Direct Observation of Competing M1 and M3 Transitions in

Excited states in ^{10}B were populated with the ^{10}B(p,p^{'}γ)^{10}B^{*} reaction at 8.5 MeV and their γ decay was investigated via coincidence γ-ray spectroscopy. The emitted γ rays were measured using large-volume LaBr_{3}:Ce and CeBr_{3} detectors placed in anti-Compton shields. This allowed the observation of weak γ-ray transitions, such as the M3 transition between the J^{π},T=0^{+},1 isobaric analog state (IAS) and the J^{π},T=3^{+},0 ground state and the E2 transition between the J^{π},T=2_{1}^{+},0 state and the IAS, i.e., performing measurements of branching ratios at the level of λ≥10^{-4}. For the first time in ^{10}B, the competing M1 and M3 transitions from the decay of the IAS have been observed in a γ spectroscopy experiment. The experimental results are compared with ab initio no-core shell model calculation using the newest version of the local position-space chiral N^{3}LO nucleon-nucleon interaction. The calculations reproduce correctly the ordering of the bound states in ^{10}B, and are in reasonable agreement with the observed branching ratios and reduced transition probabilities.

Columnar Liquid Crystals of Copper(I) Complexes with Ionic Conductivity and Solid State Emission.

Two neutral copper(I) halide complexes ([Cu(BTU)2X], X = Cl, Br) were prepared by the reduction of the corresponding copper(II) halides (chloride or bromide) with a benzoylthiourea (BTU, N-(3,4-diheptyloxybenzoyl)-N'-(4-heptadecafluorooctylphenyl)thiourea) ligand in ethanol. The two copper(I) complexes show a very interesting combination of 2D supramolecular structures, liquid crystalline, emission, and 1D ionic conduction properties. Their chemical structure was ascribed based on ESI-MS, elemental analysis, IR, and NMR spectroscopies (1H and 13C), while the mesomorphic behavior was analyzed through a combination of differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and powder X-ray diffraction (XRD). These new copper(I) complexes have mesomorphic properties and exhibit a hexagonal columnar mesophase over a large temperature range, more than 100 K, as evidenced by DSC studies and POM observations. The thermogravimetric analysis (TG) indicated a very good thermal stability of these samples up to the isotropization temperatures and over the whole temperature range of the liquid crystalline phase existence. Both complexes displayed a solid-state emission with quantum yields up to 8% at ambient temperature. The electrical properties of the new metallomesogens were investigated by variable temperature dielectric spectroscopy over the entire temperature range of the liquid crystalline phase. It was found that the liquid crystal phases favoured anhydrous proton conduction provided by the hydrogen-bonding networks formed by the NH…X moieties (X = halide or oxygen) of the benzoylthiourea ligand in the copper(I) complexes. A proton conductivity of 2.97 × 10-7 S·cm-1 was achieved at 430 K for the chloro-complex and 1.37 × 10-6 S·cm-1 at 440K for the related bromo-complex.

Prognostic factors of spinal cord decompression sickness in recreational diving: retrospective and multicentric analysis of 279 cases.

BACKGROUND: This study aims to determine the potential risk factors associated with the development of severe diving-related spinal cord decompression sickness (DCS). METHODS: Two hundred and seventy nine injured recreational divers (42 ± 12 years; 53 women) presenting symptoms of spinal cord DCS were retrospectively included from seven hyperbaric centers in France and Belgium. Diving information, symptom latency after surfacing, time interval between symptom onset and hyperbaric treatment were studied. The initial severity of spinal cord DCS was rated with the Boussuges severity score, and the presence of sequelae was evaluated at 1 month. Initial recompression treatment at 2.8 ATA with 100% oxygen breathing or deeper recompression up to 4 or 6 ATA with nitrogen or helium-oxygen breathing mixture were also recorded. RESULTS: Twenty six percent of DCS had incomplete resolution after 1 month. Multivariate analysis revealed several independent factors associated with a bad recovery: age ≥ 42 [OR 1.04 (1-1.07)], depth ≥ 39 m [OR 1.04 (1-1.07)], bladder dysfunction [OR 3.8 (1.3-11.15)], persistence or worsening of clinical symptoms before recompression [OR 2.07 (1.23-3.48)], and a Boussuges severity score >7 [OR 1.16 (1.03-1.31)]. However, the time to recompression and the choice of initial hyperbaric procedure did not significantly influence recovery after statistical adjustment. CONCLUSIONS: Clinical symptoms of spinal cord DCS and their initial course before admission to the hyperbaric center should be considered as major prognostic factors in recovery. A new severity score is proposed to optimize the initial clinical evaluation for spinal cord DCS.

