n6/11/2011
I walked to the plaza this morning. I woke up before 6 AM. This would not have been a problem, except I got in at 3 AM. So it was a big problem. I don’t function well on little sleep. Well, I function, but not happily. I was thirsty and my stomach hurt and I had a headache. The French toast I made for breakfast did help a little bit. Cinnamon has curative properties, right? Our washing machine isn’t working. It didn’t even spin for me, but my clothes soaked in hot water a bit, so that makes them clean, I think. There is still a pool of water in the machine that didn’t drain out and I guess it’ll sit there until Monday when I can ask someone in the office and they’ll probably just come to our house, flip a switch, show us that the machine now works, and laugh all the way home.
I sat in the plaza this morning for a bit. Nice morning. Free wi-fi. Music. People walking around and sitting on park benches and reading and talking. Very calm.
We stayed in all day. Except for during the rainstorm. I put my bathing suit on and we went for a nice walk in the rain. If I knew the lyrics, I would have sung the song. I have to say that walk did wonders for my headache.
Later, we tried making mofongo. Fail. I’ll just have to buy some for lunch one day, that’s all. We fried the plantains and mashed them up and everything. It was ok, nothing stellar. We had some more of the Trumpeter Cab Sauv with dinner. Now I just have to keep myself awake for another couple hours. I really don’t want to go to bed at 7 PM, wake up at 2 AM, and completely throw off my sleeping schedule.
6/12/11
We went to the beach in Cabo Rojo today. At Baqueron there was a gay pride parade, which would have been cool to see, but we were afraid there would be too much traffic so we went to a different beach, still in Cabo Rojo, but a little farther south. It amazed me that we could just walk right onto the beach. What, no bage? No one asking me to pay? Wow, fantastic! And the water was light blue – blue! – and warm. I actually went in! not just my toes, or up to my knees, or run in, dunk my head, scream it’s freakin cold and run out. Ah, so refreshing! I loved it. And there were plenty of attractive men and men who could be attractive if only they cut off that stupid rat tail! Arg, get a new hairdresser, please!
We went to lunch at a restaurant on the beach. Unfortunately no vegetarian empanadillas. : (
We stayed till about 4. Then a quiet evening at home, resting for the workweek to come. I figured I’d gather some more interesting info for everyone. Dragonfruit!
Pitayaha, pitaya, dragonfruit, strawberry pear
Hylocereus spp. (over 25 species have been identified) and Selenecereus megalanthus (the yellow or Colombian pitaya); family Cactaceae
Species of Hylocereus and hybrids thereof have a variety of flesh and skin color combinations. The yellow pitaya (Selenecereus megalanthus) has yellow thorny skin and white, translucent flesh.
Native to tropical America with a range extending from Southern Mexico to Northern South America, dragonfruit was a popular Aztec food. At the turn of the 19th century, the French brought it to Southeast Asia. Currently, Nicaragua is the main producer of red flesh varieties of Hylocereus spp. in Central America, with an estimated 800-1000 HA planted. Colombia is the leading South American producer of yellow pitaya. In Southeast Asia, Vietnam is a leading producer. Israel also produces and exports to the EU. Commercial growers typically propagate via cuttings. While germination rates for seeds are high, the plant is slow-growing and may not produce fruit for 6 years. The cactus is grown on a trellis system.
The large, night-blooming flowers are pollinated by moths and bats in Central America. Cross pollination and hand pollination, where pollinators are not common, can improve fruit set. Fruits mature in 35 – 50 days, depending on the cultivar and location.
Ants and aphids can damage young shoots and flower buds, and I saw evidence of this in the greenhouse at TARS.
References:
6/13/11
Today I worked in the chemistry lab. We prepared soil samples to be tested for phosphorus, magnesium, calcium, and potassium and also weighed out samples of seeds and fruits from Mamey Sapote. This is all in an effort to determine how well the plants take up fertilizers.
Phosphorus exists as aluminum, iron, or calcium phosphate in the soil. The relative concentrations depend upon the soil pH, with aluminum and iron phosphates dominant in low pH (acid) soils, and calcium phosphate dominant in higher pH (neutral to alkaline) soils. There are a number of procedures commonly used to extract phosphorus from soil samples. We used the Bray P2 method, which is designed for soils with low pH, low cation exchange capacity, and low organic matter. In this method, the reagents are ammonium fluoride and hydrochloric acid. The acid makes phosphorus more soluble and the fluoride anion lowers the readsorption activity of aluminum.
