bluuebunny/crossref_metadata_2025 huggingface dataset:
Summer foraging behaviour of a generalist predator, the New Zealand fur seal (Arctocephalus forsteri)
Authors: Harcourt Robert G. , Bradshaw Corey J. A. , Davis Lloyd S.
Published: September 2002

This study examined the dive behaviour of 20 lactating New Zealand fur seals
(Arctocephalus forsteri) breeding at Fuchsia Gully
(Ohinepuha, 45˚52S, 170˚44E), Otago Peninsula, New Zealand, over
five consecutive austral summers (1993/94–1997/98). We examined
annual variation in dive behaviour by classifying series of dives into dive
bouts using an iterative statistical technique. We found a non-random pattern
of dive bouts and bout classification was relatively insensitive to changes in
the clustering parameters used. Minimum bouts consisted of at least three
dives 10 m occurring within a 20-min period. Bouts were classified into three
bout types (clusters) using a multi-variate clustering procedure. These
clusters described bouts of: (1) long duration with many dives of medium depth
(LONG); (2) short duration with few, shallow dives (SHALLOW); and (3) short
duration consisting of long, deep dives and long surface intervals and bottom
times (DEEP). Diving was primarily nocturnal, and bout type varied
significantly with time of day. The proportion of LONG bouts was greatest at
dusk and least near dawn, SHALLOW bouts predominated during the night, and
DEEP bouts were of importance near dawn. Few dives occurred during the day. We
detected no annual differences in individual parameters of dive behaviour due
to low statistical power. We used randomisation tests to assess whether the
proportion of each bout type might vary in years of differing prey
consumption, but no significant differences were found. Changes in prey
composition were detected in two of these years, which suggests that using the
dive behaviour of generalist predators to detect changes in resource
availability may be a poor option. The high degree of flexibility in foraging
behaviour of the New Zealand fur seal means that, inevitably, analyses of dive
behaviour will have low statistical power. Changes in foraging behaviour may
only be useful to detect very large changes in resource availability.
Alternatively, very large sample sizes may be able to detect more subtle
changes.
Escape behaviour of feral horses during a helicopter count
Authors: Linklater W. L. , Cameron E. Z.
Published: September 2002

Animal escape behaviour in response to aircraft could influence the accuracy and precision of aerial estimates of population size but is rarely investigated. Using independent observers on the ground and in the air, we recorded the behaviour of 17 groups, including 136 individually marked horses (Equus caballus), during a helicopter count in New Zealand's Kaimanawa Mountains and compared the helicopter count with a ground-based mark-resight estimate in the same area (20.5 km2). The helicopter induced running and changes in group size and composition in all horse groups that travelled from 0.1 up to 2.75 km before leaving the ground-observer's view. One-tenth of marked horses were not counted and a quarter counted twice. The possible double-counting of a further 23 (17%) could not be confirmed because only two of the three observers' records concurred. Thus, the helicopter count over-estimated the marked sub-population by at least 15% and possibly by up to 32%. The helicopter count (228 horses) was 16.9% larger than the mark-resight estimate (195, 95% CI = 157-234). We identify the characteristics of the helicopter count that stimulated horse escape behaviour and discuss how it should be considered in the design of aerial population-estimate methods.
Effects of tropical rainforest roads on small mammals: edge changes in community composition
Authors: Goosem Miriam
Published: September 2002

In the wet tropics of north-eastern
Queensland, the composition of the small-mammal community close to the edge of
an unsealed rainforest road differed from that of the forest interior. During
the first of two trapping series, mark–recapture trapping demonstrated
that the abundance of Melomys cervinipes increased near
the road and that significantly moreRattus sp. resided
further from the road. At sites lacking canopy closure where the road clearing
width measured 20 m, these edge effects were more noticeable than where canopy
closure was maintained across narrower (12 m) clearings, with greater
proportions of M. cervinipes occurring near wider
clearing edges. During the second trapping series, edge effects also clearly
occurred at the narrower clearings: M. cervinipes again
preferred edge habitats and Rattus sp. preferred the
forest interior. However, no significant effect of clearing width or distance
from the edge for individual species was found during the second trapping
series. The proportions of Rattus sp. and
M. cervinipes had altered due to an influx of juvenile
M. cervinipes into the trappable community during and
after the breeding season, together with more individuals of
Rattus sp. colonising the previously under-utilised
habitat near the road. Edge avoidance by Rattus sp.
appeared to be linked to preference for undisturbed habitat, while
M. cervinipes was more of a generalist. Road verges with
grassy habitat allowed the occasional intrusion of
Rattus sordidus and
Melomys burtoni – species alien to the rainforest.
Pasture grazing by black-striped wallabies (Macropus dorsalis) in central Queensland
Authors: Baxter G. S. , Moll E. J. , Lisle Allan T.
Published: September 2002

Black-striped wallabies (Macropus dorsalis) are uncommon
to rare in most of their former range, yet in parts of central Queensland
where they are still locally common they are regarded as a serious pasture
pest. There is considerable pressure from cattle graziers to reduce their
density because of the putative damage that they cause to cattle pasture. Here
we examined the effects of this species and other herbivores on pasture by
monitoring vegetation cover between 1993 and 1998 in exclosures in brigalow,
and poplar box communities on three grazing properties in the Maranoa region.
The exclosures selectively allowed access to either: all vertebrate grazers
including cattle; rabbits, bettongs, and wallabies; rabbits and bettongs; no
vertebrate grazers. The greatest effects on the structure and species
composition of pasture were caused by cattle, but wallabies did consume
commercially important quantities of grass at some times of the year. This
conflicts with local opinion that sees wallabies as the major cause of pasture
degradation. Herein lies the management problem that sees continued reduction
in wallaby habitat, and fragmentation of the species.
Foraging ecology of three species of hipposiderid bats in tropical rainforest in north-east Australia
Authors: Pavey Chris R. , Burwell Chris J.
Published: September 2002

