Drought then wildfire reveals a compound disturbance in a resprouting forest.

The frequency and intensity of forest disturbances, such as drought and fire, are increasing globally, with an increased likelihood of multiple disturbance events occurring in short succession. Disturbances layered over one another may influence the likelihood or intensity of subsequent events (a linked disturbance) or impact response and recovery trajectories (a compound disturbance), with substantial implications for ecological spatiotemporal vulnerability. This study evaluates evidence for disturbance interactions of drought followed by wildfire in a resprouting eucalypt-dominated forest (the Northern Jarrah Forest) in southwestern Australia. Sites were stratified by drought (high, low), from previous modeling and ground validation, and fire severity (high, moderate, unburnt), via remote sensing using the relative difference normalized burn ratio (RdNBR). Evidence of a linked disturbance was assessed via fine fuel consumption and fire severity. Compound disturbance effects were quantified at stand scale (canopy height, quadratic mean diameter, stem density) and stem scale (mortality). There was no evidence of prior drought influencing fine fuel consumption or fire severity and, hence, no evidence of a linked disturbance. However, compound disturbance effects were evident; stands previously affected by drought experienced smaller shifts in canopy height, quadratic mean diameter, and stem density than stands without prior drought impact. At the stem scale, size and fire severity were the strongest determinants of stem survival. Proportional resprouting height was greater in high drought sites than in low drought sites (p < 0.01), meaning, structurally, the low drought stands decreased in height more than the high drought stands. Thus, a legacy of the drought was evident after the wildfire. Although these resprouting eucalypt forests have been regarded as particularly resilient, this study illustrates how multiple disturbances can overwhelm the larger tree component and promote an abundance of smaller stems. We suggest that this is early evidence of a structural destabilization of these forests under a more fire-prone, hotter, and drier future climate.

Development of a platform-based approach for the clinical production of HIV gp120 envelope glycoprotein vaccine candidates.

Preclinical development of vaccine candidates is an important link between the discovery and manufacture of vaccines for use in human clinical trials. Here, an exploratory clinical study utilizing multiple gp120 envelope proteins as vaccine antigens was pursued, which required a harmonized platform development approach for timely and efficient manufacture of the combined HIV vaccine product. Development of cell lines, processes, and analytical methods was initiated with a transmitted founder envelope protein (CH505TF), then applied to produce three subsequent gp120 Env (envelope) variants. Cell lines were developed using the commercially available Freedom CHO DG44 kit (Life Technologies). The fed-batch cell culture production process was based on a commercially-available medium with harmonized process parameters across the variants. A platform purification process was developed utilizing a mixed mode chromatography capture step, with ceramic hydroxyapatite and ion exchange polishing steps. A suite of analytical methods was developed to establish and monitor the Quality Target Profile (QTP), release and long-term stability testing of the vaccine products. The platform development strategy was successfully implemented to produce four gp120 envelope protein variants. In some cases, minor changes to the platform were required to optimize for a particular variant; however, baseline conditions for the processes (cell line type, media & feed system, chromatography resins, and analytical approaches) remained constant, leading to successful transfer and manufacture of all four proteins in a cGMP facility. This body of work demonstrates successful pursuit of a platform development approach to manufacture important vaccine candidates and can be used as a model for other vaccine glycoproteins, such as HIV gp140 trimers or other viral glycoproteins with global health implications. Clinical trial identifier. NCT03220724, NCT03856996.

Migraine-like headaches associated with nickel allergy requiring removal of atrial septal defect closure device.

There is a deficit of literature regarding the association between nickel allergy-induced symptoms and implanted devices. This report describes a case of nickel allergy causing debilitating migraine-like symptoms, failing to resolve with medical therapy, requiring surgical removal of the device and repair of the defect.

The History of Neurosurgery at Houston Methodist Hospital.

