The unbearable brightness

Here are two quick, strange observations about colored light and biology:

1. A recent study in PNAS claims that exposure to orange light could have an impact on cognitive function. The MRI results certainly appear significant but I'm not familiar enough with the field to know if they're reliable. Caveats: Their sample size was 16 people, the effects of the particular light were noticeable more than an hour post-exposure, and potential participant effects (i.e., how sleepy they felt) were all self-reported, though the researchers state these reports were consistent. I'm curious to see if the results can be replicated with a different sample of volunteers.  (The paper by Chellapa et al. is here.)

2. C. elegans glows blue when it dies. Don't take my word for it. Take the word of Coburn et al. from their 2013 PLoS Biology paper, Anthranilate Fluorescence Marks a Calcium-Propagated Necrotic Wave That Promotes Organismal Death in C. elegans: "We report that organismal death is accompanied by a burst of intense blue fluorescence, generated within intestinal cells by the necrotic cell death pathway." It turns out that, at least in C. elegans, organismal death looks like a wave of necrosis as a cascade of self-destruction propagates cell death. The short story: cells burst, pH increases, things that wouldn't normally be fluorescent suddenly are. The death-glow may have been found to happen in yeast, too (Coburn et al. cite this 2007 paper by Liang et al but I couldn't find any explicit mention in it about blue fluorescence, just yellow and red).

Gen-eralizations

I'm really not fond of the term "Millenial." I didn't like the terms "Gen Y" or "Gen X" or even the whole "baby boomer" classification for the same reason: all these terms are shorthand ways to generalize entire generations of people.

It's possible that the terms were never originally intended to be pejorative. Having a shorthand way to refer to people born during certain periods of history not only provides a chronological shorthand, but it allows us to infer some cultural context. If someone's identified as a baby boomer, their childhood likely didn't include Super Soakers or AOL chat rooms. They're statistically likely to have different opinions from more recently-born folks about a number of topics. We can, of course, raise similar arguments about different racial or ethnic groups. There are objective differences in cultural context between groups, even when we ignore the obvious physical differences (i.e., baby boomers are older than Millenials, just like Native Americans have different skin tones than people with recent European ancestors).

The problems arise when the generalizations become interpretations. Any generalization of human beings is inherently dehumanizing. It's an unavoidable element of living in a modern society, though the relationship between personal identity and broader ethical concerns only really began in the mid 1600s. That's really a distinct topic -- even so, it illustrates the difficulties involved in reconciling individual identity with the identities of the Many. We can draw conclusions about one person says or does and what groups of people generally say and do, but using the group as a model for the individual is nigh-impossible when there is high variance among group members.

Really, I'm just tired of glossy stories about Millenials. I'm tired of TIME Magazine's offerings, even when they're chock-full of Joel Stein's usual everyman sarcasm. I'm tired of Atlantic pieces about how self-centered these Millenials are supposed to be (spoiler: youth is a great time for narcissism).* I'm tired of Slate articles which may be unintentional satire, as this quote may reveal:

A generation ago, my college peers and I would buy a pint of ice cream and down a shot of peach schnapps (or two) to process a breakup. Now some college students feel suicidal after the breakup of a four-month relationship. Either ice cream no longer has the same magical healing properties, or the ability to address hardships is lacking in many members of this generation.

Isn't hindsight wonderful? I'd love to be able to labor under the pretense that This Generation Is Broken, but I suspect that humanity just generally can't handle hardships well. At best, they can imagine a fantastical, pain-free past. 

I don't even identify as a Millenial. Why would I? It's certainly not going to do me any favors.

*I won't even get started on the monthly NYT articles about That Thing Gen Y Does. A slightly more acerbic Slate article than the above one may have to suffice.

Today, I learned that naked mole rats do not feel pain if they eat capsaicin. It's not that they ever have to eat chili peppers, it's just that they can't feel that kind of pain anyway.

A new mite-mediated emaravirus may be emerging among coffee plants in Hawaii. It's too early to know whether that's a problem, but emaraviruses haven't been known to infect coffee plants before.

The most minimal bacteria

Today I learned about the existence of the bacteriome, a specialized organ found in some insect species which is just chock full of endosymbiotic bacteria. Most animals provide hosts for bacteria, but the critical part here is the endosymbiotic nature: these symbionts must live and reproduce within host cells. As a result, many insect endosymbionts are quite odd in genetic terms and have tiny genomes. They can only grow to a certain population size, too, as they're limited by the space available within those host cells.

One such example of the resulting genetic oddities is found in Hodgkinia symbionts from cicada bacteriomes. A report by McCutcheon et al in 2009 showed howHodgkinia cicadicolaappear to have re-coded their UGA codons to code for tryptophan rather than the usual Stop codon. This specific re-coding has been observed before, but only in very low-GC content species, of which Hodgkinia is not one (it has a GC% of more than 58 percent). This symbiont also has a crazy-small genome at 144 kb. That was the smallest bacterial genome yet sequenced butNasuia deltocephalinicola, another insect endosymbiont, has it beat by 22 kb.