Coral reef and associated habitat mapping using ALOS satellite imagery

Coral reefs are rich in biodiversity and ecosystem services. However increase in degradation are still occurring at an alarming rate. In management of this ecosystem, determination of its spatial distribution is of importance. Satellite imageries can be used to map distribution extent using spectral characteristics which is a fundamental parameter in mapping. The aims of this study were to determine the spectral characteristics of corals and associated habitats and to map its spatial distribution using 2009 ALOS advanced visible and near infrared radiometer type 2 (AVNIR-2) satellite imagery. Results indicated that coral and habitats surrounding the area display variation in the spectral characteristics magnitude but displays similar spectral curve. Spectral characteristics from the corals and surrounding habitats were determined by presence of benthic microalgae and calcium carbonate. Maximum likelihood classification on the image produced five main classes. Spatial distribution of coral and associated habitats indicated five main zones which are sandy shore zone, sandy intertidal zone, seagrass zone, coral/submerged sandy zone and rocky zone. Distribution of live corals indicated coverage of 0.54 km2, sea grass (0.94 km2), sandy bottom (1.31 km2) and rocky shores (0.19 km2). The results of this study indicated that ALOS satellite data was able to determine variation in spectral characteristics of coral reefs and other habitats thus is capable of mapping the ecosystems spatial distribution

Interannual variation of chlorophyll-a concentration in the exclusive economic zone waters of Peninsular Malaysia

Chlorophyll-a concentration is one of the major indicators of phytoplankton production in the ocean. Identification of chlorophyll-a distribution and productivity is important to understand physical and biological processes in the ocean. The objectives of this study are to determine the spatial and temporal distribution of chlorophyll-a and to identify influence of sea surface temperature (SST) and current on chlorophyll-a concentration variation in the Exclusive Economic Zone (EEZ) waters of Peninsular Malaysia. Satellite data of chlorophyll-a concentration and SST (2007 to 2014) were derived from MODISAqua and geostrophic current was obtained from NOAA Ocean Watch. Empirical Orthogonal Function (EOF) analysis was used to determine the spatial and temporal variation of chlorophyll-a. Five modes represented the variation of chlorophyll-a. Mode 1 (60.62%) explained seasonal pattern, Mode 2 (27.83%) indicated patterns during the southwest monsoon, Mode 3 (19.96%) highlighted the inter monsoon of northeast to southwest. Mode 4 (19.57%) represented the northeast monsoon and Mode 5 (18.98%) explained inter monsoon of southwest to northeast. Variation of chlorophyll-a concentration was influenced by variability in SST and current during the monsoons. Variability in magnitude and direction of current circulation was observed to affect SST distribution thus influences concentration and distribution of chlorophyll-a

Mitochondrial Localized STAT3 Is Involved in NGF Induced Neurite Outgrowth

Background: Signal transducer and activator of transcription 3 (STAT3) plays critical roles in neural development and is increasingly recognized as a major mediator of injury response in the nervous system. Cytokines and growth factors are known to phosphorylate STAT3 at tyrosine 705 with or without the concomitant phosphorylation at serine 727, resulting in the nuclear localization of STAT3 and subsequent transcriptional activation of genes. Recent evidence suggests that STAT3 may control cell function via alternative mechanisms independent of its transcriptional activity. Currently, the involvement of STAT3 mono-phosphorylated at residue serine 727 (P-Ser-STAT3) in neurite outgrowth and the underlying mechanism is largely unknown. Principal Findings: In this study, we investigated the role of nerve growth factor (NGF) induced P-Ser-STAT3 in mediating neurite outgrowth. NGF induced the phosphorylation of residue serine 727 but not tyrosine 705 of STAT3 in PC12 and primary cortical neuronal cells. In PC12 cells, serine but not tyrosine dominant negative mutant of STAT3 was found to impair NGF induced neurite outgrowth. Unexpectedly, NGF induced P-Ser-STAT3 was localized to the mitochondria but not in the nucleus. Mitochondrial STAT3 was further found to be intimately involved in NGF induced neurite outgrowth and the production of reactive oxygen species (ROS). Conclusion: Taken together, the findings herein demonstrated a hitherto unrecognized novel transcription independen

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Geotechnical characterisation of marine clay as potential liner material

