bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy of mulberry leaf tablets in patients with mild dyslipidemia
Authors: Aramwit Pornanong , Petcharat Kanokwan , Supasyndh Ouppatham
Published: August 2010

Mulberry leaf is well known for its several biological effects. The purpose of this study was to evaluate the hypolipidemic effect of mulberry leaf in non‐diabetic patients with mild dyslipidemia. A within‐subjects research design was conducted at the out‐patient clinic in Thailand. Twenty‐three patients who met the NCEP ATP III criteria guideline for dyslipidemia and failed a 4 week diet therapy were enrolled and assigned to receive three tablets of 280 mg mulberry leaf tablet three times a day before meals for a period of 12 weeks. Routine blood analyses including lipid parameters and liver function tests were performed every 4 weeks. At 4 and 8 weeks of mulberry leaf tablet therapy, triglyceride was significantly decreased by 10.2% (p < 0.05) and 12.5% (p < 0.05), respectively, from baseline. At the end of the study, total cholesterol, triglyceride and LDL were significantly decreased by 4.9% (p < 0.05), 14.1% (p < 0.05) and 5.6% (p < 0.05), respectively, from baseline, whereas HDL was significantly increased by 19.7% (p < 0.05). Even though some patients experienced side effects such as mild diarrhea (26%), dizziness (8.7%) or constipation and bloating (4.3%), mulberry leaf tablet therapy is still capable and safe in reducing cholesterol levels and enhancing HDL in patients with mild dyslipidemia. Copyright © 2010 John Wiley & Sons, Ltd.
Exclusivity in licensing alliances: using hostages to support technology commercialization
Authors: Somaya Deepak , Kim Youngjun , Vonortas Nicholas S.
Published: August 2010

We examine why exclusivity provisions are used in licensing alliances, and when restrictions in licensing scope (e.g., by product or geography) accompany these exclusivity provisions. We find broad support for the proposition that these features are associated with the contractual challenges of allying with licensees when they contribute valuable complementary capabilities toward the commercialization of licensed technologies. Evidence from our data suggests that exclusivity is used as a contractual hostage to safeguard licensee investments in complementary assets and to enable contracting over early stage technologies. Scope restrictions are employed to balance the tradeoffs between the value creation made possible by licensee complementary capabilities and the transactional hazards entailed in working exclusively with licensees. Our results also suggest that scope restrictions and other formal safeguards may be substitute mechanisms for managing similar transactional concerns in licensing alliances. Copyright © 2010 John Wiley & Sons, Ltd.
Fibroblast Growth Factor Type 2 Signaling Is Critical for DNA Repair in Human Keratinocyte Stem Cells
Authors: Harfouche Ghida , Vaigot Pierre , Rachidi Walid , Rigaud Odile , Moratille Sandra , Marie Mélanie , Lemaitre Gilles , Fortunel Nicolas O. , Martin Michèle T.
Published: August 2010

Tissue stem cells must be endowed with superior maintenance and repair systems to ensure genomic stability over multiple generations, which would be less necessary in more differentiated cells. We previously reported that human keratinocyte stem cells were more resistant to ionizing radiation toxicity than their direct progeny, the keratinocyte progenitor cells. In the present study we addressed the mechanisms underlying this difference. Investigations of DNA repair showed that both single and double DNA strand breaks were repaired more rapidly and more efficiently in stem cells than in progenitors. As cell signaling is a key regulatory step in the management of DNA damage, a gene profiling study was performed. Data revealed that several genes of the fibroblast growth factor type 2 (FGF2) signaling pathway were induced by DNA damage in stem cells and not in progenitors. Furthermore, an increased content of the FGF2 protein was found in irradiated stem cells, both for the secreted and the cellular forms of the protein. To examine the role of endogenous FGF2 in DNA repair, stem cells were exposed to FGF2 pathway inhibitors. Blocking the FGF2 receptor (FGF receptor 1) or the kinase (Ras-mitogen-activated protein kinase 1) resulted in a inhibition of single and double DNA strand-break repair in the keratinocyte stem cells. Moreover, supplementing the progenitor cells with exogenous FGF2 activated their DNA repair. We propose that, apart from its well-known role as a strong mitogen and prosurvival factor, FGF2 helps to maintain genomic integrity in stem cells by activating stress-induced DNA repair.
Pulmonary hemorrhage in type 3 Gaucher disease: a case report
Authors: Vellodi Ashok , Ashworth Michael , Finnegan Niamh , Wallis Colin
Published: August 2010

A 2‐year‐old boy with type 3 Gaucher disease (GD) on treatment with enzyme replacement therapy (ERT) was found dead in bed having been apparently well the night before. At the time of diagnosis, he had significant respiratory symptoms (severe and persistent bouts of coughing) that had been attributed to Gaucher lung infiltration and that were controlled by inhaled and orally administered steroids. These symptoms had begun to reappear just prior to death. Postmortem revealed extensive pulmonary hemorrhage and intra‐alveolar collections of Gaucher cells. There was very little evidence of GD elsewhere. Death was ascribed to pulmonary hemorrhage secondary to GD. The pathogenesis was unclear. To the best of our knowledge, this is the first case of isolated pulmonary hemorrhage secondary to GD and may represent a hitherto unrecognized complication of this condition. Given the apparent temporal relationship, we propose that it represented a severe, terminal event in the course of Gaucher lung disease.
Enhanced Aortic Macrophage Lipid Accumulation and Inflammatory Response in LDL Receptor Null Mice Fed an Atherogenic Diet
Authors: Wang Shu , Wu Dayong , Matthan Nirupa R. , Lamon‐Fava Stefania , Lecker Jaime L. , Lichtenstein Alice H.
Published: August 2010

