The microscopic origin of thermal cracking in rocks: An investigation by simultaneous time-of-flight neutron diffraction and acoustic emission monitoring

We demonstrate that neutron diffraction measurements make it possible to quantify elastic strains within the interior of solid samples, and thus have great potential for addressing a wide range of problems connected with the characterization of the mechanical properties of geological materials. We use the time-of-flight neutron diffraction technique, in combination with acoustic emission monitoring, to study the evolution of thermal strain within the interior of samples of a pure quartzite during slow heating, and the onset of the associated thermal cracking. Thermal cracking commences around 180 degreesC when the thermal strain deficit along the a-axes of quartz grains induces a thermal stress that is close to the bulk tensile strength of the rock

Variability of Quasilinear Diffusion Coefficients for Plasmaspheric Hiss

In the outer radiation belt, the acceleration and loss of high‐energy electrons is largely controlled by wave‐particle interactions. Quasilinear diffusion coefficients are an efficient way to capture the small‐scale physics of wave‐particle interactions due to magnetospheric wave modes such as plasmaspheric hiss. The strength of quasilinear diffusion coefficients as a function of energy and pitch angle depends on both wave parameters and plasma parameters such as ambient magnetic field strength, plasma number density, and composition. For plasmaspheric hiss in the magnetosphere, observations indicate large variations in the wave intensity and wave normal angle, but less is known about the simultaneous variability of the magnetic field and number density. We use in situ measurements from the Van Allen Probe mission to demonstrate the variability of selected factors that control the size and shape of pitch angle diffusion coefficients: wave intensity, magnetic field strength, and electron number density. We then compare with the variability of diffusion coefficients calculated individually from colocated and simultaneous groups of measurements. We show that the distribution of the plasmaspheric hiss diffusion coefficients is highly non‐Gaussian with large variance and that the distributions themselves vary strongly across the three phase space bins studied. In most bins studied, the plasmaspheric hiss diffusion coefficients tend to increase with geomagnetic activity, but our results indicate that new approaches that include natural variability may yield improved parameterizations. We suggest methods like stochastic parameterization of wave‐particle interactions could use variability information to improve modeling of the outer radiation belt

Proteoliposomes as energy transferring nanomaterials: enhancing the spectral range of light-harvesting proteins using lipid-linked chromophores

Bio-hybrid nanomaterials have great potential for combining the most desirable aspects of biomolecules and the contemporary concepts of nanotechnology to create highly efficient light-harvesting materials. Light-harvesting proteins are optimized to absorb and transfer solar energy with remarkable efficiency but have a spectral range that is limited by their natural pigment complement. Herein, we present the development of model membranes (“proteoliposomes”) in which the absorption range of the membrane protein Light-Harvesting Complex II (LHCII) is effectively enhanced by the addition of lipid-tethered Texas Red (TR) chromophores. Energy transfer from TR to LHCII is observed with up to 94% efficiency and increased LHCII fluorescence of up to three-fold when excited in the region of lowest natural absorption. The new self-assembly procedure offers the modularity to control the concentrations incorporated of TR and LHCII, allowing energy transfer and fluorescence to be tuned. Fluorescence Lifetime Imaging Microscopy provides single-proteoliposome-level quantification of energy transfer efficiency and confirms that functionality is retained on surfaces. Designer proteoliposomes could act as a controllable light-harvesting nanomaterial and are a promising step in the development of bio-hybrid light-harvesting systems

Detection and molecular characterisation of Cryptosporidium parvum in British European hedgehogs (Erinaceus europaeus)

Surveillance was conducted for the occurrence of protozoan parasites of the genus Cryptosporidium in European hedgehogs (Erinaceus europaeus) in Great Britain. In total, 108 voided faecal samples were collected from hedgehogs newly admitted to eight wildlife casualty treatment and rehabilitation centres. Terminal large intestinal (LI) contents from three hedgehog carcasses were also analysed. Information on host and location variables, including faecal appearance, body weight, and apparent health status, was compiled. Polymerase Chain Reaction (PCR) targeting the 18S ribosomal RNA gene, confirmed by sequencing, revealed an 8% (9/111) occurrence of Cryptosporidium parvum in faeces or LI contents, with no significant association between the host or location variables and infection. Archived small intestinal (SI) tissue from a hedgehog with histological evidence of cryptosporidiosis was also positive for C. parvum by PCR and sequence analysis of the 18S rRNA gene. No other Cryptosporidium species were detected. PCR and sequencing of the glycoprotein 60 gene identified three known zoonotic C. parvum subtypes not previously found in hedgehogs: IIdA17G1 (n=4), IIdA19G1 (n=1) and IIdA24G1 (n=1). These subtypes are also known to infect livestock. Another faecal sample contained C. parvum IIcA5G3j which has been found previously in hedgehogs, and for which there is one published report in a human, but is not known to affect livestock. The presence of zoonotic subtypes of C. parvum in British hedgehogs highlights a potential public health concern. Further research is needed to better understand the epidemiology and potential impacts of Cryptosporidium infection in hedgehogs

