Ontogeny of diving behaviour in the Australian sea lion: trials of adolescence in a late bloomer

1.Foraging behaviours of the Australian sea lion (Neophoca cinerea) reflect an animal working hard to exploit benthic habitats. Lactating females demonstrate almost continuous diving, maximize bottom time, exhibit elevated field metabolism and frequently exceed their calculated aerobic dive limit. Given that larger animals have disproportionately greater diving capabilities, we wanted to examine how pups and juveniles forage successfully.
2.Time/depth recorders were deployed on pups, juveniles and adult females at Seal Bay Conservation Park, Kangaroo Island, South Australia. Ten different mother/pup pairs were equipped at three stages of development (6, 15 and 23 months) to record the diving behaviours of 51 (nine instruments failed) animals.
3. Dive depth and duration increased with age. However, development was slow. At 6 months, pups demonstrated minimal diving activity and the mean depth for 23-month-old juveniles was only 44 ± 4 m, or 62% of adult mean depth.
4. Although pups and juveniles did not reach adult depths or durations, dive records for young sea lions indicate benthic diving with mean bottom times (2·0 ± 0·2 min) similar to those of females (2·1 ± 0·2 min). This was accomplished by spending higher proportions of each dive and total time at sea on or near the bottom than adults. Immature sea lions also spent a higher percentage of time at sea diving.
5. Juveniles may have to work harder because they are weaned before reaching full diving capability. For benthic foragers, reduced diving ability limits available foraging habitat. Furthermore, as juveniles appear to operate close to their physiological maximum, they would have a difficult time increasing foraging effort in response to reductions in prey. Although benthic prey are less influenced by seasonal fluctuations and oceanographic perturbations than epipelagic prey, demersal fishery trawls may impact juvenile survival by disrupting habitat and removing larger size classes of prey. These issues may be an important factor as to why the Australian sea lion population is currently at risk.

Distribution of an alien aquatic snail in relation to flow variability, human activities and water quality

1. Disturbance and anthropogenic land use changes are usually considered to be key factors facilitating biological invasions. However, specific comparisons of invasion success between sites affected to different degrees by these factors are rare.

2. In this study we related the large-scale distribution of the invading New Zealand mud snail (Potamopyrgus antipodarum) in southern Victorian streams, Australia, to anthropogenic land use, flow variability, water quality and distance from the site to the sea along the stream channel.

3. The presence of P. antipodarum was positively related to an index of flow-driven disturbance, the coefficient of variability of mean daily flows for the year prior to the study.

4. Furthermore, we found that the invader was more likely to occur at sites with multiple land uses in the catchment, in the forms of grazing, forestry and anthropogenic developments (e.g. towns and dams), compared with sites with low-impact activities in the catchment. However, this relationship was confounded by a higher likelihood of finding this snail in lowland sites close to the sea.

5. We conclude that P. antipodarum could potentially be found worldwide at sites with similar ecological characteristics. We hypothesise that its success as an invader may be related to an ability to quickly re-colonise denuded areas and that population abundances may respond to increased food resources. Disturbances could facilitate this invader by creating spaces for colonisation (e.g. a possible consequence of floods) or changing resource levels (e.g. increased nutrient levels in streams with intense human land use in their catchments).

Australian sentencing : principles and practice

Australian Sentencing: Principles and Practice explains the rules, principles, policies and practices that underpin the manner in which people are punished for criminal behaviour in Australia. As well as dealing with sentencing law today, the book provides an extensive analysis of the wider policy, moral, and political consideration which shape sentencing law. It analyses and evaluates existing standards and practices, and suggests how sentencing law should be reformed so that it operates in a fairer, more efficient and effective manner.

Content: Part A: 1. The nature of sentencing and theories of punishment; 2. Plucking figures from the air: the instinctive synthesis; 3. The objectives that are attainable through sentencing; 4. High Court sentencing jurisprudence; Part B: 5. The principle of proportionality; 6. Aggravating factors; 7. Mitigating considerations; 8. The relevance of a guilty plea to sentence; 9. The relevance of prior criminality; 10. Aboriginality; Part C: 11. The nature of criminal sanctions; 12. Imprisonment; 13. Intermediate sanctions; 14. Discharges and bonds, fines and disqualifications; Part D: 15. The way forward ? strategic sentencing.

