Biochemistry, Biophysics, and Structural Biology Commons^™

Dissecting The Loci Of Low-Level Quinine Resistance In Malaria Parasites, Michael T. Ferdig, Roland A. Cooper, Jianbing Mu, Bingbing Deng, Deirdre A. Joy, Xin-Zhuan Su, Thomas E. Wellems

Biological Sciences Faculty Publications

Quinine (QN) remains effective against Plasmodium falciparum, but its decreasing efficacy is documented from different continents. Multiple genes are likely to contribute to the evolution of QN resistance. To locate genes contributing to QN response variation, we have searched a P. falciparum genetic cross for quantitative trait loci (QTL). Results identify additive QTL in segments of chromosomes (Chrs) 13, 7 and 5, and pairwise effects from two additional loci of Chrs 9 and 6 that interact, respectively, with the QTL of Chrs 13 and 7. The mapped segments of Chrs 7 and 5 contain pfcrt, the determinant of …

Possible Use Of P20 Antigen In Serodiagnosis Of Inflammatory Bowel Disease, Shinchieh Yang

Electronic Theses and Dissertations

Crohn's disease (CD) is an idiopathic, chronic, relapsing inflammatory disorder, which is most commonly involved terminal ileum and colon. The incidence and prevalence of CD has dramatically increased during the last 50 years; however, the etiology and mechanism of this disorder remain unveiled. Besides genetic susceptibility, recent integrated researches investigated the role of environmental triggers such as microflora, measles viruses and mycobacteria in the pathogenesis of CD. The association between M. avium subsp paratuberculosis (MAP) and CD has been heightened because of clinical resemblance to Johne's disease (JD), a granulomatous enteritis in ruminants caused by MAP. Isolation of MAP from …

Reconsidering The Evolution Of Eukaryotic Selenoproteins: A Novel Nonmammalian Family With Scattered Phylogenetic Distribution, Sergi Castellano, Sergey V. Novoselov, Gregory V. Kryukov, Alain Lescure, Enrique Blanco, Alain Krol, Vadim N. Gladyshev, Roderic Guigo

Vadim Gladyshev Publications

While the genome sequence and gene content are available for an increasing number of organisms, eukaryotic selenoproteins remain poorly characterized. The dual role of the UGA codon confounds the identification of novel selenoprotein genes. Here, we describe a comparative genomics approach that relies on the genome-wide prediction of genes with in-frame TGA codons, and the subsequent comparison of predictions from different genomes, wherein conservation in regions flanking the TGA codon suggests selenocysteine coding function. Application of this method to human and fugu genomes identified a novel selenoprotein family, named SelU, in the puffer fish. The selenocysteinecontaining form also occurred in …

Reconsidering The Evolution Of Eukaryotic Selenoproteins: A Novel Nonmammalian Family With Scattered Phylogenetic Distribution, Sergi Castellano, Sergey V. Novoselov, Gregory V. Kryukov, Alain Lescure, Enrique Blanco, Alain Krol, Vadim N. Gladyshev, Roderic Guigo

Vadim Gladyshev Publications

While the genome sequence and gene content are available for an increasing number of organisms, eukaryotic selenoproteins remain poorly characterized. The dual role of the UGA codon confounds the identification of novel selenoprotein genes. Here, we describe a comparative genomics approach that relies on the genome-wide prediction of genes with in-frame TGA codons, and the subsequent comparison of predictions from different genomes, wherein conservation in regions flanking the TGA codon suggests selenocysteine coding function. Application of this method to human and fugu genomes identified a novel selenoprotein family, named SelU, in the puffer fish. The selenocysteinecontaining form also occurred in …

A Role For Talin In Presynaptic Function, Jennifer R. Morgan, Gilbert Di Paolo, Hauke Werner, Valentina A. Shchedrina, Marc Pypaert, Vincent A. Pieribone, Pietro De Camilli

Department of Biochemistry: Faculty Publications

Talin, an adaptor between integrin and the actin cytoskeleton at sites of cell adhesion, was recently found to be present at neuronal synapses, where its function remains unknown. Talin interacts with phosphatidylinositol-(4)-phosphate 5-kinase type Iγ, the major phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P₂]–synthesizing enzyme in brain. To gain insight into the synaptic role of talin, we microinjected into the large lamprey axons reagents that compete the talin–PIP kinase interaction and then examined their effects on synaptic structure. A dramatic decrease of synaptic actin and an impairment of clathrin-mediated synaptic vesicle endocytosis were observed. The endocytic defect included an accumulation of clathrin-coated pits …

