bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of planting date, intensity of tiller separation and plant density on the yield of transplanted rice
Authors: BISWAS P. K. , SALOKHE V. M.
Published: April 2008

Experiments were conducted in Bangkok clay soil to investigate the influence of planting date, tiller separation and plant density on the yield and yield attributes of parent and clone plants of two transplanted rice varieties. The 15 July transplanting of mother crop and collected vegetative tillers and retransplanting on 15 August showed significantly high grain yield (3·8 t/ha). The photoperiod-insensitive variety RD23 gave higher yield (3·8 t/ha) than the photoperiod-sensitive variety KDML105 (3·0 t/ha). Tiller separation up to 4 tillers/hill did not adversely affect the mother crop. Vegetative tillers transplanted with 2–4 tillers/hill gave a similar yield as the mother crop in both the seasons. Vegetative tillers gave a higher yield than nursery seedlings transplanted on the same date. The yield components, i.e. weight of 1000 grains, grains/panicle and per cent filled grains, showed better responses with early transplanting of KDML105 in the mother crop and vegetative tillers except for panicle number and panicle length of vegetative tillers with RD23. The results suggest that in some flood-prone lowlands, where the transplanted crop is damaged by natural hazards, vegetative propagation using tillers separated (maximum 4/hill) from the previously established transplanted crop is beneficial for higher productivity.
Genetic parameters for growth traits of a local breed of sheep in the United Arab Emirates
Authors: AL-SHOREPY S. A.
Published: April 2008

Genetic parameters were estimated for purebred and crossbred lambs of a local breed using a single trait animal model. The traits recorded were: birth weight (BWT), weight at 30 days (WT30), weaning weight (WWT), average daily gain from 1 to 30 days (ADG1) and average daily gain from 30 to 90 days (ADG2). Five different animal models were fitted for each trait; all including additive direct genetic variance and various combinations of additive maternal and environmental maternal effects. The most appropriate model was chosen based on likelihood ratio tests. Additive maternal and permanent environmental effects were important (P < 0·05) for birth weight in purebred and crossbred lambs, when compared with a model containing only additive direct effects. Inclusion of maternal permanent environmental effects provided a better fit (P < 0·05) for weaning weight in purebred lambs than a model containing only additive direct effects. Estimates of heritability from the model containing additive direct, maternal effects and maternal permanent environmental effects, but not additive direct-maternal correlation, for combined purebred and crossbred lambs were 0·32 for BWT, 0·19 for WT30, 0·24 for WWT, 0·26 for ADG1 and 0·12 for ADG2. Estimates of additive maternal and maternal permanent environmental variances, respectively, as a proportion of phenotypic variance were 0·06 and 0·07 for BWT, 0·05 and 0·02 for WT30, 0·02 and 0·03 for WWT, 0·03 and 0·05 for ADG1 and 0·00 and 0·03 for ADG2. Estimates of direct-maternal correlation in subsequent analyses were significant and ranged from −0·16 to −0·95 for live weights and from −0·73 to −1·0 for daily gains. However, the very large negative correlations probably resulted from undefined non-genetic covariances as well as possible antagonistic genetic effects. These results indicate that it would be possible to improve growth traits in a local sheep breed through genetic selection.
Long-term persistence of Lolium perenne and Trifolium repens in sown hill swards
Authors: WILMAN D. , BYRNE S. A. , OWEN H. Ll.
Published: April 2008

In order to understand better the factors which influence the persistence or non-persistence of Lolium perenne and Trifolium repens on damp hill land in a wet climate, swards in mid-Wales which had been converted from semi-natural rough grazing (predominantly Molinia caerulea or Nardus stricta or Agrostis/Festuca/Nardus) in 1961–81 were examined in 1982 and 1999, using a point quadrat technique.

There was a marked decline between 1982 and 1999 in the proportion of L. perenne in the majority of the study areas. On the other hand, in 1999 the oldest swards (sown 30–38 years before) contained at least as high a proportion of L. perenne (22% of sward on average) as the younger swards (sown 18–29 years before). In two swards sown 25–26 years before, at 390–445 m above sea level, which received 95 kg N/ha per year, L. perenne was 36% of sward. On the other hand, no L. perenne was recorded on three swards which were no longer receiving fertilizer and which were being grazed at a greatly reduced stocking rate. The proportion of T. repens was rather low and declined between 1982 and 1999 (from 10 to 4% of sward on average). The application of more lime and more K and perhaps less N would probably have increased the proportion of T. repens. On at least one farm, the use of MCPA against Cirsium spp. had probably reduced the proportion of T. repens. There were positive correlations between the proportion of L. perenne and the proportions of T. repens and Poa spp. There were negative correlations between L. perenne and each of Agrostis spp., Festuca spp. and Holcus lanatus and also between T. repens and Agrostis spp. The proportion of Poa spp. was positively correlated with exchangeable Ca, nitrate-N and total N in soil and negatively correlated with exchangeable acidity.
Interrelated neuropsychological and anatomical evidence of hippocampal pathology in the at-risk mental state
Authors: Hurlemann R. , Jessen F. , Wagner M. , Frommann I. , Ruhrmann S. , Brockhaus A. , Picker H. , Scheef L. , Block W. , Schild H. H. , Moller-Hartmann W. , Krug B. , Falkai P. , Klosterkotter J. , Maier W.
Published: April 2008

Background

Verbal learning and memory deficits are frequent among patients with schizophrenia and correlate with reduced magnetic resonance imaging (MRI) volumes of the hippocampus in these patients. A crucial question is the extent to which interrelated structural-functional deficits of the hippocampus reflect a vulnerability to schizophrenia, as opposed to the disorderper se.

