230 research outputs found
Why are Orlicz spaces useful for Statistical Physics?
We review a new formalism based on Orlicz spaces for the description of large
regular statistical systems. Our presentation includes both classical and
quantum systems. The presented approach has the advantage that statistical
mechanics is much better settled.Comment: 11 pages. arXiv admin note: text overlap with arXiv:1302.346
On applications of Orlicz Spaces to Statistical Physics
We present a new rigorous approach based on Orlicz spaces for the description
of the statistics of large regular statistical systems, both classical and
quantum. This approach has the advantage that statistical mechanics is much
better settled. In particular, a new kind of renormalization leading to states
having a well defined entropy function is presented.Comment: 20 page
Quantum Fokker-Planck Dynamics
The Fokker-Planck equation is a partial differential equation which is a key
ingredient in many models in physics. This paper aims to obtain a quantum
counterpart of Fokker-Planck dynamics, as a means to describing quantum
Fokker-Planck dynamics. Given that relevant models relate to the description of
large systems, the quantization of the Fokker-Planck equation should be done in
a manner that respects this fact, and is therefore carried out within the
setting of non-commutative analysis based on general von Neumann algebras.
Within this framework we present a quantization of the generalized Laplace
operator, and then go on to incorporate a potential term conditioned to
noncommutative analysis. In closing we then construct and examine the
asymptotic behaviour of the corresponding Markov semigroups. We also present a
noncommutative Csiszar-Kullback inequality formulated in terms of a notion of
relative entropy, and show that for more general systems, good behaviour with
respect to this notion of entropy ensures similar asymptotic behaviour of the
relevant dynamics.Comment: The final version submitted to AHP. A brief account of applied
quantization as well as the comprehensive description of closability of
quantum Laplacian is adde
Errors in drug administration by anaesthetists in public hospitals in the Free State
Objective. To investigate errors in administering drugs by anaesthetists working in public hospitals in the Free State province. Methods. Anonymous questionnaires were distributed to doctors performing anaesthesia in public hospitals in the Free State, i.e. 188 doctors at 22 public sector hospitals. Outcomes included demographic information on respondents, information regarding the administration of anaesthetics, reporting of errors, and the occurrence of errors during anaesthesia. Results. The response rate was 46.3%; 48.8% were medical officers, and 39.3% of participants were involved in at least one event of erroneous drug administration. Registrars and specialists reported the most errors. Most events were of no clinical significance, caused no permanent harm to patients, and most commonly involved fentanyl and suxamethonium. Of the respondents, 23.8% indicated that they were aware of a South African standard for colour-coding syringe labels, and 92.9% indicated that they would report anaesthetic errors if a single reporting agency for such events existed. Conclusions. More than a third of participating anaesthetists were involved in a drug error at some stage in their practice. Preventive systems and precautionary measures should be put in place to reduce drug administration errors
222Rn calibrated mercury fluxes from terrestrial surfaces of southern Africa derived from observations at Cape Point, South Africa
Gaseous elemental mercury (GEM) and 222Rn, a radioactive gas of primarily terrestrial origin with a half-life of 3.8 days, have been measured simultaneously at Cape Point, South Africa, since March 2007. Between March 2007 and December 2009 altogether 59 events with high 222Rn concentrations were
identified. GEM correlated with 222Rn in 41 of the events and was constant during the remaining events without significant correlation. The average GEM/222Rn emission ratio of all events was -0.0047 ± 0.0054 pg
mBq-1, with ± 0.0054 being the standard error of the average. With an emission rate of 1.1 222Rn atoms cm-2 s-1 and a correction for the transport duration, this emission ratio corresponds to a radon calibrated flux of about -0.53 ± 0.62 ng m-2 h-1 which is statistically not distinguishable from zero. With wet deposition, which is not included in this estimate, the terrestrial surface of southern Africa appears to be a net mercury sink. © Owned by the authors, published by EDP Sciences, 201
222Rn-calibrated mercury fluxes from terrestrial surface of southern Africa
Gaseous elemental mercury (GEM) and 222Rn, a radioactive gas of primarily terrestrial origin with a half-life of 3.8 days, have been measured simultaneously at Cape Point, South Africa, since March 2007. Between March 2007 and December 2011, altogether 191 events with high 222Rn concentrations were identified. GEM correlated with 222Rn in 94 of the events and was constant during almost all the remaining events without significant correlation. The average GEM / 222Rn flux ratio of all events including the non-significant ones was −0.0001 with a standard error of ±0.0030 pg mBq−1. Weighted with the event duration, the average GEM / 222Rn flux ratio was −0.0048 ± 0.0011 pg mBq−1. With an emission rate of 1.1 222Rn atoms cm−2 s−1 and a correction for the transport time, this flux ratio corresponds to a radon-calibrated flux of about −0.54 ng GEM m−2 h−1 with a standard error of ±0.13 ng GEM m−2 h−1 (n = 191). With wet deposition, which is not included in this estimate, the terrestrial surface of southern Africa seems to be a net mercury sink of about −1.55 ng m−2 h−1. The additional contribution of an unknown but presumably significant deposition of reactive gaseous mercury would further increase this sink.© 2013, European Geosciences Unio
