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Amherst, MA, United States

Amherst College is a private liberal arts college located in Amherst, Massachusetts, United States. Amherst is an exclusively undergraduate four-year institution and enrolled 1,817 students in the fall of 2012. Students choose courses from 38 major programs in an unusually open curriculum. Amherst is ranked as the second best liberal arts college in the country by U.S. News & World Report, and ranked tenth out of all U.S. colleges and universities by Forbes.Founded in 1821 as an attempt to relocate Williams College by its president, Zephaniah Swift Moore, Amherst is the third oldest institution of higher education in Massachusetts. Amherst was established as, and remained, a men's college until becoming coeducational in 1975.Amherst has historically had close relationships and rivalries with Williams College and Wesleyan University which form the Little Three colleges. It is also a member of the Five College Consortium. Wikipedia.

Bevers E.M.,Maastricht University | Williamson P.L.,Amherst College
FEBS Letters | Year: 2010

The best understood consequence of the collapse of lipid asymmetry is exposure of phosphatidylserine (PS) in the external leaflet of the plasma membrane bilayer, where it is known to serve at least two major functions: providing a platform for development of the blood coagulation cascade and presenting the signal that induces phagocytosis of apoptotic cells. Lipid asymmetry is collapsed by activation of phospholipid scramblase(s) that catalyze bidirectional transbilayer movement of the major classes of phospholipid. The protein corresponding to this activity is not yet known. Observations on cells from patients with Scott syndrome, a rare hereditary bleeding disorder resulting from impaired lipid scrambling, have shown that there are multiple activation pathways that converge on scramblase activity. © 2010 Federation of European Biochemical Societies. Source

Satellite images and aerial-photography following the Wenchuan earthquake show that a broad area experienced severe landsliding in association with the main earthquake and aftershocks. A zone of high density landsliding (>10% landslide surface area affected) stretches for ~240 km along the earthquake region, in proximity to the Yingxiu, Beichuan and Pennguan faults, which ruptured during the earthquake. The width of this severe landsliding zone varies along the strike, from ~25-30 km wide in the southwestern section of the earthquake region, to ~3-5 in the northeastern section. These variations coincide with differences in hillslope gradients, bedrock lithologies, co-seismic slip and ground shaking observed in these sections of the earthquake region. In general, there is good correlation between the magnitude and distribution of ground shaking experienced during the earthquake and mapped landslide density, though limited data and varying fault models prevent any in-depth comparison with high-resolution maps of ground shaking experienced. Landslides associated with Wenchuan earthquake highlight interesting aspects of erosion and tectonic evolution of the Longmen Shan. Short-term erosion rates in the Longmen Shan region measured from cosmogenic nuclides prior to the earthquake were ~0.2-0.3 mm/yr, reflecting the last 2000-3000. years - a time period shorter than the estimated recurrence interval of large earthquakes along the fault that ruptured, while long-term erosion rates measured by low-temperature thermochronology were higher, 0.5-0.7. mm/yr for the last 8-10. Ma. Integrating the total amount of erosion associated the earthquake into the short-term erosion rate estimates pushes the rate much higher. This suggests that the earthquake and associated landslide erosion was necessary for the landscape to 'catch-up' and balance the long-term tectonic growth of the Longmen Shan, particularly in the southwestern section of the earthquake region. Taken together, the earthquake and associated landslide erosion can be seen as the most recent expression of the rapid deformation/uplift and erosion that previous geomorphic evidence and geodynamic models had argued for along Longmen Shan front. © 2009 Elsevier B.V. Source

Leise T.L.,Amherst College
Journal of Circadian Rhythms | Year: 2013

We review time-frequency methods that can be useful in quantifying circadian and ultradian patterns in behavioral records. These records typically exhibit details that may not be captured through commonly used measures such as activity onset and so may require alternative approaches. For instance, activity may involve multiple bouts that vary in duration and magnitude within a day, or may exhibit day-to-day changes in period and in ultradian activity patterns. The discrete Fourier transform and other types of periodograms can estimate the period of a circadian rhythm, but we show that they can fail to correctly assess ultradian periods. In addition, such methods cannot detect changes in the period over time. Time-frequency methods that can localize frequency estimates in time are more appropriate for analysis of ultradian periods and of fluctuations in the period. The continuous wavelet transform offers a method for determining instantaneous frequency with good resolution in both time and frequency, capable of detecting changes in circadian period over the course of several days and in ultradian period within a given day. The discrete wavelet transform decomposes a time series into components associated with distinct frequency bands, thereby facilitating the removal of noise and trend or the isolation of a particular frequency band of interest. To demonstrate the wavelet-based analysis, we apply the transforms to a numerically-generated example and also to a variety of hamster behavioral records. When used appropriately, wavelet transforms can reveal patterns that are not easily extracted using other methods of analysis in common use, but they must be applied and interpreted with care. © 2013 Leise; licensee BioMed Central Ltd. Source

Williamson P.,Amherst College
Current Biology | Year: 2011

A recent study now shows that opsin catalyzes rapid movement of phospholipids from one leaflet of a membrane bilayer to the other. This capability illuminates a mechanism for this physiologically important process. © 2011 Elsevier Ltd. Source

Jaswal S.S.,Amherst College
Biochimica et Biophysica Acta - Proteins and Proteomics | Year: 2013

Over the past two decades, hydrogen exchange mass spectrometry (HXMS) has achieved the status of a widespread and routine approach in the structural biology toolbox. The ability of hydrogen exchange to detect a range of protein dynamics coupled with the accessibility of mass spectrometry to mixtures and large complexes at low concentrations result in an unmatched tool for investigating proteins challenging to many other structural techniques. Recent advances in methodology and data analysis are helping HXMS deliver on its potential to uncover the connection between conformation, dynamics and the biological function of proteins and complexes. This review provides a brief overview of the HXMS method and focuses on four recent reports to highlight applications that monitor structure and dynamics of proteins and complexes, track protein folding, and map the thermodynamics and kinetics of protein unfolding at equilibrium. These case studies illustrate typical data, analysis and results for each application and demonstrate a range of biological systems for which the interpretation of HXMS in terms of structure and conformational parameters provides unique insights into function. This article is part of a Special Issue entitled: Mass spectrometry in structural biology. © 2012 Elsevier B.V. Source

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