bluuebunny/crossref_metadata_2025 huggingface dataset:
Kainate receptor trafficking
Authors: González‐González Inmaculada M. , Konopacki Filip A. , Rocca Daniel L. , Doherty Andrew J. , Jaafari Nadia , Wilkinson Kevin A. , Henley Jeremy M.
Published: October 2011

Kainate receptors (KARs) are ligand‐gated ion channels that can regulate neuronal network activity and are involved in processes ranging from neuronal development and differentiation to neurodegeneration and neuronal cell death. They are tetrameric assemblies which can comprise different subunit combinations and are differentially targeted to specific cell surface compartments including pre‐ and postsynaptic membranes where they perform distinct functional roles. The processes regulating the constitutive and activity‐dependent trafficking of KARs are subtle and complex. Intricate combinations of protein–protein interactions and post‐translational modifications orchestrate their surface membrane delivery, residence time, internalization, and recycling or degradation. Furthermore, in addition to regulating surface expression, interacting proteins connect receptors to anchoring and signaling pathways. Although our knowledge of the processes that regulate KAR trafficking is far from complete, there has been significant progress toward defining the roles of many of these protein partners and post‐translational modifications.WIREs Membr Transp Signal2012, 1:31–44. doi: 10.1002/wmts.23

For further resources related to this article, please visit theWIREs website.
Drosophila InsP3R mutants and their effects on cellular and systemic physiology
Authors: Agrawal Neha , Hasan Gaiti
Published: October 2011

A single gene encoding two identified splice variants of the InsP3R is found in the genome of the fruit fly Drosophila melanogaster. Mutants that perturb InsP3R function differentially have helped identify systemic processes which require the InsP3R. These include larval feeding, larval molting, fluid transport in malpighian tubules, flight circuit development, and olfactory adaptation. Genetic tools that provide spatiotemporal control on overexpression or knockdown of InsP3R in the whole organism have aided in delineating cellular domains that influence these processes. Genetic interaction studies with InsP3R mutants have helped identify several intracellular signaling components that influence InsP3R function. Measurement of their Ca2+dynamics have further revealed a complex interplay between InsP3R‐mediated Ca2+ release, the endoplasmic reticular Ca2+ pump, and components of store‐operated Ca2+ entry (STIM and Orai). Together these players modulate intracellular Ca2+ signals and homeostasis. Changes in cellular Ca2+ signals brought about by altering levels of the identified intracellular Ca2+ signaling components can be correlated with the extent of changes observed in systemic phenotypes. Furthermore, molecular studies of the Drosophila InsP3R have shown that key functional properties of the InsP3R are evolutionarily conserved. Thus, insights gained from Drosophila are likely to be relevant for our understanding of human disorders caused by aberrant InsP3R‐mediated Ca2+ signaling. WIREs Membr Transp Signal 2012, 1:70–77. doi: 10.1002/wmts.7

For further resources related to this article, please visit the WIREs website.
mGlu receptors in endocrine organs
Authors: Durand Daniela , Carniglia Lila , Lasaga Mercedes
Published: October 2011

Metabotropic glutamate (mGlu) receptors in the central nervous system are known to be essential for neuroplasticity associated with normal brain functions and are also critically involved in various neurological and psychiatric disorders. A recent surge of publications supports the presence, importance, and functionality of mGlu receptors outside the central nervous system with a unique distribution within various tissues. Group I, II, and III mGlu receptors are found in a wide range of peripheral organs including parts of the peripheral nervous system and nonneural organs such as hypophysis, pancreas, adrenal medulla, and the reproductive system. The distinct distribution of mGlu receptors in peripheral tissues is discussed in terms of possible functional endocrine implications. WIREs Membr Transp Signal 2012, 1:78–84. doi: 10.1002/wmts.9

For further resources related to this article, please visit the WIREs website.
Framework‐Substituted Bismuth Zeolite‐P: Synthesis and Characterization
Authors: Samadi‐Maybodi Abdolraouf , Naser Azizi Seyed , Masoomeh Pourali S. , Ehsani Tilami Salma
Published: October 2011

Bismuth‐modified zeolite‐P (Bi‐ZP) was synthesized by hydrothermal methods during the phase transformation of analcime to zeolite‐P. The evolution of phase transformation of pure analcime to Bi‐ZP was investigated. The results showed that bismuth atoms were incorporated into the framework of the microporous zeolite‐P. The effect of various Bi/Al (0–3) and Si/Bi (1–5) mole ratios on the synthesis of bismuth modified zeolite were studied by X‐ray diffraction (XRD) technique and FT‐IR spectroscopy. Evolution of the growth process of Bi‐ZP spheres was carried out at different time intervals with XRD patterns and FE‐SEM images. The energy dispersive X‐ray (EDX) spectrum indicated the existence of bismuth atoms in the synthesized Bi‐ZP. Framework substitutions of bismuth were evidenced by a set of complementary characterizations such as diffusive reflectance UV/Vis (DRS) and Raman spectroscopy on the synthesized Bi‐ZP (Si/Bi = 1).
ITÔ’S THEOREM ON GROUPS WITH TWO CLASS SIZES REVISITED
Authors: ALEMANY ELENA , BELTRÁN ANTONIO , FELIPE MARÍA JOSÉ
Published: October 2011

