Endemic trees in a tropical biodiversity hotspot imperilled by an invasive tree

Non-native plants invade some tropical forests but there are few long-term studies of these invasions, and the consequences for plant richness and diversity are unclear. Repeated measurements of permanent plots in tropical montane rain forests in the Blue and John Crow Mountains National Park in Jamaica over 24 to 40 years coincided with invasion by a non-native tree, Pittosporum undulatum. By 2014, P. undulatum comprised, on average, 11.9% of stems ≥ 3 cm diameter and 10.4% of the basal area across 16 widespread plots within c. 250 ha of the forests. Across these plots, the more P. undulatum increased in basal area over 24 years, the greater the decline in local, plot-scale tree species richness, and the greater the reduction in the percentage of stems of endemic tree species. Plot-scale tree diversity (Shannon and Fisher\u27s alpha) also declined the more P. undulatum basal area increased, but beta diversity across the plots was not reduced. Declines in local-scale tree species diversity and richness as the invasion progresses is especially concerning because Jamaica is a global biodiversity hotspot. Native birds disperse P. undulatum seeds widely, and future hurricanes will probably further increase its invasion by reducing canopy cover and therefore promoting growth rates of its established shade-tolerant seedlings. Remedial action is needed now to identify forest communities with greatest endemism, and to protect them through a continuing programme of control and removal of P. undulatum

Non-Native Plants Disrupt Dual Promotion of Native Alpha and Beta Diversity

Abstract Non-native species can alter patterns of species diversity at multiple spatial scales, but the processes that underlie multi-scale effects remain unclear. Here we show that non-native species reduce native diversity at multiple scales through simultaneous disruption of two processes of native community assembly: species immigration, which enhances alpha diversity, and community divergence, which enhances beta diversity. Community divergence refers to the process in which local communities diverge over time in species composition because the history of species immigration and, consequently, the way species affect one another within communities are variable among communities. Continuous experimental removal of species over four years of floodplain succession revealed that, when non-native species were excluded, stochastic variation in the timing of a dominant native species' arrival allowed local communities to diverge, thereby enhancing beta diversity, without compromising promotion of alpha diversity by species immigration. In contrast, when non-native species were allowed to enter experimental plots, they not only reduced native alpha diversity by limiting immigration, but also diminished the dominant native species' role in enhancing native beta diversity. Our results highlight the importance of community assembly and succession for understanding multi-scale effects of non-native species

Educational Consciousness: Breaking Open the Category of Knowledge in Footscray

This article is the beginning of a theoretical reading of a project undertaken by the Public Pedagogies Institute a Pop Up School and Educational Consciousness. Drawing on Biesta’s notion of publicness we initially describe the Pop Up School event. We argue that in this project we look to extend the way the knowledge profile of an area can be more fully informed by turning to the community itself for their articulations and representations of their knowledge. When then offer distinct readings of this research/public event with Deleuze and Barad as they offer a dynamic engagement with knowledge. The paper then moves between the small space of the public event and the larger space of Footscray through Aboriginal and non-Aboriginal cosmologies and pedagogies. Time is called then into play as a psychoanalytic reading of Footscray, memory and knowledge are read from the interview data. The final steps bring Footscray sharply through time with a reading of ‘consumptionscapes’ of Footscray knowledge.</jats:p

Exposure to a Complex Cocktail of Environmental Endocrine-Disrupting Compounds Disturbs the Kisspeptin/GPR54 System in Ovine Hypothalamus and Pituitary Gland