Endocytic Function, Glycosaminoglycan Specificity, And Antibody Sensitivity Of The Recombinant Human 190-Kda Hyaluronan Receptor For Endocytosis (Hare), Ed Harris, Janet A. Weigel, Paul H. Weigel

Department of Biochemistry: Faculty Publications

The human hyaluronan receptor for endocytosis (hHARE) mediates the endocytic clearance of hyaluronan (HA) and chondroitin sulfate from lymph fluid and blood. Two hHARE isoforms (190 and 315 kDa) are present in sinusoidal endothelial cells of liver, spleen, and lymph nodes (Zhou, B., McGary, C. T., Weigel, J. A., Saxena, A., and Weigel, P. H. (2003) Glycobiology 13, 339–349). Here we report the specificity and function of the 190-kDa HARE, expressed without the larger isoform, in Flp-In 293 cell lines (190hHARE cells). Like the native protein, recombinant hHARE contains ~25 kDa of N-linked oligosaccharides, binds HA in a ligand blot …

5-Hydroxydecanoate Is Metabolised In Mitochondria And Creates A Rate-Limiting Bottleneck For Β-Oxidation Of Fatty Acids, Peter J. Hanley, Stefan Dröse, Ulrich Brandt, Rachel A. Lareau, Abir L. Banerjee, D. K. Srivastava, Leonard J. Banaszak, Joseph J. Barycki, Paul P. Van Veldhoven, Jürgen Daut

Department of Biochemistry: Faculty Publications

5-Hydroxydecanoate (5-HD) blocks pharmacological and ischaemic preconditioning, and

has been postulated to be a specific inhibitor of mitochondrial ATP-sensitive K+ (KATP)

channels. However, recent work has shown that 5-HD is activated to 5-hydroxydecanoyl-CoA

(5-HD-CoA), which is a substrate for the first step of β-oxidation. We have now

analysed the complete β-oxidation of 5-HD-CoA using specially synthesised (and purified)

substrates and enzymes, as well as isolated rat liver and heart mitochondria, and compared

it with the metabolism of the physiological substrate decanoyl-CoA. At the second step of

β-oxidation, catalysed by enoyl-CoA hydratase, enzyme kinetics were …

Mobilization Of Intracellular Copper Stores By The Ctr2 Vacuolar Copper Transporter, Erin M. Rees, Jaekwon Lee, Dennis J. Thiele

Department of Biochemistry: Faculty Publications

Copper plays an essential role in processes including signaling to the transcription and protein trafficking machinery, oxidative phosphorylation, iron mobilization, neuropeptide maturation, and normal development. Whereas much is known about intracellular mobilization of ions such as calcium, little information is available on how eukaryotic cells mobilize intracellular copper stores. We describe a mechanism by which the Saccharomyces cerevisiae Ctr2 protein provides bioavailable copper via mobilization of intracellular copper stores. Whereas Ctr2 exhibits structural similarity to the Ctr1 plasma membrane copper importer, microscopic and biochemical fractionation studies localize Ctr2 to the vacuole membrane. We demonstrate that Ctr2 mobilizes vacuolar copper stores …

Interactions Between Small Heat Shock Protein Subunits And Substrate In Small Heat Shock Protein-Substrate Complexes, Kenneth L. Friedrich,, Kim C. Giese, Nicole R. Buan, Elizabeth Vierling

Department of Biochemistry: Faculty Publications

Small heat shock proteins (sHSPs) are dynamic oligomeric proteins that bind unfolding proteins and protect them from irreversible aggregation. This binding results in the formation of sHSP-substrate complexes from which substrate can later be refolded. Interactions between sHSP and substrate in sHSP-substrate complexes and the mechanism by which substrate is transferred to ATP-dependent chaperones for refolding are poorly defined. We have established C-terminal affinity-tagged sHSPs from a eukaryote (pea HSP18.1) and a prokaryote (Synechocystis HSP16.6) as tools to investigate these issues. We demonstrate that sHSP subunit exchange for HSP18.1 and HSP16.6 is temperature-dependent and rapid at the optimal growth temperature …

