Liquid infiltration of monolithic open-access Fabry-Perot microcavities.

We describe a monolithic approach to fabricating large-scale arrays of high-finesse and low-mode-volume Fabry-Perot microcavities with open access to the air core. A stress-driven buckling self-assembly technique was used to form half-symmetric curved-mirror cavities, and a dry etching process was subsequently used to create micropores through the upper mirror. We show that the cavities retain excellent optical properties, with reflectance-limited finesse ∼2500 and highly predictable Laguerre-Gaussian modes. We furthermore demonstrate the ability to introduce liquids into the cavity region by microinjection through the pores. Applications in sensing, optofluidics, and cavity quantum electrodynamics are envisioned.

[Robotic-assisted laparoscopic living donor nephrectomy: Study in donors and recipients from 155 cases]. / Néphrectomie laparoscopique assistée par robot dans le cadre du donneur-vivant : étude chez les donneurs et les receveurs à partir de 155 cas.

AIM: To evaluate morbidity and renal function of the donor and recipient during a robotic-assisted laparoscopic nephrectomy procedure. PATIENTS AND METHODS: It is a retrospective study of 155 consecutive patients by robot-assisted laparoscopy in the living donor. Mean operating time, warm ischemia time, blood loss, complications according to the Clavien classification and evolution of creatinine clearance were analyzed in the donors. Recovery of graft function, complications and changes in creatinine clearance were observed in recipients. RESULTS: The mean operating time was 176 (±23) minutes. The mean warm ischemia time was 4.8 (±0.6) minutes. Twenty seven complications were noted. The loss of renal function was 19% at 5 years in donors. Renal recovery was immediate for 153 recipients. Two were delayed due to sepsis. Two patients lost their graft at 15 and 18 months. Seventeen complications have been identified. The mean kidney function of the recipients is measured at 63ml/min at 5 years. CONCLUSION: Robotic-assisted laparoscopic nephrectomy procedure appears to provide the donor with low morbidity and a moderate decrease in creatinine clearance at 19% at 5 years. Morbidity is also low in recipients with very satisfactory 5-year mean renal function. The technique should promote donation. LEVEL OF EVIDENCE: 4.

Tunable spin-orbit coupling via strong driving in ultracold-atom systems.

Spin-orbit coupling is an essential ingredient in topological materials, conventional and quantum-gas-based alike. Engineered spin-orbit coupling in ultracold-atom systems-unique in their experimental control and measurement opportunities-provides a major opportunity to investigate and understand topological phenomena. Here we experimentally demonstrate and theoretically analyze a technique for controlling spin-orbit coupling in a two-component Bose-Einstein condensate using amplitude-modulated Raman coupling.

Raman-induced interactions in a single-component Fermi gas near an s-wave Feshbach resonance.

Ultracold gases of interacting spin-orbit-coupled fermions are predicted to display exotic phenomena such as topological superfluidity and its associated Majorana fermions. Here, we experimentally demonstrate a route to strongly interacting single-component atomic Fermi gases by combining an s-wave Feshbach resonance (giving strong interactions) and spin-orbit coupling (creating an effective p-wave channel). We identify the Feshbach resonance by its associated atomic loss feature and show that, in agreement with our single-channel scattering model, this feature is preserved and shifted as a function of the spin-orbit-coupling parameters.

The spin Hall effect in a quantum gas.

Electronic properties such as current flow are generally independent of the electron's spin angular momentum, an internal degree of freedom possessed by quantum particles. The spin Hall effect, first proposed 40 years ago, is an unusual class of phenomena in which flowing particles experience orthogonally directed, spin-dependent forces--analogous to the conventional Lorentz force that gives the Hall effect, but opposite in sign for two spin states. Spin Hall effects have been observed for electrons flowing in spin-orbit-coupled materials such as GaAs and InGaAs (refs 2, 3) and for laser light traversing dielectric junctions. Here we observe the spin Hall effect in a quantum-degenerate Bose gas, and use the resulting spin-dependent Lorentz forces to realize a cold-atom spin transistor. By engineering a spatially inhomogeneous spin-orbit coupling field for our quantum gas, we explicitly introduce and measure the requisite spin-dependent Lorentz forces, finding them to be in excellent agreement with our calculations. This 'atomtronic' transistor behaves as a type of velocity-insensitive adiabatic spin selector, with potential application in devices such as magnetic or inertial sensors. In addition, such techniques for creating and measuring the spin Hall effect are clear prerequisites for engineering topological insulators and detecting their associated quantized spin Hall effects in quantum gases. As implemented, our system realizes a laser-actuated analogue to the archetypal semiconductor spintronic device, the Datta-Das spin transistor.