Ontogeny of oxygen stores and physiological diving capability in Australian sea lions

1.For air-breathing animals in aquatic environments, foraging behaviours are often constrained by physiological capability. The development of oxygen stores and the rate at which these stores are used determine juvenile diving and foraging potential.
2. We examined the ontogeny of dive physiology in the threatened Australian sea lion Neophoca cinerea. Australian sea lions exploit benthic habitats; adult females demonstrate high field metabolic rates (FMR), maximize time spent near the benthos, and regularly exceed their calculated aerobic dive limit (cADL). Given larger animals have disproportionately greater diving capabilities; we wanted to determine the extent physiological development constrained diving and foraging in young sea lions.
3. Ten different mother/pup pairs were measured at three developmental stages (6, 15 and 23 months) at Seal Bay Conservation Park, Kangaroo Island, South Australia. Hematocrit (Hct), haemoglobin (Hb) and plasma volume were analyzed to calculate blood O2 stores and myoglobin was measured to determine muscle O₂. Additionally, FMR's for nine of the juveniles were derived from doubly-labelled water measurements.
4. Australian sea lions have the slowest documented O₂ store development among diving mammals. Although weaning typically occurs by 17·6 months, 23-month juveniles had only developed 68% of adult blood O₂. Muscle O₂ was the slowest to develop and was 60% of adult values at 23 months.
5. We divided available O₂ stores (37·11 ± 1·49 mL O₂ kg−1) by at-sea FMR (15·78 ± 1·29 mL O₂ min−1 kg−1) to determine a cADL of 2·33 ± 0·24 min for juvenile Australian sea lions. Like adults, young sea lions regularly exceeded cADL's with 67·8 ± 2·8% of dives over theoretical limits and a mean dive duration to cADL ratio of 1·23 ± 0·10.
6. Both dive depth and duration appear impacted by the slow development of oxygen stores. For species that operate close to, or indeed above their estimated physiological maximum, the capacity to increase dive depth, duration or foraging effort would be limited. Due to reduced access to benthic habitat and restricted behavioural options, young benthic foragers, such as Australian sea lions, would be particularly vulnerable to resource limitation.

The relative importance of landscape properties for woodland birds in agricultural environments

1. Studies of landscape change are seldom conducted at scales commensurate with the processes they purport to investigate. Landscape change is a landscape-level process, yet most studies focus on patches. Even when landscape context is considered, inference remains at the patch-level. The unit of investigation must be extended beyond individual patches to whole mosaics in order to advance understanding of faunal responses to landscape change.

2. In this study, we aggregated data from multiple sites per landscape such that both the response and explanatory variables characterized 'whole' landscapes, allowing for landscape-level inference about factors influencing species' incidence.

3. We used hierarchical partitioning and Bayesian variable selection methods to develop species-specific models that examined the influence of four categories of landscape properties – habitat extent, habitat configuration, landscape composition and geographical location – on the incidence of 58 species of woodland-dependent birds in 24 agricultural landscapes (each 100 km2) in south-eastern Australia.

4. There was strong evidence for a positive effect of habitat extent for 27 species. Thirty species were related to at least one of the four landscape composition variables, and geographical location was important for 19 species. Habitat configuration was influential for 13 species and where important, the impacts of fragmentation per se were detrimental.

5. Variation among species in the influential landscape variables indicates that different species respond to different sets of cues in land mosaics. Thus, although all species were grouped a priori as 'woodland-dependent', expectations based on general ecological characteristics may prove unreliable.

6. Synthesis and applications. These results underscore the value of moving beyond the fragmentation paradigm focused on the spatial pattern of habitat vs. non-habitat, to a greater appreciation of the composition and heterogeneity of land mosaics. Landscape-level inference will enable improved conservation outcomes by recognizing the influence of landscape properties on biota and devising strategies at this scale to complement patch-based management. We provide strong empirical evidence that biodiversity management in agricultural landscapes must focus on habitat extent. Complementary management of other landscape attributes, such as habitat aggregation and intensity of agricultural land-use, will also enhance the value of agricultural landscapes for woodland birds.

