bluuebunny/crossref_metadata_2025 huggingface dataset:
Cover Picture: Plasma Process. Polym. 4/2005
Authors: Chen Wei , Dai Liming , Jiang Hao , Bunning Timothy J.
Published: May 2005

Cover: Carbon nanotube micropatterns are fabricated by region‐specific plasma treatments of a substrate surface (a), followed by either adsorption of funcationalized carbon nanotubes from solution (b) or the substrate‐supported nanotube growth (c). The inset of (b) gives a higher magnification image, showing the individual adsorbed carbon nanotubes. Further details can be found in the Feature Article by W. Chen, L. Dai,* H. Jiang, and T. J. Bunning on page 279.
Disordered respiratory control in children with partial cerebellar resections
Authors: Chen Maida Lynn , Witmans Manisha B. , Tablizo Mary Anne , Jubran Rima F. , Turkel Susan B. , Tavaré C. Jane , Keens Thomas G.
Published: May 2005

While the cerebellum is not traditionally thought of as having an important role in respiratory control, breathing involves cyclic motor acts that require cerebellar coordination. We postulate that children with partial cerebellar resections have disordered respiratory control due to altered synchronization of ventilatory muscles. We reviewed the records of 36 children following partial cerebellar resections due to neoplasms confined to the cerebellum. P values were elevated in 19% of patients. Six patients had apneic or bradypneic events documented within the first month after resection. Two patients required intubation with assisted ventilation, and one needed assisted ventilation for 7.3 weeks. Those with apnea had lower oxygen saturations, and a longer need for supplemental oxygen. Patients with apnea were older than those without apnea. Swallowing, which uses many of the same muscles as those needed to maintain upper airway patency, was dysfunctional in 50% of those with apneas. We conclude that children with cerebellar resections have an increased incidence of apnea, hypoventilation, and hypoxemia not otherwise explained by pulmonary disease, and some require prolonged assisted ventilation. We speculate that these abnormalities are manifestations of altered respiratory control caused by dysfunctional cerebellar coordination of ventilatory muscles. © 2005 Wiley‐Liss, Inc.
Sweat‐testing in preterm and full‐term infants less than 6 weeks of age
Authors: Eng Warren , LeGrys Vicky A. , Schechter Michael S. , Laughon Matthew M. , Barker Pierre M.
Published: May 2005

Our objective was to examine the characteristics of preterm and full‐term infants ≤6 weeks old that influence the success of obtaining sufficient sweat for diagnosis of CF, and corresponding sweat chloride concentrations. A retrospective chart review of 119 sweat tests was performed on 103 preterm and full‐term infants ≤6 weeks of age. Bivariate and multivariate regression analyses were used to determine the predictors of successful sweat testing and characteristics influencing sweat chloride concentrations. Adequate amounts of sweat (≥75 mg) were obtained for analysis in 73.8% of initial attempts in the infant group. The following characteristics were associated with increased odds of obtaining a quantity not sufficient (QNS) for sweat chloride concentration measurement: African‐American race, infant weight <2,000 g, preterm birth, and postmenstrual age (PMA) <36 weeks. With a multivariable logistic model, the only significant predictors were African‐American race (7.3, 2.4–21.7) and PMA <36 weeks (17.9, 4.2–75.9). Sweat chloride concentration in non‐CF individuals is inversely related to both gestational age and age at testing, and this effect is additive in a linear regression model. In conclusion, sweat collection can be reliably performed in infants ≥36 weeks postmenstrual age, >2,000 g, and >3 days postnatal age. Maturational factors have a mild impact on sweat chloride concentration. © 2005 Wiley‐Liss, Inc.
The POCER indicator: a decision tool for non‐agricultural pesticide use
Authors: Claeys Sara , Vagenende Bénédicte , De Smet Bart , Lelieur Liesbeth , Steurbaut Walter
Published: May 2005

Pesticides are used not only in agriculture but also by public services and households. Much information is available on the influence of agricultural applications on human health by occupational exposure and on the environment. There is still a need for adequate information on the impact of non‐agricultural applications of pesticides. The POCER indicator (Pesticide Occupational and Environmental Risk indicator) has been developed at Ghent University for agricultural situations, as a tool for applicators and decision‐makers, by calculating the impact of pesticide treatments on the applicator, the worker, the bystander, groundwater, surface water, bees, earthworms, birds, useful arthropods and persistence in soil. A few adaptations in the POCER calculation method can make the indicator also very useful for non‐agricultural conditions. The impact of plant protection products on human health and environment in public services and households can be calculated and the scores can be compared with each other, resulting in an improved pesticide programme. Decision makers might use the POCER indicator to evaluate the reduction programme of public services and communities and offer them measurements to reduce the impact of pesticides. For example, wearing protective clothing or taking into account the distance between application and surface water can greatly reduce the impact score. Copyright © 2005 Society of Chemical Industry
Novel modulation reflectance spectroscopy of semiconductor heterostructures
Authors: Ryabushkin O. A. , Lonskaya E. I. , Sotnikov A. E. , Chernikov M. A.
Published: May 2005