Peierls substitution in an engineered lattice potential.

Artificial gauge fields open the possibility to realize quantum many-body systems with ultracold atoms, by engineering Hamiltonians usually associated with electronic systems. In the presence of a periodic potential, artificial gauge fields may bring ultracold atoms closer to the quantum Hall regime. Here, we describe a one-dimensional lattice derived purely from effective Zeeman shifts resulting from a combination of Raman coupling and radio-frequency magnetic fields. In this lattice, the tunneling matrix element is generally complex. We control both the amplitude and the phase of this tunneling parameter, experimentally realizing the Peierls substitution for ultracold neutral atoms.

Synthetic partial waves in ultracold atomic collisions.

Interactions between particles can be strongly altered by their environment. We demonstrate a technique for modifying interactions between ultracold atoms by dressing the bare atomic states with light, creating an effective interaction of vastly increased range that scatters states of finite relative angular momentum at collision energies where only s-wave scattering would normally be expected. We collided two optically dressed neutral atomic Bose-Einstein condensates with equal, and opposite, momenta and observed that the usual s-wave distribution of scattered atoms was altered by the appearance of d- and g-wave contributions. This technique is expected to enable quantum simulation of exotic systems, including those predicted to support Majorana fermions.

Dynamics of a tunable superfluid junction.

We study the population dynamics of a Bose-Einstein condensate in a double-well potential throughout the crossover from Josephson dynamics to hydrodynamics. At barriers higher than the chemical potential, we observe slow oscillations well described by a Josephson model. In the limit of low barriers, the fundamental frequency agrees with a simple hydrodynamic model, but we also observe a second, higher frequency. A full numerical simulation of the Gross-Pitaevskii equation giving the frequencies and amplitudes of the observed modes between these two limits is compared to the data and is used to understand the origin of the higher mode. Implications for trapped matter-wave interferometers are discussed.

Molecular identification of candidate chemoreceptor genes and signal transduction components in the sensory epithelium of Aplysia.

An ability to sense and respond to environmental cues is essential to the survival of most marine animals. How water-borne chemical cues are detected at the molecular level and processed by molluscs is currently unknown. In this study, we cloned two genes from the marine mollusk Aplysia dactylomela which encode multi-transmembrane proteins. We have performed in situ hybridization that reveals expression and spatial distribution within the long-distance chemosensory organs, the rhinophores. This finding suggests that they could be receptors involved in binding water-borne chemicals and coupling to an intracellular signal pathway. In support of this, we found expression of a phospholipase C and an inositol trisphosphate receptor in the rhinophore sensory epithelia and possibly distributed within outer dendrites of olfactory sensory neurons. In Aplysia, mate attraction and subsequent reproduction is initiated by responding to a cocktail of water-borne protein pheromones released by animal conspecifics. We show that the rhinophore contraction in response to pheromone stimulants is significantly altered following phospholipase C inhibition. Overall, these data provide insight into the molecular components of chemosensory detection in a mollusk. An important next step will be the elucidation of how these coordinate the detection of chemical cues present in the marine environment and activation of sensory neurons.

[Bullous cutaneous mastocytosis revealed by acute disease secondary to morphine administration]. / Mastocytose cutanée bulleuse révélée par un malaise grave secondaire à la prise de morphinique.

UNLABELLED: Mastocytosis in children shows in three clinical forms. The rarest is the diffuse or bullous form. CASE REPORT: Since one month of age an infant showed a diffuse erythema and vesicle rash. At four months of age, serious discomfort after morphinic absorption led to the diagnosis of bullous cutaneous mastocytosis. Histologic examination confirmed this diagnosis. The clinical severity led to intravenous corticosteroid and antihistamine therapy. COMMENTS: Bullous cutaneous mastocytosis is unusual in children. However, it should be considered if there are any doubts because of its serious complications and iatrogenic therapeutic risks. Some serious cases require intravenous corticosteroid therapy. Appropriate care enables a normal development with a disappearance of the disease before the teenage years.

