bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation, parameterization dependence, and future projection of daily precipitation simulated with a high‐resolution atmospheric GCM
Authors: Emori S. , Hasegawa A. , Suzuki T. , Dairaku K.
Published: March 2005

A relatively high‐resolution (T106) atmospheric general circulation model (AGCM) was used to simulate the present‐day climate with two different assumptions in cumulus parameterization. While the two runs show comparable performance for the annual mean precipitation, one shows much better agreement with satellite‐based analysis data for the extreme daily precipitation than the other. Accumulation of convectively available potential energy is shown to be important for more realistic intensities of extreme precipitation. This demonstrates that the performance of an AGCM for extreme precipitation is strongly dependent on cumulus parameterization even when the resolution of the model is as high as 1°, but can be reasonably good with an adequate choice of cumulus parameterization. A time‐slice doubled CO2 experiment was also conducted with the better version of the model. Though the global mean percentage change is larger for extreme precipitation than for the annual mean, this relation is found to vary regionally.
Ability of multiangle remote sensing observations to identify and distinguish mineral dust types: Optical models and retrievals of optically thick plumes
Authors: Kalashnikova O. V. , Kahn R. , Sokolik I. N. , Li Wen‐Hao
Published: March 2005

We present a systematic theoretical study of atmospheric mineral dust radiative properties, focusing on implications for multiangle and multispectral remote sensing. We model optical properties of complex, nonspherical mineral dust mixtures in three visible‐near‐infrared satellite channels: 0.550, 0.672, and 0.866 μm, accounting for recent field and laboratory data on mineral dust morphology and mineralogy. To model the optical properties of mineral dust, we employ the discrete dipole approximation technique for particles up to 2 μm diameter and the T matrix method for particles up to 12 μm. We investigate the impact of particle irregularity, composition, and size distribution on particle optical properties, and we develop optical models for representative natural mineral dust composition‐size‐shape types. Sensitivity studies with these models indicate that Multiangle Imaging Spectroradiometer (MISR) data should be able to distinguish plate‐like from grain‐like dust particles, weakly from strongly absorbing compositional types, and monomodal from bimodal size distributions. Models containing grain‐like, weakly absorbing, bimodal distributions of dust particles were favored for optically thick Saharan and Asian dust plume examples, whereas strongly absorbing and plate‐like particles were rejected. We will present detailed, systematic MISR sensitivity studies and analysis of more complex field cases using the optical models derived here in a future paper.
Cross‐tropopause tracer transport in midlatitude convection
Authors: Mullendore G. L. , Durran D. R. , Holton J. R.
Published: March 2005

A three‐dimensional cloud‐resolving model is used to simulate the transport of lower‐tropospheric passive tracers into the lowermost stratosphere via midlatitude convection. In previous studies of troposphere‐to‐stratosphere convective transport the extent of irreversible transport is unclear because the tropopause location is difficult to determine in the highly perturbed environment directly above an active storm. To determine the irreversibility of cross‐tropopause transport in this study, 10‐hour simulations are carried out to cover the growth and decay cycles of the storm. After the decay of convection, isentropes relax to quasi‐flat surfaces, and the position of the tropopause becomes much easier to establish. Air parcels containing boundary layer tracers were able to penetrate the stable stratosphere because diabatic processes increased the parcel's potential temperature sufficiently to make the parcel neutrally buoyant at stratospheric altitudes. The boundary layer tracer was carried upward in the core of the updraft whereas tracers originating from higher levels were lifted on the flanks of the updraft and therefore underwent less transport into the stratosphere. Three different cases were simulated: a prototypical supercell, a prototypical multicell, and a supercell observed during the Severe Thunderstorm Electrification and Precipitation Study (STEPS) field campaign. In the prototypical supercell simulation, at 1 km above the tropopause the maximum concentration of boundary layer tracer is diluted to 26% of its original concentration; the maximum concentration of the tracer originating in the layer between 1 and 4 km is diluted to 23% of its original concentration. Simulation of the STEPS storm showed similar irreversible transport in a less idealized case. Both supercell storms produced more transport than the prototypical multicell storm.
Fatty acids on continental sulfate aerosol particles
Authors: Tervahattu H. , Juhanoja J. , Vaida V. , Tuck A. F. , Niemi J. V. , Kupiainen K. , Kulmala M. , Vehkamäki H.
Published: March 2005

Surface analyses of atmospheric aerosols from different continental sources, such as forest fires and coal and straw burning, show that organic surfactants are found on such aerosols. The predominant organic species detected by time‐of‐flight secondary ion mass spectrometry on the sulfate aerosols are fatty acids of different carbon chain length up to the C32 acid. These observations are consistent with literature accounts of functional group analysis of bulk samples, but this is the first direct evidence of fatty acid films on the surface of sulfate aerosols. Surface analysis leads to the conclusion that fatty acid films on continental aerosols may be more common than has been previously suggested.
Requirements of peptidoglycan structure that allow detection by the Drosophila Toll pathway
Authors: Filipe Sergio R , Tomasz Alexander , Ligoxygakis Petros
Published: March 2005

