bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing UK farmers' institutional capacity to defend their water rights and effectively manage limited water resources
Authors: Leathes W. , Knox J. W. , Kay M. G. , Trawick P. , Rodriguez‐Diaz J. A.
Published: June 2008

Developing farmers' institutional capacity to defend their water rights is central to sustaining irrigation farming in the UK. Increasing demand and competition for water and the introduction of new water regulations have led many farmers to re‐evaluate the security of their water rights. As a consequence, some have formed water abstractors groups, a trend which is strongest in eastern England, where irrigation is most concentrated and water resources are most stressed.

“Collective choice” theory attempts to explain how institutions evolve to share common resources and what key elements are needed for them to endure over the long term. This paper compares the characteristics of four existing water abstractors groups against those of “collective choice” theory. It concludes that it is applicable in the UK context and relevant when addressing a range of emerging water management challenges.

The approach taken offers a means of analysing capacity at an institutional level and suggests a way of supporting the development of existing water abstractors groups as well as developing new ones. It is argued that this approach to developing institutional capacity could be used elsewhere where problems between resource availability, environmental protection and the sustainability of agricultural production are evident. Copyright © 2008 John Wiley & Sons, Ltd.
A new look at IT governance
Authors: Higgins Leslee N. , Sinclair Debra T.
Published: June 2008

IT governance has been named the number two technology issue in the American Institute of Certified Public Accountants' 2008 Top Ten Technology Initiatives list. And IT governance affects managers and IT users throughout a company. So what is the current state of IT governance— especially regarding risk management and compliance requirements? © 2008 Wiley Periodicals, Inc.
Theoretical study on the reaction of SiH(CH3)3with SiH3radical
Authors: Zhang Hui , Zhang Gui‐Ling , Liu Jing‐Yan , Sun Miao , Liu Bo , Li Ze‐Sheng
Published: June 2008

The multiple‐channel reactions SiH3+ SiH(CH3)3→ products are investigated by direct dynamics method. The minimum energy path (MEP) is calculated at the MP2/6‐31+G(d,p) level, and energetic information is further refined by the MC‐QCISD (single‐point) method. The rate constants for individual reaction channels are calculated by the improved canonical variational transition state theory with small‐curvature tunneling correction over the temperature range of 200–2400 K. The theoretical three‐parameter expressionk(T) = 2.44 × 10−23T3.94exp(−4309.55/T) cm3/(molecule s) is given. Our calculations indicate that hydrogen abstraction channel R1 from SiH group is the major channel because of the smaller barrier height among five channels considered. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Formation pathways of DMSO from DMS‐OH in the presence of O2 and NOx: A theoretical study
Authors: Ramírez‐Anguita Juan M. , González‐Lafont Àngels , Lluch José M.
Published: June 2008

The relative importance of the reaction pathways and thus the product yields in the dimethyl sulfide (DMS) degradation scheme initiated by the hydroxyl (OH) radical has been said to be influenced by the content of nitrogen oxides (NOx) in chamber experiments. In this study, ab initio and density functional electronic structure calculations of all the possible reaction pathways corresponding to the reaction process initiated by DMS‐OH + oxygen (O2), leading to the formation of the dimethyl sulfoxide (DMSO) product in the presence of NOx (NO and NO2), are carried out for the first time. The results for the different pathways are compared with the objective of inferring their kinetic relevance in the laboratory experiments that measure DMSO formation yields. Our theoretical results clearly show the existence of NOx‐dependent pathways leading to the formation of DMSO in addition to O2‐dependent channels. So then, NOx‐containing conditions would have to modify the relative importance of the addition channel in the DMS oxidation process. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
DFT calculations on the electronic structures of BiOX (X = F, Cl, Br, I) photocatalysts with and without semicore Bi 5d states
Authors: Huang Wen Lai , Zhu Qingshan
Published: June 2008

The electronic structures of BiOX (X = F, Cl, Br, I) photocatalysts have been calculated with and without Bi 5d states using the experimental lattice parameters, via the plane‐wave pseudopotential method based on density functional theory (DFT). BiOF exhibits a direct band gap of 3.22 or 3.12 eV corresponding to the adoption of Bi 5d states or not. The indirect band gaps of BiOCl, BiOBr, and BiOI are 2.80, 2.36, and 1.75 eV, respectively, if calculated with Bi 5d states, whereas the absence of Bi 5d states reduces them to 2.59, 2.13, and 1.53 eV successively. The calculated gap characteristics and the falling trend of gap width with the increasing X atomic number agree with the experimental results, despite the common DFT underestimation of gap values. The shapes of valence‐band tops and conduction‐band bottoms are almost independent of the involvement of Bi 5d states. The indirect characteristic becomes more remarkable, and the conduction‐band bottom flattens in the sequence of BiOCl, BiOBr, and BiOI. Both O 2p and X np (n = 2, 3, 4, and 5 for X = F, Cl, Br, and I, respectively) states dominate the valence bands, whereas Bi 6p states contribute the most to the conduction bands. With the growing X atomic number, the localized X np states shift closer toward the valence‐band tops, and the valence and conduction bandwidths evolve in opposite trends. Atomic and bond populations have also been explored to elucidate the atomic interactions, along with the spatial distribution of orbital density. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Formation of the N‐methylpyridinium derivative to improve the detection of buprenorphine by liquid chromatography‐mass spectrometry
Authors: Thieme Detlef , Sachs Hans , Thevis Mario
Published: June 2008

The legally defensible identification of the narcotic, analgesic buprenorphine, in biological specimen requires considerable sensitivity due to its low therapeutic dosages and corresponding target concentrations. Application of liquid chromatography‐electrospray ionisation‐mass spectrometry, which became the default method for buprenorphine detection, is impeded by the disadvantageous fragmentation of the stable precursor ion producing unspecific product ions of comparatively low abundance.

