bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation on GaAs surface treated with dimethylaluminumhydride
Authors: Lu Hong-Liang , Wang Xiao-Liang , Sugiyama Masakazu , Shimogaki Yukihiro
Published: November 2009

The reduction and removal of surface native oxides from as-degreased and HCl-treated GaAs substrates using dimethylaluminumhydride (DMAH) have been studied by x-ray photoelectron spectroscopy. It is revealed that higher oxide states are more easily removed from the GaAs surface after exposure to DMAH at 300 °C. Complete consumption of native oxides on HCl-treated GaAs surface has been realized with 10 s DMAH exposure. In addition, the metallization of the Al–O bonding with increase of DMAH exposure confirms the reduction of native oxides on GaAs.
Freedom of movement and the stability of its unfolding in free exploration of mice
Authors: Fonio Ehud , Benjamini Yoav , Golani Ilan
Published: November 2009

Exploration is a central component of human and animal behavior that has been studied in rodents for almost a century. The measures used by neuroscientists to characterize full-blown exploration are limited in exposing the dynamics of the exploratory process, leaving the morphogenesis of its structure and meaning hidden. By unfettering exploration from constraints imposed by hunger, thirst, coercion, and the confines of small cage and short session, using advanced computational tools, we reveal its meaning in the operational world of the mouse. Exploration consists of reiterated roundtrips of increasing amplitude and freedom, involving an increase in the number of independent dimensions along which the mouse moves (macro degrees of freedom). This measurable gradient can serve as a standard reference scale for the developmental dynamics of some aspects of the mouse's emotional-cognitive state and for the study of the interface between behavior and the neurophysiologic and genetic processes mediating it.
A kinetic and thermodynamic understanding of O
2
tolerance in [NiFe]-hydrogenases
Authors: Cracknell James A. , Wait Annemarie F. , Lenz Oliver , Friedrich Bärbel , Armstrong Fraser A.
Published: November 2009

In biology, rapid oxidation and evolution of H
2
is catalyzed by metalloenzymes known as hydrogenases. These enzymes have unusual active sites, consisting of iron complexed by carbonyl, cyanide, and thiolate ligands, often together with nickel, and are typically inhibited or irreversibly damaged by O
2
. The Knallgas bacterium
Ralstonia eutropha
H16 (
Re
) uses H
2
as an energy source with O
2
as a terminal electron acceptor, and its membrane-bound uptake [NiFe]-hydrogenase (MBH) is an important example of an “O
2
-tolerant” hydrogenase. The mechanism of O
2
tolerance of
Re
MBH has been probed by measuring H
2
oxidation activity in the presence of O
2
over a range of potential, pH and temperature, and comparing with the same dependencies for individual processes involved in the attack by O
2
and subsequent reactivation of the active site. Most significantly, O
2
tolerance increases with increasing temperature and decreasing potentials. These trends correlate with the trends observed for reactivation kinetics but not for H
2
affinity or the kinetics of O
2
attack. Clearly, the rate of recovery is a crucial factor. We present a kinetic and thermodynamic model to account for O
2
tolerance in
Re
MBH that may be more widely applied to other [NiFe]-hydrogenases.
Competition between collective and individual dynamics
Authors: Grauwin Sébastian , Bertin Eric , Lemoy Rémi , Jensen Pablo
Published: November 2009

Linking microscopic and macroscopic behavior is at the heart of many natural and social sciences. This apparent similarity conceals essential differences across disciplines: Although physical particles are assumed to optimize the global energy, economic agents maximize their own utility. Here, we solve exactly a Schelling-like segregation model, which interpolates continuously between cooperative and individual dynamics. We show that increasing the degree of cooperativity induces a qualitative transition from a segregated phase of low utility toward a mixed phase of high utility. By introducing a simple function that links the individual and global levels, we pave the way to a rigorous approach of a wide class of systems, where dynamics are governed by individual strategies.
Self-assembled artificial cilia
Authors: Vilfan Mojca , Potočnik Anton , Kavčič Blaž , Osterman Natan , Poberaj Igor , Vilfan Andrej , Babič Dušan
Published: November 2009

Due to their small dimensions, microfluidic devices operate in the low Reynolds number regime. In this case, the hydrodynamics is governed by the viscosity rather than inertia and special elements have to be introduced into the system for mixing and pumping of fluids. Here we report on the realization of an effective pumping device that mimics a ciliated surface and imitates its motion to generate fluid flow. The artificial biomimetic cilia are constructed as long chains of spherical superparamagnetic particles, which self-assemble in an external magnetic field. Magnetic field is also used to actuate the cilia in a simple nonreciprocal manner, resulting in a fluid flow. We prove the concept by measuring the velocity of a cilia-pumped fluid as a function of height above the ciliated surface and investigate the influence of the beating asymmetry on the pumping performance. A numerical simulation was carried out that successfully reproduced the experimentally obtained data.
Identification of a single peridinin sensing Chl-
a
excitation in reconstituted PCP by crystallography and spectroscopy
Authors: Schulte Tim , Niedzwiedzki Dariusz M. , Birge Robert R. , Hiller Roger G. , Polívka Tomáš , Hofmann Eckhard , Frank Harry A.
Published: November 2009

