Locomotion - Science topic

Traction motors are D.C series motors, for having higher starting and reduced current with pickup speed giving best efficiency though DC traction good only for short distance for better voltage regulation, hence A.C to D.C conversion station are needed with in range of 70 to 100 miles are used in metro cities. For normal long distance trains the power is supplied by A.C transmission catenary and conversion to D.C for D.C. series motors are done on engine using rectifiers from A.C.

It is a great dissapointment to me that QUT have expelled me without notice when Prof. Ledwich retired.

I am 82 years old and would like to end my career by having my thesis accepted. I am rying to get a grant to build and prove the Traction Simulator which in my view is the most important part of the thesis.

Many investigators are using inversed light cycles in their facilities so they can perform experiments during the dark (active) phase in rodents. It requires some time for all parameters to adjust but the most complicated thing (as mentioned above) is the logistics of animal care as not a speck of light can be used (and might a problem for animal technician and vet to perform their daily routine), and many papers showed that red light is not always a good alternative to perform the experiments in the dark phase. So the use of an inversed cycle really depends on what you need to study

Ahmad Abbasian

Basically, Soft robots are systems created from materials with mechanical qualities akin to those of biological tissues, developed and manufactured in a highly inventive manner rather than artificially assembled by serial or parallel arrangements of simple blocks, as rigid-body robots were.

I suggest going through these articles:

1. https://www.sciencedirect.com/science/article/pii/S0264127521008406

2. https://www.researchgate.net/publication/224156047_Peristaltic_Locomotion_with_Antagonistic_Actuators_in_Soft_Robotics

3. https://etd.ohiolink.edu/apexprod/rws_etd/send_file/send?accession=case1579793861351961&disposition=inline

4. https://ieeexplore.ieee.org/document/5509542

5. https://groups.csail.mit.edu/drl/wiki/images/7/71/MeshwormFinal.pdf

Dear Yue Young

Have a look:

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3142868/

2. https://link.springer.com/article/10.3758/s13428-012-0221-1

Kind Regards

Hi Michelle,

In my lab we leave the main (dimmable) lights of the behaviour room switched on such that the entire room is evenly illuminated. Therefore shadows have never been a particularly pressing issue! Your current set up with the reading lights may be resulting in shadows due to the ‘spotlight’ nature of these lights. I’m curious to see if you could point the lamps towards the open field box (instead of reflecting off the ceiling) and through a translucent white sheet of plastic to diffuse the light. This should lead to more even distribution of light over the test area.

In my experience, rodents tend to be more exploratory in dimmer light, so we use usually use 50 to 100 lux when studying general movement (if you are using AnyMaze, consider increasing the camera exposure such that the rats can be tracked accurately by the video system). If you want to focus on studying anxiety on the other hand, more intense light would be better suited for teasing out any phenotypic differences. Perhaps 200-300 lux. However, as with all things behaviour related, its best to perform some validation rounds first to fine tune everything!

Hope this helps a little, cheers!

Suresh Babu Thanks so much for your kind suggestions. I shall check the relevant papers.

As for the modeling strategies for locomotion patterns, do you have any good advice alternatively?

Have you looked at Ty Hedrick's DLT? It works in Matlab. Very easy maunal tracking for just about anything. http://biomech.web.unc.edu/dltdv/

Robert's questions are very important and his comments about Gosset's t are dead-on, yet I am still not sure of the question. In this case, "multiple comparisons" would typically refer to a situation in which there are multiple contrasts between groups, and the need, therefore, to handle alpha appropriately with that in mind. Yet, from your last post, I think that I see two groups, thus only one contrast.

Now, it seems that you do not view this as repeated measures as you are averaging the three measures; this is for you to decide, and involves your research question more than statistics. I would have no difficulty using a t-test with an N of 10 in each group, unless there is another problem. For instance are there distribution irregularities? I say this because I see a recommendation of a non-parametric test. If it is so simple as heterogeneous variances, use of a Welch-type t-test is a solution.

Finally, if all else fails, you can avoid all statistical distribution theory by making your own distribution with a re-sampling plan such as bootstrapping.

Pls.could you offer more details about the question ?

Locomotion has been studied all the way from rodents to primates, and even in aquatic animals. They all seem to have a network of interneurons located in the spinal cord that drive the alternation between left and right and flexors and extensors that are called Central Pattern Generators.

