Swimming Angle Research Articles

Effect of the shape of microswimmers and slip boundary conditions on the dynamic characteristics of near-wall microswimmers

Although the interaction between microswimmers and walls during near-wall swimming has been extensively studied, the effect of microswimmer shapes and slip boundary conditions on the dynamic characteristics of near-wall microswimmers has received less attention. In this study, elliptical microswimmer models have been developed with various aspect ratios based on circular microswimmers. The lattice Boltzmann method has been used for the numerical simulation of the dynamic behaviour of microswimmers near walls. Under slip boundary conditions, the escape or capture of microswimmers by the walls is influenced by the swimming Reynolds number (Res), wall slip length (ls) and the aspect ratio (Cab) of a microswimmer. Changes in the Cab value of a microswimmer considerably affect its swimming state, especially for puller-type microswimmers. The tendency of pullers to be captured by the wall increases with increasing Cab. Moreover, changes in ls within the slip boundary condition of a puller can induce a transition in its movement state from a wall oscillation state to a stable sliding state and eventually to a wall lock-up state, a process influenced by the Cab value of the puller. Pusher-type microswimmers show a considerably increased tendency to escape from walls with increasing Cab and no wall lock-up state is observed, which is opposite to the case of pullers. Pushers and pullers show an increased tendency to be captured by the wall with increasing initial swimming angle of the microswimmer. The findings of this study enhance our understanding of the swimming patterns of natural microswimmers near walls and are of substantial importance for the design of artificial microswimmers and microfluidic devices.

Acoustic Target Strengths and Swimbladder Morphology of Chub Mackerel Scomber japonicus in the Northwest Pacific Ocean

The Northwest Pacific chub mackerel (Scomber japonicus) is one of the most productive, economically important fishery resources worldwide. Accurately assessing this species and ensuring adherence to total allowable catch limits are crucial owing to fluctuations in their abundance and distribution. Acoustic target strength measurements of S. japonicus were conducted at 38, 70, and 120 kHz using a split-beam echosounder of individuals from nine size groups (mean fork length, 10.8–28.3 cm) swimming freely in a net cage within a seawater tank. An underwater camera was utilized to simultaneously measure swimming angle. Least-squares regression analysis revealed that when the slope was constrained to 20, as per the generally applicable morphometric equation, the resulting values for the constant term (b20) were −67.7, −66.6, and −67.3 dB at 38, 70, and 120 kHz, respectively. S. japonicus mean swimming angle across the groups was −10.5–9.6° (standard deviation [SD], 16.3–33.3°). Furthermore, the ratio of swimbladder height to swimbladder length, the ratio of swimbladder length to fork length, and the tilt angle of the swimbladder (mean ± SD) were 0.191 ± 0.060, 0.245 ± 0.055, and 9.6 ± 3.0°, respectively. These results can be used for the acoustic stock assessment of S. japonicus in the Northwest Pacific Ocean.

Broadband backscattering by Atlantic herring (Clupea harengus L.) differs when measured from a research vessel vs. a silent uncrewed surface vehicle

Abstract Broadband frequency-modulated signals are believed to improve acoustic spectral-based target classification. Efficient use of uncrewed surface vehicles (USV) for fisheries science applications, with no possibility for biological sampling, is believed to be facilitated by use of broadband signals with methods for target classification. If the broadband frequency response used to train automated target classifiers are obtained from conventional research vessels (RVs), due to potential vessel avoidance, the swimming angle distribution may be different than for USVs. This may have consequences for target classification if the model is trained with RV data. The aim of this study was to assess whether the frequency response differs between platforms due to avoidance. Broadband acoustic data were collected with a conventional RV and a small USV. The broadband frequency response of Norwegian spring spawning herring obtained with the USV and RV was found to be significantly different for shallow herring layers in the 200 kHz band. This indicates that broadband frequency response has potential as a tool for real-time monitoring of behaviour reactions to vessels and to provide insight into fish behaviour in general. When using broadband frequency response for target classification, the potential platform-dependent broadband frequency response should be considered.

