The purpose of this publication is to provide examples of weeds commonly found under certain environmental conditions. While weeds can be an indicator of a certain condition, some weed species can ...thrive in many different environments and are indicated in the following tables with an asterisk. For example, spotted spurge (Euphorbia maculata) can be indicative of a dry site, but it will grow and spread very well in sites that are over-irrigated also. The presence of one or two weed species is not necessarily diagnostic to a specific cultural problem, but heavy infestations or the presence of multiple species that prefer a particular condition could indicate that cultural practices should be altered.
Existing enhancement methods are empirically expected to help the high-level end computer vision task: however, that is observed to not always be the case in practice. We focus on object or face ...detection in poor visibility enhancements caused by bad weathers (haze, rain) and low light conditions. To provide a more thorough examination and fair comparison, we introduce three benchmark sets collected in real-world hazy, rainy, and low-light conditions, respectively, with annotated objects/faces. We launched the UG 2+ challenge Track 2 competition in IEEE CVPR 2019, aiming to evoke a comprehensive discussion and exploration about whether and how low-level vision techniques can benefit the high-level automatic visual recognition in various scenarios. To our best knowledge, this is the first and currently largest effort of its kind. Baseline results by cascading existing enhancement and detection models are reported, indicating the highly challenging nature of our new data as well as the large room for further technical innovations. Thanks to a large participation from the research community, we are able to analyze representative team solutions, striving to better identify the strengths and limitations of existing mindsets as well as the future directions.
Low-light image (LLI) enhancement is an important image processing task that aims at improving the illumination of images taken under low-light conditions. Recently, a remarkable progress has been ...made in utilizing deep learning (DL) approaches for LLI enhancement. This paper provides a concise and comprehensive review and comparative study of the most recent DL models used for LLI enhancement. To our knowledge, this is the first comparative study dedicated to DL-based models for LLI enhancement. We address LLI enhancement in two ways: (i) standalone, as a separate task, and (ii) end-to-end, as a pre-processing stage embedded within another high-level computer vision task, namely object detection and classification. The paper consists of six logical parts. First, we provide an overview of the background and literature in LLI enhancement. Second, we describe the test data and experimental setup of the study. Third, we present a quantitative and qualitative comparison of the visual and perceptual quality achieved by 10 of the most recent DL-based LLI enhancement models. Fourth, we present a comparative analysis for object detection and classification performance achieved by 4 different object detection models applied on LLIs and their enhanced counterparts. Fifth, we perform a feature analysis of DL feature maps extracted from normal, low-light, and enhanced images, and perform the occlusion experiment to better understand the effect of LLI enhancement on the object detection and classification task. Finally, we provide our conclusions and highlight future steps and potential directions.
•Evaluates Deep Learning (DL) models for Low-light Image (LLI) enhancement.•Compares 10 LLI enhancement models and 4 object detection and classification models.•Provides a quantitative and qualitative comparison of visual and perceptual quality.•Evaluates impact of LLI enhancement on object detecting and classification quality.•Performs occlusion experiment to study LLI enhancement’s effect on object detection.
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•86% of P removal was achieved within a 6-hr dark-light cycle.•P was released in dark phase, followed by rapid uptake in light phase.•Pantanalinema were identified as the major ...P-accumulating algae.•P was removed via assimilation and Poly-P storage, with the latter being dominant.
Microalgal-bacterial granular sludge processes are attracting increasing research interest in fields of biological municipal wastewater treatment. However, these processes currently suffer from inefficient phosphorus removal and long hydraulic reaction time. As such, a self-sustaining synergetic microalgal-bacterial granular sludge process was explored for improving phosphorus removal. Results showed that about 86% of influent phosphorus could be removed within 6 h comprising 2-hr dark phase and 4-hr light phase. Slight phosphorus release was observed in dark phase, followed by a significant phosphorus uptake in light phase together with the accumulation of poly-phosphorus in microalgal cells. The analyses by PacBio’s sequencing and fluorescence in situ hybridization revealed that microalgal genus of Pantanalinema were the major phosphorus-accumulating organisms. Based on these experimental observations, the removal mechanisms of phosphorus by microalgal-bacterial granular sludge process were identified. It is expected that this study may shed lights on the pathways of biological phosphorus removal in microalgal-bacterial granular sludge process.
