bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface effect on the bandgap of BN one-dimensional nanostructures
Authors: Li S. , Yang G. W.
Published: August 2011

We have presented a comprehensive first-principles investigation of the structural stability and electronic structure of one-dimensional boron nitride (BN) nanostructures including nanowires (NWs), facet-nanotubes (FNTs), and nanoholes inside bulk BN. It was found that the binding energy Eb of these BN one-dimensional nanostructures satisfies a linear dependence relationship with the surface atom ratio λ, and the size-dependence of their bandgap Eg exhibits abnormal behavior compared with that of II-VI and III-V semiconductor NWs and FNTs (note that these nanostructures do not contain AlN and GaN): the Eg of BN one-dimensional nanostructures decreases with decreasing size. These unusual properties are attributed to the effects of λ and the negative/positive curvature radius α of NB NWs and NTs.
An empirical model of collective electrostatic effects for laser-beam channeling in long-scale-length relativistic plasmas
Authors: Yang Jeong-Hoon , Craxton R. Stephen
Published: August 2011

This work investigates the capability of ultraintense lasers with irradiance from 1018 to 1021 W cm−2 to produce highly energetic electron beams from a Gaussian focus in a low-density plasma. A simple particle simulation code including a physical model of collective electrostatic effects in relativistic plasmas has been developed. Without electrostatic fields, free electrons escape from the Gaussian focal region of a 10-ps petawatt laser pulse very quickly, well before the laser field reaches its maximum amplitude. However, it has been demonstrated that the electrostatic field generated by the electron flow is able to strongly modify the range and direction of the laser-generated MeV electrons by allowing trapped electrons to experience much higher laser-intensity peaks along their trajectories. This modeling predicts some collimation but not enough to meet the requirements of fast ignition.
Adaptive mechanism between dynamical synchronization and epidemic behavior on complex networks
Authors: Li Kezan , Fu Xinchu , Small Michael , Ma Zhongjun
Published: August 2011

Many realistic epidemic networks display statistically synchronous behavior which we will refer to as epidemic synchronization. However, to the best of our knowledge, there has been no theoretical study of epidemic synchronization. In fact, in many cases, synchronization and epidemic behavior can arise simultaneously and interplay adaptively. In this paper, we first construct mathematical models of epidemic synchronization, based on traditional dynamical models on complex networks, by applying the adaptive mechanisms observed in real networks. Then, we study the relationship between the epidemic rate and synchronization stability of these models and, in particular, obtain the conditions of local and global stability for epidemic synchronization. Finally, we perform numerical analysis to verify our theoretical results. This work is the first to draw a theoretical bridge between epidemic transmission and synchronization dynamics and will be beneficial to the study of control and the analysis of the epidemics on complex networks.
Observation of exponential spectra and Lorentzian pulses in the TJ-K stellarator
Authors: Hornung G. , Nold B. , Maggs J. E. , Morales G. J. , Ramisch M. , Stroth U.
Published: August 2011

An experimental investigation of the low-frequency density fluctuations in the plasma edge region of the TJ-K stellarator [N. Krause et al., Rev. Sci. Inst. 73, 3474 (2002)] finds that the ensemble-averaged frequency spectra exhibit a near exponential frequency dependence whose origin can be traced to individual pulses having a Lorentzian temporal shape. Similar features have been previously observed [D. C. Pace et al., Phys. Plasmas 15, 122304 (2008)] in a linear magnetized device under conditions in which cross-field pressure gradients are present. The reported observation of such features within the turbulent environment of a toroidal confinement device provides support for the conjecture that the underlying processes are a general feature of pressure gradients. Also presented is the magnetic field strength dependence of the pulse widths and the waiting time distribution between pulses.
Digitally gain controlled linear high voltage amplifier for laboratory applications
Authors: Koçum C.
Published: August 2011

The design of a digitally gain controlled high-voltage non-inverting bipolar linear amplifier is presented. This cost efficient and relatively simple circuit has stable operation range from dc to 90 kHz under the load of 10 kΩ and 39 pF. The amplifier can swing up to 360 Vpp under these conditions and it has 2.5 μs rise time. The gain can be changed by the aid of JFETs. The amplifiers have been realized using a combination of operational amplifiers and high-voltage discrete bipolar junction transistors. The circuit details and performance characteristics are discussed.
Non-invasive and high-sensitivity scanning detection of magnetic nanoparticles in animals using high-Tc scanning superconducting-quantum-interference-device biosusceptometry
Authors: Chieh J. J. , Hong C. Y.
Published: August 2011

Although magnetic nanoparticles (MNPs) have been widely applied to animals in biomedicine, MNPs within animals should be examined in real time, in vivo, and without bio-damaged possibility to evaluate whether the bio-function of MNPs is valid or to further controls the biomedicinal process because of accompanying complex problems such as MNPs distribution and MNPs biodegradation. The non-invasive and high-sensitivity scanning detection of MNPs in animals using ac susceptometry based on a high-Tc superconducting quantum interference device (SQUID) is presented. The non-invasive results and biopsy results show good agreement, and two gold-standard biomedicine methods, Prussian blue stain and inductively coupled plasma, prove the magnetic results. This confirms that the future clinical diagnosis of bio-functional MNPs could be operated by using scanning SQUID biosusceptometry as conveniently as an ultrasonic probe.
Design and performance of a pulse transformer based on Fe-based nanocrystalline core
Authors: Yi Liu , Xibo Feng , Lin Fuchang
Published: August 2011

