40 research outputs found

    Neuro-functional modeling of near-death experiences in contexts of altered states of consciousness

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    Near-death experiences (NDEs) including out-of-body experiences (OBEs) have been fascinating phenomena of perception both for affected persons and for communities in science and medicine. Modern progress in the recording of changing brain functions during the time between clinical death and brain death opened the perspective to address and understand the generation of NDEs in brain states of altered consciousness. Changes of consciousness can experimentally be induced in well-controlled clinical or laboratory settings. Reports of the persons having experienced the changes can inform about the similarity of the experiences with those from original NDEs. Thus, we collected neuro-functional models of NDEs including OBEs with experimental backgrounds of drug consumption, epilepsy, brain stimulation, and ischemic stress, and included so far largely unappreciated data from fighter pilot tests under gravitational stress generating cephalic nervous system ischemia. Since we found a large overlap of NDE themes or topics from original NDE reports with those from neuro-functional NDE models, we can state that, collectively, the models offer scientifically appropriate causal explanations for the occurrence of NDEs. The generation of OBEs, one of the NDE themes, can be localized in the temporo-parietal junction (TPJ) of the brain, a multimodal association area. The evaluated literature suggests that NDEs may emerge as hallucination-like phenomena from a brain in altered states of consciousness (ASCs)

    Postnatal development of absolute auditory thresholds in kittens

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    Specific expression of the retinoic acid-synthesizing enzyme RALDH2 during mouse inner ear development

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    Retinoid binding proteins and nuclear receptors are expressed in the developing mouse inner ear. Here, we report that the retinaldehyde dehydrogenase 2 (Raldh2) gene, whose product is involved in the enzymatic generation of retinoic acid (RA), exhibits a restricted expression pattern during mouse inner ear ontogenesis. The Raldh2 gene is first expressed at embryonic day (E) 10.5 in a V-shaped medio-dorsal region of the otocyst outer epithelium, which evolves as two separate domains upon otocyst morphogenesis. At E14.5, Raldh2 is expressed in two areas of the utricle epithelium and specific regions of the saccule and cochlear mesenchyme. Later, Raldh2 transcripts are restricted to two cochlear areas, the stria vascularis and Reissner membrane. Raldh2 mesenchymal expression did not correlate with migrating neural crest-derived melanoblasts. These restricted expression domains may correspond to specific sites of RA synthesis during inner ear morphogenesis

    Transmission inter- et intrahospitalière de staphylocoques dores résistants à la méticilline

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    Occurrence and spread of methicillin-resistant Staphylococcus aureus (MRSA) has become a major problem worldwide. The majority of hospitals in Switzerland have not so far been affected by this epidemic. We report two out-breaks of MRSA transmission in the surgical intensive care unit at the University Hospital of Geneva and show the possible inter- and intrahospital dissemination of MRSA. Evidence for cross-infection is confirmed by epidemiological investigation and molecular typing. Infection control measures and general precautions are necessary to halt further spread of MRSA

    Mesoscale eddy variability in the southern extension of the East Madagascar Current: Seasonal cycle, energy conversion terms, and eddy mean properties

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    International audienceIn this study, we used more than 17 years of satellite altimetry observations and output from an ocean model to investigate the mesoscale eddy variability and forcing mechanisms to the south of Madagascar. Analysis of energy conversion terms in the model has shown seasonality on eddy formation, both by barotropic and baroclinic instabilities: maximum in winter (JJA) and minimum in summer (DJF). The eddies were mainly formed in the upper ocean (0–300 m) and at intermediate depths (800–2000 m) by barotropic and baroclinic instabilities, respectively. The former dominated in the southeastern margin of Madagascar, and the latter to the southwest, where the South-East Madagascar Current (SEMC) separates from the continental shelf. Seasonality of the eddy formation appeared linked with the seasonal intensification of the SEMC. The energy conversion terms indicated that the eddies have a significant contribution to the large-scale circulation, but not being persistent throughout the year, occurring mainly during the fall season (MAM). Eddy demography from altimetry and model provided information on eddy preferential sites for birth, annual occurrence (6–13 per year), eddy mean diameter (124–178 km), mean amplitude (9–28 cm), life-time (90–183 days), and maximum traveling distances (325–1052 km). Eddies formed to the southwest of Madagascar exhibited distinct characteristics from those formed in the southeast. Nevertheless, all eddies were highly nonlinear, suggesting that they are potential vectors of connectivity between Madagascar and Africa. This may have a significant impact on the ecology of this region