Study on the interaction and motion patterns of squirmers swimming in a shear flow

In order to study the dynamic characteristics of micro-organisms or engineered swimmers, the simulations of the motion and interaction of a pair of squirmers in a shear flow are conducted using the lattice Boltzmann method (LBM) in the range of squirmer-type factor −5 ≤ β ≤ 5, self-propulsion strength 0.1 ≤ α ≤ 0.8, initial spacing between two squirmers 0.5d ≤ d′ ≤ 3d (d is the diameter of the squirmers). The interactions and motion mechanisms of squirmers in puller–puller, pusher–pusher, puller–pusher, and pusher–puller configurations are analyzed. The results show that there are three typical motion patterns in the puller–puller configuration, i.e., steady tilting motion (STM), large-amplitude oscillation motion (LAO), and small-amplitude oscillation motion (SAO). The motion of pullers has a large vertical range, and the swimming angle continues to increase in the LAO, while the pullers oscillate near the plate and have a small range of changes in swimming angles in the SAO. The situation is more complex in the pusher–pusher configuration, and there are five motion patterns, i.e., STM, LAO, SAO, limit cycle motion (LCM), and open limit cycle motion (OLCM). Three different STMs are found according to the pressure distribution around the pushers. d′ is an important parameter affecting the interaction of squirmers. In the puller–puller configuration, the backflow area on the right side of puller 1 is completely suppressed when d′ = 0.5d, but this suppression gradually weakens as d′ increases. Changes in d′ result in the differences in the final motion patterns of pullers on the upper and low plates. In the pusher–pusher configuration, changes in d′ result in transitions between different motion patterns. There exist a critical swimming angle θc when d′ changes, and the pattern changes from the STM to the LCM when θ > θc. At d′ = 0.5d, in the puller–pusher configuration, there exists a stable structure formed by the mutual repulsion caused by the high pressure area between the puller and pusher. In the pusher–puller configuration, there is a low-pressure area on one side of the pusher, which attracts the low-pressure area on the head of the puller and affects their subsequent motion patterns.

Visually Driven Behavior Assays to Study Functionality and Recovery after Damage of the Aged African Turquoise Killifish Visual System.

Loss of vision is a prominent feature of aging and vision is considered by many to be the most valuable sense to be lost. In our graying society, we are increasingly challenged by age-related deterioration of the central nervous system (CNS), as well as by age-associated neurodegenerative diseases and brain injuries, all often affecting the visual system and thus its performance. Here, we describe two visually driven behavior assays to evaluate visual performance upon aging or CNS damage in the fast-aging killifish. The first test, the optokinetic response (OKR), measures the reflexive eye movement triggered by motion in the visual field and allows assessment of visual acuity. The second assay, the dorsal light reflex (DLR), evaluates the swimming angle based on input of light coming from above. The OKR can be used to study the effect of aging on visual acuity as well as visual improvement and recovery after rejuvenation therapy or visual system injury or disease, whereas the DLR is best used to assess functional repair after a unilateral optic nerve crush.

Ex situ target strength of yellow croaker (Larimichthys polyactis) in a seawater tank

We conducted a TS study of yellow croaker (Larimichthys polyactis), a major commercial fish in Asia that has not been studied before. Ours is the first study that examines the relationship between target strength (TS) and fish length using 38, 70, and 120 kHz split-beam echosounders. We measured TS in five size groups of yellow croaker (Larimichthys polyactis) based on length (8.2–26.5 cm total length) in a seawater tank and calculated the Kirchhoff-ray mode (KRM) model. When the slope of the least-squares regression line was forced to 20 in the TS equation, the resulting values for the constant term (b20) at each frequency (38, 70, and 120 kHz) using the caged method were –67.69, –67.52, and −68.83 dB, respectively. The swimming angle (mean ± S.D.) in the net cage was − 4.2 ± 21.9°. The b20 values for the KRM model were –65.01, –64.74, and −66.27 dB at 38, 70, and 120 kHz, respectively. In both methods, the KRM model’s b20 values were relatively higher than those of the caged method by 2.68, 2.78, and 2.56 dB at 38, 70, and 120 kHz, respectively. Such TS ex situ measurements can be applied to improve the yellow croaker’s acoustic abundance estimates.

