bluuebunny/crossref_metadata_2025 huggingface dataset:
Generation of Feeder-Free Pig Induced Pluripotent Stem Cells without Pou5f1
Authors: Montserrat Nuria , De Oñate Lorena , Garreta Elena , Gonzãlez Federico , Adamo Antonio , Eguizãbal Cristina , Häfner Sophia , Vassena Rita , Belmonte Juan Carlos Izpisua
Published: December 2011

The pig represents an ideal large-animal model, intermediate between rodents and humans, for the preclinical assessment of emerging cell therapies. As no validated pig embryonic stem (pES) cell lines have been derived so far, pig induced pluripotent stem cells (piPSCs) should offer an alternative source of undifferentiated cells to advance regenerative medicine research from bench to clinical trial. We report here for the first time the derivation of piPSCs from adult fibroblast with only three transcription factors: Sox2 (sex determining region Y-box 2), Klf4 (Krüppel-like factor 4), and c-Myc (avian myelocytomatosis viral oncogene homolog). We have been able to demonstrate that exogenous Pou5f1 (POU domain class 5 transcription factor 1; abbreviated as Octamer-4: Oct4) is dispensable to achieve and maintain pluripotency in the generation of piPSCs. To the best of our knowledge, this is also the first report of somatic reprogramming in any species without the overexpression, either directly or indirectly, of Oct4. Moreover, we were able to generate piPSCs without the use of feeder cells, approaching thus xeno-free conditions. Our work paves the way for the derivation of clinical grade piPSCs for regenerative medicine.
Percutaneous Adventitial Delivery of Allogeneic Bone Marrow-Derived Stem Cells via Infarct-Related Artery Improves Long-Term Ventricular Function in Acute Myocardial Infarction
Authors: Medicetty Satish , Wiktor Dominik , Lehman Nicholas , Raber Amy , Popovic Zoran B. , Deans Robert , Ting Anthony E. , Penn Marc S.
Published: December 2011

Acute myocardial infarction (AMI) results in ischemic damage and death of cardiomyocytes and loss of vasculature. Stem cell therapy has emerged as a potentially promising strategy for maximizing cardiac function following ischemic injury. Issues of cell source, delivery, and quantification of response have challenged development of clinically viable strategies. In this study we investigate the effects of a well-defined bone marrow-derived allogeneic cell product delivered by catheter directly to the myocardium via the infarctrelated vessel on global and regional measures of left ventricular (LV) function in a porcine model of anterior wall myocardial infarction. Multipotent adult progenitor cells (MAPCs) were derived and expanded from the bone marrow of a donor Yorkshire pig. Anterior wall myocardial infarction (AMI) was induced by 90 min of mid-LAD occlusion using a balloon catheter. Two days after AMI was induced, either vehicle (Plasma Lyte-A, n = 7), low-dose (20 million, n = 6), or high-dose (200 million, n = 6) MAPCs were delivered directly to the myocardium via the infarct-related vessel using a transarterial microsyringe catheter-based delivery system. Echocardiography was used to measure LV function as a function of time after AMI. Animals that received low-dose cell treatment showed significant improvement in regional and global LV function and remodeling compared to the high-dose or control animals. Direct myocardial delivery of allogeneic MAPCs 2 days following AMI through the vessel wall of the infarct-related vessel is safe and results in delivery of cells throughout the infarct zone and improved cardiac function despite lack of long-term cell survival. These data further support the hypothesis of cell-based myocardial tissue repair by a paracrine mechanism and suggest a clinically translatable strategy for delivering cells at any time after AMI to modulate cardiac remodeling and function.
Can Magnetic Targeting of Magnetically Labeled Circulating Cells Optimize Intramyocardial Cell Retention?
Authors: Chaudeurge Aurélie , Wilhelm Claire , Chen-Tournoux Annabel , Farahmand Patrick , Bellamy Valérie , Autret Gwennhael , Ménager Christine , Hagège Albert , Larghéro Jerome , Gazeau Florence , Clément Olivier , Menasché Philippe
Published: December 2011

