bluuebunny/crossref_metadata_2025 huggingface dataset:
Field‐induced quantum critical point in the pressure‐induced superconductor CeRhIn5
Authors: Park T. , Tokiwa Y. , Ronning F. , Lee H. , Bauer E. D. , Movshovich R. , Thompson J. D.
Published: February 2010

When subjected to pressure, the prototypical heavy‐fermion antiferromagnet CeRhIn5 becomes superconducting, forming a broad dome of superconductivity (SC) centred around 2.35 GPa (=P2) with maximal Tc of 2.3 K. Above the superconducting dome, the normal state shows strange metallic behaviours, including a divergence in the specific heat and a sub‐T‐linear electrical resistivity. The discovery of a field‐induced magnetic phase that coexists with SC for a range of pressures P ≤ P2 has been interpreted as evidence for a quantum phase transition, which could explain the non‐Fermi‐liquid behaviour observed in the normal state. Here we report electrical resistivity measurements of CeRhIn5 under magnetic field at P2, where the resistivity is sub‐T‐linear for temperatures above Tc (or TFL) and a T2‐coefficient A found below TFL diverges as Hc2 is approached. These results are similar to the field‐induced quantum critical compound CeCoIn5 and confirm the presence of a quantum critical point in the pressure‐induced superconductor CeRhIn5. Temperature‐field phase diagram of CeRhIn5 at 2.35 GPa.

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The impact of period effects on dose level contrasts in alternating cross‐over designs for first‐time‐in‐human studies
Authors: Koehne‐Voss Stephan , Schmidli Heinz , Smith David M. , Pigeot Iris
Published: February 2010

For first‐time‐in‐human studies with small molecules alternating cross‐over designs are often employed and at study end are analyzed using linear models. We discuss the impact of including a period effect in the model on the precision with which dose level contrasts can be estimated and quantify the bias of least squares estimators if a period effect is inherent in the data that is not accounted for in the model. We also propose two alternative designs that allow a more precise estimation of dose level contrasts compared with the standard design when period effects are included in the model. Copyright © 2010 John Wiley & Sons, Ltd.
Adapting by calibration the sample size of a phase III trial on the basis of phase II data
Authors: De Martini Daniele
Published: February 2010

The problem of estimating the sample size for a phase III trial on the basis of existing phase II data is considered, where data from phase II cannot be combined with those of the new phase III trial. Focus is on the test for comparing the means of two independent samples. A launching criterion is adopted in order to evaluate the relevance of phase II results: phase III is run if the effect size estimate is higher than a threshold of clinical importance. The variability in sample size estimation is taken into consideration. Then, the frequentist conservative strategies with a fixed amount of conservativeness and Bayesian strategies are compared. A new conservative strategy is introduced and is based on the calibration of the optimal amount of conservativeness – calibrated optimal strategy (COS). To evaluate the results we compute the Overall Power (OP) of the different strategies, as well as the mean and the MSE of sample size estimators. Bayesian strategies have poor characteristics since they show a very high mean and/or MSE of sample size estimators. COS clearly performs better than the other conservative strategies. Indeed, the OP of COS is, on average, the closest to the desired level; it is also the highest. COS sample size is also the closest to the ideal phase III sample size MI, showing averages and MSEs lower than those of the other strategies. Costs and experimental times are therefore considerably reduced and standardized. However, if the ideal sample size MI is to be estimated the phase II sample size n should be around the ideal phase III sample size, i.e. n⩾2MI/3. Copyright © 2010 John Wiley & Sons, Ltd.
Comprehensive mass spectrometry based metabolic profiling of blood plasma reveals potent discriminatory classifiers of pancreatic cancer
Authors: Urayama Shiro , Zou Wei , Brooks Kindra , Tolstikov Vladimir
Published: February 2010

Poor outcome of pancreatic cancer necessitates development of an early diagnostic method to reduce mortality. No reliable early diagnostic test for pancreatic cancer detection has been developed and validated to date. In the current study, metabolic profiling of plasma samples from selected cancer patients and noncancerous controls was performed to seek novel metabolic biomarkers of pancreatic cancer. A comprehensive mass spectrometry based analytical platform established at the Metabolomics Core of the UC Davis Genome Center allowed detection of multiple compounds previously unreported in plasma from pancreatic cancer patients. It was found that selective amino acids, bile acids, and polar lipids were detected with increased or decreased levels in pancreatic cancer samples compared to controls. These findings on blood plasma levels of the relevant metabolites might be very useful clinical parameters for early diagnosis of pancreatic cancer. Copyright © 2010 John Wiley & Sons, Ltd.
Optimization of N‐methyl‐N‐[tert‐butyldimethylsilyl]trifluoroacetamide as a derivatization agent for determining isotopic enrichment of glycerol in very‐low density lipoproteins
Authors: Adiels Martin , Larsson Thomas , Sutton Pauline , Taskinen Marja‐Riitta , Borén Jan , Fielding Barbara A.
Published: February 2010

