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Complexity and Versatility of Calcium Signaling and Dynamics
Full text linkThe calcium ion is a universal second messenger mediating a wide range of dynamic cellular functions, such as exocytosis, contraction, transcription, and proliferation. A hallmark of calcium signaling is the transient pulsing dynamics of cytosolic calcium concentration, which is versatile tool regulating cellular processes.
The aim of this thesis is to study the calcium signals and dynamics primarily related to mechanotransduction within rod photoreceptors, primary hippocampal neurons and glioblastoma (GBM) cells.
To study calcium dynamics in rods of Xenopus laevis, which are composed of an inner segment, IS and an outer segment, OS (IS+OS), we used the fluorescent calcium dye CaSiR-1 AM working in the near-infrared (NIR) (excitation at 650 and emission at 664 nm), which allowed us investigate calcium dynamics with an unprecedented accuracy and most importantly in semi dark-adapted conditions. The experiments showed: there are spontaneous calcium flares in functional OSs, and these flares are highly localized and are more pronounced at the OS tip; a bright flash of light at 488 nm induces a drop in intracellular calcium concentration at the OS base but often a flare at the OS tip.
We also have investigated mechanosensitivity in the rods by combining electrophysiology, optical tweezers (OTs),and biochemistry, and we show that mechanical stimulation of the order of 10 pN applied briefly to either the OS or IS evokes calcium transients. The pN force evoked calcium transients can be inhibited by application of GsMTx-4 whereas spontaneous calcium flares can be seen at tip of OS.
In primary hippocampal neurons, we employed an Oscillatory Optical Tweezers (OOT) to exert a local indentation with pN forces. We found that single local indentation evokes a transient intracellular calcium change, whereas repeated mechanical stimulations induce a more sustained and variable calcium response, which can be inhibited by the GsMTx-4 treatment. Moreover, we observed a mechanically evoked activation of the CaMKII and small G protein RhoA.
Lastly, with glioblastoma cells, we investigated the calcium flares and its coupling with chloride dynamics in both flat and round GBM cells undergoing the mitosis primarily by using multi-channels imaging of calcium and chloride, ratiometric calcium imaging. The preliminary data showed that in normal flat cells, global calcium flares can last stably for at least one hour without significantly changing the morphology of the cell, and more importantly are able to activate chloride signals which can be unexpectedly localized. And within round cells undergoing mitosis, instead of finding calcium flares at the initial phase before the cell divides into two, calcium flares were frequently seen at the end of mitosis, which can be further increased by Piezo 1 agonist Yoda 1 to activate favorable chloride influx signals
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No full textThis book is already in the collection, but this copy, found thirty years later, is signed by Vincent Torre, and so I include it on its own. I am delighted to have found a copy at a reasonable price. Perhaps I am coming close to finding all of Torre's fable books! As I wrote of the copy found earlier, this is a one-man book. Seventeen fables in verse, with a predilection for off-rhymes and even some off-rhythms. An occasional moral shows wit (e.g., GGE on 60). Different: a farmer gets into FG, and the frog and the rat quarrel over the fee in mid-stream. There is one primitive drawing for each fable. The borders and print are very pleasing.Vincent Torr
Aesop Confounded: Tales and Fables old and new.
No full textFour of the booklet's eleven stories are identified as fables. The suggestion in the title is that we have anti-fables here. Most of the stories work that way, in fact. Thus the moral to Little Red Hen is Always try to get away with as little work as you can and to Buttercup Hags' bags should be knife-proof. The Cat and the Fox (8) works with a fox, the string of whose bag of tricks had become a tangled knot, to arrive at this moral: Use zippers. The Mice and the Cat (19) proclaims at its end The best-belled Cats are sleeping ones. The Sparrow Whose Tongue Was Cut (23) is strange, as the sparrow suddenly starts talking in mid-story. Perhaps I am missing something! All three of these fables have full-page illustrations. The Camel and the Jackal (27), unillustrated, seems to me to be told straight. Torre's moral for it is A Camel's revenge is dangerous. The Alligator and the Jackal (30) seems to me not to be a fable, nor is it labelled as one. It goes through five phases and involves some preternatural events. I am amazed that Carl found this book for me!#48 of 50Vincent Torr
The Fox and The Wolf
No full textA very nice piece of work from a well known source. The fable itself seems to be a somewhat rambling conflation of several. The fox has a long and unresolved interchange with the cock before he arrives famished and thirsty at the well, where the water promptly stinks to him. Once in the well, he encounters the wolf. The latter descends into the paradise the fox has described and ultimately ends up battered by monks. This text uses ? instead of paragraph indentations and ? instead of quotation marks. The four brown and one black illustrations are nice; they seem to have bled onto the facing pages despite the slip-sheets.#45 of 50Vincent Torr
Tales & Fables
