Determinantal Beam Search

Beam search is a go-to strategy for decoding neural sequence models. The algorithm can naturally be viewed as a subset optimization problem, albeit one where the corresponding set function does not reflect interactions between candidates. Empirically, this leads to sets often exhibiting high overlap, e.g., strings may differ by only a single word. Yet in use-cases that call for multiple solutions, a diverse or representative set is often desired. To address this issue, we propose a reformulation of beam search, which we call determinantal beam search. Determinantal beam search has a natural relationship to determinantal point processes (DPPs), models over sets that inherently encode intra-set interactions. By posing iterations in beam search as a series of subdeterminant maximization problems, we can turn the algorithm into a diverse subset selection process. In a case study, we use the string subsequence kernel to explicitly encourage n-gram coverage in text generated from a sequence model. We observe that our algorithm offers competitive performance against other diverse set generation strategies in the context of language generation, while providing a more general approach to optimizing for diversity

4D cell biology: big data image analytics and lattice light-sheet imaging reveal dynamics of clathrin-mediated endocytosis in stem cell-derived intestinal organoids.

New methods in stem cell 3D organoid tissue culture, advanced imaging, and big data image analytics now allow tissue-scale 4D cell biology, but currently available analytical pipelines are inadequate for handing and analyzing the resulting gigabytes and terabytes of high-content imaging data. We expressed fluorescent protein fusions of clathrin and dynamin2 at endogenous levels in genome-edited human embryonic stem cells, which were differentiated into hESC-derived intestinal epithelial organoids. Lattice light-sheet imaging with adaptive optics (AO-LLSM) allowed us to image large volumes of these organoids (70 × 60 × 40 µm xyz) at 5.7 s/frame. We developed an open-source data analysis package termed pyLattice to process the resulting large (∼60 Gb) movie data sets and to track clathrin-mediated endocytosis (CME) events. CME tracks could be recorded from ∼35 cells at a time, resulting in ∼4000 processed tracks per movie. On the basis of their localization in the organoid, we classified CME tracks into apical, lateral, and basal events and found that CME dynamics is similar for all three classes, despite reported differences in membrane tension. pyLattice coupled with AO-LLSM makes possible quantitative high temporal and spatial resolution analysis of subcellular events within tissues

Decision-making about HPV vaccination in parents of boys and girls:A population-based survey in England and Wales

BACKGROUND School-based HPV vaccination in the UK will soon be extended to boys. Based on other countries’ experience, uptake may initially be lower in boys than girls. We assessed HPV vaccine attitudes and decision-making in parents of boys and girls, to explore sex differences and inform public health messages. METHODS We carried out a cross-sectional population-based survey using home-based interviews in spring 2019. Participants were adults in England and Wales, with a child in school years 5–7 (aged 9–12 and eligible for HPV vaccination within 3 years). Measures included awareness of HPV and the vaccine, demographic factors, previous vaccine refusal and (after exposure to brief information) whether participants would allow their child to have the HPV vaccine (decided to vaccinate; decided not to vaccinate; undecided). We also assessed vaccine attitudes. Data were weighted to adjust for non-response. Multinomial logistic regression was used to explore predictors of deciding to (or not to) vaccinate compared with being undecided. RESULTS Among 1049 parents (weighted n = 1156), 55% were aware of HPV and the girls’ vaccination programme, but only 23% had heard of plans to vaccinate boys. After information exposure, 62% said they would vaccinate their child, 10% would not, and 28% were undecided. Parents of girls were more willing to vaccinate than parents of boys (adjusted odds ratio: 1.80 (1.32–2.45)). Positive attitudes and HPV/vaccine awareness were significantly independently associated with deciding to vaccinate. Previous vaccine refusal for a child was the strongest predictor of not wanting the HPV vaccine. CONCLUSIONS Our findings suggest a need for public health campaigns to raise awareness of plans to extend HPV vaccination to boys. Reassuringly only 10% of all parents were unwilling to vaccinate and our data suggest further information, including about safety and efficacy, may be important in supporting undecided parents to make the decision to vaccinate

Direct Measurements of the Stellar Continua and Balmer/4000 Angstrom Breaks of Red z>2 Galaxies: Redshifts and Improved Constraints on Stellar Populations

