Density Wave -Supersolid and Mott Insulator-Superfluid transition in presence of an artificial gauge field : a strong coupling perturbation approach

We study the effect of an artificial gauge field on the zero temperature phase diagram of extended Bose Hubbard model, that describes ultra cold atoms in optical lattices with long range interaction using strong coupling perturbation theory . We determine analytically the effect of the artificial gauge field on the density wave - supersolid (DW-SS) and the the Mott insulator-superfluid (MI -SF) transition boundary . The momentum distribution at these two transition boundaries is also calculated in this approach. It is shown that such momentum distribution which can be observed in time of flight measurement, reveals the symmetry of the gauge potential through the formation of magnetic Brillouin zone and clearly distinguishes between the DW-SS and MI-SF boundary. We also point out that in symmetric gauge the momentum distribution structure at these transition boundaries bears distinctive signatures of vortices in supersolid and superfluid phases.Comment: 18 latexed two column pages including appendix, 9 .eps figures Figure positioning readjusted and one reference adde

Frequency shifts in noble-gas magnetometers

Polarized nuclei are a powerful tool in nuclear spin studies and in searches for beyond-the-standard model physics. Noble-gas comagnetometer systems, which compare two nuclear species, have thus far been limited by anomalous frequency variations of unknown origin. We studied the self-interactions in a $^3$He-$^{129}$Xe system by independently addressing, controlling and measuring the influence of each component of the nuclear spin polarization. Our results directly rule out prior explanations of the shifts, and demonstrate experimentally that they can be explained by species dependent self-interactions. We also report the first gas phase frequency shift induced by $^{129}$Xe on $^3$He.Comment: v.

Creating Classroom Community to Welcome Children Experiencing Trauma

How elementary and early childhood classrooms engage with socio-emotional learning is deeply connected to creating a classroom community. Yet, much of socio-emotional learning curricula focuses on the individual child, rather than on the everyday interactions that build and sustain community. During the Civic Action and Young Children study, we spent a year in a Head Start preschool in Texas, where we noticed that although many children in the class struggled with varied difficult circumstances including poverty, homelessness, discrimination and threat of deportation, the teachers did not label them as homeless, illegal immigrants or poor. Additionally, children seemed to help one another more than we saw in other preschool classrooms. This paper focuses on Ms. Luz and Ms. Louisa’s classroom of 17 preschool students and how they created a community that supported a young Latino boy, Luis, who experienced housing insecurity during his year in the classroom. Luis’s story highlights how the collective idea of civicness, i.e., acting with and on behalf of the community created authentic opportunities for creating and sustaining community. Rather than working with a child experiencing trauma through an individualized and decontextualized curricula, focusing on the community created opportunities for all children to practice authentic care and for Luis to experience inclusion in the community. We offer five implications and recommendations to create classroom communities that both welcome children experiencing trauma and create authentic opportunities for children to enact civicness

Recovering from the Impact of the Covid-19 Pandemic and Accelerating to Achieving the United Nations General Assembly Tuberculosis Targets

In 2020, the novel COVID-19 pandemic replaced TB as the world's top cause of death from an infectious disease. The October 21, 2020 the UN Secretary-General report on progress towards implementation of the UNHLM political declaration on TB stresses that although high-level commitments and targets had galvanized global and national progress towards ending TB, urgent and more ambitious investments and actions were required, especially in lieu of the COVID-19 pandemic where associated public health measures and travel restrictions, have disrupted health services universally. The report sets out 10 priority recommendations to get the world on track to reach agreed targets by 2022. Political commitment is more critical than ever. COVID-19 diagnostic and vaccination health services need to be aligned to TB services with active early case finding in communities, engaging the private sector care providers and mitigation of fear and stigma. Healthcare staff and community workers and leaders need to be provided with COVID-19 vaccination and personal protective equipment. The UNHLM declaration committed to mobilize 15 billion USD per annum for TB, of which 13 billion USD is for TB care and 2 billion USD per annum for TB R&D. The Global Fund needs to increase funding for TB. Learning from the unprecedented speed of COVID-19 vaccine development, fastracking development and evaluation of TB vaccines is essential. World leaders need to urgently address and reverse the socio-economic consequences of the COVID-19 pandemic and these will determine to what extent they will impact on achieving TB targets

