Pain in traumatic upper limb amputees in Sierra Leone.

Data on 40 upper limb amputees (11 bilateral) with regard to stump pain, phantom sensation and phantom pain is presented. All the patients lost their limbs as a result of violent injuries intended to terrorise the population and were assessed 10-48 months after the injury. All amputees reported stump pain in the month prior to interview and ten of the 11 bilateral amputees had bilateral pain. Phantom sensation was common (92.5%), but phantom pain was only present in 32.5% of amputees. Problems in translation and explanation may have influenced the low incidence of phantom pain and high incidence of stump pain. In the bilateral amputees phantom sensation, phantom pain and telescoping all showed bilateral concordance, whereas stump pain and neuromas did not show concordance. About half the subjects (56%) had lost their limb at the time of injury (primary) while the remainder had an injury, then a subsequent amputation in hospital (secondary). There was no association between the incidence of phantom pain and amputation irrespective of being primary or secondary

Hemidactylus mabouia

Number of Pages: 11Integrative BiologyGeological Science

Theory of magnetism with temporal disorder applied to magnetically doped ZnO

A dynamic model of the asymmetric Ising glass is presented: an Ising model with antiferromagnet bonds with probabilities q arranged at random in a ferromagnetic matrix. The dynamics is introduced by changing the arrangement of the antiferromagnetic bonds after n Monte Carlo steps but keeping the same value of q and spin configuration. In the region where there is a second order transition between the ferromagnetic and paramagnetic states the dynamic behaviour follows that expected for motional narrowing and reverts to the static behaviour only for large n. There is a different dynamic behaviour where there is a first order transition between the ferromagnetic and spin glass states where it shows no effects of motional narrowing. The implications of this are discussed. This model is devised to explain the properties of doped ZnO where the magnetisation is reduced when the exchange interactions change with time.Comment: Paper was presented at MMM 2008 and is accepted for publication in J.A.

Isoprene oxidation by the gram-negative model bacterium variovorax sp. WS11

Plant-produced isoprene (2-methyl-1,3-butadiene) represents a significant portion of global volatile organic compound production, equaled only by methane. A metabolic pathway for the degradation of isoprene was first described for the Gram-positive bacterium Rhodococcus sp. AD45, and an alternative model organism has yet to be characterised. Here, we report the characterisation of a novel Gram-negative isoprene-degrading bacterium, Variovorax sp. WS11. Isoprene metabolism in this bacterium involves a plasmid-encoded iso metabolic gene cluster which differs from that found in Rhodococcus sp. AD45 in terms of organisation and regulation. Expression of iso metabolic genes is significantly upregulated by both isoprene and epoxyisoprene. The enzyme responsible for the initial oxidation of isoprene, isoprene monooxygenase, oxidises a wide range of alkene substrates in a manner which is strongly influenced by the presence of alkyl side-chains and differs from other well-characterised soluble diiron monooxygenases according to its response to alkyne inhibitors. This study presents Variovorax sp. WS11 as both a comparative and contrasting model organism for the study of isoprene metabolism in bacteria, aiding our understanding of the conservation of this biochemical pathway across diverse ecological niches

Regulation of plasmid-encoded isoprene metabolism in Rhodococcus, a representative of an important link in the global isoprene cycle

Emissions of biogenic volatile organic compounds (VOCs) form an important part of the global carbon cycle, comprising a significant proportion of net ecosystem productivity. They impact atmospheric chemistry and contribute directly and indirectly to greenhouse gases. Isoprene, emitted largely from plants, comprises one third of total VOCs, yet in contrast to methane, which is released in similar quantities, we know little of its biodegradation. Here, we report the genome of an isoprene degrading isolate, Rhodococcus sp. AD45, and, using mutagenesis shows that a plasmid-encoded soluble di-iron centre isoprene monooxygenase (IsoMO) is essential for isoprene metabolism. Using RNA sequencing (RNAseq) to analyse cells exposed to isoprene or epoxyisoprene in a substrate-switch time-course experiment, we show that transcripts from 22 contiguous genes, including those encoding IsoMO, were highly upregulated, becoming among the most abundant in the cell and comprising over 25% of the entire transcriptome. Analysis of gene transcription in the wild type and an IsoMO-disrupted mutant strain showed that epoxyisoprene, or a subsequent product of isoprene metabolism, rather than isoprene itself, was the inducing molecule. We provide a foundation of molecular data for future research on the environmental biological consumption of this important, climate-active compound