Let G be a finite p-solvable group. We prove that if G has exactly two conjugacy class sizes of p′-elements of prime power order, say 1 and m, then m=paqb, for two distinct primes p and q, and G either has an abelian p-complement or G=PQ×A, with P and Q a Sylow p-subgroup and a Sylow q-subgroup of G, respectively, and A is abelian. In particular, we provide a new extension of Itô’s theorem on groups having exactly two class sizes for elements of prime power order.
Anaxagoras
Authors: Freeman Kathleen
Published: October 2011

Anaxagoras was a man of one book; and that book, save for a few quotations in other authors and several summaries, is lost. A very potent and tantalizing book it must have been, to judge from all that we hear of it; the opinion of antiquity, preserved in Diogenes Laertius, was that its doctrines were expounded ‘in a pleasant and lofty style’, and the fragments which remain confirm this judgement. It was not merely a philosophical or scientific treatise; it was a work of art, in which the style rose and fell with the subject-matter.
Identification of field-caught Culicoides biting midges using matrix-assisted laser desorption/ionization time of flight mass spectrometry
Authors: KAUFMANN CHRISTIAN , SCHAFFNER FRANCIS , ZIEGLER DOMINIK , PFLÜGER VALENTIN , MATHIS ALEXANDER
Published: October 2011

Culicoides biting midges are of great importance as vectors of pathogens and elicitors of allergy. As an alternative for the identification of these tiny insects, matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) was evaluated. Protein mass fingerprints were determined for 4–5 field-caught reference (genetically confirmed) individuals of 12 Culicoides species from Switzerland, C. imicola from France, laboratory-reared C. nubeculosus and a non-biting midge. Reproducibility and accuracy of the database was tested in a validation study by analysing 108 mostly field-caught target Culicoides midges and 3 specimens from a non-target species. A reference database of biomarker mass sets containing between 24 and 38 masses for the different species could be established. Automated database-based identification was achieved for 101 of the 108 specimens. The remaining 7 midges required manual full comparison with the reference spectra yielding correct identification for 6 specimens and an ambiguous result for the seventh individual. Specimens of the non-target species did not yield identification. Protein profiling by MALDI-TOF, which is compatible with morphological and genetic identification of specimens, can be used as an alternative, quick and inexpensive tool to accurately identify Culicoides biting midges collected in the field.
The adaptive potential of a survival artist: characterization of thein vitrointeractions ofToxoplasma gondiitachyzoites with di-cationic compounds in human fibroblast cell cultures
Authors: KROPF CHRISTIAN , DEBACHE KARIM , RAMPA CHRISTOPH , BARNA FABIENNE , SCHORER MICHELLE , STEPHENS CHAD E. , ISMAIL MOHAMED A. , BOYKIN DAVID W. , HEMPHILL ANDREW
Published: October 2011

The impact of di-cationic pentamidine-analogues againstToxoplama gondii(Rh- and Me49-background) was investigated. The 72 h-growth assays showed that the arylimidamide DB750 inhibited the proliferation of tachyzoites ofT. gondii RhandT. gondii Me49with an IC50of 0·11 and 0·13μm, respectively. Pre-incubation of fibroblast monolayers with 1μmDB750 for 12 h and subsequent culture in the absence of the drug also resulted in a pronounced inhibiton of parasite proliferation. However, upon 5–6 days of drug exposure,T. gondiitachyzoites adapted to the compound and resumed proliferation up to a concentration of 1·2μm. Out of a set of 32 di-cationic compounds screened forin vitroactivity againstT. gondii,the arylimidamide DB745, exhibiting an IC50of 0·03μmand favourable selective toxicity was chosen for further studies. DB745 also inhibited the proliferation of DB750-adaptedT. gondii(IC50=0·07μm). In contrast to DB750, DB745 also had a profound negative impact on extracellular non-adaptedT. gondiitachyzoites, but not on DB750-adaptedT. gondii. Adaptation ofT. gondiito DB745 (up to a concentration of 0·46μm) was much more difficult to achieve and feasible only over a period of 110 days. In cultures infected with DB750-adaptedT. gondiiseemingly intact parasites could occasionally be detected by TEM. This illustrates the astonishing capacity ofT. gondiitachyzoites to adapt to environmental changes, at least underin vitroconditions, and suggests that DB745 could be an interesting drug candidate for further assessments in appropriatein vivomodels.
Is prior course of illness relevant to acute or longer-term outcomes in depressed out-patients? A STAR*D report
Authors: Rush A. J. , Wisniewski S. R. , Zisook S. , Fava M. , Sung S. C. , Haley C. L. , Chan H. N. , Gilmer W. S. , Warden D. , Nierenberg A. A. , Balasubramani G. K. , Gaynes B. N. , Trivedi M. H. , Hollon S. D.
Published: October 2011

Background

Major depressive disorder (MDD) is commonly chronic and/or recurrent. We aimed to determine whether a chronic and/or recurrent course of MDD is associated with acute and longer-term MDD treatment outcomes.

Method

This cohort study recruited out-patients aged 18–75 years with non-psychotic MDD from 18 primary and 23 psychiatric care clinics across the USA. Participants were grouped as: chronic (index episode >2 years) and recurrent (n=398); chronic non-recurrent (n=257); non-chronic recurrent (n=1614); and non-chronic non-recurrent (n=387). Acute treatment was up to 14 weeks of citalopram (⩽60 mg/day) with up to 12 months of follow-up treatment. The primary outcomes for this report were remission [16-item Quick Inventory of Depressive Symptomatology – Self-Rated (QIDS-SR16) ⩽5] or response (⩾50% reduction from baseline in QIDS-SR16) and time to first relapse [first QIDS-SR16 by Interactive Voice Response (IVR) ⩾11].

