Concentrations of criteria pollutants in the contiguous U.S., 1979 – 2015: Role of model parsimony in integrated empirical geographic regression

BACKGROUND: National- or regional-scale prediction models that estimate individual-level air pollution concentrations commonly include hundreds of geographic variables. However, these many variables may not be necessary and parsimonious approach including small numbers of variables may achieve sufficient prediction ability. This parsimonious approach can also be applied to most criteria pollutants. This approach will be powerful when generating publicly available datasets of model predictions that support research in environmental health and other fields. OBJECTIVES: We aim to (1) build annual-average integrated empirical geographic (IEG) regression models for the contiguous U.S. for six criteria pollutants, for all years with regulatory monitoring data during 1979 – 2015; (2) explore the impact of model parsimony on model performance by comparing the model performance depending on the numbers or variables offered into a model; and (3) provide publicly available model predictions. METHODS: We compute annual-average concentrations from regulatory monitoring data for PM10, PM2.5, NO2, SO2, CO, and ozone at all monitoring sites for 1979-2015. We also compute ~900 geographic characteristics at each location including measures of traffic, land use, and satellite-based estimates of air pollution and landcover. We then develop IEG models, employing universal kriging and summary factors estimated by partial least squares (PLS) of independent variables. For all pollutants and years, we compare three approaches for choosing variables to include in the model: (1) no variables (kriging only), (2) a limited number of variables chosen by forward selection, and (3) all variables. We evaluate model performance using 10-fold cross-validation (CV) using conventional randomly-selected and spatially-clustered test data. RESULTS: Models using 3 to 30 variables generally have the best performance across all pollutants and years (median R2 conventional [clustered] CV: 0.66 [0.47]) compared to models with no (0.37 [0]) or all variables (0.64 [0.27]). Using the best models mostly including 3-30 variables, we predicted annual-average concentrations of six criteria pollutants for all Census Blocks in the contiguous U.S. DISCUSSION: Our findings suggest that national prediction models can be built on only a small number (30 or fewer) of important variables and provide robust concentration estimates. Model estimates are freely available online

Comparison of bacterial genome assembly software for MinION data and their applicability to medical microbiology.

Translating the Oxford Nanopore MinION sequencing technology into medical microbiology requires on-going analysis that keeps pace with technological improvements to the instrument and release of associated analysis software. Here, we use a multidrug-resistant Enterobacter kobei isolate as a model organism to compare open source software for the assembly of genome data, and relate this to the time taken to generate actionable information. Three software tools (PBcR, Canu and miniasm) were used to assemble MinION data and a fourth (SPAdes) was used to combine MinION and Illumina data to produce a hybrid assembly. All four had a similar number of contigs and were more contiguous than the assembly using Illumina data alone, with SPAdes producing a single chromosomal contig. Evaluation of the four assemblies to represent the genome structure revealed a single large inversion in the SPAdes assembly, which also incorrectly integrated a plasmid into the chromosomal contig. Almost 50 %, 80 % and 90 % of MinION pass reads were generated in the first 6, 9 and 12 h, respectively. Using data from the first 6 h alone led to a less accurate, fragmented assembly, but data from the first 9 or 12 h generated similar assemblies to that from 48 h sequencing. Assemblies were generated in 2 h using Canu, indicating that going from isolate to assembled data is possible in less than 48 h. MinION data identified that genes responsible for resistance were carried by two plasmids encoding resistance to carbapenem and to sulphonamides, rifampicin and aminoglycosides, respectively.Health Innovation Challenge Fund (WT098600, HICF-T5-342) (Department of Health, Wellcome Trust)This is the final version of the article. It first appeared from the Microbiology Society via http://dx.doi.org/10.1099/mgen.0.00008

57 second oscillations in Nova Centauri 1986 (V842 Cen)

