An overview on the role and potential of forage production on lowland organic livestock farms

This report was presented at the UK Organic Research 2002 Conference of the Colloquium of Organic Researchers (COR). This paper outlines some of the factors influencing the level of forage production on organic lowland farms. Optimal forage production is achieved by maintaining soil fertility, providing a balance between N-fixing and N-demanding crops and producing sufficient quantities of quality feed to meet the requirements of the organic livestock enterprise. A key objective for organic systems is to increase the efficiency of forage production by improving the nutrient input/output balance of the wholefarm system. Improving forage quality reduces the requirement for external feed sources, leading to increased self-sufficiency in the wholefarm system. Legumes provide the main source of nitrogen for forage production with energy shortage and an erratic supply of protein the main limiting factors in the provision of balanced diets from home-grown crops

The Leeuwin current

The Leeuwin Current (LC) is a warm, poleward flowing ocean boundary current off the west and south coasts of Australia, driven by large-scale meridional (north-south) pressure gradient. On the interannual time scale, the strength of the LC is influenced by ENSO-related thermocline anomalies, and transmitted from the equatorial western Pacific into the southeast Indian Ocean through the Indonesian Archipelago. The LC and its interannual variability have profound impacts on marine ecosystems off the west and south coasts of Australia. For example, high recruitment of the western rock lobster (Panulirus cygnus) fishery of Western Australia is influenced by a stronger LC and the associated warmer water temperatures. Over the period from mid-1970s to mid-1990s, a trend of shallowing thermocline (subsurface cooling) in the equatorial western Pacific, which is coupled with a weakening trend of the trade winds in the Pacific, has transmitted into the southeast Indian Ocean and the LC region and caused a multi-decadal weakening trend of the LC. Comparing climate models and forced ocean circulation models suggests that the weakening LC is likely due to a combined effect of both global warming and natural variability in the climate system. There have been persistent warming trends observed in the LC and on the shelf in waters off the west coast during the past five decades. Over the same time period, more frequent Indian Ocean Dipole events and an upward trend of the Southern Annual Mode may have reduced the strength of the westerly winds and storm activity off the southwest coast, which may have adjusted the air-sea heat flux in the LC region and overcome the reduction of the LC heat transport to cause the warming trend. Both the changes in the LC and the air-sea freshwater flux may have also caused the observed increase in surface salinity off the coast. The surface warming and subsurface cooling, in combination with the reduction of storm activity, may have increased the vertical stratification in the water column and reduced vertical mixing in the LC region. Climate model simulations suggest that reductions of trade winds in the tropical Pacific, increase in the frequency of Indian Ocean Dipole events, and the upward trend of Southern Annual Mode in recent decades are mostly due to the effect of the increased Feng et al. 2009 www.oceanclimatechange.org.au 2 greenhouse gases in the atmosphere. Climate model projections suggest these climate trends will likely continue in the future, so that the LC could continue to weaken slowly

Attribution of the 2015 record high sea surface temperatures over the central equatorial Pacific and tropical Indian Ocean

This study assessed the anthropogenic contribution to the 2015 record-breaking high sea surface temperatures (SSTs) observed in the central equatorial Pacific and tropical Indian Ocean. Considering a close link between extreme warm events in these regions, we conducted a joint attribution analysis using a fraction of attributable risk approach. Probability of occurrence of such extreme anomalies and long-term trends for the two oceanic regions were compared between CMIP5 multi-model simulations with and without anthropogenic forcing. Results show that the excessive warming in both regions is well beyond the range of natural variability and robustly attributable to human activities due to greenhouse gas increase. We further explored associated mechanisms including the Bjerknes feedback and background anthropogenic warming. It is concluded that background warming was the main contribution to the 2015 extreme SST event over the central equatorial Pacific Ocean on a developing El Niño condition, which in turn induced the extreme SST event over the tropical Indian Ocean through the atmospheric bridge effect.113Ysciescopu

