Distribution of arboreal nocturnal mammals in northern Borneo

This study aimed to determine the distribution of arboreal nocturnal mammals in northern Borneo, in particular the Bornean Striped Palm Civet Arctogalidia stigmatica, Philippine Slow Loris Nycticebus menagensis, Western Tarsier Cephalophacus bancanus, Bornean Colugo Galeopterus borneanus and Island Palm Civet Paradoxurus philippinensis. Nocturnal mammals were surveyed at six sites in northern Borneo of varying habitat types and patterns of disturbance. Standardised point and line transects following predetermined paths were used and mammals searched for with the aid of a thermal imaging camera, a red-filtered head lamp and alternatively, a white light head lamp. With 49% of the observations, A. stigmatica (36 individuals/6 sites) was the most common species across the study sites, followed in abundance by N. menagensis (16/5), C. bancanus (14/3), G. borneanus (11/3) and P. philippinensis (2/2). The highest arboreal mammal density of 4.4 individuals/km was found at our Kiudang study site in Tutong District. In addition to the five focal arboreal mammals, 20 additional species were observed throughout the study. This study reveals variation in arboreal nocturnal mammal presence with habitat type that is likely influenced by diet preferences, habitat fragmentation, and the level of hunting pressure. Further surveys combined with arboreal camera trapping will be necessary to study the secretive and easily disturbed arboreal nocturnal mammals of Borneo.

Source and Reservoir Characteristics of the Eocene Mangahewa Formation in Taranaki Basin, New Zealand: Their implications on petroleum system

The Middle to Late Eocene Mangahewa Formation in the Taranaki Basin has been evaluated for its petroleum system (source potential and reservoir qualities). The Mangahewa Formation is generally interpreted as an alternating marginal to shallow marine environment, with lithologies consisting of sandstone, siltstone, mudstone and bitumonius coal. The pyrolysis results show very good source rock generative potential with total organic carbon content of 0.8-90.02 wt. % and hydrogen index values in the range of 54- 491 mg HC/g TOC, with a predominance of oil- and/or gas-prone, mixed Type II-III kerogen. Organic petrographical data reveal that the humic nature of coals being rich in perhydrous vitrinite whereas shales are rich in alginite and bituminite desplaying frequent of migrabitumens. Biomarker analysis suggests predominantly terrigenous origin, whereas pyrolysis Tmax data (414–447°C) and other maturity indicators such as biomarkers and vitrinite reflectance indicates immature and mature samples. Petrographic analyses show that the occurrence of compaction and cementation is succeeded by leaching of feldspars and dissolution of calcite cement. The reservoir samples exhibit largely good reservoir quality with porosity being the dominant feature. The average porosity value is 15.7%, with 21.4% average water saturation. The source and reservoir units are part of a complete petroleum system of the Mangahewa Formation, with the overlying Turi Formation seal rock. The petroleum processes of maturation, generation, and migration which started since Lower Miocene (18.8 Ma) have been recorded in many stratigraphic traps within the Mangahewa Formation or other faulted structural traps due to migration. The generation process is expected to continue to the present day as the source continues to attain maturity while it does not yet reach the peak generation.

Post-fire impacts on tree diversity in coastal heath forests of Brunei Darussalam

The adverse impacts of fires on the diversity of native plants in forest ecosystems are well documented. Tree diversity was studied in coastal heath (Kerangas) forests of Brunei Darussalam, Northwest Borneo after fire events. Eight 20 x 20 m plots were set up in once-burnt (3 plots), twice-burnt (3 plots) and unburnt heath forests (2 plots). All trees (live and dead) with stem diameters of 1 cm and above were censused, and measures of percentage canopy openness and soil variables (pH, gravimetric water and organic matter content, and concentrations of total nitrogen and phosphorus) were determined. Soil pH, gravimetric water content and total nitrogen and phosphorus concentrations, and canopy openness were significantly higher in the burnt plots. Stem diameters were significantly higher in the unburnt heath forests, with mostly Acacia species recording smaller stem sizes (<10 cm dbh). Tree species richness and diversity were significantly lower in the once-burnt plots than in unburnt, intact heath forest plots indicating substantial loss of native tree diversity in fire-affected habitats. Tree community compositions of the once-burnt plots were dominated by invasive Acacia mangium. This study highlights the negative impact of fire on native tree diversity, soil properties and canopy openness of these coastal Kerangas forests, and further provides preliminary evidence that fire events have facilitated the successful establishment of invasive Acacia species.