Auditor independence: regulation, oversight and inspection

Much of what auditors do is unobservable. Indeed, what goes on in an audit has been described as ‘secret audit business’. Audits in this context are of financial reports and those financial reports are the representations of the management of those companies, not the auditors. The audits of financial reports are of value in that they provide a competent and independent (of auditee management) attestation of the validity of those management representations. This attestation lowers the ‘information risk’ for the users of these financial reports. There has been a marked increase in activity to regulate matters relating to independence. The proposals outlined in CLERP 9 are one example of this. The requirements in the United States under the Sarbanes-Oxley Act are a further example.

Audit firms operate in a highly regulated yet highly competitive market. Evidence exists to suggest that audit firms are active competitors in respect of audit pricing and competency, including specialist industry expertise. Until recently, there has been little or no observable evidence that audit firms compete in respect of independence. The issues as they relate to audit independence are complex. One issue is that threats to independence are frequently subtle and difficult to observe and measure. Hence, controlling the decisions that relate to them cannot rely solely on regulation which itself inevitably relies on crude definitions and imprecise measures. Additionally, further regulation may not achieve the desired end without other processes being but in place in tandem.

This paper argues that:

1. auditors of certain classes of companies (in particular, those that are publicly traded) should be provided with incentives or requirements to have observable processes on independence
2. the means of observability should be in the form of an inspection and review process focussing on issues critical to the audit, such as independence
3. expert persons not having a current or past financial interest in the firm or in the commercial outcomes of the review should be used in the inspection and review process
4. the review process should have wide-ranging powers of inspection to examine the policies, processes, structures and ‘culture’ of audit firms
5. the report of the inspection and review should be made public, unedited and in full, and in a timely fashion. The primary objectives of this proposal are to (1) make more transparent to the market for information the characteristics of the audit firms and their process to ensure audit independence, and (2) provide a rigorous oversight of independence decision-making by persons who have no commercial interest in the outcome of the decision.

Comparison of the flexibility of eight-membered tetrasiloxane and stannasiloxane rings: a crystallographic and computational study

The syntheses and crystal structures of the eight-membered cyclo-stannasiloxanes cyclo-[t-Bu(OH)Si(OSnt-Bu₂O)₂Si(OH)t-Bu] (1) and cyclo-{t-Bu₂Si[OSn(CH₂SiMe₃)₂O]₂Sit-Bu₂} (2) as well as the synthesis of the six-membered cyclo-stannasiloxane cyclo-{t-Bu₂Si[OSn(CH₂SiMe₃)₂]₂O} (3) are reported. Compound 1 crystallizes as its trans isomer, but the cis isomer dominates in solution. In agreement with the experimentally obtained results, ab initio and DFT calculations on the model compounds cyclo-(H₂SiO)₄ (4), cyclo-[H₂Si(OSnH₂)OSiH₂] (5), cyclo-O(H₂SiOSnH₂)₂O (6), and cyclo-[H₂Si(OSiH₂)OSnH₂] (7) indicate that the energetic preference to adopt puckered structures increases and the ring flexibility decreases with an increasing number of tin atoms in the ring. The rich diversity of puckered conformations is attributed to the steric demand of the different organic substituents.

Incorporation of a molecular hinge into molecular tweezers by using tandem gycloadditions onto 5,6-Dimenthylenenorbornene

Site-selective 1,3-dipolar coupling at the norbornene p-bond of 5,6-dimethylenenorbornene 1 yields cycloadducts with an end-fused 1,3-diene system which have been reacted with N=N (or C=C) dienophiles to produce ribbon molecules, in which the internal diazacyclohexene (or cyclohexene) subunits are capable of acting as conformational hinges. Direct coupling of 5,6-dimethylenenorbornene with 1,3,4-oxadiazoles or dual coupling with bis(cyclobutene epoxides) afforded bis(1,3-dienes) that diastereoselectively react with dienophiles to produce new, conformationally mobile, molecular tweezers.