Their presence in humans is still a bit controversial: https://journals.sagepub.com/doi/abs/10.1177/1073858417699790?rfr_dat=cr_pub%3Dpubmed&url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&journalCode=nroa

The research that led to this : https://www.nature.com/articles/d41586-018-07251-x was first discovered and tested on rats!

I would probably say that the spinal cord networks that allow locomotion are conserved throughout the phylogeny when it it is the higher control of movement that has evolved. But to answer your question more straightforwardly I would say that bipedal monkeys would be the closest model we have to human bipedal locomotion!

You may benefit from our mice experiments where we have recorded anxiety:

I wonder if it is just that the dew claw is simply a vestigial remnant of the evolution to a simplified, faster digitigrade gait. It has no function any longer and is simply lost in many wild canids and other fast running species.

It is a very interested question

Hi Jimmy,

Check this paper. Maybe helps.

In addition you can coat your plate con E-selectin , P-selectin and Icam1.

I like more the papers methods, with endothelial cells...more physiological.

Good luck

Cynthia

In bipedalism it is not as easy as the pendulum model of an object that is rigid and that has two points of movement. It has to be considered that the vertebral column, each vertebra is more or less mobile, the same as it happens with the pelvis. Each joint has its procedure and they balance each other as it happens with the pelvis and knees. The principle is basic but the real is much more complicated to recreate, there are no single centers but there is the sum of many centers that interact with each other and if one fails, the other accepts this failure and that is not perfect, but because deficit then develops what we call a pathology to balance that deficit.

If you systematically change the photoperiod from 12:12 to another photoperiod in certain small increments that can be a useful way to ascertain the impacts of gradual shifts in the day length. Just because certain photoperiods (e.g., 6:18, 24:0, etc.) have been used should not limit you from looking at others. Having said that, you may find it beneficial to include at least one photoperiod that has been included in other studies for comparison purposes. But ultimately, it depends upon your specific hypothesis you want to test.

It's porbably very good hint to look at he above paper by W. cui et al. 

because Mast cells regulate glutamine-co-transporters.

Pelvic motion is driven by force couples driven by kinetically load ligaments and biotensegrity.  Please see.  The sacral x axes. Location, Structure, Movement, Kinetic Loading, Function, Biotensegrity Technology and Pathology.The essential pieces of the low back pain puzzle.  Under my name.

Rajit you have raised an interesting debate. Gerrit has very nicely explained too. certainly bipedalism not an exclusive human trait but much more ancient trait. even quadrupedal monkeys do at time express erect posture. among great apes bonobo carries bipedalism more than chimp. our common ancestors were must have been versatile in different locomotory repertoirs. it was bipedalism which provided selective advantage in hominin lineage for various activities in which carrying and fast running excellerated this behavior. Even aquaboreal life style enhanced bipedalism. Certainly it is a polygenic inheritance which is true for most bodily adaptations.

Dear Friends,

Thank you for your advice. I found standard procedure of Stanford Univ. for rats. It gives almost the same direction as you recommended.  (http://sbfnl.stanford.edu/Documents/datasharing/lm/SOP/ymsa.pdf ). Thank you again. BR     

Thanks, I will check these out!

I assume that these are closed chain kinetics.  If the vertical ground reaction force is known and joint kinetics (moments) are known then you could calculate mechanical advantage (in sagittal plane) by calculating the moment arms using the joint moment divided by the vertical ground reaction force for each joint and compare moment arms between the joints.  I understand that this may not be experimental data, but this method should work with experimental data.

Well I am sympathetic but also have some observations. Actually an average increase of 2 kmph presumably spread over millions of vehicle miles is a significant improvement. My bigger question is more fundamental -- how much material is moving? Has there been an increase in flows? How long does it take for major market (origin and destination) pairs to complete transactions? And, are you sure that further improvements in speed would improve PROFITS (which you mention as the goal). Why would faster trains be more profitable? I can see what you are getting at but I think you should question and explore the logic of freight movement. The profit for the provider of transport services (the rail company) derives from what the costs are and the revenues if can gain from the movement. Have expenditures in the economy on freight movement increased?

I offer using Matlab for your analyze. It will be good for the other analysis such as motion analyze too. In addition, If you couldn't filtering through EMG, Matlab can help you...

We just generate a matrix over the field and record how many times the animal is in each square. Then you can analyse it any way you want. External square use, internal square use, distance from object, activity levels etc. It's cheap and easy.

