Connecting international priorities with human wellbeing in low-income regions: lessons from hawksbill turtle conservation in El Salvador

Hawksbill turtles (Eretmochelys imbricata) are highly endangered in the eastern Pacific Ocean, yet their eggs continue to be an important subsistence resource for impoverished coastal residents in El Salvador. In this study, we use naturalistic inquiry to explain the realities experienced by coastal residents who share habitat with hawksbills in El Salvador, and then suggest implications of the disparities between these realities and international priorities for hawksbill conservation and community development in El Salvador and other low-income regions. To provide a context for understanding hawksbill conservation and its implications for similar challenges related to conservation and wellbeing, we first summarise the conservation context, including the emergence of sea turtle conservation in El Salvador. We then describe our naturalistic approach, including the ethnographic methodology for this study. Finally, we detail the analysis of interviews conducted with tortugueros (i.e. local sea turtle egg collectors), to help explain how hawksbills fit into local realities. Our results demonstrate that, from the perspective of tortugueros, (1) the primary importance of hawksbills is the economic value attached to egg sales, but there exists a deeper connection to local culture; (2) egg purchase by hatcheries is a socially just conservation strategy that benefits both hawksbill and human wellbeing; and (3) opportunities for local residents to participate in decision-making regarding sea turtle conservation are limited, and should be increased. We argue that harmonising international conservation priorities with local community development realities is one path towards simultaneously contributing to long-term sea turtle recovery and human wellbeing in low-income regions.     

Studies on nitric oxide (NO) formation by the green alga Scenedesmus obliquus and the diazotrophic cyanobacterium Anabaena doliolum.

This study provides preliminary evidence that NO production could be a general attribute of algae. Anabaena doliolum was found to be a better NO producer than Scenedesmus and Synechoccocus. Experiments conducted with inhibitors of photosynthesis (DCMU), ATP synthesis (DCCD), and the uncoupler (2,4-DNP) and its analog arsenate clearly revealed that inhibition of nitrite assimilation through the blockage of nitrite reductase (NiR) is primarily responsible for NO emission. A linear relationship between nitrite concentration in the culture medium and NO in the exhaust gas supports the view that accumulation of nitrite is responsible for NO formation. A failure of Scenedesmus, grown in the medium substituted with W for Mo, to produce either NO/NO-2 in light or a 'light-off' peak, and a resumption of these activities upon the addition of Mo proved beyond doubt that a functional nitrate reductase (NR) is necessary for the production of nitrite and NO by algae grown on nitrate as the nitrogen source. Moreover, the appearance of a NO peak immediately after nitrite supplementation under dark conditions in W-substituted cultures with or without glucose ruled out an enzymatic role of NR in NO emission.     

Dye reduction-based electron-transfer activity monitoring assay for assessing microbial electron transfer activity of microbial fuel cell inocula

Microbial fuel cells (MFC) utilize microbes as catalysts to convert chemical energy to electricity. Inocula used for MFC operation must therefore contain active microbial population. The dye reduction-based electron-transfer activity monitoring (DREAM) assay was employed to evaluate different inocula used in MFCs for their microbial bioelectrical activity. The assay utilizes the redox property of Methylene Blue to undergo color change from blue to colorless state upon microbial reduction. The extent of Methylene Blue reduction was denoted as the DREAM assay coefficient. DREAM assay was initially performed on a microbial culture along with the growth curve and estimation of colony forming units (CFUs). DREAM coefficient correlated to the CFU/mL obtained over time as growth progressed. The assay was then extended to water samples (domestic sewage, lake and a man-made pond) serving as inocula in MFCs. Domestic wastewater gave the highest DREAM coefficient (0.300 ± 0.05), followed by pond (0.224 ± 0.07) and lake (0.157 ± 0.04) water samples. Power density obtained conformed to the DREAM coefficient values, with the three samples generating power densities of 46.45 ± 5.1, 36.12 ± 3.2 and 25.08 ± 4.3 mW/m² respectively. We have also studied the role of addition of various carbon sources and their concentrations towards improving the sensitivity of the assay. The DREAM assay is a rapid, easy-to-perform and cost-effective method to assess inocula for their suitability as anolytes in terms of electron transfer potential in MFCs.     

Intracellular cyanobiont Richelia intracellularis: ultrastructure and immuno-localisation of phycoerythrin,nitrogenase, Rubisco and glutamine synthetase

In marine tropical or subtropical plankton the filamentous, heterocyst-forming cyanobacterium Richelia intracellularis forms a symbiosis with the diatom Rhizosolenia clevei. An ultrastructural analysis of the apex of Rhizosolenia clevei showed that the cytoplasm in that particular part of the cell was present only where the cyanobiont was located. The cyanobiont was, however, always outside the host cytoplasm. Vegetative cells as well as the heterocysts of the cyanobiont were devoid of gas vesicles and cyanophycin granules, while carboxysomes and large glycogen granules were common. The cyanobacterial cell wall apparently remained intact in both vegetative and heterocyst cells. In green excitation light the heterocysts and vegetative cells emitted a bright yellow fluorescence, indicating that both cell types possessed high concentrations of the pigment phycoerythrin (PE) commonly associated with photosystem (PS) II. The presence of this pigment in both cell types was verified by immunogold localisation. Using the same technique, the nitrogenase (dinitrogenase reductase) enzyme was shown to be exclusively present in the heterocysts, while Rubisco was localised primarily to the carboxy-somes, which were only detected in vegetative cells. Using an antiserum against the ammonia assimilating enzyme glutamine synthetase (GS), we could demonstrate very low levels of this enzyme, indicating repression of GS in the cyanobiont.     

