bluuebunny/crossref_metadata_2025 huggingface dataset:
Serum‐free media for periosteal chondrogenesis in vitro
Authors: Fitzsimmons James S. , Sanyal Arunik , Gonzalez Carlos , Fukumoto Takumi , Clemens Victoria R. , O'Driscoll Shawn W. , Reinholz Gregory G.
Published: December 2003

Organ culture studies involving whole explants of periosteum have been useful for studying chondrogenesis, but to date the standard culture model for these explants has required the addition of fetal bovine serum to the media. Numerous investigators have succeeded in culturing chondrocytes and embryonic cells in serum‐free conditions but there have been no studies focused on achieving a defined, serum‐free media for culturing periosteal explants. The purpose of the present investigation was to determine if whole periosteal explants can be grown and produce cartilage in serum‐free conditions, and to define the minimum media supplements that would be conducive to chondrogenesis. 321 periosteal explants were obtained from the medial proximal tibiae of 31 two month‐old NZ white rabbits and cultured using a published agarose suspension organ culture model and DMEM for six weeks. The explants were cultured with and without fetal bovine serum or bovine serum albumin and exposed to transforming growth factor beta alone, a combination of growth factors we call ChondroMix (10 ng/ml transforming growth factor beta, 50 ng/ml basic fibroblast growth factor, and 5 μ/ml growth hormone), and/or ITS+ (2.08 μg/ml each of insulin, transferrin, and selenious acid, plus 1.78 μg/ml linoleic acid and 0.42 mg/ml BSA). Maximal chondrogenic stimulation in this study was observed with the combination of ChondroMix and ITS+. However, the minimal requirement to match or exceed the level of chondrogenic stimulation seen in the standard model (TGF‐1 in 10% FBS) was achieved simply by the addition of 2.0 μg/ml insulin in 0.1% BSA‐containing medium (p< 0.05). Therefore, based on our results, it would be reasonable to assume that insulin is the component in ITS+ responsible for the observed increase in total cartilage growth. Lower concentrations of insulin were not effective, suggesting that the observed effect of insulin requires activation of the IGF‐1 receptor. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Costimulation of the Gi‐coupled ADP receptor and the Gq‐coupled TXA2 receptor is required for ERK2 activation in collagen‐induced platelet aggregation
Authors: Roger Séverine , Pawlowski Marc , Habib Aı̈da , Jandrot-Perrus Martine , Rosa Jean-Philippe , Bryckaert Marijke
Published: December 2003

The stimulation of platelets by low doses of collagen induces extracellular signal‐regulated kinase 2 (ERK2) activation. In this report, we demonstrate that collagen‐induced ERK2 activation depends on thromboxane A2 (TXA2) formation and ADP release. The collagen‐induced ERK2 activation was inhibited by indomethacin (88%) and by AR‐C69931MX (70%), a specific antagonist of P2Y12, a Gi‐coupled ADP receptor. AR‐C69931MX (10 μM) inhibition was overcome by epinephrine (1 μM), an agonist of the Gi‐coupled α2A‐adrenergic receptor, suggesting that the Gi‐coupled receptor was necessary for ERK2 activation by collagen. By contrast, MRS 2179 (10 μM), a specific antagonist of P2Y1, a Gq‐coupled ADP receptor, did not affect collagen‐induced ERK2 activation. Little or no ERK2 activation was observed with ADP alone (10 μM). By contrast, U46619 (10 μM), a stable analog of TXA2, induced ERK2 activation in an ADP‐dependent manner, via the P2Y12 receptor. These results suggest that the Gi‐dependent signaling pathway, stimulated by ADP or epinephrine, was not the only pathway required for ERK2 activation by collagen. Costimulation of the specific G12/13‐coupled TXA2 receptor with a low dose of U46619 (10 nM) and of Gi‐ and Gq‐coupled ADP receptor (10 μM) induced very low levels of ERK2 activation, similar to those observed with ADP alone, suggesting that G12/13 is not involved or not sufficient to induce the additional pathway necessary for ERK2 activation. The Gq‐coupled TXA2 receptor was required for ERK2 activation by U46619 (10 μM) and low doses of collagen, clearly showing that a coordinated pathway through both Gq from TXA2 and Gi from ADP was necessary for ERK2 activation. Finally, we demonstrate that ERK2 activation is involved in collagen‐induced aggregation and secretion.
Lipid raft‐associated catechin suppresses the FcϵRI expression by inhibiting phosphorylation of the extracellular signal‐regulated kinase1/2
Authors: Fujimura Yoshinori , Tachibana Hirofumi , Yamada Koji
Published: December 2003

The major green tea catechin, (−)‐epigallocatechin‐3‐O‐gallate (EGCG), has a suppressive effect on the expression of the high‐affinity IgE receptor FcϵRI, which is key molecule in the IgE‐mediated allergic reactions. Here we show that EGCG binds to the cell surface and highly associates with plasma membrane microdomains, lipid rafts, on the human basophilic KU812 cells. The disruption of these lipid rafts caused a reduction of the amount of raft‐associated EGCG and the FcϵRI‐suppressive effect of EGCG. We also found that EGCG has an ability to inhibit the phosphorylation of the extracellular signal‐regulated kinase1/2 (ERK1/2) and that the ERK1/2 specific inhibitor also reduced FcϵRI expression. Moreover, the inhibitory effect elicited by EGCG on ERK1/2 was prevented by disruption of rafts. Thus, these results suggest that the interaction between EGCG and the lipid rafts is important for EGCG's ability to downregulate FcϵRI expression, and ERK1/2 may be involved in this suppression signal.
Myofibrillar tightly bound calcium in skeletal muscle fibers: a possible role of this cation in titin strands aggregation
Authors: Coulis Gerald , Sentandreu Miguel A , Bleimling Nathalie , Gautel Mathias , Benyamin Yves , Ouali Ahmed
Published: December 2003

