8.24.2005

are those your flagella, or are you just happy to see me?

for thousands of years, people have been coaxing other creatures into doing chores. Now, a team of scientists has microsized the strategy. they've devised a way to make single-cell algae bear loads over distances of several centimetersa tactic that the researchers say could prove useful in tiny machines.

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ON FOR THE LONG HAUL. Beating its twin flagella, this algal cell lugs a polystyrene bead through water.
PNAS

algae and other single-celled organisms power their movements with molecular motors. scientists have long coveted these motors for use in micromachinery, notes chemist douglas b. weibel of harvard university.

however, pulling the devices from cells and modifying them to work with lab-derived machinery would require sophisticated bioengineering techniques. to avoid that hurdle, weibel and other scientists led by george m. whitesides of harvard tried something simpler. the team recruited entire organisms, leaving their motors in place.

the researchers harnessed algae of the species Chlamydomonas reinhardtii to transport tiny beads. first, the scientists engineered a molecule to have two sticky ends and a middle section that breaks apart when exposed to ultraviolet (UV) rays. one end of the molecule adheres to polystyrene, and the other to an alga's cell wall. the team used the engineered molecule to coat beads made of polystyrene plastic.

the algae, which convert sunlight to biochemical energy, tend to travel toward visible light. whitesides' team placed a few algae at one end of a thin, straight track cut into a polymer-coated glass plate. a pile of beads sat at the midpoint of the track.

when the researchers shined a low-intensity visible light from the end of the track opposite the algae, the organisms swam toward the light, each cell beating its two flagella breaststroke-style. when the algae reached the midpoint, they collided with the beads. the sticky molecules linked one or two beads to each cell, and the cells continued moving toward the light.

as long as the beads didn't adhere near an alga's flagella, each cell could haul a load of its own weight with little slowdown. "these cells are workhorses. they can really pull," says weibel.

when the cells reached their destination—swimming as much as 20 centimeters, or 20,000 of their own body lengths, from start to finish—the researchers flashed UV light to break the chemical bond that attached the beads. visible light shining from the track's opposite end coaxed the organisms back to the start.

christen brownlee
science news

nepal: children caught in the conflict

for more than nine years a conflict has raged in nepal between government security forces and fighters of the communist party of nepal (maoist). the conflict has had a devastating effect on all sections of nepali society—but especially on the lives of children. the most fundamental rights of children are being violated routinely, and nowhere is this more apparent than in schools across the country.

  • tens of thousands of children have been abducted from schools by maoist fighters to attend “political education” sessions. there is increasing evidence that some of the abducted children are recruited for armed activities.
  • many children who might otherwise attend school are kept at home to avoid abduction. in some areas children are getting less than 100 days of schooling a year.
  • hundreds of schools have been shut down or destroyed, or used as barracks. some schools, particularly private schools, have been attacked deliberately by the maoists.
  • teachers are being tortured and killed, either for not complying with the demands of one side or on suspicion of supporting the other. many are forced to make “donations” from their salaries to support Maoist activities.

both sides of the conflict have committed grave human rights abuses against children. while other amnesty international appeals call on the nepalese government to uphold the rights of children, this appeal is specifically directed at the maoists.

amnesty international is calling on the leadership of the communist party of nepal (maoist) to:
  • respect and promote children’s rights and minimise the impact of their military activities on children
  • end the abduction of children for “political education” sessions
  • end all child recruitment and the use of children for military activities, and release all children within the maoist forces
Fighting between the CPN (Maoist) and Royal Nepalese Army, drawn by a child at The Sahara Children's rehabilitation home for child victims of conflict.
Fighting between the CPN (Maoist) and Royal Nepalese Army, drawn by a child at The Sahara Children's rehabilitation home for child victims of conflict.
© AI
they are asking students and teachers from around the world to send in letters, poems and art work in support of school children and teachers in nepal.
send materials to:

Amnesty International (IS)
Asia-Pacific Programme – Nepal team
1 Easton Street
London WC1X 0DW
United Kingdom

(to arrive before 20 October 2005)


you can also send a message of support through their online form.

amnesty international will exhibit the materials in nepal on 20 november 2005 – the day established by the united nations as universal children’s day.

8.13.2005

my first driving lesson


IMG_3458
Originally uploaded by jessalauren.
i know it's taken me a long time to start learning how to drive, but it doesn't seem like there's much need where i live.

i'm happy to say that by the time i am ready to buy a car, they may already be selling used hybrids and fuel-cell cars and i won't have that guilty gas-guzzling feeling that other drivers may have.

i just figured i would follow in my sisters' footsteps and learn to drive up at the cottage. deanlea street and rosemary drive.

in this picture i actually braved it to the woodland beach parking lot and although you can't tell by the picture, i can pull in really well.

8.12.2005

a new post?

you know there are those rainy days that smell like flowers and leaves and then there are those that smell like worms? well it's definitely one of those wormy-rainy days.

my life has been hijacked by queen's pasta and every time i go to post i realize that i could just copy and paste the last month of postings and that would suffice. housesitting. chiropractor. restaurant.

i think it was right after i started reading harry potter that i stopped posting and i never seemed to come back (as you have probably noticed because there was that same picture up for three weeks). all i wanted to do was to talk about the book but i also didn't want to spoil anything for you. that definitely got me out of the swing of things. not that my blogging record has been very good lately, but i could still manage to go a couple times a week.

but it was harry potter, and without spoiling anything for you late-readers (i think i have waited long enough) i'm still not over it and i fear i have been a little shaken up. this was the first time i got harry potter nightmares.

i just want to say to jody, that when i was reading the last five chapters, i was thinking of you. and it made me really sad that we didn't get to see each other this summer.

so i am going to stop promising that i will be back every day because i just feel like i am insulting you now. i forgive you if you don't come back until september, but i will do my best not to leave it until school starts again to bring my blog up to snuff. (is it up to snuff? is that how you say it?)

but before i go, i wanted to share some baby animal stories with you because you can never have too many baby animals in your life.

a few nights ago, ryan and i were on the front porch and we saw a group of skunks walking across the street. they seemed to disappear until we saw two baby skunks chasing each other across the neighbours lawn. ryan made a couple noises to scare them in the other direction, but they seemed really excited by it and both ran right towards us. they were so adorable. ryan goes out every night to see if they are still running around, but we haven't seen them yet.

then two nights ago, we went over to mike's after work and again, we were sitting on the porch. ryan noticed that there was a little face peeking out from under the bbq cover and mike was just like "oh, yeah...that's one of the baby racoons". so it just kind of walked out past us and over my foot out into the yard. very casual-like. apparently they just hang out there all the time because he puts out leftovers for the little guys. nice life.

other than james asking me if i wanted to stay on at the restaurant through the winter, i have no news (until i can find my camera cord so i can show you the pictures of my first driving lesson). oh and later, i can tell you about what happened to ryan and i up at the cottage...scary!