bluuebunny/crossref_metadata_2025 huggingface dataset:
Western grey kangaroos, Macropus fuliginosus, in the South Australian pastoral zone: populations at the edge of their range
Authors: Cairns S. C. , Grigg G. C. , Beard L. A. , Pople A. R. , Alexander P.
Published: September 2002

As part of a large-scale monitoring program
linked to the management of kangaroos in the South Australian pastoral zone,
the western grey kangaroo populations have been surveyed annually with
fixed-wing aircraft over the 15-years-period 1978–92. Western grey
kangaroos are restricted in their distribution to the southern regions of the
pastoral zone. During the period of the study, western grey kangaroo numbers
showed no long-term trends, but did show some marked fluctuations, principally
in association with a severe drought. Despite this, and unlike red kangaroos
in the South Australian pastoral zone, no consistent, direct association
between changes in western grey kangaroo numbers and antecedent rainfall could
be demonstrated. The postulated reason for this is that most of the regional
western grey kangaroo populations examined in this study were low-density
populations at the edge of the range of this species. Outside of drought,
these populations are likely to be limited by factors other than food, such as
climate and unmodified resources in the form of suitable habitat. Also,
because boundary populations may well only be maintained by constant loss and
recolonisation, local extinctions associated with drought may result in
extended delays in the re-establishment of populations in marginal areas. Over
the period 1978–92, these populations were harvested commercially at
annual rates of 5–25%, which were, on the whole, considered to be
below the rates suggested to be maximum and sustainable.
Bat fauna of a semi-arid environment in central western Queensland, Australia
Authors: Young R. A. , Ford G. I.
Published: September 2002

The results from a survey of bats in semi-arid
Idalia National Park, central westernQueensland, are presented, with an
analysis of habitat use, species richness, seasonal activity and reproductive
patterns. Fourteen species were recorded: one megachiropteran, and thirteen
microchiropterans in eight genera and three families. Significant range
extensions were recorded for Vespadelus vulturnus,
V. finlaysoni and
Nyctophilus gouldi. Capture success using harp traps was
unusually high, with 859 bats of nine species captured in 27 trap-nights (31.4
bats per trap-night). Two species (Chalinolobus gouldii
and Scotorepens greyii) comprised almost 75% of
all captures in harp traps. The remaining five species were recorded by means
of echolocation call detection, cave searches and incidental observations. Bat
species richness, abundance and capture success was greatest in riparian
woodland and open forest adjacent to water; over 97% of captures in
harp traps occurred at these sites. Breeding in most species appears to follow
a seasonally monoestrous pattern with the ovarian and spermatogenic cycles
being asynchronous. Sex ratios were close to parity but with a slightly higher
proportion of females in some species in autumn. Females were generally larger
and heavier than males.
The impact of cats and foxes on the small vertebrate fauna of Heirisson Prong, Western Australia. II. A field experiment
Authors: Risbey Danielle A. , Calver Michael C. , Short Jeff , Bradley J. Stuart , Wright Ian W.
Published: September 2002

The hypothesis that predation by feral cats
and introduced foxes reduces population sizes of small, native vertebrates was
supported by results of a predator-removal experiment at Heirisson Prong, a
semi-arid site in Western Australia. The methods of control used against cats
and foxes to protect native mammals reintroduced to Heirisson Prong produced
three broad ‘predator zones’: a low-cat and low-fox zone, where
foxes were eradicated and spotlight counts of cats declined after intensive
cat control; a high-cat and low-fox zone where spotlight counts of cats
increased three-fold after foxes were controlled; and a zone where numbers of
cats and foxes were not manipulated. Small mammals and reptiles were monitored
for one year before and three years after predator control began. Captures of
small mammals increased in the low-cat and low-fox zone, but where only foxes
were controlled captures of small mammals declined by 80%. In the
absence of cat and fox control, captures of small mammals were variable over
the sampling period, lower than where both cats and foxes were controlled, yet
higher than where only foxes were controlled. The capture success of reptiles
did not appear to be related to changes in predator counts. This study
presents the first experimental evidence from mainland Australia that feral
cats can have a negative impact on populations of small mammals.
Home-range changes by brushtail possums in response to control
Authors: Efford Murray , Warburton Bruce , Spencer Nick
Published: September 2002

Common brushtail possums
(Trichosurus vulpecula) are intractable pests in New
Zealand. The effectiveness of local control can be limited by immigration,
some of which has been attributed to a ‘vacuum effect’ –
directed movements induced by the control itself. To characterise the vacuum
effect we examined changes in the home ranges of trapped possums following
control in a 6-ha block at one end of a 13-ha forest patch on farmland near
Dunedin, New Zealand. We also monitored a sample of possums by
radio-telemetry. After control, the density was 3
ha–1 inside the removal area and 16
ha–1 outside. During the year after the removal,
29% of possums within 100 m of the boundary of the removal area
(n = 38) shifted their range centre at least 50 m
towards it. The effect diminished rapidly with distance: only 1 of 28 animals
moved more than 200 m from the boundary. The size of the previous range was a
significant predictor of movement among males, but this may be partly a
sampling artifact. We measured a net flux of 69 possums
km–1 across the boundary in the 12 months after
control, and possums settled on average 44 6.9 m inside the boundary. The
vacuum effect in brushtail possums appears largely confined to home-range
adjustments by individuals with ranges overlapping the area of reduced
density. This limits its potential role in population recovery.
Trends in the numbers of red kangaroos and emus on either side of the South Australian dingo fence: evidence for predator regulation?
Authors: Pople A. R. , Grigg G. C. , Cairns S. C. , Beard L. A. , Alexander P.
Published: September 2002