A chemical modification to form the N‐methylpyridinium ether derivative of buprenorphine is presented to improve the selectivity and sensitivity of its detection by liquid chromatography‐mass spectrometry (LC‐MS).

The reaction of buprenorphine with 2‐fluoro‐1‐methyl‐pyridinium‐p‐toluene‐sulfonate and triethylamine as catalyst was accomplished in acetonitrile at an ambient temperature yielding a chemically stable derivative. Fragmentation of the permanently charged precursor ion (m/z = 559) leads to the formation of diagnostic and abundant fragments (e.g. m/z = 443 and 450) representing all parts of the molecule.

The application of the technique to the identification of buprenorphine in hair samples demonstrates a high specificity, availability of sufficient qualifier ions and a significant (∼8‐fold) improvement of detection limits with respect to comparable experiments based on underivatised buprenorphine. Copyright © 2008 John Wiley & Sons, Ltd.
On the unusual2Jcoupling dependence onsyn/antiCHO conformation in 5‐X‐furan‐2‐carboxaldehydes
Authors: Pérez Carlos , Suardíaz Reynier , Ortiz Pedro J. , Crespo‐Otero Rachel , Bonetto Gloria M. , Gavín José A. , García de la Vega José M. , Fabián Jesús San , Contreras Rubén H.
Published: June 2008

A remarkable difference for2Jcoupling constant insynandanticonformers of 5‐X‐furan‐2‐carboxaldehydes (X = CH3, Ph, NO2, Br) and a rationalization of this difference are reported. On the basis of the current knowledge of the Fermi‐contact term transmission, a rather unusual dual‐coupling pathway in thesynconformer is presented. The additional coupling pathway resembles somewhat that of theJHHin homoallylic couplings, which are transmitted by hyperconjugative interactions involving the πCCelectronic system. The homoallylic coupling pathway can be labeled as σ*CH← πCC→ σ*CH. In the present case, this additional coupling pathway, using an analogous notation, can be labeled as σ*← LP1(O1)··· LP2(OC) →σ*(σ*) where O1and OCstand for the ring and carbonyl O atoms, respectively. This additional coupling pathway is not activated in theanticonformers since both oxygen lone pairs do not overlap. Copyright © 2008 John Wiley & Sons, Ltd.
Quadrature for meshless methods
Authors: Babuška Ivo , Banerjee Uday , Osborn John E. , Li Qiaoluan
Published: June 2008

In this paper we discuss quadrature schemes for meshless methods. We consider the Neumann problem and derive an estimate for the energy norm error between the exact solution, u, and the quadrature approximate solution, u, in terms of a parameter, h, associated with the family of approximation spaces, and quantities η, τ, and ε that measure the errors in the stiffness matrix, in the boundary data, and in the right‐hand side vector, respectively, due to the quadrature. The major hypothesis in the estimate is that the quadrature stiffness matrix has zero row sums, a hypothesis that can be easily achieved by a simple correction of the diagonal elements. Copyright © 2008 John Wiley & Sons, Ltd.
Real‐time wide‐angle X‐ray diffraction during polyethylene blown film extrusion
Authors: Gururajan Giri , Shan H. , Lickfield G. , Ogale A.A.
Published: June 2008

Real‐time wide‐angle X‐ray diffraction (WAXD) measurements during blown film extrusion of low‐density polyethylene are reported in this study. WAXD patterns were obtained at different axial positions in the blown film line starting from a location near the die and extending up to the nip‐roller. The X‐ray diffraction patterns from the bubble were analyzed for crystalline growth along the bubble. From the evolution of (110) and (200) peaks, it is evident that the crystallization process starts near the frost‐line height (FLH), shows a steep growth immediately past the FLH, and then plateaus at higher axial distances near the nip‐rolls. The real‐time crystallinity profiles obtained from WAXD were consistent with those measured using real‐time Raman spectroscopy. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Actions of quinolizidine alkaloids onPeriplaneta americananicotinic acetylcholine receptors
Authors: Liu Lijun , Alam Mohammad Sayed , Hirata Koichi , Matsuda Kazuhiko , Ozoe Yoshihisa
Published: June 2008

BACKGROUND:Botanical insecticides do not play a major role as crop protectants, but they are beneficial in some applications. The authors investigated the actions of naturally occurring alkaloids on insect nicotinic acetylcholine (ACh) receptors (nAChRs) by evaluating their abilities to inhibit specific binding of [3H]imidacloprid (IMI) to nerve‐cord membranes fromPeriplaneta americanaL. Two alkaloids were also tested for their actions on nAChRs expressed by cockroach neurons using patch‐clamp electrophysiology.