Therapeutic intracavitary stem cell infusion currently suffers from poor myocardial homing. We examined whether cardiac cell retention could be enhanced by magnetic targeting of endothelial progenitor cells (EPCs) loaded with iron oxide nanoparticles. EPCs were magnetically labeled with citrate-coated iron oxide nanoparticles. Cell proliferation, migration, and CXCR4 chemokine receptor expression were assessed in different labeling conditions and no adverse effects of the magnetic label were observed. The magnetophoretic mobility of labeled EPCs was determined in vitro, with the same magnet as that subsequently used in vivo. Coronary artery occlusion was induced for 30 min in 36 rats (31 survivors), followed by 20 min of reperfusion. The rats were randomized to receive, during brief aortic cross-clamping, direct intraventricular injection of culture medium ( n = 7) or magnetically labeled EPCs ( n = 24), with ( n = 14) or without ( n = 10) subcutaneous insertion of a magnet over the chest cavity ( n = 14). The hearts were explanted 24 h later and engrafted cells were visualized by magnetic resonance imaging (MRI) of the heart at 1.5 T. Their abundance in the myocardium was also analyzed semiquantitatively by immunofluorescence, and quantitatively by real-time polymerase chain reaction (RT-PCR). Although differences in cell retention between groups failed to be statistically significant using RT-PCR quantification, due to the variability of the animal model, immunostaining showed that the average number of engrafted EPCs was significantly ten times higher with than without magnetic targeting. There was thus a consistent trend favoring the magnet-treated hearts, thereby suggesting magnetic targeting as a potentially new mean of enhancing myocardial homing of intravascularly delivered stem cells. Magnetic targeting has the potential to enhance myocardial retention of intravascularly delivered endothelial progenitor cells.
HLA Class I Sensitization in Islet Transplant Recipients: Report from the Collaborative Islet Transplant Registry
Authors: Naziruddin Bashoo , Wease Steve , Stablein Donald , Barton Franca B. , Berney Thierry , Rickels Michael R. , Alejandro Rodolfo
Published: December 2011

Pancreatic islet transplantation is a promising treatment option for patients severely affected with type 1 diabetes. This report from CITR presents pre- and posttransplant human leukocyte antigen (HLA) class I sensitization rates in islet-alone transplantation. Data came from 303 recipients transplanted with islet-alone between January 1999 and December 2008. HLA class I sensitization was determined by the presence of anti-HLA class I antibodies. Panel-reactive antibodies (PRA) from prior to islet infusion and at 6 months, and yearly posttransplant was correlated to measures of islet graft failure. The cumulative number of mismatched HLA alleles increased with each additional islet infusion from a median of 3 for one infusion to 9 for three infusions. Pretransplant PRA was not predictive of islet graft failure. However, development of PRA >20% posttransplant was associated with 3.6-fold ( p < 0.001) increased hazard ratio for graft failure. Patients with complete graft loss who had discontinued immunosuppression had significantly higher rate of PRA ≥ 20% compared to those with functioning grafts who remained on immunosuppression. Exposure to repeat HLA class I mismatch at second or third islet infusions resulted in less frequent development of de novo HLA class I antibodies when compared to increased class I mismatch. The development of HLA class I antibodies while on immunosuppression is associated with subsequent islet graft failure. The risk of sensitization may be reduced by minimizing the number of islet donors used per recipient, and in the absence of donor-specific anti-HLA antibodies, repeating HLA class I mismatches with subsequent islet infusions.
Le traité de Lisbonne sur la voie fédéraliste ?
Authors: Sidjanski Dusan
Published: December 2011

Résumé La coïncidence de la période de rodage du traité de Lisbonne avec le choc de la crise financière a exacerbé le dilemme entre la voie fédérale et la dérive intergouvernementale auquel sont confrontées l’Union européenne et la zone euro. Le traité de Lisbonne pourra-t-il tenir les promesses de ses innovations – président du Conseil européen et haute représentante – et de l’équilibre institutionnel entre le communautaire et l’intergouvernemental ? D’autant que dans la recherche d’une réponse à la crise, le rôle de l’Allemagne et de la France en collaboration avec le président du Conseil européen a été privilégié aux dépens de celui de la Commission. Depuis le déclenchement de la crise grecque et sa propagation au Portugal et à l’Irlande, ainsi que les risques de contagion à l’Italie et à l’Espagne, les mesures adoptées se sont avérées insuffisantes. De surcroît, l’accent a été mis sur l’austérité au détriment de la croissance. Les réticences et les atermoiements ont contribué à l’aggravation de la crise économique. Les efforts de la Commission en matière de régulation des marchés financiers, pour essentiels qu’ils soient, n’ont pas suffi à relancer l’économie de la zone euro. Le Fonds européen de stabilité financière a permis de colmater les brèches au prix de politiques d’austérité sans permettre d’éviter le risque de récession. D’où une triple nécessité : le retour à la méthode communautaire moins dépendante à l’égard des contraintes nationales ; le fédéralisme fiscal et l’émission des eurobonds dans la zone euro, soit un New Deal européen  ; la révision de la prise de décision en cas de crise, voire l’instauration d’un mécanisme ad hoc susceptible de prendre des mesures d’urgence. En bref, le retour sur la voie du fédéralisme européen.
Les institutions de l'Union européenne après le traité de Lisbonne
Authors: Quermonne Jean-Louis
Published: December 2011