A dry-type pulse transformer based on Fe-based nanocrystalline core with a load of 0.88 nF, output voltage of more than 65 kV, and winding ratio of 46 is designed and constructed. The dynamic characteristics of Fe-based nanocrystalline core under the impulse with the pulse width of several microseconds were studied. The pulse width and incremental flux density have an important effect on the pulse permeability, so the pulse permeability is measured under a certain pulse width and incremental flux density. The minimal volume of the toroidal pulse transformer core is determined by the coupling coefficient, the capacitors of the resonant charging circuit, incremental flux density, and pulse permeability. The factors of the charging time, ratio, and energy transmission efficiency in the resonant charging circuit based on magnetic core-type pulse transformer are analyzed. Experimental results of the pulse transformer are in good agreement with the theoretical calculation. When the primary capacitor is 3.17 μF and charge voltage is 1.8 kV, a voltage across the secondary capacitor of 0.88 nF with peak value of 68.5 kV, rise time (10%–90%) of 1.80 μs is obtained.
Explicitly correlated treatment of H2NSi and H2SiN radicals: Electronic structure calculations and rovibrational spectra
Authors: Lauvergnat D. , Senent M. L. , Jutier L. , Hochlaf M.
Published: August 2011

Various ab initio methods are used to compute the six dimensional potential energy surfaces (6D-PESs) of the ground states of the H2NSi and H2SiN radicals. They include standard coupled cluster (RCCSD(T)) techniques and the newly developed explicitly correlated RCCSD(T)-F12 methods. For H2NSi, the explicitly correlated techniques are viewed to provide data as accurate as the standard coupled cluster techniques, whereas small differences are noticed for H2SiN. These PESs are found to be very flat along the out-of-plane and some in-plane bending coordinates. Then, the analytic representations of these PESs are used to solve the nuclear motions by standard perturbation theory and variational calculations. For both isomers, a set of accurate spectroscopic parameters and the vibrational spectrum up to 4000 cm−1 are predicted. In particular, the analysis of our results shows the occurrence of anharmonic resonances for H2SiN even at low energies.
The stability of miscible displacement in porous media: Nonmonotonic viscosity profiles
Authors: Kim Min Chan , Choi Chang Kyun
Published: August 2011

The stability of miscible displacement in porous media is analyzed theoretically. By considering the nonmonotonic viscosity variation effects, new stability equations are derived in a similar domain with and without the quasi-steady state approximations (QSSA). An analytical approach to solve the newly driven stability equations is proposed and its validity is confirmed by comparing its solutions with numerically obtained ones. Through the growth rate analysis without the QSSA, it is shown analytically that the system is unconditionally stable for the long-wave disturbance regardless of the viscosity profile. The present growth rate obtained for small time without the QSSA is quite different from the previous analyses based on the QSSA where the growth rate of the disturbance depends strongly on the viscosity profile. Through the stability characteristics for the finite time case, the validity of the QSSA is discussed. The present stability condition explains the system more reasonably than the previous results based on the conventional QSSA.
Dynamic junction temperature measurement for high power light emitting diodes
Authors: Chen Quan , Luo Xiaobing , Zhou Shengjun , Liu Sheng
Published: August 2011

Junction temperature of high power light emitting diodes (LEDs), which is crucial for the thermal management of solid-state lighting, needs to be measured accurately. In this paper, a dynamic junction temperature measurement system for LEDs was proposed and the calibration including instrument calibration and factor K calibration were presented. The influence of the fast switch time in dynamic junction temperature test was analyzed and measurement errors caused by sampling delay were quantified. To prove the accuracy of the present system, comparison experiment was conducted. It shows a good agreement between the experimental data and reference value. Experiments also show that the measurement accuracy of the instrument can be up to 0.1 °C, and the standard error of temperature measurement can be controlled within 1%.
Homogeneity improvement of field emission beam from metallic nano-tip arrays by noble-gas conditioning
Authors: Tsujino S. , Paraliev M. , Kirk E. , Braun H.-H.
Published: August 2011

The authors explored control of field-emission electron beam homogeneity emitted from metallic nano-tips fabricated by molding. Improved beam homogeneity and increased maximum bunch charge were observed after DC operation of cathodes in low-pressure argon gas environment. They also observed average current per tip of 4.5 μA from a 1 × 104 emitter array device after conditioning in neon gas. Evolution of Fowler-Nordheim parameters as a result of noble-gas conditioning was discussed.
High charge carrier density at the NaTaO3/SrTiO3 hetero-interface
Authors: Nazir S. , Schwingenschlögl U.
Published: August 2011

The formation of a (quasi) two-dimensional electron gas between the band insulators NaTaO3 and SrTiO3 is studied by means of the full-potential linearized augmented plane-wave method of density functional theory. Optimization of the atomic positions points to only small changes in the chemical bonding at the interface. Both the p-type (NaO)−/(TiO2)0 and n-type (TaO2)+/(SrO)0 interfaces are found to be metallic with high charge carrier densities. The effects of O vacancies are discussed. Spin-polarized calculations point to the formation of isolated O 2p magnetic moments, located in the metallic region of the p-type interface.
Communication: Vacuum ultraviolet laser photodissociation studies of small molecules by the vacuum ultraviolet laser photoionization time-sliced velocity-mapped ion imaging method
Authors: Pan Yang , Gao Hong , Yang Lei , Zhou Jingang , Ng C. Y. , Jackson William M.
Published: August 2011

