446 research outputs found
Peanut allergen Ara h 6 is detectable in blood transfusion products
Peanut allergen Ara h 6 is known to maintain IgE‐binding capacity upon exposure to digestive enzymes1 and its presence in circulation after consumption of peanut has been demonstrated.2,3 Therefore, it has been speculated that food‐derived allergens could be transferred via blood transfusion products, causing an allergic reaction in food-allergic recipients.4,5 However, in published case reports, presence of food allergen in donated material could not be confirmed due to lack of remaining transfusion material and/or lack of sensitive analytical methods. Using a newly developed sensitive immune‐assay for detecting Ara h 6 in human serum, we now report to what extent consumed peanut allergens can be present in blood transfusion materials and estimate the associated risk for peanut‐allergic recipients
Strain-controlled criticality governs the nonlinear mechanics of fibre networks
Disordered fibrous networks are ubiquitous in nature as major structural
components of living cells and tissues. The mechanical stability of networks
generally depends on the degree of connectivity: only when the average number
of connections between nodes exceeds the isostatic threshold are networks
stable (Maxwell, J. C., Philosophical Magazine 27, 294 (1864)). Upon increasing
the connectivity through this point, such networks undergo a mechanical phase
transition from a floppy to a rigid phase. However, even sub-isostatic networks
become rigid when subjected to sufficiently large deformations. To study this
strain-controlled transition, we perform a combination of computational
modeling of fibre networks and experiments on networks of type I collagen
fibers, which are crucial for the integrity of biological tissues. We show
theoretically that the development of rigidity is characterized by a
strain-controlled continuous phase transition with signatures of criticality.
Our experiments demonstrate mechanical properties consistent with our model,
including the predicted critical exponents. We show that the nonlinear
mechanics of collagen networks can be quantitatively captured by the
predictions of scaling theory for the strain-controlled critical behavior over
a wide range of network concentrations and strains up to failure of the
material
Continental aridification and the vanishing of Australia\u27s megalakes
The nature of the Australian climate at about the time of rapid megafaunal extinctions and humans arriving in Australia is poorly understood and is an important element in the contentious debate as to whether humans or climate caused the extinctions. Here we present a new paleoshoreline chronology that extends over the past 100 k.y. for Lake Mega-Frome, the coalescence of Lakes Frome, Blanche, Callabonna and Gregory, in the southern latitudes of central Australia. We show that Lake Mega-Frome was connected for the last time to adjacent Lake Eyre at 50-47 ka, forming the largest remaining interconnected system of paleolakes on the Australian continent. The final disconnection and a progressive drop in the level of Lake Mega-Frome represents a major climate shift to aridification that coincided with the arrival of humans and the demise of the megafauna. The supply of moisture to the Australian continent at various times in the Quaternary has commonly been ascribed to an enhanced monsoon. This study, in combination with other paleoclimate data, provides reliable evidence for periods of enhanced tropical and enhanced Southern Ocean sources of water filling these lakes at different times during the last full glacial cycle. © 2011 Geological Society of America
Between Metabolite Relationships: an essential aspect of metabolic change
Not only the levels of individual metabolites, but also the relations between the levels of different metabolites may indicate (experimentally induced) changes in a biological system. Component analysis methods in current ‘standard’ use for metabolomics, such as Principal Component Analysis (PCA), do not focus on changes in these relations. We therefore propose the concept of ‘Between Metabolite Relationships’ (BMRs): common changes in the covariance (or correlation) between all metabolites in an organism. Such structural changes may indicate metabolic change brought about by experimental manipulation but which are lost with standard data analysis methods. These BMRs can be analysed by the INdividual Differences SCALing (INDSCAL) method. First the BMR quantification is described and subsequently the INDSCAL method. Finally, two studies illustrate the power and the applicability of BMRs in metabolomics. The first study is about the induced plant response of cabbage to herbivory, of which BMRs are a considerable part. In the second study—a human nutritional intervention study of green tea extract—standard data analysis tools did not reveal any metabolic change, although the BMRs were considerably affected. The presented results show that BMRs can be easily implemented in a wide variety of metabolomic studies. They provide a new source of information to describe biological systems in a way that fits flawlessly into the next generation of systems biology questions, dealing with personalized responses
On Scottish sawflies, with results of the 14th International Sawfly Workshop, in the southern Highlands, 2010 (Hymenoptera, Symphyta).