Fern diversity and distribution in the UBD campus

Green areas and parks are important for maintaining local biodiversity in urbanised habitats. Recent studies have demonstrated that the biodiversity retained in these areas is also important for engaging citizen scientists in conservation projects. Most of the documentation on biodiversity is from temperate regions, whereas in the tropics this field is still in its infancy. This study documented the fern and fern allies richness and abundance within the Universiti Brunei Darussalam (UBD) campus, Brunei Darussalam. We found 39 species in total, belonging to 20 families and 28 genera. Although the total richness did not differ between forest and open plots, ordination showed that forested areas retained a different species composition. Although none of the identified species were IUCN listed, nearly half of the species were recorded once or twice, indicating small population sizes and the biological value of small forest fragments. Our study contributes to understanding the flora diversity of the UBD campus. These results can be used to minimise environmental degradation during infrastructure development on the UBD campus.

Different synthetic approaches, design and applications of metal–organic frameworks with selected organic ligands

Metal-organic frameworks (MOFs) bearing a number of organic ligands of various functional groups and substituents give rise to MOFs of unique crystal structures and topologies. A number of potential applications have been considered for these materials in a wide array of scientific fields, such as in the adsorption of industrially-relevant gases, as heterogeneous catalysts for various organic reactions, as photoluminescent materials, and as antibacterial agents. This review highlights the utility of select groups of organic ligands in the assembly of main group metals, transition metals, as well as lanthanides and actinides, to generate MOFs of diverse structures in the solid state, with special attention paid on ligands bearing the carboxylate-, pyridyl-, ether-, imine (Schiff base) moieties, as well as mechanically interlocked molecules (MIMs).

Reconnaissance geochemical and geophysical exploration for gold at Iri gold field, north central Nigeria

Reconnaissance geochemical and geophysical exploration for gold was carried out at IRI Gold field. Geological mapping was conducted and rocks, soils and sediments samples were collected. The outcome revealed rocks of the basement complex of Nigeria made up of mainly, Migmatite Gneiss, Older Granite and the Schist. The major lithology in the area is silicified sheared rocks and large quartz vein. Isolated occurrence of undifferentiated schist was found as parent material on which quartzite intruded possibly during a major geological activity. Shattering of the rocks left boulders and rubbles of quartzite all around two major ridges within the study area. The rocks have shown weak geochemical anomaly except in two locations were positive anomalies were observed and identified as target for further exploration. Gold veins are prominent in the area suggesting potential gold mineralization. Interpretation of the aeromagnetic data give the orientations of the structural features, the major structural trend in the area is NE-SW. The lineaments extracted from the magnetic data range in length from 46.43m to about 1251.66m. Most of the lineaments extracted from the area are subsurface within the quartz-mica and migmatites while some of them have surface expressions even though not clearly defined. These magnetic lineaments could be the contacts between two rock types of contrasting magnetic susceptibility or edges of structures that could be faults or intrusive bodies. Interpreted satellite data show several subsurface structures which could be hosts to gold mineralization in the area. Results of the geochemical analysis of rocks, soils and sediments were super imposed on the interpreted aeromagnetic data and similar geochemical and geophysical signatures were established. Index Terms: Gold mineralization, aeromagnetic data, geochemical data, schist belt, Nigeria

Petrography of aggregates in Luzon, Philippines: Identification of components and deleterious materials

