bluuebunny/crossref_metadata_2025 huggingface dataset:
Clarence Edward Dutton (1841–1912): soldier, polymath and aesthete
Authors: Orme Antony R.
Published: November 2007

Clarence Edward Dutton (1841–1912) was one of several scientists who laid the foundations for modern geology from their work in North America during the late nineteenth century. Dutton was a career soldier who fought in the American Civil War and remained with the US Army Ordnance Corps to his retirement in 1901. Despite military obligations, Dutton developed a profound interest in geology and, on secondment first to the Powell Survey and later to the fledgling US Geological Survey, made important contributions to volcanic geology, seismology and physical geology. His lifelong fascination with volcanism led to improved understanding of the volcanic geology of the American West, Hawaii, and Central America. This work linked naturally with the emerging science of seismology, as reflected in his study of the 1886 earthquake in Charleston, South Carolina, and he is often credited with introducing the ‘new seismology’ to American scientific audiences. Awareness of volcanic and seismic hazards in turn led him to caution against a proposed sea-level canal across the Nicaraguan isthmus. His contributions to physical geology are most evident in several reports on the American West, notably the
Report on the Geology of the High Plateaus of Utah
(1880), the
Tertiary History of the Grand Cañon District
(1882), and
Mount Taylor and the Zuni Plateau
(1885). These reports, presented in colourful prose, reveal both the author's scientific acumen and his aesthetic appreciation of nature.

Whereas most of Dutton's work must now be placed in its historical context, in his recognition of isostasy, a term he coined in 1882 to reflect the debate then raging concerning Earth's crustal behaviour, his ideas were remarkably prescient. Dutton's interest in isostasy derived in part from his studies of volcanic geology, seismology, and crustal behaviour, and in part from his fieldwork in the American West. Initially, however, it was Dutton's description of the great denudation of the Colorado Plateau, rather than any isostatic implications, that influenced geomorphology during the earlier twentienth century, dominated as it was by Davis' cycle of erosion. The subsequent demise of Davisian geomorphology, and the ensuing quest for alternative models, led to a reawakening of interest in isostasy as a concept basic to the explanation of Earth's surface features. Somewhat belatedly, Dutton's concept of isostasy is once again at the centre of debate regarding denudation and crustal behaviour. Wherever these debates focus, they confront a problem fundamental to geology, geodesy and geophysics, namely the extent to which the Earth's present relief reflects a quest for balance between the subsurface forces generating uplift, subsidence and mass transfers at depth, and the climate-induced processes responsible for denudation and mass transfers of rock waste across the surface. Dutton's probing of isostasy predated modern debate in geomorphology by more than a century.
The geological observations of Robert Hooke (1635–1703) on the Isle of Wight
Authors: Drake E. T.
Published: November 2007

As Curator of Experiments at the Royal Society of London, Robert Hooke (1635–1703) was too busy to have been considered a ‘geological traveller’. Yet he made fundamental geological observations whenever he did travel. He set these observations in a series of lectures he gave at the Royal Society over a period of some thirty years. These lectures were published posthumously by Richard Waller in 1705 as
Lectures and Discourses of Earthquakes and Subterraneous Eruptions
. Although his contemporary Nicolaus Stenonis, or Steno, has been recognized as the founder of geology, Hooke's more profound and compelling observations and explanations have been largely ignored by the geological community. There is also evidence that Hutton benefited considerably from Hooke's ideas.

Hooke's writings show that he derived many of his geological hypotheses from his intimate knowledge of the processes taking place on the shores of his birthplace, the Isle of Wight. This paper presents what Hooke observed and described and is illustrated with photos taken by the author on the shores of the Isle of Wight.
Robert Jameson on the Isle of Arran, 1797–1799: in search of Hutton's ‘Theory of the Earth’
Authors: Nicholas C. J. , Pearson P. N.
Published: November 2007

The Isle of Arran lies off the Ayrshire coast in the Firth of Clyde, SW Scotland. James Hutton visited Arran in August 1787 with his companion, John Clerk, and together they made the first geological investigation of the island. Hutton returned to Edinburgh satisfied that he had at last found the critical field evidence he had been searching for in support of his ‘Theory of the Earth’. In June 1797, ten years after Hutton's first survey of Arran, Robert Jameson arrived on the island to investigate its geology and mineralogy. Jameson was still only 22 but had already become one of Hutton's most ardent critics. The previous year he had read two papers to the Royal Medical Society of Edinburgh refuting critical elements of Hutton's ‘Theory’.

Based at Kilmichael, near Brodick, on the east coast, Jameson spent most of June, July and August systematically exploring Arran entirely on foot. On returning to Edinburgh, he combined a narrative of his observations on Arran with an earlier trip to his parents' native Shetland Islands, in what became the earliest published account of the geology of Arran;
An Outline of the Mineralogy of the Shetland Islands, and of the Island of Arran
(1798). Jameson returned to Arran for a second, shorter visit in August 1799 and subsequently published a second book,
The Mineralogy of the Scottish Isles …
(1800), which presented a revised and updated geological description of Arran.

