Invariance Hints and the VC Dimension

We are interested in having a neural network learn an unknown function f. If the function satisfies an invariant of some sort, such as f is an odd function, then we want to be able to take advantage of this information and not have the network deduce the invariant based on an example of f. The invariant might be defined in terms of an explicit transformation of the input space under which f is constant. In this case it is possible to build a network thatnecessarily satisfies the invariant. In general, we define the invariant in terms of a partition of the input space such that if x, x' are in the same partition element then f (x) = f (x'). An example of the invariant would be a pair (x, x') taken from a single partition element. We can combine examples of the invariant with examples of the function in the learning process. The goal is to substitute examples of the invariant for examples of the function; the extent to which we can actually do this depends on the appropriate VC dimensions. Simulations verify, at least in simple cases, that examples of the invariant do aid the learning process

Comparing trends in the Southern Annular Mode and surface westerly jet

We examine trends in the Southern Annular Mode (SAM), and the strength, position and width of the Southern Hemisphere surface westerly wind jet in observations, reanalyses and the Coupled Model Intercomparison Phase 5 (CMIP5) models. First we consider the period over 1951 to 2011, and show that there are differences in the SAM and jet trends between the CMIP5 models, the HadSLP2r gridded sea-level pressure (SLP) dataset, and the Twentieth Century Reanalysis. The relationships between these trends demonstrates that the SAM index cannot be used to directly infer changes in any one kinematic property of the jet. The spatial structure of the observed trends in SLP and zonal winds is shown to be largest, but also most uncertain, in the southeast Pacific. To constrain this uncertainty we include six reanalyses and compare with station based observations of SLP. We find the CMIP5 mean SLP trends generally agree well with the direct observations, despite some climatological biases, while some reanalyses exhibit spuriously large SLP trends. Similarly, over the more reliable satellite era the spatial pattern of CMIP5 SLP trends is in excellent agreement with HadSLP2r, while several reanalyses are not. Then we compare surface winds with a satellite based product, and show that the CMIP5 mean trend is similar to observed in the core region of the westerlies, but that several reanalyses overestimate recent trends. We caution that studies examining the impact of wind changes on the Southern Ocean could be biased by these spuriously large trends in reanalysis products

Bioprinting of human pluripotent stem cells and their directed differentiation into hepatocyte-like cells for the generation of mini-livers in 3D

We report the first investigation into the bioprinting of human induced pluripotent stem cells (hiPSCs), their response to a valve-based printing process as well as their post-printing differentiation into hepatocyte-like cells (HLCs). HLCs differentiated from both hiPSCs and human embryonic stem cells (hESCs) sources were bioprinted and examined for the presence of hepatic markers to further validate the compatibility of the valve-based bioprinting process with fragile cell transfer. Examined cells were positive for nuclear factor 4 alpha and were demonstrated to secrete albumin and have morphology that was also found to be similar to that of hepatocytes. Both hESC and hiPSC lines were tested for post-printing viability and pluripotency and were found to have negligible difference in terms of viability and pluripotency between the printed and non-printed cells. hESC-derived HLCs were 3D printed using alginate hydrogel matrix and tested for viability and albumin secretion during the remaining differentiation and were found to be hepatic in nature. 3D printed with 40-layer of HLC-containing alginate structures reached peak albumin secretion at day 21 of the differentiation protocol. This work demonstrates that the valve-based printing process is gentle enough to print human pluripotent stem cells (hPSCs) (both hESCs and hiPSCs) while either maintaining their pluripotency or directing their differentiation into specific lineages. The ability to bioprint hPSCs will pave the way for producing organs or tissues on demand from patient specific cells which could be used for animal-free drug development and personalized medicine

Synthesis of oxindoles and benozfuranones via oxidation of 2-heterocyclic BMIDAs

The synthesis of functionalized oxindoles and benzofuranones via oxidation of 2-BMIDA indoles and benzofurans, respectively, is described. Interconversion of boron species (BMIDAàBF3K) was necessary to enable oxidation and overcome boronic acid stability issues associated with a difficult BMIDA hydrolysis. Overall, a robust process was developed that allowed access to a small library of oxindole and benzofuranone products and facilitated the step-efficient synthesis of biologically-active compounds containing the oxindole pharmacophore

Geology and Petroleum Prospectivity of the Sea of Hebrides Basin and Minch Basin, Offshore Northwest Scotland

Funding: This work was funded by the Natural Environment Research Council (RG12649-12). Acknowledgements: The work contained in this paper contains work conducted during a PhD study undertaken as part of the Natural Environment Research Council (NERC) Centre for Doctoral Training (CDT) in Oil and Gas. We are also grateful to IHS Markit for provision of, and permission to publish examples from, their 2D seismic data volumes and gravity and magnetics database, and to Schlumberger for their donation of Petrel seismic interpretation software licences to Aberdeen University. We also thank Geognostics for the kind permission to use the Frogtech Geoscience, 2016 depth to basement map (SEEBASE) of offshore northwest Scotland. We acknowledge the UKOilandGasData.com website, owned by UK National Data Repository administered by Schlumberger, for access to the seismic data volumes and released UK well database. We are also grateful to the UK National Onshore Data Library who kindly provided seismic data (UKOGL request 100891 and 100890) to the University of Aberdeen. Dr. Iain Scotchman and Dr. Clayton Grove are thanked for constructive and helpful reviews, which have improved this paper. Laura-Jane would also like to personally thank the late Professor Bernard Owens, who passed away in July 2019, for his informative discussion on Carboniferous outliers along the west coast early on in her PhD. The views held within this paper do not necessarily represent the views of IHS Markit.Peer reviewedPostprin

Blindness Due to Polymicrogyria and Asymmetrical Dilation of the Lateral Ventricles in Standard Poodles

Polymicrogyria and asymmetric dilation of the lateral ventricles were seen in related Standard poodles that had cortical blindness. Three of the affected dogs also had gait and postural abnormalities, and one of these had seizures.Two of the affected dogs were littermates. Thorough ophthalmologic and neurologic examinations (including electroretinography, electromyography, cerebrospinal fluid analysis, plain radiographs, and computerized tomography scans) revealed no significant abnormalities outside of the brain that would account for the blindness. Computerized tomography scans in three dogs demonstrated bilateral dilation of the lateral ventricles which was more severe in the right. All dogs were necropsied between 5 and 9 months of age and had strikingly similar brain abnormalities. Numerous small irregular gyri with shallow sulci covered the middle and caudal dorsal and lateral cerebral cortex. The bony ridges of the inner calvaria in this area conformed to the underlying microgyral pattern. The lateral ventricles were asymmetrically dilated with the right more severely affected, particularly in the occipital area, and the cortical grey and white matter, including the corpus callosum, were thinned in these areas. The third and fourth ventricles and mesencephalic aqueduct were normal. Histologically, there was thinning and simplification of the cortical grey matter with an increased density of medium to large neurons. The corona radiata and subcortical white matter were also thinner than normal with no evidence of demyelination of astrocytic scarring. This congenital anomaly of the visual cortex causing blindness in the Standard Poodle appears to be inherited as an autosomal recessive trait