Micromanipulation at an infertility centre
Aim. Human in vitro fertilisation (IVF) and gamete intrafallopian transfer have been used in the management of various forms of infertility. In cases of severe male-factor infertility, fertilisation can be a factor. In this study micromanipulation was used to increase fertilisation in such cases.Methods. Two micromanipulation techniques, subzonal sperm injection (SUZI) and partial zona dissection (PZD), were used to assist fertilisation in patients with abnorTl)al semen parameters. Ten couples with severe oligo-, teratoand asthenozoospermia participated in the SUZI programme. Seventy-three oocytes were obtained from these 10 patients. PZD was used on day 1 oocytes in cases of male infertility as well as a rescue attempt on day 2 oocytes when fertilisation had failed after routine insemination.Results. The SUZI technique had a fertilisation rate of 37,7%. In this group, a biochemical pregnancy was achieved. Differences between the fertilisation rate of conventionallVF (33,3%) and PZD (56,3%) in cases of male infertility, were not statistically significant although a clinical difference could be detected. PZD was statistically effective in facilitating fertilisation (37,5% v. 8,3%) in couples where this procedure was introduced to reinseminate 24-hour-old unfertilised oocytes. Four patients received PZD reinseminated embryos. An average of 1,45 PZD embryos were replaced and 1 implantation pregnancy was confirmed.Conclusion. The micromanipulation results are encouraging arid seemed to increase the efficiency of IVF in humans. Furthermore, our data support the conclusion that micromanipulation procedures can bring about pregnancies
Freeze-drying of Aegyptianella pullorum
Heparinized whole blood, parasitized with Aegyptianella pullorum, was collected from 2 fowls. Buffered lactose peptone (BLP) was added v/v as a stabilizer and the mixture lyophilized in 2ml aliquots after rapid or slow freezing. At different stages during the freeze-drying process, as well as after lyophilization and reconstitution with I ,8 ml of sterile water, samples were taken and injected into pullets. Infectivity was maintained throughout. However, the prepatent period was lengthened after freezing and particularly after lyophilization when there was some loss of viability.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201
Errors in drug administration by anaesthetists in public hospitals in the Free State
Objective. To investigate errors in administering drugs by anaesthetists working in public hospitals in the Free State province.
Methods. Anonymous questionnaires were distributed to doctors performing anaesthesia in public hospitals in the Free State Province, i.e. 188 doctors at 22 public sector hospitals. Outcomes included demographic information on respondents, information regarding the administration of anaesthetics, reporting of errors, and the occurrence of errors during anaesthesia.
Results. The response rate was 46.3%; 48.8% were medical officers, and 39.3% of participants were involved in at least one event of erroneous drug administration. Registrars and specialists reported the most errors. Most events were of no clinical significance, caused no permanent harm to patients, and most commonly involved fentanyl and suxamethonium. Of the respondents, 23.8% indicated that they were aware of a South African standard for colour coding syringe labels, and 92.9% indicated that they would report anaesthetic errors if a single reporting agency for such events existed.
Conclusions. More than a third of participating anaesthetists were involved in a drug error at some stage in their practise. Preventative systems and precautionary measures should be put in place to reduce drug administration errors
One-carbon metabolism in cancer
Cells require one-carbon units for nucleotide synthesis, methylation and reductive metabolism, and these pathways support the high proliferative rate of cancer cells. As such, anti-folates, drugs that target one-carbon metabolism, have long been used in the treatment of cancer. Amino acids, such as serine are a major one-carbon source, and cancer cells are particularly susceptible to deprivation of one-carbon units by serine restriction or inhibition of de novo serine synthesis. Recent work has also begun to decipher the specific pathways and sub-cellular compartments that are important for one-carbon metabolism in cancer cells. In this review we summarise the historical understanding of one-carbon metabolism in cancer, describe the recent findings regarding the generation and usage of one-carbon units and explore possible future therapeutics that could exploit the dependency of cancer cells on one-carbon metabolism
- …