New methods of modulation reflectance spectroscopy have been proposed for investigation of semiconductor heterostructures. Current‐, radio‐frequency‐ and microwave‐modulated reflectance are proposed and applied for determination of band structure features and band diagram of heterostructures of high electron mobility transistors and laser diodes. New physical contributions to formation of spectra of the modulation reflectance of light with quantum energy near the fundamental absorption edge are discussed. The main contributing mechanism, free carriers' heating, is associated with alternating current, radio‐frequency and microwave electric field, or with radiation with photon energy below bandgap energy of semiconductor layers. Novel techniques of local excitation of the heterostructures by radio‐frequency field or by pump light with scanning by probe signal are also proposed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The increase in serum uric acid concentration caused by diuretics might be beneficial in heart failure
Authors: Reyes Ariel J.
Published: May 2005

Patients with mild‐moderate chronic heart failure (CHF) often have raised levels of serum uric acid (UA). This is due, amongst other factors, to reduced UA excretion by the kidneys, which is partly explained by restriction of sodium intake and treatment with diuretics. The decline in renal function that parallels worsening cardiac function also contributes to elevated serum UA in patients with advanced CHF. However, UA production also appears to be augmented in CHF. Because UA scavenges various reactive oxygen species, diuretic‐induced elevations in serum UA could be beneficial in patients with CHF. This concept is supported by the superior performance of antihypertensive therapy with diuretics in preventing heart failure. The present hypothesis may be tested by examining the effects of add‐on treatment with a thiazide‐type diuretic on morbidity and mortality, or surrogate variables, in asymptomatic patients with left ventricular dysfunction but without fluid retention.
Differential interactions of the homeodomain‐interacting protein kinase 2 (HIPK2) by phosphorylation‐dependent sumoylation
Authors: Sung Ki Sa , Go Yoon Young , Ahn Jin-Hyun , Kim Young Ho , Kim Yongsok , Choi Cheol Yong
Published: May 2005

Homeodomain‐interacting protein kinase 2 (HIPK2) interacts with and phosphorylates various transcription factors that are critical regulators of cell fate decisions and apoptosis during development. Here we show that lysine 25 of HIPK2 is the major sumoylation site, both in vitro and in vivo, and that the sumoylation of this site occurs in a phosphorylation‐dependent manner. This became clear with the finding that kinase‐dead HIPK2 (K221R) could not be efficiently sumoylated in vitro. The sumoylation of HIPK2 resulted in the disruption of its interaction with a Groucho corepressor. Consequently, sumoylation inhibited the regulatory activity of HIPK2 on the Groucho‐mediated repression of transcription, whereas not on p53‐mediated transactivation. These results suggest that phosphorylation‐dependent sumoylation enables HIPK2 to drive different target gene transcription by means of differential interactions with its binding partners.
Knock‐down of LAR protein tyrosine phosphatase induces insulin resistance
Authors: Mander Ann , Hodgkinson Conrad P. , Sale Graham J.
Published: May 2005

To test the role of the leukocyte common antigen‐related protein tyrosine phosphatase (LAR) as a regulator of insulin receptor (IR) signalling, an siRNA probe against LAR was developed. Knock‐down of LAR induced post‐receptor insulin resistance with the insulin‐induced activation of PKB/Akt and MAP kinases markedly inhibited. The phosphorylation and dephosphorylation of the IR and insulin receptor substrate (IRS) proteins were unaffected by LAR knock‐down. These results identify LAR as a crucial regulator of the sensitivity of two key insulin signalling pathways to insulin. Moreover, the siRNA probe provides a molecular tool of general applicability for further dissecting the precise targets and roles of LAR.
Role of Nrf2 signaling in regulation of antioxidants and phase 2 enzymes in cardiac fibroblasts: Protection against reactive oxygen and nitrogen species‐induced cell injury
Authors: Zhu Hong , Itoh Ken , Yamamoto Masayuki , Zweier Jay L. , Li Yunbo
Published: May 2005

Understanding the molecular pathway(s) of antioxidant gene regulation is of crucial importance for developing antioxidant‐inducing agents for the intervention of oxidative cardiac disorders. Accordingly, this study was undertaken to determine the role of Nrf2 signaling in the basal expression as well as the chemical inducibility of endogenous antioxidants and phase 2 enzymes in cardiac fibroblasts. The basal expression of a scope of key cellular antioxidants and phase 2 enzymes was significantly lower in cardiac fibroblasts derived from Nrf2−/− mice than those from wild type control. These include catalase, reduced glutathione (GSH), glutathione reductase (GR), GSH S‐transferase (GST), and NAD(P)H:quinone oxidoreductase‐1 (NQO1). Incubation of Nrf2+/+ cardiac fibroblasts with 3H‐1,2‐dithiole‐3‐thione (D3T) led to a significant induction of superoxide dismutase (SOD), catalase, GSH, GR, glutathione peroxidase (GPx), GST, and NQO1. The inducibility of SOD, catalase, GSH, GR, GST, and NQO1, but not GPx by D3T was completely abolished in Nrf2−/− cells. The Nrf2−/− cardiac fibroblasts were much more sensitive to reactive oxygen and nitrogen species‐mediated cytotoxicity. Upregulation of antioxidants and phase 2 enzymes by D3T in Nrf2+/+ cardiac fibroblasts resulted in a dramatically increased resistance to the above species‐induced cytotoxicity. In contrast, D3T‐treatment of the Nrf2−/− cells only provided a slight cytoprotection. Taken together, this study demonstrates for the first time that Nrf2 is critically involved in the regulation of the basal expression and chemical induction of a number of antioxidants and phase 2 enzymes in cardiac fibroblasts, and is an important factor in controlling cardiac cellular susceptibility to reactive oxygen and nitrogen species‐induced cytotoxicity.
Heterogeneities in EGF receptor density at the cell surface can lead to concave up scatchard plot of EGF binding
Authors: Mayawala Kapil , Vlachos Dionisios G. , Edwards Jeremy S.
Published: May 2005