We studied the foraging ecology of three
species of hipposiderid bats –
Hipposideros diadema (mean forearm length: 82 mm),
H. cervinus (47 mm) and H. ater
(41 mm) – in tropical, lowland rainforest in north-east Queensland,
Australia. H. diadema foraged by perching within gaps
and flying out to intercept slow-flying insects. The two smaller species
typically foraged during flight, in undisturbed forest and gaps, and captured
insects by aerial hawking. Seven arthropod taxa were identified in faeces of
H. cervinus, with Coleoptera and Lepidoptera being
present in most faeces. Percentage volume of moth scales was generally low: 35
of 60 faeces had a volume of <10%, whereas all faeces
(n = 60) of H. ater had a
moth scale volume of >90%. No other taxa were frequently present in
faeces of H. ater. Differences in foraging ecology
between H. diadema and the smaller species were related
to its large size and low manoeuvrability. The dietary differences we found
between H. ater and H. cervinus
were unexpected, because both species have high-frequency echolocation calls
(160–164 and 144–145 kHz, respectively), which suggested that both
would capture predominantly moths. Our data show that pairs of hipposiderid
species with only small differences in call frequencies may consume different
prey taxa; however, we contend that dietary variation is more likely to result
from differences in body size, wing morphology, and tooth, jaw, and cranial
morphology.
Review of the effects of organophosphorus and carbamate insecticides on vertebrates. Are there implications for locust management in Australia?
Authors: Story Paul , Cox Michelle
Published: September 2002

The Australian Plague Locust Commission uses the organophosphorus insecticide
fenitrothion to control locust population increases across 2000000
km2 of eastern Australia. Although the impact of
fenitrothion on non-target invertebrates has been studied, effects on
vertebrates are largely unquantified. Lethal and sublethal impacts on
vertebrates are a consequence of the use of organophosphorus and carbamate
insecticides. Information detailing the effects of exposure on free-living
animals, particularly for herpetofauna, is lacking. This paper reviews
literature concerned with the impacts of organophosphorus and carbamate
insecticides on terrestrial vertebrates and highlights the need for continued
research into the effects of these chemicals, especially in Australia.
An ecological study of a population of Pseudantechinus macdonnellensis (Marsupialia : Dasyuridae) in central Australia. I. Invertebrate food supply, diet and reproductive strategy
Authors: Gilfillan Sandra L.
Published: September 2002

The invertebrate food supply, diet and reproductive strategy of a population
of the dasyurid marsupial,
Pseudantechinus macdonnellensis, living in an arid rocky
habitat was investigated at a site in the West MacDonnell National Park,
Northern Territory, over two and a half years. Invertebrate food supply
displayed high month to month predictability and no marked seasonal cycle
correlated with temperature. Analysis of faeces indicated that
P. macdonnellensis is a generalist insectivore. There
was some discrepancy between the pattern revealed by invertebrate sampling and
the prey types taken but it was concluded that the invertebrates sampled
broadly reflected those available to P. macdonnellensis.
Individual females reproduced only once per year; the estimated time of mating
was in July–August, and births occurred in September–October. The
maximum litter size was six and nearly all females in each season produced a
full complement of young. Some males survived and showed spermatorrhea in two
breeding seasons and some females survived and produced young in up to three.
The seasonal pattern of invertebrate food supply at the study site appeared to
be more dependable than that found in studies carried out in arid plains
habitats. The difference may result from a microtopographical amelioration in
the rocky habitat of the effects of extreme weather conditions that in open,
arid habitats are believed to produce increased short-term unpredictability
and pronounced, temperature-driven seasonality in food supply. The
ameliorating effect may also increase longevity in
P. macdonnellensis by reducing density-independent
mortality.
The monoestrous highly seasonal reproductive strategy in
P. macdonnellensis differs from that displayed by most
species that inhabit arid plains habitats (the latter are polyoestrous with an
extended breeding season). The shortterm predictability in food supply
together with a high longevity in P. macdonnellensis may
account for its reproductive strategy. The results of this study provide
support for the notion that habitat-specific selective pressures in arid
environments may favour divergent ecological strategies in functionally
similar species.
Parasites of the bridled nailtail wallaby (Onychogalea fraenata) (Marsupialia : Macropodidae)
Authors: Turni C. , Smales L. R.
Published: September 2002

