The SPARC tokamak is a critical next step towards commercial fusion energy. SPARC is designed as a high-field ($B_0 = 12.2$ T), compact ($R_0 = 1.85$ m, $a = 0.57$ m), superconducting, D-T tokamak with the goal of producing fusion gain $Q>2$ from a magnetically confined fusion plasma for the first time. Currently under design, SPARC will continue the high-field path of the Alcator series of tokamaks, utilizing new magnets based on rare earth barium copper oxide high-temperature superconductors to achieve high performance in a compact device. The goal of $Q>2$ is achievable with conservative physics assumptions ($H_{98,y2} = 0.7$) and, with the nominal assumption of $H_{98,y2} = 1$, SPARC is projected to attain $Q \approx 11$ and $P_{\textrm {fusion}} \approx 140$ MW. SPARC will therefore constitute a unique platform for burning plasma physics research with high density ($\langle n_{e} \rangle \approx 3 \times 10^{20}\ \textrm {m}^{-3}$), high temperature ($\langle T_e \rangle \approx 7$ keV) and high power density ($P_{\textrm {fusion}}/V_{\textrm {plasma}} \approx 7\ \textrm {MW}\,\textrm {m}^{-3}$) relevant to fusion power plants. SPARC's place in the path to commercial fusion energy, its parameters and the current status of SPARC design work are presented. This work also describes the basis for global performance projections and summarizes some of the physics analysis that is presented in greater detail in the companion articles of this collection.

Space Infrared Telescope for Cosmology and Astrophysics (SPICA), the cryogenic infrared space telescope recently pre-selected for a ‘Phase A’ concept study as one of the three remaining candidates for European Space Agency (ESA's) fifth medium class (M5) mission, is foreseen to include a far-infrared polarimetric imager [SPICA-POL, now called B-fields with BOlometers and Polarizers (B-BOP)], which would offer a unique opportunity to resolve major issues in our understanding of the nearby, cold magnetised Universe. This paper presents an overview of the main science drivers for B-BOP, including high dynamic range polarimetric imaging of the cold interstellar medium (ISM) in both our Milky Way and nearby galaxies. Thanks to a cooled telescope, B-BOP will deliver wide-field 100–350 $\mu$ m images of linearly polarised dust emission in Stokes Q and U with a resolution, signal-to-noise ratio, and both intensity and spatial dynamic ranges comparable to those achieved by Herschel images of the cold ISM in total intensity (Stokes I). The B-BOP 200 $\mu$ m images will also have a factor $\sim $ 30 higher resolution than Planck polarisation data. This will make B-BOP a unique tool for characterising the statistical properties of the magnetised ISM and probing the role of magnetic fields in the formation and evolution of the interstellar web of dusty molecular filaments giving birth to most stars in our Galaxy. B-BOP will also be a powerful instrument for studying the magnetism of nearby galaxies and testing Galactic dynamo models, constraining the physics of dust grain alignment, informing the problem of the interaction of cosmic rays with molecular clouds, tracing magnetic fields in the inner layers of protoplanetary disks, and monitoring accretion bursts in embedded protostars.

The ALMA twenty-six arcmin2 survey of GOODS-S at one millimeter (ASAGAO) is a deep (1σ ∼ 61μJy/beam) and wide area (26 arcmin2) survey on a contiguous field at 1.2 mm. By combining with archival data, we obtained a deeper map in the same region (1σ ∼ 30μJy/beam−1, synthesized beam size 0.59″ × 0.53″), providing the largest sample of sources (25 sources at 5σ, 45 sources at 4.5σ) among ALMA blank-field surveys. The median redshift of the 4.5σ sources is 2.4. The number counts shows that 52% of the extragalactic background light at 1.2 mm is resolved into discrete sources. We create IR luminosity functions (LFs) at z = 1–3, and constrain the faintest luminosity of the LF at 2 < z < 3. The LFs are consistent with previous results based on other ALMA and SCUBA-2 observations, which suggests a positive luminosity evolution and negative density evolution.

A critical question in invasion biology involves the relative importance of propagule rain and community invasibility. For plant invasions, invasibility is often related to disturbance, but few studies of forest invaders have simultaneously investigated both canopy and ground-level disturbance. We investigated the relative importance of seed rain, canopy disturbance, and soil disturbance in a mature forest in Maryland on the recruitment of four invasive species: wine raspberry (Rubus phoenicolasius Maxim.), Japanese barberry (Berberis thunbergii DC), multiflora rose (Rosa multiflora Thunb.), and Japanese stiltgrass [Microstegium vimineum (Trin.) A. Camus]. Using complete censuses of a 9-ha plot at two points in time (2011–12 and 2014), we mapped new recruits, and related their locations to canopy and soil disturbance, as well as to a seed rain index based on locations of reproducing plants and seed-dispersal kernels.

We found that propagule rain, as measured by the seed rain index, was a significant predictor of recruitment for B. thunbergii, R. phoenicolasius, and M. vimineum. For R. multiflora, seed sources were not located, precluding assessment of propagule rain, but recruitment was linked to canopy disturbance, as was recruitment of M. vimineum. However, because reproduction of R. phoenicolasius and, in some years, of B. thunbergii is higher in treefall gaps, these gaps experience higher propagule rain, with the result that recruitment is indirectly associated with these gaps. Ground-layer disturbance was an important predictor of recruitment only for B. thunbergii. Our findings reveal that the importance of propagule rain is the most consistent driver of recruitment, but canopy or ground-layer disturbance promotes recruitment of some invasive plant species.

