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See detailNear infrared reflectance spectroscopy for estimating soil characteristics valuable in the diagnosis of soil fertility
Genot, Valérie ULg; Colinet, Gilles ULg; Bock, Laurent ULg et al

in Journal of Near Infrared Spectroscopy [=JNRIS] (2011), 19(2), 117-138

Soil fertility diagnostics rely not only upon measurement of available nutrients but also upon the soil’s ability to retain these nutrients. Near-infrared reflectance spectroscopy (NIRS) is a rapid and ... [more ▼]

Soil fertility diagnostics rely not only upon measurement of available nutrients but also upon the soil’s ability to retain these nutrients. Near-infrared reflectance spectroscopy (NIRS) is a rapid and non-destructive analytical technique which allows to simultaneously estimate standard soil characteristics and does not require use of chemicals. Previous studies showed that NIRS could be used in local contexts to predict soil properties. The main goal of our research is to build a methodological framework for the use of NIRS at a more global scale. The specific goals of this study were (i) to identify the best spectra treatment and processing –LOCAL versus GLOBAL regression- methods, (ii) to compare NIRS performances to standard chemical protocols and (iii) to evaluate the ability of NIRS to predict soil total organic carbon (TOC), total Nitrogen (TN), clay content and cationic exchange capacity (CEC) for a wide range of soil conditions. We scanned 1,300 samples representative of main soil types of Wallonia under crop, grassland or forest. Various sample preparations were tested prior to NIRS measurements. The most appropriate options were selected according to ANOVA analysis and multiple means comparisons of the spectra principal components. Fifteen pre-treatments were applied to a calibration set and the prediction accuracy was evaluated for GLOBAL and LOCAL modified partial least square (MPLS) regression models. The LOCAL MPLS calibrations showed very encouraging results for all the studied characteristics. On average, for crop soil samples, the prediction coefficient of variation (CVp) was close to 15% for TOC content, 7% for TN content, and 10% for clay content and CEC. The comparisons of repeatability and reproducibility of both NIRS and standard methods showed that NIRS is as reliable as reference methods. Prediction accuracy and technique repeatability allow the use of NIRS within the framework of the soil fertility evaluation and its replacement of standard protocols. LOCAL MPLS can be applied within global datasets, such as the International global soil spectral library. However, the performance of LOCAL MPLS is linked to the number of similar spectra in the dataset and more standard measurements are needed to characterize the least widespread soils. [less ▲]

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See detailNear Infrared Spectroscopy for Non-Invasive Assessment of Intracranial Haemoglobin Oxygenation in an in Vitro Model of the Calf Head
Pringle, John; Art, Tatiana ULg; Lekeux, Pierre ULg

in Research in Veterinary Science (1998), 65(2), 103-109

An in vitro model of the calf head was used to examine the ability of near infrared spectroscopy (NIRS) to non-invasively determine oxygenation events within the calf head. The brains were removed from 16 ... [more ▼]

An in vitro model of the calf head was used to examine the ability of near infrared spectroscopy (NIRS) to non-invasively determine oxygenation events within the calf head. The brains were removed from 16 calf skulls and replaced with oxygenated dilutions of calf blood that had the oxygen progressively decreased from PO2 > 110 mmHg to < 10 mmHg. Appropriate placement of the lighting source and sensor (optodes) was examined, as were the influences of skull thickness and overlying skin of the skull (including colour). The changes in haemaglobin oxygenation in the model calf head, as observed by NIRS, were highly correlated to PO2 changes in all 16 calf skulls examined (mean r2=0.91, range 0.71 to 0.99). There was a trend for optode positioning to achieve optimal NIRS signals over the middle of the frontal bone in a longitudinal axis and with optodes spaced 4 cm apart, but with the large variation between calf heads this was not shown to be significantly different from other sites tested. The presence of skin over the skull had a significant damping effect on the NIRS signal when compared with the bare skull (P<0.01) but it was not possible to detect a difference in this damping effect between black and white coloured skin. All but the two thickest skulls (13 and 14 mm frontal bone thickness) appeared to allow sufficiently strong NIRS signals of changes in haemoglobin oxygenation. This study showed that NIRS can be used for non-invasive study of oxygenation events within the cranial cavity of calves, and established some guidelines and limitations for its use in this species. [less ▲]