The effect of an atherogenic diet on inflammatory response and elicited peritoneal macrophage (Mϕ) cholesterol accumulation in relation to aortic lesion formation was assessed in LDL receptor null (LDLr−/−) mice. Mice were fed an atherogenic or control diet for 32 weeks. The atherogenic relative to control diet resulted in significantly higher plasma monocyte chemoattractant protein‐1 (MCP‐1), tumor necrosis factor alpha (TNFα) and interleukin‐6 (IL‐6) concentrations, more aortic wall Mϕ deposition, higher serum non HDL‐cholesterol concentrations and total cholesterol to HDL‐cholesterol ratios, and greater accumulation of both aortic free and esterified cholesterol. Elicited peritoneal Mϕ selectively accumulated longer chain unsaturated fatty acids in their membrane, independent of the dietary fatty acid profile. Elicited peritoneal Mϕ isolated from mice fed the atherogenic relative to control diet had significantly less arachidonic acid levels, accumulated significantly higher esterified cholesterol, had significantly higher mRNA levels and secretion of MCP‐1, and mRNA and protein levels of ATP‐binding cassette A1. Diet treatment had no significant effect in elicited peritoneal Mϕ on TNFα and IL‐6 mRNA levels and secretion. These data suggest that the atherogenic relative to control diet resulted in higher plasma inflammatory factor concentrations, less favorable lipoprotein profile, higher elicited peritoneal Mϕ cholesterol accumulation and inflammatory factor secretion, and more aortic wall Mϕ deposition, which in turn were associated with greater aortic cholesterol accumulation.
Immediate hip spica is as effective as, but more efficient than, flexible intramedullary nailing for femoral shaft fractures in pre-school children
Authors: Jauquier Nicolas , Doerfler Martina , Haecker Frank-Martin , Hasler Carol , Zambelli Pierre-Yves , Lutz Nicolas
Published: August 2010

Flexible intramedullary nailing (FIN) is the gold standard treatment for femur fracture in school-aged children. It has been performed successfully in younger children, although Spica cast immobilisation (SCI) has been the most widely used strategy to date.

Method

A retrospective analysis was performed between two comparable groups of children aged 1–4 years with a femoral shaft fracture. Two University hospitals, each using specific treatment guidelines, participated in the study: SCI in Group I (Basel, Switzerland) and FIN in Group II (Lausanne, Switzerland).

Results

Group I included 19 children with a median age of 26 months (range 12–46 months). Median hospital stay was 1 day (range 0–5 days) and casts were retained for a median duration of 21 days (range 12–29 days). General anaesthesia was used in six children and sedation in four. Skin breakdown secondary to cast irritation occurred in two children (10.5%). The median follow-up was 114 months (range 37–171 months). No significant malunion was noted. Group II included 27 children with a median age of 38.4 months (range 18.7–46.7 months). Median hospital stay was 4 days (range 1–13 days). All children required general anaesthesia for insertion and removal of the nails. Free mobilisation and full weight bearing were allowed at a median of 2 days (range 1–10 days) and 7 days (range 1–30 days), respectively, postoperatively. Nail exteriorisation was noted in three children (11%). The median follow-up was 16.5 months (range 8–172 months). No significant malunion was reported.

Conclusions

Young children with a femoral shaft fracture treated by SCI or FIN had similarly favourable outcomes and complication rates. FIN allowed earlier mobilisation and full weight bearing. Compared to SCI, a greater number of children required general anaesthesia. In a pre-school child with a femoral shaft fracture, immediate SCI applied by a paediatric orthopaedic team following specific guidelines allowed early discharge from hospital with few complications.
White matter neuron alterations in schizophrenia and related disorders
Authors: Connor Caroline M. , Crawford Benjamin C. , Akbarian Schahram
Published: August 2010

Increased density and altered spatial distribution of subcortical white matter neurons (WMNs) represents one of the more well replicated cellular alterations found in schizophrenia and related disease. In many of the affected cases, the underlying genetic risk architecture for these WMN abnormalities remains unknown. Increased density of neurons immunoreactive for Microtubule‐Associated Protein 2 (MAP2) and Neuronal Nuclear Antigen (NeuN) have been reported by independent studies, though there are negative reports as well; additionally, group differences in some of the studies appear to be driven by a small subset of cases. Alterations in markers for inhibitory (GABAergic) neurons have also been described. For example, downregulation of neuropeptide Y (NPY) and nitric oxide synthase (NOS1) in inhibitory WMN positioned at the gray/white matter border, as well as altered spatial distribution, have been reported. While increased density of WMN has been suggested to reflect disturbance of neurodevelopmental processes, including neuronal migration, neurogenesis, and cell death, alternative hypotheses—such as an adaptive response to microglial activation in mature CNS, as has been described in multiple sclerosis –should also be considered. We argue that larger scale studies involving hundreds of postmortem specimens will be necessary in order to clearly establish the subset of subjects affected. Additionally, these larger cohorts could make it feasible to connect the cellular pathology to environmental and genetic factors implicated in schizophrenia, bipolar disorder, and autism. These could include the 22q11 deletion (Velocardiofacial/DiGeorge) syndrome, which in some cases is associated with neuronal ectopias in white matter.
Genotoxic and carcinogenic risks associated with the dietary consumption of repeatedly heated coconut oil
Authors: Srivastava Smita , Singh Madhulika , George Jasmine , Bhui Kulpreet , Murari Saxena Anand , Shukla Yogeshwer
Published: August 2010