The bridled nailtail wallaby (Onychogalea fraenata), an
endangered macropod, has been reintroduced into the wild after a
captive-breeding program. As part of a management program to assess the risks
to its survival O. fraenata were trapped and examined
for ecto- and endoparasites. From February to September 1996, 55 wallabies
from Taunton National Park, central Queensland, some trapped more than once,
were visually examined for ectoparasites. The blood of 39
O. fraenata was tested for antibodies against
Toxoplasma gondii and
Echinococcus granulosus and a total of 82 faecal samples
were examined microscopically. In addition, in a second study a complete
carcase, three complete gastro-intestinal tracts, and a single stomach,
obtained from various sources, including Idalia National Park, were examined
for helminth parasites. The most prevalent ectoparasites were the
ticksAmbylomma triguttatum and
Haemaphysalis bancrofti. Other ectoparasites included
four species of trombiculid mites and a louse,
Heterodoxus sp. A single instance of the nippoboscid
fly, Ortholfersia minuta, was found. From the
serological surveys, antibodies against Toxoplasma and
Echinococcus were detected in 15% and 21%
respectively. No trematode or cestode eggs or protozoal cysts were found in
faeces. Nematode eggs had a prevalence of 92% with a mean egg density
of 500 eggs per gram. Strongyloides sp. (larvae) was the
most prevalent nematode in faeces. In the postmortem study, seven nematode
species (Cloacina polyxo,
Hypodontus macropi,
Labiostrongylus onychogale,
Macropostrongyloides baylisi,
Macropoxyuris sp.,
Rugopharynx australis and
Zoniolaimus buccalis) and four cestode species
(Progamotaenia bancrofti,
P. zschokkei, P. abietiformis and
larval E. granulosus) were found. Six of the nematode
species are new host records. The presence of infection with the introduced
parasites T. gondii and
E. granulosus, both recognised as serious pathogens, is
of management significance. Since the definitive hosts of these parasites are
cats and canids respectively, control of cat, dog and dingo populations within
the Park will lessen the incidence of infection with these parasites.
Unusual macromorphology of the ductuli efferentes and epididymis of the koala (Phascolarctos cinereus)
Authors: Gibson Rachel J. , Leigh Chris M. , Breed William G.
Published: September 2002

The macromorphology of the ductuli efferentes and epididymis of the koala
(Phascolarctos cinereus) was investigated and found to
differ from that of other marsupial species that have been described as it
comprised four macroscopically distinct lobes. Light and electron microscopy
of epithelium of the duct within these lobes showed that there were principal
and ciliated cells lining the duct of the first lobe, indicating it to be
composed of ductuli efferentes. In the other three lobes, the epithelium
contained principal, basal, electron-lucent, and mitochondria-rich cells,
showing that these three lobes included the epithelium of the epididymis. The
height of this epithelium gradually increased along the duct (contrary to the
situation in most other species that have been studied, in which a decrease
occurs). Preliminary 1D-SDS PAGE observations of flushes from the caput and
cauda epididymides suggested that epididymal proteins were secreted along much
of the length of the duct; the greater height of the cauda epithelium may
relate to the greater protein synthetic and secretory activity in this region.
The mating behaviour of the dibbler, Parantechinus apicalis, in captivity
Authors: Wolfe Kristen M. , Robertson Helen , Bencini Roberta
Published: September 2002

A study of the mating behaviour of the dibbler,
Parantechinus apicalis, was conducted at a
captive-breeding colony at Perth Zoo. In total, 21 pairs of
P. apicalis were observed. The oestrous cycles of the
females were monitored, and the males and females were paired when the females
were approaching oestrus. Direct observations were made of the pairs over a
2-h period 3–4 times a week for the duration of the breeding season (mid
February to April). It was found that the mating behaviour of
P. apicalis was similar to that of other dasyurids; in
particular, sniffing, vocalisations, chasing and attempted mounting tended to
increase in the days leading up to mating. No significant difference was found
between successful pairs (i.e. those that did mate) and unsuccessful pairs
(i.e. those that did not) in the number of interactions and the average
distance between the pair.
Birth in the brushtail possum, Trichosurus vulpecula (Marsupialia : Phalangeridae)
Authors: Veitch Colleen E. , Nelson John , Gemmell Robert T.
Published: September 2002

Birth has been observed and described in a number of marsupials. However, the
ability of the newborn marsupial to move from the uterus to the pouch and
locate the teat is still not fully understood. Birth and the path taken by the
newborn from the urogenital sinus to the teat within the pouch were filmed in
the brushtail possum, Trichosurus vulpecula. Prior to
birth, females began to lick the pouch and urogenital sinus vigorously. The
young took approximately 2 min to transfer from the urogenital sinus to the
pouch and attached to the teat within 10–15 min. To determine the senses
used by the newborn possum to reach the pouch, young were removed from the
anaesthetised mothers immediately after birth and placed outside the pouch.
From the subsequent observations, the newborn possum instinctively crawled
upwards. However, when the newborn was in the vicinity of the pouch, odours
emanating from the pouch presumably attracted the young. Thus, the senses of
gravity and of olfaction were used by the newborn to reach the teat and
probably the sense of touch, via the mechanoreceptor Merkel cells around the
mouth, allowed the young to attach to the teat.
Bat airframe design: flight performance, stability and control in relation to foraging ecology
Authors: Bullen R. , McKenzie N. L.
Published: September 2002

We tested the airframes of a community of microbats in terms of flight
performance, stability and control, and present the first systematic
classification of bat flight manoeuvres. The tail, ears and main-wing all
contributed to these airframe functions. In combination, six airframe ratios
(aspect ratio, wing loading, tail area ratio, ear area ratio, tail length
ratio and ear length ratio) provided robust predictions of species’
foraging microhabitats and foraging strategies (including agility and speed).
Predator avoidance, feeding and habitat use in the red-necked pademelon, Thylogale thetis, at rainforest edges
Authors: Wahungu Geoffrey M. , Catterall Carla P. , Olsen Mike F.
Published: September 2002