We demonstrate that the vacuum ultraviolet (VUV) photodissociation dynamics of N2 and CO2 can be studied using VUV photoionization with time-sliced velocity-mapped ion imaging (VUV-PI-VMI) detection. The VUV laser light is produced by resonant sum frequency mixing in Kr. N2 is used to show that when the photon energy of the VUV laser is above the ionization energy of an allowed transition of one of the product atoms it can be detected and characterized as the wavelength is varied. In this case a β parameter = 0.57 for the N(2D°) was measured after exciting N2(o1Πu, v′ = 2, J′ = 2) ← N2(X1Σg+, v″ = 0, J″ = 1). Studies with CO2 show that when there is no allowed transition, an autoionization resonance can be used for the detection of a product atom. In this case it is shown for the first time that the O(1D) atom is produced with CO(1Σ+) at 92.21 nm. These results indicate that the VUV laser photodissociation combined with the VUV-PI-VMI detection is a viable method for studying the one-photon photodissociation from the ground state of simple molecules in the extreme ultraviolet and VUV spectral regions.
A survey of a low-density koala population in a major reserve system, near Sydney, New South Wales..
Authors: Curtin A , Lunney D , Matthews A
Published: August 2011

cinereus) in Yengo National Park and Parr State Recreation Area, which together form a major
reserve system where P. cinereus were known to be scarce. The first, a community survey
which was distributed to 823 residences adjoining the reserves, yielded 139 responses. Of these,
31 responses provided information that allowed 26 P. cinereus locality records to be verified. A
further eight P. cinereus locality records were obtained from interviews with neighbours. Most
records were road-based. The second, a field survey based on scat searches, produced an
additional 13 P. cinereus localities. P. cinereus scats were found under 11 tree species.
Eucalyptus punctata was most frequently recorded with scats of those that were adequately
sampled. A range of vegetation types and both ridges and gullies were used by P. cinereus.
During field surveys, P. cinereus was found to be sparse and occurring throughout much of the
survey area, concentrated in the eastern, southern and central parts of the reserve system. Both
methods identified P. cinereus to be present before and after the extensive fires of January 1994,
which burnt 60 % of the area. An appraisal of the methods revealed that they are
complementary. The survey of residents provided recent and historical information and an
indication of initial search areas for P. cinereus. The field survey yielded specific information
about local P. cinereus habitat. The combination increased the number of P. cinereus records for
the area more than four-fold. This study has provided the reserve managers with a clearer
picture of the location of the local P. cinereus population.
Redefining the activity pattern of the honey possum (Tarsipes rostratus).
Authors: Arrese C , Runham PB
Published: August 2011

ANIMALS are commonly separated into two major
categories based on their activity patterns: diurnal
and nocturnal. However, evidence of numerous
species exhibiting diverse periods of activity,
including arhythmic and crepuscular habits, broadens
the description. The honey possum (Tarsipes
rostratus), a small West-Australian marsupial feeding
exclusively on nectar and pollen, has been described
as strongly nocturnal (Wooller et al. 1981; Russell
and Renfree 1989). However, infrequent daytime
activity in captivity (Russell 1986) and in the wild
under cold, cloudy conditions, has been reported
(Hopper and Burbidge 1982; du Plessis and du
Plessis 1995). During trapping exercises in the region
of Jurien Bay (250 km north of Perth, Western
Australia), several animals were observed foraging
after sunrise and before sunset, with occasional
diurnal activity. To date, no study has investigated
directly the activity periods of the species.
Furthermore, studies of the visual capabilities of T.
rostratus revealed that its retinal organisation is not
compatible with a nocturnal lifestyle, but presents
features comparable to those found in diurnal species
(Arrese 2002; Arrese et al. 2002). Such discrepancies
warranted the monitoring of activity periods
(rhythmicity) of T. rostratus in its natural
environment, a study reported here. We discuss our
results in the context of the visual ecology of the
species.
A Symposium on the Dingo. Edited by Chris Dickman and Daniel Lunney. A Review by Peter Thomson.
Authors: Thomson P
Published: August 2011

A symposium on the dingo (Canis lupus dingo) was
held in Sydney in May 1999 to discuss issues
surrounding the conflicting views of the dingo: seen
both as a potentially threatened species, and as a
species that needs to be controlled because of its
predation on livestock. The Symposium was
particularly relevant to New South Wales (NSW)
because of consideration being given to place the
dingo on the schedule of NSW vulnerable species,
under the NSW Threatened Species Conservation Act
1995. The potential for conflict was exacerbated by
concurrent legislative changes in NSW (Rural Lands
Protection Act 1998) requiring the Crown to control
pest animals declared under the Act. Despite the
obvious focus on the NSW situation, many of the
issues discussed have wider relevance to the
management and conservation of dingoes across
Australia.
At-Sea Movements Of Female Australian Fur Seals Arctocephalus Pusillus Doriferus
Authors: Littnan CL , Arnould JPY
Published: August 2011