Jameson's handwritten journals for both his 1797 and 1799 tours of Arran survive. In this paper we draw on these first-hand accounts of Jameson's field observations and discuss them alongside his two subsequent books describing Arran's geology. The journals clearly show that Jameson was an acute observer in the field and consistently made his interpretations in accordance with Wernerian principles. Although he had read the published Volumes I and II of Hutton's ‘
Theory
’, it appears that he had not seen the unpublished Volume III manuscript prior to either tour. Nevertheless, Jameson's exploration of the island closely follows that of Hutton's and they visited many of the same field localities. Here, we use Jameson's Arran journals to retrace his field investigations and discuss them in the light of Hutton's previous work on the island and in relation to Jameson's own Wernerian views. The difference of approach and interpretation between the two in the field on Arran mirrors the wider conflict between Plutonists and Neptunists at this time.
J. D. Forbes and Naples
Authors: Dean Dennis R.
Published: November 2007

James David Forbes (1809–1868) became a geological traveller in 1826 when, at the age of 17, he visited Naples with his family. Not content to be an ordinary, superficial tourist, he undertook sophisticated geological investigations of Mount Vesuvius and other well-known volcanic phenomena. On his return to Scotland, following a trip of some fifteen months abroad, Forbes wrote two anonymous papers based on his Italian experiences. When David Brewster, editor of the
Edinburgh Journal of Sciences
, accepted both, Forbes continued his submissions with an eight-part series entitled
Physical Notices of the Bay of Naples
, all of which appeared. These essays, summarized here, were—for such a young author—remarkably accomplished. Esteemed as genuine contributions to geological literature, they were cited approvingly over a period of twenty-five years by such prominent older geologists as Charles Lyell, K. E. A. von Hoff, Ami Boué, and Sir Henry De la Beche.
The geological travels of Charles Lyell, Charlotte Murchison and Roderick Impey Murchison in France and northern Italy (1828)
Authors: Kölbl-Ebert M.
Published: November 2007

In 1828, Charles Lyell (1797–1875), Charlotte Murchison (1788–1869) and her husband Roderick Impey Murchison (1792–1871) embarked on a long journey around Europe. The party left Paris in May 1828, travelled through the Massif Central and continued southwards. The geological programme was dedicated to stratigraphical and geomorphological observations, but sightseeing was not neglected. Published papers by Lyell and Roderick Murchison report their scientific results, but it is the unpublished journals, notebooks and letters, which illuminated their research programmes, task management and daily routine. There was an effective division of labour, which increased the scientific productivity of the trio. Lyell and Roderick Murchison decided about routes and research topics and travelled long distances on foot taking stratigraphical sections and keeping track of correlations of structures, whereas it was Charlotte Murchison's task to do much of the time-consuming fossil-hunting, sketching of landscapes and geological structures and—speaking French fluently—to visit local experts, whose expertise might add to the success of the journey. Also, the different initial expectations and working styles of Charles Lyell and Roderick Murchison become evident.
Ecological Momentary Assessment
Authors: Shiffman Saul , Stone Arthur A. , Hufford Michael R.
Published: November 2007

Assessment in clinical psychology typically relies on global retrospective self-reports collected at research or clinic visits, which are limited by recall bias and are not well suited to address how behavior changes over time and across contexts. Ecological momentary assessment (EMA) involves repeated sampling of subjects’ current behaviors and experiences in real time, in subjects’ natural environments. EMA aims to minimize recall bias, maximize ecological validity, and allow study of microprocesses that influence behavior in real-world contexts. EMA studies assess particular events in subjects’ lives or assess subjects at periodic intervals, often by random time sampling, using technologies ranging from written diaries and telephones to electronic diaries and physiological sensors. We discuss the rationale for EMA, EMA designs, methodological and practical issues, and comparisons of EMA and recall data. EMA holds unique promise to advance the science and practice of clinical psychology by shedding light on the dynamics of behavior in real-world settings.
CMOS Technology Development for a Totally Digital A/D Converter
Authors: Pesenti G. C. , da Silva R. C. , Boudinov H. , de Andrade A. .. , Zani A. , Mainardi J. O. , Balen T. R. , Carro L.
Published: November 2007

A fully analog-to-digital converter was fabricated with a new developed educational poly-Si gate 5μm CMOS technology of the Laboratory of Microelectronics of Instituto de Física, Universidade Federal do Rio Grande do Sul. The ISE_TCAD simulation software was used for technology adjustment and design parameters extraction. These simulations were used to obtain data like effective channel length, junction depth, and also to determine the critical steps of the technological process. The A/D converter consists on a ring oscillator, a 8-bit counter and input/output buffers. Test structures like p-type and n-type Poly-Si/SiO2/Si MOS capacitors, PMOS and NMOS transistors, inverter and output buffer were included in the chip design. The set of 8 chromium lithography masks was ordered from DuPont, USA. After processing the chip, electrical measurements of the test structures, and circuit modules were performed.
Microsensors for Multiple-Parameter Medical Measurements
Authors: Tanase D. , Goosen J. F. , Firouzian A. , French Patrick J.
Published: November 2007

Often in medical applications a single measurement does not give sufficient information to the clinicians. IC technology allows the combination of several sensors in a small volume for instantaneous multi-measurements at a single location. This paper presents two multi-parameter sensors for catheter applications, with initial experimental results, along with the packaging issue - an important aspect for biomedical sensors.
Fractal Carbon-MEMS Electrodes: Theory and Preliminary Fabrication
Authors: Park Benjamin Y. , Zaouk Rabih , Wang Chunlei , Zoval Jim , Madou Marc J. J.
Published: November 2007

