A global non-invasive methodology for the phenotyping of potato under water deficit conditions using imaging, physiological and molecular tools.

BACKGROUND: Drought is a major consequence of global heating that has negative impacts on agriculture. Potato is a drought-sensitive crop; tuber growth and dry matter content may both be impacted. Moreover, water deficit can induce physiological disorders such as glassy tubers and internal rust spots. The response of potato plants to drought is complex and can be affected by cultivar type, climatic and soil conditions, and the point at which water stress occurs during growth. The characterization of adaptive responses in plants presents a major phenotyping challenge. There is therefore a demand for the development of non-invasive analytical techniques to improve phenotyping. RESULTS: This project aimed to take advantage of innovative approaches in MRI, phenotyping and molecular biology to evaluate the effects of water stress on potato plants during growth. Plants were cultivated in pots under different water conditions. A control group of plants were cultivated under optimal water uptake conditions. Other groups were cultivated under mild and severe water deficiency conditions (40 and 20% of field capacity, respectively) applied at different tuber growth phases (initiation, filling). Water stress was evaluated by monitoring soil water potential. Two fully-equipped imaging cabinets were set up to characterize plant morphology using high definition color cameras (top and side views) and to measure plant stress using RGB cameras. The response of potato plants to water stress depended on the intensity and duration of the stress. Three-dimensional morphological images of the underground organs of potato plants in pots were recorded using a 1.5 T MRI scanner. A significant difference in growth kinetics was observed at the early growth stages between the control and stressed plants. Quantitative PCR analysis was carried out at molecular level on the expression patterns of selected drought-responsive genes. Variations in stress levels were seen to modulate ABA and drought-responsive ABA-dependent and ABA-independent genes. CONCLUSIONS: This methodology, when applied to the phenotyping of potato under water deficit conditions, provides a quantitative analysis of leaves and tubers properties at microstructural and molecular levels. The approaches thus developed could therefore be effective in the multi-scale characterization of plant response to water stress, from organ development to gene expression.

Perceptual weighting of pain behaviours of others, not information integration, varies with expertise.

BACKGROUND: Being able to estimate effort pain in patients is important for health care providers working in physical rehabilitation services. Previous studies have shown that clinicians and physiotherapists underestimate patients' pain. METHODS: The present study examined how two sources of visual information, namely body kinematics (movement speed and postural constraints) and facial expressions are integrated in order to estimate effort pain magnitude experienced by a paraplegic person performing a sitting pivot transfer. In addition, the effect of familiarity with paraplegia on judgment was assessed by comparing performance among physiotherapists, paraplegic patients and unfamiliar participants. Functional measurement was used to determine the psychophysical law of visual information integration carried by pain behaviours (guarding and facial expression). RESULTS: Results indicate that guarding behaviour (specified by movement speed) carried important information for perceived effort pain independently of familiarity. In contrast, facial expression of pain was relevant only to unfamiliar and physiotherapist participants and not to paraplegic participants. Even if physiotherapists underestimated effort pain as compared to the other groups, they relied more strongly on facial expression, than other participants, in their estimation of effort pain expressed by a paraplegic patient. CONCLUSIONS: These results bring further insights into understanding physiotherapists' perception of patients' pain. In order to improve their ability to adapt the difficulty of the rehabilitation sessions, they should learn to raise their global level of pain magnitude estimation (for example, by performing themselves the body movement) instead of overweighting facial pain expression signals.

Accurate gamma-ray spectrometry measurements of the half-life of 92Sr.

