Spatial sampling to detect slug abundance in an arable field

Overuse of molluscicides by farmers in arable systems can lead to environmental and product contamination. Here we assess a simple and inexpensive surface trapping method for monitoring populations of slugs (Deroceras reticulatum and Arion intermedius). This method was biased against small slugs, and against A. intermedius, when compared to direct soil sampling. Regression was used to model the relationship between the results of surface trapping and soil sampling methods. Spatial Analysis by Distance IndicEs (SADIE) algorithms were used to describe the spatial relationships between the two sets of samples. Using both traditional statistical methods and spatial statistics, the spatial information collected from surface traps was sufficient to identify patches and gaps in slug numbers and possibly to allow the spot application of slug control, and thus provide land managers who experience slug damage with a way of reducing molluscicides use, whilst maintaining slug control. Further improvements and applications of the model are discussed.     

Differential diagnosis of bipolar disorder in children and adolescents

Issues complicating the differential diagnosis of bipolar disorder in young people are discussed. They include: a) the subtype of bipolar disorder being considered; b) the person’s age and stage of development; c) whether one views bipolar disorder more conservatively, requiring clear episodes that mark a distinct change from premorbid levels of function, or more liberally, focusing for instance on severe irritability/explosive outbursts as the mood change; d) who is reporting manic symptoms, and whether symptoms are past and must be recalled or current and more likely to be observed; e) impact of family history. The diagnosis of mania/bipolar I disorder may not become clear for a number of years. This is an impairing disorder, but so are the conditions from which it must be distinguished. Family history may increase the odds that certain symptoms/behaviors are manifestations of bipolar disorder but it does not make the diagnosis. Until there are biomarkers that can confirm the diagnosis, and treatments unique to the condition, it is wise to make a diagnosis of bipolar disorder in children and adolescents provisionally and keep an open mind to the likelihood that revisions may be necessary.     

Faithful vertical transmission but ineffective horizontal transmission of bacterial endosymbionts during sexual reproduction of the black bean aphid,Aphis fabae

1. Insects are commonly infected with bacterial endosymbionts. In addition to the costs and benefits associated with harbouring these symbionts, their rates of vertical and horizontal transmission are important determinants of symbiont prevalence. 2. Aphids are cyclical parthenogens and show virtually perfect maternal transmission of endosymbionts during asexual reproduction. Less clear is the role of the annual sexual generation, during which overwintering eggs are produced. Data from pea aphids (Acyrthosiphon pisum Harris) suggest that maternal transmission failures and horizontal transmission via males may occur under sexual reproduction at least occasionally. No such data exist for other aphid species. 3. In the present study, the rates of maternal and paternal transmission of facultative endosymbionts during sexual reproduction in the black bean aphid, Aphis fabae (Scopoli) were examined. Crosses were performed between clones infected with Hamiltonella defensa, clones infected with Regiella insecticola and clones without facultative endosymbionts, and eggs were overwintered under three different conditions. 4. Only one of 205 offspring from crosses testing for maternal transmission failed to inherit the symbiont present in the maternal clone, and in crosses testing for horizontal transmission, only one of 412 offspring acquired a facultative symbiont from the father. 5. These results show that in A. fabae, maternal transmission of H. defensa and R. insecticola is extremely reliable also during sexual reproduction, indicating that maternal transmission failures are unlikely to exert a significant influence on frequencies of infection in the field. Paternal transmission of endosymbionts was exceedingly rare, suggesting that this route of horizontal transmission may be less important than hitherto assumed.     

