scholarly journals Dietary Chitosan Nanoparticles: Potential Role in Modulation of Rainbow Trout (Oncorhynchus mykiss) Antibacterial Defense and Intestinal Immunity against Enteric Redmouth Disease

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 72
Author(s):  
Fatma Ahmed ◽  
Faiza M. Soliman ◽  
Mohamed A. Adly ◽  
Hamdy A. M. Soliman ◽  
Mansour El-Matbouli ◽  
...  

Bio-nanotechnology employing bio-sourced nanomaterial is an emerging avenue serving the field of fish medicine. Marine-sourced chitosan nanoparticles (CSNPs) is a well-known antimicrobial and immunomodulatory reagent with low or no harm side effects on fish or their human consumers. In this study, in vitro skin mucus and serum antibacterial activity assays along with intestinal histology, histochemical, and gene expression analyses were performed to evaluate the impact of dietary CSNPs (5 g kg−1 dry feed) on rainbow trout resistance against ‘enteric redmouth’ disease. Two treatment conditions were included; short-term prophylactic-regimen for 21 days before the bacterial challenge, and long-term therapeutic-regimen for 21 days before the challenge and extended for 28 days after the challenge. Our results revealed higher antibacterial defense ability and positive intestinal histochemical and molecular traits of rainbow trout after dietary CSNPs. The prophylactic-regimen improved trout health while the therapeutic regimen improved their disease resistance and lowered their morbidity. Therefore, it is anticipated that CSNPs is an effective antibacterial and immunomodulatory fish feed supplement against the infectious threats. However, the CSNPs seem to be more effective in the therapeutic application rather than being used for short-term prophylactic applications.

Author(s):  
Philip Niclas Just ◽  
Bernd Köllner ◽  
Matthew James Slater

AbstractPrecisely analysing and optimising feeding regimes is central to salmonid growth performance and delivery of special diets. The current study developed novel video surveillance methods and analysis techniques to assess individual feed intake and minimum pellet intake (MPI) in individually identified juvenile rainbow trout, Oncorhynchus mykiss. Three trials were conducted to test the impact of short-term starvation (N=112 [16 tanks, 7 fish per tank], average weight=27.1±3.4g, age= 119 days), portion numbers per feeding (N=105 [15 tanks, 7 fish per tank], average weight=22.8±2.1g, age= 99 days) and varied numbers of daily feeding events (N=84 [12 tanks, 7 fish per tank], average weight=32.4±3.3g, age= 133 days). All trails were carried out in a recirculating aquaculture system with 20 tanks held at 15 ± 0.5°C. All individuals were code-tagged and high quality video images were taken and analysed to identify all feeding interactions. Individual trout feeding activity under different feeding regimes could be precisely analysed with the video methods developed. Moving from one to two daily feeding events doubled pellet intake per fish from 27.4 ± 5.8 to 52.8 ± 11.5 pellets. Pellet intake (58.8 ± 24.2 pellets) did not increase at three daily feeding events but became more variable across fish. MPI nearly doubled to 30 pellets in fish receiving two daily feeding events (MPI30: chi-squared = 8.74, df = 2, p = 0.01). Short-term starvation had no influence on intake (28 ± 8 pellets/fish) or MPI. Increasing portion number from one (27.8 ± 7.4 pellets fish−1) to two (31.1 ± 7.4 pellets fish−1) or more did not significantly increase the number of ingested pellets. Adjusting the feeding regime by increasing daily feeding events to two, possibly combined with multiple portions, can increase pellet intake and reduce the heteroscedasticity of pellet intake. The methods presented in this study are viable for analysing feeding regimes for juvenile rainbow trout and controlled feedstock/supplement delivery. Implications for analyses with other species and for vaccination optimisation are discussed.


Author(s):  
I. Y. Bobel ◽  
J. I. Pivtorak

Growing trout under closed water supply is linked to economic issues such as high planting density per unit area and the choice of granular feed, which in terms of value should be inexpensive and fully meet the needs of fish with all the necessary nutrients and nutrition. This approach is reflected in the materials of the scientific and practical publication on the intensity of growth and assessment of marketable qualities of trout for use in the feeding of granulated compound feeds of the firm “Aller Aqua”. Scientific research consisted in determination of morphometric indices of different age groups of trout, studies of chemical, amino acid and lipid composition of tissues, which allowed us to draw conclusions about the efficiency of feeding fish with the investigated feed. The research and production experiment was conducted in the conditions of PJSC “Bilshevtsi-Fish”, located in the village Bilshevtsi of Ivano-Frankivsk region. In order to study the effect of different types of compound feed on the exchange processes in rainbow trout, three-stage studies were conducted. The research is based on a comparative assessment of the impact of the above granular feed on the overall functional state of fish growth and quality indicators of the products obtained. The selection of appropriate feed for the rational supply of fish needs with all the necessary nutrients is of particular importance in the planned production of salmon fisheries, the demand for which is constantly growing in human nutrition. Therefore, the nutrients contained in the feed should not only support the vital activity of the organism, but also promote its growth and ensure the normal functioning of the whole organism. The feed used granular feed from the manufacturer Aller Aqua and Biomar, the recipe and the diameter of the granules according to the age and weight of the fish. Feed composition and nutrition were consistent with the period of fish cultivation. The daily rate of feed was calculated in accordance with conventional methods in fisheries, taking into account the temperature of the water and the weight of the fish. The purpose of the study was to study the effect of the tested feed on the functional state of growth, biochemical parameters of muscle tissue and liver. Only healthy fish without visible damage, which were caught immediately prior to the study, were used for the study and were not fed for 24 h. During the research, the main linear indicators were determined using conventional techniques in fisheries. The conducted studies allow us to conclude on the direct link between the marketable qualities of rainbow trout and the feed consumed, their quality composition and nutritional value. In addition, the influence of abiotic factors, which were the same for all trout groups studied, were considered, which are equally important and, along with rational feeding, occupy a key place in production.


