bluuebunny/crossref_metadata_2025 huggingface dataset:
Highly Stable SrZrO3 Bipolar Resistive Switching Memory by Ti Modulation Layer
Authors: Wu Ming-Chi , Lin Meng-Han , Yeh Yu-Ting , Lin Chen-Hsi , Tseng Tseung-Yuen
Published: April 2010

In this paper, the resistive switching characteristic of the SrZrO3(SZO)-based resistance random access memory (RRAM) composed of Pt/Ti/SZO/LaNiO3(LNO) are investigated. The electrical testing results show that the device has lower operation voltage, lower compliance current, long retention behavior, and stable resistance ratio over 104 s under 0.3 V reading voltage. It is demonstrated that the active metal Ti as an oxygen getter can modify the resistive switching property of the SZO based RRAM. After depositing all stack films, the post annealing (PA) treatment with various conditions was carried out to form the interfacial layer (TiOx) between Ti and SZO. By using X-ray Photoelectron Spectrometer (XPS) analysis, the Ti layer as an oxygen getter is confirmed. The better SZO based RRAM device can be made with the proper TiOx film formed by suitable annealing temperature and thickness of Ti layer.
Dielectric Anomaly in Mg Doped ZnO Thin Film Deposited by Sol-Gel Method
Authors: Singh Amanpal C. , Khanna Parmod Kumar , Kumar Anuj , Kumar Mukesh , Kumar Dinesh
Published: April 2010

The magnesium doped ZnO polycrystalline thin film (Zn0.75Mg0.25O) film was grown by sol-gel method on p-type silicon substrate. The film was annealed at 1000°C in oxygen rich environment. The aluminum thin layer was used for back contact and Indium dots were used for top contacts. The doping of magnesium in lattice structure of Zinc oxide was examined by X-ray spectra. The ferroelectricity in the deposited film was confirmed by polarization and electric field (P/E) curve showing a well defined hysteresis loop. Maximum value of the spontaneous polarization (Ps) and coercive field was found to be 0.29 μC/Cm2 and 18 kV/cm respectively. The clockwise rotation in capacitance and voltage (C-V) hysteresis loop of the deposited film on p-type Si was indicated that the charge compensation on the Si surface was induced by the ferroelectric polarization existed in the film. The grain size and grain structure was analyzed by atomic force microscopy.
CeO2 Optical Properties and Electrical Characteristics
Authors: Shih Wen-chieh , Chen Chun-Heng , Chiu Fu-Chien , Lai Chih-Ming , Hwang Huey-Liang
Published: April 2010

The characterizations of optical dielectric function of the cerium dioxide (CeO2) were made by the spectroscopic ellipsometry (SE) technique using Kramers-Kronig relation and Tauc-Lorentz (TL) dispersion model. The results showed that the bandgap energy and refractive index of the CeO2 are about 3.32 eV and 2.18, respec-tively. According to the optical properties, the current conduction mechanisms in CeO2 thin films are Poole-Frenkel emission in high electric fields (> 2.36 MV/cm) at 450-500 K and Schottky emis-sion in medium electric fields (0.5-1.6 MV/cm) at 350-500 K. Consequently, the trap energy level and the Al/CeO2 barrier height are determined to be about 1.57{plus minus}0.01 eV and 0.63{plus minus}0.01 eV, re-spectively.
New Metal-High-k-High-k-Oxide-Semiconductor Capacitors and Field Effect Transistors Using Al/Y2O3/Ta2O5/SiO2/Si Structure for Nonvolatile Memory Applications
Authors: Shih Wen-chieh , Chiu Fu-Chien , Hwang Huey-Liang
Published: April 2010

A new metal −high−k−high−k−oxide−silicon (MHHOS) struc-ture was fabricated for non-volatile memory applications. Al/Y2O3/Ta2O5/SiO2/Si capacitors and field effect transistors were fabricated using Ta2O5 as the charge storage layer and Y2O3 as the blocking layer. The programming time of the Al/Y2O3/Ta2O5/SiO2/Si transistors was characterized. With a pro-gramming pulse voltage of 6 V, a threshold voltage shift of more than 0.5 V was achieved in 10 ns. As for the retention properties, the Al/Y2O3/Ta2O5/SiO2/Si transistors can keep a ΔVth window of 0.81 V for 10 years.
(Invited) Nanocrystalline Materials: Optimization of Thin Film Properties
Authors: Heitmann Johannes , Mikolajick Thomas
Published: April 2010

The approach of superlattices to enable the size control of different nanocrystalline materials was investigated. In case of size controlled Si nanocrystals synthesized by SiO/SiO2 superlattices this approach enables a precise bandgap engineering of well passivated nanocrystals. Which results in a tunable luminescence signal, a resonant energy transfer to Er3+ ions and the confirmation of the quantum confined origin of the luminescene and the prove of optical amplification. In case of Zr based dielectrics the size control by the superlattice approach enables the stabilization of the tetragonal phase, which is favorable for high capacitance applications. For HfO2 an additional doping of the films, e.g. by Si atoms for the phase stabilization is necessary. Doping or interlayer additionally improves the electrical performance of the dielectrics.
(Invited) The Chemical Composition of Low Dielectric Constant Films from Ion Beam Scattering Methodologies
Authors: Soles Christopher L. , Wang H. , Composto R. J.
Published: April 2010