Target Strength Measurements of Free-Swimming Sandeel Species, Ammodytes spp., in a Large Indoor Experimental Aquarium

The sandeel species (Ammodytes spp.) occupy a critical ecological position in connecting lower trophic levels to higher ones. However, they are strongly affected by the marine environment and their catch rates are trending downward. In this study, the target strength (TS) of sandeel species was measured in free-swimming specimens using a split-beam quantitative echo sounder with 38 and 120 kHz frequencies in a physically controlled environment. Parameters a and b used in the estimated TSmean–fork length (FL: 13.5–21.5 cm) equation were 53.7 and −124.3 dB at 38 kHz, and 71.3 and −153.2 dB at 120 kHz, respectively. The TS of the sandeel species were not proportional to the square of the FL but increased relatively rapidly with increasing body size. In addition, the mean and standard deviation of the swimming angle for the sandeel species from the acoustic data at 120 kHz were −2.2° and 7.7°, respectively, and most were in the −30° to 30°, range. Furthermore, TS was stronger at 38 kHz than at 120 kHz for all FL classes. The use of such frequency characteristics could facilitate the discrimination of fish species in the field and the sustainable assessment of sandeel species stocks.

Dynamic swimming pattern of Pseudomonas aeruginosa near a vertical wall during initial attachment stages of biofilm formation

Studying the swimming behaviour of bacteria in 3 dimensions (3D) allows us to understand critical biological processes, such as biofilm formation. It is still unclear how near wall swimming behaviour may regulate the initial attachment and biofilm formation. It is challenging to address this as visualizing the movement of bacteria with reasonable spatial and temporal resolution in a high-throughput manner is technically difficult. Here, we compared the near wall (vertical) swimming behaviour of P. aeruginosa (PAO1) and its mutants ΔdipA (reduced in swarming motility and increased in biofilm formation) and ΔfimX (deficient in twitching motility and reduced in biofilm formation) using our new imaging technique based on light sheet microscopy. We found that P. aeruginosa (PAO1) increases its speed and changes its swimming angle drastically when it gets closer to a wall. In contrast, ΔdipA mutant moves toward the wall with steady speed without changing of swimming angle. The near wall behavior of ΔdipA allows it to be more effective to interact with the wall or wall-attached cells, thus leading to more adhesion events and a larger biofilm volume during initial attachment when compared with PAO1. Furthermore, we found that ΔfimX has a similar near wall swimming behavior as PAO1. However, it has a higher dispersal frequency and smaller biofilm formation when compared with PAO1 which can be explained by its poor twitching motility. Together, we propose that near wall swimming behavior of P. aeruginosa plays an important role in the regulation of initial attachment and biofilm formation.

Analysis of sinking death using video images of the swimming performance of Pacific Bluefin tuna (Thunnus orientalis) larvae

In this study, we aimed to clarify the mechanism of sinking death during the larval stage of Pacific Bluefin tuna Thunnus orientalis by investigating the effects of swimming performance on sinking death, using a behavioral approach. Swimming performance was examined 3–9 days after hatching (DAH) under day and night light conditions in cuboid experimental tanks. Swimming behavior variables such as swimming speed and swimming angle were measured under both light conditions. Larvae in the daytime experiment and larvae with inflated swim bladders at night were distributed on the surface layer of the water column. In contrast, larvae with uninflated swim bladders at night were frequently observed swimming vertically or sinking to the bottom of the tank. Larvae with inflated swim bladders at night were always distributed beneath the surface until the next morning (survival rates were 100 %). However, larvae with uninflated swim bladders at night swam upward repeatedly and later sank to the bottom of the tank (survival rates were 60 % and 38 % at 5 and 9 DAH, respectively). Larvae with uninflated swim bladders were not always able to maintain their swimming depth by swimming until the next morning. Additionally, their swimming speed and vertical swimming frequency (ratio) depended on the illumination and swim bladder conditions. Our findings show that larvae with uninflated swim bladders at night were associated with a higher risk of sinking death. The swimming energy capacity of Pacific Bluefin tuna larvae, which indicates the total amount of the energy that enables individuals to swim throughout the night without feeding, was found to be linked to sinking death.