Stable isotope kinetic studies play an important role in the study of very‐low density lipoprotein (VLDL) metabolism, including basic and clinical research. Today, [1,1,2,3,3‐2H5]glycerol is the most cost‐effective alternative to measure glycerol and triglyceride kinetics. Recycling of glycerol from glycolysis and gluconeogenesis may lead to incompletely labelled tracer molecules. Many existing methods for the measurement of glycerol isotopic enrichment involve the production of glycerol derivatives that result in fragmentation of the glycerol molecule after ionization. It would be favourable to measure the intact tracer molecule since incompletely labelled tracer molecules may be measured as fully labelled. The number of methods available to measure the intact tracer in biological samples is limited. The aim of this project was to develop a gas chromatography/mass spectrometry (GC/MS) method for glycerol enrichment that measures the intact glycerol backbone and is suitable for electron ionization (EI), which is widely available. A previously published method for N‐methyl‐N‐[tert‐butyldimethylsilyl]trifluoroacetamide (MTBSTFA) derivatization was significantly improved; we produced a stable derivative and increased recovery 27‐fold in standards. We used the optimized MTBSTFA method in VLDL‐triglyceride and found that further modification was required to take matrix effects into account. We now have a robust method to measure glycerol isotopic enrichment by GC/EI‐MS that can be used to rule out the known problem of tracer recycling in studies of VLDL kinetics. Copyright © 2010 John Wiley & Sons, Ltd.
Transfer of Quantum Dots from Pregnant Mice to Pups Across the Placental Barrier
Authors: Chu Maoquan , Wu Qiang , Yang Hui , Yuan Ruiqi , Hou Shengke , Yang Yifeng , Zou Yajuan , Xu Shi , Xu Kaiyi , Ji Ailing , Sheng Lingyi
Published: February 2010

Fluorescent quantum dots (QDs) have great potential for in vivo biomedical imaging and diagnostic applications. However, these nanoparticles are composed of heavy metals and are very small in diameter, and their possible toxicity must therefore be considered. As yet, no studies have reported the transfer of QDs between mother and fetus. The transfer of CdTe/CdS QDs of different sizes and dosages, and with different outer capping materials, from pregnant mice to fetuses is investigated. It is shown that QDs may be transferred from female mice to their fetuses across the placental barrier. Smaller QDs are more easily transferred than larger QDs and the number of QDs transferred increases with increasing dosage. Capping with an inorganic silica shell or organic polyethylene glycol reduces QD transfer but does not eliminate it. These results suggest that the clinical utility of QDs could be limited in pregnant women.
Marine huge molecules: the longest carbon chains in natural products
Authors: Kita Masaki , Uemura Daisuke
Published: February 2010

Marine huge polyol and polyether compounds are remarkable molecules owing to their extraordinary structures and significant biological activities. Currently, palytoxin and maitotoxin are believed to have the longest carbon chains in nature (more than 100 Å in length), except for biopolymers. The structural properties of such marine huge molecules are highlighted, especially with regard to the length and shape of their carbon chains. © 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 10: 000–000; 2010: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.200900030
The Impact of Intraoperative Neuromonitoring (IONM) on Surgical Strategy in Bilateral Thyroid Diseases: Is it Worth the Effort?
Authors: Goretzki Peter E. , Schwarz Katharina , Brinkmann Jürgen , Wirowski Denis , Lammers Bernhard J.
Published: February 2010

Background

Intraoperative nerve monitoring (IONM) of the recurrent laryngeal nerve and the vagal nerve can detect nonfunctioning nerves (recurrent laryngeal nerve palsy, RLNP) that are visibly intact. The use of IONM is questionable, however, as we still lack evidence that it reduces the rate of postoperative nerve injuries. Since negative IONM results after thyroid dissection of the first side could change our surgical strategy and thus could prevent patients from bilateral RLNP, we questioned whether IONM results are reliable enough to base changes in surgical strategy and whether this has any effect on surgical outcome.

Methods

We retrospectively analyzed the data of 1333 consecutive patients with suggested benign bilateral thyroid disease who had been operated on under a defined protocol, including the use of a specific IONM technique (tube electrodes and stimulation of the vagal nerve and the inferior recurrent nerve before and after thyroid resection), between January 1, 2006 and December 31, 2008.

Results

In four patients the IONM system did not work, two nerves had not been found, and in eight patients the tube had to be readjusted. Of five permanent nerve injuries, four were visible during surgery and one was suspected. Sensitivity of IONM in detecting temporary nerve injuries of macroscopically normal‐appearing nerves was 93%. Specificity was 75–83% at first side of dissection and 55–67% at the second side, with an overall specificity of 77%. In 11 of 13 patients (85%) with known nerve injury (preexisting or visible) and in 20 of 36 patients (56%) with negative IONM stimulation at the first side of dissection, the surgical strategy was changed (specific surgeon or restricted resection) with no postoperative bilateral RLNP. This was in contrast to 3 of 18 (17%) bilateral RLNP (p < 0.05), when surgeons were not aware of a preexisting or highly likely nerve injury at the first side of thyroid dissection.

Conclusions

Failed IONM stimulation of the vagal or recurrent laryngeal nerve after resection of the first thyroid lobe is specific enough to reconsider the surgical strategy in patients with bilateral thyroid disease to surely prevent bilateral RLNP.
Changes in Quality of Life After Lung Surgery in Old and Young Patients: Are They Similar?
Authors: Möller Axel , Sartipy Ulrik
Published: February 2010

Background

The aim of the study was to compare the changes in health‐related quality of life (QOL) after lung surgery between young and old patients.