Most of Australia’s sheep rangelands are
enclosed by a dingo-proof fence. Within these rangelands, where dingoes
(Canis lupus dingo) are rare, red kangaroos
(Macropus rufus) are considered to be food limited
because their numbers respond to fluctuations in pasture biomass that are
driven by highly variable rainfall. Outside this region, where dingoes are
common, kangaroo densities are generally substantially lower, suggesting that
dingoes are an important limiting factor. However, it is unclear whether
dingoes can regulate kangaroo populations. In this study, red kangaroo and emu
(Dromaius novaehollandiae) numbers were monitored for
varying periods during 1978–92 by aerial survey on both sides of the
dingo fence in three areas in the north of the South Australian pastoral zone.
Densities of red kangaroos and emus were lower outside the fence, although the
disparity varied between areas and over time. The similarity in the
environments on both sides of the fence and the marked step in kangaroo
density at the fence are consistent with dingoes strongly limiting these prey
populations. In the north-east of the pastoral zone, where kangaroo and emu
densities are greatest, the contrast in density across the fence was most
pronounced. Furthermore, the trends in density over time differed across the
fence. Outside the fence, red kangaroos and emus remained at low densities
following drought as dingo numbers increased. Inside the fence, red kangaroo
and emu populations showed a ‘typical’ post-drought recovery. The
data therefore suggest that, in some situations, dingoes may not simply limit
red kangaroo and emu populations, but also regulate them. For this to occur,
predation rate would need to be density dependent at low prey densities. The
availability of alternative prey, and the reduction in the numbers of all prey
during drought may provide the mechanism.
An ecological study of a population of Pseudantechinus macdonnellensis (Marsupialia : Dasyuridae) in central Australia. II. Population dynamics and movements
Authors: Gilfillan Sandra L.
Published: September 2002

Population dynamics and movements were investigated in a population of
Pseudantechinus macdonnellensis, a dasyurid marsupial
occupying rocky habitats in the Australian arid zone. Intra-annual cycling in
abundance, activity and numbers of resident and transient individuals was not
regular from year to year, although the number of residents was high compared
with the number of transients. Juvenile recruitment varied between years and
was as low as 18%. Densities were low (0.05–0.2
ha–1 for females and 0.05–0.3
ha–1 for males), and individuals exhibited large
stable long-term ranges – mean Minimum Convex Polygon (MCP) area for
males was 427 m2 and for females 171
m2. The constraints of the monoestrous, synchronised
reproductive strategy of P. macdonnellensis, together
with the ameliorating effect of its rocky habitat, which may decrease food
limitation and increase survival, seem to have produced a different pattern of
population dynamics to that seen in arid-zone dasyurids that are polyoestrous
plains-dwellers. The patterns of movement in
P. macdonnellensis also differ from plains-dwelling
species, in which individuals display high life-time mobility. The existence
of large but non-drifting ranges in P. macdonnellensis
may be seen as a consequence of a low but relatively predictable food supply,
which precludes the necessity for individuals to shift their activity to
temporary patches of high food supply, but requires them to occupy a large
range to obtain enough food to meet energy requirements.
The influence of visual obstructions on the vigilance and escape behaviour of house sparrows, Passer domesticus
Authors: Harkin Emma L. , van Dongen Wouter F. D. , Herberstein Marie E. , Elgar Mark A.
Published: September 2002

The scanning and flight behaviour of birds that forage in flocks may be
influenced by several variables, including the size of the flock and the
presence of visual obstructions. Visual obstructions can conceal both
potential predators and flock mates from a foraging bird, and individuals may
increase their scanning rate accordingly, although concealing flock mates may
result in more variable scanning rates as they come in and out of vision. We
examined these ideas experimentally by observing house sparrows foraging at a
feeder with and without visual obstructions. Birds foraging in the presence of
visual obstructions had generally higher and more variable scanning rates.
When the birds were approached by a human observer, they took flight earlier
in larger flocks, although their reaction was generally delayed when there
were obstructions. These data indicate that visual obstructions increase the
probability of predation because individuals are less likely to detect a
predator and/or the alarm flight of other individuals.
Phylogeography of the Australian dunnart Sminthopsis crassicaudata (Marsupialia : Dasyuridae)
Authors: Cooper S. J. B. , Adams M. , Labrinidis A.
Published: September 2002

Analyses of mitochondrial DNA (mtDNA) and allozymes are used to investigate
the population genetic structure, phylogeography and systematics of the
fat-tailed dunnart, Sminthopsis crassicaudata.
Phylogenetic analyses of control region sequences reveal the presence of two
major mtDNA haplotype clades. A survey of the distribution of the two clades
using diagnostic restriction endonucleases shows that one clade is restricted
to southeast Australia whereas the second clade occupies the remaining central
to western range of S. crassicaudata. Allozyme
electrophoresis also shows concordant patterns of population structure, with
significant differences in allele frequency at three loci between populations
in the southeast and northwest. Together, the mtDNA and allozyme data provide
evidence that S. crassicaudata consists of two
Evolutionarily Significant Units (ESUs). The distribution of each ESU is not
concordant with the distribution of the subspecies of
S. crassicaudata, and we propose that the current
subspecies classification neither reflects the major genetic subdivisions
present within S. crassicaudata nor would be appropriate
for any future conservation management. The level of divergence between mtDNA
clades (3.4%) is indicative of cladogenesis in the Pleistocene and
reflects a long-term barrier to maternal gene flow between these two
populations. One potential historical barrier was Lake Bungunnia, which
persisted in the Murray basin over much of the Pleistocene.
Genetic variation within the dasyurid marsupial genus Planigale
Authors: Blacket Mark J. , Adams Mark , Krajewski Carey , Westerman Michael
Published: September 2002

