bluuebunny/crossref_metadata_2025 huggingface dataset:
Cellular functions of NSF: Not just SNAPs and SNAREs
Authors: Zhao Chunxia , Slevin John T. , Whiteheart Sidney W.
Published: March 2007

N‐ethylmaleimide sensitive factor (NSF) is an ATPases associated with various cellular activities protein (AAA), broadly required for intracellular membrane fusion. NSF functions as a SNAP receptor (SNARE) chaperone which binds, through soluble NSF attachment proteins (SNAPs), to SNARE complexes and utilizes the energy of ATP hydrolysis to disassemble them thus facilitating SNARE recycling. While this is a major function of NSF, it does seem to interact with other proteins, such as the AMPA receptor subunit, GluR2, and β2‐AR and is thought to affect their trafficking patterns. New data suggest that NSF may be regulated by transient post‐translational modifications such as phosphorylation and nitrosylation. These new aspects of NSF function as well as its role in SNARE complex dynamics will be discussed.
Cell–cell fusion
Authors: Chen Elizabeth H. , Grote Eric , Mohler William , Vignery Agnès
Published: March 2007

Cell–cell fusion is a highly regulated and dramatic cellular event that is required for development and homeostasis. Fusion may also play a role in the development of cancer and in tissue repair by stem cells. While virus–cell fusion and the fusion of intracellular membranes have been the subject of intense investigation during the past decade, cell–cell fusion remains poorly understood. Given the importance of this cell‐biological phenomenon, a number of investigators have begun analyses of the molecular mechanisms that mediate the specialized fusion events of a variety of cell types and species. We discuss recent genetic and biochemical studies that are beginning to yield exciting insights into the fusion mechanisms of Saccharomyces cerevisiae mating pairs, Caenorhabditis elegans epithelial cells and gametes, Drosophila melanogaster and mammalian myoblasts, and mammalian macrophages.
Dietary supplementation withtrans-11- andtrans-12-18 : 1 increasescis-9,trans-11-conjugated linoleic acid in human immune cells, but without effects on biomarkers of immune function and inflammation
Authors: Kuhnt Katrin , Kraft Jana , Vogelsang Heinz , Eder Klaus , Kratzsch Jürgen , Jahreis Gerhard
Published: March 2007

Trans-fatty acid intake is associated with an increased risk of CHD and diabetes. The effects of singletrans-fatty acid isomers are largely unexplored. The present study examined the effects of a 6-week supplementation with twotrans-18 : 1 isomers (trans-11 andtrans-12) in human subjects on immune cells, several inflammatory and immunological biomarkers (for example, IL, TNFα, C-reactive protein, adiponectin, intercellular adhesion molecule-1, prostacyclin, phagocytic process). Following a 2-week adaptation period without supplements, the test group (n12) received vaccenic acid (trans-11-18:1) andtrans-12-18 : 1 in equal amounts (6·0 g/d) for 6 weeks. The control group (n12) consumed an oil withouttrans-fatty acids and conjugated linoleic acids (CLA). Samples were collected at the end of both periods.Trans-11- andtrans-12-18 : 1 were significantly increased in cellular lipids. The endogenous synthesis ofcis-9,trans-11-CLA fromtrans-11-18 : 1 was demonstratedviaincreased CLA in cellular lipids of the test group. Generally,trans-isomer supplementation did not affect either inflammatory biomarkers (for example, IL-6, IL-8, TNFα) or immune function (for example, phagocytosis) during the present study. The dietary supplementation oftrans-11- andtrans-12-18 : 1 (6 g/d) and their accumulation in leucocytes had no effects on biomarkers of inflammation and immune function. However, because of the limited data on the safety oftrans-fatty acid intake and effects of individualtransisomers on human health (for example,trans-9-18 : 1,trans-10-18 : 1) at present, it is prudent to reducetrans-fat intake in general.
Major dietary patterns and cardiovascular risk factors from childhood to adulthood. The Cardiovascular Risk in Young Finns Study
Authors: Mikkilä Vera , Räsänen Leena , Raitakari Olli T. , Marniemi Jukka , Pietinen Pirjo , Rönnemaa Tapani , Viikari Jorma
Published: March 2007

Studies on the impact of single nutrients on the risk of CVD have often given inconclusive results. Recent research on dietary patterns has offered promising information on the effects of diet as a whole on the risk of CVD. The Cardiovascular Risk in Young Finns Study is an ongoing, prospective cohort study with a 21-year follow-up to date. The subjects were children and adolescents at baseline (3–18 years, n 1768) and adults at the latest follow-up study (24–39 years, n 1037). We investigated the associations between two major dietary patterns and several risk factors for CVD. In longitudinal analyses with repeated measurements, using multivariate mixed linear regression models, the traditional dietary pattern (characterised by high consumption of rye, potatoes, butter, sausages, milk and coffee) was independently associated with total and LDL cholesterol concentrations, apolipoprotein B and C-reactive protein concentrations among both genders, and also with systolic blood pressure and insulin levels among women and concentrations of homocysteine among men (P < 0·05 for all). A dietary pattern reflecting more health-conscious food choices (such as high consumption of vegetables, legumes and nuts, tea, rye, cheese and other dairy products, and alcoholic beverages) was inversely, but less strongly associated with cardiovascular risk factors. Our results support earlier findings that dietary patterns have a role in the development of CVD.
Flavanone plasma pharmacokinetics from blood orange juice in human subjects
Authors: Gardana Claudio , Guarnieri Serena , Riso Patrizia , Simonetti Paolo , Porrini Marisa
Published: March 2007

