is likewise almost‐periodic, ℝ → X, we establish connections between their Bohr‐transforms, and .
A generalization of Ky Fan′s inequality
Authors: Gao Peng
Published: September 2002

Let Pn,r(x) be the generalized weighted means. Let F(x) be a C1 function, y = y(x) an implicit decreasing function
defined by f(x, y) = 0 and 0 < m < M ≤ m′, n ≥ 2, xi ∈ [m, M], yi ∈ [m′, M′]. Then for −1 ≤ r ≤ 1, if , ⋅M/m′ A similar result exists for . By specifying f(x, y) and F(x), we get various generalizations of Ky Fan′s inequality. We also present some results on the comparison of and for s ≥ r, α ∈ ℝ.
Compact Hermitian operators on projective tensor products of Banach algebras
Authors: Dutta T. K. , Nath H. K. , Sarmah H. K.
Published: September 2002

Let U and V be, respectively, an infinite‐ and a
finite‐dimensional complex Banach algebras, and let
U⊗pV be their projective tensor product. We prove
that (i) every compact Hermitian operator T1 on U gives rise to a compact Hermitian operator T on U⊗pV having the properties that ‖T1‖ = ‖T‖ and sp(T1) = sp(T);
(ii) if U and V are separable and U has
Hermitian approximation property (HAP), then U⊗pV is also separable and has HAP;
(iii) every compact analytic semigroup (CAS) on U induces the existence of a CAS on U⊗pV having some nice properties. In addition, the converse of the above results are discussed and some open problems are posed.
Differences between powers of a primitive root
Authors: Vâjâitu Marian , Zaharescu Alexandru
Published: September 2002

We study the set of differences {gx − gy(modp) : 1 ≤ x,    y ≤ N} where p is a large prime number, g is a primitive
root (modp), and p2/3 < N < p.
Global attractivity in a genotype selection model
Authors: Li Xiaoping
Published: September 2002

We obtain a sufficient condition for the global attractivity of
the genotype selection model , n ∈ ℕ. Our results improve the results established by Grove et al. (1994) and Kocić and Ladas (1993).
Purity of the ideal of continuous functions with pseudocompact support
Authors: Abu Osba Emad A.
Published: September 2002

Let CΨ(X) be the ideal of functions with pseudocompact
support and let kX be the set of all points in υX having compact neighborhoods. We show that
CΨ(X) is pure if and only if βX − kX is a round subset of βX, CΨ(X) is a projective C(X)‐module if and
only if CΨ(X) is pure and kX is paracompact. We also show that if
CΨ(X) is
pure, then for each f ∈ CΨ(X) the ideal (f) is a projective (flat) C(X)‐module if and only if kX is basically disconnected (F′‐space).