894 research outputs found
Cold N+NH Collisions in a Magnetic Trap
We present an experimental and theoretical study of atom-molecule collisions
in a mixture of cold, trapped atomic nitrogen and NH molecules at a temperature
of ~mK. We measure a small N+NH trap loss rate coefficient of
~cms.
Accurate quantum scattering calculations based on {\it ab initio} interaction
potentials are in agreement with experiment and indicate the magnetic dipole
interaction to be the dominant loss mechanism. Our theory further indicates the
ratio of N+NH elastic to inelastic collisions remains large () into the
mK regime
Biphasic Culture of Arcobacter spp.
Arcobacter spp. have recently been genetically differentiated as a genus distinct from Campylobacter. Physiologically, Arcobacter spp. are aerotolerant bacteria, while Campylobacter spp. are microaerophilic. However, since Arcobacter spp. have been difficult to grow to high population densities in broth media, alternative culture techniques were investigated. A biphasic culture system was developed in 25 cm2 tissue culture flasks. Biphasic culture, consisting of a solid phase of 10% bovine blood agar and a liquid phase of Brain Heart Infusion broth, was found to increase bacterial population densities by more than 2 log10 cycles for strains of A. butzleri and A. skirrowii. A strain of A. cryaerophilus, which was non-culturable in broth culture, attained population densities of 109 cells ml-1 in biphasic culture. Neither the addition of fetal bovine serum to the liquid nor an increase in the surface area from 25 to 75 cm2 resulted in increased cell densities
Diversity of immunoglobulin light chain genes in non-teleost ray-finned fish uncovers IgL subdivision into five ancient isotypes
<p>The aim of this study was to fill important gaps in the evolutionary history of immunoglobulins by examining the structure and diversity of IgL genes in non-teleost ray-finned fish. First, based on the bioinformatic analysis of recent transcriptomic and genomic resources, we experimentally characterized the IgL genes in the chondrostean fish, Acipenser ruthenus (sterlet). We show that this species has three loci encoding IgL kappa-like chains with a translocon-type gene organization and a single VJC cluster, encoding homogeneous lambda-like light chain. In addition, sterlet possesses sigma-like VL and J-CL genes, which are transcribed separately and both encode protein products with cleavable leader peptides. The Acipenseriformes IgL dataset was extended by the sequences mined in the databases of species belonging to other non-teleost lineages of ray-finned fish: Holostei and Polypteriformes. Inclusion of these new data into phylogenetic analysis showed a clear subdivision of IgL chains into five groups. The isotype described previously as the teleostean IgL lambda turned out to be a kappa and lambda chain paralog that emerged before the radiation of ray-finned fish. We designate this isotype as lambda-2. The phylogeny also showed that sigma-2 IgL chains initially regarded as specific for cartilaginous fish are present in holosteans, polypterids, and even in turtles. We conclude that there were five ancient IgL isotypes, which evolved differentially in various lineages of jawed vertebrates.</p
Mechanism of Collisional Spin Relaxation in Triplet-Sigma Molecules
We measure and theoretically determine the effect of molecular rotational
splitting on Zeeman relaxation rates in collisions of cold Triplet-Sigma
molecules with helium atoms in a magnetic field. All four stable isotopomers of
the imidogen (NH) molecule are magnetically trapped and studied in collisions
with 3He and 4He. The 4He data support the predicted inverse square dependence
of the collision induced Zeeman relaxation rate coefficient on the molecular
rotational constant B. The measured 3He rate coefficients are much larger than
4He and depend less strongly on B, and the theoretical analysis indicates they
are strongly affected by a shape resonance. The results demonstrate the
influence of molecular structure on collisional energy transfer at low
temperatures.Comment: 10 pages, 3 figures, revised introduction and focu
The Role of Dietary Vitamin E in Experimental Listeria monocytogenes Infections in Turkeys
The current study was designed to determine if dietary vitamin E influenced either the gut clearance or levels of peripheral blood CD4+ and CD8+ T lymphocytes in adult turkeys experimentally infected with Listeria monocytogenes. Turkeys were fed vitamin E (0, 100, or 200 IU) from day of hatch to time of necropsy. After 6 wk on the experimental diet, turkeys were orally inoculated with L. monocytogenes (∼ 109 cfu). To monitor infection status, cloacal swabs were taken on selected days post-inoculation (DPI). At necropsy, samples of viscera, including liver, spleen, cecum, duodenum, ileum, and colon were collected and cultured for L. monocytogenes. In experiments 1 and 2, recovery of L. monocytogenes from cloacal swabs, tissues, and intestines from turkeys fed vitamin E was generally lower than that from turkeys fed the control diet, although these differences were not statistically significant. When data from both trials were combined, L. monocytogenes was cultured less frequently from cloacal swabs of the vitamin E-treated group (200 IU) on 2 and 3 DPI, when compared to controls (0 IU, P \u3c 0.01). There were no changes in virulence characteristics of L. monocytogenes cells, as measured by in vitro killing of Ped-2E9 cells, recovered from cloacal swabs or tissues of experimentally infected turkeys fed the control or a vitamin E treatment diet. Flow cytometric analysis indicated that CD4+ and CD8+ peripheral blood T lymphocytes were elevated at 6 and 8 DPI in infected turkeys given 200 IU vitamin E
Vainshtein Mechanism in Binary Pulsars
We compute the scalar gravitational radiation from a binary pulsar system in
the simplest model that exhibits the Vainshtein mechanism. The mechanism is
successful in screening the effect from scalar fields conformally coupled to
matter, although gravitational radiation is less suppressed relative to its
general relativity predictions than static fifth forces effects within the
pulsar system. This is due to a combination of two effects: firstly the
existence of monopole and dipole radiation; secondly the Vainshtein suppression
comes from the hierarchy of scales between the inverse frequency scale and the
Vainshtein radius, rather than the orbital radius of the pulsar system.