Simultaneous determination of imidacloprid, thiacloprid, and thiamethoxam in soil and water by high-performance liquid chromatography with diode-array detection

A high-performance liquid chromatography method with diode-array detection (HPLC-DAD) is described for the determination of three neonicotinoid insecticides imidacloprid, thiacloprid, and thiamethoxam in soil and water. The soil samples were extracted with acetonitrile, while the water samples were extracted using C18 cartridges. The mean recoveries plus standard deviations for spiked soil samples were 82 +/- 4.2% for thiamethoxam, 99 +/- 4.2% for imidacloprid and 94 +/- 1.4% for thiacloprid. The recoveries for water samples ranged from 87 +/- 3.4% for thiamethoxam to 97 +/- 3.9% for imidacloprid and 97 +/- 2.6% for thiacloprid. The limits of quantitation (LOQ) were 0.1, 0.1, 0.01 mg/kg in soil (5g), and 2, 2, 0.5, micro/L in water (50 mL) for thiamethoxam, imidacloprid, and thiacloprid, respectively.     

Soil microbial population and enzyme activity related to grazing pressure in alpine meadows of Nanda Devi Biosphere Reserve

The present study aims to analyze the interaction of prevailing biotic pressure on soil environment with emphasis on its physicochemical and microbiological characteristics determining soil fertility status and thus supporting plant and animal biodiversity in Nanda Devi Biosphere Reserve (NDBR) which is located in northern part of Uttaranchal hills between 79 degrees 40'E to 80 degrees 05'E longitude and 30 degrees 17'N to 30 degrees 41'E latitude. The experimental results revealed that the physico-chemical characteristics (viz., moisture, pH, EC, C, N, P, K, CEC) of soil were maximum in moderately grazed meadow and minimum in intensively grazed meadow. Soil microbial analysis measured in terms of total viable count (TVC) exhibited grazing sensitivity trend being maximum population of bacteria > fungi > actinomycetes. The soil microbial population was positively correlated with soil respiration, dehydrogenase activity, acid phosphatase and microbial biomass, which exhibited uneven trend with grazing pressure. Soil from moderately grazed meadow showed highest microbial count and enzyme activities, whilst intensively grazed meadow showed lowest microbial count and enzyme activities. This depicts the beneficial role of prescribed grazing up to limited extent in management of soil fertility, which might have supported luxuriant growth of a variety of grasses.     

Performance of seed germination and growth of Vicia faba L. in fly ash amended soil

The performance of Vicia faba L. in soil amended by different concentrations of fly ash has been studied. The parameters considered are seed germination, growth behaviour and nodulation frequency of the plant. Results revealed that while fly-ash amendment to the soil improved the growth performance at initial stages with application of lower concentrations, it was inhibitory at higher exposure concentrations. Although there was no difference in survival rates, but the seedling growth was reduced in comparison to control plants. Fly ash delayed the nodulation as lesser number of nodules was recorded at higher amendments. Results suggested feasibility of growing V. faba in fly ash contaminated area.     

Modeling a wetland system: The case of Keoladeo National Park (KNP), India

A model for the wetland part of KNP is presented and analyzed. Two-dimensional parameter scans suggest that this minimal model possesses dynamical complexities. Per capita availability of water to “bad” biomass (W₁) is one of the most vital parameters. One can ensure good health of the park by restricting the par capita availability of water to low values. Getting the “bad” biomass removed by granting permits to villagers should go hand in hand with water management and conservation activities. The model presented in this paper may be helpful in designing the timing and nature of human interventions in the form of implementation of well worked out policies in future.     

Investigation on Miscibility of Sodium Alginate/Pullulan Blends

Miscibility studies of Sodium alginate (NaAlg)/Pullulan have been carried out in different percentage of blend components. The ultrasonic velocity, viscosity, density and refractive index were measured at 30 and 40 °C. Further the blend films of NaAlg and Pullulan were prepared by solution casting method and characterized by differential scanning calorimetric (DSC), fourier transition infrared spectroscopic (FTIR), and scanning electron microscopic (SEM) methods. Using the viscosity data, interaction parameters were computed to determine the miscibility. The data suggest that the blend is miscible in the entire composition range. The change in temperature had no significant effect on the miscibility of NaAlg/Pullulan blends. The miscibility is confirmed by SEM, DSC, ultrasonic velocity, density, and refractive index methods. The specific interactions of hydrogen bonding type of the blends were investigated by FTIR.     

Impact of rhizobacteria on growth and chromium accumulation in Scirpus lacustris L. grown under chromium supplementation

Four chromate tolerant rhizobacterial strains viz., RZB-01, RZB-02, RZB-03 and RZB-04 were isolated from rhizosphere of Scirpus lacustris collected from Cr-contaminated area. These strains characterized at morphological and biochemical levels. The most efficient chromate tolerant strain RZB-03 was inoculated to fresh plant of S. lacustris and grown in 2 microg ml(-1) and 5 microg ml(-1) of Cr+6 supplemented nutrient solution under controlled laboratory condition. The effects of rhizobacterial inoculation on growth and chromium accumulation in S. lacustris were evaluated. The inoculation of rhizobacteria increased biomass by 59 and 104%, while total chlorophyll content by 1.76 and 15.3% and protein content increased by 23 and 138% under 2 microg ml(-1) and 5 microg ml(-1) concentrations of Cr+6, respectively after 14 d as compared to non-inoculated plant. Similarly, the Cr accumulation also increased by 97 and 75% in shoot and 114 and 68% in root of inoculated plants as compared to non inoculated plants at 2 microg ml(-1) and 5 microg ml(-1) Cr+6 concentrations, respectively after 14 d. The chromate tolerant rhizobacteria which play an important role in chromium uptake and growth promotion in plant may be useful in development of microbes assisted phytoremediation system for decontamination of chromium polluted sites.