Dark Water Research Articles

“Trauma scrambles things, trauma fragments…” A cross-cultural conversation with Corban Addison in the context of A Walk Across the Sun

ABSTRACT In this interview, Corban Addison exposes the harsh reality of child sex trafficking in India and across borders with his first-hand experiences with victims, survivors, and activists. Addison has written books on human rights, injustice in the world, and its culture. His works include A Walk Across the Sun (2012), The Garden of Burning Sand (2013), The Tears of Dark Water (2015), A Harvest of Thorns (2017), and Wastelands: The True Story of Farm Country on Trial (2022). Addison, being an engineer, lawyer, and author, began experimenting with writing at the age of fifteen years. He has used his profession as a lawyer in his writing to depict human atrocities, provide validity to victims, and advocate the abolition of modern slavery through his narratives. In this conversation, Addison talks about how he ended up writing A Walk Across the Sun while discussing sexual slavery, his background research, and how he was able to understand the experiences and trauma of sexual violence. He shares anecdotes of his journey to tsunami-affected areas, brothels, and meetings with victims and activists and how he portrays the sexual violence, trauma, and redemption from it.

Ways to Protect the Environments of the Itaúnas Cloud Fish - Xenurolebias Myersi (Carvalho, 1971) – Inhabitant of the Restinga Swamps, Conceição Da Barra, Northern Espírito Santo, Southeastern Brazil

Itaúnas is a locality of rare scenic beauty, with white sand dunes in the middle of the savanna coastal environments, known as restinga, and many flooded pools, forming a unique landscape. In these ponds of dark water, matte tea colored, lives a fish, _Xenurolebias myersi, _an endemic inhabitant of Itaúnas. The survival of this unique little fish is worrisome. The living environments of the Itaúnas cloud fish are under pressure, and it is threatened with extinction as well. As inhabiting temporary, almost isolated environments, this fish is almost unknown. Locally, the population is unaware that the region is inhabited by an endangered fish, which only exists there in Itaúnas. A form of protection comes through the awareness of their presence among the population of the village. The present contribution aims to shed light on the knowledge of _Xenurolebias myersi_, in order to turn the fish better known locally, and point out the urgency to protect the Velha Antonia stream, a river drainage closer to the village of Itaúnas, where the fish was caught for the first time.

Spatiotemporal dynamics of giant viruses within a deep freshwater lake reveal a distinct dark-water community.

Giant viruses (GVs) significantly regulate the ecological dynamics of diverse ecosystems. Although metagenomics has expanded our understanding of their diversity and ecological roles played in marine environments, little is known about GVs of freshwater ecosystems. Most previous studies have employed short-read sequencing and therefore resulted in fragmented genomes, hampering accurate assessment of genetic diversity. We sought to bridge this knowledge gap and overcome previous technical limitations. We subjected spatiotemporal (2 depths × 12months) samples from Lake Biwa to metagenome-assembled genome reconstruction enhanced by long-read metagenomics. This yielded 293 GV metagenome-assembled genomes. Of these, 285 included previously unknown species in five orders of nucleocytoviruses and the first representatives of freshwater mirusviruses, which exhibited marked divergence from marine-derived lineages. The good performance of our long-read metagenomic assembly was demonstrated by the detection of 42 (14.3%) genomes composed of single contigs with completeness values >90%. GVs were partitioned across water depths, with most species specific to either the sunlit epilimnion or the dark hypolimnion. Epilimnion-specific members tended to be transient and exhibit short and intense abundance peaks, in line with the fact that they regulate the surface algal blooms. During the spring bloom, mirusviruses and members of three nucleocytovirus families were among the most abundant viruses. In contrast, hypolimnion-specific ones, including a mirusvirus genome, were typically more persistent in the hypolimnion throughout the water-stratified period, suggesting that they infect hosts specific to the hypolimnion and play previously unexplored ecological roles in dark water microbial ecosystems.

