Snap evaporation of droplets on smooth topographies

Droplet evaporation on solid surfaces is important in many applications including printing, micro-patterning and cooling. While seemingly simple, the configuration of evaporating droplets on solids is difficult to predict and control. This is because evaporation typically proceeds as a “stick-slip” sequence—a combination of pinning and de-pinning events dominated by static friction or “pinning”, caused by microscopic surface roughness. Here we show how smooth, pinning-free, solid surfaces of non-planar topography promote a different process called snap evaporation. During snap evaporation a droplet follows a reproducible sequence of configurations, consisting of a quasi-static phase-change controlled by mass diffusion interrupted by out-of-equilibrium snaps. Snaps are triggered by bifurcations of the equilibrium droplet shape mediated by the underlying non-planar solid. Because the evolution of droplets during snap evaporation is controlled by a smooth topography, and not by surface roughness, our ideas can inspire programmable surfaces that manage liquids in heat- and mass-transfer applications

Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe

We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median $z\sim 0.03$). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between $z\sim 0.6$ and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July

Dental caries in Uruguayan adults and elders: findings from the first Uruguayan National Oral Health Survey

This study aimed to assess dental caries status and associated factors in Uruguayan adults and elders using data from the first Uruguayan National Oral Health Survey. Data were representative of the country as a whole. Socio-demographic information was collected with a closed questionnaire. Dental caries was assessed by clinical examination using the DMFT index. The final sample consisted of 769 participants. Mean DMFT was 15.20 and 24.12 for the 35-44 and 65-74-year age groups, respectively. Mean number of decayed teeth was 1.70 in adults and 0.66 in elders. Multivariate analyses showed higher prevalence of dental caries associated with age 65-74 years, low socioeconomic status, use of public dental services, presence of gingivitis; for decayed teeth, age 35-44 years, low socioeconomic status, use of public dental services, infrequent tooth brushing, need for oral health care, and presence of root caries showed higher severity. Uruguayan adults and elders from disadvantaged backgrounds concentrated a heavier burden of dental caries

Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe

We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median $z\sim 0.03$). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between $z\sim 0.6$ and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July

A genetic locus and gene expression patterns associated with the priming effect on lettuce seed germination at elevated temperatures

Seeds of most cultivated varieties of lettuce (Lactuca sativa L.) fail to germinate at warm temperatures (i.e., above 25–30°C). Seed priming (controlled hydration followed by drying) alleviates this thermoinhibition by increasing the maximum germination temperature. We conducted a quantitative trait locus (QTL) analysis of seed germination responses to priming using a recombinant inbred line (RIL) population derived from a cross between L. sativa cv. Salinas and L. serriola accession UC96US23. Priming significantly increased the maximum germination temperature of the RIL population, and a single major QTL was responsible for 47% of the phenotypic variation due to priming. This QTL collocated with Htg6.1, a major QTL from UC96US23 associated with high temperature germination capacity. Seeds of three near-isogenic lines (NILs) carrying an Htg6.1 introgression from UC96US23 in a Salinas genetic background exhibited synergistic increases in maximum germination temperature in response to priming. LsNCED4, a gene encoding a key enzyme (9-cis-epoxycarotinoid dioxygenase) in the abscisic acid biosynthetic pathway, maps precisely with Htg6.1. Expression of LsNCED4 after imbibition for 24 h at high temperature was greater in non-primed seeds of Salinas, of a second cultivar (Titan) and of NILs containing Htg6.1 compared to primed seeds of the same genotypes. In contrast, expression of genes encoding regulated enzymes in the gibberellin and ethylene biosynthetic pathways (LsGA3ox1 and LsACS1, respectively) was enhanced by priming and suppressed by imbibition at elevated temperatures. Developmental and temperature regulation of hormonal biosynthetic pathways is associated with seed priming effects on germination temperature sensitivity