Archive for March 2011
I tend to be wary of activists. To me, an activist is someone who has taken it upon themselves to support a particular opinion, regardless of that opinion’s status as right or wrong opinion (which is to say its truth value). This leads to a turbulent relationship with fact that may involve everything from cherry picking ideas to outright denialism, and generally makes for a very “fair-weather friend” relationship between opinion and (my personal tool of the trade) reason. Now, many activists can and do behave responsibly and rationally and they have my greatest respect (another tip of my hat to the intelligent and thoughtful feminists over at Fishnet Bluestockings, they are on my blogroll for a reason), but I find that it pays to be on my guard against those that don’t. Which is why I employ the following guidelines with activists:
- You are entitled to your opinion and the expression of that opinion in the appropriate forums and manner. To give you any less than that would be a violation of your rights and my moral code.
- Do not confuse an opinion with an argument. Don’t expect to persuade without evidence or reason, it will get you ignored.
- Attempts to persuade through lies & half-truths, the propagation of misinformation, shame or peer pressure, or any other end-run around mutual respect and properly formulated argumentation will get you ridiculed.
- Resorts to threats and violence will get you watched, reported, arrested, and (in the most regrettable cases) hurt.
I feel the need to bring this up today, since there is a group out to threaten, harass, and possibly attempt to kill me and my fellow students (as if a bisexual, transgendered person doesn’t have enough animosity directed towards her/him already). Negotiation is Over is a hate group directed at researchers in the life sciences. They call themselves animal rights activists, but they seem much more interested in attacking researchers than saving animals. And now they have specifically turned their gaze on students as they announced yesterday:
Every time a vivisector’s car or home — and, eventually, the abuser him/herself — blows up, flames of liberation light up the sky.
When we attack professors, we can only expect limited gains. They are deeply entrenched in the holocaust, have vested financial interests, and enjoy a network of support and protection. Students, however, have no round-the-clock police protection, no access to the FBI, and no access to legislators. The weakest link in the chain is the student body. Vivisectors-in-training can be shut down with relative ease.
Students also need to understand that making the wrong choice will result in a lifetime of grief. Aspiring scientists envision curing cancer at the Mayo Clinic. We need to impart a new vision: car bombs, 24/7 security cameras, embarrassing home demonstrations, threats, injuries, and fear. And, of course, these students need to realize that any personal risk they are willing to assume will also be visited upon their parents, children, and nearest & dearest loved ones. The time to reconsider is now.
It goes on like that for quite some time, with a lovely picture of a firebombed car just to make sure there can be no ambiguity about what they are advocating. As an added bonus their site has links to state by state directories of research universities they consider offenders via their “Animal Abuse Crime Database”. Guess whose uni is on their list?
But I’m not afraid of these creeps, and I urge you not to be either. Stay safe, don’t let them get to you, and promptly report any threats. These people are terrorists, and terrorists like to cause terror. So don’t give them the satisfaction. And if you have a forum for it, I hope you will speak out and let them know that their tactics are impotent. In time they will try to do something stupid and get arrested/shut down, or they will tire of their game. Either way, the wanna-be scary monsters will be stuffed back under the bed and we can get on with the business of saving lives.
Now, my opinions on the morality of animal research are complex, and I will talk about them in a later post and hopefully be able to present a rational basis for them. But my opinions on this issue are stark: this is unacceptable. Even if you personally find animal research reprehensible and feel that making transgenic mice is on par with Tuskegee, realize that this sort of behavior is not the way to go about effecting a change.
Violence remains the last refuge of the deluded and incompetent.
This is just a heads up that a new site has been added to the ‘Resources’ links down there on the bottom right. I was trying to look up something about mitochondrial fusion proteins and kind of stumbled across a site that hosts a number of very interesting science videos. Despite the name, DNAtube appears be a multidisciplinary site hosting videos on all aspects of science and math. Probably worth checking out, I know I would be if I had time to take a study break.
They haven’t managed to kill me with exams yet; however, it’s not from lack of trying. But I found something so interesting yesterday that I just couldn’t keep myself from blogging about it. And by interesting, I mean terrifying. I tend to find life beautiful. Even if it is something most people would find gross, or disturbing, or horrible. I’m a biologist, it’s a documented weakness of our ilk. So when I say that the following engenders in me a feeling of profound wrongness and almost disgust, I want you to take my full meaning.
- HIV comes in two flavors, CCR5 tropic and CXCR4 tropic. You might remember a post on CCR5 tropic HIV from a while back. It basically denotes which co-receptor is necessary for the virus to enter a cell (and yes, there are dual-tropic strains). We generally focus on CCR5 because, for reasons that are not entirely clear, initial infection with HIV is almost entirely CCR5 tropic with the infection shifting to CXCR4 tropic as it progresses.
