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Staten Island, NY, United States

The College of Staten Island is one of the eleven four-year senior colleges within the City University of New York system. Programs in the liberal arts and science and professional studies lead to bachelor's and associate's degrees. The master's degree is awarded in 13 professional and liberal arts and science fields of study. The College participates in doctoral programs of The City University Graduate School and University Center in Biology, Chemistry, Computer Science, Nursing, Physics, and Psychology. Wikipedia.

Loverde S.M.,CUNY - College of Staten Island
Journal of Physical Chemistry Letters | Year: 2014

This Perspective describes recent progress in the area of the molecular simulation of the interactions of hydrophobic and hydrophilic solutes with membranes. The ability to predict drug solubility prior to synthesis is an extremely desirable goal for pharmaceutical research. A major advantage of molecular dynamics is the ability to computationally probe both the drug solubility as well as the pathway for the transport of drugs across membranes. Computational methods to predict the interaction free energy of solutes with membranes have advanced significantly in recent years and can characterize the intra- and intermolecular state of the drug as well as perturbations of the drug to the membrane environment itself. In addition to a brief review on computational methods to characterize the transport of drugs across membranes, we will highlight recent discoveries and discuss the challenges and opportunities in the field. © 2014 American Chemical Society. Source

Ahmed Z.,CUNY - College of Staten Island
Journal of Applied Physiology | Year: 2011

The present study investigated the effect of trans-spinal direct current (tsDC) on the firing rate, pattern, and amplitude of spontaneous activity of the tibial nerve and on the magnitude of cortically elicited triceps surae (TS) muscle contractions. The effect of combined tsDC and repetitive cortical electrical stimulation (rCES) on the amplitude of cortically elicited TS twitches was also investigated. Stimulation was applied by two disk electrodes (0.79 cm 2): one was located subcutaneously over the vertebral column (T 10-L 1) and was used to deliver anodal DC (atsDC) or cathodal DC (c-tsDC) (density range: ± 0.64 to ± 38.2 A/m 2), whereas the other was located subcutaneously on the lateral aspect of the abdomen and served as a reference. While the application of a-tsDC significantly increased the spike frequency and amplitude of spontaneous discharges compared with c-tsDC, c-tsDC made the spontaneous discharges more rhythmic. Cortically elicited TS twitches were depressed during a-tsDC and potentiated after termination. Conversely, cortically elicited TS twitches were enhanced during c-tsDC and depressed after termination. While combined a-tsDC and rCES produced similar effects as a-tsDC alone, combined c-tsDC and rCES showed the greatest increase in cortically elicited TS twitches. tsDC appears to be a powerful neurostimulation tool that can differentially modulate spinal cord excitability and corticospinal transmission. © 2011 the American Physiological Society. Source

Chill J.H.,Bar - Ilan University | Naider F.,CUNY - College of Staten Island
Current Opinion in Structural Biology | Year: 2011

Structure determination of membrane-associated proteins (MPs) represents a frontier of structural biology that is characterized by unique challenges in sample preparation and data acquisition. No less important is our ability to study the dynamics of MPs, since MP flexibility and characteristic motions often make sizeable contributions to their function. This review focuses on solution state NMR methods to characterize dynamics of MPs in the membrane environment. NMR approaches to study molecular motions on a wide range of time-scales and their application to membrane proteins are described. Studies of polytopic and bitopic MPs demonstrating the power of such methods to characterize the dynamic behavior of MPs and their interaction with the membrane-mimicking surroundings are presented. Attempts are made to place the dynamic conclusions into a biological context. The importance and limitations of such investigations guarantee that further developments in this field will be actively pursued. © 2011 Elsevier Ltd. Source

Pyron R.A.,George Washington University | Burbrink F.T.,City University of New York | Burbrink F.T.,CUNY - College of Staten Island
Ecology Letters | Year: 2014

Viviparity has putatively evolved 115 times in squamates (lizards and snakes), out of only ~ 140 origins in vertebrates, and is apparently related to colder climates and other factors such as body size. Viviparity apparently evolves from oviparity via egg-retention, and such taxa may thus still have the machinery to produce thick-shelled eggs. Parity mode is also associated with variable diversification rates in some groups. We reconstruct ancestral parity modes accounting for state-dependent diversification in a large-scale phylogenetic analysis, and find strong support for an early origin of viviparity at the base of Squamata, and a complex pattern of subsequent transitions. Viviparous lineages have higher rates of speciation and extinction, and greater species turnover through time. Viviparity is associated with lower environmental and body temperatures in lizards and amphisbaenians, but not female mass. These results suggest that parity mode is a labile trait that shifts frequently in response to ecological conditions. © 2013 John Wiley & Sons Ltd/CNRS. Source

Ge L.,CUNY - College of Staten Island | Ge L.,The Graduate Center, CUNY | Stone A.D.,Yale University
Physical Review X | Year: 2014

We consider the role of degeneracy in parity-time (PT ) symmetry breaking for non-Hermitian wave equations beyond one dimension.We show that if the spectrum is degenerate in the absence of T breaking, and T is broken in a generic manner (without preserving other discrete symmetries), then the standard PT symmetry-breaking transition does not occur, meaning that the spectrum is complex even for infinitesimal strength of gain and loss. However, the realness of the entire spectrum can be preserved over a finite interval if additional discrete symmetries x are imposed when T is broken, if x decouples all degenerate modes. When the decoupling holds only for a subset of the degenerate spectrum, there can be a partial PT transition in which this subset remains real over a finite interval of T breaking. If the spectrum has odd degeneracy, a fraction of the degenerate spectrum can remain in the symmetric phase even without imposing additional discrete symmetries, and they are analogous to dark states in atomic physics. These results are illustrated by the example of different T -breaking perturbations of a uniform dielectric disk and sphere, and a group-theoretical analysis is given in the disk case. Finally, we show that multimode coupling is capable of restoring the PT -symmetric phase at finite T breaking.We also analyze these questions when the parity operator is replaced by another spatial symmetry operator and find that the behavior can be qualitatively different. Source

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