Aminoacyl-Trnas: Setting The Limits Of The Genetic Code, Michael Ibba, Dieter Söll

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aminoacyl-tRNAs (aa-tRNAs) are simple molecules with a single purpose—to serve as substrates for translation. They consist of mature tRNAs to which an amino acid has been esterified at the 3′-end. The 20 different types of aa-tRNA are made by the 20 different aminoacyl-tRNA synthetases (aaRSs, of which there are two classes), one for each amino acid of the genetic code (Ibba and Söll 2000). This would be fine if it were not for the fact that such a straightforward textbook scenario is not true in a single known living organism. aa-tRNAs lie at the heart of gene expression; they interpret …

Evaluation Of Immunogenicity Of Transgenic Chloroplast Derived Protect, Vijay Koya

Electronic Theses and Dissertations

Anthrax, a fatal bacterial infection is caused by Bacillus anthracis, a gram-positive, spore forming, capsulated, rod shaped organism. Centers for Disease Control (CDC) lists anthrax as Category A biological agent due to its severity of impact on human health, high mortality rate, acuteness of the disease and potential for delivery as a biological weapon. The currently available human vaccine in the United States (AVA anthrax vaccine adsorbed) is prepared from Alum adsorbed formalin treated supernatant culture of toxigenic, non-encapsulated strain of Bacillus anthracis with the principle component being protective antigen (PA83). Evaluation of anthrax vaccine given to nearly 400,000 US …

Cellular Immune Response And Gene Expression Profiling In Crohn's Dise, Claudia Romero

Electronic Theses and Dissertations

Despite the chronic debate in the etiology of crohn's disease (cd), a debilitating inflammatory bowel disease (ibd) closely related to ulcerative colitis (uc), an emerging interest in a possible mycobacterial role has been marked. Granuloma and pathologic manifestations in cd resemble aspects found in tuberculosis, leprosy and paratuberculosis. The latter, a chronic enteritis in cattle, goat, sheep and primates, which is similar to human enteritis, also known as cd, is caused by a fastidious, slow growing mycobacterium avium subspecies paratuberculosis (map). Due to the similarities between cd and paratuberculosis, a mycobacterial cause in cd has been proposed. Recent discovery of …

Characterization Of A Novel Interactor/Substrate For The Pro-Apoptotic Serine Protease Omi/Htra2, Valerie Anne Stratico

Electronic Theses and Dissertations

OmiHtrA2 is a highly conserved mammalian serine protease that belongs to the HtrA family of proteins. Omi shares homology with the bacterially expressed heat shock protease HtrA, which functions as a protease at higher temperatures and a chaperone at lower temperatures. Additionally, Omi shares sequence similarity with the mammalian homologs L56/HtrA1 and PRSP/HtrA3. Omi was first isolated as an interacting protein of Mxi2, an alternatively spliced form of the p38 stress-activated kinase, using a modified yeast two-hybrid system. Omi localizes in the mitochondria and in response to apoptotic stimuli the mature form of this protein translocates to the cytoplasm. In …

A Drosophila Protein-Interaction Map Centered On Cell-Cycle Regulators, Clement A. Stanyon, Guozhen Liu, Bernardo A. Mangiola, Nishi Patel, Loic Giot, Bing Kuang, Huamei Zhang, Jinhui Zhong, Russell L. Finley Jr

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Maps depicting binary interactions between proteins can be powerful starting points for understanding biological systems. A proven technology for generating such maps is high-throughput yeast two-hybrid screening. In the most extensive screen to date, a Gal4-based two-hybrid system was used recently to detect over 20,000 interactions among Drosophila proteins. Although these data are a valuable resource for insights into protein networks, they cover only a fraction of the expected number of interactions.

Results

To complement the Gal4-based interaction data, we used the same set of Drosophila open reading frames to construct arrays for a LexA-based two-hybrid system. We …

Self-Aligned Mechanical Attachment Of Carbon Nanotubes To Silicon Dioxide Structures By Selective Silicon Dioxide Chemical-Vapor Deposition, Jed D. Whittaker, Ghaleb A. Husseini, Matthew A. Linford, Robert C. Davis, Markus Brink

Faculty Publications

A self-aligned thin-film deposition technique was developed to mechanically attach carbon nanotubes to surfaces for the fabrication of structurally robust nanotube-based nanomechanical devices. Single-walled carbon nanotubes were grown by thermal chemical-vapor deposition (CVD) across 150-nm-wide SiO2 trenches. The nanotubes were mechanically attached to the trench tops by selective silicon tetraacetate-based SiO2 CVD. No film was deposited on the nanotubes where they were suspended across the trenches.

