Platelet consumption during neonatal extracorporeal life support (ECLS)

This paper reports the results of a retrospective study of blood use and blood loss in 40 neonates during extracorporeal life support (ECLS). Immediately after onset of bypass 39±2.5ml platelets, 59.4±6.5ml packed red blood cells (PRBC) and 15.0±5.4ml fresh frozen plasma (FFP) per patient were needed. The average daily amount given per patient was 49.0±3.0ml of platelets and 48.0±3.4ml and 9.6±3.9ml of PRBC and FFP respectively. The 10 patients who had bleeding complications received 50.0±6.3ml/day of platelets compared to 49.0±3.4ml in the other patients. The majority of blood loss during the entire period of ECLS was from samples, averaging 43.0 ± 1.5ml/day. Neck wound drainage, 6.7±2.5ml/day per patient, lasted for the entire period.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68887/2/10.1177_026765919200700106.pd

Development of heartwood in response to water stress for radiata pine in Southern New South Wales, Australia

Heartwood development and other functional changes in stem conductance in response to water stress in radiata pine were investigated using two contrasting climatic areas (high-altitude sub-alpine vs. warm–dry inland) of the Hume region of New South Wales, Australia. The study included mature (34.5–36.5 years old) and young stands (10–11 years old) measured under normal climate and during an extreme drought. The effect of water stress on heartwood development was examined using sapwood percentage, sapwood saturation, development of dry sapwood and evidence of cavitation in sapwood. Trees at the warm–dry site developed heartwood at faster rates than on the high-altitude site. At breast height, the mature stands of the warm–dry site had 8–14 % less sapwood. Extensive cavitation towards the sapwood/heartwood boundary occurred in some of the mature and young stands on the warm–dry site. We postulated that in water-limiting environments, cavitation of the inner sapwood precedes heartwood formation and is an adaptation mechanism that regulates stem conductance capacity and thus water use in the tree. The drought of 2006 led to decreases in moisture associated with cavitation not previously reported for radiata pine and demonstrated the drought hardiness of the species. In the warm–dry site, breast-height sapwood saturation dropped to 58 and 82 % for suppressed and average-sized trees in a mature unthinned stand; and 75–78 % for two young stands. These saturation levels, however, only imply average values as some cells cavitated whilst others were fully saturated. Cavitation occurred in a localized fashion affecting small to large groups of cells

The variation of microfibril angle in South African grown Pinus patula

Reduction in the rotation ages of softwood saw log plantations in South Africa is causing increased proportions of low stiffness sawn lumber at final harvest. It has been shown for some species that the microfibril angle (MFA) of the S2 layer of tracheids is strongly related to the modulus of elasticity (MOE) of wood, even more so than wood density, especially in wood formed during juvenile growth. The objectives of this study were to describe the variation in MFA in young Pinus patula trees and to determine the relationship between MFA and the dynamic MOE of sawn Pinus patula lumber. Thirty 16-20 year old trees from six compartments from the Mpumalanga escarpment were processed into discs and lumber. MFA, density and ring width were measured at two height levels using Silviscan 3. The average annual ring MFA varied between 7 o and 29o; the pattern of variation depending mainly on height level and the ring number from the pith. The MFA in P. patula followed the same within-tree variation trends as in New Zealand-grown Pinus radiata but the average MFA was lower in absolute terms and differences between height levels were less pronounced. MFA and density exhibited highly significant Pearson correlations of 0.73 and 0.70 respectively with board dynamic MOE. A multiple regression model, which included MFA, density and ring width, explained 71% of the variation in the dynamic MOE of boards. A sensitivity analysis on the model showed that MFA and density had approximately similar influences on predicting the dynamic MOE of Pinus patula boards.Sawmilling South Africa and the NRF’s THRIP programme.http://www.tandfonline.com/loi/tsfs202016-04-30hb201