Dendritic cells are critical accessory cells for thymus-dependent antibody responses in mouse and in man

We report that dendritic cells (DC) are necessary and potent accessory cells for anti-sheep erythrocyte responses in both mouse and man. In mice, a small number of DC (0.3-1% of the culture) restores the response of B/T-lymphocyte mixtures to that observed in unfractionated spleen. An even lower dose (0.03-0.1% DC) is needed if the T cells have been primed to antigen. Responses are both antigen and T cell dependent. Selective depletion of DC from unfractionated spleen with the monoclonal antibody 33D1 and complement ablates the antibody response. In contrast to DC, purified spleen macrophages are weak or inactive stimulators. However, when mixed with DC, macrophages can increase the yield of antibody-secreting cells about 2-fold. In man, small number (0.3-1%) of blood DC stimulate antibody formation in vitro. Purified human monocytes do not stimulate but in low doses (1% of the culture) inhibit the antibody response. Likewise, selective removal of human monocytes with antibody and complement enhances or accelerates the development of antibody-secreting cells. We conclude that DC are required for the development of T-dependent antibody responses by mouse and human lymphocytes in vitro

Electrodialysis for concentrating cobalt, chromium, manganese, and magnesium from a synthetic solution based on a nickel laterite processing route

[EN] Due to environmental and human health concerns, the need for cleaner techniques able to extract and recover metals from mining process solutions has been increasing. In this work, the use of electrodialysis for recovering cobalt, magnesium, manganese, and chromium ions from an acid multicomponent solution generated in the nickel laterite processing was evaluated. Values of percent extraction above 98% were obtained for Co2+, Mn2+, and Mg(2+ )ions. For Cr3+, the greatest percent extraction obtained was 83%. The results of percent concentration of the species showed the same trend: for Cr3+ ions, it was significantly lower than the others. Such difference in the transport of the metals through the membranes may have occurred due to the lower molar concentration, lower diffusion coefficient, and greater Stokes radius of chromium ions. Thus, the transfer of Cr3+ was hindered by the presence of other cationic species. This was also evidenced by the results of current efficiency and energy consumption associated with each species in solution. Lastly, the results of solution pH throughout the experiments and the final condition of the membranes, which were analyzed by SEM/EDS, indicated that the water dissociation phenomenon occurred at their surfaces.The authors gratefully acknowledge the financial support given by funding agencies CNPq (Process 141346/2016-7; 171241/2017-7; 160320/2019-4) and FAPESP (Process 2012/51871-9) . This study was financed in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior-Brasil (CAPES) -Finance Code 001 (Processes 88881.190502/2018-01 and 88887.362657/2019-00) .Feijoo, GC.; Santana-Barros, K.; Scarazzato, T.; Espinosa, D. (2021). Electrodialysis for concentrating cobalt, chromium, manganese, and magnesium from a synthetic solution based on a nickel laterite processing route. Separation and Purification Technology. 275. https://doi.org/10.1016/j.seppur.2021.11919227

Gravity and Large-Scale Non-local Bias

The relationship between galaxy and matter overdensities, bias, is most often assumed to be local. This is however unstable under time evolution, we provide proofs under several sets of assumptions. In the simplest model galaxies are created locally and linearly biased at a single time, and subsequently move with the matter (no velocity bias) conserving their comoving number density (no merging). We show that, after this formation time, the bias becomes unavoidably non-local and non-linear at large scales. We identify the non-local gravitationally induced fields in which the galaxy overdensity can be expanded, showing that they can be constructed out of the invariants of the deformation tensor (Galileons). In addition, we show that this result persists if we include an arbitrary evolution of the comoving number density of tracers. We then include velocity bias, and show that new contributions appear, a dipole field being the signature at second order. We test these predictions by studying the dependence of halo overdensities in cells of fixed matter density: measurements in simulations show that departures from the mean bias relation are strongly correlated with the non-local gravitationally induced fields identified by our formalism. The effects on non-local bias seen in the simulations are most important for the most biased halos, as expected from our predictions. The non-locality seen in the simulations is not fully captured by assuming local bias in Lagrangian space. Accounting for these effects when modeling galaxy bias is essential for correctly describing the dependence on triangle shape of the galaxy bispectrum, and hence constraining cosmological parameters and primordial non-Gaussianity. We show that using our formalism we remove an important systematic in the determination of bias parameters from the galaxy bispectrum, particularly for luminous galaxies. (abridged)Comment: 26 pages, 9 figures. v2: improved appendix

“Everything…Fell Apart Once COVID-19 Hit”—Leveraging the COVID-19 Response to Strengthen Public Health Activities toward Ending the HIV Epidemic: A Qualitative Study

COVID-19 caused widespread disruption of activities for Ending the HIV Epidemic (EHE). In this study we assessed public health perspectives on leveraging the COVID-19 response to advance the goals of EHE. We conducted a qualitative study with 33 public health partners in the Midwestern and Southern United States from October 2020 to February 2022. Participants were asked how the strategies developed for COVID-19 could be applied to the HIV epidemic. Interviews were recorded, transcribed, and examined using rapid qualitative analysis. Four themes emerged: (1) Rebuilding teams and adapting culture for success in EHE activities; (2) Recognizing and modernizing the role of disease intervention specialists (DIS); (3) Enhanced community awareness of the public health role in disease response and prevention; and (4) Leveraging COVID-19 data systems and infrastructure for EHE activities. The COVID-19 pandemic called attention to the dearth of public health funding and outdated information technology (IT) infrastructure used for HIV activities. It also led to greater public health knowledge, including increased familiarity with partner services and molecular epidemiology of HIV, and opportunities to develop new data systems for surveillance that can be applied to efforts for EHE