Résumé La mise en œuvre des dispositions d’ordre institutionnel du traité de Lisbonne s’est heurtée à de nombreux obstacles. Outre les concessions faites à l’Irlande, qui écartent la possibilité de réduire dès 2014 le format de la Commission, elles tiennent à la fois au contrôle rigoureux exercé par les cours constitutionnelles et à la montée en puissance dans différents États membres du populisme et du nationalisme. D’où une application a minima , malgré l’établissement d’un mode de législation ordinaire inspiré de la « méthode communautaire » des mesures favorisant l’intégration. Il en est résulté un renforcement des pratiques intergouvernementales qui ont profité au Conseil européen. L’inscription sur la scène européenne de la crise économique et financière déclenchée en 2008 aux États-Unis est venue ajouter paradoxalement à ces difficultés deux effets. D’une part le caractère régulier des problèmes posés a mis sur le devant de la scène les chefs d’État et de gouvernement et leurs ministres des finances. Mais, à l’inverse, au niveau de la zone euro, il a conféré un rôle de premier plan à la Banque centrale et à son président. Et la promotion suggérée dans ce cadre d’un fédéralisme économique et financier tend à soulever d’une part la question jugée antérieurement prématurée d’une nouvelle révision du traité, et d’autre part celle de la compatibilité entre un centre de gravité renforcé autour du couple franco-allemand et les autres États de l’Union. D’où la nécessité de favoriser l’avènement d’un leadership européen qui pourrait résulter de la fusion des présidences du Conseil européen et de la Commission, assorti de la formation au sein de cette dernière d’un collège restreint de commissaires, auxquels serait attribué le statut actuellement réservé au haut représentant pour la PESC.
The Lisbon Treaty: A First Assessment
Authors: Laursen Finn
Published: December 2011

Résumé Cet article analyse la formation du traité de Lisbonne, en y considérant le rôle des États membres et les présidences allemande et portugaise. Ensuite, il identifie les choix institutionnels les plus importants du traité et comment ces changements peuvent affecter les politiques majeures de l’Union. Enfin, l’auteur cherche à évaluer les changements. Même s’ils ne sont pas révolutionnaires, ces changements devraient contribuer à créer une union plus efficace et légitime. Une limitation importante du traité tient à ce que la politique étrangère et de sécurité reste intergouvernementale, malgré l’abolition formelle de la structure des piliers.
New institutional opportunities or old hegemony?
Authors: Höing Oliver , Wessels Wolfgang
Published: December 2011

Résumé Suite aux dernières vagues d’élargissement, de récentes publications, scientifiques comme journalistiques, ont indiqué une baisse de la direction franco-allemande au sein de l’UE. Cependant, depuis les débuts de la crise financière et économique, le Conseil européen – y compris le tandem franco-allemand – est revenu au centre de tous les processus de prise de décision importants dans le système de l’Union européenne. Cet article évalue le rôle du tandem franco-allemand au sein du Conseil européen par l’analyse des nouvelles dispositions du traité de Lisbonne et leur impact sur l’Allemagne et la France. Nous soutenons que les dispositions de Lisbonne n’ont pas eu un effet considérable sur l’axe franco-allemand. Néanmoins, le glissement vers une prise de décision intergouvernementale pendant la crise économique et financière, a renforcé la position des principaux hommes politiques français et allemands au sein du Conseil européen.
Constitutionalizing the European Union: The Lisbon Treaty and the Czech Republic
Authors: Rovná Lenka
Published: December 2011