Die Ergebnisse der Feldarbeit aus dem 14. Internationalen Sawfly Workshop werden vorgestellt. Dies fand im südlichen schottischen Hochland, überwiegend in Perthshire, statt. Einige Nachweise von Pflanzenwespen aus anderen Teilen von Schottland sind enthalten. Erstnachweise für die Britischen Inseln werden für acht tenthredinide Arten erbracht: Amauronematus mimus, Phyllocolpa alienata, P. erythropyga, P. plicalapponum, P. plicaphylicifolia, P. prussica, Pristiphora thalictri und Tenthredo ignobilis. A. mimus ist auch aus Irland nachgewiesen. Amauronematus stenogaster ist aus der Liste der Symphyta der Britischen Inseln zu entfernen. Erstmalig sind in Schottland eine Cephiden-Art (Hartigia xanthostoma) und zehn Tenthrediniden gefunden worden (Claremontia uncta, Dolerus brevicornis, Empria basalis, Empria parvula, Parna apicalis, Pristiphora decipiens, Pristiphora leucopus, Pristiphora testacea, Tenthredo mandibularis und Tenthredopsis ornata). Merkmale für die Unterscheidung einzelner Arten werden dargestellt. Der Locus typicus von Nematus herbaceae Cameron, 1876 ist geklärt. Geranium pratense ist als Wirtspflanze von Macrophya albipuncta bestätigt. Salix reticulata ist eine Wirtspflanze von Amauronematus mcluckieae. Sedum rosea kann eine Wirtspflanze von Tenthredo ignobilis sein. Allgemeine Schlussfolgerungen: hoher Artenreichtum der Pflanzenwespenfauna von Perthshire im Vergleich zu anderen Regionen in Schottland, darunter mehrere Arten, die auf den Britischen Inseln nur von dort bekannt sind; die Wichtigkeit der Erhaltung der Lebensräume von Felssimsen; große Defizite in unseren Kenntnissen bei vielen Arten, insbesondere zu Wirtspflanzen, Phänologie und Verbreitung; hoher Wert der Malaise-Falle in faunistischen Untersuchungen von Symphyta, weil das Spektrum von erfassten Taxa sich unterscheidet von dem was mit Streifnetz erfasst wird; Zusammensetzung des 'fall-out’ auf Schneeresten deutet darauf hin, dass Pflanzenwespen in einem größeren Ausmaß als bisher angenommen, aktiver Dispersion innerhalb von Landmassen unterliegen.StichwörterBritish Isles, Cephidae, Pamphiliidae, Tenthredinoidea, hosts, phenology, distribution.Results of fieldwork are presented from the 14th International Sawfly Workshop, held in the southern Highlands of Scotland, mostly in Perthshire. Some records of Symphyta from other parts of Scotland are included. First records in the British Isles are given for eight tenthredinid species: Amauronematus mimus, Phyllocolpa alienata, P. erythropyga, P. plicalapponum, P. plicaphylicifolia, P. prussica, Pristiphora thalictri and Tenthredo ignobilis. A. mimus is also recorded from Ireland. Amauronematus stenogaster is removed from the list of British Isles Symphyta. Recorded for the first time in Scotland are one cephid (Hartigia xanthostoma) and ten tenthredinids (Claremontia uncta, Dolerus brevicornis, Empria basalis, Empria parvula, Parna apicalis, Pristiphora decipiens, Pristiphora leucopus, Pristiphora testacea, Tenthredo mandibularis and Tenthredopsis ornata). Characters useful for the distinction of some species are illustrated. The type locality of Nematus herbaceae Cameron, 1876 is clarified. Geranium pratense is confirmed as a host of Macrophya albipuncta. Salix reticulata is a host of Amauronematus mcluckieae [mandatory correction of spelling of species name]. Sedum rosea may be a host of Tenthredo ignobilis. General conclusions: high species richness of Perthshire sawfly fauna compared to other regions of Scotland, including several species only known in British Isles from there; importance to conservation of rock-ledge habitats; large data deficits for many species, particularly on hosts, phenology and distribution; high value of Malaise traps in faunal survey of Symphyta, because spectrum of taxa captured differs from that recorded by hand-netting; as indicated by species and sex composition of ‘fall-out’ on snow patches, adult sawflies undertake active dispersal, within landmasses, to a greater extent than is often assumed.KeywordsBritish Isles, Cephidae, Pamphiliidae, Tenthredinoidea, hosts, phenology, distribution
The added value of quantitative multi-voxel MR spectroscopy in breast magnetic resonance imaging
To determine whether quantitative multivoxel MRS improves the accuracy of MRI in the assessment of breast lesions. Twenty-five consecutive patients with 26 breast lesions a parts per thousand yen1 cm assessed as BI-RADS 3 or 4 with mammography underwent quantitative multivoxel MRS and contrast-enhanced MRI. The choline (Cho) concentration was calculated using the unsuppressed water signal as a concentration reference. ROC analysis established the diagnostic accuracy of MRI and MRS in the assessment of breast lesions. Respective Cho concentrations in 26 breast lesions re-classified by MRI as BI-RADS 2 (n = 5), 3 (n = 8), 4 (n = 5) and 5 (n = 8) were 1.16 +/- 0.43 (mean +/- SD), 1.43 +/- 0.47, 2.98 +/- 2.15 and 4.94 +/- 3.10 mM. Two BI-RADS 3 lesions and all BI-RADS 4 and 5 lesions were malignant on histopathology and had Cho concentrations between 1.7 and 11.8 mM (4.03 +/- 2.72 SD), which were significantly higher (P = 0.01) than that in the 11 benign lesions (0.4-1.5 mM; 1.19 +/- 0.33 SD). Furthermore, Cho concentrations in the benign and malignant breast lesions in BI-RADS 3 category differed (P = 0.01). The accuracy of combined multivoxel MRS/breast MRI BI-RADS re-classification (AUC = 1.00) exceeded that of MRI alone (AUC = 0.96 +/- 0.03). These preliminary data indicate that multivoxel MRS improves the accuracy of MRI when using a Cho concentration cut-off a parts per thousand currency sign1.5 mM for benign lesions. Key Points aEuro cent Quantitative multivoxel MR spectroscopy can improve the accuracy of contrast-enhanced breast MRI. aEuro cent Multivoxel-MRS can differentiate breast lesions by using the highest Cho-concentration. aEuro cent Multivoxel-MRS can exclude patients with benign breast lesions from further invasive diagnostic procedures