The Drosophila immune system is able to discriminate between classes of bacteria. Detection of Gram‐positive bacteria involves a complex of two pattern recognition receptors: peptidoglycan recognition protein SA (PGRP‐SA) and Gram‐negative binding protein 1 (GNBP1). These activate the Toll signalling pathway. To define the cell wall components sensed by the host, we used highly purified peptidoglycan fragments of two principal Gram‐positive bacterial pathogens Staphylococcus aureus and Streptococcus pneumoniae. We report that in both peptidoglycans, the minimal structure needed to activate the Toll pathway is a muropeptide dimer and that the free reducing end of the N‐acetyl muramic acid residues of the muropeptides is essential for activity. Monomeric muropeptides were inactive and inhibitory in combination with dimers. Finally, peptidoglycan was degraded by the haemolymph of wild‐type but not GNBP1 mutant flies. We suggest a model whereby GNBP1 is involved in the hydrolysis of Gram‐positive peptidoglycan producing new glycan reducing ends, which are subsequently detected by PGRP‐SA.
Early Clinical Experience of Gamma-AP Nailing with Fluoro-Navigation
Authors: Leung K. S. , Tang N. , Yue W.
Published: March 2005

This is a report on the early experience of the application of fluoro-navigation in Gamma nail fixation of the peritrochanteric fractures. With the newly designed adapters that are attached to the standard Gamma nail instruments, the surgery can be done with fluoro-navigation guidance for the entry of the medullary canal, nail insertion, lag screw insertion as well as the distal locked screw insertion. The early results of fixing 28 peritrochanteric fractures are encouraging. The average duration of surgery was 42 min, the average number of X-ray screening during navigation was 10.5. The average wound length was 8.21 cm. No complication was recorded during surgery and after surgery. This report confirms the feasibility of the application of fluoro-navigation in Gamma nailing with the advantages of decreasing X-ray exposure and accurate implant position. The surgical trauma is further decreased with smaller incisions. Further improvement in the surgical technique and precautions are also discussed.
Constant-pressure and constant-surface tension simulations in dissipative particle dynamics
Authors: Jakobsen Ask F.
Published: March 2005

We present a method for constant-pressure and constant-surface tension simulations in dissipative particle dynamics using a Langevin piston approach. We demonstrate that the corresponding equations of motion lead to the relevant ensembles and propose an appropriate scheme of integration. After having identified a suitable set of parameters for the approach, we demonstrate the feasibility of the approach by applying it to two different systems, a simple isotropic fluid and an anisotropic fluid lipid-bilayer membrane in water. Results are presented for, respectively, isothermal bulk compressibility, tracer diffusion coefficient, lipid head-group area, and isothermal area compressibility. We find that our Langevin piston approach leads to improvements over other approaches in terms of faster equilibration and shorter correlation times of various system variables.
Low loss dielectrics of Ba6Ti2Ta8O30 and Sr6Ti2Ta8O30 with tungsten–bronze structure
Authors: Chen X. M. , Yuan Y. , Sun Y. H.
Published: March 2005

The dielectrics of Ba6Ti2Ta8O30 and Sr6Ti2Ta8O30 were prepared and characterized. These compounds have the tetragonal tungsten–bronze structure and paraelectric nature at room temperature. Very low dielectric loss was determined at 1 MHz in both dielectrics together with a relatively small temperature coefficient. The dielectric constant was 174 and 180 for Ba6Ti2Ta8O30 and Sr6Ti2Ta8O30, respectively.
Low-loss rib waveguides containing Si nanocrystals embedded in SiO2
Authors: Pellegrino P. , Garrido B. , Garcia C. , Arbiol J. , Morante J. R. , Melchiorri M. , Daldosso N. , Pavesi L. , Scheid E. , Sarrabayrouse G.
Published: March 2005

We report on the study and modeling of the structural and optical properties of rib-loaded waveguides working in the 600–900-nm spectral range. A Si nanocrystal (Si-nc) rich SiO2 layer with nominal Si excess ranging from 10% to 20% was produced by quadrupole ion implantation of Si into thermal SiO2 formed on a silicon substrate. Si-ncs were precipitated by annealing at 1100°C, forming a 0.4-μm-thick core layer in the waveguide. The Si content, the Si-nc density and size, the Si-nc emission, and the active layer effective refractive index were determined by dedicated experiments using x-ray photoelectron spectroscopy, Raman spectroscopy, energy-filtered transmission electron microscopy, photoluminescence and m-lines spectroscopy. Rib-loaded waveguides were fabricated by photolithographic and reactive ion etching processes, with patterned rib widths ranging from 1to8μm. Light propagation in the waveguide was observed and losses of 11dB∕cm at 633 and 780nm were measured, modeled and interpreted.
Strong, high-frequency, ac electric-field-induced rhombohedra-tetragonal phase transition in Pb(Mg1∕3Nb2∕3)O3–PbTiO3 single crystal
Authors: Zhan Chun , Wu Juntao , Yin Shizhuo , Jiang Xiaoning
Published: March 2005

Dielectric properties of Pb(Mg1∕3Nb2∕3)O3–PbTiO3 single crystals grown by a modified Bridgman method are investigated under strong, high-frequency (>100kHz) ac field. It is found that there is a phase transition due to the applied ac field, which may be due to the following reasons: (1) strong ac field periodically moves domains at fast speed that heats up the crystal due to the friction of domain change; and (2) phase transition happens because of the increase of the temperature. Compared with conventional heating techniques, ac field-induced phase transition is a quicker and more effective way. In addition, it is also found that continuous ac excitation can make the phase transition easier that may be due to the deaging effect caused by continuous ac excitation. Experimental results confirm the increase of d33 and the change of transmittance under strong ac field, which further verifies that phase transition indeed happens.
Mechanical behavior and magnetic separation of quasi-one-dimensional SnO2 nanostructures: A technique for achieving monosize nanobelts/nanowires
Authors: Jin Z. Q. , Ding Y. , Wang Z. L.
Published: March 2005

