Crocodile farms and management of saltwater crocodiles in Northern Territory: Results of a survey of NT crocodile farmers plus analysis of secondary information

After outlining some relevant background information about the NT crocodile farming industry and explaining the purpose of our survey of NT crocodile farmers conducted in the first half of 2005, this paper reports the results of the survey. The information received from the survey is supplemented by secondary data and by information from secondary sources. This report covers the location of respondents; the size of crocodile farms; farmers’ stated knowledge of and attitudes towards the NT Crocodile Management Plan; the involvement of farms in the harvesting of crocodile eggs and the costs involved; views of crocodile farmers about whether the NT Crocodile Management Plan encourages landholders to conserve crocodiles and their perceptions of the benefits to landholders; predicted production trends and trends in the number of farms operating in NT; economic characteristics of crocodile farms producing in NT including the economic advantages and disadvantages of crocodile farming in NT. Concluding comments provide, amongst other things, an overview of the structure of the crocodile farming industry in the NT gleaned from a consideration of data available from the NT Government’s Department of Business, Industry and Resource Development.

Monolithic CAD/CAM Lithium Disilicate Versus Veneered Y-TZP Crowns: Comparison of Failure Modes and Reliability After Fatigue

Purpose: The aim of this research was to evaluate the fatigue behavior and reliability of monolithic computer-aided design/computer-assisted manufacture (CAD/CAM) lithium disilicate and hand-layer-veneered zirconia all-ceramic crowns. Materials and Methods: A CAD-based mandibular molar crown preparation, fabricated using rapid prototyping, served as the master die. Fully anatomically shaped monolithic lithium disilicate crowns (IPS e.max CAD, n = 19) and hand-layer-veneered zirconia-based crowns (IPS e.max ZirCAD/Ceram, n = 21) were designed and milled using a CAD/CAM system. Crowns were cemented on aged dentinlike composite dies with resin cement. Crowns were exposed to mouth-motion fatigue by sliding a WC-indenter (r = 3.18 mm) 0.7 mm lingually down the distobuccal cusp using three different step-stress profiles until failure occurred. Failure was designated as a large chip or fracture through the crown. If no failures occurred at high loads (> 900 N), the test method was changed to staircase r ratio fatigue. Stress level probability curves and reliability were calculated. Results: Hand-layer-veneered zirconia crowns revealed veneer chipping and had a reliability of < 0.01 (0.03 to 0.00, two-sided 90% confidence bounds) for a mission of 100,000 cycles and a 200-N load. None of the fully anatomically shaped CAD/CAM-fabricated monolithic lithium disilicate crowns failed during step-stress mouth-motion fatigue (180,000 cycles, 900 N). CAD/CAM lithium disilicate crowns also survived r ratio fatigue (1,000,000 cycles, 100 to 1,000 N). There appears to be a threshold for damage/bulk fracture for the lithium disilicate ceramic in the range of 1,100 to 1,200 N. Conclusion: Based on present fatigue findings, the application of CAD/CAM lithium disilicate ceramic in a monolithic/fully anatomical configuration resulted in fatigue-resistant crowns, whereas hand-layer-veneered zirconia crowns revealed a high susceptibility to mouth-motion cyclic loading with early veneer failures. Int J Prosthodont 2010; 23: 434-442.

Mental evolution and development: Evidence for secondary representation in children, great apes, and other animals

Recent interest in the development and evolution of theory of mind has provided a wealth of information about representational skills in both children and animals, According to J, Perrier (1991), children begin to entertain secondary representations in the 2nd year of life. This advance manifests in their passing hidden displacement tasks, engaging in pretense and means-ends reasoning, interpreting external representations, displaying mirror self-recognition and empathic behavior, and showing an early understanding of mind and imitation. New data show a cluster of mental accomplishments in great apes that is very similar to that observed in 2-year-old humans. It is suggested that it is most parsimonious to assume that this cognitive profile is of homologous origin and that great apes possess secondary representational capacity. Evidence from animals other than apes is scant. This analysis leads to a number of predictions for future research.

Effect of probe stimulus intensity on the dissociation between autonomic orienting and secondary probe reaction time

Information processing accounts propose that autonomic orienting reflects the amount of resources allocated to process a stimulus. However, secondary task reaction time (RT), a supposed measure of processing resources, has shown a dissociation from autonomic orienting. The present study tested the hypothesis that secondary task RT reflects a serial processing mechanism. Participants (N = 24) were presented with circle and ellipse shapes and asked to count the number of longer-than-usual presentations of one shape (task-relevant) and to ignore presentations of a second shape (task-irrelevant). Concurrent with the counting task, participants performed a secondary RT task to an auditory probe presented at either a high or low intensity and at two different probe positions following shape onset (50 and 300 ms). Electrodermal orienting was larger during task-relevant shapes than during task-irrelevant shapes, but secondary task RT to the high-intensity probe was slower during the latter. In addition, an underadditive interaction between probe stimulus intensity and probe position was found in secondary RT. The findings are consistent with a serial processing model of secondary RT and suggest that the notion of processing stages should be incorporated into current information-processing models of autonomic orienting.