The peridinin-chlorophyll
a
-protein (PCP) of dinoflagellates is unique among the large variety of natural photosynthetic light-harvesting systems. In contrast to other chlorophyll protein complexes, the soluble PCP is located in the thylakoid lumen, and the carotenoid pigments outnumber the chlorophylls. The structure of the PCP complex consists of two symmetric domains, each with a central chlorophyll
a
(Chl-
a
) surrounded by four peridinin molecules. The protein provides distinctive surroundings for the pigment molecules, and in PCP, the specific environment around each peridinin results in overlapping spectral line shapes, suggestive of different functions within the protein. One particular Per, Per-614, is hypothesized to show the strongest electronic interaction with the central Chl-
a
. We have performed an in vitro reconstitution of pigments into recombinant PCP apo-protein (RFPCP) and into a mutated protein with an altered environment near Per-614. Steady-state and transient optical spectroscopic experiments comparing the RFPCP complex with the reconstituted mutant protein identify specific amino acid-induced spectral shifts. The spectroscopic assignments are reinforced by a determination of the structures of both RFPCP and the mutant by x-ray crystallography to a resolution better than 1.5 Å. RFPCP and mutated RFPCP are unique in representing crystal structures of in vitro reconstituted light-harvesting pigment-protein complexes.
A nonprotein thermal hysteresis-producing xylomannan antifreeze in the freeze-tolerant Alaskan beetle
Upis ceramboides
Authors: Walters Kent R. , Serianni Anthony S. , Sformo Todd , Barnes Brian M. , Duman John G.
Published: November 2009

Thermal hysteresis (TH), a difference between the melting and freezing points of a solution that is indicative of the presence of large-molecular-mass antifreezes (e.g., antifreeze proteins), has been described in animals, plants, bacteria, and fungi. Although all previously described TH-producing biomolecules are proteins, most thermal hysteresis factors (THFs) have not yet been structurally characterized, and none have been characterized from a freeze-tolerant animal. We isolated a highly active THF from the freeze-tolerant beetle,
Upis ceramboides
, by means of ice affinity. Amino acid chromatographic analysis, polyacrylamide gel electrophoresis, UV-Vis spectrophotometry, and NMR spectroscopy indicated that the THF contained little or no protein, yet it produced 3.7 ± 0.3 °C of TH at 5 mg/ml, comparable to that of the most active insect antifreeze proteins. Compositional and structural analyses indicated that this antifreeze contains a β-mannopyranosyl-(1→4) β-xylopyranose backbone and a fatty acid component, although the lipid may not be covalently linked to the saccharide. Consistent with the proposed structure, treatment with
endo
-β-(1→4)xylanase ablated TH activity. This xylomannan is the first TH-producing antifreeze isolated from a freeze-tolerant animal and the first in a new class of highly active THFs that contain little or no protein.
Photochemical deposition of cobalt-based oxygen evolving catalyst on a semiconductor photoanode for solar oxygen production
Authors: Steinmiller Ellen M. P. , Choi Kyoung-Shin
Published: November 2009

This study describes the photochemical deposition of Co-based oxygen evolution catalysts on a semiconductor photoanode for use in solar oxygen evolution. In the photodeposition process, electron-hole pairs are generated in a semiconductor upon illumination and the photogenerated holes are used to oxidize Co
2+
ions to Co
3+
ions, resulting in the precipitation of Co
3+
-based catalysts on the semiconductor surface. Both photodeposition of the catalyst and solar O
2
evolution are photo-oxidation reactions using the photogenerated holes. Therefore, photodeposition provides an efficient way to couple oxygen evolution catalysts with photoanodes by naturally placing catalysts at the locations where the holes are most readily available for solar O
2
evolution. In this study Co-based catalysts were photochemically deposited as 10–30 nm nanoparticles on the ZnO surface. The comparison of the photocurrent-voltage characteristics of the ZnO electrodes with and without the presence of the Co-based catalyst demonstrated that the catalyst generally enhanced the anodic photocurrent of the ZnO electrode with its effect more pronounced when the band bending is less significant. The presence of Co-based catalyst on the ZnO photoanode also shifted the onset potential of the photocurrent by 0.23 V to the negative direction, closer to the flat band potential. These results demonstrated that the cobalt-based catalyst can efficiently use the photogenerated holes in ZnO to enhance solar O
2
evolution. The photodeposition method described in this study can be used as a general route to deposit the Co-based catalysts on any semiconductor electrode with a valence band edge located at a more positive potential than the oxidation potential of Co
2+
ions.
Serializing languages as satellite-framed
Authors: Lambert-Brétière Renée
Published: November 2009

Languages expressing motion events through serial verb constructions are categorized in various ways according to the typology of motion events. This paper challenges the typological classification of serializing languages by proposing that a serializing language like Fon is better analyzed as a satellite-framed language, lexicalizing the core-schema of motion — Path — in a verb satellite, than as verb-framed or equipollently-framed. Semantic and syntactic arguments are presented and lead to a new definition of verbal satellite in functional terms. It is further demonstrated that there is no need for a special treatment of serializing languages like Fon when conceiving the typology of motion events as a bipolar typological continuum, with at one end the verb-framing pattern and at the other end, the satellite-framing pattern.
English posture verbs
Authors: Newman John
Published: November 2009

This paper considers a number of linguistic properties of English SIT, STAND, and LIE which are argued to be the cardinal posture verbs of English. The distinctiveness of just these three posture verbs is evidenced by their relatively high frequency within the class of posture verbs in English and matched by grammaticalization facts in other languages. The paper considers the difficulty of differentiating action and state senses of these verbs and explores the use of posture verbs with inanimate subjects. It is argued that human experiential realities of posture motivate a number of these facts.
Infoconnectivity: The value of certainty and uncertainty for interconnected transport networks
Authors: Knoflacher Hermann
Published: November 2009