Discovery of Four Gravitationally Lensed Quasars from the Sloan Digital Sky Survey

We present the discovery of four gravitationally lensed quasars selected from the spectroscopic quasar catalog of the Sloan Digital Sky Survey. We describe imaging and spectroscopic follow-up observations that support the lensing interpretation of the following four quasars: SDSS J0832+0404 (image separation \theta=1.98", source redshift z_s=1.115, lens redshift z_l=0.659); SDSS J1216+3529 (\theta=1.49", z_s=2.012); SDSS J1322+1052 (\theta=2.00", z_s=1.716); and SDSS J1524+4409 (\theta=1.67", z_s=1.210, z_l=0.320). Each system has two lensed images. We find that the fainter image component of SDSS J0832+0404 is significantly redder than the brighter component, perhaps because of differential reddening by the lensing galaxy. The lens potential of SDSS J1216+3529 might be complicated by the presence of a secondary galaxy near the main lensing galaxy.Comment: 25 pages, 10 figures, 6 tables, accepted for publication in A

Oscillatory Finite-Time Singularities in Finance, Population and Rupture

We present a simple two-dimensional dynamical system where two nonlinear terms, exerting respectively positive feedback and reversal, compete to create a singularity in finite time decorated by accelerating oscillations. The power law singularity results from the increasing growth rate. The oscillations result from the restoring mechanism. As a function of the order of the nonlinearity of the growth rate and of the restoring term, a rich variety of behavior is documented analytically and numerically. The dynamical behavior is traced back fundamentally to the self-similar spiral structure of trajectories in phase space unfolding around an unstable spiral point at the origin. The interplay between the restoring mechanism and the nonlinear growth rate leads to approximately log-periodic oscillations with remarkable scaling properties. Three domains of applications are discussed: (1) the stock market with a competition between nonlinear trend-followers and nonlinear value investors; (2) the world human population with a competition between a population-dependent growth rate and a nonlinear dependence on a finite carrying capacity; (3) the failure of a material subjected to a time-varying stress with a competition between positive geometrical feedback on the damage variable and nonlinear healing.Comment: Latex document of 59 pages including 20 eps figure

A New Survey for Giant Arcs

We report on the first results of an imaging survey to detect strong gravitational lensing targeting the richest clusters selected from the photometric data of the Sloan Digital Sky Survey (SDSS) with follow-up deep imaging observations from the Wisconsin Indiana Yale NOAO (WIYN) 3.5m telescope and the University of Hawaii 88-inch telescope (UH88). The clusters are selected from an area of 8000 deg^2 using the Red Cluster Sequence technique and span the redshift range 0.1 < z < 0.6, corresponding to a comoving cosmological volume of ~ 2 Gpc^3. Our imaging survey thus targets a volume more than an order of magnitude larger than any previous search. A total of 240 clusters were imaged of which 141 had sub-arcsecond image quality. Our survey has uncovered16 new lensing clusters with definite giant arcs, an additional 12 systems for which the lensing interpretation is very likely, and 9 possible lenses which contain shorter arclets or candidate arcs which are less certain and will require further observations to confirm their lensing origin. The number of new cluster lenses detected in this survey is likely > 30. Among these new systems are several of the most dramatic examples of strong gravitational lensing ever discovered with multiple bright arcs at large angular separation. These will likely become 'poster-child' gravitational lenses similar to Abell 1689 and CL0024+1654. The new lenses discovered in this survey will enable future sysetmatic studies of the statistics of strong lensing and its implications for cosmology and our structure formation paradigm.Comment: 19 pages, 7 pages of Figures, submitted to AJ. Fixed Typo

Three-point Correlation Functions of SDSS Galaxies in Redshift Space: Morphology, Color, and Luminosity Dependence

We present measurements of the redshift--space three-point correlation function of galaxies in the Sloan Digital Sky Survey (SDSS). For the first time, we analyze the dependence of this statistic on galaxy morphology, color and luminosity. In order to control systematics due to selection effects, we used $r$--band, volume-limited samples of galaxies, constructed from the magnitude-limited SDSS data ($14.5<r<17.5$), and further divided the samples into two morphological types (early and late) or two color populations (red and blue). The three-point correlation function of SDSS galaxies follow the hierarchical relation well and the reduced three-point amplitudes in redshift--space are almost scale-independent ($Q_z=0.5\sim1.0$). In addition, their dependence on the morphology, color and luminosity is not statistically significant. Given the robust morphological, color and luminosity dependences of the two-point correlation function, this implies that galaxy biasing is complex on weakly non-linear to non-linear scales. We show that simple deterministic linear relation with the underlying mass could not explain our measurements on these scales.Comment: order of figures are changed. 9 pages, 15 figure