In May 1999, satellite transmitters were deployed on three lactating female Australian fur seals
(Arctocephalus pusillus doriferus) at Kanowna Island (39� 10' S, 146� 18' E) and at-sea
movements were recorded for 65 ? 174 days. The mean foraging trip and on-shore durations (8
and 2 days, respectively) were not significantly different to that previously reported for the
species. The seals all foraged in three separate areas of Bass Strait with each individual
repeatedly returning to the same general location. Movements during foraging trips fell into two
distinct patterns. In one pattern, displayed by two individuals, the females travelled directly to a
presumed foraging area. In this trip type, outward and return travel consisted of relatively
constant headings at moderate speed (1.37 � 0.07 m/s) while the middle phase was
characterised by repeated changes in direction within a small area and significantly lower
speeds (0.82 � 0.07 m/s). The second pattern, displayed by the third individual, consisted of a
looping path with relatively uniform average speed (1.14 � 0.06 m/s) throughout the trip. The
three foraging areas were: 1) inshore area between Wilsons Promontory and Lakes Entrance; 2)
offshore in proximity to The Skerries; and 3) up to 200 km south of Wilsons Promontory in
central Bass Strait. The foraging areas used by these seals overlap with regions of commercial
fishing effort raising the potential for some conflict.
Satellite Tracker Deployments On Adult, Male Australian Fur Seals (Arctophalus Pusillus Doriferus): Methods And Preliminary Results
Authors: Kirkwood R , Gales N , Lynch M , Dann P
Published: August 2011

In May 1999, four adult male, Australian fur seals (Arctocephalus pusillus doriferus) from the
Seal Rocks colony, Victoria, were fitted with satellite transmitters that provided locations for
between 2 and 7 months. Foraging trips during winter and early spring averaged 7.4 days (range
for all trips 0.9 to 24.6) and between-trip rests lasted 2.8 days (range 0.3 to 5.7). Between-trip
rest sites included Seal Rocks, other colonies and other haul-out sites. The seals foraged mostly
in western Bass Strait and in water depths < 100 m.
A Northward Spread In The Breeding Distribution Of The New Zealand Sea Lion (Phocartos Hooeri)
Authors: Mcconkey SD , Mcconnell H , Lalas C , Heinrich S , Ludmerer A , Mcnally N , Parker E , Borofsky C , Schimanski K , Mcintosh G
Published: August 2011

The primary objective of the population management plan for New Zealand sea lions,
Phocarctos hookeri, is to move the species from its current conservation status of
‘Threatened’ to ‘Non-threatened’. The mechanism by which this will occur is through the
establishment of new breeding colonies away from the only existing colonies at Auckland
Islands and Campbell Island. Otago, on the southeast coast of the South Island of New
Zealand, is one of only three locations where breeding has been recorded away from these
islands in modern times. We found only one female at the initiation of our surveys here in
1991, an individual that had been tagged as a pup at Auckland Islands. This female has
remained resident at Otago and is now breeding. Her first live birth, in the 1993/94 breeding
season, represented the first record of a P. hookeri pup on the New Zealand mainland since
the elimination of the species here by humans c. 150 years ago. Up to and including the
2000/01 breeding season she had produced six pups. Her surviving pups have remained at
Otago and her eldest two daughters have started breeding, producing a further three pups.
From this total of nine live births, two pups have died. Although 6 - 8 other migrant females
have been recorded, to our knowledge none have bred at Otago. We conclude that the
initiation of breeding by P. hookeri at Otago has been a serendipitous event attributable to
atypical behaviour by a single female.
Entanglement Of Pinnipeds At Marion Island, Southern
Ocean: 1991-2001
Authors: Hofmeyr G , De Maine M , Beste Mr , Kirkman S , Pistorius P , Makhado A
Published: August 2011

Some 101 fur seals Arctocephalus spp. and five southern elephant seals Mirounga leonina were
recorded entangled in anthropogenic debris over ten years at Marion Island, Southern Ocean.
Approximately 67% of materials causing entanglement originated in the fishing industry.
Polypropylene packaging straps were the most common entangling material, followed by trawl
netting. Longline hooks embedded in animals, fishing line and portions of plastic were only
encountered after the inception in 1996 of longline fishing in the waters around Marion Island.
The incidence of entanglement of Arctocephalus spp. during the 1996-2001 longline fisheries
period increased by more than 50% over that of the 1991-1996 pre-longline fisheries period. An
estimated 0.24% of the populations of fur seals were entangled. The numbers of entangled M.
leonina are very low. Longline fishing has had a direct, albeit small, impact on the pinniped
populations
Rocky Reefs Provide Foraging Habitat For Dugongs In The Darwin Region Of Northern Australia
Authors: Whiting SD
Published: August 2011

