Genetic analysis of members of the species Oropouche virus and identification of a novel M segment sequence

Oropouche virus (OROV) is a public health threat in South America, and in particular Northern Brazil, causing frequent outbreaks of febrile illness. Using a combination of deep sequencing and Sanger sequencing approaches we have determined complete genome sequences of eight clinical isolates that were obtained from patient sera during an Oropouche fever outbreak in Amapa state, northern Brazil in 2009. We also report complete genome sequences of two OROV reassortants isolated from two marmosets in Minas Gerais state, southeast Brazil in 2012 that contain a novel M genome segment. Interestingly, all ten isolates posses a 947 nucleotide long S segment that lacks 11 residues in the S segment 3' UTR compared to the recently redetermined Brazilian prototype OROV strain BeAn19991. OROV maybe circulating more widely in Brazil and in the non-human primate population than previously appreciated and the identification of yet another reassortant highlights the importance of bunyavirus surveillance in South America

On embedding of the Bratteli diagram into a surface

We study C*-algebras O_{\lambda} which arise in dynamics of the interval exchange transformations and measured foliations on compact surfaces. Using Koebe-Morse coding of geodesic lines, we establish a bijection between Bratteli diagrams of such algebras and measured foliations. This approach allows us to apply K-theory of operator algebras to prove strict ergodicity criterion and Keane's conjecture for the interval exchange transformations.Comment: final versio

A novel method for sampling the suspended sediment load in the tidal environment using bi-directional time-integrated mass-flux sediment (TIMS) samplers

Identifying the source and abundance of sediment transported within tidal creeks is essential for studying the connectivity between coastal watersheds and estuaries. The fine-grained suspended sediment load (SSL) makes up a substantial portion of the total sediment load carried within an estuarine system and efficient sampling of the SSL is critical to our understanding of nutrient and contaminant transport, anthropogenic influence, and the effects of climate. Unfortunately, traditional methods of sampling the SSL, including instantaneous measurements and automatic samplers, can be labor intensive, expensive and often yield insufficient mass for comprehensive geochemical analysis. In estuaries this issue is even more pronounced due to bi-directional tidal flow. This study tests the efficacy of a time-integrated mass sediment sampler (TIMS) design, originally developed for uni-directional flow within the fluvial environment, modified in this work for implementation the tidal environment under bi-directional flow conditions. Our new TIMS design utilizes an ‘L’ shaped outflow tube to prevent backflow, and when deployed in mirrored pairs, each sampler collects sediment uniquely in one direction of tidal flow. Laboratory flume experiments using dye and particle image velocimetry (PIV) were used to characterize the flow within the sampler, specifically, to quantify the settling velocities and identify stagnation points. Further laboratory tests of sediment indicate that bidirectional TIMS capture up to 96% of incoming SSL across a range of flow velocities (0.3–0.6 m s−1). The modified TIMS design was tested in the field at two distinct sampling locations within the tidal zone. Single-time point suspended sediment samples were collected at high and low tide and compared to time-integrated suspended sediment samples collected by the bi-directional TIMS over the same four-day period. Particle-size composition from the bi-directional TIMS were representative of the array of single time point samples, but yielded greater mass, representative of flow and sediment-concentration conditions at the site throughout the deployment period. This work proves the efficacy of the modified bi-directional TIMS design, offering a novel tool for collection of suspended sediment in the tidally-dominated portion of the watershed

Nuclear multifragmentation and fission: similarity and differences

Thermal multifragmentation of hot nuclei is interpreted as the nuclear liquid--fog phase transition deep inside the spinodal region. The experimental data for p(8.1GeV) + Au collisions are analyzed. It is concluded that the decay process of hot nuclei is characterized by two size parameters: transition state and freeze-out volumes. The similarity between dynamics of fragmentation and ordinary fission is discussed. The IMF emission time is related to the mean rupture time at the multi-scission point, which corresponds to the kinetic freeze-out configuration.Comment: 7 pages, 3 Postscript figures, Proceedings of IWM 2005, Catani

Mode-hop-free tuning over 135 GHz of external cavity diode lasers without anti-reflection coating