The as-synthesized nanowires and nanobelts usually have a large size distribution. We demonstrate here a ball milling technique for narrowing the size distribution of oxide nanobelts and nanowires. High-resolution scanning and transmission electron microscopy reveals that the one-dimensional SnO2 nanostructures with size >150nm are sensitive to the milling effect and most of them were fractured into nanoparticles even after a short-time milling. These nanoparticles contain magnetic Fe components, which could be effectively separated from those nanobelts by employing a magnetic field. This feature promises a potentials application in the nanostructured materials separation. It was also found that the dominant size of the survived nanostructures is <100nm. The good mechanical behavior of the nanostructures are not only related to the superior mechanical toughness due to small size, but also related to the low defect density.
Collapse of single-walled carbon nanotubes
Authors: Tang Tian , Jagota Anand , Hui Chung-Yuen , Glassmaker Nicholas J.
Published: March 2005

Single-walled carbon nanotubes with a circular cross section can collapse into ribbons under the influence of self-van der Waals interactions. We present closed-form results for the energetics of this self-collapse using continuum analysis verified by molecular simulations. Two critical tube radii are predicted by the continuum analysis: Rmin, below which there is no collapse; and Rmax, above which the collapsed configuration is energetically favored. We present simple and accurate analytical results for Rmin and Rmax as functions of two length scales, d0 and D∕Wflat, where d0 is the equilibrium distance between two flat parallel graphite sheets, Wflat is the work per unit area needed to separate the two sheets, and D is the effective bending stiffness of the tube.
Structure and chirality distribution of multiwalled boron nitride nanotubes
Authors: Celik-Aktas A. , Zuo J. M. , Stubbins J. F. , Tang C. , Bando Y.
Published: March 2005

We report on a high-resolution electron diffraction study of the structure of individual multiwalled boron nitride nanotubes (MW-BNNTs). The tube chirality was determined by electron diffraction. Diffraction patterns were recorded from small sections of the nanotubes, ∼125nm long, using the nanoarea electron diffraction technique. Accurate measurements of the MW-BNNT chiral angles and their distribution were made from diffraction patterns. Generally, the tube chiralities within each MW-BNNT are strongly correlated; clustering around a single chirality with a dispersion of a few degrees. Multihelix nanotubes were rarely observed. Statistics based on 67 nanotubes revealed a dispersion of the chiral angles (α) with some preference of tubes in the ranges of 10°⩽α⩽15° and 25°⩽α⩽30°. Since various properties of nanotubes depend on the tube structure (diameter and chirality), the results presented here have general significances to nanotube growth and applications.
Two-dimensional colloidal crystals formed by thermophoresis and convection
Authors: Duhr Stefan , Braun Dieter
Published: March 2005

Temperature gradients can trap micrometer-sized particles into two-dimensional crystals. We form colloidal crystals from otherwise repellent 2μm polystyrene beads in diverse thermal convection settings. Our experiments indicate that the accumulation is driven by particle thermophoresis. Particles move along the temperature gradient and are pushed out of the warm liquid to a cold wall. We find reduced accumulation for decreased surface temperature gradients and enhanced salt concentrations. Moreover, thermophoretic fluid dynamics calculations predict flat accumulation profiles with 107-fold enhanced concentrations that are consistent with our experiments. The accumulated crystals could be used as molecular sieves for microfluidic biotechnological applications. A natural environment for similar accumulations are pores of rock near hydrothermal vents.
What is Land Cover?
Authors: Comber Alexis , Fisher Peter , Wadsworth Richard
Published: March 2005

Much geographic information is an interpretation of reality and it is possible for multiple interpretations to coexist. This is unproblematic for the research community but, as the numbers of users increase through initiatives resulting in data integration on an unprecedented scale, such as E-science and GRID, issues of information meaning and conceptualisation become more important. We explore these issues through the mapping of land cover and the variety of conceptions of land-cover features that may be held by actors in the creation, distribution, and use of the information. Current metadata do not report the wider meaning of the information categories in terms of the decisions that were made and by whom in specifying class conceptualisations.
Global energy gradients and size in colonial organisms: Worker mass and worker number in ant colonies
Authors: Kaspari Michael
Published: March 2005

Body mass shapes processes from cell metabolism to community dynamics. Little is known, however, about how the average body mass of individuals varies among ecological communities. Ants alter colony mass by independently changing worker mass and/or worker number. In a survey of 49 ecosystems from tundra to tropical rainforest, average worker mass and worker number were uncorrelated (
r
s
= 0.2,
P
> 0.14) and varied 100-fold. Data supported the hypothesis that higher mean monthly temperatures,
T
, reduce worker mass by increasing metabolic costs during worker development. In contrast, worker number was unimodal over a 1,000-fold gradient of net primary productivity (
NPP
, g of carbon per m
2
per yr), a measure of organic carbon available to consumers. At the lowest levels of
NPP
colonies appeared to be carbon-limited; above 60 g of carbon per m
2
per yr average worker number decreased to a global low. This decline in worker number with increasing
NPP
supports the hypothesis that abundant carbon ameliorates the Achilles heel of small taxa in competition with large taxa: their relatively high metabolic demands. Higher predation rates in resource-rich environments may also play a role in limiting worker number. In all, about half the global variation in worker mass and number was accounted for by gradients of
NPP
and
T
. Changes in global temperature and rainfall may thus mold gradients of ectotherm size, with consequences for the structure and function of the ecosystems.
Leptin increase in multiple sclerosis associates with reduced number of CD4
+
CD25
+
regulatory T cells
Authors: Matarese Giuseppe , Carrieri Pietro Biagio , La Cava Antonio , Perna Francesco , Sanna Veronica , De Rosa Veronica , Aufiero Daniela , Fontana Silvia , Zappacosta Serafino
Published: March 2005