Repeated heating of vegetable oils at high temperatures during cooking is a very common cooking practice. Repeated heating of edible oils can generate a number of compounds, including polycyclic aromatic hydrocarbons (PAH), some of which have been reported to have carcinogenic potential. Consumption of these repeatedly heated oils can pose a serious health hazard. The objectives of the present study were to evaluate the genotoxic and carcinogenic risks associated with the consumption of repeatedly heated coconut oil (RCO), which is one of the commonly consumed cooking and frying medium. The PAH were analysed using HPLC in fresh CO, single-heated CO (SCO) and RCO. Results revealed the presence of certain PAH, known to possess carcinogenic potential, in RCO when compared with SCO. Oral intake of RCO in Wistar rats resulted in a significant induction of aberrant cells (P < 0·05) and micronuclei (P < 0·05) in a dose-dependent manner. Oxidative stress analysis showed a significant (P < 0·05) decrease in the levels of antioxidant enzymes such as superoxide dismutase and catalase with a concurrent increase in reactive oxygen species and lipid peroxidation in the liver. In addition, RCO given alone and along with diethylnitrosamine for 12 weeks induced altered hepatic foci as noticed by alteration in positive (γ-glutamyl transpeptidase and glutathione-S-transferase) and negative (adenosine triphosphatase, alkaline phosphatase and glucose-6-phosphatase) hepatospecific biomarkers. A significant decrease in the relative and absolute hepatic weight of RCO-supplemented rats was recorded (P < 0·05). In conclusion, dietary consumption of RCO can cause a genotoxic and preneoplastic change in the liver.
More localized automorphisms of the Cuntz algebras
Authors: Conti Roberto , Kimberley Jason , Szymański Wojciech
Published: August 2010

We completely determine the localized automorphisms of the Cuntz algebras $\mathcal{O}_n$ corresponding to permutation matrices in Mn ⊗ Mn for n = 3 and n = 4. This result is obtained through a combination of general combinatorial techniques and large scale computer calculations. Our analysis proceeds according to the general scheme proposed in a previous paper, where we analysed in detail the case of $\mathcal{O}_2$ using labelled rooted trees. We also discuss those proper endomorphisms of these Cuntz algebras which restrict to automorphisms of their respective diagonals. In the case of $\mathcal{O}_3$ we compute the number of automorphisms of the diagonal induced by permutation matrices in M3 ⊗ M3 ⊗ M3.
Liberalism after Burczak: redistribution, worker self-management and the market process
Authors: ANDERSSON DAVID EMANUEL
Published: August 2010

InSocialism after Hayek, Theodore Burczak uses Hayekian insights to argue in favor of a socialist society with real markets, but also with wealth redistribution and prohibition of wage labor. In so doing, he offers not only a socialist vision but also asks questions that may challenge Hayekian liberals to reformulate their institutional analyses. A critical assessment that combines Austrian and institutional theories leads to the conclusion that some redistributive policies may enhance the knowledge-disseminating function of markets, but that a market order that is limited to worker-managed firms diminishes the knowledge dissemination properties of the market process.
Substrate controls on the longitudinal profile of bedrock channels: Implications for reach‐scale roughness
Authors: Goode Jaime R. , Wohl Ellen
Published: August 2010

In this paper we examine the relationships among bedrock properties and hydraulics in shaping bedrock channel morphology at the reach scale. The Ocoee River and four other bedrock streams in the Blue Ridge province of the southeastern United States, which have reach‐scale differences in bedrock erodibility controlled by lithologic and structural variation, are the focus of this study. We describe a simple conceptual model for concentrated erosion in bedrock channels and test three hypotheses in order to investigate the interactions among rock erodibility, characteristics of undulating rib‐like bed forms, reach‐scale gradient, and hydraulic roughness and energy dissipation. Substrate differences correlate with variation in reach morphology (i.e., gradient, bed form orientation, and amplitude), such that less erodible substrates are associated with steeper reach gradient and with transversely oriented ribs of greater amplitude. One‐dimensional modeling in HEC‐RAS indicated that in the reach with the least erodible substrate and greatest bed slope and rib amplitude, the reach‐averaged hydraulic roughness was the greatest. Increased hydraulic roughness in steeper reaches points to the importance of positive and negative feedbacks in these systems: Greater substrate erosional resistance limits profile lowering, which likely creates steeper bed slopes and greater stream power, creating a self‐enhancing feedback. This local increase in stream power is balanced by increased roughness resulting from the erosional processes that produce bedrock ribs, which represents a self‐regulating feedback. The overall result reflects quantifiable adjustments between substrate resistance and hydraulic driving forces in bedrock channels.
On the poleward boundary of the nightside auroral oval under northward interplanetary magnetic field conditions
Authors: Lee D.‐Y. , Ohtani S. , Lee J. H.
Published: August 2010

