15 research outputs found
The Brazilian Tunable Filter Imager for the SOAR telescope
This paper presents a new Tunable Filter Instrument for the SOAR telescope.
The Brazilian Tunable Filter Imager (BTFI) is a versatile, new technology,
tunable optical imager to be used in seeing-limited mode and at higher spatial
fidelity using the SAM Ground-Layer Adaptive Optics facility at the SOAR
telescope. The instrument opens important new science capabilities for the SOAR
community, from studies of the centers of nearby galaxies and the insterstellar
medium to statistical cosmological investigations. The BTFI takes advantage of
three new technologies. The imaging Bragg Tunable Filter concept utilizes
Volume Phase Holographic Gratings in a double-pass configuration, as a tunable
filter, while a new Fabry-Perot (FP) concept involves technologies which allow
a single FP etalon to act over a large range of interference orders and
spectral resolutions. Both technologies will be in the same instrument.
Spectral resolutions spanning the range between 25 and 30,000 can be achieved
through the use of iBTF at low resolution and scanning FPs beyond R ~2,000. The
third new technologies in BTFI is the use of EMCCDs for rapid and cyclically
wavelength scanning thus mitigating the damaging effect of atmospheric
variability through data acquisition. An additional important feature of the
instrument is that it has two optical channels which allow for the simultaneous
recording of the narrow-band, filtered image with the remaining (complementary)
broad-band light. This avoids the uncertainties inherent in tunable filter
imaging using a single detector. The system was designed to supply tunable
filter imaging with a field-of-view of 3 arcmin on a side, sampled at 0.12" for
direct Nasmyth seeing-limited area spectroscopy and for SAM's visitor
instrument port for GLAO-fed area spectroscopy. The instrument has seen first
light, as a SOAR visitor instrument. It is now in comissioning phase.Comment: accepted in PAS
Une approche pluridisciplinaire du processus de construction sociale de la prévention du risque CMR en entreprise -Rapport de synthèse de la recherche financée par l'Association de Recherche contre le Cancer (ARC)
The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study
AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease
Scheduling Twin Yard Cranes in a Container Block
Annually, millions of containers enter and exit the stacking area of a terminal. If the stacking operations are not efficient, long ship, train, and truck delays will result. To improve the stacking operations, new container terminals, especially in Europe, decouple the landside and seaside by deploying twin automated stacking cranes. The cranes cannot pass each other and must be separated by a safety distance. We study how to schedule twin automated cranes to carry out a set of container storage and retrieval requests in a single block of a yard. Storage containers are initially located at the seaside and landside input/output (I/O) points of the block. Each must be stacked in a specific location of the block, selected from a set of open locations suitable for stacking the storage container. Retrieval containers are initially located in the block and must be delivered to the I/O points. Based on the importance and acceptable waiting times of different modes of transport, requests have different priorities. The problem is modeled as a multiple asymmetric generalized traveling salesman problem with precedence constraints. The objective is to minimize the makespan. We have developed an adaptive large neighborhood search heuristic to quickly compute near-optimal solutions. We have performed extensive computational experiments to assess the performance of the heuristic including validation at a real terminal. It obtains near-optimal solutions for small instances. For large instances, it is shown to yield better solutions than CPLEX truncated after four hours, and it outperforms other heuristics from practice by more than 24% in terms of makespan. The average gaps between our heuristic and optimal solutions for relaxed problems are less than 3%
A Yard Crane Scheduling Problem with Practical Constraints
The problem considered in this paper is to locate storage containers while a set of container storage and retrieval requests are sequenced. Two automated cranes stack and retrieve containers in a single block of a yard. The cranes cannot pass each other and must be separated by a safety distance. Storage containers are initially located at the seaside and land side input/output (I/O) points of the block. Each must be stacked in a specific location of the block, selected from a set of open locations suitable for stacking the storage container. Retrieval containers are initially located in the block and must be delivered to the I/O points. Due to the importance and acceptable waiting times of different modes of transport, requests have different priorities. The problem is modeled as a multiple asymmetric generalized traveling salesman problem with precedence constraints. The objective is to minimize the make span. We have developed an adaptive large neighborhood search heuristic to quickly compute near-optimal solutions. The numerical experiments show that the solution method can obtain near-optimal solutions
HIGH SERUM LONG-CHAIN OMEGA-3 FATTY ACIDS ARE ASSOCIATED WITH 6-MONTHLOWER DISEASE ACTIVITY IN EARLY RA: RESULTS FROM THE ESPOIR COHORT
International audienc
Low-Temperature Preparation of Tailored Carbon Nanostructures in Water
The development of low-temperature carbonization procedures promises to provide novel nanostructured carbon materials that are of high current interest in materials science and technology. Here, we report a "wet-chemical" carbonization method that utilizes hexayne amphiphiles as metastable carbon precursors. Nearly perfect control of the nanoscopic morphology was achieved by self-assembly of the precursors into colloidal aggregates with tailored diameter in water. Subsequent carbonization furnished carbon nanocapsules with a carbon microstructure resembling graphite-like amorphous carbon materials
Additional file 1: of Evaluation of a risk-stratification strategy to improve primary care for low back pain: the MATCH cluster randomized trial protocol
Non-specific Back Pain Assessment, Management, and Follow-up Guideline. (DOCX 176 kb