Results

Most participants (85%) had a chronic and/or recurrent course; 15% had both. Chronic index episode was associated with greater sociodemographic disadvantage. Recurrent course was associated with earlier age of onset and greater family histories of depression and substance abuse. Remission rates were lowest and slowest for those with chronic index episodes. For participants in remission entering follow-up, relapse was most likely for the chronic and recurrent group, and least likely for the non-chronic, non-recurrent group. For participants not in remission when entering follow-up, prior course was unrelated to relapse.

Conclusions

Recurrent MDD is the norm for out-patients, of whom 15% also have a chronic index episode. Chronic and recurrent course of MDD may be useful in predicting acute and long-term MDD treatment outcomes.
Delineating physiologic defensive reactivity in the domain of self-report: phenotypic and etiologic structure of dispositional fear
Authors: Kramer M. D. , Patrick C. J. , Krueger R. F. , Gasperi M.
Published: October 2011

Background

Individual differences in fear and fearlessness have been investigated at their extremes in relation to markedly different forms of psychopathology – anxiety disorders and psychopathy, respectively. A documented neural substrate of fear-related traits and disorders is defensive reactivity as reflected in aversive startle potentiation (ASP).

Method

The current study extended prior work by characterizing, in a sample of adult twins from the community (n=2511), the phenotypic and etiologic structure of self-report measures of fear and fearlessness known to be associated with ASP.

Results

Analyses revealed a hierarchical structure to the trait fear domain, with an overarching, bipolar fear/fearlessness dimension saturating each measure in this domain, and subfactors labeled ‘distress,’ ‘stimulation seeking’ and ‘sociability’ accounting for additional variance in particular measures. The structure of genetic and non-shared environmental associations among the measures closely mirrored the phenotypic structure of the domain.

Conclusions

The findings have implications for proposals to reconceptualize psychopathology in neurobiological terms.
Experience Sampling Methodology studies of depression: the state of the art
Authors: Telford C. , McCarthy-Jones S. , Corcoran R. , Rowse G.
Published: October 2011

Background

Experience Sampling Methodology (ESM) is ideally suited to test the predictions, and inform the development of contemporary cognitive models of depression. Yet there has been no systematic examination of ESM in depression research.

Method

A search of databases (PsychARTICLES, PsycINFO, AMED, Ovid Medline and CINAHL) was conducted to identify studies published within the last 25 years investigating major depressive disorder (MDD) using ESM.

Results

Altogether, 19 studies using ESM, or comparable methodologies, with clinically depressed individuals were identified and critically reviewed. The identified studies examined six aspects of MDD: methodological issues; positive and negative affect; cortisol secretion; antidepressant treatment; work performance; genetic risk factors.

Conclusions

Despite some methodological limitations of existing studies, ESM has made a significant contribution to our current understanding of depression by consolidating existing theories, uncovering new and clinically relevant findings and identifying questions for future research. This review concludes by introducing the possibility of using ESM as an intervention tool in clinical practice and proposing that ESM could be useful for furthering knowledge of the causes of MDD.
Moderating effects of childhood maltreatment on associations between social information processing and adult aggression
Authors: Chen P. , Coccaro E. F. , Lee R. , Jacobson K. C.
Published: October 2011

Background

Associations between early life maltreatment, social information processing (SIP) and aggression in childhood and adolescence have been widely documented. Few studies have examined the importance of childhood maltreatment independent of SIP in the etiology of adult aggression. Furthermore, moderating effects of childhood maltreatment on the SIP–aggression links have not been explored.

Method

Hierarchical, multi-level models were fitted to data from n=2752 twins aged 20–55 years from the PennTwins Cohort. Adult aggression was assessed with the Life History of Aggression questionnaire. Childhood maltreatment was measured using the Childhood Trauma Questionnaire. Two aspects of SIP were examined: hostile attribution biases (HAB); negative emotional responses (NER).

Results

Childhood maltreatment was positively correlated with adult aggression, independently of HAB and NER. In addition, childhood maltreatment moderated the relationships between both aspects of SIP and adult aggression. Specifically, the relationship between NER and aggression was stronger among individuals with higher levels of childhood maltreatment and NER was not associated with aggression for adults who experienced low levels of childhood maltreatment. Moderating effects of childhood maltreatment on the NER–aggression link were supported for total childhood maltreatment, emotional neglect and emotional abuse. In contrast, HAB was more strongly associated with adult aggression at lower levels of emotional abuse and physical neglect.

