Déglutition et états de conscience altérée [Swallowing in disorders of consciousness.]

INTRODUCTION: Interest in studying swallowing disorders in patients with altered consciousness has increased over the past decade. Swallowing deficit is frequently encountered in severe brain-injured patients. STATE OF ART: Results of studies have highlighted different factors such as the delay between the injury and the treatment and the level of consciousness of these patients, as well as the presence or not of tracheotomy, which will determine the feasibility of resuming oral feeding. Nowadays, very few valid and sensitive scales can be used to assess swallowing deficit in patients with disorders of consciousness. The Facial Oral Tract Therapy (FOTT) scale is an inter-professional multidisciplinary approach offering a structured way to evaluate and treat patients with swallowing disorders. In contrast with other scales, patients do not have to follow verbal instructions for the FOTT. PERSPECTIVES: This paper presents a review of existing literature on the assessment and management of swallowing disorders in patients with altered state of consciousness, and a description of the FOTT method. CONCLUSION: The FOTT seems to be an interesting assessment and rehabilitation tool for patients with disorders of consciousness. However, clinical studies are needed to confirm the validity and sensitivity of this technique.

Evaluation of the reconstruction limits of a frequency-independent crosshole georadar waveform inversion scheme in the presence of dispersion

Waveform tomographic imaging of crosshole georadar data is a powerful method to investigate the shallow subsurface because of its ability to provide images of pertinent petrophysical parameters with extremely high spatial resolution. All current crosshole georadar waveform inversion strategies are based on the assumption of frequency-independent electromagnetic constitutive parameters. However, in reality, these parameters are known to be frequency-dependent and complex and thus recorded georadar data may show significant dispersive behavior. In this paper, we evaluate synthetically the reconstruction limits of a recently published crosshole georadar waveform inversion scheme in the presence of varying degrees of dielectric dispersion. Our results indicate that, when combined with a source wavelet estimation procedure that provides a means of partially accounting for the frequency-dependent effects through an "effective" wavelet, the inversion algorithm performs remarkably well in weakly to moderately dispersive environments and has the ability to provide adequate tomographic reconstructions.

The ghost of past species occurrence: improving species distribution models for presence-only data

1. Model-based approaches have been used increasingly in conservation biology over recent years. Species presence data used for predictive species distribution modelling are abundant in natural history collections, whereas reliable absence data are sparse, most notably for vagrant species such as butterflies and snakes. As predictive methods such as generalized linear models (GLM) require absence data, various strategies have been proposed to select pseudo-absence data. However, only a few studies exist that compare different approaches to generating these pseudo-absence data. 2. Natural history collection data are usually available for long periods of time (decades or even centuries), thus allowing historical considerations. However, this historical dimension has rarely been assessed in studies of species distribution, although there is great potential for understanding current patterns, i.e. the past is the key to the present. 3. We used GLM to model the distributions of three 'target' butterfly species, Melitaea didyma, Coenonympha tullia and Maculinea teleius, in Switzerland. We developed and compared four strategies for defining pools of pseudo-absence data and applied them to natural history collection data from the last 10, 30 and 100 years. Pools included: (i) sites without target species records; (ii) sites where butterfly species other than the target species were present; (iii) sites without butterfly species but with habitat characteristics similar to those required by the target species; and (iv) a combination of the second and third strategies. Models were evaluated and compared by the total deviance explained, the maximized Kappa and the area under the curve (AUC). 4. Among the four strategies, model performance was best for strategy 3. Contrary to expectations, strategy 2 resulted in even lower model performance compared with models with pseudo-absence data simulated totally at random (strategy 1). 5. Independent of the strategy model, performance was enhanced when sites with historical species presence data were not considered as pseudo-absence data. Therefore, the combination of strategy 3 with species records from the last 100 years achieved the highest model performance. 6. Synthesis and applications. The protection of suitable habitat for species survival or reintroduction in rapidly changing landscapes is a high priority among conservationists. Model-based approaches offer planning authorities the possibility of delimiting priority areas for species detection or habitat protection. The performance of these models can be enhanced by fitting them with pseudo-absence data relying on large archives of natural history collection species presence data rather than using randomly sampled pseudo-absence data.

Politicians in the Media: Determinants of Legislators' Presence and Prominence in Swiss Newspapers

In times of increasing "mediatization" of politics, when voters and their elected representatives primarily communicate through the media, the question of who gets into the news and why becomes of the utmost importance. This article examines the determinants of Swiss legislators' presence and prominence in the print media by focusing on three competing approaches drawn from communication studies. The first approach regards the media as a "mirror" of political reality and argues that the media focus on the most active deputies in parliament. Second, news values theory predicts that "authoritative" politicians in leadership positions get the most media coverage. Third, theories of "news bias" hold that the media privilege legislators who are in line with their own editorial interests. Overall, the statistical analyses show an important leadership effect and provide strong support for the second explanation. While deputies in official functions get the most extensive news coverage, media access can also be won by parliamentary activity. The least support is shown for the news bias theory, although some newspapers try to localize parliamentary news coverage by focusing on deputies from their own media market.

