Time variability of Neptune's horizontal and vertical cloud structure revealed by VLT/SINFONI and Gemini/NIFS from 2009 to 2013

New observations of Neptune's clouds in the near infrared were acquired in October 2013 with SINFONI on ESO's Very Large Telescope (VLT) in Chile. SINFONI is an Integral Field Unit spectrometer returning a 64 × 64 pixel image with 2048 wavelengths. Image cubes in the J-band (1.09-1.41 μm) and H-band (1.43-1.87 μm) were obtained at spatial resolutions of 0.1″and 0.025″per pixel, while SINFONI's adaptive optics provided an effective resolution of approximately 0.1″. Image cubes were obtained at the start and end of three successive nights to monitor the temporal development of discrete clouds both at short timescales (i.e. during a single night) as well as over the longer period of the three-day observing run. These observations were compared with similar H-band observations obtained in September 2009 with the NIFS Integral Field Unit spectrometer on the Gemini-North telescope in Hawaii, previously reported by Irwin et al. (2011) [Icarus, 216, 141-158], and previously unreported Gemini/NIFS observations at lower spatial resolution made in 2011.We find both similarities and differences between these observations, spaced over four years. The same overall cloud structure is seen with high, bright clouds visible at mid-latitudes (30-40°N,S), with slightly lower clouds observed at lower latitudes, together with small discrete clouds seen circling the pole at a latitude of approximately 60°S. However, while discrete clouds were visible at this latitude at both the main cloud deck level (at 2-3 bar) and in the upper troposphere (100-500 mb) in 2009, no distinct deep (2-3 bar), discrete circumpolar clouds were visible in 2013, although some deep clouds were seen at the southern edge of the main cloud belt at 30-40°S, which have not been observed before. The nature of the deep sub-polar discrete clouds observed in 2009 is intriguing. While it is possible that in 2013 these deeper clouds were masked by faster moving, overlying features, we consider that it is unlikely that this should have happened in 2013, but not in 2009 when the upper-cloud activity was generally similar. Meanwhile, the deep clouds seen at the southern edge of the main cloud belt at 30-40°S in 2013, should also have been detectable in 2009, but were not seen. Hence, these observations may have detected a real temporal variation in the occurrence of Neptune's deep clouds, pointing to underlying variability in the convective activity at the pressure of the main cloud deck at 2-3 bar near Neptune's south pole and also in the main observable cloud belt at 30-40°S.</p

Molecular and Cellular Mechanisms Affected in ALS

Amyotrophic lateral sclerosis (ALS) is a terminal late-onset condition characterized by the loss of upper and lower motor neurons. Mutations in more than 30 genes are associated to the disease, but these explain only ~20% of cases. The molecular functions of these genes implicate a wide range of cellular processes in ALS pathology, a cohesive understanding of which may provide clues to common molecular mechanisms across both familial (inherited) and sporadic cases and could be key to the development of effective therapeutic approaches. Here, the different pathways that have been investigated in ALS are summarized, discussing in detail: mitochondrial dysfunction, oxidative stress, axonal transport dysregulation, glutamate excitotoxicity, endosomal and vesicular transport impairment, impaired protein homeostasis, and aberrant RNA metabolism. This review considers the mechanistic roles of ALS-associated genes in pathology, viewed through the prism of shared molecular pathways

Quantitative PET reporter gene imaging of CD8+ T cells specific for a melanoma-expressed self-antigen

Adoptive transfer (AT) T-cell therapy provides significant clinical benefits in patients with advanced melanoma. However, approaches to non-invasively visualize the persistence of transferred T cells are lacking. We examined whether positron emission tomography (PET) can monitor the distribution of self-antigen-specific T cells engineered to express an herpes simplex virus 1 thymidine kinase (sr39tk) PET reporter gene. Micro-PET imaging using the sr39tk-specific substrate 9-[4-[18F]fluoro-3-(hydroxymethyl)-butyl]guanine ([18F]FHBG) enabled the detection of transplanted T cells in secondary lymphoid organs of recipient mice over a 3-week period. Tumor responses could be predicted as early as 3 days following AT when a >25-fold increase of micro-PET signal in the spleen and 2-fold increase in lymph nodes (LNs) were observed in mice receiving combined immunotherapy versus control mice. The lower limit of detection was ∼7 × 105 T cells in the spleen and 1 × 104 T cells in LNs. Quantification of transplanted T cells in the tumor was hampered by the sr39tk-independent trapping of [18F]FHBG within the tumor architecture. These data support the feasibility of using PET to visualize the expansion, homing and persistence of transferred T cells. PET may have significant clinical utility by providing the means to quantify anti-tumor T cells throughout the body and provide early correlates for treatment efficacy

The prevalence of hyperglycaemia and its relationship with mortality, readmissions and length of stay in an older acute surgical population : a multicentre study

Funding statement This research received no specific grant from any funding agency in the public, commercial or not-for-profit sector.Peer reviewedPostprin

Catalytic dehydrocoupling of Amine-Boranes Using Cationic Zirconium(IV)-Phosphine Frustrated Lewis Pairs

A series of novel, intramolecular Zr­(IV)/P frustrated Lewis pairs (FLPs) based on cationic zirconocene fragments with a variety of ancillary cyclopentadienyl and 2-phosphinoaryloxide (−O­(C₆H₄)­PR₂, R = ^tBu and 3,5-CF₃-(C₆H₃)) ligands are reported and their activity as catalysts for the dehydrocoupling of dimethylamine–borane (Me₂NH·BH₃) assessed. The FLP system [(C₉H₇)₂ZrO­(C₆H₄)­P^tBu₂]­[B­(C₆F₅)₄] is shown to give unprecedented turnover frequencies (TOF) for a catalyst based on a group 4 metal (TOF ≥ 600 h^–1), while also proving to be the most efficient FLP catalyst reported to date. The mechanism of this reaction has been probed using analogous intermolecular Zr­(IV)/P FLPs, permitting deconvolution of the reactions taking place at both the Lewis acidic and basic sites. Elucidation of this mechanism revealed an interesting cooperative two-cycle process where one cycle is FLP mediated and the other, a redistribution of a linear diborazane intermediate, relies solely on the presence of a Zr­(IV) Lewis acid