In muscle cells, part of the calcium is tightly bound to the N1‐ and N2‐line of the sarcomere but its physiological significance was unknown. In the present work we reported the ability of a recombinant titin fragment spanning titin domains Z9 to I1 to tightly bind calcium ions with a K
d of 0.049±0.004 nM. We further showed that calcium induced a spontaneous aggregation of the titin fragment and that the major aggregate is a tetramer. The implication of these findings on the organization of the six titin strands that emanate from the end of the thick filament within the I‐band is discussed.
Justice and the Coercive Taking of Cadaveric Organs
Authors: FABRE CÉCILE
Published: December 2003

One of the central questions in discussions of distributive justice is that of the interest of the badly off, or the worst off, in the financial assets of the well off. By contrast, theorists of distributive justice are remarkably silent on the important and complicated issue of access to the organs of the dead. In this article, I aim to show that if one thinks that the poor’s interest in leading a minimally flourishing life, and a fortiori in remaining alive, is important enough to confer on them a right to some of the material resources of the well off, by way of taxation and, in particular, by way of restrictions on bequests and inheritance, one must think that that very same interest is important enough to confer on the sick a right to the organs of the now-dead healthy. I make a case to that effect, and I explore disanalogies between the posthumous transfer of resources and the posthumous transfer of organs. Finally, I rebut two objections to my proposal.
Civics or Structure? Revisiting the Origins of Democratic Quality in the Italian Regions
Authors: SOLT FREDERICK
Published: December 2003

What determines the responsiveness and effectiveness of democratic governments in meeting their citizens’ needs? Based on his 1993 study of the twenty Italian regions, Robert Putnam argued that ‘civic community’, a self-reinforcing syndrome of social engagement and political participation, is the explanation. A re-examination of Putnam’s data reveals little evidence of such a syndrome, but confirms that where more citizens participate in politics outside of networks of clientelistic exchange, more effective democratic government results. To discern the causes of variation in this self-motivated political participation, I test Putnam’s measures of social engagement against aspects of Italian socio-economic structure. Economic development and the historical distribution of land, not social engagement, are found to be powerful predictors of self-motivated political participation and in turn democratic quality.
$L^{p}$ BOUNDS FOR MARCINKIEWICZ INTEGRALS
Authors: Ding Yong , Pan Yibiao
Published: December 2003

In this paper the authors establish the $L^p$ boundedness for several classes of Marcinkiewicz integral operators with kernels satisfying a condition introduced by Grafakos and Stefanov in Indiana Univ. Math. J.47 (1998), 455–469.

AMS 2000 Mathematics subject classification: Primary 42B25; 42B99
CONDITIONS FOR SOLVABILITY OF THE HARTMAN–WINTNER PROBLEM IN TERMS OF COEFFICIENTS
Authors: Chernyavskaya N. A. , Shuster L.
Published: December 2003

The Equation (1) $(r(x)y')'=q(x)y(x)$ is regarded as a perturbation of (2) $(r(x)z'(x))'=q_1(x)z(x)$. The functions $r(x)$, $q_1(x)$ are assumed to be continuous real valued, $r(x)>0$, $q_1(x)\ge0$, whereas $q(x)$ is continuous complex valued. A problem of Hartman and Wintner regarding the asymptotic integration of (1) for large $x$ by means of solutions of (2) is studied. Sufficiency conditions for solvability of this problem expressed by means of coefficients $r(x)$, $q(x)$, $q_1(x)$ of Equations (1) and (2) are obtained.

AMS 2000 Mathematics subject classification: Primary 34E20
SYMPLECTIC CONNECTIONS WITH A PARALLEL RICCI CURVATURE
Authors: Boubel Charles
Published: December 2003

A symplectic connection on a symplectic manifold, unlike the Levi-Civita connection on a Riemannian manifold, is not unique. However, some spaces admit a canonical connection (symmetric symplectic spaces, Kähler manifolds, etc.); besides, some ‘preferred’ symplectic connections can be defined in some situations. These facts motivate a study of the symplectic connections, inducing a parallel Ricci tensor. This paper gives the possible forms of the Ricci curvature on such manifolds and gives a decomposition theorem (linked with the holonomy decomposition) for them.

AMS 2000 Mathematics subject classification: Primary 53B05; 53B30; 53B35; 53C25; 53C55
DECREASE OF BOUNDED HOLOMORPHIC FUNCTIONS ALONG DISCRETE SETS
Authors: Pau Jordi , Thomas Pascal J.
Published: December 2003

We provide uniqueness results for holomorphic functions in the Nevanlinna class which bridge those previously obtained by Hayman and by Lyubarskii and Seip. In particular, we propose certain classes of hyperbolically separated sequences in the disc, in terms of the rate of non-tangential accumulation to the boundary (the outer limits of this spectrum of classes being, respectively, the sequences with a non-tangential cluster set of positive measure, and the sequences satisfying the Blaschke condition). For each of those classes, we give a critical condition of radial decrease on the modulus which will force a Nevanlinna class function to vanish identically.