Method

We combined brain structural measures and the Rey Auditory Verbal Learning Test (RAVLT) to assess hippocampal structure and function in 36 never-medicated individuals suspected to be in early (EPS) or late prodromal states (LPS) of schizophrenia relative to 30 healthy controls.

Results

Group comparisons revealed bilaterally reduced MRI hippocampal volumes in both EPS and LPS subjects. In LPS subjects but not in EPS subjects, these reductions were correlated with poorer performance in RAVLT delayed recall.

Conclusions

Our findings suggest progressive and interrelated structural-functional pathology of the hippocampus, as prodromal symptoms and behaviours accumulate, and the level of risk for psychosis increases. Given the inverse correlation of learning and memory deficits with social and vocational functioning in established schizophrenia, our findings substantiate the rationale for developing preventive treatment strategies that maintain cognitive capacities in the at-risk mental state.
LIMIT THEORY FOR EXPLOSIVELY COINTEGRATED SYSTEMS
Authors: Phillips Peter C.B. , Magdalinos Tassos
Published: April 2008

A limit theory is developed for multivariate regression in an explosive cointegrated system. The asymptotic behavior of the least squares estimator of the cointegrating coefficients is found to depend upon the precise relationship between the explosive regressors. When the eigenvalues of the autoregressive matrix Θ are distinct, the centered least squares estimator has an exponential Θn rate of convergence and a mixed normal limit distribution. No central limit theory is applicable here, and Gaussian innovations are assumed. On the other hand, when some regressors exhibit common explosive behavior, a different mixed normal limiting distribution is derived with rate of convergence reduced to

$\sqrt{n}$
.
In the latter case, mixed normality applies without any distributional assumptions on the innovation errors by virtue of a Lindeberg type central limit theorem. Conventional statistical inference procedures are valid in this case, the stationary convergence rate dominating the behavior of the least squares estimator.
REGRESSION ASYMPTOTICS USING MARTINGALE CONVERGENCE METHODS
Authors: Ibragimov Rustam , Phillips Peter C.B.
Published: April 2008

Weak convergence of partial sums and multilinear forms in independent random variables and linear processes and their nonlinear analogues to stochastic integrals now plays a major role in nonstationary time series and has been central to the development of unit root econometrics. The present paper develops a new and conceptually simple method for obtaining such forms of convergence. The method relies on the fact that the econometric quantities of interest involve discrete time martingales or semimartingales and shows how in the limit these quantities become continuous martingales and semimartingales. The limit theory itself uses very general convergence results for semimartingales that were obtained in the work of Jacod and Shiryaev (2003,Limit Theorems for Stochastic Processes). The theory that is developed here is applicable in a wide range of econometric models, and many examples are given. %One notable outcome of the new approach is that it provides a unified treatment of the asymptotics for stationary, explosive, unit root, and local to unity autoregression, and also some general nonlinear time series regressions. All of these cases are subsumed within the martingale convergence approach, and different rates of convergence are accommodated in a natural way. Moreover, the results on multivariate extensions developed in the paper deliver a unification of the asymptotics for, among many others, models with cointegration and also for regressions with regressors that are nonlinear transforms of integrated time series driven by shocks correlated with the equation errors. Because this is the first time the methods have been used in econometrics, the exposition is presented in some detail with illustrations of new derivations of some well-known existing results, in addition to the provision of new results and the unification of the limit theory for autoregression.
MATRIX FORMULAS FOR NONSTATIONARY ARIMA SIGNAL EXTRACTION
Authors: McElroy Tucker
Published: April 2008

The paper provides general matrix formulas for minimum mean squared error signal extraction for a finitely sampled time series whose signal and noise components are nonstationary autoregressive integrated moving average processes. These formulas are quite practical; in addition to being simple to implement on a computer, they make it possible to easily derive important general properties of the signal extraction filters. We also extend these formulas to estimates of future values of the unobserved signal, and we show how this result combines signal extraction and forecasting.
QUANTILE REGRESSION WITH MISMEASURED COVARIATES
Authors: Schennach Susanne M.
Published: April 2008

This paper establishes that the availability of instrumental variables enables the identification and the consistent estimation of nonparametric quantile regression models in the presence of measurement error in the regressors. The proposed estimator takes the form of a nonlinear functional of derivatives of conditional expectations and is shown to provide estimated quantile functions that are uniformly consistent over a compact set.
USING SUBSPACE METHODS FOR ESTIMATING ARMA MODELS FOR MULTIVARIATE TIME SERIES WITH CONDITIONALLY HETEROSKEDASTIC INNOVATIONS
Authors: Bauer Dietmar
Published: April 2008

This paper deals with the estimation of linear dynamic models of the autoregressive moving average type for the conditional mean for stationary time series with conditionally heteroskedastic innovation process. Estimation is performed using a particular class of subspace methods that are known to have computational advantages as compared to estimation based on criterion minimization. These advantages are especially strong for high-dimensional time series. Conditions to ensure consistency and asymptotic normality of the subspace estimators are derived in this paper. Moreover asymptotic equivalence to quasi maximum likelihood estimators based on the Gaussian likelihood in terms of the asymptotic distribution is proved under mild assumptions on the innovations. Furthermore order estimation techniques are proposed and analyzed.
TESTING FOR SEASONAL UNIT ROOTS IN PERIODIC INTEGRATED AUTOREGRESSIVE PROCESSES
Authors: Castro Tomas del Barrio , Osborn Denise R.
Published: April 2008