Methods

We performed a prospective, population‐based, cohort study to investigate health‐related QOL before and 6 months after lung surgery. We used the validated instrument Short Form‐36 (SF‐36), to investigate QOL. The main outcome measures were fractional change in the SF‐36 physical (ΔPCS%) and mental (ΔMCS%) component summary scores. We also compared the two age groups to age‐ and sex‐matched reference populations.

Results

We included 249 patients: 166 young (<70 years) and 83 old (≥70 years) patients. The overall response rate at 6 months was 84%. There was no significant difference in the primary outcome measures between young and old patients (ΔPCS% −13 vs. −16, p = 0.55; ΔMCS% 9 vs. 1, p = 0.22). The 2‐year survivals (mean follow‐up 2.1 years) were 83% and 84% in young and old patients, respectively (p = 0.72). In both groups, physical and mental QOL were lower than in the reference populations.

Conclusions

We found that at 6 months after lung surgery old patients experienced deterioration in physical and mental health‐related QOL similar to that of young patients. Survival also was similar in the two groups.
Risk Factors for Symptomatic Anastomotic Leakage After Low Anterior Resection for Rectal Cancer with 30 Gy/10 f/2 w Preoperative Radiotherapy
Authors: Wang Lin , Gu Jin
Published: February 2010

Objective

This retrospective study was designed to analyze the risk factors for symptomatic leakage after low anterior resection (LAR) for patients with rectal cancer who received 30 Gy/10 f/2 w preoperative radiotherapy.

Methods

From April 2002 to December 2008, a total of 223 patients with mid‐low rectal cancer received 30 Gy/10 f/2 w preoperative radiotherapy and underwent LAR. Six patients were excluded for positive air test, incomplete anastomotic rings, or other major adverse intraoperative events. In the 217 patients with satisfactory anastomoses, 15 probably factors relating to anastomotic leakage were recorded and statistically analyzed.

Results

The median patient age was 57 years, and 48% were women. The median level of anastomosis was 6 cm, median operating time was 130 minutes, and intraoperative blood loss was 200 ml. The symptomatic leakage rate was 11.5% (25/217). Multivariable analysis demonstrated that male gender (odds ratio (OR) = 2.63; p = 0.0474), level of anastomosis ≤4 cm (OR = 8.80; p = 0.038), no defunctioning stoma (OR = 3.80; p = 0.038), and blood loss >200 ml (OR = 3.32; p = 0.080) were the independent risk factors for anastomotic leakage.

Conclusions

For patients with rectal cancer treated with preoperative radiotherapy and low anterior resection, the risk factors for anastomotic leakage are male gender, lack of defunctioning stoma, level of anastomosis ≤4 cm, and blood loss >200 ml. A defunctioning stoma can decrease the occurrence of symptomatic anastomotic leakage and should be routinely performed in all low anterior resections after 30 Gy/10 f/2 w preoperative radiotherapy.
Profiling β-thalassaemia mutations in India at state and regional levels: implications for genetic education, screening and counselling programmes
Authors: Sinha S. , Black M. L. , Agarwal S. , Colah R. , Das R. , Ryan K. , Bellgard M. , Bittles A. H.
Published: February 2010

Thalassaemia and sickle cell disease have been recognized by the World Health Organization as important inherited disorders principally impacting on the populations of low income countries. To create a national and regional profile of β-thalassaemia mutations in the population of India, a meta-analysis was conducted on 17 selected studies comprising 8,505 alleles and offering near-national coverage for the disease. At the national level 52 mutations accounted for 97.5% of all β-thalassaemia alleles, with IVSI-5(G>C) the most common disease allele (54.7%). Population stratification was apparent in the mutation profiles at regional level with, for example, the prevalence of IVSI-5(G>C) varying from 44.8% in the North to 71.4% in the East. A number of major mutations, such as Poly A(T>C), were apparently restricted to a particular region of the country, although these findings may in part reflect the variant test protocols adopted by different centres. Given the size and genetic complexity of the Indian population, and with specific mutations for β-thalassaemia known to be strongly associated with individual communities, comprehensive disease registries need to be compiled at state, district and community levels to ensure the efficacy of genetic education, screening and counselling programmes. At the same, time appropriately designed community-based studies are required as a health priority to correct earlier sampling inequities which resulted in the under-representation of many communities, in particular rural and socioeconomically under-privileged groups.
Trans Fatty Acid‐Induced NF‐κB Activation Does Not Induce Insulin Resistance in Cultured Murine Skeletal Muscle Cells
Authors: Hommelberg Pascal P. H. , Langen Ramon C. J. , Schols Annemie M. W. J. , van Essen Anon L. M. , Snepvangers Frank J. M. , Mensink Ronald P. , Plat Jogchum
Published: February 2010