It is well known that the biology of Caligus rogercresseyi is strongly affected by environmental conditions such as temperature. However, little is known if these variables can affect antiparasitic ...sensitivity. In this context, the aim of the study was to determine how temperature and light can induce changes in the parasite sensitivity profile to azamethiphos. Temperatures of 9, 12, 15, and 17 °C and two light conditions were evaluated through sensitivity evaluation in vitro bioassays. Parasites were exposed to an azamethiphos concentration gradient of 0, 3, 10, 30, 100, and 300 ppb. A range of temperature between 12 °C and 15 °C did not significantly change the sensitivity profile of the parasite. Moreover, light conditions did not induce significant changes in the sensitivity profile either. However, the temperature of 9 °C induced higher effective concentrations (EC50) than the rest of the temperatures, but also lower affectation and mortality of the parasite. This evidence suggested that sensitivity to azamethiphos decreases with temperature, regardless of the light conditions. These results are considered relevant since strong variations of environmental conditions (like temperature) among seasons and geographical areas could impact salmon–parasite interactions, but also the effectiveness of the treatments applied in the salmon industry. Even more, in a climate change context, for which temperature is considered one of the main variables, it is expected that important changes occur in the biology, metabolism, and population dynamics of parasites, fish, and marine animals, being these changes a matter of concern in the future sustainability of aquaculture.
•Azamethiphos sensitivity profile of Caligus rogercresseyi changed with temperature.•Lower temperatures (9 °C) reduced the post-exposure mortality in C. rogercresseyi.•Light conditions did not change the sensitivity profile.•A negative association between EC50 values and seawater temperature was observed.
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•Eye flukes are suggested to change the defensive behavior of fish via vision impairment.•We tested whether changes in fish anti-predatory behavior depend on light ...conditions.•Trematodes Diplostomum pseudospathaceum manipulated Salvelinus malma behavior, making fish less vigilant.•The expression of behavioral changes did not differ under light or dark conditions.•A mechanism of manipulation other than vision impairment is likely to take place.
Trematodes localizing in the lenses of fish change the behavior of their hosts. These behavioral changes are widely suggested to be parasitic manipulations of host behavior aimed at increasing the possibility of eye flukes completing their life cycle. It is often assumed that fish change their behavior due to the vision deterioration caused by trematode larvae. We checked this assumption by testing Salvelinus malma infected with eye flukes (Diplostomum pseudospathaceum) under different lighting conditions. We suggested that if the parasite alters the host’s behavior through vision impairment, then in the dark (when fish do not rely on vision to navigate), the difference in the behavior of infected and uninfected fish would disappear. Eye flukes, indeed, changed fish behavior, making their hosts less vigilant. We believe this is the first evidence of possible parasitic manipulation in this study system. However, contrary to expectations, the difference in the behavior of infected and control fish was independent of the lighting conditions. Our results suggest that mechanisms of behavioral change other than vision impairment should be taken into account in this fish-eye fluke study system.
Wastewater from the leather finishing step in tanneries contains high nutrient loads and toxic compounds, such as dyes, acids, toxic metals among others. To our best knowledge, for the first time, ...the influence of light period on the treatment of wet-end and finishing leather wastewaters with a microalgae consortium containing mainly Tetraselmis sp. was investigated. In this work, a microalgae consortium present the ability to grow well in this kind of tannery wastewater and was used for reducing nitrogen, phosphorus, ammonium, chemical and biochemical oxygen demands. Additionally, the wastewater presents high turbidity, which has an influence on the penetration of light, during the cultivations. Therefore, the influence of the illumination period was also studied: continuous light (24-light), 12 h light/dark (12-light) and without light (0-light); in addition to the influence of compositions, 50% and 75% of raw wastewater. The maximum concentration of biomass in the wastewater was observed in the 24-light culture: 50R50S (1.40 gL-1) and 75R25S (1.04 gL-1), with maximum removals of total nitrogen (71.74%), total phosphorus (97.64%), total organic carbon (31.35%), chemical oxygen demand (56.70%), biological oxygen demand (20.68%) and ammonium (100%). These results show that this microalgae consortium is a promising alternative treatment for wastewaters of the leather wet-end and finishing steps.
