Building Interaction with an Isolated Population through Social Media: The Deaf Community

The purpose of the study is to discover the effects of social media on the deaf community. Ten individuals, aged from 21 to 29, participated in this study. There was no control for race, ethnicity, or socioeconomic status. An Internet survey was used to gather data. Results suggest that hearing impaired individuals do use social media and that the ways in which is it used varies as a function of degree of hearing loss

Scale-up of Polyaniline Cellulose Membranes

Polyaniline coated cellulose membranes show impressive conductive properties that may be used to innovate traditional charged separation techniques, such as electrodeionization. However, these membranes are not sold to consumers, so they cannot be easily integrated into such systems. This research focuses on the scale-up and development of positively charged anion exchange membranes to be used in EDI cells. Novel cellulose membranes were made using lab-specific cellulose. These membranes were then coated using a polyaniline technique adopted from a paper titled, “Flexible Electrically Conductive Nanocomposite Membrane Based on Bacterial Cellulose and Polyaniline. This paper details the methods used to add the polyaniline coating to lab-scale cellulose membranes. Fourier transfer infrared spectrometry (FTIR) was used to determine that the chemical composition of the material was altered. The carboxyl functional groups were most likely altered to imine groups judging by the shifted FTIR peaks. The theoretical chemical analysis performed before the experiment supports this conclusion. More work needs to be done to compile important data on the novel material, but the proof of concept has been shown within this research

Chemical vapor deposition of MoS₂ on distributed Bragg reflector for room temperature polariton condensation

The creation of a room temperature Bose Einstein Condensate has been the goal of much research since the phenomenon was first experimentally realized in 1995. Currently, polaritons stand out as a particularly viable option to achieve this goal as their low effective mass should in theory allow for a high condensation temperature. One proposed system to realize such a condensate is a semiconductor optical microcavity. In a semiconductor microcavity distributed Bragg reflectors (DBR) are used to trap photons in the cavity, while a direct band gap semiconductor placed in the cavity would allow for the creation of excitons for those photons to couple with. In this work we explore the growth of crystalline monolayer Molybdenum Disulfide (MoS₂) directly onto the DBR to create such a microcavity. Growth of MoS₂ is well studied, however the DBR substrate presents unique challenges as the surface is inconducive for crystalline growth and the substrate itself warps and deteriorates at high temperatures. We then present techniques to overcome these challenges and recipes by which large area growth of monolayer MoS₂ growth on DBR can be attained.Electrical and Computer Engineerin

Thomas Wolfe's Romantic Affinity for Germany

This thesis explores the politics and views of Thomas Wolfe's romantic affinity for Germany

PKC Regulates a Farnesyl-Electrostatic Switch on K-Ras that Promotes its Association with Bcl-Xl on Mitochondria and Induces Apoptosis

K-Ras associates with the plasma membrane (PM) through farnesylation that functions in conjunction with an adjacent polybasic sequence. We show that phosphorylation by protein kinase C (PKC) of S181 within the polybasic region promotes rapid dissociation of K-Ras from the PM and association with intracellular membranes, including the outer membrane of mitochondria where phospho-K-Ras interacts with Bcl-Xl. PKC agonists promote apoptosis of cells transformed with oncogenic K-Ras in a S181-dependent manner. K-Ras with a phosphomimetic residue at position 181 induces apoptosis via a pathway that requires Bcl-Xl. The PKC agonist bryostatin-1 inhibited the growth in vitro and in vivo of cells transformed with oncogenic K-Ras in a S181-dependent fashion. These data demonstrate that the location and function of K-Ras are regulated directly by PKC and suggest an approach to therapy of K-Ras-dependent tumors with agents that stimulate phosphorylation of S18

Hypochromicity in red blood cells: an experimental and theoretical investigation

Multiwavelength UV-visible transmission spectrophotometry is a useful tool for the examination of micron-size particle suspensions in the context of particle size and chemical composition. This paper reports the reliability of this method to characterize the spectra of purified red blood cells both in their physiological state and with modified hemoglobin content. Previous studies have suggested the contribution of hypochromism on the particle spectra caused by the close electronic interaction of the encapsulated chromophores. Our research shows, however, that this perceived hypochromism can be accounted for by considering two important issues: the acceptance angle of the instrument and the combined scattering and absorption effect of light on the particles. In order to establish these ideas, spectral analysis was performed on purified and modified red cells where the latter was accomplished with a modified hypotonic shock protocol that altered the hemoglobin concentration within the cells. Moreover, the Mie theory was used to successfully simulate the spectral features and trends of the red cells. With this combination of experimental and theoretical exploration, definition of hypochromism has been extended to two subcategories