Natural clay is commonly used as a liner material to contain landfill leachate from contaminating the environment. A key characteristic of liner material is its hydraulic conductivity. It is recommended that the hydraulic conductivity of the potential liner material should be of 1×10-9 m/s or less. This paper presents the geotechnical characteristics of marine clay that may be used as landfill liner material. The tests were consistency index, compaction behaviour, compressibility and hydraulic conductivity. The marine clay was dominated by finer fraction of silt and clay (78%-88%) followed by sand (12%-22%). The clay minerals commonly present were montmorillonite, kaolinite and illite as well as quartz as the non-clay mineral. The consistency index for the liquid limit, wL and plastic limit, wP were 56.6%-80.5% and 36%-45%, respectively. The plastic index, Ip of the marine clay samples ranged from 19% to 37%. The permeability test indicated that the hydraulic conductivity of the samples ranged between 1.10 × 10-9 and 2.44 × 10-9 m/s. The very low permeability showed by the marine clay can be related to the presence of high content of finer fraction. Compaction of marine clay samples resulted in maximum dry density, ρdmax that ranged between 1.5 and 1.6 g/cm3 and optimum moisture content, wopt that ranged between 18.2% and 25%. During the consolidation of the marine clay, the hydraulic conductivity decreased within the recommended permeability for landfill liners. This study showed that some geotechnical characteristics of the studied marine clay were in favour of being used as landfill liner material

Effects of surfactant on geotechnical characteristics of silty soil

Surfactants are often used as a cleaning agent for restoration of oil-contaminated soil. However the effect of surfactant on the geotechnical properties of soil is not clearly understood. In this study, the effects of surfactant on silty soil were investigated for consistency index, compaction, permeability and shear strength. Sodium dodecyl sulfate (SDS) was used in this study to prepare the surfactant-treated soil. Our results showed that the soil with added surfactant exhibited a decrease in liquid and plastic limit values. Maximum dry densities increased and optimum moisture contents decreased as contents of added surfactant were increased. The presence of surfactant assists the soil to achieve maximum density at lower water content. The addition of surfactant decreased the permeability of soil from 6.29×10-4 to 1.15×10-4 ms-1. The shear strength of soil with added surfactant was examined using the undrained unconsolidated triaxial tests. The results showed that the undrained shear strength, Cu was significantly affected, decreased from 319 kPa to 50 kPa for soil with 20% of added surfactant. The results of this study showed that the presence of surfactant in soil can modify the mechanical behaviour of the soil

Correcting bias in extreme groups design using a missing data approach

Extreme groups design (EGD) refers to the use of a screening variable to inform further data collection, such that only participants with the lowest and highest scores are recruited in subsequent stages of the study. It is an effective way to improve the power of a study under a limited budget, but produces biased standardized estimates. We demonstrate that the bias in EGD results from its inherent missing at random mechanism, which can be corrected using modern missing data techniques such as full information maximum likelihood. Further, we provide a tutorial on computing correlations in EGD data with FIML using R

Ca2+, NAD(P)H and membrane potential changes in pancreatic beta-cells by methyl succinate: comparison with glucose

The present study was undertaken to determine the main metabolic secretory signals generated by the mitochondrial substrate MeS (methyl succinate) compared with glucose in mouse and rat islets and to understand the differences. Glycolysis and mitochondrial metabolism both have key roles in the stimulation of insulin secretion by glucose. Both fuels elicited comparable oscillatory patterns of Ca2+ and changes in plasma and mitochondrial membrane potential in rat islet cells and clonal pancreatic beta-cells (INS-1). Saturation of the Ca2+ signal occurred between 5 and 6 mM MeS, while secretion reached its maximum at 15 mM, suggesting operation of a K(ATP)-channel-independent pathway. Additional responses to MeS and glucose included elevated NAD(P)H autofluorescence in INS-1 cells and islets and increases in assayed NADH and NADPH and the ATP/ADP ratio. Increased NADPH and ATP/ADP ratios occurred more rapidly with MeS, although similar levels were reached after 5 min of exposure to each fuel, whereas NADH increased more with MeS than with glucose. Reversal of MeS-induced cell depolarization by Methylene Blue completely inhibited MeS-stimulated secretion, whereas basal secretion and KCl-induced changes in these parameters were not affected. MeS had no effect on secretion or signals in the mouse islets, in contrast with glucose, possibly due to a lack of malic enzyme. The data are consistent with the common intermediates being pyruvate, cytosolic NADPH or both, and suggest that cytosolic NADPH production could account for the more rapid onset of MeS-induced secretion compared with glucose stimulatio

Spatial and temporal variability of chlorophyll-<i>a</i> concentration in Makassar Strait using Empirical Orthogonal Function analysis of satellite images

1381-1389Nine years of monthly data of MODIS derived chl-a around Makassar Strait of Indonesia were used to investigate the spatial and temporal variability of chl-a concentration. The variability was further analyzed by empirical orthogonal function (EOF). The first mode (62.08% of variance) showed variability of seasonal pattern. The second mode (5.75% of variance) showed variability during the Northwest monsoon and the Southeast monsoon. Meanwhile, the third mode (2.72% of variance) and the fourth mode (2.25% of variance) showed variability during the Transition monsoon I and II, respectively.The variability of chl-a along the Borneo Island is influenced by river runoff during the Northwest monsoon, while the variability of chl-a along the Sulawesi Island is induced by strong wind and current during the Southeast monsoon