Human-caused Indo-Pacific warm pool expansion

The Indo-Pacific warm pool (IPWP) has warmed and grown substantially during the past century. The IPWP is Earth's largest region of warm sea surface temperatures (SSTs), has the highest rainfall, and is fundamental to global atmospheric circulation and hydrological cycle. The region has also experienced the world's highest rates of sea-level rise in recent decades, indicating large increases in ocean heat content and leading to substantial impacts on small island states in the region. Previous studies have considered mechanisms for the basin-scale ocean warming, but not the causes of the observed IPWP expansion, where expansion in the Indian Ocean has far exceeded that in the Pacific Ocean. We identify human and natural contributions to the observed IPWP changes since the 1950s by comparing observations with climate model simulations using an optimal fingerprinting technique. Greenhouse gas forcing is found to be the dominant cause of the observed increases in IPWP intensity and size, whereas natural fluctuations associated with the Pacific Decadal Oscillation have played a smaller yet significant role. Further, we show that the shape and impact of human-induced IPWP growth could be asymmetric between the Indian and Pacific basins, the causes of which remain uncertain. Human-induced changes in the IPWP have important implications for understanding and projecting related changes in monsoonal rainfall, and frequency or intensity of tropical storms, which have profound socioeconomic consequences.116Yscopu

Evaluating source-sink relationships of the western rock lobster fishery using oceanographic modelling: Final FRDC Report – Project 2008/087

Objectives 1. To determine the relative contribution of larval production from different areas to the abundance and spatial distribution of puerulus settlement over 15 years using a larval advection mode

Identifying factors affecting the low western rock lobster puerulus settlement in recent years Final FRDC Report – Project 2009/18

Objectives 1. To use a larval advection model and the rock lobster population dynamics model to assess the effect of the spatial distribution of the breeding stock on the puerulus settlement 2. To assess environmental factors (water temperature, current, wind, productivity, eddies) and breeding stock affecting puerulus settlement 3. To examine climate change trends of key environmental parameters and their effect on the western rock lobster fisher

The reversal of the multi-decadal trends of the equatorial Pacific easterly winds, and the Indonesian Throughflow and Leeuwin Current transports

Multi-decadal weakening trend of the equatorial Pacific easterly winds since 1960 has reversed after 1993. The trend reversal has induced cooling (shallow thermocline) trend in the equatorial western Pacific before 1993, followed by a warming (deep thermocline) trend from 1993 to the present. All available atmospheric reanalysis products corroborate the trend reversal during the two multi-decadal periods. The magnitudes of the multi-decadal trends of the easterly winds, however, differ among the reanalysis products. The trend reversals of regional ocean circulations are assessed using linear regressions between wind and transport anomalies in an eddy-permitting numerical model, suggesting that since 1993 the Indonesian Throughflow and the Leeuwin Current transports have also reversed their multi-decadal weakening trends. Key Points: - There have been reversals of the multi-decadal weakening trends of trade winds - Different reanalysis products capture different trends in trade wind

Federated learning enables big data for rare cancer boundary detection.

Although machine learning (ML) has shown promise across disciplines, out-of-sample generalizability is concerning. This is currently addressed by sharing multi-site data, but such centralization is challenging/infeasible to scale due to various limitations. Federated ML (FL) provides an alternative paradigm for accurate and generalizable ML, by only sharing numerical model updates. Here we present the largest FL study to-date, involving data from 71 sites across 6 continents, to generate an automatic tumor boundary detector for the rare disease of glioblastoma, reporting the largest such dataset in the literature (n = 6, 314). We demonstrate a 33% delineation improvement for the surgically targetable tumor, and 23% for the complete tumor extent, over a publicly trained model. We anticipate our study to: 1) enable more healthcare studies informed by large diverse data, ensuring meaningful results for rare diseases and underrepresented populations, 2) facilitate further analyses for glioblastoma by releasing our consensus model, and 3) demonstrate the FL effectiveness at such scale and task-complexity as a paradigm shift for multi-site collaborations, alleviating the need for data-sharing