Food acquisition and predator avoidance are principal, but often conflicting,
components of the survival strategies of most animals. We investigated the
behaviour of red-necked pademelons, Thylogale thetis,
(Marsupialia: Macropodidae) in pasture adjacent to rainforest edges in eastern
Australia, by testing the relationships among age and sex of individuals, time
of day, season, site, distance from cover (forest edge), feeding, vigilance
and group size. Foraging behaviour was responsive to changes in predation
risk. Feeding and vigilance activities accounted for most of the activity
budget of foraging pademelons, and were negatively correlated. Reproductive
females and individuals in smaller groups foraged closer to forest edges, were
more vigilant and spent less time feeding. Vigilance decreased with increasing
group size even after controlling for other confounding factors. Increased
predation risks of feeding further from forest cover were offset by the
pademelons doing so only if their group size was large, so that the time
allocated to vigilance did not increase.
Hydric environment and sex determination in the flatback turtle (Natator depressus Garman) (Chelonia : Cheloniidae)
Authors: Hewavisenthi Suhashini , Parmenter C. John
Published: September 2002

Eggs of Natator depressus (from eastern Queensland,
Australia) were incubated at a constant temperature of 29.5˚C on
vermiculite substrate with three different moisture levels: wet (~–180
kPa), intermediate (~–1200 kPa) and dry (~–2000 kPa). The male :
female ratios on wet, intermediate and dry substrates were 8 : 7, 5 : 5 and 5
: 8 respectively. Sex determination was not influenced by the hydric
environment but was significantly affected by different clutches. A clutch
with smaller eggs appeared to produce a higher proportion of females. The
pivotal temperature was close to 29.5˚C, with a possibly narrow
transitional temperature range of 1˚C. Visual designation of sex was
confirmed (100%) by histological examination. Hatching success and the
incubation duration were not influenced by the hydric environment.
Nest utilisation and recognition by juvenile gryllacridids (Orthoptera : Gryllacrididae)
Authors: Hale Roderick J.
Published: September 2002

Gryllacridid ensiferans (Orthoptera : Gryllacrididae) appear to display a
degree of nest-site fidelity comparable to that of most social insects. The
nesting behaviour of juvenile gryllacridids was studied to determine when
nests were first built and whether juveniles were able to subsequently
recognise their own nests. Additionally, the hypothesis that juvenile
gryllacridids could orient to their nest over distance by chemical means was
examined via a directional choice experiment within a simple olfactometer.
Juveniles of a known ‘nest-building’ gryllacridid constructed
nests within days of hatching, reflecting current ideas that nesting is an
integral component of gryllacridid biology. Such nests were occupied
preferentially over extended periods. Furthermore, individual juveniles were
capable of recognising their own nest from that of their conspecifics. Such a
result supports recent findings of an individual/nest-specific chemical
odour amongst adult gryllacridids. However, the results provide no evidence
that juvenile gryllacridids are able to detect the presence of their own nest
over any substantial distance and some mechanism other than chemically based
orientation is necessary to explain the apparent homing ability of these
orthopterans.
The response of foraging Argentine ants, Linepithema humile, to disturbance
Authors: Halley Julianne D. , Elgar Mark A.
Published: September 2002

Reducing the risk of predation is an important feature of the feeding
behaviour of most animals. In social insects, foraging workers are
particularly vulnerable, and the ability to trade-off mortality risk against
food value may provide a considerable competitive advantage for the colony. We
investigated the response of Argentine ants,
Linepithema humile, to different kinds of disturbance
while workers foraged on food of differing quality. The behaviour of disturbed
individuals was influenced by group size, by the behaviour of nearby nestmates
and by how much food had already been consumed. When in large groups, workers
were less likely to leave the foraging arena and resumed feeding more rapidly.
This response was even more marked among workers whose gasters were only
partially replete. However, individuals took more time to resume feeding and
became more likely to run away from a food source when greater numbers of ants
were disturbed. These influences may allow foraging groups to maximise food
intake while minimising the mortality of workers.
Agonistic behaviour in final-instar larvae of Agriocnemis pygmaea (Odonata : Coenagrionidae)
Authors: Rowe R. J.
Published: September 2002

Larval agonistic displays are reported from Agriocnemis pygmaea, a small coenagrionid damselfly. Twenty-five major displays were distinguished. The behavioural repertoire of A. pygmaea is broadly consistent with published information on other coenagrionid larvae. The 'abdomen lift' behaviour, largely restricted to smaller instars of other examined species, occurs with some frequency in final-instar A. pygmaea. The use of larval agonistic display characters in phylogenetic analysis is discussed.
Temperature regulation in mounds of three sympatric species of megapode (Aves : Megapodiidae) in Papua New Guinea: testing the 'Seymour Model'
Authors: Sinclair J. Ross
Published: September 2002

Most megapode species rake organic material into mounds in which they incubate
their eggs. To test predictions of a model proposed for temperature regulation
in incubation mounds (the ‘Seymour Model’), I collected data on
the physical characteristics of these mounds of the sympatric wattled
brush-turkey (Aepypodius arfakianus), brown-collared
talegalla (Talegalla jobiensis) and New Guinea megapode
(Megapodius decollatus) in Papua New Guinea. Data from
mounds supported several predictions of the Seymour Model: (1) there is a
critical mass needed for mounds to heat to incubation temperatures, (2) mounds
are stable homeotherms, (3) mounds cool after they are abandoned, and (4)
mounds with different proportions of organic material differ in size. Data did
not support predictions that (1) mound size will change with changes in
ambient air temperature, and (2) mounds in high-rainfall areas will be convex
to shed water. Mounds of New Guinea megapodes and brown-collared talegallas
were similar and differed from those of wattled brush-turkeys in size,
composition, temperature profile and location of eggs. These differences were
consistent with the Seymour Model. The Seymour Model is robust enough to
explain differences in mounds of sympatric megapodes, which differ in their
taxonomy, behaviour and ecology.
Evidence for continuous iteroparity in a temperate-zone frog, the red-crowned toadlet, Pseudophryne australis (Anura : Myobatrachidae)
Authors: Thumm K. , Mahony M. J.
Published: September 2002

