521 research outputs found
Processing 3D form and 3D motion: Respective contributions of attention-based and stimulus-driven activity
International audienceThis study aims at segregating the neural substrate for the 3D-form and 3D-motion attributes in structure-from-motion perception, and at disentangling the stimulus-driven and endogenous-attention-driven processing of these attributes. Attention and stimulus were manipulated independently: participants had to detect the transitions of one attribute âform, 3D motion or colourâ while the visual stimulus underwent successive transitions of all attributes. We compared the BOLD activity related to form and 3D motion in three conditions: stimulus-driven processing (unattended transitions), endogenous attentional selection (task) or both stimulus-driven processing and attentional selection (attended transitions). In all conditions, the form versus 3D-motion contrasts revealed a clear dorsal/ventral segregation. However, while the form-related activity is consistent with previously described shape-selective areas, the activity related to 3D motion does not encompass the usual âvisual motionâ areas, but rather corresponds to a high-level motion system, including IPL and STS areas. Second, we found a dissociation between the neural processing of unattended attributes and that involved in endogenous attentional selection. Areas selective for 3D-motion and form showed either increased activity at transitions of these respective attributes or decreased activity when subjectsâ attention was directed to a competing attribute. We propose that both facilitatory and suppressive mechanisms of attribute selection are involved depending on the conditions driving this selection. Therefore, attentional selection is not limited to an increased activity in areas processing stimulus properties, and may unveil different functional localization from stimulus modulation
Towards the Opening of a Magnetic Observatory at Dome C (Antarctica)
The opening of a new magnetic observatory is one of the activities aimed at by the creation of a scientific base at DomeC, Antarctica (lat. 75° 06âS, long. 123° 21âE, elev. 3200m). There are many reasons supporting this objective: all Antarctic magnetic observatories providing absolute values are located along the shore and are therefore subject to coast effects and crustal field contamination. DomeC and Vostok will be so far the sole observatories free from these effects. On one hand, high latitude absolute observatories are very useful to global or regional modeling based upon satellite data, because, at high latitudes, only total field measurements can be used due to the strong influence of field aligned currents. On the other hand, the availability of magnetic data from the well distributed observatories of Terra Nova Bay (TNB), Scott Base (SBA), Dumont dâUrville (DRV), Casey (CSY) and Vostok (VOS) will provide strong support to auroral and polar cap ionosphere studies as well as asymmetry analyses between Northern and Southern hemispheres. This paper summarizes the results gathered during three summer campaigns, in 1999-2000, 2001 and 2003-2004
Angiostrongylus cantonensis DNA in cerebrospinal fluid of persons with eosinophilic meningitis, Laos
Definitive identification of Angiostrongylus cantonensis parasites from clinical specimens is difficult. As a result, regional epidemiology and burden are poorly characterized. To ascertain presence of this parasite in patients in Laos with eosinophilic meningitis, we performed quantitative PCRs on 36 cerebrospinal fluid samples; 4 positive samples confirmed the parasite's presence
Status of the âMangrove tunicateâ Ecteinascidia turbinata (Ascidiacea: Perophoridae) in the Mediterranean Sea
The ascidian Ecteinascidia turbinata is reported from Maltese waters for the first time. Mature colonies were recorded on artificial substrata at two different sites (and on natural substrata at one of these), 4 km apart, during the summer months. The appearance of this ascidian is expected to be seasonal as the winter temperature in Malta may fall below that required for the maintenance of zooid growth. A second species, E. moorei, which was described in 1890 is here confirmed to be the same as E. turbinata, meaning that the species has existed in the Mediterranean since at least ~1880. The possibility that the Mediterranean population is a relic one from warmer periods cannot yet be excluded, so it is best described as being cryptogenic. The species appears to be spreading slowly, perhaps as a result of the rise in surface sea temperature. The Maltese sites offer an opportunity to monitor the species as they are accessible dive sites. This will allow assessment of whether this species remains restricted to these sites, or if it spreads perhaps to impact other species
Pre-cut filter paper for detecting anti-Japanese encephalitis virus IgM from dried cerebrospinal fluid spots
