1,285 research outputs found
Overview of Microbial Monitoring Technologies Considered for Use Inside Long Duration Spaceflights and Planetary Habitats
The purpose of this presentation is to start a conversation including the Crew Health, ECLSS, and Planetary Protection communities about the best approach for inflight microbial monitoring as part of a risk mitigation strategy to prevent forward and back contamination while protecting the crew and vehicle
Synchronization of non-chaotic dynamical systems
A synchronization mechanism driven by annealed noise is studied for two
replicas of a coupled-map lattice which exhibits stable chaos (SC), i.e.
irregular behavior despite a negative Lyapunov spectrum. We show that the
observed synchronization transition, on changing the strength of the stochastic
coupling between replicas, belongs to the directed percolation universality
class. This result is consistent with the behavior of chaotic deterministic
cellular automata (DCA), supporting the equivalence Ansatz between SC models
and DCA. The coupling threshold above which the two system replicas synchronize
is strictly related to the propagation velocity of perturbations in the system.Comment: 16 pages + 12 figures, new and extended versio
Corynebacterium diphtheriae invasion-associated protein (DIP1281) is involved in cell surface organization, adhesion and internalization in epithelial cells
<p>Abstract</p> <p>Background</p> <p><it>Corynebacterium diphtheriae</it>, the causative agent of diphtheria, is well-investigated in respect to toxin production, while little is known about <it>C. diphtheriae </it>factors crucial for colonization of the host. In this study, we investigated the function of surface-associated protein DIP1281, previously annotated as hypothetical invasion-associated protein.</p> <p>Results</p> <p>Microscopic inspection of DIP1281 mutant strains revealed an increased size of the single cells in combination with an altered less club-like shape and formation of chains of cells rather than the typical V-like division forms or palisades of growing <it>C. diphtheriae </it>cells. Cell viability was not impaired. Immuno-fluorescence microscopy, SDS-PAGE and 2-D PAGE of surface proteins revealed clear differences of wild-type and mutant protein patterns, which were verified by atomic force microscopy. DIP1281 mutant cells were not only altered in shape and surface structure but completely lack the ability to adhere to host cells and consequently invade these.</p> <p>Conclusions</p> <p>Our data indicate that DIP1281 is predominantly involved in the organization of the outer surface protein layer rather than in the separation of the peptidoglycan cell wall of dividing bacteria. The adhesion- and invasion-negative phenotype of corresponding mutant strains is an effect of rearrangements of the outer surface.</p
Microbial Monitoring Challenges and Needs for Mars Applications
The monitoring of microorganisms will be an important part of a mission to Mars. Microbial monitoring equipment will be needed to look for the presence of microorganisms on the planet, to confirm that planetary protection measures are working, to monitor the health of plants, bioreactors and humans living in a habitat and to monitor the performance of the life support systems that will keep them alive during their stay on Mars. Coordinating the different microbial monitoring needs during the early days of mission planning, can provide NASA with equipment that could meet more than one need while also providing complementary analysis options, which can enhance the research capabilities. The early coordination between the different NASA groups that will need microbial monitoring equipment on the surface of Mars, could also make the mission more affordable, as development of the needed equipment could be potentially cost shared
Quantitative Comparison of Mast cells in Major Salivary Glands in Hypothyroid State
Background: This experimental study was carried out to compare the number of mast cells in major salivary glands of albino rat in hypothyroid state.Methods: An experimental study was carried out on twenty male albino rats, weighing between 130-150 grams. The rats were divided into two groups; control group (A) and an experimental group (B), with 10 animals in each group. Hypothyroid condition was modeled in albino rats of experimental group (B) by giving them 0.02% w/v Methimazole (MMI) for three weeks in drinking water. After 4-weeks animals from both the groups were euthanized with chloroform. The blood sample was taken from each rat for determination of thyroid hormone concentrations in the serum by cardiac puncture. Serum T3, T4 and TSH levels were determined by enzyme immunoassay to confirm hypothyroid state of the animal. Major salivary glands; parotid, submandibular and sublingual were dissected and removed from the body. They were fixed in Bouin’s solution. Glands were further processed for light microscopy and for histological analysis of mast cells Toluidine blue stain was used. Counting of mast cells (MCs) was performed by superimposing the ocular graticule on the salivary gland preparation.Results: Statistically significant difference was observed between the MCs of parotid gland in group A (2.25±1.34/mm2) and B (3.70+1.11/mm2), p<0.017. No significant difference was observed in the mean number of MCs in the sublingual and submandibular salivary glands with p=0.511 and p=0.187 respectively.Conclusion: In hypothyroid state, there is significant difference in the number of MCs in the parotid glands and there is no significant difference in the number of MCs of submandibular and sublingual glands
Methodology for cost-effective energy and carbon emissions optimization in building renovation (Annex 56): methodology and assessment of renovation measures by parametric calculations
Buildings are responsible for a major share of energy use and have accordingly been a special target in the global actions for climate change mitigation, with measures that aim at improving their energy efficiency, reduce carbon emissions and increase renewable energy use.
