Dimensional and crystallographic fabric development in experimentally deformed synthetic aggregate and natural rocks

Calcite Portland-cement aggregate samples were deformed triaxially at 25 deg. with confining pressures of 200 Mpa. The samples were deformed under experimental approximations of pure shear (dry and wet experimental conditions), transpressional shear and simple shear. The pore fluid pressure during the wet pure shear test was less than 195 MPa. Extensive grain rotation accompanied by twinning of the calcite grains occurred. Optical analyses of calcite crystallographic fabrics have been used to infer the orientation of the maximum principal compressive stress. Stress orientations in the deformed specimens agree well with the externally imposed stresses. A new method has been successfully used to determine the a, orientation. The method uses contouring of the lamellae index associated with the compression direction determined from Turner's Dynamic analysis method. In pure shear, preferred dimensional orientation (PDO) of the calcite grains are produced more efficiently in the presence of a pore fluid pressure. In dry specimens, transpressional shear is more effective in producing a PDO in the calcite grain than either pure shear or simple shear. Grain shape fabrics do not conform to the symmetry of the bulk deformation when extensive rotation of calcite grains is involved. Mean grain alignment is perpendicular to the shortening in pure shear, initially inclined and later parallel to the shear zone wall in transpressional shear, and inclined to the shear zone wall in simple shear. The mean orientation of the grain-alignment fabrics is, therefore, a reliable kinematic indicator under the conditions investigated. Transpressional shear and dry pure shear exhibit higher lamellae indices than either wet pure shear or simple shear. Strain analysis of calcite grains by Robin's method (1977) , the linearization method (Yu and Zheng, 1984) and Harmonic mean method (Lisle, 1977) yields overestimates of the experimental bulk strain in wet pure shear. These methods fail to take into account interparticle motions that occur in the presence of a high pore fluid pressure. The triaxial deformation of the Ancaster oolitic limestone was preformed with a confining pressure of 200 Mpa, a natural strain rate of 10-5/s and at a temperature of 135°C. The samples were deformed under dry and wet experimental conditions. The pore fluid pressure, during the wet test, was less than 60 % of the confining pressure. The deformation process of ooids in the dry experimental test is rigid rotation of the ooid particles. In the case of wet experimental conditions, it appears that the pore fluid pressure produces particulate flow in the fine grained ooid matrix. Due to a viscosity contrast, between ooids and cement matrix, strain analysis on the ooids exhibits an overestimate of strain compared to the experimental bulk strain. This holds true for both wet and dry experimental conditions. Experimental triaxial deformation was conducted on the China Beach sandstone by pure shear for dry experimental conditions. The temperature was held constant at 25°C, with computer controlled natural strain rates of 10-5/s and a confining pressure of 200 Mpa. Mechanical heterogeneities in the grains of the China Beach sample play an important role in the development of cleavage. Altered feldspar grains and lithic fragments deform by ductile processes, while unaltered feldspar and quartz grain deform by rigid rotation and brittle processes. Strain analysis of each grain type in the China Beach sandstone yield a range of strain estimates depending on the deformation process compared to the experimental bulk strain. Comparison of Robin's method, the linearization method and Harmonic mean method suggest that Robin's method generates the best estimates of the bulk experimental strain ratio

The First HET Planet: A Companion to HD 37605

We report the first detection of a planetary-mass companion to a star using the High Resolution Spectrograph (HRS) of the Hobby-Eberly Telescope (HET). The HET-HRS now gives routine radial velocity precision of 2-3 m/s for high SNR observations of quiescent stars. The planetary-mass companion to the metal-rich K0V star HD37605 has an orbital period of 54.23 days, an orbital eccentricity of 0.737, and a minimum mass of 2.84 Jupiter masses. The queue-scheduled operation of the Hobby-Eberly Telescope enabled us to discovery of this relatively short-period planet with a total observation time span of just two orbital periods. The ability of queue-scheduled large-aperture telescopes to respond quickly to interesting and important results demonstrates the power of this new approach in searching for extra-solar planets as well as in other ares of research requiring rapid response time critical observations.Comment: 4 Pages, 2 figures. Accepted in Astrophysical Journal Letters, http://austral.as.utexas.edu/planets/hd37605/hd37605.htm

Responsive Operations for Key Services (ROKS): A Modular, Low SWaP Quantum Communications Payload

Quantum key distribution (QKD) is a theoretically proven future-proof secure encryption method that inherits its security from fundamental physical principles. With a proof-of-concept QKD payload having flown on the Micius satellite since 2016, efforts have intensified globally. Craft Prospect, working with a number of UK organisations, has been focused on miniaturising the technologies that enable QKD so that they may be used in smaller platforms including nanosatellites. The significant reduction of size, and therefore the cost of launching quantum communication technologies either on a dedicated platform or hosted as part of a larger optical communications will improve potential access to quantum encryption on a relatively quick timescale. The Responsive Operations for Key Services (ROKS) mission seeks to be among the first to send a QKD payload on a CubeSat into low Earth orbit, demonstrating the capabilities of newly developed modular quantum technologies. The ROKS payload comprises a quantum source module that supplies photons randomly in any of four linear polarisation states fed from a quantum random number generator; an acquisition, pointing, and tracking system to fine-tune alignment of the quantum source beam with an optical ground station; an imager that will detect cloud cover autonomously; and an onboard computer that controls and monitors the other modules, which manages the payload and assures the overall performance and security of the system. Each of these modules have been developed with low Size, Weight and Power (SWaP) for CubeSats, but with interoperability in mind for other satellite form factors. We present each of the listed components, together with the initial test results from our test bench and the performance of our protoflight models prior to initial integration with the 6U CubeSat platform systems. The completed ROKS payload will be ready for flight at the end of 2022, with various modular components already being baselined for flight and integrated into third party communication missions