Background The use of filter paper as a simple, inexpensive tool for storage and transportation of blood, 'Dried Blood Spots' or Guthrie cards, for diagnostic assays is well-established. In contrast, there are a paucity of diagnostic evaluations of dried cerebrospinal fluid (CSF) spots. These have potential applications in low-resource settings, such as Laos, where laboratory facilities for central nervous system (CNS) diagnostics are only available in Vientiane. In Laos, a major cause of CNS infection is Japanese encephalitis virus (JEV). We aimed to develop a dried CSF spot protocol and to evaluate its diagnostic performance using the World Health Organisation recommended anti-JEV IgM antibody capture enzyme-linked immunosorbent assay (JEV MAC-ELISA). Methodology and Principal Findings Sample volumes, spotting techniques and filter paper type were evaluated using a CSF-substitute of anti-JEV IgM positive serum diluted in Phosphate Buffer Solution (PBS) to end-limits of detection by JEV MAC-ELISA. A conventional protocol, involving eluting one paper punch in 200 mu l PBS, did not detect the end-dilution, nor did multiple punches utilising diverse spotting techniques. However, pre-cut filter paper enabled saturation with five times the volume of CSF-substitute, sufficiently improving sensitivity to detect the end-dilution. The diagnostic accuracy of this optimised protocol was compared with routine, neat CSF in a pilot, retrospective study of JEV MAC-ELISA on consecutive CSF samples, collected 2009-15, from three Lao hospitals. In comparison to neat CSF, 132 CSF samples stored as dried CSF spots for one month at 25-30 degrees C showed 81.6%(65.7-92.3 95%CI) positive agreement, 96.8% (91.0-99.3 95% CI) negative agreement, with a kappa coefficient of 0.81 (0.70-0.92 95% CI). Conclusions/Significance The novel design of pre-cut filter paper saturated with CSF could provide a useful tool for JEV diagnostics in settings with limited laboratory access. It has the potential to improve national JEV surveillance and inform vaccination policies. The saturation of filter paper has potential use in the wider context of pathogen detection, including dried spots for detecting other analytes in CSF, and other body fluids
On two-dimensional Bessel functions
The general properties of two-dimensional generalized Bessel functions are
discussed. Various asymptotic approximations are derived and applied to analyze
the basic structure of the two-dimensional Bessel functions as well as their
nodal lines.Comment: 25 pages, 17 figure
Development of a short form of Mini-Mental State Examination for the screening of dementia in older adults with a memory complaint: a case control study
<p>Abstract</p> <p>Background</p> <p>Primary care physicians need a brief and accurate screening test of dementia. The objective of this study was to determine whether a short form of Mini-Mental State Examination (SMMSE) was as accurate as the Mini-Mental State Examination (MMSE) in screening dementia.</p> <p>Methods</p> <p>Based on case control design study, SMMSE and MMSE were assessed in 184 community-dwelling older adults (mean age 81.3 ± 6.5 years, 71.7% women) with memory complaint sent by their primary care physician to a memory clinic. Included participants were separated into two groups: cognitively healthy individuals and demented individuals.</p> <p>Results</p> <p>The trade-off between sensitivity and specificity of the SMMSE for clinically diagnosed dementia was 4. Based on the cut-off value †4 for SMMSE and a cut-off value †24 for MMSE, the sensitivity of both tests was similar (89.5% for SMMSE versus 90.0% for MMSE), whereas the specificity, the positive predictive values (PPV) and the negative predictive values (NPV) were higher for SMMSE compared to MMSE (85.4 versus 75.5% for specificity; 95.5% versus 92.8% for PPV; 70.0 versus 68.9 for NPV). The positive and negative Likehood Ratio (LR) of SMMSE were higher than those of MMSE (respectively, 6.1 versus 3.7; 8.1 versus 7.7). In addition, odds ratio (OR) for dementia was higher for the SMMSE compared to the MMSE (OR = 49.8 with 95% confident interval (CI) [18.0; 137.8] versus OR = 28.6 with 95% CI [11.6; 70.3]).</p> <p>Conclusions</p> <p>SMMSE seems to be an efficient short screening test for dementia among community-dwelling older adults with a memory complaint. Further research is needed to confirm its predictive values among unselected primary care older patients.</p
Scintillator-based ion beam profiler for diagnosing laser-accelerated ion beams
Next generation intense, short-pulse laser facilities require new high repetition rate diagnostics for the detection of ionizing radiation. We have designed a new scintillator-based ion beam profiler capable of measuring the ion beam transverse profile for a number of discrete energy ranges. The optical response and emission characteristics of four common plastic scintillators has been investigated for a range of proton energies and fluxes. The scintillator light output (for 1 MeV > Ep < 28 MeV) was found to have a non-linear scaling with proton energy but a linear response to incident flux. Initial measurements with a prototype diagnostic have been successful, although further calibration work is required to characterize the total system response and limitations under the high flux, short pulse duration conditions of a typical high intensity laser-plasma interaction
The contribution of the European Society for Soil Conservation (ESSC) to scientific knowledge, education and sustainability
Soil is an integral component of the global environmental system which supports the quality and diversity of terrestrial life on Earth. Therefore, it is vital to consider the processes and impacts of soil degradation on society, especially on the provision of environmental goods and services, including food security and climate change mitigation and adaptation. Scientific societies devoted to soil science play significant roles in reducing soil degradation and promoting soil conservation by advancing scientific knowledge, education and environmental sustainability.