The breeding behaviour of the red-crowned toadlet, Pseudophryne australis, was observed both in the field and in captivity. Female and male red-crowned toadlets were active in the field throughout the year. New egg masses were observed all year except mid-winter. Females returned in a gravid condition repeatedly to the breeding site over years and presumably deposited eggs, and a captive female has laid 34 clutches over 7.25 years. P. australis has evolved continuous iteroparity in a region where most frogs breed once a year, seasonally, in reliable long-lasting ponds or permanent creeks. We suggest that the comparatively extreme iteroparity observed is a result of the limitations imposed on the species in the choice of oviposition time, due to unpredictable rainfall, and of the limited availability and suitability of nesting sites.

Further, iteroparity may have evolved because there is high variance in reproductive success, or particularly high recruitment losses incurred as a result of the desiccation of embryos or larvae in the ephemeral breeding sites. The adaptive response is to lay small clutches often and to gamble that follow up rains will occur on some occasions to enable recruitment. The alternative, to lay a large clutch of eggs at one time and have the ephemeral pond dry because there was no follow-up rain, would lead to total reproductive loss.
Sphingosine-1-phosphate phosphohydrolase in regulation of sphingolipid metabolism and apoptosis
Authors: Le Stunff Hervé , Galve-Roperh Ismael , Peterson Courtney , Milstien Sheldon , Spiegel Sarah
Published: September 2002

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid metabolite that regulates diverse biological processes by binding to a family of G protein–coupled receptors or as an intracellular second messenger. Mammalian S1P phosphatase (SPP-1), which degrades S1P to terminate its actions, was recently cloned based on homology to a lipid phosphohydrolase that regulates the levels of phosphorylated sphingoid bases in yeast. Confocal microscopy surprisingly revealed that epitope-tagged SPP-1 is intracellular and colocalized with the ER marker calnexin. Moreover, SPP-1 activity and protein appeared to be mainly enriched in the intracellular membranes with lower expression in the plasma membrane. Treatment of SPP-1 transfectants with S1P markedly increased ceramide levels, predominantly in the intracellular membranes, diminished survival, and enhanced apoptosis. Remarkably, dihydro-S1P, although a good substrate for SPP-1 in situ, did not cause significant ceramide accumulation or increase apoptosis. Ceramide accumulation induced by S1P was completely blocked by fumonisin B1, an inhibitor of ceramide synthase, but only partially reduced by myriocin, an inhibitor of serine palmitoyltransferase, the first committed step in de novo synthesis of ceramide. Furthermore, S1P, but not dihydro-S1P, stimulated incorporation of [3H]palmitate, a substrate for both serine palmitoyltransferase and ceramide synthase, into C16-ceramide. Collectively, our results suggest that SPP-1 functions in an unprecedented manner to regulate sphingolipid biosynthesis and is poised to influence cell fate.
The role of the Tim8p–Tim13p complex in a conserved import pathway for mitochondrial polytopic inner membrane proteins
Authors: Curran Sean P. , Leuenberger Danielle , Schmidt Einhard , Koehler Carla M.
Published: September 2002

Tim23p is imported via the TIM (translocase of inner membrane)22 pathway for mitochondrial inner membrane proteins. In contrast to precursors with an NH2-terminal targeting presequence that are imported in a linear NH2-terminal manner, we show that Tim23p crosses the outer membrane as a loop before inserting into the inner membrane. The Tim8p–Tim13p complex facilitates translocation across the intermembrane space by binding to the membrane spanning domains as shown by Tim23p peptide scans with the purified Tim8p–Tim13p complex and crosslinking studies with Tim23p fusion constructs. The interaction between Tim23p and the Tim8p–Tim13p complex is not dependent on zinc, and the purified Tim8p–Tim13p complex does not coordinate zinc in the conserved twin CX3C motif. Instead, the cysteine residues seemingly form intramolecular disulfide linkages. Given that proteins of the mitochondrial carrier family also pass through the TOM (translocase of outer membrane) complex as a loop, our study suggests that this translocation mechanism may be conserved. Thus, polytopic inner membrane proteins, which lack an NH2-terminal targeting sequence, pass through the TOM complex as a loop followed by binding of the small Tim proteins to the hydrophobic membrane spanning domains.
Sec16p potentiates the action of COPII proteins to bud transport vesicles
Authors: Supek Frantisek , Madden David T. , Hamamoto Susan , Orci Lelio , Schekman Randy
Published: September 2002