Fractal electrode designs are proposed for electrochemical devices. A zeroth-order approximation fractal model is analyzed and basic insights into the scaling laws of the electrical properties and the surface-to-area ratio are derived. Fractal electrodes can minimize internal resistance while maximizing surface to volume ratios. Recent C-MEMS techniques show great promise for use in the fabrication of fractal electrodes for electrochemical applications. Preliminary results showing carbon fractal electrodes fabricated using C-MEMS techniques are presented.
Rapid Prototyping of Microfludic Systems
Authors: Kido Horacio , Zoval Jim , Madou Marc J. J.
Published: November 2007

We use a rapid, simple, and cost-efficient system for making prototypes of microfluidic systems. It combines the use of a computer numerical controlled (CNC) unit to machine polymer substrates, a cutting plotter to cut transfer adhesives, and roller lamination equipment to press the polymer substrates and adhesives together. When assembled, the processed parts contain fluidic chambers and channels. The system enables the testing of new microfluidic designs within hours after their inception.
Relative Humidity Sensor Based on Rough Polysilicon Thin Films
Authors: Zambrozi P. , Teixeira R. C. , Fruett F.
Published: November 2007

In this work we present the development, fabrication and characterization of a microelectronic humidity sensor, based on an especially designed capacitor with a hygroscopic dielectric. The hygroscopic dielectric was obtained through deposition of a roughness polycrystalline silicon (polysilicon) by LPCVD using a vertical reactor. Surface morphology of the polysilicon film was obtained by Atomic Force Microscope - AFM. A circuit converter based on the switched-capacitor technique was implemented to obtain a sensor with output voltage. The sensitivity and temperature coefficient of the sensor system were determinated experimentally. Experimental results presented an exponential dependence of the output voltage with the relative humidity.
Microsensor for the Measurement of Concentration of Liquid Solutions
Authors: Dias Mendonça Lucas G. , Ibrahim Ricardo C.
Published: November 2007

This work consists on the design, fabrication and characterization of a sensor to measure the concentration of a liquid solution with dielectric components. The sensor is of capacitive type, and it is processed using conventional microfabrication techniques. A thick interdigital structure made of nickel was electroplated on an alumina substrate. In this way, the interdigital structure forms the capacitor plates while the liquid solution is the dielectric material. The dielectric constant of the solution has an intermediate value when compared to the respective values of the pure components of the mixture. Such microsensors have been successfully applied to distinguish amongst different types of fuels commonly used in Brazilian automobiles (gasoline and ethanol).
Ammonia Sensor Based on Polyaniline and Nickel Tetrasulfonated Phtalocyanine
Authors: Heleno Cassia M. , Dirani Ely A. , de Andrade A. ..
Published: November 2007

An ammonia sensor based on Polyaniline and Nickel Tetrasulfonated Phthalocyanine is proposed. The films were fabricated via electrostatic layer-by-layer (LbL) technique where polyaniline (PAni) was assembled with tetrasulfonated nickel phtalocyanines (NiTsPc). The sensor performance on the ammonia concentration and the humidity level variation was investigated. The combined use of Pani and NiTsPc yield high sensitivity to ammonia and at the same time a low sensitivity to the humidity, a desirable feature of an ammonia sensor.
Charge-Based Continuous Explicit Equations for the Transconductance and Output Conductance of Submicron Graded-Channel SOI MOSFET'S
Authors: de Souza Michelly S. , Pavanello M. A.
Published: November 2007

This paper presents charge-based continuous explicit equations for the transconductance and output conductance of submicron Graded- Channel (GC) Silicon-On-Insulator (SOI) nMOSFET. Short-channel effects like channel length modulation, velocity saturation and drain- induced barrier lowering have been considered in the proposed expressions. Experimental results were used to test the equations by comparing not only the transconductance and the output conductance, but also the Early voltage and the open-loop voltage gain, showing a good agreement as well as smooth transitions between the different regions of operation, validating the proposed equations.
Analysis of Self-Heating Effect in Graded-Channel Silicon-on-Insulator nMOSFETs
Authors: de Souza Costa Sára E. , Pavanello M. A. , Martino João A.
Published: November 2007

This paper presents a Self-Heating (SH) analysis using conventional Silicon-On-Insulator (SOI) in comparison to Graded- Channel (GC) SOI nMOSFETs devices. The analysis is performed comparing devices with the same mask channel length and with the same effective channel length. Two-dimensional numerical simulations are performed in both studies considering the lattice heating. The models and the thermal conductive constant used in these simulations are also presented. It is demonstrated that GC devices with the same mask channel length presents similar occurrence of SH independently of the length of lightly doped region despite the larger drain current. On the other hand, for similar effective channel length, the SH is less pronounced in GC transistors as the mask channel length has to be increased in order to compensate the current difference.
Influence of Non-Vertical Sidewall on FinFET Threshold Voltage
Authors: Giacomini Renato , Martino João A.
Published: November 2007

The FinFET structure is one of the most promising architecture approaches to double-gate devices. Due to limitations of process uniformity, most fabricated FinFETs have width variation along the vertical direction, resulting in non-vertical sidewalls. The impact of nonvertical sidewalls on the threshold voltage of FinFETs is studied in this work through three-dimensional simulation. The main purpose of this study is to verify the applicability of some analytical models developed to double-gate devices with parallel gates to FinFETs with inclined sidewalls. The behavior of the threshold voltage for different doping levels and silicon film width is discussed. The use of the existing models taking an average width of the silicon film as the device width is proposed and shows to be a good approximation.
Early Voltage Behavior in Circular Gate SOI nMOSFET Using 0.13 μm Partially-Depleted SOI CMOS Technology
Authors: Gimenez Salvador P. , Ferreira Rodrigo M. , Martino João A.
Published: November 2007

