The discovery and comparative expression analysis of three distinct type I interferons in the perciform fish, meagre (Argyrosomus regius)

Type I interferons (IFN) play an important role in anti-viral responses. In teleost fish multiple genes exist, that are classified by group/subgroup. That multiple subgroups are present in Acanthopterygian fish has only become apparent recently, and 3 subgroups are now known to be expressed, including a new subgroup termed IFNh. However, the potential to express multiple IFN subgroups and their interplay is not well defined. Hence this study aims to clarify the situation and undertook the first in-depth analysis into the nature and expression of IFNc, IFNd and IFNh in the perciform fish, meagre. Constitutive expression was analysed initially during larval development and in adult tissues (gills, mid-gut, head kidney, spleen). During early ontogeny IFNc was the highest expressed IFN, and this was also the case in adult tissues with the exception of gills where IFNd was highest. However, comparison between tissues for individual isoforms showed that spleen had high transcript levels of all three IFNs, IFNd/IFNh were also highly expressed in gills. The expression of each sub-group was increased significantly in the four tissues following injection of poly I:C, however, this increase was only seen in the mid-gut for IFNh. Following in vitro stimulation with poly I:C again all three isoforms were upregulated, although with differences in kinetics and the cell source used. For example, early induction was seen for IFNc/IFNh in gill cells, IFNd/IFNh in splenocytes and all three isoforms in head kidney cells. Induction was sustained in splenocytes and head kidney cells, but in gut cells only a late induction was seen. These results demonstrate a complex pattern of regulation between the different IFN isoforms present in meagre and highlights potential sub-functionalisation of these IFN subgroups during perciform anti-viral responses.

Monitoring indicates rapid and severe decline of native small mammals in Kakadu National Park, northern Australia

Context. Australia has a lamentable history of mammal extinctions. Until recently, the mammal fauna of northern Australia was presumed to have been spared such loss, and to be relatively intact and stable. However, several recent studies have suggested that this mammal fauna may be undergoing some decline, so a targeted monitoring program was established in northern Australia’s largest and best-resourced conservation reserve. Aims. The present study aims to detect change in the native small-mammal fauna of Kakadu National Park, in the monsoonal tropics of northern Australia, over the period of 1996–2009, through an extensive monitoring program, and to consider factors that may have contributed to any observed change. Methods. The small-mammal fauna was sampled in a consistent manner across a set of plots established to represent the environmental variation and fire regimes of Kakadu. Fifteen plots were sampled three times, 121 plots sampled twice and 39 plots once. Resampling was typically at 5-yearly intervals. Analysis used regression (of abundance against date), and Wilcoxon matched-pairs tests to assess change. For resampled plots, change in abundance of mammals was related to fire frequency in the between-sampling period. Key results. A total of 25 small mammal species was recorded. Plot-level species richness and total abundance decreased significantly, by 54% and 71%, respectively, over the course of the study. The abundance of 10 species declined significantly, whereas no species increased in abundance significantly. The number of ‘empty’ plots increased from 13% in 1996 to 55% in 2009. For 136 plots sampled in 2001–04 and again in 2007–09, species richness declined by 65% and the total number of individuals declined by 75%. Across plots, the extent of decline increased with increasing frequency of fire. The most marked declines were for northern quoll, Dasyurus hallucatus, fawn antechinus, Antechinus bellus, northern brown bandicoot, Isoodon macrourus, common brushtail possum, Trichosurus vulpecula, and pale field-rat, Rattus tunneyi. Conclusions. The native mammal fauna of Kakadu National Park is in rapid and severe decline. The cause(s) of this decline are not entirely clear, and may vary among species. The most plausible causes are too frequent fire, predation by feral cats and invasion by cane toads (affecting particularly one native mammal species). Implications. The present study has demonstrated a major decline in a key conservation reserve, suggesting that the mammal fauna of northern Australia may now be undergoing a decline comparable to the losses previously occurring elsewhere in Australia. These results suggest that there is a major and urgent conservation imperative to more precisely identify, and more effectively manage, the threats to this mammal fauna.