Seasonal Variation And Ecosystem Dependence Of Emission Factors For Selected Trace Gases And Pm2.5 For Southern African Savanna Fires, S. Korontzi, Darold E. Ward, Ronald A. Susott, Robert J. Yokelson, C. O. Justice, Peter V. Hobbs, E.A. H. Smithwick, Wei Min Hao

Chemistry and Biochemistry Faculty Publications

[1] In this paper we present the first early dry season (early June-early August) emission factor measurements for carbon dioxide (CO₂), carbon monoxide (CO), methane (CH₄), nonmethane hydrocarbons (NMHC), and particulates with a diameter less than 2.5 μm (PM_2.5) for southern African grassland and woodland fires. Seasonal emission factors for grassland fires correlate linearly with the proportion of green grass, used as a surrogate for the fuel moisture content, and are higher for products of incomplete combustion in the early part of the dry season compared with later in the dry season. Models of …

Comprehensive Laboratory Measurements Of Biomass-Burning Emissions: 1. Emissions From Indonesian, African, And Other Fuels, Ted J. Christian, B. Kleiss, Robert J. Yokelson, R. Holzinger, P. J. Crutzen, Wei Min Hao, B. H. Saharjo, Darold E. Ward

Chemistry and Biochemistry Faculty Publications

[1] Trace gas and particle emissions were measured from 47 laboratory fires burning 16 regionally to globally significant fuel types. Instrumentation included the following: open-path Fourier transform infrared spectroscopy; proton transfer reaction mass spectrometry; filter sampling with subsequent analysis of particles with diameter <2.5 μm for organic and elemental carbon and other elements; and canister sampling with subsequent analysis by gas chromatography (GC)/flame ionization detector, GC/electron capture detector, and GC/mass spectrometry. The emissions of 26 compounds are reported by fuel type. The results include the first detailed measurements of the emissions from Indonesian fuels. Carbon dioxide, CO, CH₄, NH₃, HCN, methanol, and acetic acid were the seven most abundant emissions (in order) from burning Indonesian peat. Acetol (hydroxyacetone) was a major, previously unobserved emission from burning rice straw (21–34 g/kg). The emission factors for our simulated African fires are consistent with field data for African fires for compounds measured in both …

Explore Variable Potential Ion Guide For Mass Spectrometry, Curtiss D. Hanson

Patents (University of Northern Iowa)

A variable potential ion guide for placement within the reflectron of a time-of-flight mass spectrometer includes an elongate resistive electrode placed axially within the reflectron. The electrode may be a non-conductive monofilament coated with a resistive polymer coating, with one end of the electrode coupled to a high potential source, the electrode carrying a potential gradient along its length.

Tolerance Of The Fetus By The Maternal Immune System: Role Of Inflammatory Mediators At The Feto-Maternal Interface, Colette Kanellopoulos-Langevin, Stephane M. Caucheteux, Philippe Verbeke, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

The adaptive immune system of placental mammals has evolved to tolerate the fetus. Rejection of the fetus by adaptive immune responses is therefore a rare event, with abortion being caused more frequently by inflammation in the placenta. This review will cover recent aspects of immune privilege and the innate immune system at the feto-maternal interface, citing examples of the role played by microbial infections in fetal demise.

Determination Of The Optimal Form Of A Dna Vaccine To Induce An Effective Immune Response Against A Murine B-Cell Lymphoma, Deepti Aurora

All-Inclusive List of Electronic Theses and Dissertations

Tumor vaccines are a promising alternative to chemotherapy for the treatment of cancer. To be effective and safe, a cancer vaccine should specifically target antigens expressed only on tumor cells. The B-cell tumor-derived Ig receptor may be considered a model tumor antigen for cancer vaccine development. Specifically the immunoglobulin idiotype (ld) encoded by the variable region genes (VH and VL) provides a target antigen. Promising results have been obtained in clinical studies of ld vaccination using ld proteins. However, ld protein is laborious and time-consuming to produce. Gene-based vaccines, on the other hand, are inexpensive and offer ease of manipulation …

