Molecular nitrogen in comet 67P/Churyumov-Gerasimenko indicates a low formation temperature

Molecular nitrogen (N2) is thought to have been the most abundant form of nitrogen in the protosolar nebula. It is the main N-bearing molecule in the atmospheres of Pluto and Triton and probably the main nitrogen reservoir from which the giant planets formed. Yet in comets, often considered the most primitive bodies in the solar system, N2 has not been detected. Here we report the direct in situ measurement of N2 in the Jupiter family comet 67P/Churyumov-Gerasimenko, made by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis mass spectrometer aboard the Rosetta spacecraft. A N2/CO ratio of Embedded Image (2σ standard deviation of the sampled mean) corresponds to depletion by a factor of ~25.4 ± 8.9 as compared to the protosolar value. This depletion suggests that cometary grains formed at low-temperature conditions below ~30 kelvin.

Cool Glacial Temperatures and Changes in Moisture Source Recorded in Oman Groundwaters

Concentrations of atmospheric noble gases (neon, argon, krypton, and xenon) dissolved in groundwaters from northern Oman indicate that the average ground temperature during the Late Pleistocene (15,000 to 24,000 years before present) was 6.5° ± 0.6°C lower than that of today. Stable oxygen and hydrogen isotopic groundwater data show that the origin of atmospheric water vapor changed from a primarily southern, Indian Ocean source during the Late Pleistocene to a dominantly northern, Mediterranean source today. The reduced northern water vapor source is consistent with a drier Last Glacial Maximum through much of northern Africa and Arabia.

Tyrosine kinase inhibitor-induced CD70 expression mediates drug resistance in leukemia stem cells by activating Wnt signaling.

In chronic myelogenous leukemia (CML), oncogenic BCR-ABL1 activates the Wnt pathway, which is fundamental for leukemia stem cell (LSC) maintenance. Tyrosine kinase inhibitor (TKI) treatment reduces Wnt signaling in LSCs and often results in molecular remission of CML; however, LSCs persist long term despite BCR-ABL1 inhibition, ultimately causing disease relapse. We demonstrate that TKIs induce the expression of the tumor necrosis factor (TNF) family ligand CD70 in LSCs by down-regulating microRNA-29, resulting in reduced CD70 promoter DNA methylation and up-regulation of the transcription factor specificity protein 1. The resulting increase in CD70 triggered CD27 signaling and compensatory Wnt pathway activation. Combining TKIs with CD70 blockade effectively eliminated human CD34(+) CML stem/progenitor cells in xenografts and LSCs in a murine CML model. Therefore, targeting TKI-induced expression of CD70 and compensatory Wnt signaling resulting from the CD70/CD27 interaction is a promising approach to overcoming treatment resistance in CML LSCs.

A versatile toolkit to produce sensitive FRET biosensors to visualize signaling in time and space

Genetically encoded, ratiometric biosensors based on fluorescence resonance energy transfer (FRET) are powerful tools to study the spatiotemporal dynamics of cell signaling. However, many biosensors lack sensitivity. We present a biosensor library that contains circularly permutated mutants for both the donor and acceptor fluorophores, which alter the orientation of the dipoles and thus better accommodate structural constraints imposed by different signaling molecules while maintaining FRET efficiency. Our strategy improved the brightness and dynamic range of preexisting RhoA and extracellular signal-regulated protein kinase (ERK) biosensors. Using the improved RhoA biosensor, we found micrometer-sized zones of RhoA activity at the tip of F-actin bundles in growth cone filopodia during neurite extension, whereas RhoA was globally activated throughout collapsing growth cones. RhoA was also activated in filopodia and protruding membranes at the leading edge of motile fibroblasts. Using the improved ERK biosensor, we simultaneously measured ERK activation dynamics in multiple cells using low-magnification microscopy and performed in vivo FRET imaging in zebrafish. Thus, we provide a construction toolkit consisting of a vector set, which enables facile generation of sensitive biosensors.