Model Lipid Membranes Assembled from Natural Plant Thylakoids into 2D Microarray Patterns as a Platform to Assess the Organization and Photophysics of Light‐Harvesting Proteins

Natural photosynthetic “thylakoid” membranes found in green plants contain a large network of light‐harvesting (LH) protein complexes. Rearrangement of this photosynthetic machinery, laterally within stacked membranes called “grana”, alters protein–protein interactions leading to changes in the energy balance within the system. Preparation of an experimentally accessible model system that allows the detailed investigation of these complex interactions can be achieved by interfacing thylakoid membranes and synthetic lipids into a template comprised of polymerized lipids in a 2D microarray pattern on glass surfaces. This paper uses this system to interrogate the behavior of LH proteins at the micro‐ and nanoscale and assesses the efficacy of this model. A combination of fluorescence lifetime imaging and atomic force microscopy reveals the differences in photophysical state and lateral organization between native thylakoid and hybrid membranes, the mechanism of LH protein incorporation into the developing hybrid membranes, and the nanoscale structure of the system. The resulting model system within each corral is a high‐quality supported lipid bilayer that incorporates laterally mobile LH proteins. Photosynthetic activity is assessed in the hybrid membranes versus proteoliposomes, revealing that commonly used photochemical assays to test the electron transfer activity of photosystem II may actually produce false‐positive results

The IBER study: a feasibility randomised controlled trial of imagery based emotion regulation for the treatment of anxiety in bipolar disorder

BACKGROUND: Intrusive mental imagery is associated with anxiety and mood instability within bipolar disorder and therefore represents a novel treatment target. Imagery Based Emotion Regulation (IBER) is a brief structured psychological intervention developed to enable people to use the skills required to regulate the emotional impact of these images. METHODS: Participants aged 18 and over with a diagnosis of bipolar disorder and at least a mild level of anxiety were randomly assigned (1:1) to receive IBER plus treatment as usual (IBER + TAU) or treatment as usual alone (TAU). IBER was delivered in up to 12 sessions overs 16 weeks. Clinical and health economic data were collected at baseline, end of treatment and 16-weeks follow-up. Objectives were to inform the recruitment process, timeline and sample size estimate for a definitive trial and to refine trial procedures. We also explored the impact on participant outcomes of anxiety, depression, mania, and mood stability at 16-weeks and 32-weeks follow-up. RESULTS: Fifty-seven (28: IBER + TAU, 27: TAU) participants from two sites were randomised, with 50 being recruited within the first 12 months. Forty-seven (82%) participants provided outcome data at 16 and 32-weeks follow-up. Thirty-five participants engaged in daily mood monitoring at the 32-week follow-up stage. Retention in IBER treatment was high with 27 (96%) attending ≥ 7 sessions. No study participants experienced a serious adverse event. DISCUSSION: The feasibility criteria of recruitment, outcome completion, and intervention retention were broadly achieved, indicating that imagery-focused interventions for bipolar disorder are worthy of further investigation

Are autistic traits measured equivalently in individuals with and without an Autism Spectrum Disorder?:An invariance analysis of the Autism Spectrum Quotient Short Form

It is common to administer measures of autistic traits to those without autism spectrum disorders (ASDs) with, for example, the aim of understanding autistic personality characteristics in non-autistic individuals. Little research has examined the extent to which measures of autistic traits actually measure the same traits in the same way across those with and without an ASD. We addressed this question using a multi-group confirmatory factor invariance analysis of the Autism Quotient Short Form (AQ-S: Hoekstra et al. in J Autism Dev Disord 41(5):589-596, 2011) across those with (n = 148) and without (n = 168) ASD. Metric variance (equality of factor loadings), but not scalar invariance (equality of thresholds), held suggesting that the AQ-S measures the same latent traits in both groups, but with a bias in the manner in which trait levels are estimated. We, therefore, argue that the AQ-S can be used to investigate possible causes and consequences of autistic traits in both groups separately, but caution is due when combining or comparing levels of autistic traits across the two group