Some blood orange juice (BOJ) flavanones may have antioxidant, anti-inflammatory, anti-allergic, hypolipidaemic, vasoprotective and anticarcinogenic properties. The aim of the present study was to evaluate the pharmacokinetics of hesperetin and naringenin in human subjects after BOJ intake. In a cross-over study, seven healthy female volunteers consumed 150 and 300 ml BOJ corresponding to about 51–102 mg hesperetin and to 6–12 mg naringenin, respectively. Plasma samples were collected before, each hour for 8 h and 24 h after BOJ administration and analysed for their content of hesperetin and naringenin by liquid chromatography–MS/MS. The plasma concentrations of these compounds were dose dependent and the peak concentration (Cmax) was reached in 5·1 (sd0·6) h after BOJ intake. TheCmaxof hesperetin was 43·4 (sd32·4) and 79·8 (sd60·1) ng/ml after 150 and 300 ml intake, respectively. For naringenin the plasma peak was 16·4 (sd11·9) and 34·0 (sd20·6) ng/ml. Moreover, the conjugated forms of these flavanones represent more than 95 % of the plasma concentration. The results indicate that both hesperetin and naringenin are bioavailable after BOJ intake; naringenin seemingly more so than hesperetin.
Voluntary Association Activity in Quebec and English Canada: Assessing the Effects of Region and Language
Authors: Hwang Monica , Andersen Robert , Grabb Edward
Published: March 2007

Abstract.This paper presents the first multivariate analysis of the combined effects of region and language on voluntary association membership in Canada. National survey data from 2000 indicate that Quebecers have the lowest average number of memberships, with Western Canadians highest and Atlantic and Ontario residents in between. Preliminary results also confirm that francophones report fewer memberships than anglophones. Findings from Poisson regression models, however, indicate a significant interaction between region and language: francophones have lower membership levels only in Quebec, and in Western Canada have higher levels than anglophones or allophones. These results hold even with controls for a number of possible explanatory factors suggested in the literature, including religious and socioeconomic differences across the regions and language groups. The implications for understanding patterns of voluntary association activity in Canada are discussed.

Résumé.Cet article présente la première analyse multivariable des effets combinés de la région et de la langue sur l'adhésion d'aux associations volontaires au Canada. Les données nationales de 2000 indiquent que les Québécois ont le plus bas nombre moyen d'adhésions, avec les Canadiens de l'Ouest plus hauts et des résidants de la région atlantique et de l'Ontario entre les deux. Les résultats préliminaires confirment que les francophones ont moins d'adhésions que les anglophones. Les résultats indiquent une interaction significative entre la région et la langue: les francophones ont moins d'adhésion seulement au Québec; dans le Canada de l'Ouest les francophones ont plus d'adhésion que les anglophones et les allophones. Ces résultats se tiennent même avec contrôle d'un certain nombre de facteurs explicatifs possibles suggérés dans la littérature, y compris des différences religieuses et socio-économiques à travers les régions et les groupes linguistic. Nous discutons les implications quant aux modèles d'association volontaire au Canada.
Authorizing Humanitarian Intervention: Hard Choices in Saving Strangers
Authors: Badescu Cristina G.
Published: March 2007

Abstract.In recent years, the question of authorization for the use of force for humanitarian purposes has become more contentious than ever. Participants on both sides of the debate, namely those rejecting any exception to the requirement for UN authorization and the proponents of surpassing this in cases of exceptional humanitarian emergencies, do not seem to have reached any consensus. This article examines these opposing arguments, their legal interpretations, and tests the theoretical assumptions against state practice through a review of the record of humanitarian interventions since the 1990s. The final purpose is to assess two of the most promising alternatives for authorization: the UN and regional organizations. This analysis suggests some implications of the debate for the perception of the UN role in authorizing interventions, in addition to determining the need for alternative mechanisms to authorize interventions for humanitarian purposes.

Résumé.Dans les dernières années, la question de l'autorisation du recours à la force dans des missions à but humanitaire est devenu un sujet particulièrement contesté de l'actualité. Les participants aux deux côtés du débat, ceux qui rejettent toute exception à l'autorisation préalable des Nations Unies et ceux qui proposent de court-circuiter l'ONU dans des situations humanitaires d'une urgence exceptionnelle seulement, ne semblent pas pourvoir atteindre de consensus. Cet article examime ces deux vues opposées et leurs interprétations juridiques et met leurs hypothèses théoriques à l'épreuve de la pratique en considérant les missions humanitaires entreprises depuis 1990. Le but ultime consiste à évaluer deux des alternatives d'autorisation les plus prometteuses : celle des Nations Unies et celle d'organisations régionales. Cette analyse suggère certaines implications du débat quant à la perception du rôle des Nations Unies dans le processus d'autorisation des interventions et révèle, d'autre part, le besoin de mécanismes nouveaux pour autoriser ces missions humanitaires.
Internal carotid artery aneurysm presenting as sinus pain
Authors: Al-Reefy H , Johnson C A , Balfour A , Dilkes M
Published: March 2007

Sinusitis and its associated facial pain are frequently seen by ENT surgeons. However, it is important to have a high index of suspicion in cases with atypical symptoms, particularly those with unexplained, unilateral, severe facial pain, and to consider an internal carotid artery dissection. This important diagnosis accounts for almost 20 per cent of all strokes in the young, and anti-coagulation can help to prevent thrombosis and embolism. Two cases are presented for illustration.
Product family design knowledge representation, aggregation, reuse, and analysis
Authors: NANDA JYOTIRMAYA , THEVENOT HENRI J. , SIMPSON TIMOTHY W. , STONE ROBERT B. , BOHM MATT , SHOOTER STEVEN B.
Published: March 2007