AMS 2000 Mathematics subject classification: Primary 30D50; 30D55
DUALITY AND CONTACT OF HYPERSURFACES IN $\mathbb{R}^4$ WITH HYPERPLANES AND LINES
Authors: Nabarro A. C.
Published: December 2003

Given an embedded hypersurface $M$ in $\mathbb{R}^4$ we consider families of projections $H$ of $M$ to lines and families of projections $P$ of $M$ to 3-spaces. We characterize generically the singularities of these projections. We also show that there is a duality relation between some strata of the bifurcation sets of $H$ and $P$, and deduce geometric properties about these sets.

AMS 2000 Mathematics subject classification: Primary 58K05. Secondary 58K40
SIMILARITY AND THE POINT SPECTRUM OF SOME NON-SELFADJOINT JACOBI MATRICES
Authors: Janas Jan , Malejki Maria , Mykytyuk Yaroslav
Published: December 2003

In this paper spectral properties of non-selfadjoint Jacobi operators $J$ which are compact perturbations of the operator $J_0=S+\rho S^*$, where $\rho\in(0,1)$ and $S$ is the unilateral shift operator in $\ell^2$, are studied. In the case where $J-J_0$ is in the trace class, Friedrichs’s ideas are used to prove similarity of $J$ to the rank one perturbation $T$ of $J_0$, i.e. $T=J_0+(\cdot,p)e_1$. Moreover, it is shown that the perturbation is of ‘smooth type’, i.e. $p\in\ell^2$ and

$$ \varlimsup_{n\rightarrow\infty}|p(n)|^{1/n}\le\rho^{1/2}. $$

When $J-J_0$ is not in the trace class, the Friedrichs method does not work and the transfer matrix approach is used. Finally, the point spectrum of a special class of Jacobi matrices (introduced by Atzmon and Sodin) is investigated.

AMS 2000 Mathematics subject classification: Primary 47B36. Secondary 47B37
COUNTABLE VERSUS UNCOUNTABLE RANKS IN INFINITE SEMIGROUPS OF TRANSFORMATIONS AND RELATIONS
Authors: Higgins P. M. , Howie J. M. , Mitchell J. D. , Ruškuc N.
Published: December 2003

The relative rank $\rank(S:A)$ of a subset $A$ of a semigroup $S$ is the minimum cardinality of a set $B$ such that $\langle A\cup B\rangle=S$. It follows from a result of Sierpiński that, if $X$ is infinite, the relative rank of a subset of the full transformation semigroup $\mathcal{T}_{X}$ is either uncountable or at most $2$. A similar result holds for the semigroup $\mathcal{B}_{X}$ of binary relations on $X$.

A subset $S$ of $\mathcal{T}_{\mathbb{N}}$ is dominated (by $U$) if there exists a countable subset $U$ of $\mathcal{T}_{\mathbb{N}}$ with the property that for each $\sigma$ in $S$ there exists $\mu$ in $U$ such that $i\sigma\le i\mu$ for all $i$ in $\mathbb{N}$. It is shown that every dominated subset of $\mathcal{T}_{\mathbb{N}}$ is of uncountable relative rank. As a consequence, the monoid of all contractions in $\mathcal{T}_{\mathbb{N}}$ (mappings $\alpha$ with the property that $|i\alpha-j\alpha|\le|i-j|$ for all $i$ and $j$) is of uncountable relative rank.

It is shown (among other results) that $\rank(\mathcal{B}_{X}:\mathcal{T}_{X})=1$ and that $\rank(\mathcal{B}_{X}:\mathcal{I}_{X})=1$ (where $\mathcal{I}_{X}$ is the symmetric inverse semigroup on $X$). By contrast, if $\mathcal{S}_{X}$ is the symmetric group, $\rank(\mathcal{B}_{X}:\mathcal{S}_{X})=2$.

AMS 2000 Mathematics subject classification: Primary 20M20
CAPACITIES AND JACOBI MATRICES
Authors: Sebbar Ahmed , Falliero Thérèse
Published: December 2003

In this paper, we use the theorem of Burchnall and Shaundy to give the capacity of the spectrum $\sigma(A)$ of a periodic tridiagonal and symmetric matrix. A special family of Chebyshev polynomials of $\sigma(A)$ is also given. In addition, the inverse problem is considered: given a finite union $E$ of closed intervals, we study the conditions for a Jacobi matrix $A$ to exist satisfying $\sigma(A)=E$. We relate this question to Carathéodory theorems on conformal mappings.

AMS 2000 Mathematics subject classification: Primary 31B15; 30C20; 39A70
SELF-INTERSECTIONS OF SURFACES AND WHITNEY STRATIFICATIONS
Authors: Achilles Rüdiger , Manaresi Mirella
Published: December 2003

Let $X$ be a surface in $\mathbb{C}^n$ or $\mathbb{P}^n$ and let $C_{X}(X\times X)$ be the normal cone to $X$ in $X\times X$ (diagonally embedded). For a point $x\in X$, denote by $g(x):=e_x(C_X(X\times X))$ the multiplicity of $C_X(X\times X)$ at $x$. It is a former result of the authors that $g(x)$ is the degree at $x$ of the Stückrad–Vogel cycle $v(X,X)=\sum_C j(X,X;C)[C]$ of the self-intersection of $X$, that is, $g(x)=\sum_Cj(X,X;C)e_x(C)$. We prove that the stratification of $X$ by the multiplicity $g(x)$ is a Whitney stratification, the canonical one if $n=3$. The corresponding result for hypersurfaces in $\mathbb{A}^n$ or $\mathbb{P}^n$, diagonally embedded in a multiple product with itself, was conjectured by van Gastel. This is also discussed, but remains open.