Genetic variation within the genus Planigale was
examined through analyses of 12S rRNA gene sequences and allozymes. The level
of genetic divergence between the five currently recognised
Planigale species was compared and the magnitude of
divergence among populations assessed. This examination of molecular variation
within the genus revealed that Planigale contains far
more taxonomic diversity than is currently recognised. Specifically, the
Pilbara region of Western Australia probably contains two currently
unrecognised Planigale species and there is substantial
genetic heterogeneity within the widespread species
P. maculata. Ambiguity over the status of several
genetic and/or morphological forms within the genus indicates that further
taxonomic changes are likely to be warranted in the future. This study also
demonstrates that the currently accepted geographic ranges of many planigale
species require careful re-evaluation and that many specimens in collections
are apparently misidentified. This is especially true of
P. ingrami, which appears to have a much greater range
than is currently recognised, being present in South Australia.
New evidence for facultative male die-off in island populations of dibblers, Parantechinus apicalis
Authors: Mills Harriet R. , Bencini Roberta
Published: September 2002

The post-mating mortality of males in dasyurid species is thought to be a
specific life-history strategy, associated with a tightly synchronised
breeding season, that may enhance survivorship of juveniles.
Parantechinus apicalis has been reported to exhibit male
die-off in island populations but not in mainland populations, and males
originating from both island and mainland populations are known to survive
post-mating in captivity. However, males in the island populations have been
reported to sometimes survive to breed in a second year. This study monitored
captive and island populations over a three-year period (April 1997 –
May 2000) to examine the extent of male die-off. In captivity, males showed no
evidence of post-mating mortality. Males on one island were also found to
survive post-mating, while another island population appeared to have high
mortality of males in three years, and a complete male die-off after the 1999
breeding season. We conclude that P. apicalis may
warrant inclusion in a new category of life-history strategy for species
exhibiting facultative male die-off.
The skull of Nimbacinus dicksoni (Thylacinidae : Marsupialia)
Authors: Wroe S. , Musser A.
Published: September 2002

The exceptionally well preserved skull and mandible of the Miocene thylacinid
Nimbacinus dicksoni is described. Phylogenetic analysis
supports the contention that, within the family, the dentition of
N. dicksoni is unspecialised, less derived than the
recent Thylacinus cynocephalus for at least 12 features.
However, relatively few cranial specialisations evident in
T. cynocephalus clearly distinguish it from
N. dicksoni. These two taxa share at least three derived
cranial features not present in the most generalised thylacinid known from
significant cranial material, the late Oligocene
Badjcinus turnbulli. On the other hand, where comparison
is possible, even the most specialised thylacinid,
T. cynocephalus, is plesiomorphic for at least 10
cranial features common to modern dasyurids and five present in the Miocene
dasyurid, Barinya wangala. Two character states found in
thylacinids are more derived than in B. wangala.
Relative to the remaining dasyuromorphian family, Myrmecobiidae, represented
by the monotypic Myrmecobius fasciatus, thylacinids are
derived for five cranial features and plesiomorphic for five. It appears that
despite considerable anatomical diversity among the dentitia of thylacinids
and the presence of many highly specialised dental features in some species,
the crania of thylacinids have remained remarkably conservative. Even with
respect to dentitia, in terms of overall similarity, the Miocene
Thylacinus macknessiand late Oligocene material referred
to Thylacinus does not differ greatly from the recently
extinct T. cynocephalus. It now also seems probable that
T. macknessi was also very similar to
T. cynocephalus with respect to cranial anatomy.
Numerical parsimony analysis incorporating this new material produced moderate
bootstrap and Bremer support for a monophyletic Thylacinidae. In this same
treatment strict consensus placed Myrmecobius fasciatus
as the sister taxon to Thylacinidae–Dasyuridae, but bootstrap and Bremer
support was lacking. Both of these results are contra
those of the most recent attempt to resolve dasyuromorphian relationships
using numerical parsimony and anatomical data. In the present analysis, the
early Eocene Australian taxon, Djarthia murgonensis,
fell outside a clade inclusive of all other Australian taxa and was
monophyletic with the borhyaeniod, Mayulestes ferox.
This latter relationship is based on limited material, poorly supported and
considered highly unlikely, but it does strengthen the argument that formal
placement of D. murgonensis beyond the level of
Marsupialia incertae sedisis unwarranted at present.
Design, calibration and calculation for flow-through respirometry systems
Authors: Withers P. C.
Published: September 2002