Complexes of the tripodal nitrilotrimethylenetrisphosphonic (H6L) and P,P',P''-triphenylnitrilotrimethylenetrisphosphinic (H3L) acids with the copper(II) ion. Synthesis and charaterization of [Hpy][Cu(H3L)(H2O)] and [Cu(HL)(py)]2.2Me2CO

The complexes [Hpy][Cu(H₃L)(H2O)] 1 (L⁶ = nitrilotrimethylenetrisphosphonate) and [Cu(HL°)(py)]₂·2Me₂CO 2 [(L°)³ = P,P,P" -triphenylnitrilotrismethylenetrisphosphinate)] have been isolated and characterized by X-ray crystallography, near IR-visible spectroscopy and magnetic measurements. The structure determination has shown the complexes to be constituted by monomeric and dimeric units respectively. In the monomer the metal atom is surrounded by the phosphonate ligand and a water molecule, with a geometry between a trigonal bipyramid and a square pyramid. The two copper atoms in the dimer are held together by an arm of the tripod ligand, with a pyridine molecule as additional ligand, and display octahedral geometry. The presence of monomeric and dimeric species in aqueous solutions of 1 and 2 has been shown by ESMS studies. The formation in water solution of the dimer [{Cu(H₃L)}₂]^2-, as a minor species, has been supported by potentiometric measurements, whereas only the monomeric anion [CuL°] has been ascertained to be present. In general the ligand H₃L° forms less stable copper(II) complexes than H₆L.

New insights in asymmetric tetraorganodistannoxane ladder formation. A NMR-spectroscopic and crystallographic study

The syntheses of the asymmetrically substituted tetraorganodistannoxanes [t-Bu₂(X)SnOSn(Y)(CH₂SiMe₃)₂1₂ (1, X = Y = OH; 2, X = Cl, Y = OH; 3, X = Y = Cl) are reported and their structures in solution and in the solid state are characterized by multinuclear NMR spectroscopy and single crystal X-ray analyses. In toluene, the tetrahydroxy-substituted derivative 1 is in equilibrium with the organotin oxides cyclo-[t-Bu₂Sn{OSn(CH₂SiMe₃)₂}₂O] (4), cyclo[(Me₃SiCH₂)₂Sn(OSnt-Bu₂)₂O] (5), and cyclo-(t-Bu₂SnO)₃, and some additional, undefined species containing pentacoordinated tin atoms. In contrast, the dihydroxydichloro-substituted derivative 2 is inert in solution.

Hydrolysis of bis((trimethylsilyl)methyl)tin dihalides. Crystallographic and spectroscopic study of the hydrolysis pathway

The synthesis and characterization by multinuclear NMR spectroscopy of the diorganotin dihalides (Me₃SiCH₂)₂SnX₂ (1, X = Cl; 2, X = Br), the diorganotin dichloride water adduct (Me₃SiCH₂)₂SnCl₂·H₂O (1a), the dimeric tetraorganodistannoxanes [(Me₃SiCH₂)₂(X)SnOSn(Y)(CH₂SiMe₃)₂]₂ (3, X = Y = Cl; 4, X = Br, Y = OH; 5, X = Br, Y = F; 6, X = Y = OH; 8, X = Cl, Y = OH), and the molecular diorganotin oxide cyclo-[(Me₃SiCH₂)₂SnO]₃ (7) are reported. The structures in the solid state of compounds 1a, 3, 6, and 7 were determined by single-crystal X-ray analysis. In toluene solution, the hydroxy-substituted tetraorganodistannoxane 6 is in equilibrium with the diorganotin oxide 7 and water. The eight-membered diorganotin oxide cyclo-[(Me₃SiCH₂)₂SnO]₄ (7a) is proposed to be involved in this equilibrium. On the basis of the results of this and previous works, a general hydrolysis pathway is developed for diorganotin dichlorides containing reasonably bulky substituents.

Solvent-controlled assembling by hydrogen bridges and halogen-halogen interactions of novel organotin oxo clusters

The crystal structure of the novel methylene-bridged tetraorganodistannoxane {[Ph(HO)SnCH₂Sn(I)Ph]O}₄ (1) depends on the solvent it is crystallised from and is controlled by hydrogen bridges and interhalogen interactions.