Target strength measurements of pointhead flounder, Cleisthenes pinetorum, a flatfish without a bladder

There are only a few acoustic surveys of the bladderless fish. As is known by all, Atlantic mackerel was surveyed these years by echo-sounder and showed the high target strength at high frequency. In northern Japan, an interesting fish attracted the attention these years which called pointhead flounder, Cleisthenes pinetorum, without a bladder. It is a flatfish but captures prey in the middle water column. And the body shape is not the normal spindle-shaped, but a flat shape, which may cause different acoustic characteristics with Atlantic mackerel. We did the surveys in Funka Bay, northern Japan and keep the samples to the tank to measure the acoustic characteristics of live flounder. The acoustic characteristics of pointhead flounder measured both using the tether method (38, 120 kHz) and free swimming method (120 kHz). During the measurements of free swimming method, we also observed the swimming actions of pointhead flounder and calculated the swimming angle at the same time. We also discussed the characteristics of TS of the swimming angle.There are only a few acoustic surveys of the bladderless fish. As is known by all, Atlantic mackerel was surveyed these years by echo-sounder and showed the high target strength at high frequency. In northern Japan, an interesting fish attracted the attention these years which called pointhead flounder, Cleisthenes pinetorum, without a bladder. It is a flatfish but captures prey in the middle water column. And the body shape is not the normal spindle-shaped, but a flat shape, which may cause different acoustic characteristics with Atlantic mackerel. We did the surveys in Funka Bay, northern Japan and keep the samples to the tank to measure the acoustic characteristics of live flounder. The acoustic characteristics of pointhead flounder measured both using the tether method (38, 120 kHz) and free swimming method (120 kHz). During the measurements of free swimming method, we also observed the swimming actions of pointhead flounder and calculated the swimming angle at the same time. We also discussed the cha...

Study on acoustic characteristics of pointhead flounder Cleisthenes pinetorum and juvenile walleye pollock Gadus chalcogrammus

In this study, the acoustic differences between the pointhead flounder and the juvenile walleye pollock were examined using a quantitative echo-sounder around the Funka Bay, Japan and the acoustic characteristics of the pointhead flounder have been surveyed. Acoustics data of the fish were monitored using a Simrad EK60 (38, 120, 200 kHz) split-beam echo sounder in the field. The target strength (TS) and swimming angle of free swimming pointhead flounders were measured in a seawater tank (length: 10 m, width: 5 m, and height: 6 m). As the result, pointhead flounder schools presented a patch shaped echo on the echograms, whereas the distribution patterns of the juvenile walleye pollock schools were layered. The volume backscattering strength (SV) of the target schools extracted from the echograms showed that the pointhead flounder presented a higher SV at high frequency. In contrast, the juvenile walleye pollock showed higher SV at a low frequency. For pointhead flounder, the distribution of pitch angle was measured both by camera and echo-sounder at the experiments in the tank and shown the same distribution pattern. The TS of pointhead flounder is large bigger than other bladderless fish.

Behavioral patterns and in-situ target strength of the hairtail (Trichiurus lepturus) via coupling of scientific echosounder and acoustic camera data

The present study focuses on the influence of target strength (TS) changes in the swimming angle of the hairtail (Trichiurus lepturus). We measured in-situ TS at 38 and 120 kHz with luring lamps at a fishing ground for jigging boats near the coastal waters of Jeju-do in Korea. Swimming angle and size of hairtails were measured using an acoustic camera. Results showed that mean preanal length was estimated to be 13.5 cm (SD = 2.7 cm) and mean swimming tilt angle was estimated to be 43.9° (SD = 17.6°). The mean TS values were −35.7 and −41.2 dB at 38 and 120 kHz, respectively. The results will assist in understanding the influence of swimming angle on the TS of hairtails and, thus, improve the accuracy of biomass estimates.