SEC16 encodes a 240-kD hydrophilic protein that is required for transport vesicle budding from the ER in Saccharomyces cerevisiae. Sec16p is tightly and peripherally bound to ER membranes, hence it is not one of the cytosolic proteins required to reconstitute transport vesicle budding in a cell-free reaction. However, Sec16p is removed from the membrane by salt washes, and using such membranes we have reconstituted a vesicle budding reaction dependent on the addition of COPII proteins and pure Sec16p. Although COPII vesicle budding is promoted by GTP or a nonhydrolyzable analogue, guanylimide diphosphate (GMP-PNP), Sec16p stimulation is dependent on GTP in the reaction. Details of coat protein assembly and Sec16p-stimulated vesicle budding were explored with synthetic liposomes composed of a mixture of lipids, including acidic phospholipids (major–minor mix), or a simple binary mixture of phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Sec16p binds to major–minor mix liposomes and facilitates the recruitment of COPII proteins and vesicle budding in a reaction that is stimulated by Sar1p and GMP-PNP. Thin-section electron microscopy confirms a stimulation of budding profiles produced by incubation of liposomes with COPII and Sec16p. Whereas acidic phospholipids in the major–minor mix are required to recruit pure Sec16p to liposomes, PC/PE liposomes bind Sar1p-GTP, which stimulates the association of Sec16p and Sec23/24p. We propose that Sec16p nucleates a Sar1-GTP–dependent initiation of COPII assembly and serves to stabilize the coat to premature disassembly after Sar1p hydrolyzes GTP.
Intracrine Cysteinyl Leukotriene Receptor–mediated Signaling of Eosinophil Vesicular Transport–mediated Interleukin-4 Secretion
Authors: Bandeira-Melo Christianne , Woods Lesley J. , Phoofolo Mojabeng , Weller Peter F.
Published: September 2002

We investigated whether cysteinyl leukotrienes (cysLT) are intracrine signal transducers that regulate human eosinophil degranulation mechanisms. Interleukin (IL)-16, eotaxin, and RANTES stimulate vesicular transport–mediated release of preformed, granule-derived IL-4 and RANTES from eosinophils and the synthesis at intracellular lipid bodies of LTC4, the dominant 5-lipoxygenase–derived eicosanoid in eosinophils. 5-Lipoxygenase inhibitors blocked IL-16–, eotaxin-, and RANTES-induced IL-4 release; but neither exogenous LTC4, LTD4, nor LTE4 elicited IL-4 release. Only after membrane permeabilization enabled cysLTs to enter eosinophils did LTC4 and LTD4 stimulate IL-4, but not RANTES, release. LTC4-elicited IL-4 release was pertussis toxin inhibitable, but inhibitors of the two known G protein–coupled cysLT receptors (cysLTRs) (CysLT1 and CysLT2) did not block LTC4-elicited IL-4 release. LTC4 was 10-fold more potent than LTD4 and at low concentrations (0.3–3 nM) elicited, and at higher concentrations (>3 nM) inhibited, IL-4 release from permeabilized eosinophils. Likewise with intact eosinophils, LTC4 export inhibitors, which increased intracellular LTC4, inhibited eotaxin-elicited IL-4 release. Thus, LTC4 acts, via an intracellular cysLTR distinct from CysLT1 or CysLT2, as a signal transducer to selectively regulate IL-4 release. These results demonstrate that LTC4, well recognized as a paracrine mediator, may also dynamically govern inflammatory and immune responses as an intracrine mediator of eosinophil cytokine secretion.
A Role for Immune Complexes in Enhanced Respiratory Syncytial Virus Disease
Authors: Polack Fernando P. , Teng Michael N. , L.Collins Peter , Prince Gregory A. , Exner Marcus , Regele Heinz , Lirman Dario D. , Rabold Richard , Hoffman Scott J. , Karp Christopher L. , Kleeberger Steven R. , Wills-Karp Marsha , Karron Ruth A.
Published: September 2002

Respiratory syncytial virus (RSV) is the leading cause of bronchiolitis and viral pneumonia in infants and young children. Administration of a formalin inactivated vaccine against RSV to children in the 1960s resulted in increased morbidity and mortality in vaccine recipients who subsequently contracted RSV. This incident precluded development of subunit RSV vaccines for infants for over 30 years, because the mechanism of illness was never clarified. An RSV vaccine for infants is still not available.

Here, we demonstrate that enhanced RSV disease is mediated by immune complexes and abrogated in complement component C3 and B cell–deficient mice but not in controls. Further, we show correlation with the enhanced disease observed in children by providing evidence of complement activation in postmortem lung sections from children with enhanced RSV disease.
Regulation of sex-specific differentiation and mating behavior in C. elegans by a new member of the DM domain transcription factor family
Authors: Lints Robyn , Emmons Scott W.
Published: September 2002

Mutations in Caenorhabditis elegans gene mab-23cause abnormal male tail morphology and abolish male fecundity but have no obvious effect in the hermaphrodite. Here we show thatmab-23 encodes a DM (Doublesex/MAB-3) domain transcription factor necessary for specific aspects of differentiation in sex-specific tissues of the male. mab-23 is required for the patterning of posterior sensory neurons in the male nervous system, sex muscle differentiation, and morphogenesis of the posterior hypodermis, spicules, and proctodeum. Failure of mab-23 mutant males to sire progeny is due primarily to defective sex muscle-mediated turning during copulatory behavior and likely compounded by impairment of sperm passage through the proctodeum. In the male nervous system,mab-23 refines ray neuron subtype distribution by restricting expression of dopaminergic neurotransmitter identity through interactions with the Hox gene egl-5 and a TGF-β-related signaling pathway. mab-23 has distinct roles and functions independent of mab-3, indicating different aspects of C. elegans male sexual differentiation are coordinated among DM domain family members. Our results support the hypothesis that DM domain genes derive from an ancestral male sexual regulator and suggest how regulation of sexual development has evolved in distinct ways in different phyla.
A requirement for replication in activation of the ATR-dependent DNA damage checkpoint
Authors: Lupardus Patrick J. , Byun Tony , Yee Muh-ching , Hekmat-Nejad Mohammad , Cimprich Karlene A.
Published: September 2002