Assessment of Antioxidant Status of Oreochromis mossambicus in Fresh and Brackish Water of Thiruvarur District, Tamil Nadu from India

Antioxidant biomarkers have been used to demonstrate the effects of various’ environmental stressors on certain aquatic organisms. The objective of the study is to analyze the antioxidant status of freshwater and brackish fish such as Oleochromis mosambicus in 2022. Antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase, glutathione S transferase (GST) and 、 Glutathione content (GSH) was with gills, and, Livers and muscles of fresh water fish of Oreochromis mosambicus analyzed. The results of the study showed that superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione S transferase and glutathione contained in different tissues (gills, gills and various tissues) Antioxidant enzymes such as glutathione content have been demonstrated and the liver and muscles have been reduced in Oreochromis mossambicus. The decreased activities of these enzymes may be due to contaminant exposure. This modulation in enzyme activity could be due to the mechanism by which Tilapia Oreochromis mossambicus circumvents the salinity stress caused by contaminants. The research will provide more detailed information on the response of antioxidant defenses to tilapia species in dark water environments and the mechanisms of regulation of this response. This future research will undoubtedly benefit some aspects of aquaculture and aquaculture production as well.

Long-term unialgal seaweed cultivation in artificial seawater without water change. I. Laboratory investigations of Ulva

Abstract Unialgal stock cultures for seeding the tank water can be used for the mass cultivation of seaweeds in artificial seawater, as in microalgal mass cultivation. High costs for artificial sea salt mixtures and distilled water would be required, however, to use artificial seawater in big tanks for commercial purposes, but frequent medium changes may not be required, since the major ions contained in artificial seawater, such as sodium, will barely be utilised by the cultured algae during long periods of time, even over years. Similar growth rates were obtained at the start and end of an experiment conducted with Ulva pseudocurvata cultivated unialgally for two years without water change, at a low algal density and with weekly addition of Provasoli Enrichment. Growth in this experiment was increasingly impeded due to gamete swarming events causing dark greenish water every few weeks. The experimental water had then to be boiled in order to kill the gametes. In a second experiment, this time performed at a high algal density, maximum yield values were 20–30 g fresh weight m−2 d−1, both for 2-year-old and newly prepared artificial seawater. These results verified the hypothesis that long-term Ulva cultivation in artificial seawater is possible without frequent medium changes.

Ecological advantage of polarized light pollution: positive effect of a dark lake patch at a canal inflow on habitat of non-biting midges

AbstractDark artificial surfaces reflecting highly and horizontally polarized light usually have negative effects on polarotactic aquatic insects detecting their habitats by the horizontal polarization of water-reflected light. This ecologically disadvantageous phenomenon is called polarized light pollution. We have observed that the water between the concrete walls of a harbour of the Hungarian Lake Balaton is continuously dark from autumn to spring due to the inflow of a canal rich in dissolved humic substances. Using ground-born imaging polarimetry, we demonstrated that this dark water patch reflects light with higher degrees of polarization than the brighter lake water. Our hypothesis was that the stronger horizontally polarized light reflected from the dark water patch is more attractive to swarming, water-seeking and egg-laying non-biting midges (Chironomidae) than the surrounding brighter lake water. With larval samplings, we showed that both the density and the average size of chironomid larvae were significantly larger in the harbour than in the surrounding lake. This finding may represent an ecological advantage of polarized light pollution: polarotactic chironomids are intensely attracted to a strongly and horizontally polarizing, seasonally dark water patch at the canal inflow, where the abundance of larvae increases. It should be taken into consideration that increased larval abundance might result in increased swarming intensity which could affect humans by causing considerable nuisance.

Expanding the coverage of Multi-angle Imaging SpectroRadiometer (MISR) aerosol retrievals over shallow, turbid, and eutrophic waters

Abstract. Shallow and coastal waters are often rich in nutrients (eutrophic), biologically productive, turbid from runoff, and located where the atmosphere above can be more aerosol-laden than over open-ocean waters due to proximity to aerosol sources on land. Although the NASA Earth Observing System's Multi-angle Imaging SpectroRadiometer (MISR) on board the Terra satellite has been monitoring global aerosols for over 23 years, the current operational retrieval algorithm (V23) is not applied over waters less than 50 m in depth or within 5 km of land, designated as “shallow water.” This is due to the simplicity of the Dark Water algorithm, applied operationally over deep waters, which assumes the surface is essentially black in the primarily used red and near-infrared spectral bands. In this work, we describe the implementation and validation of a “Shallow Water” aerosol retrieval algorithm for MISR, which takes advantage of all four available spectral bands and includes a Lambertian surface reflectivity term to account for water-leaving radiance. This algorithm compares well to independent, surface-based observations and demonstrates better performance over shallow waters than the operational Dark Water retrieval algorithm. Globally, aerosol retrievals over shallow waters increase the total number of MISR over-water measurements by more than 7 %, including new retrievals made over some of the most biologically productive parts of the ocean.