AMS 2000 Mathematics subject classification: Primary 32S15. Secondary 13H15;14C17
Simplified time series representations for efficient analysis of industrial process data
Authors: ALHONIEMI ESA
Published: December 2003

The data storage capacities of modern process automation systems have grown rapidly. Nowadays, the systems are able to frequently carry out even hundreds of measurements in parallel and store them in databases. However, these data are still rarely used in the analysis of processes. In this article, preparation of the raw data for further analysis is considered using feature extraction from signals by piecewise linear modeling. Prior to modeling, a preprocessing phase that removes some artifacts from the data is suggested. Because optimal models are computationally infeasible, fast heuristic algorithms must be utilized. Outlines for the optimal and some fast heuristic algorithms with modifications required by the preprocessing are given. In order to illustrate utilization of the features, a process diagnostics framework is presented. Among a large number of signals, the procedure finds the ones that best explain the observed short-term fluctuations in one signal. In the experiments, the piecewise linear modeling algorithms are compared using a massive data set from an operational paper machine. The use of piecewise linear representations in the analysis of changes in one real process measurement signal is demonstrated.
Distributed coordination of project schedule changes using
agent-based compensatory negotiation methodology
Authors: KIM KEESOO , PAULSON BOYD C. , LEVITT RAYMOND E. , FISCHER MARTIN A. , PETRIE CHARLES J.
Published: December 2003

In the construction industry, projects are becoming increasingly
large and complex, necessitating multiple subcontractors. Traditional
centralized coordination techniques used by general contractors become
insufficient as subcontractors perform most work and provide their own
resources. When subcontractors cannot provide enough resources, they
hinder their own performance, that of other subcontractors, and
ultimately the entire project. Thus, projects need a new distributed
coordination approach wherein all of the concerned subcontractors can
respond to changes and reschedule a project dynamically. This paper
presents a new distributed coordination framework for project schedule
changes (DCPSC) that is based on an agent-based negotiation approach
wherein software agents evaluate the impact of changes, simulate
decisions, and give advice on behalf of the human subcontractors. A
case example demonstrates the significance of the DCPSC. It compares
two centralized coordination methodologies used in current practice to
the DCPSC framework. We demonstrate that our DCPSC framework always
finds a solution that is better than or equal to any of two centralized
coordination methodologies.
A feature ontology to support construction cost estimating
Authors: STAUB–FRENCH SHERYL , FISCHER MARTIN , KUNZ JOHN , ISHII KOS , PAULSON BOYD
Published: December 2003

Construction cost estimators are confronted with the challenging task
of estimating the cost of constructing one of a kind facilities. They
must first recognize the design conditions of the facility design that
are important (i.e., incur a cost) and then determine how the design
conditions affect the cost of construction. Current product models of
facility designs explicitly represent components, attributes of
components, and relationships between components. These
designer-focused product models do not represent many of the
cost-driving features of building product models, such as penetrations
and component similarity. Previous research efforts identify many of
the different features that affect construction costs, but they do not
provide a formal and general way for practitioners to represent the
features they care about according to their preferences. This paper
presents the formal ontology we developed to represent construction
knowledge about the cost-driving features of building product models.
The ontology formalizes three classes of features, defines the
attributes and functions of each feature type, and represents the
relationships between the features explicitly. The descriptive
semantics of the model allow estimators to represent their varied
preferences for naming features, specifying features that result from
component intersections and the similarity of components, and grouping
features that affect a specific construction domain. A software
prototype that implements the ontology enables estimators to transform
designer-focused product models into estimator-focused, feature-based
product models. Our tests show that estimators are able to generate and
maintain cost estimates more accurately, consistently, and
expeditiously with feature-based product models than with industry
standard product models.
A policy of cooperation: the cartelisation of American fire insurance, 1873–1906
Authors: BARANOFF DALIT
Published: December 2003

In the era before state regulation of insurance rates, the American fire insurance industry succeeded in regulating itself. The final quarter of the nineteenth century witnessed a sustained movement towards organisation in the fire insurance industry. Through the establishment of local rate-setting boards fire insurers were able to manage the risks that had plagued their industry since its inception. The local insurance ‘cartels’ of the late nineteenth century differed from their mid-century predecessors in their longevity. As the organisations became stronger, they were able to stabilise prices throughout the industry and enhance diversification. As a result, economic downturns no longer routinely resulted in destructive competition, and major fires no longer led to waves of bankruptcies.
Writing the clock: the reconstruction of time in the late Middle Ages
Authors: SCATTERGOOD JOHN
Published: December 2003

For most of the Middle Ages, diurnal timekeeping depended on sundials, water-clocks, and occasionally flame-clocks. However, towards the end of the thirteenth century, the mechanical clock, weight driven and regulated by a verge escapement and foliot mechanism, was developed. The earliest mechanical clocks appeared in Northern Italy but rapidly spread throughout Europe. In Jacques le Goff’s words, ‘Henceforth the clock became the measure of all things’. Early clocks were neither particularly accurate nor reliable, but the machine, because it was better than anything that had preceded it, acquired the reputation for perfect regularity and dependability. This paper seeks to show how the clock came to be regarded as a model and a reference point, invoked by writers in relation to the ordering of the universe, the nature of a well-regulated society, and as an image of proper moral behaviour.
Social Attention
Authors: Spikman Jacoba M.
Published: December 2003

