Long-term exposure of Pacu (Piaractus mesopotamicus) fish to dietary aflatoxin B1: residues in tissues and performance

2021 ◽  
pp. 1-10
Author(s):  
E.C. Michelin ◽  
C.M. Bedoya-Serna ◽  
L.C.S. Carrion ◽  
S.H.S. Godoy ◽  
J.C. Baldin ◽  
...  
Keyword(s):  
High Performance ◽  
Fish Muscle ◽  
Negative Influence ◽  
Fish Feed ◽  
Piaractus Mesopotamicus ◽  
And Performance ◽  
Aflatoxin B ◽  
Slight Amount ◽  
Standard Weight

The objective of this work was to evaluate the aflatoxins residues on tissues of Pacu (Piaractus mesopotamicus) fish chronically exposed to dietary aflatoxins, also evaluating the effects on fish performance. Aflatoxins were incorporated into the extruded fish feed and the concentrations were confirmed by high performance liquid chromatography (HPLC). The experimental design comprised the following treatments: Control – feed without toxin; Treatment A: feed + 10 μg aflatoxin B1 (AFB1)/kg; Treatment B: feed + 20 μg AFB1/kg and Treatment C: feed + 50 μg AFB1/kg. Pacu juvenile were allocated in tanks with density of one fish per litter. The experiment lasted 180 days with monthly sampling, and approximately ten fish per treatment were used to compose a sample. Biometric surveys were performed every 30 days, including standard weight and length. Aflatoxins were detected and quantified in fish muscle and liver by HPLC, using immunoafinity columns. Results showed AFB1 deposition in the liver throughout the experiment in all treatments, but only treatment C differed significantly (P<0.05) from the others after 150 days, while in muscle there was low residual deposition. Long-term exposed fish had negative influence in weight and length. The higher mortality was observed in treatment C. Although there were AFB1 residues at low levels in liver and only a slight amount in fish muscle, it should be noted that accumulation is possible in the Pacu species. The diets contaminated with AFB1 negatively interfered in weight and length of fish when compared to control. Therefore, it can be concluded that long-term exposure of Pacu to dietary AFB1 can cause losses to producers.

scholarly journals Evaluation of a Cold-Mixed High-Performance Polyurethane Mixture

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Sun Min ◽  
Yufeng Bi ◽  
Mulian Zheng ◽  
Sai Chen ◽  
Jingjing Li
Keyword(s):  
Energy Consumption ◽  
High Performance ◽  
Greenhouse Gas Emission ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
Water Stability ◽  
High Temperature Stability ◽  
Forming Mechanism ◽  
And Performance

The energy consumption and greenhouse gas emission of asphalt pavement have become a very serious global problem. The high-temperature stability and durability of polyurethane (PU) are very good. It is studied as an alternative binder for asphalt recently. However, the strength-forming mechanism and the mixture structure of the PU mixture are different from the asphalt mixture. This work explored the design and performance evaluation of the PU mixture. The PU content of mixtures was determined by the creep slope (K), tensile strength ratios (TSR), immersion Cantabro loss (ICL), and the volume of air voids (VV) to ensure better water stability. The high- and low-temperature stability, water stability, dynamic mechanical property, and sustainability of the PU mixture were evaluated and compared with those of the stone matrix asphalt mixture (SMA). The test results showed that the dynamic stability and bending strain of the PU mixture were about 7.5 and 2.3 times of SMA. The adhesion level of PU and the basalt aggregate was one level greater than the limestone, and basalt aggregates were proposed to use in the PU mixture to improve water stability. Although the initial TSR and ICL of PU mixture were lower, the long-term values were higher; the PUM had better long-term water damage resistance. The dynamic modulus and phase angles (φ) of the PU mixture were much higher. The energy consumption and CO2 emission of the PU mixture were lower than those of SMA. Therefore, the cold-mixed PU mixture is a sustainable material with excellent performance and can be used as a substitute for asphalt mixture.

scholarly journals High performance leadership in unusually challenging educational circumstances