IEA-EBC project «Cost-Effective Energy and Carbon Emissions Optimization in Building Renovation» intends to develop a calculation basis for future standards, which aim at maximum effects on reducing carbon emissions and primary energy use. Thereby, the project pays special attention to the renovation of existing residential buildings and to cost effective building renovatio
Microbial Monitoring from the Frontlines to Space: Department of Defense Small Business Innovation Research Technology Aboard the International Space Station
The RAZOR (trademark) EX, a quantitative Polymerase Chain Reaction (qPCR) instrument, is a portable, ruggedized unit that was designed for the Department of Defense (DoD) with its reagent chemistries traceable to a Small Business Innovation Research (SBIR) contract beginning in 2002. The PCR instrument's primary function post 9/11 was to enable frontline soldiers and first responders to detect biological threat agents and bioterrorism activities in remote locations to include field environments. With its success for DoD, the instrument has also been employed by other governmental agencies including Department of Homeland Security (DHS). The RAZOR (Trademark) EX underwent stringent testing by the vendor, as well as through the DoD, and was certified in 2005. In addition, the RAZOR (trademark) EX passed DHS security sponsored Stakeholder Panel on Agent Detection Assays (SPADA) rigorous evaluation in 2011. The identification and quantitation of microbial pathogens is necessary both on the ground as well as during spaceflight to maintain the health of astronauts and to prevent biofouling of equipment. Currently, culture-based monitoring technology has been adequate for short-term spaceflight missions but may not be robust enough to meet the requirements for long-duration missions. During a NASA-sponsored workshop in 2011, it was determined that the more traditional culture-based method should be replaced or supplemented with more robust technologies. NASA scientists began investigating innovative molecular technologies for future space exploration and as a result, PCR was recommended. Shortly after, NASA sponsored market research in 2012 to identify and review current, commercial, cutting edge PCR technologies for potential applicability to spaceflight operations. Scientists identified and extensively evaluated three candidate technologies with the potential to function in microgravity. After a thorough voice-of-the-customer trade study and extensive functional and safety evaluations, the RAZOR (trademark) EX PCR instrument(Bio-Fire Defense, Salt Lake City, UT) was selected as the most promising current technology for spaceflight monitoring applications
ALMA Observations of a Quiescent Molecular Cloud in the Large Magellanic Cloud
We present high-resolution (sub-parsec) observations of a giant molecular
cloud in the nearest star-forming galaxy, the Large Magellanic Cloud. ALMA Band
6 observations trace the bulk of the molecular gas in CO(2-1) and high
column density regions in CO(2-1). Our target is a quiescent cloud (PGCC
G282.98-32.40, which we refer to as the "Planck cold cloud" or PCC) in the
southern outskirts of the galaxy where star-formation activity is very low and
largely confined to one location. We decompose the cloud into structures using
a dendrogram and apply an identical analysis to matched-resolution cubes of the
30 Doradus molecular cloud (located near intense star formation) for
comparison. Structures in the PCC exhibit roughly 10 times lower surface
density and 5 times lower velocity dispersion than comparably sized structures
in 30 Dor, underscoring the non-universality of molecular cloud properties. In
both clouds, structures with relatively higher surface density lie closer to
simple virial equilibrium, whereas lower surface density structures tend to
exhibit super-virial line widths. In the PCC, relatively high line widths are
found in the vicinity of an infrared source whose properties are consistent
with a luminous young stellar object. More generally, we find that the smallest
resolved structures ("leaves") of the dendrogram span close to the full range
of line widths observed across all scales. As a result, while the bulk of the
kinetic energy is found on the largest scales, the small-scale energetics tend
to be dominated by only a few structures, leading to substantial scatter in
observed size-linewidth relationships.Comment: Accepted by ApJ; 21 pages in AASTeX two-column styl
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