The influenced of PAC, zeolite, and Moringa oleifera as biofouling reducer (BFR) on hybrid membrane bioreactor of palm oil mill effluent (POME)

The main objective of this work was to determine the effectiveness of various biofouling reducers (BFRs) to operational condition in hybrid membrane bioreactor (MBR) of palm oil mill effluent (POME). A series of tests involving three bench scale (100 L) hybrid MBR were operated at sludge retention times (SRTs) of 30 days with biofouling reducer (BFR). Three different biofouling reducers (BFRs) were powdered actived carbon (PAC), zeolite (Ze), and Moringa oleifera (Mo) with doses of 4, 8 and 12 g L⁻¹ respectively were used. Short-term filtration trials and critical flux tests were conducted. Results showed that, all BFRs successfully removed soluble microbial products (SMP), for PAC, Ze, and Mo at 58%, 42%, and 48%, respectively. At their optimum dosages, PAC provided above 70% reductions and 85% in fouling rates during the short-term filtration and critical flux tests.     

Why Don't We Ask? A Complementary Method for Assessing the Status of Great Apes

Species conservation is difficult. Threats to species are typically high and immediate. Effective solutions for counteracting these threats, however, require synthesis of high quality evidence, appropriately targeted activities, typically costly implementation, and rapid re-evaluation and adaptation. Conservation management can be ineffective if there is insufficient understanding of the complex ecological, political, socio-cultural, and economic factors that underlie conservation threats. When information about these factors is incomplete, conservation managers may be unaware of the most urgent threats or unable to envision all consequences of potential management strategies. Conservation research aims to address the gap between what is known and what knowledge is needed for effective conservation. Such research, however, generally addresses a subset of the factors that underlie conservation threats, producing a limited, simplistic, and often biased view of complex, real world situations. A combination of approaches is required to provide the complete picture necessary to engage in effective conservation. Orangutan conservation (Pongo spp.) offers an example: standard conservation assessments employ survey methods that focus on ecological variables, but do not usually address the socio-cultural factors that underlie threats. Here, we evaluate a complementary survey method based on interviews of nearly 7,000 people in 687 villages in Kalimantan, Indonesia. We address areas of potential methodological weakness in such surveys, including sampling and questionnaire design, respondent biases, statistical analyses, and sensitivity of resultant inferences. We show that interview-based surveys can provide cost-effective and statistically robust methods to better understand poorly known populations of species that are relatively easily identified by local people. Such surveys provide reasonably reliable estimates of relative presence and relative encounter rates of such species, as well as quantifying the main factors that threaten them. We recommend more extensive use of carefully designed and implemented interview surveys, in conjunction with more traditional field methods.     

Ultrafast dynamics-driven biomolecular recognition where fast activities dictate slow events

In general, biological macromolecules require significant dynamical freedom to carry out their different functions, including signal transduction, metabolism, catalysis and gene regulation. Effectors (ligands, DNA and external milieu, etc) are considered to function in a purely dynamical manner by selectively stabilizing a specific dynamical state, thereby regulating biological function. In particular, proteins in presence of these effectors can exist in several dynamical states with distinct binding or enzymatic activity. Here, we have reviewed the efficacy of ultrafast fluorescence spectroscopy to monitor the dynamical flexibility of various proteins in presence of different effectors leading to their biological activity. Recent studies demonstrate the potency of a combined approach involving picosecond-resolved Förster resonance energy transfer, polarisation-gated fluorescence and time-dependent stokes shift for the exploration of ultrafast dynamics in biomolecular recognition of various protein molecules. The allosteric protein–protein recognition following differential protein–DNA interaction is shown to be a consequence of some ultrafast segmental motions at the C-terminal of Gal repressor protein dimer with DNA operator sequences O_E and O_I. Differential ultrafast dynamics at the C-terminal of λ-repressor protein with two different operator DNA sequences for the protein–protein interaction with different strengths is also reviewed. We have also systemically briefed the study on the role of ultrafast dynamics of water molecules on the functionality of enzyme proteins α-chymotrypsin and deoxyribonuclease I. The studies on the essential ultrafast dynamics at the active site of the enzyme α-chymotrypsin by using an anthraniloyl fluorescent extrinsic probe covalently attached to the serine-195 residue for the enzymatic activity at homeothermic condition has also been reviewed. Finally, we have highlighted the evidence that a photoinduced dynamical event dictates the molecular recognition of a photochromic ligand, dihydroindolizine with the serine protease α-chymotrypsin and with a liposome (L-α-phosphatidylcholine).     