Treatment of Dark Humic Water Using Photocatalytic Advanced Oxidation (PAO) Processes under Visible and UV Light

Treatment of Dark Humic Water Using Photocatalytic Advanced Oxidation (PAO) Processes under Visible and UV Light

Drone-Based Imaging Polarimetry of Dark Lake Patches from the Viewpoint of Flying Polarotactic Insects with Ecological Implication

Aquatic insects detect water by the horizontal polarization of water-reflected light and thus are attracted to such light. Recently, in the Hungarian Lake Balaton we observed dark water patches forming between every autumn and spring because of the inflow of black suspended/dissolved organic matter into the bright lake water. Earlier, the polarization characteristics of such water surfaces were mapped by imaging polarimeters from the ground. In order to measure the reflection-polarization patterns of these dark lake patches from the higher viewpoint of flying polarotactic aquatic insects, we designed a drone-based imaging polarimeter. We found that the dark lake patches reflected light with very high (60% ≤ d ≤ 80%) degrees of horizontal polarization at the Brewster’s angle, while the bright lake water was only weakly (d < 20%) horizontally polarizing. There was a large contrast in both the radiance and degree of polarization between dark lake patches and bright lake water, while there was no such contrast in the angle of polarization. The ecological implication of these findings could be that these dark lake patches attract water-seeking polarotactic insects, which may oviposit more frequently in them than in the brighter lake water. However, it might not matter if they lay their eggs in these dark patches rather than the bright lake water, because this may simply increase the abundance of breeding flying insects in areas where dark patches are common.

Dark Current Water Splitting Employing Ni3TeO6 as a Photocharged Photoelectrocatalyst

Herein, the photoelectrocatalytic and photocharging activity of a Ni3TeO6 (NTO‐700) photoelectrocatalyst for water oxidation in alkaline medium is demonstrated and calcined at 700 °C. The photoelectrocatalytic (PEC) activity of the sample is increased upon an increase in the illumination time. With a twofold increase in photocurrent density at 1.8 V, the PEC 150 sample (having been illuminated for 150 min) attained the highest PEC activity. The synthesized material has displayed an excellent charge storage capacity in KOH and Na2SO4 electrolyte solutions (both 0.1 m). The chrono‐amperometry measurement, subsequent to light interruption, has sustained almost 44% higher current density (even after 200 min) compared to the pure electrocatalytic baseline in a Na2SO4 electrolyte. The charge transfer resistance, Rct, decreases from 633.40 to 170.40 Ω, while the charge transfer rate constant, kct, increases from 7.93 to 27.03 s−1, as a function of illumination time. This points to fast separation of electron–hole (e−–h+) pairs and a slower recombination rate. The lower values of the charge transfer resistance and the time constant recorded for the light interrupted samples, as compared to the electrochemical sample, are attributed to the stored charge that drives water oxidation at a higher rate.

Two Anecdotes of Pie

Two Anecdotes of Pie Donald Platt I Wallace Stevens lovedpie. His neighbor brought him a chocolatesilk pie, dark as a starless night. “What do youcall this pie?” he asked, he who had “placed a jarin Tennessee.” She smiled and replied,“Heavenly Pie.” That jar had tamed “the slovenlywilderness” around him. “Well,” he said,raising a piece on his fork slowly towardshis mouth, hungry after having walked home froma long day writing surety bonds at theHartford Accident and IndemnityCompany on Asylum Avenue,“Open the pearly gates.” II I am so loved byyou, who walk through rain [End Page 106] for twenty minutesto my apartment, carrying ina glass pie pan wrapped in a soft burlapbag to keep it warm from the oven, onewhole, paw-paw, lemon grass, and ginger pie.You grew the paw-paws, shook them when ripe downfrom the tree. Deseeded them. Scooped out theirbutter-colored flesh. Puréed it. Mixed itwith vanilla sugar, spices, whole milk, eggs.Poured it into its graham-cracker crust.Baked it until it turned golden as theharvest moon rising over a lake, castingits moonlight on the dark water to makean upside-down exclamation pointof light the color of gnarled ginger root.You are allergic [End Page 107] to paw-paws. You stayhungry and smile while you watch me devour onelarge slice, then clamor for more caramelizedmoonlight. [End Page 108] Donald Platt Lafayette, Indiana Copyright © 2023 Johns Hopkins University Press

