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Background: Live fuel comprises a significant portion of the fuel consumed in forest and scrub crown fires. However, its flammability remains poorly understood. Although live fuel differs from dead fuel in moisture content, chemical composition, cellular structure and physiological characteristics, its higher moisture content masks the effect of other characteristics on its flammability. Aims: The aim of the study was to delineate and assess the effects of live/dead condition, moisture content and particle size on flammability of gorse (Ulex europaeus L.). Methods: Live and dead gorse material of three size classes (0–3, 3–6, and 6–10 mm in diameter) at six moisture contents (0, 10, 25, 50, 75 and 100%) was tested in a cone calorimeter to evaluate its flammability using new sample preparation and moisture conditioning techniques. Key results: On average, live fuel ignited 21% slower, reached 11% higher peak heat release rate, and had a 12% shorter burn duration than dead fuel of the same moisture content. These differences were most pronounced in coarser material. Conclusions: For gorse, fine dead fuels increase the likelihood of ignition, fine live fuels contribute to high burning intensities, and coarser live and dead fuels prolong combustion. Implications: These findings highlight the need to account for flammability differences between live and dead fuels in fire behaviour models beyond those driven by variations in moisture content. This study compares the flammability of live and dead vegetation at a range of moisture contents and particle sizes. Live fuel took longer to ignite but burned faster and more intensely than dead fuel of the same moisture content, emphasising the importance of live fuel flammability in fire prediction models. [ABSTRACT FROM AUTHOR]

Determining the magnitude of climate change effects is crucial for informing national economic strategies, forest management and offsetting increasing carbon emissions. This study synthesizes predicted climate change impacts and future biosecurity threats to New Zealand's plantation forests. Projected productivity increases for radiata pine (Pinus radiata D. Don), the main commercial forest species in New Zealand, are slight due to changing climatic conditions. However including photosynthetic effects from increasing CO2, productivity gains across New Zealand averaged 19 per cent by 2040 and 37 per cent by 2090. This increased productivity results in marked increases in wind risk due to trees becoming taller and more slender. The average season length with 'very high and extreme' climatic fire risk increases by 71 per cent up to 2040 and by 83 per cent up to 2090. Currently, the most significant biotic disturbances in New Zealand plantations come from two needle cast diseases, for which climate projections show slight increases or decreases depending on the disease and region. Although insect pests currently cause little damage to New Zealand plantations, damage may increase in the future with projected increases in population and host susceptibility. It has not been possible to fully account for the effects of any new introductions of pests and pathogens and evidence from other countries with a significant resource of planted forests suggest this should not be underestimated. Potentially invasive weedy and damaging tree species are likely to expand their range under climate change and compete more strongly with plantations. [ABSTRACT FROM AUTHOR]

The finite element modeling of bundle-pinch in a transmission line conductor bundle, caused by large short-circuit currents, is discussed. The characteristics of the finite element model have a significant effect on the accuracy of the simulation, and are described. The finite element package ABAQUS has been used to successfully simulate the phenomenon of bundle pinch, as shown by the agreement of the results obtained with previously published experimental results.

We report the results of a comprehensive study of the relationship between galaxy size, stellar mass and specific star formation rate (sSFR) at redshifts 1.3 < z < 1.5. Based on a mass-complete (M⋆ ≥ 6 × 1010 M⊙), spectroscopic sample from the UK Infrared Deep Sky Survey (UKIDSS) Ultradeep Survey, with accurate stellar-mass measurements derived from spectro-photometric fitting, we find that at z ≃ 1.4 the location of massive galaxies on the size–mass plane is determined primarily by their sSFR. At this epoch, we find that massive galaxies which are passive (sSFR ≤ 0.1 Gyr−1) follow a tight size–mass relation, with half-light radii a factor of fg = 2.4 ± 0.2 smaller than their local counterparts. Moreover, amongst the passive sub-sample we find no evidence that the off-set from the local size–mass relation is a function of stellar population age. In contrast, we find that massive star-forming galaxies at this epoch lie closer to the local late-type size–mass relation and are only a factor of fg = 1.6 ± 0.2 smaller than observed locally. Based on a sub-sample with dynamical-mass estimates, which consists of both passive and star-forming objects, we also derive an independent estimate of fg = 2.3 ± 0.3 for the typical growth in half-light radius between z ≃ 1.4 and the present day. Focusing on the passive sub-sample, we conclude that to produce the necessary evolution predominantly via major mergers would require an unfeasible number of merger events and overpopulate the high-mass end of the local stellar-mass function. In contrast, we find that a scenario in which mass accretion is dominated by minor mergers can comfortably produce the necessary evolution, whereby an increase in stellar mass of only a factor of ≃2, accompanied by size growth of a factor of ≃3.5, is required to reconcile the size–mass relation at z ≃ 1.4 with that observed locally. Finally, we note that a significant fraction (44 ± 12 per cent) of the passive galaxies in our sample have a disc-like morphology, providing additional evidence that separate physical processes are responsible for the quenching of star formation and morphological transformation in massive galaxies. [ABSTRACT FROM PUBLISHER]

