bluuebunny/crossref_metadata_2025 huggingface dataset:
Oncoplastic Breast‐Conserving Surgery: Analysis of Quadrantectomy and Immediate Reconstruction with Latissimus Dorsi Flap
Authors: Hernanz Fernando , Regaño Sara , Redondo‐Figuero Carlos , Orallo Victoria , Erasun Fernando , Gómez‐Fleitas Manuel
Published: August 2007

Background

Oncoplastic breast‐conserving surgery satisfies oncologic principles and improves cosmetic outcomes, even when an important breast volume excision is required.

Methods

We reviewed 28 patients suffering from breast cancer treated with quadrantectomy and immediate myocutaneous latissimus dorsi flap reconstruction. We evaluated the status of the surgical margins, early complications, and cosmetic outcome. Cosmetic assessment was carried out by a panel made up of three women and one man: a female member of an association against breast cancer, a female general practitioner, a female gynecologic resident, and a male breast‐specialized surgeon.

Results

Free margins were obtained in all cases. There were 11 postoperative complications: 9 seromas at the donor site, 1 dehiscence of the back wound, and 1 minor partial flap skin necrosis. Chemotherapy and radiotherapy adjuvant treatment was not compromised. The cosmesis outcome was deemed to be good in 43.75% of the cases and satisfactory in 56.25%. The score for overall cosmesis outcome was 6.92 out of 10. Symmetry and the scar of the reconstructed breast were the most influential criteria in the quantitative assessment of overall cosmetic results.

Conclusion

Partial mastectomy (quadrantectomy) and immediate reconstruction with a myocutaneous latissimus dorsi flap allows extensive resection, which fits oncologic requirements, without serious morbidity and a good cosmetic outcome.
Recommendation Recall and Satisfaction After Attending Breast/Ovarian Cancer Risk Counseling
Authors: Bober Sharon L. , Hoke Lizbeth A. , Duda Rosemary B. , Tung Nadine M.
Published: August 2007

This study examined women's recall of physician recommendations as well as patient satisfaction following participation in a breast/ovarian cancer risk and prevention program. Participants were 41 high risk women who attended a cancer risk program 4–6 months earlier. Two‐thirds of women who received recommendations for tamoxifen treatment and genetic testing did not recall these recommendations upon follow‐up. A number of women misunderstood recommendations and a quarter of the sample recalled recommendations that were not made during the consultation. Although these high risk women were generally satisfied with their counseling visit, those individuals who received particularly complex sets of recommendations reported feeling less understood and were less satisfied with the counseling. Findings underline the importance of examining recommendation recall, in addition to perceptions of cancer risk, when evaluating the clinical implications of cancer risk assessment.
Small‐scale spatial variability in the diet of pampas foxes (Pseudalopex gymnocercus) and human‐induced changes in prey base
Authors: Farias Ariel A. , Kittlein Marcelo J.
Published: August 2007

Predators display functional responses to variation in prey availability that result in dietary distinction at different spatial scales. Such differentiation can be enhanced when human‐induced changes in land use increase spatial heterogeneity in prey availability. This has been recorded for canids, but available information is skewed to regional scales. Further, though human activities have strongly altered neotropical biomes, knowledge about small‐scale dietary differentiation of canids come mainly from holartic species. Thus, we quantified variability in the diet of a ubiquitous South American canid species (i.e., the pampas fox, Pseudalopex gymnocercus) over a relatively small area of grasslands in Argentina, comparing its diet at three close sampling sites varying in human disturbance. We found that small‐scale dietary differentiation was influenced by human‐induced habitat modifications, both directly by local subsidizing of introduced prey (e.g., livestock carrion and hares) and indirectly by altering the availability of native prey. Overall, pampas foxes seemed to be highly flexible in their trophic ecology, being able to cope with marked habitat alterations and likely benefiting from food cross‐subsidizing from agricultural landscape to protected grassland relicts. This has implications for management and conservation purposes, and highlights the importance of quantifying variability in foraging behavior of carnivores over small spatial scales.
Optimal Partitioning of a Data Set Based on the p-Median Model
Authors: Brusco Michael J. , Köhn Hans-Friedrich
Published: August 2007

Although the K-means algorithm for minimizing the within-cluster sums of squared deviations from cluster centroids is perhaps the most common method for applied cluster analyses, a variety of other criteria are available. The p-median model is an especially well-studied clustering problem that requires the selection of p objects to serve as cluster centers. The objective is to choose the cluster centers such that the sum of the Euclidean distances (or some other dissimilarity measure) of objects assigned to each center is minimized. Using 12 data sets from the literature, we demonstrate that a three-stage procedure consisting of a greedy heuristic, Lagrangian relaxation, and a branch-and-bound algorithm can produce globally optimal solutions for p-median problems of nontrivial size (several hundred objects, five or more variables, and up to 10 clusters). We also report the results of an application of the p-median model to an empirical data set from the telecommunications industry.
Oxidative degradation kinetics of lycopene, lutein, and 9‐cis and all‐trans β‐carotene
Authors: Henry L. K. , Catignani G. L. , Schwartz S. J.
Published: August 2007