This paper examines the implications of applying the Hylleberg, Engle, Granger, and Yoo (1990,Journal of Econometrics44, 215–238) (HEGY) seasonal root tests to a process that is periodically integrated. As an important special case, the random walk process is also considered, where the zero-frequency unit roott-statistic is shown to converge to the Dickey–Fuller distribution and all seasonal unit root statistics diverge. For periodically integrated processes and a sufficiently high order of augmentation, the HEGYt-statistics for unit roots at the zero and semiannual frequencies both converge to the same Dickey–Fuller distribution. Further, the HEGY joint test statistic for a unit root at the annual frequency and all joint test statistics across frequencies converge to the square of this distribution. Results are also derived for a fixed order of augmentation. Finite-sample Monte Carlo results indicate that, in practice, the zero-frequency HEGY statistic (with augmentation) captures the single unit root of the periodic integrated process, but there may be a high probability of incorrectly concluding that the process is seasonally integrated.
Land markets in late imperial and republican China
Authors: POMERANZ KENNETH
Published: April 2008

China has had very active markets for both the sale and the rental of land since Song times (960–1279), if not longer. By the sixteenth century, most of the institutional arrangements that would characterize these markets until 1949 were in place. These institutions differed sharply from those of emerging land markets in early modern Western Europe: in particular, government played a lesser role in adjudicating disputes over land contracts, and customary arrangements included features that (a) gave some sellers of land claims on purchasers that could last for many years and (b) gave some tenants, especially in South and East China, very strong usufruct rights, which themselves became a form of tradable property. However, despite these and other differences from Western models, Chinese land markets were quite efficient, and provided the incentives needed for a very productive agriculture; secure tenants, for instance, responded to their strong position by behaving like owners and investing heavily in improving the land.
Isolation compliance among university students during a mumps outbreak, Kansas 2006
Authors: SOUD F. A. , CORTESE M. M. , CURNS A. T. , EDELSON P. J. , BITSKO R. H. , JORDAN H. T. , HUANG A. S. , VILLALON-GOMEZ J. M. , DAYAN G. H.
Published: April 2008

A large mumps outbreak occurred among students at a Kansas university in 2006. To reduce transmission, students with mumps were asked to isolate themselves. We describe isolation measures and student compliance with these measures. Questionnaires were administered to students suspected of having mumps. Of the 132 students instructed to stay isolated, 75% stayed isolated for the number of days recommended and were considered compliant. Case-students told to stay isolated for 1–4 days were more likely to be compliant [86% vs. 66%; adjusted odds ratio (aOR) 3·6, 95% CI 1·4–9·0] than those told to stay isolated for 5–9 days. Those who rated avoiding contact with others during isolation as very important were also more likely to be compliant (83% vs. 60%; aOR 3·6, 95% CI 1·5–8·4) than those who rated the importance lower. In a college setting, it may be difficult to achieve high compliance with guidelines recommending that persons stay isolated for much longer than 4 days.
Heavy and light money in the Netherlands Indies and the Dutch Republic: dilemmas of monetary management with unit of account systems
Authors: Wolters Willem G.
Published: April 2008

In its Asian operations the Dutch United East Indies Company (VOC) (1602–1798) acted both as a territorial ruler and as a trading company. The company shipped large amounts of precious metals to Asia, both in the form of bullion and as coins, to pay for its trade and to provide currency for the areas under its control. The Company faced the problem that silver coins rapidly disappeared from circulation, as demand for silver was high in Asia. The Company attempted to manage the problem with a monetary policy using a unit of account, modelled after the policy of the Dutch Republic. It turned out that the two purposes of the money of account system, viz., putting the bookkeeping on a systematic basis and managing the currency in circulation, were conflicting. The first demanded a fixed unit of account, the second demanded a flexible policy of linking and de-linking the unit of account to real coins. Although the Company managed to muddle through this dilemma, it only succeeded in finding temporary solutions.
The dual currency system of Renaissance Europe
Authors: Fantacci Luca
Published: April 2008

The monetary system of late medieval and early modern Europe has been commonly described as irrational, in the light of later commodity money standards. In particular, the alterations in the legal value and/or in the metal content of most coins throughout this period have been regarded as a source of disorder and as a product of ignorance and abuse. This article suggests that the whole system, and its apparently awkward articulations, may have been deliberately designed to ensure complementarity between domestic and foreign trade. From this perspective, monetary alterations appear as the levers of a peculiar form of monetary policy, with an extra degree of freedom compared to more modern instruments, and equally open to being managed or mismanaged.
EDITORIAL
Authors: BROWN MARSHALL
Published: April 2008