Novel 10- and 20- membered tin- and silicon-containing rings: synthesis, complexation behavior and conversion into a lewis acidic polymer

Reaction of the dimethylsilylmethyl-substituted tetraorganotin derivative CH₂[CH₂Sn(Ph₂)CH₂Si(H)Me₂]₂ (1) and CH₂[CH₂Sn(Ph₂)CH₂Si(i-PrO)Me₂]₂ (3), respectively, with mercuric chloride afforded the novel silicon- and tin-containing 10- and 20-membered rings cyclo-CH₂[CH₂Sn(Cl₂)CH₂Si(Me₂)]₂O (4) and cyclo-CH₂[CH₂Sn(Cl₂)CH₂Si(Me₂)OSi(Me₂)CH₂Sn(Cl₂)CH₂]₂CH₂ (5). Both compounds 4 and 5 can be converted into the soluble Lewis acidic polymer poly-[Si(Me₂)CH₂Sn(Cl₂)(CH₂)₃Sn(Cl₂)CH₂Si(Me₂)O] (8). ¹¹⁹Sn NMR studies indicate that 4 acts as a bidentate Lewis acid toward chloride ions, exclusively forming the 1:1 complex [cyclo-CH₂[CH₂Sn(Cl₂)CH₂Si(Me₂)]₂O·Cl]-[(Ph₃P)₂N]⁺ (7). The molecular structures as determined by single-crystal X-ray diffraction analysis of 4 and 7 are reported.

The reactivity of bis(para-methoxyphenyl)telluroxide towards triflic acid and diphenylphosphinic acid. Theoretical considerations of the protonation and hydration process of diorganotelluroxanes

The reaction of (p-MeOC₆H₄)₂TeO with two equivalents of HO₃SCF₃ and HO₂PPh₂ provided the tetraorganoditelluroxanes (F₃CSO₃)(p-MeOC₆H₄)₂TeOTe(p-MeOC₆H₄)₂(O₃SCF₃) (1) and (Ph₂PO₂)(p-MeOC₆H₄)₂TeOTe(p-MeOC₆H₄)₂(O₂PPh₂)·2 Ph₂PO₂H (2) in good yields. Compounds 1 and 2 were characterized by solution and solid-state ³¹P and ¹²⁵Te NMR spectroscopy, IR spectroscopy, electrospray mass spectrometry, conductivity measurements and single crystal X-ray diffraction. In solution, compound 1 undergoes an electrolytic dissociation and reversibly reacts with traces of water to give the mononuclear cation [(p-MeOC₆H₄)₂TeOH]⁺ and triflate anions. Theoretical aspects of the protonation and hydration of model telluroxanes R₂TeO (R = H, Me, Ph) were investigated by preliminary DFT calculations and compared to the corresponding selenoxanes R₂SeO. The tellurium dihydroxides R₂Te(OH)₂ seem to be more stable than the hydrogen-bonded complexes R₂TeO·H₂O.

Observation of Te···π and X···X Bonding in para-Substituted Diphenyltellurium Dihalides, (p-Me2NC6H4)(p-YC6H4)TeX2(X=Cl, Br, I; Y=H, EtO, Me2N)-

The supramolecular association of the previously described para-dimethylaminophenyl-substituted diorganotellurium dihalides (p-Me₂NC₆H₄)₂TeX₂ (X = Cl (1), Br (2), I (3)) and (p-Me₂NC₆H₄)RTeCl₂ (R = Ph (4), p-EtOC₆H₄ (5)), was investigated by X-ray crystallography. Unlike almost all other structurally characterized diorganotellurium dihalides, (p-Me₂NC₆H₄)₂TeX₂ (X = Cl (1), Br (2), I (3)) reveal no secondary Te∙∙∙X interactions, but X∙∙∙X interactions. The structure of (p-Me₂NC₆H₄)PhTeCl₂ (4) resembles that of Ph₂TeCl₂ and shows one secondary Te∙∙∙Cl contact, whereas (p-Me₂NC₆H₄)(p-EtOC₆H₄)TeCl₂ (5) exhibits neither secondary Te∙∙∙Cl nor Cl∙∙∙Cl interactions. The unusual structural characteristics of 1–5 are attributed to the occurrence of intermolecular Te∙∙∙π and π∙∙∙π contacts associated with quinoid π-electron delocalization across the para-dimethylaminophenyl (1–5) and para-ethoxyphenyl (5) groups.