Résumé L’article examine le débat sur l’avenir de l’Union européenne lancé après l’an 2000, du point de vue de la République tchèque. Le fait que les processus de transformation et d’adhésion aient été interconnectés conduisit à une dichotomie entre révolution inachevée de la modernité dans la société tchèque et adhésion à l’entité postmoderne que l’UE représente. Le manque de débats n’a pas permis d’échange et surtout de formulation d’opinions et de visions de la société tchèque. L’article analyse l’attitude des acteurs politiques tchèques dans la convention pour l’avenir de l’Europe, son processus de ratification, le traité de Lisbonne et sa propre ratification. La République tchèque a été le dernier pays à ratifier le traité. L’article soutient que ce fut essentiellement Václav Klaus qui a défini l’ordre du jour du débat et que les autres acteurs se sont seulement limités à formuler des réponses défensives. Les médias de masse en général n’ont reflété que des opinions controversées et ils n’ont pas vraiment non plus initié de débats. Selon des sondages d’opinion, la société tchèque dans son ensemble ne rejette pas le projet européen. Cela fut l’action des principaux acteurs politiques, au cours de l’adhésion comme des processus de ratification, qui conduisit à considérer la République tchèque comme un partenaire difficile. Néanmoins, les attitudes à l’égard de l’UE de la part des élites et de l’opinion publique sont variées, et comparables aux approches des différents groupes sociaux dans les autres États membres.
Deux ans après Lisbonne, l'Europe dans la crise
Authors: Toulemon Robert
Published: December 2011

Résumé Entré en vigueur le 1 er  décembre 2009, le traité de Lisbonne a marqué quelques progrès dans le mode de fonctionnement de l’Union : renforcement des pouvoirs du Parlement européen, élargissement du domaine permettant des décisions à la majorité au Conseil, mode de désignation du président de la Commission. Mais le traité a laissé subsister plusieurs des faiblesses principales des textes antérieurs (révision, ressources budgétaires, fiscalité). Il a affaibli, en la divisant, la fonction exécutive et de représentation de l’Union tout en renonçant à afficher ses symboles. Dans l’ordre intérieur, l’Union a traversé sa plus grave crise bancaire, financière, monétaire, économique et sociale. Elle a imposé aux États membres en difficulté des plans de sauvetage tardifs marqués par plus de rigueur que de solidarité. Elle a franchi un pas significatif vers une coordination des politiques nationales en donnant priorité à l’assainissement des finances publiques sur le soutien à la croissance et à l’emploi. Le rôle de la Banque centrale s’est révélé décisif dans la sauvegarde de l’union monétaire. Dans le domaine extérieur, l’affaire libyenne a montré les limites de la politique étrangère et de sécurité commune. Face aux révoltes du monde arabe et au problème palestinien, le nouveau service européen d’action extérieure, tout juste mis en place, n’est pas parvenu à obtenir une attitude commune des diplomaties nationales. L’avenir de la nouvelle Union pour la Méditerranée est incertain. À partir d’une situation confuse, plusieurs scénarios sont envisageables. Le plus probable est celui de la continuité. Le marché unique et l’union monétaire sont préservés au prix de difficultés et de tensions. L’Union peine à s’affirmer comme un acteur majeur de la scène internationale. Elle poursuit un lent processus d’élargissement limité aux Balkans sans nouvelles réformes institutionnelles. Un deuxième scénario plus sombre ne peut être exclu. La primauté de l’intergouvernemental et l’effacement concomitant de la Commission conduisent à des tensions croissantes à la fois entre petits et grands et entre les grands. La solidarité insuffisante menace l’intégrité de la zone euro. Le scénario le plus positif n’est pas le plus vraisemblable. Il suppose que le désir de sauver l’euro coïncidant avec un renouveau d’intérêt pour l’Europe des dirigeants allemands conduise à un pas en avant vers plus de discipline et de solidarité, c’est-à-dire vers plus d’Europe politique. Ainsi l’Union sortirait renforcée de la crise mais limitée à la zone euro. Dans un climat transformé et grâce à des progrès de nature à montrer à quoi peut servir l’Europe, le centième anniversaire de la grande guerre civile européenne, coïncidant avec le renouvellement du Parlement et de la Commission, pourrait être l’occasion de rouvrir le chantier institutionnel. Il resterait à définir les sources de légitimité d’un gouvernement à la fois proche et distinct des gouvernements nationaux et à organiser la différenciation entre les États prêts à franchir une nouvelle étape et les autres.
Structural Insights into the Substrate Specificity of Human Granzyme H: The Functional Roles of a Novel RKR Motif
Authors: Wang Li , Zhang Kai , Wu Lianfeng , Liu Shengwu , Zhang Honglian , Zhou Qiangjun , Tong Liang , Sun Fei , Fan Zusen
Published: December 2011