We analyzed the serum and cerebrospinal fluid (CSF) leptin secretion and the interaction between serum leptin and CD4
+
CD25
+
regulatory T cells (T
Regs
) in naïve-to-therapy relapsing-remitting multiple sclerosis (RRMS) patients. Leptin production was significantly increased in both serum and CSF of RRMS patients and correlated with IFN-γ secretion in the CSF. T cell lines against human myelin basic protein (hMBP) produced immunoreactive leptin and up-regulated the expression of the leptin receptor (ObR) after activation with hMBP. Treatment with either anti-leptin or anti-leptin-receptor neutralizing antibodies inhibited
in vitro
proliferation in response to hMBP. Interestingly, in the RRMS patients, an inverse correlation between serum leptin and percentage of circulating T
Regs
was also observed. To better analyze the finding, we enumerated T
Regs
in leptin-deficient (
ob
/
ob
) and leptin-receptor-deficient (
db
/
db
) mice and observed the significant increase in T
Regs
. Moreover, treatment of WT mice with soluble ObR fusion protein (ObR:Fc) increased the percentage of T
Regs
and ameliorated the clinical course and progression of disease in proteolipid protein peptide (PLP
139–151
)-induced relapsing-experimental autoimmune encephalomyelitis (R-EAE), an animal model of RRMS. These findings show an inverse relationship between leptin secretion and the frequency of T
Regs
in RRMS and may have implications for the pathogenesis of and therapy for multiple sclerosis.
Structural origins of efficient proton abstraction from carbon by a catalytic antibody
Authors: Debler Erik W. , Ito Shuichiro , Seebeck Florian P. , Heine Andreas , Hilvert Donald , Wilson Ian A.
Published: March 2005

Antibody 34E4 catalyzes the conversion of benzisoxazoles to salicylonitriles with high rates and multiple turnovers. The crystal structure of its complex with the benzimidazolium hapten at 2.5-Å resolution shows that a combination of hydrogen bonding, π stacking, and van der Waals interactions is exploited to position both the base, Glu
H50
, and the substrate for efficient proton transfer. Suboptimal placement of the catalytic carboxylate, as observed in the 2.8-Å structure of the Glu
H50
Asp variant, results in substantially reduced catalytic efficiency. In addition to imposing high positional order on the transition state, the antibody pocket provides a highly structured microenvironment for the reaction in which the carboxylate base is activated through partial desolvation, and the highly polarizable transition state is stabilized by dispersion interactions with the aromatic residue Trp
L91
and solvation of the leaving group oxygen by external water. The enzyme-like efficiency of general base catalysis in this system directly reflects the original hapten design, in which a charged guanidinium moiety was strategically used to elicit an accurately positioned functional group in an appropriate reaction environment and suggests that even larger catalytic effects may be achievable by extending this approach to the induction of acid-base pairs capable of bifunctional catalysis.
The complete genomes and proteomes of 27
Staphylococcus aureus
bacteriophages
Authors: Kwan Tony , Liu Jing , DuBow Michael , Gros Philippe , Pelletier Jerry
Published: March 2005

Bacteriophages are the most abundant life forms in the biosphere. They play important roles in bacterial ecology, evolution, adaptation to new environments, and pathogenesis of human bacterial infections. Here, we report the complete genomic sequences, and predicted proteins of 27 bacteriophages of the Gram-positive bacterium
Staphylococcus aureus
. Comparative nucleotide and protein sequence analysis indicates that these phages are a remarkable source of untapped genetic diversity, encoding 2,170 predicted protein-encoding ORFs, of which 1,402 cannot be annotated for structure or function, and 522 are proteins with no similarity to other phage or bacterial sequences. Based on their genome size, organization of their gene map and comparative nucleotide and protein sequence analysis, the
S. aureus
phages can be organized into three groups. Comparison of their gene maps reveals extensive genome mosaicism, hinting to a large reservoir of unidentified
S. aureus
phage genes. Among the phages in the largest size class (178–214 kbp) that we characterized is phage Twort, the first discovered bacteriophage (responsible for the Twort-D'Herelle effect). These phage genomes offer an exciting opportunity to discern molecular mechanisms of phage evolution and diversity.
An extremal function for the Chang-Marshall inequality over the Beurling functions
Authors: Andreev Valentin
Published: March 2005

S.-Y. A. Chang and D. E. Marshall showed that the functional
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="normal upper Lamda left-parenthesis f right-parenthesis equals left-parenthesis 1 slash 2 pi right-parenthesis integral Subscript 0 Superscript 2 pi Baseline exp left-brace StartAbsoluteValue f left-parenthesis e Superscript i theta Baseline right-parenthesis EndAbsoluteValue squared right-brace d theta">

Λ
(
f
)
=
(
1

/

2
π
)

