Spectroscopy of D-type asteroids

We have performed a spectroscopic survey of 19 D-type asteroids. Comparison with previous photometry shows excellent agreement. Although the majority have similar colors to cometary nuclei, no cometary emission bands were present in any of the spectra. Absorption bands sporadically appearing were apparently due to stellar objects, and no features inherent to the asteroids were observed

Antagonism of neuromuscular blockade but not muscle relaxation affects depth of anaesthesia

Background. Conflicting effects of neuromuscular blocking drugs and anticholinesterases on depth of anaesthesia have been reported. Therefore we evaluated the effect of atracurium and neostigmine on bispectral index (BIS) and middle-latency auditory evoked potentials (AAI). Methods. We studied 40 patients (ASA I-II) aged 18-69 yr. General anaesthesia consisted of propofol and remifentanil by target-controlled infusion and neuromuscular function was monitored by electromyography. When BIS reached stable values, patients were randomly assigned to one of two groups. Group 1 received atracurium 0.4 mg kg−1 and, 5 min later, the same volume of NaCl 0.9%; group 2 received saline first and then atracurium. When the first twitch of a train of four reached 10% of control intensity, patients were again randomized: one group (N) received neostigmine 0.04 mg kg−1 and glycopyrrolate 0.01 mg kg−1, and the control group (G) received only glycopyrrolate. Results. Injection of atracurium or NaCl 0.9% had no effect on BIS or AAI. After neostigmine-glycopyrrolate, BIS and AAI increased significantly (mean maximal change of BIS 7.1 [sd 7.5], P<0.001; mean maximal change of AAI 9.7 [10.5], P<0.001). When glycopyrrolate was injected alone BIS and AAI also increased (mean maximal change of BIS 2.2 [3.4], P=0.008; mean maximal change of AAI 3.5 [5.7], P=0.012), but this increase was significantly less than in group N (P=0.012 for BIS; P=0.027 for AAI). Conclusion. These data suggest that neostigmine alters the state of propofol-remifentanil anaesthesia and may enhance recover

Memory and superposition in a spin glass

Non-equilibrium dynamics in a Ag(Mn) spin glass are investigated by measurements of the temperature dependence of the remanent magnetisation. Using specific cooling protocols before recording the thermo- or isothermal remanent magnetisations on re-heating, it is found that the measured curves effectively disclose non-equilibrium spin glass characteristics such as ageing and memory phenomena as well as an extended validity of the superposition principle for the relaxation. The usefulness of this "simple" dc-method is discussed, as well as its applicability to other disordered magnetic systems.Comment: REVTeX style; 8 pages, 4 figure

Interactional Structure Applied to the Identification and Generation of Visual Interactive Behavior: Robots that (Usually) Follow the Rules

Peer reviewe

Non-equilibrium dynamics in an interacting nanoparticle system

Non-equilibrium dynamics in an interacting Fe-C nanoparticle sample, exhibiting a low temperature spin glass like phase, has been studied by low frequency ac-susceptibility and magnetic relaxation experiments. The non-equilibrium behavior shows characteristic spin glass features, but some qualitative differences exist. The nature of these differences is discussed.Comment: 7 pages, 11 figure

Relaxation of the field-cooled magnetization of an Ising spin glass

The time and temperature dependence of the field-cooled magnetization of a three dimensional Ising spin glass, Fe_{0.5}Mn_{0.5}TiO_{3}, has been investigated. The temperature and cooling rate dependence is found to exhibit memory phenomena that can be related to the memory behavior of the low frequency ac-susceptibility. The results add some further understanding on how to model the three dimensional Ising spin glass in real space.Comment: 8 pages RevTEX, 5 figure

Fatal myocardial infarction after lung resection in a patient with prophylactic preoperative coronary stenting†

In this report we present the case of a 77-yr-old man who underwent resection of the upper lobe of the left lung for a carcinoma, six weeks after percutaneous transluminal coronary angioplasty (PTCA) with stenting of the left anterior descending (LAD) and circumflex coronary arteries. Antiplatelet therapy with clopidogrel was interrupted two weeks before surgery to allow for epidural catheter placement and to minimize haemorrhage. The surgical procedure was uneventful. In the immediate postoperative period, however, the patient suffered severe myocardial ischaemia. Emergency coronary angiography showed complete thrombotic occlusion of the LAD stent. In spite of successful recanalization, reinfarction occurred and the patient died in cardiogenic shock. Prophylactic preoperative coronary stenting may put the patient at risk of stent thrombosis if surgery cannot be postponed for three months. In such cases, other strategies such as perioperative β-blockade for preoperative cardiac management should be considered. Br J Anaesth 2004; 92: 743-