- Hematopoietic stem cells (HSC) are the source of all of your blood. ALL of your blood, myeloid and lymphoid. They are a self-renewing pool of multipotent cells, which means that they can be used to make new blood as needed (this is why you can donate blood and bone marrow have it regenerate). Among the offspring of the lymphoid lineage are the T-cells that HIV usually attacks.
Got all that? Good. Sit down. Are you sitting comfortably?
In sum, we have shown that multipotent HSPCs and HSCs can be infected by HIV and that this infection is primarily accomplished by CXCR4-tropic HIVs. The infection and destruction of multipotent HSPCs may contribute to the more rapid decline in CD4 counts associated with CXCR4-tropic HIV isolate emergence. Alternatively, as infected HSCs could create an extremely long-lived reservoir of virus, preferential infection of these cells by CXCR4-tropic virus could provide a reservoir for the emergence of CXCR4-tropic isolates late in disease: as other viral reservoirs are depleted, CXCR4-tropic virus from the HSC and HSPC reservoir could begin to predominate. In addition, our demonstration that HIV can infect cells capable of stably engrafting for months in the xenograft model indicates that HIV can infect HSCs that are capable of self-renewal and, if the integrated viral genome is latent, that it can be maintained and even expanded by cell division.
The above quote comes from an article published in this month’s Cell: Host & Microbe, and I have to say that their work looks pretty solid (at least to my exam addled brain). They performed a series of experiments using viruses generated from a minimal HIV genome and expressing three variant (R5, R4, or dual) envelope proteins. With this they demonstrated that not only could CXCR4 tropic and dual tropic viruses infect hematopoeitic progenitor cells in general, but that they could specifically do so to cells capable of multilineage reconstitution in immunocomrpmised mice. Or to put it another way: XR4 and dual tropic HIV infects HSC.
Now active HIV infection appears to kill HSC cells outright, and HSC death is really bad, but if you have been following closely you’ll realize that that isn’t the biggest worry here. Latent infection of HSC could lead to a near impossible to purge, continually renewing reservoir of infection, moreover it appears that it is possible for infected HSC to differentiate and produce daughter cells that are already infected. This means that in advanced cases of HIV infection, we might need to start looking for integrated provirus in cells that HIV technically can’t infect.
This is a blow struck to the heart of our immune system. Sure, there are genetic disorders that screw with HSC, cancers even, but a pathogen? I feel like they are breaking the rule about fighting on holy ground. It is still important to see if wild-type HIV is capable of latently infecting HSC instead of killing them outright, but given the versatility of this virus, it wouldn’t surprise me, and if that is the case it is all the more reason to lock down HIV infection as early as possible. We are really close to finding a way to flush latent infection from T-cells, and it would be a serious blow if we succeed in that only to find that HIV has yet another reservoir lying in wait.
(And okay, I admit that my disgust is laced with a teensy bit of: Oh wow that is so awesome.)
Notes & Sources
- HIV-1 Utilizes the CXCR4 Chemokine Receptor to Infect Multipotent Hematopoietic Stem and Progenitor Cells (Carter, et al. 2011)
- Thats only the second Highlander joke in three months of science blogging. I am falling behind schedule.
Now that we have a basic idea of what ionizing radiation is, let’s talk about what it does to you. Today we will focus on acute radiation syndrome (also known as radiation sickness and radiation poisoning). This is the sort of thing that occurs due to short-term, high-dose exposure to ionizing radiation, such as that from nuclear weapon discharge or nuclear industrial accidents. We’ll take a look at the long term effects and generation of neoplasms in a future post.
The precise nature of radiation syndrome varies by dose, radiation type, tissue exposed, and duration of exposure. These factors are all rolled together in an SI unit called the Sievert (Sv), which is known as the dose equivalent. The measure of dose is known as the Gray (Gy), but that raw information doesn’t tell us much about biological effect. So the Gray is transformed as a function of quality factor Q which is the ratio between the effects of gamma radiation and the effects of your radiation type of interest (e.g. Q[gamma]=1, Q[alpha]=20). There is a further factor called N which relates the effects of radiation based on differences in species and tissue, for simplicity’s sake N[human]=1. The final product of this calculation is the dose equivalents in Sv, which gives us useful info on biological effect. The units of Gy and Sv are J/kg and because time is an important factor we usually see Gy and Sv expressed over seconds, hours, or days. Both the Gy and Sy deal with pretty large amounts of radiation, so it is much more likely to see quantities expressed in milli or micro versions (for instance at one point the ongoing Fukushima I accident peaked at 400 mSv/hour).