Human granzyme H (GzmH) is constitutively expressed in human NK cells that have important roles in innate immune responses against tumors and viruses. GzmH is a chymotrypsin-like serine protease. Its substrate preference and its mechanism of substrate recognition are poorly understood. To provide structural insights into the substrate recognition mechanisms for GzmH, we solved the crystal structures of a D102N-GzmH mutant alone and in complex with a decapeptide substrate and an inhibitor to 2.2 Å, 2.4 Å, and 2.7 Å, respectively. The Thr189, Gly216, and Gly226 specificity triad in the S1 pocket of GzmH defines its preference for bulky, aromatic residues (Tyr and Phe) at the P1 position. Notably, we discovered that an unusual RKR motif (Arg39-Lys40-Arg41), conserved only in GzmH, helps define the S3′ and S4′ binding regions, indicating the preference for acidic residues at the P3′ and P4′ sites. Disruption of the RKR motif or the acidic P3′ and P4′ residues in the substrate abolished the proteolytic activity of GzmH. We designed a tetrapeptide chloromethylketone inhibitor, Ac-PTSY-chloromethylketone, which can selectively and efficiently block the enzymatic and cytotoxic activity of GzmH, providing a useful tool for further studies on the function of GzmH.
Cutting Edge: Histamine Is Required for IL-4–Driven Eosinophilic Allergic Responses
Authors: Swartzendruber Julie A. , Byrne Adam J. , Bryce Paul J.
Published: December 2011

Histamine is an important allergic mediator, and studies have defined roles for both histamine 1 and 4 receptors in allergic airway inflammation. In this study, we show that histamine is necessary to generate IL-4–driven eosinophilic inflammation, as histamine-deficient mice cannot generate eosinophilic lung inflammation in response to intratracheal IL-4 and exogenous histamine restores responsiveness. This is histamine 2 receptor (H2R) dependent because H2R knockout mice fail to respond to IL-4, and a H2R agonist restores inflammation in histidine decarboxylase knockout. Furthermore, alveolar epithelial cells require H2R to produce CCL24, an eosinophil recruitment factor, whereas H2R blockade reduces CCL24 production from wild-type cells. In an allergic inflammation model, H2R knockout mice show significantly reduced eosinophilic inflammation and CCL24 expression. These data demonstrate a previously unidentified role for H2R in allergic inflammation and establishes a synergy between endogenous histamine and IL-4 that supports eosinophilic recruitment to the lung.
Intracranial Aspergillus Granuloma
Authors: Sundaram C. , Murthy J. M. K.
Published: December 2011

Intracranial fungal granulomas are rare and of the histologically verified granulomas, Aspergillus spp. is the commonest causative fungal pathogen. Most of the reported large series of aspergillus granulomas are from countries with temperate climate like India, Pakistan, Sudan, and Saudi Arabia. In contrast to disseminated aspergillosis that occurs in immunosuppressed individuals, most of the intracranial aspergillus granulomas are reported in immunocompetent individuals. The temperature, humidity, high spore content in the atmosphere during ploughing, and occupation as agricultural worker are implicated in the pathogenesis. The sinocranial spread is the most common route of intracranial extension. Extracerebral firm fibrotic lesions and skull base lesions are common. Extensive fibrosis and large number of multinucleated giant cells are the characteristic histological features and these pathological features have therapeutic relevance.
Integrated Evaluation of Age-Related Changes in Structural and Functional Vascular Parameters Used to Assess Arterial Aging, Subclinical Atherosclerosis, and Cardiovascular Risk in Uruguayan Adults: CUiiDARTE Project
Authors: Bia Daniel , Zócalo Yanina , Farro Ignacio , Torrado Juan , Farro Federico , Florio Lucía , Olascoaga Alicia , Brum Javier , Alallón Walter , Negreira Carlos , Lluberas Ricardo , Armentano Ricardo L.
Published: December 2011