The capacity of imaging sonar for quantifying the abundance, species richness, and size of reef fish assemblages

Reef fish assemblages across tropical and temperate latitudes are increasingly threatened by human impacts and climate change. Accurate and efficient survey methods are essential for quantifying these communities to inform management strategies. Imaging sonars (ISs) are high-frequency acoustic devices that produce camera-like images of objects. Unlike optical instruments, IS functions effectively in turbid and dark water and has proven valuable in detecting fishes in poor visibility and at night. Abundance, species richness, and fish size are desirable metrics in most reef fish surveys. This review investigates previous attempts to quantify these metrics using IS across different habitats. These metrics are often quantified in comparison with alternative methods (e.g. cameras, extractive techniques). This review examines the causes of agreement or incongruence between estimates from IS and estimates from these alternatives. Any instrument employed to quantify reef fishes should be able to operate in structurally complex habitats, and thus the ability of IS to function in these circumstances is also reviewed. Finally, 5 notable limitations of IS are described and solutions discussed. Overall, this review underlines the net value of IS for surveying reef fishes but advises using alternative methods to complement IS estimates of abundance, species richness, and fish size.

Stratigraphy, isotope geochemistry, seismic stratigraphy and paleogeography of the Lagoa do Jacaré Formation, Bambuí Foreland Basin (Ediacaran-Cambrian), Southeast Brazil

The Bambuí Group is a lithostratigraphic unit that comprises a mixed carbonate-siliciclastic platform deposited in a foreland basin. It is a 1st order sequence that filled the São Francisco Basin during the Ediacaran-Cambrian in southeast Brazil. The Lagoa do Jacaré Formation is the second carbonate unit of the Bambuí Group and is related to a 2nd-order regressive hemicycle composed of dark gray shallow water carbonates with high positive ẟ1³C values (>+10‰) related to the upper part of the Middle Bambuí Excursion (MIBE). We described four outcrops in the center-north of Minas Gerais state (Paraopeba, Curvelo, Montes Claros and Ubaí areas) coupled with ẟ13C and ẟ18O, and SEM-EDS analysis in order to support detailed facies analyses. One seismic line and three well logs in the south part of the Januária High were also used to define the stratigraphic framework of the Lagoa do Jacaré Formation in the Bambuí Foreland Basin system. Eight facies were interpreted from the outcrop data and grouped into five facies associations, that represent peritidal zone (FA1), ooidal sand shoals (FA5), tempestites of mid ramp (FA3), fine-grained carbonate of outer ramp (FA4), and fine-grained siliciclastic from offshore (FA2). The strong presence of terrigenous material (quartz, feldspars, muscovite, biotite, apatite) with some authigenic/diagenetic minerals (pyrite, titanite, rutile) in all facies are the main petrographic aspect of the studied carbonate rocks, related to high sedimentary input and some events during early diagenesis. FA1 with lower mean values of ẟ1³C (+9‰) predominates in the north, meanwhile FA3 is the main association in the south with higher ẟ1³C mean values (+12‰). This difference is probably related to the stratigraphic differences between the basal section (at south) and upper section (at north) of the Lagoa do Jacaré Formation. The Januária High was the main controlling element for the deposition of the carbonate ramp in the north sector of the basin, close to the Ubaí and Montes Claros cities. Probably, this structural high also played an important role as source area in the forebulge sector, uplifted by flexure due to the orogeny of the Brasília and Araçuaí (still in development) Belts (∼540-520 Ma). To the east, a N–S carbonate ramp system was developed in the back-bulge sector according to the main paleocurrents measurements. This ramp is related to a 300 m thickness section of the Lagoa do Jacaré Formation that was firstly identified and correlated to the successions on the surface using well logs, possibly registering at the top the decreasing in the ẟ1³C values, after the main stages of the MIBE probably in close association with Ediacaran-Cambrian boundary, related to the assembling of the Gondwana Supercontinent recorded in this region of southeast Brazil.