Certain types of (particle based) ionizing radiation are of greater or less concern depending on the location of their source. For instance, alpha and beta-particles have low penetrance. They can cause surface skin burns, but generally can’t penetrate far enough to cause excessive internal damage. However, an internal source of alpha or beta-particles is a more dire circumstance because just as they do not have the penetrance to enter the body, they cannot leave. This is why contamination of food, water, and dust is such a concern. High penetrance radiation, like neutron radiation or (photon based) gamma-rays is less affected by location of source.
The symptoms of radiation syndrome begin at 1 Sv and at about 8 Sv they become invariably fatal. Not all symptoms present at once, and it can take up to four weeks for the full effects of minor radiation poisoning to be seen. Usually the time between exposure and onset decreases as the Sv increase (with there being very little delay at the 8 Sv level). The immediate symptoms include: nausea and vomiting, diarrhea, headache, and fever. These occur within ten minutes to six hours after exposure. In the next one to four weeks (or sooner in the case of extremely high doses) the victim may suffer: fatigue, hair loss, bloody vomit and stools, infections, poor wound healing, low blood pressure, dizziness, and disorientation. Usually there is also some level of skin redness, peeling, ulceration, and possibly necrosis.
All of these symptoms result from a disturbance in cellular chemistry. As we discussed last time, ionizing radiation generates ions (particularly reactive ions known as free radicals). The cell is an impressive machine dedicated to controlling multiple ongoing, complex chemical reactions. So we can see why the spontaneous introduction of new reactants would be bad, and why a high concentration of them at one time would be very bad. Essentially cells will be faced with a critical failure of their functions and this will lead to massive cell death. And this is not going to be the pretty, well-controlled cell death either (no, that isn’t facetious, remind me to tell you about the pathways of cell death sometime). In most cases the immediate cause of death is opportunistic infection due to a failure of the immune system caused by the destruction of large amounts of bone marrow; however, in extreme cases the victim just basically falls apart at a cellular level.
As mentioned, these are only the acute affects of radiation exposure, even if you survive these, there are still the long-term consequences of cell damage to look forward to.
This is what is at stake in Japan. This is what a whole host of brave rescue workers are risking to try to keep everyone else safe. Show a little compassion and (if you can) a little support.
Sources & Further Reading
With an eye towards discussing the effects of ionizing radiation on humans, particularly with respect to cancer, I thought it would be best to write up a quick and dirty reference post on what exactly ionizing radiation is. This is a good example of my continuing struggle to find an appropriate voice for this blog. I never really know what I can safely assume my readers know. So, let’s (hopefully) review:
Ionizing radiation consists of particles or photons capable of inducing detachment of electrons from their atoms resulting in free electrons and a corresponding positive ion. There are five broad types of ionizing radiation: alpha-particles, beta-particles, neutron radiation, gamma rays, and X-rays.
- alpha-particles: result from radioactive decay, and consist of two protons and two neutrons. They are directly ionizing.
- beta-particles: result from radioactive decay, and consist of either an electron or positron. They are directly ionizing.
- neutron radiation: results from nuclear fission, and is simply a free neutron. They are indirectly ionizing as they have no charge themselves, but can collide with and excite charged particles that then directly ionize.
- gamma rays: are high frequency photons emitted to right the energy of a decayed atomic nucleus. They are also indirectly ionizing as they are chargeless wave-packets that when absorbed can cause electron expulsion which then ionizes directly.
- X-rays: kind of overlap with gamma rays. They are high frequency photons. The only major difference is their origin.
The ionizing capability is dependent on the energy of the individual unit (particle or photon) interacting with the atom (this is why high frequency electromagnetic waves are ionizing and low frequency are not). Thus, high energy, low concentration radiation can still have an ionizing effect.
As we will discuss next time, it is generally the chemical characteristics of the resulting ions that cause damage in cell physiology and DNA.
Okay, so I had a friend ask me to talk a little bit about the basics of nuclear radiation and its effect on humans. This question specifically prompted by the tragedy that has recently occurred in Japan. And I intend to do that throughout the rest of the week, but today was…taxing (and technically it is Tuesday here now).
I just want to make a brief note about something else that has happened recently. A massive outpouring of (predominantly American) online vitriol against Japan. Ignorant and Online is doing a good job cataloging the more egregious of these. This ranges from insensitive jokes to rage filled tirades, and seems to be motivated by everything from old grudges to crazy religious theories. I had an acquaintance trying to send me his own crude jokes not two hours ago. He seemed unabashed when I politely explained that he wasn’t being witty and called me a person who prefers to cry at tragedy rather than laugh at it. I wish I did cry more, it would probably be healthier.