A suite of ion beam scattering methodologies is described for determining the atomic composition of the thin films commonly used as interlayer dielectric barriers (low-k) in next generation integrated circuits. These Si based films typically also contain light elements, such as O, C, and H, that are not easily detected with traditional elastic Rutherford backscattering spectrometry (RBS) and nuclear resonance enhanced RBS measurements when the thin film is supported on a substrate that also contain heavy elements like Si. To circumvent this difficulty, 2 MeV forward scattering (FS) spectrometry is used to enhance the light element sensitivity by separating their characteristic energies from those of the Si substrate and increasing their relative scattering cross-section. This allows an accurate determination the Si:O:C ratio. The absolute H abundance is determined from forward recoil spectrometry (FRES) on both the unknown low-k film and polystyrene (PS) reference film of known H content (defined by the stoichiometry and film thickness). The complete stoichiometry and atomic density of the low-k film are fit from either the RBS or grazing angle backscattering (GBS) spectrum using constraints implied by the absolute aerial H density and the Si:O:C ratio.
(Invited) MgO Tunnel Barriers in Magnetic Nanostructures and Devices
Authors: Heindl Ranko , Pufall Matthew , Rippard William
Published: April 2010

In recent years, there has been a great deal of success in the development of MgO based tunnel barriers for use in magnetic devices, such as nanoscale magnetic random access memory (MRAM) elements and magnetic field sensors. Much of the focus has been on creating tunnel barriers that have ever-increasing tunneling magnetoresistance values, which today approach as much as 500%, and lower resistance-area products, which are as low as a few Ohm-micrometers squared. These improvements afford the potential for future scaling of MRAM devices into the deep nanometer regime and solid-state CMOS compatible sensors with much improved sensitivity. This paper gives an overview of the fundamental device concepts of these MgO-based structures. Contribution of NIST, not subject to copyright
(Invited) PE-TEOS Wafer Bonding Enhancement at Low Temperature with a High-k Dielectric Capping Layer
Authors: Tan Chuan Seng , Chong Gang Yih
Published: April 2010

The bond strength of plasma-enhanced tetraethyl-orthosilicate (PE-TEOS) oxide bonded and annealed at low temperature (300 oC and below) is enhanced using a thin layer of high-K dielectric at the bonding interface. Prior to bonding, thin (~5 nm) capping layer of Al2O3 high-K dielectric is deposited using atomic layer deposition (ALD) on polished PE-TEOS wafers followed by surface activation. It is found that after 300 oC anneal in N2 ambient for 3 h, bond strength of wafer pair bonded with PE-TEOS oxide is enhanced by 73.3%. The bonding interface is seamless with no presences of micro-void.
(Invited) Whisker Formation in Pb-Free Surface Finishes
Authors: Stafford Gery , Williams Maureen , Shin Jae Wook , Moon Kil-Won , Beauchamp Carlos , Boettinger William
Published: April 2010

Tin-lead (Sn-Pb) alloys have been used extensively for surface finishing of electronic components in part because Pb was found to be effective in retarding Sn whisker growth in electrodeposits. Although whiskers appear to be a local response to the existence of residual compressive stress in the electrodeposited film, questions remain as to the dominant source of stress and the precise growth mechanism. Using both deflection measurements of plated cantilever beams and x-ray diffraction methods (sin2Ψ), we have determined the in-plane residual stress in Sn, Sn-Cu, and Sn-Pb alloys electrodeposited from both bright- and matte-finish methanesulfonate-based electrolytes. Stress measurements were made soon after deposition, and as a function of time. The appearance of hillocks and/or whiskers following plating is influenced by several factors such as intrinsic growth stress, stress induced by Cu6Sn5 formation at the Sn-Cu interface, and the deposit microstructure.
(Invited) Three-Dimensionally Structured Thin Film Heterojunction Photovoltaics on Interdigitated Back-Contacts
Authors: Josell Daniel , Beauchamp Carlos , Hamadani Behrang H. , Jung Suyong , Guyer Jonathan , Motayed Abhishek , Hangarter Carlos , Gergel-Hackett Nadine , Xu Hua , Zhitenev Nikolai
Published: April 2010

Fabrication and properties of three-dimensionally structured back-contact heterojunction solar cells are described. A variety of devices are explored, all of which were fabricated by electrochemical deposition of a semiconducting material on one of two interdigitated electrodes in a comb structure followed by deposition of a second semiconducting material over the entire surface, including over both the bare and coated electrodes in the comb. The performance of fabricated devices is described and interpreted using a simplified model of the device geometry, light absorption and carrier transport. The results demonstrate that the processes and structures are amenable to a broad array of materials and deposition techniques, providing well-defined geometries amenable to fabrication and study of 3-D structured photovoltaic devices.
Interfacial Electrochemistry of ZnO: An Influence of the Surface Polarity?
Authors: Joudrier Anne-Laure , Levy François , Simon Nathalie , Bouttemy M. , Levy François , Feuillet G. , Etcheberry Arnaud
Published: April 2010

The question of the nature of the polar surface on ZnO single-crystal is studied using different approaches. XPS, etching rate determinations and electrochemical measurements are performed to collect information about the nature of the polar character of these faces. Different behaviors are detected that can be related to polarity effects.
Dye-Sensitized Solar Cells Using Localized Surface Plasmon of Gold and Silver Nanoparticles with Comb-shaped Block Copolymer
Authors: Enomoto Mikio , Taniguchi Katsuhiko , Ihara Manabu
Published: April 2010

The conversion efficiency of dye-sensitized solar cells using 2 μm thickness of TiO2 and N3 dye was improved from 1.5 to 2.4% by adding Ag nanoparticles covered with comb-shaped block copolymer (amine AgNP). Two methods of adding amine AgNP to porous TiO2 films were used. Absorption enhancement of the dyes on quartz substrates by adding AuNP was investigated. Absorption enhancement of the dyes occurred when adding the heat-treated amine AuNP, and the prepared AuNP covered with 16-mercapto hexadecanoic acid (thiol AuNP). Absorption enhancement was higher for Black Dye (BD) than for N3. The dependences of the absorption enhancement on the treating conditions could be explained by the distance between BD and AuNPs. The main absorption enhancement peak for thiol AuNP was longer side of wavelength than that for amine AuNP because thiol AuNP had a longer absorption wavelength of localized surface plasmon than amine AuNP had.
Photo-Induced Alcohol Electro-Reforming for H2 Production
Authors: Seferlis Andreas K. , Neophytides Stylianos G.
Published: April 2010