Similarity analysis for DNA sequences based on chaos game representation. Case study: the albumin.

Using chaos game representation we introduce a novel and straightforward method for identifying similarities/dissimilarities between DNA sequences of the same type, from different organisms. A matrix is associated to each CGR pattern and the similarities result from the comparison between the matrices of the sequences of interest. Three different methods of analysis of the resulting difference matrix are considered: a 3-dimensional representation giving both local and global information, a numerical characterization by defining an n-letter word similarity measure and a statistical evaluation. The method is illustrated by implementation to the study of albumin nucleotides sequences from eight mammal species taking as reference the human albumin.

Effects of tryptophan and probiotic supplementation on growth and behavior in quail.

In laying hens, a diet supplemented with tryptophan (Trp) has been shown to affect their pecking behavior. However, unlike this positive effect, Trp is also involved in negative effects on behavior and stress through indolic pathways. Indole production can be reduced by probiotics (Pro), thus we hypothesized that Pro may prevent negative effects of Trp and increase beneficial effects on behavior in birds. Combined effects of Pro and Trp were also expected. To investigate the effects on behavior in birds of supplementing with a high level of Trp with or without Pro, Japanese quail were used because their behavior can be influenced by Pediococcus acidilactici, and they can be highly aggressive. Quails (n = 120) were assigned to 4 groups in a 2 × 2 factorial design for 55 d: C-C (control diet with usual Trp level, 0.3%; without Pro; n = 30), Trp-C (Trp: 2%; without Pro; n = 30), C-Pro (control diet; with Pro: 1 x 109 CFU/L P. acidilactici in drinking water; n = 30), and Trp-Pro (Trp 2%; with Pro; n = 30). Body weight was measured every week, and different tests were conducted to investigate behavioral characteristics of each quail. Contrary to our hypothesis, there was almost no interaction between Trp and Pro treatments. Tryptophan supplementation significantly (P < 0.05) reduced live weight up to 27 d, whereas Pro treatment had no effect. There was no significant difference between groups for tonic immobility variables (P > 0.05). The birds fed the high Trp diet spent significantly less time in the periphery of the open field than those fed the control diet and moved less in the arena during the social isolation test. Interindividual distances were significantly lower in males fed with Trp 2% than with the control diet, whereas Trp and Pro supplements interacted in females. The treatments did not affect sexual motivation in males. These results indicate that a high level of Trp reduced growth and appeared to enhance emotional reactivity in quails and that supplementing with Pro did not reduce these effects. In conclusion, feeding high Trp for 55 d cannot be recommended as a strategy to improve social behavior unlike effects observed in laying hens.

Two- and three-dimensional magnetic reconnection observed in the Eulerian-Lagrangian analysis of magnetohydrodynamics equations.

We study reconnection phenomena in magnetohydrodynamics on the basis of a magnetohydrodynamic version of the Eulerian-Lagrangian analysis. We find that the methods are useful in capturing time scales associated with magnetic reconnection both in two and three dimensions. Visualizations show that the determinants of the Jacobian determinants of the diffusive labels are small where active reconnection takes place. The resetting of the diffusive labels extracts a short time scale during reconnection.

