Improving productivity reduces methane intensity but increases the net emissions of sheepmeat and wool enterprises

Greenhouse gas emissions from Western Australia's sheep flock account for 26% of the state's agricultural emissions, principally as a result of enteric methane emissions. A decrease in emissions between 2005 and 2019 can be partly explained by a 44% drop in sheep numbers over that period, but less is known about potential changes in the methane intensity of sheepmeat and wool kg CO₂ equivalents/kg product. Using the livestock systems modelling software GrassGro™, we assessed the changes in methane intensity of sheepmeat and wool produced in two major sheep-producing regions in Western Australia. We also evaluated a series of future scenarios. Our results demonstrate that the observed emissions reductions are largely a result of a decrease in flock size, although methane intensity has also decreased somewhat by 11.1%. Simulation of future trajectories indicates that methane intensity could be as much as 18.8% lower by 2030, compared to 2005, with further reductions of up to 42% considered possible. The primary driver of the decreased methane intensity to date is increased flock reproductive performance through increased marking rates, higher rates of ewe lamb mating, and lower ewe death rates. However, despite reductions in methane intensity per kg of product, net emissions per ewe have risen 11.6% since 2005 and are forecast to rise by up to 21.8% by 2030, with potential further increases of up to 61% considered possible. This is driven by increased feed intake due to an increased number of lambs produced per ewe, higher ewe standard reference weights, and lower ewe death rates. Therefore, achieving absolute net reductions in the methane emissions through productivity improvements is unlikely to be prospective. Reducing net emissions is instead likely to be contingent on a reduction in flock numbers, breakthroughs in anti-methanogenic research, or via emissions offsetting. Our approach can be applied in other major livestock producing regions to evaluate emissions performance, with potential implications for agricultural and trade policy as markets increasingly seek lower emissions product.

Net protein contribution and enteric methane production of pasture and grain-finished beef cattle supply chains

Ruminant red meat production systems around the world often include a grain feeding phase. The role of red meat in the food system is therefore often discussed in terms of the food vs feed debate, as well as invoking the comparatively poor feed conversion efficiency of ruminants and climate impacts from enteric methane. The concept of net protein contribution (NPC) incorporates the quality attributes of protein produced by livestock systems into estimates of the efficiency of production systems. We applied the NPC method to two Australian beef supply chains, i) Grass-fed and ii) Grain-finished beef, using an established model of ruminant grazing systems (GrassGro®) and these are reflective of beef production systems in other countries. The beef supply chains evaluated did not compete with humans for protein. The Grain-finished beef supply chain, while positively contributing to human protein requirements (NPC value 1.96), had markedly lower NPC values than the Grass-fed system (NPC value 1 597). However, Grass-fed beef production systems have a higher methane intensity than the Grain-finished supply chain. The two examples of pasture-based beef production systems examined provide a positive net protein contribution to human food supply, even with extended periods of finishing on grain-based diets. This is achieved by ruminant grazing on pastures converting low-quality forage into high value human edible protein. The efficiency of protein production varies according to the system design, and other considerations such as land use and enteric methane production are elements that need consideration in the overall assessment of the production footprint.

A partial nucleated differential cell count of the bone marrow aspirate that is independent of peripheral blood dilution

In the bone marrow (BM) nucleated differential cell count (NDC), myeloblasts are enumerated as a percentage of total nucleated cells, which are inevitably diluted with peripheral blood nucleated cells (PBNC) during BM aspiration. We propose a partial NDC (PNDC) comprising only immature haemopoietic cells capable of division, i.e. myeloblasts, promyelocytes, myelocytes and erythroblasts. We show that the myeloid : erythroid (M : E) ratio of the PNDC remains approximately constant in progressively dilute aliquots of BM aspirates. We determined the PNDC in 22 healthy subjects and investigated the effect of peripheral blood dilution on disease stratification of 66 BM aspirates with myelodysplastic syndromes (MDS). NDC and PNDC myeloblast counts were compared and the equivalent PNDC myeloblast counts for NDC myeloblast threshold counts of 5, 10 and 20% were derived. Reclassification of MDS samples with the PNDC resulted in a change in disease category in 33.3% of 51 MDS samples with NDC myeloblast counts ranging from 3 to 26%. The PNDC is independent of PBNC dilution and can be determined in dilute BM samples. It alters the disease category in a significant proportion of BM aspirates with MDS and has the potential to better stratify MDS to improve clinical outcomes and treatment.

Identification of a 14-3-3 binding sequence in the common beta chain of the granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 receptors that is serine-phosphorylated by GM-CSF

The common beta chain (beta(c)) of the granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 receptors is the major signaling subunit of these receptors coupling ligand binding to multiple biological activities. It is thought that these multiple functions arise as a consequence of the recruitment of specific signaling molecules to tyrosine-phosphorylated residues in the cytoplasmic domain of beta(c). However, the contribution of serine phosphorylation in beta(c) to the recruitment of signaling molecules is not known. We show here the identification of a phosphoserine motif in the cytoplasmic domain of beta(c) that interacts with the adaptor protein 14-3-3zeta. Coimmunoprecipitation and pull-down experiments with a glutathione S-transferase (GST):14-3-3zeta fusion protein showed that 14-3-3 directly associates with beta(c) but not the GM-CSF receptor alpha chain. C-terminal truncation mutants of beta(c) further showed that a region between amino acids 544 and 626 in beta(c) was required for its association with 14-3-3zeta. This region contains the sequence (582)HSRSLP(587), which closely resembles the RSXSXP (where S is phosphorylated) consensus 14-3-3 binding site identified in a number of signaling molecules, including Raf-1. Significantly, substitution of (582)HSRSLP(587) for EFAAAA completely abolished interaction of beta(c) with GST-14-3-3zeta. Furthermore, the interaction of beta(c) with GST-14-3-3 was greatly reduced in the presence of a peptide containing the 14-3-3 binding site, but only when (585)Ser was phosphorylated. Direct binding experiments showed that the peptide containing phosphorylated (585)Ser bound 14-3-3zeta with an affinity of 150 nmol/L. To study the regulation of (585)S phosphorylation in vivo, we raised antibodies that specifically recognized (585)Ser-phosphorylated beta(c). Using these antibodies, we showed that GM-CSF stimulation strongly upregulated (585)Ser phosphorylation in M1 myeloid leukemic cells. The proximity of the SHC-binding site ((577)Tyr) to the 14-3-3-binding site ((582)HSRSLP(587)) and their conservation between mouse, rat, and human beta(c) but not in other cytokine receptors suggest that they form a distinct motif that may subserve specialized functions associated with the GM-CSF, IL-3, and IL-5 receptors.

Image data-processing system for solar astronomy

Image processing has become an invaluable tool in the analysis of solar astronomy and other scientific data. In particular, a number of powerful and intricate image-processing systems have been developed. One such system is the MSFC/S-056 Image Data Processing System (IDAPS), especially designed for the analysis of the Skylab/ATM S-056 X-Ray Telescope experiment data. This paper describes the IDAPS, discusses its unique interactive capabilities, and shows some recent results obtained using the IDAPS.