The mechanism responsible for the concave up nature of the Scatchard plot of epidermal growth factor (EGF) binding on EGF receptor (EGFR) has been a controversial issue for more than a decade. Past efforts to mechanistically simulate the concave up nature of the Scatchard plot of EGF binding have shown that negative cooperativity in EGF binding on an EGFR dimer or inclusion of some external site or binding event can describe this behavior. However, herein we show that heterogeneity in the density of EGFR due to localization in certain regions of the plasma membrane, which has been experimentally reported, can also lead to concave up shape of the Scatchard plot of the EGF binding on EGFR.
Crustal xenoliths in Triassic lamprophyre dykes in western Morocco: tectonic implications for the Rheic Ocean suture
Authors: DOSTAL J. , KEPPIE J. D. , HAMILTON M. A. , AARAB E. M. , LEFORT J. P. , MURPHY J. B.
Published: May 2005

Dykes of calc-alkaline lamprophyre cutting granite of the Hercynian Jebilet Massif of the Moroccan Meseta (western Morocco) contain crustal xenoliths. The xenoliths range in composition from mafic (cognate cumulates) and upper crustal granitic rocks through gneisses to middle crustal felsic granulites. SHRIMP U–Th–Pb zircon analyses of these rocks indicate that the dykes were likely intruded during Middle Triassic times (∼235 Ma), whereas the xenoliths contain zircons with concordant Carboniferous–Early Permian, Neoproterozoic and Palaeoproterozoic ages (280–328 Ma, c. 540–615 Ma, 700 Ma and ∼2000 Ma). The 280–328 Ma ages appear to record synchronous intrusive and high-grade (up to granulite facies) Variscan metamorphic events, suggesting that high-grade metamorphism may have facilitated the S-type granitic magmatism. On the other hand, the ∼540–615 Ma, 700 Ma and 2000 Ma ages correspond with Pan-African and Eburnian orogenic events recorded in the West African Craton. In a Triassic reconstruction, Morocco is juxtaposed against Nova Scotia (Canada), and some have proposed that the basement of the easternmost terrane (Meguma terrane) is a piece of the West African craton. However, lower crustal xenoliths from Devonian dykes (∼370 Ma) cutting the Meguma terrane have yielded Late Devonian, Neo- and Mesoproterozoic ages (378 Ma, 575–629 Ma, ∼880–1050 Ma and ∼1530 Ma). The presence of ∼1 Ga ages suggests that the basement of the Meguma terrane is Avalonian rather than West African, implying that in a Pangean reconstruction, the Rheic Ocean suture between NW Africa and Maritime Canada coincides with the Atlantic Ocean.
Prosodic evidence for incipient VO order in Old English
Authors: TAYLOR ANN
Published: May 2005

In this article I investigate the prosodic structure of verb–object sequences in three Old English metrical texts: Beowulf, Ælfric's Lives of Saints, and The Metres of Boethius. I show that while OV sequences are rarely separated by a line break in any of the texts, the prosodic structure of VO sequences is different in each text, with a high rate of separation of the verb and object in Beowulf, followed by the Metres with less separation, and finally the Lives of Saints with less again. I relate these facts to the ongoing change in headedness in the VP that has been claimed to begin in the Old English period. I take a separated verb–object sequence to indicate a postposed object, and thus the fall in the frequency of separation across the texts indicates a fall in the proportion of VO sequences that are derived by postposition, with a concomitant increase in base-generated VO order.
Changing EPP parameters in the history of English: accounting for variation and change
Authors: BIBERAUER THERESA , ROBERTS IAN
Published: May 2005

This article presents a novel ‘Kaynian’ analysis of Old and Middle English (OE and ME) word-order patterns in terms of which the patterns attested at the various stages of OE and ME are analysed as the output of a single grammar which, however, permits restricted types of variation. We propose that the West Germanic-like OE word orders were derived via the application of two types of ‘large XP’ movement – VP raising to SpecvP and vP raising to SpecTP – which are in fact pied-piping operations: in both cases, a DP contained within VP and vP – the object and the subject respectively – constitutes the actual Goal of movement, with the larger structure simply being pied piped along. Orders unlike West Germanic in both OE and ME, and synchronic variation more generally, are shown to be derived from the side-by-side availability in the OE and ME grammar of pied piping and ‘stranding’, and the word-order changes that occurred in ME are analysed as the consequence of a reanalysis of the ever more liberal ‘stranding’-permitting pied-piping grammar as one which specifically targets DPs.
OV–VO in English and the role of case marking in word order
Authors: McFADDEN THOMAS
Published: May 2005