On the functional use of the membrane compartmentalized pool of ATP by the Na+ and Ca++ pumps in human red blood cell ghosts

Previous evidence established that a sequestered form of adenosine triphosphate (ATP pools) resides in the membrane/cytoskeletal complex of red cell porous ghosts. Here, we further characterize the roles these ATP pools can perform in the operation of the membrane's Na+ and Ca2+ pumps. The formation of the Na+- and Ca2+-dependent phosphointermediates of both types of pumps (ENa-P and ECa-P) that conventionally can be labeled with trace amounts of [γ-3P]ATP cannot occur when the pools contain unlabeled ATP, presumably because of dilution of the [γ-3P]ATP in the pool. Running the pumps forward with either Na+ or Ca2+ removes pool ATP and allows the normal formation of labeled ENa-P or ECa-P, indicating that both types of pumps can share the same pools of ATP. We also show that the halftime for loading the pools with bulk ATP is 10–15 minutes. We observed that when unlabeled “caged ATP” is entrapped in the membrane pools, it is inactive until nascent ATP is photoreleased, thereby blocking the labeled formation of ENa-P. We also demonstrate that ATP generated by the membrane-bound pyruvate kinase fills the membrane pools. Other results show that pool ATP alone, like bulk ATP, can promote the binding of ouabain to the membrane. In addition, we found that pool ATP alone functions together with bulk Na+ (without Mg2+) to release prebound ouabain. Curiously, ouabain was found to block bulk ATP from entering the pools. Finally, we show, with red cell inside-outside vesicles, that pool ATP alone supports the uptake of 45Ca by the Ca2+ pump, analogous to the Na+ pump uptake of 22Na in this circumstance. Although the membrane locus of the ATP pools within the membrane/cytoskeletal complex is unknown, it appears that pool ATP functions as the proximate energy source for the Na+ and Ca2+ pumps

Regulation of Rnd3 Localization and Function By PKCα-Mediated Phosphorylation

The Rnd proteins (Rnd1, Rnd2 and Rnd3/RhoE) form a distinct branch of the Rho family of small GTPases. Altered Rnd3 expression causes changes in cytoskeletal organization and cell cycle progression. Rnd3 functions to decrease RhoA activity, but how Rnd3 itself is regulated to cause these changes is still under investigation. Unlike other Rho family proteins, Rnd3 is regulated not by GTP/GDP cycling, but at the level of expression and by posttranslational modifications such as prenylation and phosphorylation. We show here that, upon PKC agonist stimulation, Rnd3 undergoes an electrophoretic mobility shift and its subcellular localization becomes enriched at internal membranes. These changes are blocked by inhibition of conventional PKC isoforms and do not occur in PKCα-null cells or to a nonphosphorylatable mutant of Rnd3. We further show that PKCα directly phosphorylates Rnd3 in an in vitro kinase assay. Additionally, we provide evidence that the phosphorylation status of Rnd3 has a direct effect on its ability to block signaling from the Rho-ROCK pathway. These results identify an additional mechanism of regulation and provide clarification of how Rnd3 modulates Rho signaling to alter cytoskeletal organization

GOPred: GO Molecular Function Prediction by Combined Classifiers

Functional protein annotation is an important matter for in vivo and in silico biology. Several computational methods have been proposed that make use of a wide range of features such as motifs, domains, homology, structure and physicochemical properties. There is no single method that performs best in all functional classification problems because information obtained using any of these features depends on the function to be assigned to the protein. In this study, we portray a novel approach that combines different methods to better represent protein function. First, we formulated the function annotation problem as a classification problem defined on 300 different Gene Ontology (GO) terms from molecular function aspect. We presented a method to form positive and negative training examples while taking into account the directed acyclic graph (DAG) structure and evidence codes of GO. We applied three different methods and their combinations. Results show that combining different methods improves prediction accuracy in most cases. The proposed method, GOPred, is available as an online computational annotation tool (http://kinaz.fen.bilkent.edu.tr/gopred)