2015 ◽  
Vol 3 (1) ◽  
pp. 28-49 ◽  
Author(s):  
Andy Hargreaves ◽  
Alma Harris
Keyword(s):  
High Performance ◽  
Educational Achievement ◽  
Limited Resources ◽  
Short Term ◽  
Past Performance ◽  
High Performing ◽  
The Face ◽  
Oecd Pisa ◽  
And Performance

This paper draws on findings from the results of a study of leadership in high performing organizations in three sectors. Organizations were sampled and included on the basis of high performance in relation to no performance, past performance, performance among similar peers and performance in the face of limited resources or challenging circumstances. The paper concentrates on leadership in four schools that met the sample criteria.  It draws connections to explanations of the high performance ofEstoniaon the OECD PISA tests of educational achievement. The article argues that leadership in these four schools that performed above expectations comprised more than a set of competencies. Instead, leadership took the form of a narrative or quest that pursued an inspiring dream with relentless determination; took improvement pathways that were more innovative than comparable peers; built collaboration and community including with competing schools; and connected short-term success to long-term sustainability.

Effects of dietary aflatoxin on biochemical parameters and histopathology of liver in Matrinxã (Brycon cephalus) and Pacu (Piaractus mesopotamicus) fish

2021 ◽  
pp. 1-10
Author(s):  
E. C. Michelin ◽  
C. M. Bedoya-Serna ◽  
L. C. S. Carrion ◽  
N. Levy-Pereira ◽  
F. S. Cury ◽  
...  
Keyword(s):  
Biochemical Parameters ◽  
Juvenile Fish ◽  
Fatty Degeneration ◽  
Hepatic Tissue ◽  
Blood Collection ◽  
Fish Feed ◽  
Hydropic Degeneration ◽  
Piaractus Mesopotamicus ◽  
Liver Changes ◽  
Aflatoxin B

The objective of this study was to evaluate biochemical parameters and histopathology of liver in Matrinxã (Brycon cephalus) and Pacu (Piaractus mesopotamicus) fish chronically exposed to dietary aflatoxins. Fish feed was artificially contaminated with aflatoxins and the treatments were: Control – feed without toxin; Treatment A – feed + 10 μg aflatoxin B1 (AFB1)/kg; Treatment B – feed + 20 μg AFB1/kg; and Treatment C – feed + 50 μg AFB1/kg. Matrinxã and Pacu juvenile fish were placed in tanks for 180 days. Five experimental units per treatment were monthly sampled and submitted to blood collection and removal of hepatic tissue. Thus, twenty blood and liver samples for each species were collected monthly, adding up to 240 samples analysed. To verify biochemical changes, analyses included total proteins, albumin, globulins, aspartate aminotransferase (AST) and alkaline phosphatase (ALP). The hepatic tissue was examined microscopically and the slides presenting histopathological changes were photo-documented. There was effect of treatment (P<0.05) for AST and ALP in Matrinxã, while no effect (P>0.05) was observed in Pacu. A reduction (P<0.05) in AST and ALP values during the time of exposure was observed in all treatments for both species. Fatty degeneration and liver damage were observed for both species in treatments exposed to aflatoxins. Fatty degeneration in Pacu was noticed after 30 days of exposure, while in Matrinxã it was observed after 60 days. Disorganisation of the hepatocyte cord arrangement was also observed in those treatments exposed to aflatoxin, following 90 days of exposure in Matrinxã, and after 60 days in Pacu. Therefore, aflatoxins have little influence on biochemical parameters in the species evaluated. However, exposure to aflatoxins caused liver changes, such as cell death, fatty and hydropic degeneration, thus it could be concluded that both species are susceptible to the toxic effects of long-term exposure to dietary AFB1.