The thermal and oxidative degradation of carotenoids was studied in an oil model system to determine their relative stabilities and the major β‐carotene isomers formed during the reaction. All‐trans β‐carotene, 9‐cis β‐carotene, lycopene, and lutein were heated in safflower seed oil at 75, 85, and 95°C for 24, 12, and 5 h, respectively. The major isomers formed during heating of β‐carotene were 13‐cis, 9‐cis, and an unidentified cis isomer. The degradation kinetics for the carotenoids followed a first‐order kinetic model. The rates of degradation were as follows: lycopene>all‐trans β‐carotene≈9‐cis β‐carotene>lutein. The values for the thermodynamic parameters indicate that a kinetic compensation effect exists between all of the carotenoids. These data suggest that lycopene was most susceptible to degradation and lutein had the greatest stability in the model system of the carotenoids tested. Furthermore, there was no significant difference in the rates of degradation for 9‐cis and all‐trans β‐carotene under the experimental conditions.
Hydrophobicity, solubility, and emulsifying properties of soy protein peptides prepared by papain modification and ultrafiltration
Authors: Wu W. U. , Hettiarachchy N. S. , Qi M.
Published: August 2007

Peptide size control is important for obtaining desirable functional properties so that these peptides can be better utilized. Proteolytic enzymatic modification of soy protein isolates (SPI), followed by ultrafiltration, is an effective way to fractionate these proteins into peptides with controlled molecular size. SPI was predenatured by mild alkali at pH 10 and heated at 50°C for 1 h prior to partial hydrolysis by papain at pH 7.0 and 38°C for 10, 30, and 60 min (PMSPI10, PMSPI30, and PMSPI60). The hydrolysate PMSPI60 was further fractionated by ultrafiltration with a stirred cell and disc membranes (100‐, 50‐, and 20‐kDa molecular weight cut‐off) into one retentate (R100) and three permeates (P100, P50, and P20). Molecular weight distribution, surface hydrophobicity (S0), protein solubility (PS), emulsifying activity index (EAI), and emulsion stability index (ESI) of the control SPI (without added papain), hydrolysates, and ultrafiltrates were investigated. Significant increases (P<0.001) in S0, PS, EAI, and ESI were observed in the hydrolysates. Peptides in the permeates had higher PS and EAI but lower S0 than the peptides in the retentate and hydrolysate. Soy protein peptides that were prepared from SPI by papain modification and ultrafiltration had lower molecular weight, higher solubility, and higher emulsifying properties. They could find use in products that require these properties, especially in the cosmetic and health food industries.
Fatty acid bioconversions by Pseudomonas aeruginosa PR3
Authors: Kuo T. M. , Manthey L. K. , Hou C. T.
Published: August 2007

The bioconversions of oleic acid, linoleic acid, and ricinoleic acid by Pseudomonas aeruginosa PR3 were investigated. The conversion of oleic acid to 7,10‐dihydroxy‐8(E)‐octadecenoic acid (DOD) was improved to better than 80% yields by modifying the culture medium and reaction parameters. The microbial cultures were stable and retained the same level of DOD production capacity for up to 6 mon as examined herewith. Strain PR3 did not bioconvert linoleic acid. However, strain PR3 converted ricinoleic acid to a novel compound, 7,10,12‐trihydroxy‐8(E)‐octadecenoic acid (TOD), with a yield of about 35%. The product was further metabolized by strain PR3. TOD was purified by thin‐layer chromatography, and its structure was determined by 1H and 13C nuclear magnetic resonance and mass spectrometry. This is the first report on the production of 7,10,12‐trihydroxy unsaturated fatty acid by microbial transformation.
Effect of enzymatic transesterification on the melting points of palm stearin‐sunflower oil mixtures
Authors: Lai O. M. , Ghazali H. M. , Chong C. L.
Published: August 2007

Transesterification with lipases may be used to convert mixtures of fats to plastic fats, making them more suitable for use in edible products. In our study, 1,3‐specific (Aspergillus niger, Mucor javanicus, Rhizomucor miehei, Rhizopus javanicus, and Rhizopus niveus) and nonspecific (Pseudomonas sp. and Candida rugosa) lipases were used to transesterify mixtures of palm stearin and sunflower oil (PS‐SO) at a 40:60 ratio in a solvent‐free medium. The transesterified mixtures of PS‐SO were analyzed for their percentage free fatty acids (FFA), degree and rate of transesterification, solid fat content, slip melting point (SMP), and melting characteristics by differential scanning calorimetry. Results indicated that Pseudomonas sp. lipase produced the highest degree (77.3%) and rate (50.0 h−1) of transesterification, followed by R. miehei lipase at 32.7% and 27.1 h−1, respectively. The highest percentage FFA liberated was also in the reaction mixtures catalyzed by Pseudomonas sp. (2.5%) lipase and R. miehei (2.4%). Pseudomonas‐catalyzed mixtures produced the biggest drop in SMP (13.5°C) and showed complete melting at below body temperature. All results indicated conversion of the PS‐SO mixtures to a more fluid product. The findings also suggest that the specificity of lipases may not play a significant role in lowering the melting point of the PS‐SO mixtures.
Coating properties of alkyd‐ketonic (cyclohexanone formaldehyde) resin blends
Authors: Athawale V. D. , Chamankar A. V.
Published: August 2007

The present article describes the preparation and coating properties of long oil‐length alkyd and ketonic (cyclohexanone formaldehyde) resin blends. A unique solvent system, which shows a one‐phase clear solution and a clear coat of the binder system, was used. The scope of the article is to produce a better combination of properties than those of the individual components. It has been observed that, when a 30% concentration of ketonic resin was blended with the alkyd resin, a significant improvement in adhesion, hardness, gloss, storage stability, acid resistance, and drying time was achieved over that of the alkyd resin alone.
Genetik der idiopathischen Epilepsien
Authors: Sander T. , Gaus V.
Published: August 2007