The history of neurosurgery in Texas is linked with the development over the past century of the Houston Methodist Hospital (HMH) from a 30-bed hospital in downtown Houston to an academic medical center with 900 beds in the Texas Medical Center. Neurosurgery at HMH has developed to meet the needs of the Houston Metropolitan Area, which has grown from 130,000 people in 1919 to 7 million people today. Neurosurgery at HMH has had steady growth and stable leadership with Dr. James Greenwood Jr. 1936-1980, Dr. Robert Grossman 1980-2013, and Dr. Gavin Britz 2013-present, as Chiefs of the Neurosurgical Service. HMH has been affiliated with 2 medical schools: Baylor College of Medicine 1950-2003 and Weill College of Medicine Cornell University 2004-present. Neurosurgical training began at HMH with the establishment of the Baylor College of Medicine Neurosurgery Residency Program with Dr. George Ehni as Program Director 1959-1979 and Dr. Robert Grossman as Program Director 1980-2006. Training has continued in the HMH residency program from 2006 to present with Dr. David Baskin as Program Director. As of 2019, 138 neurosurgical residents have been trained at HMH. The goals of delivering responsible patient care, advancing neurosurgical knowledge, and training the next generation of practitioners and teachers of neurosurgery have remained constant and have been met and remain the mission of the department.

Drought can offset potential water use efficiency of forest ecosystems from rising atmospheric CO2.

Increasing atmospheric CO2 is both leading to climate change and providing a potential fertilisation effect on plant growth. However, southern Australia has also experienced a significant decline in rainfall over the last 30 years, resulting in increased vegetative water stress. To better understand the dynamics and responses of Australian forest ecosystems to drought and elevated CO2, the magnitude and trend in water use efficiency (WUE) of forests, and their response to drought and elevated CO2 from 1982 to 2014 were analysed, using the best available model estimates constrained by observed fluxes from simulations with fixed and time-varying CO2. The ratio of gross primary productivity (GPP) to evapotranspiration (ET) (WUEe) was used to identify the ecosystem scale WUE, while the ratio of GPP to transpiration (Tr) (WUEc) was used as a measure of canopy scale WUE. WUE increased significantly in northern Australia (p < 0.001) for woody savannas (WSA), whereas there was a slight decline in the WUE of evergreen broadleaf forests (EBF) in the southeast and southwest of Australia. The lag of WUEc to drought was consistent and relatively short and stable between biomes (≤3 months), but notably varied for WUEe, with a long time-lag (mean of 10 months). The dissimilar responses of WUEe and WUEc to climate change for different geographical areas result from the different proportion of Tr in ET. CO2 fertilization and a wetter climate enhanced WUE in northern Australia, whereas drought offset the CO2 fertilization effect in southern Australia.

Vegetation trends associated with urban development: The role of golf courses.

Globally, cities are growing rapidly in size and density and this has caused profound impacts on urban forest ecosystems. Urbanization requiring deforestation reduces ecosystem services that benefit both city dwellers and biodiversity. Understanding spatial and temporal patterns of vegetation changes associated with urbanization is thus a vital component of future sustainable urban development. We used Landsat time series data for three decades from 1988 to 2018 to characterize changes in vegetation cover and habitat connectivity in the Perth Metropolitan Area, in a rapidly urbanising Australian biodiversity hotspot, as a case study to understand the impacts of urbanization on urban forests. Moreover, as golf courses are a major component in urban areas, we assessed the role of golf courses in maintaining vegetation cover and creating habitat connectivity. To do this we employed (1) land use classification with post-classification change detection, and (2) Morphological Spatial Pattern Analysis (MSPA). Over 17,000 ha of vegetation were cleared and the area of vegetation contributing to biodiversity connectivity was reduced significantly over the three decades. The spatial patterns of vegetation loss and gain were different in each of the three decades (1988-2018) reflecting the implementation of urban planning. Furthermore, MSPA analysis showed that the reduction in vegetation cover led to habitat fragmentation with a significant decrease in the core and bridge classes and an increase in isolated patches in the urban landscape. Golf courses played a useful role in maintaining vegetation cover and contributing to connectivity in a regional biodiversity hotspot. Our findings suggest that for future urban expansion, urban planning needs to more carefully consider the impacts of deforestation on connectivity in the landscape. Moreover, there is a need to take into consideration opportunities for off-reserve conservation in smaller habitat fragments such as in golf courses in sustainable urban management.

Off- vs. On-Pump Coronary Artery Bypass Grafting Long-Term Survival is Driven by Incompleteness of Revascularisation.