Effects of temperature and light exposure on the decay characteristics of fecal indicators, norovirus, and Legionella in mesocosms simulating subarctic river water

Knowledge of the decay characteristics of health-related microbes in surface waters is important for modeling the transportation of waterborne pathogens and for assessing their public health risks. Although water temperature and light exposure are major factors determining the decay characteristics of enteric microbes in surface waters, such effects have not been well studied in subarctic surface waters. This study comprehensively evaluated the effect of temperature and light on the decay characteristics of health-related microbes [Escherichia coli, enterococci, microbial source tracking markers (GenBac3 & HF183 assays), coliphages (F-specific and somatic), noroviruses GII and Legionella spp.] under simulated subarctic river water conditions. The experiments were conducted in four different laboratory settings (4 °C/dark, 15 °C/dark, 15 °C/light, and 22 °C/light). The T90 values (time required for a 90 % reduction in the population of a target) of all targets were higher under cold and dark (2.6–51.3 days depending upon targets) than under warm and light conditions (0.6–3.5 days). Under 4 °C/dark (simulated winter) water conditions, F-specific coliphages had 27.2 times higher, and coliform bacteria had 3.3 times higher T90 value than under 22 °C/light (simulated summer) water conditions. Bacterial molecular markers also displayed high variation in T90 values, with the greatest difference between 4 °C/dark and 22 °C/light recorded for HF183 DNA (20.6 times) and the lowest difference for EC23S857 RNA (6.6 times). E. coli, intestinal enterococci, and somatic coliphages were relatively more sensitive to light than water temperature, but F-specific coliphages, norovirus, and all bacterial rDNA and rRNA markers were relatively more sensitive to temperature than light exposure. Due to the slow microbial decay in winter under subarctic conditions, the microbial quality of river water might remain low for a long time after a sewage spill. This increased risk associated with fecal pollution during winter may deserve more attention, especially when river waters are used for drinking water production.

First Report of Achromobacter Xylosoxidans Causing Stem Soft Rot on Amorphophallus Konjac in China.

Amorphophallus konjac is one of the important commercial crops cultivated in south China and has long been used as a food source and a traditional medicine, because it is the only species with glucomannan and other trace elements (Ban et al. 2009; Melinda et al. 2010). In June of 2021, an outbreak of stem soft rot disease was observed on A. konjac plants in more than 2,000 square meters of agricultural planting fields in the Fuyuan country (25°34'50″N, 104°04'21″E), Qujing City, Yunnan Province, China. The disease incidence ranged from 30 to 35% in severely infested fields. The diseased plants displayed the first symptoms were damp brown spots. As the brown spots expanded, dark brown water stains appeared at the basal part of the stem and the bulbs were rotting with a foul smell, gradually extending to the underground parts. Progressively, the whole plants wilted and collapsed, and even the plants ultimately died. To identify the pathogen, symptomatic stems were cut into pieces, surface sterilized with 75% (v/v) ethanol, and placed on LB (tryptone/yeast extract/NaCl) medium for 24 to 48 hours at 28 ± 2°C. Six single-colony isolates were obtained from the diseased stems. The colonies on LB present a raised milky white opaque colonies moisture on the surface, round and convex in shape, with neat edges. Scanning electron microscopy showed that the cells were short rods (0.3∼0.5) × (1.9∼2.1)μm in size without any flagellum and were often arranged in pairs or clusters at certain angles. The 16S rDNA sequence of the randomly selected strain MY-G1 with primers 27F/1492R (Ying et al. 2012) and the housekeeping genes nusA, eno, lepA and nuoL (Spilker et al. 2012) were amplified and sequenced. The 16S rDNA sequence of the 1326 bp product was deposited in GenBank (accession no. ON786717) and showed a 99.77% similarity to A. xylosoxidans strain E2 (accession no. MK849863.1). The nusA (OP680477), eno (OP680479), lepA (OP680481) and nuoL (OP680482) sequences showed 94.71%, 97.24%, 94.64% and 95.95% similarity to A. xylosoxidans strain DN002 (accession no. CP045222.1), respectively. The phylogenetic trees built based on 16S rRNA and the nusA-eno-lepA-nuoL multilocus analysis showed the isolate MY-G1 to cluster with A. xylosoxidans. Based on morphological and molecular analysis, the isolated MY-G1 was identified as A. xylosoxidans, which indicates that MY-G1 is a new strain of A. xylosoxidans. Pathogenicity tests were confirmed on the stem and petiole of one-year-old A. konjac. The wounds were made by puncturing with a MY-G1 bacteria suspension containing 108 CFU/ml (15ul/inoculation site). As a negative control, control seedlings were injected with the same amount of sterilized distilled water. Control and inoculated seedlings (each six) were kept in greenhouses and watered as needed in controlled conditions: 28°C, 75% relative humidity. Inoculated seedlings presented similar symptoms of stem soft rot, inner medulla disintegration, and wilt of leaves on developed within 3 to 9 days. The bacterial pathogen was re-isolated from inoculated seedlings and identified by morphological and molecular methods to fulfill Koch's postulates test. According to previous research, A. xylosoxidans can cross-kingdom infect animals and plants (Aisenberg et al.,2004; Ye et al.,2018). To the best of our knowledge, this is the first report of A. xylosoxidans causing stem soft rot of A. konjac in China, expanding the known pathogen for the soft rot of A. konjac, and also the host range of A. xylosoxidans.