Uptake of choline from salmon flesh and its conversion to glycine betaine in response to salt stress in Shewanella putrefaciens.

When cultured in M63 minimal medium plus 0.6 M NaCl, the growth of Shewanella putrefaciens was strongly inhibited. The addition of an extract from smoked salmon to this medium restored the growth almost to the unstressed level. A comparison of the 13C NMR spectra of intracellular solutes extracted from S. putrefaciens cells cultured in both conditions revealed the accumulation of glycine betaine (GB) from the smoked salmon extract (SSE). Analysis of the osmoprotective properties of this extract for several strains of Escherichia coli (which differ from each other in their ability to accumulate GB (i) from the surrounding environment, and (ii) from its hydroxylated precursor choline), demonstrated the absence of GB in the SSE. From the overall results, we inferred that salt-stressed S. putrefaciens cells accumulated GB from choline present in the SSE. Furthermore, the use of [14C]-labeled betaines gave evidence that S. putrefaciens (i) oxidised choline to GB, (ii) accumulated GB as a non-metabolisable osmolyte (up to 1300 nmol (mg dw)(-1) when cultured in a medium containing 0.5 M NaCl and either 1 mM choline or 1 mM GB), and (iii) both choline and GB uptake activities were osmotically upregulated (both activities were increased more than 50-fold in media containing 0.4 to 0.6 M NaCl). In all, our results suggest that in salted smoked salmon, S. putrefaciens imports and oxidises choline, leading to the intracellular accumulation of GB.

Monitoring cerebral perfusion after subarachnoid hemorrhage using CT.

The aim of this prospective study was to assess the feasibility and diagnostic relevance of repetitive dynamic (contrast-enhanced) CT measurements of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) in the first 3 weeks after aneurysmal subarachnoid hemorrhage (SAH). In 15 patients with SAH, 59 dynamic CT studies including 944 regions of interest (ROI) were analyzed. The results were correlated with the clinical course and time after the event and the occurrence of vasospasm. Values for the entire series were 33.8+/-19.3 ml/100 g/min (CBF), 3.3+/-1.3 ml/100 g (CBV), and 7.3+/-3.9 s (MTT). Significant differences in CBF and CBV were found between ROI in grey and white matter, with time after the event, between patients with significant and absent or minor vasospasm, and between patients with and without a presumed vasospasm-related infarct.

Circadian phase-shifted rats show normal acquisition but impaired long-term retention of place information in the water task.

It is thought that circadian rhythms may influence learning and memory processes. However, research supporting this view does not dissociate a mnemonic impairment from other performance deficits. Furthermore, published reports do not specify the type of memory system influenced by the circadian system. The present study assessed the effects of phase shifting on acquisition and expression of place navigation in the water maze, a task sensitive to hippocampal dysfunction. The results showed that phase-shifting circadian rhythms in rats impaired the expression of place information on a retention test but not initial acquisition or encoding of place information. These results suggest that disruption of circadian rhythms may impair consolidation of previously encoded hippocampal place information.

Recent advances in the assessment of aberrant behavior maintained by automatic reinforcement in individuals with developmental disabilities.

Many aberrant behaviors exhibited by individuals with developmental disabilities are maintained by "automatic reinforcement". These behaviors are often difficult to treat, with the most effective behavioral interventions often resulting in only moderate success. However, a series of recent studies has advanced our ability to understand and treat these behaviors through the innovative use of behavioral assessment. We review the recent development of three categories of assessments: (a) nonhypothesis-based stimulus preference assessments, (b) hypothesis-based stimulus preference assessments, and (c) hypothesis-based assessments incorporating noncontingent reinforcement and sensory extinction procedures. We consider each category's contribution to both our ability to prescribe effective behavioral interventions and our ability to more fully understand the concept of automatic reinforcement.

Characterization of the ccpA gene of Enterococcus faecalis: identification of starvation-inducible proteins regulated by ccpA.

