Phytochemical screening and in vitro antioxidant assessment of Cassia alata (Linn) leaf extracts

This study investigated the phytochemical components and assessed the antioxidant activity of Cassia alata leaf extracts. The results showed that alkaloids were present in all the extracts, while saponins, phenols and flavonoids were detected in ethyl acetate and methanol extracts. The antioxidant capacities of the extracts, determined using four models in the presence of vitamin C and quercetin as standards at four different concentrations (0.25, 5.0, 1.0 and 2.0 mg/L), demonstrated that the activities were concentration-dependent in all the extracts. Thus, Cassia alata having important phytochemicals may be used in therapeutic medicine as a source of natural antioxidants

Interpreting granulite facies events through rare earth element partitioning arrays

The use of rare earth element (REE) partition coefficients is an increasingly common tool in metamorphic studies, linking the growth or modification of accessory mineral geochronometers to the bulk silicate mineral assemblage. The most commonly used mineral pair for the study of high-grade metamorphic rocks is zircon and garnet. The link from U–Pb ages provided by zircon to the P–T information recorded by garnet can be interpreted in relation to experimental data. The simplistic approach of taking the average REE abundances for zircon and garnet and comparing them directly to experimentally derived partition coefficients is imperfect, in that it cannot represent the complexity of a natural rock system. This study describes a method that uses all the zircon analyses from a sample, and compares them to different garnet compositions in the same rock. Using the most important REE values, it is possible to define zircon–garnet equilibrium using an array rather than an average. The array plot describes partitioning between zircon and garnet using DYb and DYb/DGd as the defining features of the relationship. This approach provides far more sensitivity to mineral reactions and diffusional processes, enabling a more detailed interpretation of metamorphic history of the sample

High-temperature Hydrogen Chloride Releases from Mixtures of Sodium Chloride with Sulfates: Implications for the Chlorine-Mineralogy as Determined by the Sample Analysis at Mars Instrument on the Curiosity Rover in Gale Crater, Mars

Hydrogen chloride releases above 500 C occurred in several samples analyzed by the Sample Analysis at Mars (SAM) evolved gas analyzer on the Curiosity rover in Gale crater. These have been attributed to reactions between chlorides (original or from oxychlorine decomposition) and water. Some of these HCl releases that peaked below the melting temperature of common chlorides did not co-evolve with oxygen or water, and were not explained by laboratory analog work (Figure 1). Therefore, these HCl releases were not caused by MgCl2 or soley due to reactions between water and melting chlorides. The goal of this work was to explain the HCl releases that did not co-evolve with oxygen or water and occurred below the melting point of common chlorides, which have not been explained by previous laboratory analog work. This work specifically evaluates the role of evolved SO2 in the production of HCl

Graded Exercise Therapy Guided Self-Help Trial for Patients with Chronic Fatigue Syndrome (GETSET): Protocol for a Randomized Controlled Trial and Interview Study

Background: Chronic fatigue syndrome, also known as myalgic encephalomyelitis (CFS/ME), is characterized by chronic disabling fatigue and other symptoms, which are not explained by an alternative diagnosis. Previous trials have suggested that graded exercise therapy (GET) is an effective and safe treatment. GET itself is therapist-intensive with limited availability. Objective: While guided self-help based on cognitive behavior therapy appears helpful to patients, Guided graded Exercise Self-help (GES) is yet to be tested. Methods: This pragmatic randomized controlled trial is set within 2 specialist CFS/ME services in the South of England. Adults attending secondary care clinics with National Institute for Health and Clinical Excellence (NICE)-defined CFS/ME (N=218) will be randomly allocated to specialist medical care (SMC) or SMC plus GES while on a waiting list for therapist-delivered rehabilitation. GES will consist of a structured booklet describing a 6-step graded exercise program, supported by up to 4 face-to-face/telephone/Skype™ consultations with a GES-trained physiotherapist (no more than 90 minutes in total) over 8 weeks. The primary outcomes at 12-weeks after randomization will be physical function (SF-36 physical functioning subscale) and fatigue (Chalder Fatigue Questionnaire). Secondary outcomes will include healthcare costs, adverse outcomes, and self-rated global impression change scores. We will follow up all participants until 1 year after randomization. We will also undertake qualitative interviews of a sample of participants who received GES, looking at perceptions and experiences of those who improved and worsened. Results: The project was funded in 2011 and enrolment was completed in December 2014, with follow-up completed in March 2016. Data analysis is currently underway and the first results are expected to be submitted soon. Conclusions: This study will indicate whether adding GES to SMC will benefit patients who often spend many months waiting for rehabilitative therapy with little or no improvement being made during that time. The study will indicate whether this type of guided self-management is cost-effective and safe. If this trial shows GES to be acceptable, safe, and comparatively effective, the GES booklet could be made available on the Internet as a practitioner and therapist resource for clinics to recommend, with the caveat that patients also be supported with guidance from a trained physiotherapist. The pragmatic approach in this trial means that GES findings will be generalizable to usual National Health Service (NHS) practice

The Neoarchaean Uyea Gneiss Complex, Shetland: an onshore fragment of the Rae Craton on the European Plate

A tract of amphibolite facies granitic gneisses and metagabbros in northern Shetland, U.K., is here named the Uyea Gneiss Complex. Zircon U–Pb dating indicates emplacement of the igneous protoliths of the complex c. 2746–2726 Ma, at a later time than most of the Archaean protoliths of the Lewisian Gneiss Complex of mainland Scotland. Calc-alkaline geochemistry of the Uyea Gneiss Complex indicates arc-affinity and a strong genetic kinship among the mafic and felsic components. Zircon Hf compositions suggest an enriched mantle source and limited interaction with older crust during emplacement. Ductile fabrics developed soon after emplacement, with zircon rims at c. 2710 Ma, but there was little further deformation until Caledonian reworking east of the Uyea Shear Zone. There is no evidence for the Palaeoproterozoic reworking that dominates large tracts of the Lewisian Gneiss Complex and of the Nagssugtoqidian Orogen of East Greenland. The more northerly location of the Uyea Gneiss Complex and extensive offshore basement of similar age implies that, prior to the opening of the North Atlantic Ocean, these rocks were contiguous with the Archaean Rae Craton

