Printing Multistrain Bacterial Patterns with a Piezoelectric Inkjet Printer

Many studies involving interacting microorganisms would benefit from simple devices able to deposit cells in precisely defined patterns. We describe an inexpensive bacterial piezoelectric inkjet printer (adapted from the design of the POSaM oligonucleotide microarrayer) that can be used to “print out” different strains of bacteria or chemicals in small droplets onto a flat surface at high resolution. The capabilities of this device are demonstrated by printing ordered arrays comprising two bacterial strains labeled with different fluorescent proteins. We also characterized several properties of this piezoelectric printer, such as the droplet volume (of the order of tens of pl), the distribution of number of cells in each droplet, and the dependence of droplet volume on printing frequency. We established the limits of the printing resolution, and determined that the printed viability of Escherichia coli exceeded 98.5%

Investigation of rising nitrate concentrations in groundwater in the Eden Valley, Cumbria. 3, saturated zone studies

This component Work Package of the Eden Valley Project was undertaken with the objective of determining the hydrogeological regime and hydrochemical stratification in selected boreholes. The subsequent aim is to apply this to better understand timescales for water movement through the saturated zone along a transect ending near to the River Eden where the Permo-Triassic sandstone aquifer is exposed or underlies thin superficial deposits. A previous report in this series confirmed rising nitrate trends in groundwater in the study area, and suggested that with continued land use practices and with no evidence of denitrification, that this trend would continue. Another concluded that the average recharge rate is probably in the range 425-470 mm/y and the rate of water movement through the unsaturated zone is c. 3.5-3.85 m/y. Based on this estimate of water movement in the unsaturated zone, the travel time for recharge to migrate from the soil to the water table (or the delay imposed by the unsaturated zone) over most of the area where the sandstone is free of superficial deposits in the Eden Valley is c. 14 years. However if the higher fells are not considered - closer to 10 years. Given the inherent uncertainties and limitations associated with the various methods for determining the hydrogeological regime in a boreholem, methods proposed were: (i) to date the pore water profile within the saturated zone using CFC and SF6 tracers (ii) to determine the variation of aquifer properties with depth, for the matrix (using laboratory techniques) and the aquifer (using field pumping techniques). (iii) To use groundwater models to estimate groundwater travel times in the saturated zones (this part of the project has not yet been funded). A transect approach was adopted using existing boreholes to the east of Penrith to the Eden floodplain and addressing gaps with infill drilling. Despite early promise other boreholes (on a ‘southern’ transect) were discounted due to inaccessibility or unsuitable construction. A c. 4km transect from the east of Penrith in a north-western direction to the floodplain of the River Eden was selected starting at previously drilled project borehole

‘Media events’ reconsidered: from ritual theory to simulation and performativity

This paper re-examines the long-established notion of ‘media events’ by contrasting and critically appraising three distinct approaches to the question of media events. These are: ritual theory associated with Daniel Dayan and Elihu Katz, secondly, Jean Baudrillard’s approach rooted in his notions of simulation and ‘non-events’ and, finally, the more recent performative approaches to media and mediation. I take Sarah Kember and Joanna Zylinska’s reading of media events presented in Life After New Media (2012) as exemplary of the performative approach. An argument is made that the accounts of media events offered by performative approaches add very little, and, indeed, lack the critical insightfulness of the earlier approaches. Both ritual theory and Baudrillard’s thought are briefly reappraised and, against Nick Couldry, I try to show that these accounts are not characterised by binary and reductive thinking. The major misunderstandings concern the nature of the sacred and profane dualism and the further dualisms developed in Baudrillard’s thought, particularly the figures of implosion and reversibility. Finally, Baudrillard’s position on technology is addressed and the paper concludes with the suggestion that his account is not solely negative, since technological developments are not only at the mercy of ironic reversals they may also enable new rituals of disappearance