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See detailNear infrared spectroscopy in large animals: optical pathlengh and influence of hair covering and epidemal pigmentation
Pringle, J.; Roberts, C.; Kohl, M. et al

in Veterinary Journal (1999), 158

The effects of epidermal pigmentation and hair covering on the relative transparency of various animal tissues to near infrared (NIR) light were examined, and the pathlengths of NIR light through tissues ... [more ▼]

The effects of epidermal pigmentation and hair covering on the relative transparency of various animal tissues to near infrared (NIR) light were examined, and the pathlengths of NIR light through tissues at four wavelengths in the NIR range were subsequently determined. Black hair covering and black or dark-coloured hooves prevented NIR light from penetration sufficient for conduction of pathlength or NIR spectroscopy measurements. Non-pigmented hair covering of the head did not appear to be a barrier to successful NIR light transmission. Tissues sufficiently transparent to NIR light had the differential pathlength factor (DPF, i.e. the ratio of the observed light pathlength and the geometric light source-detector separation) of NIR light determined by intensity modulated spectroscopy at the wavelengths 744, 806, 834 and 860 nm. Horse gluteal muscles had DPFs of 6.2, 6.2, 6.0, and 5.6, whereas forelimb muscles had DPF of 4.7, 4.4, 4.5 and 3.9 at the respective wavelengths. Sheep heads had DPF of 7.2 +/- 0.3, 5.8 +/- 0.5, 5.5 +/- 0.4 and 4.4 +/- 0.6 (+/- SEM) for the above respective wavelengths, of which the pathlengths all differed significantly from the other, except for between 806 and 834 nm, and 834 and 860 nm. The DPF of horse hooves were 4.8 +/- 0.1, 4.8 +/- 0.1, 4.7 +/- 0.1 and 4.4 +/- 0.1 (SEM) for the above noted wavelengths, of which the pathlength at 744 and 806 nm differed from the pathlength at 860 nm (P>0.05). These results show that NIRS is possible through lighter pigmented hair and epidermal tissues, and provide DPFs of horse feet and muscle and the sheep head that enables quantitative NIRS in these species. [less ▲]

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See detailNear Infrared Spectroscopy of the Normal Bovine Claw
Pringle, John; Uystepruyst, Christophe; Art, Tatiana ULg et al

in Veterinary Journal (1998), 156(2), 155-158

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See detailNear integrable systems
Bogomolny, E.; Dennis, M. R.; Dubertrand, Rémy ULg

in Journal of Physics : A Mathematical & General (2009)

A two-dimensional circular quantum billiard with unusual boundary conditions introduced by Berry and Dennis (2008 J. Phys. A: Math. Theor. 41 135203) is considered in detail. It is demonstrated that most ... [more ▼]

A two-dimensional circular quantum billiard with unusual boundary conditions introduced by Berry and Dennis (2008 J. Phys. A: Math. Theor. 41 135203) is considered in detail. It is demonstrated that most of its eigenfunctions are strongly localized and the corresponding eigenvalues are close to eigenvalues of the circular billiard with Neumann boundary conditions. Deviations from strong localization are also discussed. These results agree well with numerical calculations. [less ▲]

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See detailNear Optimal Closed-Loop Control. Application to Electric Power Systems
Ernst, Damien ULg

Doctoral thesis (2003)

Detailed reference viewed: 56 (18 ULg)
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See detailNear real time assessment of the ionosphere effect on high accuracy GNSS applications which require ambiguity resolution
Lejeune, Sandrine; Warnant, René ULg

in Proceedings of the 2nd COST296 Workshop (2006, October)

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See detailNear real time assessment of the Space Weather effect on navigation based on the DGPS technique
Lejeune, Sandrine; Warnant, René ULg; Barré, Aline et al

Conference (2005)

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See detailNear real-time assessment of the ionospheric effect on navigation based on DGPS corrections
Lejeune, Sandrine; Warnant, René ULg; Barré, Aline et al

in Proceedings of Beacon Satellite Symposium 2004 (2005)

