331 research outputs found
A systematic approach to the Planck LFI end-to-end test and its application to the DPC Level 1 pipeline
The Level 1 of the Planck LFI Data Processing Centre (DPC) is devoted to the
handling of the scientific and housekeeping telemetry. It is a critical
component of the Planck ground segment which has to strictly commit to the
project schedule to be ready for the launch and flight operations. In order to
guarantee the quality necessary to achieve the objectives of the Planck
mission, the design and development of the Level 1 software has followed the
ESA Software Engineering Standards. A fundamental step in the software life
cycle is the Verification and Validation of the software. The purpose of this
work is to show an example of procedures, test development and analysis
successfully applied to a key software project of an ESA mission. We present
the end-to-end validation tests performed on the Level 1 of the LFI-DPC, by
detailing the methods used and the results obtained. Different approaches have
been used to test the scientific and housekeeping data processing. Scientific
data processing has been tested by injecting signals with known properties
directly into the acquisition electronics, in order to generate a test dataset
of real telemetry data and reproduce as much as possible nominal conditions.
For the HK telemetry processing, validation software have been developed to
inject known parameter values into a set of real housekeeping packets and
perform a comparison with the corresponding timelines generated by the Level 1.
With the proposed validation and verification procedure, where the on-board and
ground processing are viewed as a single pipeline, we demonstrated that the
scientific and housekeeping processing of the Planck-LFI raw data is correct
and meets the project requirements.Comment: 20 pages, 7 figures; this paper is part of the Prelaunch status LFI
papers published on JINST:
http://www.iop.org/EJ/journal/-page=extra.proc5/jins
Observations of Energetic-particle Population Enhancements along Intermittent Structures near the Sun from the Parker Solar Probe
Observations at 1 au have confirmed that enhancements in measured energetic-particle (EP) fluxes are statistically associated with "rough" magnetic fields, i.e., fields with atypically large spatial derivatives or increments, as measured by the Partial Variance of Increments (PVI) method. One way to interpret this observation is as an association of the EPs with trapping or channeling within magnetic flux tubes, possibly near their boundaries. However, it remains unclear whether this association is a transport or local effect; i.e., the particles might have been energized at a distant location, perhaps by shocks or reconnection, or they might experience local energization or re-acceleration. The Parker Solar Probe (PSP), even in its first two orbits, offers a unique opportunity to study this statistical correlation closer to the corona. As a first step, we analyze the separate correlation properties of the EPs measured by the Integrated Science Investigation of the Sun (IS⊙IS) instruments during the first solar encounter. The distribution of time intervals between a specific type of event, i.e., the waiting time, can indicate the nature of the underlying process. We find that the IS⊙IS observations show a power-law distribution of waiting times, indicating a correlated (non-Poisson) distribution. Analysis of low-energy (~15 – 200 keV/nuc) IS⊙IS data suggests that the results are consistent with the 1 au studies, although we find hints of some unexpected behavior. A more complete understanding of these statistical distributions will provide valuable insights into the origin and propagation of solar EPs, a picture that should become clear with future PSP orbits
Characteristics of the colorectal cancers diagnosed in the early 2000s in Italy. Figures from the IMPATTO study on colorectal cancer screening
The impact of organized screening programmes on colorectal cancer (CRC) can be observed at a population level only several years after the implementation of screening. We compared CRC characteristics by diagnostic modality (screen-detected, non-screen-detected) as an early outcome to monitor screening programme effectiveness. Data on CRCs diagnosed in Italy from 2000 to 2008 were collected by several cancer registries. Linkage with screening datasets made it possible to divide the cases by geographic area, implementation of screening, and modality of diagnosis (screen-detected, non-screen-detected).We compared the main characteristics of the different subgroups of CRCs through multivariate logistic regression models. The study included 23,668 CRCs diagnosed in subjects aged 50-69 years, of which 11.9%were screendetected (N=2,806), all from the North-Centre of Italy. Among screen-detected CRCs, we observed a higher proportion of males, of cases in the distal colon, and a higher mean age of the patients. Compared with pre-screening cases, screen-detected CRCs showed a better distribution by stage at diagnosis (OR for stage III or IV: 0.40, 95%CI: 0.36-0.44) and grading (OR for poorly differentiated CRCs was 0.86, 95%CI: 0.75-1.00). Screen-detected CRCs have more favourable prognostic characteristics than non-screen-detected cases. A renewed effort to implement screening programmes throughout the entire country is recommended
Genetic correlation between amyotrophic lateral sclerosis and schizophrenia
We have previously shown higher-than-expected rates of schizophrenia in relatives of patients with amyotrophic lateral sclerosis (ALS), suggesting an aetiological relationship between the diseases. Here, we investigate the genetic relationship between ALS and schizophrenia using genome-wide association study data from over 100,000 unique individuals. Using linkage disequilibrium score regression, we estimate the genetic correlation between ALS and schizophrenia to be 14.3% (7.05-21.6; P=1 × 10-4) with schizophrenia polygenic risk scores explaining up to 0.12% of the variance in ALS (P=8.4 × 10-7). A modest increase in comorbidity of ALS and schizophrenia is expected given these findings (odds ratio 1.08-1.26) but this would require very large studies to observe epidemiologically. We identify five potential novel ALS-associated loci using conditional false discovery rate analysis. It is likely that shared neurobiological mechanisms between these two disorders will engender novel hypotheses in future preclinical and clinical studies
On Buchsbaum bundles on quadric hypersurfaces
Let be an indecomposable rank two vector bundle on the projective space
\PP^n, n \ge 3, over an algebraically closed field of characteristic zero. It
is well known that is arithmetically Buchsbaum if and only if and
is a null-correlation bundle. In the present paper we establish an analogous
result for rank two indecomposable arithmetically Buchsbaum vector bundles on
the smooth quadric hypersurface Q_n\subset\PP^{n+1}, . We give in
fact a full classification and prove that must be at most 5. As to
-Buchsbaum rank two vector bundles on , , we prove two
boundedness results.Comment: 22 pages, no figur
No laughing matter: subacute degeneration of the spinal cord due to nitrous oxide inhalation.