Flow-through respirometry systems that measure oxygen consumption
(VO2), carbon dioxide production
(VCO2) and evaporative water loss (EWL) require the
accurate calibration of the flow meter and three separate analysers
(O2, CO2 and
H2O vapour). Correct measurement of
VO2, VCO2 and EWL depends on the
incurrent air flow (VI) and its condition (e.g. dry,
CO2-free), and the excurrent air flow
(VE) and its condition (e.g. dry,
CO2-free), which can differ in different parts of the
excurrent circuit. Usually either VI or
VE is measured and the other is calculated from the gas
composition. I describe here a procedure for precise calibration of
CO2 and H2O analysers in a
flow-through respirometry system by reference to a calibrated
O2 analyser, using a small gas flame. Generic equations
are derived for calculation of VO2,
VO2 and EWL with a variety of configurations for a
flow-through respirometry system. Procedures for selection of data from
continuous records of VO2, VCO2
and EWL for calculation of minimal (basal or standard) values are briefly
described. Finally, the importance of the correct order of data treatment
prior to calculation is described.
Nesting climate and behaviour of Cape Barren geese (Cereopsis novaehollandiae Latham)
Authors: Wagner Kerstin , Seymour Roger S.
Published: September 2002

Embryonic development of birds is directly affected by nest temperature and
humidity. Nest site selection may therefore have a large impact on
reproductive success. Cape Barren geese
(Cereopsis novaehollandiae) use a variety of nesting
materials and sites that potentially create quite different environments for
the eggs. We categorised nests according to their protective cover and
monitored nest temperature, cooling rate, nest humidity, solar radiation
level, female incubation constancy and reproductive success on Kangaroo
Island, South Australia. Nest type was not correlated with clutch size or
timing of incubation. Nest temperature and water vapour pressure were slightly
lower in exposed nests (33.6–33.7°C, 2.60–2.94 kPa) than
in more protected nests (34.7–35.0°C, 3.34–3.83 kPa), but
incubation constancy and cooling rate during recesses did not differ between
exposed and protected nests. Incubation constancy was 92.4%
± 4.2% (s.d.). Three to four recesses of 38 ± 10
min were undertaken, mainly between 08:00 and 16:30 hours. Total recess time,
but not individual recess duration, was positively correlated with mean daily
temperature, whereas rainfall had no effect on incubation constancy. Solar
radiation input was generally stronger during recesses. Nests of Cape Barren
geese were well insulated with large amounts of down; thus, nest type had
minor influences on nest temperature and humidity and female behaviour.
Hatching success was 88% overall, and did not depend on nest type.
Taxonomy of rock-wallabies, Petrogale (Marsupialia : Macropodidae). III. Molecular data confirms the species status of the purple-necked rock-wallaby (Petrogale purpureicollis Le Souef)
Authors: Eldridge M. D. B. , Wilson A. C. C. , Metcalfe C. J. , Dollin A. E. , Bell J. N. , Johnson P. M. , Johnston P. G. , Close R. L.
Published: September 2002

Mitochondrial DNA (mtDNA) analysis was undertaken to resolve the systematic
uncertainties surrounding the morphologically distinct purple-necked
rock-wallaby (P. lateralis purpureicollis) of north-west
Queensland, Australia. A comparison of mtDNA sequence divergence using both
whole mtDNA restriction site and control-region sequence analyses revealed
that P. l. purpureicollis was as well differentiated
from other P. lateralis (black-footed rock-wallaby) taxa
as P. lateralis was from
P. penicillata (brush-tailed rock-wallaby) or
P. assimilis (allied rock-wallaby). Phylogenetic
analysis of the sequence data suggests thatP. lateralis
(sensu lato) is paraphyletic, with
P. l. purpureicollis being more closely aligned to
P. penicillataand P. assimilis
than to P. lateralis
(sensu stricto). Data are also presented that
demonstrate significant differences in the distribution of the telomeric
repeat sequence (TTAGGG)n between the chromosomes of
P. l. purpureicollis and the karyotypically similar
MacDonnell Ranges race of P. lateralis. In addition,
meiosis appears to be severely disrupted in the majority (73%) of
oocytes examined from two P. l. purpureicollis
MacDonnell Ranges race hybrids. In light of these findings we recommend that
the purple-necked rock-wallaby be reinstated as a full species,
P. purpureicollis Le Souef 1924.
Effect of food availability and habitat on the distribution of platypus (Ornithorhynchus anatinus) foraging activity
Authors: Serena M. , Worley M. , Swinnerton M. , Williams G. A.
Published: September 2002

While the diet of the platypus
(Ornithorhynchus anatinus) is known to include a wide
range of benthic macro-invertebrates, little is known about how the animals
distribute their feeding behaviour along a waterway. This radio-tracking study
aimed to determine whether the spatial distribution of platypus foraging
activity varied in relation to habitat attributes and/or the amount of
food present along a southern Victorian stream. Five
O. anatinus were tracked nocturnally for a total of
nearly 95 h in March and April 2000. Attributes of the channel and bank were
described both in the area used by the animals and adjoining unused sections
of stream, and macro-invertebrates were sampled quantitatively in six
substrates that varied in abundance in the used and unused areas. Eleven
habitat variables showed a significant positive relationship with the
occurrence of platypus activity (including the number of medium and large
Eucalyptus, Acacia and
Populus trees growing along the bank; presence of
gravel, pebbles, cobbles, large rocks and coarse particulate organic matter in
the channel substrate; amount of riffle habitat; amount of large woody debris
in the channel; and amount of undercut banks). Six habitat variables showed a
significant negative relationship with platypus activity (including the number
of medium and large Salix trees growing along the bank;
the presence of silt, solid clay and Salix roots in the
channel substrate; the amount of pool habitat; and the maximum channel depth).
Substrates that were relatively abundant in the area used by
O. anatinus (gravel/pebbles,
Eucalyptus litter, Populus litter)
did not consistently support more macro-invertebrates than substrates that
dominated the unused area (silt, Salix roots,
Salix litter). This may reflect the fact that the
platypus population was not food-limited (and hence not under pressure to
optimise foraging) at the time of the study, that platypus feeding patterns
were influenced by habitat features that were not considered in relation to
invertebrate abundance, or that the choice of foraging areas by
O. anatinus may be influenced by factors other than the
total abundance of food items, e.g. the nutritional quality and/or
accessibility of prey.
Kingfishers in paradise: the breeding biology of Tanysiptera sylvia at the Iron Range National Park, Cape York
Authors: Legge Sarah , Legge Sarah , Heinsohn Robert , Heinsohn Robert
Published: September 2002