Ben, I don't understand your question very well.  I gather that you have a rotating drive shaft that presumably connects a drive motor to one or more wheels.  Are you trying to control a regenerative braking system by switching the resistance in the braking circuit?  Are you trying to detect wheel slip?  What determines how much braking you need?  What is your requirement for "accuracy"?  How were you planning to use the Hall Effect Sensor--to measure the braking current?   Hall sensors are typically used to measure DC current and can be fairly accurate, but if you are just dissipating power in a resistor bank you can do the same thing quite cheaply by just measuring the voltage across the load resistors.  This solution would not give you any information about the rotational speed of the shaft or wheel slip, however.   If you need to measure the speed of he shaft/wheel, then the suggestion above about encoders is valid, although you may be able to build a more robust system by using an inductive proximity sensor to sense a keyway on the shaft or the teeth of a gear or sprocket.  Inductive sensors are typically impervious to water, dirt, grease, etc. and also much less fragile if mechanical shock is an issue than an optical encoder would be.  And many PLCs do have inputs specifically for pulse inputs from speed sensors.

I believe there is some research on using harnesses for cannulated rats, rather than head caps. I'm not sure if anything has been published yet though. 

A procedural animation is any animation controlled by programmer goal, not real-life one. Examples: procedural generation of plants, particle systems, movement along motion graph, etc. Often such applications are designed just to provide nice look and widely use random elements. But still in the simulation Physics and Dynamics can be used.

If planning of the next group of steps in your case of locomotion depends on game events and interaction with the scene objects, this is not “procedural-based” animation. If the actor or animals walk through the scene in random direction this is a kind of procedure generated animation. In any case algorithm of locomotion simulation still is based on Dynamics or Inverse Kinematics.

Yes. Sure. Please let describe the exact situation. Is an rpm sensor in place?

Although a fluid lubricant alleviates channelling problem, traction motor  gear cases are often poor sealed. Thus a fluid lubricant is more prone to leakage.And having  insufficient oil can be more problematic than chanelling. There have been sufficient significant advances in sealing gear cases thus enabling railways to take advantages of oil lubrication.

Ref.1. Oil lubrication of locomotive traction gears-Theory and Practice by William D Hawson;  Journal of Society of Tribologists and Lubrication ; 46( 7), 455-464

Hi Stefano,

I've just noticed your question. If you mean that the performance should not be influenced by altered locomotion due to hyperactivity or coordination/gait problems, then you have several opportunities. My favorite is a test that we have developed for mice exactly with the purpose to analyze hippocampus-dependent spatial learning in a test that is not influenced by stress/anxiety and major motor functions. The unofficial name is Reeperbahn test, but we published it with the name "one-trial spatial learning test". It is very simple and works well in male mice as long as they do not have a massively altered social and sexual behavior. You do not need anything else than a modified open field arena, a camera and a tracking system. The test requires only two trials: one learning and one recall trial. The idea is to test whether the experimental mouse (e.g., a male) remember the location in an arena at which it experienced the presence of an unfamiliar female. The test works for testing both short-term and long-term memory as well as extinction and reversal learning. We published the test for the first time in 2010 (Meier et al., Hippocampus, 2010, 20:1027-1036.) but a complete description of it (as well as the validation of the role of the hippocampus) was published in 2013 (Fellini and Morellini F, J Neurosci, 2013. 33:1038-1043.). In the 2013 paper we also used this paradigm to test whether mice have episodic-like memories, something that had been shown before for other species but not yet for mice. The beauty of the test is also that the "spatial learning" occurs in one trial, a very important feature in terms of hippocampus function as well as "model" for human episodic memory.

Ciao,

Fabio

In principle, I do not see why this woild make a difference in the inverse dynamics. The outcome will be different, for sure, but that is just what you are looking for....

Hi, yes should be 45°. I agree with you. Position the mirror slightly above the lizard with the camera positioned laterally slightly above the height of the animal. Now you can record the lateral and the dorsal aspect with one camera simultaneously... I would try to avoid oblique views. Cheers

You will find most of your answers in the literature dealing with leaping performance in primates, and more particularly strepsirrhines. However, I really doubt, if my memory does not fail me, that you will find any detailed biomechanical study for this. Some helpful references would be Dunbar DC 1988. Am J Primatol 16: 291-303, Demes et al. 1996. J. Hum. Evol 31: 367-388 (and a series of papers by the Stony Brook lab), as well as Legreneur et al. 2011. Zoology 114: 247-254. If you also check the locomotion/positional behavior literature (again unfortunately mainly on primates) you can find drawings and photos of leaping primates and the position of the tail. I hope that this was of some help!

Good luck