Sweeping a molecular Bose-Einstein condensate across a Feshbach resonance

We consider the dissociation of a molecular Bose-Einstein condensate during a magnetic-field sweep through a Feshbach resonance that starts on the molecular side of the resonance and ends on the atomic side. In particular, we determine the energy distribution of the atoms produced after the sweep. We find that the shape of the energy distribution strongly depends on the rate of the magnetic-field sweep, in a manner that is in good agreement with recent experiments.Comment: 4.2 pages, 4 figure

Trapped fermionic clouds distorted from the trap shape due to many-body effects

We present a general approach for calculating densities and other local quantities of trapped Fermi gases, when the cloud shape is distorted with respect to the trap shape due to global energy considerations. Our approach provides a consistent way to explore physics beyond the local density approximation, if this is necessary due to the distortion. We illustrate this by analyzing in detail experimentally observed distortions in an imbalanced Fermi mixture in an elongated trap. In particular, we demonstrate in that case dramatic deviations from ellipsoidal cloud shapes arising from the competition between surface and bulk energies.Comment: 4+ pages, 3 figures. Formalism for distorted trapped fermi systems + treatment of polarized fermion experiments. Version 2: slightly shortened, published versio

Strongly interacting one-dimensional bosons in arbitrary-strength optical lattices: from Bose-Hubbard to sine-Gordon and beyond

We analyze interacting one-dimensional bosons in the continuum, subject to a periodic sinusoidal potential of arbitrary depth. Variation of the lattice depth tunes the system from the Bose-Hubbard limit for deep lattices, through the sine-Gordon regime of weak lattices, to the complete absence of a lattice. Using the Bose-Fermi mapping between strongly interacting bosons and weakly interacting fermions, we derive the phase diagram in the parameter space of lattice depth and chemical potential. This extends previous knowledge from tight-binding (Bose-Hubbard) studies in a new direction which is important because the lattice depth is a readily adjustable experimental parameter. Several other results (equations of state, energy gaps, profiles in harmonic trap) are presented as corollaries to the physics contained in this phase diagram. Generically, both incompressible (gapped) and compressible phases coexist in a trap; this has implications for experimental measurements

Ultracold Superstrings in atomic boson-fermion mixtures

We propose a setup with ultracold atomic gases that can be used to make a nonrelativistic superstring in four spacetime dimensions. In particular, we consider for the creation of the superstring a fermionic atomic gas that is trapped in the core of a vortex in a Bose-Einstein condensate. We explain the required tuning of experimental parameters to achieve supersymmetry between the fermionic atoms and the bosonic modes describing the oscillations in the vortex position. Furthermore, we discuss the experimental consequences of supersymmetry.Comment: 4 pages, 4 figures; published versio

Narco Trafficking, Corruption, and Perpetuated Violence in Guatemala

ABSTRACT: Narco-trafficking and Perpetuated Violence in Guatemala Over the years drug cartels have made their way into Guatemala through their borders. Drug trafficking is the main reason why the border between Guatemala and Honduras is one of the most violent locations in Central America. Due to lawlessness and corruption, wealthy drug traffickers assume an authoritative role in the region (Crisis Group, 2014). A 2010 report done by U.S. International Narcotics Control Strategy says that “Guatamala is the epicenter of the drug threat.” (Brice, CNN, 2011). However, the increase in drug related violence is due to Zetas, a Mexican drug cartel. The criminal gangs from Zetas have so much power that their permission is required to enter and leave certain neighborhoods and streets in Guatemala. Narco-trafficking related crimes also includes kidnapping. The amount of missing persons has increased to 207 percent from 2009 to 2013 (OASC, 2014). Kidnapping occurs so that drug traffickers can demand ransom and they have a reputation of killing the victim even after a ransom has been paid. A recommendation to solve the drug trafficking problem in Guatemala would be to fix the corruption which permeates throughout the Guatemalan government, including the police forces. After dealing with governmental and political corruption, there will be a better chance to properly train and equip the police forces in order to prevent gangsters and traffickers from having power in the streets. Drug trafficking is the gateway to many other crimes in Guatemala and is the core reason why there is so much violence and unease in the State. Fixing up the government is necessary for the livelihood of the Guatemalan people.https://scholarscompass.vcu.edu/uresposters/1136/thumbnail.jp