∫
0

2
π

exp
⁡
{

|

f
(

e

i
θ

)

|

2

}
d
θ

\Lambda (f) =(1/2\pi ) \int _0^{2\pi }\exp \{ |f(e^{i\theta })|^2\}d\theta

is bounded on the unit ball

B

\mathcal {B}

of the space

D

\mathcal {D}

of analytic functions in the unit disk with

f
(
0
)
=
0

f(0)=0

and Dirichlet integral not exceeding one. Andreev and Matheson conjectured that the identity function

f
(
z
)
=
z

f(z)=z

is a global maximum on

B

\mathcal {B}

for the functional

Λ
\Lambda

. We prove that

Λ
\Lambda

attains its maximum at

f
(
z
)
=
z

f(z)=z

over a subset of

B

\mathcal {B}

determined by kernel functions, which provides a positive answer to a conjecture of Cima and Matheson.
The homological determinant of quantum groups of type 𝐴
Authors: Hai Phùng
Published: March 2005

LetRRbe a Hecke symmetry depending algebraically on a parameterq∈Cq\in \mathbb {C}. We show that the homology of the Koszul complex associated withRRis one-dimensional whenqqis not a root of unity. A generator of this homology group then induces the homological determinant of the quantum group associated withRR.
The linear space of generalized Brownian motions with applications
Authors: Lee Jeong
Published: March 2005

In this paper, we define, motivated by recent works of Chang and Skoug, stochastic integrals for a generalized Brownian motion (

gBm

{\textrm {gBm}}

)

X
X

and then use it to study the representation problem on the linear space

H
(
X
)

H(X)

spanned by

X
X

. We next establish a translation theorem for

L
p

L^p

-functionals of

X
X

,

p
≥
1

p \geq 1

, and then use this translation to establish an integration by parts formula for

L
p

L^p

-functionals of

X
X

.
Concentration of area in half-planes
Authors: Barnard Roger , Richardson Clint , Solynin Alexander
Published: March 2005

For the standard class

S
S

of normalized univalent functions

f
f

analytic in the unit disk

U

\mathbb {U}

, we consider a problem on the minimal area of the image

f
(

U

)

f(\mathbb {U})

concentrated in any given half-plane. This question is related to a well-known problem posed by A. W. Goodman in 1949 that regards minimizing area covered by analytic univalent functions under certain geometric constraints. An interesting aspect of this problem is the unexpected behavior of the candidates for extremal functions constructed via geometric considerations.
A note on adjoint linear systems
Authors: Lee Seunghun
Published: March 2005

In this note, we give a weak estimate on the separation of tangent directions of the conjecture of Fujita for adjoint linear systems on smooth varieties.
The PCH Family Member MAYP/PSTPIP2 Directly Regulates F-Actin Bundling and Enhances Filopodia Formation and Motility in Macrophages
Authors: Chitu Violeta , Pixley Fiona J. , Macaluso Frank , Larson Daniel R. , Condeelis John , Yeung Yee-Guide , Stanley E. Richard
Published: March 2005

Macrophage actin-associated tyrosine phosphorylated protein (MAYP) belongs to the Pombe Cdc15 homology (PCH) family of proteins involved in the regulation of actin-based functions including cell adhesion and motility. In mouse macrophages, MAYP is tyrosine phosphorylated after activation of the colony-stimulating factor-1 receptor (CSF-1R), which also induces actin reorganization, membrane ruffling, cell spreading, polarization, and migration. Because MAYP associates with F-actin, we investigated the function of MAYP in regulating actin organization in macrophages. Overexpression of MAYP decreased CSF-1–induced membrane ruffling and increased filopodia formation, motility and CSF-1-mediated chemotaxis. The opposite phenotype was observed with reduced expression of MAYP, indicating that MAYP is a negative regulator of CSF-1–induced membrane ruffling and positively regulates formation of filopodia and directional migration. Overexpression of MAYP led to a reduction in total macrophage F-actin content but was associated with increased actin bundling. Consistent with this, purified MAYP bundled F-actin and regulated its turnover in vitro. In addition, MAYP colocalized with cortical and filopodial F-actin in vivo. Because filopodia are postulated to increase directional motility by acting as environmental sensors, the MAYP-stimulated increase in directional movement may be at least partly explained by enhancement of filopodia formation.
The Prion Protein and Its Paralogue Doppel Affect Calcium Signaling in Chinese Hamster Ovary Cells
Authors: Brini Marisa , Miuzzo Manuela , Pierobon Nicola , Negro Alessandro , Sorgato Maria Catia
Published: March 2005

The function of the prion protein (PrPc), implicated in transmissible spongiform encephalopathies (TSEs), is largely unknown. We examined the possible influence of PrPcon Ca2+homeostasis, by analyzing local Ca2+fluctuations in cells transfected with PrPcand Ca2+-sensitive aequorin chimeras targeted to defined subcellular compartments. In agonist-stimulated cells, the presence of PrPcsharply increases the Ca2+concentration of subplasma membrane Ca2+domains, a feature that may explain the impairment of Ca2+-dependent neuronal excitability observed in TSEs. PrPcalso limits Ca2+release from the endoplasmic reticulum and Ca2+uptake by mitochondria, thus rendering unlikely the triggering of cell death pathways. Instead, cells expressing Doppel, a PrPcparalogue, display opposite effects, which, however, are abolished by the coexpression of PrPc. These findings are consistent with the functional interplay and antagonistic role attributed to the proteins, whereby PrPcprotects, and Doppel sensitizes, cells toward stress conditions.
Myosin Va Transports Dense Core Secretory Vesicles in Pancreatic MIN6 β-Cells
Authors: Varadi Aniko , Tsuboi Takashi , Rutter Guy A.
Published: March 2005

