Uncovering how plants see blue light

Plants can perceive and react to light across a wide spectrum. New research from Prof. Nitzan Shabek’s laboratory in the Department of Plant Biology, College of Biological Sciences shows how plants can respond to blue light in particular.

“Plants can see much better than we can,” Shabek said.

Plants don’t have dedicated light-detecting organs, like our eyes. They do have a variety of dedicated receptors that can sense almost every single wavelength. One such are the blue light photoreceptors called cryptochromes. When the cryptochrome detects an incoming photon, it reacts in a way that triggers a unique physiological response.

Cryptochromes probably appeared billions of years ago with the first living bacteria and they are very similar across bacteria, plants and animals. We have cryptochromes in our own eyes, where they are involved in maintaining our circadian clock. In plants, cryptochromes govern a variety of critical processes including seed germination, flowering time and entrainment of the circadian clock. However, the photochemistry, regulation, and light-induced structural changes remain unclear.

In a new study, published Jan. 4 in Nature Communications Biology, Shabek’s lab determined the crystal structure of part of the blue-light receptor, cryptochrome-2, in the model plant Arabidopsis thaliana. They found that the light-detecting part of the molecule changes its structure when it reacts with light particles, going from a single unit to a structure made of four units linked together, or tetramer.

Rearrangement leads to gene activation

“This rearrangement process, called photo-induced oligomerization, is also very intriguing because certain elements within the protein undergo changes when exposed to blue light. Our molecular structure suggests that these light-induced changes release transcriptional regulators that control expression of specific genes in plants,” Shabek said.

The researchers were able to work out the structure of cryptochrome-2 with the aid of the Advanced Light Source X-ray facility at the Lawrence Berkeley National Laboratory.

The Shabek lab broadly studies how plants sense their environment from the molecular to the organismal levels.

“This work is part of our long-term goals to understand sensing mechanisms in plants. We are interested in hormone perceptions as well as light signaling pathways,” Shabek said.

The team first solved the crystal structure of the blue light receptor two years ago, using X-ray crystallography and biochemical approaches. With recent advances in plant sciences and structural biology, they were able to update the model and reveal the missing piece of the puzzle.

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Materials provided by University of California – Davis. Original written by Andy Fell. Note: Content may be edited for style and length.

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Beginning a Year of Raw Foods

For the first time ever, I’m doing back-to-back one-year challenges. Yesterday I completed my one-year daily blogging challenge (and wrote a retrospective of the experience on the final day). Today I’m rolling into Day 1 of an entirely different kind of challenge, which is to be a raw foodist for the 2021 year.

While 30-day challenges can be good for building self-discipline, I don’t normally think of one-year challenges like that. The framing tends to be different. There may be some discipline involved for the first few weeks to get into a good rhythm, but once you’ve established the new habits, it doesn’t feel like a discipline challenge, especially when you’re a few months in.

I tend to see 365-day challenges as experiential deep dives that focus on exploring and deepening my relationship with some part of life. I regard them as having more to do with the Truth and Love principles of personal growth rather than the Power principle. They’re action-based, but the daily actions become easy and natural after a while. So once you’re into the second or third month, it’s really about the exploration and the ongoing relationship.

With this raw foods challenge, I want to explore my relationship with eating raw and how it affects me. I may have some cooked food cravings during the first few weeks, but those will likely go away after a while, and it should feel pretty natural to keep eating raw throughout the year.

In fact, part of the exploration of a one-year challenge is to make sure to get the relationship right, so it doesn’t feel like a discipline-based slog – that would be exhausting. The point isn’t to wear yourself down with an extra layer of struggle for a whole year.

I’ve eaten all raw for hundreds of days of my life, including for six months in a row before, so I have a lot of experience with this way of eating already. I’ve also been vegan for 24 years, and I normally include lots of raw foods like smoothies and salads in my diet. But it’s been a while since I’ve really invested in my relationship with raw foods, other than some additional 30-day stretches. The last time I was really into this way of eating was in 2008 and 2009.

I’ve been thinking about getting back into raw foods for a while now, and framing this as a one-year commitment feels good to me. I like the idea of taking a whole year to more deeply explore this relationship. That feels abundant to me.

It’s almost like giving myself permission to play video games for 1-2 hours every day for a year – you probably won’t see that as a struggle but rather as an interesting kind of exploration if you like games. While you could play games anytime, there’s something more meaningful about committing to one-year deep dive into gaming. You might be inclining to think more carefully about which games you’ll play during that year and why. If you do it right, you could really enjoy the experience, and you may appreciate the memories of that year of gaming for a long time afterwards.

I’m not concerned about having the ability to complete the year. That part seems relatively easy since I have a lot of experience eating raw already.

I want to see how a longer stretch of continuous raw eating will affect me. It’s possible that I’ll go longer than a year, but a year seems like a good minimum to really explore this as I’d like.