In this paper we examined the dependence of the poleward boundary of the nightside auroral oval on interplanetary magnetic field (IMF) conditions. In particular, we performed the study for periods after the IMF Bz becomes northward at or some time during the recovery phase of major storms. For the selected periods, we used the precipitating particle energy flux observed by the Defense Meteorological Satellite Program satellites to determine the poleward boundary of the nightside oval. The following results were obtained. (1) We confirmed the expected result that under a more strongly northward IMF Bz, the poleward boundary of the nightside oval tends to be located more poleward, implying a smaller polar cap. (2) However, it tends to take a very long time after the IMF Bz turns northward for the polar cap size to substantially reduce (e.g., ∼15 h or longer for a poleward movement by ∼5°). This is likely because the magnetosphere during the selected northward IMF periods was still under the substantial influence of the preceding southward IMF conditions associated with the storm's main phase and also because a finite IMF By can support dayside reconnection to sustain an open polar cap region of substantial size. (3) We found that for a given sign of the IMF By, the poleward boundary of the nightside oval is asymmetric between premidnight and postmidnight regions in a given hemisphere and between hemispheres at a given magnetic local time region. For example, for a positive IMF By, the Northern (Southern) Hemispheric oval boundary is more poleward (equatorward) in the premidnight region, and the situation is opposite in the postmidnight region and for a negative IMF By. We suggest a possible reason that may be responsible for the asymmetry. (4) A similar (in an opposite sense) asymmetric feature can be seen with the IMF Bx but only when the IMF happens to be of a Parker spiral angle type. We conclude that the magnetosphere during the recovery phase of major storms likely remains open even after the IMF turns northward and the polar cap field lines are still connected to the IMF. The role of the finite IMF By is prominent in determining both the size and shape of the polar cap, which can affect details of the dynamical evolution during the storm recovery phase.
The 2007 M5.4 Alum Rock, California, earthquake: Implications for future earthquakes on the central and southern Calaveras Fault
Authors: Oppenheimer David H. , Bakun William H. , Parsons Tom , Simpson Robert W. , Boatwright John , Uhrhammer Robert A.
Published: August 2010

The similarity of seismograms recorded by two seismic stations demonstrate that the 31 October 2007 moment magnitude M5.4 Alum Rock earthquake is a repeat of a 1955 ML5.5 earthquake. Both occurred on Oppenheimer et al.'s (1990) Zone V “stuck patch” on the central Calaveras fault, providing new support for their model of Calaveras fault earthquake activity. We suggest that Zone V fails only in a family of recurring M ∼ 5.4–5.5 earthquakes. The 1955 and 2007 earthquakes are the penultimate and ultimate Zone V events. Earthquakes in 1891 and 1864 are possible earlier Zone V events. The next Zone V event is not expected in the next few decades, assuming a time‐dependent recurrence model: the mean forecast date is 2064 (2035–2104, 95% confidence range). We further suggest that Zones I, II, III, and IV fail in recurring M ∼ 5.1–5.3, M ∼ 5.6–5.8, M ∼ 6.1–6.3, and M ∼ 4.9–5.0 earthquakes, respectively. If our earthquake recurrence model is correct, the next Zone I event is overdue and could occur anytime, and M5–6 earthquakes should not occur on Zones II, III, and IV before 2014, 2012, and 2026, respectively. We cannot rule out the possibility that Zone VI, which lies at the southern end of the Mission Seismic Trend, where the southern Hayward and central Calaveras faults appear to connect at depth, fails aseismically or in large events on the southern Hayward fault, such as last occurred in 1868, or in large events on the adjoining northern Calaveras fault segment.
Phase relations and equation of state of a natural MORB: Implications for the density profile of subducted oceanic crust in the Earth's lower mantle
Authors: Ricolleau Angèle , Perrillat Jean‐Philippe , Fiquet Guillaume , Daniel Isabelle , Matas Jan , Addad Ahmed , Menguy Nicolas , Cardon Hervé , Mezouar Mohamed , Guignot Nicolas
Published: August 2010

The phase relations and density of a natural mid‐ocean ridge basalt (MORB) were investigated from 28 to 89 GPa and 1600 to 2700 K by in situ X‐ray diffraction measurements and chemical analysis of the quenched samples using transmission electron microscopy (TEM). We observed an assemblage of five phases up to 50 GPa, namely an aluminum‐bearing magnesium perovskite phase, a calcium perovskite phase, a stishovite phase, the new aluminum‐rich (NAL) phase, and a calcium ferrite‐type phase. The NAL phase was no longer observed above 50 GPa. The phase proportions were obtained by Rietveld refinement of the in situ X‐ray diffraction patterns. After the disappearance of the NAL phase beyond 50 GPa, the proportion of each phase remains constant up to 89 GPa. The density of MORB was calculated using the measured volumes, phase proportions, and chemical compositions of the coexisting phases. The thermoelastic parameters of the MORB sample were estimated from the fit of the measured densities at various pressure and temperature conditions. Resulting MORB density profiles were calculated for different subducting slab temperature profiles. MORB densities are 0.5% to 2% greater than those of the surrounding mantle over the entire lower mantle range, suggesting MORB likely subducts to the core–mantle boundary.
Dyke propagation and sill formation in a compressive tectonic environment
Authors: Menand T. , Daniels K. A. , Benghiat P.
Published: August 2010