    The retinoic acid receptors RARalpha and RARgamma are required for inner ear development

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    International audienceTo define the signal transduction pathway of retinoic acid during inner ear development, we analyzed the expression patterns of transcripts encoding the three retinoic acid receptors (RARalpha, beta, and gamma) and related them to phenotypes resulting from single or compound inactivation of these nuclear receptors. The expression of all three RARs was observed in the developing mouse otocyst as early as embryonic day 10.5 (E10.5)-E12.5 and continued into adulthood. Expression domains of the three RAR receptors, however, were largely non-overlapping: RARalpha was predominantly expressed in the developing sensory epithelium, RARbeta in inner ear mesenchymal tissues and RARgamma in the differentiating otic capsule. In the adult, RARalpha and RARgamma transcripts were found in the organ of Corti and the spiral ganglion, whereas RARbeta transcripts were localized in mesenchyme-derived tissues. RARalpha, beta, and gamma null mutant mice, as well as RARalpha/RARbeta and RARbeta/RARgamma combined null fetuses, did not present any noticeable morphological abnormalities in the inner ear. In contrast, RARalpha/RARgamma null mutants displayed a severe hypoplasia of the otocyst that was already visible at E10.5 without any visible endolymphatic duct. The hypoplastic otocyst in RARalpha/RARgamma null mutants was characterized by impaired chondrocyte differentiation and neural development. After the second week of gestation, these mutant fetuses lacked all of the semi-circular canals and the endolymphatic duct and displayed strong anomalies in the inner ear structures. The morphological deficits were generally more severe in the cochlear portion than in the vestibular portion of the inner ear. Altogether, these results demonstrate that RARalpha and RARgamma play an essential role in the initial differentiation of otic placode derivatives, whereas RARbeta plays a minimal role in this process

    Prevention of severe Candida infections in nonneutropenic, high-risk, critically ill patients: a randomized, double-blind, placebo-controlled trial in patients treated by selective digestive decontamination

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    OBJECTIVE: Infections caused by Candida spp. are a major cause of morbidity and mortality in critically ill patients and usually develop from endogenous colonization. We assessed the effectiveness of adding fluconazole to a selective digestive decontamination regimen to prevent candidal infections. DESIGN AND SETTING: We performed a prospective, randomized, double-blind, placebo-controlled trial among medical and surgical intensive care unit patients at a large university hospital. PATIENTS: All adult patients mechanically ventilated for at least 48 h with an expectation to remain so for at least an additional 72 h, and receiving selective decontamination of the digestive tract. INTERVENTIONS: Patients were randomly assigned fluconazole 100 mg daily (n=103) or placebo (n=101). MEASUREMENTS AND RESULTS: Candida infections occurred less frequently in the fluconazole group (5.8%) than in the placebo group (16%; rate ratio 0.35; Cl(95) 0.11-0.94). Some 90% of candidemia episodes occurred in the placebo group (rate ratio for fluconazole use 0.10; Cl(95) 0.02-0.74). The rate of treatment failure, development of candidal infection, or increased colonization, was 32% in the fluconazole group and 67% in the placebo group (P<0.001). Crude in-hospital mortality was similar in the two groups (39% fluconazole vs. 41% placebo). CONCLUSIONS: Prophylactic use of fluconazole in a selected group of mechanically ventilated patients at high risk for infection reduces the incidence of Candida infections, in particular candidemia
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