‘Music and …’ is the concluding topic in Ludmilla Jordanova’s editorial in an earlier issue of this journal (Eighteenth-Century Music 1/2 (2004), 153–155), and in reverse it will be the starting-point in mine. I fell into writing about music as an active amateur (and briefly professional) cellist with a background in theory consisting of a year’s tutoring in old-fashioned species counterpoint as an unruly fourteen-year-old. In the autumn of 1979 I was writing about the origins of reverie – that is, of representations and discussions of unfocused or unconscious awareness – in writings of the 1780s, chiefly by Rousseau, Kant and William Cowper. It occurred to me that the drifting sensibility I was describing was perfectly captured by the introduction to Mozart’s Dissonance Quartet. It started as a footnote, but finally required a small essay to define the contexts and work out the details. Then, however, I could invoke the representation of a state of feeling not encumbered by the rational straitjacket of concepts. Whether they knew it or not – Kant certainly didn’t, Rousseau at some level certainly did – music was what my authors were after!
PARTIMENTO FUGUE IN EIGHTEENTH-CENTURY GERMANY: A BRIDGE BETWEEN THOROUGHBASS LESSONS AND FUGAL COMPOSITION
Authors: GINGRAS BRUNO
Published: April 2008

The pervasiveness of thoroughbass in eighteenth-century German musical pedagogy is illustrated by
the way that it extends from continuo realization exercises and chorale harmonizations to complete fugues. This article seeks to demonstrate how partimento fugue can be construed as the missing link between thoroughbass exercises and fully fledged keyboard fugues, by expanding on ideas first advanced by William Renwick. Through an examination of partimento fugues from J. S. Bach’s Precepts and Principles, Handel’s Lessons for Princess Anne, the Langloz manuscript and Heinichen’s Der General-Bass in der Composition, this study outlines a progression from basic realization exercises, in which the emphasis lies on the recognition and execution of continuo figures, to advanced recomposition assignments in which the performer is expected to project a rich contrapuntal texture from a simple figured-bass line, a task which is crucially dependent on the ability to memorize and reuse thematic material. The pedagogical value of partimento fugues also hinges on the acquisition of commonplace patterns such as the scalar descent and the harmonization of a chromatic line in alternating thirds and sixths. Although these patterns are often merely implied, they are found repeatedly in specific musical contexts, suggesting that they may function as generative melodic lines from which the composer derived both the harmonic progression and the underlying bass line, in a striking reversal of the standard compositional paradigm proposed by eighteenth-century theorists such as Niedt. Finally, the occurrence of these formulas in thoroughbass exercises, as well as in masterpieces such as J. S. Bach’s Well-Tempered Clavier, points to their ubiquitous character and demonstrates that they were part of a common language shared by many German composers of the period, thus emphasizing the need for an increased familiarity with the German partimento repertory and its conventions.
RECUPERATION, TRANSFORMATION AND THE TRANSCENDENCE OF MAJOR OVER MINOR IN THE FINALE OF HAYDN’S STRING QUARTET OP. 76 NO. 1
Authors: GRAVE FLOYD
Published: April 2008

When the French critic Bernard Germain Lacépède identified minor harmony with inner pain, restlessness and torment (La poétique de la musique, 1785), he was recognizing what had evolved as a lopsided dichotomy within the tonal system: rather than viewing major and minor as equivalent, mutually defining opposites, later eighteenth-century musicians often viewed the latter as a site of disturbing associations and thus potentially problematic as the foundation for large-scale instrumental compositions. Against this backdrop, it is notable that Haydn ended most of his later minor-key works in major, and in the finales of his quartets Op. 76 Nos 1–3 he exploits modal reversal as a special theme by having each begin in minor before undergoing an artfully contrived switch to major. Because the tonality of two of these quartets was major to begin with, Nos 1 in G and 3 in C, this entailed a double reversal: from major to minor as the finale began, from minor to major at a crucial moment prior to the end. The finale of Op. 76 No.1 surpasses the others of this group in tonal range, intricate play of symmetries and palpable connections to its preceding movements. Crowning it is a coda that turns the movement’s stark opening unison into a cheerful rustic tune. Thus opening theme and coda, although diametrically opposed in topic and imagery, are heard to share the same underlying identity. The result may be read as a vividly evoked musical subject whose vicissitudes trace a path from darkness to light, from turmoil and confusion to a state of pastoral joy and contentment.
MUCH ADO ABOUT SOMETHING; OR, COSÌ FAN TUTTE IN THE ROMANTIC IMAGINATION: A COMMENTARY ON AND TRANSLATION OF AN EARLY NINETEENTH-CENTURY EPISTOLARY EXCHANGE
Authors: GOEHRING EDMUND J.
Published: April 2008

Among the gems buried in Johann Friedrich Reichardt’s short-lived Berlinische musikalische Zeitung is a ‘Musikalischer Briefwechsel’ that appeared over three volumes in September 1805. The text, cast as an epistolary exchange between the fictional characters Arithmos and Phantasus, argues the merits of Mozart’s Così fan tutte. (The opera had recently returned to the Berlin stage after a thirteen-year absence.) The exchange has received little scholarly attention, and yet it is a remarkable document for the glimpse it gives both into Berlin’s musical politics and, most of all, the reception history of Mozart’s opera.

The authorship of the ‘Briefwechsel’, which appeared pseudonymously, has been attributed to Georg Christian Schlimbach, a frequent contributor to the journal. This article, in contrast, argues that Reichardt himself makes the more likely author: the correspondence more closely reflects his personality, his ambitions for the advancement of opera in the Prussian capital and his theory of art. Indeed, arising from his defence of Mozart’s opera is an extraordinary claim in the history of Così’s reception: that the work exemplifies romantic irony. E. T. A. Hoffmann is famous for his terse praise of the opera’s ‘ergötzlichste Ironie’. Reichardt, however, goes further by showing how the opera amalgamates, in quintessentially romantic fashion, the opposing forces of the comic and serious. Employing a Shakespearean conceit, he argues that Mozart’s music amounts to more than ‘much ado about nothing’.