A 2 R_⊕ Planet Orbiting the Bright Nearby K Dwarf Wolf 503

Since its launch in 2009, the Kepler telescope has found thousands of planets with radii between that of Earth and Neptune. Recent studies of the distribution of these planets have revealed a gap in the population near 1.5–2.0 R⊕, informally dividing these planets into "super-Earths" and "sub-Neptunes." The origin of this division is difficult to investigate directly because the majority of planets found by Kepler orbit distant, dim stars and are not amenable to radial velocity follow-up or transit spectroscopy, making bulk density and atmospheric measurements difficult. Here, we present the discovery and validation of a newly found 2.03^(+0.08)_(-0.07) R⊕ planet in direct proximity to the radius gap, orbiting the bright (J = 8.32 mag), nearby (D = 44.5 pc) high proper motion K3.5V star Wolf 503 (EPIC 212779563). We determine the possibility of a companion star and false positive detection to be extremely low using both archival images and high-contrast adaptive optics images from the Palomar observatory. The brightness of the host star makes Wolf 503b a prime target for prompt radial velocity follow-up, and with the small stellar radius (0.690 ± 0.025R⊙), it is also an excellent target for HST transit spectroscopy and detailed atmospheric characterization with JWST. With its measured radius near the gap in the planet radius and occurrence rate distribution, Wolf 503b offers a key opportunity to better understand the origin of this radius gap as well as the nature of the intriguing populations of "super-Earths" and "sub-Neptunes" as a whole

Adherence to isoniazid preventive therapy in Indonesian children: A quantitative and qualitative investigation

<p>Abstract</p> <p>Background</p> <p>It is recommended that young child contacts of sputum smear positive tuberculosis cases receive isoniazid preventive therapy (IPT) but reported adherence is low and risk factors for poor adherence in children are largely unknown.</p> <p>Methods</p> <p>We prospectively determined rates of IPT adherence in children < 5 yrs in an Indonesian lung clinic. Possible risk factors for poor adherence, defined as ≤3 months prescription collection, were calculated using logistic regression. To further investigate adherence barriers in-depth interviews were conducted with caregivers of children with good and poor adherence.</p> <p>Results</p> <p>Eighty-two children eligible for IPT were included, 61 (74.4%) of which had poor adherence. High transport costs (OR 3.3, 95% CI 1.1-10.2) and medication costs (OR 20.0, 95% CI 2.7-414.5) were significantly associated with poor adherence in univariate analysis. Access, medication barriers, disease and health service experience and caregiver TB and IPT knowledge and beliefs were found to be important determinants of adherence in qualitative analysis.</p> <p>Conclusion</p> <p>Adherence to IPT in this setting in Indonesia is extremely low and may result from a combination of financial, knowledge, health service and medication related barriers. Successful reduction of childhood TB urgently requires evidence-based interventions that address poor adherence to IPT.</p

A 2 Earth Radius Planet Orbiting the Bright Nearby K-Dwarf Wolf 503

Since its launch in 2009, the Kepler telescope has found thousands of planets with radii between that of Earth and Neptune. Recent studies of the distribution of these planets have revealed a rift in the population near 1.5-2.0$R_{\bigoplus}$, informally dividing these planets into "super-Earths" and "sub-Neptunes". The origin of this division is not well understood, largely because the majority of planets found by Kepler orbit distant, dim stars and are not amenable to radial velocity follow-up or transit spectroscopy, making bulk density and atmospheric measurements difficult. Here, we present the discovery and validation of a newly found $2.03^{+0.08}_{-0.07}~R_{\bigoplus}$ planet in direct proximity to the radius gap, orbiting the bright ($J=8.32$~mag), nearby ($D=44.5$~pc) high proper motion star Wolf 503 (EPIC 212779563). We classify Wolf 503 as a K3.5V star and member of the thick disc population. We determine the possibility of a companion star and false positive detection to be extremely low using both archival images and high-contrast adaptive optics images from the Palomar observatory. The brightness of the host star makes Wolf 503b a prime target for prompt radial velocity follow-up, HST transit spectroscopy, as well as detailed atmospheric characterization with JWST. With its measured radius near the gap in the planet radius and occurrence rate distribution, Wolf 503b offers a key opportunity to better understand the origin of this radius gap as well as the nature of the intriguing populations of "super-Earths" and "sub-Neptunes" as a whole

