Mexican Investment After the Tequila Crisis: Basic Economics, "Confidence" Effects, or Market Imperfections?

This study provides an empirical investigation of the determinants of the growth of investment in Mexico, especially after the Tequila crisis. The paper uses the Generalized Method of Moments estimator to determine if investment can be explained with a standard investment function. The model predicts well the recovery of investment; the tradable sector has an accelerator effect that exceeds that of the non-tradable sector. Domestic real interest rates and real exchange rate volatility are also significant. Results support the hypothesis of a "confidence" effect during the 1982-1983 crisis, but not during the Tequila crisis. There is also evidence of credit rationing

Tethered tertiary amines as solid-state n-type dopants for solution-processable organic semiconductors

A scarcity of stable n-type doping strategies compatible with facile processing has been a major impediment to the advancement of organic electronic devices. Localizing dopants near the cores of conductive molecules can lead to improved efficacy of doping. We and others recently showed the effectiveness of tethering dopants covalently to an electron-deficient aromatic molecule using trimethylammonium functionalization with hydroxide counterions linked to a perylene diimide core by alkyl spacers. In this work, we demonstrate that, contrary to previous hypotheses, the main driver responsible for the highly effective doping observed in thin films is the formation of tethered tertiary amine moieties during thin film processing. Furthermore, we demonstrate that tethered tertiary amine groups are powerful and general n-doping motifs for the successful generation of free electron carriers in the solid-state, not only when coupled to the perylene diimide molecular core, but also when linked with other small molecule systems including naphthalene diimide, diketopyrrolopyrrole, and fullerene derivatives. Our findings help expand a promising molecular design strategy for future enhancements of n-type organic electronic materials

Global declines in coral reef calcium carbonate production under ocean acidification and warming

Ocean warming and acidification threaten the future growth of coral reefs. This is because the calcifying coral reef taxa that construct the calcium carbonate frameworks and cement the reef together are highly sensitive to ocean warming and acidification. However, the global-scale effects of ocean warming and acidification on rates of coral reef net carbonate production remain poorly constrained despite a wealth of studies assessing their effects on the calcification of individual organisms. Here, we present global estimates of projected future changes in coral reef net carbonate production under ocean warming and acidification. We apply a meta-analysis of responses of coral reef taxa calcification and bioerosion rates to predicted changes in coral cover driven by climate change to estimate the net carbonate production rates of 183 reefs worldwide by 2050 and 2100. We forecast mean global reef net carbonate production under representative concentration pathways (RCP) 2.6, 4.5, and 8.5 will decline by 76, 149, and 156%, respectively, by 2100. While 63% of reefs are projected to continue to accrete by 2100 under RCP2.6, 94% will be eroding by 2050 under RCP8.5, and no reefs will continue to accrete at rates matching projected sea level rise under RCP4.5 or 8.5 by 2100. Projected reduced coral cover due to bleaching events predominately drives these declines rather than the direct physiological impacts of ocean warming and acidification on calcification or bioerosion. Presently degraded reefs were also more sensitive in our analysis. These findings highlight the low likelihood that the world’s coral reefs will maintain their functional roles without near-term stabilization of atmospheric CO2 emissions

LSPM J1112+7626: detection of a 41-day M-dwarf eclipsing binary from the MEarth transit survey

We report the detection of eclipses in LSPM J1112+7626, which we find to be a moderately bright (I_C = 12.14 +/- 0.05) very low-mass binary system with an orbital period of 41.03236 +/- 0.00002 days, and component masses M_1 = 0.395 +/- 0.002 Msol and M_2 = 0.275 +/- 0.001 Msol in an eccentric (e = 0.239 +/- 0.002) orbit. A 65 day out of eclipse modulation of approximately 2% peak-to-peak amplitude is seen in I-band, which is probably due to rotational modulation of photospheric spots on one of the binary components. This paper presents the discovery and characterization of the object, including radial velocities sufficient to determine both component masses to better than 1% precision, and a photometric solution. We find that the sum of the component radii, which is much better-determined than the individual radii, is inflated by 3.8 +0.9 -0.5 % compared to the theoretical model predictions, depending on the age and metallicity assumed. These results demonstrate that the difficulties in reproducing observed M-dwarf eclipsing binary radii with theoretical models are not confined to systems with very short orbital periods. This object promises to be a fruitful testing ground for the hypothesized link between inflated radii in M-dwarfs and activity.Comment: 23 pages, 11 figures, 12 tables, emulateapj format. Accepted for publication in Ap

