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Minimizing the cost function that corresponds to propositional logic is vital to ensure the learning phase of HNN can occur optimally. In that regard, optimal and non-biased algorithm is required to ensure HNN will always converge to global solution. Ant Colony Optimization (ACO) is a population-based and nature-inspired algorithm to solve various combinatorial optimization problems. ACO simulates the behaviour of the real ants that forage for food and communication of ants through pheromone density. In this work, ACO will be used to minimize the cost function that corresponds to the logical rule in Hopfield Neural Network. ACO will utilize pheromone density to find the optimal path that leads to zero cost function without consuming more learning iteration. Performance for all learning models will be evaluated based on various performance metrics. Results collected from computer simulation implies that ACO outperformed conventional learning model in minimizing the logical cost function.

Water table conditions in drained peatlands affect peat decomposition, fluvial carbon and greenhouse gas emissions, and plant growth in oil palm plantations. This study illustrates the spatial heterogeneity of soil moisture profiles in cultivated tropical peat under oil palm plantation and uncultivated secondary forest, using maps. At a study plot under each land use the geographical coordinates of sampling points, tree locations and other features were recorded. Peat soil samples were taken at depths of 0–50 cm, 50–100 cm, 100–150 cm and 150–200 cm, and their moisture contents were determined. Overall, soil moisture content was higher in secondary forest than in oil palm plantation due to land management activities such as drainage and peat compaction in the latter. Significant differences were observed between the topsoil (0–50 cm) and deeper soil layers under both land uses. Soil moisture maps of the study plots interpolated using geographical information system (GIS) software were used to visualise the spatial distributions of moisture content in soil layers at different depths (0–50 cm, 50–100 cm, 100–150 cm, 150–200 cm). Moisture content in the 0–50 cm soil layer appeared to be inversely related to elevation, but the correlation was not statistically significant. On the other hand, there was a significant positive correlation between soil moisture content and the diameters of oil palm trunks. Palm trees with negative growth of trunk diameter were mostly located in subplots which were relatively dry and/or located near drains. The results of this study indicate that soil moisture mapping using GIS could be a useful tool in improving the management of peatland to promote oil palm growth.

Background The number of bariatric procedures is increasing worldwide. No consensus or guidelines about the emergency management of long-term complications following bariatric surgery are currently available. The aim of this study is to investigate by a web survey how an emergency surgeon approaches this unique group of patients in an emergency medical scenario and to report their personal experience. Method An international web survey was sent to 197 emergency surgeons with the aim to collect data about emergency surgeons' experience in the management of patients admitted in the emergency department for acute abdominal pain after bariatric surgery. The survey was conceived as a questionnaire composed by 26 (multiple choice and open) questions and approved by a steering committee. Results One hundred seventeen international emergency surgeons decided to join the project and answered to the web survey with a response rate of 59.39%. Conclusions The aim of this WSES web survey was to highlight the current management of patients previously submitted to bariatric surgical procedures by ES. Emergency surgeons must be mindful of postoperative bariatric surgery complications. CT scan with oral intestinal opacification may be useful in making a diagnosis if carefully interpreted by the radiologist and the surgeon. In case of inconclusive clinical and radiological findings, when symptoms fail to improve, surgical exploration for bariatric patients presenting acute abdominal pain, by laparoscopy if expertise is available, is mandatory in the first 12-24 h, to have good outcomes and decrease morbidity rate.

The tropical forests on the island of Borneo are among of the richest in the world in terms of tree diversity, and their capacity to store a large reservoir of carbon. The Southeast Asian forests are fundamentally different from Neotropical and African forests, with their single-family dominance by dipterocarp trees, and with inherently greater stature and biomass. The carbon productivity and allocation in Asian tropical forests is still poorly quantified, and their responses to environmental drivers are still poorly understood. Almost all recent advances in tropical forest carbon cycling research have occurred in the Neotropics, with very few studies in Asia. The principal aim of this thesis is to quantify the carbon budget of a lowland dipterocarp forest in the Lambir Hills National Park, Miri, Sarawak, Malaysian Borneo. I examined and explored the productivity and carbon cycling processes and their responses to environmental factors across two major and contrasting soil types, in particular the clay and sandy loam soils. I recorded and analysed the Net Primary Productivity (NPP) and respiration for the above- and below-ground components, and observed the responses to seasonal variation and environmental drivers. Total soil respiration was relatively high and contributed a great deal to ecosystem respiration. Variation in soil respiration rates appeared closely related to soil moisture content. I found a strong diurnal cycle in soil respiration. On the basis of the first soil carbon dioxide (CO2) efflux partitioning study undertaken in a tropical forest, the diurnal cycle in total soil respiration appeared to be entirely driven by the diurnal cycle in litter respiration, and in turn litter is strongly controlled by moisture. There was little seasonal variation in allocation of net primary productivity (NPP), but there was evidence showing potential inter-annual variability for several components of NPP. Further, the allocation of NPP showed a strong seasonal shift between the forest plots on clay and sandy loam soils. Combining all the data measured and obtained in this D.Phil. thesis, the overall carbon budget assessed in this lowland dipterocarp forest showed a high level of agreement with other studies in Asia using micrometeorological techniques and the situation appears to be comparable to tropical forests in Amazonia. The key difference is that the aboveground NPP is higher and is the largest component contributing to the overall carbon budget, with relatively higher carbon use efficiency (CUE). The lowland dipterocarp forest in Lambir shows higher allocation in the above-ground NPP, and there were also differences in NPP and its allocation between sandy and clay-rich plots.

The seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combination of seasonal pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measurements and 35 litter productivity measurements), their associated canopy photosynthetic capacity (enhanced vegetation index, EVI) and climate, we ask how carbon assimilation and aboveground allocation are related to climate seasonality in tropical forests and how they interact in the seasonal carbon cycle. We found that canopy photosynthetic capacity seasonality responds positively to precipitation when rainfall is