The Sentinel 2 MSI Spectral Mixing Space

A composite spectral feature space is used to characterize the spectral mixing properties of Sentinel 2 Multispectral Instrument (MSI) spectra over a wide diversity of landscapes. Characterizing the linearity of spectral mixing and identifying bounding spectral endmembers allows the Substrate Vegetation Dark (SVD) spectral mixture model previously developed for the Landsat and MODIS sensors to be extended to the Sentinel 2 MSI sensors. The utility of the SVD model is its ability to represent a wide variety of landscapes in terms of the areal abundance of their most spectrally and physically distinct components. Combining the benefits of location-specific spectral mixture models with standardized spectral indices, the physically based SVD model offers simplicity, consistency, inclusivity and applicability for a wide variety of land cover mapping applications. In this study, a set of 110 image tiles compiled from spectral diversity hotspots worldwide provide a basis for this characterization, and for identification of spectral endmembers that span the feature space. The resulting spectral mixing space of these 13,000,000,000 spectra is effectively 3D, with 99% of variance in 3 low order principal component dimensions. Four physically distinct spectral mixing continua are identified: Snow:Firn:Ice, Reef:Water, Evaporite:Water and Substrate:Vegetation:Dark (water or shadow). The first 3 continua exhibit complex nonlinearities, but the geographically dominant Substrate:Vegetation:Dark (SVD) continuum is conspicuous in the linearity of its spectral mixing. Bounding endmember spectra are identified for the SVD continuum. In a subset of 80 landscapes, excluding the 3 nonlinear mixing continua (reefs, evaporites, cryosphere), a 3 endmember (SVD) linear mixture model produces endmember fraction estimates that represent 99% of modeled spectra with <6% RMS misfit. Two sets of SVD endmembers are identified for the Sentinel 2 MSI sensors, allowing Sentinel 2 spectra to be unmixed globally and compared across time and space. In light of the apparent disparity between the 11D spectral feature space and the statistically 3D spectral mixing space, the relative contribution of 11 Sentinel 2 MSI spectral bands to the information content of this space is quantified using both parametric (Pearson Correlation) and nonparametric (Mutual Information) metrics. Comparison of linear (principal component) and nonlinear (Uniform Manifold Approximation and Projection) projections of the SVD mixing space reveal both physically interpretable spectral mixing continua and geographically distinct spectral properties not resolved in the linear projection.

Stable carbon isotopes of dissolved inorganic carbon in the Western North Pacific Ocean: Proxy for water mixing and dynamics

The uptake of atmospheric CO2 and the cycle of dissolved inorganic carbon (DIC) in the ocean are the major mechanisms and pathways controlling global climate change and carbon cycling. The stable carbon isotope (δ13C) of DIC, therefore, provides an important tracer for processes such as air-sea exchange, photosynthesis, and water dynamics in the ocean. Here, we present new δ13C-DIC data on water samples collected from a north-south transect (13°N–40°N, 150°E) in the western North Pacific (NP) Ocean in November 2019 and compare the results with those previously reported for similar transects (149.3°E) during WOCE and CLIVAR projects over the past three decades. The values of δ13C-DIC, ranging from -0.83‰ to 0.86‰, were higher in the surface waters and decreased with depth. The high δ13C-DIC values in the surface waters were influenced primarily by isotopic fractionation during air-sea exchange and photosynthesis. With depth, the movement of different water masses and mixing, as well as bathypelagic respiration in the dark water of the ocean, all play important roles in influencing the distribution and isotopic signatures of δ13C-DIC in the western NP Ocean. The δ13C-DIC values of the 0–200 m water layer varied from -0.17‰ to 0.86‰, with lower values at high latitudes, affected by the low δ13C-DIC values carried by the Oyashio Current to the Kuroshio Extension (KE) region. A downward trend was present in the δ13C-DIC signature from north to south in the North Pacific Intermediate Water (NPIW) and Pacific Deep Water (PDW) in the western NP, which reflected the remineralization of organic matter with a horizontal transport of NPIW and PDW. We found a strong 13C Suess Effect in the upper 2,000 m in the western NP Ocean, and δ13C-DIC at the surface (<50 m) has decreased by 0.60‰-0.85‰ since 1993. The mean δ13C-DIC change in the surface ocean was estimated at 0.28‰ per decade between 1993 and 2019. The air-sea exchange and water mixing in the study area may have accelerated the absorption of anthropogenic CO2 in recent years, which likely caused a slightly faster rate of decrease in the δ13C-DIC from 2005–2019 than that observed from 1993–2005.