Genetic selection on a behavioural fear trait is associated with changes in heart rate variability in quail.

This study investigated whether genetic selection on a divergent behavioural trait of fearfulness (tonic immobility duration) was related to changes in the nervous control of the heart. Quail selected for either long or short tonic immobility (LTI or STI, respectively) duration was compared with an unselected control line (CTI). The autonomic control of the heart was assessed by heart rate variability analysis and pharmacological blockades. Quail were surgically fitted with a telemetric device. Heart rate before injection did not differ between the three lines. The vagal-sympathetic effect (VSE) at rest differed significantly from 1 in CTI and STI quail, suggesting that parasympathetic activity was dominant. In LTI quail, VSE did not differ from 1, suggesting a balance between parasympathetic and sympathetic activities. The intrinsic heart rate reached after the successive injections of propranolol and atropine did not differ between lines and was higher than the heart rate at rest in STI, which was in line with results of VSE at rest. After atropine injection, the sympathetic activity indicated by the low-frequency power was lower in CTI than in the two selected quail. After propranolol injection, the parasympathetic activity indicated by the root of the mean squares of successive differences and the high-frequency power was higher in STI than in CTI and LTI quail. Selection on tonic immobility duration thus appears to be associated with changes in the sympathovagal control of the heart, which may influence behavioural responses to stressful situations.

Emotional reactivity modulates autonomic responses to an acoustic challenge in quail.

Emotional reactivity modulates autonomic responses to an acoustic challenge in quail. Physio Behav 00(0) 000-000, 2006. This study investigated the relationship between emotional reactivity and behavioral and autonomic responses to an acoustic stimulus in quail. It was hypothesized that birds with high emotional reactivity would have higher motor inhibition combined with higher sympathetic activation than birds with low emotional reactivity. Two experiments were performed. The first looked for correlations between emotional reactivity, evaluated by a tonic immobility test, and motor and Heart Rate Variability in relation to an acoustic stimulus. The second experiment compared the motor and autonomic responses to the acoustic stimulus of quail selected on either long (LTI) or short (STI) duration of tonic immobility. The first experiment showed that the acoustic stimulation induced motor inhibition and cardiac activation. Correlations were found between tonic immobility duration and both autonomic activity before stimulation and sympathovagal balance after stimulation. In the second experiment, LTI quail showed strong sympathetic activation, whereas STI quail showed parasympathetic and sympathetic activation. The activation of the parasympathetic system induced by the noise in STI quail can be explained by the predominance of this system at rest in this line. In conclusion, both the basal autonomic activity and the autonomic responses differed according to the emotional reactivity, and changes in autonomic activity appear to be related to the genetic selection process.

An exploratory clinical trial to evaluate the efficacy of an experimental dentifrice formulation in the relief of dentine hypersensitivity.

OBJECTIVES: This study aimed to investigate whether addition of an octadecene/maleic anhydride copolymer (O/MA) to a potassium nitrate (KNO3) dentifrice could facilitate delivery of potassium to dentine and enhance its efficacy in dentine hypersensitivity relief. METHODS: This was a randomised, examiner-blind, controlled, parallel group study in 139 healthy subjects with at ≥2 sensitive teeth. Assessment of dentine hypersensitivity to tactile (Yeaple probe) and evaporative (air) stimuli (Schiff Sensitivity Scale, visual analogue scale [VAS]) was carried out at baseline and after 1, 2, 4 and 8 weeks twice daily treatment with an experimental 5% KNO3/3% O/MA dentifrice, a comparator 5% KNO3 dentifrice (active comparator), a 0% KNO3/3% O/MA dentifrice (placebo) and a regular fluoride dentifrice (negative control). This study was not powered to detect statistically significant differences between treatments. RESULTS: Across the treatment period an improvement in sensitivity to evaporative air stimulus was observed for all products and to a tactile stimulus for the potassium-containing treatments, with the greatest reductions for the experimental dentifrice (5% KNO3/3% O/MA). Reductions in sensitivity observed for the potassium-containing dentifrices compared to the placebo and negative control dentifrices were statistically significantly for Schiff sensitivity score and tactile threshold at all time-points and for VAS at Weeks 4 and 8. Trends in the study data also favoured the experimental dentifrice, compared to the active comparator dentifrice, for all clinical measures. Study treatments were generally well tolerated. CONCLUSION: This study provides initial clinical evidence to suggest that addition of a polymer excipient may enhance the anti-sensitivity efficacy of potassium-containing dentifrices. CLINICAL SIGNIFICANCE: Daily use potassium-containing dentifrices are established as efficacious for the relief of dentine hypersensitivity. Inclusion of a polymer excipient in such formulations may facilitate delivery of potassium to the dentine surface and so enhance clinical efficacy. Further clinical studies are required to confirm this hypothesis.