Die idiopathischen Epilepsien sind ätiologisch überwiegend genetisch determiniert und repräsentieren etwa 40% aller Epilepsien. Mutationen in Genen von Ionenkanälen spielen eine zentrale Rolle bei der Pathogenese von eher monogenen Epilepsieformen. Molekulargenetische Forschungsansätze bei den häufigen genetisch komplexen Epilepsien stehen noch am Anfang der Aufklärung der molekularen Mechanismen der Epileptogenese. Erst die umfassende Identifizierung der wichtigsten genetischen Risikofaktoren wird es ermöglichen, verlässliche individuelle Risikoprofile zu erstellen und präventiv ausgerichtete Therapieansätze zu entwickeln.
CAMTAs: Calmodulin‐binding transcription activators from plants to human
Authors: Finkler Aliza , Ashery-Padan Ruth , Fromm Hillel
Published: August 2007

Recently, a novel family of calmodulin‐binding transcription activators (CAMTAs) was reported in various eukaryotes. All CAMTAs share a similar domain organization, with a novel type of sequence‐specific DNA‐binding domain (designated CG‐1). This domain could bind DNA directly and activate transcription, or interact with other transcription factors, not through DNA binding, thus acting as a co‐activator of transcription. Investigations of CAMTAs in various organisms imply a broad range of functions from sensory mechanisms to embryo development and growth control, highlighted by the apparent involvement of mammalian CAMTA2 in cardiac growth, and of CAMTA1 in tumor suppression and memory performance.
Eukaryotic initiation factor 2α kinase is a nitric oxide‐responsive mercury sensor enzyme: Potent inhibition of catalysis by the mercury cation and reversal by nitric oxide
Authors: Martinkova Marketa , Igarashi Jotaro , Shimizu Toru
Published: August 2007

The activity of one of the eukaryotic initiation factor 2α kinases, heme‐regulated inhibitor (HRI), is modulated by heme binding. Here, we demonstrate for the first time that Hg2+ strongly inhibits the function of HRI (IC50
= 0.6 μM), and nitric oxide fully reverses this inhibition. Other divalent metal cations, such as Fe2+, Cu2+, Cd2+, Zn2+ and Pb2+, also significantly inhibit kinase activity with IC50 values of 1.9–8.5 μM. Notably, inhibition by cations other than Hg2+ is not reversed by nitric oxide. Our present data support dual roles of Hg2+ and nitric oxide in the regulation of protein synthesis during cell emergency states.
Main antimicrobial components of Tinospora capillipes, and their mode of action against Staphylococcus aureus
Authors: Yu Yan , Yi Zhi-biao , Liang Yi-Zeng
Published: August 2007

In this investigation, the antibacterial modes of action of Radix Tinosporae, its major single components, and nine antibiotics with different targets or modes‐of‐action on Staphylococcus aureus were studied. Metabolic profiles of cultures treated with different medicines were acquired by HPLC/ESI‐MS. After HPLC‐MS data pretreatment, those profiles acquired were reduced into several MS vectors. Then statistical processing by principal components analysis was carried out upon those vectors, two conclusions could be drawn: (1) the antibacterial mode of action of Radix Tinosporae is similar to that of rifampicin and norfloxacin, which act on nucleic acid; (2) its active components playing main antimicrobial roles on Staphylococcus aureus might be alkaloids, such as palmatine and jatrorrhizine.
Genetic diversity of cultivated and wild-type peanuts evaluated with M13-tailed SSR markers and sequencing
Authors: BARKLEY NOELLE A. , DEAN ROB E. , PITTMAN ROY N. , WANG MING L. , HOLBROOK CORLEY C. , PEDERSON GARY A.
Published: August 2007

Thirty-one genomic SSR markers with a M13 tail attached were used to assess the genetic diversity of the peanut mini core collection. The M13-tailed method was effective in discriminating almost all the cultivated and wild accessions. A total of 477 alleles were detected with an average of 15·4 alleles per locus. The mean polymorphic information content (PIC) score was 0·687. The cultivated peanut (Arachis hypogaea L.) mini core produced a total of 312 alleles with an average of 10·1 alleles per locus. A neighbour-joining tree was constructed to determine the interspecific and intraspecific relationships in this data set. Almost all the peanut accessions in this data set classified into subspecies and botanical varieties such as subsp. hypogaea var. hypogaea, subsp. fastigiata var. fastigiata, and subsp. fastigiata var. vulgaris clustered with other accessions with the same classification, which lends further support to their current taxonomy. Alleles were sequenced from one of the SSR markers used in this study, which demonstrated that the repeat motif is conserved when transferring the marker across species borders. This study allowed the examination of the diversity and phylogenetic relationships in the peanut mini core which has not been previously reported.
Poetic Genius and Poetic Jinni: The Case of Ibn Shuhayd
Authors: STETKEVYCH SUZANNE PINCKNEY
Published: August 2007