Conclusions

The current study provides insight into the mechanisms by which early life experiences influence adult aggression. Our findings suggest that childhood maltreatment may not only lead to increased levels of aggression in adulthood but may also modify the associations between SIP and adult aggression.
The Employment of Migrant Workers in Long-Term Care: Dynamics of Choice and Control – ERRATUM
Authors: Shutes Isabel
Published: October 2011

Within the article by Shutes (first published online, 15 September 2011) the Author's affiliation was incorrectly inserted during the production process. The correct affiliation is the ESRC Centre on Migration, Policy and Society, University of Oxford, and the Department of Social Policy, London School of Economics and Political Science. The publisher apologises for any inconvenience this has caused.
Changing residential mobility rates of older people in Sweden
Authors: ANDERSSON EVA , ABRAMSSON MARIANNE
Published: October 2011

The lifestyle of the baby boomers as retirees has been assumed to differ from older cohorts due to them being financially more stable and having grown up during the welfare state expansion. Many baby boomers live in large houses with gardens that require maintenance and labour. Recent studies have indicated that a growing share of those born in the 1940s in Sweden express a wish to change residence at retirement or in old age. A need to verify such results statistically was identified to confirm whether there has been an increase in residential mobility among older people. As a result, moves that took place during 2001–06 of the total cohort born in the 1940s were compared to similar moves by those born in the 1930s, ten years earlier during 1991–96,i.e.those aged 57–66 in 1996 and 2006. The study used a register database, Geoswede, containing the entire Swedish population. The study showed increased residential mobility rates among the 1940s cohort compared to the cohort born in the 1930s. However, explanations for the differences between the cohorts were not evident.
Successful ageing and development: the contribution of generativity in older age
Authors: VILLAR FELICIANO
Published: October 2011

This paper examines the contributions that generativity in older age may make to the concept of successful ageing. To this end, two perspectives on successful ageing are described: successful ageing as a set of clinical criteria, and successful ageing as the application of adaptive processes aimed at achieving efficient functioning. After showing the limitations of the first perspective, particularly from a developmental point of view, the paper argues that the adaptive version of successful ageing helps to put ageing into a developmental frame, but needs to be complemented by identifying specific content and goals that guide these adaptive processes and establish new feasible gains for older people. Generativity in older age could play that role and provides a conceptual framework that enriches the concept of successful ageing, both by emphasising the social context in which people age and by highlighting a personal growth component.
Universal models and definability
Authors: CARAMELLO OLIVIA
Published: October 2011

We establish some general results on universal models in Topos Theory and show that the investigation of such models can shed light on problems of definability in Logic as well as on De Morgan's law and the law of excluded middle for Grothendieck toposes.
Computing nilpotent and unipotent canonical forms: a symmetric approach
Authors: CLARKE MATTHEW C.
Published: October 2011

Let k be an algebraically closed field of any characteristic except 2, and let G = GLn(k) be the general linear group, regarded as an algebraic group over k. Using an algebro-geometric argument and Dynkin–Kostant theory for G we begin by obtaining a canonical form for nilpotent Ad(G)-orbits in (k) which is symmetric with respect to the non-main diagonal (i.e. it is fixed by the map f : (xi,j) ↦ (xn+1−j,n+1−i)), with entries in {0,1}. We then show how to modify this form slightly in order to satisfy a non-degenerate symmetric or skew-symmetric bilinear form, assuming that the orbit does not vanish in the presence of such a form. Replacing G by any simple classical algebraic group we thus obtain a unified approach to computing representatives for nilpotent orbits of all classical Lie algebras. By applying Springer morphisms, this also yields representatives for the corresponding unipotent classes in G. As a corollary we obtain a complete set of generic canonical representatives for the unipotent classes in finite general unitary groups GUn(q) for all prime powers q.
A maximin characterisation of the escape rate of non-expansive mappings in metrically convex spaces
Authors: GAUBERT STÉPHANE , VIGERAL GUILLAUME
Published: October 2011

We establish a maximin characterisation of the linear escape rate of the orbits of a non-expansive mapping on a complete (hemi-)metric space, under a mild form of Busemann's non-positive curvature condition (we require a distinguished family of geodesics with a common origin to satisfy a convexity inequality). This characterisation, which involves horofunctions, generalises the Collatz–Wielandt characterisation of the spectral radius of a non-negative matrix. It yields as corollaries a theorem of Kohlberg and Neyman (1981), concerning non-expansive maps in Banach spaces, a variant of a Denjoy–Wolff type theorem of Karlsson (2001), together with a refinement of a theorem of Gunawardena and Walsh (2003), concerning order-preserving positively homogeneous self-maps of symmetric cones. An application to zero-sum stochastic games is also given.
Detection of West Nile virus genome and specific antibodies in Iranian encephalitis patients
Authors: CHINIKAR S. , JAVADI A. , ATAEI B. , SHAKERI H. , MORADI M. , MOSTAFAVI E. , GHIASI S. M.
Published: October 2011

West Nile virus (WNV) is a mosquito-borne flavivirus which circulates in birds, horses and humans. An estimated 80% of WNV infections are asymptomatic. Fewer than 1% of infected persons develop neuroinvasive disease, which typically presents as encephalitis, meningitis, or acute flaccid paralysis. This study was conducted from January 2008 to June 2009 in Isfahan, Iran. Patients attending the emergency department with fever and loss of consciousness were consecutively included. Cerebrospinal fluids (CSF) were initially analysed through bacteriology and biochemistry examinations, resulting in those with evidence of meningitis being excluded. Patients' CSF and serum were diagnosed by serological and molecular assays. A total of 632 patients with fever and loss of consciousness were tested by CSF analyses. Samples of the remaining patients (39·4%) were referred for WNV investigation. Three (1·2%) of the patients were positive for both serum and CSF by RT–PCR, and six (2·4%) were positive only for IgG antibodies. History of insect bite, and blood transfusion and transplantation were risk factors for being positive by RT–PCR (P=0·048) and being IgG positive (P=0·024), respectively. The results of this study showed that the prevalence of West Nile fever is low in patients with encephalitis.
Organic zero-till in the northern US Great Plains Region: Opportunities and obstacles
Authors: Carr Patrick M. , Anderson Randy L. , Lawley Yvonne E. , Miller Perry R. , Zwinger Steve F.
Published: October 2011