Using the Xenopus egg extract system, we investigated the involvement of DNA replication in activation of the DNA damage checkpoint. We show here that DNA damage slows replication in a checkpoint-independent manner and is accompanied by replication-dependent recruitment of ATR and Rad1 to chromatin. We also find that the replication proteins RPA and Polα accumulate on chromatin following DNA damage. Finally, damage-induced Chk1 phosphorylation and checkpoint arrest are abrogated when replication is inhibited. These data indicate that replication is required for activation of the DNA damage checkpoint and suggest a unifying model for ATR activation by diverse lesions during S phase.
Fluoroquinolone-Resistant
Streptococcus pneumoniae
Strains Occur Frequently in Elderly Patients in Japan
Authors: Yokota Shin-ichi , Sato Kiyoshi , Kuwahara Osamu , Habadera Satoshi , Tsukamoto Naoyuki , Ohuchi Hironori , Akizawa Hirotsugu , Himi Tetsuo , Fujii Nobuhiro
Published: September 2002

We identified and genetically characterized seven fluoroquinolone-resistant
Streptococcus pneumoniae
strains among 293 clinical strains isolated from 1999 to 2001 in Japan. The resistant strains were isolated only from adults, and 7 of 31 isolates (22.6%) were from patients more than 20 years old. Resistant strains were not found in 262 isolates from children under age 10.
STATISTICAL ASSESSMENT OF SELF-AFFINE METHODS APPLIED TO SHORT PROFILES
Authors: GONZÁLEZ VIRGILIO A. , CHACÓN OSCAR , HINOJOSA M'OISÉS , GUERRERO CARLOS
Published: September 2002

Considering the small range of values that the self-affine exponent can take (0 to 1), the accuracy and precision of its determination are very important when it is used as a characteristic related to the evolution of physical phenomena or to the morphological nature of objects. In this work, a careful statistical evaluation of four common self-affine determination methods, applied to synthetic small profiles (N = 512) is reported. Accuracy, precision, confidence in the linear interval selection and computation speed are the parameters used to evaluate box counting (BC), rescaled-range analysis (Zmax), covariance analysis (Zdev) and wavelet transform (Wt) methods applied to profiles synthesized using the Weierstrass-Mandelbrot function (WMf) and the middle point displacement (Mp) methods. The results show that the log-log plot from which the self-affine exponent is computed, does not have the linear form of the BC and Zmax methods; the Wt and Zstd are the most accurate while Wt has the lowest precision. In light of these results, it is recommended to use only the Zstd or Wt methods for sample sizes of more than 100 profiles.
MULTIFRACTAL CHARACTERIZATION OF REMOTELY SENSED VOLCANIC FEATURES: A CASE STUDY FROM KILAUEA VOLCANO, HAWAII
Authors: HARVEY DANY C. , GAONAC'H HÉLÈNE , LOVEJOY SHAUN , STIX JOHN , SCHERTZER DANIEL
Published: September 2002

We used a multifractal approach to characterize scale by scale, the remotely sensed visible and thermal-infrared volcanic field, at Kilauea Volcano, Hawaii, USA. Our results show that (1) the observed fields exhibit a scaling behavior over a resolution range of ~ 2.5 m to 6 km, (2) they show a strong multifractality, (3) the multifractal parameters α, C1 and H are sensitive to volcanic structural classes such as vent cones, lava ponds and active to inactive lava flows, (4) vegetation area and volcanic gas plumes have a strong effect on the multifractal estimates, and (5) vegetation and cloud-free images show statistical characteristics due to topography related albedo in the visible and predominantly solar heating in the thermal infrared wavelengths.
THE MULTIFRACTAL SCALING OF CLOUD RADIANCES FROM 1M TO 1KM
Authors: SACHS D. , LOVEJOY S. , SCHERTZER D.
Published: September 2002

The cloud radiances and atmospheric dynamics are strongly nonlinearly coupled, the observed scaling of the former from 1 km to planetary scales is prima facae evidence for scale invariant dynamics. In contrast, the scaling properties of radiances at scales <1 km have not been well studied (contradictory claims have been made) and if a characteristic vertical cloud thickness existed, it could break the scaling of the horizontal radiances. In order to settle this issue, we use ground-based photography to study the cloud radiance field through the range scales where breaks in scaling have been reported (30 m to 500 m). Over the entire range 1 m to 1 km the two-dimensional (2D) energy spectrum (E(k)) of 38 clouds was found to accurately follow the scaling form E(k)≈ k-β where k is a wave number and β is the spectral exponent. This indirectly shows that there is no characteristic vertical cloud thickness, and that "radiative smoothing" of cloud structures occurs at all scales. We also quantitatively characterize the type of (multifractal) scaling showing that the main difference between transmitted and reflected radiance fields is the (scale-by-scale) non-conservation parameter H. These findings lend support to the unified scaling model of the atmosphere which postulates a single anisotropic scaling regime from planetary down to dissipation scales.
THE CORRELATION BETWEEN THE FRACTAL DIMENSION OF FRACTURED SURFACES AND MECHANICAL PROPERTIES OF 6061/Al2O3/10-20%p
Authors: DOSSOU FAUSTIN , GAUVIN RAYNALD
Published: September 2002

The mechanical properties of a 6061 aluminium alloy and of a composite material 6061/ Al 2 O 3/10-20% p have been mesured after heat treatments using a tensile test. Fracture surfaces profiles were used to mesure fractal dimension using the step divider method. The fractal dimension of the fractured surfaces of the composite material 6061/ Al 2 O 3/10-20% p depend on the aging and on the particle volume fraction but is independent of aging time for the unreinforced alloy.
Double and triple summation expressions obtained using perturbation theory
Authors: Mavromatis Harry A.
Published: September 2002

Using standard perturbation theory, simple new double and triple
summation expressions are obtained.
Uniformly convergent schemes for singularly perturbed differential equations based on collocation methods
Authors: Konate Dialla
Published: September 2002

It is well known that a polynomial‐based approximation scheme
applied to a singularly perturbed equation is not uniformly
convergent over the geometric domain of study. Such scheme results
in a numerical solution, say σ which suffers from severe
inaccuracies particularly in the boundary layer. What we say in the
current paper is this: when one uses a grid which is not “too
coarse” the resulted solution, even being nonuniformly convergent
may be used in an iterated scheme to get a “good” approximation
solution that is uniformly convergent over the whole geometric
domain of study.

