17 research outputs found
Mapped aboveground carbon stocks to advance forest conservation and recovery in Malaysian Borneo
Forest carbon stocks in rapidly developing tropical regions are highly heterogeneous, which challenges efforts to develop spatially-explicit conservation actions. In addition to field-based biodiversity information, mapping of carbon stocks can greatly accelerate the identification, protection and recovery of forests deemed to be of high conservation value (HCV). We combined airborne Light Detection and Ranging (LiDAR) with satellite imaging and other geospatial data to map forest aboveground carbon density at 30m (0.09ha) resolution throughout the Malaysian state of Sabah on the island of Borneo. We used the mapping results to assess how carbon stocks vary spatially based on forest use, deforestation, regrowth, and current forest protections. We found that unlogged, intact forests contain aboveground carbon densities averaging over 200MgChaâ1, with peaks of 500MgChaâ1. Critically, more than 40% of the highest carbon stock forests were discovered outside of areas designated for maximum protection. Previously logged forests have suppressed, but still high, carbon densities of 60â140MgChaâ1. Our mapped distributions of forest carbon stock suggest that the state of Sabah could double its total aboveground carbon storage if previously logged forests are allowed to recover in the future. Our results guide ongoing efforts to identify HCV forests and to determine new areas for forest protection in Borneo
Incorporating connectivity into conservation planning for the optimal representation of multiple species and ecosystem services
Funding was provided by the Rainforest Trust foundation. Support was also provided by the Sabah Forest Department, Forest Research Centre, the South East Asia Rainforest Research Partnership, the U.N. Development Programme, the Universiti Malaysia Sabah (FRGS0414-STWN-1/2015), PACOS Trust, BC Initiative, the Natural Environment Research Council UK (grant NE/R009597/1), and the Universities of Aberdeen, Montana, and York. We are grateful to the numerous researchers that collected the data used in our analyses, as well as the local communities and government staff who manage forested areas across Sabah.Peer reviewedPostprin
Utilising biological geotextiles: Introduction to the BORASSUS project and global perspectives
Field and laboratory studies indicate that utilisation of biological geotextiles constructed from palm-leaves and other selected organic materials are an effective, sustainable and economically viable soil conservation technique. The three-year plus (1 July 2005â28 February 2009) EU-funded BORASSUS Project (contract no. INCO-CT-2005-510745) evaluated the long-term effectiveness of biological geotextiles in controlling soil erosion and assessing their sustainability and economic viability. These studies progressed in ten countries, both in the âindustrial northâ (in Europe) and in the âdeveloping southâ (Africa, South America and South East Asia). The studied countries in the âdeveloping southâ included Brazil, China, The Gambia, South Africa, Thailand and Vietnam. The âindustrial northâ countries included Belgium, Hungary, Lithuania and the UK. The main findings of these studies are summarised in this paper and thematic information is presented in the other four papers in this Special Issue. Biological geotextiles offer potentially novel bioengineering solutions to environmental problems, including technologies for soil conservation, sustainable plant production and use of indigenous plants, improved ecosystem management by decreasing deforestation, improving agroforestry and cost-effective biogeotextile applications in diverse environments. Biogeotextiles may provide socio-economic platforms for sustainable development and the benefits for developing countries may include poverty alleviation, engagement of local people as stakeholders, employment for disadvantaged groups, small and medium enterprise (SME) development, earning hard currency, environmental education and local community involvement in land reclamation and environmental education programmes. These benefits are achieved through: (i) promotion of sustainable and environmentally friendly palm-agriculture to discourage deforestation, promoting both reforestation and agroforestry; (ii) construction of biogeotextiles enabling development of a rural labour-intensive industry, particularly encouraging employment of socially disadvantaged groups and (iii) export of biogeotextiles to industrialised countries could earn hard currency for developing economies, based on the principles of fair trade. Research and development activities of the BORASSUS Project have improved our knowledge on the effect of biogeotextile mats on the micro- and macro-soil environments and at larger scales through controlled laboratory and field experiments in diverse environments
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Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.
Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (nâ=â143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (nâ=â152), or no hydrocortisone (nâ=â108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (nâ=â137), shock-dependent (nâ=â146), and no (nâ=â101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 nonâcritically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (nâ=â257), ARB (nâ=â248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; nâ=â10), or no RAS inhibitor (control; nâ=â264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ supportâfree days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ supportâfree days among critically ill patients was 10 (â1 to 16) in the ACE inhibitor group (nâ=â231), 8 (â1 to 17) in the ARB group (nâ=â217), and 12 (0 to 17) in the control group (nâ=â231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ supportâfree days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
Peaty clay improvement with prefabricated vertical drains
Peaty clay obtained from the Colombo-Katunayake Expressway route was tested in the laboratory for its consolidation characteristics. The main objective was to quantify the improvement in peaty clay by the use of pre-fabricated vertical drains (PVD). Two large-scale model set-ups were erected to monitor the consolidation process of peaty clay, one without the use of PVD, and the other with the PVD installed. Both tests were conducted by depositing remoulded peaty clay in cylindrical barrels, and load was applied by several increments. Settlements and pore-water pressure were monitored over a long period. Axi-symmetric conditions were simulated by these tests. Based on the test results, the performance of PVD in accelerating the consolidation process is quantified. The model test results are back-analysed using the finite difference method, in order to give an indication of an appropriate numerical modeling process which can be used to model other instances of similar process.