Planetary Candidates Observed by Kepler VI: Planet Sample from Q1-Q16 (47 Months)

\We present the sixth catalog of Kepler candidate planets based on nearly 4 years of high precision photometry. This catalog builds on the legacy of previous catalogs released by the Kepler project and includes 1493 new Kepler Objects of Interest (KOIs) of which 554 are planet candidates, and 131 of these candidates have best fit radii <1.5 R_earth. This brings the total number of KOIs and planet candidates to 7305 and 4173 respectively. We suspect that many of these new candidates at the low signal-to-noise limit may be false alarms created by instrumental noise, and discuss our efforts to identify such objects. We re-evaluate all previously published KOIs with orbital periods of >50 days to provide a consistently vetted sample that can be used to improve planet occurrence rate calculations. We discuss the performance of our planet detection algorithms, and the consistency of our vetting products. The full catalog is publicly available at the NASA Exoplanet Archive.Comment: 18 pages, to be published in the Astrophysical Journal Supplement Serie

Response to sunitinib in combination with proton beam radiation in a patient with chondrosarcoma: a case report

<p>Abstract</p> <p>Introduction</p> <p>Chondrosarcoma is well-known to be primarily resistant to conventional radiation and chemotherapy.</p> <p>Case presentation</p> <p>We present the case of a 32-year-old Caucasian man with clear cell chondrosarcoma who presented with symptomatic recurrence in his pelvis and metastases to his skull and lungs. Our patient underwent systemic therapy with sunitinib and then consolidation with proton beam radiation to his symptomatic site. He achieved complete symptomatic relief with a significantly improved performance status and had an almost complete and durable metabolic response on fluorine-18-fluorodeoxyglucose positron emission tomography.</p> <p>Conclusions</p> <p>Our findings have important clinical implications and suggest novel clinical trials for this difficult to treat disease.</p

Using a Human Challenge Model of Infection to Measure Vaccine Efficacy: A Randomised, Controlled Trial Comparing the Typhoid Vaccines M01ZH09 with Placebo and Ty21a

Background Typhoid persists as a major cause of global morbidity. While several licensed vaccines to prevent typhoid are available, they are of only moderate efficacy and unsuitable for use in children less than two years of age. Development of new efficacious vaccines is complicated by the human host-restriction of Salmonella enterica serovar Typhi (S. Typhi) and lack of clear correlates of protection. In this study, we aimed to evaluate the protective efficacy of a single dose of the oral vaccine candidate, M01ZH09, in susceptible volunteers by direct typhoid challenge. Methods and Findings We performed a randomised, double-blind, placebo-controlled trial in healthy adult participants at a single centre in Oxford (UK). Participants were allocated to receive one dose of double-blinded M01ZH09 or placebo or 3-doses of open-label Ty21a. Twenty-eight days after vaccination, participants were challenged with 104CFU S. Typhi Quailes strain. The efficacy of M01ZH09 compared with placebo (primary outcome) was assessed as the percentage of participants reaching pre-defined endpoints constituting typhoid diagnosis (fever and/or bacteraemia) during the 14 days after challenge. Ninety-nine participants were randomised to receive M01ZH09 (n = 33), placebo (n = 33) or 3-doses of Ty21a (n = 33). After challenge, typhoid was diagnosed in 18/31 (58.1% [95% CI 39.1 to 75.5]) M01ZH09, 20/30 (66.7% [47.2 to 87.2]) placebo, and 13/30 (43.3% [25.5 to 62.6]) Ty21a vaccine recipients. Vaccine efficacy (VE) for one dose of M01ZH09 was 13% [95% CI -29 to 41] and 35% [-5 to 60] for 3-doses of Ty21a. Retrospective multivariable analyses demonstrated that pre-existing anti-Vi antibody significantly reduced susceptibility to infection after challenge; a 1 log increase in anti-Vi IgG resulting in a 71% decrease in the hazard ratio of typhoid diagnosis ([95% CI 30 to 88%], p = 0.006) during the 14 day challenge period. Limitations to the study included the requirement to limit the challenge period prior to treatment to 2 weeks, the intensity of the study procedures and the high challenge dose used resulting in a stringent model. Conclusions Despite successfully demonstrating the use of a human challenge study to directly evaluate vaccine efficacy, a single-dose M01ZH09 failed to demonstrate significant protection after challenge with virulent Salmonella Typhi in this model. Anti-Vi antibody detected prior to vaccination played a major role in outcome after challenge

Re-visiting Meltsner: Policy Advice Systems and the Multi-Dimensional Nature of Professional Policy Analysis

10.2139/ssrn.15462511-2