Petrography is one of a series of standard tests used to assess an aggregate’s components, mechanical qualities, durability, chemical stability, and alkali reactivity. In this study, aggregate materials were collected from rock exposures and/or alluvial deposits from four areas near Metro Manila, Philippines: Bulacan, Rizal, Pampanga, and Zambales. Transmitted light microscopy was conducted to identify rock types and characterise physical and chemical properties that may present potential problems when used as aggregate materials. The results show that the aggregates vary in terms of rock types and alteration type. Samples from Bulacan are mostly porphyritic basalt and fine to coarse-grained sandstone with veinlets of silica and carbonate. The presence of cavities and microfractures caused mainly by vesicles from the volcanic rocks was also observed. Rizal aggregates are composed predominantly of chloritized basalts and andesites with minor clastic rocks and tuffs. The aggregates from Zambales are products of erosion of the Zambales Ophiolite, mixed with the lahar deposits from the Pinatubo eruption. On the other hand, Pampanga aggregates are mostly lahar deposits, containing pumice, a poor choice for aggregate composition due to its low hardness, brittleness and vesiculated texture. Aside from the lithological classification, potentially alkali-reactive constituents were also observed in selected samples from the four sampling areas.

Partition behaviour of iron and zinc in the catchment alluvial sediments of River Gbako flood plains around Baddegi, central Bida basin, Nigeria

Partition behaviors of iron (Fe) and zinc (Zn) were studied in the alluvial sediments of River Gbako floodplains around Baddegi using empirical formulas. The samples were cored from three pits locations (TR-1, TR-2, and TR-3). Particle size distribution and geochemical analysis were performed. Particle size distribution results indicated that the sediments are sand dominated. They have more than 50% sand with smaller percentages of clay and silt. Average partition coefficient values of Fe in the sediments are 1.02, 0.83, and 0.88 for TR-1, TR-2, and TR-3, respectively, and for Zn are 1.02, 0.95, and 0.83, for TR-1, TR-2 and TR-3, respectively. The average velocities of Fe mobilization in the sediments are 0.08 m/day, 0.07 m/day and 0.09 m/day for TR-1, TR-2 and TR-3, respectively, and for Zn mobilization are 0.07 m/day, 0.07 m/day and 0.09 m/day, for TR-1, TR-2, and TR-3, respectively. The metals were preferentially partitioned in the sediments than the water percolating through them, with average hydraulic conductivity (K) of 4.2 m/day. The partition behavior of the metals is used to explain contaminant transportation in the alluvial sediments of the River Gbako floodplains around Baddegi and the principle behind groundwater purification in the shallow alluvial aquifers of these floodplains. Index Terms: Partition coefficient, hydraulic conductivity, alluvial sediments, floodplain, Nigeria

Oleanane- and ursane- type triterpenoids from Eugenia grandis

Arjunolic acid (an oleanane-type triterpenoid) and asiatic acid (an ursane-type triterpenoid) were obtained as an inseparable mixture from a chloroform extract of stem-bark of Eugenia grandis (Myrtaceae). They were characterised mainly by analysis of their spectral data. Arjunolic acid and asiatic acid are reported to have a variety of biological and pharmacological activities, which include antibacterial, anti-inflammatory, antioxidant, antidiabetic, antihyperlipidemic, cardiacprotective, antitumor, anticancer and hepatoprotective activities. Arjunolic acid has been used as a cardio-protective phytotonic in traditional Ayurvedic medicine for centuries.

215 new seed plant species recorded for Brunei Darussalam

We provide a checklist of new seed plant species (Angiosperms and Gymnosperms) in Brunei Darussalam with detailed information. The plant database for Brunei, extracted from the Global Biodiversity Information Facility (GBIF) was compared with the existing plant checklist for Brunei and plant holdings of the UBD herbarium (UBDH). 215 species of seed plants, belonging to 59 families, were found in the GBIF list that were absent in both the Brunei checklist and UBDH collections. The plant family that recorded the highest number of new plant species was Orchidaceae, but overall, tree species dominate the list. Only 8% of the new species were IUCN Red-List evaluated. Most new species collections came from Tutong district, but the highest number of new species was from Temburong district. Almost all new species collections came from areas with easy access such as near roads and around the Kuala Belalong Field Study Centre. As much of the Brunei rainforest remains unexplored, new discoveries are likely to occur.