This paper studies the Early voltage behavior in circular gate partiallydepleted SOI nMOSFET. The drain/source asymmetric effects are considered in terms of drain current as a function of the gate and drain voltages. Drain current comparisons with rectangular gate partiallydepleted SOI nMOSFET are performed, regarding the same effective channel length and width. Experimental results and three- dimensional simulations are used to qualify the results.
A New Electrocn Microscopy Facility in the Mountain of Minas Gerais
Authors: Bergmann José A. , de Oliveira Alfredo G. , Queiroz Dulciene M. , Machado Conceição , Ciminelli Virgínia , Soares Cristina D. , Brandão Dagoberto S. , da Silva Elizabeth R. , Kitten Gregory , Gonzalez Juan C. , Balzuweit Karla , Souza Luiz A. , de Albuquerque Lagares Monique , Mohallem Nelcy D. , Dussin Tânia M. , Rodrigues Wagner N.
Published: November 2007

The new Microscopy Center at the Federal University of Minas Gerais (UFMG) is presently in the final stages of construction. Here, we will describe the history as well as the technical aspects of this new facility, which will be fully available to the scientific, state and private enterprise communities in 2007. We envision that this multi-user facility will be a place where researchers from material sciences and biomedical areas will share space, microscopes and knowledge. Such cross- discipline interactions should promote a better interface between these diverse areas and enhance the growth of emerging areas such as nanotechnology and bioengineering.
Controlled Deposition of Carbon Nanotubes by Dielectrophoresis for Micro and Nanodevices
Authors: León Jorge , de Moraes Mario B. , Veríssimo Carla , Moshkalyov S. A.
Published: November 2007

We present results of the study of the aligned carbon nanotubes deposition using a process of dielectrophoresis with AC eletric fields. Multi-walled nanotubes were deposited from aqueous suspensions over the systems of electrodes with separation of a few microns using frequencies in the range 10 Hz - 10 MHz and peak-to-peak voltages between 2 and 10 V. Better orientation of the nanotubes with reduced content of impurities deposition is achieved for frequencies higher than 1MHz. Electrical measurements confirmed that low resistivities between the electrodes (i.e., better quality of the nanotube deposition) were obtained for higher frequencies. The method can be used for fabrication of nanotube based micro and nanodevices.
Fabrication of Metal-Semiconductor-Metal Photodetectors Using Low Temperature Rapid Thermal Annealing
Authors: Ohta R. L. , Viana C. E. , Morimoto N. , Borges B. V.
Published: November 2007

The electrical properties of Ti-Si-Ti Metal-Semiconductor-Metal (MSM) photodetector were studied as a function of annealing temperature using the Rapid Thermal Annealing (RTA) process. Low temperatures were used at the RTA (200-350{degree sign}C) in order to avoid the formation of silicides. We observed a decrease in the dark current on samples annealed between 200 and 300{degree sign}C. The lowest dark current obtained was in the sample annealed at 250{degree sign}C (4.8 nA), which is one order of magnitude lower than as-deposited sample (53.5 nA). The sample annealed at 350 {degree sign}C had an increase in dark current (82.9 nA). This behavior of the dark current can be explained by the increase in the barrier height at 200-300 {degree sign}C annealing temperature range (due to increase of the thickness of the amorphous interdiffused Ti-Si interfacial layer) and decrease in the barrier value at sample annealed at 350{degree sign }C (due to pre formation of C49 TiSi2).
SEM/EDS Characterization of Ni and Ni/Pt Silicide Formation
Authors: dos Santos R. E. , Doi I. , Swart J. , dos Santos Filho S. G.
Published: November 2007

Ni and Ni(Pt) silicides have been used as a crucial part of ultra-high speed CMOS technologies. Nisi has many advantages to be a suitable candidate to self-align contact for ULSI devices. The Ni(Pt) silicide present all good NiSi characteristics and also the improved thermal stability. This paper investigates the agglomeration formation on Ni and Ni(Pt) silicides thin films and its material compositions. The samples were characterized by Scanning Electron Microscopy (SEM) with an Energy Dispersive Spectroscopy (EDS). NiSi exhibited high surface precipitate formation around 600ºC, and Ni(Pt)Si low precipitate formations up to 820ºC and film degradations at annealing temperatures around 900ºC. EDS analysis revealed the composition of the agglomerations of NiSi films as consisted of Si and Ni, being the Si the major constitutive element of the agglomerates in 600{degree sign}C films and Ni of the agglomerates in 820{degree si gn}C films. The agglomerations of Ni(Pt)Si films formed at 900ºC are consisted of Si, Ni and Pt, with Si and Ni(Pt) in large quantities characterizing the agglomerations as Ni(Pt) silicide. Moreover, EDS spectra taken in the region out of agglomerations show a very high quantities of Si against a low quantities of Ni and Pt, indicating high degradation of the film with less Ni(Pt) silicide layer on Si.
Energy Transfer Between ALQ3 and Rhodamine in a Thin Solid Film
Authors: Fazenda R. D. , Fernandez Francisco J. , Salcedo Walter J.
Published: November 2007