BACKGROUND: Ubiquitous environmental chemicals, including endocrine-disrupting chemicals (EDCs), are associated with declining human reproductive health, as well as an increasing incidence of cancers of the reproductive system. Verifying such links requires animal models exposed to "real-life," environmentally relevant concentrations/mixtures of EDC, particularly in utero, when sensitivity to EDC exposure is maximal. OBJECTIVES: We evaluated the effects of maternal exposure to a pollutant cocktail (sewage sludge) on the ovine fetal reproductive neuroendocrine axes, particularly the kisspeptin (KiSS-1)/GPR54 (G-protein-coupled receptor 54) system. METHODS: KiSS-1, GPR54, and ERalpha (estrogen receptor alpha) mRNA expression was quantified in control (C) and treated (T) maternal and fetal (110-day) hypothalami and pituitary glands using semiquantitative reverse transcription polymerase chain reaction, and colocalization of kisspeptin with LHbeta (luteinizing hormone beta) and ERalpha in C and T fetal pituitary glands quantified using dual-labeling immunohistochemistry. RESULTS: Fetuses exposed in utero to the EDC mixture showed reduced KiSS-1 mRNA expression across three hypothalamic regions examined (rostral, mid, and caudal) and had fewer kisspetin immunopositive cells colocalized with both LHbeta and ERalpha in the pituitary gland. In contrast, treatment had no effect on parameters measured in the adult ewe hypothalamus or pituitary. CONCLUSIONS: This study demonstrates that the developing fetus is sensitive to real-world mixtures of environmental chemicals, which cause significant neuroendocrine alterations. The important role of kisspeptin/GPR54 in regulating puberty and adult reproduction means that in utero disruption of this system is likely to have long-term consequences in adulthood and represents a novel, additional pathway through which environmental chemicals perturb human reproduction

AAV-mediated ERdj5 overexpression protects against P23H rhodopsin toxicity

Rhodopsin misfolding caused by the P23H mutation is a major cause of autosomal dominant retinitis pigmentosa (adRP), to date there are no effective treatments for adRP. The BiP co-chaperone and reductase ERdj5 (DNAJC10) is part of the ER quality control machinery and previous studies have shown that overexpression of ERdj5 in vitro enhanced the degradation of P23H rhodopsin; whereas knockdown of ERdj5 increased P23H rhodopsin ER retention and aggregation. Here, we investigated the role of ERdj5 in photoreceptor homeostasis in vivo by using an Erdj5 knock-out mouse crossed with the P23H knock-in mouse, and by adeno associated viral (AAV) vector-mediated gene augmentation of ERdj5 in P23H-3 rats. Electroretinogram (ERG) and optical coherence tomography (OCT) of Erdj5−/− and P23H+/−:Erdj5−/− mice showed no effect of ERdj5 ablation on retinal function or photoreceptor survival. Rhodopsin levels and localisation were similar to those of control animals at a range of time points. By contrast, when AAV2/8-ERdj5-HA was subretinally injected into P23H-3 rats, analysis of the full field ERG suggested that overexpression of ERdj5 reduced visual function loss 10 weeks post-injection. This correlated with a significant preservation of photoreceptor cells at 4 and 10 weeks post-injection. Assessment of the outer nuclear layer (ONL) morphology showed preserved ONL thickness and reduced rhodopsin retention in the ONL in the injected superior retina. Overall, these data suggest that manipulation of the ER quality control and ERAD factors to promote mutant protein degradation could be beneficial for the treatment of adRP caused by mutant rhodopsin

Observation of light echoes around very young stars

The goal of the paper is to present new results on light echoes from young stellar objects. Broad band CCD images were obtained over three months at one-to-two week intervals for the field of NGC 6726, using the large field-of-view remotely-operated telescope on top of Cerro Burek. We detected scattered light echoes around two young, low-amplitude, irregular variable stars. Observations revealed not just one, but multiple light echoes from brightness pulses of the T Tauri star S CrA and the Herbig Ae/Be star R CrA. Analysis of S CrA's recurring echoes suggests that the star is located 138 +/- 16 pc from Earth, making these the closest echoes ever detected. The environment that scatters the stellar light from S CrA is compatible with an incomplete dust shell or an inclined torus some 10,000 AU in radius and containing $\sim$ $2 \times 10^{-3}$ M_{\sun} of dust. The cause of such concentration at $\sim$ 10,000AU from the star is unknown. It could be the remnant of the envelope from which the star formed, but the distance of the cloud is remarkably similar to the nominal distance of the Oort cloud to the Sun, leading us to also speculate that the dust (or ice) seen around S CrA might have the same origin as the Solar System Oort cloud.Comment: A&A, in press Received: 16 March 2010 / Accepted: 01 June 201