In this paper, we use the collocation method as model of
polynomial approximation. We start from a precise localization of
the boundary layer then we decompose the domain of study, say
Ω into the boundary layer, say Ωϵ and its
complementary Ω0. Next we go to the heart of our work
which is to make a repeated use of the collocation method. We show
that the second generation of polynomial approximation is
convergent and it yields an improved error bound compared to those
usually appearing in the literature.
Uniqueness of weak solution for nonlinear elliptic equations in divergence form
Authors: Zhang Xu
Published: September 2002

We study the uniqueness of weak solutions for quasilinear elliptic
equations in divergence form. Some counterexamples are given to
show that our uniqueness result cannot be improved in the general
case.
Waves due to initial disturbances at the inertial surface in a stratified fluid of finite depth
Authors: Ghosh Prity , Basu Uma , Mandal B. N.
Published: September 2002

This paper is concerned with a Cauchy‐Poisson problem in a weakly stratified
ocean of uniform finite depth bounded above by an inertial surface (IS). The
inertial surface is composed of a thin but uniform distribution of
noninteracting materials. The techniques of Laplace transform in time and
either Green′s integral theorem or Fourier transform have been utilized in the
mathematical analysis to obtain the form of the inertial surface in terms of
an integral. The asymptotic behaviour of the inertial surface is obtained for
large time and distance and displayed graphically. The effect of
stratification is discussed.
On 3‐topological version of θ‐regularity
Authors: Kovár Martin M.
Published: September 2002

We modify the concept of θ‐regularity for
spaces with 2 and 3 topologies. The new, more general property is
fully preserved by sums and products. Using some bitopological
reductions of this property, Michael′s theorem for several variants
of bitopological paracompactness is proved.
Noninclusion theorems: some remarks on a paper by J. A. Fridy
Authors: Beekmann W.
Published: September 2002

In 1997, J. A. Fridy gave conditions for noninclusion of
ordinary and of absolute summability domains. In the present note,
these conditions are interpreted in a natural topological context
thus giving new proofs and also explaining why one of these
conditions is too weak. Also an open question posed in Fridy′s paper is
answered.
Superconvergence of a finite element method for linear integro‐differential problems
Authors: Kwak Do Y. , Lee Sungyun , Li Qian
Published: September 2002

We introduce a new way of approximating initial condition to the
semidiscrete finite element method for integro‐differential
equations using any degree of elements. We obtain several
superconvergence results for the error between the approximate
solution and the Ritz‐Volterra projection of the exact solution.
For k > 1, we obtain first order gain in Lp(2 ≤ p ≤ ∞) norm, second order in W1,p(2 ≤ p ≤ ∞) norm and almost
second order in W1,∞ norm. For k = 1, we obtain first order gain in W1,p(2 ≤ p ≤ ∞) norms. Further,
applying interpolated postprocessing technique to the approximate
solution, we get one order global superconvergence between the
exact solution and the interpolation of the approximate solution
in the Lp and W1,p(2 ≤ p ≤ ∞).
The Coxeter group Dn
Authors: Albar M. A. , Al-Saleh Norah
Published: September 2002

We show that the Coxeter group Dn is the split extension of
n − 1 copies of Z2 by Sn for a given action of Sn described in the paper. We also find the centre of Dn and some
of its other important subgroups.
A Geometric characterization of Finsler manifolds of constant curvature K = 1
Authors: Bejancu A. , Farran H. R.
Published: September 2002

We prove that a Finsler manifold 𝔽m is of constant
curvature K = 1 if and only if the unit horizontal Liouville vector
field is a Killing vector field on the indicatrix bundle IM of
𝔽m.
An application of almost increasing sequences
Authors: Bor Hüseyin
Published: September 2002

We extended a theorem of Mishra and Srivastava (1983–1984) on
|C, 1|k summability factors, using almost increasing sequences,
to summability under weaker conditions.
Banach‐Mackey, locally complete spaces, and ℓp,q‐summability
Authors: Bosch Carlos , García Armando
Published: September 2002

We defined the ℓp,q‐summability property and study the
relations between the ℓp,q‐summability property,
the Banach‐Mackey spaces and the locally complete spaces.

We prove that, for c0‐quasibarrelled spaces, Banach‐Mackey and locally complete are equivalent. Last section is devoted to the
study of CS‐closed sets introduced by Jameson and Kakol.
On p‐closed spaces
Authors: Dontchev Julian , Ganster Maximilian , Noiri Takashi
Published: September 2002

We will continue the study of p‐closed spaces. This class of
spaces is strictly placed between the class of strongly compact
spaces and the class of quasi‐H‐closed spaces. We will provide
new characterizations of p‐closed spaces and investigate their
relationships with some other classes of topological spaces.