‘Test Driving’ a Financing Instrument for Climate Adaptation: Analyzing Institutional Dilemmas using Simulation Gaming
Urban physical public infrastructure is a frontline defense mechanism to manage and mitigate climate-related impacts. Market instruments are often cited as possible means to spread risk and reduce financial burdens on the public sector. The authors argue that existing research tends to focus on the technical issues of instruments and neglects considering institutional dynamics that may enable or constrain local market-based financing mechanisms. In this article, three core dilemmas (values uncertainty, planning horizon, and indirect benefits) are used to analyze the responses of practitioners to a possible financing instrument. The findings indicate that the practitioner’s responses to tax increment financing were largely shaped by the adaptation dilemmas and not the characteristics of the instrument per se. By mapping the dilemmas onto whether they would recommend it, participants imposed a financial barrier on climate adaptation investments. The authors conclude that a key imperative in the design of policy instruments is to pay attention to the congruency of informal institutions at the ‘street level’ in order to be in-step with the current sociopolitical conditions. The findings also point to four key attributes that a local market-based instrument would need to be aligned and responsive to the Dutch planning and development context
Anti-plasmodial polyvalent interactions in Artemisia annua L. aqueous extract – possible synergistic and resistance mechanisms
Artemisia annua hot water infusion (tea) has been used in in vitro experiments against P. falciparum malaria parasites to test potency relative to equivalent pure artemisinin. High performance liquid chromatography (HPLC) and mass spectrometric analyses were employed to determine the metabolite profile of tea including the concentrations of artemisinin (47.5±0.8 mg L-1), dihydroartemisinic acid (70.0±0.3 mg L-1), arteannuin B (1.3±0.0 mg L-1), isovitexin (105.0±7.2 mg L-1) and a range of polyphenolic acids. The tea extract, purified compounds from the extract, and the combination of artemisinin with the purified compounds were tested against chloroquine sensitive and chloroquine resistant strains of P. falciparum using the DNA-intercalative SYBR Green I assay. The results of these in vitro tests and of isobologram analyses of combination effects showed mild to strong antagonistic interactions between artemisinin and the compounds (9-epi-artemisinin and artemisitene) extracted from A. annua with significant (IC50 <1 μM) anti-plasmodial activities for the combination range evaluated. Mono-caffeoylquinic acids, tri-caffeoylquinic acid, artemisinic acid and arteannuin B showed additive interaction while rosmarinic acid showed synergistic interaction with artemisinin in the chloroquine sensitive strain at a combination ratio of 1:3 (artemisinin to purified compound). In the chloroquine resistant parasite, using the same ratio, these compounds strongly antagonised artemisinin anti-plasmodial activity with the exception of arteannuin B, which was synergistic. This result would suggest a mechanism targeting parasite resistance defenses for arteannuin B’s potentiation of artemisinin
Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR
New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and
NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a
quiescent state since at least early 2015, reactivated between 2017 March 19
and April 5. The radio flux density, while variable, is approximately 100x
larger than during its dormant state. The X-ray flux one month after
reactivation was at least 800x larger than during quiescence, and has been
decaying exponentially on a 111+/-19 day timescale. This high-flux state,
together with a radio-derived rotational ephemeris, enabled for the first time
the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV
pulsed fraction is comparable to the smallest observed for magnetars. The
overall pulsar geometry inferred from polarized radio emission appears to be
broadly consistent with that determined 6-8 years earlier. However, rotating
vector model fits suggest that we are now seeing radio emission from a
different location in the magnetosphere than previously. This indicates a novel
way in which radio emission from magnetars can differ from that of ordinary
pulsars. The torque on the neutron star is varying rapidly and unsteadily, as
is common for magnetars following outburst, having changed by a factor of 7
within six months of reactivation.Comment: Published in ApJ (2018 April 5); 13 pages, 4 figure
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