For me this deep dive actually seems relaxing. I love how I feel on raw foods. It does give me less flexibility when eating out, but with the pandemic still ongoing, it seems like a good lifestyle fit for at least the first half of the year.

While Rachelle isn’t doing this particular challenge with me on a daily basis, she enjoys making and eating raw meals too. She’s the better chef between us, so it will be nice to enjoy some of her raw creations throughout the year. I’m also looking forward to making some new raw creations myself, such as those in the new raw food cookbook Rachelle gave me for Christmas. Having her support makes this challenge seem even easier.

I’m normally a happy person, but I tend to feel significantly happier and even more optimistic while eating raw. So you may notice some shifts in the emotional tone of my work this year because of that. I expect this will be a good year for me emotionally.

On the other hand, eating raw also makes me more sensitive emotionally. I especially want to explore this aspect of my relationship with raw foods. I found this aspect hard to handle in the past, and I want to see if I can improve in this area.

I once tried to eat all raw during a 3-day workshop many years ago, figuring that it would give me the best energy. My physical and mental energy were great. The overall experience was rough though. During our workshops, the people in the room go through all sorts of transformations. Some are facing tough decisions like whether to quit their job or break up with a relationship partner. Some people in the room are processing deep emotions, even when they appear to be stone-faced. I know this from talking to them afterwards, and they tell me how the workshop has been affecting them. When I crank up my sensitivity by eating raw, I feel the flood of their emotions streaming into me while I’m trying to deliver the material. It feels overwhelming sometimes, like I just want to get off the stage and go hug them and cry with them.

Consequently, after that experience I favored eating heavier foods during live events like pasta, which had a very grounding effect. Just being vegan keeps me sensitive enough to stay in tune with what people are feeling, but cooked food gives me enough emotional padding to stay focused on the material and the overall energy in the room without feeling flooded by people’s strong emotions. I’ve been wondering if there’s a better way to handle this though. Can I handle more sensitivity to other people’s emotions without being knocked off balance by it so much?

One way I can explore this is on our group coaching calls in Conscious Growth Club, which we do 3x per month. I’ve done more than 100 of these calls, so I have a good baseline for what to expect. I can see how eating raw affects my emotional sensitivity and what effect that has on the coaching. I think this will be an especially good year for coaching in CGC because of that. The coaching is done with one person at a time, and it’s over Zoom, so it’s unlikely to be emotionally overpowering. I think more sensitivity and awareness will be beneficial in this context.

I also tend to be way more intuitive when eating raw, so that will be nice to explore more deeply as well. I’m especially curious as to what new personal growth insights and business ideas I might generate this year. My mind is clearer and sharper while eating raw, like I have about 30% more mental RAM for thinking.

My life is also in a very different place than it was when I was last really into raw foods. Back then I was in my first marriage. Eating raw for a significant stretch raised my sensitivity and awareness to the point where long-term issues had to be dealt with. I went through a period of major changes, leading to the end of that marriage and getting into a beautiful new relationship with Rachelle. I had some wicked misalignments to deal with back then. Eating raw helped me find aligned solutions in a way that nothing else did.

Today I’m not feeling the presence of major misalignments. Even given the pandemic situation, I like my lifestyle. I’m super happy in my marriage with Rachelle. I enjoy my work and the way it’s flowing so nicely. I love connecting with people in CGC each day. So eating raw doesn’t seem like it would turn my life upside down like it did in the past. I’m glad for those transitions, but it was a lot of change to go through in a relatively short period of time.

Given how my life is now, eating raw seems like it will be more of a gift. I’ll feel better and will have more energy. Exercise will be easier. I’ll feel happier. This will probably be one of the best years of my life.

Sex feels significantly better too when eating raw. It’s more pleasurable. The sensations are stronger, richer, and more nuanced. The emotional connection is stronger, so it’s like pleasure and love woven together. I definitely enjoy that aspect of being a raw foodist.

With a one-year challenge, I like to give myself a decent amount of flexibility. Some wiggle room is good but not too much. If there’s too much, you could wiggle your way out of the challenge. But the right amount of wiggle room can improve your relationship with the challenge by making the experience feel more casual and relaxed, so you don’t feel too boxed in.

I let myself do batch blogging in advance last year, so I could take some days off from writing when I wanted to. I committed to publishing every day but not to writing every day. Then if my mind ever started to think, “I could really use a day off of writing,” I could say in response, “You can have one. Just write an extra post today, and queue it up to publish tomorrow.” Most of the time I didn’t do that, but just knowing that I could was like a pressure release valve. It kept me from feeling trapped by the challenge. I didn’t want to feel trapped at any point since that would mess up my relationship with the challenge.