A flexible information model for systematic development and deployment of product families during all phases of the product realization process is crucial for product-oriented organizations. In current practice, information captured while designing products in a family is often incomplete, unstructured, and is mostly proprietary in nature, making it difficult to index, search, refine, reuse, distribute, browse, aggregate, and analyze knowledge across heterogeneous organizational information systems. To this end, we propose a flexible knowledge management framework to capture, reorganize, and convert both linguistic and parametric product family design information into a unified network, which is called a networked bill of material (NBOM) using formal concept analysis (FCA); encode the NBOM as a cyclic, labeled graph using the Web Ontology Language (OWL) that designers can use to explore, search, and aggregate design information across different phases of product design as well as across multiple products in a product family; and analyze the set of products in a product family based on both linguistic and parametric information. As part of the knowledge management framework, a PostgreSQL database schema has been formulated to serve as a central design repository of product design knowledge, capable of housing the instances of the NBOM. Ontologies encoding the NBOM are utilized as a metalayer in the database schema to connect the design artifacts as part of a graph structure. Representing product families by preconceived common ontologies shows promise in promoting component sharing, and assisting designers search, explore, and analyze linguistic and parametric product family design information. An example involving a family of seven one-time-use cameras with different functions that satisfy a variety of customer needs is presented to demonstrate the implementation of the proposed framework.
Stability of patterns with arbitrary period for a Ginzburg-Landau equation with a mean field
Authors: NORBURY J. , WEI J. , WINTER M.
Published: March 2007

We consider the following system of equations:where the spatial average ⟨B⟩ = 0 and μ > σ > 0. This system plays an important role as a Ginzburg-Landau equation with a mean field in several areas of the applied sciences and the steady-states of this system extend to periodic steady-states with periodLon the real line which are observed in experiments. Our approach is by combining methods of nonlinear functional analysis such as nonlocal eigenvalue problems and the variational characterization of eigenvalues with Jacobi elliptic integrals. This enables us to give a complete classification of all stable steady-states for any positiveL.
High-Quality Sample Preparation by Low kV FIB Thinning for
Analytical TEM Measurements
Authors: Bals Sara , Tirry Wim , Geurts Remco , Yang Zhiqing , Schryvers Dominique
Published: March 2007

Focused ion beam specimen preparation has been used for NiTi samples
and SrTiO3/SrRuO3 multilayers with prevention of
surface amorphization and Ga implantation by a 2-kV cleaning procedure.
Transmission electron microscopy techniques show that the samples are of
high quality with a controlled thickness over large scales. Furthermore,
preferential thinning effects in multicompounds are avoided, which is
important when analytical transmission electron microscopy measurements
need to be interpreted in a quantitative manner. The results are compared
to similar measurements acquired for samples obtained using conventional
preparation techniques such as electropolishing for alloys and ion milling
for oxides.
Friction of sheared granular layers: Role of particle dimensionality, surface roughness, and material properties
Authors: Knuth Matthew , Marone Chris
Published: March 2007

We report on laboratory experiments designed to investigate three fundamental deformation mechanisms for frictional shear of granular fault gouge: sliding, rolling, and dilation. Mechanisms were isolated by shearing layers composed of rods in geometric configurations that resulted in one‐dimensional, two‐dimensional, and rolling‐only particle interactions. Results of digital video are presented with measurements of friction and strain to illuminate the distribution of shear and the relationship between particle motions and friction. The double‐direct‐shear configuration was used with boundary conditions of constant layer normal stress (1 MPa) and controlled shear loading rate (10 μm/s) with initial layer thickness of 6 mm. Layers were sheared in a servo‐hydraulic testing machine at room temperature (22°C) and relative humidity (5 to 10%). Three materials were studied: alloy 260 brass, dried semolina pasta, and hardwood dowels, with particle diameters of 1.59 mm, 1.86 mm, and 2.06 mm, respectively. Pasta layers had mean sliding friction coefficients of 0.24, 0.11, and 0.02 in 2‐D, 1‐D, and rolling configurations, respectively. Layers of brass rods had average friction coefficients of 0.23, 0.15, and 0.01, respectively, in 2‐D, 1‐D, and rolling configurations; and the wood samples exhibited friction values of 0.18, 0.19, and 0.09, respectively. Evolution of strength during shear correlated strongly with the displacement derivative of layer thickness. SEM images document the role of surface finish on frictional properties. Rapid reorientations of particles correspond to stick‐slip stress drops and may be related to the collapse and reformation of granular force chains. We find a systematic relationship between the strength of granular layers and (1) the surface roughness of particles and (2) the number of particle contact dimensions. Our data provide important insights on the mechanics of granular fault gouge and constraints on the fundamental parameters used in numerical models of tectonic faulting.
Observations of streamer formation in sprites
Authors: McHarg Matthew G. , Stenbaek‐Nielsen Hans C. , Kammae Takeshi
Published: March 2007

Sprites have been recorded at 10,000 fps with 50 μs image exposure time. At this time resolution it is possible to resolve the temporal development of streamer tips. The recordings show that sprites start with a streamer head forming at an altitude near 80 km. The streamer head moves rapidly downwards while brightening, and ∼300 μs after streamer passage longer lasting emissions ensues. This is essentially the C‐sprite. In some events upward moving streamer heads are also observed, in which case we have a carrot‐sprite. The streamer speeds vary between 106 and 107 m/s. Both positive and negative accelerations, of magnitude 105 – 1010 m/s2, were observed. Upward streamers, when present, always start later and from a lower altitude than downward streamers, and they start from existing structure in the sprite.
Modelling vegetated dune landscapes
Authors: Baas A. C. W. , Nield J. M.
Published: March 2007