We describe the breeding biology and site fidelity of the buff-breasted
paradise kingfisher (Tanysiptera sylvia), which migrates
each year from New Guinea to breed in north-east Australia. In a three-year
study at the Iron Range National Park in Cape York, Australia, we collected
data from 91 breeding attempts (49 territories), and banded 77 adults and 101
nestlings (47 broods) to determine site fidelity. Paradise kingfishers arrived
at Iron Range when the first major rains fell after the dry season. They
nested exclusively in terrestrial termitaria, avoiding mounds that were too
small, too close to a neighbouring territory, or mounds where the termites
were absent. They were single-brooded, but laid a second clutch if their first
attempt failed early. Clutch size was usually three, incubation lasted 25
days, nestlings hatched asynchronously and fledged after 27 days. Of 114
nestlings, 48.2% were male. Each breeding territory produced an average
of 1.5 fledglings per year. The main factors influencing nesting success were
predation, which ended 33% of all attempts, and brood reduction, which
affected 24% of nests. Hatch failure was rare (3.2%). Birds were
sexually mature at one year. Nearly half of the breeding adults banded in the
first year of the study were still alive two years later, making them at least
four years old. The return rates of banded adults varied among years
(56–84%), but were similar for the two sexes. Returning birds
almost always settled on the same territory with the same partner as the
previous year, thus they formed long-term pair-bonds. In all, 7% of
breeding pairs were assisted at the nest by an additional male, who was
probably not their offspring.
Morphometric variation and taxonomic status of brush-tailed phascogales, Phascogale tapoatafa (Meyer, 1793) (Marsupialia: Dasyuridae)
Authors: Rhind S. G. , Bradley J. S. , Cooper N. K.
Published: September 2002

This study details morphometric variation among the marsupial brush-tailed
phascogale, Phascogale tapoatafa. The validity of
phascogales from south-western and south-eastern Australia being classified as
the single subspecies P. t. tapoatafa was questioned
because of the substantial isolation of the south-west population; the
northern Australian subspecies P. t. pirata was included
in the inquiry. Discriminant function analysis performed on 18 skull
characteristics (n = 50 skulls) produced
separation between P. t. pirata, south-western
P. t. tapoatafa, and south-eastern
P. t. tapoatafa. Separation was also achieved between
female phascogales from Victoria and those from New South Wales and southern
Queensland, but not between the males of these two populations. Univariate
tests identified significant size differences between the groups. Field data
gathered on wild P. t. tapoatafa illustrate large size
differences between phascogales of Victoria and south-western Australia.
Phascogales from south-western Australia also exhibit a polymorphism in teat
number (6, 7 or 8 teats; n = 72) that is not
observed in other phascogales. This isolated population may represent a
distinct taxon.
Protein requirements of rainbow lorikeets, Trichoglossus haematodus
Authors: Frankel T. L. , Avram D.
Published: September 2002

The natural diet of rainbow lorikeets is low in protein but in captivity their
diets contain relatively high concentrations of protein. A nitrogen (N)
balance study was carried out to determine the protein requirements of
lorikeets for maintenance. Five lorikeets were fed each of three diets,
containing 3, 7 or 11 g egg white protein (100 g powdered
diet)–1 (‘as is’ basis). After 10 days
on a diet, lorikeets were placed in metabolism cages and N intakes and N
excretion determined over three days. From the regression of N excretion on N
intake (y = 0.8664x+
0.032) endogenous nitrogen loss (ENL) was calculated as 32 mg N (kg body
mass)–0.75 day–1 and
the maintenance N requirement as 240 mg N kg–0.75
day–1. The ENL is lower than that of other
nectarivores but maintenance requirement is greater, indicating an unusually
low digestibility for egg white protein (13.3%). Using a conservatively
low digestibility of 4.5% for pollen, it can be calculated that
5–6 g pollen (dry matter) per day would provide the 8 mg N
day–1 required by a 150-g lorikeet to replace ENL.
By eating 150–200 mL nectar, about 30% of requirement could be
obtained.
Incubation temperature, energy expenditure and hatchling size in the green turtle (Chelonia mydas), a species with temperature-sensitive sex determination
Authors: Booth David T. , Astill Katherine
Published: September 2002

Eggs from the Heron Island, Great Barrier Reef, nesting population of green
turtles (Chelonia mydas) were incubated at
all-male-determining (26˚C) and all-female-determining (30˚C)
temperatures. Oxygen consumption and embryonic growth were monitored
throughout incubation, and hatchling masses and body dimensions were measured
from both temperatures. Eggs hatched after 79 and 53 days incubation at
26˚C and 30˚C respectively. Oxygen consumption at both temperatures
increased to a peak several days before hatching, a pattern typical of turtle
embryos, and the rate of oxygen was higher at 30˚C than 26˚C. The
total amount of energy consumed during incubation, and hatchling dimensions,
were similar at both temperatures, but hatchlings from 26˚C had larger
mass, larger yolk-free mass and smaller residual yolks than hatchlings from
30˚C. Because of the difference in mass of hatchlings, hatchlings from
30˚C had a higher production cost.
Variation in the foot muscles of frogs of the family Myobatrachidae
Authors: Burton Thomas C.
Published: September 2002

