The non-invasive assessment of the ischaemic limb, with particular reference to thermography.

Skin temperature (Tsk) has long been used in assessing limb circulation, and in recent years thermography has been used as an accurate way of measuring Tsk. However, apart from the general proposition that Tsk must be related to that of the blood, the precise relationship between the blood supply to a limb and its Tsk remains poorly understood. Without this knowledge full use cannot be made of thermography in the assessment of the limb with peripheral vascular disease. The purpose of these studies was to provide a scientific basis for the use of thermography on limbs. Previous work had indicated that Tsk was related to skin blood flow in the hand and foot, but not in the forearm or calf. This work has been confirmed and extended by studies on normal subjects at different ambient temperatures, and on subjects with a peripheral A-V fistula. I have shown that Tsk over the forearm and calf is related to the core temperature of the limb, i.e. to the arterial inflow. An attempt was then made to see if these findings could be used to interpret the abnormal thermograms found in a group of patients with intermittent claudication, and in a group with more severe peripheral vascular disease. In claudicants the regression line relating mean calf Tsk to total blood flow was parallel to, but higher than that in normal subjects, i.e. for the same blood flow, claudicants' Tsk was higher than in normal subjects. The reasons for this difference are not apparent. Thermograms in patients with more severe limb ischaemia were often difficult to interpret because of the confusion introduced by other pathologies. Thermography is a useful adjunct in the assessment of the ischaemic limb, but is unlikely to replace more conventional methods of investigation

Genomic insights into the biosynthesis and physiology of the cyanobacterial neurotoxin 2,4-diaminobutanoic acid (2,4-DAB)

Cyanobacteria are an ancient clade of photosynthetic prokaryotes, whose worldwide occurrence, especially in water, presents health hazards to humans and animals due to the production of a range of toxins (cyanotoxins). These include the sometimes co-occurring, non-encoded diaminoacid neurotoxins 2,4-diaminobutanoic acid (2,4-DAB) and its structural analogue β-N-methylaminoalanine (BMAA). Knowledge of the biosynthetic pathway for 2,4-DAB, and its role in cyanobacteria, is lacking. The aspartate 4-phosphate pathway is a known route of 2,4-DAB biosynthesis in other bacteria and in some plant species. Another pathway to 2,4-DAB has been described in Lathyrus species. Here, we use bioinformatics analyses to investigate hypotheses concerning 2,4-DAB biosynthesis in cyanobacteria. We assessed the presence or absence of each enzyme in candidate biosynthesis routes, the aspartate 4-phosphate pathway and a pathway to 2,4-DAB derived from S-adenosyl-L-methionine (SAM), in 130 cyanobacterial genomes using sequence alignment, profile hidden Markov models, substrate specificity/active site identification and the reconstruction of gene phylogenies. In the aspartate 4-phosphate pathway, for the 18 species encoding diaminobutanoate-2-oxo-glutarate transaminase, the co-localisation of genes encoding the transaminase with the downstream decarboxylase or ectoine synthase – often within hybrid non-ribosomal peptide synthetase (NRPS)-polyketide synthases (PKS) clusters, NRPS-independent siderophore (NIS) clusters and incomplete ectoine clusters – is compatible with the hypothesis that some cyanobacteria use the aspartate 4-phosphate pathway for 2,4-DAB production. Through this route, in cyanobacteria, 2,4-DAB may be functionally associated with environmental iron-scavenging, via the production of siderophores of the schizokinen/synechobactin type and of some polyamines. In the pathway to 2,4-DAB derived from SAM, eight cyanobacterial species encode homologs of SAM-dependent 3-amino-3-carboxypropyl transferases. Other enzymes in this pathway have not yet been purified or sequenced. Ultimately, the biosynthesis of 2,4-DAB appears to be either restricted to some cyanobacterial species, or there may be multiple and additional routes, and roles, for the synthesis of this neurotoxin.</p