Author(s):  
Florian Arendt

A test was done to see if reading a newspaper which consistently overrepresents foreigners as criminals strengthens the automatic association between foreign country and criminal in memory (i.e., implicit cultivation). Further, an investigation was done to find out if reading articles from the same newspaper produces a short-term effect on the same measure and if (1) emotionalization of the newspaper texts, (2) emotional reactions of the reader (indicated by arousal), and (3) attributed text credibility moderate the short-term treatment effect. Eighty-five participants were assigned to one of three experimental conditions. Participants in the control group received short factual crime texts, where the nationality of the offender was not mentioned. Participants in the factual treatment group received the same texts, but the foreign nationality was mentioned. Participants in the emotionalized treatment group received emotionalized articles (i.e., texts which are high in vividness and frequency) covering the same crimes, with the foreign nationality mentioned. Supporting empirical evidence for implicit cultivation and a short-term effect was found. However, only emotionalized articles produced a short-term effect on the strength of the automatic association, indicating that newspaper texts must have a minimum of stimulus intensity to overcome an effect threshold. There were no moderating effects of arousal or credibility pertaining to the impact on the implicit measure. However, credibility moderated the short-term effect on a first-order judgment (i.e., estimated frequency of foreigners of all criminals). This indicates that a newspaper’s effect on the strength of automatic associations is relatively independent from processes of propositional reasoning.


Author(s):  
Irina A. Prushkovskaya ◽  
Ira B. Tsoy

The study of diatoms in the sediments of the Amur Bay (Sea of Japan), formed over the last 2000 years, showed that the sharp short-term drops in the concentration of diatoms coincide with the minima of bromine content, which can be explained by the influence of typhoons or other catastrophic events leading to floods and used later in paleoreconstructions.


2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Masruchin Masruchin

Corporate Social Responsibilityis a concept that a company has various forms of responsibility to all stakeholders including consumers, employees, shareholders, communities and the environment in all aspects of the company's operations that include economic, social, and environmental aspects. Therefore CSR is closely related to "sustainable development", in which a company, in carrying out its activities must base its decisions not only on the impact on economic aspects, such as the level of profits or dividends (profits), but also must consider the social and environmental impacts that arise from that decision, both for the short term and the longer term.Pondok Modern Darussalam Gontor (PMDG), in managing its Productive Waqf by establishing business units which mostly involve workers from the local society around PMDG. They are employed according to their skills. This is a form of implementing CSR in order to help advance and improve the welfare of the local society. The existence of these various business units is one of the educational facilities and as a form of CSR application which is actually intended to educate in the fields of independence, entrepreneurship, sincerity and sacrifice.PMDG involvement in social activities that are useful for the local society such as infrastructure development and village facilities, regeneration of students who are from around PMDG to be able to get higher education with funding from the PMDG, doing guidance to the local society through various religious activities, educational and economic activities is a form of PMDG responsibility to the local society environment and also to all stakeholders such as students, Ustadz, employees, so as to provide social and environmental impacts for the short term and the longer term.Keywords: Corporate Social Responsibilityandproductive waqf.


Psibernetika ◽  
2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Devina Calista ◽  
Garvin Garvin

<p><em>Child abuse by parents is common in households. The impact of violence on children will bring short-term effects and long-term effects that can be attributed to their various emotional, behavioral and social problems in the future; especially in late adolescence that will enter adulthood. Resilience factors increase the likelihood that adolescents who are victims of childhood violence recover from their past experiences</em><em>,</em><em> become more powerful individuals and have a better life. The purpose of this study was to determine the source of resilience in late adolescents who experienced violence from parents in their childhood. This research uses qualitative research methods with in-depth interviews as a method of data collection. The result shows that the three research participants have the aspects of "I Have", "I Am", and "I Can"; a participant has "I Can" aspects as a source of resilience, and one other subject has no source of resilience. The study concluded that parental affection and acceptance of the past experience have role to the three sources of resilience (I Have, I Am, and I Can)</em></p><p><em> </em></p><p><strong><em>Keyword : </em></strong><em>Resilience, adolescence, violence, parents</em></p>


Erdkunde ◽  
2020 ◽  
Vol 74 (3) ◽  
pp. 191-204
Author(s):  
Marcus Hübscher ◽  
Juana Schulze ◽  
Felix zur Lage ◽  
Johannes Ringel

Short-term rentals such as Airbnb have become a persistent element of today’s urbanism around the globe. The impacts are manifold and differ depending on the context. In cities with a traditionally smaller accommodation market, the impacts might be particularly strong, as Airbnb contributes to ongoing touristification processes. Despite that, small and medium-sized cities have not been in the centre of research so far. This paper focuses on Santa Cruz de Tenerife as a medium-sized Spanish city. Although embedded in the touristic region of the Canary Islands, Santa Cruz is not a tourist city per se but still relies on touristification strategies. This paper aims to expand the knowledge of Airbnb’s spatial patterns in this type of city. The use of data collected from web scraping and geographic information systems (GIS) demonstrates that Airbnb has opened up new tourism markets outside of the centrally established tourist accommodations. It also shows that the price gap between Airbnb and the housing rental market is broadest in neighbourhoods that had not experienced tourism before Airbnb entered the market. In the centre the highest prices and the smallest units are identified, but two peripheral quarters stand out. Anaga Mountains, a natural and rural space, has the highest numbers of Airbnb listings per capita. Suroeste, a suburban quarter, shows the highest growth rates on the rental market, which implies a linkage between Airbnb and suburbanization processes.


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