The hind-foot musculature of representatives of all myobatrachid frog genera
was examined with a view to finding phylogenetic characters and characters
correlated with the burrowing habit. Despite much intraspecific variation,
evidence was found to support the monophyly of
Mixophyes(possession of a fibrous section in the tendon
of insertion of the m. lumbricalis longus digiti V, tendinous insertion of the
m abductors brevis dorsalis digiti V), Rheobatrachus
(threefold insertion of the m. extensor longus digiti IV),
Neobatrachus +Heleioporus
(possession of the m. lumbricalis longus digiti II),
Pseudophryne +
Metacrinia(loss or reduction of medial slip of the m.
lumbricalis brevis digiti V), Adelotus +
Heleioporus +Limnodynastes
(minus L. ornatus-group)
+Neobatrachus+Notaden
(possession of a transversus-like muscle between the first metatarsus and the
prehallux), and Rheobatrachus + Myobatrachinae
(reduction of the m. plantaris brevis plantaris digiti V). Differences were
found in the musculature associated with the metatarsal tubercles between (a)
rear-foot-burrowing frogs of the genera Notaden,
Neobatrachus,Heleioporus and
Limnodynastes (minus
L. ornatusandL. spenceri);
(b)L. ornatus and L. spenceri; and
(c)Uperoleia. The differences indicate separate
evolution of burrowing in these taxa. A new muscle, the m. adductor
praehallucis, is described. From its structure and distribution among species,
this muscle appears to be associated with the burrowing habit.
Computer simulations reveal motor properties generating stable antiparallel microtubule interactions
Authors: Nédélec François
Published: September 2002

An aster of microtubules is a set of flexible polar filaments with dynamic plus ends that irradiate from a common location at which the minus ends of the filaments are found. Processive soluble oligomeric motor complexes can bind simultaneously to two microtubules, and thus exert forces between two asters. Using computer simulations, I have explored systematically the possible steady-state regimes reached by two asters under the action of various kinds of oligomeric motors. As expected, motor complexes can induce the asters to fuse, for example when the complexes consist only of minus end–directed motors, or to fully separate, when the motors are plus end directed. More surprisingly, complexes made of two motors of opposite directionalities can also lead to antiparallel interactions between overlapping microtubules that are stable and sustained, like those seen in mitotic spindle structures. This suggests that such heterocomplexes could have a significant biological role, if they exist in the cell.
α1-Syntrophin–deficient skeletal muscle exhibits hypertrophy and aberrant formation of neuromuscular junctions during regeneration
Authors: Hosaka Yukio , Yokota Toshifumi , Miyagoe-Suzuki Yuko , Yuasa Katsutoshi , Imamura Michihiro , Matsuda Ryoichi , Ikemoto Takaaki , Kameya Shuhei , Takeda Shin'ichi
Published: September 2002

α1-Syntrophin is a member of the family of dystrophin-associated proteins; it has been shown to recruit neuronal nitric oxide synthase and the water channel aquaporin-4 to the sarcolemma by its PSD-95/SAP-90, Discs-large, ZO-1 homologous domain. To examine the role of α1-syntrophin in muscle regeneration, we injected cardiotoxin into the tibialis anterior muscles of α1-syntrophin–null (α1syn−/−) mice. After the treatment, α1syn−/− muscles displayed remarkable hypertrophy and extensive fiber splitting compared with wild-type regenerating muscles, although the untreated muscles of the mutant mice showed no gross histological change. In the hypertrophied muscles of the mutant mice, the level of insulin-like growth factor-1 transcripts was highly elevated. Interestingly, in an early stage of the regeneration process, α1syn−/− mice showed remarkably deranged neuromuscular junctions (NMJs), accompanied by impaired ability to exercise. The contractile forces were reduced in α1syn−/− regenerating muscles. Our results suggest that the lack of α1-syntrophin might be responsible in part for the muscle hypertrophy, abnormal synapse formation at NMJs, and reduced force generation during regeneration of dystrophin-deficient muscle, all of which are typically observed in the early stages of Duchenne muscular dystrophy patients.
Interleukin 2 Signaling Is Required for CD4+ Regulatory T Cell Function
Authors: Furtado Gláucia C. , de Lafaille Maria A. Curotto , Kutchukhidze Nino , Lafaille Juan J.
Published: September 2002

Mice deficient in interleukin (IL)-2 production or the IL-2 receptor α or β chains develop a lethal autoimmune syndrome. CD4+ regulatory T cells have been shown to prevent autoimmune diseases, allograft rejection, and to down-regulate antibody responses against foreign antigens. To assess the role of IL-2 in the generation and function of regulatory T cells, we transferred CD4+ T cells from mice genetically deficient in IL-2 or IL-2Rα (CD25) expression. A small number of splenic or thymic CD4+ T cells from IL-2 knockout mice can protect mice from spontaneous experimental autoimmune encephalomyelitis (EAE). In contrast, splenic or thymic CD4+ T cells from CD25 knockout donor mice conferred little or no protection. We conclude that T cells with regulatory potential can develop, undergo thymic selection, and migrate to the peripheral lymphoid organs in the absence of IL-2, and do not protect from disease by means of IL-2 secretion. However, IL-2 signaling in regulatory T cells is essential for their protective function. Altogether, our results favor a model whereby IL-2 induces regulatory T cell activity.
Specification of the mammalian cochlea is dependent on Sonic hedgehog
Authors: Riccomagno Martin M. , Martinu Lenka , Mulheisen Michael , Wu Doris K. , Epstein Douglas J.
Published: September 2002

