MDRS Crew 122 (HI-SEAS)
Science Report #9
01/22/13
Microbiology Studies
By: Yajaira Sierra-Sastre
Food microbiology:
Bacterial counts were conducted for two samples of rehydrated beef TVP (textured vegetable protein). One sample was refrigerated for 24 hrs and the other sample was left at room temperature for 24 hrs. In both cases, Petrifilm plates showed no colonies for E. coli/coliforms and S. aureus.
A refrigerated tortilla soup sample, which previously showed the highest numbers of red-violet S. aureus colonies (501 cfu/g) of the food samples analyzed, was subjected to a thermal killing treatment. The homogenized sample solution (10mL) was placed in a sterile falcon tube, heated in the lab oven at 60C for 40min and finally inoculated in Petrifilms and incubated for 24hrs at 35C. For comparison, the refrigerated tortilla soup sample (no heat treatment) was also inoculated. The bacteria count for these two samples were: 703 cfu/g (n =2) for the refrigerated sample and 693 cfu/g (n =2) for the heated sample. Although the thermal death times for S. aureus are 1 min at 78C and 19min at 60C, it should be noted that the falcon tube containing the sample homogenate was not placed in either preheated sand or water; therefore, an inappropriate thermal treatment was applied in this case. Next experiments should make use of a heating block or preheated sand or water in order to achieve the right temperature to kill S. aureus. On the other hand, it should be noted that in this last experiment no red-violet colonies were present in the plates, only black colonies which may or may not be S. aureus. These colonies will be isolated and stored in RNAlater for further identification.
Green Hab microbiological analysis:
Total aerobic bacteria counts were also conducted for water samples taken from the watercress plants at the Green Hab. Too numerous to count colonies (TNTC) were observed in this inoculated sample.
Sleep-Light Study
By: Kate Greene
Most of the crew continues to grow accustom to wearing the Zeo headbands. One crew member, however, has experienced skin irritation. I’ve investigated possible causes and solutions. While Zeo has tested the headbands shown them to be hypo-allergenic and non-irritating (bearing the CSA safety mark), the company concedes that a small percentage of the population may experience irritation. (http://www.myzeo.com/sleep/welts-and-missing-data)
One cause might be an irritation from chemicals used during manufacturing. The irritation might subside if the headband is washed in a fabric detergent such as Woolite. Another cause might be something called acne mechanica, which can sometimes affect people who show no other signs of acne when an object of fabric is put in contact with their face. One untested solution offered by the company might be to use a clear plastic wrap to cover the soft silver sensors that come in contact with the forehead. This would create a barrier between the headband fabric and the skin while still allowing electrical impulses from the brian and face to be recorded.We will be exploring the plastic wrap option soon.
In addition to trouble-shooting headband issues, I’ve begun testing two lighting protocols that could help me eventually choose the manner in which to provide a dose of morning light to the crew. Both protocols use the Litebook light, a bright, compact light source that has been validated in studies of seasonal effective disorder.
Protocol #1 requires the crew to turn on the Litebook in their room within five minutes of waking up. While traditional light therapy techniques suggest a light-dose duration of 30 minutes to 1 hour, we kept the dose at 15 minutes due to morning schedule constraints. I wanted to know if even15 minutes of dedicated light in sleeping quarters upon waking felt like a burden. During the light dose, crew members were allowed to use computers, tablets, phones, read, or simply be still.
We tested this protocol for two days, and most crew members were amenable to spending 15 minutes in their room with the light after waking up. The consensus was that with our current schedule, spending much more time in our rooms in the morning would be a burden. It’s possible that a novel schedule could be developed for HI-SEAS in which work is scheduled during a 45 minute light dose, so it wouldn’t feel like a burden. Additionally, light therapy using Litebook could be used during morning exercise if that exercise is done on stationary equipment like a bike or treadmill.
Tomorrow and Thursday we will test protocol #2 in which the crew will bring their Litebook lights with them to breakfast and set them up on the table. The light dose will be 45 minutes long, and will therefore extend into our morning meeting time. I’ll collect informal feedback about the burden and experience of this protocol.
There’s a chance that neither of these protocols will be employed at HI-SEAS as they’ve been tested at MDRS. I’m in talks with a collaborator to provide a full-habitat lighting scheme that would obviate the need for individual lights. Instead of staying in their sleeping quarters or bringing a light to breakfast, the crew could simply conduct their normal morning activities while all the HI-SEAS habitat lights provide a 45-minute bright-white dose. This lighting scheme would mimic the morning mode of the lighting system to be installed in the ISS in the coming years, and would be ideal for the HI-SEAS sleep-light study.
Thermal Analysis and Evaluation
By: Oleg Abramov
A nighttime thermographic survey of the Greenhab was conducted yesterday, 1/21/2013, at approx. 10 pm. Results are currently being analyzed.
Today, a thermal survey of the observatory was conducted at the request of Simon Engler, crew astronomer. Infrared images of the dome exterior and the telescope were taken at 5-minute intervals between 17:12 and 17:37 to document cooling after sundown. Results are currently being analyzed.
A replacement receiver for wireless temperature sensors arrived today, and will be tested later tonight.
Green Hab Activities
By: Angelo Vermeulen
I continued my plant cultivating work at the GreenHab. A new tray with cress seeds was started and placed on top of the heat mat. A layer of soil of 1.5” was used in this tray. The goal is to compare seed growth in a thick layer of soil on a heat mat, with seed growth in an unheated thin layer of soil. The hypothesis is that seeds will sprout and grow better on the heat mat. However if seeds can be equally sprouted using less soil and no heating, that might be advantageous for space applications. All pots and containers are being labeled for the next rotation, and a full inventory is being compiled. Below is a first overview of all plants currently grown at MDRS. During the rest of the week this overview will be further refined. It can be used as a guide to develop a protocol for future GreenHab work.
The temperature is less fluctuating than last week because of the thermostat-regulated fan. However current system is unsustainable: pumping in heat with propane burners, and then immediately discharging the heat through the fan is not energy-efficient. It would be better to regulate the propane burners first. This would save propane, electricity, and retain air moisture.
Tonight crew member Oleg Abramov installed a wireless temperature sensor that is logging the temperature inside the GreenHab every 20 secs. We’ll have the first detailed temperature cycle by the next comms window tomorrow.
More herbs came in today sent by Jean Hunter: basil, parsley, dill, thyme and mint. The basil showed severe damage upon arrival, probably caused by low temperatures during transport. The other herbs are in a medium condition. The herb cuttings that were planted on Sunday are also inside the hab. Some are in medium condition, others are wilted and seem dying. More details in the Science Report of tomorrow. One problem with the herbs in the hab is the lack of space to put them. I currently placed most of the new herbs on the window sills of the kitchen (unfortunately partially blocking the view).
Temperature in GreenHab
01/21 8:00am 46°F
01/21 1:00pm 79°F
01/21 2:30pm fan thermostat lowered to 60°F
01/21 5:00pm 68°F
01/21 6:00pm 58°F
01/22 8:00am -
01/22 1:00pm 73°F
01/22 4:00pm 68°F
01/22 5:00pm 62°F
01/22 6:00pm 57°F