Inactivation of ccpA in Enterococcus faecalis leads to reduction of the growth rate, derepression of the galKETR operon in the presence of a mixture of glucose and galactose, and reduction of transcription of ldh in the presence of glucose. Moreover, the E. faecalis ccpA gene fully complements a Bacillus subtilis ccpA mutant, arguing for similar functions of these two homologous proteins. Protein comparison on two-dimensional gels from the wild-type cells and the ccpA mutant cells revealed a pleiotropic effect of the mutation on gene expression. The HPr protein of the carbohydrate-phosphotransferase system was identified by microsequencing, and a modification of its phosphorylation state was observed between the wild-type and the mutant strains. Moreover, at least 16 polypeptides are overexpressed in the mutant, and 6 are repressed. Interestingly, 13 of the 16 polypeptides whose synthesis is enhanced in the mutant were also identified as glucose starvation proteins. The N-terminal amino acid sequences of four of them match sequences deduced from genes coding for L-serine dehydratase, dihydroxyacetone kinase (two genes), and a protein of unknown function from Deinococcus radiodurans.

Noncontingent attention for the treatment of excessive medical complaints in a medically fragile man with mental retardation.

Providing medical care to individuals with developmental disabilities who have medical problems may pose several challenges with regard to accurate and reliable report of symptoms. In addition, medical complaints may take on operant functions such as an attention function or an escape function as a result of the natural consequences in the environment. It may be difficult to withhold reinforcers for medical complaints such as attention or escape, making a standard analog functional analysis or extinction-based intervention less appropriate. Recent studies have shown that noncontingent reinforcement without extinction and noncontingent reinforcement using alternative reinforcers can be effective in reducing problem behavior. One practical implication of these findings is that noncontingent reinforcement may be an appropriate treatment in cases where the reinforcer responsible for behavioral maintenance cannot be identified or withheld. In the current study, attention served as a reinforcer for a young man with medical complaints and noncontingent attention without ignoring effectively reduced the participant's excessive medical complaints.

Do stresses encountered during the smoked salmon process influence the survival of the spoiling bacterium Shewanella putrefaciens?

The influence of different treatments (i.e. cold, NaCl, phenol and anaerobiosis) encountered during the smoked salmon process was studied by analysing the survival capacity of two Shewanella putrefaciens strains (CIP 69.29 and J13.1). Our results indicated that only the salt stress was critical for the survival of S. putrefaciens. Nevertheless, both strains of S. putrefaciens grown at low temperatures developed a cross-protection to a lethal NaCl treatment. To our knowledge, this is the first report showing that growth at low temperatures induces cross-protection towards NaCl challenge. Moreover, we observed a significant sensitization by moderate salt concentration to a phenol treatment. From our combined data, we propose that control of S. putrefaciens proliferation could take place during the smoked salmon process rather than during storage of the final product.

Calcium affinity of regulatory sites in skeletal troponin-C is attenuated by N-cap mutations of helix C.

Site-directed mutagenesis was used to make amino acid substitutions at position 54 of skeletal troponin C, testing a relationship between the stability of helix C and calcium ion affinity at regulatory sites in the protein. Normally, threonine at position 54 is the first helical residue, or N-cap, of the C helix; where helices C and D, and the loop between, comprise binding site II. Mutations were made in the context of a previously described phenylalanine 29--> tryptophan (F29W) variant (Trigo-Gonzalez et al., Biochemistry 31, 7009-7015 (1992)), which allows binding events to be monitored through changes in the intrinsic fluorescence of the protein. N-Cap substitutions at position 54 were shown to attenuate the calcium affinity of regulatory sites in the N-terminal domain. Calcium affinities diminished according to the series T54 T54S > T54A > T54V > T54G with dissociation constants of 1.36 x 10(-6), 1.36 x 10(-6), 2.09 x 10(-6), 2.28 x 10(-6), and 4.24 x 10(-6) M, respectively. The steady state binding of calcium to proteins in the mutant series was seen to be monophasic and cooperative. Calcium off-rates were measured by stopped flow fluorescence and in every instance two transitions were observed. The rate constant of the first transition, corresponding to approximately 99% of the change in fluorescence, was between 900+/-20 and 1470+/-100 s(-1), whereas the rate constant of the second transitions was between 94+/-9 and 130+/-23 s(-1). The significance of two transitions remains unclear, though both rate constants occur on a time scale consistent with the regulation of contraction.