The Role Of Monocytes In Pristane-Induced Plasmacytoma Escape, Tina L. Sumpter

All-Inclusive List of Electronic Theses and Dissertations

Multiples myelomas are untreatable neoplasias in humans, arising from terminally differentiated B cells (plasma cells). The murine pristane-induced plasmacytoma model offers a system for studying the cellular interactions involved in sustaining the growth of plasma cell tumors. In accord with this model, syngenic plasma cell tumors transplanted into the peritoneal cavity of a genetically susceptible mouse are normally cleared by the mouse's immune system. If the mouse is pretreated with pristane (2,6,10,14- tetramethylpentadecane) intraperitoneally, prior to the transplantation of the plasma cell tumor, the tumor thrives, culminating in the death of the mouse. Intraperitoneal administration of pristane results in an …

The Drosophila Selenoprotein Bthd Is Required For Survival And Has A Role In Salivary Gland Development, So Yeon Kwon, Paul Badenhorst, F. Javier Martin-Romero, Bradley A. Carlson, Bruce M. Paterson, Vadim Gladyshev, Byeong Jae Lee, Dolph L. Hatfield

Vadim Gladyshev Publications

Selenium is implicated in many diseases, including cancer, but its function at the molecular level is poorly understood. BthD is one of three selenoproteins recently identified in Drosophila. To elucidate the function of BthD and the role of selenoproteins in cellular metabolism and health, we analyzed the developmental expression profile of this protein and used inducible RNA interference (RNAi) to ablate function. We find that BthD is dynamically expressed during Drosophila development. bthD mRNA and protein are abundant in the ovaries of female flies and are deposited into the developing oocyte. Maternally contributed protein and RNA persist during early …

K+- Induced Dilation Of Cremasteric Arterioles Involves Na+/K+Atpase And Inward Rectifier K+ Channels, Wendy Burns

Dissertations

The purpose of this study was to evaluate the possible mechanisms involved in cremasteric arteriolar dilation as a result of increased concentrations of ([K⁺]_o) extracellular potassium. Many other studies suggested that Na⁺/K⁺ ATPase or K_IR channels are responsible for potassium-induced vasodilation in other systems (2, 12, 22, 40, 46, 52, 16, 17, 25, 33, 34, 85, 99, 151). However, these studies show only partial inhibition of dilation as a result of independent blockageof each mechanism. The hypothesis of this study was that both mechanisms contribute to potassium-induced dilation seen in cremasteric arterioles. …

Disulfide Bond Formation Involves A Quinhydrone-Type Charge–Transfer Complex, James Regeimbal, Stefan Gleiter, Bernard L. Trumpower, Chang-Ang Yu

Dartmouth Scholarship

The chemistry of disulfide exchange in biological systems is well studied. However, the detailed mechanism of how oxidizing equivalents are derived to form disulfide bonds in proteins is not clear. In prokaryotic organisms, it is known that DsbB delivers oxidizing equivalents through DsbA to secreted proteins. DsbB becomes reoxidized by reducing quinones that are part of the membrane-bound electron-transfer chains. It is this quinone reductase activity that links disulfide bond formation to the electron transport system. We show here that purified DsbB contains the spectral signal of a quinhydrone, a charge-transfer complex consisting of a hydroquinone and a quinone in …

The Stromal Cell-Derived Factor-1alpha/Cxcr4 Ligand-Receptor Axis Is Critical For Progenitor Survival And Migration In The Pancreas., Ayse G. Kayali, Kurt Van Gunst, Iain L. Campbell, Aleksandr Stotland, Marcie Kritzik, Guoxun Liu, Malin Flodström-Tullberg, You-Qing Zhang, Nora Sarvetnick

Journal Articles: Regenerative Medicine

The SDF-1alpha/CXCR4 ligand/chemokine receptor pair is required for appropriate patterning during ontogeny and stimulates the growth and differentiation of critical cell types. Here, we demonstrate SDF-1alpha and CXCR4 expression in fetal pancreas. We have found that SDF-1alpha and its receptor CXCR4 are expressed in islets, also CXCR4 is expressed in and around the proliferating duct epithelium of the regenerating pancreas of the interferon (IFN) gamma-nonobese diabetic mouse. We show that SDF-1alpha stimulates the phosphorylation of Akt, mitogen-activated protein kinase, and Src in pancreatic duct cells. Furthermore, migration assays indicate a stimulatory effect of SDF-1alpha on ductal cell migration. Importantly, blocking …