Magnesium, calcium, and potassium are all cations, though they may be present in multiple forms in soil. We used the solvent ammonium acetate at pH 7. The ammonium acts as an exchange ion, essentially pushing the magnesium, calcium, and potassium into solution. Therefore, extractions using this reagent give the concentrations of exchangeable cations.
A group of high school students came in to tour the lab and see what we do. Of course the tour was given in Spanish. I followed with my notebook and tried to pick out key words. The lab head was a little disappointed they weren’t more interested.
We’re getting a new washing machine tomorrow! The one we had didn’t work – didn’t even spin! I was afraid we’d have to wash our clothes in the bathtub for the next 5 weeks!
I learned some new Spanish words today. So proud of myself. Labradora – washing machine. Semilla – seed. Hoja – leaf. See you’re learning with me!
Later in the week, we may test the concentrations of reducing sugars in banana pulp. I guess biochemistry is good for something! Reducing sugars include glucose and fructose. Sucrose is not a reducing sugar. They have aldehyde or ketone groups which can reduce other molecules. Aldehyde groups can be oxidized to carboxylate groups.
I’m in the plaza. I just saw people riding horses down the street. Awesome.
6/14/2011
Today, we extracted iron, manganese, and zinc. These are all micronutrients, as are boron, chlorine, and copper. They are needed in amounts less than 0.10% of the plant’s total dry matter. We followed the Mehlich Number 1 method, which is designed for acid soils, with low cation exchange capacity and low organic matter content. This method uses hydrochloric and sulfuric acids. The filtrate (the liquid after the solids have been filtered out) will be examined using inductively coupled plasma emission spectroscopy (ICP) to determine the concentrations of these elements. In spectrophotometry, an element is identified by the wavelength of radiation emitted when an excited electron returns to ground state. The intensity of the radiation at this characteristic wavelength is indicative of the concentration. ICP can measure the concentrations of multiple elements simultaneously.
We also determined prepared samples for nitrogen content determination.
In the evening, I went to the Teatro Yaguez, in the town center, for a free movie screening. I didn’t know what the movie would be, but it was free and in walking distance, so why not? I was pleasantly surprised. There was also complimentary wine before the screening. I had arranged to meet up with some UPR girls at the theater. I also saw one of the researchers (and his father) and two technicians there! While I was waiting for the girls to arrive, I people-watched (this sounds better than: I watched people”). A lot of people were eating Rex Cream (yum…). Most of the people walking into the theater were quite well-dressed – I was certainly not prepared for this! Some really cute dresses…and some really, umm, clunky?, shoes. Chunky platforms that were pretty damn tall! How were these women walking around in them? I never could. If I had a choice between heels and platforms, I’d opt for the former, but apparently that is not the style here. When one of the girls arrived, I shared my observations with her. Yea, you’ll see those shoes a lot, she replied calmly. Oh gosh, how do they do it? My friend also looked very nice. I mean, the way she did her eye makeup, it really was like one of those magazine ads. Black and white eyeshadow, black inside (closer to her nose) and white outside…or was it the other way around? Doesn’t matter. She looked pretty damn good…not like that? Umm, oops…moving on. I miss when my sister would do my makeup. She’s a great makeup artist. Did my makeup for my prom – I got so many comments. Better than any professional job (and a heck of a lot cheaper). I’m pretty clueless. I just learned to put on mascara this past December.
So, onto the movies. The screening was hosted by the UPR-Mayaguez film society, or at least that’s what I was able to gather. They have a pretty strong certificate program in cinema studies.
They showed a short film first. It left me very confused – was I supposed to be happy or sad? I wasn’t sure, and I still haven’t made up my mind. However, it was very well done.
Then, the feature film. A Hindi film (with English subtitles, thank goodness!). There were plenty of funny parts, but it was also pretty depressing. Udaal was the title, I believe. This boy gets kicked out of boarding school and is sent home to live with his abusive father. He wants to be a writer, but his father wants him to be an engineer, to follow in his footsteps and work in his factory.
The movie was much longer than I expected, and it had started later, too. (My friend assured me it was normal for Puerto Ricans to be late.) I didn’t get home till quarter to 11. So late, especially since I’ve been going to bed by ten every night!
