Cryptosporidium cuniculus - new records in human and kangaroo in Australia

BACKGROUND: To date, Cryptosporidium cuniculus has been found exclusively in rabbits and humans. The present study provides the first published molecular evidence for C. cuniculus in an Australian human patient as well as a kangaroo. FINDINGS: Using PCR-based sequencing of regions in the actin, 60 kDa glycoprotein (gp60) and small subunit of ribosomal RNA (SSU) genes, we identified a new and unique C. cuniculus genotype (akin to VbA25) from a human, and C. cuniculus genotype VbA26 from an Eastern grey kangaroo (Macropus giganteus) in Australia. CONCLUSIONS: The characterisation of these genotypes raises questions as to their potential to infect humans and/or other animals in Australia, given that C. cuniculus has been reported to cause cryptosporidiosis outbreaks in Europe

Di- and Tri-nuclear VIII^{III} and CrIII^{III} Complexes of Dipyridyltriazoles: Ligand Rearrangements, Mixed Valency and Ferromagnetic Coupling

The first dinuclear and trinuclear chromium(III) and dinuclear vanadium(III) complexes of N$^{4}$-R-substituted-3,5-di(2-pyridyl)-1,2,4-triazole (Rdpt) ligands have been prepared by solvothermal complexations under inert atmospheres, and characterized. The reactions of Cr$^{III}$ and V$^{III}$ with adpt (R = amino) resulted in deamination of the ligand and yielded the dinuclear doubly-triazolate bridged complexes [V$_{2}^{III}$(dpt$^{-}$)$_{2}$Cl$_{4}$] (1) and [Cr$_{2}^{III}$(dpt$^{-}$)$_{2}$Cl$_{4}$] (2). In the case of the Cr$^{III}$ complex 2 this bridging results in a rare example of ferromagnetic coupling for a dinuclear Cr$^{III}$ compound. DFT studies confirm that in 2 the ferromagnetic coupling pathways dominate over the antiferromagnetic pathways, whereas in 1 the reverse occurs, consistent with the observed overall antiferromagnetic coupling in that case. It was also found that the use of different additives in the reaction allows the nuclearity of the Cr$^{III}$ product to be manipulated, giving either the dinuclear system, or the first example of a trinuclear circular helicate for a Rdpt complex, [Cr$_{3}^{III}$(dpt)$_{3}$Cl$_{6}$]·1¾MeCN·¼DCM (3). Reaction of N$^{4}$-pydpt (R = 4-pyridyl) with V$^{III}$ led to an unusual shift of the pyridyl substituent from N$^{4}$ to N$^{1}$ of the triazole, forming the ligand isomer N$^{1}$-pydpt, and giving a dinuclear doubly-triazole bridged complex, [V$_{2}^{III}$(N$^{1}$-pydpt)$_{2}$Cl$_{6}$]·2MeCN (4). Reaction with Cr$^{III}$ results in loss of the 4-pyridyl ring and a mixture of the di- and trinuclear complexes, 2 and 3. Interestingly, partial oxidation of the V$^{III}$ in dinuclear complex 4 to vanadyl V$^{IV}$=O was identified by crystallographic analysis of partially oxidized single crystals, [(V$^{IV}$O)$_{0.84}$(V$^{III}$)$_{1.16}$(N$^{1}$-pydpt)$_{2}$Cl$_{5.16}$] 0.84H$_{2}$O 1.16MeCN (5)

A Bayesian palaeoenvironmental transfer function model for acidified lakes

A Bayesian approach to palaeoecological environmental reconstruction deriving from the unimodal responses generally exhibited by organisms to an environmental gradient is described. The approach uses Bayesian model selection to calculate a collection of probability-weighted, species-specific response curves (SRCs) for each taxon within a training set, with an explicit treatment for zero abundances. These SRCs are used to reconstruct the environmental variable from sub-fossilised assemblages. The approach enables a substantial increase in computational efficiency (several orders of magnitude) over existing Bayesian methodologies. The model is developed from the Surface Water Acidification Programme (SWAP) training set and is demonstrated to exhibit comparable predictive power to existing Weighted Averaging and Maximum Likelihood methodologies, though with improvements in bias; the additional explanatory power of the Bayesian approach lies in an explicit calculation of uncertainty for each individual reconstruction. The model is applied to reconstruct the Holocene acidification history of the Round Loch of Glenhead, including a reconstruction of recent recovery derived from sediment trap data.The Bayesian reconstructions display similar trends to conventional (Weighted Averaging Partial Least Squares) reconstructions but provide a better reconstruction of extreme pH and are more sensitive to small changes in diatom assemblages. The validity of the posteriors as an apparently meaningful representation of assemblage-specific uncertainty and the high computational efficiency of the approach open up the possibility of highly constrained multiproxy reconstructions

An experiment to assess the effects of diatom dissolution on oxygen isotope ratios