The energy transfer between tris(8-hydroxyquinoline) aluminum (Alq3) and rhodamine (Rh590) molecules is investigated in thin solid films. The films were obtained by spin-coating of polystyrene(PS) solution doped with these molecules on a glass slide. The energy transfer was inferred through emission spectra, of each molecule film and blend films, and absorbance spectra of blend film. Changing the molecules concentration in the blend films an optimised transfer rate of 86% (Rh590 radioactive photons / Alq3 radioactive photons) was reached.
Phosphorus Double-Diffused Emitter Silicon Solar Cells: Emitter and Metal-Grid Theoretical Optimizations on the Contour Plot View
Authors: Stem N. , Cid M.
Published: November 2007

Despite many theoretical optimizations have been presented, a reoptimization aiming to completely understand Gaussian profile and Phosphorus emitters was performed, considering the currently adopted parameters and light trapping effect. This work is focused on studying doublediffused (n++n+) emitter solar cells (DD), keeping constant a low sheet resistance under the metal-contacted region, 13W/square. The metal-grid optimization was done taking into account the dependence on the metalsemiconductor contact resistance and on each studied emitter sheet resistance. The optimum emitters presented high quality: high collection efficiency and low total emitter recombination (<12 fA/cm2). Complete structures (n++n+p) were also studied. The best efficiencies, h=25.7 - 26.0% were found for emitter surface doping concentration and thickness ranges, Ns=1x1018cm-3 - 1x1019cm-3 and 0.5mm<We<10mm, respectively.
Carbon Outdiffusion from Ni(C)/Pt/Si Structures During Nickel Silicide Formation by Rapid Thermal Annealing
Authors: Reise Ronaldo W. , dos Santos Filho S. G. , Doi I. , Furlan Rogério , Landers Richard
Published: November 2007

In this work, it is investigated the carbon outdiffusion from Ni (C)/Pt/Si structures during nickel monosilicide formation at temperatures ranging from 600 to 800 ºC and its role on the thermal stability of the formed silicide. The Ni(C) films were codeposited onto Pt(1.5nm)/Si by e-beam having 60 % of Ni and 40 % of C. The results revealed partial carbon outdiffusion after Rapid Thermal Annealing (RTA) process at 600 ºC during 120s, as well as a complete carbon outdiffusion above 700 ºC. On the other hand, carbon does not react with nickel and silicon during silicidation process by RTA. It outdiffuses from the silicide films and promotes decreasing of the volumetric density of the NiSi by increasing its thickness. The nickel silicide films were characterized by Rutherford Backscattering (RBS) spectrometry, X-Ray Diffraction (XRD) analysis and Auger Electron Spectroscopy (AES). From these characterization techniques, it was obtained crystallographic phases (XRD), silicide stoichiometry (AES and RBS) and thickness (Profilometry). The nickel silicide stoichiometry resulted NiSi for an RTA processing performed at 600 ºC during 120 s for both: with and without carbon in the Ni film.
Use of Discharge at Near Atmospheric Pressure for DLC Films Etching
Authors: Marcuzzo Jossano S. , Urruchi Wilfredo I. , Massi Marcos , Grigorov Kornely , Maciel Homero S.
Published: November 2007

Diamond-Like Carbon (DLC) films are promising materials for micro and nano electronic industries, by their particular physical-chemical properties. For these applications, DLC films are usually etched by using plasma reactors that operate at low gas pressure thus requiring sophisticated vacuum and gas admission systems. In this work a much simple and inexpensive plasma etching system was used which is based on a dielectric barrier discharge (DBD), operating with oxygen at near atmospheric pressure. The DBD was integrated to a working chamber where a substrate holder was placed to intercept the plasma flow at a distance from the discharge outlet. The performance of the etch process in this system was evaluated by etching DLC films under various operating conditions: pressures in the range (55.0 75.0) kPa, time of process varying from 1min to 20min and electrode-substrate distance (5 and 10 mm). The main characterization techniques to analy ze the etched films were atomic force microscopy (AFM), Raman spectroscopy and profilometry. The results show that etching rates up to 7nm/min can be attained with power as low as 2.3W for a 2.0cm2 exposed area. Overall the etching process in this high pressure oxygen plasma medium differs substantially from the case of low pressure etching. It causes low damage to the substrate and promotes more homogeneous etching.
Effect of sex differences on human MEF2 regulation during endurance exercise
Authors: Vissing Kristian , McGee Sean L. , Roepstorff Carsten , Schjerling Peter , Hargreaves Mark , Kiens Bente
Published: November 2007

Women exhibit an enhanced capability for lipid metabolism during endurance exercise compared with men. The underlying regulatory mechanisms behind this sex-related difference are not well understood but may comprise signaling through a myocyte enhancer factor 2 (MEF2) regulatory pathway. The primary purpose of this study, therefore, was to investigate the protein signaling of MEF2 regulatory pathway components at rest and during 90 min of bicycling exercise at 60% V̇o2peak in healthy, moderately trained men ( n = 8) and women ( n = 9) to elucidate the potential role of these proteins in substrate utilization during exercise. A secondary purpose was to screen for mRNA expression of MEF2 isoforms and myogenic regulatory factor (MRF) family members of transcription factors at rest and during exercise. Muscle biopsies were obtained before and immediately after exercise. Nuclear AMP-activated protein kinase-α (αAMPK) Thr172 ( P < 0.001), histone deacetylase 5 (HDAC5) Ser498 ( P < 0.001), and MEF2 Thr ( P < 0.01) phosphorylation increased with exercise. No significant sex differences were observed at rest or during exercise. At rest, no significant sex differences were observed in mRNA expression of the measured transcription factors. mRNA for transcription factors MyoD, myogenin, MRF4, MEF2A, MEF2C, MEF2D, and peroxisome proliferator-activated receptor-γ coactivator 1α (PGC1α) were significantly upregulated by exercise. Of these, MEF2A mRNA increased 25% specifically in women ( P < 0.05), whereas MEF2D mRNA tended to increase in men ( P = 0.11). Although minor sex differences in mRNA expression were observed, the main finding of the present study was the implication of a joint signaling action of AMPK, HDAC5, and PGC1α on MEF2 in the immediate regulatory response to endurance exercise. This signaling response was independent of sex.
The effect of exercise and insulin on AS160 phosphorylation and 14-3-3 binding capacity in human skeletal muscle
Authors: Howlett Kirsten F. , Mathews Alicia , Garnham Andrew , Sakamoto Kei
Published: November 2007