Saturn's icy satellites and rings investigated by Cassini - VIMS. III. Radial compositional variability

In the last few years Cassini-VIMS, the Visible and Infared Mapping Spectrometer, returned to us a comprehensive view of the Saturn's icy satellites and rings. After having analyzed the satellites' spectral properties (Filacchione et al. (2007a)) and their distribution across the satellites' hemispheres (Filacchione et al. (2010)), we proceed in this paper to investigate the radial variability of icy satellites (principal and minor) and main rings average spectral properties. This analysis is done by using 2,264 disk-integrated observations of the satellites and a 12x700 pixels-wide rings radial mosaic acquired with a spatial resolution of about 125 km/pixel. The comparative analysis of these data allows us to retrieve the amount of both water ice and red contaminant materials distributed across Saturn's system and the typical surface regolith grain sizes. These measurements highlight very striking differences in the population here analyzed, which vary from the almost uncontaminated and water ice-rich surfaces of Enceladus and Calypso to the metal/organic-rich and red surfaces of Iapetus' leading hemisphere and Phoebe. Rings spectra appear more red than the icy satellites in the visible range but show more intense 1.5-2.0 micron band depths. The correlations among spectral slopes, band depths, visual albedo and phase permit us to cluster the saturnian population in different spectral classes which are detected not only among the principal satellites and rings but among co-orbital minor moons as well. Finally, we have applied Hapke's theory to retrieve the best spectral fits to Saturn's inner regular satellites using the same methodology applied previously for Rhea data discussed in Ciarniello et al. (2011).Comment: 44 pages, 27 figures, 7 tables. Submitted to Icaru

The Christiansen Effect in Saturn's narrow dusty rings and the spectral identification of clumps in the F ring

Stellar occultations by Saturn's rings observed with the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft reveal that dusty features such as the F ring and the ringlets in the Encke and the Laplace Gaps have distinctive infrared transmission spectra. These spectra show a narrow optical depth minimum at wavelengths around 2.87 microns. This minimum is likely due to the Christiansen Effect, a reduction in the extinction of small particles when their (complex) refractive index is close to that of the surrounding medium. Simple Mie-scattering models demonstrate that the strength of this opacity dip is sensitive to the size distribution of particles between 1 and 100 microns across. Furthermore, the spatial resolution of the occultation data is sufficient to reveal variations in the transmission spectra within and among these rings. For example, in both the Encke Gap ringlets and F ring, the opacity dip weakens with increasing local optical depth, which is consistent with the larger particles being concentrated near the cores of these rings. The strength of the opacity dip varies most dramatically within the F ring; certain compact regions of enhanced optical depth lack an opacity dip and therefore appear to have a greatly reduced fraction of grains in the few-micron size range.Such spectrally-identifiable structures probably represent a subset of the compact optically-thick clumps observed by other Cassini instruments. These variations in the ring's particle size distribution can provide new insights into the processes of grain aggregation, disruption and transport within dusty rings. For example, the unusual spectral properties of the F-ring clumps could perhaps be ascribed to small grains adhering onto the surface of larger particles in regions of anomalously low velocity dispersion.Comment: 42 pages, 15 figures, accepted for publication in Icarus. A few small typographical errors fixed to match correction in proof

Test of Sum Rules in Nucleon Transfer Reactions

The quantitative consistency of nucleon transfer reactions as a probe of the occupancy of valence orbits in nuclei is tested. Neutron-adding, neutron-removal, and proton-adding transfer reactions were measured on the four stable even Ni isotopes, with particular attention to the cross section determinations. The data were analyzed consistently in terms of the distorted wave Born approximation to yield spectroscopic factors. Valence-orbit occupancies were extracted, utilizing the Macfarlane-French sum rules. The deduced occupancies are consistent with the changing number of valence neutrons, as are the vacancies for protons, both at the level of <5%. While there has been some debate regarding the true “observability” of spectroscopic factors, the present results indicate that empirically they yield self-consistent results

Transverse field muon-spin rotation signature of the skyrmion-lattice phase in Cu2OSeO3

We present the results of transverse field (TF) muon-spin rotation (μ+SR) measurements on Cu2OSeO3, which has a skyrmion-lattice (SL) phase. We measure the response of the TF μ+SR signal in that phase along with the surrounding ones, and suggest how the phases might be distinguished using the results of these measurements. Dipole field simulations support the conclusion that the muon is sensitive to the SL via the TF line shape and, based on this interpretation, our measurements suggest that the SL is quasistatic on a time scale τ > 100 ns

Valence nucleon populations in the Ni isotopes

Measurements of neutron-adding, neutron-removing, and proton-adding reactions were carried out for the four stable even Ni isotopes. Particular attention was paid to obtaining precise values of the cross sections at the peaks of the angular distributions. Tests with sum rules for the neutron data indicate that the results are self-consistent at the level of a few tenths of a nucleon. Data on proton-adding reactions were also obtained and analyzed with a slightly different method—while these data are also consistent, the ambiguities are larger. The occupancies of the neutron orbits derived from the data, the proton vacancies, and the energy centroids of the neutron, neutron-hole, and proton single-particle excitations are obtained. The data also provide some estimate about the closure of the 0f7/2 shell. The results are compared to shell-model calculations and may serve as a reference point for future exploration