This letter presents a self‐organising cellular automaton model capable of simulating the evolution of vegetated dunes with multiple types of plant response in the environment. It can successfully replicate hairpin, or long‐walled, parabolic dunes with trailing ridges as well as nebkha dunes with distinctive deposition tails. Quantification of simulated landscapes with eco‐geomorphic state variables and subsequent cluster analysis and PCA yields a phase diagram of different types of coastal dunes developing from blow‐outs as a function of vegetation vitality. This diagram indicates the potential sensitivity of dormant dune fields to reactivation under declining vegetation vitality, e.g. due to climatic changes. Nebkha simulations with different grid resolutions demonstrate that the interaction between the (abiotic) geomorphic processes and the biological vegetation component (life) introduces a characteristic length scale on the resultant landforms that breaks the typical self‐similar scaling of (un‐vegetated) bare‐sand dunes.
Tectonic and climatic controls on rift escarpments: Erosion and flexural rebound of the Dhofar passive margin (Gulf of Aden, Oman)
Authors: Petit C. , Fournier M. , Gunnell Y.
Published: March 2007

We investigate the respective roles of climatic parameters and the flexural rigidity of the lithosphere in the erosion history and behavior of two adjacent rift escarpments along the northern coast of the Gulf of Aden, in Oman. At this 25 Myr old passive margin, we define a type 1 scarp, which is high, sharp‐crested and has retreated 25–30 km inland from its master fault, and a type 2 scarp, which exhibits a more rounded profile, lower relief, and still coincides with its mapped normal fault trace. Since about 15 Ma, the margin has been seasonally affected by monsoon precipitation but with contrasting effects at the type 1 and type 2 escarpments depending on the position of the Intertropical Convergence Zone in the geologic past: during peak monsoon conditions, both scarps experienced heavy rainfall and runoff, whereas during monsoon‐starved conditions (such as today), the type 2 scarp experienced a foggy, moist climate while the type 1 scarp remained much drier. In order to assess the relative effects of climate and flexural parameters on the present‐day morphology of the Dhofar margin, we present one‐dimensional numerical models of erosion and flexure along two profiles representative of the type 1 and type 2 scarps. Unlike most surface process models previously published, where present‐day topography is the only criterion by which to evaluate the quality of model outputs, model behavior here is additionally constrained by independent estimates of denudation provided by geological cross sections, well‐defined fault traces, and other stratigraphic markers. The best fitting models indicate that the type 1 escarpment formed under relatively arid climatic conditions and was affected by significant erosion, recession and flexural uplift due to a low (7 km) effective elastic thickness. In contrast, the morphology of the type 2 fault scarp was smoothed by a more humid climate, but a high effective elastic thickness (≥15 km) prevented it from uplifting or receding. In addition, we show that the sedimentary load acting at the foot of the escarpments exerts significant influence on their morphological evolution, though this parameter is often neglected in other scarp evolution models.
Infrared reflection spectra of Ba6−3xSm8+2xTi18O54 (x=0.5, 0.67, and 0.75) microwave dielectric ceramics
Authors: Qin N. , Fan X. C. , Wu S. Y. , Chen X. M.
Published: March 2007

Infrared reflection spectra of the tungsten bronze-type Ba6−3xSm8+2xTi18O54 (x=0.5, 0.67, and 0.75) ceramics were measured and analyzed by a combined method using Kramers-Kroning relation and the classical oscillator model, and the selection rules and vibration modes of the tungsten bronze-type structure were investigated by a detailed group theory analysis. Microwave dielectric properties were calculated using the dispersion parameters obtained by the classical oscillator model. The error in reflectance due to the random scattering on sample surfaces indicated obvious effect on the calculated dielectric constant, but only slightly influenced the calculated Qf, and therefore, the present analysis provided a reasonable means to predict the intrinsic microwave dielectric loss. The predicted intrinsic Qf values (>30000GHz) were much higher than the experimental ones (∼10000GHz), and this suggested the great potential of significant improvement of Qf value in Ba6−3xSm8+2xTi18O54 ceramics by controlling the extrinsic dielectric loss.
The crystal structure of two macrolide glycosyltransferases provides a blueprint for host cell antibiotic immunity
Authors: Bolam David N. , Roberts Shirley , Proctor Mark R. , Turkenburg Johan P. , Dodson Eleanor J. , Martinez-Fleites Carlos , Yang Min , Davis Benjamin G. , Davies Gideon J. , Gilbert Harry J.
Published: March 2007

Glycosylation of macrolide antibiotics confers host cell immunity from endogenous and exogenous agents. The
Streptomyces antibioticus
glycosyltransferases, OleI and OleD, glycosylate and inactivate oleandomycin and diverse macrolides including erythromycin, respectively. The structure of these enzyme–ligand complexes, in tandem with kinetic analysis of site-directed variants, provide insight into the interaction of macrolides with their synthetic apparatus. Erythromycin binds to OleD and the 23S RNA of its target ribosome in the same conformation and, although the antibiotic contains a large number of polar groups, its interaction with these macromolecules is primarily through hydrophobic contacts. Erythromycin and oleandomycin, when bound to OleD and OleI, respectively, adopt different conformations, reflecting a subtle effect on sugar positioning by virtue of a single change in the macrolide backbone. The data reported here provide structural insight into the mechanism of resistance to both endogenous and exogenous antibiotics, and will provide a platform for the future redesign of these catalysts for antibiotic remodelling.
Transversals for strongly almost disjoint families
Authors: Szeptycki Paul
Published: March 2007

For a family of sets

A
A

, and a set

X
X

,

X
X

is said to be a transversal of

A
A

if

X
⊆
⋃
A

X\subseteq \bigcup A

and

|

a
∩
X

|

=
1

|a\cap X|=1

for each

a
∈
A

a\in A

.