Introduction: Emergency Department Overcrowding (EDOC) is a multifactorial issue that leads to Access Block for patients needing emergency care. Identified as a national problem, patients presenting to a Canadian Emergency Department (ED) at a time of overcrowding have higher rates of admission to hospital and increased seven-day mortality. Using the well accepted input-throughput-output model to study EDOC, current research has focused on throughput as a measure of patient flow, reported as ED length of stay (LOS). In fact, ED LOS and ED beds occupied by inpatients are two “extremely important indicators of EDOC identified by a 2005 survey of Canadian ED directors. One proposed solution to improve ED throughput is to utilize a physician at triage (PAT) to rapidly assess newly arriving patients. In 2017, a pilot PAT program was trialed at Kelowna General Hospital (KGH), a tertiary care hospital, as part of a PDSA cycle. The aim was to mitigate EDOC by improving ED throughput by the end of 2018, to meet the national targets for ED LOS suggested in the 2013 CAEP position statement. Methods: During the fiscal periods 1-6 (April 1 to September 7, 2017) a PAT shift occurred daily from 1000-2200, over four long weekends. ED LOS, time to inpatient bed, time to physician initial assessment (PIA), number of British Columbia Ambulance Service (BCAS) offload delays, and number of patients who left without being seen (LWBS) were extracted from an administrative database. Results were retrospectively analyzed and compared to data from 1000-2200 of non-PAT trial days during the trial periods. Results: Median ED LOS decreased from 3.8 to 3.4 hours for high-acuity patients (CTAS 1-3), from 2.1 to 1.8 hours for low-acuity patients (CTAS 4-5), and from 9.3 to 8.0 hours for all admitted patients. During PAT trial weekends, there was a decrease in the average time to PIA by 65% (from 73 to 26 minutes for CTAS 2-5), average number of daily BCAS offload delays by 39% (from 2.3 to 1.4 delays per day), and number of patients who LWBS from 2.4% to 1.7%. Conclusion: The implementation of PAT was associated with improvements in all five measures of ED throughput, providing a potential solution for EDOC at KGH. ED LOS was reduced compared to non-PAT control days, successfully meeting the suggested national targets. PAT could improve efficiency, resulting in the ability to see more patients in the ED, and increase the quality and safety of ED practice. Next, we hope to prospectively evaluate PAT, continuing to analyze these process measures, perform a cost-benefit analysis, and formally assess ED staff and patient perceptions of the program.

We have assembled a new sample of some of the most FIR-luminous galaxies in the Universe and have imaged them in 1.1 mm dust emission and measured their redshifts 1 < z < 4 via CO emission lines using the 32-m Large Millimeter Telescope / Gran Telescopio Milimétrico (LMT/GTM). Our sample of 31 submm galaxies (SMGs), culled from the Planck and Herschel all-sky surveys, includes 14 of the 21 most luminous galaxies known, with LFIR > 1014 L ⊙ and SFR > 104M⊙/yr. These extreme inferred luminosities – and multiple / extended 1.1 mm images – imply that most or all are strongly gravitationally lensed, with typical magnification μ ~ 10 × . The gravitational lensing provides two significant benefits: (1) it boosts the S/N, and (2) it allows investigation of star formation and gas processes on sub-kpc scales.

DX Cha (HD 104237) is a southern, optically bright Herbig Ae star with an infrared excess, that is part of a small stellar group younger than 5 Myr. We used the APEX and ASTE submillimeter telescopes in Chile to search for continuum and gas emission around this system. Using LABOCA on APEX we detect strong continuum emission around HD104237-A and system component HD104237-E. Our ASTE spectrum detects a double-peaked 12CO(3-2) line profile towards the system, typical of a rotating disk. The new data are used as constraints with MCFOST to produce a disk model that fits the entire SED as well as the observed CO line profile.

The protozoan parasite Toxoplasma gondii is prevalent worldwide and can infect a remarkably wide range of hosts despite felids being the only definitive host. As cats play a major role in transmission to secondary mammalian hosts, the interaction between cats and these hosts should be a major factor determining final prevalence in the secondary host. This study investigates the prevalence of T. gondii in a natural population of Apodemus sylvaticus collected from an area with low cat density (<2·5 cats/km2). A surprisingly high prevalence of 40·78% (95% CI: 34·07%–47·79%) was observed despite this. A comparable level of prevalence was observed in a previously published study using the same approaches where a prevalence of 59% (95% CI: 50·13%–67·87%) was observed in a natural population of Mus domesticus from an area with high cat density (>500 cats/km2). Detection of infected foetuses from pregnant dams in both populations suggests that congenital transmission may enable persistence of infection in the absence of cats. The prevalences of the related parasite, Neospora caninum were found to be low in both populations (A. sylvaticus: 3·39% (95% CI: 0·12%–6·66%); M. domesticus: 3·08% (95% CI: 0·11%–6·05%)). These results suggest that cat density may have a lower than expected effect on final prevalence in these ecosystems.

We present new, wide, and deep images in the AzTEC/ASTE 1.1 mm continuum and the 12 CO (J = 1–0) emission toward the northern part of the Orion-A GMC. We have found evidence for interactions between molecular clouds and the external forces that may trigger star formation. Two types of possible triggers were revealed: (1) Collisions of the diffuse gas on the cloud surface, particularly at the eastern side of the OMC-2/3 region, and (2) Irradiation of UV on the pre-existing filaments and dense molecular cloud cores. Our wide-field and high-sensitivity imaging has provided the first comprehensive view of the potential sites of triggered star formation in the Orion-A GMC.