Rationale: Current studies which use the oxygen isotope composition from diatom silica (δ18Odiatom) as a palaeoclimate proxy assume that the δ18Odiatom value reflects the isotopic composition of the water in which the diatom formed. However, diatoms dissolve post mortem, preferentially losing less silicified structures in the water column and during/after burial into sediments. The impact of dissolution on δ18Odiatom values and potential misinterpretation of the palaeoclimate record are evaluated. Methods: Diatom frustules covering a range of ages (6 samples from the Miocene to the Holocene), environments and species were exposed to a weak alkaline solution for 48 days at two temperatures (20 °C and 4 °C), mimicking natural dissolution post mucilage removal. Following treatment, dissolution was assessed using scanning electron microscope images and a qualitative diatom dissolution index. The diatoms were subsequently analysed for their δ18O values using step-wise fluorination and isotope ratio mass spectrometry. Results: Variable levels of diatom dissolution were observed between the six samples; in all cases higher temperatures resulted in more frustule degradation. Dissolution was most evident in younger samples, probably as a result of the more porous nature of the silica. The degree of diatom dissolution does not directly equate to changes in the isotope ratios; the δ18Odiatom value was, however, lower after dissolution, but in only half the samples was this reduction outside the analytical error (2σ analytical error = 0.46‰). Conclusions: We have shown that dissolution can have a small negative impact on δ18Odiatom values, causing reductions of up to 0.59‰ beyond analytical error (0.46‰) at natural environmental temperatures. These findings need to be considered in palaeoenvironmental reconstructions using δ18Odiatom values, especially when interpreting variations in these values of <1‰

Measurement of the Parity-Violating Longitudinal Single-Spin Asymmetry for W± Boson Production in Polarized Proton-Proton Collisions at √s=500 GeV

We report the first measurement of the parity-violating single-spin asymmetries for midrapidity decay positrons and electrons from W+ and W- boson production in longitudinally polarized proton-proton collisions at √s = 500 GeV by the STAR experiment at RHIC. The measured asymmetries, A(L)(W+) = -0.27± 0.10(stat.) ± 0.02(syst.) ± 0.03(norm.) and A(L)(W-) = 0.14 ± 0.19(stat.) ± 0.02(syst.) ± 0.01(norm.), are consistent with theory predictions, which are large and of opposite sign. These predictions are based on polarized quark and antiquark distribution functions constrained by polarized deep-inelastic scattering measurements

Jet Dipolarity: Top Tagging with Color Flow

A new jet observable, dipolarity, is introduced that can distinguish whether a pair of subjets arises from a color singlet source. This observable is incorporated into the HEPTopTagger and is shown to improve discrimination between top jets and QCD jets for moderate to high pT.Comment: 8 pages, 6 figures (updated to JHEP version

System Size and Energy Dependence of Near-Side Dihadron Correlations

Two-particle azimuthal (Δφ) and pseudorapidity (Δη) correlations using a trigger particle with large transverse momentum (PT)in d+Au, Cu+Cu, and Au+Au collisions at √ sNN = 62.4 GeV and 200 GeV from the STAR experiment at the Relativistic Heavy Ion Collider are presented. The near-side correlation is separated into a jet-like component, narrow in both Δφ and Δη, and the ridge, narrow in Δφ but broad in Δη. Both components are studied as a function of collision centrality, and the jet-like correlation is studied as a function of the trigger and associated PT. The behavior of the jet-like component is remarkably consistent for different collision systems, suggesting it is produced by fragmentation. The width of the jet-like correlation is found to increase with the system size. The ridge, previously observed in Au+Au collisions at √ sNN = 200 GeV, is also found in Cu+Cu collisions and in collisions at √ sNN = 62.4 GeV, but is found to be substantially smaller at √ sNN = 62.4 GeV than at √ sNN = 200 GeV for the same average number of participants (Npart ). Measurements of the ridge are compared to models

ρ0 Photoproduction in AuAu Collisions at √ sNN = 62.4 GeV Measured With the STAR Detector

Vector mesons may be photoproduced in relativistic heavy-ion collisions when a virtual photon emitted by one nucleus scatters from the other nucleus, emerging as a vector meson. The STAR Collaboration has previously presented measurements of coherent ρ0 photoproduction at center of mass energies of 130 GeV and 200 GeV in AuAu collisions. Here, we present a measurement of the cross section at 62.4 GeV; we find that the cross section for coherent ρ0 photoproduction with nuclear breakup is 10.5 ± 1.5 ± 1.6mb at 62.4 GeV. The cross-section ratio between 200 GeV and 62.4 GeV is 4.4 ± 0.6, less than is predicted by most theoretical models. It is, however, proportionally much larger than the previously observed 15% ± 55% increase between 130 GeV and 200 GeV

Evolution of the Differential Transverse Momentum Correlation Function with Centrality in Au + Au Collisions at √sNN = 200 GeV

We present first measurements of the evolution of the differential transverse momentum correlation function, C, with collision centrality in Au + Au interactions at √sNN = 200 GeV. This observable exhibits a strong dependence on collision centrality that is qualitatively similar to that of number correlations previously reported. We use the observed longitudinal broadening of the near-side peak of C with increasing centrality to estimate the ratio of the shear viscosity to entropy density, η / s , of the matter formed in central Au + Au interactions. We obtain an upper limit estimate of η / s that suggests that the produced medium has a small viscosity per unit entropy

Constitutive Model for Predicting Ultimate Drying Shrinkage of Concrete

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65271/1/j.1151-2916.1987.tb05003.x.pd