Bialgebra deformations and algebras of trees

Let A denote a bialgebra over a field k and let A sub t = A((t)) denote the ring of formal power series with coefficients in A. Assume that A is also isomorphic to a free, associative algebra over k. A simple construction is given which makes A sub t a bialgebra deformation of A. In typical applications, A sub t is neither commutative nor cocommutative. In the terminology of Drinfeld, (1987), A sub t is a quantum group. This construction yields quantum groups associated with families of trees

Opening up and closing down : how teachers and TAs manage turn-taking, topic and repair in mathematics lessons

Support for children with special educational needs in inclusive classrooms is increasingly provided by teaching assistants (TAs). They often have a direct pedagogical role, taking responsibility for instruction in mathematics. The quality of TAs' oral skills is crucial for learning but has rarely been researched. Using conversation analysis, this study compares teacher and TA talk in terms of turn allocation, topic generation and repair. From 130 recordings, transcripts of mathematics teaching in four lessons were analysed in depth. We found that teachers open up students whilst TAs close down the talk. Teachers, with whole classes, adopt inclusive teaching strategies to ensure oral participation whereas TAs, working with individuals, emphasise task completion. Teachers use open strategies for topic generation whilst TAs ask closed questions. Teachers withhold correction with prompts and hints whilst TAs supply answers. The findings are interpreted with reference to the TA role and implications for management and training

Peptide-based targeting of fluorescent zinc sensors to the plasma membrane of live cells

Combining fluorescent zinc sensors with the facile syntheses and biological targeting capabilities of peptides, we created green- and blue-emitting probes that (i) are readily prepared on the solid-phase, (ii) retain the photophysical and zinc-binding properties of the parent sensor, and (iii) can be directed to the extracellular side of plasma membranes in live cells for detection of mobile zinc.National Institute of General Medical Sciences (U.S.) (Grant GM065519

Eavesdropping magpies respond to the number of heterospecifics giving alarm calls but not the number of species calling

Social information varies in its reliability and relevance, requiring individuals to use rules to avoid inappropriate responses to false information. A simple rule is to respond only when a certain number of individuals provide similar information. Although individuals within social groups can use such numerical rules to assess conspecific information and make consensus decisions, it is unknown whether individuals apply similar rules when assessing the value of heterospecific information. We consider the case of individuals eavesdropping on heterospecific alarm calls. Eavesdroppers may be particularly vulnerable to false alarms because of the large pool of potential callers and variability in the specific threats to which they call. Individuals might therefore value alarm calls more if they come from multiple callers or multiple species than from a single caller or a single species. We tested these predictions using field playback experiments on wild Australian magpies, Gymnorhina tibicen. Magpies responded more strongly to alarm calls coming from two callers versus one caller of the same heterospecific species. However, in contrast to our prediction, magpies responded similarly to alarm calls from two individuals of different species as they did to alarm calls from two individuals of the same species. We conclude that the number of calling individuals does affect response, probably because information from multiple callers is more reliable, but that the value or reliability of information from multiple species may depend on the types of alarm calls and combination of species involved.The work was funded by an Australian Research Council Discovery grant to R.D.M., A.N.R, and Esteban Fernandez- Juricic

Forming Human-Robot Teams Across Time and Space

NASA pushes telerobotics to distances that span the Solar System. At this scale, time of flight for communication is limited by the speed of light, inducing long time delays, narrow bandwidth and the real risk of data disruption. NASA also supports missions where humans are in direct contact with robots during extravehicular activity (EVA), giving a range of zero to hundreds of millions of miles for NASA s definition of "tele". . Another temporal variable is mission phasing. NASA missions are now being considered that combine early robotic phases with later human arrival, then transition back to robot only operations. Robots can preposition, scout, sample or construct in advance of human teammates, transition to assistant roles when the crew are present, and then become care-takers when the crew returns to Earth. This paper will describe advances in robot safety and command interaction approaches developed to form effective human-robot teams, overcoming challenges of time delay and adapting as the team transitions from robot only to robots and crew. The work is predicated on the idea that when robots are alone in space, they are still part of a human-robot team acting as surrogates for people back on Earth or in other distant locations. Software, interaction modes and control methods will be described that can operate robots in all these conditions. A novel control mode for operating robots across time delay was developed using a graphical simulation on the human side of the communication, allowing a remote supervisor to drive and command a robot in simulation with no time delay, then monitor progress of the actual robot as data returns from the round trip to and from the robot. Since the robot must be responsible for safety out to at least the round trip time period, the authors developed a multi layer safety system able to detect and protect the robot and people in its workspace. This safety system is also running when humans are in direct contact with the robot, so it involves both internal fault detection as well as force sensing for unintended external contacts. The designs for the supervisory command mode and the redundant safety system will be described. Specific implementations were developed and test results will be reported. Experiments were conducted using terrestrial analogs for deep space missions, where time delays were artificially added to emulate the longer distances found in space