It is shown that the connection posited by Roberts (1997) between the loss of case marking and the shift from OV to VO in English is contradicted by the facts of English and the other Germanic languages. It is argued that this failure is not the result of an incorrect handling of the syntactic or morphological details, but of the way that the proposal straddles the syntax–morphology interface. Parallels are explored with research on verb raising and agreement, and it is proposed that, in order to be more than a descriptive generalization, the claim that some morphological property has a syntactic effect must be couched in terms that both the morphology and the syntax can refer to in a principled way.
Object–verb order in early sixteenth-century English prose: an exploratory study
Authors: MOERENHOUT MIKE , VAN DER WURFF WIM
Published: May 2005

Recent work on word-order change in the history of English has shown that late Middle English prose retains object–verb order as a productive option in contexts with an auxiliary and a quantified or negated object, and also in topicalization structures. In order to determine when these limited types of object–verb order became impossible, we have examined a collection of sixteenth-century prose texts. Our findings are that the patterns attested in late Middle English in fact continue until 1550, but then appear to dwindle away. We present the relevant object–verb data, discuss the reasons for the survival of the patterns found, provide an explanation for a difference at the level of detail between the fifteenth- and sixteenth-century data, and offer some suggestions about the reasons for the eventual loss of the structures in question.
Inflammation and atherosclerosis in rheumatoid arthritis
Authors: Stevens Robert J. , Douglas Karen M.J. , Saratzis Athanasios N. , Kitas George D.
Published: May 2005

Rheumatoid arthritis (RA) associates with increased cardiovascular mortality. This appears to be predominantly due to ischaemic causes, such as myocardial infarction and congestive heart failure. The higher prevalence of cardiac ischaemia in RA is thought to be due to the accelerated development of atherosclerosis. There are two main reasons for this, which might be inter-related: the systemic inflammatory load, characteristic of RA; and the accumulation in RA of classical risk factors for coronary heart disease, which is reminiscent of the metabolic syndrome. We describe and discuss in the context of RA the involvement of local and systemic inflammatory processes in the development and rupture of atherosclerotic plaques, as well as the role of individual risk factors for coronary heart disease. We also present the challenges facing the clinical and scientific communities addressing this problem, which is receiving increasing attention.
Decoupling of iron and phosphate in the global ocean
Authors: Parekh P. , Follows M. J. , Boyle E. A.
Published: May 2005

We formulate a mechanistic model of the coupled oceanic iron and phosphorus cycles. The iron parameterization includes scavenging onto sinking particles, complexation with an organic ligand, and a prescribed aeolian source. Export production is limited by the availability of light, phosphate, and iron. We implement this biogeochemical scheme in a coarse resolution ocean general circulation model using scavenging rates and conditional stability constants guided by laboratory studies and a suite of box model sensitivity studies. The model is able to reproduce the broad regional patterns of iron and phosphorus. In particular, the high macronutrient concentrations of the Southern Ocean, tropical Pacific, and subarctic Pacific emerge from the explicit iron limitation of the model. In addition, the model also qualitatively reproduces the observed interbasin gradients of deep, dissolved iron with the lowest values in the Southern Ocean. The ubiquitous presence of significant amounts of free ligand is also explicitly captured. We define a tracer, Fe* which quantifies the degree to which a water mass is iron limited, relative to phosphorus. Surface waters in high‐nutrient, low‐chlorophyll regions have negative Fe* values, indicating Fe limitation. The extent of the decoupling of iron and phosphorus is determined by the availability and binding strength of the ligand relative to the scavenging by particulate. Global iron concentrations are sensitive to changes in scavenging rate and physical forcing. Decreasing the scavenging rate 40% results in ∼0.1 nM increase in dissolved iron in deep waters. Forcing the model with weaker wind stresses leads to a decrease in surface [PO4] and [Fe] in the Southern Ocean due to a reduction in the upwelling strength.
Fire emissions from C3 and C4 vegetation and their influence on interannual variability of atmospheric CO2 and δ13CO2
Authors: Randerson J. T. , van der Werf G. R. , Collatz G. J. , Giglio L. , Still C. J. , Kasibhatla P. , Miller J. B. , White J. W. C. , DeFries R. S. , Kasischke E. S.
Published: May 2005

Measurements of atmospheric trace gases provide evidence that fire emissions increased during the 1997/1998 El Niño event and these emissions contributed substantially to global CO2, CO, CH4, and δ13CO2 anomalies. Interpretation and effective use of these atmospheric observations to assess changes in the global carbon cycle requires an understanding of the amount of biomass consumed during fires, the molar ratios of emitted trace gases, and the carbon isotope ratio of emissions. Here we used satellite data of burned area, a map of C4 canopy cover, and a global biogeochemical model to quantitatively estimate contributions of C3 and C4 vegetation to fire emissions during 1997–2001. We found that although C4 grasses contributed to 31% of global mean emissions over this period, they accounted for only 24% of the interannual emissions anomalies. Much of the drought and increase in fire emissions during the 1997/1998 El Niño occurred in tropical regions dominated by C3 vegetation. As a result, the δ13CO2 of the global fire emissions anomaly was depleted (−23.9‰), and explained approximately 27% of the observed atmospheric decrease in δ13CO2 between mid‐1997 and the end of 1998 (and 61% of the observed variance in δ13CO2 during 1997–2001). Using fire emissions that were optimized in an atmospheric CO inversion, fires explained approximately 57% of the observed atmospheric δ13CO2 decrease between mid‐1997 and the end of 1998 (and 72% of the variance in δ13CO2 during 1997–2001). The severe drought in tropical forests during the 1997/1998 El Niño appeared to allow humans to ignite fires in forested areas that were normally too moist to burn. Adjacent C4 grasses (in woodlands and moist savannas) also burned, but emissions were limited, in part, by aboveground biomass levels that were 2 orders of magnitude smaller than C3 biomass levels. Reduced fuel availability in some C4 ecosystems may have led to a negative feedback on emissions.
Statistical survey of magnetic and velocity fluctuations in the near‐Earth plasma sheet: International Sun Earth Explorer (ISEE‐2) measurements
Authors: Neagu Elena , Borovsky Joseph E. , Gary S. Peter , Jorgensen A. M. , Baumjohann Wolfgang , Treumann Rudolf A.
Published: May 2005