REEP6 Deficiency Leads to Retinal Degeneration through Disruption of ER Homeostasis and Protein Trafficking

Retinitis pigmentosa (RP) is the most common form of inherited retinal dystrophy. We recently identified mutations in REEP6, which encodes the receptor expression enhancing protein 6, in several families with autosomal recessive RP. REEP6 is related to the REEP and Yop1p family of ER shaping proteins and potential receptor accessory proteins, but the role of REEP6 in the retina is unknown. Here we characterise the disease mechanisms associated with loss of REEP6 function using a Reep6 knockout mouse generated by CRISPR/Cas9 gene editing. In control mice REEP6 was localised to the inner segment and outer plexiform layer of rod photoreceptors. The Reep6-/- mice exhibited progressive photoreceptor degeneration from P20 onwards. Ultrastructural analyses at P20 by transmission electron microscopy and 3View serial block face scanning EM revealed an expansion of the distal ER in the Reep6-/- rods and an increase in their number of mitochondria. Electroretinograms revealed photoreceptor dysfunction preceded degeneration, suggesting potential defects in phototransduction. There was no effect on the traffic of rhodopsin, Rom1 or peripherin/rds; however, the retinal guanylate cyclases GC1 and GC2 were severely affected in the Reep6 knockout animals, with almost undetectable expression. These changes correlated with an increase in C/EBP homologous protein (CHOP) expression and the activation of caspase 12, suggesting that ER stress contributes to cell death. Collectively, these data suggest that REEP6 plays an essential role in maintaining cGMP homeostasis though facilitating the stability and/or trafficking of guanylate cyclases and maintaining ER and mitochondrial homeostasis

Projected sea level rise and changes in extreme storm surge and wave events during the 21st century in the region of Singapore

Singapore is an island state with considerable population, industries, commerce and transport located in coastal areas at elevations less than 2 m making it vulnerable to sea-level rise. Mitigation against future inundation events requires a quantitative assessment of risk. To address this need, regional projections of changes in (i) long-term mean sea level and (ii) the frequency of extreme storm surge and wave events have been combined to explore potential changes to coastal flood risk over the 21st century. Local changes in time mean sea level were evaluated using the process-based climate model data and methods presented in the IPCC AR5. Regional surge and wave solutions extending from 1980 to 2100 were generated using ~ 12 km resolution surge (Nucleus for European Modelling of the Ocean – NEMO) and wave (WaveWatchIII) models. Ocean simulations were forced by output from a selection of four downscaled (~ 12 km resolution) atmospheric models, forced at the lateral boundaries by global climate model simulations generated for the IPCC AR5. Long-term trends in skew surge and significant wave height were then assessed using a generalised extreme value model, fit to the largest modelled events each year. An additional atmospheric solution downscaled from the ERA-Interim global reanalysis was used to force historical ocean model simulations extending from 1980–2010, enabling a quantitative assessment of model skill. Simulated historical sea surface height and significant wave height time series were compared to tide gauge data and satellite altimetry data respectively. Central estimates of the long-term mean sea level rise at Singapore by 2100 were projected to be 0.52 m (0.74 m) under the RCP 4.5 (8.5) scenarios respectively. Trends in surge and significant wave height 2 year return levels were found to be statistically insignificant and/or physically very small under the more severe RCP8.5 scenario. We conclude that changes to long-term mean sea level constitute the dominant signal of change to the projected inundation risk for Singapore during the 21st century. We note that the largest recorded surge residual in the Singapore Strait of ~ 84 cm lies between the central and upper estimates of sea level rise by 2100, highlighting the vulnerability of the region