Long appreciated for its combination of lyric charm and mordant wit, Ibn Shuhayd al-Andalusi's (992–1035) Risalat al-tawabiʿ wa-l-zawabiʿ (Epistle of Attendant Jinn and Whirling Demons), as I have argued recently, also offers a sophisticated treatise on poetic influence and inspiration. Composed around 1013–17, the epistle consists of the young poet's highly ironic and parodic defense against accusations of plagiarism leveled by one Abu Bakr ibn Hazm. The epistle, as edited by Butrus al-Bustani, is divided into an introduction and four chapters on the attendant jinn of poets, the attendant jinn of writers (kuttāb), the jinn of critics, and animal jinn. These are held together by the conceit of a visit by Ibn Shuhayd, conducted by his own attendant jinni (“poetic muse”), Zuhayr, to the Valley of the Jinn. During what I have termed his “initiatory journey,” Ibn Shuhayd encounters and tests himself against his major poetic and literary influences, attends a literary majlis, and finally is asked to serve as judge for the poetry of a group of asses and mules (presumably the jinn of his contemporaries/competitors). The journey, however parodic and humorous, provides a revealing allegory of the poet–littérateur's struggles with his poetic and literary forebears, critics, and competitors on the one hand and his individual poetic “genius” on the other hand.
Pensée 2: Between the Hammer and the Anvil: Middle East Studies in the Aftermath of 9/11
Authors: SHAMI SETENEY , GODOY-ANATIVIA MARCIAL
Published: August 2007

Although it may be too early to determine whether the events of 9/11 will significantly transform key questions and analytic approaches driving research and teaching in the field of Middle East studies (MES), we can say with certainty that 9/11 has dramatically affected the political and institutional environments within which this research and teaching takes place in the United States. Thus, “impact” or “change” must be evaluated across three distinct yet interrelated arenas: (1) the quotidian environment in which scholars, teachers, and students conduct their activities; (2) the varied institutional architectures through which research and teaching on the Middle East are undertaken inside and outside the university; and (3) the long-term intellectual history of the field.
Aesthetic Democracy: Walt Whitman and the Poetry of the People
Authors: Frank Jason
Published: August 2007

This essay argues for Walt Whitman's significance to contemporary democratic theory, neither as a theorist of moral or aesthetic individualism nor as a theorist of communitarian nationalism, but as a theorist of the democratic sublime. Whitman's account of “aesthetic democracy” emphasizes the affective and autopoetic dimensions of political life. For Whitman, popular attachment to democracy requires an aesthetic component, and he aimed to enact the required reconfiguration of popular sensibility through a poetic depiction of the people as themselves a sublimely poetic, world-making power. Through his poetic translation of the vox populi, Whitman hoped to engender a robustly transformative democratic politics. He found the resources for political regeneration in the poetics of everyday citizenship, in the democratic potentials of ordinary life.
Microbial reductive dehalogenation in Antarctic melt pond sediments
Authors: Griffin Benjamin M. , Tiedje James M.
Published: August 2007

Due to its geographic isolation and relatively limited human impact, Antarctica is a promising location to study the eco-physiology of natural halogen cycles. Anaerobic sediments from Antarctic melt ponds on Ross Island and on the McMurdo Ice Shelf near Bratina Island were tested for activity of microbial reductive dehalogenation. Anaerobic enrichment cultures were established with potential electron donors and tetrachloroethene, trichloroethene, 2-bromophenol, 2-chlorophenol, 3-bromobenzoate, or 3-chlorobenozoate, as model halocarbon electron acceptors. Dechlorination of aromatic compounds was limited, whereas 2-bromophenol was debrominated in seven of the eight sediments and one site also showed debromination of 3-bromobenzoate. A most probable number estimate with 2-bromophenol at one site revealed 103–104cultivatable debrominators per gram of sediment (wet weight). Chloroethene dechlorination was slow and primarily produced trichloroethene from tetrachloroethene, although bothcis-andtrans-dichloroethene were detected in certain enrichments upon extended incubation. These results demonstrate the presence of reductive dehalogenating activity in anaerobic, Antarctic melt-pond sediments and expand the known metabolic diversity of Antarctic microorganisms.
A projective formalism applied to topological and probabilistic event structures
Authors: ABBES SAMY
Published: August 2007

This paper introduces projective systems for topological and probabilistic event structures. The projective formalism is used for studying the domain of configurations of a prime event structure and its space of maximal elements. This is done from both a topological and a probabilistic viewpoint. We give probability measure extension theorems in this framework.
Genetic diversity of male sterile and low fertility germplasm ofCitrusrevealed using SSR markers
Authors: Qing-Qin Cao , Hai-Jun Meng , Xiao-Peng Wen , Hua-Lin Yi , Xiu-Xin Deng
Published: August 2007

The genetic diversity of 43 male sterile and low fertilityCitrusaccessions, as well as 13 fertile ones, were assessed using simple sequence repeat markers (SSRs). Thirty-five polymorphic alleles were generated from eight primers (on average 4.4 alleles per primer). Cluster analysis was performed via unweighted pair group method analysis (UPGMA) using the NTSYS-pc version 2.10. The results showed that the accessions could be classified into three groups: cultivars of mandarin were classified into group 1; those of sweet orange, grapefruit, ponkan or tangor into group 2; andMicrocitruswith male sterile cytoplasm into group 3. Cluster analysis also revealed that Satsuma mandarin was more closely related to Bendiguangju mandarin than to Zaoju, Mankieh or Huangyan Bendizao tangerine. The present study on genetic diversity of male sterile and low fertilityCitruswill provide useful information for further collection, preservation and utilization of this plant.
Genetic diversity analysis ofMystus guttatusfrom Xijiang Branch of Pearl River
Authors: Zhong-Yao Jiao , Sai Chen , Xin-Ping Zhu , He-Jun Du , Guan-Min Zheng , Kun-Ci Chen
Published: August 2007