Extensions of these results will have direct relevance to infrared
modifications of gravity, such as massive gravity theories, which are known to
exhibit a Vainshtein mechanism. Generalization to Galileon models with higher
order interactions are likely to provide stronger constraints.Comment: minor revisions to match published version in pr
Development of a Culinary Medicine Toolkit to Improve Implementation of Virtual Cooking Classes for Low-Income Adults with Type 2 Diabetes
Culinary medicine (CM) addresses diseases through nutrition and culinary education. To promote access to educational material for people with diabetes and engagement in virtual classes, we created a virtual culinary medicine toolkit (VCMT) sensitive to literacy levels and language preferences. The VCMT was developed to accompany existing virtual CM programs and help improve participant interaction and retention, offering educational materials for providers and participants. The provider VCMT offers level-setting education to reduce mixed nutrition messaging, including educational resources discussing inclusive nutrition and mindful eating topics. Each handout has a QR code and link to engaging, animated videos that provide further explanation. The participant VCMT offers a range of fundamental cooking skill videos and infographics, including knife skills and preparing whole grains and healthy beverages. Participant handouts and animated videos, which are played during the virtual CM class, allow participants to learn more about diabetes management and food literacy topics, including interpreting nutrition labels, and are employed during a CM to facilitate discussion and reflection. The animated videos replace a traditional slide-based lecture, allowing space for patient-centered facilitated discussions during virtual cooking sessions. The VCMT could guide the development of virtual CM interventions to shift learning from lecture-based to patient-centered discussions via a visual and inclusive medium
Development of a Culinary Medicine toolkit to Improve Implementation of Virtual Cooking Classes For Low-income adults With Type 2 Diabetes
Culinary medicine (CM) addresses diseases through nutrition and culinary education. to promote access to educational material for people with diabetes and engagement in virtual classes, we created a virtual culinary medicine toolkit (VCMT) sensitive to literacy levels and language preferences. The VCMT was developed to accompany existing virtual CM programs and help improve participant interaction and retention, offering educational materials for providers and participants. The provider VCMT offers level-setting education to reduce mixed nutrition messaging, including educational resources discussing inclusive nutrition and mindful eating topics. Each handout has a QR code and link to engaging, animated videos that provide further explanation. The participant VCMT offers a range of fundamental cooking skill videos and infographics, including knife skills and preparing whole grains and healthy beverages. Participant handouts and animated videos, which are played during the virtual CM class, allow participants to learn more about diabetes management and food literacy topics, including interpreting nutrition labels, and are employed during a CM to facilitate discussion and reflection. The animated videos replace a traditional slide-based lecture, allowing space for patient-centered facilitated discussions during virtual cooking sessions. The VCMT could guide the development of virtual CM interventions to shift learning from lecture-based to patient-centered discussions via a visual and inclusive medium
The Prevalence of L. monocytogenes in Cull Sows
The goal of this study was to determine the distribution of Listeria monocytogenes in cull sows and their pork. Two trials were conducted at a single packing plant in 2001 (n=179 cull sows) and in 2002 (n= 160 cull sows). Fecal samples collected antemortem (trial 1) as well as animal tissues, carcass, and environmental swabs, and meat block samples collected at the abattoir (trials 1 and 2) were analyzed. When results from both trials were combined, overall L. monocytogenes was detected in five or 0.17% of the total samples (n=2,858). Specifically, L. monocytogenes was confirmed in a tonsil sample (0.55% of tonsils positive) and in a carcass swab sample (0.56% of carcasses) before the organic acid rinse. L. monocytogenes was recovered in three (1.21%) meat block samples (n=213). These data indicate that L. monocytogenes is present in the cull sow and their pork
Sculpting the Extra Dimensions: Inflation from Codimension-2 Brane Back-reaction
We construct an inflationary model in 6D supergravity that is based on
explicit time-dependent solutions to the full higher-dimensional field
equations, back-reacting to the presence of a 4D inflaton rolling on a
space-filling codimension-2 source brane. Fluxes in the bulk stabilize all
moduli except the `breathing' modulus (that is generically present in
higher-dimensional supergravities). Back-reaction to the inflaton roll causes
the 4D Einstein-frame on-brane geometry to expand, a(t) ~ t^p, as well as
exciting the breathing mode and causing the two off-brane dimensions to expand,
r(t) ~ t^q. The model evades the general no-go theorems precluding 4D de Sitter
solutions, since adjustments to the brane-localized inflaton potential allow
the power p to be dialed to be arbitrarily large, with the 4D geometry becoming
de Sitter in the limit p -> infinity (in which case q = 0). Slow-roll solutions
give accelerated expansion with p large but finite, and q = 1/2. Because the
extra dimensions expand during inflation, the present-day 6D gravity scale can
be much smaller than it was when primordial fluctuations were generated -
potentially allowing TeV gravity now to be consistent with the much higher
gravity scale required at horizon-exit for observable primordial gravity waves.
Because p >> q, the 4 on-brane dimensions expand more quickly than the 2
off-brane ones, providing a framework for understanding why the observed four
dimensions are presently so much larger than the internal two. If uplifted to a
10D framework with 4 dimensions stabilized, the 6D evolution described here
could describe how two of the six extra dimensions evolve to become much larger
than the others, as a consequence of the enormous expansion of the 4 large
dimensions we can see.Comment: 27 pages + appendices, 2 figure
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