Abstract: Many TBI patients suffer from cognitive impairments, affecting their abilities to function on a previous level. However, some patients exhibit personality changes, manifesting themselves in inadequate or inappropriate social behavior, which are considered to have even more debilitating consequences on successful social and vocational rehabilitation. The term “impaired social attention” was put forward by Dr. van Zomeren as a description of a part of these problems: Patients' analysis of social situations seems incomplete, and they seem to lack awareness of consequences of their actions. In this paper the concept of social attention will be explored, whereby it is hypothesized that impaired social attention results from underlying emotional impairments. Two aspects of emotional behavior are considered essential prerequisites for intact social attention: The ability to perceive emotional expressions of others, and the ability to form a Theory of Mind (ToM). The literature will be reviewed in order to find out whether these aspects are impaired in TBI patients.
Functional Anatomy of Intensity Aspects of Attention
Authors: Sturm Walter
Published: December 2003

Abstract: Behavioral and PET/fMRI-data are presented to delineate the functional networks subserving alertness, sustained attention, and vigilance as different aspects of attention intensity. The data suggest that a mostly right-hemisphere frontal, parietal, thalamic, and brainstem network plays an important role in the regulation of attention intensity, irrespective of stimulus modality. Under conditions of phasic alertness there is less right frontal activation reflecting a diminished need for top-down regulation with phasic extrinsic stimulation. Furthermore, a high overlap between the functional networks for alerting and spatial orienting of attention is demonstrated. These findings support the hypothesis of a co-activation of the posterior attention system involved in spatial orienting by the anterior alerting network. Possible implications of these findings for the therapy of neglect are proposed.
Divided Attention After Closed Head Injury
Authors: Withaar Frederiec K. , Brouwer Wiebo H.
Published: December 2003

Abstract: One of the most persisting sequelae of closed head injury (CHI) is a general slowing of information processing. With neuropsychological testing, the effect is already apparent in simple reaction time tests. The slowing is more pronounced in complex tasks requiring divided attention. This study aims at explaining impairments in divided attention in terms of reduced speed of information processing, and impaired mental flexibility. Three types of mental flexibility are proposed: Stimulus driven (four choice reaction time and auditory reaction time task), memory driven (Trailmaking B test), and strategy driven flexibility tasks (continuous tracking task and arrow identification task). Divided attention paradigms were studied in 26 subacute CHI patients and 25 orthopedic control subjects. Results demonstrated that a reduced speed of information processing was largely responsible for divided attention impairments. Additional impairments in complex divided attention tasks only emerged in the most complex tasks (that is in the strategy driven flexibility task).
«Körper und Seele und Freundschaften kaputt»
Authors: Becker K. , Fuhrmann A. , Holtmann M. , Schmidt M. H.
Published: December 2003

Zusammenfassung: Fragestellung: Schätzungsweise 250000 Kinder und Jugendliche in Deutschland sind alkoholabhängig oder stark alkoholgefährdet. Während es für erwachsene alkoholkranke Patienten sowohl Therapiemanuale als auch störungsspezifische Nachsorgeeinrichtungen gibt, ist dies für jugendliche Patienten nur unzureichend der Fall. Methoden: Es wird die Kasuistik eines 14-jährigen alkoholabhängigen Patienten beschrieben mit Schwerpunkt auf Darstellung des für Jugendliche adaptierten störungsspezifischen Alkoholtherapiemanuals in Anlehnung an das Original von Petry (1996). Beispielhaft werden Arbeitsblätter dargestellt, die zur Ergänzung anderer verhaltens-, sozio- oder familientherapeutischen Interventionen hilfreich sein könnten.
Ein Fragebogen zur Erfassung des «frühkindlichen Temperaments» im Elternurteil *Teile der präsentierten Daten wurden im Rahmen einer durch die Deutsche Forschungsgemeinschaft (DFG) geförderten Studie gewonnen (Kennziffern: Pa 543/2-1, 2-2, 2-3, 2-4).
Authors: Pauli-Pott U. , Mertesacker B. , Beckmann D.
Published: December 2003

Zusammenfassung: Fragestellung: Eine deutschsprachige Adaptation des Infant Behavior Questionnaire von Rothbart wird hinsichtlich der internen Konsistenzen der Skalen, der Skaleninterkorrelationen und Stabilität untersucht. Mögliche Zusammenhänge der Skalen mit der Depressivität und Ängstlichkeit der beurteilenden Mutter werden geprüft. Methode: Untersucht werden unabhängige Stichproben 6-8- und 10-12-monatiger Säuglinge (n = 149 resp. n = 109) und deren Bezugspersonen. Eine Stichprobe von 101 Mutter-Säugling-Paaren wird im Längsschnitt, im Alter der Säuglinge von vier, acht und 12 Monaten untersucht. Ergebnis: Die fünf Skalen des Fragebogens sind in den beiden Altersgruppen zufriedenstellend intern konsistent und unabhängig voneinander. Die Stabilitätskoeffizienten entsprechen denen der amerikanischen Version des Verfahrens. Schlussfolgerung: Damit liegt ein in der Forschung und Praxis verwendbares deutschsprachiges Verfahren zur Messung frühkindlicher Temperamentsmerkmale im Elternurteil vor.
Vertical distribution of nighttime smoke following a wildland biomass fire in boreal Alaska
Authors: Ferguson Sue A. , Collins Richard L. , Ruthford Julia , Fukuda Masami
Published: December 2003

