Sabertooth: A High Mobility Quadrupedal Robot Platform

Team Sabertooth aimed to design and realize an innovative high mobility, quadrupedal robot capable of delivering a payload over terrain impassable by wheeled vehicles at a speed of 5fps. The robot is designed to ascend and descend stairs. The robot uses a spring system in each of its legs for energy efficient locomotion. The 4\u27x3\u27x3\u27 freestanding four legged robot weighs approximately 300lbs with an additional payload capacity of 30lbs. The passive two degree of freedom body joint allows flexibility in terms of robot motion for going around tight corners and ascending stairs. The system integrates sensors for staircase recognition, obstacle avoidance, and distance calculation. A distributed control and software architecture is used for world mapping, path planning and motion control

Clinical Severity of Clostridium difficile PCR Ribotype 027: A Case-Case Study

BACKGROUND: Clostridium difficile is a leading infectious cause of health care associated diarrhoea. Several industrialised countries have reported increased C. difficile infections and outbreaks, which have been attributed to the emergent PCR ribotype 027 strain. METHODS AND FINDINGS: We conducted a case-case study to compare severity of C. difficile disease for patients with 027 versus non-027 ribotypes. We retrospectively collected clinical information about 123/136 patients with C. difficile infections admitted to hospitals in the East of England region in 2006 and from whom stool isolates were cultured and ribotyped as part of an earlier national survey. We defined severe C. difficile disease as having one or more of shock, paralytic ileus, pseudo membranous colitis or toxic megacolon. Patient median age was 83 years old (range 3 to 98, interquartile range 75 to 89), 86% were prescribed antibiotics in the eight weeks before illness onset, 41% had ribotype 027 and 30-day all cause mortality during hospital admission was 21%. Severe disease occurred in 24% (95%CI 13% to 37%) and 17% (95%CI 9% to 27%) of patients with PCR ribotype 027 and non-027 ribotypes respectively. In a multivariable model, ribotype 027 was not associated with severe disease after adjusting for sex, discharge from hospital prior to 60 days of current admission, gastroenteritis on admission, number of initiator antibiotics for C. difficile disease, and hospital where the patient was admitted. CONCLUSIONS: Our study found no evidence to support previous assertions that ribotype 027 is more virulent than other PCR ribotypes. This finding raises questions about the contribution of this strain to the recent increase in C. difficile disease throughout North America and Europe

The tempo of cetacean cranial evolution

The evolution of cetaceans (whales and dolphins) represents one of the most extreme adaptive transitions known, from terrestrial mammals to a highly specialized aquatic radiation that includes the largest animals alive today. Many anatomical shifts in this transition involve the feeding, respiratory, and sensory structures of the cranium, which we quantified with a high-density, three-dimensional geometric morphometric analysis of 201 living and extinct cetacean species spanning the entirety of their ∼50-million-year evolutionary history. Our analyses demonstrate that cetacean suborders occupy distinct areas of cranial morphospace, with extinct, transitional taxa bridging the gap between archaeocetes (stem whales) and modern mysticetes (baleen whales) and odontocetes (toothed whales). This diversity was obtained through three key periods of rapid evolution: first, the initial evolution of archaeocetes in the early to mid-Eocene produced the highest evolutionary rates seen in cetaceans, concentrated in the maxilla, frontal, premaxilla, and nasal; second, the late Eocene divergence of the mysticetes and odontocetes drives a second peak in rates, with high rates and disparity sustained through the Oligocene; and third, the diversification of odontocetes, particularly sperm whales, in the Miocene (∼18-10 Mya) propels a final peak in the tempo of cetacean morphological evolution. Archaeocetes show the fastest evolutionary rates but the lowest disparity. Odontocetes exhibit the highest disparity, while mysticetes evolve at the slowest pace, particularly in the Neogene. Diet and echolocation have the strongest influence on cranial morphology, with habitat, size, dentition, and feeding method also significant factors impacting shape, disparity, and the pace of cetacean cranial evolution

Low and intermediate energy electron collisions with the C2−_2^- molecular anion

Calculations are presented which use the molecular R-matrix with pseudo-states (MRMPS) method to treat electron impact electron detachment and electronic excitation of the carbon dimer anion. Resonances are found above the ionisation threshold of C$_2^-$ with $^1\Sigma^+_g$, $^1\Pi_g$ and $^3\Pi_g$ symmetry. These are shape resonances trapped by the effect of an attractive polarisation potential competing with a repulsive Coulomb interaction. The $\Pi_g$ resonances are found to give structure in the detachment cross section similar to that observed experimentally. Both excitation and detachment cross sections are found to be dominated by large impact parameter collisions whose contribution is modelled using the Born approximation.Comment: 18 pages, 5 figures constructed from 8 file

Predicting success of oligomerized pool engineering (OPEN) for zinc finger target site sequences