The use of killed cover crop mulch for weed suppression, soil erosion prevention and many other soil and crop benefits has been demonstrated in organic no-till or zero-till farming systems in eastern US regions and in Canada. Implements have been developed to make this system possible by terminating cover crops mechanically with little, if any, soil disturbance. Ongoing research in the US northern Great Plains is being conducted to identify cover crop species and termination methods for use in organic zero-till (OZ) systems that are adapted to the crop rotations and climate of this semi-arid region. Current termination strategies must be improved so that cover crop species are killed consistently and early enough in the growing season so that subsequent cash crops can be grown and harvested successfully. Delaying termination until advanced growth stages improves killing efficacy of cover crops and may provide weed-suppressive mulch for the remainder of the growing season, allowing no-till spring seeding of cash crops during the next growing season. Excessive water use by cover crops, inability of legume cover crops to supply adequate amounts of N for subsequent cash crops and failure of cover crops to suppress perennial weeds are additional obstacles that must be overcome before the use of killed cover crop mulch can be promoted as a weed control alternative to tillage in the US northern Great Plains. Use of vegetative mulch produced by killed cover crops will not be a panacea for the weed control challenges faced by organic growers, but rather one tool along with crop rotation, novel grazing strategies, the judicious use of high-residue cultivation equipment, such as the blade plow, and the use of approved herbicides with systemic activity in some instances, to provide organic farmers with new opportunities to incorporate OZ practices into their cropping systems. Emerging crop rotation designs for organic no-till systems may provide for more efficient use of nutrient and water resources, opportunities for livestock grazing before, during or after cash crop phases and improved integrated weed management strategies on organic farms.
Pb isotopes and geochemical monitoring of Arctic sedimentary supplies and water mass export through Fram Strait since the Last Glacial Maximum
Authors: Maccali Jenny , Hillaire‐Marcel Claude , Carignan Jean , Reisberg Laurie C.
Published: October 2011

Elemental and Pb isotope measurements were performed on leachates and residues from surface sediments and two <50 cm cores (MC04 and MC16) collected along a NE‐SW transect through Fram Strait. Geochemical and isotopic properties of residues from surface sediments define three distinct spatial domains within the Strait: 1) the easternmost edge of the Strait; 2) the eastern part of the Strait off the Svalbard margins; and 3) the western part of the Strait, influenced by supplies from Svalbard, the Nordic seas with possible contributions from northwestern Siberian margins, and sea ice and water outflow from the Arctic, respectively. Core MC16, in the third domain beneath the outflowing Arctic waters, spans the Last Glacial Maximum present interval. Sediments from this core were leached to obtain detrital (residues) and exchangeable (leachates) fractions. Detrital supplies to core MC16 are believed to originate mainly from melting of the overlying sea ice and thus can be used to document changes in Arctic sedimentary sources. Detrital 206Pb/204Pb and 208Pb/206Pb ratios illustrate two mixing trends, Trends A and B, corresponding to the pre‐ and post‐Younger Dryas (YD) intervals, respectively. These trends represent binary mixtures with a common end‐member (Canadian margins) and either a Siberian (Trend A) or Greenland (Trend B) margin end‐member. The YD is marked by an isotopic excursion toward the Canadian end‐member, suggesting a very active Beaufort Gyre possibly triggered by massive drainage of the Laurentide ice sheet. Pb isotope compositions of leachates, thought to represent the signature of the overlying water masses, define a unique linear trend coincident with Trend A. This suggests that water masses acquired their signature through exchange with particulate fluxes along the Canadian and Siberian continental margins.
A new hydrogeologic model to predict anthropogenic uplift of Venice
Authors: Teatini P. , Castelletto N. , Ferronato M. , Gambolati G. , Tosi L.
Published: October 2011

Recent numerical studies based on a simplified lithostratigraphy of the Venice subsurface suggest that the city may be raised by pumping seawater into deep aquifers through 12 wells located on a 10 km diameter circle. Using an updated 3‐D reconstruction of the Quaternary deposits, developed very recently from about 1050 km of multichannel seismic profiles and eight exploration wells, along with a more accurate representation of the injection boreholes, novel finite‐element predictions are performed. The new model simulates the lithostratigraphy of the lagoon subsurface and allows for a reliable assessment of the water volumes injected into the geologic formations based on the actual bottom hole overpressure that can vary both in space and time. Pumping occurs into two Pleistocene sequences that are originated from the Alps and Apennine sedimentation and terminate just south and north of Venice, respectively, and the shelf portion of a Pliocene sequence that is rather continuous below the central lagoon with arenite layers to depths as much as 1000 m below mean sea level. With a proper tuning of the injection pressure the new hydrogeologic model allows for a prediction of a quite uniform 25–30 cm uplift over 10 years after the inception of injection. The gradient of the vertical displacement ξz does not exceed 5 × 10−5 and 1 × 10−5 in the whole lagoon and Venice, respectively, i.e., well below the most conservative bound recommended for the safety of the structures. If ad hoc calibrated injection overpressures are implemented in each single well, ξz may be reduced to as much as 0.1 × 10−5 throughout the city.
End-linked, amphiphilic, degradable polymer conetworks: synthesis by sequential atom transfer radical polymerization using a bifunctional, cleavable initiator
Authors: Rikkou-Kalourkoti Maria , Loizou Elena , Porcar Lionel , Matyjaszewski Krzysztof , Patrickios Costas S.
Published: October 2011