Human behavior regarding transport depends on travel time estimation and not on measured travel times. Travel time is dependent on human body energy consumption for diff erent activities, which has been studied by the author over the last 30 years. Uncertainty can enhance time perception up to a factor of 5 compared to measured time, dependent on the certainty or uncertainty of the information system. Quantitative analysis has shown that information improvements at interchanges of transport systems can have a value equal to or even greater than time saving produced by expensive, huge infrastructure projects. The paper will present empirical results from studies over the last 40 years and the theoretical background.
Angiotensin II impairs endothelial function via tyrosine phosphorylation of the endothelial nitric oxide synthase
Authors: Loot Annemarieke E. , Schreiber Judith G. , Fisslthaler Beate , Fleming Ingrid
Published: November 2009

Proline-rich tyrosine kinase 2 (PYK2) can be activated by angiotensin II (Ang II) and reactive oxygen species. We report that in endothelial cells, Ang II enhances the tyrosine phosphorylation of endothelial NO synthase (eNOS) in an AT1-, H2O2-, and PYK2-dependent manner. Low concentrations (1–100 µmol/liter) of H2O2 stimulated the phosphorylation of eNOS Tyr657 without affecting that of Ser1177, and attenuated basal and agonist-induced NO production. In isolated mouse aortae, 30 µmol/liter H2O2 induced phosphorylation of eNOS on Tyr657 and impaired acetylcholine-induced relaxation. Endothelial overexpression of a dominant-negative PYK2 mutant protected against H2O2-induced endothelial dysfunction. Correspondingly, carotid arteries from eNOS−/− mice overexpressing the nonphosphorylatable eNOS Y657F mutant were also protected against H2O2. In vivo, 3 wk of treatment with Ang II considerably increased levels of Tyr657-phosphorylated eNOS in the aortae of wild-type but not Nox2y/− mice, and this was again associated with a clear impairment in endothelium-dependent vasodilatation in the wild-type but not in the Nox2y/− mice. Collectively, endothelial PYK2 activation by Ang II and H2O2 causes the phosphorylation of eNOS on Tyr657, attenuating NO production and endothelium-dependent vasodilatation. This mechanism may contribute to the endothelial dysfunction observed in cardiovascular diseases associated with increased activity of the renin–angiotensin system and elevated redox stress.
Germinal center reutilization by newly activated B cells
Authors: Schwickert Tanja A. , Alabyev Boris , Manser Tim , Nussenzweig Michel C.
Published: November 2009

Germinal centers (GCs) are specialized structures in which B lymphocytes undergo clonal expansion, class switch recombination, somatic hypermutation, and affinity maturation. Although these structures were previously thought to contain a limited number of isolated B cell clones, recent in vivo imaging studies revealed that they are in fact dynamic and appear to be open to their environment. We demonstrate that B cells can colonize heterologous GCs. Invasion of primary GCs after subsequent immunization is most efficient when T cell help is shared by the two immune responses; however, it also occurs when the immune responses are entirely unrelated. We conclude that GCs are dynamic anatomical structures that can be reutilized by newly activated B cells during immune responses.
Clostridium difficile Infections in Outpatient Dialysis Cohort
Authors: Sheth Heena , Bernardini Judith , Burr Renee , Lee Sophie , Miller Rachel G. , Shields Michele , Vergis Emanuel N. , Piraino Beth
Published: November 2009

We examined the Clostridium difficile infection rate and risk factors in an outpatient dialysis cohort. The Cox proportional hazard for developing C. difficile infection was significantly higher with high comorbidity index and low serum albumin level. Conversely, it was lower for patients who had frequent bloodstream and dialysis access-related infections.
Risk Factors Associated with Methicillin Resistance amongStaphylococcus aureusInfections in Veterans
Authors: McCarthy Natalie L. , Sullivan Patrick S. , Gaynes Robert , Rimland David
Published: November 2009

Background.

Methicillin-resistantStaphylococcus aureus(MRSA) is an emerging concern in infectious disease practice. Although MRSA infections occur in a wide variety of anatomic sites, the majority of studies considering the risk factors for methicillin resistance amongS. aureusinfections have focused on MRSA bacteremia.

Objective.

To describe risk factors associated with methicillin resistance amongS. aureusinfections at different anatomic sites.

Methods.

We collected information on the demographic and clinical characteristics of patients examined at the Atlanta Veterans Affairs Medical Center withS. aureusinfections during the period from June 2007 through May 2008. We used multivariate logistic regression to describe factors significantly associated with methicillin resistance.

Results.

There were 568 cases ofS. aureusinfection among 528 patients. We identified 352 cases (62%) of MRSA infection and 216 cases (38%) of methicillin-sensitiveS. aureusinfection. The adjusted odds of methicillin resistance were higher among infections that occurred among patients who had a prior history of MRSA infection (odds ratio [OR], 3.9 [95% confidence interval {CI}, 2.3–6.4]) or resided in a long-term care facility during the past 12 months (OR, 2.0 [95% CI, 1.0-4.0]) but were lower for infections that occurred among patients who had undergone a biopsy procedure during the past 12 months (OR, 0.7 [95% CI, 0.6-0.9]). Most cases of infection were community-onset infections (523 [92%] of 568 cases), and about one-half (278 [49%]) were not healthcare associated.

Conclusions.

