The Fazzan Basin of south-west Libya is at present arid with less than 20
mm of rainfall per annum. However, regionally extensive limestones, lacustrine sands and coquina (fossiliferous carbonate ...rock) deposits show that the Fazzan Basin previously contained a large palaeolake, indicating that the climate in the past was more humid. Optically stimulated luminescence (OSL) dating techniques have been applied to key lacustrine deposits within the basin in an attempt to provide an internally consistent chronology for this humidity record. Results indicate that palaeolake sediments within the Fazzan Basin record a very long history of palaeohydrological change, ranging from present day arid conditions to humidity capable of sustaining a lake with an approximate area of 76,250
km
2. The existence of humid periods in mid oxygen isotope stage 5 and the early Holocene is confirmed. An older lacustrine event, tentatively correlated to oxygen isotope stage 11, is also recognized. In addition, evidence is presented for at least two humid phases beyond the age range over which the conventional OSL dating technique is applicable. This study demonstrates that OSL dating of palaeolake sediments within the Fazzan Basin offers the potential to provide a detailed record of North African humidity spanning several glacial–interglacial cycles.
A naturally functioning riparian zone is essential for the ecological health of a river, filtering pollutants, supplying organic matter and providing a structural habitat for wildlife. Most lowland ...rivers would also naturally flood the riparian zone at regular intervals, thereby providing direct inputs of nutrients and water that create additional habitats and breeding opportunities for riverine species. We examined the relationship between the quality of the riparian habitat and foraging and activity of bats (Chiroptera), which are good indicators of ecosystem health. Twenty paired sites in the Rivers Lee and Colne catchments in England were selected to test the hypothesis that degradation in the quality of riparian habitat reduces foraging and activity in bats; paired sites were similar in terms of size, flow rate and water chemistry but differed in the quality of their riparian zones. AnaBat detectors were used to measure bat activity from 30 min before dusk to 30 min after sunrise on the same night at paired sites because recording frequency-divided bat echolocation calls in real time allows large amounts of data to be collected over long time periods in a digitized format. Significantly more feeding buzzes were recorded in sites with better quality riparian zones; no differences in overall bat activity were found between the two habitat types. Pipistrellus pipistrellus and Pipistrellus pygmaeus accounted for 96% of bat passes. Pipistrellus pygmaeus was significantly more active in high quality sites than P. pipistrellus; there was no difference between the two species in poor quality sites. We show that the quality of riparian buffer zones is important for the activity and feeding behaviour of pipistrelle bats.
Our aim was to use the opportunity provided by the European Scleroderma Observational Study to (1) identify and describe those patients with early diffuse cutaneous systemic sclerosis (dcSSc) with ...progressive skin thickness, and (2) derive prediction models for progression over 12 months, to inform future randomised controlled trials (RCTs).
The modified Rodnan skin score (mRSS) was recorded every 3 months in 326 patients. 'Progressors' were defined as those experiencing a 5-unit and 25% increase in mRSS score over 12 months (±3 months). Logistic models were fitted to predict progression and, using receiver operating characteristic (ROC) curves, were compared on the basis of the area under curve (AUC), accuracy and positive predictive value (PPV).
66 patients (22.5%) progressed, 227 (77.5%) did not (33 could not have their status assessed due to insufficient data). Progressors had shorter disease duration (median 8.1 vs 12.6 months, P=0.001) and lower mRSS (median 19 vs 21 units, P=0.030) than non-progressors. Skin score was highest, and peaked earliest, in the anti-RNA polymerase III (Pol3+) subgroup (n=50). A first predictive model (including mRSS, duration of skin thickening and their interaction) had an accuracy of 60.9%, AUC of 0.666 and PPV of 33.8%. By adding a variable for Pol3 positivity, the model reached an accuracy of 71%, AUC of 0.711 and PPV of 41%.
Two prediction models for progressive skin thickening were derived, for use both in clinical practice and for cohort enrichment in RCTs. These models will inform recruitment into the many clinical trials of dcSSc projected for the coming years.
NCT02339441.
The authors show that the diverse mutations in
CALR
that occur in nonmutated
JAK2
myeloproliferative diseases all introduce frameshift mutations that alter the C-terminal part of the protein and ...affect its distribution within cells.
The myeloproliferative neoplasms are chronic myeloid cancers that are characterized by the overproduction of mature blood cells, and that may evolve into acute myeloid leukemia.
1
,
2
In addition to chronic myeloid leukemia with the
BCR-ABL
fusion gene, the three most common myeloproliferative neoplasms are essential thrombocythemia, polycythemia vera, and myelofibrosis.
Many patients with a
BCR-ABL–
negative myeloproliferative neoplasm carry a Janus kinase 2 (
JAK2
) V617F mutation.
3
–
6
The
JAK2
V617F mutation or
JAK2
exon 12 mutations are found in most patients with polycythemia vera,
7
,
8
whereas the
JAK2
V617F mutation is found in only 50 to 60% of . . .