End-linked amphiphilic conetworks prepared using an ATRP bifunctional, bis(hemiacetal ester) initiator were hydrolyzed by HCl, yielding novel amphiphilic star copolymers.
Synthesis and photovoltaic properties of D–A copolymers of benzodithiophene and naphtho[2,3-c]thiophene-4,9-dione
Authors: Cui Chaohua , Fan Haijun , Guo Xia , Zhang Maojie , He Youjun , Zhan Xiaowei , Li Yongfang
Published: October 2011

Two D–A copolymers containing naphtho[2,3-c]thiophene-4,9-dione (NTDO) acceptor unit were synthesized, and the PSC based on PBDTNTDO-2/PC70BM showed PCE of 1.52%.
S-passivation of the Ge gate stack: Tuning the gate stack properties by changing the atomic layer deposition oxidant precursor
Authors: Sioncke S. , Lin H. C. , Nyns L. , Brammertz G. , Delabie A. , Conard T. , Franquet A. , Rip J. , Struyf H. , De Gendt S. , Müller M. , Beckhoff B. , Caymax M.
Published: October 2011

The passivation of the interface between Ge and the gate dielectric is a critical issue for the integration of Ge into next generation CMOS devices. GeO2 has recently garnered a lot of interest, but there is always a trade-off between low interface state densities and a low equivalent oxide thickness. In this paper we investigate the S-passivation of the Ge gate stack in which only 1 monolayer of S is needed in order to improve the interface properties of the gate stack. S-passivation is achieved via exposure of the clean Ge(100) surface to H2S. The high-k dielectric is deposited via atomic layer deposition. We show that the oxidant precursor type (H2O versus O3) will result not only in different growth behavior but also in different interface properties. The H2O based process results in low defect densities at the valence bandedge, whereas the O3 based process results in low defect densities at the conduction bandedge.
Reduced fluid-kinetic equations for low-frequency dynamics, magnetic reconnection, and electron heating in low-beta plasmas
Authors: Zocco Alessandro , Schekochihin Alexander A.
Published: October 2011

A minimal model for magnetic reconnection and, generally, low-frequency dynamics in low-beta plasmas is proposed. The model combines analytical and computational simplicity with physical realizability: it is a rigorous limit of gyrokinetics for plasma beta of order the electron-ion mass ratio. The model contains collisions and can be used both in the collisional and collisionless reconnection regimes. It includes gyrokinetic ions (not assumed cold) and allows for the topological rearrangement of the magnetic field lines by either resistivity or electron inertia, whichever predominates. The two-fluid dynamics are coupled to electron kinetics—electrons are not assumed isothermal and are described by a reduced drift-kinetic equation. The model, therefore allows for irreversibility and conversion of magnetic energy into electron heat via parallel phase mixing in velocity space. An analysis of the exchanges between various forms of free energy and its conversion into electron heat is provided. It is shown how all relevant linear waves and regimes of the tearing instability (collisionless, semicollisional, and fully resistive) are recovered in various limits of our model. An efficient way to simulate our equations numerically is proposed, via the Hermite representation of the velocity space. It is shown that small scales in velocity space will form, giving rise to a shallow Hermite-space spectrum, whence it is inferred that, for steady-state or sufficiently slow dynamics, the electron heating rate will remain finite in the limit of vanishing collisionality.
A paradigm for the stability of the plasma sheath against fluid perturbations
Authors: Delzanno G. L.
Published: October 2011

The stability of the sheath created by a collisionless, unmagnetized plasma interacting with a material boundary at floating potential is studied with a fluid plasma model. In the limit where the sonic sheath ion flow is neglected, ion perturbations can be unstable to the Rayleigh-Taylor instability, driven by the sheath ion density gradient and electric field. The sonic sheath ion flow, however, is very effective in stabilizing these modes by convective stabilization. Therefore, within the assumptions of our model and the parameters considered, the sheath is stable.
Anomalous evolution of Ar metastable density with electron density in high density Ar discharge
Authors: Park Min , Chang Hong-Young , You Shin-Jae , Kim Jung-Hyung , Shin Yong-Hyeon
Published: October 2011

Recently, an anomalous evolution of argon metastable density with plasma discharge power (electron density) was reported [A. M. Daltrini, S. A. Moshkalev, T. J. Morgan, R. B. Piejak, and W. G. Graham, Appl. Phys. Lett. 92, 061504 (2008)]. Although the importance of the metastable atom and its density has been reported in a lot of literature, however, a basic physics behind the anomalous evolution of metastable density has not been clearly understood yet. In this study, we investigated a simple global model to elucidate the underlying physics of the anomalous evolution of argon metastable density with the electron density. On the basis of the proposed simple model, we reproduced the anomalous evolution of the metastable density and disclosed the detailed physics for the anomalous result. Drastic changes of dominant mechanisms for the population and depopulation processes of Ar metastable atoms with electron density, which take place even in relatively low electron density regime, is the clue to understand the result.
Photo-triggering and secondary electron produced ionization in electric discharge ArF* excimer lasers
Authors: Xiong Zhongmin , Kushner Mark J.
Published: October 2011