This work was carried out in a Uruguayan (South American) population to characterize aging-associated physiological arterial changes. Parameters markers of subclinical atherosclerosis and that associate age-related changes were evaluated in healthy people. A conservative approach was used and people with nonphysiological and pathological conditions were excluded. Then, we excluded subjects with (a) cardiovascular (CV) symptoms, (b) CV disease, (c) diabetes mellitus or renal failure, and (d) traditional CV risk factors (other than age and gender). Subjects (n=388) were submitted to non-invasive vascular studies (gold-standard techniques), to evaluate (1) common (CCA), internal, and external carotid plaque prevalence, (2) CCA intima-media thickness and diameter, (3) CCA stiffness (percentual pulsatility, compliance, distensibility, and stiffness index), (4) aortic stiffness (carotid-femoral pulse wave velocity), and (5) peripheral and central pressure wave-derived parameters. Age groups: ≤20, 21–30, 31–40, 41–50, 51–60, 61–70, and 71–80 years old. Age-related structural and functional vascular parameters profiles were obtained and analyzed considering data from other populations. The work has the strength of being the first, in Latin America, that uses an integrative approach to characterize vascular aging-related changes. Data could be used to define vascular aging and abnormal or disease-related changes.
Potentiometric Polymeric Film Sensors Based on 5,10,15-tris(4-aminophenyl) Porphyrinates of Co(II) and Cu(II) for Analysis of Biological Liquids
Authors: Lvova Larisa , Paolesse Roberto , Di Natale Corrado , D'Amico Arnaldo , Bergamini Alberto
Published: December 2011

Novel carbonate-selective potentiometric sensors based on 5,10,15-tris(4-aminophenyl)-20-phenyl porphyrinates of Cu(II) and Co(II) have been developed. Ionophore functioning mechanism and possible source of carbonate sensitivity have been evolved. Potentiometric properties of Co(II)- and Cu(II)TATPP-based sensors were compared with common carbonate-ISEs containing trifluoroacetophenone derivatives. The analytical utility of newly developed sensors has been demonstrated by measuring the bicarbonate content in human blood plasma.
Wavelets obtained by continuous deformations of the Haar wavelet
Authors: Bonami Aline , Durand Sylvain , Weiss Guido
Published: December 2011

One might obtain the impression, from the wavelet literature, that the class of orthogonal wavelets is divided into subclasses, like compactly supported ones on one side, band-limited ones on the other side. The main purpose of this work is to show that, in fact, the class of low-pass filters associated with "reasonable" (in the localization sense, not necessarily in the smooth sense) wavelets can be considered to be an infinite dimensional manifold that is arcwise connected. In particular, we show that any such wavelet can be connected in this way to the Haar wavelet.
Correspondances géodésiques entre les surfaces euclidiennes à singularités coniques
Authors: Mesmoudi Mohammed Mostefa
Published: December 2011

A.J. Montesinos has shown that a geodesic correspondence between to complete Riemannian manifolds with transitive topological geodesic flow is a homothety. In this paper we prove a similar result for a conformal geodesic correspondence between two singular flat surfaces with conical singularities and negative concentrated curvature.
Generalized Fock spaces, interpolation, multipliers, circle geometry
Authors: Peetre Jaak , Thangavelu Sundaram , Wallin Nils-Olof
Published: December 2011

By a (generalized) Fock space we understand a Hilbert space of entire analytic functions in the complex plane

\mathbb C

which are square integrable with respect to a weight of the type

e^{–Q(z)}

, where

Q(z)

is a quadratic form such that tr

Q>0

. Each such space is in a natural way associated with an (oriented) circle

C

in

\mathbb C

. We consider the problem of interpolation betweeumn two Fock spaces. If

C_0

and

C_1

are the corresponding circles, one is led to consider the pencil of circles generated by

C_0

and

C_1

. If

H

is the one parameter Lie group of Moebius transformations leaving invariant the circles in the pencil, we consider its complexification

H^c

which permutes these circles and with the aid of which we can construct the "Calderón curve" giving the complex interpolation. Similarly, real interpolation leads to a multiplier problem for the transforrnation that diagonalizes all the operators in

H^c

. It turns out that the result is rather sensitive to the nature of the pencil, and we obtain nearly complete results for elliptic and parabolic pencils only.
On fractional differentiation and integration on spaces of homogeneous type
Authors: Gatto A. Eduardo , Segovia Carlos , Vági Stephen
Published: December 2011