Compared with previous studies of methicillin resistance among patients withS. aureusbacteremia, we found similar factors to be associated with methicillin resistance amongS. aureusisolates recovered from more diverse anatomic sites of infection. Of note, nearly one-half of our cases of MRSA infection were not healthcare associated.
Mortality Associated with Acinetobacter baumannii Complex Bacteremia among Patients with War-Related Trauma
Authors: Kang Grace , Hartzell Joshua D. , Howard Robin , Wood-Morris Robert N. , Johnson Mark D. , Fraser Susan , Weintrob Amy , Wortmann Glenn
Published: November 2009

We investigated the mortality associated with Adnetobacter baumannii complex bacteremia among a cohort of patients hospitalized for war-related trauma. Despite a high prevalence of multidrug-resistant strains, the 30-day mortality rate was 2%. For relatively young patients with war-related trauma, A. baumannii complex bacteremia appears to be associated with a low risk of death.
Reversibility of a simple random walk on periodic trees
Authors: Altok Serdar
Published: November 2009

We show that if

μ
\mu

is a reversible measure for simple random walk on rooted trees whose branches are covers of finite connected directed graphs, then

μ
\mu

is supported on rooted covers of finite connected undirected graphs. For a given finite connected directed graph

G
G

and a cover

T
T

of

G
G

, we give an algorithm to determine whether there exists a finite connected undirected graph whose cover has a branch isomorphic to

T
T

.
On the global attractivity of monotone random dynamical systems
Authors: Cao Feng , Jiang Jifa
Published: November 2009

Suppose that

(
θ
,
φ
)

(\theta ,\varphi )

is a monotone (order-preserving) random dynamical system (RDS for short) with state space

V
V

, where

V
V

is a real separable Banach space with a normal solid minihedral cone

V

+

V_{+}

. It is proved that the unique equilibrium of

(
θ
,
φ
)

(\theta ,\varphi )

is globally attractive if every pull-back trajectory has compact closure in

V
V

.
Further improvements of lower bounds for the least common multiples of arithmetic progressions
Authors: Hong Shaofang , Kominers Scott
Published: November 2009

For relatively prime positive integers

u
0

u_0

and

r
r

, we consider the arithmetic progression

{

u
k

:=

u
0

+
k
r

}

k
=
0

n

\{u_k:=u_0+kr\}_{k=0}^n

.

Define

L
n

:=
lcm
⁡
{

u
0

,

u
1

,
.
.
.
,

u
n

}

L_n:=\operatorname {lcm}\{u_0, u_1, ..., u_n\}

and let

a
≥
2

a\ge 2

be any integer. In this paper, we show that for integers

α
,
r
≥
a

\alpha , r\geq a

and

n
≥
2
α
r

n\geq 2\alpha r

, we have
\[

L
n

≥

u
0

r

α
+
a
−
2

(
r
+
1

)
n

.

L_n\geq u_0r^{\alpha +a-2}(r+1)^n.

\]
In particular, letting

a
=
2

a=2

yields an improvement to the best previous lower bound on

L
n

L_n

(obtained by Hong and Yang) for all but three choices of

α
,
r
≥
2

\alpha , r\geq 2

.
A two-parameter family of complex Hadamard matrices of order 6 induced by hypocycloids
Authors: Szöllősi Ferenc
Published: November 2009

We construct a

2
2

-parameter family of complex Hadamard matrices of order

6
6

by a natural block construction. We combine this family with an earlier result of Zauner to derive a

2
2

-parameter family of triplets of mutually unbiased bases (MUBs) in

C

6

\mathbb C^6

. This invalidates some numerical evidence given by Brierley and Weigert and sheds new light on the problem of determining the maximal number of MUBs in

C

6

\mathbb C^6

.
Fibrations and fundamental groups of Kähler–Weyl manifolds
Authors: Kokarev G. , Kotschick D.
Published: November 2009

We extend the Siu–Beauville theorem to a certain class of compact Kähler–Weyl manifolds, proving that they fiber holomorphically over hyperbolic Riemannian surfaces whenever they satisfy the necessary topological hypotheses. As applications we obtain restrictions on the fundamental groups of such Kähler–Weyl manifolds, and we show that in certain cases they are in fact Kähler.
The span for Hausdorff continua
Authors: Peláez Antonio
Published: November 2009

The author previously defined the surjective semispan for Hausdorff continua and he proved that chainable continua have empty surjective semispan. In this paper, we define the semispan, the surjective span and the span of a Hausdorff continuum. We characterize the emptiness of these notions in terms of universal mappings to prove that a continuum has empty span (semispan) if and only if each of its subcontinua has empty surjective span (semispan). We also prove that the emptiness of these notions is invariant under inverse limits.
On bimodules over Noetherian PI rings
Authors: Braun Amiram
Published: November 2009

Let

R
R

be a prime Noetherian PI ring, and let

I
I

be an ideal in

R
R

satisfying

x
I
⊆
I
x

xI \subseteq Ix

for some

x
x

in

R
R

. We prove that

x
I
=
I
x

xI=Ix

. This is obtained as a corollary of a similar more general result, where

I
I

can be taken as any finitely generated torsion-free central

R
R

-bimodule.
Rates of convergence for the iterates of Cesàro operators
Authors: Adell José , Lekuona A.
Published: November 2009