Sills could potentially form as a result of dykes modifying their trajectory in response to remote tectonic compression. Here, we use analogue experiments to investigate how a buoyant vertical dyke adjusts its trajectory to a compressive remote stress to form a sill, and over which vertical distance this sill formation does occur. Our investigation is restricted to an intrusion propagating through a homogeneous solid, which enables us to identify the characteristic length‐scale over which a dyke responds to remote stress compression, independently of the presence of crustal layers. The experiments involve the injection of air in a gelatine solid that experiences lateral deviatoric compression. The response of the buoyant air crack to the compressive stress in not instantaneous but operates over some distance. An important observation is that some cracks reach the surface despite the compressive environment. Dyke‐to‐sill rotation occurs only for large compressive stress or small effective buoyancy. Dimensional analysis shows that the length‐scale over which this rotation takes place increases exponentially with the ratio of crack effective buoyancy to horizontal compressive stress. Up‐scaled to geological conditions, our analysis indicates that a dyke‐to‐sill transition in response to tectonic compression in homogeneous rocks cannot occur over less than two hundred meters and would need several kilometers in most cases. This is typically greater than the average thickness of lithological units, which supports the idea that crustal heterogeneities play an important role in determining the fate of dykes and in controlling where sills could form.
Fine‐ and microstructure observations in the Urup Strait, Kuril Islands, during August 2006
Authors: Itoh S. , Yasuda I. , Nakatsuka T. , Nishioka J. , Volkov Y. N.
Published: August 2010

For the first time, we performed continuous observations of turbulent mixing upon the sill of the Urup Strait, Kuril Islands, for a period of 1 day during August of 2006. Time series of velocity profiles, water properties, and isopycnal depths show variability with a period of about 1 day; however, the water mass variability is not explained by simple water exchange between the Sea of Okhotsk and the North Pacific. Empirical orthogonal function (EOF) analysis of isopycnal coordinates extracted variability presumed to represent tidal flows as major EOFs. In profiles of the residual flow after subtracting the mean flow and major EOFs, we detected phase propagations consistent with internal gravity waves, with an approximate period of 9.1–11.4 h. The turbulent energy dissipation rate ɛ and vertical diffusivity Kρ ranged from 1 × 10−9 to 3 × 10−8 W kg−1 and from 3 × 10−5 to 2 × 10−3 m2s−1, respectively. Occurrences of high dissipation rates generally corresponded to either strong shear or weak stratification. A significant contribution of shear S to the dissipation rate ɛ was indicated with a relationship of ɛ ∼ S1.4–S1.8, probably related to propagating internal waves. A strong mixing event was observed within the water column, with extremely weak stratification and a Richardson number below the critical value of 0.25, when the flow direction changed from up‐sill to down‐sill.
HCFC‐22 flux estimates over East Asia by inverse modeling from hourly observations at Hateruma monitoring station
Authors: Shirai Tomoko , Yokouchi Yoko , Sugata Seiji , Maksyutov Shamil
Published: August 2010

A series of high‐frequency observations of chlorodifluoromethane (HCFC‐22) at Hateruma Island (latitude 24.1°N, longitude 123.8°E) was used to evaluate the strength of various sources in East Asia by a tracer transport inversion. The forward calculation was conducted with a regional meteorological model using an online tracer transport scheme, and the inversion calculation used a Bayesian approach. On the basis of winter observations during 2005–2007, we estimated the annual HCFC‐22 emission from China to be 32 Gg, which is nine times current estimates. The total uncertainty of the Chinese emission was reduced from 50% (a priori) to 15% (a posteriori) by the inversion calculation. A sensitivity study showed that the a posteriori values for China showed little dependency on the a priori values, whereas those for Japan, Korea, and Taiwan were considerably affected by the a priori values used. This can be explained by the more frequent high‐concentration events from China observed at the Hateruma site. The a posteriori emission estimates from central China accounted for half of the total emissions from China.
Variations of the Antarctic Circumpolar Current intensity during the past 500 ka
Authors: Mazaud A. , Michel E. , Dewilde F. , Turon J. L.
Published: August 2010

We examine the past variations of the Antarctic Circumpolar Current (ACC) by using variations in size and abundance of the magnetic grains deposited by this current at a site east the Kerguelen‐Crozet plateau. Core MD00‐2375G was taken at a midlatitude site during the ANTAUS cruise conducted in 2000 by the French R/V Marion Dufresne. Marine isotope stages (MIS) down to MIS 13 are identified, and an age model is derived from a correlation to the ice core isotopic record obtained from EPICA in Antarctica. Continuous records of abundance and size of the magnetic grains were obtained using environmental magnetism methods. Results show a strong modulation of the ACC flow intensity in response to glacial and interglacial cycles. The low abundance and the small size of magnetic grains indicate that the ACC was weak during warm stages and strong during glacial epochs. A large modulation is also observed at the sub‐stage scale during the interglacials. A minimum in concentration and grain size occurs at the onset of MIS 11. At the MIS 6–5, 10–9, and possibly 12–11 transitions, observed variations suggest a mechanism involving both rapid and progressive variations of the ACC flow at deglaciations.
Iceberg calving during transition from grounded to floating ice: Columbia Glacier, Alaska
Authors: Walter Fabian , O'Neel Shad , McNamara Daniel , Pfeffer W. T. , Bassis Jeremy N. , Fricker Helen Amanda
Published: August 2010

