Linear plasma experiment for non-linear microwave interaction experiments

As a non-linear medium, plasma can exhibit diverse dynamics when excited bymultiple EM waves. Electromagnetic waves are vital to the introduction of energyin laser plasma interactions and the heating of magnetically confined fusion reactors.In laser plasma applications Raman coupling via a Langmuir oscillation or Brillouinscattering mediated by ion-acoustic waves are of interest. Signals with normalisedintensities approaching those used in some recent laser plasma interactions can begenerated using powerful and flexible microwave amplifiers, interacting in relativelytenuous, cool and accessible plasma. Other multi-wave interactions are interesting formagnetic confinement fusion plasmas, for example beat-wave interactions betweentwo microwave signals coupling to cyclotron motion of the ions and electrons or thelower hybrid oscillations may be useful in heating the plasmas or for driving currents.A linear plasma experiment is being built to test such multifrequency microwaveinteraction in plasma, based on prior research on geophysical cyclotron wave emissionand propagation [1,2]. The main section of the plasma will be magnetised at up to0.05T, with the plasma created by an RF helicon source to generate a dense, large,cool plasma with a high ionisation fraction. A range of frequency-flexible sources willprovide microwave beams to enable multi-wave coupling experiments. The paper willpresent progress on this apparatus and experiments.The authors gratefully acknowledge support from the EPSRC, MBDA UK Ltd andTMD Technologies Ltd.[1] Ronald K., Speirs D.C., McConville S.L., Phelps A.D.R., Robertson C.W., WhyteC.G., He W., Gillespie K.M., Cross A.W., Bingham R., 2008, Phys. Plasmas, 15,art.056503[2] Speirs, D.C., Bingham, R., Cairns, R.A., Vorgul, I., Kellett, B.J., Phelps, A.D.R.,Ronald, K, 2014, Phys. Rev. Lett., 113, art 15500

Hepatitis C Virus Transmission Clusters in Public Health and Correctional Settings, Wisconsin, USA, 2016-20171.

Ending the hepatitis C virus (HCV) epidemic requires stopping transmission among networks of persons who inject drugs. Identifying transmission networks by using genomic epidemiology may inform community responses that can quickly interrupt transmission. We retrospectively identified HCV RNA-positive specimens corresponding to 459 persons in settings that use the state laboratory, including correctional facilities and syringe services programs, in Wisconsin, USA, during 2016-2017. We conducted next-generation sequencing of HCV and analyzed it for phylogenetic linkage by using the Centers for Disease Control and Prevention Global Hepatitis Outbreak Surveillance Technology platform. Analysis showed that 126 persons were linked across 42 clusters. Phylogenetic clustering was higher in rural communities and associated with female sex and younger age among rural residents. These data highlight that HCV transmission could be reduced by expanding molecular-based surveillance strategies to rural communities affected by the opioid crisis

Impact of IVS8-(TG)m(T)n on IRT and sweat chloride levels in newborns identified by California CF newborn screening.

We examined the relation between the number of (TG) repeats at the (IVS8)-(TG)m(T)5 locus of the CFTR gene with neonatal serum immunoreactive trypsinogen (IRT) and sweat chloride (SC) concentrations in hypertrypsinogenemic infants with genotype ΔF508-9T/5T identified by California cystic fibrosis newborn screening. SC and IRT distributions increased with increasing (TG) repeats

Characterisation oga helicon source for non-linear microwave coupling experiments in a magnetised plasma

As a non-linear medium, parametric instabilities arise when powerful EM waves propagate in plasma. Such effects are seen in laser-plasma, RF–ionospheric and tokamak heating scenarios. Fusion plasmas in a spherical aspect tokamak are difficult to heat due to their high densities, making the lower cyclotron resonances unreachable via direct means. Beat-wave interactions involving multiple EM waves can be used to excite such resonances. Laser, fusion and ionospheric environments pose diagnostic challenges to fully investigate these processes and measure their impact on macroscopic properties such as density, temperature and energy distributions. For this reason a helicon source driven between 3 & 30 MHz has been commissioned. The 1 m diameter, 3 m long stainless-steel vessel is immersed in a static B-field of up to 90 mT formed by 6 electromagnets. The resulting relatively tenuous (1018 m-3), cool (<10 eV) plasma is ideal for parametric wave coupling experiments with powerful microwave beams. Microwave interferometry, frequency compensated Langmuir and RF pickup probes will diagnose how these processes impact the plasma. This paper presents initial experiments characterising the apparatus, with comparison to numerical simulations. *Supported by UK EPSRC (EP/R004773/1)

Sexually dimorphic estrogen sensing in skeletal stem cells controls skeletal regeneration

Sexually dimorphic tissues are formed by cells that are regulated by sex hormones. While a number of systemic hormones and transcription factors are known to regulate proliferation and differentiation of osteoblasts and osteoclasts, the mechanisms that determine sexually dimorphic differences in bone regeneration are unclear. To explore how sex hormones regulate bone regeneration, we compared bone fracture repair between adult male and female mice. We found that skeletal stem cell (SSC) mediated regeneration in female mice is dependent on estrogen signaling but SSCs from male mice do not exhibit similar estrogen responsiveness. Mechanistically, we found that estrogen acts directly on the SSC lineage in mice and humans by up-regulating multiple skeletogenic pathways and is necessary for the stem cell's ability to self- renew and differentiate. Our results also suggest a clinically applicable strategy to accelerate bone healing using localized estrogen hormone therapy