Studies of the nuclear fuel cycle require an accurate knowledge of the energy release from the decay of radioactive nuclides produced in a reactor, including precise half-life data for the short-lived radionuclides. Moreover, short-lived fission products are crucial for fission rate distribution measurements performed in low-power facilities, such as EOLE and MINERVE of CEA Cadarache [Fougeras, P., 2005. EOLE, MINERVE and MASURCA facilities and their associated neutron experimental programs. In: 13th International Conference on Nuclear Engineering, Beijing, China, 16-20 May 2005], and their nuclear decay data need to be known to high precision. For these reasons, the half-life of (92)Sr has been measured to solve a recently observed inconsistency identified with the quoted value in the main nuclear applications libraries (including JEFF3.1): T(1/2)=2.71+/-0.01 h [Parsa, B., Ashari, A., Goolvard, L., Nobar, Y.M., 1971. Decay scheme of 2.71 h (92)Sr. Nucl. Phys. A 175, 629-640]. An overestimation of 4.5% has been identified in this work, based on two independent methods. Specific gamma-ray spectrometry measurements on activated fissile foils have been carried out, using two HPGe detectors. Influencing factors such as net area measurements of photopeaks, pulse pile-up accuracy and dead time corrections in the presence of decaying activity are discussed. A new value has been obtained by combining eight series of measurements: T(1/2)=2.594+/-0.006 h. The uncertainty has been reduced by a factor of two with respect to previous evaluations. This measured value also shows good agreement with the most recent studies of T(1/2)=2.627+/-0.009 h [Nir-El, Y., 2003. Private Communications. Soreq Research Centre, Yavne, Israel].

Amniocentesis and amnioinfusion during pregnancy. Report of four complicated cases.

We report two foetal complications after amnioinfusion with dye injection for evaluation of severe oligohydramnios in pregnancy. In the first case, an underskin colouring was to disappear within a few days. In the second case, an irreversible skin after-effect with muscular atrophy and lesion of the underskin tissues developed progressively, although the trained practitioner did not notice any particular resistance during the injection of the dye and the ultrasonographer did not point out that the foetus had been stuck by the needle. Both later reported cases concern two life threatening maternal complications due to amniocentesis for foetal karyotyping indicated by maternal age, a septic shock occurred 24h after entering the amniotic cavity, leading to a long stay in intensive care units. In one of those cases, the patient recovered from a cardiac arrest. We come to the conclusion that the essential continuous ultrasonographic monitoring cannot avoid all complications, some of which may lead to severe adverse foetal effects and others may need an intensive medical care for the mother, mainly after iatrogenic chorioamnionitis. Experience of the perinatologist remains an important factor to limit the complications without avoiding them completely. The indications must be carefully evaluated, the information given to the patients must be clear and in the future, intraamniotic injections of dyes will have to be avoided and replaced by non-invasive tests for diagnosis of preterm premature rupture of membranes, such as diamine-oxidase, foetal fibronectin or PROM-tests. The rules of a good practice will have to be defined and widely spread.

Diurnal variations of tonic electrodermal activity.

Diurnal variability of skin conductance level (SCL) was examined in two complementary experiments, simultaneously with variability of skin temperature (ST) and that of simple reaction time (RT) which was recorded as a behavioural index of arousal. In Experiment I, 6 subjects spent 6 days in the laboratory in homogeneous conditions. Three recording sessions, each lasting 2 h, began, respectively, at 9:00 a.m. (morning), 1:00 p.m. (afternoon) and 5:00 p.m. (evening). Results indicated that SCL increased linearly throughout the day. Experiment II was undertaken to test whether this effect could still be observed in more heterogeneous conditions. Subjects (n = 12) attended to their own activities between the two 30-min sessions beginning, respectively, at 9:30 a.m. and 6:00 p.m. during a single experimental day. Again, SCL was higher in the evening than in the morning. In both experiments the SCL pattern seemed to be asynchronous with ST and RT variations. Taken as a whole, these data bring additional evidence of temporal electrodermal variation, a phenomenon which should be further taken into account in EDA research.

Comparison of the effects of zolpidem and flunitrazepam on sleep structure and daytime cognitive functions. A study of untreated unsomniacs.