Long‐chain saturated fatty acids such as palmitic acid induce insulin resistance and NF‐κB activation in skeletal muscle cells. Here we investigated the effects of long‐chain fatty acid (FA) saturation and configuration on NF‐κB activity and insulin sensitivity in cultured skeletal muscle cells. Of all tested unsaturated FAs, only elaidic acid (3‐fold), cis9,trans11‐CLA (3‐fold) and trans10,cis12‐CLA (13‐fold) increased NF‐κB transactivation in myotubes. This was not accompanied by decreased insulin sensitivity (measured as insulin‐induced glucose uptake and GLUT4 translocation). We therefore conclude that FA‐induced NF‐κB activation is not sufficient for the induction of insulin resistance in skeletal muscle cells.
Cardiac Surgery Essentials for Critical Care Nursing
Authors: Goddard‐Gerrald Sue
Published: February 2010

Cardiac Surgery Essentials for Critical Care Nursing Sonya R. Hardin, Roberta Kaplow 2010, Jones and Bartlett Publishers 462 pages, $59.95 softcover
Clinical Issues—February 2010
Authors: Burlingame Byron , Petersen Carol , Denholm Bonnie
Published: February 2010

This Month

Continuously monitoring an open but unused sterile field

Key words: procedural delay, continuous monitoring, sterile field.

Documentation of skin status after pneumatic tourniquet use

Key words: pneumatic tourniquet, skin assessment, perfusion status.

Blanket warmer settings

Key words: blanket warming cabinets, fluid warming cabinets, temperature settings.
Successful treatment of Bartonella henselae endocarditis in a cat
Authors: Perez Cristina , Hummel James B. , Keene Bruce W. , Maggi Ricardo G. , Diniz Pedro P.V.P. , Breitschwerdt Edward B.
Published: February 2010

This report describes the clinical presentation, diagnosis and treatment of a cat with vegetative valvular endocarditis temporally associated with natural infection with Bartonella henselae. Lethargy, abnormal gait and weakness were the main clinical signs that resulted in referral for diagnostic evaluation. Using a novel and sensitive culture approach, B henselae was isolated from the blood. Following antibiotic therapy there was total resolution of clinical signs, the heart murmur, the valvular lesion by echocardiography, and no Bartonella species was isolated or amplified from a post-treatment blood culture. In conjunction with previous case reports, infective endocarditis can be associated with natural B henselae infection in cats; however, early diagnosis and treatment may result in a better prognosis than previously reported.
A basal bird from the Campanian (Late Cretaceous) of Dinosaur Provincial Park (Alberta, Canada)
Authors: BUFFETAUT ERIC
Published: February 2010

A fragmentary bone from the Dinosaur Park Formation (Campanian) of Dinosaur Provincial Park (Alberta, Canada), originally described as a pterosaur tibiotarsus, is reinterpreted as the distal end of the tibiotarsus of a basal bird, probably an enantiornithine, on the basis of several distinctive characters. It is the first report of such a bird from the Dinosaur Park Formation and shows that this group was present, together with various more derived ornithurines, in the relatively high-latitude environments of Late Cretaceous western Canada.
Neoriojatrema mokokchungensis n. g., n. sp. (Monogenea: Polystomatidae: Polystomatinae) from the urinary bladder of a megophryid frog, Xenophrys glandulosa, in Nagaland, north-eastern India
Authors: Imkongwapang R. , Tandon V.
Published: February 2010

A new monogenean fluke, collected from the urinary bladder of a megophryid frog, Xenophrys glandulosa Fei, Ye & Huang, 1991 from Mokokchung and Tuensang districts of Nagaland, north-eastern India is described. Of the six genera under the subfamily Polystomatinae (Polystomatidae) known so far, the present form comes closer to Eupolystoma Kaw, 1950; Pseudopolystoma Yamaguti, 1963 and Riojatrema Lamothe-Argumedo, 1964, in all of which the opisthaptor lacks large hooks. However, a combination of characters, namely, shape of the body, rounded or bulbous pharynx, intestinal caeca not joining posteriorly in the opisthaptoral region, ovary located in the anterior third of the body and presence of vaginal apertures, sets the present form apart from all these genera, and also from the known species of Riojatrema. These differences warrant the establishment of a new species and a new genus to accommodate the present form. The validity of this new monogenean, named as Neoriojatrema mokokchungensis after the type locality of the fluke, is discussed.
Parasitic castration of Buccinanops cochlidium (Gastropoda: Nassariidae) caused by a lepocreadiid digenean in San José Gulf, Argentina
Authors: Averbuj A. , Cremonte F.
Published: February 2010

Parasitic castration of Buccinanops cochlidium from San José Gulf, Argentina, caused by a lepocreadiid digenean, is reported for the first time. Rediae and ophtalmotrichocercous cercariae probably belonging to Opechona sp. were identified in the gonad and digestive gland. Opechona sp. has been reported previously parasitizing B. monilifer from a northern locality in the Argentine Sea. Overall prevalence of infection was 15.5%; it varied seasonally, rising during the warm months after the host oviposition period. Cercariae were expelled at the same time as the hatching of snail embryos (during the higher water temperature period). Rediae affected male and female snails equally, but prevalence increases along with host size. The parasite causes the complete castration of the host. Parasitized adult snails showed a reduction of penis size in comparison with healthy males. It remains to be confirmed whether the peak of cercariae emission coincides with the presence of jellyfishes and scombrid or other fishes in the area, which could act as second intermediate and definitive hosts, respectively.
The dust ion acoustic waves propagation in collisional dusty plasmas with dust charge fluctuations: Effect of ion loss and ionization
Authors: EL-LABANY S. K. , SHALABY M. , EL-SHAMY E. F. , KHALED M. A.
Published: February 2010