BACKGROUND: Off-pump coronary artery bypass grafting (CABG) negates the requirement for extracorporeal circulation used with the traditional on-pump approach. However, off-pump CABG is technically more challenging and may theoretically lead to less complete revascularisation. Recent data suggests a prognostic benefit for traditional on-pump CABG, but the mechanism for this remains unclear. We hypothesised that the inferior outcomes with off-pump CABG could be driven by the need for repeat revascularisation, with this benefit only becoming clear at long-term follow-up. We therefore evaluated short, medium and long-term outcomes of patients undergoing revascularisation with on vs. off-pump CABG. METHODS: Electronic databases were searched to identify suitable randomised controlled trials enrolling ≥100 patients in each arm. Clinical outcomes were extracted at 30-days, 12-months or >4years. The primary outcome was long-term all-cause death, while secondary outcomes included 30-day, 12-month and >4-year cardiac death, stroke, myocardial infarction or revascularisation. RESULTS: Thirteen (13) studies comprising 13,234 patients were included. Off-pump CABG was associated with an increased risk of all-cause death (Odds Ratio [OR] 1.18, 95% confidence interval [CI] 1.02-1.32, p=0.01) and repeat bypass surgery (OR 2.57, 95%CI 1.23-5.39, p=0.01) at long-term follow-up. A significant, increased requirement for revascularisation in off-pump was seen at 12-month follow-up (OR 1.59, 95%CI 1.09-2.33, p=0.02). No differences were noted between groups at 30-days, 12-months and >4years for myocardial infarction or stroke. CONCLUSIONS: Off-pump CABG is associated with significantly higher rates of all-cause mortality rate at long-term follow-up. These outcomes demonstrate a temporal relationship that may be driven by a greater requirement for repeat revascularisation at 1- and 5-year follow-up. STUDY REGISTRATION: CRD42018102019 (PROSPERO).

Adult and Paediatric Cardiac Intervention in Timor-Leste: Disease Burden, Demographics and Clinical Outcomes.

BACKGROUND: The East Timor Hearts Fund (ETHF) is a charitable organisation of Australian cardiologists providing outreach screening in Timor-Leste. For patients requiring intervention, ETHF arranges logistics, procedures, and postoperative care. The aim of this project is to evaluate outcomes of patients requiring intervention. METHODS: The ETHF database of all patients was utilised to identify patients with disease warranting surgical or percutaneous intervention. Both patients who underwent intervention and those who did not proceed to intervention were included in this study. Patients who had intervention arranged by other organisations but have then had follow-up with ETHF were also included. Overall demographics and pre and postoperative factors were assessed, with sub-group analysis of adult and paediatric patients to identify any differences in care. RESULTS: Of 221 patients requiring intervention, 101 patients underwent intervention, receiving 22 different operations or procedures. Patients were predominantly young (median age 17.5 years) and female (64.7%), with rheumatic heart disease (63.8%). Twenty-four (24) (33.3%) women aged 15-45 years old with cardiac disease warranting intervention were documented as pregnant or breastfeeding at time of clinic assessment. Of patients who did not proceed to intervention, adults were more likely to be lost to follow-up (42.4% vs 18.5%) while paediatric patients were more likely to experience progression of disease (18.5% vs 7.5%, p=0.005). Median waitlist time was 5 months, with no significant difference between adults and children, correlating with a preoperative mortality rate of 5.4%. For patients who underwent intervention, post-procedure mortality was extremely low (0.9%) and attendance of at least one post-procedure review was excellent (99.0%). Eleven (11) (10.9%) patients have required repeat intervention, with no difference in rates between adult and paediatric patients. Length of follow-up extends up to 20 years for some patients. CONCLUSION: The Timor-Leste interventional cohort was predominantly a young female population with rheumatic and congenital cardiac disease. There were also high rates of pregnancy amongst female patients with severe cardiac disease. Delayed access to intervention may result in preoperative adverse events and mortality, and is a key target for improvement. Patients who undergo intervention have very low post-procedural mortality, good adherence to early medical follow-up and good long-term outcomes.

Contribution of Binary Organic Layers to Soil Water Repellency: A Molecular Level Perspective.