X
X

is said to be a Bernstein set for

A
A

if

∅
≠
a
∩
X
≠
a

\emptyset \not =a\cap X\not =a

for each

a
∈
A

a\in A

. Erdős and Hajnal first studied when an almost disjoint family admits a set such as a transversal or Bernstein set. In this note we introduce the following notion: a family of sets

A
A

is said to admit a

σ
\sigma

-transversal if

A
A

can be written as

A
=
⋃
{

A
n

:
n
∈
ω
}

A=\bigcup \{A_n:n\in \omega \}

such that each

A
n

A_n

admits a transversal. We study the question of when an almost disjoint family admits a

σ
\sigma

-transversal and related questions.
Form estimates for the 𝑝(𝑥)-Laplacean
Authors: Allegretto W.
Published: March 2007

We consider the problem of establishing conditions on

p
(
x
)

p(x)

that ensure that the form associated with the

p
(
x
)

p(x)

-Laplacean is positive bounded below. It was shown recently by Fan, Zhang and Zhao that—unlike the

p
=

p=

constant case—this is not possible if

p
p

has a strict extrema in the domain. They also considered the closely related problem of eigenvalue existence and estimates. Our main tool is the adaptation of a technique, employed by Protter for

p
=
2
,

p=2,

involving arbitrary vector fields. We also examine related results obtained by a variant of Picone Identity arguments. We directly consider problems in

Ω
⊂

R
n

\Omega \subset R^n

with

n
≥
1
,

n\ge 1,

and while we focus on Dirichlet boundary conditions we also indicate how our approach can be used in cases of mixed boundary conditions, of unbounded domains and of discontinuous

p
(
x
)
.

p(x).

Our basic criteria involve restrictions on

p
(
x
)

p(x)

and its gradient.
Burgers equation with random boundary conditions
Authors: Bakhtin Yuri
Published: March 2007

We prove an existence and uniqueness theorem for stationary solutions of the inviscid Burgers equation on a segment with random boundary conditions. We also prove exponential convergence to the stationary distribution.
Ideals defining Gorenstein rings are (almost) never products
Authors: Huneke Craig
Published: March 2007

This note proves that if

S
S

is an unramified regular local ring and

I
,
J

I,J

proper ideals of height at least two, then

S

/

I
J

S/IJ

is never Gorenstein.
An ideal separating extension of affine space
Authors: Pedersen Paul
Published: March 2007

In affine space the set of solutions to a system of polynomial equations does not uniquely determine the system. We extend affine space so that the solutions (in the extension) to a system of equations uniquely determines the system.
An analogue of the Descartes-Euler formula for infinite graphs and Higuchi’s conjecture
Authors: DeVos Matt , Mohar Bojan
Published: March 2007

Let

R

\mathcal {R}

be a connected 2-manifold without boundary obtained from a (possibly infinite) collection of polygons by identifying them along edges of equal length. Let

V
V

be the set of vertices, and for every

v
∈
V

v \in V

, let

κ
(
v
)

\kappa (v)

denote the (Gaussian) curvature of

v
v

:

2
π

2 \pi

minus the sum of incident polygon angles. Descartes showed that

∑

v
∈
V

κ
(
v
)
=
4
π

\sum _{v \in V} \kappa (v) = 4 \pi

whenever

R

\mathcal {R}

may be realized as the surface of a convex polytope in

R

3

\mathbb {R}^3

. More generally, if

R

\mathcal {R}

is made of finitely many polygons, Euler’s formula is equivalent to the equation

∑

v
∈
V

κ
(
v
)
=
2
π
χ
(

R

)

\sum _{v \in V} \kappa (v) = 2 \pi \chi (\mathcal {R})

where

χ
(

R

)

\chi (\mathcal {R})

is the Euler characteristic of

R

\mathcal {R}

. Our main theorem shows that whenever

∑

v
∈
V
:
κ
(
v
)
>
0

κ
(
v
)

\sum _{v \in V : \kappa (v) > 0} \kappa (v)

converges and there is a positive lower bound on the distance between any pair of vertices in

R

\mathcal {R}

, there exists a compact closed 2-manifold

S

\mathcal {S}

and an integer

t
t

so that

R

\mathcal {R}

is homeomorphic to

S

\mathcal {S}

minus

t
t

points, and further

∑

v
∈
V

κ
(
v
)
≤
2
π
χ
(

S

)
−
2
π
t

\sum _{v \in V} \kappa (v) \le 2 \pi \chi (\mathcal {S}) - 2 \pi t

. In the special case when every polygon is regular of side length one and

κ
(
v
)
>
0

\kappa (v) > 0

for every vertex

v
v

, we apply our main theorem to deduce that

R

\mathcal {R}

is made of finitely many polygons and is homeomorphic to either the 2-sphere or to the projective plane. Further, we show that unless

R

\mathcal {R}

is a prism, antiprism, or the projective planar analogue of one of these that

|

V

|

≤
3444

|V| \le 3444

. This resolves a recent conjecture of Higuchi.
Torsion freeness of symmetric powers of ideals
Authors: Tchernev Alexandre
Published: March 2007

Let

I
I

be an ideal in a Noetherian commutative ring

R
R

with unit, let

k
≥
2

k\ge 2

be an integer, and let

α
k

:
 