The effects of zolpidem 10 mg, flunitrazepam 1 mg, and placebo, administrated at bedtime, were studied in 12 healthy male insomniac patients. The assessments included polygraphic sleep recordings during the night and a battery of cognitive tests (sign crossing test, dichotic listening test, digit span test, visual recognition test and free recall test during four times during the following day. Compared with placebo, both active drugs improved sleep parameters. However, with zolpidem, the results were not statistically different from placebo. Zolpidem dit not alter sleep architecture in contrast to flunitrazepam, which significantly increased stage 2 and decreased slow wave sleep and REM sleep. No significant interaction was found between time of day for the evaluation of cognitive function. Flunitrazepam significantly impaired attention and memory compared with zolpidem and placebo, while zolpidem did not differ from placebo. These results indicate that zolpidem 10 mg preserved sleep structure and daytime cognitive functions in contrast to flunitrazepam.

Comparative study of methods of measuring acute pain intensity in an ED.

The best one-dimensional method for routine self-assessment of acute pain intensity in a hospital emergency department is unknown. In this study, an 11-point numerical rating scale (NRS), a simple verbal rating scale describing five pain states (VRS), and a visual analogue scale (VAS) were presented successively on admission to 290 patients with acute pain (200 with and 90 without trauma). VAS and NRS were closely correlated for both traumatic (r = .795) and nontraumatic pain (r = .911). The VAS could not be used with 19.5% of patients with trauma and the VRS with 11% of patients without trauma, whereas the NRS could be used with 96% of all patients. The NRS proved more reliable for patients with trauma, giving equivalent results to those with the VAS for patients without trauma. These two scales showed better discriminant power for all patients. Thus, the NRS would appear to be the means for self-evaluation of acute pain intensity in an emergency department.

Generation effect in short-term verbal and visuospatial memory: comparisons between dementia of Alzheimer type and dementia of frontal lobe type.

Memory deficit is the predominant presenting symptom in dementia. To compare short-term memory (STM) deficit in early dementia of Alzheimer type (DAT) vs frontal lobe type (DFT), and determine the residual memory capacity for stimulation, the generation effect (the memory advantage of items generated rather than read) was tested on verbal and visuospatial STM in patients with DAT (n = 10), DFT (n = 9) and in age-matched normal controls (n = 12). The generation effect enhanced performance in all groups. However, the profile of STM deficit differed in the two dementias: verbal and visuospatial memory were both decreased in DAT vs verbal memory only in DFT. These results provide a further criterion for differentiating between DAT and DFT, and show that memory performance can be enhanced in early dementia using techniques such as the generation effect.

Sleep, brain activation and cognition.

Some data have shown the presence of time-of-day effects in learning processes. We explore here whether the same phenomenon occurs during the night and how it relates to REM sleep. In an initial approach to the question, this paper points out the relationships between: 1) REM sleep and brain activation, and 2) REM sleep and information processing. The data are discussed in terms of a REM sleep implication on information processing and we examine the possibility of modifying this processing by acting on REM sleep.

REM sleep modifications following a Morse code learning session in humans.

Various experimental data indicate that rapid eye movement (REM) sleep is involved in learning processes. In animals, any complex task in a learning environment leads to an increase of the consecutive total REM sleep time, especially just before learning completion. In humans, the oculomotor activity during REM sleep seems to constitute an interesting marker of learning performance. In this work, we focus on the qualitative analysis of REM sleep characteristics after a Morse code learning session. Eight male subjects were polygraphically recorded during three consecutive nights. A computer aided teaching session was performed just before bedrest onset of the experimental night. The learning performance (percentage of saving) was checked on awakening. The Morse code learning led to some modifications in REM sleep components, particularly increases of REM sleep time and number of REM episodes. We did not observe any significant modification in the total number of REMs in the experimental night. However, the correlative analysis between learning performance and sleep parameters indicates a superior r for the oculomotor activity than for the tonic components. This is consistent with the information processing hypothesis in which the temporal distribution of REMs reflects the subject's ability to increase the signal-noise ratio from environmental information intake.

Enhancement of memory by auditory stimulation during postlearning REM sleep in humans.