RESULTS:Four natural quinolizidine alkaloids (matrine, sophocarpine, cytisine and aloperine) exhibited more than 50% inhibition of [3H]IMI binding at 10 µM, although other compounds were found to have no or low inhibitory activity. The rank order of potency based on concentration–inhibition curves was cytisine > sophocarpine ≥ aloperine ≥ matrine. Patch‐clamp analysis indicated that sophocarpine and aloperine were not agonists of nAChRs expressed inP. americananeurons, yet, at 10 µM, aloperine, but not sophocarpine, suppressed ACh‐induced inward currents significantly.

CONCLUSION:Three of the four natural alkaloids tested possess structural moieties that are necessary for interaction withP. americananAChRs. Aloperine, which possesses a unique structure and showed a distinctive dose–response curve, was found to act as an antagonist. Appropriate modifications of these alkaloids might result in novel insecticidal nAChR ligands. Copyright © 2008 Society of Chemical Industry
Searching the global minimum of a peptide/bilayer potential energy surface by fast heating and cooling cycles of simulated annealing
Authors: Fuzo C. A. , Castro J. R. M. , Degrève L.
Published: June 2008

The total time reached by molecular dynamics simulation in the study of the interactions between hydrated bilayers and peptides is still very short. A scheme of fast heating and cooling cycles of simulated annealing (FHCCSA) is proposed to improve the efficiency of the search for the global minimum of the peptide/bilayer potential energy surface. In FHCCSA, the high temperatures facilitate the transitions between stable configurations; i.e., heating and cooling cycles make easier the escape of the system outside the local energy minimum. The FHCCSA efficiency is confirmed by comparing its results with conventional NpT simulations. The new scheme saves more than 90% of the total cpu time compared with ordinary NpT simulations. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Do chronic psychological stressors accelerate the progress of cardiovascular disease?
Authors: Goble Alan , Le Grande Michael
Published: June 2008

This critical review discusses available evidence concerning whether chronic psychological stressors affect the progress of cardiovascular disease. Emphasis is placed upon prospective cohort studies. The report largely reflects comprehensive reviews by others, but also discusses recent empirical research attempting to understand the basis for conflicting conclusions. The role of stressors is reviewed in the framework of possible personality features. It is probable that personality differences affect behavioural responses to stressors in a subset of subjects prone to introversion and negative affectivity. It is also probable that psychological depression is a factor inducing adverse outcomes including death and acute myocardial infarction. We remain unable to assert a definite cause and effect relationship between some stressors such as occupational characteristics. There appears to be sufficient evidence to suggest that psychological depression as a response to life's stressors may well accelerate the progress of cardiovascular disease. Copyright © 2008 John Wiley & Sons, Ltd.
Climatic and hydrologic variability during the past millennium in the eastern Rocky Mountains and northern Great Plains of western Canada
Authors: Edwards Thomas W.D. , Birks S. Jean , Luckman Brian H. , MacDonald Glen M.
Published: June 2008

Modelling of tree-ring δ13C and δ18O data from the Columbia Icefield area in the eastern Rocky Mountains of western Canada provides fuller understanding of climatic and hydrologic variability over the past 1000 yr in this region, based on reconstruction of changes in growth season atmospheric relative humidity (RHgrs), winter temperature (Twin) and the precipitation δ18O–Twin relation. The Little Ice Age (~ AD 1530s–1890s) is marked by low RHgrs and Twin and a δ18O–Twin relation offset from that of the present, reflecting enhanced meridional circulation and persistent influence of Arctic air masses. Independent proxy hydrologic evidence suggests that snowmelt sustained relatively abundant streamflow at this time in rivers draining the eastern Rockies. In contrast, the early millennium was marked by higher RHgrs and Twin and a δ18O–Twin relation like that of the 20th century, consistent with pervasive influence of Pacific air masses because of strong zonal circulation. Especially mild conditions prevailed during the “Medieval Climate Anomaly” ~ AD 1100–1250, corresponding with evidence for reduced discharge in rivers draining the eastern Rockies and extensive hydrological drought in neighbouring western USA.
IS LAW REALLY A SOCIAL SCIENCE? A VIEW FROM COMPARATIVE LAW
Authors: Samuel Geoffrey
Published: June 2008

The question to be pursued in this article has the merit of simplicity even if the response to it proves somewhat complex. The question is this: is law truly a social science? This may seem an odd question to many in the common law world since it is not uncommon, at least in England, for law schools to find themselves located in faculties of social science. Moreover there are a number of individuals, perhaps a considerable number in common law departments and faculties throughout the world, whose research and scholarship undoubtedly qualifies as social science research. So, before one can even begin to reflect upon the question to be pursued in this paper, a preliminary question must first be asked. Why should one wish even to pose the question?
LEGAL HUMANISM AND LAW-AS-INTEGRITY
Authors: Walters Mark D.
Published: June 2008

According to Ronald Dworkin, all judges are by necessity philosophers, and no judge is a better philosopher than Hercules. This superhuman jurist understands that law's empire embraces not just decisions about rights made in the past, but also rights implicit in the theory of political morality that those decisions presuppose. He is able to survey all of the diverse laws within a system and then construct a comprehensive theory of political morality that shows those laws to be as coherent and unified and just as they can be. From this theory not only will right answers in hard cases emerge, but the value of integrity-the value of extending to everyone the rights extended to some so that equal concern and respect is secured for all-will be honoured. In contrast, Herbert, the judge Dworkin introduces as Hercules' nemesis, thinks that law ends just at the point where hard cases begin. Herbert is intellectually flatfooted in the face of legal challenges that Hercules can handle adeptly and accurately.
Definiteness marking and the structure of Danish pseudopartitives
Authors: HANKAMER JORGE , MIKKELSEN LINE
Published: June 2008