In addition, the effect of sample size and the duration of the load increment period on
consolidation in peaty clay is investigated. Tests were carried out in three different sizes of specimen dimensions. Values of c, were calculated by several methods found in the literature, after carrying out tests using different load increment periods. Load increment periods for different sample thicknesses were calculated according to Terzaghi theory, for time simulation tests. The time necessary to obtain a specified degree of consolidation was calculated by an appropriate equation. The values of c, obtained by these methods are of the same order for the time simulation tests. The secondary compression index of the peaty clay is found to be very high.
The improvement of shear strength in peaty clay due to consolidation is also investigated. Shear strength of peaty clay was measured at the end of laboratory tests and the results were compared with the strength of sample taken prior to consolidation. Soil strength after the treatment was evaluated by undrained triaxial tests, vane shear tests and consolidated drained triaxial tests. Soil strength before the treatment was evaluated only by vane shear tests as sample preparation with the soft
soil was not possible. Gain in shear strength in peaty clay due to consolidation is quantified
Ilizarov frame delayed internal fixation of Lisfranc fracture dislocation with severe soft tissue injury: New technique
We describe a new technique of temporary stabilisation of a divergent Lisfranc fracture dislocation of foot with severe crush injury using an Ilizarov frame. A 69-year-old man presented with severe crush injury and complete disruption of the midfoot. Examination revealed full thickness skin necrosis, haemorrhagic blisters and extensive swelling. A staged technique was used with temporary application of an Ilizarov frame followed by delayed limited internal fixation. Excellent result was achieved with restoration of medial arch, complete pain relief and good functional outcome. A staged treatment initially using an Ilizarov frame prior to limited internal fixation allows soft tissue to settle in severe crush injury. Keywords: Lisfranc, Ilizarov frame, Crush injur
Consolidation testing of peaty clay
The first rational theory to explain the settlements occurring in saturated clays was the 1-
D theory of consolidation proposed by Terzaghi (1925). One of the main advantages of the
theoretical modelling of consolidation is that it becomes possible to carryout laboratory
tests on thin samples of clay. a few centimetres thick (with one increment of load normally
maintained for 24 hours). and then from the laboratory results predict the settlements in the
field where the clay layer may be several meters thick and where the settlements may take
place over a long period of time
The contribution of biogeotextiles to sustainable development and soil conservation in European countries: The BORASSUS Project
Field and laboratory experiments has shown that geotextile mats made from palm leaves are an effective, sustainable and economically-viable soil conservation method, with huge global potential. The EU-funded BORASSUS Project (2005-09; Contract Number INCO-CT-2005-510745) is evaluating the long-term effectiveness of biogeotextiles in controlling soil erosion and assessing their sustainability and economic viability. These experiments are in progress in 10 countries, both in the âindustrial northâ (in Europe) and in the âdeveloping southâ (Africa, South America and South-East Asia). This paper discusses the significance of geotextile palm mats in European countries (Belgium, Hungary, Lithuania and the UK). Geotextile mats were effective in reducing splash erosion, runoff and soil erosion on arable sloping land in Shropshire, UK. The use of Borassus-mats on bare soil reduced soil splash height by ~31% and splash erosion by ~42%. The application of Borassus-mats as complete cover on bare soil reduced runoff by ~49% and soil erosion by ~75%. Borassus and Buriti mats as 1 m buffer strips reduced runoff by ~56 and 34%, respectively, and soil erosion by ~83 and 77%, respectively. Results from selected types of vineyards in Hungary suggest that the geotextile mats are effective in reducing soil erosion, particularly erosive rainfall. The geotextiles mats are also helpful in maintaining moisture and temperature conditions in the surface soil at levels particularly conducive to the establishment and growth of young plants. Experiments in Lithuania show that geotextile mats are effective in encouraging the establishment and growth of natural vegetation, thereby reducing erosion on roadside slopes. Simulated experiments in controlled laboratory conditions in Belgium suggest that palm-leaf geotextiles are effective in increasing infiltration rates and reducing interrill runoff and erosion rates on medium (i.e. 15%) and steep (i.e. 45%) slope gradients. The effectiveness of geotextile mats when used as technical materials for the construction industry in ground strengthening was investigated. Generally, the tensile strength of the Buriti mats was approximately twice that of the Borassus mats. The tensile strength of the palm-leaf geotextile mats is influenced by the mat strip formation pattern. Research and development activities of the BORASSUS Project have improved our knowledge on the effect of palm geotextile mats on the micro- and macro- soil environments and at larger scales through controlled laboratory and field experiments in diverse environments