Na 1 Nachlass Max Horkheimer, 1 - Korrespondenzen u.a. mit Franz Alexander (p. I 1, 1-205)

1 Brief von Max Horkheimer an Abel, 16.03.1936; 3 Briefe zwischen Hubert Abrahamsohn und Max Horkheimer, 1935-1936, 21.12.1936; 2 Briefe zwischen Emanuel Adler und Max Horkheimer, 12.04.1946, 26.04.1946; 2 Briefe zwischen Max Adler und Max Horkheimer, 16.03.1935, 29.03.1935; 1 Brief von Eva Ahamson an Max Horkheimer, 01.11.1944; 2 Briefe der Aircraft Warning Service Brentwood an Max Horkheimer, Mai 1942; 6 Briefe zwischen Librairie Félix Alcan und Max Horkheimer, 1935, 18.12.1935; 11 Briefe zwischen Franz Alexander und Max Horkheimer, 1938-1940; 2 Briefe zwischen der American Historical Review New York und Max Horkheimer, 01.04.1941, 07.04.1941; 1 Brief von Paul Reiwald an Max Horkheimer, 18.10.1940; 2 Briefe zwischen Helen Manice Alexander und Max Horkheimer, 1936; 2 Briefe zwischen Bernardine Allen und Max Horkheimer, 17.06.1938, 24.06.1938; 1 Brief der Alumni Federation of Columbia University an Max Horkheimer, 21.07.1942; 1 Brief der American Friends Service Comittee an Max Horkheimer, 10.12.1940; 3 Briefe zwischen der American Academy of Political and Social Science Philadelphia und Max Horkheimer, 1939,1940, 16.01.1939; 1 Brief der American Automobile Association Washington an Max Horkheimer, 22.03.1938; 1 Brief der American Association for the Advancement of Science Washington an Max Horkheimer, 16.08.1937; 2 Briefe von Max Horkheimer an den American Consulate General Berlin, 1939; 1 Brief von Max Horkheimer an den American Consulate General Havana, 03.03.1941; 4 Briefe von Max Horkheimer an den American Consul London, 1939-1941; 2 Briefe von Max Horkheimer an den American Consulate General Stuttgart, 1939-1941; 1 Brief von Max Horkheimer an den American Consul Zürich, 1939; 1 Brief von Friedrich Pollock an den American Council of Learned Society, Washington, 27.06.1941; 2 Briefe von Max Horkheimer an die American Friends of German Freedom New York, 1941; 4 Briefe der American Historical Association Washington an Max Horkheimer, 1937-1938; 1 Brief von Max Horkheimer an den American Red Cross Westwood Office, 21.06.1943; 18 Briefe zwschen der American Society for the Prevention of Cruelty to Animals New York und Max Horkheimer, 1936-1941; 1 Brief von Max Horkheimer an die American Women's Volunteer Service Pacific Palisades, 27.07.1942; 23 Briefe zwischen Eugene Anderson und Max Horkheimer, 1937-1941; 2 Briefe zwischen Norah Andreae und Max Horkheimer, 27.10.1944, 09.09.1946; 1 Brief von Rosa Nebel-Schenk, 04.03.1946; 1 Brief von der National Catholic Welfare Conference, 14.08.1944; 12 Briefe zwischen Werner Andreae und Max Horkheimer, 1945-1954; 1 Brief von Julius Marx an Werner Andreae, 10.05.1946, 11.05.1950; 2 Briefe von Josef Messinger an Werner Andreae, 23.10.1946, ohne Datum; 3 Briefe zwischen dem Advokatenbüro Hodler und Max Horkheimer, 1946, 09.05.1946;

Novel multiple sclerosis susceptibility loci implicated in epigenetic regulation.

We conducted a genome-wide association study (GWAS) on multiple sclerosis (MS) susceptibility in German cohorts with 4888 cases and 10,395 controls. In addition to associations within the major histocompatibility complex (MHC) region, 15 non-MHC loci reached genome-wide significance. Four of these loci are novel MS susceptibility loci. They map to the genes L3MBTL3, MAZ, ERG, and SHMT1. The lead variant at SHMT1 was replicated in an independent Sardinian cohort. Products of the genes L3MBTL3, MAZ, and ERG play important roles in immune cell regulation. SHMT1 encodes a serine hydroxymethyltransferase catalyzing the transfer of a carbon unit to the folate cycle. This reaction is required for regulation of methylation homeostasis, which is important for establishment and maintenance of epigenetic signatures. Our GWAS approach in a defined population with limited genetic substructure detected associations not found in larger, more heterogeneous cohorts, thus providing new clues regarding MS pathogenesis.

General program /

Description based on: 60th (1979).

Proceedings.

Meeting for 1894 held in conjunction with the American Association for the Advancement of Science

Report and transactions.

Place of publication varies: <2000-> Plymouth.

Pest control by chemical, biological, genetic, and physical means; a symposium.

Includes bibliographies.

Philosophy and psychology pamphlets

A collection of miscellaneous pamphlets.

Report & transactions

Vol. 31-40 also called ser. 2, v. 1-10; v. 41-50, ser. 3, v. 1-10; v. 51-60, ser. 4, v. 1-10