Mig 27 Fulcrum

[Silvana Fleischacker]

Fulcrumwhich means "bedpost" in Latin, comes from the verb fulcire, which means "to prop." When the word fulcrum was first used in the 17th century, it referred to the point on which a lever or similar device (such as the oar of a boat) is supported. The literal use easily supported figurative use, and it didn't take long for the word to develop a meaning referring to one deemed essential to the function or development of something. Despite fulcrum's multiple senses, the word's meanings have kept a steady theme. In zoology, fulcrum refers to a part of an animal that serves as a hinge or support, such as the joint supporting a bird's wing.

According to Human Rights Watch, black males are incarcerated at a rate more than six times that of white males resulting in one in 10 black males aged 25-29 being held in prison or jail in 2009. The same report states:

blacks constitute 33.6 percent of drug arrests, 44 percent of persons convicted of drug felonies in state court, and 37 percent of people sent to state prison on drug charges, even though they constitute only 13 percent of the US population and blacks and whites engage in drug offenses at equivalent rates.

Scot is a past Alston/Bannerman Fellow, an Open Society Foundations Fellow, and a recipient of the Association of Asian American Studies Community Leader Award. His writings have been included in Race, Gender, and Class in the United States: An Integrated Study, 9th Edition, and Killing Trayvons: An Anthology of American Violence.

Scot's political essays, briefings, and other educational media can be found at his newsletter, We Fight the Right at scotna...@substack.com. He is a sought after public speaker and educator who provides consultation on campaign and communications strategy, and fundraising.

There are some important implications in all of this that need to be untangled. Somehow we need to use this understanding practically, to figure out how to counter appeals to racism, sexism, and the lust for fictional power, to aggregate ourselves along new lines to begin to aspire toward seeking the well-being of all.

Our concept of ownership rights, the structure of our federal elections system, the segregated state of our society, the glut of money in politics, our conservative political culture, our criminal codes and federal penitentiaries all evolved around or were/are facilitated by anti-black racism.

@pt- America was fuelled by anti-blackness because it was literally built by unpaid black people who were, and continue in some areas to be systematically maligned and dehumanised to justify their mistreatment.

To suggest otherwise or attempt to turn this into a philosophical discussion about how the country MIGHT have been built had there been no slave labour is just avoiding the fact that there WAS, in prisons there still IS, and it benefits many other ethnic groups to varying degrees at the expense of black people.

To me, the genocide of Native Americans is the basis on which the entire machinery, fulcrum and all lies. Without the theft of that land, America as it is would never have existed.

Lastly to call a comment that denies how anti-blackness has shaped America feminism is acceptable only to someone who does not consider black women to be a group worthy of representation by feminists.

Yes women were not represented in the constitution but white women COULD and did own black women, abuse them and participate n their rape and murder on many occasions.

While white women suffered gender based discrimination their acknowledgement as legal persons gave them protection that black women did not have and to this day white American women, although still discriminated against, are still the best paid and most protected from crime of any women in America.

Anti-black racism stems from a system that did not legally consider black people to be HUMAN, to suggest it was the same as every other form of discrimination is mind boggling.

To put it bluntly, we are still counting the degree of blacksness/ brownness of a persons skin as the first standard measurement for being deserving of human respect and honor. That is why whiter skin remains the lever by which society moves. The question to be answered is, how can we all free ourselves from from the mechanics of this so that we can all collectively exercise our power to effect good for all mankind instead.

A friend just forwarded this post to me and asked me what I thought. I guess it makes sense to share my response with all of you in the web-world instead of keeping it a private discussion. It is a bit different in tone than other comments, but I hope you find it is helpful criticism. Here is what I wrote:

Hence, in my interpretation, the author attributes the fulcrum of White Supremacy to Blackness. I very much agree with his opinion. What you did not take into consideration is the rooted network of White Supremacy and the system of mechanisms in place to keep that system alive. In America, it IS RACIALLY BASED. It is encoded into the architecture of the American system. Anyone who arrives or is born there is necessarily going to encounter it, whether they want to or not.

