37 research outputs found

    The Identification of Heavy Metal Accumulator Ferns in Abandoned Mines in the Philippines With Applications to Mine Rehabilitation and Metal Recovery

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    This paper focuses on the identification of some plant accumulators of heavy metals that can facilitate mine remediation and rehabilitation in the Philippines and metal recovery or phytomining. Most of these hyperaccumulators are ferns that thrive very well in different terrains and of particular interest are Pityrogramma calomelanos, Pteris vittata, and Pteris melanocaulon that are abundant in abandoned CueAu mining areas. The amounts of Cu and As in the soil and in the aboveground (AG) and belowground (BG) components of the accumulator ferns were determined and the Bioaccumulation Factor (BF) and the Translocation Factor (TF) were derived. Efforts to propagate the accumulator ferns identified from spores were successful, thus providing the opportunity of using them for various experiments on mine rehabilitation and metal recovery. The results of these experiments indicated that these hyperaccumulator ferns have the greatest potential for the remediation of metal contaminated soils, the rehabilitation of abandoned mines, and phytomining

    Phytoremediation of Heavy Metal Contaminated Wastes From Small-Scale Gold Mining Using Pityrogramma calomelanos

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    In this study, viability of employing the waste treatment technique for industrial application was conducted by setting up a phytoremediation protocol for field application where heavy metal (Arsenic and Copper) contaminated adsorbents, i.e. coco peat and nanofiber membrane, used for the treatment of wastewater were also included. An arsenic hyperaccumulator, Pityrogramma calomelanos was used for the treatment of mine wastes-tailings, coco peat and nanofiber membrane. Phytoremediation procedure was established by investigating planting parameters namely ; plot height - (9 cm and 15 cm) and planting distance- (15 cm and 20 cm) for a period of five months. Translocation factor and % uptake of As and Cu by ferns were measured. According to the results, % uptake of As and Cu by P. Calomelanos was 0.16 % and 0.01 % and translocation factor of As and Cu was 6.78 and 0.04, respectively. Plant growth factors (root length, frond height and dry weight) in tailings mixture plant boxes and control soil were also determined. Accordingly, P. calomelanos grew well in tailings mixture without the symptom of phytotoxicity. Therefore, P. calomelanos can be used for the phytoremediation of the said heavy metal contaminated mine wastes. Based on this study, 15 cm plot height and 20 cm plant distance were suitable for field experiment although long term research data is required. The overall protocol for the treatment of mine wastes as field experiment was proposed based on the results

    A review of community-based solar home system projects in the Philippines

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    Solar Home Systems (SHS) are easy to deploy in island and in remote communities where grid connection is costly. However, issues related to maintenance of these systems emerge after they are deployed because of the remoteness and inaccessibility of the communities. This study looked into community-based programs in the Philippines and investigated the following: (1) social preparation, (2) role of the community in the project, and (3) sustainability of the program. In this paper, three communities under two government programs offering SHS are presented. These programs are the Solar Power Technology Support (SPOTS) program of the Department of Agrarian Reform (DAR) and the Household Electrification Program (HEP) of the Department of Energy (DOE). A focused group discussion and key informant interviews were conducted in two communities in Bukidnon province and in a community in Kalinga to obtain information from the project beneficiaries and SHS users on the preparation, implementation and maintenance of the projects. The results revealed that emphasis on the economic value of the technology, proper training of the locals on the technical and management aspects of the project, as well as the establishment of a supply chain for replacement parts are crucial factors for the sustainability of the programs

    Association between convalescent plasma treatment and mortality in COVID-19: a collaborative systematic review and meta-analysis of randomized clinical trials.

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    Funder: laura and john arnold foundationBACKGROUND: Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, https://doi.org/10.17605/OSF.IO/GEHFX ). METHODS: In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung-Knapp-Sidik-Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence. RESULTS: A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis. CONCLUSIONS: Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care

    Biological monitoring in west bay, Laguna Lake: Phytoplankton composition and water pollution

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    Abstract only.Phytoplankton composition and density were studied in three (3) stations in West Bay, Laguna Lake. Blue-green algae and diatoms were the most abundant in terms of cell density. Green algae had the most number of species. Diatoms predominated in the early parts of the year, under intense light conditions. Pulses of green algae were evident toward the end of the year, under high nitrogen concentrations. BIP (Biological Index of Pollution) values were very much affected by seasonal variations in the phytoplankton community

    Response of phytoplankton to temporal changes in nutrients in Taal Lake, Batangas, Philippines