Knowledge and performance in action

2004 ◽  
Vol 8 (4) ◽  
pp. 38-53 ◽  
Author(s):  
Thomas Schack
Keyword(s):  
High Performance ◽  
Human Performance ◽  
Cognitive Architecture ◽  
Long Term Memory ◽  
Object Knowledge ◽  
Training Techniques ◽  
Action Knowledge ◽  
And Performance ◽  
High Level

This article addresses the functional links between knowledge and performance in human activity. Starting with the evolutionary roots of knowledge and activity, it shows how the combination of adaptive behavior and knowledge storage has formed over various stages of evolution. The cognitive architecture of human actions is discussed against this background, and it is shown how knowledge is integrated into action control. Then, methodological issues in the study of action knowledge are considered, and an experimental method is presented that can be used to assess the structure of action knowledge in long‐term memory. This method is applied in studies on the relation between object knowledge and performance in mechanics and between movement knowledge and performance in high‐performance sportswomen. These studies show how experts’ knowledge systems can be assessed, and how this may contribute to the optimization of human performance. In high‐level experts, these representational frameworks were organized in a highly hierarchical tree‐like structure, were remarkably similar between individuals, and matched well the functional demands of the task. In comparison, the action representations in low‐level performers were organized less hierarchically, were more variable between persons, and were not so well in accordance with functional demands. These results support the hypothesis that voluntary actions are planned, executed, and stored in memory directly by way of representations of their anticipated perceptual effects. The method offers new possibilities to investigate knowledge structures. Based on such results it is possible to improve performance via special training‐techniques. This paper fulfils an identified research need concerning the interaction of knowledge and performance and offers new perspectives for future forms of knowledge management.

scholarly journals Athletes’ and Coaches’ Perceptions of Nutritional Advice: Eating More Food for Health and Performance

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1925
Author(s):  
Danielle M. Logue ◽  
Laura Mahony ◽  
Clare A. Corish ◽  
David Tobin ◽  
Ronan Doherty ◽  
...  
Keyword(s):  
High Performance ◽  
Online Communication ◽  
Self Awareness ◽  
Structured Interviews ◽  
Meal Preparation ◽  
Nutritional Advice ◽  
Physiological Adaptations ◽  
And Performance ◽  
Low Energy Availability

Background: Low energy availability results in physiological adaptations which contribute to unfavourable health outcomes. Little information exists on perceptions of nutritional advice to eat more food to maintain health and enhance performance. The aim of this study was to explore athletes’ and coaches’ perceptions towards advice to athletes to eat larger than their current quantities of food and to explore how nutritionists could deliver this advice. Methods: Semi-structured interviews (~20 minutes in length) were conducted using online communication technology, audio-recorded, and transcribed verbatim. The interview explored perceptions of the nutritional advice provided, its role in health and performance, and the challenges to eating larger amounts of food. Data were analysed using NVIVO 1.2 using an inductive thematic approach. Results: Nine elite athletes (female = 6; males = 3) and nine high-performance coaches (female = 3; male = 6) completed the semi-structured interviews. Athletes reported improved training consistency, fewer injuries and illnesses, and improved resilience when consuming adequate energy and nutrients to meet their needs. Lack of time and meal preparation difficulties were the main challenges faced to fuelling. Conclusions: Although education about under-fuelling is important, motivating, enabling, and supporting athletes to change behaviour is pivotal to increasing athlete self-awareness and to make long-term nutritional changes.

Measuring Psychological Load in Sport

2021 ◽  
Author(s):  
Stephen Mellalieu ◽  
Christopher Jones ◽  
Christopher Wagstaff ◽  
Simon Kemp ◽  
Matthew J. Cross
Keyword(s):  
High Performance ◽  
Subjective Assessment ◽  
Physical Load ◽  
Future Research ◽  
Conceptual Clarity ◽  
Future Research Directions ◽  
And Performance ◽  
The Impact ◽  
Mental And Physical Health

AbstractMonitoring the physical load undertaken by athletes and examining the subsequent relationship with performance and injury and illness risk is common practice in high performance sport. Less attention has been paid to the psychological factors contributing to the overall load experienced and the impact upon health status and performance. This paper discusses considerations for the conceptualization and measurement of psychological load in sport. First, we outline the importance of ensuring conceptual clarity is adopted in the measurement of psychological load. Next, we discuss the challenges to measuring psychological load in a comparable manner to which physical load is currently evaluated, including use of subjective assessment, adoption of specific and global approaches, and development of measurement instrumentation, techniques, and expertise. We then offer recommendations for practitioners when undertaking assessment of psychological load in sport. We conclude with future research directions to advance the study and measurement of the construct, including the interaction between psychological and physical load, the appraisal of the load faced, and personal and social resources available to successfully cope. We also highlight the need to consider groups of athletes (e. g., transitioning athlete, long-term injured) at greater risk from threats to mental and physical health from increased psychological load.