High speed photometry in 2008 shows that the light curve of V842 Cen possesses a coherent modulation at 56.825 s, with sidebands at 56.598 s and 57.054 s. These have appeared since this nova remnant was observed in 2000 and 2002. We deduce that the dominant signal is the rotation period of the white dwarf primary and the sidebands are caused by reprocessing from a surface moving with an orbital period of 3.94 h. Thus V842 Cen is an intermediate polar (IP) of the DQ Herculis subclass, is the fastest rotating white dwarf among the IPs and is the third fastest known in a cataclysmic variable. As in other IPs we see no dwarf nova oscillations, but there are often quasi-periodic oscillations in the range 350 - 1500 s. There is a strong brightness modulation with a period of 3.78 h, which we attribute to negative superhumps, and there is an even stronger signal at 2.886 h which is of unknown origin but is probably a further example of that seen in GW Lib and some other systems. We used the Swift satellite to observe V842 Cen in the ultra-violet and in X-rays, although no periodic modulation was detected in the short observations. The X-ray luminosity of this object appears to be much lower than that of other IPs in which the accretion region is directly visible.Comment: 6 pages, 10 figures, accepted for publication in MNRA

At the horizon of a supersymmetric AdS_5 black hole: Isometries and half-BPS giants

The near-horizon geometry of an asymptotically AdS_5 supersymmetric black hole discovered by Gutowski and Reall is analysed. After lifting the solution to 10 dimensions, we explicitly solve the Killing spinor equations in both Poincare and global coordinates. It is found that exactly four supersymmetries are preserved which is twice the number for the full black hole. The full set of isometries is constructed and the isometry supergroup is shown to be SU(1,1|1) X SU(2) X U(3). We further study half-BPS configurations of D3-branes in the near-horizon geometry in Poincare and global coordinates. Both giant graviton probes and dual giant graviton probes are found.Comment: 26 pages. v2:Typos corrected, minor change

Adoptive immunotherapy of cancer with polyclonal, 10(8)-fold hyperexpanded, CD4(+ )and CD8(+ )T cells

T cell-mediated cancer immunotherapy is dose dependent and optimally requires participation of antigen-specific CD4(+ )and CD8(+ )T cells. Here, we isolated tumor-sensitized T cells and activated them in vitro using conditions that led to greater than 10(8)-fold numerical hyperexpansion of either the CD4(+ )or CD8(+ )subset while retaining their capacity for in vivo therapeutic efficacy. Murine tumor-draining lymph node (TDLN) cells were segregated to purify the CD62L(low )subset, or the CD4(+ )subset thereof. Cells were then propagated through multiple cycles of anti-CD3 activation with IL-2 + IL-7 for the CD8(+ )subset, or IL-7 + IL-23 for the CD4(+ )subset. A broad repertoire of TCR Vβ families was maintained throughout hyperexpansion, which was similar to the starting population. Adoptive transfer of hyper-expanded CD8(+ )T cells eliminated established pulmonary metastases, in an immunologically specific fashion without the requirement for adjunct IL-2. Hyper-expanded CD4(+ )T cells cured established tumors in intracranial or subcutaneous sites that were not susceptible to CD8(+ )T cells alone. Because accessibility and antigen presentation within metastases varies according to anatomic site, maintenance of a broad repertoire of both CD4(+ )and CD8(+ )T effector cells will augment the overall systemic efficacy of adoptive immunotherapy

Gamma-ray bursts: Restarting the Engine

Recent gamma-ray burst observations have revealed late-time, highly energetic events which deviate from the simplest expectations of the standard fireball picture. Instead they may indicate that the central engine is active or restarted at late times. We suggest that fragmentation and subsequent accretion during the collapse of a rapidly rotating stellar core offers a natural mechanism for this.Comment: 8 pages, 1 figure; accepted by ApJ Letter

3D-nanoprinted on-chip antiresonant waveguide with hollow core and microgaps for integrated optofluidic spectroscopy

Here, we unlock the properties of the recently introduced on-chip hollow-core microgap waveguide in the context of optofluidics which allows for intense light-water interaction over long lengths with fast response times. The nanoprinted waveguide operates by the antiresonance effect in the visible and near-infrared domain and includes a hollow core with defined gaps every 176 µm. The spectroscopic capabilities are demonstrated by various absorption-related experiments, showing that the Beer-Lambert law can be applied without any modification. In addition to revealing key performance parameters, time-resolved experiments showed a decisive improvement in diffusion times resulting from the lateral access provided by the microgaps. Overall, the microgap waveguide represents a pathway for on-chip spectroscopy in aqueous environments