Reichardt’s move is the more significant given that he builds his reading not on Da Ponte’s libretto but on German adaptations by Bretzner and Treitschke, translations that modern scholarship has widely faulted for lacking the original’s subtlety. Thus, although Così fan tutte has generally been viewed as a work that runs counter to romantic tastes, Reichardt’s ‘Briefwechsel’, along with some newly discovered material, provides a basis for revisiting that claim about the opera’s place in nineteenth-century thought.
Optimal Economic Design and Operation of Single‐ and Multi‐column Chromatographic Processes
Authors: Chan Sharon , Titchener‐Hooker Nigel , Sørensen Eva
Published: April 2008

Single‐column chromatography is widely used in the biopharmaceutical industries, although multi‐column alternatives in the form of simulated moving bed (SMB) processes are now emerging. It may be difficult, however, to determine which column alternative will be best suited for a given application, and this work sets out to address this issue. A systematic approach is presented that is based on a full economic appraisal of each process alternative based on an optimization of the net annual profit. Single‐column processes with and without recycling are considered, as are both the SMB and the Varicol process. The cyclic steady state for the SMB and Varicol processes is determined directly by complete discretization. The approach is applied to a case study based on a linear isotherm where it is found that for this particular system, a recycling policy is not necessary for the single column. When comparing the single‐column process with the multi‐column alternatives, the single column is the most economical provided the life time of the project is short; however, the economic benefits of the more capital‐intensive multi‐column processes are greater if the life time of the project is over 5 years. The SMB process is found to perform marginally better than the Varicol process over 15 years; however, this may be because not all extra degrees of freedom for the Varicol process were considered.
Differences in the Effects of Solution Additives on Heat‐ and Refolding‐Induced Aggregation
Authors: Hamada Hiroyuki , Takahashi Ryouta , Noguchi Takumi , Shiraki Kentaro
Published: April 2008

Although a number of low‐molecular‐weight additives have been developed to suppress protein aggregation, it is unclear whether these aggregation suppressors affect various aggregation processes in the same manner. In this study, we evaluated the differences in the effect of solution additives on heat‐ and refolding‐induced aggregation in the presence of guanidine (Gdn), arginine (Arg), and spermidine (Spd), and the comparable analysis showed the following differences: (i) Gdn did not suppress thermal aggregation but increased the yield of oxidative refolding. (ii) Spd showed the highest effect for heat‐induced aggregation suppression among tested compounds, although it promoted aggregation in oxidative refolding. (iii) Arg was effective for both aggregation processes. Lysozyme solubility assay and thermal unfolding experiment showed that Spd was preferentially excluded from native lysozyme and Arg and Gdn solubilized the model state of intermediates during oxidative refolding. This preference of additives to protein surfaces is the cause of the different effect on aggregation suppression.
Die Interrater-Reliabilität der Braden-Skala
Authors: Kottner Jan , Tannen Antje , Dassen Theo
Published: April 2008

Dekubitusrisikoskalen können Pflegenden helfen, das individuelle Dekubitusrisiko zu bestimmen. Obwohl die Braden-Skala in Deutschland weit verbreitet ist, ist über deren psychometrischen Eigenschaften nichts bekannt. Ziel der Untersuchung war es, die Interrater-Reliabilität der deutschen Version der Braden-Skala zu bestimmen und diese mit bereits vorhandenen Ergebnissen zu vergleichen. Mithilfe einer Literaturrecherche wurden 20 Studien ausgewertet, die die Interrater-Reliabilität der Braden-Skala zum Gegenstand hatten. Davon beschäftigten sich nur drei Arbeiten mit der Interrater-Reliabilität der einzelnen Items. Für den gesamten Braden-Score wurde überwiegend der Produkt-Moment-Korrelationskoeffizient (0,80 bis 1,00) berechnet, obwohl er für die Abbildung der Interrater-Reliabilität ungeeignet ist. Für den Intraklassen-Korrelationskoeffizienten liegen Werte von 0,83 bis 0,99 vor. Die Bestimmung der Interrater-Reliabilität der deutschen Version der Skala wurde 2006 in einem deutschen Pflegeheim durchgeführt. Pflegekräfte schätzten 18 und 32 Pflegeheimbewohner zweimal unabhängig voneinander ein. Die höchste absolute Übereinstimmung erzielten die Beurteiler bei den Items «Reibung und Scherkräfte» und «Aktivität» (beobachtete Übereinstimmung = 67–84%, Cohen’s Kappa = 0,57–0,73). Die niedrigste Übereinstimmung ergab sich beim Item «Ernährung» (absolute Übereinstimmung = 47–51%, Cohen’s Kappa = 0,28–0,30). Bei 66% aller eingeschätzten Bewohner unterschied sich der eingeschätzte Braden-Score um höchstes den Wert 1. Intraklassen-Korrelationskoeffizienten betrugen 0,91 (95% Konfidenzintervall 0,82–0,96) und 0,88 (95% Konfidenzintervall 0,61–0,96). Die Interrater-Reliabilität der Skala im untersuchten Setting wird als hoch angesehen.
Assessment of microbial methane oxidation above a petroleum‐contaminated aquifer using a combination of in situ techniques
Authors: Urmann Karina , Schroth Martin H. , Noll Matthias , Gonzalez‐Gil Graciela , Zeyer Josef
Published: April 2008