Acoustic scattering characteristic depend on length and swimming angle of scorpion fish (Sebasiscus marmoratus) based on ex-situ method

Scorpion fish Sebastiscus marmoratus are hatched and released in marine ranching areas in Korea to assist in the recovery and management of fishery resources in coastal areas. Information on the acoustic target strength (TS) of marine organisms in order to convert volume backscattering strength into estimates of biomass. The aim of this study were TS of scorpion fish. The TS was measured in acoustic seawater tank (5 m (L)×5 m (H)×5 m (D)) at the fisheries science institute of Chonnam National University, Korea. Acoustic data was collected with a 200 kHz quantitative echo sounder (dual-beam, BioSonics). Behavior of scorpion fish was observed underwater camera installed side and bottom in tank. Acoustic and behavior data were synchronized intervals of 0.5 sec. The scorpion fish ranged from 14.0 to 26.0 cm in length and from 40 to 310g in wet weight. The relationships between and fish total length were as follows: TSSUBmax/SUB.=20 log (TL)‑69.22 and TSSUBavg/SUB.=20 log (TL)‒73.8. This result will be provided basic information for conducting acoustic survey of the scorpion fish.

Hydrodynamic Trapping of Swimming Bacteria by Convex Walls.

Swimming bacteria display a remarkable tendency to move along flat surfaces for prolonged times. This behavior may have a biological importance but can also be exploited by using microfabricated structures to manipulate bacteria. The main physical mechanism behind the surface entrapment of swimming bacteria is, however, still an open question. By studying the swimming motion of Escherichia coli cells near microfabricated pillars of variable size, we show that cell entrapment is also present for convex walls of sufficiently low curvature. Entrapment is, however, markedly reduced below a characteristic radius. Using a simple hydrodynamic model, we predict that trapped cells swim at a finite angle with the wall and a precise relation exists between the swimming angle at a flat wall and the critical radius of curvature for entrapment. Both predictions are quantitatively verified by experimental data. Our results demonstrate that the main mechanism for wall entrapment is hydrodynamic in nature and show the possibility of inhibiting cell adhesion, and thus biofilm formation, using convex features of appropriate curvature.

Three dimensional tracking of exploratory behavior of barnacle cyprids using stereoscopy.

Surface exploration is a key step in the colonization of surfaces by sessile marine biofoulers. As many biofouling organisms can delay settlement until a suitable surface is encountered, colonization can comprise surface exploration and intermittent swimming. As such, the process is best followed in three dimensions. Here we present a low-cost transportable stereoscopic system consisting of two consumer camcorders. We apply this novel apparatus to behavioral analysis of barnacle larvae (≈800 μm length) during surface exploration and extract and analyze the three-dimensional patterns of movement. The resolution of the system and the accuracy of position determination are characterized. As a first practical result, three-dimensional swimming trajectories of the cypris larva of the barnacle Semibalanus balanoides are recorded in the vicinity of a glass surface and close to PEG2000-OH and C11NMe3+Cl− terminated self-assembled monolayers. Although less frequently used in biofouling experiments due to its short reproductive season, the selected model species [Marechal and Hellio (2011), Int Biodeterior Biodegrad, 65(1):92–101] has been used following a number of recent investigations on the settlement behavior on chemically different surfaces [Aldred et al. (2011), ACS Appl Mater Interfaces, 3(6):2085–2091]. Experiments were scheduled to match the availability of cyprids off the north east coast of England so that natural material could be used. In order to demonstrate the biological applicability of the system, analysis of parameters such as swimming direction, swimming velocity and swimming angle are performed.Electronic supplementary materialThe online version of this article (doi:10.1007/s13758-012-0050-x) contains supplementary material, which is available to authorized users.

