Effects of a low dose infusion of racemic and S-ketamine on the nociceptive withdrawal reflex in standing ponies

OBJECTIVE: To investigate the effect of plasma concentrations obtained by a low dose constant rate infusion (CRI) of racemic ketamine or S-ketamine on the nociceptive withdrawal reflex (NWR) in standing ponies. STUDY DESIGN: Prospective, blinded, cross-over study. ANIMALS: Six healthy 5-year-old Shetland ponies. METHODS: Ponies received either 0.6 mg kg(-1) racemic ketamine (group RS) or 0.3 mg kg(-1) S-ketamine (group S) intravenously (IV), followed by a CRI of 20 microg kg(-1)minute(-1) racemic ketamine (group RS) or 10 microg kg(-1)minute(-1) S-ketamine (group S) for 59 minutes. The NWR was evoked by transcutaneous electrical stimulation of a peripheral nerve before drug administration, 15 and 45 minutes after the start of the bolus injection and 15 minutes after the end of the CRI. Electromyographic responses were recorded and analysed. Arterial blood was collected before stimulation and plasma concentrations of ketamine and norketamine were measured enantioselectively using capillary electrophoresis. Ponies were video recorded and monitored to assess drug effects on behaviour, heart rate (HR), mean arterial blood pressure (MAP) and respiratory rate. RESULTS: The NWR was significantly depressed in group RS at plasma concentrations between 20 and 25 ng mL(-1) of each enantiomer. In group S, no significant NWR depression could be observed; plasma concentrations of S-ketamine (9-15 ng mL(-1)) were lower, compared to S-ketamine concentrations in group RS, although this difference was not statistically significant. Minor changes in behaviour, HR and MAP only occurred within the first 5-10 minutes after bolus drug administration in both groups. CONCLUSION: Antinociceptive activity in standing ponies, demonstrated as a depression of the NWR, could only be detected after treatment with racemic ketamine. S-ketamine may have lacked this effect as a result of lower plasma concentrations, a more rapid metabolism or a lower potency of S-ketamine in Equidae so further investigation is necessary.

Bone mineral density in young women with long-standing amenorrhea: limited effect of hormone replacement therapy with ethinylestradiol and desogestrel

To assess bone mineral density (BMD) at different skeletal sites in women with hypothalamic or ovarian amenorrhea and the effect of estrogen-gestagen substitution on BMD we compared BMD of 21 amenorrheic patients with hypothalamic or ovarian amenorrhea with that of a control population of 123 healthy women. All amenorrheic patients were recruited from the outpatient clinic of the Division of Gynecological Endocrinology at the University of Berne, a public University Hospital. One hundred and twenty-three healthy, regularly menstruating women recruited in the Berne area served as a control group. BMD was measured using dual-energy X-ray absorptiometry (DXA). At each site where it was measured, mean BMD was lower in the amenorrheic group than in the control group. Compared with the control group, average BMD in the amenorrheic group was 85% at lumbar spine (p < 0.0001), 92% at femoral neck (p < 0.02), 90% at Ward's triangle (p < 0.03), 92% at tibial diaphysis (p < 0.0001) and 92% at tibial epiphysis (p < 0.03). Fifteen amenorrheic women received estrogen-gestagen replacement therapy (0.03 mg ethinylestradiol and 0.15 mg desogestrel daily for 21 days per month), bone densitometry being repeated within 12-24 months. An annual increase in BMD of 0.2% to 2.9% was noted at all measured sites, the level of significance being reached at the lumbar spine (p < 0.0012) and Ward's triangle (p < 0.033). In conclusion BMD is lower in amenorrheic young women than in a population of normally menstruating, age-matched women in both mainly trabecular (lumbar spine, Ward's triangle, tibial epiphysis) and mainly cortical bone (femoral neck, tibial diaphysis).(ABSTRACT TRUNCATED AT 250 WORDS)

Catheter ablation of persistent and long-standing persistent atrial fibrillation. Strategies and results

