Letter to Daniel A. Whedon. New York. April 13, 1867

Handwritten 1867 letter from Daniel D. Whedon to his nephew, Daniel A. Whedon, requesting books.

Letter to Daniel Avery Whedon. Brooklyn, NY. Nov. 22, 1865.

Handwritten 1865 handwritten letter from Daniel D. Whedon to Daniel A. Whedon, his nephew, regarding slavery in relation to the Church as well as the Christian Union.

Letter to D. A. Whedon. Pittsfield. July 12, 1844.

Letter from Daniel Denison Whedon to Daniel A. Whedon, his nephew.

Letter to nephew, August 9 1867

Hanwritten letter from Daniel Denison Whedon to nephew. Dated 08/09/1867.

Letter to nephew, 02/06/1868

Letter from Daniel Whedon to nephew, Daniel Avery Whedon. Dated February, 6, 1868.

Letter to V.V. Haynes, 04/02/1878

Two page letter from Daniel D. Whedon to V.V. Haynes. Dated March 2, 1878.

Letter to Gershom Cox, dated January 29, 1844

This is a letter from Phoebe Palmer and her husband written on January 29, 1844 to Gershom Cox.

Optimized, unequal pulse spacing in multiple echo sequences improves refocusing in magnetic resonance.

A recent quantum computing paper (G. S. Uhrig, Phys. Rev. Lett. 98, 100504 (2007)) analytically derived optimal pulse spacings for a multiple spin echo sequence designed to remove decoherence in a two-level system coupled to a bath. The spacings in what has been called a "Uhrig dynamic decoupling (UDD) sequence" differ dramatically from the conventional, equal pulse spacing of a Carr-Purcell-Meiboom-Gill (CPMG) multiple spin echo sequence. The UDD sequence was derived for a model that is unrelated to magnetic resonance, but was recently shown theoretically to be more general. Here we show that the UDD sequence has theoretical advantages for magnetic resonance imaging of structured materials such as tissue, where diffusion in compartmentalized and microstructured environments leads to fluctuating fields on a range of different time scales. We also show experimentally, both in excised tissue and in a live mouse tumor model, that optimal UDD sequences produce different T(2)-weighted contrast than do CPMG sequences with the same number of pulses and total delay, with substantial enhancements in most regions. This permits improved characterization of low-frequency spectral density functions in a wide range of applications.

The spacing effect depends on an encoding deficit, retrieval, and time in working memory: evidence from once-presented words.

The spacing effect in list learning occurs because identical massed items suffer encoding deficits and because spaced items benefit from retrieval and increased time in working memory. Requiring the retrieval of identical items produced a spacing effect for recall and recognition, both for intentional and incidental learning. Not requiring retrieval produced spacing only for intentional learning because intentional learning encourages retrieval. Once-presented words provided baselines for these effects. Next, massed and spaced word pairs were judged for matches on their first three letters, forcing retrieval. The words were not identical, so there was no encoding deficit. Retrieval could and did cause spacing only for the first word of each pair; time in working memory, only for the second.

Letter from Wilfred T. Grenfell Esq., M.R.C.S.

An account of of the 1892(?) voyage from Yarmouth to St John's, Newfoundland, Canada.

Identification of tone duration, line length and letter position: An experimental approach to timing and working memory deficits in schizophrenia.

Patients with schizophrenia display numerous cognitive deficits, including problems in working memory, time estimation, and absolute identification of stimuli. Research in these fields has traditionally been conducted independently. We examined these cognitive processes using tasks that are structurally similar and that yield rich error data. Relative to healthy control participants (n = 20), patients with schizophrenia (n = 20) were impaired on a duration identification task and a probed-recall memory task but not on a line-length identification task. These findings do not support the notion of a global impairment in absolute identification in schizophrenia. However, the authors suggest that some aspect of temporal information processing is indeed disturbed in schizophrenia.