The Danish pseudopartitive constructions differ in their possibilities of definiteness marking: the Indirect Partitive Construction (IPC) (D N1 P N2) permits N1 to bear the definite suffix, while the Direct Partitive Construction (DPC) (D N1 N2) does not; in addition, neither construction permits the prenominal definite article in the absence of a prenominal modifier. Drawing on previous work regarding the morphosyntax of definiteness marking in Danish, we use the distribution of definiteness marking as a probe to illuminate the structure of the pseudopartitive constructions. Our conclusion is that despite superficial similarities the two constructions are quite different in structure, the IPC having a lexical N head and a PP complement, and the DPC a functional n head with an NP complement, forming a single extended projection of N2. These assumptions allow us to account for a number of differences in the behavior of these constructions, shedding light on the nature of pseudopartitives as well as on the theory of extended projections.
On the variability of negative scope in Japanese
Authors: KISHIMOTO HIDEKI
Published: June 2008

This article shows how the Japanese negative expressionnai‘not’ changes its scope depending on whether it is overtly head-raised to T or not. In Japanese, overt Neg-head raising takes place when a negative head acts as a functional predicate, devoid of its lexical (i.e. adjectival) properties in an analogous way to the aspectual verbshaveandbein English. When the negative headnaiundergoes overt head raising, it takes scope over TP. In some cases, however, the scope of negation becomes narrower due to the absence of overt Neg-head raising. The data provide us with empirical evidence showing that overt head raising – the kind of functional predicate raising observed in English and elsewhere in Japanese – is instantiated at the level of syntax, rather than at PF.
Development and evaluation ofLeishmania infantumrK26 ELISA for serodiagnosis of visceral leishmaniasis in Iran
Authors: FARAJNIA S. , DARBANI B. , BABAEI H. , ALIMOHAMMADIAN M. H. , MAHBOUDI F. , GAVGANI A. M.
Published: June 2008

The purpose of this study was to prepare recombinant K26 antigen fromLeishmania infantumand evaluate its performance by enzyme-linked immunosorbent assay (ELISA) test for serodiagnosis of visceral leishmaniasis (VL) in endemic regions of Iran. The results were compared with those obtained by direct agglutination test (DAT) and whole cell ELISA using crude parasite antigen. Of 93 sera from patients with confirmed VL, 90 sera were positive with rK26 ELISA (sensitivity=96·8%), whereas 85 sera were positive with DAT (sensitivity=91·4%) and 89 sera were positive with whole cell ELISA (sensitivity=95·7%). Of 130 subjects who either had other infectious diseases (n=30) or were healthy (n=100), rK26 ELISA were negative in all cases (specificity=100%), whereas DAT were negative in 116 cases (specificity=89·2%) and whole cell ELISA was negative in 114 cases (specificity=87·7%). The results of this study indicate that the rK26 ELISA is more sensitive and specific than conventional methods and could be used for reliable diagnosis of VL caused byLeishmania infantum.
Sex ratio in flea infrapopulations: number of fleas, host gender and host age do not have an effect
Authors: KRASNOV B. R. , SHENBROT G. I. , KHOKHLOVA I. S. , HAWLENA H. , DEGEN A. A.
Published: June 2008

This study set out to determine whether the sex ratio of fleas collected from host bodies is a reliable indicator of sex ratio in the entire flea population. To answer this question, previously published data on 18 flea species was used and it was tested to see whether a correlation exists between the sex ratio of fleas collected from host bodies and the sex ratio of fleas collected from host burrows. Across species, the female:male ratio of fleas on hosts correlated strongly with the female:male ratio of fleas in their burrows, with the slope of the regression overlapping 1. Controlling for flea phylogeny by independent contrasts produced similar results. It was also ascertained whether a host individual is a proportional random sampler of male and female fleas and whether the sex ratio in flea infrapopulations depends on the size of infrapopulations and on the gender and age of a host. Using field data, the sex ratio in infrapopulations of 7 flea species parasitic on 4 rodent species was analysed. Populations of 3 species (Nosopsyllus iranus,Parapulex chephrenisandXenopsylla conformis) were significantly female-biased, whereas male bias was found in 1 species (Synosternus cleopatrae). In general, the sex ratio of fleas collected from an individual rodent did not differ significantly from the sex ratio in the entire flea population. Neither host gender, and age nor number of fleas co-occurring on a host affected (a) the sex ratio in flea infrapopulations and (b) the probability of an infrapopulation to be either female- or male-biased.
The struggle between the ‘image of God’ and Satan in theGreek Life of Adam and Eve
Authors: Nir Rivka
Published: June 2008