Emissions of the greenhouse gas CH4, which is often produced in contaminated aquifers, are reduced or eliminated by microbial CH4 oxidation in the overlying vadose zone. The aim of this field study was to estimate kinetic parameters and isotope fractionation factors for CH4 oxidation in situ in the vadose zone above a methanogenic aquifer in Studen, Switzerland, and to characterize the involved methanotrophic communities. To quantify kinetic parameters, several field tests, so‐called gas push‐pull tests (GPPTs), with CH4 injection concentrations ranging from 17 to 80 mL L−1 were performed. An apparent Vmax of 0.70 ± 0.15 mmol CH4 (L soil air)−1 h−1 and an apparent Km of 0.28 ± 0.09 mmol CH4 (L soil air)−1 was estimated for CH4 oxidation at 2.7 m depth, close to the groundwater table. At 1.1 m depth, Km (0.13 ± 0.02 mmol CH4 (L soil air)−1) was in a similar range, but Vmax (0.076 ± 0.006 mmol CH4 (L soil air)−1 h−1) was an order of magnitude lower. At 2.7 m, apparent first‐order rate constants determined from a CH4 gas profile (1.9 h−1) and from a single GPPT (2.0 ± 0.03 h−1) were in good agreement. Above the groundwater table, a Vmax much higher than the in situ CH4 oxidation rate prior to GPPTs indicated a high buffer capacity for CH4. At both depths, known methanotrophic species affiliated with Methylosarcina and Methylocystis were detected by cloning and sequencing. Apparent stable carbon isotope fractionation factors α for CH4 oxidation determined during GPPTs ranged from 1.006 to 1.032. Variability was likely due to differences in methanotrophic activity and CH4 availability leading to different degrees of mass transfer limitation. This complicates the use of stable isotopes as an independent quantification method.
A refined view of vertical mass transport by cumulus convection
Authors: Jonker Harm J. J. , Heus Thijs , Sullivan Peter P.
Published: April 2008

The purpose of this letter is to show that the traditional view of transport by shallow cumulus clouds needs important refinement. On the basis of a straightforward geometrical analysis of Large Eddy Simulation results of shallow cumulus clouds, we conclude (1) that the upward mass transport by clouds is strongly dominated by regions close to the edge of clouds rather than by the core region of clouds and (2) that the downward mass transport is dominated by processes just outside the cloud. The latter finding contradicts the accepted view of a uniformly descending dry environment. We therefore advocate a refined view which distinguishes between the near‐cloud environment and the distant environment. The near‐cloud environment is characterized by coherent descending motions, whereas the distant environment is rather quiescent and plays no significant role in vertical transport.
Extra‐tropical synoptic cyclones and downward propagating anomalies in the Northern Annular Mode
Authors: Breiteig Tarjei
Published: April 2008

During most winters, anomalies in the Northern Annular Mode (NAM) propagate downward from the stratosphere to the troposphere. In this paper, the relationship between extra‐tropical synoptic‐scale cyclones and downward propagating positive (NAM+) and negative (NAM−) anomalies is investigated. Both Pacific and Atlantic storm tracks are significantly influenced by the downward propagating NAM+ anomalies, while only the Atlantic storm tracks are significantly influenced by the downward propagating NAM− anomalies. The number of cyclones changes by up to 30 % during both NAM+ and NAM− within certain regions. Also, fluctuations in the NAM follow corresponding fluctuations in the storm activity with a lag of three days during NAM+ and NAM−.
Model simulations of global change in the ionosphere
Authors: Qian Liying , Solomon Stanley C. , Roble Raymond G. , Kane Timothy J.
Published: April 2008

Observations of secular trends in the E and F1 regions of the ionosphere indicate that electron densities have increased, and that the height of the E‐region peak has decreased, during the past several decades. Detection of trends in the upper ionosphere through analysis of F2‐layer parameters has been more complex and controversial. In order to facilitate observational detection of long‐term trends in the ionosphere, simulations were performed using a single‐column upper atmosphere model. CO2 concentrations for the year 2000 and projected for the year 2100 were used to investigate changes of electron densities and the altitudes of ionospheric layers. Results show that increased CO2 concentration increases electron density in the lower regions of the ionosphere, but decreases electron density in the upper ionosphere. The transition altitude occurs slightly below the F2 peak altitude (hmF2). The proximity of hmF2 to the transition altitude may explain why different analyses of long‐term trends in F2 peak density have shown both positive and negative trends. The altitudes of the E, F1 and F2 regions all decrease with increased CO2 concentration.
The existence and properties of the distant magnetotail during 32 hours of strongly northward interplanetary magnetic field
Authors: Øieroset M. , Phan T. D. , Fairfield D. H. , Raeder J. , Gosling J. T. , Drake J. F. , Lin R. P.
Published: April 2008