We use near-infrared (NIR) spectroscopy obtained with GNIRS on Gemini, NIRSPEC on KECK, and ISAAC on the VLT to study the rest-frame optical continua of three `Distant Red Galaxies' (having Js - Ks > 2.3) at z>2. All three galaxy spectra show the Balmer/4000 Angstrom break in the rest-frame optical. The spectra allow us to determine spectroscopic redshifts from the continuum with an estimated accuracy dz/(1+z) ~ 0.001-0.04. These redshifts agree well with the emission line redshifts for the 2 galaxies with Halpha emission. This technique is particularly important for galaxies that are faint in the rest-frame UV, as they are underrepresented in high redshift samples selected in optical surveys and are too faint for optical spectroscopy. Furthermore, we use the break, continuum shape, and equivalent width of Halpha together with evolutionary synthesis models to constrain the age, star formation timescale, dust content, stellar mass and star formation rate of the galaxies. Inclusion of the NIR spectra in the stellar population fits greatly reduces the range of possible solutions for stellar population properties. We find that the stellar populations differ greatly among the three galaxies, ranging from a young dusty starburst with a small break and strong emission lines to an evolved galaxy with a strong break and no detected line emission. The dusty starburst galaxy has an age of 0.3 Gyr and a stellar mass of 1*10^11 Msun. The spectra of the two most evolved galaxies imply ages of 1.3-1.4 Gyr and stellar masses of 4*10^11 Msun. The large range of properties seen in these galaxies strengthens our previous much more uncertain results from broadband photometry. Larger samples are required to determine the relative frequency of dusty starbursts and (nearly) passively evolving galaxies at z~2.5.Comment: Accepted for publication in the Astrophysical Journal. 12 pages, 6 figure

Exploring the Relationship between Diet and TV, Computer and Video Game Use in a Group of Canadian Children

Increased screen-time has been linked to unhealthy dietary practices but most studies have looked primarily at television viewing or an amalgam. Therefore the purpose of this study was to investigate the relationship between specific screen-time (TV, computer, video game) and a selection of healthy dietary intake measures (calories, carbohydrate, fat, sugar, fruit, vegetables, fibre and sugar-sweetened beverages (SSB)) in a group of Canadian children. We used single day sedentary and dietary recalls to assess sedentary behaviour and diet in 1423 children (9.90 (0.58) y; 737 girls, 686 boys) from the Action Schools! BC Dissemination study. Correlations and multiple regression analyses were used to explore sedentary behaviour-diet relationships. TV and video game use were correlated with higher calories, fat, sugar and SSB consumption (r = 0.07 to 0.09; p <.01) and lower fibre intake (r = -0.05 to -0.06; p <.05). TV use was also correlated with lower fruit and vegetable intake. Regression analyses showed that when controlling for other variables, only TV and video game use predicted sugar and SSB consumption (β =.06 to.08; p <.05). Computer use was correlated with calories but did not significantly predict any of the measures of dietary intake. Although screen time was significantly associated with less healthy eating profiles, it did not account for much variance in dietary behaviour of these children

The role of community-based Hubs in reef restoration: Collaborative monitoring at Moore Reef

The Cairns-Port Douglas region is home to multiple coral rehabilitation and stewardship projects supported by scientists, Traditional Owners, and a range of local stakeholders. The Cairns-Port Douglas Reef Hub has been a platform for collaboration across Traditional Owners, tourism operators, not-for-profits and scientists from the Reef Restoration and Adaptation Program (AIMS and CSIRO) to design and deliver a project at Moore Reef that assesses how new techniques for assisted coral recovery can be applied in rubble habitats. The collaborative project evaluates the viability of newly engineered coral seeding devices developed by AIMS, for deploying coral recruits that were spawned in the National Sea Simulator in December 2022 to sites at Moore Reef close to tourist pontoons. This project provides important data to inform future scaling up of restoration activities and provides a model for active involvement of a range of partners. Through this work, the project builds understanding around key ingredients for best-practice, place-based engagement opportunities for Reef communities and the general public

The Origin of Line Emission in Massive z~2.3 Galaxies: Evidence for Cosmic Downsizing of AGN Host Galaxies

