Temporally resolved laser induced plasma diagnostics of single crystal silicon - effects of ambient pressure

Laser-Induced Breakdown Spectroscopy of silicon was performed using a nanosecond pulsed frequency doubled Nd:YAG (532 nm) laser. The temporal evolution of the laser ablation plumes in air at atmospheric pressure and at an ambient pressure of ∼10−5 mbar is presented. Electron densities were determined from the Stark broadening of the Si (I) 288.16 nm emission line. Electron densities in the range of 6.91×1017 to 1.29×1019 cm−3 at atmospheric pressure and 1.68×1017 to 3.02×1019 cm−3 under vacuum were observed. Electron excitation temperatures were obtained from the line to continuum ratios and yielded temperatures in the range 7600–18,200 K at atmospheric pressure, and 8020–18,200 K under vacuum. The plasma morphology is also characterized with respect to time in both pressure regimes

Blast mines: physics, injury mechanisms and vehicle protection.

Since World War II, more vehicles have been lost to land mines than all other threats combined. Anti-vehicular (AV) mines are capable of disabling a heavy vehicle, or completely destroying a lighter vehicle. The most common form of AV mine is the blast mine, which uses a large amount of explosive to directly damage the target. In a conventional military setting, landmines are used as a defensive force-multiplier and to restrict the movements of the opposing force. They are relatively cheap to purchase and easy to acquire, hence landmines are also potent weapons in the insurgents armamentarium. The stand-offnature of its design has allowed insurgents to cause significant injuries to security forces in current conflicts with little personal risk. As a result, AV mines and improvised explosive devices (IEDs) have become the most common cause of death and injury to Coalition and local security forces operating in Iraq and Afghanistan. Detonation of an AV mine causes an explosive, exothermic reaction which results in the formation of a shockwave followed by a rapid expansion of gases. The shockwave is mainly reflected by the soillair interface and fractures the soil cap overthe mine. The detonation products then vent through the voids in the soil, resulting in a hollow inverse cone which consists of the detonation gases surrounded by the soil ejecta. It is the combination of the detonation products and soil ejecta that interact with the target vehicle and cause injury to the vehicle occupants. A number of different strategies are required to mitigate the blast effects of an explosion. Primary blast effects can be reduced by increasing the standoff distance between the seat of the explosion and the crew compartment. Enhancement of armour on the base of the vehicle, as well as improvements in personal protection can prevent penetration of fragments. Mitigating tertiary effects can be achieved by altering the vehicle geometry and structure, increasing vehicle mass, as well as developing new strategies to reduce the transfer of the impulse through the vehicle to the occupants. Protection from thermal injury can be provided by incorporating fire resistant materials into the vehicle and in personal clothing. The challenge for the vehicle designer is the incorporation of these protective measures within an operationally effective platform.Published versio

Patient empowerment: designing technology that supports people’s coping strategies

Background: Self-management technologies, such as patient-controlled electronic health records (PCEHRs), have the potential to help people manage and cope with disease. Objectives: This study set out to investigate patient families’ lived experiences of working with a PCEHR. Method: We conducted a semi-structured qualitative field study with patient families and clinicians at a children’s hospital in the UK that uses a PCEHR. All families were managing the health of a child with a serious chronic condition, who was typically under the care of multiple clinicians. As data gathering and analysis progressed, it became clear that while much of the literature assumes that patients are willing and waiting to take more responsibility for and control over their health management (for example, with PCEHRs), only a minority of participants in our study responded in this way. Their experiences with the PCEHR were diverse and strongly shaped by their coping styles. Theory on coping identifies a continuum of coping styles, from approach- to avoidance-oriented, and proposes that patients’ information needs depend on their style. Results: Based on themes that emerged from the data analysis, and informed by prior research on coping styles, we identified three groups of patient families and an outlier, distinguished by their coping style and their PCEHR use. We refer to the outlier as controlling (approach-oriented, highly motivated to use PCEHR), and the three groups as collaborating (approach-oriented, motivated to use PCEHR), cooperating (avoidance-oriented, less motivated to use PCEHR) and avoiding (very avoidance-oriented, not motivated to use PCEHR). Conclusions: The PCEHR met the needs of controller and collaborators better than the needs of co-operators and avoiders. We draw on Self-Determination Theory (SDT) to propose ways in which PCEHR design might better meet the needs of avoidance-oriented users. Further, we high-light the need for families to also relinquish control at times, and propose ways in which PCEHR design might support a better distribution of control, based on effective training, ease of use, com-prehensibility of data security mechanisms, timely information provision (recognising people’s dif-ferent needs), personalisation of use, and easy engagement with clinicians through the PCEHR

The inheritance of halothane susceptibility in pigs

International audienc

Unraveling the B. pseudomallei Heptokinase WcbL: from structure to drug discovery

Journal ArticleOpen Access funded by Biotechnology and Biological Sciences Research Council under a Creative Commons Attribution 4.0 International Public LicenseGram-negative bacteria utilize heptoses as part of their repertoire of extracellular polysaccharide virulence determinants. Disruption of heptose biosynthesis offers an attractive target for novel antimicrobials. A critical step in the synthesis of heptoses is their 1-O phosphorylation, mediated by kinases such as HldE or WcbL. Here, we present the structure of WcbL from Burkholderia pseudomallei. We report that WcbL operates through a sequential ordered Bi-Bi mechanism, loading the heptose first and then ATP. We show that dimeric WcbL binds ATP anti-cooperatively in the absence of heptose, and cooperatively in its presence. Modeling of WcbL suggests that heptose binding causes an elegant switch in the hydrogen-bonding network, facilitating the binding of a second ATP molecule. Finally, we screened a library of drug-like fragments, identifying hits that potently inhibit WcbL. Our results provide a novel mechanism for control of substrate binding and emphasize WcbL as an attractive anti-microbial target for Gram-negative bacteria.Biotechnology and Biological Sciences Research Counci