A shift from passive teaching at medical conferences to more interactive methods improves physician learning

Conferences that deliver interactive sessions designed to enhance physician participation, such as role play, small discussion groups, workshops, hands-on training, problem- or case-based learning and individualised training sessions, are effective for physician education.

Experimental control of single-mode laser chaos by using continuous, time-delayed feedback

Control of chaos in the single-mode optically pumped far-infrared (NH3)-N-15 laser is experimentally demonstrated using continuous time-delay control. Both the Lorenz spiral chaos and the detuned period-doubling chaos exhibited by the laser have been controlled. While the laser is in the Lorenz spiral chaos regime the chaos has been controlled both such that the laser output is cw, with corrections of only a fraction of a percent necessary to keep it there, and to period one. The laser has also been controlled while in the period-doubling chaos regime, to both the period-one and -two states.

Aminotriazines as locking fragments in macrocyclic synthesis

The macrocyclic compounds (6-(4',6'-diamino-1',3',5'-triazinyl)-1,4,6,8,11-pentaazacyclotetradecane)copper(II) triperchlorate dihydrate, [Cu(HL2)](ClO4)(3). 2H(2)O, (6-(6'-amino-4'-oxo-1'H-1',3',5'-triazinyl)-1,4,6,8,11-pentaazacyclotetradecane)copper(II) diperchlorate hydrate, [CuL3](ClO4)(2). H2O, and [(6-(4',6'-dioxo-1'H-1',3',5'-triazinyl) 1,4,6,8,11-pentaazacyclotetradecane)copper(II)] diperchlorate, [CuL4](ClO4)(2), have been synthesized. The macrocycles synthesized contain respectively pendant melamine, ammeline,and ammelide rings. The X-ray cyrstallographic analyses of [Cu(HL2)](ClO4)(3). 2H(2)O, triclinic, space group P (1) over bar, a = 9.489(10) Angstrom, b = 12.340(2) Angstrom, c = 24.496(4) Angstrom, alpha = 87.74(10)degrees beta = 85.51(10)degrees gamma = 70.95(10)degrees and Z = 4, and {[CuL3](ClO4)(2). H2O}2, monoclinic, space group C2/c, a = 18.624(8) Angstrom, b = 17.160(2) Angstrom, c = 15.998(6) Angstrom, beta = 117.82(2)degrees, and Z = 4, are reported. The structure of [Cu(HL2)](ClO4)(3). 2H(2)O shows the formation of linear tapes, formed by a combination of hydrogen bonds and pi-pi stacking interactions. The structure of [CuL3](ClO4)(2). H2O displays formation of dimers, formed by a coordinate bond from the oxygen in one molecule to the copper atom of another. The tautomeric forms of the ammeline and ammelide moieties have been determined. The potential of these compounds as subunits for cocrystallization has been investigated.

A new small molecule C5a receptor antagonist inhibits the reverse-passive arthus reaction and endotoxic shock in rats

C5a is implicated as a pathogenic factor in a wide range of immunoinflammatory diseases, including sepsis and immune complex disease, Agents that antagonize the effects of C5a could be useful in these diseases. We have developed some novel C5a antagonists and have determined the acute anti-inflammatory properties of a new small molecule C5a receptor antagonist against C5a- and LPS-induced neutrophil adhesion and cytokine expression, as well as against some hallmarks of the reverse Arthus reaction in rats. We found that a single i.v. dose (1 mg/kg) of this antagonist inhibited both C5a- and LPS-induced neutropenia and elevated levels of circulating TNF-alpha, as well as polymorphonuclear leukocyte migration, increased TNF-alpha levels and vascular leakage at the site of immune complex deposition. These results indicate potent anti-inflammatory activities of a new C5a receptor antagonist and provide more evidence for a key early role for C5a in sepsis and the reverse Arthus reaction. The results support a role for antagonists of C5a receptors in the therapeutic intervention of immunoinflammatory disease states such as sepsis and immune complex disease.

Passive smoking and lung cancer: a cumulative meta-analysis

Objective: To review the epidemiological evidence for the association between passive smoking and lung cancer. Method: Primary studies and meta-analyses examining the relationship between passive smoking and lung cancer were identified through a computerised literature search of Medline and Embase, secondary references, and experts in the field of passive smoking. Primary studies meeting the inclusion criteria were meta-analysed. Results From 1981 to the end of 1999 there have been 76 primary epidemiological studies of passive smoking and lung cancer, and 20 meta-analyses. There were 43 primary studies that met the inclusion criteria for this meta-analysis; more studies than previous assessments. The pooled relative risk (RR) for never-smoking women exposed to environmental tobacco smoke (ETS) from spouses, compared with unexposed never-smoking women was 1.29 (95% CI 1.17-1.43). Sequential cumulative meta-analysed results for each year from 1981 were calculated: since 1992 the RR has been greater than 1.25. For Western industrialised countries the RR for never-smoking women exposed to ETS compared with unexposed never-smoking women, was 1.21 (95% CI 1.10-1.33). Previously published international spousal meta-analyses have all produced statistically significant RRs greater than 1.17. Conclusions The abundance of evidence in this paper, and the consistency of findings across domestic and workplace primary studies, dosimetric extrapolations and meta-analyses, clearly indicates that non-smokers exposed to ETS are at increased risk of lung cancer. Implications: The recommended public health policy is for a total ban on smoking in enclosed public places and work sites.