International Sun‐Earth Explorer (ISEE‐2) satellite observations of low‐frequency magnetic field and ion velocity fluctuations in the Earth's magnetotail are compared with corresponding observations from the Active Magnetospheric Particle Tracer Explorers/Ion Release Module (AMPTE/IRM). Solar activity during these two missions is different and thus also considered. The ISEE‐2 analysis is performed on the data taken from satellite passes through the Earth's plasma sheet in 1978 and 1979 near solar maximum. The data is divided into 2298 ten‐minute‐long intervals where the averages of the magnetic field, ion velocity, and plasma parameter's amplitudes are statistically calculated for each interval. We find no significant dependence of the amplitude of the ion velocity and magnetic field fluctuations on the magnetotail distance or on the distance from the neutral sheet. The correlation coefficient between the geomagnetic activity and the amplitude of both ion velocity and magnetic field fluctuations in the ISEE‐2 measurements is smaller than the one found for the AMPTE/IRM passes through the plasma sheet. When comparing the two satellite data sets for the same plasma sheet region, we obtain a significantly higher upper bound for the ISEE‐2 fluctuating magnetic field energy density. Our results suggest that the significantly increased magnetic field fluctuation amplitude in the plasma sheet during the ISEE‐2 satellite passes is due to the increased solar activity near solar maximum.
Global and local equatorward expansion of the ion auroral oval before substorm onsets
Authors: Jayachandran P. T. , Donovan E. F. , MacDougall J. W. , Moorcroft D. R. , Liou K. , Newell P. T. , St‐Maurice J.‐P.
Published: May 2005

The temporal variation of the equatorward boundary of the proton aurora/high‐energy ion precipitation is a manifestation of diurnal and seasonal (i.e., dipole tilt) effects as well as magnetic activity. In particular, during the substorm growth phase this boundary moves equatorward, an effect due primarily to thinning and earthward motion of the cross‐tail current in the inner magnetosphere as the field evolves toward a more stretched topology. Recent advances in monitoring this boundary using ground‐based instruments have opened up the possibility of following its temporal evolution across several hours in local time. This in turn allows one to explore whether this magnetotail stretching is a global or local phenomenon. We have examined this boundary evolution during the growth phases of 68 substorms over the Canadian sector. We use the equatorward boundary of SuperDARN E region echoes as a proxy for the proton auroral boundary as described by Jayachandran et al. (2002b). We find that in 21 of the 68 substorms the equatorward motion of the auroral boundary is restricted to several hours of local time in the evening sector. In the remaining 47 substorms, the equatorward motion was global so that the boundary retained its shape throughout the growth phase. Our results indicate dramatically different growth phase phenomenology in these two classes of substorms. In one, the growth phase involves stretching in the inner magnetosphere that is most pronounced around the onset meridian. In the other, the stretching extends many hours in local time away from the onset meridian.
Coupling of mixed layer processes and thermocline variations in the Arabian Sea
Authors: Ramesh K. V. , Krishnan R.
Published: May 2005

This study presents an analysis of observed data sets from multiple sources, including observations from a network of Argo floats during (2002–2003), with the aim of investigating the role of the southwest monsoon circulation in affecting the interactions between the oceanic mixed layer and the underlying thermocline in the northern Indian Ocean. Examination of the seasonal cycle of the upper‐ocean thermal structure shows that the surface cooling of the Arabian Sea, during the southwest monsoon season, is accompanied by significant warming of the thermocline. It is seen that the thermocline is warmer by about 1.2°C in the south‐central Arabian Sea during the southwest monsoon season relative to other months. Offline computations of the profiles of vertical diffusivity of heat reveal stronger and deeper penetration of heat into the Arabian Sea during the southwest monsoon season. The results presented in the paper demonstrate that the combined effects of strong wind‐driven mixing by the monsoonal winds, weak density stratification in the upper‐ocean, and downwelling in south‐central Arabian Sea, along with strong vertical diffusivity, favor downward transfer of warm waters from the surface into the thermocline. Besides the climatological seasonal cycle, the present study also examines the impact of monsoon interannual variability on the upper‐ocean response, by analysis of long‐term observed records during (1955–2001) as well as the Argo observations for (2002–2003). It is found that the interannual variations in the ocean response reveal signatures of the influence of strong and weak southwest monsoons on the mixed layer and thermocline variabilities.
Formation of Martian gullies by the action of liquid water flowing under current Martian environmental conditions
Authors: Heldmann Jennifer L. , Toon Owen B. , Pollard Wayne H. , Mellon Michael T. , Pitlick John , McKay Christopher P. , Andersen Dale T.
Published: May 2005