DUGONGS (Dugong dugon) are large mammalian
herbivores found in tropical and sub-tropical waters
from the east coast of Africa to Vanuatu in the western
Pacific Ocean (Rice 1998). Foraging studies throughout
their range indicate that their diet is dominated by
seagrass (Marsh et al. 1982; Preen 1995; Preen and
Marsh 1995; Anderson 1998; Das and Dey 1999).
Aerial surveys (Marsh and Saalfeld, 1989; Preen et al.
1997), land-based and boat-based observations
(Anderson 1982 1994; Aragones 1994) and satellite
tracking data (Marsh and Rathbun 1990) indicate that
dugong distribution is closely associated with seagrass
beds. Algae is known to occur in food samples from
dugongs (Heinsohn and Birch 1972; Marsh et al. 1982;
Erftemeijer 1994; Preen 1995) but its presence in the
diet has been described as incidental (Marsh et al. 1982)
or linked to large-scale losses of seagrass (Spain and
Heinsohn 1973; Marsh et al. 1982; Preen and Marsh
1995). This note contains opportunistic observations of
long-term feeding by D. dugon on algal covered rocky
reefs in the Darwin region of the Northern Territory.
Ecology of the Honey possum, Tarsipes rostratus, in Scott National Park, Western Australia
Authors: Bradshaw S.D. , Phillips R.D. , Tomlinson S. , Holley R. J. , Jennings S. , Bradshaw F.J.
Published: August 2011

The Honey possum, Tarsipes rostratus, is an obligate nectarivore, known to feed on plant species from only three Families in south-western Western Australia: Myrtaceae, Proteaceae and Epacridaceae. These plants can be adversely affected by fire, decreased rainfall or groundwater levels and the pathogen Phytophthora cinnamomi. We investigated the ecology of T. rostratus in terms of: (i) how the population fluctuated in response to rainfall and fire over a 20-year period and (ii) changes in diet and movements during a period of decreased food availability in late summer. Mean capture rates were significantly positively correlated with mean flowering rates of Banksia ilicifolia over a 20-year period. Winter capture rates were also significantly positively correlated with both annual and winter rainfall two years prior to trapping in recently burnt areas, but not in long unburnt� areas. Capture rates were significantly higher in unburnt Banksia woodland during winter but densities there have declined since 1996, associated with the death of many Banksia ilicifolia trees from persistent Phytophthora infection. Notwithstanding this decline, winter capture rates in the unburnt areas were still approximately double those in the burnt areas 6 years after the last fire. Short-term capture rates were negatively correlated with barometric pressure, showing that movement and foraging is stimulated by the passage of low pressure frontal weather systems. Despite the paucity of known food sources flowering in late summer and autumn, there was no evidence of T. rostratus using plant species from other than the three above-noted Families. Utilisation areas in summer were also no larger than those previously recorded across all seasons in Scott National Park. Some individuals, however, moved extensive distances to locate spatially restricted food sources. The conservatism of their diet and the sensitivity of the population to changes in rainfall and fire history indicate that T. rostratus populations are particularly vulnerable to some of the environmental changes now occurring in south-western Australia.
Aspects of the ecology of the eastern pygmy-possum Cercartetus nanus at Jervis Bay, New South Wales.
Authors: Harris J.M. , Goldingay R.L. , Broome L. , Craven P. , Maloney K.S.
Published: August 2011

A variety of ecological data were collected on the eastern pygmy-possum Cercartetus nanus at Jervis Bay, in south-eastern New South Wales between March 2006 and January 2007. Elliott traps, pitfall traps, nest-boxes and spotlighting were used to survey for the species. Data on habitat suitability including abundance of food plants (flowering trees and shrubs) and potential nest sites were also collected. Home range data were gathered via radio telemetry. Three individuals were caught in 2150 trap-nights and one animal was re-trapped once. Radio-collars were attached to one animal of each sex and tracked for 11 days during March 2006. These possums used areas (using minimum convex polygons) of 0.85 ha (male) and 0.19 ha (female). The average overnight distance moved was 44 m for the male (range = 4-81 m) and 19 m for the female (range = 0-56 m). Nest-sites included hollows in the proteaceous shrubs Banksia serrata and B. ericifolia, and in the myrtaceous trees Corymbia gummifera, Eucalyptus sclerophylla, and Syncarpia glomulifera. Cercartetus nanus captures were confined to two sites that had the most prolific flowering of potential food plants and the highest availability of potential nest-sites. A review of literature and previous surveys of the surrounding area was a necessary precursor to field study and produced 57 records. Greater understanding of the impacts of development and fire are needed for conservation and management of this species.
Surprise in the pouch ? a case of adoption in the common brushtail possum (Trichosurus vulpecula)
Authors: Eymann J. , Neaves L. , Eldridge M.D.B. , Cooper D.W. , Herbert C.A.
Published: August 2011

The common brushtail possum (Trichosurus vulpecula) is usually a strictly monotocous species, presenting one offspring at a time. Two concurrent offspring is a rare occurrence, but twin pouch young or young spaced one oestrous cycle apart have been reported. We investigated the biology of urban T. vulpecula populations within the Sydney metropolitan area between November 2002 and April 2005. As part of these studies, we trapped one adult female T.�vulpecula with two young. Analysis of morphological data from the young and development of the female?s mammary gland suggest that only one young was her offspring. The results of genetic analysis support this conclusion. Herewith, we describe an apparent case of adoption in T. vulpecula.
. Predation on Australian sea lions Neophoca cinerea by white sharks Carcharodon carcharias in South Australia
Authors: Shaughnessy PD, , Berris M , Dennis T. E.
Published: August 2011