The photoelectrochemical anodic decomposition of alcohols was studied on a porous nanoparticulate TiO2 film which was illuminated with a 365 nm UV radiation. The open circuit potential (OCP) developed and the produced photocurrent (Iph) was dependent on the nature of the alcohol molecule and on the TiO2 film thickness. With increasing film thickness the OCP becomes more negative acquiring values varying between -120 mV to -210mV. Correspondingly the photocurrent was enhanced at thicker TiO2 films and more negative OCP values. This behavior can be attributed to the possibility that characterizes a nanoparticulate porous TiO2 film, to be penetrated by the electrolyte and depleted from the majority charge carriers (electrons in the conduction band). The optimum film thickness for the given UV radiation depends on the applied positive reversed bias potential and lies, between 3-7μm.
Prolonged Sleep Restriction Affects Glucose Metabolism in Healthy Young Men
Authors: van Leeuwen Wessel M. A. , Hublin Christer , Sallinen Mikael , Härmä Mikko , Hirvonen Ari , Porkka-Heiskanen Tarja
Published: April 2010

This study identifies the effects of sleep restriction and subsequent recovery sleep on glucose homeostasis, serum leptin levels, and feelings of subjective satiety. Twenty-three healthy young men were allocated to a control group (CON) or an experimental (EXP) group. After two nights of 8 h in bed (baseline, BL), EXP spent 4 h in bed for five days (sleep restriction, SR), followed by two nights of 8 h (recovery, REC). CON spent 8 h in bed throughout the study. Blood samples were taken after the BL, SR, and REC period. In EXP, insulin and insulin-to-glucose ratio increased after SR. IGF-1 levels increased after REC. Leptin levels were elevated after both SR and REC; subjective satiety remained unaffected. No changes were observed in CON. The observed increase of serum IGF-1 and insulin-to-glucose ratio indicates that sleep restriction may result in an increased risk to develop type 2 diabetes.
Using Differential Transform Method and Padé Approximant for Solving MHD Flow in a Laminar Liquid Film from a Horizontal Stretching Surface
Authors: Rashidi Mohammad Mehdi , Keimanesh Mohammad
Published: April 2010

The purpose of this study is to approximate the stream function and temperature distribution of the MHD flow in a laminar liquid film from a horizontal stretching surface. In this paper DTM‐Padé method was used which is a combination of differential transform method (DTM) and Padé approximant. The DTM solutions are only valid for small values of independent variables. Comparison between the solutions obtained by the DTM and the DTM‐Padé with numerical solution (fourth‐order Runge–Kutta) revealed that the DTM‐Padé method is an excellent method for solving MHD boundary‐layer equations.
The Optimal Upper and Lower Power Mean Bounds for a Convex Combination of the Arithmetic and Logarithmic Means
Authors: Xia Wei-Feng , Chu Yu-Ming , Wang Gen-Di
Published: April 2010

For p ∈ ℝ, the power mean Mp(a, b) of order p, logarithmic mean L(a, b), and arithmetic mean A(a, b) of two positive real values a and b are defined by Mp(a, b) = ((ap + bp)/2) 1/p, for p ≠ 0 and , for p = 0, L(a, b) = (b − a)/(log b − log a), for a ≠ b and L(a, b) = a, for a = b and A(a, b) = (a + b)/2, respectively. In this paper, we answer the question: for α ∈ (0,1), what are the greatest value p and the least value q, such that the double inequality Mp(a, b) ≤ αA(a, b)+(1 − α)L(a, b) ≤ Mq(a, b) holds for all a, b > 0?
Biomarkers for Lupus Nephritis: A Critical Appraisal
Authors: Mok Chi Chiu
Published: April 2010

Kidney disease is one of the most serious manifestations of systemic lupus erythematosus (SLE). Despite the improvement in the medical care of SLE in the past two decades, the prognosis of lupus nephritis remains unsatisfactory. Besides exploring more effective but less toxic treatment modalities that will further improve the remission rate, early detection and treatment of renal activity may spare patients from intensive immunosuppressive therapies and reduce renal damage. Conventional clinical parameters such as creatinine clearance, proteinuria, urine sediments, anti-dsDNA, and complement levels are not sensitive or specific enough for detecting ongoing disease activity in the lupus kidneys and early relapse of nephritis. Thus, novel biomarkers are necessary to enhance the diagnostic accuracy and sensitivity of lupus renal disease, prognostic stratification, monitoring of treatment response, and detection of early renal flares. This paper reviews promising biomarkers that have recently been evaluated in longitudinal studies of lupus nephritis.
Molecular Structure of Sarcomere-to-Membrane Attachment at M-Lines inC. elegansMuscle
Authors: Qadota Hiroshi , Benian Guy M.
Published: April 2010