Organization of the inner ear into auditory and vestibular components is dependent on localized patterns of gene expression within the otic vesicle. Surrounding tissues are known to influence compartmentalization of the otic vesicle, yet the participating signals remain unclear. This study identifies Sonic hedgehog (Shh) secreted by the notochord and/or floor plate as a primary regulator of auditory cell fates within the mouse inner ear. Whereas otic induction proceeds normally in Shh−/− embryos, morphogenesis of the inner ear is greatly perturbed by midgestation. Ventral otic derivatives including the cochlear duct and cochleovestibular ganglia failed to develop in the absence of Shh. The origin of the inner ear defects in Shh−/− embryos could be traced back to alterations in the expression of a number of genes involved in cell fate specification including Pax2, Otx1, Otx2,Tbx1, and Ngn1. We further show that several of these genes are targets of Shh signaling given their ectopic activation in transgenic mice that misexpress Shh in the inner ear. Taken together, our data support a model whereby auditory cell fates in the otic vesicle are established by the direct action of Shh.
Nodal activity in the node governs left-right asymmetry
Authors: Brennan Jane , Norris Dominic P. , Robertson Elizabeth J.
Published: September 2002

Nodal is expressed at the lateral edges of the mouse node, but its function in this “organizer” tissue remains unknown due to the early lethality of Nodal mutant embryos. Here we used a genetic strategy to selectively remove Nodal activity from the node. Embryos lacking Nodal in the node fail to initiate molecular asymmetry in the left lateral plate mesoderm and exhibit multiple left-right patterning defects. Nodal may also act as a short-range signal to establish a functional midline barrier. Our findings confirm that the mouse node is instrumental in initiating left-right axis specification and identify Nodal as the key morphogen regulating this process.
Developments in the market for client‐based management education
Authors: Prince Christopher
Published: September 2002

This article explores the growing popularity and importance of client‐based management education. The article argues that an increasing number of UK organisations are seeking to develop partnerships with business schools to deliver and accredit their management development initiatives. The article describes a number of innovative developments in client‐based management education using case illustrations drawing upon the experience of Nottingham Business School’s Corporate Business Unit. The article concludes by providing guidance to organisations seeking to develop partnerships with higher education institutions.
Endogenous Reactive Oxygen Species Is an Important Mediator of Miconazole Antifungal Effect
Authors: Kobayashi Daisuke , Kondo Kei , Uehara Nobuyuki , Otokozawa Seiko , Tsuji Naoki , Yagihashi Atsuhito , Watanabe Naoki
Published: September 2002

We investigated the significance of endogenous reactive oxygen species (ROS) produced by fungi treated with miconazole. ROS production inCandida albicanswas measured by a real-time fluorogenic assay. The level of ROS production was increased by miconazole at the MIC (0.125 μg/ml) and was enhanced further in a dose-dependent manner, with a fourfold increase detected when miconazole was used at 12.5 μg/ml. This increase in the level of ROS production was completely inhibited by pyrrolidinedithiocarbamate (PDTC), an antioxidant, at 10 μM. In a colony formation assay, the decrease in cell viability associated with miconazole treatment was significantly prevented by addition of PDTC. Moreover, the level of ROS production by 10 clinical isolates ofCandidaspecies was inversely correlated with the miconazole MIC (r= −0.8818;P< 0.01). These results indicate that ROS production is important to the antifungal activity of miconazole.
Discovery of a Novel and Potent Class of FabI-Directed Antibacterial Agents
Authors: Payne David J. , Miller William H. , Berry Valerie , Brosky John , Burgess Walter J. , Chen Emile , DeWolf Walter E. , Fosberry Andrew P. , Greenwood Rebecca , Head Martha S. , Heerding Dirk A. , Janson Cheryl A. , Jaworski Deborah D. , Keller Paul M. , Manley Peter J. , Moore Terrance D. , Newlander Kenneth A. , Pearson Stewart , Polizzi Brian J. , Qiu Xiayang , Rittenhouse Stephen F. , Slater-Radosti Courtney , Salyers Kevin L. , Seefeld Mark A. , Smyth Martin G. , Takata Dennis T. , Uzinskas Irene N. , Vaidya Kalindi , Wallis Nicola G. , Winram Scott B. , Yuan Catherine C. K. , Huffman William F.
Published: September 2002

