Search results for "Fish"
showing 10 items of 3164 documents
Detection of changes in mitochondrial hydrogen sulfide i n vivo in the fish model Poecilia mexicana (Poeciliidae)
2019
ABSTRACT In this paper, we outline the use of a mitochondria-targeted ratiometric mass spectrometry probe, MitoA, to detect in vivo changes in mitochondrial hydrogen sulfide (H2S) in Poecilia mexicana (family Poeciliidae). MitoA is introduced via intraperitoneal injection into the animal and is taken up by mitochondria, where it reacts with H2S to form the product MitoN. The MitoN/MitoA ratio can be used to assess relative changes in the amounts of mitochondrial H2S produced over time. We describe the use of MitoA in the fish species P. mexicana to illustrate the steps for adopting the use of MitoA in a new organism, including extraction and purification of MitoA and MitoN from tissues foll…
The predictability of helminth community structure in space: a comparison of fish populations from adjacent lakes
2002
Patterns in helminth community structure can suggest that various processes are acting to shape parasite communities into organised, non-random assemblages of species. It is not clear, however, whether a pattern observed in one host population at one time would be observed again at another time, or at the same time in a different but comparable host population. Here, we test the repeatability of parasite community structure in space, and to a lesser extent time, with data on helminth parasites of two fish species, perch Perca fluviatilis and roach Rutilus rutilus, collected in different seasons from four adjacent lakes in Central Finland. Since populations of the same fish species harbour t…
Soils with Specific Features
2016
This chapter deals with some specific features of soil that are relevant for interpretation of infiltration experiments. Infiltration in water repellent soils is first examined. After summarizing the causes of hydrophobicity, phenomena associated to infiltration in water repellent soil, including reduced infiltration rates and irregular wetting front advance, are illustrated. The Water Drop Penetration Time (WDPT), the Molarity of an Ethanol Droplet (MED) and the Repellency tests for quantitative assessment of soil water repellency are presented. Particular attention is given to estimation of subcritical soil water repellency by means of soil sorptivity measurements conducted with infiltrat…
Application of low intensity ultrasonics to cheese manufacturing processes.
2002
Ultrasound has been used to non-destructively assess the quality of many foods such as meat, fish, vegetables and dairy products. This paper addresses the applications of low intensity ultrasonics in the cheese manufacturing processes and highlights the areas where ultrasonics could be successfully implemented in the future. The decrease of ultrasonic attenuation during the renneting process can be used to determine the optimum cut time for cheese making. The ultrasonic velocity increases during maturation for those types of cheese that become harder during this manufacturing stage, thus being an indicator of the maturity degree. Moreover, ultrasonic measurements could be linked to sensory …
Influence of mode stirrer and air renewal on controlled microwave drying of sliced zucchini
2017
An on-line temperature-controlled microwave (MW) system, based on infrared thermography, was developed for drying zucchini slices. Moreover, the effects of different configurations, including turntable rotation, mode stirrer and air renewal, alone or in combination, on drying kinetics and quality of dried product were evaluated. The combination of stirrer and air renewal reduced the drying time of zucchini slices by about 48% with respect to the basic configuration and by 22% with respect to air renewal only. The lowest oscillation of temperatures about the fixed level (65 °C) was found when operating with the stirrer mode, because of the improved uniformity of the MW distribution. The sa…
Building large molecular models with plastic screw-on bottle caps and sturdy connectors
2016
An improved method of connecting atoms formed with screw-on bottle caps is described. Fishing line (artificial polymer), steel wire, and countersunk bolts with nyloc nuts are proposed as sturdy connectors. Advantages and disadvantages of each method are described. The molecular models are stable while handling, can be built in a relatively short time at low cost, and can be useful at every level of education. The method is an alternative to professional model kits, in particular in construction of large models for long-term usage.
Drying rate control in microwave assisted processing of sliced apples
2018
The most enhanced microwave systems for the preparation of quality-dehydrated fruits continuously adjust the power level in order to maintain the product temperature above a target value. As a result, typical drying curves that exhibit high drying rates in the middle stage are obtained. This can often lead to quality damage or undesirable changes on food colour and texture. In response to these issues, a microwave system is proposed that can realise drying processes keeping drying rates constant. This approach required a continuous temperature adjustment of the apple slices under test, whose temperature was detected by a computer-aided infrared thermography system. Since temperature correct…
Diode laser reliability in dynamic laser speckle application: Stability and signal to noise ratio
2018
Abstract The biospeckle, or dynamic laser speckle, is used as a potential tool to monitor activity in many biological and non-biological materials from agriculture to medicine, and it is usually based on the use of He-Ne and diode lasers, the latter of which has great potential to be embedded in portable equipment. Some queries about the stability of the diode laser were raised, such as the real influence of the mode hopping phenomenon as a drawback in solid-state devices in comparison to the well-known He-Ne lasers, and thus we decided to test it . In addition, we present an alternative way to enhance the stability and the signal-to-noise ratio of the information using a relative index rat…
Fast whole-brain imaging of seizures in zebrafish larvae by two-photon light-sheet microscopy
2022
Light-sheet fluorescence microscopy (LSFM) enables real-time whole-brain functional imaging in zebrafish larvae. Conventional one photon LSFM can however induce undesirable visual stimulation due to the use of visible excitation light. The use of two-photon (2P) excitation, employing near-infrared invisible light, provides unbiased investigation of neuronal circuit dynamics. However, due to the low efficiency of the 2P absorption process, the imaging speed of this technique is typically limited by the signal-to-noise-ratio. Here, we describe a 2P LSFM setup designed for non-invasive imaging that enables quintuplicating state-of-the-art volumetric acquisition rate of the larval zebrafish bra…
Statistical validation of rival models for observable stochastic process and its identification
2011
In this paper, for statistical validation of rival (analytical or simulation) models collected for modeling observable process in stochastic system (say, transportation or service system), a uniformly most powerful invariant (UMPI) test is developed from the generalized maximum likelihood ratio (GMLR). This test can be considered as a result of a new approach to solving the Behrens-Fisher problem when covariance matrices of multivariate normal populations (compared with respect to their means) are different and unknown. The test makes use of an invariant statistic whose distribution, under the null hypothesis, does not depend on the unknown (nuisance) parameters. The sample size and thresho…