Separating effects of species identity and species richness on predation,pathogen dissemination and resistance to invasive species in tropical ant communities

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Seasonal patterns of egg parasitism and natural biological control of rice brown planthopper in Indonesia

1 Egg mortality is known to be an important factor in brown planthopper (BPH) (Nilaparvata lugens) population dynamics in tropical Asia, but few quantitative data are available on the role of egg parasitoids. 2 Field studies are reported at two sites in Java, Indonesia, over a period of 4 years in both wet and dry seasons, where no chemical pesticides were used. Rice plants previously infested in the laboratory with BPH eggs were exposed to natural parasitism and predation in experimental fields for periods of 5 days. 3 Egg batches were dissected from both experimental and control plants after field exposure at seven fortnightly intervals through the rice growing season and BPH nymphs and adult parasitoids were allowed to emerge. 4 Parasitism by species of Oligosita (Hymenopera, Trichogrammatidae) and Anagrus (Hym., Mymaridae) varied between 18% and 61% in dry, and from 1% to 65% in wet, seasons. There was generally a trend from low to higher rates through wet seasons, contrasting with more uniform higher levels through dry seasons. 5 Reduction in BPH survival as a result of egg parasitism varied between 29% and 91%. Generally parasitism was density independent. 6 It is suggested that lower initial levels of parasitism in dry seasons may be due to the longer fallow period between dry and wet, than between wet and dry, resulting in lower local populations of appropriate natural enemies. 7 Unlike previous studies in Asia, little evidence was found for egg predation as an important mortality factor. 8 The conservation of egg parasitoids should form part of any rice pest management programmes in tropical Asia.     

Local and landscape drivers of arthropod diversity and decomposition processes in oil palm leaf axils

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In vitro propagation and rhizome formation in Curcuma longa Linn

Turmeric (Curcuma longa Linn.) which is cultivated by underground rhizomes is a slow propagating species. Multiplication and callus induction starting from the rhizome buds and shoot tips of C. longa in MS medium was carried out. A combination of naphthalene acetic acid (NAA; 1.0 mg/l) with kinetin (Kn; 1.0 mg/l) or NAA (1.0 mg/l) with 6-benzylaminopurine (BAP; 2.0 mg/l) was optimum for rapid clonal propagation of turmeric. A concentration of 2.5-3.0 mg/l of 2,4-dichlorophenoxy-acetic acid (2,4-D) was found to be optimum for callus induction. Regeneration of plantlets from a callus was successfully conducted in MS medium supplemented with standard growth hormones for multiplication at 25 +/- 2 degrees C under a 16 h photoperiod. These plantlets were successfully transferred to the field. Plantlets (4-month-old) were incubated in a medium containing different concentrations of sucrose supplemented with NAA (0.1 mg/l) and Kn (1.0 mg/l) at 27 +/- 2 degrees C under an 8 h photoperiod for induction of rhizomes. In vitro rhizome formation was observed in media containing 6 and 8% sucrose.     

The Contribution of Tropical Secondary Forest Fragments to the Conservation of Fruit-feeding Butterflies: Effects of Isolation and Age

Concomitant with the rapid loss of tropical mature forests, the relative abundance of secondary forests is increasing steadily and the latter are therefore of growing interest for conservation. We analysed species richness of fruit-feeding nymphalid butterflies in secondary forest fragments of different age and isolation and in mature forest at the eastern margin of the Lore Lindu National Park in Central Sulawesi, Indonesia. From April to August 2001 we collected 2322 individuals of fruit-feeding butterflies, belonging to 33 species. Butterfly species richness increased with succession, but was significantly higher in mature forests than in all types of secondary forest. Isolation of the forest fragments did not have a significant effect on butterfly species richness in the range of distances (up to 1700 m) studied. Rather it appeared to affect only a few species. Species richness of endemic species was higher than of non-endemic species. Although endemic species were most diverse in mature forests, many species captured were restricted to secondary forests. Our results show that mature forest is essential for the conservation of nymphalid butterflies and for the endemic species in this area. However, considering the relatively large number of species found in these rather small habitat islands, secondary forest fragments, especially older successional stages, can be taken into account in conservation efforts and thus contribute to the preservation of tropical biodiversity on a landscape scale.