Mechanism of Action and Structural Requirements of Constrained Peptide Inhibitors of RGS Proteins

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66199/1/j.1747-0285.2006.00373.x.pd

The Elusive Majority of Young Moving Groups. I. Young Binaries and Lithium-rich Stars in the Solar Neighborhood

Young stars in the solar neighborhood serve as nearby probes of stellar evolution and represent promising targets to directly image self-luminous giant planets. We have carried out an all-sky search for late-type (≈K7-M5) stars within 100 pc selected primarily on the basis of activity indicators from the Galaxy Evolution Explorer and ROSAT. Approximately 2000 active and potentially young stars are identified, of which we have followed up over 600 with low-resolution optical spectroscopy and over 1000 with diffraction-limited imaging using Robo-AO at the Palomar 1.5 m telescope. Strong lithium is present in 58 stars, implying ages spanning ≈10-200 Myr. Most of these lithium-rich stars are new or previously known members of young moving groups including TWA, β Pic, Tuc-Hor, Carina, Columba, Argus, AB Dor, Upper Centaurus Lupus, and Lower Centaurus Crux; the rest appear to be young low-mass stars without connections to established kinematic groups. Over 200 close binaries are identified down to 0.″2 - the vast majority of which are new - and will be valuable for dynamical mass measurements of young stars with continued orbit monitoring in the future

Same data, different conclusions: Radical dispersion in empirical results when independent analysts operationalize and test the same hypothesis

In this crowdsourced initiative, independent analysts used the same dataset to test two hypotheses regarding the effects of scientists’ gender and professional status on verbosity during group meetings. Not only the analytic approach but also the operationalizations of key variables were left unconstrained and up to individual analysts. For instance, analysts could choose to operationalize status as job title, institutional ranking, citation counts, or some combination. To maximize transparency regarding the process by which analytic choices are made, the analysts used a platform we developed called DataExplained to justify both preferred and rejected analytic paths in real time. Analyses lacking sufficient detail, reproducible code, or with statistical errors were excluded, resulting in 29 analyses in the final sample. Researchers reported radically different analyses and dispersed empirical outcomes, in a number of cases obtaining significant effects in opposite directions for the same research question. A Boba multiverse analysis demonstrates that decisions about how to operationalize variables explain variability in outcomes above and beyond statistical choices (e.g., covariates). Subjective researcher decisions play a critical role in driving the reported empirical results, underscoring the need for open data, systematic robustness checks, and transparency regarding both analytic paths taken and not taken. Implications for organizations and leaders, whose decision making relies in part on scientific findings, consulting reports, and internal analyses by data scientists, are discussed

Structural simplicity of the Zonula Occludens in the electrolyte secreting epithelium of the avian salt gland

The structure of the zonula occludens in the secretory epithelium of the salt gland of the domestic duck was determined by thin section and freeze-fracture electron microscopy. These glands secrete an effluent with a NaCl concentration four times that of plasma, and thus maintain a steep ionic gradient across their secretory epithelium. Freezefracture replicas from salt stressed ducks demonstrate that the zonula occludens is surprisingly shallow in depth (20–25 nm) and generally consists of two parallel junctional strands which are juxaposed along their entire length. In addition to the simplicity of the junction separating mucosal and serosal compartments, the ratio of junctional length to apical surface area is large since luminal surfaces of secretory cells are narrow and intermesh with one another. The zonula occludens in nonsecreting fresh water-adapted birds is similar to the salt stressed group except that two sets of double strand junctions are seen in addition to junctions consisting of a single set. Based on previous ultrastructural, cytochemical and physiological studies in salt glands and in other epithelia, a model for salt secretion was suggested in which intercellular space Na + , generated by basolateral ouabain-sensitive Na + pumps, reaches the lumen via a paracellular route (Ernst & Mills, 1977, J. Cell Biol. 75 :74). The simplicity of the morphological appearance of the zonula occludens in the salt gland, which resembles that described for several epithelia known to be leaky to ions, is consistent with this hypothesis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48028/1/232_2005_Article_BF01869292.pd