Geomorphic evidence suggests that recent gullies on Mars were formed by fluvial activity. The Martian gully features are significant because their existence implies the presence of liquid water near the surface on Mars in geologically recent times. Irrespective of the ultimate source of the fluid carving the gullies, we seek to understand the behavior of this fluid after it reaches the Martian surface. We find that contrary to popular belief, the fluvially carved Martian gullies are consistent with formation conditions such as now occur on Mars, outside of the temperature‐pressure stability regime of liquid water. Our model of the action of flowing pure liquid water produces the observed gully length distribution only at surface pressures and temperatures below the triple point where liquid water simultaneously boils and freezes and thus suggests that gullies were formed under conditions similar to present‐day Mars. Our results suggest a typical flow rate of 30 m3/s to carve the gully channels. At least 0.15 km3 has flowed across the surface of Mars to carve the gully systems observed today, and this would require an aquifer recharge rate of ∼10−13–10−12 m/yr. The absence of gullies on Mars that are long enough to have been created above the triple point pressure argues that the atmospheric pressure has not been significantly larger than it is now since the origin of the gullies. This result may imply that Mars does not possess a significant reservoir of condensed CO2.
Standardization of anhysteretic magnetization curves
Authors: Kwiczala Jozef , Kasperczyk Bogusław
Published: May 2005

Anhysteretic magnetization curves B=B(H) can be transformed to normalized curve B*=B(H*) by affinity transformation. Interdependencies between coordinates (B,H) in the first coordinate system and (B*,H*) in the second one can be described as linear function. There are exactly two parameters (Bb and Hb) which allow us to execute this transformation under the condition of minimal transform error. These parameters are called the base values of transformation. Magnetic material properties are described by the characteristics of the base values Bbi=B(P) and Hbi=H(P), where P is the affected parameter. Reverse affinity transformation is also possible.
Microstructure and magnetic properties of sintered NdFeB magnets with improved impact toughness
Authors: Liu J. F. , Vora P. , Walmer M. H. , Kottcamp E. , Bauser S. A. , Higgins A. , Liu S.
Published: May 2005

An effort to increase the impact toughness of Nd–Fe–B sintered magnets by adding small amounts of Al, Nd, Ga, Cu, and Nb was successful. No significant compromise to magnetic properties occurred. Based on this work, a series of sintered Nd–Fe–B magnets with improved toughness was developed, which we call ToughNEO™. Small precipitates, which may contribute to the improvement of toughness, were observed using scanning electron microscope for all samples with improved toughness. Tumbling and drilling tests further verified the improved toughness of these developed ToughNEO™ magnets.
Numerical micromagnetics of an assembly of (Fe,Co)Pt nanoparticles
Authors: Fidler Josef , Speckmayer Peter , Schrefl Thomas , Suess Dieter
Published: May 2005

A micromagnetic model has been developed describing the influence of the K1 and the particle size on the magnetization reversal processes in (Co,Fe)Pt nanoparticles on the order of 4to80nm in diameter The magnetostatic interactions between the particles are calculated using an accelerated boundary element method. From the comparison of the results of the finite-element simulations with “macrospin” calculations in which only precessional rotational magnetization processes are possible, it is obvious that inhomogeneous rotational magnetization and nucleation processes are dominant in larger particles. Depending on the K1 values and the volume fraction of the hard (fct) and soft (fcc) (Co,Fe)Pt nanoparticles, the calculated coercive field values are on the order of μ0Hc=0,1to1,2T, in good agreement with experimental results.
Order-disordered structure and magnetic properties of Li0.5Fe2.5−xRhxO4
Authors: Kang Kun Uk , Kim Chul Sung , Oak Hang Nam
Published: May 2005

Li 0.5 Fe 2.5 − x Rh x O 4  (x=0.25–1.50) has been studied by Mössbauer spectroscopy, superconducting quantum interference device magnetometry, and x-ray diffraction. The crystals are found to be a cubic spinel structure and have been classified into two different sets by crystallographic symmetry, the space group Fd3m for x=0.25–1.25 and the space group F4¯3m for x=1.50, respectively. The migration of Li ion has been confirmed by x-ray patterns and the results of Mössbauer analysis. The saturated magnetic moment measured at 4.2K and Mössbauer spectra taken at various temperatures with 6.0T applied field show that the spin structure of Li0.5Fe2.5−xRhxO4 has the collinear Néel model.
Simple derivation of four-level permittivity relations for magneto-optical applications
Authors: Dionne Gerald F.
Published: May 2005