BACKGROUND: Whilst the dangers of 'legal highs' have been widely publicised in the media, very few cases of the neurological syndrome associated with the inhalation of nitrous oxide (N2O) have been reported. Here we set out to raise awareness of subacute degeneration of the spinal cord arising from recreational N2O use so that formal surveillance programs and public health interventions can be designed. METHODS: Case series documenting the clinical and investigational features of ten consecutive cases of subacute degeneration of the spinal cord presenting to a hospital with a tertiary neurosciences service in East London. RESULTS: Sensory disturbance in the lower (± upper) limbs was the commonest presenting feature, along with gait abnormalities and sensory ataxia. MRI imaging of the spine showed the characteristic features of dorsal column hyperintensity on T2 weighted sequences. Serum B12 levels may be normal because subacute degeneration of the spinal cord in this situation is triggered by functional rather than absolute B12 deficiency. DISCUSSION: A high index of suspicion is required to prompt appropriate investigation, make the diagnosis and commence treatment early. This is the largest reported series of patients with subacute degeneration of the spinal cord induced by recreational use of N2O. However, the number of patients admitted to hospital likely represents the 'tip of the iceberg', with many less severe presentations remaining undetected. After raising awareness, attention should focus on measuring the extent of the problem, the groups affected, and devising ways to prevent potentially long-term neurological damage
Influenza vaccination for immunocompromised patients: systematic review and meta-analysis from a public health policy perspective.
Immunocompromised patients are vulnerable to severe or complicated influenza infection. Vaccination is widely recommended for this group. This systematic review and meta-analysis assesses influenza vaccination for immunocompromised patients in terms of preventing influenza-like illness and laboratory confirmed influenza, serological response and adverse events
Temporal Evolution of the Solar-Wind Electron Core Density at Solar Minimum by Correlating SWEA Measurements from STEREO A and B
The twin STEREO spacecraft provide a unique tool to study the temporal evolution of the solar-wind properties in the ecliptic since their longitudinal separation increases with time. We derive the characteristic temporal variations at ∼ 1 AU between two different plasma parcels ejected from the same solar source by excluding the spatial variations from our datasets. As part of the onboard IMPACT instrument suite, the SWEA electron experiment provides the solar-wind electron core density at two different heliospheric vantage points. We analyze these density datasets between March and August 2007 and find typical solar minimum conditions. After adjusting for the theoretical time lag between the two spacecraft, we compare the two density datasets. We find that their correlation decreases as the time difference increases between two ejections. The correlation coefficient is about 0.80 for a time lag of a half day and 0.65 for two days. These correlation coefficients from the electron core density are somewhat lower than the ones from the proton bulk velocity obtained in an earlier study, though they are still high enough to consider the solar wind as persistent after two days. These quantitative results reflect the variability of the solar-wind properties in space and time, and they might serve as input for solar-wind models
Solar physics in the 2020s: DKIST, parker solar probe, and solar orbiter as a multi-messenger constellation
The National Science Foundation (NSF) Daniel K. Inouye Solar Telescope
(DKIST) is about to start operations at the summit of Haleakala (Hawaii). DKIST
will join the early science phases of the NASA and ESA Parker Solar Probe and
Solar Orbiter encounter missions. By combining in-situ measurements of the
near-sun plasma environment and detail remote observations of multiple layers
of the Sun, the three observatories form an unprecedented multi-messenger
constellation to study the magnetic connectivity inside the solar system. This
white paper outlines the synergistic science that this multi-messenger suite
enables
Detecção de polissacarídeos neutros em cutícula de fêmeas ingurgitadas de Amblyomma sculptum sensíveis à deltametrina e ao amitraz.
O conhecimento acerca dos mecanismos de resposta de Amblyomma sculptum à exposição a acaricidas utilizados no seu controle, como a deltametrina e o amitraz, é escasso
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