The terminus of Columbia Glacier, Alaska, unexpectedly became ungrounded in 2007 during its prolonged retreat. Visual observations showed that calving changed from a steady release of low‐volume bergs, to episodic flow‐perpendicular rifting, propagation, and release of very large icebergs ‐ a style reminiscent of calving from ice shelves. Here, we compare passive seismic and photographic observations through this transition to examine changes in calving. Mechanical changes accompany the visible changes in calving style post flotation: generation of seismic energy during calving is substantially reduced. We propose this is partly due to changes in source processes.
Salmonella transcriptional signature in Tetrahymena phagosomes and role of acid tolerance in passage through the protist
Authors: Rehfuss Marc Yi Ming , Parker Craig Thomas , Brandl Maria Theresa
Published: August 2010

Salmonella enterica Typhimurium remains undigested in the food vacuoles of the common protist, Tetrahymena. Contrary to its interaction with Acanthamoeba spp., S. Typhimurium is not cytotoxic to Tetrahymena and is egested as viable cells in its fecal pellets. Through microarray gene expression profiling we investigated the factors in S. Typhimurium that are involved in its resistance to digestion by Tetrahymena. The transcriptome of S. Typhimurium in Tetrahymena phagosomes showed that 989 and 1282 genes were altered in expression compared with that in water and in LB culture medium, respectively. A great proportion of the upregulated genes have a role in anaerobic metabolism and the use of alternate electron acceptors. Many genes required for survival and replication within macrophages and human epithelial cells also had increased expression in Tetrahymena, including mgtC, one of the most highly induced genes in all three cells types. A ΔmgtC mutant of S. Typhimurium did not show decreased viability in Tetrahymena, but paradoxically, was egested at a higher cell density than the wild type. The expression of adiA and adiY, which are involved in arginine-dependent acid resistance, also was increased in the protozoan phagosome. A ΔadiAY mutant had lower viability after passage through Tetrahymena, and a higher proportion of S. Typhimurium wild-type cells within pellets remained viable after exposure to pH 3.4 as compared with uningested cells. Our results provide evidence that acid resistance has a role in the resistance of Salmonella to digestion by Tetrahymena and that passage through the protist confers physiological advantages relevant to its contamination cycle.
Phonological Activation During Visual Word Recognition in Deaf and Hearing Children
Authors: Ormel Ellen , Hermans Daan , Knoors Harry , Hendriks Angelique , Verhoeven Ludo
Published: August 2010

Purpose

Phonological activation during visual word recognition was studied in deaf and hearing children under two circumstances: (a) when the use of phonology was not required for task performance and might even hinder it and (b) when the use of phonology was critical for task performance.

Method

Deaf children mastering written Dutch and Sign Language of the Netherlands were compared with hearing children. Two word–picture verification experiments were conducted, both of which included pseudohomophones. In Experiment 1, the task was to indicate whether the word was spelled correctly and whether it corresponded to the picture. The presence of pseudohomophones was expected to hinder performance only when phonological recoding occurred. In Experiment 2, the task was to indicate whether the word sounded like the picture, which now made phonological recoding essential in order to enable the acceptance of pseudohomophones.

Results

The hearing children showed automatic activation of phonology during visual word recognition, regardless of whether they were instructed to focus on orthographic information (Experiment 1) or phonological information (Experiment 2). The deaf children showed little automatic phonological activation in either experiment.

Conclusion

Deaf children do not use phonological information during word reading.
A density functional theory study of the atomic structure, formation energy, and vibrational properties of nitrogen-vacancy-oxygen defects in silicon
Authors: Karoui F. Sahtout , Karoui A.
Published: August 2010

The atomic structure, energy, stability, vibrational spectra, and infrared absorption intensities of major intrinsic nitrogen-related defects in nitrogen doped silicon crystals have been investigated using ab initio density functional theory and semi-empirical quantum mechanics methods. The defects that are of interest are nitrogen-vacancy-oxygen complexes which are believed to affect oxygen precipitation and void formation as well as nitrogen concentration measurement in nitrogen-doped silicon. Several chemical reactions involving nitrogen, Si vacancies and oxygen interstitial have been studied. After relaxation, the local vibrational modes of each complex are calculated within the harmonic oscillator approximation and the infrared absorption intensities are evaluated from the dipole moment derivatives. By cross correlating the stability and the infrared active lines of the defect, and taking into consideration the symmetry group of each complex, we were able to emphasize which nitrogen related complexes are likely to control the oxygen precipitation and voids formation and to assert a new calibration relationship for nitrogen concentration measurement in nitrogen doped Czochralski and float zone silicon wafers.
Consensus and synchronization problems on small-world networks
Authors: Gu Lei , Zhang Xiao-Dong , Zhou Qing
Published: August 2010

In this paper, it is discovered that the statistical property of the consensus and synchronization of the small-world networks, that is, the Cheeger constant, is a major determinant to measure the convergence rate of the consensus and synchronization of the small-world networks. Further, we give a mathematical rigorous estimation of the lower bound for the algebraic connectivity of the small-world networks, which is much larger than the algebraic connectivity of the regular circle. This result explains why the consensus problems on the small-world network have an ultrafast convergence rate and how much it can be improved. Moreover, it also characterizes quantitatively what kind of the small-world networks can be synchronized.
On the heating rate dependence of crystallization temperatures of metallic glasses
Authors: Zhuang Y. X. , Xing P. F. , Shi H. Y. , Chen J. , Wang P. W. , He J. C.
Published: August 2010