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    It is important to note that different adaptations are successful at different times and in different environments, so that different algal species become dominant at different times and locations. Hence, the species composition of the phytoplankton community is arbitrary, but allows the alert observer to discover the characteristics of the lake or pond investigated, including nutrient status, climate acidity, and the composition of the grazer community. Phytoplankton taxa collected and identified within the sampling regime were subjected to ordination within the set of environmental axes and revealed that indeed, and the vectors in the absorbed data of Ceratium can be assumed largely for NH4-N, and soluble and total P. A positive correlation between Ceratium and NH4 is stronger than that of total P and soluble P. Vectors in the absorbed data for centric diatoms, Selenastrum, Phormidium, Coelastrum, Chroococcus, and Oscillatoria, can be assumed for largely by NO3. The location of the sampling stations, months and depths within the Canonical Correspondence Analysis (CCA) ordination field with the same environmental factors defining the axes were also analyzed. The least important environmental variable considered in this study was the soluble phosphate with the shortest vector among the other factors. The study also found out that the nutrient status of the lake appears to influence it during the dry season. It must be noted though that 2.5 m depth collections were considered in this data and may not be very reliable because of the nature of the flow of nutrient in a deep lake being dispersed in the deeper portion and remains drift to the bottom (Smith, 1996). Previous discussions on statistical analyses support these results from Multivariate Statistical Package (MVSP). Observations on the temporal changes in nutrients and the phytoplankton biomass and cell count are found parallel to the studies of Lewis (1978) in Lake Lanao, Martines (1977) and Zafaralla (1990) in Laguna de Bay

    Exploring Filipiniana Rare Books and the State of Filipiniana Rare Books Management

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    This paper provides an overview of Filipiniana rare books and Filipiniana rare books management. It discusses the nature and scope of Filipiniana rare books and by surveying their status in select libraries in the Philippines, this study attempts to draw the state of Filipiniana rare books management in the country. Accordingly, it posts recommendations on how the issues and concerns identified in this study may be addressed

    Assessment of Alternanthera sessilis and Aster philippinensis as Excluders in a Small-Scale CU–AU Processing Site at Kias, Benguet, Philippines

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    In unregulated mining and processing for Cu and Au, large amounts of heavy metals and metalloids are generated as tails. These wasted by-products could actually pose serious environmental problems. The objective of this study was to assess the potential ability of Alternanthera sessilis and Aster philippinensis thriving abundantly in a small-scale mine processing site at Kias, Benguet, for possible Cu, Pb, Zn, and As uptake. It also aimed to determine the cellular localization of the contaminants within the plant biomass. Alternanthera sessilis and Aster philippinensis exhibited low bioaccumulation factor (BF) and translocation factor (TF) values for Cu, Pb, Zn, and As. The BF and TF values could suggest possible exclusion mechanisms of the plants in avoiding phytotoxicity. SEM-EDX analysis of the Alternanthera sessilis roots indicated higher weight % of Cu, Pb, and As in the epidermis, and Zn in the cortex. On the other hand, Aster philippinensis roots showed high weight % of Zn and As in the epidermis and Cu and Pb in the cortex. The localization of the contaminants in the root epidermal and cortical cells signifies restriction of their mobility to the xylem, preventing migration to the shoot system. The findings of this study suggest that Alternanthera sessilis and Aster philippinensis are considered potential phytostabilizers capable of immobilizing contaminant toxicity in the soil and in the rhizosphere

    The identification of indigenous Cu and As metallophytes in the Lepanto Cu-Au, Luzon, Philippines

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    The mining activities in the Lepanto Cu-Au Mine which is situated within the Mankayan Mineral District in the Philippines have exposed the arsenic (As)-rich copper (Cu)-gold (Au) and polymetallic ores to surface conditions. Cu and As dispersal into nearby soils and waters could pose health hazards to the natural ecosystems and human settlements. The study focused on the identification of indigenous metallophytes thriving in the area as well as the bioavailability of Cu and As in soils and its implication to the growth of the indigenous plants. Particular interests were on plant species that are capable of Cu and As absorption and have potential applications to mine rehabilitation. The samples were analyzed for total Cu and As contents. The soil samples were also subjected to different physicochemical analyses such as pH, organic matter, and nutrient content. Fern species had relatively high Cu and As contents in their biomass than other plant species found in the study area. The Cu and As concentrations in the plants might have been strongly influenced by the bioavailability of the metal and metalloid which were dependent on the physicochemical properties of the soil such as pH, organic matter, and nutrient contents. These identified metallophytes namely Dicranopteris linearis, Histiopteris incisa, Pityrogramma calomelanos, Pteris vittata, Nephrolepis hirsutula, Pteris sp., Pinus sp., Thysanolaena latifolia, and Melastoma malabathricum have tolerated the different Cu and As concentrations in the soil thus could be useful and effective for ecological restoration as an option to post-mining rehabilitation

    Pteris melanocaulon Fée is an As hyperaccumulator

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    Pteris melanocaulon is noted to thrive very well in selected Cu–Au mines in the Philippines such as the Carmen Cu mine in Cebu and the Manila Mining Cu–Au mine in Surigao. Soil and plant samples were collected from field surveys as well as potted experiments. The computed bioaccumulation factor (BF) and translocation factor (TF) values from the analyses of As contents of the soil and the belowground and above ground components of the plant, apparently were comparable to known As hyperaccumulators Pteris vittata and Pityrogramma calomelanos. It is inferred with probability that the factors that influence the bioavailability of As as well as the uptake mechanisms for P. melanocaulon would be similar to the 2 known As hyperaccumulators. Previous works have noted P. melanocaulon as a very good Cu accumulator with very high Cu values in the belowground components and this study further identified it to be an excellent As hyperaccumulator with high As values in the aboveground components
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