Eye Movements Predict Recollective Experience

Previously encountered stimuli can bring to mind a vivid memory of the episodic context in which the stimulus was first experienced ("remembered'' stimuli), or can simply seem familiar ("known'' stimuli). Past studies suggest that more attentional resources are required to encode stimuli that are subsequently remembered than known. However, it is unclear if the attentional resources are distributed differently during encoding and recognition of remembered and known stimuli. Here, we record eye movements while participants encode photos, and later while indicating whether the photos are remembered, known or new. Eye fixations were more clustered during both encoding and recognition of remembered photos relative to known photos. Thus, recognition of photos that bring to mind a vivid memory for the episodic context in which they were experienced is associated with less distributed overt attention during encoding and recognition. The results suggest that remembering is related to encoding of a few distinct details of a photo rather than the photo as a whole. In turn, during recognition remembering may be trigged by enhanced memory for the salient details of the photos

A Phylogeny and Timescale for the Evolution of Pseudocheiridae (Marsupialia: Diprotodontia) in Australia and New Guinea

Pseudocheiridae (Marsupialia: Diprotodontia) is a family of endemic Australasian arboreal folivores, more commonly known as ringtail possums. Seventeen extant species are grouped into six genera (Pseudocheirus, Pseudochirulus, Hemibelideus, Petauroides, Pseudochirops, Petropseudes). Pseudochirops and Pseudochirulus are the only genera with representatives on New Guinea and surrounding western islands. Here, we examine phylogenetic relationships among 13 of the 17 extant pseudocheirid species based on protein-coding portions of the ApoB, BRCA1, ENAM, IRBP, Rag1, and vWF genes. Maximum parsimony, maximum likelihood, and Bayesian methods were used to estimate phylogenetic relationships. Two different relaxed molecular clock methods were used to estimate divergence times. Bayesian and maximum parsimony methods were used to reconstruct ancestral character states for geographic provenance and maximum elevation occupied. We find robust support for the monophyly of Pseudocheirinae (Pseudochirulus + Pseudocheirus), Hemibelidinae (Hemibelideus + Petauroides), and Pseudochiropsinae (Pseudochirops + Petropseudes), respectively, and for an association of Pseudocheirinae and Hemibelidinae to the exclusion of Pseudochiropsinae. Within Pseudochiropsinae, Petropseudes grouped more closely with the New Guinean Pseudochirops spp. than with the Australian Pseudochirops archeri, rendering Pseudochirops paraphyletic. New Guinean species belonging to Pseudochirops are monophyletic, as are New Guinean species belonging to Pseudochirulus. Molecular dates and ancestral reconstructions of geographic provenance combine to suggest that the ancestors of extant New Guinean Pseudochirops spp. and Pseudochirulus spp. dispersed from Australia to New Guinea ∼12.1–6.5 Ma (Pseudochirops) and ∼6.0–2.4 Ma (Pseudochirulus). Ancestral state reconstructions support the hypothesis that occupation of high elevations (>3000 m) is a derived feature that evolved on the terminal branch leading to Pseudochirops cupreus, and either evolved in the ancestor of Pseudochirulus forbesi, Pseudochirulus mayeri, and Pseudochirulus caroli, with subsequent loss in P. caroli, or evolved independently in P. mayeri and P. forbesi. Divergence times within the New Guinean Pseudochirops clade are generally coincident with the uplift of the central cordillera and other highlands. Diversification within New Guinean Pseudochirulus occurred in the Plio-Pleistocene after the establishment of the Central Range and other highlands

Selective targeting of neuroblastoma tumour-initiating cells by compounds identified in stem cell-based small molecule screens

Neuroblastoma (NB) is the most deadly extra-cranial solid tumour in children necessitating an urgent need for effective and less toxic treatments. One reason for the lack of efficacious treatments may be the inability of existing drugs to target the tumour-initiating or cancer stem cell population responsible for sustaining tumour growth, metastases and relapse. Here, we describe a strategy to identify compounds that selectively target patient-derived cancer stem cell-like tumour-initiating cells (TICs) while sparing normal paediatric stem cells (skin-derived precursors, SKPs) and characterize two therapeutic candidates. DECA-14 and rapamycin were identified as NB TIC-selective agents. Both compounds induced TIC death at nanomolar concentrations in vitro, significantly reduced NB xenograft tumour weight in vivo, and dramatically decreased self-renewal or tumour-initiation capacity in treated tumours. These results demonstrate that differential drug sensitivities between TICs and normal paediatric stem cells can be exploited to identify novel, patient-specific and potentially less toxic therapies