<p>Abstract</p> <p>Background</p> <p>Precise and efficient methods for gene targeting are critical for detailed functional analysis of genomes and regulatory networks and for potentially improving the efficacy and safety of gene therapies. Oligomerized Pool ENgineering (OPEN) is a recently developed method for engineering C2H2 zinc finger proteins (ZFPs) designed to bind specific DNA sequences with high affinity and specificity <it>in vivo</it>. Because generation of ZFPs using OPEN requires considerable effort, a computational method for identifying the sites in any given gene that are most likely to be successfully targeted by this method is desirable.</p> <p>Results</p> <p>Analysis of the base composition of experimentally validated ZFP target sites identified important constraints on the DNA sequence space that can be effectively targeted using OPEN. Using alternate encodings to represent ZFP target sites, we implemented Naïve Bayes and Support Vector Machine classifiers capable of distinguishing "active" targets, i.e., ZFP binding sites that can be targeted with a high rate of success, from those that are "inactive" or poor targets for ZFPs generated using current OPEN technologies. When evaluated using leave-one-out cross-validation on a dataset of 135 experimentally validated ZFP target sites, the best Naïve Bayes classifier, designated ZiFOpT, achieved overall accuracy of 87% and specificity⁺of 90%, with an ROC AUC of 0.89. When challenged with a completely independent test set of 140 newly validated ZFP target sites, ZiFOpT performance was comparable in terms of overall accuracy (88%) and specificity⁺(92%), but with reduced ROC AUC (0.77). Users can rank potentially active ZFP target sites using a confidence score derived from the posterior probability returned by ZiFOpT.</p> <p>Conclusion</p> <p>ZiFOpT, a machine learning classifier trained to identify DNA sequences amenable for targeting by OPEN-generated zinc finger arrays, can guide users to target sites that are most likely to function successfully <it>in vivo</it>, substantially reducing the experimental effort required. ZiFOpT is freely available and incorporated in the Zinc Finger Targeter web server (<url>http://bindr.gdcb.iastate.edu/ZiFiT</url>).</p

Single crewing in English and Welsh policing: frequency and associations with violence towards and injuries in officers

There is limited contemporary evidence concerning whether single crewing – the deployment of unaccompanied police officers – presents a risk to officer safety. This exploratory self-report study examined the frequency of single crewing in England and Wales and associations with violence-related variables. Officers represented by the Police Federation of England and Wales contributed survey data on four forms of violent victimisation and injuries requiring medical attention arising from workrelated violence experienced over the 12 months to February 2016. Respondents for whom crewing was applicable to their role indicated the frequency with which they had been single crewed during the same period. Pearson’s χ 2 tests were used to characterise socio- and occupational-demographic factors associated with single crewing, violence, and injuries. Associations between single crewing frequency and the target variables were assessed using adjusted binary logistic regression to generate odds ratios and 95% confidence intervals. Among the 11,397 respondents who indicated that crewing was applicable to their role, 53% were often and 21% always single crewed. Relative to those who were never single crewed, the odds of being subjected to verbal insults and verbal threats were significantly elevated in officers who were often or always single crewed. The odds of physical attacks and injuries requiring medical attention were significantly elevated in officers who were always single crewed. There was no association between single crewing frequency and physical attacks with a weapon. These initial cross-sectional findings suggest that tailored crewing options might represent a means by which to reduce violence towards police officers. Keywords: crewing, injury, police, violence

The while of participation: A systematic review of participatory research involving people with sensory impairments and/or intellectual impairments.

This paper reports on the first systematic review of literature associated with participatory research involving people identified with sensory impairments and/or intel- lectual impairments. It was initiated as part of ARCHES, an European Union-funded heritage project. The review sought to examine processes and activities used for organising participatory research involving people identified with sensory and/or intellectual impairments. 54 papers were included, involving studies from 14 countries and varying numbers of participants across different time scales. Insights were gained into use of advisory groups, organisation and support, collecting and analysing data, sharing findings and activity types. Emergent themes enabled an identification of the while of participation. The while represents the tensions, outcomes and component parts which are evident within the multiple moments that span an experience of participatory research. Participation is not about types of activity but how any activity is undertaken

Direct observation of active material concentration gradients and crystallinity breakdown in LiFePO4 electrodes during charge/discharge cycling of lithium batteries

The phase changes that occur during discharge of an electrode comprised of LiFePO4, carbon, and PTFE binder have been studied in lithium half cells by using X-ray diffraction measurements in reflection geometry. Differences in the state of charge between the front and the back of LiFePO4 electrodes have been visualized. By modifying the X-ray incident angle the depth of penetration of the X-ray beam into the electrode was altered, allowing for the examination of any concentration gradients that were present within the electrode. At high rates of discharge the electrode side facing the current collector underwent limited lithium insertion while the electrode as a whole underwent greater than 50% of discharge. This behavior is consistent with depletion at high rate of the lithium content of the electrolyte contained in the electrode pores. Increases in the diffraction peak widths indicated a breakdown of crystallinity within the active material during cycling even during the relatively short duration of these experiments, which can also be linked to cycling at high rate

The Murchison Widefield Array: Design Overview

The Murchison Widefield Array (MWA) is a dipole-based aperture array synthesis telescope designed to operate in the 80-300 MHz frequency range. It is capable of a wide range of science investigations, but is initially focused on three key science projects. These are detection and characterization of 3-dimensional brightness temperature fluctuations in the 21cm line of neutral hydrogen during the Epoch of Reionization (EoR) at redshifts from 6 to 10, solar imaging and remote sensing of the inner heliosphere via propagation effects on signals from distant background sources,and high-sensitivity exploration of the variable radio sky. The array design features 8192 dual-polarization broad-band active dipoles, arranged into 512 tiles comprising 16 dipoles each. The tiles are quasi-randomly distributed over an aperture 1.5km in diameter, with a small number of outliers extending to 3km. All tile-tile baselines are correlated in custom FPGA-based hardware, yielding a Nyquist-sampled instantaneous monochromatic uv coverage and unprecedented point spread function (PSF) quality. The correlated data are calibrated in real time using novel position-dependent self-calibration algorithms. The array is located in the Murchison region of outback Western Australia. This region is characterized by extremely low population density and a superbly radio-quiet environment,allowing full exploitation of the instrumental capabilities.Comment: 9 pages, 5 figures, 1 table. Accepted for publication in Proceedings of the IEE