In the present research paper, the nonlinear propagation of dust ion acoustic solitary waves in a collisional dusty plasma, which consists of negatively charged small dust grains, positively charged ions and isothermal electrons with background neutral particles, is investigated. The low rates compared to the ion oscillation frequency, of the charge-fluctuation dynamics of the dust grains, the ionization, ion-neutral and dust-neutral collisions (i.e. weak dissipations) are considered. Using the reductive perturbation theory, a damped Korteweg-de Vries (DKdV) equation is derived. On the other hand, the dynamics of solitary waves at a critical phase velocity is governed by a damped modified Korteweg-de Vries (DMKdV) equation. The nonlinear properties of dust ion acoustic waves in the presence of weak dissipations in the two cases are discussed.
On Sidgwick's Demise: A Reply to Professor Deigh
Authors: SKELTON ANTHONY
Published: February 2010

In ‘Sidgwick's Epistemology’, John Deigh argues that Henry Sidgwick'sThe Methods of Ethics‘was not perceived during his lifetime as a major and lasting contribution to British moral philosophy’ and that interest in it declined considerably after Sidgwick's death because the epistemology on which it relied ‘increasingly became suspect in analytic philosophy and eventually [it was] discarded as obsolete’. In this article I dispute these claims.
Size noun constructions as collocationally constrained constructions: lexical and grammaticalized uses
Authors: BREMS LIESELOTTE
Published: February 2010

Basing myself on synchronic and diachronic data analysis, I argue in this article that size nouns (SNs) such asbunch/load(s)/heap(s) ofwithin binominal NPs display synchronic variation which can be hypothesized to be the result of grammaticalization processes. Synchronically, I propose that SNs have two major non-head uses, a quantifier use, e.g.a bunch of people walked in, and a valuing(-quantifying) use, in which the referent is evaluated rather than quantified. The latter is restricted mainly tobunch/load of, e.g.What a bunch of gobbledygook. The semantic and syntactic reanalysis of SNs as quantifiers has recently been acknowledged (e.g. Traugott forthcoming), but the valuing use of SNs remains largely unrecognized (see Brems 2007). On a theoretical level, it will be argued that head, quantifier and valuing(-quantifier) SN-uses synchronically have to be studied ascollocationally constrained constructionsin that the semantico-syntactic parsing of each SN-use links up with specific collocational patterns (Sinclair 1991). Head uses are restricted to sets of (un)count concrete nouns, whereas quantifier uses team up with all sorts of (un)count concrete as well as abstract nouns. Valuing uses show restrictions to concrete animate and abstract nouns, which they typically evaluate negatively, and have negative semantic prosody patterns, in which the SNs themselves come to predict negative collocates (see Louw 1993; Stubbs 1995; Bublitz 1996). The grammaticalization of SNs will be hypothesized to involve not only processes of semantic generalization and collocational extension, but also collocational reclusterings characterized by particular semantic prosody constraints. The latter are not traditionally associated with processes of grammaticalization and hence offer new insights into the semantic changes that may accompany grammaticalization.
Tracing global biogeochemical cycles and meridional overturning circulation using chromophoric dissolved organic matter
Authors: Nelson Norman B. , Siegel David A. , Carlson Craig A. , Swan Chantal M.
Published: February 2010

Basin‐scale distributions of light absorption by chromophoric dissolved organic matter (CDOM) are positively correlated (R2 > 0.8) with apparent oxygen utilization (AOU) within the top kilometer of the Pacific and Indian Oceans. However, a much weaker correspondence is found for the Atlantic (R2 < 0.05). Strong correlation between CDOM and AOU indicates that CDOM is created as a byproduct of the oxidation of organic matter from sinking particles. The observed meridional‐depth sections of CDOM result from a balance between biogeochemical processes (autochthonous production and solar bleaching) and the meridional overturning circulation. Rapid mixing in the Atlantic dilutes CDOM in the interior and implies that the time scale for CDOM accumulation is greater than ∼50 years. CDOM emerges as a unique tracer for diagnosing changes in biogeochemistry and the overturning circulation, similar to dissolved oxygen, with the additional feature that it can be quantified from satellite observation.
Atmospheric Ionization Module Osnabrück (AIMOS): 2. Total particle inventory in the October–November 2003 event and ozone
Authors: Wissing J. M. , Kallenrode M.‐B. , Wieters N. , Winkler H. , Sinnhuber M.
Published: February 2010