According to a tradition in theGreek Life of Adam and Eve(GLAE), Seth and his mother Eve were confronted by a wild beast that attacked Seth. This article asserts that Seth's battle with the beast should be understood as a struggle between the ‘image of God’ and Satan, and viewed in a Christian context. The claim is based on three aspects of the story: how the beast is described, why it attacked Seth and onlyhecould control it, and why the beast was confined to its dwelling place until the Day of Judgement. The struggle between Seth and the beast/Satan should be seen as a link in the chain of struggle between the image of God and Satan. It begins in Paradise between Adam, the image of God, and Satan, as recounted in the story of Satan's fall from heaven, continues on earth between Seth, Adam's descendant, and Satan, and will culminate with the final victory of Jesus, the ultimate image of God, over Satan at the end of times.
Torture and the Christian conscience: a response to Jeremy Waldron
Authors: Porter Jean
Published: June 2008

In remarks offered in 2006 at a conference at Princeton Theological Seminary, inaugurating a National Religious Campaign against Torture, the legal philosopher Jeremy Waldron observed that Christian leaders have contributed relatively little to the recent debate over the use of torture. This is regrettable, in his view, because secular morality does not have resources sufficient to address the question of torture, and a Christian perspective emphasising the absoluteness and divine character of the relevant moral norms would represent an important contribution to our reflections on this question. This article offers a response to Waldron's timely and important challenge, setting forth a Christian theological argument that the practice of torture is categorically prohibited. The basis for this prohibition does not rest, however, on the absoluteness of moral norms as such – rather, it rests on the distinctive character of torture as an egregious assault on the human person regarded as image of God.
Some reflections on the Contextualist approach to ethico-legal texts of the Quran
Authors: Saeed Abdullah
Published: June 2008

A “contextualist” reading of the Quran is becoming increasingly popular, particularly among those Muslims referred to as “progressive-ijtihadis”. One of the primary concerns of this reading is that in order to understand and interpret the ethico-legal content of the Quran and relate that content to the changing needs and circumstances of Muslims today, it is important to approach the text at different levels, giving a high degree of emphasis to the socio-historical context of the text. In the classical tafsīr this emphasis on socio-historical context was not considered important, particularly in the interpretation of the ethico-legal texts, despite the frequent use of asbāb al-nuzūl literature. In this paper, I will explore how progressive-ijtihadis are adopting a contextualist reading of ethico-legal texts of the Quran. To illustrate this, I will use one or two such texts (verses) and their interpretations by the progressive-ijtihadis and will seek to demonstrate the contours of this approach, and highlight some of the challenges this approach is facing.
Fish consumption among young overweight European adults and compliance to varying seafood content in four weight loss intervention diets
Authors: Thorsdottir I , Birgisdottir BE , Kiely M , Martinez JA , Bandarra NM
Published: June 2008

Background

Fish is considered an important part of a healthy diet and is frequently recommended as a main course at least twice a week.

Objective

To study the frequency of fish consumption among young overweight European adults and their compliance to varying seafood consumption in weight loss intervention diets.

Design

After meeting the inclusion criteria, the subject’s seafood intake was evaluated. Subjects were randomly assigned into four groups and were advised energy-restricted diets for 8 weeks, including no seafood (control), cod, salmon or fish oil. A validated FFQ was used to evaluate the consumption of seafood at baseline, midpoint and endpoint, and long-chain n-3 fatty acids in blood erythrocytes were measured.

Setting

Iceland, Ireland and Spain.

Subjects

The sample (n 324); 20–40-year-olds with BMI = 27·5–32·5 kg/m2; 85 % participated.

Results

At baseline, 34 % of the participants reported eating fish at least twice a week as the main course. During the intervention, six participants reported that they did not finish their fish portions, 15 % of the participants consumed small amount of fish additional to the study protocol in weeks 1–4 and 23 % in weeks 5–8 (P = 0·010). Changes in erythrocyte long-chain n-3 fatty acids confirmed good compliance, with increases in the salmon (P < 0·001) and fish oil (P < 0·001) groups, smaller increase in the cod group (P = 0·037) and decrease in the control group (P = 0·030).

Conclusion

Frequency of fish consumption among 66 % of young European overweight adults is lower than frequently recommended. Compliance to varying seafood consumption was good. Therefore, including more fish in the diet of this group should be encouraged.
Wie stark hängen die HAWIK-IV-Befunde vom Bildungsstand der Eltern ab?
Authors: Gienger Claudia , Petermann Franz , Petermann Ulrike
Published: June 2008

Es wird der Zusammenhang zwischen dem Bildungsstand der Eltern und der kognitiven Leistungsfähigkeit des Kindes an zwei Stichproben untersucht. Die Stichproben bestehen aus jeweils 360 Kindern und Jugendlichen im Alter von sieben bis zehn Jahren (Stichprobe 1) und von elf bis 14 Jahren (Stichprobe 2). Der Bildungsstand wird über den formalen Bildungsabschluss der Mutter, des Vaters und des höchsten formalen Bildungsabschlusses in der Familie erfasst; die kognitive Leistungsfähigkeit des Kindes wird anhand des HAWIK-IV erhoben. Es zeigen sich positive und fast ausnahmslos signifikante korrelative Zusammenhänge zwischen den drei Arten des erfassten Bildungsstandes und der kognitiven Leistungsfähigkeit des Kindes in beiden Altersgruppen, wobei altersspezifische Effekte zu verzeichnen sind. Unterschiede zwischen den zwei Stichproben sind ebenso bei einem Vergleich des mittleren Gesamt-IQ in den fünf Gruppen des höchsten familiären Bildungsabschlusses festzustellen. Die Ergebnisse werden vor dem Hintergrund der elterlichen Erziehungskompetenz diskutiert.
Net ecosystem exchange over heterogeneous Arctic tundra: Scaling between chamber and eddy covariance measurements
Authors: Fox Andrew M. , Huntley Brian , Lloyd Colin R. , Williams Mathew , Baxter Robert
Published: June 2008