C. elegansis an excellent model for studying nonmuscle cell focal adhesions and the analogous muscle cell attachment structures. In the major striated muscle of this nematode, all of the M-lines and the Z-disk analogs (dense bodies) are attached to the muscle cell membrane and underlying extracellular matrix. Accumulating at these sites are many proteins associated with integrin. We have found that nematode M-lines contain a set of protein complexes that link integrin-associated proteins to myosin thick filaments. We have also obtained evidence for intriguing additional functions for these muscle cell attachment proteins.
Update of the National Surgical Adjuvant Breast and Bowel Project Study of Tamoxifen and Raloxifene (STAR) P-2 Trial: Preventing Breast Cancer
Authors: Vogel Victor G. , Costantino Joseph P. , Wickerham D. Lawrence , Cronin Walter M. , Cecchini Reena S. , Atkins James N. , Bevers Therese B. , Fehrenbacher Louis , Pajon Eduardo R. , Wade James L. , Robidoux André , Margolese Richard G. , James Joan , Runowicz Carolyn D. , Ganz Patricia A. , Reis Steven E. , McCaskill-Stevens Worta , Ford Leslie G. , Jordan V. Craig , Wolmark Norman ,   for the National Surgical Adjuvant Breast and Bowel Project
Published: April 2010

The selective estrogen-receptor modulator (SERM) tamoxifen became the first U.S. Food and Drug Administration (FDA)–approved agent for reducing breast cancer risk but did not gain wide acceptance for prevention, largely because it increased endometrial cancer and thromboembolic events. The FDA approved the SERM raloxifene for breast cancer risk reduction following its demonstrated effectiveness in preventing invasive breast cancer in the Study of Tamoxifen and Raloxifene (STAR). Raloxifene caused less toxicity (versus tamoxifen), including reduced thromboembolic events and endometrial cancer. In this report, we present an updated analysis with an 81-month median follow-up. STAR women were randomly assigned to receive either tamoxifen (20 mg/d) or raloxifene (60 mg/d) for 5 years. The risk ratio (RR; raloxifene:tamoxifen) for invasive breast cancer was 1.24 (95% confidence interval [CI], 1.05–1.47) and for noninvasive disease, 1.22 (95% CI, 0.95–1.59). Compared with initial results, the RRs widened for invasive and narrowed for noninvasive breast cancer. Toxicity RRs (raloxifene:tamoxifen) were 0.55 (95% CI, 0.36–0.83; P = 0.003) for endometrial cancer (this difference was not significant in the initial results), 0.19 (95% CI, 0.12–0.29) for uterine hyperplasia, and 0.75 (95% CI, 0.60–0.93) for thromboembolic events. There were no significant mortality differences. Long-term raloxifene retained 76% of the effectiveness of tamoxifen in preventing invasive disease and grew closer over time to tamoxifen in preventing noninvasive disease, with far less toxicity (e.g., highly significantly less endometrial cancer). These results have important public health implications and clarify that both raloxifene and tamoxifen are good preventive choices for postmenopausal women with elevated risk for breast cancer. Cancer Prev Res; 3(6); 696–706. ©2010 AACR.
Interleukin-15 and Interleukin-12 Are Elevated in Serum and Cerebrospinal Fluid of Patients with Amyotrophic Lateral Sclerosis
Authors: Rentzos Michael , Rombos Antonis , Nikolaou Chryssoula , Zoga Margarita , Zouvelou Vassiliki , Dimitrakopoulos Antonis , Alexakis Theodoros , Tsoutsou Anthousa , Samakovli Anastasia , Michalopoulou Maria , Evdokimidis Ioannis
Published: April 2010

Background: There is evidence that immunological factors may be involved in pathogenic mechanisms of amyotrophic lateral sclerosis (ALS). Interleukin (IL)-15 and IL-12 are proinflammatory cytokines produced by activated blood and glial cells. They promote T cell differentiation and proliferation. Patients and Methods: We measured by ELISA serum and cerebrospinal fluid (CSF) levels of IL-15 and IL-12 in 21 patients with ALS and 19 patients with other noninflammatory neurological disorders (NIND) studied as a control group. IL-15 and IL-12 serum and CSF levels were also correlated with duration of the disease, the disability level determined using the revised ALS Functional Rating Scale and the clinical subtype of the disease onset in patients with ALS. Results: IL-15 and IL-12 serum levels were higher in patients with ALS as compared with patients with NIND (p = 0.014 and p = 0.011, respectively). IL-15 and IL-12 CSF levels were also increased in patients with ALS (p = 0.011 and p = 0.005, respectively). IL-15 and IL-12 levels were not correlated with disease duration, disability scale or clinical subtype of the disease onset in ALS patients. Conclusions: Our findings suggest that these molecules may be involved in the pathogenic mechanisms acting as potential markers of immune activation in ALS.
Immunization with pVAXhsp65 Decreases Inflammation and Modulates Immune Response in Experimental Encephalomyelitis
Authors: Gonçalves Zorzella-Pezavento Sofia Fernanda , Chiuso-Minicucci Fernanda , Donegá França Thaís Graziela , Lumi Watanabe Ishikawa Larissa , Rodrigues Martins Douglas , Lopes Silva Célio , Sartori Alexandrina
Published: April 2010

Background: A DNA vaccine (pVAXhsp65) containing the gene of a heat-shock protein (hsp65) from Mycobacterium leprae showed high immunogenicity and protective efficacy against tuberculosis in BALB/c mice. A possible deleterious effect related to autoimmunity needed to be tested because hsp65 is highly homologous to the correspondent mammalian protein. In this investigation we tested the effect of a previous immunization with DNAhsp65 in the development of experimental autoimmune encephalomyelitis (EAE), a rat model of multiple sclerosis. Methods: Female Lewis rats were immunized with 3 pVAXhsp65 doses by intramuscular route. Fifteen days after the last DNA dose the animals were evaluated for specific immunity or submitted to induction of EAE. Animals were evaluated daily for weight loss and clinical score, and euthanized during the recovery phase to assess the immune response and inflammatory infiltration at the central nervous system. Results: Immunization with pVAXhsp65 induced a specific immune response characterized by production of IgG2b anti-hsp65 antibodies and IFN-γ secretion. Previous immunization with pVAXhsp65 did not change EAE clinical manifestations (weight and clinical score). However, the vaccine clearly decreased brain and lumbar spinal cord inflammation. In addition, it downmodulated IFN-γ and IL-10 production by peripheral lymphoid organs. Conclusion: Our data demonstrated that this vaccine does not trigger a deleterious effect on EAE development and also points to a potential protective effect.
The Effect of Restraint Stress on Glucocorticoid Receptors in Mouse Spleen Lymphocytes: Involvement of the Sympathetic Nervous System
Authors: Warner Arielle , Ovadia Haim , Tarcic Nora , Weidenfeld Joseph
Published: April 2010