Anti‐neutrophil cytoplasmic antibody (ANCA) tests are a routine clinical assay in most UK hospitals. We examined the role of routine ANCA testing in achieving a diagnosis of systemic vasculitis in a ...routine clinical setting. From April 1996 to March 2000, 2734 samples from five hospital departments were tested for ANCA by indirect immunofluorescence (IIF) at a single laboratory. After April 1999, enzyme‐linked immunosorbent assays (ELISAs) were performed on all IIF‐positive samples. Clinical diagnosis was determined for all patients with a positive IIF ANCA, and a sample of the ANCA‐negative patients. Some 2–18% of patients with suspected ANCA‐associated systemic vasculitis (AASV) had positive IIF ANCA. The AASV diagnosis was confirmed in 0–56% of these cases. Analysis by department suggested that 88–100% of patients with a positive IIF ANCA did not have AASV, except in the Rheumatology department. The positive predictive value (PPV) of IIF ANCA for AASV was 59% and the negative predictive value (NPV) was 84%. Of the patients with proven AASV, 41% did not have ANCA on IIF. Combined ANCA testing by IIF/ELISA had a higher sensitivity and PPV but lower specificity than IIF alone for AASV. For the combined IIF/ELISA test, only the Rheumatology department had a sensitivity or PPV >0% for AASV. The PPV of ANCA by IIF/ELISA for AASV was 79% and the NPV was 63%. The ANCA test is being widely applied with very poor return. Guidelines for more effective usage are proposed.
During the decade to 1999, the incidence of human infections with the zoonotic pathogen verocytotoxin-producing Escherichia coli O157 (VTEC O157) increased in England and Wales. This paper describes ...the results of a survey of 75 farms to determine the prevalence of faecal excretion of VTEC O157 by cattle, its primary reservoir host, in England and Wales. Faecal samples were collected from 4663 cattle between June and December 1999. The prevalence of excretion by individual cattle was 4.2 per cent (95 per cent confidence interval CI 2.0 to 6.4) and 10.3 per cent (95 per cent CI 5.8 to 14.8) among animals in infected herds. The within-herd prevalence on positive farms ranged from 1.1 to 51.4 per cent. At least one positive animal was identified on 29 (38.7 per cent; 95 per cent CI 28.1 to 50.4) of the farms, including dairy, suckler and fattening herds. The prevalence of excretion was least in the calves under two months of age, peaked in the calves aged between two and six months and declined thereafter. The phage types identified most widely were 4, 34 and 2, which were each found on six of the 29 positive farms.
The amygdala was more responsive to fearful (larger) eye whites than to happy (smaller) eye whites presented in a masking paradigm that mitigated subjects' awareness of their presence and aberrant ...nature. These data demonstrate that the amygdala is responsive to elements of biologically relevant configural stimuli.
We examined the effect of increasing photoperiod, at a constant low temperature, on the body mass and energy budget of the bank vole Clethrionomys glareolus. Simultaneously, we determined the ...hypothalamic gene expression of neuropeptides and receptors known to be involved in short-term energy balance. Despite an increase in body mass (approximately 10% of initial mass), we found no significant changes in any energetic parameters (food intake, energy assimilation rate, resting metabolic rate and total daily energy expenditure by doubly-labelled water). Apparent energy assimilation efficiency was higher in voles exposed to long-days (LD) compared to short-days (SD). Surprisingly, gene expression of corticotrophin releasing factor (CRF; in the paraventricular nucleus), and the melanocortin-3 receptor (in the arcuate nucleus), both known to be involved in appetite suppression and elevation of energy expenditure in short-term energy balance, were higher in voles kept in LD compared to SD. CRF expression was also elevated in females compared to males. These paradoxical data suggest an alternative mechanism for the control of seasonal body mass changes compared to short-term body mass changes, and between male and female voles. Furthermore, they highlight the need for studies to perform simultaneous measurements at both the molecular and whole animal levels.
Aerobic organisms continually face exposure to reactive oxygen species (ROS) and many have evolved sophisticated antioxidant systems to effectively remove them. Any increase in ROS production or ...weakening in this defense system may ultimately lead to oxidative stress and cellular damage. We investigated whether long-term cold exposure, which is known to lead to an elevation in metabolic rate, increased the activities of the ROS-scavenging enzymes, catalase (CAT), selenium-dependent glutathione peroxidase (GPx), and total superoxide dismutase (Total-SOD) in liver, cardiac muscle, kidney, skeletal muscle (
vastus lateralis), and duodenum of short-tailed field voles (
Microtus agrestis), born and maintained at either 8 ± 3°C or 22 ± 3°C. CAT, GPx, and Total-SOD activities were determined at age 61 ± 1.9 days. An increase in CAT activity in voles maintained at 8 ± 3°C was observed in skeletal muscle (71%) and kidney (20%), with both CAT and GPx activities significantly elevated (by 40 and 43%, respectively) in cardiac muscle, when compared to voles at 22 ± 3°C. Total-SOD activity and protein content did not differ significantly between groups in any tissue. We suggest that the compensatory increases in CAT (skeletal muscle, cardiac muscle, kidney) and GPx (cardiac muscle), but not Total-SOD activities, resulting from long-term cold exposure may reflect the elevated metabolic rate, and possibly also increased ROS production, at this time.
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