We obtain sharp rates of convergence in the usual sup-norm for thennth iteratesDnfD^nfandCnfC^nfof continuous and discrete Cesàro operators, respectively. In both cases the best possible rate of convergence isn−1/2n^{-1/2}, and such a rate is attained under appropriate integrability conditions onff. Otherwise, the rates of convergence could be extremely poor, depending on the behavior offfnear the boundary. We introduce probabilistic representations ofDnfD^nfandCnfC^nfinvolving standardized sums of independent identically distributed random variables and binomial mixtures, respectively, which allow us to use the classical Berry-Esseen theorem.
On generic rotationless diffeomorphisms of the annulus
Authors: Addas-Zanata Salvador , Tal Fábio
Published: November 2009

Let

f
f

be a

C
r

C^r

-diffeomorphism of the closed annulus

A
A

that preserves the orientation, the boundary components and the Lebesgue measure. Suppose that

f
f

has a lift

f
~

\tilde f

to the infinite strip

A
~

\tilde A

which has zero Lebesgue measure rotation number. If the rotation number of

f
~

\tilde f

restricted to both boundary components of

A
A

is positive, then for such a generic

f
f

(

r
≥
16

r\geq 16

), zero is an interior point of its rotation set. This is a partial solution to a conjecture of P. Boyland.
On the periodic “good” Boussinesq equation
Authors: Farah Luiz , Scialom Márcia
Published: November 2009

We study the well-posedness of the initial-value problem for the periodic nonlinear “good” Boussinesq equation. We prove that this equation is locally well posed for initial data in Sobolev spaces

H
s

(

T

)

H^s(\mathbb {T})

for

s
>
−
1

/

4

s>-1/4

, the same range of the real case obtained by Farah (Comm. Partial Differential Equations 34 (2009), 52–73).
Shadowing, entropy and a homeomorphism of the pseudoarc
Authors: Kościelniak Piotr , Oprocha Piotr
Published: November 2009

In this article we provide a method of constructing continuous maps

f
:
[
0
,
1
]
→
[
0
,
1
]

f\colon [0,1]\rightarrow [0,1]

such that

f
f

is topologically mixing, has the shadowing property, and the inverse limit of copies of

[
0
,
1
]

[0,1]

with

f
f

as the bonding map is the pseudoarc. Such a map can be obtained as an arbitrarily small

C

0

\mathcal {C}^0

-perturbation of any topologically exact map on

[
0
,
1
]

[0,1]

. We have therefore answered, in the affirmative, a question posed by Chen and Li in 1993.
Global stability of a class of non-autonomous delay differential systems
Authors: Liu Bingwen
Published: November 2009

This paper is concerned with a class of systems of non-autonomous delay differential equations which are defined on the non-negative function space. Under proper conditions, we employ a novel proof to establish several criteria of the global stability of a positive equilibrium. Moreover, we give two examples to illustrate our main results.
The cardinality of some symmetric differences
Authors: Huang Po-Yi , Ke Wen-Fong , Pilz Günter
Published: November 2009

In this paper, we prove that for positive integers

k
k

and

n
n

, the cardinality of the symmetric differences of

{
1
,
2
,
…
,
k
}

\{1,2,\dots ,k\}

,

{
2
,
4
,
…
,
2
k
}

\{2,4,\dots ,2k\}

,

{
3
,
6
,
…
,
3
k
}

\{3,6,\dots ,3k\}

, …,

{
n
,
2
n
,
…
,
k
n
}

\{n,2n,\dots ,kn\}

is at least

k
k

or

n
,

n,

whichever is larger. This solved a problem raised by Pilz in which binary composition codes were studied.
On convex to pseudoconvex mappings
Authors: Ivashkovich S.
Published: November 2009

In the works of Darboux and Walsh, it was remarked that a one-to-one self-mapping of

R

3

\mathbb {R}^{3}

which sends convex sets to convex ones is affine. It can be remarked also that a

C

2

\mathcal {C}^{2}

-diffeomorphism

F
:
U
→

U

′

F:U\to U^{’}

between two domains in

C

n

\mathbb {C}^{n}

,

n
≥
2

n\ge 2

, which sends pseudoconvex hypersurfaces to pseudoconvex ones is either holomorphic or antiholomorphic.

In this paper we are interested in the self-mappings of

C

n

\mathbb {C}^{n}

which send convex hypersurfaces to pseudoconvex ones. Their characterization is the following: A

C

2

\mathcal {C}^{2}

-diffeomorphism

F
:

U
′

→
U

F:U’\to U

(where

U
′

,
U
⊂

C

n

U’, U\subset \mathbb {C}^{n}

are domains) sends convex hypersurfaces to pseudoconvex ones if and only if the inverse map

Φ
:=

F

−
1

\Phi := F^{-1}

is weakly pluriharmonic, i.e., if it satisfies some nice second order PDE very close to

∂

∂
¯

Φ
=
0

\partial \bar {\partial }\Phi = 0

. In fact all pluriharmonic

Φ
\Phi

’s do satisfy this equation, but there are also other solutions.
How Informed is “Informed Consent” for Robotic Cardiothoracic Surgery?
Authors: Ryan Sean , Chirumamilla Vasu , Bello Ricardo A. , D'Alessandro David A. , Michler Robert E. , Rabin Jonathan , Ashton Robert C. , DeRose Joseph J.
Published: November 2009

Objective

The education of patients in the informed consent process remains a challenge for many surgeons. In cardiothoracic surgery, emerging minimally invasive techniques including robotics add another level of complexity to the patient education process. We sought to evaluate our patients’ perceptions and informed knowledge after robotic-assisted cardiothoracic surgery.

