2,580 research outputs found
Time comparison via OTS-2
The time comparisons carried out via OTS-2 between the Technical University Graz (Austria) and the Van Swinden Laboratory Delft (Netherlands) are discussed. The method is based on the use of the synchronization pulse in the TV-frame of the daily evening broadcasting of a French TV-program to Northern Africa. Corrections, as a consequence of changes in the position of the satellite coordinates are applied weekly after reception of satellite coordinates. A description of the method is given as well as some of the particular techniques used in both the participating laboratories. Preliminary results are presented
Space construction system analysis. Part 2: Platform definition
The top level system requirements are summarized and the accompanying conceptual design for an engineering and technology verification platform (ETVP) system is presented. An encompassing statement of the system objectives which drive the system requirements is presented and the major mission and subsystem requirements are described with emphasis on the advanced communications technology mission payload. The platform design is defined and used as a reference configuration for an end to space construction analyses. The preferred construction methods and processes, the important interactions between the platform design and the construction system design and operation, and the technology development efforts required to support the design and space construction of the ETVP are outlined
Super-resolution provided by the arbitrarily strong superlinearity of the blackbody radiation
Blackbody radiation is a fundamental phenomenon in nature, and its explanation by Planck marks a cornerstone in the history of Physics. In this theoretical work, we show that the spectral radiance given by Planck's law is strongly superlinear with temperature, with an arbitrarily large local exponent for decreasing wavelengths. From that scaling analysis, we propose a new concept of super-resolved detection and imaging: if a focused beam of energy is scanned over an object that absorbs and linearly converts that energy into heat, a highly nonlinear thermal radiation response is generated, and its point spread function can be made arbitrarily smaller than the excitation beam focus. Based on a few practical scenarios, we propose to extend the notion of super-resolution beyond its current niche in microscopy to various kinds of excitation beams, a wide range of spatial scales, and a broader diversity of target objects
Complications after pancreatic resection: diagnosis, prevention and management
BACKGROUND: Although mortality after pancreaticoduodenectomy (PD) or distal pancreatectomy (DP) has decreased, morbidity still remains high. The aim of this review article is to present, define, predict, prevent, and manage the main complications after pancreatic resection (PR).
METHODS: A non-systematic literature search on morbidity and mortality after PR was undertaken using the PubMed/MEDLINE and Embase databases.
RESULTS: The main complications after PR are delayed gastric emptying (DGE), pancreatic fistula (PF), and bleeding, as defined by the International Study Group on Pancreatic Surgery. PF occurs in 10% to 15% of patients after PD and in 10% to 30% of patients after DP. The different techniques of pancreatic anastomosis and pancreatic remnant closure do not show significant advantages in the prevention of PF, nor does the perioperative use of somatostatin and its analogues. The trend is for conservative or interventional radiology therapy for PF (with enteral nutrition), which achieves a success rate of approximately 80%. DGE after PD occurs in 20% to 50% of patients. Prophylactic erythromycin may reduce the incidence of DGE. Gastric aspiration with erythromycin is usually effective in one to three weeks. Bleeding (gastrointestinal and intraabdominal) occurs in 4% to 16% of patients after PD and in 2% to 3% of patients after DP. Endovascular treatment can only be used for a haemodynamically stable patient. In cases of haemodynamic instability or associated septic complications, surgical treatment is necessary. In expert centres, the mortality rates can be less than 1% after DP and less than 3% after PD.
CONCLUSION: There is a need for improved strategies to prevent and treat complications after PR
A study on using genetic niching for query optimisation in document retrieval
International audienceThis paper presents a new genetic approach for query optimisation in document retrieval. The main contribution of the paper is to show the effectiveness of the genetic niching technique to reach multiple relevant regions of the document space. Moreover, suitable merging procedures have been proposed in order to improve the retrieval evaluation. Experimental results obtained using a TREC sub-collection indicate that the proposed approach is promising for applications
Effects of dietary zinc oxide and chlortetracycline on nursery pig growth performance
Swine Industry Day, 2014 is known as Swine Day, 2014A total of 240 weaned pigs (PIC 1050; initially 13.4 lb) were used in a 47-d study to
compare the effects of added Zn from zinc oxide (ZnO), alone or in combination with
a low or high dose of chlortetracycline (CTC), on nursery pig performance. Pigs were
allotted to pens at weaning (d 0) and fed a common starter diet with no antimicrobial
for 5 d before the start of the experiment. On d 5, pens of 5 pigs were allotted to 1 of 6
dietary treatments in a randomized complete block design with 8 replications per treatment.
Dietary treatments were arranged in a 2 × 3 factorial with main effects of added
ZnO (0 vs. 2,500 ppm of Zn) and CTC (0, 50, or 400 g/ton). Pigs were fed experimental
diets from d 5 to 26 after weaning followed by a common corn-soybean meal–based
diet without antimicrobial from d 26 to 47. Pigs on the 50 g/ton treatment received
CTC continuously from d 5 to 26; however, to comply with FDA guidelines, CTC was
removed on d 15 from the diets of pigs fed 400 g/ton CTC, then added again from d
16 to 26. All diets contained 110 ppm of Zn from ZnO in the trace mineral premix. No
ZnO × CTC interactions were observed. Pigs fed added ZnO had increased
(P = 0.001) ADG, ADFI, and ending BW during the treatment period but increased
F/G (P = 0.03) from d 26 to 47 when a common diet was fed. Pigs fed CTC had
increased (linear, P < 0.05) ADG, ADFI, and ending BW during the treatment
period as well as a tendency (quadratic, P = 0.08) for improved F/G. Overall (d 5 to
47), pigs fed added ZnO had increased (P < 0.05) ADG and ADFI. Overall, pigs fed
CTC tended to have increased (linear, P = 0.06) ADG and ADFI, but F/G tended
(quadratic, P = 0.07) to decrease then increase as CTC increased. In summary, when
ZnO or CTC were added to the diets, increased ADG and ADFI were observed, but
additional carryover benefits were not evident after these feed additives were removed
from the diets. The benefits of added Zn from ZnO and CTC are additive and could
be included together in diets to get the maximum benefit in growth performance of
weaned pigs
- …