scholarly journals The Efficacy of an Online Cognitive Assessment Tool for Enhancing and Improving Student Academic Outcomes

2019 ◽  
Vol 23 (2) ◽  
Author(s):  
Lindsay Shaw ◽  
Jann MacIsaac ◽  
Jill A. Singleton-Jackson
Keyword(s):  
Learning Outcomes ◽  
Learning Strategies ◽  
Undergraduate Students ◽  
High Performance ◽  
Assessment Tool ◽  
Cognitive Learning ◽  
Educational Environments ◽  
And Performance ◽  
Improved Learning

With technology at the fingertips of most undergraduate students, it has been difficult for instructors to fully engage students in the classroom, which has resulted in the creation of several innovative assessment platforms, such as mTuner. mTuner integrates several cognitive learning strategies within an assessment, with the goal of actually enhancing learning, as opposed to just measuring it. In the current study, students’ level of engagement and performance with mTuner were compared to their final multiple-choice paper and pencil exam mark to determine the efficacy of mTuner in achieving improved learning outcomes. Results indicated that students had high performance scores on the mTuner assessment despite their limited engagement in the cognitive learning features, putting to question mTuner’s facilitation of long-term learning. Implications and future recommendations of mTuner implementation in educational environments are discussed.

Design and Performance of Hand-Struck Tools Using High Performance Polymers

2003 ◽  
Author(s):  
J. L. Glancey ◽  
P. Popper ◽  
T. Nasr ◽  
P. Truitt ◽  
M. Orgovan ◽  
...  
Keyword(s):  
High Performance ◽  
Field Tests ◽  
Element Model ◽  
Lumped Parameter Model ◽  
Force Transmission ◽  
Transmission Characteristics ◽  
High Performance Polymers ◽  
Lumped Parameter ◽  
And Performance

One of the oldest tools in the world, the hand-struck chisel, has been improved with the addition of a polymer cap. The cap enhances the safety and ergonomic features without compromising chisel cutting performance. During the development of this new design, a lumped-parameter model was used to quantify force transmission characteristics, and select a suitable polymer-reinforced nylon (Minlon™). In addition, a finite element model together with laboratory and field tests were used to demonstrate that the addition of the polymer cap significantly reduces chisel vibration and noise. Additional long term tests confirmed the cutting effectiveness and durability of the capped chisel.

Trace nanoanalysis

1994 ◽  
Vol 52 ◽  
pp. 940-941
Author(s):  
D. E. Newbury ◽  
R. D. Leapman
Keyword(s):  
High Performance ◽  
Secondary Ion Mass Spectrometry ◽  
Detection Efficiency ◽  
Volume Element ◽  
And Performance ◽  
Trace Constituents ◽  
Secondary Ion ◽  
Concentration Levels ◽  
Structure Properties

Trace constituents, which can be very loosely defined as those present at concentration levels below 1 percent, often exert influence on structure, properties, and performance far greater than what might be estimated from their proportion alone. Defining the role of trace constituents in the microstructure, or indeed even determining their location, makes great demands on the available array of microanalytical tools. These demands become increasingly more challenging as the dimensions of the volume element to be probed become smaller. For example, a cubic volume element of silicon with an edge dimension of 1 micrometer contains approximately 5×1010 atoms. High performance secondary ion mass spectrometry (SIMS) can be used to measure trace constituents to levels of hundreds of parts per billion from such a volume element (e. g., detection of at least 100 atoms to give 10% reproducibility with an overall detection efficiency of 1%, considering ionization, transmission, and counting).

Sign in / Sign up

Export Citation Format

Share Document