The spotted longbarbel catfish (Mystus guttatus) is a member of the family Bagridae and is mainly distributed in the Pearl River Valley and Nandujiang River of Hainan Island. It is one of the four most famous fishes in the history of Pearl River Valley. Nowadays,M. guttatushas become a potential target for aquaculture in China due to its high nutritional value, but its genetic background is still unknown. This study was carried out to estimate its population genetic diversity in Pearl River. The random amplified polymorphic DNA (RAPD) technique was performed on 30 samples, using 20 random primers of length 10 nucleotides. The results showed that each primer amplified 3–9 bands per sample. Twenty primers produced 3210 well-amplified DNA fragments with reproducible band patterns and the average number of amplified DNA fragments reached 107 in each individual. Broadly speaking, 48 (44.9%) of 107 loci were polymorphic. Only the S30 primer did not produce polymorphic loci. The genetic distance of individuals ranged from 0.0467 to 0.2804. The average genetic distance among the 30 individuals was 0.1526±0.037. Genetic data in this study could be useful in genetic resource assessment as well as in wild population conservation and exploitation ofM. guttatusin the future.
Analysis of isozymes related to energy metabolism of adultTegillarca granosa
Authors: Xiu-Rong Su , Zhen-Ming Lv , Tai-Wu Li , Zhi-Ming Liu , Chien Paul K.
Published: August 2007

The isozymes of 10 enzymes connected with energy metabolism inTegillarca granosawere analysed by vertical polyacrylamide gel electrophoresis. Esterase and α-amylase are enzymes related to energy intake, their activities were high in the digestive gland. Malate dehydrogenase, malic enzyme, isocitrate dehydrogenase, succinate dehydrogenase, alcohol dehydrogenase, lactate dehydrogenase, 6-phosphogluconate dehydrogenase (G-6-PDH) and adenosine triphosphatase (ATPase) are enzymes related to energy metabolism. The main energy supply ofT. granosacomes from aerobic respiration; anaerobic metabolism and the pentose phosphate pathway take an auxiliary role in energy metabolism. The high activity of G-6-PDH inT. granosamight mean a considerable proportion of carbohydrates metabolized through this pathway. This reaction could provide abundant NADP for metabolism inT. granosa. Compared with other shellfish,T. granosahad lower activity of ATPase, which might have some relationship with the amnicolous life and low motility of this animal.
Mass loading of Saturn's magnetosphere near Enceladus
Authors: Khurana Krishan K. , Dougherty Michele K. , Russell Christopher T. , Leisner Jared S.
Published: August 2007

The Cassini spacecraft has made three close flybys of Enceladus. The magnetic field from the first flyby clearly showed that Enceladus acts as an obstacle to the magnetized flow resulting in field line draping. The second flyby confirmed the draping pattern but hinted that the effective source must be located below Enceladus and demonstrated that Enceladus does not possess a measurable internal magnetic field. In situ and remote sensing observations on the third flyby provided conclusive evidence of a large vent outgassing near the south pole of Enceladus and confirmed the southern offset of the center of draping. In this work, we model the magnetic field data collected from the three flybys in order to quantify the strength of the Enceladus/plasma interaction. We show that the effective diameter of the obstacle is at least 6 RE, and the obstacle is displaced by >2 RE south of Enceladus and downstream by at least ∼1 RE. The total current produced in the interaction is <105 Amps (40–60% of the Neubauer limit). We estimate that the mass picked up by the plasma within 5 RE of Enceladus is <3 kg/s. Additional pick up must be occurring in the neutral torus extending outward from the orbital location of Enceladus.
Glacio‐isostatic deformation around the Vatnajökull ice cap, Iceland, induced by recent climate warming: GPS observations and finite element modeling
Authors: Pagli Carolina , Sigmundsson Freysteinn , Lund Björn , Sturkell Erik , Geirsson Halldór , Einarsson Páll , Árnadóttir Thóra , Hreinsdóttir Sigrún
Published: August 2007

Glaciers in Iceland began retreating around 1890, and since then the Vatnajökull ice cap has lost over 400 km3of ice. The associated unloading of the crust induces a glacio‐isostatic response. From 1996 to 2004 a GPS network was measured around the southern edge of Vatnajökull. These measurements, together with more extended time series at several other GPS sites, indicate vertical velocities around the ice cap ranging from 9 to 25 mm/yr, and horizontal velocities in the range 3 to 4 mm/yr. The vertical velocities have been modeled using the finite element method (FEM) in order to constrain the viscosity structure beneath Vatnajökull. We use an axisymmetric Earth model with an elastic plate over a uniform viscoelastic half‐space. The observations are consistent with predictions based on an Earth model made up of an elastic plate with a thickness of 10–20 km and an underlying viscosity in the range 4–10 × 1018Pa s. Knowledge of the Earth structure allows us to predict uplift around Vatnajökull in the next decades. According to our estimates of the rheological parameters, and assuming that ice thinning will continue at a similar rate during this century (about 4 km3/year), a minimum uplift of 2.5 meters between 2000 to 2100 is expected near the current ice cap edge. If the thinning rates were to double in response to global warming (about 8 km3/year), then the minimum uplift between 2000 to 2100 near the current ice cap edge is expected to be 3.7 meters.
Seafloor evidence for the interaction between cascading and along‐slope bottom water masses
Authors: Trincardi Fabio , Verdicchio Giuseppe , Miserocchi Stefano
Published: August 2007