Adjuvant bleomycin, vincristine and cisplatin (BOP) for high-risk stage I non-seminomatous germ cell tumours: a prospective trial (MRC TE17)

Adjuvant BEP (bleomycin, etoposide, cisplatin) is effective treatment for high-risk clinical stage I (HRCS1) non-seminomatous germ cell tumours (NSGCT), but the known toxicities of etoposide, and the expansion of the HR group to any patient with vascular invasion (50% of patients), led the Medical Research Council to pilot the BOP regimen. Patients received two courses of BOP 14 days apart: cisplatin 50 mg m−2 days 1 and 2, vincristine 1.4 mg m−2 (max. 2 mg) days 2 and 8, bleomycin 30 000 IU days 2 and 8. Primary outcome was relapse rate; quality of life, fertility, hearing and lung function were assessed pre- and post-treatment. In all, 100 patients were required. A total of 115 eligible patients were registered, all received two courses of chemotherapy. Median follow-up is 70 months; two relapses have occurred and the 5-year relapse-free rate is 98.3% (95% confidence interval (CI) 95.5%, 99.9%). As assessed by clinicians during treatment, complete (reversible) alopecia was present in 20% of patients; World Health Organization (WHO) grade 1/2 neurotoxicity was present in 41%/5% of patients during treatment and 22%/1% at 6 months. However, 12% of patients reported ‘quite a bit' or ‘very much' pain/numbness/tingling in hands/feet 2 years after chemotherapy. Mature follow-up confirms high efficacy for two courses of cisplatin-based adjuvant chemotherapy in HRCS1 NSGCT. Substituting vincristine for etoposide decreases alopecia, but gives a low incidence of significant neuropathy. There are no clearcut advantages to 2 × BOP over 2 × BEP, except for patients who wish to maximise the chance of avoiding significant alopecia

A Modified Consumer Inkjet for Spatiotemporal Control of Gene Expression

This paper presents a low-cost inkjet dosing system capable of continuous, two-dimensional spatiotemporal regulation of gene expression via delivery of diffusible regulators to a custom-mounted gel culture of E. coli. A consumer-grade, inkjet printer was adapted for chemical printing; E. coli cultures were grown on 750 µm thick agar embedded in micro-wells machined into commercial compact discs. Spatio-temporal regulation of the lac operon was demonstrated via the printing of patterns of lactose and glucose directly into the cultures; X-Gal blue patterns were used for visual feedback. We demonstrate how the bistable nature of the lac operon's feedback, when perturbed by patterning lactose (inducer) and glucose (inhibitor), can lead to coordination of cell expression patterns across a field in ways that mimic motifs seen in developmental biology. Examples of this include sharp boundaries and the generation of traveling waves of mRNA expression. To our knowledge, this is the first demonstration of reaction-diffusion effects in the well-studied lac operon. A finite element reaction-diffusion model of the lac operon is also presented which predicts pattern formation with good fidelity

Diversified actin protrusions promote environmental exploration but are dispensable for locomotion of leukocytes

Most migrating cells extrude their front by the force of actin polymerization. Polymerization requires an initial nucleation step, which is mediated by factors establishing either parallel filaments in the case of filopodia or branched filaments that form the branched lamellipodial network. Branches are considered essential for regular cell motility and are initiated by the Arp2/3 complex, which in turn is activated by nucleation-promoting factors of the WASP and WAVE families. Here we employed rapid amoeboid crawling leukocytes and found that deletion of the WAVE complex eliminated actin branching and thus lamellipodia formation. The cells were left with parallel filaments at the leading edge, which translated, depending on the differentiation status of the cell, into a unipolar pointed cell shape or cells with multiple filopodia. Remarkably, unipolar cells migrated with increased speed and enormous directional persistence, while they were unable to turn towards chemotactic gradients. Cells with multiple filopodia retained chemotactic activity but their migration was progressively impaired with increasing geometrical complexity of the extracellular environment. These findings establish that diversified leading edge protrusions serve as explorative structures while they slow down actual locomotion