An analysis based on the gyromagnetic permeability tensor is applied to electric dipole transitions between orbital angular momentum terms of the four-level SLz=02↔PLz=0,,±12 group that serves as the model for magneto-optical properties in the near-infrared region. The final expressions for the permittivity tensor elements are obtained by combining the line shape functions for the two pairs of resonance and nonresonance contributions of the respective circular polarization modes that are separated by the multiplet splitting of the P2 term. For a split ground state, the effect of temperature on population differences is introduced by a simple Boltzmann approximation. This approach affords complete flexibility in the selection of permittivity for all weightings of circular polarization. By direct algebraic summations, the combined permittivities can be readily computed for systems with various magneto-optical spectra. Signal loss effects can be introduced at any stage by substitution of the standard ferrimagnetic resonance damping models that characterize the resonance linewidth.
Stress, microstructure, and magnetic softness of high saturation magnetization (Bs) FeCoN films
Authors: Sun N. X. , Xiao Q. F. , York B.
Published: May 2005

High saturation magnetization soft magnetic FeCoN films were deposited under different conditions. Their soft magnetic properties and microstructures were characterized. Good magnetic softness with a low coercivity of ∼240A∕m(3Oe) was achieved in FeCoN films on glass with a thickness of up to 640nm. A correlation was found to exist between the FeCoN film coercivities and their compressive strains, with higher coercivities corresponding to larger compressive strains. FeCoN film coercivities were lower for samples with larger grain sizes, exhibiting a typical 1∕D relationship with D being the mean grain size, a mechanism that is different from the reported fine grain size-induced magnetic softness in FeCo thin films.
Soft magnetic granular material Co–Fe–Hf–O for micromagnetic device applications
Authors: Li Liangliang , Crawford Ankur M. , Wang Shan X. , Marshall Ann F. , Mao Ming , Schneider Thomas , Bubber Randhir
Published: May 2005

A granular magnetic material, Co–Fe–Hf–O, has been developed-using dc pulsed magnetron reactive sputtering. The deposition rate is as high as 1.3nm∕s. The electrical and magnetic properties of Co–Fe–Hf–O film can be tuned by changing O2 during deposition. A highly resistive, magnetically soft film has been achieved in a small range of the O2∕(Ar+O2) gas flow ratio. The origin of the dependence of magnetic and electrical properties of this material is studied and explained by monitoring the evolution of the film microstructure, using x-ray diffraction and transmission electron microscopy.
Structural and magnetic properties of NiZn and Zn ferrite thin films obtained by laser ablation deposition
Authors: Sorescu Monica , Diamandescu L. , Swaminathan R. , McHenry M. E. , Feder M.
Published: May 2005

Laser ablation deposition has been used to synthesize nanoscale ferrite structures. Our investigations were performed on NiZn and Zn ferrite films deposited on silicon(100) substrates. Films produced by laser ablation at room temperature were annealed at 550°C for 1h. Other films were deposited directly at a 550°C substrate temperature without subsequent annealing. Complementary x-ray diffraction and superconducting quantum interference device magnetometry measurements helped identify the optimum laser ablation deposition conditions for obtaining the desired nanoferrite structures. From the hysteresis loops at 300 and 10K we identified the paramagnetic or ferromagnetic behavior of the films. The zero field cooled–field cooled (ZFC–FC) magnetization, M(T), curves yielded the value of the blocking temperature in both NiZn and Zn ferrite systems.
(Towards) Spin-polarized scanning tunneling microscopy of NiFe films on a chromium(001) single crystal: Growth and electronic structure of Permalloy
Authors: Dreyer M. , Lee J. , Krafft C. , Gomez R.
Published: May 2005

This paper shows spin-polarized tunneling on the terraces of antiferromagnetic chromium(001). Details on the morphological and chemical composition are shown as a function of various stages of surface preparation, and protocols for obtaining Cr(001) that reveal spin-polarized contrast are reported. On the clean crystal the chromium surface state at the Fermi level could be observed. The spin splitting of the state was measured by using an iron coated tungsten tip. A spin polarization of 10% was observed. The properties of NiFe grown on Cr(001) measured using nonpolarized tunneling spectroscopy are also reported. Monolayer thick permalloy grows in Volmer–Weber mode, exhibiting pyramidal islands oriented along the chromium ⟨110⟩ direction. Spectroscopic data reveal that NiFe alloying is preserved.
Effect of crystal fraction on hardness in FINEMET and NANOPERM nanocomposite alloys
Authors: Um C.-Y. , Johnson F. , Simone M. , Barrow J. , McHenry M. E.
Published: May 2005

Nanocrystallization kinetics of a FINEMET (Fe71.1Si18.5B6.3Nb3Cu1.1) and a NANOPERM alloy (Fe91Zr7B2) were studied and the variation of mechanical properties (hardness) with volume fraction of the crystalline (VFC) phase determined. Time-dependent magnetization and hysteresis loop measurements were used to determine VFC for FINEMET and NANOPERM, respectively. Kinetic results are presented to provide the information necessary to interpret the hardness measurements. Hardness was measured by nanoindentation as a function of VFC to investigate the effect of the evolution of the nanocomposite structure on the mechanical properties. Strengthening mechanisms to understand the linear increase of hardness with the increase of VFC are presented.
Magnetic and structural properties of pulsed laser deposited CuFe2O4 films
Authors: Yang Aria , Zuo X. , Chen L. , Chen Z. , Vittoria C. , Harris V. G.
Published: May 2005