Net ecosystem exchange (NEE) was estimated for an area of tundra near Abisko using both eddy covariance (EC) data and chamber measurements. This area of tundra is heterogeneous with six principal elements forming a landscape mosaic. Chamber measurements in patches of the individual mosaic elements were used to model NEE as a function of irradiance and temperature. The area around the EC mast was mapped, and a footprint model was used to simulate the varying source fraction attributable to each mosaic element. Various upscaling approaches were used to estimate NEE for comparison with NEE calculated from the EC observations. The results showed that EC measurements made for such a heterogeneous site are robust to the variations in NEE between mosaic elements that also vary substantially in their source fractions. However, they also revealed a large (∼60%) bias in the absolute magnitude of the cumulative negative NEE for a 40‐day study period simulated by various upscaling approaches when compared to the value calculated from the EC observations. The magnitude of this bias, if applied to estimates for the entire tundra region, is substantial in relation to other components of the global carbon budget. Various hypotheses to account for this bias are discussed and, where possible, evaluated. A need is identified for more systematic sampling strategies when performing chamber measurements in order to assess the extent to which subjectivity of chamber location may account for much of the observed bias. If this is the origin of the bias, then upscaling approaches using chamber measurements may generally overestimate CO2 uptake.
Plasma plume circulation and impact in an MHD substorm
Authors: Moore T. E. , Fok M.‐C. , Delcourt D. C. , Slinker S. P. , Fedder J. A.
Published: June 2008

We investigate the fate of a plasmaspheric plume generated by a discrete period of southward interplanetary magnetic field (IMF) to assess its contribution to plasma sheet and ring current pressure and compare with that for other sources. We use test particle motions in Lyon‐Fedder‐Mobarry (LFM) global circulation model fields. The inner magnetosphere is simulated with the Comprehensive Ring Current Model (CRCM) model of Fok and Wolf, driven by the transpolar potential developed by the LFM magnetosphere. A variant of the Ober plasmasphere model is embedded within the models and driven by them. Global circulation is stimulated by a period of southward IMF embedded within a long interval of northward IMF. This leads to the production of a well‐defined plasmaspheric plume, enhancing the plasma density sunward of the plasmasphere. Test particles are launched with the properties of plasmaspheric ions on the L = 6.6 RE shell and weighted with densities as specified by the Ober model, as it responds to convection imposed by CRCM. Particles are tracked until they are lost from the system downstream or into the atmosphere, using the Delcourt full equations of motion, implemented for finite element fields. Results are compared with earlier computations of polar and auroral wind outflows. The plume produces an enhanced flow of plasma ∼10 times the normal polar wind global fluence. However, we find that most of the “plasmaspheric wind” is lost from the magnetosphere such that its contribution to the ring current energy density is comparable to that of the normal polar wind for this type of event.
High aromatic ring-cleavage diversity in birch rhizosphere: PAH treatment-specific changes of I.E.3 group extradiol dioxygenases and 16S rRNA bacterial communities in soil
Authors: Sipilä Timo P , Keskinen Anna-Kaisa , Åkerman Marja-Leena , Fortelius Carola , Haahtela Kielo , Yrjälä Kim
Published: June 2008

Genes encoding key enzymes of catabolic pathways can be targeted by DNA fingerprinting to explore genetic degradation potential in pristine and polluted soils. We performed a greenhouse microcosm experiment to elucidate structural and functional bacterial diversity in polyaromatic hydrocarbon (PAH)-polluted soil and to test the suitability of birch (Betula pendula) for remediation. Degradation of PAHs was analysed by high-performance liquid chromatography, DNA isolated from soil amplified and fingerprinted by restriction fragment length polymorphism (RFLP) and terminal restriction fragment length polymorphism (T-RFLP). Bacterial 16S rRNA T-RFLP fingerprinting revealed a high structural bacterial diversity in soil where PAH amendment altered the general community structure as well as the rhizosphere community. Birch augmented extradiol dioxygenase diversity in rhizosphere showing a rhizosphere effect, and further pyrene was more efficiently degraded in planted pots. Degraders of aromatic compounds upon PAH amendment were shown by the changed extradiol ring-cleavage community structure in soil. The RFLP analysis grouped extradiol dioxygenase marker genes into 17 distinct operational taxonomic units displaying novel phylogenetic clusters of ring-cleavage dioxygenases representing putative catabolic pathways, and the peptide sequences contained conserved amino-acid signatures of extradiol dioxygenases. A branch of major environmental TS cluster was identified as being related to Parvibaculum lavantivorans ring-cleavage dioxygenase. The described structural and functional diversity demonstrated a complex interplay of bacteria in PAH pollution. The findings improve our understanding of rhizoremediation and unveil the extent of uncharacterized enzymes and may benefit bioremediation research by facilitating the development of molecular tools to detect and monitor populations involved in degradative processes.
Urokinase induces survival or pro-apoptotic signals in human mesangial cells depending on the apoptotic stimulus
Authors: Tkachuk Natalia , Kiyan Julia , Tkachuk Sergey , Kiyan Roman , Shushakova Nelli , Haller Hermann , Dumler Inna
Published: June 2008