Bacterial enoyl-acyl carrier protein (ACP) reductase (FabI) catalyzes the final step in each elongation cycle of bacterial fatty acid biosynthesis and is an attractive target for the development of new antibacterial agents. High-throughput screening of the
Staphylococcus aureus
FabI enzyme identified a novel, weak inhibitor with no detectable antibacterial activity against
S. aureus
. Iterative medicinal chemistry and X-ray crystal structure-based design led to the identification of compound 4 [(
E
)-
N
-methyl-
N
-(2-methyl-1
H
-indol-3-ylmethyl)-3-(7-oxo-5,6,7,8-tetrahydro-1,8-naphthyridin-3-yl)acrylamide], which is 350-fold more potent than the original lead compound obtained by high-throughput screening in the FabI inhibition assay. Compound 4 has exquisite antistaphylococci activity, achieving MICs at which 90% of isolates are inhibited more than 500 times lower than those of nine currently available antibiotics against a panel of multidrug-resistant strains of
S. aureus
and
Staphylococcus epidermidis
. Furthermore, compound 4 exhibits excellent in vivo efficacy in an
S. aureus
infection model in rats. Biochemical and genetic approaches have confirmed that the mode of antibacterial action of compound 4 and related compounds is via inhibition of FabI. Compound 4 also exhibits weak FabK inhibitory activity, which may explain its antibacterial activity against
Streptococcus pneumoniae
and
Enterococcus faecalis
, which depend on FabK and both FabK and FabI, respectively, for their enoyl-ACP reductase function. These results show that compound 4 is representative of a new, totally synthetic series of antibacterial agents that has the potential to provide novel alternatives for the treatment of
S. aureus
infections that are resistant to our present armory of antibiotics.
In Vitro Antimicrobial Activity of GSQ1530, a New Heteroaromatic Polycyclic Compound
Authors: Ge Yigong , Difuntorum Stacey , Touami Sofia , Critchley Ian , Bürli Roland , Jiang Vernon , Drazan Ken , Moser Heinz
Published: September 2002

GSQ1530 is a compound derived from a newly identified class of antibiotics referred to as heteroaromatic polycyclic (HARP) antibiotics. The aim of this study was to assess the in vitro antimicrobial activity of GSQ1530. By using an NCCLS broth microdilution assay, the activities of GSQ1530 and other antibiotics were coevaluated against 215 clinical isolates. The MICs at which 90% of isolates are inhibited (MIC
90
s) of GSQ1530 for methicillin-susceptible
Staphylococcus aureus
and methicillin-resistant
S. aureus
(MRSA) were 2 and 4 μg/ml, respectively. The MIC
90
s of GSQ1530 for the streptococci tested were 2 μg/ml or less, regardless of their susceptibilities to other antibiotics. The MIC
90
of GSQ1530 for the enterococci tested (including vancomycin-resistant enterococci) was 4 μg/ml. No cross-resistance was found between GSQ1530 and other known antibiotics. In a separate assay, GSQ1530 demonstrated excellent activity against vancomycin-intermediate-susceptible staphylococci (MIC
90
, 1 μg/ml). The minimal bactericidal concentration test was conducted with 73 clinical isolates; GSQ1530 was cidal against streptococci and staphylococci but static against enterococci. An in vitro killing kinetic study revealed a time-dependent profile, with at least a 3-log reduction of bacterial growth within 6 h after exposure to four times the MICs of GSQ1530 for both
S. aureus
and
Streptococcus pneumoniae
. The checkerboard study showed that GSQ1530 had a synergistic interaction with rifampin against MRSA. The test medium was found to have little effect on in vitro antimicrobial potency. The MICs of GSQ1530 for gram-positive cocci were 4- to 32-fold higher in the presence of serum proteins. GSQ1530 has high levels of plasma protein binding (91 and 89% for rat and human plasma, respectively). These preliminary results demonstrate that GSQ1530, a representative compound of our novel HARP antibiotics, has broad-spectrum activity against gram-positive bacteria. This novel class of antibacterial compounds is profiled in vivo to assess the therapeutic potential in humans. Ongoing in vivo studies will assess whether this class of molecules has promising in vivo efficacy and safety profiles.
Itraconazole Preexposure Attenuates the Efficacy of Subsequent Amphotericin B Therapy in a Murine Model of Acute Invasive Pulmonary Aspergillosis
Authors: Lewis Russell E. , Prince Randall A. , Chi Jingduan , Kontoyiannis Dimitrios P.
Published: September 2002

Antagonism has been described in vitro and in vivo for azole-polyene combinations againstAspergillusspecies. Using an established murine model of invasive pulmonary aspergillosis, we evaluated the efficacy of several amphotericin B (AMB) dosages given alone or following preexposure to itraconazole (ITC). Mice were immunosuppressed with cortisone acetate and cyclophosphamide. During immunosuppression, animals were administered either ITC solution (50 mg/kg of body weight) or saline by oral gavage twice daily for 3 days prior to infection. Infection was induced by intranasally inoculating mice with a standardized conidial suspension (1 × 108CFU/ml) ofAspergillus fumigatusstrain AF 293. AMB was then administered by daily intraperitoneal injections (0.25, 0.5, 1.0, and 3.0 mg/kg) starting 24 h after inoculation and continuing for a total of 72 h. Drug pharmacokinetics of AMB and ITC in plasma were determined by high-performance liquid chromatography. Four different endpoints were used to examine the efficacy of antifungal therapy: (i) viable counts from harvested lung tissue (in CFU per milliliter), (ii) the whole-lung chitin assay, (iii) mortality at 96 h, and (iv) histopathology of representative lung sections. At AMB doses of >0.5 mg/kg/day, fewer ITC-preexposed mice versus non-ITC-preexposed mice were alive at 96 h (0 to 20 versus 60%, respectively). At all time points, the fungal lung burden was consistently and significantly higher in animals preexposed to ITC, as measured by the CFU counts (P= 0.001) and the chitin assay (P= 0.03). Higher doses of AMB did not overcome this antagonism. ITC preexposure was associated with poorer mycological efficacy and survival in mice treated subsequently with AMB for invasive pulmonary aspergillosis.