From January 1988 to December 2002, 182 Australian sea lions Neophoca cinerea with injuries attributable to white sharks Carcharodon carcharias were recorded in the N. cinerea colony at Seal Bay, Kangaroo Island. The mean number per month was 1.0 (s.d. 1.3), and the number per calendar year varied from 5 to 25 (mean 12.1, s.d. 6.1). The incidence was highest in summer (December to February) and autumn (March to May). The month with the greatest incidence of injured sea lions was January, when it was 17% of the total. This coincides with the higher proportion of white shark records around Kangaroo Island in summer and autumn than in other seasons (Bruce 1992). Adult female and juvenile sea lions were attacked most frequently, with 38% and 26%, respectively. Adult females pass through the waters near the colony more frequently than other sea lions, which makes them more susceptible than other age-sex groups to attacks by white sharks. Most (42%) injuries were to the head and central parts of the sea lions' bodies and 39% were to the rear of their bodies ('rear trunk' and 'hind flippers' areas). The stomach contents of a white shark caught in a bottom-set monofilament gill-net at Cape Gantheaume, Kangaroo Island in April 1992 included two N. cinerea pups aged 10-12 months. They formed about 75% of the shark?s stomach contents.
Louse infestations of the Australian sea lion Neophoca cinerea.
Authors: McIntosh R.R. , Murray M.D.
Published: August 2011

Sea lions (Neophoca cinerea) at several South Australian islands were infested with the anopluran louse Antarctophthirus microchir.
The value of germplasm nurseries in selecting species for field evaluation
Authors: Snowball R. , D'Antuono M. F. , Cohen B. J. , Gajda K. , Bennett R.
Published: August 2011

This paper documents observations made in irrigated seed multiplication nurseries of novel pasture germplasm to aid in the selection of species for field trials. For the first time it also compares these observations to results from past and concurrent field trials to ascertain the value of observations made in germplasm nurseries in predicting performance in the field. Flowering abundance, seed yield and plant survival over a 2-year period was assessed at four consecutive germplasm nurseries used for seed multiplication between 2002 and 2007. Germplasm included 373 accessions from 67 species and 28 genera of exotic and native perennial forage species, mostly legumes with potential in recharge environments. Classification and regression tree analysis was used to allocate accessions within a species to fewer groups of accessions using the germplasm characteristics. Plant survival and ratings for herbage production in germplasm nurseries were compared to results from field trials for the same species and for the same accessions in order to identify which plant characteristics gave good concordance.
Observations from germplasm nurseries were, on the whole, useful in predicting survival of species and accessions in field trials. Ratings for herbage production in germplasm nurseries corresponded poorly with measurements or ratings of herbage production in field trials but, nevertheless, were useful in eliminating some poor-performing germplasm. Several species were identified that had superior survival and seed production in germplasm nurseries, some of which also performed well in field trials, including Dorycnium hirsutum, Kennedia prostrata, Lespedeza juncea var. sericea, Lotononis bainesii and Sanguisorba minor. Western Australian native species had mixed performance in germplasm nurseries but showed promise in field trials, and should be further investigated for their potential in farming systems in southern Australia.
Influence of stocking rate and phosphate fertiliser application on the composition of annual legume seedbanks within a Mediterranean grassland
Authors: Norman Hayley C. , Cocks Philip S. , Galwey Nicholas W.
Published: August 2011

This paper tested the general hypothesis that differences in grazing intensity and phosphate application lead to adjustments in the structure of an annual legume community in natural and diverse grassland at Tel Hadya, Syria, due to changes in competitive relationships between species. The management treatments imposed were a factorial design of 0 or 60 kg/ha of superphosphate fertiliser (applied annually) and relatively low or high continuous sheep stocking intensities. These management treatments were applied for 13 years across three replicate paddocks for each treatment before the annual legume seed banks were sampled. The seed was sorted and representative plants were grown in a common garden in Perth, Australia, to assess reproductive and morphological traits.
We found that phosphate application had more influence on species composition than stocking rate and favoured species with relatively competitive reproductive strategies (plants with relatively large seeds, low fecundity and early maturity). Contrary to our expectations, a higher stocking rate did not result in an increase in the proportion of small seeds in the legume seed bank or favour species with other strongly ruderal-type reproductive strategies (high fecundity and high seed dormancy). In paddocks without phosphate application, the high and low stocking rate paddocks were dominated by different species (Trifolium tomentosum and T. campestre), each with a similar reproductive strategy. Plant architecture and/or differences in animal selectivity may account for these differences. The study highlights the importance of phosphate fertiliser for maintaining seedbanks of competitive-type (large seed size, highly productive with good early vigour) annual legume species.
Mapping quantitative trait loci for resistance against Russian wheat aphid (Diuraphis noxia) in wheat (Triticum aestivum L.)
Authors: Ricciardi M. , Tocho E. , Tacaliti M. S. , Vasicek A. , Giménez D. O. , Paglione A. , Simmonds J. , Snape J. W. , Cakir M. , Castro A. M.
Published: August 2011