Blood Lead Levels During Pregnancy And Pregnancy Outcome In Karachi Women, A Rahman, A Hakeem

Department of Biological & Biomedical Sciences

objective: To evaluate association of blood lead levels with pregnancy outcome in the obstetrics and gynaecology unit.
Methods: Blood lead levels were measured in 73 pregnant women at the time of delivery and assessed its association with pregnancyoutcome.
Results: Mean maternal lead level was 9.91+/-4.44 mg/dL (range 2.28-36.35 mg/dL). Mothers of boys had significantly higher (p=0.013, one-tailed t test) blood lead levels (11.05+/-5.19) when compared to mothers of girls (8.74+/-3.18 mg/dL.
Conclusion: Maternal lead levels at the time of delivery showed no association with gestational age, birth weight, recumbent length, or head circumference.

Live And Let Die: Regulatory Mechanisms In Fas-Mediated Apoptosis, James Curtin, Thomas Cotter

Articles

Activation of Fas receptor by Fas ligand causes caspase 8 activation and apoptosis in cells and is an important mechanism by which normal tissue homeostasis and function are maintained. Activation of caspase 8 is preceded by the formation of a death-inducing signalling complex (DISC), and a number of redundant mechanisms regulate DISC formation in vivo. Fas receptor is widely expressed in tissues, and dysfunction of the regulatory mechanisms in Fas receptor signalling has been reported in several diseases including autoimmune disease and cancer. This review aims to identify and discuss the various mechanisms employed by cells to alter their sensitivity …

Defects In Death-Inducing Signalling Complex Formation Prevent Jnk Activation And Fas-Mediated Apoptosis In Du 145 Prostate Carcinoma Cells, James Curtin, Thomas Cotter

Articles

Androgen-independent prostate carcinomas are resistant to chemotherapy and cell lines derived from androgen-independent prostate carcinomas such as DU 145 cells are highly resistant to Fas-mediated apoptosis. The incubation of DU 145 cells with anti-Fas IgM agonistic antibody of Fas receptor fails to activate JNK, a stress kinase involved in regulating apoptosis. We have previously shown that JNK activation is sufficient and necessary to promote Fas-mediated apoptosis in DU 145 cells. We investigate the mechanisms by which JNK activation and apoptosis are abrogated. HSP27 is overexpressed in DU 145 cells and has previously been reported to sequester DAXX and prevent JNK …

Evaluation Of Adsorption Effects On Measurements Of Ammonia, Acetic Acid, And Methanol, Robert J. Yokelson, Ted J. Christian, Isaac T. Bertschi, Wei M. Hao

Chemistry and Biochemistry Faculty Publications

[1] We examined how adsorption and desorption of gases from inlets and a cell could affect the accuracy of closed-cell FTIR measurements of carbon dioxide (CO₂), carbon monoxide (CO), methane (CH₄), nitric oxide (NO), nitrogen dioxide (NO₂), methanol (CH₃OH), acetic acid (CH₃COOH), and ammonia (NH₃). When standards were delivered to the cell through a stainless steel inlet, temporarily reduced transmission was observed for CH₃OH and NH₃. However, a halocarbon wax coated inlet (normally used on the system) had excellent transmission (comparable to room temperature …

Magnetic Storage Device Using Induced Magnetic Reversal Of A Cobalt Element Array, Hanning Chen, Scott L. Whittenburg

Chemistry and Biochemistry Faculty Publications

The effects of the applied field, cell size, and cutting area on the ‘‘seed’’ induced magnetic reversal of a cobalt element array have been studied by a stochastic dynamic micromagnetics code using the Laudau–Lifshitz–Gilbert equation. Three magnetic reversal mechanisms under different magnitudes of the applied field have been investigated by examining the energy profiles. To minimize the effect of the thermal fluctuations on the switching time, an applied field with magnitude around 0.7 or 0.8 T and an element array with cutting area less than 10 nm X 10 nm are required. By using the smaller cellsize, the switching time …