Detailed reference viewed: 13 (1 ULg)
See detailNear real-time evaluation of the EGNOS ionospheric correction at mid-latitude
Bavier, Michaël; Warnant, René ULg; Barré, Aline et al

in Proceedings of Beacon Satellite Symposium 2004 (2005)

Detailed reference viewed: 22 (1 ULg)
See detailNear real-time validation of GPS-TEC using ionosonde TEC at Dourbes
Warnant, René ULg; Nebdi, Hamid; Pottiaux, Eric

Report (2003)

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See detailNear- and mid-infrared colours of star-forming galaxies in European Large Area ISO Survey fields
Vaisanen, Petri; Morel, Thierry ULg; Rowan-Robinson, M. et al

in Monthly Notices of the Royal Astronomical Society (2002), 337

We present J- and K-band near-infrared (near-IR) photometry of a sample of mid-infrared (mid-IR) sources detected by the Infrared Space Observatory (ISO) as part of the European Large Area ISO Survey ... [more ▼]

We present J- and K-band near-infrared (near-IR) photometry of a sample of mid-infrared (mid-IR) sources detected by the Infrared Space Observatory (ISO) as part of the European Large Area ISO Survey (ELAIS) and study their classification and star-forming properties. We have used the Preliminary ELAIS Catalogue for the 6.7-μm (LW2) and 15-μm (LW3) fluxes. All of the high-reliability LW2 sources and 80 per cent of the LW3 sources are identified in the near-IR survey reaching K~ 17.5 mag. The near-IR/mid-IR flux ratios can effectively be used to separate stars from galaxies in mid-IR surveys. The stars detected in our survey region are used to derive a new accurate calibration for the ELAIS ISOCAM data in both the LW2 and LW3 filters. We show that near- to mid-IR colour-colour diagrams can be used to classify galaxies further, as well as to study star formation. The ELAIS ISOCAM survey is found mostly to detect strongly star-forming late-type galaxies, possibly starburst-powered galaxies, and it also picks out obscured active galactic nuclei. The ELAIS galaxies yield an average mid-IR flux ratio LW2/LW3 = 0.67 +/- 0.27. We discuss the f[SUB]ν[/SUB](6.7 μ m)/f[SUB]ν[/SUB](15 μ m) ratio as a star formation tracer using ISO and IRAS data of a local comparison sample. We find that the f[SUB]ν[/SUB](2.2 μ m)/f[SUB]ν[/SUB](15 μ m) ratio is also a good indicator of activity level in galaxies and conclude that the drop in the f[SUB]ν[/SUB](6.7 μ m)/f[SUB]ν[/SUB](15 μ m) ratio seen in strongly star-forming galaxies is a result of both an increase of 15-μm emission and an apparent depletion of 6.7-μm emission. Near-IR together with the mid-IR data make it possible to estimate the relative amount of interstellar matter in the galaxies. [less ▲]

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See detailNear-Death Experiences : Real or imagined memories?
Thonnard, Marie ULg; Laureys, Steven ULg; Brédart, Serge ULg et al

Poster (2010, September)

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See detailNear-death experiences in non-life-threatening events and coma of different etiologies.
Charland-Verville, Vanessa ULg; Jourdan, Jean-Pierre; Thonnard, Marie ULg et al

Poster (2014, September 16)

Near death experiences (NDEs) are increasingly being reported as a clearly identifiable physiological and psychological reality of clinical significance. Empirical studies of NDEs have mostly been ... [more ▼]

Near death experiences (NDEs) are increasingly being reported as a clearly identifiable physiological and psychological reality of clinical significance. Empirical studies of NDEs have mostly been conducted in patients with life threatening situations such as cardiac arrest [1-5] or (albeit more rarely) in patients with severe traumatic brain injury[6]. To the best of our knowledge, no study has formally compared the influence of the cause of coma to the intensity or content of the NDE. Using the Greyson NDE scale [7], the present retrospective study aimed at: (1) exploring the NDE intensity and content in “NDE-like” accounts following non-life-threatening events versus “real NDE” following coma; (2) comparing the “real NDE” characteristics according to the etiology of the brain damage (anoxic, traumatic or other) and; (3) comparing our retrospectively obtained data in anoxic coma to historical previously published prospectively collected post-anoxic NDEs. [less ▲]

