Macroscelideans (Myohyracinae and Rhynchocyoninae) from the late Oligocene Nsungwe formation of the Rukwa Rift Basin, southwestern Tanzania

The fossil record of macroscelidean mammals is notoriously patchy, with a significant spatial and temporal gap separating faunas from the early Oligocene localities of northern Africa and the early Miocene localities of eastern and southern Africa. Here we describe fossil macroscelideans representing Myohyracinae and Rhynchocyoninae recovered from a rift-fill sequence of richly fossiliferous sandstones in the late Oligocene Nsungwe Formation in the Rukwa Rift Basin of southwestern Tanzania. Radiometrically dated to 25.2 Ma, a new Palaeogene myohyracine taxon (Rukwasengi butleri) is represented by a partial maxilla (RRBP 05409) preserving a lightly worn M2-M3. The M2 exhibits a less hypsodont and mesiodistally elongate morphology than the early Miocene Myohyrax oswaldi, and the three-rooted M3 exhibits a tiny mesially positioned fossette. A new rhynchocyonine (Oligorhynchocyon songwensis) is represented by specimens more brachyodont than the early Miocene Miorhynchocyon. Taken together these finds document a rare window into macroscelidean evolutionary history with diversification of the group near the Palaeogene-Neogene Transition (PNT). Continued exploration offers a refined perspective on mid-Cenozoic faunal and ecosystem dynamics on continental Africa, expanding opportunities for recognising trends in palaeobiological diversity across habitat types and through time

Modular Invariance of Finite Size Corrections and a Vortex Critical Phase

We analyze a continuous spin Gaussian model on a toroidal triangular lattice with periods $L_0$ and $L_1$ where the spins carry a representation of the fundamental group of the torus labeled by phases $u_0$ and $u_1$. We find the {\it exact finite size and lattice corrections}, to the partition function $Z$, for arbitrary mass $m$ and phases $u_i$. Summing $Z^{-1/2}$ over phases gives the corresponding result for the Ising model. The limits $m\rightarrow0$ and $u_i\rightarrow0$ do not commute. With $m=0$ the model exhibits a {\it vortex critical phase} when at least one of the $u_i$ is non-zero. In the continuum or scaling limit, for arbitrary $m$, the finite size corrections to $-\ln Z$ are {\it modular invariant} and for the critical phase are given by elliptic theta functions. In the cylinder limit $L_1\rightarrow\infty$ the ``cylinder charge'' $c(u_0,m^2L_0^2)$ is a non-monotonic function of $m$ that ranges from $2(1+6u_0(u_0-1))$ for $m=0$ to zero for $m\rightarrow\infty$.Comment: 12 pages of Plain TeX with two postscript figure insertions called torusfg1.ps and torusfg2.ps which can be obtained upon request from [email protected]

Imaging of ischemia, obstruction and infection in the abdomen

Intestinal ischemia is a serious condition that continues to be associated with mortalities in excess of 70%. Intestinal obstruction and gastrointestinal tract sepsis are common conditions, accounting for a large proportion of patients admitted to emergency departments with acute abdominal symptoms. This article discusses the imaging methods and key findings of these entities in the emergency radiology department. The article includes imaging examples, diagnostic options, protocol selections, diagnostic criteria, and differential diagnoses

Minimization of Radiation Exposure due to Computed Tomography in Inflammatory Bowel Disease

Patient awareness and concern regarding the potential health risks from ionizing radiation have peaked recently (Coakley et al., 2011) following widespread press and media coverage of the projected cancer risks from the increasing use of computed tomography (CT) (Berrington et al., 2007). The typical young and educated patient with inflammatory bowel disease (IBD) may in particular be conscious of his/her exposure to ionising radiation as a result of diagnostic imaging. Cumulative effective doses (CEDs) in patients with IBD have been reported as being high and are rising, primarily due to the more widespread and repeated use of CT (Desmond et al., 2008). Radiologists, technologists, and referring physicians have a responsibility to firstly counsel their patients accurately regarding the actual risks of ionizing radiation exposure; secondly to limit the use of those imaging modalities which involve ionising radiation to clinical situations where they are likely to change management; thirdly to ensure that a diagnostic quality imaging examination is acquired with lowest possible radiation exposure. In this paper, we synopsize available evidence related to radiation exposure and risk and we report advances in low-dose CT technology and examine the role for alternative imaging modalities such as ultrasonography or magnetic resonance imaging which avoid radiation exposure

GWIPS-viz: 2018 update

The GWIPS-viz browser (http://gwips.ucc.ie/) is an on-line genome browser which is tailored for exploring ribosome profiling (Ribo-seq) data. Since its publication in 2014, GWIPS-viz provides Ribo-seq data for an additional 14 genomes bringing the current total to 23. The integration of new Ribo-seq data has been automated thereby increasing the number of available tracks to 1792, a 10-fold increase in the last three years. The increase is particularly substantial for data derived from human sources. Following user requests, we added the functionality to download these tracks in bigWig format. We also incorporated new types of data (e.g. TCP-seq) as well as auxiliary tracks from other sources that help with the interpretation of Ribo-seq data. Improvements in the visualization of the data have been carried out particularly for bacterial genomes where the Ribo-seq data are now shown in a strand specific manner. For higher eukaryotic datasets, we provide characteristics of individual datasets using the RUST program which includes the triplet periodicity, sequencing biases and relative inferred A-site dwell times. This information can be used for assessing the quality of Ribo-seq datasets. To improve the power of the signal, we aggregate Ribo-seq data from several studies into Global aggregate tracks for each genome

Osteogenic Activity of Locally Applied Small Molecule Drugs in a Rat Femur Defect Model

The long-term success of arthroplastic joints is dependent on the stabilization of the implant within the skeletal site. Movement of the arthroplastic implant within the bone can stimulate osteolysis, and therefore methods which promote rigid fixation or bone growth are expected to enhance implant stability and the long-term success of joint arthroplasty. In the present study, we used a simple bilateral bone defect model to analyze the osteogenic activity of three small-molecule drug implants via microcomputerized tomography (micro-CT) and histomorphometry. In this study, we show that local delivery of alendronate, but not lovastatin or omeprazole, led to significant new bone formation at the defect site. Since alendronate impedes osteoclast-development, it is theorized that alendronate treatment results in a net increase in bone formation by preventing osteoclast mediated remodeling of the newly formed bone and upregulating osteoblasts

Enhanced monography in a collaboratively evolved hub for systematic biology

No abstract available