The steep slope of the SW Adriatic margin (Central Mediterranean) is impacted today by two water masses having markedly different origin but a similar southward flow component: the Levantine Intermediate Water (LIW) and the North Adriatic Deep Water (NAdDW). The LIW forms through evaporation in the eastern Mediterranean and enters the Adriatic along a counterclockwise path. The NAdDW forms through winter cooling on the North Adriatic shelf and cascades across the western slope of the South Adriatic basin. Bathymetric and side‐scan sonar (TOBI) images of the SW Adriatic margin, accompanied by Chirp sonar profiles, define an area of extreme seafloor complexity characterized by a variety of sediment waves, erosional scours, longitudinal furrows, and giant comet marks. These distinctive bottom‐current features are not randomly distributed but appear genetically linked and have a consistent down‐current arrangement. We ascribe this seafloor pattern to the constructive interference of the highly saline LIW, flowing along the slope between 200‐ and 600‐m water depth, and the cold NAdDW, plunging off‐shelf obliquely to the slope. Stratigraphic data indicate that this oceanographic regime has been active since the last glacial‐interglacial transition. The cascading NAdDW is density driven but is not short‐lived (as a turbidity current would be); consequently, the interaction between downslope and along‐slope currents is here more dynamical as two water masses act simultaneously over a prolonged interval, somewhat diverting their paths and leading to locally enhanced energetic conditions at the seafloor.
Surface water quality evaluation using multivariate methods and a new water quality index in the Indian River Lagoon, Florida
Authors: Qian Yun , Migliaccio Kati White , Wan Yongshan , Li Yuncong
Published: August 2007

Appropriate assessment of long‐term water quality monitoring data is essential to evaluation of water quality and this often requires use of multivariate techniques. Our objective was to evaluate water quality in the south Indian River Lagoon (IRL), Florida using several multivariate techniques and a comprehensive water quality index (WQI). Clustering was used to cluster the six monitoring stations into three groups, with stations on the same or characteristic‐similar canals being in the same group. The first five factors from exploratory factor analysis (EFA) explain around 70% of the total variance and were used to interpret water quality characterized by original constituents for the purpose of data reduction. Nutrient species (phosphorus and nitrogen) were major variables involved in the construction of the principal components (PCs) and factors. Seasonal and spatial differences were observed in compositional patterns of factors and principal water quality constituents. Positive or negative trends were detected for different factor at different monitoring groups identified by clustering during different seasons. The composite WQI was developed based on principal water quality constituents greatly contributing to the construction of factors which were derived from EFA. The WQI showed significant difference among the three clustering groups with the greatest WQI median in group 1 stations (C23S48, C23S97, and C24S49). Medians of WQI were significantly greater in the wet than in the dry season, which implied more natural nutrient water status during the dry than the wet season probably due to the different contribution of nonpoint sources between two seasons.
Pulse of the seafloor: Tidal triggering of microearthquakes at 9°50′N East Pacific Rise
Authors: Stroup D. F. , Bohnenstiehl D. R. , Tolstoy M. , Waldhauser F. , Weekly R. T.
Published: August 2007

Unequivocal evidence of tidal triggering is observed for microearthquakes (−0.4 to 2.0 ML) recorded between October 2003 to April 2004 near 9°50′N on the East Pacific Rise (EPR). Although semidiurnal tidal stress changes are small (<2 kPa), seismicity exhibits a significant (>99.9%) nonrandom temporal distribution, with events occurring preferentially near times of peak extension. Due to the proximity of this site to an ocean tidal node, where changes in sea surface height are minimal, periodic stress changes are dominated by the solid Earth tide. In contrast, previous studies on the Juan de Fuca Ridge have shown microearthquake triggering to be a response to seafloor unloading during times of low ocean tide. The modulation of 9°50′N microearthquakes by small‐amplitude periodic stresses is consistent with earthquake nucleation within a high stressing rate environment that is maintained near a critical state of failure by on‐axis magmatic and hydrothermal processes.
Investigation on the mesopause energetics and its possible implications on the equatorial MLTI processes through coordinated daytime airglow and radar measurements
Authors: Pant Tarun Kumar , Tiwari Diwakar , Vineeth C. , Thampi Smitha V. , Sridharan S. , Devasia C. V. , Sridharan R. , Gurubaran S. , Sekar R.
Published: August 2007

This paper investigates the simultaneous presence of a prominent planetary scale modulations of quasi 16‐day period observed in the daytime mean mesopause temperature and in the phase velocity of Type I electrojet irregularities during January–March 2001 over Trivandrum (8.5°N, 76.5°E, 0.5°N diplat.). The temperature was estimated from the Multiwavelength Dayglow Photometer (MWDPM) measurements of OH (8–3) Meinel band dayglow emissions. The radar measured phase velocity of the irregularities is found not only exhibiting ∼8 and quasi 16‐day modulations, but also exceeding the isothermal ion‐acoustic threshold i.e. ∼360 m/s for Trivandrum. The modulation in the mesopause temperature is attributed to the presence of planetary wave of quasi 16‐day periodicity. Further, it is proposed that the temperature modulations which cause composition changes in the mesopause and equatorial electrojet region manifest as changes in the phase velocity through fluctuations in ion‐neutral collisions corroborating with St.‐Maurice et al. (2003).
Characterization of a semidiurnal eastward‐propagating tide at high northern latitudes with Mars Global Surveyor electron density profiles
Authors: Cahoy K. L. , Hinson D. P. , Tyler G. L.
Published: August 2007