The ESSC was founded on 4 November 1988, with the aims to:
1.
Support research on soil degradation, soil protection and soil and water conservation.
2.
Provide a network for the exchange of knowledge about soil degradation processes and soil conservation research and practises.
3.
Produce publications on major issues relating to soil degradation and soil and water conservation.
4.
Advise regulators and policy-makers on soil issues, especially soil degradation, protection and conservation.
The societal challenges that can be addressed through better soil protection, advancing knowledge and scientific approaches to soil protection and sustainable management, mean the ESSC embraces the on-going development, application, review and constructive criticism of highly innovative scientific soil conservation methods. In this context, the ESSC analyses and publicizes the roles and functions of soil in natural and human-modified systems and the functional optimization of soils to ensure sustainable environmental protection.
âThe thin layer of soil that forms a patchy covering over the continents controls our own existence and that of every other animal of the landâ (Rachel Carson (1962) in âSilent Springâ).European Society for Soil Conservatio
Orientia, rickettsia, and leptospira pathogens as causes of CNS infections in Laos: a prospective study
Background Scrub typhus (caused by Orientia tsutsugamushi), murine typhus (caused by Rickettsia typhi), and
leptospirosis are common causes of febrile illness in Asia; meningitis and meningoencephalitis are severe
complications. However, scarce data exist for the burden of these pathogens in patients with CNS disease in endemic
countries. Laos is representative of vast economically poor rural areas in Asia with little medical information to guide
public health policy. We assessed whether these pathogens are important causes of CNS infections in Laos.
Methods Between Jan 10, 2003, and Nov 25, 2011, we enrolled 1112 consecutive patients of all ages admitted with CNS
symptoms or signs requiring a lumbar puncture at Mahosot Hospital, Vientiane, Laos. Microbiological examinations
(culture, PCR, and serology) targeted so-called conventional bacterial infections (Streptococcus pneumoniae, Neisseria
meningitidis, Haemophilus infl uenzae, S suis) and O tsutsugamushi, Rickettsia typhi/Rickettsia spp, and Leptospira spp
infections in blood or cerebrospinal fl uid (CSF). We analysed and compared causes and clinical and CSF characteristics
between patient groups.
Findings 1051 (95%) of 1112 patients who presented had CSF available for analysis, of whom 254 (24%) had a CNS
infection attributable to a bacterial or fungal pathogen. 90 (35%) of these 254 infections were caused by O tsutsugamushi,
R typhi/Rickettsia spp, or Leptospira spp. These pathogens were signifi cantly more frequent than conventional bacterial
infections (90/1051 [9%] vs 42/1051 [4%]; p<0·0001) by use of conservative diagnostic defi nitions. CNS infections had
a high mortality (236/876 [27%]), with 18% (13/71) for R typhi/Rickettsia spp, O tsutsugamushi, and Leptospira spp
combined, and 33% (13/39) for conventional bacterial infections (p=0·076).
Interpretation Our data suggest that R typhi/Rickettsia spp, O tsutsugamushi, and Leptospira spp infections are
important causes of CNS infections in Laos. Antibiotics, such as tetracyclines, needed for the treatment of murine
typhus and scrub typhus, are not routinely advised for empirical treatment of CNS infections. These severely neglected infections represent a potentially large proportion of treatable CNS disease burden across vast endemic areas and need more attention
- âŠ