S
k

I
⟶

I
k

\alpha _k\! :\ S_k I\longrightarrow I^k

be the canonical surjective

R
R

-module homomorphism from the

k
k

th symmetric power of

I
I

to the

k
k

th power of

I
I

. When

p
d

R

I
≤
1

\mathrm {pd}_R I\le 1

or when

I
I

is a perfect Gorenstein ideal of grade

3
3

, we provide a necessary and sufficient condition for

α
k

\alpha _k

to be an isomorphism in terms of upper bounds for the minimal number of generators of the localisations of 

I
I

. When

I
=

m

I=\mathfrak {m}

is a maximal ideal of

R
R

we show that

α
k

\alpha _k

is an isomorphism if and only if

R

m

R_{\mathfrak {m}}

is a regular local ring. In all three cases for

I
I

our results yield that if

α
k

\alpha _k

is an isomorphism, then

α
t

\alpha _t

is also an isomorphism for each

1
≤
t
≤
k

1\le t\le k

.
The McMullen domain: Rings around the boundary
Authors: Devaney Robert , Marotta Sebastian
Published: March 2007

In this paper we show that there are infinitely many rings

S

k

,
k
≥
1

{\mathcal S}^k, k \geq 1

, around the McMullen domain in the parameter plane for the family of complex rational maps of the form

z
n

+
λ

/

z
n

z^n + \lambda /z^n

where

λ
∈

C

\lambda \in \mathbb {C}

and

n
≥
3

n \geq 3

. These rings converge to the boundary of the McMullen domain as

k
→
∞

k \rightarrow \infty

. The rings

S

k

{\mathcal S}^k

contain

(
n
−
2
)

n

k
−
1

+
1

(n-2)n^{k-1} + 1

parameter values that lie at the center of Sierpinski holes. That is, these parameters lie at the center of an open set in the parameter plane in which all of the corresponding maps have Julia sets that are Sierpinski curves. The rings also contain the same number of superstable parameter values, i.e., parameter values for which one of the critical points is periodic of period either

k
k

or

2
k

2k

.
Nonsmooth calculus
Authors: Heinonen Juha
Published: March 2007

We survey recent advances in analysis and geometry, where first order differential analysis has been extended beyond its classical smooth settings. Such studies have applications to geometric rigidity questions, but are also of intrinsic interest. The transition from smooth spaces to singular spaces where calculus is possible parallels the classical development from smooth functions to functions with weak or generalized derivatives. Moreover, there is a new way of looking at the classical geometric theory of Sobolev functions that is useful in more general contexts.
Real-time Monitoring of Propofol in Expired Air in Humans Undergoing Total Intravenous Anesthesia
Authors: Hornuss Cyrill , Praun Siegfried , Villinger Johannes , Dornauer Albert , Moehnle Patrick , Dolch Michael , Weninger Ernst , Chouker Alexander , Feil Christian , Briegel Josef , Thiel Manfred , Schelling Gustav
Published: March 2007

Background

The physicochemical properties of propofol could allow diffusion across the alveolocapillary membrane and a measurable degree of pulmonary propofol elimination. The authors tested this hypothesis and showed that propofol can be quantified in expiratory air and that propofol breath concentrations reflect blood concentrations. This could allow real-time monitoring of relative changes in the propofol concentration in arterial blood during total intravenous anesthesia.

Methods

The authors measured gas-phase propofol using a mass spectrometry system based on ion-molecule reactions coupled with quadrupole mass spectrometry which provides a highly sensitive method for on-line and off-line measurements of organic and inorganic compounds in gases. In a first sequence of experiments, the authors sampled blood from neurosurgery patients undergoing total intravenous anesthesia and performed propofol headspace determination above the blood sample using an auto-sampler connected to the mass spectrometry system. In a second set of experiments, the mass spectrometry system was connected directly to neurosurgery patients undergoing target-controlled infusion via a T piece inserted between the endotracheal tube and the Y connector of the anesthesia machine, and end-expiratory propofol concentrations were measured on-line.

Results

A close correlation between propofol whole blood concentration and propofol headspace was found (range of Pearson r, 0.846-0.957; P < 0.01; n = 6). End-expiratory propofol signals mirrored whole blood values with close intraindividual correlations between both parameters (range of Pearson r, 0.784-0.985; n = 11).

Conclusion

Ion-molecule reaction mass spectrometry may allow the continuous and noninvasive monitoring of expiratory propofol levels in patients undergoing general anesthesia.
Fascia Iliaca Compartment Blockade for Acute Pain Control in Hip Fracture Patients
Authors: Foss Nicolai B. , Kristensen Billy B. , Bundgaard Morten , Bak Mikkel , Heiring Christian , Virkelyst Christina , Hougaard Sine , Kehlet Henrik
Published: March 2007

Background

Hip fracture patients are in severe pain upon arrival at the emergency department. Pain treatment is traditionally based on systemic opioids. No study has examined the effect of fascia iliaca compartment blockade (FICB) in acute hip fracture pain management within a double-blind, randomized setup.

Methods

Forty-eight patients with suspected hip fracture were included immediately after arrival in the emergency department, before x-ray confirmation of their fracture. Included patients were randomly assigned to two groups of 24. In the FICB group, the patients received an FICB with 1.0% mepivacaine and a placebo intramuscular injection of isotonic saline. In the morphine group, the patients received a placebo FICB with 0.9% saline and an intramuscular injection of 0.1 mg/kg morphine. Patients received intravenous rescue morphine when necessary.

Results

Maximum pain relief was superior in the FICB group both at rest (P < 0.01) and on movement (P = 0.02). The median total morphine consumption was 0 mg (interquartile range, 0-0 mg) in the FICB group and 6 mg (interquartile range, 5-7 mg) in the morphine group (P < 0.01). More patients (P = 0.05) were sedated in the morphine group at 180 min after block placement as compared with the FICB group.