I don’t want to feel trapped by my raw foods challenge either. I know I can do it strictly because I’ve done that before, including sharing photos of everything I ate for 30 days in a row back in January 2008, but that was my least favorite way of eating raw. For a whole year I don’t want to have an overly strict relationship with raw foods. I want to have a little bit of wiggle room, enough that I can feel good about my relationship with this challenge throughout the whole year.

Part of my intention for this challenge is to see what it’s like to eat raw as my baseline way of eating. So my default way of thinking will be to eat raw vegan food for every meal. After I’ve been doing that for a while, eating a meal of cooked foods isn’t going to feel good. It will probably make me sick. I’ve tested that in the past. So as long as I stick with raw as my baseline for the year, I’m unlikely to be tempted to sneak a meal of cooked food from time to time. It’s not going to be a very pleasant experience.

However, I do like the idea of giving myself a little bit of wiggle room for emotional reasons. Suppose Rachelle makes a really nice cooked food meal for herself one night, and I would love a little taste of it. I might have a small nibble, which would probably be plenty to satisfy me emotionally, and then go back to my big salad or raw soup. I don’t expect that I’d actually want to do this too often, but I like having the option.

In fact, this is an aspect of a raw food lifestyle I’d like to explore in more detail this year. What wiggle room would I appreciate that would actually improve my relationship with this lifestyle? Where do I appreciate having some flexibility but not too much? In my case I expect such wiggle room to be bite-sized, not meal-sized, and definitely not a daily thing.

Another thing I would like to test at some point during the year is whether it feels good to include some lightly steamed veggies now and then. Some raw foodists think it’s better to incorporate such foods, especially if it means eating less raw fat. I’m not sure sure if I’d feel good eating a cup of steamed zucchini with a salad from time to time. But I may want to test it during the year to see how it feels. I’d also like to devise more small experiments to test the boundaries around eating raw as my baseline. I want to discover what feels good and what creates negative effects. I want to fill in some gaps in my knowledge and experience.

So my intention for the year isn’t to be 100% purist as a raw foodist. Few long-term raw foodists are like that. There are a lot of different ways to eat a raw foods diet, and many include some wiggle room. A little bit of flexibility can go a long way with this lifestyle.

My framing for this year’s challenge is really about the experience and what I’ll learn and discover as I go. I’m not thinking of this as a succeed or fail type of challenge. I know I can trust myself to stay aligned with the purpose as I go through the year. There’s a sort of lock-in that occurs as I get into eating raw foods, where cooked foods seem lifeless and unappealing after a while, and I just naturally want to keep eating raw. It takes a deliberate decision to push me back to cooked foods and to overcome the raw inertia, so I don’t see there being a significant risk of that happening by accident or mistake.

Mostly I’m going to begin by reloading the way I’ve eaten raw in the past. That seems like a good place to start. Then I can experiment around that baseline. I like that a year gives me a feeling of time abundance for exploring my relationship with this lifestyle. It doesn’t feel stressful, and even though I might call it a challenge, it doesn’t seem challenging. It feels like I’ve allocated an abundant stretch of time to explore something that fascinates me.

I also see this as a gift for my future self. I want him to know what it’s like to eat raw for a full year. I want him to understand this diet and lifestyle even better than I do now. I want him to have the memory of delving into this relationship for all of 2021, so he can make wiser decisions regarding his diet and lifestyle going forward.

Today I began with a green smoothie, which I’ve been sipping on while writing this. This will be an interesting year. 🙂

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Putty-like composites of gallium metal with potential for real-world application

Gallium is a highly useful element that has accompanied the advancement of human civilization throughout the 20th century. Gallium is designated as a technologically critical element, as it is essential for the fabrication of semiconductors and transistors. Notably, gallium nitride and related compounds allowed for the discovery of the blue LED, which was the final key in the development of an energy-efficient and long-lasting white LED lighting system. This discovery has led to the awarding of the 2014 Nobel Prize in Physics. It is estimated that up to 98% of the demand for gallium originates from the semiconductor and electronics industry.

In addition to its use in electronics, the unique physical properties of gallium have led to its use in other areas. Gallium itself is a metal with a very low melting point and is a liquid at just above room temperature (30 °C). Also, gallium is capable of forming several eutectic systems (alloys that have a lower melting point than any of its constituents, including gallium) with a number of other metals. Both pure gallium and these gallium based liquid metal alloys have high surface tension and are considered “non-spreadable” on most surfaces. This renders them difficult to handle, shape, or process, which limits their potential for real-world application. However, a recent discovery may have unlocked the possibility for broader use of gallium in the field of functional materials.