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•A microalgae consortium was isolated from a deactivated tannery wastewater plant.•Consortium containing mainly Tetraselmis sp. was used in tannery wastewater treatment.•The microalgae consortium grew (1.40 g L−1) in the wastewater from the leather finishing stage.•Nutrient removal of tannery wastewater reached: 95.54% of P-PO4, 58.84% of TN and 100% of N–NH3.•Continuous light favored the cultivation mixotrophic of the microalgae consortium.
Alternative acceptors for fullerene-derivatives need to be considered for indoor organic photovoltaics (OPVs) due to their spectrally inefficient light absorption ability and photo-instability which ...limits performance. Here, we report a highly efficient and photo-stable indoor OPV comprising an amalgamation of a wide band-gap donor(poly(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo1,2-b:4,5-b’dithiophene))-alt-(5,5-(1′,3′-di-2-thienyl-5′,7′-bis(2-ethylhexyl)benzo1′,2′-c:4′,5′-c’dithiophene-4,8-dionz) and a modified ITIC-based NFA (3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis (4-hexylmeta-phenyl)-dithieno 2,3-2′,3′-d’-s indaceno 1,2b:5,6b dithiopheneethylexyloxy) (m-ITIC-O-EH)) with alkoxy side chains. Due to its excellent absorption properties in the near-infrared region, the m-ITIC-O-EH-based OPV exhibited an extraordinarily high maximum output power density (Pmax) (95.6 μW/cm2), >3 times greater than the Pmax (31.9 μW/cm2) of a reference fullerene acceptor-based (PC70BM) OPV under a 1000 lx halogen lamp (Pin = 8.4 mW/cm2). Furthermore, the m-ITIC-O-EH-based OPV exhibited satisfactory photo-stability with >80% retention of its initial power conversion efficiency (PCE) under the continuous light soaking of the halogen lamp (1000 lx) for 12 h. The high-indoor performance of the alkoxy-substituted NFA-based OPVs highlights their potential for implementation in Internet of Things applications.
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•ITIC-based NFA material (m-ITIC-O-EH) is utilized in indoor organic photovoltaics.•NFA-based OPVs exhibited outstanding Pmax of 95.6 μW/cm2 under 1000lx halogen lamp.•The NFA has an excellent absorption property in the near-infra red region.•NFA-based OPVs exhibited remarkable efficiency of 21.6% under 1000-lx LED lamp.•NFA-based OPVs revealed superb photostability under 1000-lx halogen lamp.
We report the indoor performance of flexible organic photovoltaic devices utilizing quasi-amorphous ZnO/Ag/ZnO as the transparent conducting electrode. A ZnO/Ag/ZnO electrode with specific thickness ...values of 40/9/50 nm provides excellent transparent conducting electrode properties with transmittances up to 92% in the visible region, a sheet resistance of 4.8 Ω/sq, and a root-mean squared surface roughness value of 2.1 nm. In addition, the micro-cavity effect and quasi-amorphous structural properties of the ZnO/Ag/ZnO electrode allow further enhanced light absorption and mechanical stability, respectively. Poly (3-hexylthiophene):indene-C60 bisadduct photoactive layer-based inverted organic photovoltaics with the ZnO/Ag/ZnO (40/9/50 nm) electrode yield an averaged power-conversion efficiency of 12.3% under a light-emitting diode lamp with a luminance of 500 lux, which is 20% greater than the power-conversion efficiency value of the reference organic photovoltaics with an indium tin oxide electrode. Furthermore, the same organic photovoltaics on flexible polyethylene terephthalate substrates exhibit excellent mechanical stability (i.e., 92% of the initial power-conversion efficiency value is maintained even after 400 bending cycles with a bending radius of 9.55 mm), with averaged power-conversion efficiency values of 10.2% under the 500-lux light-emitting diode.
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•OPVs with clear and flexible ZnO/Ag/ZnO electrodes are fabricated.•Quasi-amorphous ZnO/Ag/ZnO electrodes provide excellent mechanical flexibility.•Micro-cavity effects via ZnO/Ag/ZnO enhance light absorption into OPVs.•ZnO/Ag/ZnO-based OPVs show a 12.3% conversion efficiency under a 500 lux LED.