Deregulated apoptosis of MCs (mesangial cells) is associated with a number of kidney diseases including end-stage diabetic nephropathy. Cell death by apoptosis is a tightly orchestrated event, whose mechanisms are not completely defined. In the present study we show that the uPA (urokinase-type plasminogen activator)/uPAR (uPA receptor) system can initiate both cell survival and pro-apoptotic signals in human MCs in response to different apoptotic stimuli. uPA abrogated MC apoptosis induced by serum withdrawal conditions and enhanced apoptosis initiated in MCs by high glucose. Effects of uPA were independent of its proteolytic activity and required uPAR for both pro- and anti-apoptotic effects. Studies on the uPAR interactome provide evidence that the opposing effects of uPA were directed via different uPAR-interacting transmembrane partners. Exposure of MCs to RGD (Arg-Gly-Asp) peptide led to abrogation of the anti-apoptotic effect of uPA, which implies involvement of integrins in this process. A pro-apoptotic effect of uPA under high-glucose conditions was mediated via association of uPAR and the cation-independent M6P (mannose-6-phosphate)/IGF2R (insulin-like growth factor 2 receptor). Both receptors were co-precipitated and co-localized in MCs. Studies on the underlying signalling indicate that the ERK1/2 (extracellular-signal-regulated kinase 1/2), Akt and BAD (Bcl-2/Bcl-XL-antagonist, causing cell death) protein were involved in regulation of apoptosis by uPA in MCs. M6P/IGF2R mediated BAD perinuclear localization during apoptosis initiated by uPA and high glucose. In conclusion, we provide evidence that, in MCs, the uPA/uPAR system regulates survival/apoptosis processes in a stimulus-specific fashion via a mitochondria-dependent mechanism and that BAD protein serves as a downstream molecule.
Nonlinear electron magnetohydrodynamics physics. V. Triggered whistler emissions
Authors: Stenzel R. L. , Strohmaier K. D. , Urrutia J. M.
Published: June 2008

Laboratory experiments on whistler instabilities in the presence of small trigger waves have been performed. The instabilities arise from energizing electrons in magnetic null lines with time-varying magnetic fields. Such fields are created with loop antennas carrying large oscillating currents in the low-frequency whistler branch. X-type and O-type magnetic nulls are produced with electric fields along the toroidal separator. The magnetic field convects in the form of whistler spheromaks and whistler mirrors. Counterpropagating spheromaks merge and form field-reversed configurations (FRCs). Counterpropagating mirrors colliding with an FRC also energize electrons and produce high-frequency whistler emissions. The possibility that these emissions are triggered by incident waves from other null lines in the plasma has been investigated. A controlled experiment on triggered emissions where a test wave has been created with an independent antenna and propagated into the source region to investigate its amplification has also been performed. It is observed that the test wave does not grow but triggers a much larger instability in a spheromak. The enhanced emission has a different magnetic topology and a slightly different frequency from that of the test wave. Space-time measurements in the source region show both convective wave amplification occurs as well as an absolute instability in the current ring.
On the R-dependence of the spin-orbit coupling constant: Potential energy functions of Xe2+ by high-resolution photoelectron spectroscopy and ab initio quantum chemistry
Authors: Zehnder O. , Mastalerz R. , Reiher M. , Merkt F. , Dressler R. A.
Published: June 2008

The pulsed-field-ionization zero-kinetic-energy photoelectron spectrum of Xe2 has been measured between 97 350 and 108200cm−1, following resonant two-photon excitation via selected vibrational levels of the C0u+ Rydberg state of Xe2. Transitions to three of the six low-lying electronic states of Xe2+ could be observed. Whereas extensive vibrational progressions were observed for the transitions to the I(3∕2g) and I(3∕2u) states, only the lowest vibrational levels of the II(1∕2u) state could be detected. Assignments of the vibrational quantum numbers were derived from the analysis of the isotopic shifts and from the modeling of the potential energy curves. Adiabatic ionization energies, dissociation energies, and vibrational constants are reported for the I(3∕2g) and the I(3∕2u) states. Multireference configurational interaction and complete active space self-consistent field calculations have been performed to investigate the dependence of the spin-orbit coupling constant on the internuclear distance. The energies of vibrational levels, measured presently and in a previous investigation (Rupper et al., J. Chem. Phys. 121, 8279 (2004)), were used to determine the potential energy functions of the six low-lying electronic states of Xe2+ using a global model that includes the long-range interaction and treats, for the first time, the spin-orbit interaction as dependent on the internuclear separation.
Enhanced active piezoelectric 0-3 nanocomposites fabricated through electrospun nanowires
Authors: Feenstra Joel , Sodano Henry A.
Published: June 2008