A comprehensive evaluation of the vertical structure of a smoldering smoke plume was afforded by a unique combination of tethersonde measurements (from ground level to about 400 m above ground level (AGL) or 274–674 m above sea level (ASL)), lidar sounding (from about 1.5 to 5 km ASL), and a video recording during the FROSTFIRE experimental burn in July 1999. Tethersonde and lidar measurements were made at local midnight. The video camera operated continuously for 1 week. Estimates of mass concentration were derived from the light‐scattering measurements. Every night, upper level smoke concentrations were estimated to be about 1000 times lower than near‐surface concentrations. The tethersonde instrument indicated maximum mass concentrations on the night following the most active burning (10–11 July), with the smoke trapped below an inversion at 115 m AGL. The lidar measurements indicated that maximum mass concentrations aloft (∼2000 m AGL) occurred on the next night (11–12 July), when the inversion was weaker, and estimated mass concentrations in the first few hundred meters ASL were smaller. The opportunistic combination of instruments offers the first available quantitative information on vertical plume structure in smoldering biomass smoke and holds promise for more a rigorous understanding of smoldering smoke as it significantly impacts visibility and human health.
An updated anthropogenic CO2 inventory in the Atlantic Ocean
Authors: Lee K. , Choi S.‐D. , Park G.‐H. , Wanninkhof R. , Peng T.‐H. , Key R. M. , Sabine C. L. , Feely R. A. , Bullister J. L. , Millero F. J. , Kozyr Alex
Published: December 2003

This paper presents a comprehensive analysis of the basin‐wide inventory of anthropogenic CO2 in the Atlantic Ocean based on high‐quality inorganic carbon, alkalinity, chlorofluorocarbon, and nutrient data collected during the World Ocean Circulation Experiment (WOCE) Hydrographic Program, the Joint Global Ocean Flux Study (JGOFS), and the Ocean‐Atmosphere Carbon Exchange Study (OACES) surveys of the Atlantic Ocean between 1990 and 1998. Anthropogenic CO2 was separated from the large pool of dissolved inorganic carbon using an extended version of the ΔC* method originally developed by Gruber et al. [1996]. The extension of the method includes the use of an optimum multiparameter analysis to determine the relative contributions from various source water types to the sample on an isopycnal surface. Total inventories of anthropogenic CO2 in the Atlantic Ocean are highest in the subtropical regions at 20°–40°, whereas anthropogenic CO2 penetrates the deepest in high‐latitude regions (>40°N). The deeper penetration at high northern latitudes is largely due to the formation of deep water that feeds the Deep Western Boundary Current, which transports anthropogenic CO2 into the interior. In contrast, waters south of 50°S in the Southern Ocean contain little anthropogenic CO2. Analysis of the data collected during the 1990–1998 period yielded a total anthropogenic CO2 inventory of 28.4 ± 4.7 Pg C in the North Atlantic (equator‐70°N) and of 18.5 ± 3.9 Pg C in the South Atlantic (equator‐70°S). These estimated basin‐wide inventories of anthropogenic CO2 are in good agreement with previous estimates obtained by Gruber [1998], after accounting for the difference in observational periods. Our calculation of the anthropogenic CO2 inventory in the Atlantic Ocean, in conjunction with the inventories calculated previously for the Indian Ocean [Sabine et al., 1999] and for the Pacific Ocean [Sabine et al., 2002], yields a global anthropogenic CO2 inventory of 112 ± 17 Pg C that has accumulated in the world oceans during the industrial era. This global oceanic uptake accounts for approximately 29% of the total CO2 emissions from the burning of fossil fuels, land‐use changes, and cement production during the past 250 years.
Major implication of the littoral zone for methane release from boreal lakes
Authors: Juutinen Sari , Alm Jukka , Larmola Tuula , Huttunen Jari T. , Morero Micaela , Martikainen Pertti J. , Silvola Jouko
Published: December 2003

Transitions between aquatic and terrestrial environments can be recognized as biogeochemically active ecotones that support high CH4 release. We studied the links between littoral CH4 fluxes and aquatic vegetation, hydrologic conditions, and sediment quality, and integrated the CH4 fluxes into a whole‐lake assessment. Methane fluxes were measured using a closed chamber method in the littoral and pelagic zones of three Finnish mid‐boreal lakes from May to October. The cumulative CH4 fluxes were spatially integrated over the lake relative to the vegetation coverage in the littoral, and to depth zones in the pelagic regions. During the ice‐free period, 66–77% of the CH4 was released from the littoral zone, and the mean CH4 effluxes from these lakes were 0.08–0.42 mol m−2 ice‐free season−1. Littoral and pelagic productivity was reflected in CH4 release from the lakes. Our results show that estimates of lake CH4 release should include an assessment of the vegetated littoral zone.
Observation of pressure variations in the Martian atmosphere
Authors: Gendrin Aline , Erard Stéphane , Drossart Pierre , Melchiorri Riccardo
Published: December 2003

Pressure waves in the Martian atmosphere could so far be observed only in the presence of clouds. Thanks to the Mars Global Surveyor/Mars Orbiter Laser Altimeter (MGS/MOLA), a direct observation is now possible, with the method presented here. Many more events are thus potentially observable. We compare altimetry measurements from MGS/MOLA and spectral observations from ISM, the infrared spectrometer aboard the Phobos‐2 spacecraft, to infer pressure variations in the Martian atmosphere. We identify variations of pressure above Martian volcanoes and we observe lee vortices of wavelength ∼200–250 km and amplitude ∼0.05 mbar in two different occasions. The application of this technique should constrain Martian meteorology with data from future imaging spectrometers.
First observations of the PMSE overshoot effect and its use for investigating the conditions in the summer mesosphere
Authors: Havnes O. , La Hoz C. , Næsheim L. I. , Rietveld M. T.
Published: December 2003

