An Unusual Transmission Spectrum for the Sub-Saturn KELT-11b Suggestive of a Sub-Solar Water Abundance

We present an optical-to-infrared transmission spectrum of the inflated sub-Saturn KELT-11b measured with the Transiting Exoplanet Survey Satellite (TESS), the Hubble Space Telescope (HST) Wide Field Camera 3 G141 spectroscopic grism, and the Spitzer Space Telescope (Spitzer) at 3.6 $\mu$m, in addition to a Spitzer 4.5 $\mu$m secondary eclipse. The precise HST transmission spectrum notably reveals a low-amplitude water feature with an unusual shape. Based on free retrieval analyses with varying molecular abundances, we find strong evidence for water absorption. Depending on model assumptions, we also find tentative evidence for other absorbers (HCN, TiO, and AlO). The retrieved water abundance is generally $\lesssim 0.1\times$ solar (0.001--0.7$\times$ solar over a range of model assumptions), several orders of magnitude lower than expected from planet formation models based on the solar system metallicity trend. We also consider chemical equilibrium and self-consistent 1D radiative-convective equilibrium model fits and find they too prefer low metallicities ($[M/H] \lesssim -2$, consistent with the free retrieval results). However, all the retrievals should be interpreted with some caution since they either require additional absorbers that are far out of chemical equilibrium to explain the shape of the spectrum or are simply poor fits to the data. Finally, we find the Spitzer secondary eclipse is indicative of full heat redistribution from KELT-11b's dayside to nightside, assuming a clear dayside. These potentially unusual results for KELT-11b's composition are suggestive of new challenges on the horizon for atmosphere and formation models in the face of increasingly precise measurements of exoplanet spectra.Comment: Accepted to The Astronomical Journal. 31 pages, 20 figures, 7 table

TRPA1 is essential for the vascular response to environmental cold exposure

This work was supported by the British Heart Foundation and a Capacity Building Award in Integrative Mammalian Biology. It was also supported by Arthritis Research UK and XK is supported by a British Pharmacological Society AJ Clark studentship

Computational Design of Auxotrophy-Dependent Microbial Biosensors for Combinatorial Metabolic Engineering Experiments

Combinatorial approaches in metabolic engineering work by generating genetic diversity in a microbial population followed by screening for strains with improved phenotypes. One of the most common goals in this field is the generation of a high rate chemical producing strain. A major hurdle with this approach is that many chemicals do not have easy to recognize attributes, making their screening expensive and time consuming. To address this problem, it was previously suggested to use microbial biosensors to facilitate the detection and quantification of chemicals of interest. Here, we present novel computational methods to: (i) rationally design microbial biosensors for chemicals of interest based on substrate auxotrophy that would enable their high-throughput screening; (ii) predict engineering strategies for coupling the synthesis of a chemical of interest with the production of a proxy metabolite for which high-throughput screening is possible via a designed bio-sensor. The biosensor design method is validated based on known genetic modifications in an array of E. coli strains auxotrophic to various amino-acids. Predicted chemical production rates achievable via the biosensor-based approach are shown to potentially improve upon those predicted by current rational strain design approaches. (A Matlab implementation of the biosensor design method is available via http://www.cs.technion.ac.il/~tomersh/tools)

Vascular hypertrophy and hypertension caused by transgenic overexpression of profilin 1.

We have overexpressed either the cDNA of human profilin 1 or expressed the mutant (88R/L) in the blood vessels of transgenic FVB/N mice. Reverse transcription-PCR indicated selective overexpression of profilin 1 and 88R/L in vascular smooth muscle cells. Polyproline binding showed increased profilin 1 and 88R/L proteins in transgenic mice compared with control (~30%, p 400%, p < 0.05). Tail cuff and circadian monitoring of blood pressure showed significant increases in systolic and mean arterial blood pressures of profilin 1 mice starting at age 6 months compared with controls (~25 mm Hg, p < 0.05). These results suggest that increased actin polymerization in blood vessels triggers activation of the hypertrophic signaling cascades and results in elevation of blood pressure at advanced age

Isolation of an oxalate-resistant Ashbya gossypii strain and its improved riboflavin production

An oxalate-resistant strain of Ashbya gossypii was naturally isolated from spores grown on an oxalate-containing medium, and its medium was optimized to improve riboflavin production. Riboflavin production by the resistant strain was three-fold higher than that by the wild-type organism when grown in flask cultures. Medium optimization increased the riboflavin production by the resistant strain to 5 g l(-1), which was five-fold higher than that obtained by the wild-type strain. The productivity was reproduced in a 3-l bioreactor. During the early growth phase, the specific activity of isocitrate lyase in the oxalate-resistant strain was slightly higher than that in the wild-type strain. Proteomic analysis of the oxalate-resistant strain revealed that the expression of aldose reductase and cobalamin-independent methionine synthase decreased significantly. This is the first report that describes the natural isolation of a riboflavin producer using an antimetabolite-containing medium to enhance the riboflavin production level. This method should also be useful for improving the productivity of other bioproducts since it does not require any mutations or genetic modifications of the microorganism.publishe