AS160 is an Akt substrate of 160 kDa implicated in the regulation of both insulin- and contraction-mediated GLUT4 translocation and glucose uptake. The effects of aerobic exercise and subsequent insulin stimulation on AS160 phosphorylation and the binding capacity of 14-3-3, a novel protein involved in the dissociation of AS160 from GLUT4 vesicles, in human skeletal muscle are unknown. Hyperinsulinemic-euglycemic clamps were performed on seven men at rest and immediately and 3 h after a single bout of cycling exercise. Skeletal muscle biopsies were taken before and after the clamps. The insulin sensitivity index calculated during the final 30 min of the clamp was 8.0 ± 0.8, 9.1 ± 0.5, and 9.2 ± 0.8 for the rest, postexercise, and 3-h postexercise trials, respectively. AS160 phosphorylation increased immediately after exercise and remained elevated 3 h after exercise. In contrast, the 14-3-3 binding capacity of AS160 and phosphorylation of Akt and AMP-activated protein kinase were only increased immediately after exercise. Insulin increased AS160 phosphorylation and 14-3-3 binding capacity and insulin receptor substrate-1 and Akt phosphorylation, but the response to insulin was not enhanced by prior exercise. In conclusion, the 14-3-3 binding capacity of AS160 is increased immediately after acute exercise in human skeletal muscle, but this is not maintained 3 h after exercise completion despite sustained AS160 phosphorylation. Insulin increases AS160 phosphorylation and 14-3-3 binding capacity, but prior exercise does not appear to enhance the response to insulin.
Zebrafish ae2.2 encodes a second slc4a2 anion exchanger
Authors: Shmukler Boris E. , Clark Jeffrey S. , Hsu Ann , Vandorpe David H. , Stewart Andrew K. , Kurschat Christine E. , Choe Seong-Kyu , Zhou Yi , Amigo Julio , Paw Barry H. , Alper Seth L.
Published: November 2007

The genome of zebrafish ( Danio rerio) encodes two unlinked genes equally closely related to the SLC4A2/AE2 anion exchanger genes of mammals. One of these is the recently reported zebrafish ae2 gene (Shmukler BE, Kurschat CE, Ackermann GE, Jiang L, Zhou Y, Barut B, Stuart-Tilley AK, Zhao J, Zon LI, Drummond IA, Vandorpe DH, Paw BH, Alper SL. Am J Physiol Renal Physiol Renal Physiol 289: F835–F849, 2005), now called ae2.1. We now report the structural and functional characterization of Ae2.2, the product of the second zebrafish Ae2 gene, ae2.2. The ae2.2 gene of zebrafish linkage group 24 encodes a polypeptide of 1,232 aa in length, sharing 70% amino acid identity with zebrafish Ae2.1 and 67% identity with mouse AE2a. Zebrafish Ae2.2 expressed in Xenopus oocytes encodes a 135-kDa polypeptide that mediates bidirectional, DIDS-sensitive Cl−/Cl− exchange and Cl−/HCO3− exchange. Ae2.2-mediated Cl−/Cl− exchange is cation independent, voltage insensitive, and electroneutral. Acute regulation of anion exchange mediated by Ae2.2 includes activation by NH4+ and independent inhibition by acidic intracellular pH and by acidic extracellular pH. In situ hybridization reveals low-level expression of Ae2.2 mRNA in zebrafish embryo, most notably in posterior tectum, eye, pharynx, epidermal cells, and axial vascular structures, without notable expression in the Ae2.1-expressing pronephric duct. Knockdown of Ae2.2 mRNA, of Ae2.1 mRNA, or of both with nontoxic or minimally toxic levels of N-morpholino oligomers produced no grossly detectable morphological phenotype, and preserved normal structure of the head and the pronephric duct at 24 h postfertilization.
STDP Provides the Substrate for Igniting Synfire Chains by Spatiotemporal Input Patterns
Authors: Hosaka Ryosuke , Araki Osamu , Ikeguchi Tohru
Published: November 2007

