Extracellular vesicles released by ALL patients contain HNE-adducted proteins: Implications of collateral damage

Off-target neuronal injury is a serious side-effect observed in cancer survivors. It has previously been shown that pediatric acute lymphoblastic leukemia (ALL) survivors have a decline in neurocognition compared to healthy age-matched counterparts. Elevated oxidative stress has been documented to be a mediator in off- target tissue damage in cancer survivors. Early detection of oxidative stress markers may provide an opportunity to prevent off-target tissue damage. Extracellular vesicles (EVs) have surfaced as a potential diagnostic tool due to molecular cargo they contain. We investigated the potential for EVs to be a sensitive indicator of oxidative stress and off-target tissue damage by isolating EVs from pediatric ALL patients throughout their first 2 months of treatment. EVs were measured throughout the collection points for: 1) number of EV particles generated using nanoparticle tracking analysis (NTA); 2) markers of neurons (NeuN), astrocyte activation (GFAP), neuronal stability (BDNF), 3) markers of pre-B cell ALL (CD19 and CD22); and) 4-hydroxy-2-nonenal (HNE) adducted proteins. HNE protein adductions were measured in the patient sera and CSF. Pro-inflammatory cytokine levels were also measured in patient sera because of their contribution to oxidative stress and neuronal injury. Our results: 1) demonstrate EVs are a sensitive indicator of oxidative damage; 2) suggest EVs as a marker of a decline in neuronal stability; and 3) show the presence of leukemia has a greater contribution to pro-inflammatory cytokine production in the patient’s serum than the cancer treatment. Spe- cifically, we observed a significant decrease in cytokine levels (e.g., TNF-α, IL-1β, IL-6, and IL-8) following the initiation of treatment, highlighting the influence of leukemia burden on systemic inflammation. The results support the utilization of EVs as a sensitive marker of oxidative stress and off-target tissue damage

Land Condition and Overgrazing: A Management Paradox for the Savannas of Northern Australia

The tropical savannas of northern Australia have been an important resource for the production of beef for over a century. Excessive stocking rates regimes have led, in some areas, to degradation of the soil and vegetation resource. A state-and-transition model is used to describe the decline in land condition with overgrazing. A grazing study has been established at 2 sites to determine the consequences of a change in land condition for animal production, and pasture production and quality are being related to land condition at additional small sites. Preliminary results indicate that as pasture condition declines, pasture production decreases but animal production; at low stocking rates, can be higher than from pasture in poor condUion

Managing Woody Weeds in Grazing Ecosystems: Application for Tropical Woodlands of North-eastern Australia

Shrub invasion of tropical woodlands is reducing the viability of native ecosystems as well as the livestock industry, After shrub invasion, forage supply is reduced and over-grazing and soil erosion are exacerbated. We propose a non-equilibrium model of the system and use that model to develop hypotheses and design experiments to test both competition- and disturbance-based management regimes. This model proposes that disturbance in the form of burning is the primary limiting factor in excluding and limiting shrub seedling establishment and suggests that management decisions focus on maintaining adequate herbaceous biomass for a burning regime that limits woody plant success

Management and Use of Complex Landscapes: Some Implications of Spatial Variation for Pasture and Animal Production

This paper describe.s some of the spatial variation in microclimate,\u27 soils and vegetation across the black speargrass (Heteropogon contorus) grazing lands of south-east Queensland. Differences in the establishment and survival of oversown legumes, and in animal production\u27, associated with this variation were examined in a large­scale grazing trial. The consequences of spatial heterogeneity are discussed in relation to species evaluation, restoration of degraded grazing lands and the development of sustainable grazing systems

Molecular mechanisms and comparative transcriptomics of diapause in two corn rootworm species (Diabrotica spp.)

Diapause is a programmed developmental arrest that can occur at any developmental stage depending on species, but the mechanisms that underscore embryonic diapause are poorly understood. Here, we identified molecular mechanisms underscoring distinct phases of diapause in the Diabrotica spp. complex. This species complex in- cludes economically significant agricultural pests, notably the western corn rootworm (WCR) and northern corn rootworm (NCR), which cause major losses in maize production. Rootworms undergo an obligate embryonic diapause to synchronize their life cycles with host plants, and we sequenced transcriptomes from both species at five time points (pre-diapause, diapause initiation, diapause maintenance, diapause termination, and post- diapause). Our results indicate that transcriptional regulation is dynamic during diapause. Diapause initiation involves shutdown of the cell cycle by downregulating cyclin-related genes, downregulation of aerobic meta- bolism, with concurrent upregulation of stress-related genes, especially heat shock proteins, the proteasome, and immune-related genes. During post-diapause development, there is a dramatic activation cellular respiration, which may be controlled by insulin signaling. Comparative transcriptomic analyses between WCR and NCR indicated that while many gene expression changes were conserved across species, overall gene expression profiles were distinct, indicating that many transcriptional changes are species-specific, despite the close phylogenetic relationship and phenotypic similarity between these species. This study sheds light on the suite of mechanisms that allow some organisms to pause the symphony of cellular events that occur during embryonic development and persist for several months as a tiny egg. Further, the mechanisms identified here may contribute to further research and pest management efforts in this economically important pest group

Milk Yield of Cows with Different Genetic Potential on Grass and Grass-Legume Tropical Pastures

A grazing experiment was carried out at CIAT\u27s Quilichao research station to assess the effect of legumes selected for acid soils on milk production of cows with different genetic potential. Pastures of Brahiaria dictyoneura cv. Llanero and Andropogen gayanus cv. Carimagua l, alone and in association with Centrosema acutifolium (CIAT 5568) and C. macrocarpum (CJAT 5713), were grazed by Holstein and Zebu crossbred cows using a Latin square crossover design. Fat corrected milk (FCM) yield of Holstein cows was 17 and 19% higher in the associations of B. dictyoneura and A. gayanus, respectively, than in the grass-only pastures. With the Zebu crosses PCM yield was 13% higher in the B. dictyoneura ra-legume pastures, but no response was observed in the A. gaya,ms-legume pastures. Milk composition was not affected by pasture treatment. Results suggest that grass-legume pastures selected for acid soils can significantly increase milk production, particularly when cows have medium genetic potential

Importance of Legume Nitrogen Fixation in Sustainability of Pasture in the Cerrados of Brazil

A pure Andropogon gayanus sward was compared with a Stylosanthes spp.-A. gayanus mixed sward in order to assess the benefit of introducing N2-fixing legumes on the long-term sustainability of grazed pastures. There was no difference between the total dry matter and animal production of the 2 pastures, although the legumes fixed 67-117 kg/ha of N in 1991 with 80% of the legume N obtained from N2 fixation. Litter deposition was 20-35% greater in the mixed sward and the % N in this litter was also higher, leading to twice the amount of N mineralised in the 0-5 cm layer compared with the pure grass pasture. Calculations using a simple N cycling model indicated that the introduction of the legume caused the annual N balance of the system to increase from -58 kg/ha of N to a zero or positive balance (-5 to +45 kg/ha of N)