Highly crystal textured copper ferrite films have been grown on (100) MgO substrates using pulsed laser deposition. Deposition temperatures were varied from 600–900°C, with deposition oxygen pressure varied from 1mTorr to 120mTorr. Saturation magnetization was measured to increase monotonically with substrate temperature approaching the bulk value of 1700G near 900°C. Magnetization was also shown to increase with oxygen pressure with a maximum value of 2481G obtained at a pressure of 90mTorr. Although divalent Cu prefers octahedral sites (i.e., 85% under equilibrium conditions), cation inversion was measured to decrease with increasing oxygen pressure and magnetization.
Stochastic resonance in magnetic systems described by Preisach hysteresis model
Authors: Mantegna Rosario N. , Spagnolo Bernardo , Testa Luigi , Trapanese Marco
Published: May 2005

We present a numerical study of stochastic resonance in magnetic systems described by Preisach hysteresis model. It is shown that stochastic resonance occurs in these systems. Specifically, the signal-to-noise ratio (SNR) and the signal amplification (SA) present a maximum as a function of noise intensity. We also found that the hysteresis loops, dynamically described by the system, are strongly modified near the maxima of SNR and of SA.
Slit-patterned CoNbZr∕Nb∕CoNbZr magnetic film for rf noise suppressor
Authors: Ikeda Shinji , Kim Ki Hyeon , Yamaguchi Masahiro
Published: May 2005

In this paper, we discuss the elimination of magnetic closure domains in a micropatterned film in order to have the desired loss generation profile against the operating frequency and describe a demonstration of the rf loss generation profile over a thin-film coplanar transmission line using micropatterned films with various slit designs. It was demonstrated that the micropatterned film causes loss in the transmission line in a narrow frequency band and the loss ratio in the other bands is smaller than in the nonpatterned film we measured. The peak frequency of loss generation is controllable according to the pattern dimension of the magnetic film. This technique is useful as a notch filter for integrated transmission lines.
Sheaths: More complicated than you think
Authors: Hershkowitz Noah
Published: May 2005

Sheaths in low temperature collisionless and weakly collisional plasmas are often viewed as simple examples of nonlinear physics. How well do we understand them? Closer examination indicates that they are far from simple. Moreover, many predicted sheath properties have not been experimentally verified and even the appropriate “Bohm velocity” for often encountered two-ion species plasma is unknown. In addition, a variety of sheathlike structures, e.g., double layers, can exist, and many two- and three-dimensional sheath effects have not been considered. Experimental studies of sheaths and presheaths in weakly collisional plasmas are described. A key diagnostic is emissive probes operated in the “limit of zero emission.” Emissive probes provide a sensitive diagnostic of plasma potential with a resolution approaching 0.1V and a spatial resolution of 0.1cm. Combined with planar Langmuir probes and laser-induced fluorescence, they have been used to investigate a wide variety of sheath, presheath, and sheathlike structures. Our experiments have provided some answers but have also raised more questions.
Rates of complex formation in collisions of rotationally excited homonuclear diatoms with ions at very low temperatures: Application to hydrogen isotopes and hydrogen-containing ions
Authors: Dashevskaya E. I. , Litvin I. , Nikitin E. E. , Troe J.
Published: May 2005

State-selected rate coefficients for the capture of ground and rotationally excited homonuclear molecules by ions are calculated, for low temperatures, within the adiabatic channel classical (ACCl) approximation, and, for zero temperature, via an approximate calculation of the Bethe limit. In the intermediate temperature range, the accurate quantal rate coefficients are calculated for j=0 and j=1 states of hydrogen isotopes (H2, HD, and D2) colliding with hydrogen-containing ions, and simple analytical expressions are suggested to approximate the rate coefficients. For the ground rotational state of diatoms, the accurate quantal rate coefficients are higher compared to their ACCl counterparts, while for the first excited rotational state the reverse is true. The physical significance of quantum effects for low-temperature capture and the applicability of the statistical description of capture are considered. Particular emphasis is given to the role of Coriolis interaction. The relevance of the present capture calculations for rates of ortho-para conversion of H2 in collisions with hydrogen-containing ions at low temperatures is discussed.
Quasiequilibrium approximation of fast reaction kinetics in stochastic biochemical systems
Authors: Goutsias John
Published: May 2005

We address the problem of eliminating fast reaction kinetics in stochastic biochemical systems by employing a quasiequilibrium approximation. We build on two previous methodologies developed by [Haseltine and Rawlings, J. Chem. Phys. 117, 6959 (2002)] and by [Rao and Arkin, J. Chem. Phys. 118, 4999 (2003)]. By following Haseltine and Rawlings, we use the numbers of occurrences of the underlying reactions to characterize the state of a biochemical system. We consider systems that can be effectively partitioned into two distinct subsystems, one that comprises “slow” reactions and one that comprises “fast” reactions. We show that when the probabilities of occurrence of the slow reactions depend at most linearly on the states of the fast reactions, we can effectively eliminate the fast reactions by modifying the probabilities of occurrence of the slow reactions. This modification requires computation of the mean states of the fast reactions, conditioned on the states of the slow reactions. By assuming that within consecutive occurrences of slow reactions, the fast reactions rapidly reach equilibrium, we show that the conditional state means of the fast reactions satisfy a system of at most quadratic equations, subject to linear inequality constraints. We present three examples which allow analytical calculations that clearly illustrate the mathematical steps underlying the proposed approximation and demonstrate the accuracy and effectiveness of our method.