In this paper we define derivatives of fractional order on spaces of homogeneous type by generalizing a classical formula for the fractional powers of the Laplacean [S1], [S2], [SZ] and introducing suitable quasidistances related to an approximation of the identity. We define integration of fractional order as in [GV] but using quasidistances related to the approximation of the identity mentioned before.We show that these operators act on Lipschitz spaces as in the classical cases. We prove that the composition

T_\alpha

of a fractional integral

I_\alpha

and a fractional derivative

D_\alpha

of the same order and its transpose (a fractional derivative composed with a fractional integral of the same order) are Calderón-Zygmund operators. We also prove that for small order

\alpha

a,

T_\alpha

is an invertible operator in

L^2

. In order to prove that

T_\alpha

is invertible we obtain Nahmod type representations for

I_\alpha

and

D_\alpha

and then we follow the method of her thesis [N1], [N2].
Good metric spaces without good parameterizations
Authors: Semmes Stephen
Published: December 2011

A classical problem in geometric topology is to recognize when a topological space is a topological manifold. This paper addresses the question of when a rnetric space admits a quasisymmetric parameterization by providing counterexamples to the obvious optimistic conjectures, or, in other words, by providing examples of spaces with many Euclidean-like properties which are nonetheless substantially different from Euclidean geometry. These examples are geometrically self-similar versions of classical topologically self-similar examples from geometric topology, and they can be realized as codimension 1 subsets of Euclidean spaces. Unlike earlier examples going back to Rickman, these sets enjoy good bounds on their geodesic distance functions and good mass bounds (AhIfors regularity). They are also smooth except for reasonably tame degenerations near small sets, they are uniform1y rectifiable, and they have good properties in terms of analysis (like Sobolev and Poincaré inequalities). The construction also produces uniform domains which have many nice properties but which are not quasiconformally equivalent to balls.
On the nonexistence of bilipschitz parameterizations and geometric problems about $A_\infty$-weights
Authors: Semmes Stephen
Published: December 2011

How can one recognize when a metric space is bilipschitz equivalent to a Euclidean space? One should not take the abstraction of metric spaces too seriously here; subsets of

\mathbb R^n

are already quite interesting. It is easy to generate geometric conditions which are necessary for bilipschitz equivalence, but it is not clear that such conditions should ever be sufficient. The main point of this paper is that the optimistic conjectures about the existence of bilipschitz parameterizations are wrong. In other words, there are spaces whose geometry is very similar to but still distinct from Euclidean geometry. Related questions of bilipschitz equivalence and embeddings are addressed for metric spaces obtained by deforming the Euclidean metric on

\mathbb R^n

using an

A_\infty

weight.
Self-similar solutions in weak $L^p$-spaces of the Navier-Stokes equations
Authors: Barraza Oscar A.
Published: December 2011

The most important result stated in this paper is a theorem on the existence of global solutions for the Navier-Stokes equations in

\mathbb R^n

when the initial velocity belongs to the space weak

L^n(\mathbb R^n)

with a sufficiently small norm. Furthermore, this fact leads us to obtain self-similar solutions if the initial velocity is, besides, an homogeneous function of degree -1. Partial uniqueness is also discussed.
The spectrum of singularities of Riemann's function
Authors: Jaffard Stéphane
Published: December 2011

We determine the Holder regularity of Riemann's function at each point; we deduce from this analysis its spectrum of singularities, thus showing its multifractal nature.
A new technique to estimate the regularity of refinable functions
Authors: Cohen Albert , Daubechies Ingrid
Published: December 2011

We study the regularity of refinable functions by analyzing the spectral properties of special operators associated to the refinement equation; in particular, we use the Fredholm determinant theory to derive numerical estimates for the spectral radius of these operators in certain spaces. This new technique is particularly useful for estimating the regularity in the cases where the refinement equation has an infinite number of nonzero coefficients and in the multidimensional cases.
Quasisymmetry, measure and a question of Heinonen
Authors: Semmes Stephen
Published: December 2011

In this paper we resolve in the affirmative a question of Heinonen on the absolute continuity of quasisymmetric mappings defined on subsets of Euclidean spaces. The main ingredients in the proof are extension results for quasisymmetric mappings and metric doubling measures.
Rough maximal functions and rough singular integral operators applied to integrable radial functions
Authors: Sjögren Peter , Soria Fernando
Published: December 2011