Soil water repellency (SWR) is an extensively occurring phenomenon on natural and agricultural soils with a severe impact on soil water relations and thus crop yields and ecosystem productivity. It is caused by long chain amphiphilic compounds that originate from plant cuticular waxes. However, the severity of SWR varies with soil physical properties and the concentration of the compounds closely associated with producing hydrophobic coatings on soil surfaces. The induction of SWR by hexadecane, isopropyl tetradecanoate, and palmitic acid (PA), as pure (individual) coatings and as coatings composed of binary mixtures, was investigated by applying a range of loadings on acid-washed sand (AWS) (300-500 µm diameter) and AWS with 5% kaolinite. Molarity of ethanol droplet (MED) tests were conducted to assess the severity of SWR. Palmitic acid was very effective at inducing SWR at loadings of >0.5 × 10-6 mol g-1. Hexadecane and isopropyl tetradecanoate had no effect on SWR when applied as single component coatings. However, when hexadecane was combined with palmitic acid, it enhanced the SWR effect of palmitic acid. In comparison, isopropyl tetradecanoate was found to partially mitigate the SWR caused by palmitic acid. The experimental measurements of SWR were complemented by fully atomistic molecular dynamics simulations that suggested variations of SWR could be explained through molecular level interactions, packing on different soil mineral surfaces and the surface characteristics of the mineral surfaces. In addition, H-donor interactions of PA were found to be instrumental in intermolecular and surface interactions. Furthermore, cohesion and packing of hydrocarbon chains were found to be important parameters favoring surface adhesion, which in turn led to the formation of hydrophobic molecular coatings. The finding that ester derivatives of long chain fatty acids do not induce water repellency suggests that the introduction of chemical or biological processes that promote esterification of fatty acids could be a mechanism for reducing soil water repellency in agricultural soils.

"Liver or Let Die": Percutaneous PFO Closure Through Hepatic Vein Access.

A 73-year-old farmer presented with platypnoea-orthodeoxia syndrome (POS). A transoesophageal echocardiogram (TOE) disclosed a patent foramen ovale (PFO) with significant right-to-left shunt on assuming upright posture. An initial attempt at PFO closure through the femoral vein was abandoned due to a completely occluded inferior vena cava. A second attempt through the internal jugular vein was also unsuccessful due to the steep angulation between superior vena cava and septum primum flap. Because of disabling symptoms, an attempt through a hepatic vein (HV) was scheduled and performed under general anaesthesia with TOE guidance. Ultrasound-guided access through an intercostal window to a peripheral HV was performed and the position confirmed with contrast injections. The PFO was easily crossed with a glide wire which was exchanged to a stiffer guide wire. A 25mm closure device was successfully deployed across the PFO. After retrieval of the delivery system, haemostasis of the HV was attained with a contrast-guided Gelfoam (Pfizer, New York, NY, USA) injection. Unfortunately, the patient had to undergo subsequent emergency coiling to an iatrogenically injured hepatic artery branch leading to full recovery and significant clinical improvement. Subsequent echocardiography demonstrated a well-positioned device with no residual shunt. This case illustrates that percutaneous PFO closure through a HV is a feasible procedure and should be considered in anatomy that is otherwise prohibitive for conventional approach. Extra care should be taken with initial vascular access into the HV and final haemostasis of the access site.

Carbon consequences of drought differ in forests that resprout.

Prolonged drought and intense heat-related events trigger sudden forest die-off events and have now been reported from all forested continents. Such die-offs are concerning given that drought and heatwave events are forecast to increase in severity and duration as climate change progresses. Quantifying consequences to carbon dynamics and storage from die-off events are critical for determining the current and future mitigation potential of forests. We took stand measurements five times over 2+ years from affected and unaffected plots across the Northern Jarrah Forest, southwestern Australia, following an acute drought/heatwave in 2011. We found a significant loss of live standing carbon (49.3 t ha-1 ), and subsequently a significant increase in the dead standing carbon pool by 6 months post-die-off. Of the persisting live trees, 38% experienced partial mortality contributing to the rapid regrowth and replenishment (82%-88%) of labile carbon pools (foliage, twigs, and branches) within 26 months. Such regrowth was not substantial in terms of net carbon changes within the timeframe of the study but does reflect the resprouting resilience of this forest type. Dead carbon generated by the die-off may persist for centuries given low fragmentation and decay rates resulting in low biogenic emission rates relative to other forest types. However, future fire may threaten persistence of both dead and live pools via combustion and mortality of live tissue and impaired regrowth capacity. Resprouting forests are commonly regarded as resilient systems, however, a changing climate could see vulnerable portions of forests become carbon sources rather than carbon sinks.