Precipitating solar protons contribute to ozone depletion in the atmosphere; α particles and electrons also precipitate during solar energetic particle (SEP) events. If the SEP is accompanied by a shock, then magnetospheric particles can also be injected into the atmosphere as the shock hits the magnetosphere. Both particle species in both particle populations show distinct energy spectra (and thus penetration depth in the atmosphere) and precipitate in different regions: the SEP inside the polar cap and the magnetospheric particles inside the auroral oval. In this paper, we reevaluate the 3‐D spatial and temporal precipitation patterns of these particle populations for the October–November 2003 event and compare the results to conventional approaches using only protons in evaluating SEP consequences. The main results are as follows: (1) The 3‐D model AIMOS gives a very differentiated picture of the global ionization maps; (2) if only protons are considered, the differences between the 3‐D model and the conventional approach of homogeneous precipitation inside the polar cap are small in NOx production and ozone depletion in the mesosphere and stratosphere; and (3) the consideration of electrons in addition to protons leads to significant increases in atmospheric ionization in the mesosphere, less so in the stratosphere. This is reflected in changes in the chemical composition as shown here for ozone depletion and an increase of NOx.
Source model of the 2007 Mw 8.0 Pisco, Peru earthquake: Implications for seismogenic behavior of subduction megathrusts
Authors: Sladen A. , Tavera H. , Simons M. , Avouac J. P. , Konca A. O. , Perfettini H. , Audin L. , Fielding E. J. , Ortega F. , Cavagnoud R.
Published: February 2010

We use Interferometric Synthetic Aperture Radar, teleseismic body waves, tsunami waveforms recorded by tsunameters, field observations of coastal uplift, subsidence, and runup to develop and test a refined model of the spatiotemporal history of slip during the Mw 8.0 Pisco earthquake of 15 August 2007. Our preferred solution shows two distinct patches of high slip. One patch is located near the epicenter while another larger patch ruptured 60 km further south, at the latitude of the Paracas peninsula. Slip on the second patch started 60 s after slip initiated on the first patch. We observed a remarkable anticorrelation between the coseismic slip distribution and the aftershock distribution determined from the Peruvian seismic network. The proposed source model is compatible with regional runup measurements and open ocean tsunami records. From the latter data set, we identified the 12 min timing error of the tsunami forecast system as being due to a mislocation of the source, caused by the use of only one tsunameter located in a nonoptimal azimuth. The comparison of our source model with the tsunami observations validate that the rupture did not extend to the trench and confirms that the Pisco event is not a tsunami earthquake despite its low apparent rupture velocity (<1.5 km/s). We favor the interpretation that the earthquake consists of two subevents, each with a conventional rupture velocity (2–4 km/s). The delay between the two subevents might reflect the time for the second shock to nucleate or, alternatively, the time it took for afterslip to increase the stress level on the second asperity to a level necessary for static triggering. The source model predicts uplift offshore and subsidence on land with the pivot line following closely the coastline. This pattern is consistent with our observation of very small vertical displacement along the shoreline when we visited the epicentral area in the days following the event. This earthquake represents, to our knowledge, one of the best examples of a link between the geomorphology of the coastline and the pattern of surface deformation induced by large interplate ruptures.
Estimating uplift rate histories from river profiles using African examples
Authors: Roberts Gareth G. , White Nicky
Published: February 2010

We describe and apply a method for estimating uplift rate histories from longitudinal river profiles. Our strategy is divided into three parts. First, we develop a forward model, which calculates river profiles from uplift rate histories. Height variation along a river profile is controlled by uplift rate and moderated by the erosional process. We assume that the erosional process can be represented by a combination of advection and diffusion, which are parameterized using four erosional constants. Second, we have posed and solved the geologically more interesting inverse problem: which uplift rate history minimizes the misfit between calculated and observed river profiles? The inverse algorithm has been tested on synthetic river profiles, which demonstrates that uplift rate histories can be reliably retrieved. Our tests show that the erosional process is dominated by advection (i.e., knickpoint retreat) and that changes in lithology and discharge play a secondary role in determining the transient form of a river profile. Finally, we have inverted river profiles from a series of African topographic swells, namely the Bié, South African, Namibian, Hoggar, and Tibesti domes. Fits between calculated and observed river profiles are excellent. Calculated uplift rate histories suggest that these domes grew rapidly during the last 30–40 million years. Uplift rate histories vary significantly from dome to dome but cumulative uplift histories agree closely with independent geologic estimates.
Methane emissions from a freshwater marsh in response to experimentally simulated global warming and nitrogen enrichment
Authors: Flury Sabine , McGinnis Daniel F. , Gessner Mark O.
Published: February 2010

We determined methane (CH4) emissions in a field enclosure experiment in a littoral freshwater marsh under the influence of experimentally simulated warming and enhanced nitrogen deposition. Methane emissions by ebullition from the marsh composed of Phragmites australis were measured with funnel traps deployed in a series of enclosures for two 3 week periods. Diffusive fluxes were estimated on the basis of measured CH4 concentrations and application of Fick's law. Neither diffusive nor ebullitive fluxes of methane were significantly affected by warming or nitrate enrichment, possibly because variability both within and among replicate experimental enclosures was high. Average emission rates resulted primarily from ebullition (0.2–30.3 mmol CH4 m−2 d−1), which were 4 orders of magnitude higher than estimated diffusive fluxes and were of similar importance as the coarsely estimated advective methane transport through plants. Significant correlations between dissolved oxygen and dissolved methane and ebullition flux suggest that methane release from the sediment might feed back positively on methane production by reducing dissolved oxygen in the water column and oxygen flux into the sediment. Nitrate may have a similar effect. Extrapolation of our limited data indicates that total methane fluxes from vegetated littoral zones of temperate lakes may contribute 0.5%–7% of the global natural CH4 emissions. These results emphasize the importance of freshwater marshes as sources of methane emissions to the atmosphere, even when they occupy only relatively small littoral areas. More detailed investigations are clearly needed to assess whether global warming and nitrogen deposition can have climate feedbacks by altering methane fluxes from these wetlands.
On the spatiotemporal variability of soil moisture and evapotranspiration in a mountainous basin within the North American monsoon region
Authors: Vivoni Enrique R. , Rodríguez Julio C. , Watts Christopher J.
Published: February 2010