Objective: Reciprocal pathways of interaction between the nervous and immune systems during stress may be regulated by stress-induced circulating glucocorticoids that act via type II glucocorticoid receptors (GRs). The aim of the present study was to investigate the effect of restraint stress on GRs in lymphocytes and the role of the sympathetic system in this effect. Methods: We used male Balb/c mice which were adrenalectomized 3 days before exposure to restraint stress (4 h). Specific binding of 3H-dexamethasone (Dex) and the expression of GR protein were measured in the cytosol of spleen cells. Results: Restraint stress caused a significant increase in the maximal binding of 3H-Dex to GRs in the cytosol of spleen cells but not in the binding affinity. In correlation with this increase in binding, restraint stress caused an increase in the amount of GR protein. To establish the relation of the nervous system in this stress response, we blocked the autonomic innervations to the spleen with the ganglionic blocker chlorisondamine. This blocker abrogated the stress-induced increase in the binding of 3H-Dex to GRs and in the GR protein levels. Abrogation of the stress response was also achieved by blocking β-adrenergic receptors. Conclusion: These results suggest that stress-induced increase in the level of GRs is mediated by the sympathetic nervous system via β-adrenergic receptors. It is possible that stress modulation of lymphocyte GR levels may be implicated in the bidirectional communication between the nervous and the immune systems.
Cytokines Induce NF-ĸB, Nurr1 and Corticotropin-Releasing Factor Gene Transcription in Hypothalamic 4B Cells
Authors: Kageyama Kazunori , Kagaya Saeko , Takayasu Shinobu , Hanada Komaki , Iwasaki Yasumasa , Suda Toshihiro
Published: April 2010

Objective: In the hypothalamus, corticotropin-releasing factor (CRF) plays a central role in regulating stress responses. Cytokines are important mediators of the interaction between the neuroendocrine and immune systems, and are implicated in the regulation of CRF expression. Following inflammatory challenges, interleukin (IL)-1 or IL-6 stimulates the hypothalamic-pituitary-adrenal axis. CRF promoter contains multiple nuclear factor (NF)-ĸB and Nurr1 binding sites. In the present study, we determined the ability of the signaling pathways to activate the CRF gene in the hypothalamic paraventricular nucleus following inflammatory challenge. Methods: Cytokine-induced changes in CRF gene expression were examined in the hypothalamic system. Luciferase assay and Western blotting were performed to assess transcriptional activity and the nuclear translocation of transcriptional factors. Results: IL-1β, IL-6 and tumor necrosis factor (TNF)-α stimulated the nuclear expression levels of NF-ĸB, NF-ĸB-dependent Nurr1 and c-Fos proteins. Direct stimulatory effects of TNF-α and IL-1β, in addition to IL-6, were found on the transcriptional activity of the CRF gene in hypothalamic 4B cells. Conclusion: These cytokines are involved in the regulation of CRF gene activity in hypothalamic cells.
Alcohol Intake Effects on the Dorsal Vagal Complex of the Rat: A Cellular Morphometric Study
Authors: Bañuelos-Pineda J. , Carmona-Calero E. , Peris-Sanchis R. , Perez-Gonzalez H. , Marrero-Gordillo N. , Perez-Delgado M.M. , Castañeyra-Perdomo A.
Published: April 2010

We have analyzed the morphometric effects on the dorsal vagal complex (DVC) of the rat of alcohol exposure and/or hypoproteic diet intake during 8 weeks. In the area postrema (AP), alcohol treatment (combined with normal isoproteic or hypoproteic diet) caused a significant decrease in karyometric parameters. In the dorsal motor nucleus of the vagus (DMV) and nucleus tractus solitarii (NTS), the alcohol isoproteic intake (Al) produced an increase in neuron size (expressed by an increase in the neuronal nuclear area and the cell/neuropil coefficient). The hypoproteic diets produced a reduction in the global volume of each structure of the DVC which was accompanied by a decrease in global brain volume. These results indicate that after 8 weeks of treatment, alcohol is the main cause of the morphometric alteration found in the DVC, while variations in the amount of protein intake appear to produce global effects on the whole brain.
Genomic Variation Associated With Mortality Among Adults of European and African Ancestry With Heart Failure
Authors: Morrison Alanna C. , Felix Janine F. , Cupples L. Adrienne , Glazer Nicole L. , Loehr Laura R. , Dehghan Abbas , Demissie Serkalem , Bis Joshua C. , Rosamond Wayne D. , Aulchenko Yurii S. , Wang Ying A. , Haritunians Talin , Folsom Aaron R. , Rivadeneira Fernando , Benjamin Emelia J. , Lumley Thomas , Couper David , Stricker Bruno H. , O'Donnell Christopher J. , Rice Kenneth M. , Chang Patricia P. , Hofman Albert , Levy Daniel , Rotter Jerome I. , Fox Ervin R. , Uitterlinden Andre G. , Wang Thomas J. , Psaty Bruce M. , Willerson James T. , van Duijn Cornelia M. , Boerwinkle Eric , Witteman Jacqueline C.M. , Vasan Ramachandran S. , Smith Nicholas L.
Published: April 2010

Background—

Prognosis and survival are significant concerns for individuals with heart failure (HF). To better understand the pathophysiology of HF prognosis, the association between 2 366 858 single-nucleotide polymorphisms (SNPs) and all-cause mortality was evaluated among individuals with incident HF from 4 community-based prospective cohorts: the Atherosclerosis Risk in Communities Study, the Cardiovascular Health Study, the Framingham Heart Study, and the Rotterdam Study.