I can see the value in pain based physical comedy, I enjoy dark humor, and I don’t shirk away from death in my entertainment media. But to be perfectly clear: when real people begin to suffer and die, things stop being entertaining. When confronted with a tragedy, the appropriate response is to do something about it, and leave people who are more concerned with laughing or crying on the sidelines because you don’t need them getting in your way. Human suffering is not a spectator sport.
There are earthquake victims, tsunami victims, radiation victims, and a host of people without water, power, or food. Dedicated members of Japan’s SDF and international aid organizations are risking their lives to do something about it. As I write this, a skeleton force of fifty people have taken it upon themselves to wage an uncertain war pumping sea water into a nuclear complex to try and prevent more explosions, more radiation, more sickness, and more death.
This is not funny. Making a litany of (predominantly racist) jokes about this is not a way of “whistling in the dark” or a “valid method of dealing with tragedy”. Either do whatever you can to help these people (which may validly be very little, I personally can’t do much more than donate to aid organizations) and show a little bit of decorum and decency. The last thing you should do is laugh at their suffering and the work of those trying to help.
It’s Friday, and Spring Break, so time to focus on something a little less mentally taxing. Namely: anime. Now, with age and taste comes a little less of the geeky obsession I had with it in my highschool and undergraduate years, but certain, select titles still make up a solid twenty percent or so of our DVD collection. Why? Because it is a great vehicle for speculative fiction. By using an animated medium you dodge the cost spikes of practical and computer generated effects and it becomes no more difficult to make breathtaking and bizarre scenes than it does to make mundane ones. You can take an interesting premise or setting and explore it in a manner unconstrained by skyrocketing budgets.
This is exactly what Daphne in the Brilliant Blue fails to do.
Animated by J.C. Staff and produced by Genco, Daphne in the Brilliant Blue is a sci-fi/action story set in a flooded world. Humanity survived the deluge by building underwater cities where they preserved themselves and a great deal of Earth’s animal life. At an appointed time, 100 years before the start of the series, all (but one) of the submerged cities rise to the surface to form floating city states associated with whatever remaining land masses they can find. Society is rebuilt under the watchful gaze of a centralized government, scientific, law-enforcement organization known as the Ocean Agency.
The story opens with our young heroine, Maia Mizuki, completing her application for employment with said agency. Despite receiving top marks she is denied a position with the Ocean Agency, and not having made any alternate plans, winds up frantically looking for work. After a few traumatic incidents and with a bit of luck she finds a job with a rough and tumble company of freelance problem solvers called Nereids. Over the next year with Nereids, Maia grows up and begins to unravel her (apparently requisite in these sorts of series) mysterious past.
I love this premise and setting. Further, it is animated by a great studio. About a week ago, when I saw that this was up on Hulu and realized that my weekend was mostly free, I wound up sitting down to watch it with high hopes. Those hopes were quickly dashed.
The beginning of the first episode seems almost promising. We open on a young girl salvaging a box from a wrecked ship, some friendly ocean life, and a submersible hover bike/jetski. But right after that things begin to go…well, not really bad, but weird. From the second episode on I felt like I had stumbled into a different show: some kind of all-female scantily clad Cowboy Bebop/Firefly knockoff with a bit too much absurdist comedy tossed in for good measure. And things never really circled back until the last one or two episodes of the twenty-four episode series. But by that time I had mostly lost interest and none of the reveals that they were poorly building to seemed that important or surprising (save for the one about the true nature of Maia’s grandfather, that was kind of neat).
I don’t think I have ever been so let down by a show. I was really hoping for at least some sense of curiosity or wonder about this cool world with its strange cities and tech. Where does their food come from? How do the mouthpieces that let the characters breath under water work? What terrestrial life has been preserved and what hasn’t? How do they obtain fresh water? How were these cities constructed? How the hell do those bathing suits even stay on…spirit gum? There is quite a bit to explore here and the setup is so interesting, yet the creators seem to think that the only thing their audience should be interested in is guns and T & A. Which is profoundly disappointing.
This is not a bad show. It’s certainly well animated and I am sure that a number of people will be able to find it passably entertaining. There are even obscene amounts of exploitative fanservice (I will grant that the whole aquatic world concept well justifies putting their characters in swimsuits…but nothing justifies the specific swimsuits they decide to use) for those who are into that. But it is certainly not a good show and really fails to live up to the promise of its setting. I suppose if I want my aquatic cyberpunk fix I will just have to go read Starfish again.