The role of unconventional myosins in neuroendocrine cells is not fully understood, with involvement suggested in the movement of both secretory vesicles and mitochondria. Here, we demonstrate colocalization of myosin Va (MyoVa) with insulin in pancreatic β-cells and show that MyoVa copurifies with insulin in density gradients and with the vesicle marker phogrin-enhanced green fluorescent protein upon fluorescence-activated sorting of vesicles. By contrast, MyoVa immunoreactivity was poorly colocalized with mitochondrial or other markers. Demonstrating an important role for MyoVa in the recruitment of secretory vesicles to the cell surface, a reduction of MyoVa protein levels achieved by RNA interference caused a significant decrease in glucose- or depolarization-stimulated insulin secretion. Similarly, expression of the dominant-negative–acting globular tail domain of MyoVa decreased by ∼50% the number of vesicles docked at the plasma membrane and by 87% the number of depolarization-stimulated exocytotic events detected by total internal reflection fluorescence microscopy. We conclude that MyoVa-driven movements of vesicles along the cortical actin network are essential for the terminal stages of regulated exocytosis in β-cells.
DrosophilaActivating Transcription Factor-2 Is Involved in Stress Response via Activation by p38, but Not c-Jun NH2-Terminal Kinase
Authors: Sano Yuji , Akimaru Hiroshi , Okamura Tomoo , Nagao Tomoko , Okada Masahiro , Ishii Shunsuke
Published: March 2005

Activating transcription factor (ATF)-2 is a member of the ATF/cAMP response element-binding protein family of transcription factors, and its trans-activating capacity is enhanced by stress-activated protein kinases such as c-Jun NH2-terminal kinase (JNK) and p38. However, little is known about the in vivo roles played by ATF-2. Here, we identified the Drosophila homologue of ATF-2 (dATF-2) consisting of 381 amino acids. In response to UV irradiation and osmotic stress, Drosophila p38 (dp38), but not JNK, phosphorylates dATF-2 and enhances dATF-2-dependent transcription. Consistent with this, injection of dATF-2 double-stranded RNA (dsRNA) into embryos did not induce the dorsal closure defects that are commonly observed in the Drosophila JNK mutant. Furthermore, expression of the dominant-negative dp38 enhanced the aberrant wing phenotype caused by expression of a dominant-negative dATF-2. Similar genetic interactions between dATF-2 and the dMEKK1-dp38 signaling pathway also were observed in the osmotic stress-induced lethality of embryos. Loss of dATF-2 in Drosophila S2 cells by using dsRNA abrogated the induction of 40% of the osmotic stress-induced genes, including multiple immune response-related genes. This indicates that dATF-2 is a major transcriptional factor in stress-induced transcription. Thus, dATF-2 is critical for the p38-mediated stress response.
German Lawyers and Globalisation: Changing Professional Identity
Authors: Shaw Gisela
Published: March 2005

abstract

The emergence of modern professions on the continent of Europe has generally been associated with the emergence of nation states. This is particularly true of the legal professions which, by their very nature, are characterised by a special interest in and relationship with the state. The late arrival on the scene of a German nation state meant that the process of professionalisation also suffered relative delay. No truly unified liberal professions could emerge before there was a national government with which to negotiate their roles.

Today, harmonisation initiatives of the European Union, embedded in and reinforced by growing globalisation of world markets, have set in motion a process of unprecedented professional de‐ and/or re‐regulation, curtailing nation state control and exposing professions to increasing internal and external competition at national and international levels. This paper looks at the impact of these processes on the ‘Rechtsanwaltschaft’, a key player in the German legal services market. Current developments are assessed in the light of a tradition of strict state regulation coupled with a high level of state‐protected privileges. The conceptual framework draws on research from the sociology of the professions.
6‐Tioguanine monitoring in steroid‐dependent patients with inflammatory bowel diseases receiving azathioprine
Authors: Roblin X. , Serre‐Debeauvais F. , Phelip J.‐M. , Faucheron J.‐L. , Hardy G. , Chartier A. , Helluwaert F. , Bessard G. , Bonaz B.
Published: March 2005

Background : 6‐Thioguanine (6‐tioguanine) nucleotides are the active metabolites of azathioprine.

Aim : The aim of the study was to evaluate the rate of clinical remission without steroids in steroid‐dependent Crohn's disease and ulcerative colitis patients receiving azathioprine, the medium‐ and long‐term efficacy and the predictive factors of clinical response when monitoring 6‐tioguanine.

Methods : Steroid‐dependent Crohn's disease and ulcerative colitis patients receiving either azathioprine or not (treated later with a daily dose of 2.5 mg/kg) were prospectively included. 6‐Tioguanine was monitored at 1 and 2 months and every 3 months thereafter for 1 year. The azathioprine dose was adapted to reach a 6‐tioguanine level of >250 pmol/8 × 108 red blood cells. Thiopurine methyltransferase genotype/phenotype was evaluated in some patients.

Results : A total of 106 patients were prospectively included (70 Crohn's disease, 36 ulcerative colitis). The clinical remission rate without steroids in patients receiving azathioprine, in intention‐to‐treat analysis, was 72% and 59% at 6 and 12 months, respectively. The remission rate was significantly higher in patients with 6‐tioguanine >250 pmol/8 × 108 RBC (86% and 69% at 6 and 12 months, respectively; P < 0.01). No significant difference was observed between Crohn's disease and ulcerative colitis patients whether treated by azathioprine or not on inclusion. In the univariate analysis, the absence of Crohn's disease stenosis, a 6‐tioguanine level >250 pmol/8 × 108 RBC, and an increase of erythrocyte mean corpuscular volume were the factors predictive of a favourable clinical response. In the multivariate analysis, only a 6‐tioguanine level of >250 pmol/8 × 108 red blood cells was a predictive factor of favourable clinical remission.