Methods and Results—

Participants were 2526 individuals of European ancestry and 466 individuals of African ancestry who experienced an incident HF event during follow-up in the respective cohorts. Within each study, the association between genetic variants and time to mortality among individuals with HF was assessed by Cox proportional hazards models that included adjustment for sex and age at the time of the HF event. Prospective fixed-effect meta-analyses were conducted for the 4 study populations of European ancestry (N=1645 deaths) and for the 2 populations of African ancestry (N=281 deaths). Genome-wide significance was set at
P
=5.0×10
−7
. Meta-analytic findings among individuals of European ancestry revealed 1 genome-wide significant locus on chromosome 3p22 in an intron of CKLF-like MARVEL transmembrane domain containing 7 (
CMTM7
,
P
=3.2×10
−7
). Eight additional loci in individuals of European ancestry and 4 loci in individuals of African ancestry were identified by high-signal SNPs (
P
<1.0×10
−5
) but did not meet genome-wide significance.

Conclusions—

This study identified a novel locus associated with all-cause mortality among individuals of European ancestry with HF. This finding warrants additional investigation, including replication, in other studies of HF.
Subtropical Cloud-Regime Transitions: Boundary Layer Depth and Cloud-Top Height Evolution in Models and Observations
Authors: Karlsson Johannes , Svensson Gunilla , Cardoso Sambingo , Teixeira Joao , Paradise Susan
Published: April 2010

In this study, the mean and variability of boundary layer height (BLH) are analyzed along a transect in the eastern Pacific Ocean for the summer of 2003 using BLH estimates based on the height of the main relative humidity (RH) inversion and the height of low cloud tops (CTH). The observations and the regional and global model data have been prepared in the context of the Global Energy and Water Cycle Experiment (GEWEX) Cloud System Study (GCSS) Pacific Cross-Section Intercomparison (GPCI). The GPCI transect covers the transition from a stratocumulus-topped marine boundary layer (MBL) off the coast of California to a trade cumulus–topped, less-well-defined, MBL, and finally to the deep-convection regions in the intertropical convergence zone (ITCZ). The Atmospheric Infrared Sounder (AIRS) and the Multiangle Imaging Spectroradiometer (MISR) have been used to derive observational records of the two BLH estimates. Analyses from the ECMWF are also used in the study. Both BLH estimates in the models, the ECMWF analysis, and the observations agree on a southward vertical growth of the MBL along the GPCI transect in the stratocumulus region. Away from the region typically associated with extensive cloud cover, the two BLH estimates depict different evolutions of the MBL. In most models, the height of the main RH inversion decreases southward from ∼18°N, reaching a minimum at the ITCZ, whereas the height of the RH inversion in the ECMWF analysis and a few of the models is fairly constant all the way to the ITCZ. As a result of insufficient vertical resolution of the gridded dataset, the AIRS data only manage to reproduce the initial growth of the BLH. The median-model CTH increases from the stratocumulus-topped MBL to the ITCZ. In contrast, the observed MISR CTHs decrease southward from 20°N to the ITCZ, possibly indicative of the fact that in these regions MISR manages to capture a variety of cloud tops with a mean that is below the subsidence inversion while the models and the ECMWF analysis mainly simulate CTHs corresponding to the height of the subsidence inversion. In most models and in the ECMWF analysis, the height of the main RH inversion and the CTH tend to coincide in the northern part of the GPCI transect. In the regions associated with trade cumuli and deep convection there is a more ambiguous relation between the two BLH estimates. In this region, most of the models place the CTH above the main RH inversion. The ECMWF analysis shows a good agreement between the BLH estimates throughout the transect.
A Conceptual View on Inertial Oscillations and Nocturnal Low-Level Jets
Authors: Van de Wiel B. J. H. , Moene A. F. , Steeneveld G. J. , Baas P. , Bosveld F. C. , Holtslag A. A. M.
Published: April 2010

In the present work Blackadar’s concept of nocturnal inertial oscillations is extended. Blackadar’s concept describes frictionless inertial oscillations above the nocturnal inversion layer. The current work includes frictional effects within the nocturnal boundary layer. It is shown that the nocturnal wind speed profile describes an oscillation around the nocturnal equilibrium wind vector, rather than around the geostrophic wind vector (as in the Blackadar case). By using this perspective, continuous time-dependent wind profiles are predicted. As such, information on both the height and the magnitude of the nocturnal low-level jet is available as a function of time. Preliminary analysis shows that the proposed extension performs well in comparison with observations when a simple Ekman model is used to represent the equilibrium state in combination with a realistic initial velocity profile.