Production of Bio-composite Films from Gum Arabic and Galangal Extract to Prolong the Shelf Life of Agaricus bisporus

The current study was performed to develop biodegradable films with matrix composed from gum Arabic (GA) and different concentrations from Alpinia officinarum phenolic extract (AOE). The color indices, physical properties, surface shape, crystallinity, mechanical properties and thermal stability of produced films were investigated. The incorporation of AOE extract (0.25 g/100 mL) inside GA films increased dark yellow color, reduced moisture, swelling, solubility and water vapor permeability (WVP) of films up to 10.29%, 21.05%, 14.15% and 4.20 × 10−10 g H2O/m s p.a., respectively. Furthermore, the scanning electron micrographs showed uniform structure with rough surface and turmoil spots in the structure by increasing AOE concentration inside films. The FT-IR analysis showed typically bands that proved physical interaction between AOE extract and GA polymer. The fabricated films showed satisfied thermal stability manners with declining trend by incorporation of AOE inside GA films. Furthermore, the developed films showed significant effects on reducing the changes of browning index from 17.20 to 24.54 and firmness from 33.98 to 22.65 N of Agaricus bisporus caps during storage days compared with commercial packaging materials.

Monitoring fish using imaging sonar: Capacity, challenges and future perspective

AbstractThe demand for fish products, which provide crucial protein for humans, is rising as the global population grows. In contrast, fish stock is declining due to human activity, environmental changes and overfishing. Fish monitoring provides valuable support data for effective fishery management and ecosystem conservation. The common monitoring methods are based on manual sampling, which is time‐consuming, laborious and intrusive. Imaging sonar is a hydroacoustic system that produces acoustic images similar to optical images by transmitting and receiving sound waves, allowing for in situ monitoring of fish non‐intrusively in the dark and turbid water environments where optical cameras are limited. In the last decade, imaging sonar, especially high frequency multibeam forward‐looking sonar and side‐scan sonar, has been widely used in fish monitoring. We reviewed the literature from the previous decade on the use of these two types of imaging sonar in fish species identification, abundance estimation, length measurement and behaviour analysis, as well as the sonar imagery processing concerning fish. The review results show that these imaging sonars are efficient and effective tools for fish monitoring in complex environments. The challenges include (1) the recognition of small fish forming dense aggregations; (2) species identification, which limits their use in species‐specific studies; (3) time‐consuming massive data processing. Therefore, advanced algorithms for sonar imagery processing and integrations with other sampling technologies are needed for future development.

Rational durability of optical properties of chameleon effect of Omnichroma and Essentia composite thermocycled in black dark drinks (in vitro study)

BackgroundThis study evaluated the durability of optical properties of chameleon effect of Omnichroma and Essentia composite thermocycled in black dark drinks. 180 specimens of 10 mm diameter × 2 mm thickness from each tested composite material were prepared; Omnichroma and Essentia. 60 specimens were thermo-cycled for 2500 and 5000 cycles in Coffee and Coca-Cola in addition to Distilled water as a reference group for color change evaluation. Color change (ΔE) was calculated and water sorption and solubility were measured after thermocycling for 2500 and 5000 cycles in different dark drinks and water. The surface chemical changes were assessed by FTIR. All data were statistically analyzed.ResultsIn all tested groups, Omnichroma recorded the highest significant color change (35.80 ± 4.13) and sorption values (8.30 ± 0.48) on the contrary the least solubility value (− 8.29 ± 0.81) in all tested drinks after thermocycling to 5000.ConclusionsColor durability of Omnichroma negatively affected in dark drinks. Water sorption of Omnichroma negatively affected after aging 3 and 6 months. Water solubility might not adversely affect the color change. Thermocycling in different dark drinks adversely affected the color stability of both selected Chameleon composite types.