Spike-timing-dependent synaptic plasticity (STDP), which depends on the temporal difference between pre- and postsynaptic action potentials, is observed in the cortices and hippocampus. Although several theoretical and experimental studies have revealed its fundamental aspects, its functional role remains unclear. To examine how an input spatiotemporal spike pattern is altered by STDP, we observed the output spike patterns of a spiking neural network model with an asymmetrical STDP rule when the input spatiotemporal pattern is repeatedly applied. The spiking neural network comprises excitatory and inhibitory neurons that exhibit local interactions. Numerical experiments show that the spiking neural network generates a single global synchrony whose relative timing depends on the input spatiotemporal pattern and the neural network structure. This result implies that the spiking neural network learns the transformation from spatiotemporal to temporal information. In the literature, the origin of the synfire chain has not been sufficiently focused on. Our results indicate that spiking neural networks with STDP can ignite synfire chains in the cortices.
Minimum Acceleration Criterion with Constraints Implies Bang-Bang Control as an Underlying Principle for Optimal Trajectories of Arm Reaching Movements
Authors: Ben-Itzhak Shay , Karniel Amir
Published: November 2007

Rapid arm-reaching movements serve as an excellent test bed for any theory about trajectory formation. How are these movements planned? A minimum acceleration criterion has been examined in the past, and the solution obtained, based on the Euler-Poisson equation, failed to predict that the hand would begin and end the movement at rest (i.e., with zero acceleration). Therefore, this criterion was rejected in favor of the minimum jerk, which was proved to be successful in describing many features of human movements. This letter follows an alternative approach and solves the minimum acceleration problem with constraints using Pontryagin's minimum principle. We use the minimum principle to obtain minimum acceleration trajectories and use the jerk as a control signal. In order to find a solution that does not include nonphysiological impulse functions, constraints on the maximum and minimum jerk values are assumed. The analytical solution provides a three-phase piecewise constant jerk signal (bang-bang control) where the magnitude of the jerk and the two switching times depend on the magnitude of the maximum and minimum available jerk values. This result fits the observed trajectories of reaching movements and takes into account both the extrinsic coordinates and the muscle limitations in a single framework. The minimum acceleration with constraints principle is discussed as a unifying approach for many observations about the neural control of movements.
Minimization of Error Functionals over Perceptron Networks
Authors: Kůrková Věra
Published: November 2007

Supervised learning of perceptron networks is investigated as an optimization problem. It is shown that both the theoretical and the empirical error functionals achieve minima over sets of functions computable by networks with a given number n of perceptrons. Upper bounds on rates of convergence of these minima with n increasing are derived. The bounds depend on a certain regularity of training data expressed in terms of variational norms of functions interpolating the data (in the case of the empirical error) and the regression function (in the case of the expected error). Dependence of this type of regularity on dimensionality and on magnitudes of partial derivatives is investigated. Conditions on the data, which guarantee that a good approximation of global minima of error functionals can be achieved using networks with a limited complexity, are derived. The conditions are in terms of oscillatory behavior of the data measured by the product of a function of the number of variables d, which is decreasing exponentially fast, and the maximum of the magnitudes of the squares of the L1-norms of the iterated partial derivatives of the order d of the regression function or some function, which interpolates the sample of the data. The results are illustrated by examples of data with small and high regularity constructed using Boolean functions and the gaussian function.
Context-Sensitive Inquiry in Comparative Judicial Research
Authors: VonDoepp Peter
Published: November 2007

Research on the behavior of the Namibian judiciary highlights the importance of context-sensitivity in comparative courts research. Drawing from strategic understandings of judicial behavior, the analysis examines the extent to which political influences are affecting the behavior of judges in Namibia. The findings indicate that, for the most part, Namibia's judges have exercised high levels of independence in their decision making. Yet deference to other branches has been apparent among certain expatriate judges who have faced unique vulnerabilities in the Namibian political system. Context sensitivity proved critical to the study, as it enabled more effective operationalization of concepts and generation of variables to test existing theory. Beyond this, such awareness enhanced the ability to interpret the findings about judicial behavior in Namibia and generate new insights to inform inquiry.
Juvenile Justice
Authors: Hinton W. Jeff , Sims Patricia L. , Adams Mary Ann , West Charles
Published: November 2007

An increasing public focus on the effects of juvenile crime on society has dramatically impacted juvenile justice policy decisions in recent years. Historically, juvenile justice policy makers have attempted to address juvenile crime by promoting policies that address the rehabilitative needs of the offender. However, throughout the last 20 years of the 20th century, policy makers have advocated more punitive offense-based policies to address juvenile crime. This article examines the differences between these two approaches and the implications associated with the continued emergence of a more offense-based approach compared to the offender-based approach, which historically has been the foundation of the American juvenile justice system. The authors hope to stimulate discussion among stakeholders in the juvenile justice system to promote sound policy decisions based on scientific evidence.
Dying in a Nursing Home
Authors: Decker Frederic H.
Published: November 2007

Objective: The relationship of nursing home (NH) discharges due to death to NH bed supply and hospital bed supply was examined. Method: Data on discharges came from the 1999 National Nursing Home Survey ( N = 6,335). County-level bed supply, controls for hospice agency supply, and a nursing facility's percentage of area NH beds came from the Area Resource File. Multinomial logistic regression was used to compare deaths with live discharges. Marginal effects were calculated. Results: Discharges due to death increased with increasing NH bed supply and decreased in areas with greater hospital bed supply, areas where hospitalizations were more likely. Hospice supply and a facility's share of area NH beds also affected the probability of discharges due to death. Discussion: Supply factors appear related to discharge decisions in a manner affecting the probability of discharges due to death, although the magnitude of the relationship may be less than expected.
Long-term imatinib therapy promotes bone formation in CML patients
Authors: Fitter Stephen , Dewar Andrea L. , Kostakis Panagiota , To L. Bik , Hughes Timothy P. , Roberts Marion M. , Lynch Kevin , Vernon-Roberts Barrie , Zannettino Andrew C. W.
Published: November 2007