It is well known that the crystallization temperatures of metallic glasses show strong dependence on the heating rate. The right relationship between the crystallization temperatures and the heating rate are very important in illustrating crystallization behavior and in evaluating thermal stability of the metallic glasses. Up to now, the dependence is usually illustrated using Kissinger equation, Ozawa equation, Augis–Bennett equation, Lasocka equation, and Vogel–Fulcher–Tammann (VFT) nonlinear equation. The paper aims to exam the relationship between the crystallization temperature and the heating rates for several metallic glasses, mainly rare earth-based and Zr-based metallic glasses. The validity of the relationship has been evaluated using additional experimental data at even lower or/and higher heating rates as well as the continuous heating transformation diagrams for the metallic glasses. The difference of the five equations has been compared in the paper. Among the five equations, the Kissinger, Ozawa, and Augis–Bennett equations show similar trends for the studied metallic glasses. The VFT equation is considered as a better model to describe the heating rate dependence of the crystallization temperature for the metallic glasses investigated.
Quantum Hall Fabry–Pérot interferometer: Logic gate responses
Authors: Bellucci S. , Onorato P.
Published: August 2010

We discuss the electron transport through a quantum Hall Fabry–Pérot interferometer (QHFPI) obtained with two quantum point contacts (QPCs) in series along a ballistic quantum wire by focusing on the effects due to quantum interference and to quantum Hall effect. We calculate the conductance-energy and conductance-magnetic field characteristics as functions of the geometrical parameters and gate voltages. QHFPI may be utilized in designing electronic logic gates: XOR and OR (NOR and XNOR) gates responses are investigated. The width of each QPC is modulated by metallic electrodes where two gate voltages, namely, Va and Vb, are applied. Those external voltages are treated as the two inputs of the gates. After fixing appropriately the working Fermi energy, the magnetic field strength, and the distance between the barriers, a low output Hall current (0) (in the logical sense) appears just if both inputs are low (0), while a high output Hall current (1) results otherwise. It clearly demonstrates the OR gate behavior. By changing the parameters, a XOR gate can be produced, where a high output current (1) appears, when just one of the two inputs is low (0), while a low output current (0) results if both inputs are low (0) or high (1).
Coupling integrable couplings and bi-Hamiltonian structure associated with the Boiti–Pempinelli–Tu hierarchy
Authors: Zhang Yufeng , Fan Engui
Published: August 2010

A kind of new Lie algebra is introduced whose corresponding loop algebra is followed to define. From which two isospectral problems are established whose compatibility condition gives rise to a coupling integrable coupling of the Boiti–Pempinelli–Tu (BPT) hierarchy. By making use of the quadratic-form identity, its bi-Hamiltonian structure is obtained. Finally, we reduce the coupling integrable coupling to obtain two integrable couplings of the BPT hierarchy. Furthermore, the well-known mKdV equation and a new coupled equation with two dependent variables are produced, respectively.
Bipolar and unipolar electrical fatigue in ferroelectric lead zirconate titanate thin films: An experimental comparison study
Authors: Lou X. J. , Wang J.
Published: August 2010

By performing standard positive-up-negative-down, hysteresis-loop and dielectric measurements on the ferroelectric lead zirconate titanate thin-film capacitors subject to bipolar/unipolar electrical cycling, we show that unipolar fatigue is evident though still less severe than bipolar fatigue conducted at the same voltage. That has been attributed to a series of periodic events of polarization backswitching (driven by the residual depolarization field) and switching (driven by the residual applied field) during unipolar electrical cycling, and explained using the LPD-SICI model (LPD-SICI stands for local phase decomposition caused by switching-induced charge injection). The dielectric results have been used to estimate the effective thickness di of the fatigue-induced degraded (pyrochlorelike) interfacial layer after bipolar/unipolar fatigue, which has not been done so far to our best knowledge. The fact that di is still much less than the film thickness even after the most severe bipolar fatigue strongly suggests that polarization fatigue in ferroelectrics is an interface effect, not a bulk one.
Composition and phase dependence of the intrinsic and extrinsic piezoelectric activity of domain engineered (1−x)Pb(Mg1/3Nb2/3)O3−xPbTiO3 crystals
Authors: Li Fei , Zhang Shujun , Xu Zhuo , Wei Xiaoyong , Luo Jun , Shrout Thomas R.
Published: August 2010

The piezoelectric response of [001] poled domain engineered (1−x)Pb(Mg1/3Nb2/3)O3−xPbTiO3 (PMN-PT) crystals was investigated as a function of composition and phase using Rayleigh analysis. The results revealed that the intrinsic (reversible) contribution plays a dominant role in the high piezoelectric activity for PMN-PT crystals. The intrinsic piezoelectric response of the monoclinic (MC) PMN−xPT crystals, 0.31≤x≤0.35, exhibited peak values for compositions close to R-MC and MC-T phase boundaries, however, being less than 2000 pC/N. In the rhombohedral phase region, x≤0.30, the intrinsic piezoelectric response was found to increase as the composition approached the rhombohedral-monoclinic (R-MC) phase boundary. The maximum piezoelectric response was observed in rhombohedral PMN-0.30PT crystals, being on the order of 2500 pC/N. This ultrahigh piezoelectric response was determined to be related to the high shear piezoelectric activity of single domain state, corresponding to an ease in polarization rotation, for compositions close to a morphotropic phase boundary (MPB). The role of monoclinic phase is only to form a MPB with R phase, but not directly contribute to the ultrahigh piezoelectric activity in rhombohedral PMN-0.30PT crystals. The extrinsic contribution to piezoelectric activity was found to be less than 5% for the compositions away from R-MC and MC-T phase boundaries, due to a stable domain engineered structure. As the composition approached MPBs, the extrinsic contribution increased slightly (<10%), due to the enhanced motion of phase boundaries.
External efficiency and carrier loss mechanisms in InAs/GaInNAs quantum dot light-emitting diodes
Authors: Montes M. , Hierro A. , Ulloa J. M. , Guzmán A. , Al Khalfioui M. , Hugues M. , Damilano B. , Massies J.
Published: August 2010

