harmful species
Recently Published Documents


TOTAL DOCUMENTS

89
(FIVE YEARS 35)

H-INDEX

11
(FIVE YEARS 2)

2022 ◽  
Author(s):  
Syreina SAYEGH ◽  
Fida Tanos ◽  
Amr Nada ◽  
Geoffroy Lesage ◽  
Francois Zaviska ◽  
...  

The demand for fresh and clean water sources increases globally, and there is a need to develop novel routes to eliminate micropollutants and other harmful species from water. Photocatalysis is...


2021 ◽  
Author(s):  
Xudong Li ◽  
Ye Tao ◽  
Longwei Zhu ◽  
Shuaishuai Ma ◽  
Shipeng Luo ◽  
...  

Abstract. In ambient air, aqueous-phase oxidation may turn precursors into more light-absorbing and toxic products, leading to air quality deterioration and adverse health effects. In this study, we investigated eugenol degradation in aqueous phase under direct photolysis, and triplet excited organic (3C*) and hydroxyl radical (OH) as oxidants. Results showed degradation rates of eugenol followed the order of 3C* > OH > direct photolysis. Relative contributions of reactive oxygen species (ROS) and 3C* were evaluated via quenching and O2-free experiments. 3C* played a dominant role in eugenol degradation for 3C*-initiated oxidation, while both O2 and O2•-generated were important for eugenol degradation for OH-initiated oxidation. Rate constants under O2, air and N2 followed the order of ko2>kAir>kN2 under both direct photolysis and OH oxidation, and it changed to kAir>kN2>ko2 in 3C*-initiated oxidation. Light absorption spectra showed absorbance at 300–400 nm increased as photolysis progressed, and there were new broad fluorescent spectra at excitation/emission (Ex/Em) = 250/(400–500) nm, suggesting the formation of new chromophores and fluorophores, such as humic-like substances (HULIS). Additionally, distinct fluorescence peaks appeared at Ex/Em=(300–350)/300 nm at different stages. Concentration of generated HULIS increased gradually over time, then leveled off. Dithiothreitol (DTT) assay was applied to assess the oxidation potential of products, which was greater than pure eugenol, suggesting more harmful species were produced during oxidation. Detailed reaction pathways were elucidated via analyses of chemical characteristics of the products.


2021 ◽  
Vol 944 (1) ◽  
pp. 012027
Author(s):  
T Sidabutar ◽  
H Cappenberg ◽  
E S Srimariana ◽  
A Muawanah ◽  
S Wouthuyzen

Abstract The first disaster caused by harmful algal blooms in Lampung Bay was reported in 1991, where mass mortality of cultivated shrimp occurred in the brackish water ponds due to a Trichodesmium bloom. After this incident, the phenomenon reoccured in the following years continuously. Around nine species bloom makers in this bay are namely Pyrodinium sp., Noctiluca sp., Phaeocystis sp., Dinophysis sp., Trichodesmium sp., Ceratium sp., Prorocentrum sp., Pseudonitzhia sp., and Cochlodinium sp. The most frequent causative species, such as green Noctiluca and Trichodesmium, co-occurring during blooms and causing fish mortalities in the fish farming floating nets (KJA). Two species are known as the most potentially harmful species, namely Pyrodinium sp. and Cochlodinium sp. Cochlodinium blooms happened at the end of 2012, and since then, this species has continuously reappeared in the following years. The outbreak of Cochlodinium sp. still appeared in 2017 and 2018, but no fish-killing occurred. Phytoplankton bloom events occur at specific locations, mainly at fish farming floating nets on the west side of the bay, next to Hurun Cove. This paper discusses the occurrence of algal blooms in Lampung Bay and the triggering factors for increasing phytoplankton populations that cause harmful algal blooms.


Author(s):  
Anuranjan Pandey

Abstract: In the tropical jungle, hearing a species is considerably simpler than seeing it. The sounds of many birds and frogs may be heard if we are in the woods, but the bird cannot be seen. It is difficult in this these circumstances for the expert in identifying the many types of insects and harmful species that may be found in the wild. An audio-input model has been developed in this study. Intelligent signal processing is used to extract patterns and characteristics from the audio signal, and the output is used to identify the species. Sound of the birds and frogs vary according to their species in the tropical environment. In this research we have developed a deep learning model, this model enhances the process of recognizing the bird and frog species based on the audio features. The model achieved a high level of accuracy in recognizing the birds and the frog species. The Resnet model which includes block of simple and convolution neural network is effective in recognizing the birds and frog species using the sound of the animal. Above 90 percent of accuracy is achieved for this classification task. Keywords: Bird Frog Detection, Neural Network, Resnet, CNN.


2021 ◽  
Vol 13 (31) ◽  
pp. 44-55
Author(s):  
Ivelina Nikolova ◽  

The field work was performed at the experimental field of the Institute of Forage Crops, Pleven, Bulgaria during the period of 2006-2009. The share distribution of the orders Coleoptera, Thysanoptera, Diptera, Orthoptera and Hemiptera, suborder Sternorrhyncha, Heteroptera, Fulgoromorpha and Cicadomorpha was established for every four alfalfa growth cycles during the vegetation period for four years. It was found that the share participation of orders was determined primarily by the population dynamics of the dominant insect species and it was closely dependent on plant development following a characteristic course over the years. Depending on the food specialization and the division of the species into harmful and beneficial, the share of predators in regrowth corresponded to that of their prey. A clear trend was observed of increasing the share of harmful species and reducing the beneficial ones (Coleoptera, Thysanoptera, Hemiptera: Heteroptera) with the alfalfa development over the years.


Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1824
Author(s):  
Gaetana Napolitano ◽  
Gianluca Fasciolo ◽  
Paola Venditti

Mitochondria in aerobic eukaryotic cells are both the site of energy production and the formation of harmful species, such as radicals and other reactive oxygen species, known as ROS. They contain an efficient antioxidant system, including low-molecular-mass molecules and enzymes that specialize in removing various types of ROS or repairing the oxidative damage of biological molecules. Under normal conditions, ROS production is low, and mitochondria, which are their primary target, are slightly damaged in a similar way to other cellular compartments, since the ROS released by the mitochondria into the cytosol are negligible. As the mitochondrial generation of ROS increases, they can deactivate components of the respiratory chain and enzymes of the Krebs cycle, and mitochondria release a high amount of ROS that damage cellular structures. More recently, the feature of the mitochondrial antioxidant system, which does not specifically deal with intramitochondrial ROS, was discovered. Indeed, the mitochondrial antioxidant system detoxifies exogenous ROS species at the expense of reducing the equivalents generated in mitochondria. Thus, mitochondria are also a sink of ROS. These observations highlight the importance of the mitochondrial antioxidant system, which should be considered in our understanding of ROS-regulated processes. These processes include cell signaling and the progression of metabolic and neurodegenerative disease.


2021 ◽  
Vol 65 (3) ◽  
pp. 79-85
Author(s):  
J. Němeček ◽  
P. Trávníček ◽  
J. Němečková ◽  
J. Kruis

Abstract The paper is primarily focused on the description of transport of harmful species in concrete such as chlorides on one side and transport of corrosion inhibitors and nanoparticles used to diminish corrosion of steel reinforcement or seal the microstructure of concrete on the other side. The studied processes are helpful in reverting the chloride induced corrosion of the reinforcement in reinforced concrete structures. The transport mechanisms are summarized with the emphasis on their mathematical description and numerical solution. The paper shows modeling results of the processes including a comparison with experimental data on several typical examples. The efficiency of the methods is shown supported by experimental and numerical results. A good correlation of the models with experiments is achieved.


Amino Acids ◽  
2021 ◽  
Author(s):  
Patricia Padilla ◽  
María J. Andrade ◽  
Fernando J. Peña ◽  
Alicia Rodríguez ◽  
Mario Estévez

AbstractThis study was designed to gain information about the underlying mechanisms of the effects of a food-occurring free oxidized amino acid, α-aminoadipic acid (AAA), on the probiotic Lactobacillus reuteri PL503. This bacterium was incubated in colonic-simulated conditions (37 °C for 24 h in microaerophilic conditions) and exposed to three food-compatible AAA concentrations, namely, 1 mM, 5 mM, and 10 mM. A control group with no AAA exposure was also considered. Each of the four experimental conditions was replicated three times and samplings were collected at 12, 16, 20, and 24 h. The downregulation of the uspA gene by AAA (0.5-fold decrease as compared to control) suggests that AAA is identified as a potential chemical threat. The dhaT gene, implicated in the antioxidant defense, was found to be upregulated in bacteria treated with 1 and 5 mM AAA (up to twofold increase, as compared to control), which suggest the ability of the oxidized amino acid to impair the redox status of the bacterium. In fact, AAA caused an increased production of reactive oxygen species (ROS) and the accretion of post-translational changes (protein carbonylation) in L. reuteri (up to 13 nmol allysine/mg protein vs 1.8 nmol allysine/mg protein in control). These results suggest that probiotic bacteria identify oxidized amino acids as harmful species and activate mechanisms that may protect themselves and the host against their noxious effects.


2021 ◽  
Vol 785 ◽  
pp. 147378
Author(s):  
Camilo Rodríguez-Villegas ◽  
Matthew R. Lee ◽  
Pablo Salgado ◽  
Rosa I. Figueroa ◽  
Ángela Baldrich ◽  
...  

2021 ◽  
Vol 02 (05) ◽  
pp. 39-42
Author(s):  
Gulnoz Yarashovna Samandarova ◽  

This article reveals the basics of Uzbek folk paremas formed on the basis of the lexical-spiritual group of "Insects''. According to it, the Uzbek folk parems, formed on the basis of the lexical-spiritual group of "Insects'', are mostly formed by the appearance, biological characteristics, color and lifestyle of insects. It was noted that in the Uzbek folk paremas formed on the basis of insect names, paremas formed on the basis of harmful insect names are more common. The reason for this is that there are more harmful species of insects than beneficial ones, and another reason is the idea that bad people are quick to notice, indifferent to everything, indifferent to everything that does no good to those around them, rather than good people who benefit society. The Uzbek folk parems formed on the basis of the names of "Insects" are substantiated by the fact that they appear in the semaphores as a positive character-defining, moderate-character-defining, negative-character-determining factor. In Uzbek folk paremas, it is said that the names of insects serve as a means of providing imagery to express people's appearance, behavior, character, speech, just to name a few, and building a proper comparison, analogy, transfer of meaning.


Sign in / Sign up

Export Citation Format

Share Document