We report from the first campaign, with the EISCAT radars and heating facility, which looked for a proposed new PMSE overshoot effect resulting when PMSE is being affected by a specific cycling of artificial electron heating. The overshoot was predicted to appear after unaffected PMSE dusty plasma had been acted upon, for a comparatively short time, by the EISCAT Heating facility. We show model results and observational examples of the overshoot effect. For the overshoot to be clearly observable, a long relaxation time after the heater is switched off is necessary to get the dust charges back to those of dust unaffected by the heated electrons or, to bring unaffected PMSE dusty plasma into the radar beams by horizontal wind transport. The overshoot characteristic curve (OCC) contain a substantial amount of information on the conditions during PMSE and must lead to new possibilities in the study of PMSE and the conditions close to the summer mesopause.
Dehydration in cold clouds is enhanced by a transition from cubic to hexagonal ice
Authors: Murphy D. M.
Published: December 2003

Cubic ice (Ic) is a metastable form of ice with very similar physical properties but different crystal symmetry than normal, hexagonal ice (Ih). Below 200 K, water preferentially nucleates to Ic, then transforms to the more stable Ih in minutes to days. As a metastable phase, Ic will necessarily have a higher vapor pressure than Ih. A cloud parcel model shows that nucleation to Ic, conversion to Ih, and the vapor pressure differential together produce larger ice crystals that can more effectively dehydrate air. The modelled effect is largest at 180 to 200 K, just the range most important for the tropical tropopause and polar stratospheric clouds. The cloud model also produces a wider size distribution when Ic is included, in agreement with observations.
Advection and dissipation rates in the upper ocean mixed layer heat anomaly budget over the North Atlantic in summer
Authors: Ostrovskii Alexander , Font Jordi
Published: December 2003

Processes contributing to the heat anomaly budget of the upper ocean mixed layer are examined over the North Atlantic in summer season on the basis of the inversion of the sea temperature profiles. The net advection velocity, the subgrid heat diffusivity, and the surface heat flux feedback are estimated. Two inversion strategies are pursued, with and without the explicit parameterization of the entrainment heat flux into the upper mixed layer. The regression estimator is employed for the inversion. The data involved are the compilation of the Comprehensive Ocean‐Atmosphere Data Set sea surface temperature (SST) and World Ocean Database 2001 temperature profiles over a 2° latitude × 3° longitude grid for sequential 10‐day intervals in June–September during 1965–2000. The inversion is constrained by the autocorrelation of the National Centers for Environmental Prediction net air‐sea heat flux. The regression estimator allows for prediction of up to 60–70% of the SST anomaly value 10 days in advance by using the regressions on the SST anomalies lagged by two time steps. The SST anomaly transport over the North Atlantic agrees broadly with the known features of the surface circulation, although the quantitative details of the SST anomaly propagation obtained in this inversion have not previously been available. The heat anomaly that originates in the Gulf Stream region near the western boundary either moves northeastward with speed of up to 0.12 m s−1 downstream of the North Atlantic Current and the North Atlantic Drift Current or it turns southeastward and then propagates southwestward along the broad subtropical recirculation; in the subtropics the westward propagation is seemingly reinforced by the effects of the planetary waves. The air‐sea feedback is negative with the feedback factor having the average value of 39 W m−2 K−1 with substantial variations throughout the North Atlantic. The entrainment rate is generally about 0.15 m d−1; relatively rapid deepening of the mixed layer by more than 2 × 10−6 m s−1 occurs near the Gulf Stream.
An automated cloud detection method for daily NOAA 16 advanced very high resolution radiometer data over Texas and Mexico
Authors: Chen Pei‐yu , Srinivasan Raghavan , Fedosejevs Gunar
Published: December 2003

The advanced very high resolution radiometer (AVHRR) data acquired from the National Oceanic and Atmospheric Administration (NOAA) satellites have been widely applied to a variety of environmental research. A single AVHRR scene is seldom completely cloud‐free. Maximum value compositing (MVC) to create a single image from multiple orbits and dates has become the most valuable method to minimize cloud contamination. Composite images are not absolutely cloud‐free. Postcomposite cloud screening of the composite aggregates was developed to overcome the residual cloud contamination problem, but this is not possible for real‐time delivery of composite data or not suitable for compositing based on AVHRR data from multiple NOAA satellites. Another approach is to detect and remove cloud‐contaminated pixels from daily AVHRR scenes prior to applying the MVC method to provide real‐time composite images. This study developed an automated cloud detection method for daily NOAA 16 AVHRR scenes over the state of Texas and Mexico. The accuracy of the cloud detection algorithm was greater than 93% based on a random test sample from 36 images. Unidentified cloud shadow pixels as well as misidentified barren land pixels and water pixels contributed to more than 5% of the accumulated errors. The error from misidentification of water pixels can be reduced by assigning different threshold values for channel 4 brightness temperature according to the geographical latitude of the data. The resulting daily cloud‐free AVHRR data can be used to construct short‐time period composite images valuable for detecting subtle but critical environment changes. In addition, compositing methods other than MVC, such as multidate averaging or minimum value selection, can be applied for various research purposes, once the daily AVHRR data are cloud‐free.
Three‐dimensional ozone data analysis with an air quality model over the Paris area
Authors: Blond N. , Bel L. , Vautard R.
Published: December 2003