Influence of climate on the presence of colour polymorphism in two montane reptile species.

The coloration of ectotherms plays an important role in thermoregulation processes. Dark individuals should heat up faster and be able to reach a higher body temperature than light individuals and should therefore have benefits in cool areas. In central Europe, montane local populations of adder (Vipera berus) and asp viper (Vipera aspis) exhibit a varying proportion of melanistic individuals. We tested whether the presence of melanistic V. aspis and V. berus could be explained by climatic conditions. We measured the climatic niche position and breadth of monomorphic (including strictly patterned individuals) and polymorphic local populations, calculated their niche overlap and tested for niche equivalency and similarity. In accordance with expectations, niche overlap between polymorphic local populations of both species is high, and even higher than that of polymorphic versus monomorphic montane local populations of V. aspis, suggesting a predominant role of melanism in determining the niche of ectothermic vertebrates. However, unexpectedly, the niche of polymorphic local populations of both species is narrower than that of monomorphic ones, indicating that colour polymorphism does not always enable the exploitation of a greater variability of resources, at least at the intraspecific level. Overall, our results suggest that melanism might be present only when the thermoregulatory benefit is higher than the cost of predation.

Proliferation of chick embryo neuroblasts grown in the presence of horse serum requires exogenous transferrin.

We have previously shown that neuroblasts from cerebral hemispheres of 6-day-old chick embryos are able to proliferate when grown in the presence of fetal calf serum. We report here that in the presence of horse serum alone the proliferative rate of neuroblasts is strongly reduced. A high proliferative rate is restored upon the addition of bovine transferrin and to a lesser extent with added FeSO4 or hemin. These findings suggest that the transferrin of horse serum cannot be used by chick neuroblasts in vitro, while bovine transferrin exogenously added is active in promoting cell proliferation. We propose that the stimulatory activity of the fetal calf serum is due to bovine transferrin, since when this serum is fractionated by gel filtration, the fractions that stimulate the proliferation of neuroblasts grown in the presence of horse serum are located in the molecular weight area of transferrin, and they do contain transferrin as seen by immunoblotting with a specific anti-transferrin antibody.

Activation of HTLV-I transcription in the presence of Tax is independent of the acetylation of CREB-2 (ATF-4).

We have previously demonstrated that the bZIP transcription factor CREB-2, also called ATF-4, trans-activates, in association with the viral protein Tax, the human T-cell leukemia virus type I (HTLV-I) promoter. In this study, we have examined whether CREB-2 acetylation affects transcriptional activation mediated by Tax. We present evidence that CREB-2 is acetylated in vitro and in vivo. CREB-2 is acetylated in two regions: the basic domain of the bZIP (from amino acid residue 270 to 300) and the short basic domain (from 342 to 351) located downstream from the bZIP. We also demonstrate that CREB-2 is acetylated by p300/CBP but not by p/CAF. Moreover, replacement of lysine by arginine in the basic domains decreases the trans-activating capacity of CREB-2. However, in the presence of Tax, the HTLV-I transcription remains fully activated by these CREB-2 mutants. Although we cannot totally exclude that the mutations could also affect CREB-2 structure and activity independent of acetylation, our results suggest that activation of the viral promoter in the presence of Tax is independent of the CREB-2 acetylation.

Segmentation of brain structures in presence of a space-occupying lesion.

Brain deformations induced by space-occupying lesions may result in unpredictable position and shape of functionally important brain structures. The aim of this study is to propose a method for segmentation of brain structures by deformation of a segmented brain atlas in presence of a space-occupying lesion. Our approach is based on an a priori model of lesion growth (MLG) that assumes radial expansion from a seeding point and involves three steps: first, an affine registration bringing the atlas and the patient into global correspondence; then, the seeding of a synthetic tumor into the brain atlas providing a template for the lesion; finally, the deformation of the seeded atlas, combining a method derived from optical flow principles and a model of lesion growth. The method was applied on two meningiomas inducing a pure displacement of the underlying brain structures, and segmentation accuracy of ventricles and basal ganglia was assessed. Results show that the segmented structures were consistent with the patient's anatomy and that the deformation accuracy of surrounding brain structures was highly dependent on the accurate placement of the tumor seeding point. Further improvements of the method will optimize the segmentation accuracy. Visualization of brain structures provides useful information for therapeutic consideration of space-occupying lesions, including surgical, radiosurgical, and radiotherapeutic planning, in order to increase treatment efficiency and prevent neurological damage.

Early DNA vaccination of puppies against canine distemper in the presence of maternally derived immunity.