Conclusions : Clinical remission without steroids is significantly more likely when monitoring 6‐tioguanine so as to reach a level of >250 pmol/8 × 108 red blood cells in steroid‐dependent Crohn's disease and ulcerative colitis patients receiving azathioprine (86% and 69% at 6 and 12 months, respectively).
The out‐patient management of patients with acute mild‐to‐moderate colonic diverticulitis
Authors: Mizuki A. , Nagata H. , Tatemichi M. , Kaneda S. , Tsukada N. , Ishii H. , Hibi T.
Published: March 2005

Background : There are no management criteria for optimum out‐patient care in mild‐to‐moderate acute colonic diverticulitis.

Aim : To enable such patients to be managed in an out‐patient setting, by establishing criteria and treatment protocols.

Methods : We conducted an open trial and follow‐up study from 1997 to 2002. On the basis of ultrasonography, we defined and categorized mild‐to‐moderate acute colonic diverticulitis ranging from limited inflammation within diverticulum to an abscess < 2 cm in diameter. Subjects were treated as out‐patients and followed a 10‐day treatment protocol consisting of an oral antibiotic and a sports drink for the first 3 days. Physical examination and laboratory testing helped determine whether or not a patient could resume a liquid diet on day 4, and a regular diet on day 7.

Results : Of the 70 patients, 68 were successfully treated. Two patients required hospitalization. Of the 65 patients who were tracked over several months [median (intraquarter range) = 30.8 (11.9–44.2) months], 16 had one or more clinical recurrences. The medical cost per episode was 80% lower than in‐patient treatment.

Conclusions : Patients with mild‐to‐moderate acute colonic diverticulitis can be safely and successfully treated as out‐patients using this protocol.
Helicobacter pylori duodenal colonization is a strong risk factor for the development of duodenal ulcer
Authors: Pietroiusti A. , Luzzi I. , Gomez M. J. , Magrini A. , Bergamaschi A. , Forlini A. , Galante A.
Published: March 2005

Aim : To test the hypothesis that duodenal colonization represents the final crucial step in the development of Helicobacter pylori related duodenal ulcer.

Methods : Patients with non‐ulcer dyspepsia who had gastric colonization by H. pylori were included in the study. At baseline endoscopy, we evaluated the prevalence of duodenal colonization (culture, urease testing and histology), and cytotoxin‐associated gene A status (polymerase chain reaction). No patients received eradication during 1 year follow‐up. At this time, endoscopy was repeated and the incidence of duodenal ulcer was assessed.

Results : Among 181 patients completing follow‐up, 53 (29%) had duodenal colonization: 72% of them were cytotoxin‐associated gene A positive, versus 37% patients without duodenal colonization (P < 0.001). Duodenal ulcer developed in 12 (22.6%) patients with duodenal colonization and in two (1.6%) without duodenal colonization (odds ratio for duodenal ulcer: 6.29, 95% confidence intervals 2.44–17.45). The incidence of duodenal ulcer was similar among cytotoxin‐associated gene A positive and cytotoxin‐associated gene A negative subjects with duodenal colonization: 21.05% versus 26.6%.

Conclusions : The assessment of duodenal colonization by H. pylori in patients with non‐ulcer dyspepsia is strongly predictive for the subsequent development of duodenal ulcer and may help to stratify patients at risk for this disease.
Genotypes of the pancreatic β‐cell K‐ATP channel and clinical phenotypes of Japanese patients with persistent hyperinsulinaemic hypoglycaemia of infancy
Authors: Ohkubo Kumiko , Nagashima Mariko , Naito Yuko , Taguchi Tomoaki , Suita Sachiyo , Okamoto Nobuhiko , Fujinaga Hideshi , Tsumura Kumi , Kikuchi Kiyoshi , Ono Junko
Published: March 2005

Objective  Persistent hyperinsulinaemic hypoglycaemia of infancy (PHHI) is a disorder of glucose metabolism that is characterized by dysregulated secretion of insulin from pancreatic β‐cells. This disease has been reported to be associated with mutations of the sulfonylurea receptor SUR1 (ABCC8) or the inward‐rectifying potassium channel Kir6.2 (KCNJ11), which are two subunits of the pancreatic β‐cell ATP‐sensitive potassium channel.

Patients and Methods  In 14 Japanese PHHI patients, all exons of SUR1 and Kir6.2 genes were analysed by polymerase chain reaction (PCR) and direct sequencing. Four patients responded to diazoxide, and nine patients underwent a subtotal pancreatectomy. Histologically, seven patients were diagnosed to have a focal form and two a diffuse form of the disease.

Results  We found nine novel mutations in the SUR1 gene and two in the Kir6.2 gene. In the SUR1 gene mutations, three were nonsense mutations (Y512X, Y1354X and G1469X), one was a one‐base deletion in exon 7, and two were missense mutations in the nucleotide‐binding domain 2 (K1385Q, R1487K). The other three mutations occurred in introns 14, 29 and 36, which might cause aberrant splicing of RNA. Two siblings in one family were heterozygotes for a missense mutation, K1385Q, which was maternally inherited. In Kir6.2 gene screening, one patient was found to be a compound heterozygote of a missense mutation (R34H) and a one‐base deletion (C344fs/ter).