Swimming angle and target strength of larval Japanese anchovy (Engraulis japonicus)

The swimming angle of larval Japanese anchovy (Engraulis japonicus) was measured in a tank, and target strength (TS) was calculated using a theoretical scattering model. The mean swimming angle was 12.8° (SD ±22.1). Increased speeds of flow led to increased mean swimming angles. The mean swimming angle at flow of 5 cm s−1 was higher than at other speeds. TS values were estimated using a distorted-wave Born approximation model for two cases. Average values were 1–3 cm s−1 (11.5° ± 22.1) and 5 cm s−1 (16.6° ± 21.7) for cases 1 and 2, respectively. For case 1, TS ranged from −92.0 to −74.7 dB with a mean of −79.4 dB at 120 kHz. For case 2, TS ranged from −92.2 to −75.2 dB with a mean of −79.9 dB. The mean TS in case 2 was lower than that in case 1, with the maximum difference being 1.0 dB at 120 kHz (standard length 22.0 mm). However, there were no significant differences between the regression lines of cases 1 and 2. Thus, changes in flow speed altered the swimming angle of larval Japanese anchovy, but had little influence on TS.

노무라입깃해파리의 박동에 따른 음향산란 특성

The large jellyfish Nemopilema nomurai causes serious damage to fisheries, particularly around the seas of Korea and Japan. Decreasing this damage requires knowledge of the distribution and abundance of jellyfish. Acoustic technology using quantitative echosounders is one method of studying the distribution and abundance of jellyfish. Such methods are commonly used worldwide because they have the advantage of providing substantial information about all water layers in a wide area in a short time. However, in order to conduct an acoustic survey, the acoustic characteristics of the target organism must be known. These can be altered by a number of factors, including pulsation, swimming angle, frequency and size. Accordingly, this study determined the variation in target strength according to pulsation of N. nomurai. Data were analyzed for two jellyfish with bell diameters in air of (a) was 32.0 and (b) 25.0 cm. The pulsation cycle of jellyfish (a) was 1.5~2.0 sec and the target strength (TS) cycle was 1.0~2.5 sec, while jellyfish (b) had a pulsation cycle of 1.0~1.5 sec and TS cycle of 1.0~3.0 sec. The variation width of the TS with the change in pulsation was 7.8 dB (-72.4~-64.6 dB) for jellyfish (a) and 10.3 dB (-71.6~-61.3 dB) for jellyfish (b). The variation in bell diameter was about 0.28 and 0.35, respectively. These results confirmed that the variation in bell diameter caused by pulsation is closely related to the variation in TS.

Behavioural responses to pressure changes in cultured Atlantic cod ( Gadus morhua): Defining practical limits for submerging and lifting sea-cages

Farmed Atlantic cod ( Gadus morhua) are occasionally exposed to buoyancy changes in sea-cages, through lifting or lowering of cage nets. Physiological processes regulate the level of gas in the closed swim bladders of cod and thus the ability of cod to control their buoyancy. Rapid net lifting may cause positive buoyancy, leading to barotrauma, while net lowering may lead to negative buoyancy and alter cod behaviours. We tested how groups of farmed cod responded immediately after lifting events from 5 different start depths equivalent to 40% pressure reductions, and how long they took to return to pre-lifting pressure levels. In addition, we tested immediate responses and recovery times to cage lowering events equivalent to 100–300% pressure increases. Trials were conducted with 100 cod of 1.1–1.7 kg in a 63 m 3 sea-cage at the lower (5 °C) and upper (16 °C) water temperature limits experienced during culture. Swimming behaviours were measured at fixed intervals before and after cage lifting or lowering, and a feeding test was used to assess appetite. In general, lifting events increased swimming speeds 1.5–4 times and tail beats 2–3 times and fish swam with an average −14° head-down angle, indicating positive buoyancy. The depth before lifting affected the immediate response as the fish became more active after lifting events from shallow compared to deeper depths. Appetite levels decreased for about 2 h after cage lifting, independent of temperature or start depth. The overall recovery time of 8 h after lifting did not depend upon start depth or temperature. Lowering events appeared to cause negative buoyancy. Swimming speeds (1.3–2.3 times) and tail beat frequencies (1.4–2.3 times) increased immediately after cage lowering, and cod swam with an average 30° head-up swimming angle. Neither pressure level nor temperature affected this immediate response. Time to recover to neutral buoyancy for 300% pressure increases took 42–90 h, but only 18–34 h for 100% pressure increases. We conclude that a 40% pressure reduction is an upper limit for lifts of healthy farmed cod. Secondary lifts should not be done until at least 10 h after the first lift. Cage lowering should be done slowly to avoid potentially stressful crowding of negatively buoyant fish on the cage bottom, especially at low temperatures.