A research team at the Center for Multidimensional Carbon Materials (CMCM) within the Institute for Basic Science (IBS) in Ulsan, South Korea and the Ulsan National Institute of Science and Technology (UNIST) has invented a new method for incorporating filler particles in liquid gallium to create functional composites of liquid metal. The incorporation of fillers transforms the material from a liquid state into either a paste- or putty-like form (with consistency and “feel” similar to the commercial product “Plasticine”) depending on the amount of added particles. In the case when graphene oxide (G-O) was used as a filler material, G-O content of 1.6~1.8% resulted in a paste-like form, while 3.6% was optimal for putty formation. A variety of new gallium composites and the mechanism of their formation is described in a recent article published in the journal Science Advances.

The mixing of particles inside the gallium based liquid metal alters the physical properties of the material, which allows for much easier handling. First author Chunhui Wang notes: “The ability for liquid gallium composites to form pastes or putties is extremely beneficial. It removes most of the issues of handling of gallium for applications. It no longer stains surfaces, it can be coated or “painted” onto almost any surface, it can be molded into a variety of shapes. This opens up a wide variety of applications for gallium not seen before.” The potential application of this discovery includes situations where soft and flexible electronics are required, such as in wearable devices and medical implants. The study even showed that the composite can be fashioned into a porous foam-like material with extreme heat resistance, with the ability to withstand a blowtorch for 1 minute without sustaining any damage.

In this study, the team was able to identify the factors that would allow the fillers to successfully mix with liquid gallium. Co-corresponding author Benjamin Cunning described the prerequisites: “Liquid gallium develops an oxide ‘skin’ when exposed to air, and this is crucial for mixing. This skin coats the filler particle and stabilizes it inside the gallium, but this skin is resilient. We learned that particles of a large enough size have to be used otherwise mixing cannot occur and a composite cannot be formed.”

The researchers used four different materials as fillers in their study: graphene oxide, silicon carbide, diamond, and graphite. Among these, two of them in particular displayed excellent properties when incorporated in liquid gallium: reduced graphene oxide (rG-O) for electromagnetic interference (EMI) shielding and diamond particles for thermal interface materials. A 13-micron thick coating of Ga/rG-O composite on a reduced graphene oxide film was able to improve the film’s shielding efficiency from 20 dB up to 75 dB, which is sufficient for both commercial (>30 dB) and military (>60 dB) applications. However, the most remarkable property of the composite was its ability to provide EMI shielding property to any everyday common material. The researchers demonstrated that a similar 20-micron thick coating of Ga/rG-O applied on a simple sheet of paper yielded a shielding efficiency of over 70 dB.

Perhaps most exciting was the thermal performance when diamond particles were incorporated into the material. The CMCM team measured the thermal conductivities in collaboration with UNIST researchers Dr. Shalik Joshi and Prof. KIM Gun-ho, and the “real-world” application experiments were carried out by LEE Seunghwan and Prof. LEE Jaeson. The thermal conductivity experiment showed that the diamond containing composite had bulk thermal conductivities of up to ~110 W m-1 K-1, with larger filler particles yielding greater thermal conductivity. This exceeded the thermal conductivity of the commercially available thermal paste (79 W m-1 K-1) by more than 50%. The application experiment further proved the gallium-diamond mixture’s effectiveness as a thermal interface material (TIM) between a heat source and a heat sink. Interestingly, the composite with smaller size diamond particles showed superior real-world cooling capability despite having lower thermal conductivity. The reason for this discrepancy is due to the larger diamond particles being more prone to protruding through the bulk gallium and creating air gaps at the interface of the heat sink or heat source and the TIM, reducing its effectiveness. (Ruoff notes that there are some likely ways to solve this issue in the future.)

Lastly, the group has even created and tested a composite made from a mixture of gallium metal and commercial silicone putty — better known as “Silly Putty” (Crayola LLC). This last type of gallium containing composite is formed by an entirely different mechanism, which involves small droplets of gallium being dispersed throughout the Silly Putty. While it does not have the impressive EMI shielding ability of the above-mentioned Ga/rG-O (the material requires 2 mm of coating to achieve the same 70 dB shielding efficiency), it is compensated with superior mechanical properties. Since this composite uses silicone polymer rather than gallium metal as the base material, it is stretchable in addition to being malleable.

Prof. Rod Ruoff, director of CMCM who conceived of the idea of mixing such carbon fillers with liquid metals notes: “We first submitted this work in September 2019, and it has undergone a few iterations since then. We have discovered that a wide variety of particles can be incorporated into liquid gallium and have provided a fundamental understanding of how particle size plays a role in successful mixing. We found this behavior extends to gallium alloys that are liquids at temperatures below room temperature such as indium-gallium, tin-gallium, and indium-tin-gallium. The capabilities of our UNIST collaborators have demonstrated outstanding applications for these composites, and we hope our work inspires others to discover new functional fillers with exciting applications.”

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Materials provided by Institute for Basic Science. Note: Content may be edited for style and length.

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