Electric discharge excimer lasers are sustained in multi-atmosphere attaching gas mixtures that are typically preionized to enable a reproducible, uniform glow, which maximizes optical quality and gain. This preionization is often accomplished using UV light produced by a corona discharge within the plasma cavity. To quantify the relationship between corona discharge properties and those of the laser discharge, the triggering of electron avalanche by preionizing UV light in an electric discharge-pumped ArF* excimer laser was numerically investigated using a two-dimensional model. The preionizing UV fluxes were generated by a corona-bar discharge driven by the same voltage pulse as the main discharge sustained in a multi-atmospheric Ne/Ar/Xe/F2 gas mixture. The resulting peak photo-electron density in the inter-electrode spacing is around 108 cm−3, and its distribution is biased toward the UV source. The preionization density increases with increasing dielectric constant and capacitance of the corona bar. The symmetry and uniformity of the discharge are, however, improved significantly once the main avalanche develops. In addition to bulk electron impact ionization, the ionization generated by sheath accelerated secondary electrons was found to be important in sustaining the discharge current at experimentally observed values. At peak current, the magnitude of the ionization by sheath accelerated electrons is comparable to that from bulk electron impact in the vicinity of the cathode.
Measurements of time average series resonance effect in capacitively coupled radio frequency discharge plasma
Authors: Bora B. , Bhuyan H. , Favre M. , Wyndham E. , Chuaqui H. , Kakati M.
Published: October 2011

Self-excited plasma series resonance is observed in low pressure capacitvely coupled radio frequency discharges as high-frequency oscillations superimposed on the normal radio frequency current. This high-frequency contribution to the radio frequency current is generated by a series resonance between the capacitive sheath and the inductive and resistive bulk plasma. In this report, we present an experimental method to measure the plasma series resonance in a capacitively coupled radio frequency argon plasma by modifying the homogeneous discharge model. The homogeneous discharge model is modified by introducing a correction factor to the plasma resistance. Plasma parameters are also calculated by considering the plasma series resonances effect. Experimental measurements show that the self-excitation of the plasma series resonance, which arises in capacitive discharge due to the nonlinear interaction of plasma bulk and sheath, significantly enhances both the Ohmic and stochastic heating. The experimentally measured total dissipation, which is the sum of the Ohmic and stochastic heating, is found to increase significantly with decreasing pressure.
A study of dust grain screening in a weakly ionized plasma based on the numerical solution of the Vlasov-Bhatnagar-Gross-Krook kinetic equations
Authors: Semenov I. L. , Zagorodny A. G. , Krivtsun I. V.
Published: October 2011

Screening of a dust grain in a weakly ionized plasma is studied for a wide range of collisional regimes. The problem is considered on the basis of the Vlasov-Bhatnagar-Gross-Krook equations for plasma particles. The equations are solved numerically on parallel processors by means of a high-order finite-volume method. The computations are carried out for different pressures of plasma background and different grain sizes. The values of the total grain charge, distributions of the electric potential, and basic macroscopic parameters of plasma particles (concentration, temperature, and velocity) are obtained. For two limiting cases of the collisionless and strongly collisional background, the obtained results are found to be in good agreement with those computed using the commonly known models (nonlinear collisionless models of Bystrenko et al. [Phys. Lett. A 299, 383 (2002)] and Ratynskaia et al. [Phys. Plasmas 13, 104508 (2006)] and drift-diffusion approach). For the transitional collisional regime, it is shown that the electric potential also has the Coulomb-type asymptotical behavior related to the presence of charging currents and existence of some residual (unscreened) grain charge. Both total and residual grain charges are found to increase as the collisional regime tends to the continuum limit. In addition, the influence of collisions on the ion distribution function near the grain surface is demonstrated.
Inertial modes of a periodically forced buoyant drop attached to a capillary
Authors: Chebel Nicolas Abi , Risso Frédéric , Masbernat Olivier
Published: October 2011

A drop of heptane attached to a capillary tip immersed in water is submitted to small amplitude volume oscillations. Its interface is imaged by means of a high-speed camera and its shape decomposed into spherical harmonics. The forcing frequency is varied over a large range including the frequencies of resonance of the three first modes of inertial shape oscillations. For a small drop, which remains almost spherical at rest, the geometrical constraint imposed by the attachment on the capillary tip causes the oscillation modes to be very different from those of a free drop. Surprisingly, the resonance of large drops is observed at the frequency predicted for a free, pure, and neutrally buoyant drop and mainly involves a single spherical harmonic; only the damping rate is observed to be moderately larger. Since it gives rise to oscillations close to this ideal case, the present experimental method could be used, complementary to quasi-static oscillation of a pendant drop, to investigate dynamic interfacial tension at high frequency of various fluid systems.
Short-time rheology and diffusion in suspensions of Yukawa-type colloidal particles
Authors: Heinen Marco , Banchio Adolfo J. , Nägele Gerhard
Published: October 2011