The electroluminescence (EL) characteristics of a set of InAs/GaInNAs quantum dot (QD) light-emitting diodes with varying In and N contents are analyzed. Room-temperature EL around 1.5 μm is obtained with 15% In and 2% N in the QD capping layer. It is shown that the addition of N results in a degradation of the external efficiency, ηext, probably due to an increase in the nonradiative recombination in the QD heterostructure and an increase in the carrier escape from the QD to the capping layer, which yield a degradation of the current injection efficiency into the QD. Nevertheless, ηext can be partially recovered if a postgrowth rapid thermal annealing is performed, although this also results in a blueshift in the EL peak wavelength. The different contributions to the EL spectra are also analyzed and identified by looking at their dependence on injected current and temperature. It is found that N-containing devices show two radiative transitions. The lowest energy transition has been ascribed to the QD ground state recombination, whereas the higher energy transition has been attributed to recombination of carriers confined in the capping layer. Moreover, the carrier loss mechanisms responsible for the quenching of the EL in the dilute nitride-based devices are studied. It is found that the EL thermal quenching has an activation energy which can be ascribed to carrier escape from the QD to the capping layer.
Nonlocal spin valves with thin Co electrodes for spin-transfer
Authors: Zou H. , Wang X. J. , Ji Y.
Published: August 2010

Cobalt/copper nonlocal spin valve devices with AlOx barriers are fabricated for the purpose of spin-transfer with a pure spin current. The submicron planar device consists of a Co spin injector (F1), a Co spin detector (F2), and a Cu channel. The F2 Co electrode is only 2.5 nm thick, but sizable nonlocal spin signals of 2–4 mΩ are measured at 4.2 K. The spin-transfer switching has been achieved with the assistance of a magnetic field. The magnetizations of F1 and F2 electrodes are set to an antiparallel state by sweeping the magnetic field. The magnetic field is then held at a value smaller but close to the switching field of F2. A small dc current (0.1–1 mA) is sufficient to switch F2 into being parallel with F1. Analysis has been done to rule out possible artifacts due to Oersted fields.
Highly doped layers as efficient electron–hole recombination contacts for tandem organic solar cells
Authors: Timmreck Ronny , Olthof Selina , Leo Karl , Riede Moritz K.
Published: August 2010

A key feature of stacked organic solar cells is an efficient recombination contact at the interface between the solar cells in the stack. Here, an electron current has to be converted into a hole current without loss of energy. Furthermore, the recombination contact has to be highly transparent. We present a new approach for small molecule organic solar cells using highly doped organic layers. Our approach adapts the use of tunnel diodes known from inorganic tandem solar cells. We compare a metal cluster based recombination contact reported in literature to the new approach using different organic tandem solar cell structures. For this purpose, current-voltage characteristics of adequate solar cells are measured. The experiments show that highly doped layers as recombination contacts in tandem organic solar cells are superior to the metal cluster based approach. The proposed concept allows an addition of the open circuit voltages of the subcells of a tandem solar cell, without absorption or reflection at the recombination contact. The results further show that our concept does not depend on the specific choice of materials as it is seen for metal cluster based recombination contacts. It therefore represents a general approach which is compatible to mass manufacturing.
The melting curve of ten metals up to 12 GPa and 1600 K
Authors: Errandonea Daniel
Published: August 2010

The melting curve of Mg, Mn, Cu, Ag, Au, Zn, Cd, Al, In, and Pb has been measured up to 12 GPa using a Bridgman-type cell. Melting at high-pressure was identified detecting discontinuities in the electrical resistance of the studied metals. The results are compared with previous experimental and theoretical studies when possible. A comparison with the Lindemann’s law predictions is also done. In particular we found that among the studied metals Pb has the steepest melting curve (dTM/dP=78 K/GPa). In contrast, Mn has the flattest melting curve (dTM/dP=29 K/GPa). The reported results suggest that the electronic structure of an element might play a key role in determining the pressure dependence of its melting curve.
Transistor gating by polar molecular monolayers
Authors: Shaya O. , Einati H. , Fishelson N. , Shacham-Diamand Y. , Rosenwaks Y.
Published: August 2010

In order to determine the role of polar monolayers in molecular-gated transistors we combine Kelvin probe force microscopy and current-voltage measurements of hybrid silicon-on-insulator metal-oxide-semiconductor field-effect transistors. Layers having alternating net-dipole direction were self-assembled on the top dielectric layer of the transistors. Nonzero field-effect was observed only with an amine-terminated monolayer and is attributed to the protonation of the amine groups. No correlation between the field-effect and the net-dipole of the molecular layers was found; this effect is discussed and explained.