Its not about Blacks only, its about the concept of white vs Other, aka white supremacy. The whites also have their own whiteness hierarchy, the whitest of the whites have managed to assimilate the lesser others that pass as whites, strip them of their voice and identity, and program them into an amplification tool to help perpetuate their paradigm of white supremacy.

I think the easiest way to find the coordinate of a point in the map is: open the map in COOT, navigate to the point of interest (control-drag if there is no PDB to click on), place a water over it, middle click at the water and read the coordinate at the bottom of the screen.

For question 2, I can always see a one-voxel peak near the centre of the map, not necessarily the geometric centre of the unit cell (can be a few Angstroms off). If I get its coordinate and use it as the centre for symmetry operations it seems to give very good result. So I guess the answer is to look at the center of the map and find that little peak.

You can also use measure center directly on a volume or atomic model (including arbitrary atom selection). However, be aware that the coordinates are in Angstroms for the volume eraser* and atomic model based methods, but are in voxels when measuring the center of mass of a regular volume.

Hi @olibclarke - just a quick note: I believe Chimera reports coordinates in Angstroms, but the local refinement job expects fulcrum coordinates in voxels, so you would have to divide the reported values by the pixel size.

Yes, the reported fulcrum is indexed at the center of the volume. So, if your box size is 400, the reported coordinates would be offset by N/2 + 1, as it is in your case. And yes, C1 is assumed - I believe Ali P. addressed the question about local symmetry in another thread.

Thanks - yes Ali addressed the question about symmetry expansion - but the lack of enforced symmetry means that one also cannot use this for example for performing a masked refinement of the TM region of a symmetric ion channel then (where the local symmetry axis is the same as the global symmetry axis), which is a shame.

Hi @ali.h,

Can I also suggest marking the fulcrum position on the map slices in the output? This would help to quickly identify if a mistake has been made, or if optimization of the fulcrum position is unstable (when this option is switched on).

I agree the CoM of the mask is a very good approximation to the CoM of the particle and is easier to compute stably (although see phase_cog() in EMAN2 which solves the problem elegantly by determining the phase of the DC component).

The cryoSPARC paper supplemental says a uniform prior over shifts is used (is this true? IMHO no prior is better than a uninformative one), but Relion and cisTEM both have alignment probabilities affected by the shift magnitude (Relion uses a Gaussian prior centered at the origin). Thus, it is desirable to obtain particles with shifts normally distributed around zero, by targeting the center of the subparticle and re-rextracting after subtracting shifts from the particle coordinates and setting shifts to the remaining subpixel values. All these additional transformations just need to be memoized so you can undo them at the end to aid the user in putting humpty dumpty together again.

Agreed on all points Dan. I just realized that the center of the shown slices during local refinement is the fulcrum - you can see this if you set the fulcrum to the center of the mask. Still might be worth putting a white dot in the center of the slice as an indicator.

Fulcrum Positioning: The model we are working with assumes that in every image, the relative positioning of two bodies (V1 and V2) will be related by a rotation around a connection point (fulcrum). This is a simple approximation to the bending of the structure around the interface between the two bodies. From this model, it seems that in each particle image, the center of mass of the secondary volume will be in a different location with respect to the primary volume. However, the fulcrum position will be in the same location (or at least close) wrt the primary volume. This is why we think of the fulcrum as the hinge point in our model, as that will minimize the amount of shift required to align each image. Though, we are looking into the radial blurring @DanielAsarnow mentioned to see how significant the effect is in cryoSPARC to see if we can mitigate it. In the future, the fulcurm optimization will be done automatically which should give us a more concrete answer.

Hi all, and especially to our customers and backers. I am very sorry for the current state of communications and production. I also understand that there are some very frustrated customers and rightly so. I feel like all we have managed to do is miss deadlines and annoy customers. It is no secret around here that we are been seriously late with shipments, this has been for various reasons.

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