In the North American monsoon (NAM) region, in‐phase seasonality in precipitation and radiation should lead to corresponding changes in the catchment hydrologic response and its spatiotemporal variability. Nevertheless, relatively little is known on the catchment response in the NAM region because of the paucity of observations. Numerical watershed models, tested against field and remote sensing data, can aid in identifying catchment hydrologic patterns and the controls exerted by climate, soil, vegetation, and terrain properties. In this study, we utilize a distributed hydrologic model to explore the soil moisture and evapotranspiration distributions in a semiarid mountain basin. Results indicate a reliable and consistent model performance at the point and catchment scales for a set of tested hydrologic states and fluxes. Distributed model simulations reveal that soil, vegetation, and terrain controls on catchment spatial patterns vary according to the wetness state in a manner similar to that found across a wider range of climate conditions. Spatiotemporal variations in soil moisture and evapotranspiration exhibit hysteresis as an emergent pattern induced by climate variability and the underlying hydrologic interactions in the catchment.
Aqueous solubilization of photochromic compounds by bile salt aggregates
Authors: Li Rui , Santos Cerize S. , Norsten Tyler B. , Morimitsu Kentaro , Bohne Cornelia
Published: February 2010

Bile salt aggregates in water readily solubilize aqueous insoluble photochromic compounds.
Interaction of vacuum ultraviolet excimer laser radiation with fused silica. I. Positive ion emission
Authors: George Sharon R. , Leraas John A. , Langford S. C. , Dickinson J. T.
Published: February 2010

We report time- and mass-resolved measurements of Si+ and O+ emission from ultraviolet-grade fused silica during exposure to pulsed 157 nm excimer laser radiation at fluences below the threshold for optical breakdown. The emission intensities are increased by treatments that increase the density of surface defects, such as abrasion, and are reduced by treatments that reduce the density of surface defects, such as annealing. Ion emission is a sensitive probe of mechanical damage on silica surfaces. The mean ion kinetic energies are typically several eV: 8–9 eV for Si+ and about 4 eV for O+. Hartree–Fock studies of candidate defect sites suggest that antibonding states excited by 157 nm photons play a critical role in the release of these ions. We propose that positive ion emission from fused silica under these conditions is best explained by a hybrid mechanism involving (a) the excitation of an antibonding chemical state (Menzel–Gomer–Redhead mechanism) and (b) the acceleration of the positive ion by repulsive electrostatic forces due to the photoionization of nearby electron traps.
Fundamental experiments on evaporation of cesium in ion sources
Authors: Fantz U. , Gutser R. , Wimmer C.
Published: February 2010

Basic experiments are carried out to study the cesium evaporation and desorption from surfaces at different temperatures in an environment, which is very close to the conditions of negative hydrogen ion sources for fusion applications: in a vacuum base pressure of 10−5 mbar and in a hydrogen plasma in the Pa-range. Several diagnostic techniques such as emission and absorption spectroscopy, a surface ionization detector, and a quartz-microbalance have been utilized to determine the cesium densities, evaporation and desorption rates. The work function of a cesiated surface measured by the photoelectric effect degrades with increasing plasma-off time. Impurities and cesium compounds are detected by a residual mass analyzer.
Ion beam oscillation due to fluctuation of a hot filament driven magnetized plasma
Authors: Imakita S. , Miyamoto N. , Kasuya T. , Kimura Y. , Wada M.
Published: February 2010

Ion beam current extracted from a modified Bernas type ion source occasionally exhibits an oscillation at a frequency of several 100 kHz. Increase in the strength of a linear magnetic field induced to the ion source has either decreased or increased the frequency of this oscillation. The frequency showed an increase in proportion to the ion extraction voltage when the frequency decreased with increasing magnetic field. The change of extraction voltage did not affect the frequency when the frequency increased with the increasing magnetic field. Mechanisms causing these oscillations of an ion beam had been investigated.
Enhancement in ion beam current with layered-glows in a constricted dc plasma ion source
Authors: Park Yeong-Shin , Hwang Y. S.
Published: February 2010

High current mode has been discovered and investigated in a constricted dc plasma ion source. As discharge currents exceed a certain threshold, voltage to sustain the constricted dc plasma suddenly falls down to almost half of the value. In this sense, constricted dc plasmas can be sustained at much higher current than in conventional mode operation at a fixed discharge voltage. Phenomenally, several discrete layered-glows are created between an anode glow and a cathode glow. The layers are thin and divided by dark spaces where charged particles can be accelerated. In this high current mode, ion beam current density is about 100 times higher than in conventional mode at the same voltage. It is noteworthy that lower gas pressure is desirable to sustain the layered-glow mode, which is also profitable for ion source in terms of differential pumping. Ion current density exceeds 300 mA/cm2 at low discharge power of 175 W where ion density of plasma ball is estimated to be over 3.7×1012 cm−3.
Progress in ion source injector development at the ion beam therapy center (Heidelberg Ion Beam Therapy Center)
Authors: Winkelmann T. , Cee R. , Haberer T. , Naas B. , Peters A.
Published: February 2010

