Photodissociation and chemistry of N2 in the circumstellar envelope of carbon-rich AGB stars

The envelopes of AGB stars are irradiated externally by ultraviolet photons; hence, the chemistry is sensitive to the photodissociation of N$_2$ and CO, which are major reservoirs of nitrogen and carbon, respectively. The photodissociation of N$_2$ has recently been quantified by laboratory and theoretical studies. Improvements have also been made for CO photodissociation. For the first time, we use accurate N$_2$ and CO photodissociation rates and shielding functions in a model of the circumstellar envelope of the carbon-rich AGB star, IRC +10216. We use a state-of-the-art chemical model of an AGB envelope, the latest CO and N$_2$ photodissociation data, and a new method for implementing molecular shielding functions in full spherical geometry with isotropic incident radiation. We compare computed column densities and radial distributions of molecules with observations. The transition of N$_2$ $\to$ N (also, CO $\to$ C $\to$ C$^+$) is shifted towards the outer envelope relative to previous models. This leads to different column densities and radial distributions of N-bearing species, especially those species whose formation/destruction processes largely depend on the availability of atomic or molecular nitrogen, for example, C$_n$N ($n$=1, 3, 5), C$_n$N$^-$ ($n$=1, 3, 5), HC$_n$N ($n$=1, 3, 5, 7, 9), H$_2$CN and CH$_2$CN. The chemistry of many species is directly or indirectly affected by the photodissociation of N$_2$ and CO, especially in the outer shell of AGB stars where photodissociation is important. Thus, it is important to include N$_2$ and CO shielding in astrochemical models of AGB envelopes and other irradiated environments. In general, while differences remain between our model of IRC +10216 and the observed molecular column densities, better agreement is found between the calculated and observed radii of peak abundance.

Ran GTPase in Nuclear Envelope Formation and Cancer Metastasis

Ran is a small ras-related GTPase that controls the nucleocytoplasmic exchange of macromolecules across the nuclear envelope. It binds to chromatin early during nuclear formation and has important roles during the eukaryotic cell cycle, where it regulates mitotic spindle assembly, nuclear envelope formation and cell cycle checkpoint control. Like other GTPases, Ran relies on the cycling between GTP-bound and GDP-bound conformations to interact with effector proteins and regulate these processes. In nucleocytoplasmic transport, Ran shuttles across the nuclear envelope through nuclear pores. It is concentrated in the nucleus by an active import mechanism where it generates a high concentration of RanGTP by nucleotide exchange. It controls the assembly and disassembly of a range of complexes that are formed between Ran-binding proteins and cellular cargo to maintain rapid nuclear transport. Ran also has been identified as an essential protein in nuclear envelope formation in eukaryotes. This mechanism is dependent on importin-β, which regulates the assembly of further complexes important in this process, such as Nup107–Nup160. A strong body of evidence is emerging implicating Ran as a key protein in the metastatic progression of cancer. Ran is overexpressed in a range of tumors, such as breast and renal, and these perturbed levels are associated with local invasion, metastasis and reduced patient survival. Furthermore, tumors with oncogenic KRAS or PIK3CA mutations are addicted to Ran expression, which yields exciting future therapeutic opportunities

Envelope sent to Mr. Welland D. Woodruff at Thomas Cooks and Sons, Columbo, Indiana

Envelope postmarked Indo-Ceylon, special flight X’mas 1936, Bombay, Jan. 1937 and Thomas Cook and Son, Jan. 2, 1937. The letter is addressed to Mr. Welland D. Woodruff at Thomas Cook and Son, Columbo, India. This is crossed out and sent on to Royal Trust Co. 3 St. James St., London, England. This is crossed out and finally sent to the Mayfair Hotel, London, England, 1936-1937.

Letter and envelope addressed to Mr. Samuel D. Woodruff of St. Catharines

Letter and envelope addressed to Mr. Samuel D. Woodruff of St. Catharines. The envelope is postmarked St. Catharines, Dec. 31, 1887, Port Robinson, Dec. 31, 1887 and Welland, Dec. 31, 1887. The letter to S.D. Woodruff from Calvin Cudney and it says that he has enclosed $35 in interest, Dec. 29, 1887.

Application for Loan, Mortgage Loan Envelope, and Abstract of Title

Atkins, Sarah A. and Carlisle A. Gardner includes: Application for Loan, July 26, 1884; Mortgage Loan Envelope no. 255 for July 1, 1884 – July 1, 1889 and Abstract of Title, August 28, 1884.

Crew, Isaac M., includes: Application for Loan, Mortgage Loan Envelope, and Abstract of Title

Crew, Isaac M., includes: Application for Loan, March 10, 1885; Mortgage Loan Envelope no. 679 for Jan. 1, 1885 – Jan. 1, 1890 and Abstract of Title, April 13, 1885.

Crick, Henry A., includes Application for Loan, and Mortgage Loan Envelope

Crick, Henry A., includes Application for Loan, Jan. 8, 1885 and Mortgage Loan Envelope no. 637 for Jan. 1, 1885 – Jan. 1, 1890.

Schmidt, John, includes: Application for Loan, and Mortgage Loan Envelope, and Abstract of Title

Schmidt, John, includes: Application for Loan, Aug. 8, 1884 and Mortgage Loan Envelope no. 302 for July 1, 1884 – July 1, 1889 and Abstract of Title, Sept. 6, 1884.

Port Dalhousie and the Thorold Railway pay roll for the months of June, July and August, 1855, signed by S.D. Woodruff. There is an envelope included with this document, Aug. 21, 1855

Port Dalhousie and the Thorold Railway pay roll for services of engineering and contingencies furnished for the months of June, July and August, 1855, signed by S.D. Woodruff. There is an envelope included with this document, Aug. 21, 1855.

Registered letter and envelope addressed to S.D. Woodruff from John I. Mackenzie

Registered letter and envelope addressed to S.D. Woodruff from John I. Mackenzie regarding the 5 shares that have been held in trust for Mr. Woodruff (1 ½ pages, handwritten), Dec. 15, 1881.

Letter and envelope addressed to S.D. Woodruff from A. Hemenway

Letter and envelope addressed to S.D. Woodruff from A. Hemenway in which Mr. Hemenway thanks Mr. Woodruff for his letter and clippings and he says that he cannot believe such astounding reports which seem incredible, July 12, 1886.

Letter and envelope marked “private” addressed to S.D. Woodruff from William Turner of Port Maitland

Letter and envelope marked “private” addressed to S.D. Woodruff from William Turner of Port Maitland. He says that he has enclosed a bill for all the trouble and fatigue that he has had since he saw Mr. Woodruff. He states that it has been a tiresome job wading through the books for 1857 and 1858, Feb. 5, 1862.

Letter and envelope addressed to S.D. Woodruff from the office of T.B. Stewart and Co. of New York

Letter and envelope addressed to S.D. Woodruff from the office of T.B. Stewart and Co. of New York, Manufacturers of Mantles, Marble and Wood Mantels. The letter states that the heater and grates have been shipped, July 14, 1876.

Envelope addressed to Mr. Welland D. Woodruff from Caldwell, Masslich and Reed

Envelope addressed to Mr. Welland D. Woodruff from Caldwell, Masslich and Reed, Attorneys and Counsellors at Law, New York, postmarked Hudson Terminal Station, New York, Sept. 23, 1913.