No full textThis is one of three Torre books identical in format that I was able to get in a group from Scottsbooks. Might it mean that I now have all of Torre's fable books? Like the other Torre books I have found, it is a beautifully produced book, set by hand and bound by hand. This book has twenty-three offerings on 118 pages. Each of the stories has an accompanying full-page silkscreen, and these seem to me to be again the strength of the book. Most of these verse stories are done in ababcc rhymes. The first is a surprising story of a stork who counsels an innocent young frog to take refuge in the stork's bill but then has conscience pangs and lets him free. One of my prizes goes to The Peacock & the Penguin (25) for the clever repartee, the good silkscreen image, and the well-fitted moral that his own beauty is in the eye of the beholder. Another favorite is The Parrot & the Polar Bear (59): the two meet going in opposite directions to lands envisioned as charming. As each hears the other proclaiming the problems of his own habitat, he turns back to his own land. This illustration is one of the more complex and colorful, I think. I also like The Gargoyle & the Chilmney Swift (80). The mean-spirited gargoyle eventually finds his complaining mouth stuffed by the nest of the happy and grateful swift. Among the non-fable tales might be The Pearl & the Oyster on 89. My grand prize goes to The Pig & the Fox (94) for its story. The fox convinces the pig that fat is now fashionable. The pig begins eating even more, and the farmer decides to slaughter him and make him into sausage, which the fox steals. The flatterer seeks only to serve himself (98). A last favorite, for both story and silkscreen, is The Horse of a Different Color (114). The carousel horse rejects the real horse when he finally sees one. Notice did'nt on 66 and concensus on 100.This is a hardbound book (hard cover)Signed#119 of 150Written and Illustrated by Vincent Torr
Aesop's Fables
No full textA one-man book. Seventeen fables in verse, with a predilection for off-rhymes and even some off-rhythms. An occasional moral shows wit (e.g., GGE on 60). Different: a farmer gets into FG, and the frog and the rat quarrel over the fee in mid-stream. There is one primitive drawing for each fable. The borders and print are very pleasing.Vincent Torr
Verse & Fables
No full textA beautifully produced book, set by hand and bound by hand. It contains five fables, the first three of them labelled as Aesop's fables. The Country Mouse & the Subway Mouse (1) is a strong starter for this collection. Its moral: To know your mind, you ought to hear/Two sides to every story. The Cat and the Mice (8), like the previously mentioned fable, has a strong illustration. LM (43) has a different ending: The mouse goes away from the lion unbefriended and unthanked. The Rabbit and the Rat (55) is new to me and engaging. The Old Man and the Sparrows (75) plays on the borders of fable. Its sparrows not only talk; they are polite. Torre's silkscreens are much better than his (or most other people's) verse. The best non-Aesopic illustrations are of the mockingbird (65) and the mock turtle (95).This is a hardbound book (hard cover)Signed#28 of 150Vincent Torr
The Fables of Leonardo da Vinci
No full textGradually I am finding the various fable works of Vincent Torre. This is another beautiful piece. The booklet includes fifteen fables and seventeen entries from Leonardo's Bestiary. The fables are strong on one-upping arguments. The usual question is: Who will laugh last? Among them is a favorite of mine from Leonardo, The Nut and the Campanile (18). Leonardo's fables are sometimes very sad, like The Willow & The Gourd (9). The willow's romance turns into her destruction. The Ant & The Grain of Millet (15) is much happier. The grain asks the ant to let it reproduce, offering a hundredfold. The ant takes the offer. The Beaver shows up in the Bestiary as Peace, and Leonardo tells the story often found among fables. The beaver bites off its testacles (sic) and leaves them for its enemies and so escapes. The mole is Lies, since it lives as long as it remains in the dark but dies as soon as it comes into the light. The first nine fables get a delightful woodcut each. There is also a repeated design cut in wood.Original language: ita#6 of 50First editionBy Edwin P. Barro
The use of optical flow for the analysis of non-rigid motions
No full textThis paper analysis the 2D motion field on the image plane produced by the 3D motion of a plane undergoing simple deformations. When the deformation can be represented by a planar linear vector field, the projected vector field, i.e., the 2D motion field of the deformation, is at most quadratic. This 2D motion field has one singular point, with eigenvalues identical to those of the singular point describing the deformation. As a consequence, the nature of the singular point of the deformation is a projective invariant. When the plane moves and experiences a linear deformation at the same time, the associated 2D motion field is at most quadratic with at most 3 singular points. In the case of a normal rototranslation, i.e., when the angular velocity is normal to the plane, and of a linear deformation, the 2D motion field has one singular point and substantial information on the rigid motion and on the deformation can be recovered from it. Experiments with image sequences of planes moving and undergoing linear deformations show that the proposed analysis can provide accurate results. In addition, experiments with deformable objects, such as water, oil, textiles and rubber show that the proposed approach can provide information on more general 3D deformations
``Optical flow and deformable objects''.
No full textWhen a plane undergoes a deformation that can be represented by a planar linear vector field, the projected vector field on the image plane of an optical device is at most quadratic. This 2D motion field has one singular point, with eigenvalues identical to those of the singular point describing the deformation. As a consequence, the nature of the singular point of the deformation is a projective invariant. When the plane moves and experiences a linear deformation at the same time, the associated 2D motion field is still quadratic with at most 3 singular points. In the case of a normal rototranslation, i.e. when the angular velocity is normal to the plane, and of a linear deformation, the 2D motion field has at most one singular point and substantial information on the rigid motion and on the deformation can be recovered from it. Experiments with simulated deformations and real deformable objects show that the proposed analysis can provide accurate results and information on more general 3D deformations
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