Conclusion  The novel mutations reported here could be pathological candidates for PHHI in Japan. They also reveal that SUR1 and Kir6.2 mutations in the Japanese population exhibit heterogeneity and that they occurred at a frequency similar to other genetic populations.
Prevalence and progression of subclinical hypothyroidism in women with type 2 diabetes: the Fremantle Diabetes Study
Authors: Chubb S. A. P. , Davis W. A. , Inman Z. , Davis T. M. E.
Published: March 2005

Objective  To assess the prevalence and progression of subclinical hypothyroidism in women with type 2 diabetes.

Design and Patients  Cross‐sectional and longitudinal observational assessment of thyroid function in 420 adult females with type 2 diabetes randomly selected from participants in the community‐based Fremantle Diabetes Study.

Measurements  Serum TSH, antibodies to thyroperoxidase (anti‐TPO) and serum free T4 were measured at baseline and after 5 years. Baseline glycated haemoglobin (HbA1c), serum glucose, serum total and high density lipoprotein (HDL) cholesterol, serum triglycerides and antibodies to glutamic acid decarboxylase (anti‐GAD) were also used in analyses.

Results  After exclusion of patients with known thyroid disease or taking amiodarone or lithium at baseline, the prevalence of subclinical hypothyroidism (a raised serum TSH and normal serum free T4) was 8·6%. Subclinical hypothyroidism was associated with anti‐TPO status and age, but there were no independent associations with serum cholesterol, history of coronary heart disease, HbA1c or hypoglycaemic therapy. In the subgroup of patients restudied after 5 years, none of those who had subclinical hypothyroidism at baseline had overt hypothyroidism regardless of anti‐TPO status.

Conclusions  In women with type 2 diabetes without known thyroid disease, subclinical hypothyroidism is a common but incidental finding. The routine screening of thyroid function in type 2 diabetes is questionable.
Beyond the regeneration phase: differentiation of height–light trajectories among tropical tree species
Authors: POORTER LOURENS , BONGERS FRANS , STERCK FRANK J. , WÖLL HANNSJÖRG
Published: March 2005

A height–light trajectory (HLT, a fitted curve relating canopy exposure to tree height) was determined for populations of individuals of each of 47 tree species in a Liberian lowland rainforest. The HLTs were compared and related to tree allometry and adult stature. Crown exposure was measured for 7460 trees and related to tree height using a multinomial regression analysis. Individual trees were followed for 2.8–9.8 years.

The trajectories of the 47 species were compared with the average vertical light profile in the forest canopy. Evidence was found for the existence of all nine trajectories hypothesized on the basis of three possible light environments (high, intermediate and low) for juveniles and adults. The classical paradigm of pioneer vs. shade tolerant, based on seed and seedling responses, does not therefore apply to post‐seedling stages.

The majority of the species followed the vertical light profile in the forest canopy, starting in low light environments in the juvenile stage and ending up in high light environments in the adult stage. Only two species complied with the classic notion of whole‐life shade tolerants and whole‐life shade intolerants (one each).

The predictable vertical light gradient in the forest canopy has led to a close association between adult height, light trajectories and allometric traits. Large‐stature species tend to have relatively slender stems and narrow crowns, and therefore realize a faster temporal and height‐related increase in crown exposure.

Tree species have different height–light trajectories when they grow from seedling to adulthood. This may have profound repercussions for our current views on plasticity and adaptation, light partitioning and species coexistence, and on silviculture and management.
A monocarpic tree species in a polycarpic world: how can Tachigali vasquezii maintain itself so successfully in a tropical rain forest community?
Authors: POORTER LOURENS , ZUIDEMA PIETER A. , PEÑA‐CLAROS MARIELOS , BOOT RENE G. A.
Published: March 2005

Although monocarpy is rare among long‐lived plant species that grow in stable habitats, one monocarpic species, Tachigali vasquezii, is extremely abundant in the rain forests of the Bolivian Amazon. We analyse how T. vasquezii is able to maintain itself successfully by comparing its life‐history traits with those of polycarpic tree species of the same community. We then evaluate the relative importance of such traits using population matrix models.

Monocarpic species are expected to have a high fecundity. Seed production per basal area for T. vasquezii is indeed nearly twice that of an average polycarpic species, but this is not sufficient to maintain stable populations.

Life‐history theory predicts that a monocarpic strategy is advantageous if juvenile survival rates are high compared with adult survival. Although seedlings of T. vasquezii have a lower mortality rate than polycarpic species, its sapling have higher mortality.

We found that the success of T. vasquezii is due to its very high diameter growth rates in the larger size classes, which are four times higher than that of an average, co‐occurring polycarpic species. Fast diameter growth is enabled by investment in large, leafy crowns and by a low wood density. Applying this high diameter growth in a population model yielded a population growth rate close to that of polycarpic species. Life table response experiment analysis of Tachigali and polycarp models showed that higher growth compensated for the negative demographic effect of 100% adult mortality following reproduction.

Rapid growth enables T. vasquezii to reach reproductive maturity in only 49 years, compared with 79 years for an average polycarpic species. It also reduces the risk of dying before reproducing, and 50% more seedlings survive to maturity for T. vasquezii compared with polycarpic species.

The dramatic negative demographic consequences of one‐time flowering can therefore be completely balanced by taking a shorter time to reach maturity. Taking a time perspective, it appears that Tachigali vasquezii has an advanced, rather than a delayed, reproduction.