Conclusion

Pain relief was superior at all times and at all measurements in the FICB group. The study supports the use of FICB in acute management of hip fracture pain because it is an effective, easily learned procedure that also may reduce opioid side effects in this fragile, elderly group of patients.
Factor V Leiden Does Not Affect Bleeding in Aprotinin Recipients after Cardiopulmonary Bypass
Authors: Boehm Johannes , Grammer Joachim Burkhard , Lehnert Fabian , Dietrich Wulf , Wagenpfeil Stefan , Wildhirt Stephen Michael , Wottke Michael , Braun Siegmund , Lange Rüdiger , Bauernschmitt Robert
Published: March 2007

Background

Carriers of the factor V Leiden mutation (FVL) are resistant to activated protein C proteolysis. Therefore, they are at increased risk of thromboembolic events. Aprotinin is an unspecific proteinase inhibitor frequently used during cardiac surgery procedures to reduce bleeding. However, aprotinin may cause thromboembolic complications after cardiopulmonary bypass (CPB). The primary endpoint of this study was the amount of blood loss after CPB in aprotinin recipients, and secondary endpoints were thromboembolic complications.

Methods

A total of 1,447 consecutive patients who underwent cardiac surgery with CPB were prospectively enrolled. All patients were screened for FVL by a fluorescence-based polymerase chain reaction method. Linear and logistic regression analyses were performed to assess associations of FVL on bleeding and thromboembolic complications.

Results

One hundred seven individuals (7.4%) were heterozygous FVL carriers. No difference was found between FVL carriers and noncarriers regarding age, sex, CPB, type of operation, EuroSCORE, antiplatelet treatment, and reoperation. FVL was not significantly associated with postoperative blood loss, whereas a significant influence was found for female sex (P < 0.0001), duration of CPB (P < 0.0001), reoperation (P = 0.001), and preoperative antiplatelet treatment (P < 0.002). Multiple linear regression analysis for total blood loss had an observed power of at least 99%. FVL carriers faced the same risk for postoperative transfusion (P = 0.391), reoperation (P = 0.675), myocardial infarction (P = 0.44), stroke (P = 0.701), and 30-day mortality (P = 0.4) as did noncarriers.

Conclusions

These data suggest that FVL carriers do not have reduced blood loss compared with noncarriers. Furthermore, the combination of aprotinin and FVL does not enhance the risk for thromboembolic complications.
Behavior of Entropy/Complexity Measures of the Electroencephalogram during Propofol-induced Sedation
Authors: Ferenets Rain , Vanluchene Ann , Lipping Tarmo , Heyse Björn , Struys Michel M. R. F.
Published: March 2007

Background

Several new measures based on the regularity of the electroencephalogram signal for the assessment of depth of anesthesia/sedation have been proposed recently. In this study we analyze the influence of remifentanil and electroencephalogram frequency content of the performance of a set of such measures.

Methods

Forty-five patients with American Society of Anesthesiologists physical status I were randomly allocated to one of three groups according to the received dose of predicted effect compartment-controlled remifentanil (0, 2, and 4 ng/ml). All 45 patients received stepwise increased effect site concentration-controlled dose of propofol. At every step of propofol increase, the Observer's Assessment of Alertness/Sedation score was assessed. The following measures were calculated from the electroencephalographic signal: spectral entropy, approximate entropy, Higuchi fractal dimension, Lempel-Ziv complexity, relative beta ratio, and SyncFastSlow measure.

Results

The behavior of the electroencephalogram-based measures is highly sensitive to the frequency content of the signal and the dose of remifentanil. The prediction probability with respect to the Observer's Assessment of Alertness/Sedation score of the most discriminative measure, the Higuchi fractal dimension, dropped from 0.90 (electroencephalographic frequency band 6-47 Hz, no remifentanil) to 0.55 when the frequency band was changed to 0.5-19 Hz and to 0.83 when remifentanil concentration was increased to 4 ng/ml. The coeffect of remifentanil on electroencephalographic regularity is bimodal depending on the frequency band of the signal.

Conclusions

Cutting off high frequencies from the electroencephalogram and increased remifentanil concentration deteriorate the performance of the electroencephalogram-based entropy/complexity measures as indicators of the depth of propofol sedation.
A Prospective Assessment of Food and Nutrient Intake in a Population of Malawian Children at Risk for Kwashiorkor
Authors: Lin Carol A , Boslaugh Sarah , Ciliberto Heather M , Maleta Kenneth , Ashorn Per , Briend André , Manary Mark J
Published: March 2007

Objective:

To determine what foods, nutrients, and dietary patterns are associated with development of kwashiorkor in populations of vulnerable 1‐ to 3‐year‐old Malawian children.

Patients and Methods:

This was a prospective observational study conducted in 8 rural villages. Upon enrollment, demographic, anthropometric, and dietary intake data were collected. Children were studied every 2 weeks for 10 weeks to determine whether they developed kwashiorkor. Dietary intake was assessed on enrollment using a food frequency questionnaire, which included all possible foods in the child's diet. Food frequency data were used to estimate energy, protein, vitamins C and A, niacin, thiamin, zinc, and iron intake using food composition and serving size data. Dietary diversity was assessed with a 7‐point score. Regression modeling was used to determine whether the consumption of any food or nutrient was associated with the development of kwashiorkor.