Methods

A survey containing questions designed to elicit patients’ perceptions about robotic cardiothoracic surgery was given postoperatively by telephone 1 month to 12 months after surgery. The survey included questions about the type of procedure, function of the organ operated on, purpose of the operation, primary “surgeon” (robot vs. human), patients’ opinion about robotic-assisted surgery, educational level, and socioeconomic background. Continuous variables are reported as mean ± SD. Continuous and categorical variables were compared using the Student t test and Pearson χ2 test, respectively. Ordinal variables were compared using the Mann-Whitney U test. P values of <0.05 were considered significant.

Results

Between 2002 and 2007, 198 patients underwent robotic cardiothoracic surgery. One hundred fifty patients (76%) were contacted and 89 (45%) fully completed the survey. Of the respondents, there were 31 coronary artery bypasses, 33 pacemaker lead implantations, esophageal resections, 8 thymectomies, and 9 others. The mean age of the patients was 61.1 ± 15 years (range, 23–87) and there were 52 men (58.4%). A total of 96.6% of patients were satisfied with the information provided by the surgeon and 92.1% felt that they understood the information. The diagnosis, target organ, and procedure were correctly identified by 81 (91.0%), 83 (93.3%), and 76 (85.4%) of the patients, respectively. A total of 80 (89.9%) knew a robot was involved and 73.8% understood the role of the robot in the surgery. These results were independent of age, income, and education level achieved.

Conclusions

Overall, patients demonstrated an understanding of the role of the robot in their cardiothoracic surgery. Despite the increasing complexity of robotics, preoperative patient education can result in patients who are both satisfied and well educated about their cardiothoracic surgery procedures.
Butterfly-Needle Video-Assisted Thoracoscopic Segmentectomy
Authors: Kamiyoshihara Mitsuhiro , Kakegawa Seiichi , Ibe Takashi , Takeyoshi Izumi
Published: November 2009

Objective

A pulmonary segmentectomy is requires the identification of the segmental planes, making it technically more difficult than a lobectomy. Therefore, we present a new method that uses a butterfly needle to distinguish the intersegmental plane under video-assisted thoracoscopic surgery (VATS).

Methods

From May 2005 to August 2008, 15 patients underwent anatomic segmentectomy using VATS. In this approach, a working port 4 to 7 cm in length was made in the fifth intercostal space. Additional 1.2-cm thoracic ports were made in the seventh intercostal space on the anterior axillary line and the ninth intercostal space on the posterior axillary line. Each segment was selectively isolated, and the targeted bronchovascular pedicle was divided. For the segmentectomy, the lung was deflated, and the pulmonary artery and vein to the involved segment were divided. The segmental bronchus was divided using a stapling device. Using a butterfly needle, oxygen/air (1–2 L) was used to inflate the involved segment, and the involved segment was severed and removed using electrocautery or a stapling device. The raw surface was covered with an absorbable sealing material such as polyglycolic acid to prevent air leaks.

Results

Using this method, apical segment of the right upper lobe (S1), apical posterior segment of the left upper lobe (S1 + 2), upper division, and posterior segment of the right upper lobe (S2), superior segment of the right or left lower lobe (S6), and basal segmentectomies could be performed with VATS. However, the technique did not work in one patient with severe emphysematous changes, because the plane was not readily identifiable.

Conclusions

Butterfly-needle video-assisted segmentectomy is a useful technique. Selective segmental inflation allows the intersegmental plane to be identified completely under the surgeon's control, eliminating the need for an anesthesiologist to pass a bronchoscope or insufflate the lung in a particular manner.
Clinical Results of Minimally Invasive Mitral Valve Surgery
Authors: Ius Fabio , Mazzaro Enzo , Tursi Vincenzo , Guzzi Giorgio , Spagna Enrico , Vetrugno Luigi , Bassi Flavio , Livi Ugolino
Published: November 2009

Objective

This study was carried out with the aim of presenting our experience with minimally invasive mitral surgery and compare the endoaortic clamp with the external aortic clamp (EAC) techniques.

Methods

Between December 2002 and May 2009, 139 patients (75 men, aged 63 ± 11 years) underwent video-assisted mitral valve surgery through right thoracotomy. Twelve (9%) patients were operated without clamping the aorta, 32 (23%) patients (group A) were operated on by using the endoaortic clamp, and 95 (68%) patients were operated on by using the EAC (group B). There was no significant difference between groups A and B regarding preoperative variables.

Results

Intraoperative procedure-associated problems were experienced in three group A patients (9.3%, two aortic dissections with conversion to sternotomy; one conversion due to bad exposure) and in two group B patients (2%, one conversion to sternotomy for bleeding and one for ascending aorta hematoma). At a mean follow-up of 32 months, 121 patients (97%) were in New York Heart Association class I–II, with satisfactory echocardiographic results. There was one in-hospital and six late deaths (three noncardiac, two cardiac, and one valve related). Five-year actuarial survival was 88% ± 8%. There were three reoperations, one early (<30 days) after complex mitral valve repair, with a 5-year freedom from reoperation of 97% ± 2%. Postoperative levels of myocardial cytonecrosis enzymes as well as the extracorporeal circulation time were significantly lower in group B patients (P < 0.05).