The use of monolithic piezoceramic materials in sensing and actuation applications has become quite common over the past decade. However, these materials have several properties that limit their application in practical systems. These materials are very brittle due to the ceramic nature of the monolithic material, making them vulnerable to accidental breakage during handling and bonding procedures. In addition, they have very poor ability to conform to curved surfaces and result in large add-on mass associated with using a typically lead-based ceramic. These limitations have motivated the development of alternative methods of applying the piezoceramic material, including piezoceramic fiber composites and piezoelectric 0-3 composites (also known as piezoelectric paint). Piezoelectric paint is desirable because it can be spayed or painted on and can be used with abnormal surfaces. However, the piezoelectric paint developed in prior studies has resulted in low coupling, limiting its application. In order to increase the coupling of the piezoelectric paint, this effort has investigated the use of piezoelectric nanowires rather than spherical piezoelectric particle, which are difficult to strain when embedded in a polymer matrix. The piezoceramic wires were electrospun from a barium titanate (BaTiO3) sol gel to produce fibers with 500–1000nm diameters and subsequently calcinated to acquire perovskite BaTiO3. An active nanocomposite paint was formed using the resulting piezoelectric wires and was compared to the same paint with piezoelectric nanoparticles. The results show that the piezoceramic wires produce 0-3 nanocomposites with as high as 300% increase in electromechanical coupling.
The surface tension of water under high magnetic fields
Authors: Fujimura Yuu , Iino Masaaki
Published: June 2008

The surface tension of water-air interface was measured by means of a surface-wave resonance method under magnetic field up to 10 T. It was found that the surface tension increased linearly with an increase in the square of the magnetic field. The surface tension increased by 1.32±0.13 mN/m or 1.83±0.18% at 10 T. One possible explanation for this is that the stabilization of hydrogen bonds increases the bulk Helmholtz free energy, which thereby increases the surface tension. Another explanation is that the Lorentz force dampens the surface excitation of ripplons, decreases the surface pressure at the surface, and thereby increases the surface tension.
Polar confinement modulates solvation behavior of methane molecules
Authors: Xu Weixin , Mu Yuguang
Published: June 2008

Polar confinement induces an amorphous solidlike state of water characterized by an orientational correlation time longer than hundreds of picoseconds and significant structural disorder. Solvation behavior of methane molecules is dramatically modulated under polar confinement. Moreover our simulations indicate that the charges equivalent to those borne by atoms of amino acids could generate an electric field which is strong enough to stimulate the phase transition of water. In our results, polar confinement is found to be more capable of aggregating hydrophobic molecules. This study raises an interesting mechanism by which the cagelike structure of the Escherichia coli chaperonin GroEL and the cochaperonin GroES complex helps protein folding.
SiO
2
nanoparticles as scatterers for random organic laser action in red fluorescent dye 4-(dicyanomethylene)-2-tert-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran doped polystyrene films
Authors: Zhang Dingke , Wang Yanping , Ma Dongge
Published: June 2008

Random multimode lasers are achieved in 4-(dicyanomethylene)-2-tert-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) doped polystyrene thin films by introducing silicon dioxide (SiO2) nanoparticles as scatterers. The devices emit a resonance multimode peak at a center wavelength of 640 nm with a mode linewidth less than 0.87 nm. The threshold excitation intensity is as low as 0.25 mJ pulse−1 cm−2. It can be seen that the microscopic random resonance cavities can be formed by multiple scattering of SiO2 nanoparticles. The transport mean free length is estimated to be about 156 μm. The demonstration of random organic lasers opens up the possibility of using scattering as an alternative source of coherent light emission.
Nanoengineering of a negative-index binary-staircase lens for the optics regime
Authors: Casse B. D. F. , Banyal R. K. , Lu W. T. , Huang Y. J. , Selvarasah S. , Dokmeci M. , Sridhar S.
Published: June 2008

We show that a binary-staircase optical element can be engineered to exhibit an effective negative index of refraction, thereby expanding the range of optical properties theoretically available for future optoelectronic devices. The mechanism for achieving a negative-index lens is based on exploiting the periodicity of the surface corrugation. By designing and nanofabricating a planoconcave binary-staircase lens in the InP∕InGaAsP platform, we have experimentally demonstrated at 1.55μm that such negative-index concave lenses can focus plane waves. The beam propagation in the lens was studied experimentally and was in excellent agreement with the three-dimensional finite-difference time-domain numerical simulations.
Folding of proteins with an all-atom Gō-model
Authors: Wu L. , Zhang J. , Qin M. , Liu F. , Wang W.
Published: June 2008

The Gō-like potential at a residual level has been successfully applied to the folding of proteins in many previous works. However, taking into consideration more detailed structural information in the atomic level, the definition of contacts used in these traditional Gō-models may not be suitable for all-atom simulations. Here, in this work, we develop a rational definition of contacts considering the screening effect in the crowded intramolecular environment. In such a scheme, a large amount of screened atom pairs are excluded and the number of contacts is decreased compared to the case of the traditional definition. These contacts defined by such a new definition are compatible with the all-atom representation of protein structures. To verify the rationality of the new definition of contacts, the folding of proteins CI2 and SH3 is simulated by all-atom molecular dynamics simulations. A high folding cooperativity and good correlation of the simulated Φ-values with those obtained experimentally, especially for CI2, are found. This suggests that the all-atom Gō-model is improved compared to the traditional Gō-model. Based on the comparison of the Φ-values, the roles of side chains in the folding are discussed, and it is concluded that the side-chain structures are more important for local contacts in determining the transition state structures. Moreover, the relations between side chain and backbone orderings are also discussed.