Conversion in Turkish : an overview

This paper presents an overview of possible cases of conversion in Turkish. I argue that apparent cases of conversion between nouns and adjectives are cases of syntactic transposition, and apparent cases of conversion between nouns/adjectives and verbs are end products of phonological changes in the history of the language, which resulted in pairs of lexemes that are formally identical synchronically, but not historically. This does not mean that no cases of morphological conversion can be traced in the language. I will present two cases of secondary word-class conversion from derived, inflected and uninflected words to toponyms which might be taken as instances of morphological conversion or derivation by zero-affixation

Push from the Bush: Revitalisation Strategies for Smaller Rural Towns

Generally, Australians consider that small towns are declining and there is not much that can be done about This paper argues that only certain sorts of towns (largely inland) are declining and that a lot can be done about it, provided there is the will. A small town in South-Western Queensland is used as a case study over a five year period and key issues are identified which can assist small towns to help themselves revitalise

Quantitative mineral mapping of drill core surfaces II: long-wave infrared mineral characterization using μXRF and machine learning

Long-wave infrared (LWIR) spectra can be interpreted using a Random Forest machine learning approach to predict mineral species and abundances. In this study, hydrothermally altered carbonate rock core samples from the Fourmile Carlin-type Au discovery, Nevada, were analyzed by LWIR and micro-X-ray fluorescence (μXRF). Linear programming-derived mineral abundances from quantified μXRF data were used as training data to construct a series of Random Forest regression models. The LWIR Random Forest models produced mineral proportion estimates with root mean square errors of 1.17 to 6.75% (model predictions) and 1.06 to 6.19% (compared to quantitative X-ray diffraction data) for calcite, dolomite, kaolinite, white mica, phlogopite, K-feldspar, and quartz. These results are comparable to the error of proportion estimates from linear spectral deconvolution (±7–15%), a commonly used spectral unmixing technique. Having a mineralogical and chemical training data set makes it possible to identify and quantify mineralogy and provides a more robust and meaningful LWIR spectral interpretation than current methods of utilizing a spectral library or spectral end-member extraction. Using the method presented here, LWIR spectroscopy can be used to overcome the limitations inherent with the use of short-wave infrared (SWIR) in fine-grained, low reflectance rocks. This new approach can be applied to any deposit type, improving the accuracy and speed of infrared data interpretation

Information discernment and the psychophysiological effects of misinformation

Purpose The purpose of this paper is to determine to what extent a person’s psychophysiological well-being is affected by misinformation and whether their level of information discernment has any positive or negative effect on the outcome. Design/methodology/approach Participants (n = 48) were randomly and blindly allocated to one of two groups: control group participants were told a person they were working with was a student; experimental group participants were additionally led to believe that this other participant had extreme religious views. This was both stigmatising and misinforming, as this other person was an actor. Participants completed a pre-screening booklet and a series of tasks. Participants’ cardiovascular responses were measured during the procedure. Findings Participants with high levels of information discernment, i.e. those who are curious, use multiple sources to verify information, are sceptical about search engine information, are cognisant of the importance of authority and are aware that knowledge changes and is contradictory at times exhibited an adaptive stress response, i.e. healthy psychophysiological outcomes and responded with positive emotions before and after a stressful task. Social implications The findings indicate the potential harmful effects of misinformation and discuss how information literacy or Metaliteracy interventions may address this issue. Originality/value The first study to combine the hitherto unrelated theoretical areas of information discernment (a sub-set of information literacy), affective states (positive affect negative affect survey) and stress (challenge and threat cardiovascular measures)

Genomic insights into the biosynthesis and physiology of the cyanobacterial neurotoxin 3-N-methyl-2,3-diaminopropanoic acid (BMAA)