Canine distemper (CD) is a disease in carnivores caused by CD virus (CDV), a member of the morbillivirus genus. It still is a threat to the carnivore and ferret population. The currently used modified attenuated live vaccines have several drawbacks of which lack of appropriate protection from severe infection is the most outstanding one. In addition, puppies up to the age of 6-8 weeks cannot be immunized efficiently due to the presence of maternal antibodies. In this study, a DNA prime modified live vaccine boost strategy was investigated in puppies in order to determine if vaccinated neonatal dogs induce a neutralizing immune response which is supposed to protect animals from a CDV challenge. Furthermore, a single DNA vaccination of puppies, 14 days after birth and in the presence of high titers of CDV neutralizing maternal antibodies, induced a clear and significant priming effect observed as early as 3 days after the subsequent booster with a conventional CDV vaccine. It was shown that the priming effect develops faster and to higher titers in puppies preimmunized with DNA 14 days after birth than in those vaccinated 28 days after birth. Our results demonstrate that despite the presence of maternal antibodies puppies can be vaccinated using the CDV DNA vaccine, and that this vaccination has a clear priming effect leading to a solid immune response after a booster with a conventional CDV vaccine.

Accuracy of sentinel lymph node dissection for melanoma staging in the presence of a collision tumour with a lymphoproliferative disease.

Sentinel lymph node dissection (SLND) identifies melanoma patients with metastatic disease who would benefit from radical lymph node dissection (RLND). Rarely, patients with melanoma have an underlying lymphoproliferative disease, and melanoma metastases might develop as collision tumours in the sentinel lymph node (SLN). The aim of this study was to measure the incidence and examine the effect of collision tumours on the accuracy of SLND and on the validity of staging in this setting. Between 1998 and 2012, 750 consecutive SLNDs were performed in melanoma patients using the triple technique (lymphoscintigraphy, gamma probe and blue dye). The validity of SLND in collision tumours was analysed. False negativity was reflected by the disease-free survival. The literature was reviewed on collision tumours in melanoma. Collision tumours of melanoma and chronic lymphocytic leukaemia (CLL) were found in two SLN and in one RLND (0.4%). Subsequent RLNDs of SLND-positive cases were negative for melanoma. The patient with negative SLND developed relapse after 28 months with an inguinal lymph node metastasis of melanoma; RLND showed collision tumours. The literature review identified 12 cases of collision tumours. CLL was associated with increased melanoma incidence and reduced overall survival. This is, to our knowledge, the first assessment of the clinical value of SLND when collision tumours of melanoma and CLL are found. In this small series of three patients with both malignancies present in the same lymph node basin, lymphocytic infiltration of the CLL did not alter radioisotope uptake into the SLN. No false-negative result was observed. Our data suggest the validity of SLND in collision tumours, but given the rarity of the problem, further studies are necessary to confirm this reliability.

Glucose competence of the hepatoportal vein sensor requires the presence of an activated glucagon-like peptide-1 receptor.

Activation of the hepatoportal glucose sensors by portal glucose infusion leads to increased glucose clearance and induction of hypoglycemia. Here, we investigated whether glucagon-like peptide-1 (GLP-1) could modulate the activity of these sensors. Mice were therefore infused with saline (S-mice) or glucose (P-mice) through the portal vein at a rate of 25 mg/kg. min. In P-mice, glucose clearance increased to 67.5 +/- 3.7 mg/kg. min as compared with 24.1 +/- 1.5 mg/kg. min in S-mice, and glycemia decreased from 5.0 +/- 0.1 to 3.3 +/- 0.1 mmol/l at the end of the 3-h infusion period. Coinfusion of GLP-1 with glucose into the portal vein at a rate of 5 pmol/kg. min (P-GLP-1 mice) did not increase the glucose clearance rate (57.4 +/- 5.0 ml/kg. min) and hypoglycemia (3.8 +/- 0.1 mmol/l) observed in P-mice. In contrast, coinfusion of glucose and the GLP-1 receptor antagonist exendin-(9-39) into the portal vein at a rate of 0.5 pmol/kg. min (P-Ex mice) reduced glucose clearance to 36.1 +/- 2.6 ml/kg. min and transiently increased glycemia to 9.2 +/- 0.3 mmol/l at 60 min of infusion before it returned to the fasting level (5.6 +/- 0.3 mmol/l) at 3 h. When glucose and exendin-(9-39) were infused through the portal and femoral veins, respectively, glucose clearance increased to 70.0 +/- 4.6 ml/kg. min and glycemia decreased to 3.1 +/- 0.1 mmol/l, indicating that exendin-(9-39) has an effect only when infused into the portal vein. Finally, portal vein infusion of glucose in GLP-1 receptor(-/-) mice failed to increase the glucose clearance rate (26.7 +/- 2.9 ml/kg. min). Glycemia increased to 8.5 +/- 0.5 mmol/l at 60 min and remained elevated until the end of the glucose infusion (8.2 +/- 0.4 mmol/l). Together, our data show that the GLP-1 receptor is part of the hepatoportal glucose sensor and that basal fasting levels of GLP-1 sufficiently activate the receptor to confer maximum glucose competence to the sensor. These data demonstrate an important extrapancreatic effect of GLP-1 in the control of glucose homeostasis.