Using the Gemini Near-InfraRed Spectrograph (GNIRS), we have assembled a complete sample of 20 K-selected galaxies at 2.0<z<2.7 with high quality near-infrared spectra. As described in a previous paper, 9 of these 20 galaxies have strongly suppressed star formation and no detected emission lines. The present paper concerns the 11 galaxies with detected Halpha emission, and studies the origin of the line emission using the GNIRS spectra and follow-up observations with SINFONI on the VLT. Based on their [NII]/Halpha ratios, the spatial extent of the line emission and several other diagnostics, we infer that four of the eleven emission-line galaxies host narrow line active galactic nuclei (AGNs). The AGN host galaxies have stellar populations ranging from evolved to star-forming. Combining our sample with a UV-selected galaxy sample at the same redshift that spans a broader range in stellar mass, we find that black-hole accretion is more effective at the high-mass end of the galaxy distribution (~2.9x10^11 Msun) at z~2.3. Furthermore, by comparing our results with SDSS data, we show that the AGN activity in massive galaxies has decreased significantly between z~2.3 and z~0. AGNs with similar normalized accretion rates as those detected in our K-selected galaxies reside in less massive galaxies (~4.0x10^10 Msun) at low redshift. This is direct evidence for downsizing of AGN host galaxies. Finally, we speculate that the typical stellar mass-scale of the actively accreting AGN host galaxies, both at low and at high redshift, might be similar to the mass-scale at which star-forming galaxies seem to transform into red, passive systems.Comment: Accepted for publication in the Astrophysical Journa

Nitrogen Production in Starburst Galaxies Detected by GALEX

We investigate the production of nitrogen in star-forming galaxies with ultraviolet (UV) radiation detected by the Galaxy Evolution Explorer Satellite (GALEX). We use a sample of 8745 GALEX emission-line galaxies matched to the Sloan Digital Sky Survey (SDSS) spectroscopic sample. We derive both gas-phase oxygen and nitrogen abundances for the sample and apply stellar population synthesis models to derive stellar masses and star formation histories of the galaxies. We compare oxygen abundances derived using three different diagnostics. We derive the specific star formation rates of the galaxies by modeling the seven-band GALEX+SDSS photometry. We find that galaxies that have log (SFR/M_*) ≳ − 10.0 typically have values of log (N/O) ~ 0.05 dex less than galaxies with log (SFR/M_*) ≾ − 10.0 and similar oxygen abundances

The Galaxy Evolution Explorer

The Galaxy Evolution Explorer (GALEX), a NASA Small Explorer Mission planned for launch in Fall 2002, will perform the first Space Ultraviolet sky survey. Five imaging surveys in each of two bands (1350-1750Å and 1750-2800Å) will range from an all-sky survey (limit m_(AB)~20-21) to an ultra-deep survey of 4 square degrees (limit m_(AB)~26). Three spectroscopic grism surveys (R=100-300) will be performed with various depths (m_(AB)~20-25) and sky coverage (100 to 2 square degrees) over the 1350-2800Å band. The instrument includes a 50 cm modified Ritchey-Chrétien telescope, a dichroic beam splitter and astigmatism corrector, two large sealed tube microchannel plate detectors to simultaneously cover the two bands and the 1.2 degree field of view. A rotating wheel provides either imaging or grism spectroscopy with transmitting optics. We will use the measured UV properties of local galaxies, along with corollary observations, to calibrate the UV-global star formation rate relationship in galaxies. We will apply this calibration to distant galaxies discovered in the deep imaging and spectroscopic surveys to map the history of star formation in the universe over the red shift range zero to two. The GALEX mission will include an Associate Investigator program for additional observations and supporting data analysis. This will support a wide variety of investigations made possible by the first UV sky survey

Synthesis and characterisation of ruthenium complexes containing a pendent catechol ring

A series of [Ru(bipy)₂L]⁺ and [Ru(phen)₂L]⁺ complexes where L is 2-[5-(3,4-dimethoxyphenyl)-4H-1,2,4-triazol-3-yl]pyridine (HL1) and 4-(5-pyridin-2-yl-4H-1,2,4-triazol-3-yl)benzene-1,2-diol (HL2) are reported. The compounds obtained have been characterised using X-ray crystallography, NMR, UV/Vis and emission spectroscopies. Partial deuteriation is used to determine the nature of the emitting state and to simplify the NMR spectra. The acid-base properties of the compounds are also investigated. The electronic structures of [Ru(bipy)₂L1]⁺ and Ru(bipy)₂HL1]²⁺ are examined using ZINDO. Electro and spectroelectrochemical studies on [Ru(bipy)₂(L2)]⁺ suggest that proton transfer between the catechol and triazole moieties on L2 takes place upon oxidation of the L2 ligand