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See detailNear-death experiences in non-life-threatening events and coma of different etiologies.
Charland-Verville, Vanessa ULg; Jourdan, Jean-Pierre; Thonnard, Marie ULg et al

in Frontiers in human neuroscience (2014), 8(203),

BACKGROUND: Near death experiences (NDEs) are increasingly being reported as a clearly identifiable physiological and psychological reality of clinical significance. However, the definition and causes of ... [more ▼]

BACKGROUND: Near death experiences (NDEs) are increasingly being reported as a clearly identifiable physiological and psychological reality of clinical significance. However, the definition and causes of the phenomenon as well as the identification of NDE experiencers is still a matter of debate. To date, the most widely used standardized tool to identify and characterize NDEs in research is the Greyson NDE scale. Using this scale, retrospective and prospective studies have been trying to estimate their incidence in various populations but few studies have attempted to associate the experiences' intensity and content to etiology. METHODS: This retrospective investigation assessed the intensity and the most frequently recounted features of self-reported NDEs after a non-life-threatening event (i.e., "NDE-like" experience) or after a pathological coma (i.e., "real NDE") and according to the etiology of the acute brain insult. We also compared our retrospectively acquired data in anoxic coma with historical data from the published literature on prospective post-anoxic studies using the Greyson NDE scale. RESULTS: From our 190 reports who met the criteria for NDE (i.e., Greyson NDE scale total score >7/32), intensity (i.e., Greyson NDE scale total score) and content (i.e., Greyson NDE scale features) did not differ between "NDE-like" (n = 50) and "real NDE" (n = 140) groups, nor within the "real NDE" group depending on the cause of coma (anoxic/traumatic/other). The most frequently reported feature was peacefulness (89-93%). Only 2 patients (1%) recounted a negative experience. The overall NDE core features' frequencies were higher in our retrospective anoxic cohort when compared to historical published prospective data. CONCLUSIONS: It appears that "real NDEs" after coma of different etiologies are similar to "NDE-like" experiences occurring after non-life threatening events. Subjects reporting NDEs retrospectively tend to have experienced a different content compared to the prospective experiencers. [less ▲]

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See detailNEAR-DEATH EXPERIENCES IN PATIENTS WITH LOCKED-IN SYNDROME
Charland-Verville, Vanessa ULg; Lugo Ramirez, Zulay del Rosario ULg; Jourdan, Jean-Pierre et al

Poster (2014, October 04)

Near-Death Experiences (NDEs) are classically associated with positive emotions like peacefulness, happiness and joy [1-3]. To date, few negative NDEs reports have been documented [4]. Although NDEs ... [more ▼]

Near-Death Experiences (NDEs) are classically associated with positive emotions like peacefulness, happiness and joy [1-3]. To date, few negative NDEs reports have been documented [4]. Although NDEs classically arise in the context of an acute severe brain damage, their associated memories are reported as being phenomenologically very rich and detailed [5]. To date, no satisfactory explanatory model exits to fully account for the rich phenomenology of NDEs following a severe acute brain injury [6]. Neurobiological hypotheses include cerebral hypoxia [7, 8] and temporal lobe dysfunctions [9] to account for some of the features occurring during NDEs. However, it has been recently shown that anoxic/hypoxic, traumatic and other supratentorial brain lesions do not seem to influence the content of a NDE when assessed with a standardized tool (i.e., Greyson NDE scale; [1]). Due to their particular brain lesion (i.e., pontine brainstem), locked-in syndrome (LIS) patients provide a unique opportunity to further investigate the neural correlates of NDEs. We here aimed at retrospectively characterizing the content of NDEs in patients with LIS having suffered from an acute brainstem lesion (cerebrovascular accident (CVA) or trauma; i.e., “LIS NDEs”) and to compare these experiences to those collected in a cohort of matched NDE experiencers after coma with supratentorial lesions (CVA or trauma; i.e., “classical NDEs”). [less ▲]

Detailed reference viewed: 139 (6 ULg)