Primary to secondary LOTE articulation: A local case in Australia

In this study of articulation issues related to languages other than English (LOTE), "articulation" is defined and the challenges surrounding it are overviewed. Data taken from an independent school's admission documents over a 4-year period provide insights and reveal trends concerning students' preferences for language study, LOTE study continuity, and reasons for LOTE selection. The data also provides an accounting of some multiple LOTE learning experiences. The analysis indicates that many students who begin a LOTE in the early grades are thwarted in becoming proficient, because (1) continuation in the language is impossible due to unavailability of instruction; (2) expanded learning is hampered by teachers' inability to deal with a range of learners, (3) extended learning is hampered by administrative decisions or policies, or (4) students lose interest in the first LOTE and switch to another. Finally, a call is made for data gathering and research in local contexts to gain a better understanding of LOTE articulation challenges at the local, state, national, and international levels.

Severe hypokalaemia secondary to dicloxacillin (Case report)

No Abstract

Evolution of the secondary structure of the rRNA internal transcribed spacer 2 (ITS2) in hard ticks (Ixodidae, Arthropoda)

ITS2 sequences are used extensively in molecular taxonomy and population genetics of arthropods and other animals yet little is known about the molecular evolution of ITS2. We studied the secondary structure of ITS2 in species from each of the six main lineages of hard ticks (family Ixodidae). The ITS2 of these ticks varied in length from 679 bp in Ixodes scapularis to 1547 bp in Aponomma concolor. Nucleotide content varied also: the ITS2 of ticks from the Prostriata lineage (Ixodes spp.) had 46-49% GC whereas ITS2 sequences of ticks from the Metastriata lineage (all other hard ticks) had 61-62% GC. Despite variation in nucleotide sequence, the secondary structure of the ITS2 of all of these ticks apparently has five domains. Stems 1, 3, 4 and 5 of this secondary structure were obvious in all of the species studied. However, stem 2 was not always obvious despite the fact that it is flanked by highly conserved sequence motifs in the adjacent stems, stems 1 and 3. The ITS2 of hard ticks has apparently evolved mostly by increases and decreases in length of the nucleotide sequences, which caused increases, and decreases in the length of stems of the secondary structure. This is most obvious when stems of the secondary structures of the Prostriata (Ixodes spp.) are compared to those of the Metastriata (all other hard ticks). Increases in the size of the ITS2 may have been caused by replication slippage which generated large repeats, like those seen in Haemaphysalis humerosa and species from the Rhipicepalinae lineage, and the small repeats found in species from the other lineages of ticks.

Phylogeography of the pipefish, Urocampus carinirostris, suggests secondary intergradation of ancient lineages

We assayed the pattern of mitoehondrial DNA evolution in the live bearing, seagrass specialist pipefish, Urocampus carinirostris, in eastern Australia. These life history attributes were predicted to result in strong phylogeographic structure in U. carinirostris. Phylogenetic analysis of cytochrome b sequences detected two monophyletic mtDNA clades that differed by 8.69% sequence divergence - a large level of intraspecific divergence for a marine fish. The geographical distribution of clades was non-random and resembled clinal secondary intergradation over a 130-km stretch of coastline. Contrary to phylogeographic predictions, this large phylogeographic break does not occur across a traditionally recognised biogeographic boundary. Analyses of historical demography suggested that individuals belonging to the most widespread clade underwent a population expansion from a small refuge population during the Pleistocene.

Expression of specific glycoconjugates in both primary and secondary olfactory pathways in BALB/C mice

Binding of cell surface carbohydrates to their receptors specifically promotes axon growth and synaptogenesis in select regions of the developing nervous system. In some cases these interactions depend upon cell-cell adhesion mediated by the same glycoconjugates present on the surface of apposing cells or their processes. We have previously shown that the plant lectin Dolichos biflorus agglutinin (DBA) binds to: a subpopulation of mouse primary olfactory neurons whose axons selectively fasciculate prior to terminating in the olfactory bulb. In the present study, we investigated whether these glycoconjugates were also expressed by postsynaptic olfactory neurons specifically within the olfactory pathway. We show here for the first time that DBA ligands were expressed both by a subset of primary olfactory neurons as well as by the postsynaptic mitral/tufted cells in BALB/C mice. These glycoconjugates were first detected on mitral/tufted cell axons during the early postnatal period, at a time when there is considerable synaptogenesis and synaptic remodelling in the primary olfactory cortex. This is one of the few examples of the selective expression of molecules in contiguous axon tracts in the mammalian nervous system. These results suggest that glycoconjugates recognized by DBA may have a specific role in the formation and maintenance of neural connections within a select functional pathway in the brain. J. Comp. Neurol. 443:213-225, 2002. (C) 2002 Wiley-Liss, Inc.