Conclusions

Intraoperative procedure-associated complications with endoclamping combined with an apparently better myocardial protection forced us to change our practice to the more simple and economic EAC technique.
Evolution: like any other science it is predictable
Authors: Conway Morris Simon
Published: November 2009

Evolutionary biology rejoices in the diversity of life, but this comes at a cost: other than working in the common framework of neo-Darwinian evolution, specialists in, for example, diatoms and mammals have little to say to each other. Accordingly, their research tends to track the particularities and peculiarities of a given group and seldom enquires whether there are any wider or deeper sets of explanations. Here, I present evidence in support of the heterodox idea that evolution might look to a general theory that does more than serve as a tautology (‘evolution explains evolution’). Specifically, I argue that far from its myriad of products being fortuitous and accidental, evolution is remarkably predictable. Thus, I urge a move away from the continuing obsession with Darwinian mechanisms, which are entirely uncontroversial. Rather, I emphasize why we should seek explanations for ubiquitous evolutionary convergence, as well as the emergence of complex integrated systems. At present, evolutionary theory seems to be akin to nineteenth-century physics, blissfully unaware of the imminent arrival of quantum mechanics and general relativity. Physics had its Newton, biology its Darwin: evolutionary biology now awaits its Einstein.
Linking biodiversity and ecosystems: towards a unifying ecological theory
Authors: Loreau Michel
Published: November 2009

Community ecology and ecosystem ecology provide two perspectives on complex ecological systems that have largely complementary strengths and weaknesses. Merging the two perspectives is necessary both to ensure continued scientific progress and to provide society with the scientific means to face growing environmental challenges. Recent research on biodiversity and ecosystem functioning has contributed to this goal in several ways. By addressing a new question of high relevance for both science and society, by challenging existing paradigms, by tightly linking theory and experiments, by building scientific consensus beyond differences in opinion, by integrating fragmented disciplines and research fields, by connecting itself to other disciplines and management issues, it has helped transform ecology not only in content, but also in form. Creating a genuine evolutionary ecosystem ecology that links the evolution of species traits at the individual level, the dynamics of species interactions, and the overall functioning of ecosystems would give new impetus to this much-needed process of unification across ecological disciplines. Recent community evolution models are a promising step in that direction.
The social brain: allowing humans to boldly go where no other species has been
Authors: Frith Uta , Frith Chris
Published: November 2009

The biological basis of complex human social interaction and communication has been illuminated through a coming together of various methods and disciplines. Among these are comparative studies of other species, studies of disorders of social cognition and developmental psychology. The use of neuroimaging and computational models has given weight to speculations about the evolution of social behaviour and culture in human societies. We highlight some networks of the social brain relevant to two-person interactions and consider the social signals between interacting partners that activate these networks. We make a case for distinguishing between signals that automatically trigger interaction and cooperation and ostensive signals that are used deliberately. We suggest that this ostensive signalling is needed for ‘closing the loop’ in two-person interactions, where the partners each know that they have the intention to communicate. The use of deliberate social signals can serve to increase reputation and trust and facilitates teaching. This is likely to be a critical factor in the steep cultural ascent of mankind.
Crossing scales, crossing disciplines: collective motion and collective action in the Global Commons
Authors: Levin Simon
Published: November 2009

Two conflicting tendencies can be seen throughout the biological world: individuality and collective behaviour. Natural selection operates on differences among individuals, rewarding those who perform better. Nonetheless, even within this milieu, cooperation arises, and the repeated emergence of multicellularity is the most striking example. The same tendencies are played out at higher levels, as individuals cooperate in groups, which compete with other such groups. Many of our environmental and other global problems can be traced to such conflicts, and to the unwillingness of individual agents to take account of the greater good. One of the great challenges in achieving sustainability will be in understanding the basis of cooperation, and in taking multicellularity to yet a higher level, finding the pathways to the level of cooperation that is the only hope for the preservation of the planet.
Understanding and using quantitative genetic variation
Authors: Hill William G.
Published: November 2009

Quantitative genetics, or the genetics of complex traits, is the study of those characters which are not affected by the action of just a few major genes. Its basis is in statistical models and methodology, albeit based on many strong assumptions. While these are formally unrealistic, methods work. Analyses using dense molecular markers are greatly increasing information about the architecture of these traits, but while some genes of large effect are found, even many dozens of genes do not explain all the variation. Hence, new methods of prediction of merit in breeding programmes are again based on essentially numerical methods, but incorporating genomic information. Long-term selection responses are revealed in laboratory selection experiments, and prospects for continued genetic improvement are high. There is extensive genetic variation in natural populations, but better estimates of covariances among multiple traits and their relation to fitness are needed. Methods based on summary statistics and predictions rather than at the individual gene level seem likely to prevail for some time yet.
Evolutionary dynamics in structured populations
Authors: Nowak Martin A. , Tarnita Corina E. , Antal Tibor
Published: November 2009

Evolutionary dynamics shape the living world around us. At the centre of every evolutionary process is a population of reproducing individuals. The structure of that population affects evolutionary dynamics. The individuals can be molecules, cells, viruses, multicellular organisms or humans. Whenever the fitness of individuals depends on the relative abundance of phenotypes in the population, we are in the realm of evolutionary game theory. Evolutionary game theory is a general approach that can describe the competition of species in an ecosystem, the interaction between hosts and parasites, between viruses and cells, and also the spread of ideas and behaviours in the human population. In this perspective, we review the recent advances in evolutionary game dynamics with a particular emphasis on stochastic approaches in finite sized and structured populations. We give simple, fundamental laws that determine how natural selection chooses between competing strategies. We study the well-mixed population, evolutionary graph theory, games in phenotype space and evolutionary set theory. We apply these results to the evolution of cooperation. The mechanism that leads to the evolution of cooperation in these settings could be called ‘spatial selection’: cooperators prevail against defectors by clustering in physical or other spaces.
Genome-wide scans for footprints of natural selection
Authors: Oleksyk Taras K. , Smith Michael W. , O'Brien Stephen J.
Published: November 2009