Diuraphis noxia (Russian wheat aphid, RWA), one of the most aggressive pests of wheat, has evolved several biotypes with virulence matching known Dn resistance genes. This paper was aimed at determining the location of plant-defence genes triggered by RWA in a set of doubled haploid (DH) lines obtained from the cross of winter wheat varieties ‘Spark’ and ‘Rialto’. Both parental lines, 110 DH and CItr2401 (a RWA-resistant line) were screened for antixenosis, tolerance and antibiotic mechanisms of resistance with a population of RWA collected in Argentina. Antixenosis was not significantly linked to any marker locus. Tolerance traits showed significant associations with several chromosomes. Quantitative trait loci (QTL) for the foliar area developed during infestation was significantly associated with marker loci Xpsp3103 on 4DS, and Xgdm3 on 5DS. QTL for chlorophyll content in the infested plants were significantly associated with the marker loci Xgwm533 on 3BS and Xpsp3094 on 7AL, and a QTL for the number of expanded leaves was associated with the marker loci Xwmc264 on 3AS and XwPt8836 on 4DS. QTL for most of the tolerance traits were significantly associated with the same chromosome intervals on chromosomes 4DS and 5DS. The 4DS QTL were linked to or had a pleiotropic effect on Rht-D1. Most of the antibiosis traits were significantly associated with the same marker loci on chromosomes 4A (XwPt7405), 1B (XwPt9032) and 5B (Xbarc109 and Xbarc74). Several novel genes conferring tolerance and antibiosis to RWA were identified and these could be transferred into wheat cultivars to enlarge the genetic base of defence against this aphid pest. These new genes can be designated as QDn.unlp genes, following the rules for gene nomenclature in wheat.
Seedling resistances to rust diseases in international triticale germplasm
Authors: Zhang J. , Wellings C. R. , McIntosh R. A. , Park R. F.
Published: August 2011

Seedling resistances to stem rust, leaf rust and stripe rust were evaluated in the 37th International Triticale Screening Nursery, distributed by the International Wheat and Maize Improvement Centre (CIMMYT) in 2005. In stem rust tests, 12 and 69 of a total of 81 entries were postulated to carry Sr27 and SrSatu, respectively. When compared with previous studies of CIMMYT triticale nurseries distributed from 1980 to 1986 and 1991 to 1993, the results suggest a lack of expansion in the diversity of stem rust resistance. A total of 62 of 64 entries were resistant to five leaf rust pathotypes. In stripe rust tests, ~93% of the lines were postulated to carry Yr9 alone or in combination with other genes. The absence of Lr26 in these entries indicated that Yr9 and Lr26 are not genetically associated in triticale. A high proportion of nursery entries (63%) were postulated to carry an uncharacterised gene, YrJackie. The 13 lines resistant to stripe rust and the 62 entries resistant to leaf rust represent potentially useful sources of seedling resistance in developing new triticale cultivars. Field rust tests are needed to verify if seedling susceptible entries also carry adult plant resistance.
Critical review perspective: elemental speciation analysis methods in environmental chemistry - moving towards methodological integration
Authors: Feldmann Jörg , Salaün Pascal , Lombi Enzo
Published: August 2011

Environmental context. Elemental speciation defines mobility, accumulation behaviour and toxicity of elements in the environment. Environmental processes are then modelled using species information. Hence, it is important for environmental chemists to rely on unequivocal, precise and accurate analytical data for the identification and quantification of elemental species.
Abstract. We review the application of speciation analysis used in environmental chemistry studies to gain information about the molecular diversity of elements in various environmental compartments. The review focuses on three major analytical methodologies: electrochemical, X-ray absorption spectroscopy, and methods that couple chromatography with mass spectrometric detection. In particular, the review aims to highlight the advantages and disadvantages of the three methods, and to demonstrate that both the chemistry of the element and the nature of the environmental compartment determine the choice of the preferred analytical technique. We demonstrate that these two factors can lead to technique-dependent shortcomings that contribute to the current gaps in knowledge of elemental speciation in the environment. In order to fill those gaps, multi-method approaches are urgently needed. Finally, we present a selection of recent studies that exhibit the potential to use complementary techniques to overcome method-dependent limitations in order to reduce ambiguities and to gain more confidence in the assignment of the molecular structure of elements in environmental samples.
Metal speciation and bioavailability: revisiting the 'big questions'
Authors: Hering Janet G.
Published: August 2011

Environmental context. Four decades of research on metal speciation and bioavailability have failed to answer the ‘big questions’ of the ecological consequences of metal stress. Important, though still insufficient, insights have been gained from analytical approaches derived from inorganic environmental chemistry (targeting the quantification of free metal ion or ‘labile’ metal concentrations) and from organic environmental chemistry (focusing on the structure of ambient metal species). The ‘omics’ approach, not yet widely applied to this topic, offers the possibility of providing sufficient information to identify a quantitative signature of metal stress.
Insect excretes unusual six-coordinate pentavalent arsenic species
Authors: Andrahennadi Ruwandi , Fu Juxia , Pushie M. Jake , Wiramanaden Cheryl I. E. , George Graham N. , Pickering Ingrid J.
Published: August 2011