We report observations made by the Wind spacecraft in the distant magnetotail on 22–24 October 2003 when the interplanetary magnetic field (IMF) was strongly northward for more than 32 h. A well‐defined magnetotail was observed down to at least XGSM = −125 RE even after 32 h of strongly northward IMF conditions. However, the observed tail properties were strikingly different from the typical magnetotail. Although the closed field line plasma sheet was observed throughout the northward IMF interval, the usual mantle/lobe disappeared one hour after the northward IMF front reached the frontside magnetopause. Instead, open field lines were observed populated by field‐aligned solar wind strahl electrons as well as plasma sheet electrons predominantly at 90° pitch angle. In essence, these observations provide evidence for reconnection between the IMF and a previously closed nightside cold dense plasma sheet during long periods of northward IMF, after poleward‐of‐the‐cusp reconnection has depleted all open lobe field lines.
Environmental and biological controls on water and energy exchange in Florida scrub oak and pine flatwoods ecosystems
Authors: Bracho Rosvel , Powell Thomas L. , Dore Sabina , Li Jiahong , Hinkle C. Ross , Drake Bert G.
Published: April 2008

Scrub oak and pine flatwoods are two contrasting ecosystems common to the humid subtropical climate of Florida. Scrub oak forests are short in stature (<2 m) and occur on well‐drained sandy soils, and pine flatwoods are much taller and occur in areas with poorly drained soils. Eddy covariance measurements were made from January 2001 to February 2003 over a scrub oak forest and from January 2002 to February 2003 over an adjacent pine flatwoods located on in central Florida, USA, and exposed to similar atmospheric conditions to evaluate how the dynamics of latent heat (λE) and sensible heat (H) exchanges are affected by environmental and biological variables. Annual evapotranspiration (Et) for the scrub oak was 737 and 713 mm in 2001 and 2002, respectively. Et was comparatively higher, 812 mm, in 2002 at the pine flatwoods due to higher soil moisture and leaf area. In both ecosystems, springtime increases in λE coincided with increasing leaf area and evaporative demand. However, H was the main energy‐dissipating component in the spring due to the seasonal decrease in soil water content in the upper soil profile. In the spring, mean weekly Bowen ratio (β, i.e. H/λE) values reached 1.6 and 1.2 in the scrub oak and pine flatwoods, respectively. With the onset of the summertime rainy season, λE became the dominant energy flux and β fells to < 0.4. In both ecosystems, β was strongly controlled by the interaction between leaf area and soil moisture. The lowest values of the decoupling coefficient (Ω, 0.2 and 0.25 scrub oak and pine flatwoods, respectively) also occurred during the dry springtime period indicating that surface conductance (gs) was the mechanism controlling energy partitioning causing high β in both ecosystems. Et increases in the spring, when water in the upper soil profile was scarce and strongly retained by soil particles, indicated that plants in both ecosystems obtained water from deeper sources. The results from this research elucidate how energy partitioning differs and is regulated in contrasting ecosystems within the Florida landscape, which is important for refining regional hydrological and climate models.
Spatially explicit simulation of peatland hydrology and carbon dioxide exchange: Influence of mesoscale topography
Authors: Sonnentag O. , Chen J. M. , Roulet N. T. , Ju W. , Govind A.
Published: April 2008

Carbon dynamics in peatlands are controlled, in large part, by their wetness as defined by water table depth and volumetric liquid soil moisture content. A common type of peatland is raised bogs that typically have a multiple‐layer canopy of vascular plants over a Sphagnum moss ground cover. Their convex form restricts water supply to precipitation and water is shed toward the margins, usually by lateral subsurface flow. The hydraulic gradient for lateral subsurface flow is governed by the peat surface topography at the mesoscale (∼200 m to 5 km). To investigate the influence of mesoscale topography on wetness, evapotranspiration (ET), and gross primary productivity (GPP) in a bog during the snow‐free period, we compare the outputs of a further developed version of the daily Boreal Ecosystem Productivity Simulator (BEPS) with observations made at the Mer Bleue peatland, located near Ottawa, Canada. Explicitly considering mesoscale topography, simulated total ET and GPP correlate well with measured ET (r = 0.91) and derived gross ecosystem productivity (GEP; r = 0.92). Both measured ET and derived GEP are simulated similarly well when mesoscale topography is neglected, but daily simulated values are systematically underestimated by about 10% and 12% on average, respectively, due to greater wetness resulting from the lack of lateral subsurface flow. Owing to the differences in moss surface conductances of water vapor and carbon dioxide with increasing moss water content, the differences in the spatial patterns of simulated total ET and GPP are controlled by the mesotopographic position of the moss ground cover.
A multiple‐realizations chance‐constrained model for optimizing nutrient removal in constructed wetlands
Authors: Ng Tze Ling , Eheart J. Wayland
Published: April 2008

High nutrient loads in surface waters are a cause of hypoxia in coastal ecosystems. Constructed wetlands offer a means of nutrient removal, but their design is complicated by environmental fluctuations. In the present work, a chance‐constrained model is developed on the basis of satisfying performance constraints for a subset of the period of hydrologic and meteorological record. The model incorporates a nonsteady state wetland model and is used to determine the most cost‐efficient wetland design given the nutrient removal requirements. Three candidate wetlands are considered. For two of them a comparison is made between operating the wetlands individually versus operating them concurrently. Results show that the factors limiting wetland performance are low flow availability and low inflow nutrient concentrations. Further, for the case considered, a two‐wetland design is found to be more cost‐effective than a single‐wetland design. On average, wetlands have huge potential for nutrient removal but have a higher risk of failure than conventional treatment and could, under unfavorable conditions, be more expensive.
Use of groundwater lifetime expectancy for the performance assessment of a deep geologic waste repository: 1. Theory, illustrations, and implications
Authors: Cornaton F. J. , Park Y.‐J. , Normani S. D. , Sudicky E. A. , Sykes J. F.
Published: April 2008