Sequential feeding can increase activity and improve gait score in meat-type chickens.

This study investigated the short- and long-term effects of sequential feeding by alternating low-and high-lysine diets during the day on growth, gait score (GS), and behavior in broilers. From Days 2 to 12, 6 pens of 10 birds were assigned to control treatment and fed a standard normal lysine diet (NL) (ME = 3,250 kcal/kg, CP = 23%, Lys = 1.19%) and six pens of 10 birds were assigned to the sequential treatment and fed a low-lysine diet (LL) (Lys = 0.85%) for half of the day and NL for the other half of the day. From Days 13 to 21, all groups were fed NL, and from Days 21 to 42, they were fed a grower diet. Sequential (S) chicks were lighter than Control chicks at Days 13 (304 +/- 6 vs. 378 +/- 7 g) and 42 (2,588 +/- 31 vs. 2,714 +/- 10 g) and had better leg condition at Day 42 (mean GS = 1.6 +/- 0.1 vs. 2.1 +/- 0.1, P < or = 0.05). During a day of S feeding, S birds ate less and wasted more LL than NL. Sequential birds spent less time standing and more time lying idle when fed LL than when fed NL. Sequential birds spent more time eating than Control birds, and they gradually increased the number of pecks in the litter during a sequential feeding day. The results suggest a major effect of food composition on behavior. Sequential feeding could be a means of decreasing leg problems in broilers.

Early locomotor behaviour in genetic stocks of chickens with different growth rates.

Reduction in exercise increases the occurrence of lameness in meat-type chickens. Locomotor activity is dramatically reduced during the finishing period in chickens from fast-growing genetic types compared to slow-growing genetic types, but it is not known whether this difference is already present during the starting period and may be influenced by genetic factors. In order to define the effect of genetic origin on early locomotor behaviour, exercise was compared from 1 to 22 days of age in two meat-type chicken stocks differing in growth rate: male broilers (B) which grow fast and are often lame, and male "label rouge" chickens (L) which grow slowly and are rarely lame.Time budget (lying, standing, drinking, eating, walking) was measured by scanning in six repetitions of five birds (density=2.5 birds/m(2)) at 1, 8, 15 and 17 days of age. Standing bouts were analysed by focal sampling at 2-3, 6-7, 13-14 and 20-21 days of age.B chicks spent less time standing than L chicks at 15 days of age (B=13+/-2%, L=24+/-1%, P<0.01) and 17 days of age, and spent more time lying at 17 days of age (B=73+/-3%, L=60+/-4%, P<0.05).The major part (74%) of the total active time observed by focal sampling was linked to feeding activity. At 2 and 3 days, the activity of B chicks was half that of L chicks during standing bouts (duration of walking per bout: 19+/-4 s for B; 45+/-4 s for L, P<0.05). The activity observed by focal sampling during non-feeding bouts at 20-21 days was significantly correlated with the corresponding data recorded at 2-3 days in the same chicks in the B stock but not in the L stock.We concluded that (1) both B and L genetic stocks have the same overall activity during the first 3 days of age (scanning) but they exhibit different organisation and composition of standing bouts (focal sampling). (2) Genetic factors are probably involved in the expression of locomotor behaviour in very young chicks. (3) The correlations between the levels of activity at early and later ages suggest that selection of young mobile broiler chicks might increase activity at a later age and might therefore reduce the occurrence of leg abnormalities.