Environmental context. Arsenate, in which oxidised arsenic is coordinated to four oxygen atoms, is common in the environment. We have found that a moth larva excretes an unusual form of oxidised arsenic which is bound to six oxygen atoms. Since the chemical groups which give rise to this species are abundant in environmental and biological systems, more research is needed into the possible presence of such six-coordinate complexes in natural systems.
Abstract. Arsenate, in which pentavalent arsenic (AsV) is approximately tetrahedrally coordinated by oxygen, is common in biological or environmental systems. Octahedral coordination of AsV by oxygen is known chemically but hitherto has not been observed in natural systems. In an effort to understand the effect of elevated levels of arsenic on insects and other insectivorous animals in the food chain, larvae of the moth bertha armyworm (Mamestra configurata Walker) [Lepidoptera : Noctuidae] were examined under laboratory conditions. Synchrotron X-ray absorption spectroscopy was used to show that the exuvia (shed skin) and frass (fecal matter) contain an unusual AsV species six-coordinated by oxygen. The species is modelled as a low pH octahedral chelation complex with vicinal dihydroxyls such as glycerol or catechol. Structural characterisation using extended X-ray absorption fine structure (EXAFS) shows interatomic distances which are more similar to those of the glycerol complex and the near-edge also shows more similarity with the aliphatic chelator. The larvae may be using the six-coordinate AsV species as a specific excretory molecule. Since vicinal dihydroxyl species are common, more research is needed into the possible presence of such six-coordinate complexes in natural systems.
Fast determination of methyl chloride and methyl bromide emissions from dried plant matter and soil samples using HS-SPME and GC-MS: method and first results
Authors: Yassaa Noureddine , Wishkerman Asher , Keppler Frank , Williams Jonathan
Published: August 2011

Environmental context. Headspace solid-phase microextraction (HS-SPME) and analysis by gas chromatography–mass spectrometry (GC/MS) system has been employed for quantifying the emissions of methyl chloride (CH3Cl) and methyl bromide (CH3Br) from plants and soils. Compared with more commonly used techniques, HS-SPME coupled to GC/MS is simple, fast, sensitive, economical and non-destructive, with potential for laboratory-based and field studies. Abstract. Headspace solid-phase microextraction (HS-SPME) and gas chromatography–mass spectrometry (GC/MS) system have been employed for quantifying the emissions of methyl chloride (CH3Cl) and methyl bromide (CH3Br) from plants and soils. Seven SPME fibre coatings including 75 μm Carboxen-polydimethylsiloxane (CAR-PDMS), 85 μm Carboxen-PDMS (CAR-PDMS), 50/30 μm divinylbenzene-CAR-PDMS (DVB-CAR-PDMS), 65 μm DVB-PDMS, 65 μm carbowax-DVB (CW-DVB), 30 μm PDMS (PDMS) and 100 μm PDMS, were tested by comparing their sampling efficiencies towards CH3Cl and CH3Br. Key parameters such as extraction time, desorption temperature and time were all optimised in this work. The optimum conditions were found with CAR-PDMS 75 μm as an SPME fibre coating, a 1-min sampling time, a 50°C incubation temperature and a 2-min desorption time and a 250°C desorption temperature. These conditions were used for the determination of CH3Cl and CH3Br emission rates from different plant species as well as soil samples. Compared with more commonly used techniques, HS-SPME coupled to GC/MS is simple, fast, sensitive, economical and non-destructive, with potential for laboratory-based and field studies.
Enhancing reliability of elemental speciation results - quo vadis?
Authors: Sturgeon Ralph E. , Francesconi Kevin A.
Published: August 2011

Environmental context. The majority of publications reporting research in the field of metal speciation devote too little effort to ensuring quality, reliability or traceability of data. This essay discusses the current state of practice and proposes that we adopt a minimum set of standards or benchmarks to which such studies should be held accountable.
Detection of predation on Australian native fishes by Gambusia holbrooki
Authors: Ivantsoff Walter , Aarn
Published: August 2011

Clearing and staining of Gambusia holbrooki facilitated
identification of juvenile fishes among the gut contents, and a feeding trial
with captive Gambusia allowed assessment of gut transit
time and degradation of melanotaeniid larvae. Regurgitated fishes and eggs in
fixative solutions were also investigated. These techniques, extending to 12 h
the post-feeding interval in which fishes may be found and differentiated
among Gambusia gut contents, were tested on 631
wild-caught Gambusia collected in eastern Australia; an
ingested native fish could be identified in the gut of 18
Gambusia, and a cannibalized fish in the gut of three.
Characteristics of spiny lobster, Jasus edwardsii, aggregations in exposed reef and sandy areas
Authors: Kelly S. , MacDiarmid A. B. , Babcock R. C.
Published: August 2011

The behaviour and characteristics of J. edwardsii within
offshore aggregations in northern New Zealand are described. Groups of up to
200 lobsters were found aggregating beyond the coastal reefs by day, on open
sand, amongst beds of the emergent bivalve
Atrina zelandica, and around low-lying patch reefs which
had little topographical relief. Lobsters within the aggregations displayed
behaviour consistent with the use of mutual defence. In areas of open sand,
aggregations were circular, with individuals on the perimeter always facing
outwards. These lobsters held their stout, spiny antennae upright and used
them to fend off potential threats. On patch reefs and around
Atrina beds, aggregations were less uniform in shape,
and lobsters increased their level of physical protection by clustering
against irregularities in the substratum. Offshore aggregations were found
over 7 months of the year, but the size and sex ratio of aggregating lobsters
varied considerably between seasons. Seasonal peaks in the proportion of male
lobsters within the aggregations coincided with peak feeding rates in captive
males. The presence of females was not as clearly related to their feeding
patterns and probably also reflected behavioural adaptations associated with
the carrying of eggs and release of larvae.