Cyanobacteria are an ancient clade of photosynthetic prokaryotes, present in many habitats throughout the world, including water resources. They can present health hazards to humans and animals due to the production of a wide range of toxins (cyanotoxins), including the diaminoacid neurotoxin, β-N-methylaminoalanine (BMAA). Knowledge of the biosynthetic pathway for BMAA, and its role in cyanobacteria, is lacking. Present evidence suggests that BMAA is derived by 3-N methylation of 2,3-diaminopropanoic acid (2,3-DAP) and, although the latter has never been reported in cyanobacteria, there are multiple pathways to its biosynthesis known in other bacteria and in plants. Here, we used bioinformatics analyses to investigate hypotheses concerning 2,3-DAP and BMAA biosynthesis in cyanobacteria. We assessed the potential presence or absence of each enzyme in candidate biosynthetic routes known in Albizia julibrissin, Lathyrus sativus seedlings, Streptomyces, Clostridium, Staphylococcus aureus, Pantoea agglomerans, and Paenibacillus larvae, in 130 cyanobacterial genomes using sequence alignment, profile hidden Markov models, substrate specificity/active site identification and the reconstruction of gene phylogenies. Most enzymes involved in pathways leading to 2,3-DAP in other species were not found in the cyanobacteria analysed. Nevertheless, two species appear to have the genes sbnA and sbnB, responsible for forming the 2,3-DAP constituent in staphyloferrin B, a siderophore from Staphylococcus aureus. It is currently undetermined whether these species are also capable of biosynthesising BMAA. It is possible that, in some cyanobacteria, the formation of 2,3-DAP and/or BMAA is associated with environmental iron-scavenging. The pam gene cluster, responsible for the biosynthesis of the BMAA-containing peptide, paenilamicin, so far appears to be restricted to Paenibacillus larvae. It was not detected in any of the cyanobacterial genomes analysed, nor was it found in 93 other Paenibacillus genomes or in the genomes of two BMAA-producing diatom species. We hypothesise that the presence, in some cyanobacterial species, of the enzymes 2,3-diaminopropionate ammonia-lyase (DAPAL) and reactive intermediate deaminase A (RidA) may explain the failure to detect 2,3-DAP in analytical studies. Overall, the taxonomic distribution of 2,3-DAP and BMAA in cyanobacteria is unclear; there may be multiple and additional routes, and roles, for the biosynthesis of 2,3-DAP and BMAA in these organisms.Output Status: Forthcoming/Available Onlin

Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

Severe early onset preeclampsia: short and long term clinical, psychosocial and biochemical aspects

Preeclampsia is a pregnancy specific disorder commonly defined as de novo hypertension and proteinuria after 20 weeks gestational age. It occurs in approximately 3-5% of pregnancies and it is still a major cause of both foetal and maternal morbidity and mortality worldwide1. As extensive research has not yet elucidated the aetiology of preeclampsia, there are no rational preventive or therapeutic interventions available. The only rational treatment is delivery, which benefits the mother but is not in the interest of the foetus, if remote from term. Early onset preeclampsia (<32 weeks’ gestational age) occurs in less than 1% of pregnancies. It is, however often associated with maternal morbidity as the risk of progression to severe maternal disease is inversely related with gestational age at onset2. Resulting prematurity is therefore the main cause of neonatal mortality and morbidity in patients with severe preeclampsia3. Although the discussion is ongoing, perinatal survival is suggested to be increased in patients with preterm preeclampsia by expectant, non-interventional management. This temporising treatment option to lengthen pregnancy includes the use of antihypertensive medication to control hypertension, magnesium sulphate to prevent eclampsia and corticosteroids to enhance foetal lung maturity4. With optimal maternal haemodynamic status and reassuring foetal condition this results on average in an extension of 2 weeks. Prolongation of these pregnancies is a great challenge for clinicians to balance between potential maternal risks on one the eve hand and possible foetal benefits on the other. Clinical controversies regarding prolongation of preterm preeclamptic pregnancies still exist – also taking into account that preeclampsia is the leading cause of maternal mortality in the Netherlands5 - a debate which is even more pronounced in very preterm pregnancies with questionable foetal viability6-9. Do maternal risks of prolongation of these very early pregnancies outweigh the chances of neonatal survival? Counselling of women with very early onset preeclampsia not only comprises of knowledge of the outcome of those particular pregnancies, but also knowledge of outcomes of future pregnancies of these women is of major clinical importance. This thesis opens with a review of the literature on identifiable risk factors of preeclampsia