We report an external cavity diode laser (ECDL), using a diode whose front facet is not antireflection (AR) coated, that has a mode-hop-free (MHF) tuning range greater than 135 GHz. We achieved this using a short external cavity and by simultaneously tuning the internal and external modes of the laser. We find that the precise location of the pivot point of the grating in our laser is less critical than commonly believed. The general applicability of the method, combined with the compact portable mechanical and electronic design, makes it well suited for both research and industrial applications.Comment: 5 pages, 5 figure

Electron Spin Relaxation in a Semiconductor Quantum Well

A fully microscopic theory of electron spin relaxation by the D'yakonov-Perel' type spin-orbit coupling is developed for a semiconductor quantum well with a magnetic field applied in the growth direction of the well. We derive the Bloch equations for an electron spin in the well and define microscopic expressions for the spin relaxation times. The dependencies of the electron spin relaxation rate on the lowest quantum well subband energy, magnetic field and temperature are analyzed.Comment: Revised version as will appear in Physical Review

Optimal Hypercontractivity for Fermi Fields and Related Non-Commutative Integration

Optimal hypercontractivity bounds for the fermion oscillator semigroup are obtained. These are the fermion analogs of the optimal hypercontractivity bounds for the boson oscillator semigroup obtained by Nelson. In the process, several results of independent interest in the theory of non-commutative integration are established. {}.Comment: 18 p., princeton/ecel/7-12-9

Research from therapeutic radiographers : an audit of research capacity within the UK

Research from Allied Health Professionals (AHPs) is anecdotally known to lag behind that of other professions. The developing research landscape within other therapies and internationally led us to question how UK practice in therapeutic radiography was developing. The aim of the survey was to audit research capacity across therapy radiography in the UK. Method: An electronic survey was sent to Radiotherapy Service Managers (RSM) and research leads in each of the radiotherapy centres in the UK. An adapted version of the 'Auditing Research Capacity' tool (ARC © tool) was used as the basis of the questionnaire. Results: A total of 45 RSM responded to the survey (67% response rate) and 30 Research radiographers (RR) (45% response rate). A total of 51 RR were in post equating to 40.3 whole time equivalents and averaging 1 RR per centre. Variation was evident in the commitment to the development of a research culture identified by practices such as linking research to the business planning cycle, inclusion of research in recruitment and advertising materials, or having a nominated therapeutic radiographer lead on research for the department. Over a third of responding centres did not have a research strategy and training for RRs was limited; specifically in areas such as writing funding bids, writing for publication and the research and governance process. Conclusion: A number of short and long-term strategies are proposed that should enhance a positive research culture and improve research capacity for therapeutic radiography led research. These include utilisation of the existing infrastructure provided by the National Institute for Health Research, a lead or co-ordinator for research activity with a remit to motivate others. Development of links and networks, and the development of a research strategy linked to wider Trust research priorities. The research strategy should include mentoring or developing appropriate research skills for those engaged in research (including higher degree qualifications). RSMs should also encourage peer-reviewed publications, and conference presentations from all staff to ensure research results are disseminated to the wider profession

Keeping calm in the face of change: towards optimisation of FRP by reasoning about change

Functional Reactive Programming (FRP) is an approach to reactive programming where systems are structured as networks of functions operating on signals (time-varying values). FRP is based on the synchronous data-flow paradigm and supports both (an approximation to) continuous-time and discrete-time signals (hybrid systems).What sets FRP apart from most other languages for similar applications is its support for systems with dynamic structure and for higher-order reactive constructs. This paper contributes towards advancing the state of the art of FRP implementation by studying the notion of signal change and change propagation in a setting of structurally dynamic networks of n-ary signal functions operating on mixed continuous-time and discrete-time signals. We first define an ideal denotational semantics (time is truly continuous) for this kind of FRP, along with temporal properties, expressed in temporal logic, of signals and signal functions pertaining to change and change propagation. Using this framework, we then show how to reason about change; specifically, we identify and justify a number of possible optimisations, such as avoiding recomputation of unchanging values. Note that due to structural dynamism, and the fact that the output of a signal function may change because time is passing even if the input is unchanging, the problem is significantly more complex than standard change propagation in networks with static structure