Apparent phase velocities of zonal structure, estimated from Mars Global Surveyor (MGS) electron density profiles, are used to identify and characterize SE1, the semidiurnal eastward‐propagating tide with zonal wave number one, at high northern latitudes during the summer of Mars Year 26. SE1 shows impressive phase stability with altitude, season, and local time. SE1 maintains a presence at amplitudes between 5 and 15% of the zonal mean at 125 ± 10 km altitude for most of the summer season. Further analyses using MGS electron density profiles will contribute to the identification and characterization of nonmigrating tides in the upper atmosphere of Mars.
Relative impacts of vegetation coverage and leaf area index on climate change in a greener north
Authors: Zhang Jing , Walsh John E.
Published: August 2007

To identify relative impacts of vegetation coverage and leaf area index (LAI) on climate in a greener north, a set of climate model sensitivity experiments was conducted in which vegetation coverage and/or LAI were increased over the land poleward of 60°N. The simulation results indicate that an increase in vegetation coverage makes a significant contribution to surface warming, while increasing LAI does not. The increased vegetation coverage reduces both background (snow‐free) and snow‐covered surface albedos and results in a maximum surface warming (>2°C) during spring and early summer. The increase in vegetation coverage also alters the partitioning between soil evaporation and vegetation evapotranspiration, and consequently reduces soil moisture loss from surface soil. Increased LAI leads to an enhancement of both convective and large scale components of precipitation, while the increase in vegetation coverage primarily increases the ratio of convective to large‐scale precipitation.
Lidar measurements of Asian dust storms and dust cloud interactions
Authors: Nee Jan B. , Chiang Chih‐Wei , Hu Huan‐ling , Hu Shun‐xing , Yu Jia‐Yuh
Published: August 2007

Long‐range transport of Asian dust storms has been investigated by using lidar at Chungli (24.6°N, 121.1°E) in 2002–2004. One of the dust storms that occurred in the period of 27–31 March 2002 was also observed by lidar at Hefei (31.9°N, 117.16°E). The lidar height distributions of dust extinction were compared with back trajectory calculation and atmospheric data including First Global GARP Experiment (FGGE)‐type ground observations and National Center for Environment Prediction/Atmospheric Research (NCEP/NCAR) reanalysis. Dust layers had an average total (aerosol and molecular) depolarization ratio (DR) about 0.2; however, formation of droplets with near‐zero depolarization ratio (0.02) was also measured. The cloud condensation nuclei (CCN) activities of dust particles were considered based on chemical properties observed from the ground. We observed that dust transport to the south may interact strongly with the moisture from the active weather system in the region producing significant climate effects.
Doubled length of western European summer heat waves since 1880
Authors: Della‐Marta P. M. , Haylock M. R. , Luterbacher J. , Wanner H.
Published: August 2007

We analyzed a new data set of 54 high‐quality homogenized daily maximum temperature series from western Europe (Austria, Belgium, Croatia, Czech Republic, Denmark, Finland, France, Germany, Ireland, Netherlands, Portugal, Spain, Sweden, Switzerland, United Kingdom) to define more accurately the change in extreme warm Daily Summer Maximum Temperature (DSMT). Results from the daily temperature homogeneity analysis suggest that many instrumental measurements in the late 19th and early 20th centuries were warm‐biased. Correcting for these biases, over the period 1880 to 2005 the length of summer heat waves over western Europe has doubled and the frequency of hot days has almost tripled. The DSMT Probability Density Function (PDF) shows significant changes in the mean (+1.6 ± 0.4°C) and variance (+6 ± 2%). These conclusions help further the evidence that western Europe's climate has become more extreme than previously thought and that the hypothesized increase in variance of future summer temperature has indeed been a reality over the last 126 years.
Water properties and potential of mean force for hydrophobic interactions of methane and nanoscopic pockets studied by computer simulations
Authors: Setny Piotr
Published: August 2007

We consider model systems consisting of a methane molecule and hemispherical pockets of subnanometer radii whose walls are made of hydrophobic material. The potential of mean force for process of translocation of the methane molecule from bulk water into the pockets’ interior is obtained, based on an explicit solvent molecular dynamics simulations. Accompanying changes in water density around the interacting objects and spatial distribution of solvent’s potential energy are analyzed, allowing for interpretation of details of hydrophobic interactions in relation to hydrophobic hydration properties. Applicability of surface area–based models of hydrophobic effect for systems of interest is also investigated. A total work for the translocation process is not dependent on pocket’s size, indicating that pocket desolvation has little contribution to free energy changes, which is consistent with the observation that solvent density is significantly reduced inside “unperturbed” pockets. Substantial solvent effects are shown to have a longer range than in case of a well investigated methane pair. A desolvation barrier is present in a smaller pocket system but disappears in the larger one, suggesting that a form of a “hydrophobic collapse” is observed.
Nanosecond delay with subpicosecond uncertainty
Authors: Larson Donald R. , Paulter Nicholas G.
Published: August 2007

We have combined a commercially available, variable-length coaxial delay line (trombone line) with a high-resolution linear translation system. The result is better resolution and lower uncertainty in the achievable delays than previously available. The range of delay is 0ps to approximately 1250ps, the bidirectional resolution is 2.0ps, the unidirectional resolution is 0.2ps, and the uncertainty (95% confidence interval) in the measured delay is ±0.09ps. Drift, temperature dependence, repeatability, linearity, and hysteresis were also examined.
New Cs sputter ion source with polyatomic ion beams for secondary ion mass spectrometry applications
Authors: Belykh S. F. , Palitsin V. V. , Veryovkin I. V. , Kovarsky A. P. , Chang R. J. H. , Adriaens A. , Dowsett M. G. , Adams F.
Published: August 2007

