Presence and Quantification of Microplastic in Urban Tap Water: A Pre-Screening in Brasilia, Brazil

Plastic pollution is a rapidly growing environmental and human health crisis, with no sign of improvement. From 2012 to 2020, the number of studies on plastic pollution increased, and macro to nano-sized plastics have been documented in the most remote biomes of the planet. Studies have shown contamination by microplastics (MPs) in various types of food consumed by humans, including seafood, honey, sugar, salt, tap and bottled water and beer. This study’s objective was to detect the possible contamination by MPs in drinking water samples collected from two main residential and commercial areas of Brasilia. A total of 32 samples (500 mL) of tap water were collected from residential and commercial areas. Samples were processed and transferred to a Sedgewick-Rafter counting cell chamber. The presence of MP particles was analyzed using a Nikon Eclipse fluorescence microscope. MPs were found in 100% of the samples. The mean microplastic particles per 500 mL found in the South Wing area was 97 ± 55, while the mean number of particles in the North Wing area was 219 ± 158, and the MPs found ranged in size from 6–50 microns. The study results reveal a disturbing amount of MP particles in Brasilia’s tap water. This surprising number of particles in residential and commercial tap water is especially considering that tap water is not the only source of MPs to which people are exposed.

ANALISIS KESUBURAN PERAIRAN BERDASARKAN KELIMPAHAN FITOPLANKTON DI MUARA SUNGAI PORONG, SIDOARJO

<p>Pembuangan lumpur lapindo yang membawa nutrien dan bahan organik terlarut lainnya dapat menyebabkan pengayaan dan kematian massal organisme karena berkurangnya jumlah cahaya yang masuk ke dalam perairan. Keberadaan fitoplankton dapat memberikan informasi mengenai keadaan perairan. Penelitian ini bertujuan untuk mengetahui kesuburan perairan Sungai Porong melalui kelimpahan fitoplankton. Penelitian ini dilakukan pada Oktober hingga Januari 2021. Pengambilan sampel dilakukan di tiga stasiun. Metode pengambilan sampel plankton dilakukan secara horizontal dan diidentifikasi menggunakan <em>Sedgwick Rafter Counting Cell</em> (SRCC). Analisa data meliputi densitas fitoplankton, indeks keanekaragaman, indeks keseragaman, dan indeks dominansi. Hasil penelitian menunjukkan bahwa komposisi jenis fitoplankton yang ditemukan selama pengamatan didominasi oleh kelas diatom (13 genus) dan Dinoflagellata (2 genus). Status kesuburan perairan di Sungai Porong Sidoarjo tergolong dalam kategori eutrofik yaitu perairan dengan tingkat kesuburan tinggi.</p>

Community structure of phytoplankton in the surface and thermocline layers of Sangihe and Talaud waters, Indonesia

Sriwijayanti LA, Djumanto, Setiawan RY, Firdaus MR, Fitriya N, Sugeha HY. 2019. Community structure of phytoplankton in the surface and thermocline layers of Sangihe and Talaud waters, Indonesia. Bonorowo Wetlands 9: 51-58. The aim of this study was to determine the species dominance and distribution, and community structure of phytoplankton in the surface and thermocline layers of Sangihe and Talaud waters Indonesia. Phytoplankton samples were collected at the Sangihe-Talaud waters in October 2018 at 14 research stations. Water samples were collected at 5 m (surface) and thermoclines layers using rosette sampler equipped with Conductivity, Temperature, and Depth (CTD) recorder. Samples were concentrated to 40 ml using hand plankton net (mesh size 20 µm), then preserved with 4% formaldehyde. Phytoplankton species were identified using a guidebook based on morphological character traits. The cell count of each species of plankton was calculated using a Sedgwick rafter counting cell chamber. The result showed that there were 4 classes of phytoplankton (Bacillariophyceae, Dinophyceae, Cyanophyceae, and Raphydophyceae) which consisted of 59 species in the surface and 56 species in the thermocline, respectively. The abundance of phytoplankton at surface ranged from 77,333-4,024,000 cell m-3, meanwhile in the thermocline layer 8,000-542,222 cell m-3. The average of phytoplankton diversity of the surface was 0.82 and the thermocline was 1.71. The surface layer was dominated by Leptocylindrus danicus (8.92 x 106 cell m-3), Trichodesmium erythareum (5.83 x 106 cell m-3), and Detonula converfacea (0.62 x 106 cell m-3). The thermocline layer was dominated by Chaetoceros affinis (2.74 x 105 cell m-3), Thalassionema nitzchioides (2.21 x 105 cell m-3), and Chaertoceros dichaeta (1.38 x 105 cell m-3). The low phytoplankton abundance was found at the stations 12 and 13 caused by higher salinity concentration. The highest phytoplankton abundance was found in the stations with warmer temperatures, both in the surface and in the thermocline. The shallow depth thermocline layer (75-100 m) has a higher abundance than the deeper thermocline layer (110-150 m). Temperature was the environmental parameter that has the greatest influence on the abundance and species of phytoplankton, the phytoplankton in the surface layer reached 10 times more abundant than the thermocline layer.