Natural forests exhibit higher carbon sequestration and lower water consumption than planted forests in China.

Large-scale planted forests (PF) have been given a higher priority in China for improving the environment and mitigating climate change relative to natural forests (NF). However, the ecological consequences of these PF on water resource security have been less considered in the national scale. Moreover, a critically needed comparison on key ecological effects between PF and NF under climate change has rarely been conducted. Here, we compare carbon sequestration and water consumption in PF and NF across China using combination of remote sensing and field inventory. We found that, on average, NF consumed 6.8% (37.5 mm per growing season) less water but sequestered 1.1% (12.5 g C m-2  growing season-1 ) more carbon than PF in the period of 2000-2012. While there was no significant difference in water consumption (p = 0.6) between PF and NF in energy-limited areas (dryness index [DI] < 1), water consumption was significantly (p < 0.001) higher in PF than that in NF in water-limited regions (DI > 1). Moreover, a distinct and larger shift of water yield was identified in PF than in NF from the 1980s to the 2000s, indicating that PF were more sensitive to climate change, leading to a higher water consumption when compared with NF. Our results suggest NF should be properly valued in terms of maximizing the benefits of carbon sequestration and water yield. Future forest plantation projects should be planned with caution, particularly in water-limited regions where they might have less positive effect on carbon sequestration but lead to significant water yield reduction.

The Establishment of the Victorian Cardiac Outcomes Registry (VCOR): Monitoring and Optimising Outcomes for Cardiac Patients in Victoria.

BACKGROUND: The Victorian Cardiac Outcomes Registry (VCOR) was established in 2012 to ensure the safety and quality of cardiac based therapies across Victoria. As a clinical quality registry, VCOR monitors the performance of health services in both the public and private sectors, by measuring and reporting on trends in the quality of patient care over time, within individual hospitals, comparatively with other hospitals, and aggregated at the state level. The current paper describes the VCOR registry aims, methods, governance structure and progress to date. METHODS: Primary management of the registry is undertaken at Monash University in association with the Victorian Cardiac Clinical Network, Department of Health and Human Services Victoria. RESULTS: The Victorian Cardiac Outcomes Registry has currently collected data on more than 33,000 cardiac patients across three separate areas of interest in 35 hospitals. These include percutaneous coronary intervention (PCI), the early treatment of acute myocardial infarction in rural and regional settings, and data relating to in-hospital management of heart failure. CONCLUSIONS: The Victorian Cardiac Outcomes Registry is a clinical cardiac registry that commenced data collection in 2013, providing a detailed description of selected aspects of contemporary cardiology clinical practice in a majority of Victorian hospitals. This information enables hospitals and cardiac units to benchmark their practice, clinical outcomes and quality of care to other similar units and hospitals across the state. If replicated by other states in Australia, there will be the potential for important national comparisons, with the goal to foster continuous improvement in patient care and outcomes across the entire Australian health system.

A Practical Guide for Fractional Flow Reserve Guided Revascularisation.

The presence and extent of myocardial ischaemia is a major determinant of prognosis and benefit from revascularisation in patients with stable coronary artery disease. Fractional Flow Reserve (FFR) is accepted as the reference standard for invasive assessment of ischaemia. Its ability to detect lesion specific ischaemia makes it a useful test in a wide range of patient and lesion subsets, with FFR guided intervention improving clinical outcomes and reducing health care costs compared to assessment with coronary angiography alone. This article will review the basic principles in FFR, practical tips in FFR guided revascularisation and the role of emerging non-hyperaemic indices of ischaemia.

Successful percutaneous closure of an extremely large secundum atrial septal defect during pregnancy.

Atrial septal defects (ASDs) are one of the most of the most common acyanotic congenital heart lesions. Awareness of potential clinical presentations and complications during pregnancy is essential for those managing these patients. We report successful percutaneous closure of an extremely large secundum ASD, using the largest available percutaneous ASD closure device in a 27-year-old pregnant female. Large ASDs may have their initial clinical presentation and diagnosis during pregnancy. If indicated, percutaneous closure can be performed safely. Only a very small number of cases have previously reported this being performed safely during pregnancy.

Superior Petrosal Vein Sacrifice During Microvascular Decompression: Perioperative Complication Rates and Comparison with Venous Preservation.

