1,001 research outputs found
Lyophilized spore dispenser
A lyophilized spore dispenser is provided which produces a finely divided, monoparticulate cloud of bacterial spores. The spores are contained within a tightly sealed chamber, and a turbulator orifice connected to an air supply source provides a jet of air which stirs up the spores and causes the spores to be suspended in eddy currents within the chamber. This air jet also produces a positive pressure within the chamber which forces the spores out of an injection orifice
An Electrolysis Experiment for a Middle School Summer Science Camp
Higher education is often culturally deemphasized in the geographic area served by our rural, regional campus. As a result, faculty members have the opportunity to spearhead teaching efforts designed to educate the community about the importance of obtaining a post-secondary degree. To this end, we recently held a Science Summer Camp for middle school students, designed to infuse young people with an increased excitement for STEM (Science, Technology, Engineering, and Math) education. In this report, we summarize a chemical electrolysis experiment we carried out with middle school students for our annual Science Summer Camp. We also provided procedural guidelines for small- and large-scale experiments. In the latter case, evolved H2 gas can be detonated for effect. Two modifications from literature procedure include: (1) using glass burettes, instead of test tubes, to collect the evolving H2 and O2 gases for the small-scale setup; and (2) prefilling the 100-mL graduated collection cylinders with aqueous NaOH prior to beginning electrolysis. Because these modifications provide aqueous solution in the collection reservoirs prior to starting the experiment, the total time required for the experiment is greatly reduced (~30 minutes)
Regional differences in nutrient-induced secretion of gut serotonin
Enterochromaffin (EC) cells located in the gastrointestinal (GI) tract provide the vast majority of serotonin (5-HT) in the body and constitute half of all enteroendocrine cells. EC cells respond to an array of stimuli, including various ingested nutrients. Ensuing 5-HT release from these cells plays a diverse role in regulating gut motility as well as other important responses to nutrient ingestion such as glucose absorption and fluid balance. Recent data also highlight the role of peripheral 5-HT in various pathways related to metabolic control. Details related to the manner by which EC cells respond to ingested nutrients are scarce and as that the nutrient environment changes along the length of the gut, it is unknown whether the response of EC cells to nutrients is dependent on their GI location. The aim of the present study was to identify whether regional differences in nutrient sensing capability exist in mouse EC cells. We isolated mouse EC cells from duodenum and colon to demonstrate differential responses to sugars depending on location. Measurements of intracellular calcium concentration and 5-HT secretion demonstrated that colonic EC cells are more sensitive to glucose, while duodenal EC cells are more sensitive to fructose and sucrose. Short-chain fatty acids (SCFAs), which are predominantly synthesized by intestinal bacteria, have been previously associated with an increase in circulating 5-HT; however, we find that SCFAs do not acutely stimulate EC cell 5-HT release. Thus, we highlight that EC cell physiology is dictated by regional location within the GI tract, and identify differences in the regional responsiveness of EC cells to dietary sugars.Alyce M. Martin, Amanda L. Lumsden, Richard L. Young, Claire F. Jessup, Nick J. Spencer, Damien J. Keatin
Miocene paleoaltimetry of the Mt. Everest region
Abstract HKT-ISTP 2013
A
What do you need? 2007-08 findings from a national survey of people with diagnosed HIV
Over the past twenty-five years, both the needs of people with diagnosed HIV and our
understanding of them have changed dramatically. During this time there have been many
assessments of need, usually within specific geographic boundaries (such as Primary Care Trusts)
but no consistent approach to describing needs has been adopted. Most needs assessments have
been shaped by a variety of local factors, including the profile of existing services.
This study provides an insight into the needs of people with diagnosed HIV living in the UK, based
on a final sample of 1777 people. The approach taken to measuring and describing need is the same
as our previous national survey (Weatherburn et al. 2002). This approach was shaped by our earlier
qualitative studies exploring the experience of people with diagnosed HIV in the early days
of anti-HIV treatments (Anderson et al. 2000, Anderson & Weatherburn 1999, Anderson &
Weatherburn 1998).
While this study uses the same methods as our 2001-2002 survey we do not draw direct
comparisons with our previous data or discuss change over time. The limitations of self-completion
surveys using convenience samples make change comparisons hazardous. However, it is worth
noting that in any comparison with our prior data (Weatherburn et al. 2002) current levels of need
very rarely seem lower than we have previously reported.
The range and extent of medical and social care, support and information needs we present here
reveal significant challenges for service commissioners and providers. The first challenge is to avoid
drawing quick conclusions about what the patterns of need mean for service commissioning and
delivery. Needs have deliberately been separated from service use because the question of what
services are ‘needed’ cannot be answered simply by identifying the extent of personal needs. The
overall pattern of need is a useful starting point, but this pattern is complex
Induction of carcinoembryonic antigen expression in a three-dimensional culture system
MIP-101 is a poorly differentiated human colon carcinoma cell line established from ascites that produces minimal amounts of carcinoembryonic antigen (CEA), a 180 kDa glycoprotein tumor marker, and nonspecific cross-reacting antigen (NCA), a related protein that has 50 and 90 kDa isoforms, in vitro in monolayer culture. MIP-101 produces CEA when implanted into the peritoneum of nude mice but not when implanted into subcutaneous tissue. We tested whether MIP-101 cells may be induced to express CEA when cultured on microcarrier beads in three-dimensional cultures, either in static cultures as non-adherent aggregates or under dynamic conditions in a NASA-designed low shear stress bioreactor. MIP- 101 cells proliferated well under all three conditions and increased CEA and NCA production 3 - 4 fold when grown in three-dimensional cultures compared to MIP-101 cells growing logarithmically in monolayers. These results suggest that three-dimensional growth in vitro simulates tumor function in vivo and that three-dimensional growth by itself may enhance production of molecules that are associated with the metastatic process
Models of the SL9 Impacts II. Radiative-hydrodynamic Modeling of the Plume Splashback
We model the plume "splashback" phase of the SL9 collisions with Jupiter
using the ZEUS-3D hydrodynamic code. We modified the Zeus code to include gray
radiative transport, and we present validation tests. We couple the infalling
mass and momentum fluxes of SL9 plume material (from paper I) to a jovian
atmospheric model. A strong and complex shock structure results. The modeled
shock temperatures agree well with observations, and the structure and
evolution of the modeled shocks account for the appearance of high excitation
molecular line emission after the peak of the continuum light curve. The
splashback region cools by radial expansion as well as by radiation. The
morphology of our synthetic continuum light curves agree with observations over
a broad wavelength range (0.9 to 12 microns). A feature of our ballistic plume
is a shell of mass at the highest velocities, which we term the "vanguard".
Portions of the vanguard ejected on shallow trajectories produce a lateral
shock front, whose initial expansion accounts for the "third precursors" seen
in the 2-micron light curves of the larger impacts, and for hot methane
emission at early times. Continued propagation of this lateral shock
approximately reproduces the radii, propagation speed, and centroid positions
of the large rings observed at 3-4 microns by McGregor et al. The portion of
the vanguard ejected closer to the vertical falls back with high z-component
velocities just after maximum light, producing CO emission and the "flare" seen
at 0.9 microns. The model also produces secondary maxima ("bounces") whose
amplitudes and periods are in agreement with observations.Comment: 13 pages, 9 figures (figs 3 and 4 in color), accepted for Ap.J.
latex, version including full figures at:
http://oobleck.tn.cornell.edu/jh/ast/papers/slplume2-20.ps.g
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