Revised calibration of the MBT-CBT paleotemperature proxy

The MBT-CBT proxy for the reconstruction of paleotemperatures and past soil pH is based on the distribution of branched glycerol dialkyl glycerol tetraether (brGDGT) membrane lipids. The Methylation of Branched Tetraether (MBT) and the Cyclisation of Branched Tetraether (CBT) indices were developed to quantify these distributions, and significant empirical relations between these indices and annual mean air temperature (MAT) and/or soil pH were found in a large data set of soils. In this study, we extended this soil dataset to 278 globally distributed surface soils. Of these soils, 26% contains all nine brGDGTs, while in 63% of the soils the seven most common brGDGTs were detected, and the latter were selected for calibration purposes. This resulted in new transfer functions for the reconstruction of pH based on the CBT index: pH = 7.90-1.97 × CBT (r**2 = 0.70; RMSE = 0.8; n = 176), as well as for MAT based on the CBT index and methylation index based on the seven most abundant GDGTs (defined as MBT'): MAT = 0.81-5.67 × CBT + 31.0 × MBT' (r**2 = 0.59; RMSE = 5.0 °C; n = 176). The new transfer function for MAT has a substantially lower correlation coefficient than the original equation (r**2 = 0.77). To investigate possible improvement of the correlation, we used our extended global surface soil dataset to statistically derive the indices that best describe the relations of brGDGT composition with MAT and soil pH. These new indices, however, resulted in only a relatively minor increase in correlation coefficients, while they cannot be explained straightforwardly by physiological mechanisms. The large scatter in the calibration cannot be fully explained by local factors or by seasonality, but MAT for soils from arid regions are generally substantially (up to 20 °C) underestimated, suggesting that absolute brGDGT-based temperature records for these areas should be interpreted with caution. The applicability of the new MBT'-CBT calibration function was tested using previously published MBT-CBT-derived paleotemperature records covering the last deglaciation in Central Africa and East Asia, the Eocene-Oligocene boundary and the Paleocene-Eocene thermal maximum. The results show that trends remain similar in all records, but that absolute temperature estimates and the amplitude of temperature changes are lower for most records, and generally in better agreement with independent proxy data.

Reduced synchronization persistence in neural networks derived from atm-deficient mice

Many neurodegenerative diseases are characterized by malfunction of the DNA damage response. Therefore, it is important to understand the connection between system level neural network behavior and DNA. Neural networks drawn from genetically engineered animals, interfaced with micro-electrode arrays allowed us to unveil connections between networks’ system level activity properties and such genome instability. We discovered that Atm protein deficiency, which in humans leads to progressive motor impairment, leads to a reduced synchronization persistence compared to wild type synchronization, after chemically imposed DNA damage. Not only do these results suggest a role for DNA stability in neural network activity, they also establish an experimental paradigm for empirically determining the role a gene plays on the behavior of a neural network.

Assessment of urban parameterizations in the WRF model for air quality modelling purposes in Madrid (Spain)

This study aims to assess the performance or multi-layer canopy parameterizations implemented in the mesoscale WRF model in order to understand their potential contribution to improve the description of energy fluxes and wind fields in the Madrid city. It was found that the Building Energy Model (BEP+BEM) parameterization yielded better results than the bulk standard scheme implemented in the Noah LSM, but very close to those of the Building Energy Parameterization (BEP). The later was deemed as the best option since data requirements and CPU time were smaller. Two annual runs were made to feed the CMAQ chemical-transport model to assess the impact of this feature in routinely air quality modelling activities.

Prediction of protein deamidation rates from primary and three-dimensional structure

A method for the quantitative estimation of instability with respect to deamidation of the asparaginyl (Asn) residues in proteins is described. The procedure involves the observation of several simple aspects of the three-dimensional environment of each Asn residue in the protein and a calculation that includes these observations, the primary amino acid residue sequence, and the previously reported complete set of sequence-dependent rates of deamidation for Asn pentapeptides. This method is demonstrated and evaluated for 23 proteins in which 31 unstable and 167 stable Asn residues have been reported and for 7 unstable and 63 stable Asn residues that have been reported in 61 human hemoglobin variants. The relative importance of primary structure and three-dimensional structure in Asn deamidation is estimated.

Declaration signed by Harvard students to not speak in the vernacular for one year, 1712 August 23

The declaration, handwritten in Latin and signed by members of the junior and sophomore classes (Harvard Classes of 1714 and 1715), promises that the undersigned will not use the vernacular but instead "whenever, at meals, at banquets,...in our rooms, in all our gatherings, wherever and whenever" will speak in Latin, Greek, or Hebrew through the next May. Additional Latin text appears on both the front and back of the document. The original is accompanied by a typed transcription and two partial handwritten translations. Note at top of original: "Script. Leonardo Dowding, Composit. a Tho. Foxcroft."

Oratio salutatoria et oratio valedictoria, ca. 1763

Undated and unattributed handwritten Latin salutatory and valedictory orations composed for the Harvard College Commencement. A modern note with the materials suggests Nathaniel Sparhawk (Harvard AB 1765) as the author, but the author was more likely Joseph Hooper (Harvard AB 1763), who delivered the orations for the 1763 Harvard Commencement. While the documents are undated, textual clues include mention of the command of George III in recent war against France and Spain, suggesting the speech was written soon after the Treaty of Paris which was signed in February 1763 to end the Seven Years' War. The speech also celebrates Harvard Tutor William Kneeland, who resigned from his position in July 1763, and mentions the illness of Professor Edward Wigglesworth (who died before the 1765 Commencement). The text also mentions Professor John Winthrop and Massachusetts Governor Francis Bernard.

Letter from Benjamin Colman to Edward Wigglesworth about John Leverett, 1728 March 4

Benjamin Colman wrote this letter to Edward Wigglesworth on March 4, 1728; it was sent from Colman, in Boston, to Wigglesworth, in Cambridge. The letter concerns their mutual friend, John Leverett, who had died several years before. It appears that Wigglesworth was charged with writing an epitaph for Leverett and had solicited input from Colman. Colman writes of his great admiration for Leverett, praising his "virtue & piety, wisdom & gravity [...] majesty & authority [...] eye & voice, goodness & courtesie."

1994 University of Michigan Football Team

1995 University of Michigan Football Team

1996 University of Michigan Football Team

1997 University of Michigan Football Team