Imatinib inhibits tyrosine kinases important in osteoclast (c-Fms) and osteoblast (platelet-derived growth factor receptor [PDGF-R], c-Abl) function, suggesting that long-term therapy may alter bone homeostasis. To investigate this question, we measured the trabecular bone volume (TBV) in iliac crest bone biopsies taken from chronic myeloid leukemia (CML) patients at diagnosis and again after 2 to 4 years of imatinib therapy. Half the patients (8 of 17) showed a substantive increase in TBV (> 2-fold), after imatinib therapy, with the TBV in the posttreatment biopsy typically surpassing the normal upper limit for the patient's age group. Imatinib-treated patients exhibited reduced serum calcium and phosphate levels with hypophosphatemia evident in 53% (9 of 17) of patients. In vitro, imatinib suppressed osteoblast proliferation and stimulated osteogenic gene expression and mineralized-matrix production by inhibiting PDGF receptor function. In PDGF-stimulated cultures, imatinib dose-dependently inhibited activation of Akt and Crk-L. Using pharmacologic inhibitors, inhibition of PI3-kinase/Akt activation promoted mineral formation, suggesting a possible molecular mechanism for the imatinib-mediated increase in TBV in vivo. Further investigation is required to determine whether the increase in TBV associated with imatinib therapy may represent a novel therapeutic avenue for the treatment of diseases that are characterized by generalized bone loss.
Etanercept plus methylprednisolone as initial therapy for acute graft-versus-host disease
Authors: Levine John E. , Paczesny Sophie , Mineishi Shin , Braun Thomas , Choi Sung W. , Hutchinson Raymond J. , Jones Dawn , Khaled Yasser , Kitko Carrie L. , Bickley Daniel , Krijanovski Oleg , Reddy Pavan , Yanik Gregory , Ferrara James L. M.
Published: November 2007

Graft-versus-host disease (GVHD) is a principal cause of morbidity following allogeneic hematopoietic cell transplantation (HCT). Standard therapy for GVHD, high-dose steroids, results in complete responses (CRs) in 35% of patients. Because tumor necrosis factor-α (TNFα) is an important effector of experimental GVHD, we treated patients with new-onset GVHD with steroids plus the TNFα inhibitor etanercept on a previously reported pilot trial (n = 20) and a phase 2 trial (n = 41). We compared their outcomes with those of contemporaneous patients with GVHD (n = 99) whose initial therapy was steroids alone. Groups were similar with respect to age, conditioning, donor, degree of HLA match, and severity of GVHD at onset. Patients treated with etanercept were more likely to achieve CR than were patients treated with steroids alone (69% vs 33%; P < .001). This difference was observed in HCT recipients of both related donors (79% vs 39%; P = .001) and unrelated donors (53% vs 26%; P < .001). Plasma TNFR1 levels, a biomarker for GVHD activity, were elevated at GVHD onset and decreased significantly only in patients with CR. We conclude that etanercept plus steroids as initial therapy for acute GVHD results in a substantial majority of CRs. This trial was referenced at www.clinicaltrials.gov as NCT00141713.
LysoPC acyltransferase/PC transacylase activities in plant plasma membrane and plasma membrane-associated endoplasmic reticulum
Authors: Larsson Karin E , Kjellberg J Magnus , Tjellström Henrik , Sandelius Anna Stina
Published: November 2007

Background

The phospholipids of the plant plasma membrane are synthesized in the endoplasmic reticulum (ER). The majority of these lipids reach the plasma membrane independently of the secretory vesicular pathway. Phospholipid delivery to the mitochondria and chloroplasts of plant cells also bypasses the secretory pathway and here it has been proposed that lysophospholipids are transported at contact sites between specific regions of the ER and the respective organelle, followed by lysophospholipid acylation in the target organelle. To test the hypothesis that a corresponding mechanism operates to transport phospholipids to the plasma membrane outside the secretory pathway, we investigated whether lysolipid acylation occurs also in the plant plasma membrane and whether this membrane, like the chloroplasts and mitochondria, is in close contact with the ER.

Results

The plant plasma membrane readily incorporated the acyl chain of acyl-CoA into phospholipids. Oleic acid was preferred over palmitic acid as substrate and acyl incorporation occurred predominantly into phosphatidylcholine (PC). Phospholipase A2 stimulated the reaction, as did exogenous lysoPC when administered in above critical micellar concentrations. AgNO3 was inhibitory. The lysophospholipid acylation reaction was higher in a membrane fraction that could be washed off the isolated plasma membranes after repeated freezing and thawing cycles in a medium with lowered pH. This fraction exhibited several ER-like characteristics. When plasma membranes isolated from transgenic Arabidopsis expressing green fluorescent protein in the ER lumen were observed by confocal microscopy, membranes of ER origin were associated with the isolated plasma membranes.

Conclusion

We conclude that a lysoPC acylation activity is associated with plant plasma membranes and cannot exclude a PC transacylase activity. It is highly plausible that the enzyme(s) resides in a fraction of the ER, closely associated with the plasma membrane, or in both. We suggest that this fraction might be the equivalent of the mitochondria associated membrane of ER origin that delivers phospholipids to the mitochondria, and to the recently isolated ER-derived membrane fraction that is in close contact with chloroplasts. The in situ function of the lysoPC acylation/PC transacylase activity is unknown, but involvement in lipid delivery from the ER to the plasma membrane is suggested.