H-reflex modulation during passive lengthening and shortening of the human triceps surae

1. The present study investigated the effects of lengthening and shortening actions on IT-reflex amplitude. H-reflexes were evoked in the soleus (SOL) and medial gastroenemius (MG) of human subject, during passive isometric, lengthening and shortening actions performed at angular velocities of 0, +/-2, +/-5 and +/- 15 deg s(-1). 2. H-reflex amplitude, in froth SOL and MG were significantly depressed during passive lengthening actions and facilitated during passive shortening actions, when compared with the isometric R-reflex amplitude. 3. Four experiments were performed in which the latencies front the onset of movement to delivery of the stimulus were altered. Passive H-reflex modulation during lengthening actions was found tee begin at latencies of less than 60 ms suggesting that this inhibition was due to peripheral and/or spinal mechanisms. 4. It is postulated that, the H-reflex modulation seen in the present study is related to the tunic discharge of muscle spindle afferents and the consequent effects of transmission within the la pathway. Inhibition of the H-reflex at less than 60 ms after the onset of muscle lengthening may he attributed to several mechanisms, which cannot be distinguished using the current protocol. These may include the inability to evoke volleys in la fibres that are refractory following muscle spindle discharge during; rapid muscle lengthening, a reduced probability of transmitter release front the presynaptic terminal (homosynaptic post.-activation depression) and presynaptic inhibition of la afferents from plantar flexor agonists. Short latency facilitation of the H-reflex may be attributed to temporal summation of excitatory postsynaptic potentials arising from muscle spindle afferents during rapid muscle lengthening. At longer latencies, presynaptic inhibition of Ia afferents cannot be excluded as a potential inhibitory mechanism.

Active and passive smoking and the risk of subarachnoid hemorrhage - An international population-based case-control study

Background and Purpose - This study was undertaken to better clarify the risks associated with cigarette smoking and subarachnoid hemorrhage (SAH). Methods - The study included 432 incident cases of SAH frequency matched to 473 community SAH-free controls to determine dose-dependent associations of active and passive smoking ( at home) and smoking cessation with SAH. Results - Compared with never smokers not exposed to passive smoking, the adjusted odds ratio for SAH among current smokers was 5.0 (95% confidence interval [CI], 3.1 to 8.1); for past smokers, 1.2 ( 95% CI, 0.8 to 2.0); and for passive smokers, 0.9 ( 95% CI, 0.6 to 1.5). Current and lifetime exposures showed a clear dose-dependent effect, and risks appeared more prominent in women and for aneurysmal SAH. Approximately 1 in 3 cases of SAH could be attributed to current smoking, but risks decline quickly after smoking cessation, even among heavy smokers. Conclusions - A strong positive association was found between cigarette smoking and SAH, especially for aneurysmal SAH and women, which is virtually eliminated within a few years of smoking cessation. Large opportunities exist for preventing SAH through smoking avoidance and cessation programs.

Mode of action of back-line application of spinosad, a non-systemic parasiticide, on sheep

Spinosad, applied as a jetting solution or dip is an efficacious, non-systemic treatment for the control of Bovicola ovis in sheep. This paper describes the effect of back-line treatment width and group housing of animals on the efficacy of spinosad for the control of lice. A 0.4 mg/kg liveweight dose was found to be the suboptimal dose of spinosad for the control of body lice in a dose titration study and was used to investigate application and housing effects in a second study. Lousy Merino sheep were treated with either a narrow 3-cm application of spinosad or with a wider 25-cm swathe. After treatment they were either kept alone or in groups of 6 sheep per pen. Lice were counted at day 0 and every 14 days to 70 days after treatment before estimation of the percentage of lice control and analysis of treatment effects. A much higher percentage of lice control was achieved with 0.4 mg/kg in the second study than in the first, possibly because of differences in formulation used. The wider application width gave significantly higher (P < 0.05) control of lice than the narrow application when sheep were either housed alone or in groups up to day 42 post-treatment. Greater control of lice was seen in group-housed sheep compared with sheep housed individually (P < 0.05) up to day 70. Using broader application widths combined with holding the animals together after treatment with pour-on formulations may optimise the delivery and efficacy of ectoparasiticides for livestock.

Phase waves in mode-locked superfluorescent lasers

We present results from both theoretical and experimental studies of the noise characteristics of mode-locked superfluorescent lasers. The results show that observed macroscopic broadband amplitude noise on the laser pulse train has its origin in quantum noise-initiated ''phase-wave'' fluctuations, and we find an associated phase transition in the noise characteristics as a function of laser cavity detuning.

White matter microstructure underlying default mode network connectivity in the human brain

Resting state functional magnetic resonance imaging (fMRI) reveals a distinct network of correlated brain function representing a default mode state of the human brain The underlying structural basis of this functional connectivity pattern is still widely unexplored We combined fractional anisotropy measures of fiber tract integrity derived from diffusion tensor imaging (DTI) and resting state fMRI data obtained at 3 Tesla from 20 healthy elderly subjects (56 to 83 years of age) to determine white matter microstructure e 7 underlying default mode connectivity We hypothesized that the functional connectivity between the posterior cingulate and hippocampus from resting state fMRI data Would be associated with the white matter microstructure in the cingulate bundle and fiber tracts connecting posterior cingulate gyrus With lateral temporal lobes, medial temporal lobes, and precuneus This was demonstrated at the p<0001 level using a voxel-based multivariate analysis of covariance (MANCOVA) approach In addition, we used a data-driven technique of joint independent component analysis (ICA) that uncovers spatial pattern that are linked across modalities. It revealed a pattern of white matter tracts including cingulate bundle and associated fiber tracts resembling the findings from the hypothesis-driven analysis and was linked to the pattern of default mode network (DMN) connectivity in the resting state fMRI data Out findings support the notion that the functional connectivity between the posterior cingulate and hippocampus and the functional connectivity across the entire DMN is based oil distinct pattern of anatomical connectivity within the cerebral white matter (C) 2009 Elsevier Inc All rights reserved