Contagious dispersal of seeds of synchronously fruiting species beneath invasive and native fleshy‐fruited trees

In subtropical Australia, many native and invasive plant species rely on a shared suite of frugivores, largely birds, for seed dispersal. Many native plants fruit during summer in this region, whereas most invasive plants fruit during winter, thus providing the opportunity for contagious dispersal of seeds beneath synchronously fruiting species. We sampled invasive and native seed rain beneath the canopy of a native summer‐fruiting tree Guioa semiglauca and an invasive winter‐fruiting tree Cinnamomum camphora, in three study sites over the course of a year. In July, during peak fruiting season for C. camphora and other invasive species, seed rain of invasive species was higher beneath C. camphora than G. semiglauca. This was partly due to the invasive tree Ligustrum lucidum, whose seed rain was three times higher beneath C. camphora than beneath the native tree. In February, seed rain of native species was more abundant beneath the canopy of G. semiglauca than beneath C. camphora, despite the fact that C. camphora was also fruiting at this time. This was probably due to the larger fruit crop produced by G. semiglauca at this time of year. Our study provides evidence that the presence of invasive bird‐dispersed plants may facilitate contagious seed dispersal of other invaders, and likewise native species may facilitate seed spread of other native plants.     

River macrophyte indices: not the Holy Grail!

1. Recent studies have demonstrated that there is generally no unambiguous relationship between plant species composition and specific environmental conditions in rivers. Nevertheless, indices of environmental pressures based on macrophytes are flourishing, because of the requirements of the Water Framework Directive (WFD). 2. We first reviewed nine such indices against 13 criteria for bioindicators. Then, using data from France and England, we tested whether the IBMR (Macrophyte Biological Index for Rivers) and LEAFPACS (predictions and classification system for macrophytes) methods could reliably indicate nutrient and hydromorphological pressures. Finally, we used an improved bootstrapping method to estimate accuracy. 3. Currently, most indices lack ecological meaning for a variety of reasons, including partial sampling (backwaters are excluded); reliance on list of taxa (there are identification difficulties) rather than structure and functions; correlation rather than causation; application within a limited biogeographical area; reliance on ‘expert’ judgement; high precision but poor accuracy; poorly defined reference conditions; lack of independent tests; and an inability to discriminate reliably between the target pressures of interest from confounding background variables. 4. IBMR was a far better indicator of pH (or HCO₃‐pCO₂) than it was of soluble reactive phosphorus, SRP (or SRP‐NH₄). While there was a highly significant correlation between IBMR and SRP after removing the effect of pH, the relationship was weak (r² = 0.08, n = 215, P < 0.001). 5. LEAFPACS is a multi‐metric method summing up five individual indices, each compliant with the WFD. Its individual metrics were not better correlated with nutrient and hydromorphological pressures (with r² < 0.1, n = 62, P < 0.05) than was the IBMR. The meaning of the overall metric is questionable. 6. There are problems in determining the precision of the indices, owing to uncertainties in recording, but they are less than the uncertainties in determining accuracy (because species optima and tolerances are sometimes poorly known). 7. Reliable information is needed to improve the state of our rivers. Macrophyte indices are able to detect statistically significant pressures from a large population of sites but cannot be applied at specific sites, as required by the WFD, owing to large uncertainties and low explanatory power. Typically, more than 90% of the variability in macrophyte indices is attributed to factors other than human pressure. The WFD would be better served by a simpler, holistic approach based on our current mechanistic understanding of river processes. These findings are likely to apply also to other taxonomic groups (macroinvertebrates, diatoms, fish) used in the assessment of purported ecological quality and to palaeolimnological measures of reference status.     

Cell and gene therapy manufacturing capabilities in Australia and New Zealand

Cell and gene therapy products are rapidly being integrated into mainstream medicine. Developing global capability will facilitate broad access to these novel therapeutics. An initial step toward achieving this goal is to understand cell and gene therapy manufacturing capability in each region. We conducted an academic survey in 2018 to assess cell and gene therapy manufacturing capacity in Australia and New Zealand. We examined the following: the number and types of cell therapy manufacturing facilities; the number of projects, parallel processes and clinical trials; the types of products; and the manufacturing and quality staffing levels. It was found that Australia and New Zealand provide diverse facilities for cell therapy manufacturing, infrastructure and capability. Further investment and development will enable both countries to make important decisions to meet the growing need for cell and gene therapy and regenerative medicine in the region.     