Catheter ablation for paroxysmal atrial fibrillation is a meanwhile established therapy option, which is most frequently performed using radiofrequency ablation. Mid-term success rate of 70 % are achievable with a single ablation procedure. However, the mechanistics of persistent atrial fibrillation are less well understood and catheter ablation is a far more challenging procedure. Different ablation approaches are being performed to treat persistent atrial fibrillation ranging from sole pulmonary vein isolation to additional ablation of fractionated electrograms aiming for termination of atrial fibrillation. Thus far, it has not been investigated which strategy is most successful in treating persistent atrial fibrillation. After extended ablation of atrial fibrillation, occurrence of organized atrial arrhythmias is not uncommon and can be successfully ablated. These consecutive arrhythmias can be considered as a next step towards stable sinus rhythm after repeat ablation. Improvement of mapping methods as well as a better understanding of mechanisms of atrial fibrillation may increase success rate of catheter ablation of persistent atrial fibrillation and may also help to improve success rate of these complex procedures.

A 20-day period standing oscillation in the northern winter stratosphere

Observations of the ozone profile by a ground-based microwave radiometer in Switzerland indicate a dominant 20-day oscillation in stratospheric ozone, possibly related to oscillations of the polar vortex edge during winter. For further understanding of the nature of the 20-day oscillation, the ozone data set of ERA Interim meteorological reanalysis is analyzed at the latitude belt of 47.5° N and in the time from 1979 to 2010. Spectral analysis of ozone time series at 7 hPa indicates that the 20-day oscillation is maximal at two locations: 7.5° E, 47.5° N and 60° E, 47.5° N. Composites of the stream function are derived for different phases of the 20-day oscillation of stratospheric ozone at 7 hPa in the Northern Hemisphere. The streamline at Ψ = −2 × 107 m2 s−1 is in the vicinity of the polar vortex edge. The other streamline at Ψ = 4 × 107 m2 s1 surrounds the Aleutian anticyclone and goes to the subtropics. The composites show 20-day period standing oscillations at the polar vortex edge and in the subtropics above Northern Africa, India, and China. The 20-day period standing oscillation above Aral Sea and India is correlated to the strength of the Aleutian anticyclone.

Assessing the effectiveness of a long-standing rocky intertidal protected area and its contribution to the regional conservation of species, habitats and assemblages

1. The acceptance of reserves as a useful management strategy relies on evidence of their effectiveness in preserving stocks of harvested species and conserving biodiversity. A history of ad hoc decisions in terrestrial and marine protected area planning has meant that many of these areas are contributing inefficiently to conservation goals. The conservation value of existing protected areas should be assessed when planning the placement of additional areas in a reserve network. 2. This study tested (1) the effectiveness of protection for intertidal molluscs of a marine reserve (Bouddi Marine Extension, NSW, Australia) established in 1971, and (2) the contribution of the protected area to the conservation of regional species, assemblages, and habitats. 3. The shell length and population density of one harvested (Cellana tramoserica), and three non-harvested species (Bembicium nanum, Morula marginalba, Nerita atramentosa) of intertidal molluscs were examined in the protected area and two reference locations over two seasons. 4. The heavily collected limpet C. tramoserica was significantly larger in the protected area and was the only species to exhibit a significant difference. No species significantly differed in population density between the protected area and reference locations. 5. Temporally replicated surveys of macro-molluscs at 21 locations over 75km of coastline identified that the existing protected area included 50% of species, two of five assemblage types and 19 of 20 intertidal rocky shore habitats surveyed in the study region. Reservation of a further three rocky reefs would protect a large proportion of species (71%), a representative of each assemblage and all habitat types. 6. Despite originally being selected in the absence of information on regional biodiversity, the protected area is today an effective starting point for expansion to a regional network of intertidal protected areas.