Detecting recent selected ‘genomic footprints’ applies directly to the discovery of disease genes and in the imputation of the formative events that molded modern population genetic structure. The imprints of historic selection/adaptation episodes left in human and animal genomes allow one to interpret modern and ancestral gene origins and modifications. Current approaches to reveal selected regions applied in genome-wide selection scans (GWSSs) fall into eight principal categories: (I) phylogenetic footprinting, (II) detecting increased rates of functional mutations, (III) evaluating divergence versus polymorphism, (IV) detecting extended segments of linkage disequilibrium, (V) evaluating local reduction in genetic variation, (VI) detecting changes in the shape of the frequency distribution (spectrum) of genetic variation, (VII) assessing differentiating between populations (FST), and (VIII) detecting excess or decrease in admixture contribution from one population. Here, we review and compare these approaches using available human genome-wide datasets to provide independent verification (or not) of regions found by different methods and using different populations. The lessons learned from GWSSs will be applied to identify genome signatures of historic selective pressures on genes and gene regions in other species with emerging genome sequences. This would offer considerable potential for genome annotation in functional, developmental and evolutionary contexts.
No cardiac effects of therapeutic and supratherapeutic doses of rupatadine: results from a ‘thorough QT/QTc study’ performed according to ICH guidelines
Authors: Donado Ester , Izquierdo Iñaki , Pérez Iñaki , García Olga , Antonijoan Rosa Ma , Gich Ignaci , Solans Anna , Peña Juana , Morganroth Joel , Barbanoj Manuel J.
Published: November 2009

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Drug‐induced prolongation of QTc interval on the ECG increases the risk of ventricular tachyarrhythmias.

• This problem beset the antihistamine class of drugs in the 1990s and resulted in the withdrawal of two drugs, terfenadine and astemizole.

• In 2005 the International Conference on Harmonization approved guideline E14, which has been termed a ‘thorough QT/QTc study’, for the routine clinical testing of the proarrhythmic potential of pharmacotherapy.

WHAT THIS PAPER ADDS

• To our knowledge, this is one of the first published trials to evaluate multiple doses of antihistamine therapy using the new criteria and it confirms the cardiac safety of rupatadine, an anti‐H1 compound with activity on platelet‐activating factor.

AIMS To evaluate the effects of therapeutic and supratherapeutic doses of rupatadine on cardiac repolarization in line with a ‘thorough QT/QTc study’ protocol performed according to International Conference on Harmonization guidelines.

METHODS This was a randomized (gender‐balanced), parallel‐group study involving 160 healthy volunteers. Rupatadine, 10 and 100 mg day−1, and placebo were administered single‐blind for 5 days, whilst moxifloxacin 400 mg day−1 was given on days 1 and 5 in open‐label fashion. ECGs were recorded over a 23‐h period by continuous Holter monitoring at baseline and on treatment days 1 and 5. Three 10‐s ECG samples were downloaded at regular intervals and were analysed independently. The primary analysis of QTc was based on individually corrected QT (QTcI). Treatment effects on QTcI were assessed using the largest time‐matched mean difference between the drug and placebo (baseline‐subtracted) for the QTcI interval. A negative ‘thorough QT/QTc study’ is one where the main variable is around ≤5 ms, with a one‐sided 95% confidence interval that excludes an effect >10 ms.

RESULTS The validity of the trial was confirmed by the fact that the moxifloxacin‐positive control group produced the expected change in QTcI duration (around 5 ms). The ECG data for rupatadine at both 10 and 100 mg showed no signal effects on the ECG, after neither single nor repeated administration. Furthermore, no pharmacokinetic/pharmacodynamic relationship, gender effects or clinically relevant changes in ECG waveform outliers were observed. No deaths or serious or unexpected adverse events were reported.

CONCLUSIONS This ‘thorough QT/QTc study’ confirmed previous experience with rupatadine and demonstrated that it had no proarrhythmic potential and raised no concerns regarding its cardiac safety.
Association of childhood perennial allergic rhinitis with subclinical airflow limitation
Authors: Ciprandi G. , Capasso M.
Published: November 2009

Background
Allergic rhinitis (AR) is a relevant risk factor for the onset of asthma, and a close association exists between the nose and the bronchi. Recently, it has been evidenced that the duration of AR and mite allergy represent high risks for spirometric impairment in allergic adults.

Aim
To evaluate a group of AR children, without bronchial symptoms, to investigate spirometric impairments.

Methods
Two hundred children with moderate‐severe AR were consecutively evaluated. Clinical examination, skin prick test, and spirometry were performed in all children.

Results
Thirty‐one percent of the children had forced expiratory flow at 25% and 75% of the pulmonary volume (FEF25–75%)<80% of the predicted values and 11% had both forced expiratory volume in 1 s and FEF25–75%<80% of the predicted values. Rhinitis duration and sensitization to house dust mites were significantly associated with impaired values of these spirometric parameters.

Conclusion
This study highlights the close link between the upper and the lower airways and the role of some risk factors, such as long duration and mite sensitization, as early prognostic markers of bronchial involvement in children with ARand perceiving nasal symptoms alone.

Cite this as: G. Ciprandi and M. Capasso, Clinical & Experimental Allergy, 2010 (40) 398–402.