CC-1065 and the duocarmycins: unraveling the keys to a new class of naturally derived DNA alkylating agents.

Key studies defining the DNA alkylation properties and selectivity of a new class of exceptionally potent, naturally occurring antitumor antibiotics including CC-1065, duocarmycin A, and duocarmycin SA are reviewed. Recent studies conducted with synthetic agents containing deep-seated structural changes and the unnatural enantiomers of the natural products and related analogs have defined the structural basis for the sequence-selective alkylation of duplex DNA and fundamental relationships between chemical structure, functional reactivity, and biological properties. The agents undergo a reversible, stereoelectronically controlled adenine-N3 addition to the least substituted carbon of the activated cyclopropane within selected AT-rich sites. The preferential AT-rich non-covalent binding selectivity of the agents within the narrower, deeper AT-rich minor groove and the steric accessibility to the alkylation site that accompanies deep AT-rich minor groove penetration control the sequence-selective DNA alkylation reaction and stabilize the resulting adduct. For the agents that possess sufficient reactivity to alkylate DNA, a direct relationship between chemical or functional stability and biological potency has been defined.

Herschel discovery of a new class of cold, faint debris discs

We present Herschel PACS 100 and 160 μm observations of the solar-type stars α Men, HD 88230 and HD 210277, which form part of the FGK stars sample of the Herschel open time key programme (OTKP) DUNES (DUst around NEarby Stars). Our observations show small infrared excesses at 160 μm for all three stars. HD 210277 also shows a small excess at 100 μm, while the 100 μm fluxes of α Men and HD 88230 agree with the stellar photospheric predictions. We attribute these infrared excesses to a new class of cold, faint debris discs. Both α Men and HD 88230 are spatially resolved in the PACS 160 μm images, while HD 210277 is point-like at that wavelength. The projected linear sizes of the extended emission lie in the range from ~115 to ≤ 250 AU. The estimated black body temperatures from the 100 and 160 μm fluxes are ≲22 K, and the fractional luminosity of the cold dust is L_dust/L_⋆ ~ 10^-6, close to the luminosity of the solar-system’s Kuiper belt. These debris discs are the coldest and faintest discs discovered so far around mature stars, so they cannot be explained easily invoking “classical” debris disc models.

On the Result of Invariance of the Closure Set of the Real Projections of the Zeros of an Important Class of Exponential Polynomials

In this paper we provide the proof of a practical point-wise characterization of the set RP defined by the closure set of the real projections of the zeros of an exponential polynomial P(z) = Σn j=1 cjewjz with real frequencies wj linearly independent over the rationals. As a consequence, we give a complete description of the set RP and prove its invariance with respect to the moduli of the c′ js, which allows us to determine exactly the gaps of RP and the extremes of the critical interval of P(z) by solving inequations with positive real numbers. Finally, we analyse the converse of this result of invariance.

Letter from Thomas Crafts to Edward Wigglesworth, 1781 May 22

This brief letter from Thomas Crafts (1759-1819; Harvard AB 1783) to Professor Wigglesworth concerns Craft's work on the catalogue of pamphlets in the library.

Letter from Robert Bell to Edward Wigglesworth, 1781 June 16

This brief letter from Robert Bell in Boston, Massachusetts, to Professor Edward Wigglesworth concerns the donation of books to the College Library.

Binding cost estimates, 1801

This six-page undated list contains volume titles and estimates for the cost of binding them. The list is undated, but one of the first entries contains the note, "from the year 1774 to the present time [1801]."

Classed book list, undated

This four-page undated list contains book titles primarily arranged into classes. The last page is titled, "Books for the red stamp."

Diplomas from Harvard College and Yale University, 1750

The diplomas are accompanied by a silver case in which the documents were stored.

Letter from Samuel Willard, Harvard College, Cambridge, Massachusetts, to Catherine Willard, Petersham, Massachusetts, May 1, 1801

Willard alludes to a situation regarding his father and praises him profusely.

Letter from Samuel Willard, Harvard College, Cambridge, Massachusetts, to Abigail Willard, Petersham, Massachusetts, May 1, 1801

Willard thanks his sister for writing to him and asks her to write as often as possible. He also mentions his cousin Sophia Chadwick, who has been living with President Willard.

Letter from Samuel Willard, Harvard College, Cambridge, Massachusetts, to William Willard, Petersham, Massachusetts, October 16, 1801

Willard reports on President Willard’s travels and general well-being and asks his father to apologize to his sister for not writing to her often enough. He also tells his father that he is in debt, details his purchases, and asks for money.

Letter from Samuel Willard, Harvard College, Cambridge, Massachusetts, to William Willard, Petersham, Massachusetts, February 28, 1802

Willard describes his trip back to Harvard from Petersham, reports that President Willard and family were doing well, although “he has had an ill turn since, but has recovered,” and concludes the letter by asking for more money.

Letter from Samuel Willard, Harvard College, Cambridge, Massachusetts, to William Willard, Petersham, Massachusetts, November 30, 1802

Willard discusses President Willard’s son Sheafe, who he has been tutoring, explains his education and argues for well-rounded studies. He also mentions that Doctor Aaron Dexter, a lecturer on chemistry, gave him a recipe for paint “which I enclose [separately] in this letter,” as well as a recipe for mortar. He explains that his vacation plans are to teach at a school in Groton for eighteen dollars a month, and asks for a loan from his parents to pay a bill.

Letter from Samuel Willard, Harvard College, Cambridge, Massachusetts, to Catherine Willard, Petersham, Massachusetts, June 22, 1803

Willard mentions his brother’s poor health, his plans to go to teach at Phillips Exeter, and describes various objects that he has sent to different family members, including a razor and books. In his post script, he asks to have a shirt mended.