FLUOXETINE ATTENUATES MAST CELL FUNCTION BY TARGETING PURINERGIC SIGNALING

Mast cells are tissue resident, innate immune cells that provide protection against parasitic and bacterial infections and venom poisoning. Mast cells also play a pathogenic role in atopy and allergic diseases. Atopy and allergic diseases are increasing in the developed world and are predicted to continue to increase at an alarming rate. Current treatment options include corticosteroids, anti-histamines, anti-IgE and avoidance of allergen. These interventions have limitations: some patients are steroid resistant; anti-histamines have low efficacy since they need to be administered early during allergen exposure; and anti-IgE is costly. Thus there is a clinical need for new treatment options. An efficient approach is to re-purpose FDA-approved drugs. Selective serotonin reuptake inhibitors (SSRIs) are a class of anti-depressants used to treat depression and other psychiatric disorders. SSRIs have been shown to possess anti-inflammatory properties, but the mechanism of action is unclear. The possibility to treat allergic diseases with SSRIs has not been studied. Using primary mouse bone marrow derived, ex vivo cultured mouse peritoneal, and primary skin derived human mast cells, we show that the SSRI fluoxetine suppresses IgE-mediated degranulation, cytokine production, and inflammatory lipid secretion. Several other SSRIs showed similar effects on mouse mast cells. Cytokine suppression occurs at a transcriptional level, as evidenced by decreased signaling downstream of the IgE receptor and reduced cytokine mRNA induction. We found that fluoxetine-mediated suppression requires the purinergic receptor, P2X3. Furthermore, we show that IgE stimulation elicits rapid ATP release from mast cells, and that ATP and purinergic signaling is a positive feedback regulator of mast cell activation. Fluoxetine can also suppress ATP-mediated cytokine production, degranulation, and lipid production most likely via NFkb suppression and diminished purinergic receptor expression. Importantly, fluoxetine effects are consistent in an in vivo passive systemic anaphylaxis (PSA) model and in a house dust mite (HDM) airway hyperresponsiveness and lung inflammation model of asthma. In the PSA model, fluoxetine reduced hypothermia and cytokine production. In the asthma model, the drug suppressed bronchoresponsiveness as well as pulmonary mast cell hyperplasia and eosinophilia, and the recruitment of Th2 cells, neutrophils, eosinophils, and lymphocytes to the bronchoalveolar space, as well as cytokine levels in the bronchoalveolar fluid in sensitized mice. Overall, we show that fluoxetine broadly suppresses mast cell activation in vitro and in vivo, most likely by impeding an ATP-P2X3 positive feedback loop

Larval ontogeny of a percichthyid fish, Synagrops philippinensis (Günther) in Kagoshima Bay, southern Japan

The larval ontogeny of a developmental series (1.2-8.3mm body length, BL) of Synagrops philippinensis from Kagoshima Bay, southern Japan is described and illustrated. The yolk was completely absorbed in larva of ≥1.5 mm BL. Notochord flexion commenced at about 3.5mm BL and was completed by about 4.0-4.5mm BL. S. philippinensis larvae were distinguished from their congeners based on melanophore patterns, head spination and fin spines and rays. Larvae of 7.5-8.3 mm BL were characterized by anteriorly serrated pelvic spine, two anal spines, nine inner preopercular spines and no melanophore on lateral side of the caudal peduncle; 7.0 to 7.5mm BL larvae by the above characters except serration on pelvic spine; and yolk-sac, pre-flexion, flexing and post-flexion larvae up to 7.0mm BL by unique melanophores on lower lobe of pectoral finfold/fin

Hypoxic Culture Conditions as a Solution for Mesenchymal Stem Cell Based Regenerative Therapy

Cell-based regenerative therapies, based on in vitro propagation of stem cells, offer tremendous hope to many individuals suffering from degenerative diseases that were previously deemed untreatable. Due to the self-renewal capacity, multilineage potential, and immunosuppressive property, mesenchymal stem cells (MSCs) are considered as an attractive source of stem cells for regenerative therapies. However, poor growth kinetics, early senescence, and genetic instability during in vitro expansion and poor engraftment after transplantation are considered to be among the major disadvantages of MSC-based regenerative therapies. A number of complex inter-and intracellular interactive signaling systems control growth, multiplication, and differentiation of MSCs in their niche. Common laboratory conditions for stem cell culture involve ambient O-2 concentration (20%) in contrast to their niche where they usually reside in 2-9% O-2. Notably, O-2 plays an important role in maintaining stem cell fate in terms of proliferation and differentiation, by regulating hypoxia-inducible factor-1 (HIF-1) mediated expression of different genes. This paper aims to describe and compare the role of normoxia (20% O-2) and hypoxia (2-9% O-2) on the biology of MSCs. Finally it is concluded that a hypoxic environment can greatly improve growth kinetics, genetic stability, and expression of chemokine receptors during in vitro expansion and eventually can increase efficiency of MSC-based regenerative therapies.Article Link: http://www.hindawi.com/journals/tswj/2013/632972

Managing Nitrogen and Phosphorus Nutrients for Switchgrass Produced for Bioenergy Feedstock in Phosphorus-Deficient Soil

There is limited information available explaining the agronomic and economic relationships between yield and nitrogen and phosphorus applications to growing switchgrass produced in phosphorus-deficient soils. The objective of this study was to determine the effects of nitrogen and phosphorus fertilizers on feedstock yield and measures of expected total cost, gross revenue, net return, and breakeven price of feedstock produced in phosphorus-deficient soils in the southern Great Plains. Data were collected from a three-year, two-location agronomic field study conducted in south-central Oklahoma. Two discrete nitrogen treatments (0 and 134 kg ha-1) and four discrete phosphorus treatments (0, 30, 60 and 90 kg ha-1) were randomly assigned to small plots arranged in a randomized complete block designed (RCBD) study. Random effects mixed ANOVA models were used to estimate the effects of nitrogen, phosphorus and nitrogen by phosphorus interactions on feedstock yield and the economic variables specified. Results showed that, on average over site-years, switchgrass yield increases from 10.5 to 12.3 Mg ha-1 with the highest (101-kg ha-1) treatment; however, we found no statistical difference in net profitability between phosphorus treatments. Yield and net return did respond significantly to 135 kg-1 of N ha-1. Our results suggest that phosphorus-deficient soils do not seem to have the same impact on switchgrass yield and profitability as they do for the yields and profitability of other crops traditionally grown in this region.bioenergy feedstock, economics, phosphorus-deficient soils, nitrogen, switchgrass, Crop Production/Industries, Environmental Economics and Policy, Production Economics,