REM sleep involvement in memory processes was demonstrated in animals and humans: 1) REM sleep deprivation impairs the memory fixation, 2) learning sessions are followed by modifications of REM sleep characteristics. Moreover, sleep patterns can be modified by applying auditory stimulations during REM sleep. We show that REM actual auditory stimulations significantly improve the retention of a Morse code learning task. These results are discussed in terms of brain activation.

Chronobiological rhythm constraints of memory processes.

Memory performances are not constant but undergo fluctuations whose periodicity may be analyzed. Low frequency infradian rhythms (periods longer than 28 hours), circadian rhythms (periods between 20 and 28 hours) and ultradian rhythms (periods less than 20 hours) are involved in memory disorders. Paradoxical sleep represents a preferential period in which certain processes, such as the activation of the central nervous system for example, may facilitate learning process. Relations between sleep and memory lead to the discussion of the incidence of the cyclic nature of sleep (and notably the rhythm of 90 minutes' paradoxical sleep) on the daily course of cerebral activation and its effects on the variable aptitude of our capacity for remembering. The close interrelation between biological rhythms and cognition is demonstrated using two examples of mental disorders in which severe memory deficiencies are observed.

[Confluent tuberculomas of the vermis cerebelli associated with an occipital localization. Report of a case and review of the literature]. / Tuberculomes confluents du vermis cérébelleux associés à une autre localisation occipitale. Rapport d'un cas et revue de la littérature.

An unusual case of multiple cerebral tuberculomas is reported. The patient, a 19-year-old woman, presented with a 6-month history of raised intracranial pressure and cerebellar symptoms. CT scan disclosed a conglomerate of several ring-enhancing lesions within the cerebellar vermis and another homogeneously enhancing mass against the right occipital horn. Solid and ring-enhancing lesions are the main mode of presentation of cerebral tuberculomas. Although the patient had no history of systemic tuberculosis, this diagnosis was considered highly probable in this geographic area and was confirmed by pathological examination of the cerebellar mass, the excision of which was considered necessary. Antitubercular medications led to complete regression of the associated occipital lesion, as demonstrated by sequential CT scan examinations.

[Memory facilitation by auditory stimulation during paradoxal sleep in man]. / Facilitation mnésique par stimulation auditive au cours du sommeil paradoxal (SP) chez l'homme.

REM sleep involvement in memory processes was demonstrated in animals and humans. Learning sessions are followed by modifications of REM sleep patterns. Furthermore, one can modify sleep patterns by applying auditory stimulation during REM sleep oculomotor activity. We show that such a procedure facilitates the retention of Morse code learning.

Modification of EEG asymmetry induced by auditory biofeedback loop during REM sleep in man.

Several studies have emphasized the relationship between (1) rapid eye movement sleep (REM sleep) and learning, and (2) between REM sleep and asymmetry in EEG activity. Since we have shown that obtaining operant conditioned responses via auditory biofeedback during REM sleep is feasible, we demonstrate here that REM contingent auditory stimulations (white noise stimulation or interruption of a continuous white noise stimulation) lead to differential changes in phasic and tonic components of REM sleep. Whereas during baseline nights a relative right activation is found in the medium bands of EEG frequencies, our procedure seems to induce a systematic interhemispheric change during experimental nights. A new approach to the information processing hypothesis during REM sleep is proposed in terms of functional lateralized modifications of the EEG.

[5th day syndrome after appendectomy. Plea against surgical treatment straight off]. / "Syndrome de 5e jour" après appendicectomie. Plaidoyer contre le traitement chirurgical d'emblée.

Thirteen cases of post-appendicectomy "fifth day syndrome" (0.45% of 2,919 children operated upon) are reported. The diagnosis must be established on precise criteria. Treatment is primarily medical, using antibiotics and anti-inflammatory drugs, and it must produce rapid and complete results. It is only when it fails (2 cases in our series) that a second operation is justified.