Coordinated allele-specific histone acetylation at the differentially methylated regions of imprinted genes

Genomic imprinting is an epigenetic inheritance system characterized by parental allele-specific gene expression. Allele-specific DNA methylation and chromatin composition are two epigenetic modification systems that control imprinted gene expression. To get a general assessment of histone lysine acetylation at imprinted genes we measured allele-specific acetylation of a wide range of lysine residues, H3K4, H3K18, H3K27, H3K36, H3K79, H3K64, H4K5, H4K8, H4K12, H2AK5, H2BK12, H2BK16 and H2BK46 at 11 differentially methylated regions (DMRs) in reciprocal mouse crosses using multiplex chromatin immunoprecipitation SNuPE assays. Histone acetylation marks generally distinguished the methylation-free alleles from methylated alleles at DMRs in mouse embryo fibroblasts and embryos. Acetylated lysines that are typically found at transcription start sites exhibited stronger allelic bias than acetylated histone residues in general. Maternally methylated DMRs, that usually overlap with promoters exhibited higher levels of acetylation and a 10% stronger allele-specific bias than paternally methylated DMRs that reside in intergenic regions. Along the H19/Igf2 imprinted domain, allele-specific acetylation at each lysine residue depended on functional CTCF binding sites in the imprinting control region. Our results suggest that many different histone acetyltransferase and histone deacetylase enzymes must act in concert in setting up and maintaining reciprocal parental allelic histone acetylation at DMRs

TESS hunt for young and maturing exoplanets (THYME). III. A two-planet system in the 400 Myr Ursa major group

A.W.M. was supported through NASA's Astrophysics Data Analysis Program (80NSSC19K0583). M.L.W. was supported by a grant through NASA's K2 GO program (80NSSC19K0097). This material is based on work supported by the National Science Foundation Graduate Research Fellowship Program under grant No. DGE-1650116 to P.C.T. A.V.'s work was performed under contract with the California Institute of Technology/Jet Propulsion Laboratory funded by NASA through the Sagan Fellowship Program executed by the NASA Exoplanet Science Institute. D.D. acknowledges support from NASA through Caltech/JPL grant RSA-1006130 and through the TESS Guest Investigator Program grant 80NSSC19K1727.Exoplanets can evolve significantly between birth and maturity, as their atmospheres, orbits, and structures are shaped by their environment. Young planets (<1 Gyr) offer an opportunity to probe the critical early stages of this evolution, where planets evolve the fastest. However, most of the known young planets orbit prohibitively faint stars. We present the discovery of two planets transiting HD 63433 (TOI 1726, TIC 130181866), a young Sun-like (M∗=0.99±0.03) star. Through kinematics, lithium abundance, and rotation, we confirm that HD 63433 is a member of the Ursa Major moving group (τ=414±23 Myr). Based on the TESS light curve and updated stellar parameters, we estimate the planet radii are 2.15±0.10R⊕ and 2.67±0.12R⊕, the orbital periods are 7.11 and 20.55 days, and the orbital eccentricities are lower than about 0.2. Using HARPS-N velocities, we measure the Rossiter-McLaughlin signal of the inner planet, demonstrating that the orbit is prograde. Since the host star is bright (V=6.9), both planets are amenable to transmission spectroscopy, radial velocity measurements of their masses, and more precise determination of the stellar obliquity. This system is therefore poised to play an important role in our understanding of planetary system evolution in the first billion years after formation.PostprintPeer reviewe