Patients' self-report and family caregivers' perception of quality of life in patients with advanced cancer: how do they compare?

This study describes the concordance between advanced cancer patients' self-report of quality of life and their caregivers' perception of the patients' quality of life at two time points. It is often necessary for health professionals to rely on information about the patients' quality of life that is provided by family caregivers (proxy), even though information from the patients is considered 'the gold standard'. Therefore, it is important to establish how reliable this proxy information is. Data were collected 4-6 weeks following diagnosis of recurrent or progressive disease, and again 12 weeks later. Fifty-one patients and their caregivers completed the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30), version 2.0 at both time points. Descriptive statistics were used to calculate patient and caregiver scores and describe the sample. The level of agreement between the two scores, the patients' self-report and the family caregivers' score, was calculated on the mean scores of each scale. In general, most caregivers were able to accurately rate the global quality of life, the level of functioning and the degree of symptom distress experienced by the person they were caring for, when compared with the patients' self-rating. Caregiver ratings for physical domains tended to be more in agreement with those of patients as compared with ratings of the psychosocial domains. This study suggests information from proxy raters is reliable when the proxy is a family caregiver, and this remains true over time.

The relationship between echolocation-call frequency and moth predation of a tropical bat fauna

The allotonic frequency hypothesis proposes that the proportion of eared moths in the diet should be highest in bats whose echolocation calls are dominated by frequencies outside the optimum hearing range of moths i.e., <20 and >60 kHz. The hypothesis was tested on an ecologically diverse bat assemblage in northern tropical Australia that consisted of 23 species (5 families, 14 genera). Peak frequency of signals of bats within the echolocation assemblage ranged from 19.8 to 157 kHz but was greatest between 20 and 50 kHz. A strong positive relationship existed between peak call frequency and percentage of moths in the diet for a sample of 16 bats from the assemblage representing 13 genera (R2 = 0.54, p = 0.001). The relationship remained strong when the three species with low-intensity calls were excluded. When the two species with high duty cycle, constant-frequency signals were removed, the relationship was weaker but still significant. In contrast to previous research, eared moths constituted only 54% of moth captures in light traps at bat foraging grounds, and eared moths were significantly larger than non-eared individuals. These results show that the pattern of moth predation by tropical bats is similar to that already established for bat faunas in subtropical and temperate regions.

Structure and environmental relationships of insectivorous bat assemblages in tropical Australian savannas

Abstract  Patterns in the composition of assemblages of microbat species sampled during the late dry season (the 'build-up') in north Australian savannas were assessed against a range of environmental factors as well as four a priori defined habitat types (riparian, escarpments, coastal and woodlands). Distinct species assemblages were most strongly associated with topographic and climatic variables. There were also limited associations with vegetation structure, fire and local roost potential but no associations with insects or water availability. Total species diversity at sample sites was associated with distance to rivers and rainfall. In general, species assemblages were not clearly defined and the number of significant environmental associations was relatively few. We compare these associations with those reported for bat assemblages elsewhere in Australia.

A comparison of three survey methods for collecting bat echolocation calls and species-accumulation rates from nightly Anabat recordings

Bat surveys are frequently undertaken using ultrasonic detectors to determine the species present in an area on the basis of the identity of echolocation calls. We compared three techniques for using the Anabat II detector: the detector pointed along tracks (flyways) versus the detector pointed across tracks (non-flyways); recording output to audio cassette (analogue) versus direct recording to computer (digital); and active hand-held recording versus static automatic recording. In addition, we derived a species-accumulation curve from all-night Anabat recordings in the wet–dry tropics of the Northern Territory. We found no significant difference between flyway and non-flyway recordings; significantly more calls were identified from digital recordings; and significantly more species were detected using hand-held than static recordings. Species-accumulation analysis suggests that the minimum time required to achieve a satisfactory (80%) inventory of bat species at a site is during the three-hour period immediately after sunset. We use our findings to make recommendations for the design of bat surveys using the Anabat II detector.