ABSTRACT We present spectroscopic confirmation of 10 highly luminous ( L≥ 2 L★) Lyα emitters (LAEs) in the redshift range 6.01 < z < 6.49 (nine galaxies and one active galactic nucleus), initially drawn from a sample of 14 zphot≥ 6 Lyman-break galaxies (LBGs) selected from an area of 0.25 deg2 within the UK Infrared Deep Sky Survey (UKIDSS) Ultra-Deep Survey (UDS). Overall, our high rate of spectroscopic confirmation (≥71 per cent) and low rate of contamination provides a strong vindication of the photometric redshift analysis used to define the original sample. By considering star formation rate estimates based on the Lyα and ultraviolet continuum luminosity we conclude that our sample is consistent with a Lyα escape fraction of ≃25 per cent. Moreover, after careful consideration of the potential uncertainties and biases, we find that 40-50 per cent of our sample of L≥ 2 L★ galaxies at 6.0 < z < 6.5 display strong Lyα emission (rest-frame equivalent width ≥25 Å), a fraction which is a factor of ≃2 higher than previously reported for L≤ L★ galaxies at z≃ 6. Our results suggest that, as the epoch of reionization is approached, it is plausible that the LAE fraction amongst luminous ( L≥ 2 L★) LBGs shows a similarly sharp increase to that observed in their lower luminosity ( L≤ L★) counterparts. [ABSTRACT FROM AUTHOR]

, , 432-436. Sterility tests of homograft heart valves sterilized by antibiotics were found to be invalidated by carry-over of the antibiotics. A method was devised to test the efficacy of different antibiotic mixtures using membrane filters. Fifty-five organisms, including 13 species, were tested, and sterility was achieved with only 35. [ABSTRACT FROM PUBLISHER]

Summary: Long-term hematopoietic stem cells (LT-HSCs) maintain hematopoietic output throughout an animal’s lifespan. However, with age, the balance is disrupted, and LT-HSCs produce a myeloid-biased output, resulting in poor immune responses to infectious challenge and the development of myeloid leukemias. Here, we show that young and aged LT-HSCs respond differently to inflammatory stress, such that aged LT-HSCs produce a cell-intrinsic, myeloid-biased expression program. Using single-cell RNA sequencing (scRNA-seq), we identify a myeloid-biased subset within the LT-HSC population (mLT-HSCs) that is prevalent among aged LT-HSCs. We identify CD61 as a marker of mLT-HSCs and show that CD61-high LT-HSCs are uniquely primed to respond to acute inflammatory challenge. We predict that several transcription factors regulate the mLT-HSCs gene program and show that Klf5, Ikzf1, and Stat3 play an important role in age-related inflammatory myeloid bias. We have therefore identified and isolated an LT-HSC subset that regulates myeloid versus lymphoid balance under inflammatory challenge and with age. : Mann et al. show an age-dependent inflammatory response of hematopoietic stem cells (HSCs) and unveil a CD61-high subpopulation primed for inflammatory response. This CD61-high subpopulation is more prevalent in aged mice and has a cell-intrinsic myeloid-biased potential, which is regulated in part by Ikzf1, Klf5, and Stat3 transcription factors. Keywords: hematopoietic stem cells, stem cell aging, inflammation, single-cell RNA sequencing

Six different mixtures of antibiotics used for treating heart valve allografts at the National Heart Hospital have been compared and the formulation of the medium in current use is described. The abilities of antibiotic-resistant bacteria, and of fungi with low sensitivities to antifungal agents, to survive treatment are also described. These abilities emphasise the need for routine microbiological screening of every valve. [ABSTRACT FROM PUBLISHER]