In addition to jet dynamics, backward inertial oscillations are predicted at lower levels close to the surface, which also appear to be present in observations. The backward oscillation forms an important mechanism behind weakening low-level winds during the afternoon transition. Both observational and theoretical modeling studies are needed to explore this phenomenon further.
Transient Dynamics of Nonsymmetric Perturbations versus Symmetric Instability in Baroclinic Zonal Shear Flows
Authors: Mamatsashvili G. R. , Avsarkisov V. S. , Chagelishvili G. D. , Chanishvili R. G. , Kalashnik M. V.
Published: April 2010

The linear dynamics of symmetric and nonsymmetric perturbations in unbounded zonal inviscid flows with a constant vertical shear of velocity, when a fluid is incompressible and density is stably stratified along the vertical and meridional directions, is investigated. A small–Richardson number Ri ≲ 1 and large–Rossby number Ro ≳ 1 regime is considered, which satisfies the condition for symmetric instability. Specific features of this dynamics are closely related to the nonnormality of linear operators in shear flows and are well interpreted in the framework of the nonmodal approach by tracing the linear dynamics of spatial Fourier harmonics (Kelvin modes) of perturbations in time. The roles of stable stratification, the Coriolis parameter, and vertical shear in the dynamics of perturbations are analyzed. Classification of perturbations into two types or modes—vortex (i.e., quasigeostrophic balanced motions) and inertia–gravity wave—is made according to the value of potential vorticity. The emerging picture of the (linear) transient dynamics for these two modes at Ri ≲ 1 and Ro ≳ 1 indicates that vortex mode perturbations are able to gain basic flow energy and undergo exponential transient amplification and in this process generate inertia–gravity waves. Transient growth of the vortex mode and, consequently, the effectiveness of the wave generation both increase with decreasing Ri and increasing Ro. This linear coupling of perturbation modes is, in general, specific to shear flows but is not fully appreciated yet.

A parallel analysis of the transient dynamics of nonsymmetric perturbations versus symmetric instability is also presented. It is shown that the nonnormality-induced transient growth of nonsymmetric perturbations can prevail over the symmetric instability for a wide range of Ri and Ro. The current analysis suggests that the dynamical activity of fronts and jet streaks at Ri ≲ 1 and Ro ≳ 1 should be determined by nonsymmetric perturbations rather than by symmetric ones, as was accepted in earlier papers. It is noteworthy that the transient growth of perturbations is asymmetric in the wavenumber space—the constant phase plane of maximally amplified perturbations is inclined in a direction northeast to the zonal one and the inclination angle is different for different Ri and Ro.
A Piecewise Potential Vorticity Inversion Algorithm and Its Application to Hurricane Inner-Core Anomalies
Authors: Kieu Chanh Q. , Zhang Da-Lin
Published: April 2010

In this study, a piecewise potential vorticity (PV) inversion algorithm for an arbitrary number of PV pieces is developed by extending Wang and Zhang’s PV inversion scheme, and then the nonlinear responses to various types and magnitudes of axisymmetric PV anomalies (PVAs) in hurricane vortices are investigated. Results show that the upper- and lower-level PVAs in the eye help enhance cyclonic flows in the eyewall, but with weak vertical interactions between them. The balanced flows corresponding to the PVAs in the eyewall appear to account for a substantial portion of the warm core and the minimum pressure in the eye. However, the lower-level PVA in the eye inversion layer is more effective in contributing to the hurricane intensity than that at the upper levels. Results also show that the radius of the balanced response of PVAs is more sensitive to the mean vortex intensity than the vertical penetration; the weaker the mean vortex intensity, the larger the radius of the influence will be. Similar behaviors are also observed for the quasi-balanced secondary circulations. That is, given a diabatic heating profile in the eyewall, the weaker the background vortex or the PVAs, the stronger the secondary circulations will be.

It is found that the development of an outer eyewall (or spiral rainbands) could be inimical to the inner eyewall in several ways, such as by 1) adding an anticyclonic flow inside to offset the cyclonic rotation of the inner eyewall, 2) enhancing a ring of a lower pressure zone underneath to broaden the inner-core lower pressure region, 3) inducing an inward (outward) radial flow outside (inside) in the PBL (upper level) to block the energy supply to (outflow of) the inner eyewall, and 4) generating subsidence between the two eyewalls to suppress the development of deep convection in the inner eyewall.
The Polar Summer Tropopause Inversion Layer
Authors: Randel William J. , Wu Fei
Published: April 2010

Temperature profiles in polar latitudes during summer reveal a strong and persistent inversion layer associated with the polar summer tropopause. This inversion layer is characterized by a temperature increase of ∼8 K in the first 2–3 km above the tropopause and is observed throughout summer polar latitudes in both hemispheres. Radiosonde and GPS radio occultation temperature observations are used to document characteristics of the inversion layer, including its seasonal variability and modulation by synoptic meteorological systems (cyclones and anticyclones). Previous analyses have suggested a radiative mechanism for formation and maintenance of tropopause inversions, related to water vapor and ozone near the tropopause. Fixed dynamical heating (FDH) calculations are used herein to investigate this behavior in polar regions, based on observed seasonally varying profiles of water vapor (from satellite measurements) and ozone (from ozonesondes). Water vapor exhibits a strong seasonal cycle throughout the troposphere and lowest stratosphere, with a pronounced summer maximum, which is primarily a result of the seasonally varying tropospheric temperatures. The FDH calculations suggest that enhanced summer water vapor leads to strong radiative cooling in a narrow layer near the tropopause, so that the radiative influence of water vapor provides a primary mechanism for the summer inversion layer.
Automated Retrievals of Precipitation Parameters Using Non-Rayleigh Scattering at 95 GHz
Authors: Giangrande Scott E. , Luke Edward P. , Kollias Pavlos
Published: April 2010