Radiotherapy with heavy ions is an upcoming cancer treatment method with to date unachieved precision. It associates higher control rates particularly for radio-resistant tumor species with reduced adverse effects compared to conventional photon therapy. At Heidelberg Ion Beam Therapy Center two 14.5 GHz electron cyclotron resonance ion sources are routinely used to produce a variety of ion beams from protons up to oxygen. The operating time is 330 days per year; our experience after 3 yr of continuous operation will be presented, with special emphasis on stability and breakdowns of components. In addition, the latest enhancement and the results for the operation will be shown.
Intermittent contact scanning nonlinear dielectric microscopy
Authors: Hiranaga Yoshiomi , Cho Yasuo
Published: February 2010

Intermittent contact scanning nonlinear dielectric microscopy (IC-SNDM) was developed as a novel technique for surface topography measurements and observation of domain structures. Domain structures on ferroelectric single crystals were observed with nanoscale resolution using IC-SNDM. The reproducibility of measurements was improved in comparison to a conventional SNDM operated under contact mode, because the tip and/or sample damage are reduced when using intermittent contact mode. The minimum loading force of the probe to provide basic performance was experimentally determined for IC-SNDM.
Ultrafast studies of carrier and magnetization dynamics in GaMnAs
Authors: Zahn J. P. , Gamouras A. , March S. , Liu X. , Furdyna J. K. , Hall K. C.
Published: February 2010

We have investigated the carrier and magnetization dynamics in a GaMnAs structure with perpendicular uniaxial anisotropy using time-resolved pump probe techniques. Experiments were performed over two orders of magnitude variation in pump fluence, revealing an ultrafast demagnetization response that saturates at fluence values larger than 1 mJ/cm2. Dichroic bleaching contributions exhibit no dependence on the circular polarization state of the pump beam, indicating no signature of electron spin dynamics, in contrast to experiments at similar pump pulse fluence in other III-Mn-V semiconductors. We observe no evidence of a transient hole spin depolarization despite the strong demagnetization effects in our experiments, suggesting that more studies are needed to elucidate the influence of hot holes on the nonlinear optical response of diluted magnetic semiconductors. Differential reflectivity experiments indicate an electron trapping time of 1 ps, followed by carrier recombination on a time scale of several nanoseconds. The demagnetization observed is incomplete, reaching only 80% of the equilibrium magnetization at saturation. We attribute this to the optical saturation of the band edge absorption in GaMnAs.
The algebra of Grassmann canonical anticommutation relations and its applications to fermionic systems
Authors: Keyl Michael , Schlingemann Dirk-M.
Published: February 2010

We present an approach to a noncommutativelike phase space which allows to analyze quasifree states on the algebra of canonical anti-commutation relations (CAR) in analogy to quasifree states on the algebra of canonical commutation relations (CCR). The used mathematical tools are based on a new algebraic structure the “Grassmann algebra of canonical anticommutation relations” (GAR algebra) which is given by the twisted tensor product of a Grassmann and a CAR algebra. As a new application, the corresponding theory provides an elegant tool for calculating the fidelity of two quasifree fermionic states which is needed for the study of entanglement distillation within fermionic systems.
Constitutive modeling of intrinsic silicon monocrystals in easy glide
Authors: Cochard J. , Yonenaga I. , Gouttebroze S. , M’Hamdi M. , Zhang Z. L.
Published: February 2010

Constitutive modeling of silicon materials is currently restricted to the very early stage of deformation. Uniaxial tensile testing of monocrystals oriented for single glide is traditionally simulated by a scalar model relying on the so-called machine equation. The present work uses a crystal plasticity framework to identify the role of secondary slip systems in the yield region. A three-dimensional finite element model of a tensile apparatus is validated by comparison of its outputs to the results yielded by a scalar formulation. Best fits of the constitutive model of Alexander and Haasen to experimental data reveal strong variations in its parameters with temperature. An improved constitutive model for intrinsic silicon monocrystals deformed in single slip is described. Its parameters are identified as analytical functions of temperature. We show its excellent agreement with the observed steady state of deformation in stage I.
Optical transition dynamics in ZnO/ZnMgO multiple quantum well structures with different well widths grown on ZnO substrates
Authors: Li Song-Mei , Kwon Bong-Joon , Kwack Ho-Sang , Jin Li-Hua , Cho Yong-Hoon , Park Young-Sin , Han Myung-Soo , Park Young-Sik
Published: February 2010

We report the optical properties of ZnO/ZnMgO multiple quantum well (MQW) structures with different well widths grown on ZnO substrates by molecular beam epitaxy. Photoluminescence (PL) spectra show MQW emissions at 3.387 and 3.369 eV for the ZnO/ZnMgO MQW samples with well widths of 2 and 5 nm, respectively, due to the quantum confinement effect. Time-resolved PL results show an efficient photogenerated carrier transfer from the barrier to the MQWs, which leads to an increased intensity ratio of the well to barrier emissions for the ZnO/ZnMgO MQW sample with the wider well width.