Distribusi dan Kelimpahan Fitoplankton di Teluk Gerupuk, Nusa Tenggara Barat

Penelitian dilakukan di perairan Teluk Gerupuk pada bulan April, September 2015 dan Mei 2016 dengan tujuan untuk mengetahui distribusi dan kelimpahan fitoplankton di Teluk Gerupuk Nusa Tenggara Barat. Metode yang digunakan untuk menghitung kelimpahan fitoplankton menggunakan” Sedgewick-Rafter Counting Cell” dan analisis kualitas air merujuk pada APHA (2005). Penelitian di lakukan di 9 (Sembilan) stasiun penelitian dengan hasil kelimpahan fitoplankton berkisar antara: 619.958 – 7.456.476 sel/l; yang terdiri dari 2 kelas fitoplankton yaitu: Kelas Bacillariophycea, terdapat 32 jenis dan Kelas Dinophyceae terdapat 5 jenis yang ditemukan pada 9 (sembilan) stasiun pengamatan dengan lima jenis diatom potensial, yaitu Coscinodiscus sp., Chaetoceros sp., Nitzschia sp., Pleurosigma sp., dan Bidduphia sp. Berdasarkan indeks biologi terlihat bahwa kelimpahan tertinggi dan dominansi fitoplankton dari genus Chaetoceros sp. Keanekaragaman fitoplankton yang rendah dengan kisaran 0,24-98 dengan rata-rata 0,58±0,29, dan keseragaman fitoplankton berkisar antara: 0,01-0,05 dengan rata-rata 0,03±0,02 atau dengan kata lain 0<E<0,5 berarti komunitas fitoplankton tertekan.

EFFECTS OF DEPTH AND CONCENTRATION OF DIGESTATE ON GROWTH OF THREE MICROALGAL SPECIES

In order to design a culture system for microalgal biomass production with a low cost and convenient cell collection, growth performance of mixtures of microalgal cells, including Euglena gracilis, Chlorella vulgaris, and Dunaliella tertiolecta cultured in a volume of 1 L were investigated at a PPFD of 300 µmol m-2 s-1 at the surface of the solution with continuous illumination at 30 °C. Each culture container contained diluted digestate at concentrations of 5, 10, 15, 20, and 50 %. Sample cells for counting cell number were collected daily at three depths: 0–50 mm (the surface layer), 10–15 mm (the middle layer), and 25–30 mm (the bottom layer). Pseudo-specific growth rates (ms) of each species at each depth were calculated as cellular multiplication rates using number of cells per time. In each layer, the average ms of each species was highest in 5 % digestate. The average ms of all three microalgal species (0.035 h-1) was observed in all layers in 5 % digestate solution. The ms of each species was highest in the bottom layer in 5% digestate (0.048 h-1, 0.041 h-1, and 0.022 h-1, respectively for C. vulgaris, E. gracilis, and D. tertiolecta). In conclusion, E. gracilis, C. vulgaris, and D. tertiolecta showed the highest specific growth rate in 5 % digestate in all layer.

Spatial Marking and Quantitative Counting Cell Membrane αIIbβ3Integrin in Single Cells via Peptide-Au Cluster Probes

ABSTRACTWe propose a theoretical designed peptide-Au cluster probe and realize spatially marking and quantitatively counting αIIbβ3integrin via this novel nanoprobe. On single cell level, we find the number of αIIbβ3integrin ranges from 5.75 to 9.11×10-17mol for the heteroexpression of individual cells. Because the variation of proteins (including integrin and other biomarkers) on single cell has a tight correlation with many serious human diseases, our quantifying protein method on a single cell level is helpful for estimating the disease progression for diagnosis and detecting the drug response for therapy.

Counting cell numberin situby quantification of dimethyl sulphide in culture headspace

Enzymatic activity by cells reduces DMSO to DMS that can be analysed non-invasively to determine cell numbers in a culture.

CELLCOUNTER: Novel Open-Source Software for Counting Cell Migration and InvasionIn Vitro

Transwell Boyden chamber based migration/invasion assay is a simple and extensively used approach for the characterization of cell motilityin vitro. Cell motility is quantified by counting the number of cells that pass through the filter membrane. The counting is usually performed manually, which is laborious and error prone. We have therefore developed CELLCOUNTER, an application that is capable of recognizing and counting the total number of cells through an intuitive graphical user interface. The counting can be performed in batch, and the counting results can be visualized and further curated manually. CELLCOUNTER will be helpful in streamlining the experimental process and improving the reliability of the data acquisition.

An Optimized Design of Single-Channel Beta-Gamma Coincidence Phoswich Detector by Geant4 Monte Carlo Simulations

An optimized single-channel phoswich well detector design has been proposed and assessed in order to improve beta-gamma coincidence measurement sensitivity of xenon radioisotopes. This newly designed phoswich well detector consists of a plastic beta counting cell (BC404) embedded in a CsI(Tl) crystal coupled to a photomultiplier tube. The BC404 is configured in a cylindrical pipe shape to minimise light collection deterioration. The CsI(Tl) crystal consists of a rectangular part and a semicylindrical scintillation part as a light reflector to increase light gathering. Compared with a PhosWatch detector, the final optimized detector geometry showed 15% improvement in the energy resolution of a131mXe 129.4 keV conversion electron peak. The predicted beta-gamma coincidence efficiencies of xenon radioisotopes have also been improved accordingly.