Early bone growth in chickens genetically selected for a high and low growth rate.

Male chickens from lines divergently selected for fast (FGL) and slow (SGL) growth were compared for the growth of cortical bone. Morphology, histomorphometric, compositional and biomechanical properties of the tibiotarsi were analysed in both lines at 1, 8, 15 and 22 d of age. Tibial morphology (length, volume, cross-section and diameters) was similar in FGL and SGL chickens when compared at an equal body weight. Cortical area was also similar in both lines at an equal body weight but cortex porosity was higher in FGL. Tibial mineral density (ash:volume) was higher in FGL than in SGL at hatching and at 8 d of age. Biomechanical properties were lower in SGL than in FGL at 8 d of age, but then became higher in this line when compared at equal body weight. The very slow growth rate in SGL did not modify bone size when chickens were compared at equal body weight. Bone quality was modified in various ways: in SGL bone structure was strengthened by a lower porosity of the cortex while bone tissue was less mineralized up to 22 d of age. In both lines, cortical growth was slower than in commercial cross-breeds and bone quality (structure and composition) was improved compared to broilers.

Sex differences in bone growth of broiler chickens.

Females are often supposed to have a lighter skeleton than males, even in avian domestic species. However, in broiler chickens, females are less susceptible to bone deformities than males. In order to better understand these conflicting facts, male and female broilers were compared for the growth of cortical bone. Morphology, histomorphometry, composition and biomechanical properties of the tibiotarsi were analysed in both sexes at 1, 12, 26 and 42 days of age. The quantity of bone tissue of the tibiotarsus (weight, volume, diameter of the diaphysis, area of the cortex) was smaller in females, although the occurrence of varus-valgus deformations of the intertarsal joint was largely reduced in female chickens (8.8% versus 19.9% in males at 42 days of age). The tibia became significantly lighter in females from 26 d of age. Differences in tibia length and volume became significant at 42 d of age only, while cross-sections of the diaphysis were smaller in females from the hatching, leading to thinner bones in females. The percentage of dry matter of tibiae was higher in females from hatching. From 12 days old, tibiotarsi of females tended to be less porous and were more mineralized (higher ash/dry matter ratio). In females, mineralization proceeded at a higher rate (MAR) until 26 d of age and MAR became higher in males afterwards. The stiffness of the tibia diaphysis was similar in males and females all along the growth. In conclusion, the growth of cortical bone is very different in male and female broilers. In female broilers, the thinness of bone diaphysis is counter-balanced by modifications in the composition of the matrix and in the porosity of the cortex, leading to equal biomechanical characteristics of tibiotarsi in both sexes.

A higher inherent trait for fearfulness is associated with increased anxiety-like behaviours and diazepam sensitivity in Japanese quail.

This study tested whether lines of Japanese quails divergently selected for a fear response, the tonic immobility, might constitute a reliable bird model for studying anxiety. Previous studies demonstrated that the selection modifies the general underlying emotionality of the birds rather than exerting its effect only on tonic immobility. The behavioural effects of intraperitoneal injections of diazepam, an anxiolytic drug, were assessed in two lines of quail selected either for their short (STI) or long (LTI) duration of tonic immobility. Effects of diazepam were examined in two tests used for measuring emotionality in birds, the open field and the tonic immobility tests. After being placed in the centre of the open field, birds with a high emotionality (LTI quails) stayed longer in the centre of the apparatus than STI quail. Diazepam had anxiolytic effect in LTI birds as it increased the time spent in the outer area. This effect of diazepam appears to be selective because the drug has no effect on other behaviours such as distress calls or escape attempts. The drug has also no effect on the tonic immobility response in any of the two lines. These findings reveal an "anxiogenic" trait of LTI birds in the open field test that can be modulated by the administration of an anxiolytic drug. Therefore quails selected for LTI and STI represent a valuable model to study the mechanisms underlying anxiety in birds.