Results:

A total of 43 (2.6%) of the 1651 healthy children ages 1 to 3 years enrolled developed kwashiorkor. Children who developed kwashiorkor were younger and had more nutritional wasting than those who did not. Thirty children (70%) who developed kwashiorkor were breast‐fed. In the combined regression model no foods or nutrients were found to be associated with the development of kwashiorkor. There were no differences in the dietary diversity between children who developed kwashiorkor and those who did not.

Conclusions:

No association between the development of kwashiorkor and the consumption of any food or nutrient was found.
Prospective Controlled Long‐term Follow‐up for Functional Outcome After Anoplasty in Boys With Perineal Fistula
Authors: Pakarinen Mikko P , Koivusalo Antti , Lindahl Harry , Rintala Risto J
Published: March 2007

Background:

Functional outcomes after treatment of low anorectal anomalies remain controversial. To address this, we conducted a controlled, prospective single‐center long‐term follow‐up study of functional outcome in boys treated for perineal fistula with anoplasty.

Patients and Methods:

Twenty‐four consecutive boys treated exclusively for perineal fistula from 1992 to 2001 underwent prospective follow‐up after completion of toilet training. All of the patients had identical surgical treatment. Functional outcome was assessed according to a previously validated bowel function score (7 questions, maximum score of 20). Daytime and nighttime wetting, as well as the age at toilet training, were also recorded. Thirty‐seven age‐matched boys served as healthy controls. An independent nurse specialist interviewed caregivers.

Results:

Age of the patients (9.1 ± 2.6 years) and controls (9.0 ± 2.9 years) were similar. Seven patients (32%) had bowel function scores below the 10th percentile (17.2) of the controls, which was chosen as a lower limit of normality. The overall mean bowel function score was significantly lower (P < 0.01) among the patients (17.9 ± 1.9) compared with the controls (19.1 ± 1.2). The difference was attributed mainly to significantly lower scores (0–3) among patients in questions assessing constipation (2.4 ± 0.8 vs 2.9 ± 0.3; P < 0.05) and soiling (2.5 ± 0.5 vs 2.8 ± 0.4; P = 0.05). Constipation and soiling were significantly more common (P < 0.05) among patients (41% and 55%, respectively) compared with controls (8% and 24%, respectively).

Conclusions:

Overall long‐term bowel function is impaired in one third of boys with perineal fistula. The main reasons for impaired functional outcome are constipation and soiling, which affect as many as half the patients.
Fecal Lactoferrin Is a Sensitive and Specific Marker of Disease Activity in Children and Young Adults With Inflammatory Bowel Disease
Authors: Walker Thomas R , Land Michelle L , Kartashov Alex , Saslowsky Tracee M , Lyerly David M , Boone James H , Rufo Paul A
Published: March 2007

Background and Aims:

Fecal lactoferrin (FLA) is a neutrophil‐derived surrogate marker of intestinal inflammation that is elevated in patients with inflammatory bowel disease. However, the correlation between FLA levels and serological markers of disease activity has not been previously reported, to our knowledge. In the present study we evaluated the ability of FLA levels to reflect disease activity in pediatric patients with inflammatory bowel disease. We further assessed the relationship between FLA levels and customary laboratory and clinical measures of inflammation.

Patients and Methods:

Fecal specimens were collected from 148 consecutive pediatric patients (79 with Crohn disease, 62 with ulcerative colitis, and 7 with irritable bowel syndrome) and 22 healthy control individuals. Lactoferrin was measured by enzyme‐linked immunosorbent assay (IBD‐SCAN, TECHLAB, Inc). Disease activity was assessed at the time of sample provision by laboratory measures (including erythrocyte sedimentation rate [ESR] and albumin) and previously validated disease activity indices (Pediatric Crohn Disease Activity Index, Kozarek, Harvey Bradshaw Activity Index).

Results:

Lactoferrin levels were significantly higher in patients with ulcerative colitis (1880 ± 565 μg/mL) (mean ± SE) or Crohn disease (1701 ± 382 μg/mL) than in healthy control individuals under 21 years of age (1.17 ± 0.47 μg/mL, P < 0.001). Lactoferrin levels correlated significantly with ESR, hematocrit, albumin, and platelet count (P < 0.001). Receiver operating characteristic curve analysis revealed that FLA levels were comparable to ESR in detecting patients with clinically active disease (P < 0.001). Patients who experienced a clinical flare within 2 months of specimen collection displayed higher lactoferrin levels (845 ± 452 μg/mL) than did those who remained in clinical remission (190 ± 90 μg/mL, P = 0.003).

Conclusions:

Data presented here demonstrate that FLA is a sensitive and specific biochemical marker of inflammation for use in the diagnosis and interval assessment of pediatric patients with IBD, and its level correlates well with both clinical disease activity indices and ESR. Elevated levels of FLA may also identify patients at greater risk for the development of subsequent clinical flares.
Dose requirements of ICI 35,868 (Propofol, ‘Diprivan’) in a new formulation for induction of anaesthesia
Authors: CUMMINGS G. C. , DIXON J. , KAY N. H. , WINDSOR J. P. W. , MAJOR E. , MORGAN M. , SEAR J. W. , SPENCE A. A. , STEPHENSON D. K.
Published: March 2007

In order to avoid Cremophor‐related reactions and reduce the incidence of pain on injection, di‐isopropylphenol (ICI 35,868; propofol) has been reformulated as an emulsion. One hundred and fifteen patients received an induction dose of propofol in the new formulation. The dose required to induce anaesthesia in 95% of healthy, unpremedicated patients was 2.5 mg/kg. Induction was associated with a degree of cardiovascular and respiratory depression. There were no adverse reactions although there were a number of minor side‐effects. The incidence of pain on injection was low (3%) and the overall quality of induction was assessed as good or adequate in 92% of patients.