6/15/2011
I weighed more fruit and seed samples this morning – my favorite task…not! So tedious. Makes me really appreciate the work behind the large sample sizes demanded for statistical analysis and publishable research.
In the afternoon, however I wasn’t sent to that little room to weigh samples. Instead, I helped with the nitrogen determination assay. We added boric acid and indicator solution to the digested samples. In the procedure we used, nitrogen in the sample is converted to ammonium. We add sodium hydroxide to convert the ammonium to ammonia and then distill it so that the ammonia is added to the boric acid-indicator solution. We then titrate with hydrochloric acid to determine the amount of ammonia present. Using an equation, we can determine the amount of nitrogen present in the original sample.
I saw another movie that evening. The movie started early though! Wait, aren’t we in Puerto Rico? It was a documentary on the Freedom Riders. This group of people, black and white, Jew and Christian, rode buses throughout the segregationist South in the early 1960s. They hoped that, through nonviolence, they could create change and achieve equality. Eventually, after much struggle, and after suffering greatly from the violent acts of others, they did succeed. I finally learned who James R. Hoffa was. I receive a scholarship named after him from the Teamsters’ Union. He was head of that union at the time of the Freedom Rides. He spoke on behalf of the bus drivers – they did not want to drive any bus with the Freedom Riders as passengers. I was disappointed to hear that. However, I understand that it must have been quite difficult for them. These bus drivers only wanted to earn a living, to provide for their families. There was so much violence surrounding the Freedom Rides (which was part of the non-violence movement for equality!) that to drive a bus with these riders on board meant you were putting your life on the line! It was a powerful documentary. The family behind me almost ruined it. They were all chewing gum, all 5 of them! Maybe if only one was chewing gum I could’ve ignored it, but all 5! And the mother was making comments, like, Oh my gosh, and laughing (some of the riders’ stories were funny, yes) and sighing and gasping and…seriously?!? I mean, come on! This is pretty powerful stuff! I do not need your chewing and your commentary.
I didn’t stay for the second film. I didn’t want to be out past 11 PM really. I was told it was about Iraq and was a tad depressing.
6/16/11
Today we were supposed to analyze samples in the ICP for phosphorus, magnesium, potassium, calcium, iron, zinc, and manganese. The machine was acting up. We didn’t have enough of the internal standard on hand, unfortunately. So this was delayed for next week.
I finally finished weighing all the samples, all 204 of them! Gold star please.
In the afternoon we discussed how we would be testing the dried banana pulp for sugars and starches. This is the first time we’re doing this….we’ll see how it goes!
6/17/2011
We extracted starch from dried banana and determined starch concentration. I found this very exciting – today was my favorite day in the chemistry lab, no doubt about it. We first dissolved the dried banana in DMSO and HCl. Some of the solutions were a nice bright pink. We then raised the pH to 4-5. The color changed – no more hot pink : ( I love these experiments in which colors change. I find it so exciting. I wonder what compounds in banana are responsible for color, what other compounds have been extracted and identified. I will definitely need to look this up. I’m just so curious (and I like hot pink). The chemist teased me because I asked for more scientific articles to read. What else do I have to do though, without tv or internet in the house?
In order to determine starch concentration, we had to first extract starch (see above) and then degrade it to glucose (enzymatic reaction using ATP), which can then reduce NAD to NADH (another enzymatic reaction), which can be detected at 340 nm wavelength. Today was the first time we did this assay so we had to work through some issues, such as how much starting material to use, how much do we dilute it, how long should it sit for, etc. etc.
We did find that starch content decreased as the banana aged, which we expected. We also found that the variety already in commercial production had a greater starch content than the variety the team is trying to introduce. This new variety is tolerant of sigatoca, a fungal disease of banana.
The chemist will conduct this experiment again, after making a few changes to the protocol.
I do miss the pollination work I did last summer. I loved going around to the different farms, watching the bees fly from flower to flower. I especially loved the blue-green bees – they’re freakin awesome. Yes, I am a geek.
I also miss blueberries. I don’t like raw blueberries, but I love them in oatmeal and in my father’s pancakes. My sister assured me she would freeze some extras for me. And make muffins. : ) Fantastic.
This week I'm reading The Chosen by Chaim Potok.
I'm also editing my autobiogrpahy, which I wrote two summers ago. How Precocious.
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