The Goldilocks effect: intermittent streams sustain more plant species than those with perennial or ephemeral flow

1. Drylands worldwide are typified by extreme variability in hydrologic processes, which structures riparian communities at various temporal and spatial scales. One key question is how underlying differences in hydrology over the length of interrupted perennial rivers influence spatial and temporal patterns in species richness and species composition. 2. We examined effects of differences in dry season hydrology on species richness, composition and cover of herbaceous plant communities in the streamside zone (the zone influenced directly by low flows in the channel). Data were collected at ephemeral, intermittent and perennial flow reaches on three rivers of the desert Southwest (Arizona, U.S.A.): Lower Cienega Creek, Hassayampa River and Lower San Pedro River. 3. Patterns of species richness varied with temporal scale of analysis, that is between single‐year and multi‐year time frames. At the annual timescale, quadrat species richness (m^?2) and herbaceous cover were higher at sites with perennial flow than at either intermittent or ephemeral sites. In contrast to this single‐year pattern, the highest long‐term richness occurred at intermittent sites. 4. Quadrat species richness, total species richness at a site (per 18 1‐m² plots) and cover were more variable year to year at non‐perennial sites than at perennial flow sites. On two of the three rivers, ephemeral sites had the highest inter‐annual compositional variance, while the perennial sites had the lowest. 5. Compositional differences between the hydrologic site types were dominated by species turnover, not nestedness. The perennial sites had more wetland and perennial species than the other two site types. The intermittent sites had more annual species than did the other two types. 6. High long‐term species richness and distinct species composition of intermittent sites are probably sustained by pronounced temporal variability in environmental conditions (i.e. frequent and persistent flow events, and dry periods). Plants at these sites take advantage of greater moisture than those at ephemeral sites and also experience less competition from resident species than those at perennial sites. 7. Conservation of desert riparian diversity depends upon the protection of consistently wet conditions at perennial flow sites, as well as the maintenance of the processes that cause fluctuations in environmental conditions at non‐perennial sites.     

Habitat Selection and Movement of Pond-Breeding Amphibians in Experimentally Fragmented Pine Forests

ABSTRACT Population-level responses of amphibians to forest management regimes are partly dictated by individual behavioral responses to habitat alteration. We examined the short-term (i.e., 24-hr) habitat choices and movement patterns of 3 amphibian species—southern leopard frogs (Rana sphenocephala), marbled salamanders (Ambystoma opacum), and southern toads (Bufo terrestris)—released on edges between forest habitats and recent clear-cuts in the Upper Coastal Plain of South Carolina, USA. We predicted that adult frogs and salamanders would preferentially select forest using environmental cues as indicators of habitat suitability. We also predicted that movement patterns would differ in clear-cuts relative to forests, resulting in lower habitat permeability of clear-cuts for some or all of the species. Using fluorescent powder tracking, we determined that marbled salamanders selected habitat at random, southern toads preferred clear-cuts, and southern leopard frogs initially selected clear-cuts but ultimately preferred forests. Frogs exhibited long-distance, directional movement with few turns. In contrast, toads exhibited wandering behavior and salamanders moved relatively short distances before locating cover. Southern toads and southern leopard frogs moved farther in forests, and all 3 species made more turns in clear-cuts than in forests. Habitat selection by southern toads did not vary according to body size, sex, or the environmental cues we measured. However, marbled salamanders were more likely to enter clear-cuts when soil moisture was high, and southern leopard frogs were more likely to enter clear-cuts when relative humidity and air temperature were higher in the clear-cut than in adjacent forest. Although we found evidence of reduced habitat permeability of clear-cuts for southern leopard frogs and southern toads, none of the species exhibited strong behavioral avoidance of the small (4-ha) clear-cuts in our study. Further studies of long-term habitat use and the potential physiological and other costs to individuals in altered forests are needed to understand the effects of forest management on population persistence. To reduce potentially detrimental effects of clear-cutting on amphibians in the Southeast, wildlife managers should consider the vagility and behavior of species of concern, especially in relation to the size of planned harvests adjacent to breeding sites.