We present a description, an evaluation, and a comparison of four methods designed to produce objective and physically consistent maps of ozone concentration fields. These methods are based on the use of a chemistry‐transport model (CTM) and available observations. In most existing analysis systems, the error covariance is modeled using assumptions of homogeneity and isotropy. However, these assumptions may fail in the case of strongly heterogeneous terrain or emission patterns. Therefore we propose a simple method for specifying an anisotropic and heterogeneous background error covariance model in a statistical interpolation. We illustrate the positive impact of the implementation of this model. Since the covariance model is independent of the state of the atmosphere and invariant in time, we simultaneously test kriging techniques that are generally used for spatial interpolations. Kriging is applied to the observed values or to the differences between simulated and observed concentrations, namely the innovations. We perform an objective statistical validation of all methods for data recorded over an entire summer season, in contrast to other evaluations of data assimilation methods made in air quality modeling. We demonstrate that the RMS error of the ozone analyses at the surface is 30–50% smaller than the one from simulations, regardless of the method used. Most of the time, the kriging method applied to the innovations gives results equivalent to that of the anisotropic statistical interpolation, in spite of very different formulations. In addition, we show that this method outperforms the classical kriging method applied to only observations. The information provided by the CTM is therefore essential to a good‐quality representation of ozone patterns such as city plumes or urban/suburban gradients. We also use the Atmospheric Pollution Over the Paris Area (ESQUIF) airborne measurements to demonstrate that the anisotropic method efficiently corrects CTM fields in altitude.
A blind test retrieval experiment for infrared limb emission spectrometry
Authors: von Clarmann T. , Ceccherini S. , Doicu A. , Dudhia A. , Funke B. , Grabowski U. , Hilgers S. , Jay V. , Linden A. , López‐Puertas M. , Martín‐Torres F.‐J. , Payne V. , Reburn J. , Ridolfi M. , Schreier F. , Schwarz G. , Siddans R. , Steck T.
Published: December 2003

The functionality and characteristics of six different data processors (i.e., retrieval codes in their actual software and hardware environment) for analysis of high‐resolution limb emission infrared spectra recorded by the space‐borne Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) have been validated by means of a blind test retrieval experiment based on synthetic spectra. For this purpose a self‐consistent set of atmospheric state parameters, including pressure, temperature, vibrational temperatures, and abundances of trace gases and aerosols, has been generated and used as input for radiative transfer calculations for MIPAS measurement geometry and configuration. These spectra were convolved with the MIPAS field of view, spectrally degraded by the MIPAS instrument line shape, and, finally, superimposed with synthetic measurement noise. These synthetic MIPAS measurements were distributed among the participants of the project “Advanced MIPAS level‐2 data analysis” (AMIL2DA), who performed temperature and species abundance profile retrievals by inverse radiative transfer calculations. While the retrieved profiles of atmospheric state parameters reflect some characteristics of the individual data processors, it was shown that all the data processors under investigation are capable of producing reliable results in the sense that deviations of retrieved results from the reference profiles are within the margin that is consistent with analytical error estimation.
Constraints on the composition and petrogenesis of the Martian crust
Authors: McSween Harry Y. , Grove Timothy L. , Wyatt Michael B.
Published: December 2003

Spectral interpretation that silicic rocks are widespread on Mars implies that Earth's differentiated crust is not unique. Evaluation of observations bearing on the composition of the Martian crust (Martian meteorite petrology and a possible crustal assimilant, analysis of Mars Pathfinder rocks, composition of Martian fines, interpretation of spacecraft thermal emission spectra, and inferred crustal densities) indicates that the crust can be either basalt plus andesite or basalt plus weathering products. New calculated chemical compositions for Thermal Emission Spectrometer (TES) global surface units indicate that surface type 1 has basaltic andesite composition and surface type 2 has the composition of andesite. If these materials represent volcanic rocks, their calc‐alkaline compositions on a FeO*/MgO versus silica diagram suggest formation by hydrous melting and fractional crystallization. On Earth, this petrogenesis requires subduction, and it may suggest an early period of plate tectonics on Mars. However, anorogenic production of andesite might have been possible if the primitive Martian mantle was wet. Alternatively, chemical weathering diagrams suggest that surface type 2 materials could have formed by partial weathering of surface type 1 rocks, leading to depletion in soluble cations and mobility of silica. A weathered crust model is consistent with the occurrence of surface type 2 materials as sediments in a depocenter and with the alpha proton X‐ray spectrometer (APXS) analysis of excess oxygen suggesting weathering rinds on Pathfinder rocks. If surface type 1 materials are also weathered or mixed with weathered materials, this might eliminate the need for hydrous melting, consistent with a relatively dry Martian mantle without tectonics.
Using group communication to monitor web‐based group learning
Authors: Chen G.D. , Wang C.Y. , Ou K.L.
Published: December 2003

Abstract  In a web group‐learning environment, students must communicate with other group members on the Internet to accomplish group projects and share knowledge. Communication is likely to affect performance and so analysing the relationship between communicative relationships and group performance may help teachers to monitor groups effectively. Certain tasks are necessary to perform such an analysis — recording group communication, extracting communication relationships and determining the relationship between group communication and group performance. This study developed a method for determining relationships and rules for predicting performance to enable teachers to take act appropriately according to the predicted performance of the group. Four group performance indicators are considered — average grades within a group, project grade, frequency of resource‐sharing and drop‐out rate. Experimental results are presented, concerning the application of the methodology to a web class of 706 students, divided into 70 groups. The experimental results show that group communication patterns significantly affect group performance.