Automated retrievals of vertical air motion and the drop size distribution (DSD) slope parameter from the surface to the base of the melting layer are presented using a technique for W-band (95 GHz) profiling radars. The technique capitalizes on non-Rayleigh resonance signatures found in the observed Doppler spectra to estimate the mean vertical air motion. The slope parameter of the DSD for an assumed exponential form is retrieved through an inversion of the Doppler spectra. Extended testing is performed in central Oklahoma for a monthlong period of observation that includes several midlatitude convective line trailing stratiform events featuring low to moderate rainfall rates (<1 to 30 mm h−1). Low-level DSD slope parameter retrievals are shown in agreement (bias of −1.48 cm−1 and rms error of 4.38 cm−1) with collocated surface disdrometer DSD observations. Velocity retrievals indicate a net downward motion in stratiform rain of 0.05 m s−1 with a standard deviation of 0.24–0.3 m s−1. Time–height examples drawn from the available dataset illustrate finescale structures, as well as evidence of drop sorting due to differential terminal velocity and wind shear.
Radiance Comparisons of MODIS and AIRS Using Spatial Response Information
Authors: Schreier M. M. , Kahn B. H. , Eldering A. , Elliott D. A. , Fishbein E. , Irion F. W. , Pagano T. S.
Published: April 2010

The combination of multiple satellite instruments on a pixel-by-pixel basis is a difficult task, even for instruments collocated in space and time, such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and Atmospheric Infrared Sounder (AIRS) on board the Earth Observing System (EOS) Aqua. Toward the goal of an improved collocation methodology, the channel- and scan angle–dependent spatial response functions of AIRS that were obtained from prelaunch measurements and calculated impacts from scan geometry are shown within the context of radiance comparisons. The AIRS spatial response functions are used to improve the averaging of MODIS radiances to the AIRS footprint, and the variability of brightness temperature differences (ΔTb) between MODIS and AIRS are quantified on a channel-by-channel basis. To test possible connections between ΔTb and the derived level 2 (L2) datasets, cloud characteristics derived from MODIS are used to highlight correlations between these quantities and ΔTb, especially for ice clouds in H2O and CO2 bands. Furthermore, correlations are quantified for temperature lapse rate (dT/dp) and the magnitude of water vapor mixing ratio (q) obtained from AIRS L2 retrievals. Larger values of dT/dp and q correlate well to larger values of ΔTb in the H2O and CO2 bands. These correlations were largely eliminated or reduced after the MODIS spectral response functions were shifted by recommended values. While this investigation shows that the AIRS spatial response functions are necessary to reduce the variability and skewness of ΔTb within heterogeneous scenes, improved knowledge about MODIS spectral response functions is necessary to reduce biases in ΔTb.
Relationships between Large-Scale Regime Transitions and Major Cool-Season Precipitation Events in the Northeastern United States
Authors: Archambault Heather M. , Keyser Daniel , Bosart Lance F.
Published: April 2010

This observational study investigates statistical and synoptic–dynamic relationships between regime transitions, defined as a North Atlantic Oscillation (NAO) or Pacific–North American pattern (PNA) index change from at least a 1 standard deviation anomaly to at least a 1 standard deviation anomaly of opposite sign within 7 days, and cool-season (November–April) northeastern U.S. (NE) precipitation. A statistical analysis is performed of daily cool-season NE precipitation during all NAO and PNA transitions for 1948–2003, and a composite analysis and case study of a major cool-season NE precipitation event occurring during a positive-to-negative NAO transition are conducted. Datasets used are the 0.25° NCEP Unified Precipitation Dataset, the 2.5° NCEP–NCAR reanalysis, and the 1.125° 40-yr ECMWF Re-Analysis (ERA-40).

Results of the statistical analysis suggest that cool-season NE precipitation tends to be enhanced during positive-to-negative NAO and negative-to-positive PNA transitions, and suppressed during negative-to-positive NAO and positive-to-negative PNA transitions. Of the four types of regime transitions, only the positive-to-negative NAO transition is associated with substantially more frequent major cool-season NE precipitation events compared to climatology. Results of the composite analysis and case study indicate that a surface cyclone and cyclonic wave breaking associated with the major NE precipitation event can help produce a high-latitude blocking pattern over the North Atlantic characteristic of a negative NAO pattern via thermal advection, potential vorticity transport, and diabatic processes.
An Analysis of the Relationship between Weather and Aggressive Crime in Cleveland, Ohio
Authors: Butke Paul , Sheridan Scott C.
Published: April 2010

This study investigated the relationship between weather and aggressive crime for the period from 1999 through 2004 for the city of Cleveland, Ohio. The majority of the analysis focused on meteorological summer (June–August), because this is the time when the most oppressive conditions occur. Citywide analysis (nonspatial) was performed for many temporal variations, which accounted for season, time of day, and day of week (weekend or weekday). The linear regression model explored the relationship between apparent temperature and aggressive crime counts. Results show that summer has the highest aggressive crime counts, while winter has the lowest crime counts. Aggressive crime generally increases linearly as apparent temperature increases, with nonaggravated assaults and domestic violence assaults having the largest response as the weather becomes hotter. The midday and early night hours (i.e., 0300–1200 LT) have the greatest significant findings relating apparent temperature to aggressive crime.

Further analysis was performed at the subcity level. A threshold of mean apparent temperature of 24°C was used in order to investigate spatial patterns of aggressive crime when it is “hot” compared to when it is “cold.” Overall, the spatial patterns of crime counts are minimally influenced by hotter weather. Despite the numerous different spatial analyses that were performed, there was no significant evidence suggesting that spatial patterns of aggressive crime are greatly affected by hotter weather. Rather, it appears that warmer weather brings relatively similar percentage increases in aggressive crime activity citywide. Further exploration and analysis of the weather–crime relationship could be of significant benefit to law enforcement officials and emergency response personnel, who increasingly use geographic information system (GIS)-based tools in their work to assist in determining where and when intervention is most beneficial.