[Hyperbaric oxygen therapy and inert gases in cerebral ischemia and traumatic brain injury]. / Oxygénothérapie hyperbare et gaz inertes dans l'ischémie cérébrale et le traumatisme crânien.

Cerebral ischemia is a common thread of acute cerebral lesions, whether vascular or traumatic origin. Hyperbaric oxygen (HBO) improves tissue oxygenation and may prevent impairment of reversible lesions. In experimental models of cerebral ischemia or traumatic brain injury, HBO has neuroprotective effects which are related to various mechanisms such as modulation of oxidative stress, neuro-inflammation or cerebral and mitochondrial metabolism. However, results of clinical trials failed to prove any neuroprotective effects for cerebral ischemia and remained to be confirmed for traumatic brain injury despite preliminary encouraging results. The addition of inert gases to HBO sessions, especially argon or xenon which show neuroprotective experimental effects, may provide an additional improvement of cerebral lesions. Further multicentric studies with a strict methodology and a better targeted definition are required before drawing definitive conclusions about the efficiency of combined therapy with HBO and inert gases in acute cerebral lesions.

Impact of high and low anxiety trait on object habituation and discrimination: evidence from selected lines of Japanese quail.

Compared to rodents, the relationship between anxiety and cognitive performances has been less studied in birds. Yet, birds are frequently exposed to stimulations that constitute a potential source of anxiety and can affect their adaptation to their living conditions. The present study was aimed at evaluating, in birds, the relationship between levels of anxiety and object habituation and discrimination with the use of Japanese quail lines divergently selected for a fear response, tonic immobility. Previous studies demonstrated that the selection programme has modified the general anxiety trait of the birds. The task consisted in 4 daily sessions of 8 successive presentations of the same object in the home cage of the quail in order to habituate each bird to the object. The observation that both quail with a high and a low anxiety trait progressively spent more time close to the object indicated that habituation occurred. Dishabituation was assessed during a single session of 8 presentations of a novel object. Only quail with a high anxiety trait exhibited significant discrimination. They spent significantly less time close to the novel object than to the habituated object. It is hypothesised that a high anxiety trait is associated with a more accurate processing of environmental cues or events resulting in better discriminative performances.

Higher inherent fearfulness potentiates the effects of chronic stress in the Japanese quail.

There is considerable variability in the susceptibility of individuals to the adverse effects of chronic stress. In humans and other mammals, individual traits such as high anxiety are proposed as a vulnerability factor for the development of stress-related disorders. In the present study, we tested whether a similar behavioural trait in birds, higher emotional reactivity, also favours the occurrence of chronic stress-related behavioural and physiological dysfunction. For this, lines of Japanese quail divergently selected for a typical fear response in birds, the duration of tonic immobility, were subjected to unpredictable aversive stimulation over 2 weeks. Previous studies demonstrate that the selection program modifies the general underlying emotionality of the birds rather than exerting its effect only on tonic immobility. Interestingly, only birds selected for their higher emotionality exhibited significantly enhanced latency to first step and decreased locomotor activity in the open-field test after exposure to chronic stress compared to non-stressed control birds. This effect of chronic stress was selective for the tested dimension of bird emotional reactivity because there was no observed effect on the tonic immobility response. Moreover, chronically stressed birds selected for their higher emotionality exhibited significantly decreased basal corticosterone levels, a physiological marker of stress. These findings show that chronic stress is associated with changes in emotional reactivity and related physiological markers in birds. They also highlight emotional reactivity as an important predisposing factor for the occurrence of the adverse effects of chronic stress in birds.