Psychomotor development of exposed mice offspring to fenugreek seeds

Event Abstract Back to Event Psychomotor development of exposed mice offspring to fenugreek seeds L. Khalki1*, Z. Sokar1 and S. B. M'hamed1 1 University Cadi Ayyad, Laboratory of Pharmacology, Neurobiology and Behavior,Faculty of science, Semlalia, Morocco It is recognized that some medicinal plants have harmful effects on maternal and fetal health. However, most clinical claims of medicinal plants, made available, to consumers do not have any scientific data support. The present study was undertaken to evaluate the prenatal effects of butanol extract from deeds of fenugreek on neurodevelopment behavior in mice. The effect of prenatal exposure to fenugreek seeds extract on behavioral motor skills parameters in Swiss mice offspring was assessed. Pregnant mice were treated by gavages with 300 mg / kg / day of a butanolic extract dissolved in saline solution throughout the gestational period. Control animals received the vehicle for the same period. Before weaning, the pops were examined using the swimming behavior (PND10, 12 and 14) and the cliff avoidance test (PND 6). In the treated offspring, swimming angle was significantly lower in scores than controls. Cliff avoidance test was significantly affected in treated group compared to controls. These results showed a delay of early response development and motor coordination in the offspring of mice exposed to fenugreek seeds butanolic extract during all pregnancy period. We concluded that the fenugreek seeds consumption during pregnancy could be a cause of offspring developmental toxicity. Conference: 2nd NEUROMED Workshop, Fez, Morocco, 10 Jun - 12 Jun, 2010. Presentation Type: Poster Presentation Topic: Poster session 1: Neurodegenerative diseases Citation: Khalki L, Sokar Z and M'hamed SB (2010). Psychomotor development of exposed mice offspring to fenugreek seeds. Front. Neurosci. Conference Abstract: 2nd NEUROMED Workshop. doi: 10.3389/conf.fnins.2010.12.00010 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 03 Jun 2010; Published Online: 03 Jun 2010. * Correspondence: L. Khalki, University Cadi Ayyad, Laboratory of Pharmacology, Neurobiology and Behavior,Faculty of science, Semlalia, Marrakesh, Morocco, bamhamed@ucam.ac.ma Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers L. Khalki Z. Sokar S. B M'hamed Google L. Khalki Z. Sokar S. B M'hamed Google Scholar L. Khalki Z. Sokar S. B M'hamed PubMed L. Khalki Z. Sokar S. B M'hamed Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

황해에 분포하는 살오징어의 음향산란강도 특성 및 분포밀도 추정

Due to change of various marine environments according to seawater temperature rising, Japanese common squid(Todarodes pacificus), which was distributed in East Sea, was recently caught in Yellow Sea during a summer season from 2006. The fishery resources density research was carried out in Korea-China Provisional Water Zone using trawl fishing gear and acoustics in National Fisheries Research & Development Institute in Korea. This paper showed the analysis on the acoustical backscattering strength by two frequencies(38kHz, 120kHz) for Japanese common squid by acoustical scattering theoretical model based on size distribution for survey period, and estimate the density distribution for squid s integrated layer which was extracted from any scatterers distributed in water column using two frequency difference method which has been used to distinguish fish shoals or specific target scatterers from sound scattering layer which is composed of various zooplankton. Furthermore, the entire range of their density estimation was suggested using by Monte Carlo simulation under considering each uncertainty such as size distributions or swimming angle and so on in survey area.