Should mentoring be routinely introduced into general dental practice to reduce the risk of occupational stress?

Introduction: Occupational stress within general dental practice can potentially have an adverse impact on a practitioner's wellbeing and the quality of healthcare provided by that individual. Mentoring has routinely been utilised in other professions for stress management, however, there is little in the dental literature discussing the benefits of mentorship on the reduction of occupational stress for dental practitioners. Aim: The aim of this study was to explore the perceptions of experienced foundation dental trainers within the Health Education, Kent, Surrey and Sussex postgraduate deanery as to the usefulness of routine mentoring as a tool to reduce occupational stress. Methods: Using a qualitative approach, six individual semi-structured interviews were undertaken. Recorded interviews were transcribed and transcriptions were analysed using thematic coding to identify overarching themes. Results: Both similarities and differences with the existing literature on routine mentoring within professional settings were identified. Foundation dental trainers were positive towards the concept of routine mentoring, although there was also a degree of scepticism regarding the potential uptake among colleagues. There was a perception that mentoring might more practically be used as a reactionary tool. Multiple potential barriers to routine mentoring were identified, included funding, scheduling and a lack of training. Conclusions: The analysis identified that currently, experienced foundation dental practitioners do not consider routine mentoring as a practical option in the prevention of occupational stress. The results would suggest that further education is required as to the benefits of routine mentoring as a strategy for occupational stress management. However, with additional resources buying time, a hybrid model of mentoring and coaching has significant potential in general dental practice

Mincle polarizes human monocyte and neutrophil responses to Candida albicans

The distribution and function of the C-type lectin Mincle has not previously been investigated in human cells, although mouse models have demonstrated a non-redundant role for Mincle in the host response to fungal infections. This study identified an unusual pattern of reciprocal expression of Mincle on peripheral blood monocytes or neutrophils isolated from the same donor. Expression on monocytes was inversely correlated with phagocytosis and yeast killing, but was necessary for the induction of inflammatory cytokines in response to ex vivo Candida challenge. In contrast, Mincle expression on neutrophils was associated with phagocytic and candidacidal potential of those cells. Candida challenge upregulated Mincle expression but only in Mincle+ cells. These data highlight species-specific differences between the regulation of Mincle expression in mouse and man. Reciprocal expression of Mincle modified the candidacidal potential of monocytes or neutrophils, suggesting it may also polarize the type of host response to fungal infection. Immunology and Cell Biology (2012) 90, 889-895; doi:10.1038/icb.2012.24; published online 29 May 201

The Role of MAPK in Drug-Induced Kidney Injury

This paper focuses on the role that mitogen-activated protein kinases (MAPKs) play in drug-induced kidney injury. The MAPKs, of which there are four major classes (ERK, p38, JNK, and ERK5/BMK), are signalling cascades which have been found to be broadly conserved across a wide variety of organisms. MAPKs allow effective transmission of information from the cell surface to the cytosolic or nuclear compartments. Cross talk between the MAPKs themselves and with other signalling pathways allows the cell to modulate responses to a wide variety of external stimuli. The MAPKs have been shown to play key roles in both mediating and ameliorating cellular responses to stress including xenobiotic-induced toxicity. Therefore, this paper will discuss the specific role of the MAPKs in the kidney in response to injury by a variety of xenobiotics and the potential for therapeutic intervention at the level of MAPK signalling across different types of kidney disease