Long‐term solutions for the disposal of toxic wastes usually involve isolation of the wastes in a deep subsurface geologic environment. In the case of spent nuclear fuel, if radionuclide leakage occurs from the engineered barrier, the geological medium represents the ultimate barrier that is relied upon to ensure safety. Consequently, an evaluation of radionuclide travel times from a repository to the biosphere is critically important in a performance assessment analysis. In this study, we develop a travel time framework based on the concept of groundwater lifetime expectancy as a safety indicator. Lifetime expectancy characterizes the time that radionuclides will spend in the subsurface after their release from the repository and prior to discharging into the biosphere. The probability density function of lifetime expectancy is computed throughout the host rock by solving the backward‐in‐time solute transport adjoint equation subject to a properly posed set of boundary conditions. It can then be used to define optimal repository locations. The risk associated with selected sites can be evaluated by simulating an appropriate contaminant release history. The utility of the method is illustrated by means of analytical and numerical examples, which focus on the effect of fracture networks on the uncertainty of evaluated lifetime expectancy.
NAD(P)H quinone oxidoreductase 1 inhibits the proteasomal degradation of the tumour suppressor p33ING1b
Authors: Garate Marco , Wong Ronald P C , Campos Eric I , Wang Yemin , Li Gang
Published: April 2008

The tumour suppressor p33ING1b (ING1b for inhibitor of growth family, member 1b) is important in cellular stress responses, including cell‐cycle arrest, apoptosis, chromatin remodelling and DNA repair; however, its degradation pathway is still unknown. Recently, we showed that genotoxic stress induces p33ING1b phosphorylation at Ser 126, and abolishment of Ser 126 phosphorylation markedly shortened its half‐life. Therefore, we suggest that Ser 126 phosphorylation modulates the interaction of p33ING1b with its degradation machinery, stabilizing this protein. Combining the use of inhibitors of the main degradation pathways in the nucleus (proteasome and calpains), partial isolation of the proteasome complex, and in vitro interaction and degradation assays, we set out to determine the degradation mechanism of p33ING1b. We found that p33ING1b is degraded in the 20S proteasome and that NAD(P)H quinone oxidoreductase 1 (NQO1), an oxidoreductase previously shown to modulate the degradation of p53 in the 20S proteasome, inhibits the degradation of p33ING1b. Furthermore, ultraviolet irradiation induces p33ING1b phosphorylation at Ser 126, which, in turn, facilitates its interaction with NQO1.
The physical picture and the essential elements of the dynamical process for dispersive cloaking structures
Authors: Liang Zixian , Yao Peijun , Sun Xiaowei , Jiang Xunya
Published: April 2008

We investigate the dynamical process of dispersive cloak by finite-difference time-domain numerical experiments. We find that there is a strong scattering process before achieving the stable state and its time length can be tuned by the dispersive strength. Poynting-vector directions show that the stable cloaking state is constructed locally while an intensity front sweeps through the cloak. Deeper studies demonstrate that the group velocity tangent component Vgθ is the dominant element in the process. This study is helpful not only for clear physical pictures but also for designing better cloaks to defend pulsive radars.
Whispering gallery modes in hollow cylindrical microcavities containing silicon nanocrystals
Authors: Rodríguez J. R. , Veinot J. G. C. , Bianucci P. , Meldrum A.
Published: April 2008

A straightforward and inexpensive solution-based method to coat cylindrical microcavities with silicon nanocrystals is described. By using this method, high-quality films of oxide-embedded silicon nanocrystals (Si-ncs) were formed on the inner wall of hollow glass fibers. The resulting films were uniform and crack-free over lengths of 2–3cm and were strongly luminescent due to the presence of well-passivated Si-ncs. The optical confinement provided by the film gave rise to resonant modes in the photoluminescence spectrum, with high-quality factors compared to Si-ncs in planar microcavities or microdisks or coated on glass spheres.
III-nitride heterostructure field-effect transistors grown on semi-insulating GaN substrate without regrowth interface charge
Authors: Liu J. P. , Ryou J.-H. , Yoo D. , Zhang Y. , Limb J. , Horne C. A. , Shen S.-C. , Dupuis R. D. , Hanser A. D. , Preble E. A. , Evans K. R.
Published: April 2008

Charge is observed at the regrowth interface for heterostructure field-effect transistors (HFETs) grown on semi-insulating (SI) bulk GaN substrates, even with Fe doping in the regrown buffer layer for reduction of the interface charge. Ultraviolet photoenhanced chemical (PEC) etching is used to treat the surface of SI bulk GaN substrates. Employing optimized etching conditions, a very smooth surface is achieved for the bulk GaN substrate after the etching. The charge at the regrowth interface is eliminated for HFETs grown on etched SI GaN substrates. Secondary ion mass spectrometry measurements show that the Si impurity concentration at the regrowth interface for HFETs grown on etched SI GaN substrates is much lower than that for HFETs grown on unetched SI GaN substrates, which suggests that the charge-containing layer on the SI substrate is removed by PEC etching and that the effects of the reduced charge layer near the regrowth interface can be eliminated by Fe doping for HFETs grown on etched SI substrates.