Pupil size dynamics predict dLGN firing mode over a wide range of timescales

Pupil size is a commonly used proxy for waking brain states such as arousal, and has been related to activity modulations in cortical sensory areas. Here, we asked whether the dorsolateral geniculate nucleus (dLGN), which provides sensory input to the visual cortex, is modulated by pupil-indexed arousal. Observing that the pupil size oscillates at multiple timescales, we developed a method to show that the spiking mode of the dLGN is predicted by pupil size oscillations over several of these timescales. Overall, we found that tonic spikes preferentially occurred during pupil dilation, while bursts occurred during contraction. These preferences could not be explained solely by pupil size per se or by the locomotion of the animal, and were also present during periods of stimulus viewing. We conclude that dLGN spiking activity is modulated by pupil-indexed arousal processes on various timescales, influencing the mode in which sensory signals are passed on to the cortex

Rockets, Men and Medicine

Space Medicine has at last become an accepted entity in the vast field of medical research after many years of ridicule and scorn. The recent successes of the U .S.S.R. and U .S.A. in launching earth and sun satellites would seem adequate to justify the existence of space medicine. It seems Man's avowed intention to conquer the third dimension, the vertical, which leads to space and as such it is the duty of the medical scientist to make this journey as safe as possible for the would-be space traveller.Space is not a well defined region since it has no accurate topographical boundaries and in the context of this article the best way of defining space is to think in terms of levels of space equivalency, i.e. levels at which various protective functions of the Earth's atmosphere are lost so creating a space-like state for a certain phenomenon at a particular altitude. From the viewpoint of respiratory physiology space begins at a height of 52,500 feet since the effects of explosive decompression assume a constant value at and over this level. In similar terms the atmosphere acts as a filter against cosmic factors and this function of itself provides a variety of space equivalencies ranging from sea level in the case of infra-red rays, to 10-20 miles for cosmic primaries and as high as 75 miles for visible light. Space, therefore, is a concept which of necessity is a variable and its effects may be just as varied

Precipitation Hardenable High Temperature Shape Memory Alloy

A composition of the invention is a high temperature shape memory alloy having high work output, and is made from (Ni+Pt+Y),Ti(100-x) wherein x is present in a total amount of 49-55 atomic % Pt is present in a total amount of 10-30 atomic %, Y is one or more of Au, Pd. and Cu and is present in a total amount of 0 to 10 atomic %. The alloy has a matrix phase wherein the total concentration of Ni, Pt, and the one or more of Pd. Au, and Cu is greater than 50 atomic %

Latex allergy at Groote Schuur hospital prevalence, clinical features and outcome

Background. The incidence of latex allergy is increasing worldwide but there is very little information available on the clinical outcome for affected individuals.Objective. To determine the prevalence of latex allergy at Groote Schuur Hospital, a large teaching hospital in Cape Town, and to study the outcome for affected individuals.Method. Using a questionnaire, we screened 2 316 hospital workers for the presence of work-related symptoms. Workers who were symptomatic had Immunocap RAST (CAP RAST) or skin-prick tests to confirm latex sensitivity. Latexavoidance measures were implemented in positive subjects. One hundred symptomatic, sensitised individuals were followed up 3 months after intervention to assess their clinical status. A further cohort of 25 individuals with ongoing nasal symptoms were studied in detail.Results. Latex sensitisation was confirmed in 182 of 717 symptomatic workers (25.3%). SenSitised symptomatic workers were significantly more likely to have had a previous history of urticaria (P = < 0.001), oral allergy syndrome (P = < 0.001), or allergic conjunctivitis (P = 0.001), but not hay fever, perennial rhinitis, eczema or insect allergies. Latex sensitisation occurred among all classes of health care workers. Ocular and cutaneous symptoms were significantly associated with positive latex sensitisation (P = < 0.001). After latex intervention, ocular symptoms (P = < 0.001), skin rashes (P = < 0.001) and wheezing (P = 0.001) reduced significantly. Nasal symptoms did not improve. Undiagnosed and untreated underlying allergies to common aero-allergens were present in the majority of latexsensitised patients with ongoing nasal symptomatology.Conclusion. The prevalence of symptomatic sensitisation to latex allergy at Groote Schuur Hospital is between 9.2 and 11.2%. Ocular and cutaneous symptoms are the most prevalent in sensitised workers, and unlike nasal symptoms are significantly reduced when latex-avoidance measures are introduced. Ongoing nasal symptoms after intervention is instituted are probably due to other allergic sensitivities in latex-sensitised health care workers

Coherently coupled photonic-crystal surface-emitting laser array

The realization of a 1 × 2 coherently coupled photonic crystal surface emitting laser array is reported. New routes to power scaling are discussed and the electronic control of coherence is demonstrated