A simple design for a cesium sputter ion source compatible with vacuum and ion-optical systems as well as with electronics of the commercially available Cameca IMS-4f instrument is reported. This ion source has been tested with the cluster primary ions of Sin− and Cun−. Our experiments with surface characterization and depth profiling conducted to date demonstrate improvements of the analytical capabilities of the secondary ion mass spectrometry instrument due to the nonadditive enhancement of secondary ion emission and shorter ion ranges of polyatomic projectiles compared to atomic ones with the same impact energy.
Effect of Co and Fe on the inverse magnetocaloric properties of Ni-Mn-Sn
Authors: Krenke Thorsten , Duman Eyüp , Acet Mehmet , Moya Xavier , Mañosa Lluís , Planes Antoni
Published: August 2007

At certain compositions Ni-Mn-X Heusler alloys (X: group IIIA–VA elements) undergo martensitic transformations, and many of them exhibit inverse magnetocaloric effects. In alloys where X is Sn, the isothermal entropy change is largest among the Heusler alloys, particularly in Ni50Mn37Sn13, where it reaches a value of 20 J kg−1 K−1 for a field of 5 T. We substitute Ni with Fe and Co in this alloy, each in amounts of 1 and 3 at % to perturb the electronic concentration and examine the resulting changes in the magnetocaloric properties. Increasing both Fe and Co concentrations causes the martensitic transition temperature to decrease, whereby the substitution by Co at both compositions or substituting 1 at % Fe leads to a decrease in the magnetocaloric effect. On the other hand, the magnetocaloric effect in the alloy with 3 at % Fe leads to an increase in the value of the entropy change to about 30 J kg−1 K−1 at 5 T.
Simulation and optimization of GaN-based metal-oxide-semiconductor high-electron-mobility-transistor using field-dependent drift velocity model
Authors: Hu W. D. , Chen X. S. , Quan Z. J. , Zhang X. M. , Huang Y. , Xia C. S. , Lu W. , Ye P. D.
Published: August 2007

Undoped GaN-based metal-oxide-semiconductor high-electron-mobility-transistors (MOS-HEMTs) with atomic-layer-deposited Al2O3 gate dielectrics are fabricated with gate lengths from 1 μm up to 40 μm. With a two-dimensional numerical simulator, we report simulation results of the GaN-based MOS-HEMTs using field-dependent drift velocity model. A developed model, taking into account polarization-induced charges and defect-induced traps at all of the interfaces and process-related trap levels of bulk traps measured from experiments, is built. The simulated output characteristics are in good agreement with reported experimental data. The effect of the high field at the drain-side gate edge and bulk trap density of GaN on the output performance is discussed in detail for the device optimization. AlGaN/GaN/AlN quantum-well (QW) MOS-HEMTs have been proposed and demonstrated based on numerical simulations. The simulation results also link the current collapse with electrons spreading into the bulk, and confirm that a better electron localization can dramatically reduce the current collapse for the QW-MOS-HEMTs. Due to the large band edge discontinuity and effective quantum confinement of the AlGaN/GaN/AlN quantum well, the parasitic conduction in the bulk is completely eliminated.
Nucleation of HfO2 atomic layer deposition films on chemical oxide and H-terminated Si
Authors: Hackley Justin C. , Gougousi Theodosia , Demaree J. Derek
Published: August 2007

HfO 2 thin films have been deposited by an atomic layer deposition (ALD) process using alternating pulses of tetrakis-ethylmethylamino hafnium and H2O precursors at 250 °C. The as-deposited films are mainly amorphous and nearly stoichiometric HfO2 (O/Hf ratio ∼1.9) with low bonded carbon content (∼3 at. %). A comparison of the nucleation stage of the films on OH- and H-terminated Si(100) surfaces has been performed using Rutherford backscattering spectrometry, x-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). We find for the initial 5–7 process cycles that the film nucleates more efficiently on the OH-terminated surface. However, after the 7th cycle both surfaces exhibit similar surface coverage, which takes about 40 cycles to reach a steady growth rate per cycle. Angle resolved XPS measurements reveal the formation of a ∼6 Å interfacial layer after four ALD cycles on the H-terminated surface and the thickness of the interfacial layer does not change substantially between the 4th and the 50th process cycles as shown by transmission electron microscopy. Although the surface coverage is comparable for both starting surfaces, film measurements performed by SE suggest that thick films deposited on H-terminated Si are ∼5% thicker than similar films on the chemical oxide surface. Atomic force microscopy (AFM) measurements reveal higher surface roughness for the films deposited in the H-terminated surface. The SE and the AFM data are consistent with higher porosity for the films on H-terminated surfaces.
Silicon based organic semiconductor laser
Authors: Vasdekis A. E. , Moore S. A. , Ruseckas A. , Krauss T. F. , Samuel I. D. W. , Turnbull G. A.
Published: August 2007

The authors demonstrate silicon based visible lasers as potential optical interconnects by combining silicon processed resonators and solution processed light-emitting polymers. The high refractive index and absorption coefficient of silicon at these wavelengths were addressed by developing distributed Bragg reflector resonators on a silicon-on-insulator substrate. The performance of the hybrid structure was characterized and analyzed in comparison to an all-silica counterpart and mechanisms for controlling the number of longitudinal modes and for tuning the emission wavelength were explored.