Key diffusion mechanisms involved in regulating bidirectional water permeation across E. coli outer membrane lectin

Capsular polysaccharides (CPSs) are major bacterial virulent determinants that facilitate host immune evasion. E. coli group1 K30CPS is noncovalently attached to bacterial surface by Wzi, a lectin. Intriguingly, structure based phylogenetic analysis indicates that Wzi falls into porin superfamily. Molecular dynamics (MD) simulations further shed light on dual role of Wzi as it also functions as a bidirectional passive water specific porin. Such a functional role of Wzi was not realized earlier, due to the occluded pore. While five water specific entry points distributed across extracellular &periplasmic faces regulate the water diffusion involving different mechanisms, a luminal hydrophobic plug governs water permeation across the channel. Coincidently, MD observed open state structure of "YQF" triad is seen in sugar-binding site of sodium-galactose cotransporters, implicating its involvement in K30CPS surface anchorage. Importance of Loop 5 (L5) in membrane insertion is yet another highlight. Change in water diffusion pattern of periplasmic substitution mutants suggests Wzi's role in osmoregulation by aiding in K30CPS hydration, corroborating earlier functional studies. Water molecules located inside β-barrel of Wzi crystal structure further strengthens the role of Wzi in osmoregulation. Thus, interrupting water diffusion or L5 insertion may reduce bacterial virulence

Correlation of structure and stellar properties of galaxies in Stripe 82

Establishing a correlation (or lack thereof) between the bimodal colour distribution of galaxies and their structural parameters is crucial to understand the origin of bimodality. To achieve that, we have performed 2D mass-based structural decomposition (bulge+disc) of all disc galaxies (total$=$1263) in the Herschel imaging area of the Stripe 82 region using $K_s$ band images from the VICS82 survey. The scaling relations thus derived are found to reflect the internal kinematics and are employed in combination to select an indubitable set of classical and pseudo bulge hosting disc galaxies. The rest of the galaxies ($<20\%$) are marked as discs with "ambiguous" bulges. Pseudo and classical bulge disc galaxies exhibit clear bimodality in terms of all stellar parameters ($M_*$, sSFR, $r-K_s$). All pseudo bulge disc galaxies are blue and star-forming and all classical bulge disc galaxies are red and quiescent with less than $5\%$ digressions. Ambiguous bulge disc galaxies are intermittent to pseudo and classical bulge disc galaxies in the distribution of all structural and stellar parameters. $\Delta$$\langle\mu_{eb}\rangle$ - based on the placement of bulges on the Kormendy relation - is found to be the most efficient single structural indicator of both bulge type and stellar activity. The placement of ambiguous bulge disc galaxies on scaling relations and fundamental plane, in addition to their peculiar stellar properties suggest that they are dominantly a part of the green valley.Comment: Accepted for publication in ApJ, 16 pages, 10 figure

In vivo co-localization of enzymes on RNA scaffolds increases metabolic production in a geometrically dependent manner

Co-localization of biochemical processes plays a key role in the directional control of metabolic fluxes toward specific products in cells. Here, we employ in vivo scaffolds made of RNA that can bind engineered proteins fused to specific RNA binding domains. This allows proteins to be co-localized on RNA scaffolds inside living Escherichia coli. We assembled a library of eight aptamers and corresponding RNA binding domains fused to partial fragments of fluorescent proteins. New scaffold designs could co-localize split green fluorescent protein fragments to produce activity as measured by cell-based fluorescence. The scaffolds consisted of either single bivalent RNAs or RNAs designed to polymerize in one or two dimensions. The new scaffolds were used to increase metabolic output from a two-enzyme pentadecane production pathway that contains a fatty aldehyde intermediate, as well as three and four enzymes in the succinate production pathway. Pentadecane synthesis depended on the geometry of enzymes on the scaffold, as determined through systematic reorientation of the acyl-ACP reductase fusion by rotation via addition of base pairs to its cognate RNA aptamer. Together, these data suggest that intra-cellular scaffolding of enzymatic reactions may enhance the direct channeling of a variety of substrates