The Swiss Schools have been Governed by Local Lay Authorities

After the introduction of the liberal-democratic constitutions in the Swiss cantons in the first half of the 1830ies the grid of existing schools has been systemized and broadly expanded. The school systems have ever since been characterized by one key element: a special local authority type called „Schulkommission“ or „Schulpflege“. They take the form of committees consisting of laymen that are appointed by democratic elections like all the other executive bodies on the different federal levels in Switzerland. When it comes to their obligations and activities these community level school committees conform very much to the school boards in the American and Canadian school systems. They are accountable for the selection and supervision of the teachers. They approve decisions about the school careers of pupils and about curricular matters like the choice of school books. Normally their members are elected by the local voters for four year terms of office (reelection remains possible) and with regard to pedagogics they normally are non-professionals. The board members are responsible for classes and teachers assigned to them and they have to go to see them periodically. These visitations and the board meetings each month together with the teachers enable the board members to attain a deep insight into what happens in their schools over the course of their term of office. But they are confronted as laymen with a professional teaching staff and with educational experts in the public administration. Nevertheless this form of executive power by non-professionals is constitutive for the state governance in the Swiss as well as in other national political environments. It corresponds to the principles of subsidiarity and militia and therefore allows for a strong accentuation of liberty and the right of self-determination, two axioms at the very base of democratic federalist ideology. This governance architecture with this strong accent on local anchorage features substantial advantages for the legitimacy and acceptability of political and administrative decisions. And this is relevant especially in the educational area because the rearing of the offspring is a project of hope and, besides, quite costly. In the public opinion such supervision bodies staffed by laymen seem to have certain credibility advances in comparison with the professional administration. They are given credit to be capable of impeding the waste of common financial resources and of warranting the protection and the fostering of the community’s children at once. Especially because of their non-professional character they are trusted to be reliably immune against organizational blindness and they seem to be able to defend the interests of the local community against the standardization and centralization aspirations originating from the administrational expertocracy. In the paper these common rationales will be underpinned by results of a comprehensive historical analysis of the Session protocols of three Bernese school commissions from 1835 to 2005.

Standing waves as an explanation for generic stationary correlation patterns in noninvasive EEG of focal onset seizures.

Cerebral electrical activity is highly nonstationary because the brain reacts to ever changing external stimuli and continuously monitors internal control circuits. However, a large amount of energy is spent to maintain remarkably stationary activity patterns and functional inter-relations between different brain regions. Here we examine linear EEG correlations in the peri-ictal transition of focal onset seizures, which are typically understood to be manifestations of dramatically changing inter-relations. Contrary to expectations we find stable correlation patterns with a high similarity across different patients and different frequency bands. This skeleton of spatial correlations may be interpreted as a signature of standing waves of electrical brain activity constituting a dynamical ground state. Such a state could promote the formation of spatiotemporal neuronal assemblies and may be important for the integration of information stemming from different local circuits of the functional brain network.

Oxygen consumption while standing iwth and unstable shoe design

This study explored the effects of unstable shoe design on oxygen consumption. Methods. Oxygen consumption (VO2) and heart rate (HR) were measured in 16 individuals while barefoot, wearing unstable shoes (Masai Barefoot Technology) and wearing conventional sport shoes while standing and walking on a treadmill and for 5 individuals while walking around a 400 m track. Results. When wearing the MBT shoes, a significant (p < 0.01) increase of 9.3 ± 5.2% in VO2 was measured while standing quietly for 6 min. No differences in VO2 and HR were observed between the MBT shoes or weight-adjusted conventional shoes (to match the weight of the MBT shoes) while walking on a treadmill. However, significant increases (p < 0.01) in VO2 (4.4 ± 8.2%) and HR (3.6 ± 7.3%) were observed for the MBT shoes compared with being barefoot. No significant differences in VO2 and HR were recorded while walking around a 400 m track either with MBT shoes, weight-adjusted conventional shoes or barefoot. Nonetheless, a comparison of the MBT shoes with barefoot revealed a tendency for VO2 to be higher when wearing the MBT shoes (7.1 ± 6.5%, p < 0.1) although HR was not significantly affected. Conclusions. The unstable shoe design predominantly effects oxygen consumption while standing, most likely due to increased muscle activity of the lower extremities.