A comprehensive study is presented on the short-time dynamics in suspensions of charged colloidal spheres. The explored parameter space covers the major part of the fluid-state regime, with colloid concentrations extending up to the freezing transition. The particles are assumed to interact directly by a hard-core plus screened Coulomb potential, and indirectly by solvent-mediated hydrodynamic interactions. By comparison with accurate accelerated Stokesian Dynamics (ASD) simulations of the hydrodynamic function H(q), and the high-frequency viscosity η∞, we investigate the accuracy of two fast and easy-to-implement analytical schemes. The first scheme, referred to as the pairwise additive (PA) scheme, uses exact two-body hydrodynamic mobility tensors. It is in good agreement with the ASD simulations of H(q) and η∞, for smaller volume fractions up to about 10% and 20%, respectively. The second scheme is a hybrid method combining the virtues of the δγ scheme by Beenakker and Mazur with those of the PA scheme. It leads to predictions in good agreement with the simulation data, for all considered concentrations, combining thus precision with computational efficiency. The hybrid method is used to test the accuracy of a generalized Stokes-Einstein (GSE) relation proposed by Kholodenko and Douglas, showing its severe violation in low salinity systems. For hard spheres, however, this GSE relation applies decently well.
Large amplitude microwave emission and reduced nonlinear phase noise in Co2Fe(Ge0.5Ga0.5) Heusler alloy based pseudo spin valve nanopillars
Authors: Sinha Jaivardhan , Hayashi Masamitsu , Takahashi Yukiko K. , Taniguchi Tomohiro , Drapeko Maksim , Mitani Seiji , Hono Kazuhiro
Published: October 2011

We have studied microwave emission from a current-perpendicular-to-plane pseudo spin valve nanopillars with Heusler alloy Co2Fe(Ga0.5Ge0.5) electrodes. Large emission amplitude exceeding 150 nV/Hz0.5, partly owing to the large magnetoresistance, and narrow generation linewidth below 10 MHz are observed. We also find that the linewidth shows significant dependence on the applied field magnitude and its angle within the film plane. A minimum in the linewidth is observed when the slope of the frequency versus current becomes near zero. This agrees with theoretical prediction that takes into account non-linear phase noise as a source for linewidth broadening.
A magnetic-bottle multi-electron-ion coincidence spectrometer
Authors: Matsuda Akitaka , Fushitani Mizuho , Tseng Chien-Ming , Hikosaka Yasumasa , Eland John H. D. , Hishikawa Akiyoshi
Published: October 2011

A novel multi-electron-ion coincidence spectrometer developed on the basis of a 1.5 m-long magnetic-bottle electron spectrometer is presented. Electrons are guided by an inhomogeneous magnetic field to a detector at the end of the flight tube, while a set of optics is used to extract counterpart ions to the same detector, by a pulsed inhomogeneous electric field. This setup allows ion detection with high mass resolution, without impairing the high collection efficiency for electrons. The performance of the coincidence spectrometer was tested with double ionization of carbon disulfide, CS2 → \documentclass[12pt]{minimal}\begin{document}${\rm CS}_2^{2+}$\end{document} CS 22+ + e− + e−, in ultrashort intense laser fields (2.8 × 1013 W/cm2, 280 fs, 1030 nm) to clarify the electron correlation below the rescattering threshold.
Experimental and first-principles study on the magnetic and transport properties of Ti-doped Fe3O4 epitaxial films
Authors: Jin C. , Mi W. B. , Li P. , Bai H. L.
Published: October 2011

Structure, magnetic, and transport properties of the epitaxial Fe3–xTixO4 films with x ≤ 0.09 fabricated by reactive co-sputtering were investigated systematically. The lattice constant expands from 0.8360 to 0.8376 nm with x increases from 0 to 0.09. The room-temperature saturation magnetization increases by 31.7%, and the negative magnetoresistance (at 100 K) increases from 3.7% to 6.9% as x increases from 0 to 0.09. The results indicate that Ti atoms might exist at the tetrahedral sites in the spinel structure. Theoretical calculations based on the density-functional theory suggest that the doped Ti on the tetrahedral sites indeed enhances the lattice constant and magnetic moment. Meanwhile, the calculated results also imply that the Ti-doped Fe3O4 has a high spin polarization near 100%.
Subdiffusion as a model of transport through the nuclear pore complex
Authors: Chatterjee Debarati , Cherayil Binny J.
Published: October 2011

Cargo transport through the nuclear pore complex continues to be a subject of considerable interest to experimentalists and theorists alike. Several recent studies have revealed details of the process that have still to be fully understood, among them the apparent nonlinearity between cargo size and the pore crossing time, the skewed, asymmetric nature of the distribution of such crossing times, and the non-exponentiality in the decay profile of the dynamic autocorrelation function of cargo positions. In this paper, we show that a model of pore transport based on subdiffusive particle motion is in qualitative agreement with many of these observations. The model corresponds to a process of stochastic binding and release of the particle as it moves through the channel. It suggests that the phenylalanine-glycine repeat units that form an entangled polymer mesh across the channel may be involved in translocation, since these units have the potential to intermittently bind to hydrophobic receptor sites on the transporter protein.
Solvable rational extensions of the Morse and Kepler-Coulomb potentials
Authors: Grandati Yves
Published: October 2011

We show that it is possible to generate an infinite set of solvable rational extensions from every exceptional first category translationally shape invariant potential. This is made by using Darboux-Bäcklund transformations based on unphysical regular Riccati-Schrödinger functions which are obtained from specific symmetries associated with the considered family of potentials.