OBJECTIVE: To investigate potential effect of sacrifice of the superior petrosal vein (SPV) on postoperative complications after microvascular decompression (MVD). METHODS: Retrospective review of 98 consecutive patients undergoing MVD of cranial nerve V was performed. Frequency of division of the SPV during surgery was recorded, and postoperative complications and imaging were recorded and analyzed. In patients with complications, the specific anatomic variation of the superior petrosal venous complex was noted. RESULTS: Of 98 patients undergoing MVD, 83 (84.7%) had sacrifice of the SPV at the time of surgery, 12 (12.2%) had the SPV preserved, and 3 (3.1%) were revision operations. Four patients (4.8%) had complications deemed to be attributable to venous insufficiency or congestion. These included sigmoid sinus thrombosis with coincident cerebellar hemorrhage, midbrain and pontine infarction, hemiparesis with midbrain and pontine edema, and facial paresis with ischemia in the middle cerebellar peduncle. None of the patients with preserved SPV were symptomatic or had imaging changes consistent with venous congestion. CONCLUSIONS: Sacrifice of the SPV is often performed during MVD. This is associated with a complication rate that is significant in frequency and severity compared with preserving the vein. SPV sacrifice should be limited to cases where it is deemed absolutely necessary for successful cranial nerve decompression.

Comparative Effectiveness of Routine Invasive Coronary Angiography for Managing Unstable Angina.

BACKGROUND: Non-ST-segment elevation acute coronary syndromes include unstable angina and non-ST-segment elevation myocardial infarction. Most randomized controlled trials of routine versus selective invasive coronary angiography have high rates of crossover from control to intervention groups and do not include subgroup analysis for unstable angina. Consequently, no clear, specific recommendations exist regarding the use of angiography in unstable angina. OBJECTIVE: To assess the effect of angiography on mortality in unstable angina, incorporating the results of additional cardiac procedures and events. DESIGN: Longitudinal study using hospital discharge data, discrete-time survival analysis with propensity score adjustment, and sensitivity analysis. SETTING: Victoria, Australia, 2001 to 2011. PARTICIPANTS: All residents, all ages. INTERVENTION: Routine invasive coronary angiography. MEASUREMENTS: 12-month all-cause mortality. RESULTS: Emergently admitted patients with unstable angina (n = 33 901) who did or did not receive angiography during their first hospitalization were balanced on 44 covariates of propensity score. Routine angiography was associated with a 52% decrease in 12-month mortality (hazard ratio, 0.48 [95% CI, 0.38 to 0.61]); revascularization offered no additional statistical mortality benefit compared with diagnostic angiography alone. The predicted cumulative probability of death at 12 months was 0.024 (CI, 0.021 to 0.027) for patients receiving angiography within 2 months of their index unstable angina versus 0.097 (CI, 0.090 to 0.105) for those not receiving it. Sensitivity analysis demonstrated that to negate the observed effect size, an unmeasured confounder must independently decrease mortality by 90% and have a prevalence gap of 15% or greater between the angiographic groups. LIMITATION: Nonrandom allocation of angiography. CONCLUSION: Patients with unstable angina benefit from an invasive management pathway initiated by invasive coronary angiography during their hospitalization and up to 2 months after discharge. PRIMARY FUNDING SOURCES: National Health and Medical Research Council, Australia and BUPA Health Foundation.

Documenting and harnessing the biological potential of molecules in Distributed Drug Discovery (D3) virtual catalogs.

Virtual molecular catalogs have limited utility if member compounds are (i) difficult to synthesize or (ii) unlikely to have biological activity. The Distributed Drug Discovery (D3) program addresses the synthesis challenge by providing scientists with a free virtual D3 catalog of 73,024 easy-to-synthesize N-acyl unnatural α-amino acids, their methyl esters, and primary amides. The remaining challenge is to document and exploit the bioactivity potential of these compounds. In the current work, a search process is described that retrospectively identifies all virtual D3 compounds classified as bioactive hits in PubChem-cataloged experimental assays. The results provide insight into the broad range of drug-target classes amenable to inhibition and/or agonism by D3-accessible molecules. To encourage computer-aided drug discovery centered on these compounds, a publicly available virtual database of D3 molecules prepared for use with popular computer docking programs is also presented.