Let

\Omega

be homogeneous of degree 0 in

\mathbb R^n

and integrable on the unit sphere. A rough maximal operator is obtained by inserting a factor

\Omega

in the denition of the ordinary maximal function. Rough singular integral operators are given by principal value kernels

\Omega(y)/|y|^n

, provided that the mean value of

\Omega

vanishes. In an earlier paper, the authors showed that a two-dimensional rough maximal operator is of weak type (1,1) when restricted to radial functions. This result is now extended to arbitrary finite dimension, and to rough singular integrals.
Fonctions d'échelles interpolantes, polynômes de Bernstein et ondelettes non stationnaires
Authors: Lemarié-Rieusset Pierre Gilles
Published: December 2011

The theory of convergence for nonstationary scaling functions and the approximation of interpolating scaling lters by means of Bernstein polynomials, allow us to construct a nonstationary interpolating scaling function with interesting approximation properties.
The phase of the Daubechies filters
Authors: Kateb Djalil , Lemarié-Rieusset Pierre Gilles
Published: December 2011

We give the first term of the asymptotic development for the phase of the

N

-th (minimum-phased) Daubechies filter as

N

goes to

+\infty

. We obtain this result through the description of the complex zeros of the associated polynomial of degree

2N+1

.
Complete interpolating sequences for Paley-Wiener spaces and Muckenhoupt's ($A_p$) condition
Authors: Lyubarskii Yurii I. , Seip Kristian
Published: December 2011

We describe the complete interpolating sequences for the Paley-Wiener spaces

L^p_\pi (1 < p < \infty)

in terms of Muckenhoupt's (

A_p

) condition. For

p=2

, this description coincides with those given by Pavlov [9], Nikol'skii [8], and Minkin [7] of the unconditional bases of complex exponentials in

L^2 (– \pi , \pi)

. While the techniques of these authors are linked to the Hilbert space geometry of

L^2_\pi

, our method of proof is based on turning the problem into one about boundedness of the Hilbert transform in certain weighted

L^p

spaces of functions and sequences.
Statistic of the winding of geodesics on a Riemann surface with finite area and constant negative curvature
Authors: Enriquez Nathanaël , Le Jan Yves
Published: December 2011

In this paper we show that the windings of geodesics around the cusps of a Riemann surface of finite area behave asymptotically as independent Cauchy variables.
The bilinear Hilbert transform is pointwise finite
Authors: Lacey Michael T.
Published: December 2011

Let

f \in L^\infty

and

g \in L^2

be supported on [0,1]. Then the principal value integral below exists in

L^1

.

\mathrm {p.v.} \int f(x + y) g (x – y) \frac{dy}{y}.
Diffusive limit for finite velocity Boltzmann kinetic models
Authors: Lions Pierre-Louis , Toscani Giuseppe
Published: December 2011

We investigate in the diffusive scaling the limit to the macroscopic description of finite-velocity Boltzmann kinetic models, where the rate coefficient in front of the collision operator is assumed to be dependent of the mass density. It is shown that in the limit the flux vanishes while the evolution of the mass density is governed by a nonlinear parabolic equation of porous medium type. In the last part of the paper we show that our method adapts to prove the so-called Rosseland approximation in radiative transfer theory.
A generalization of a theorem by Kato on Navier-Stokes equations
Authors: Cannone Marco
Published: December 2011

We generalize a classical result of T. Kato on the existence of global solutions to the Navier-Stokes system in

C(|0, \infty); L^3 (\mathbb R^3)

. More precisely, we show that if the initial data are sufficiently oscillating, in a suitable Besov space, then Kato's solution exists globally. As a corollary to this result, we obtain a theorem on existence of self-similar solutions for the Navier-Stokes equations.
Primary and secondary sources of formaldehyde in urban atmospheres: Houston Texas region
Authors: Parrish D. D. , Ryerson T. B. , Mellqvist J. , Johansson J. , Fried A. , Richter D. , Walega J. G. , Washenfelder R. A. , de Gouw J. A. , Peischl J. , Aikin K. C. , McKeen S. A. , Frost G. J. , Fehsenfeld F. C. , Herndon S. C.
Published: December 2011

Abstract. We evaluate the rates of secondary production and primary emission of formaldehyde (CH2O) from petrochemical industrial facilities and on-road vehicles in the Houston Texas region. This evaluation is based upon ambient measurements collected during field studies in 2000, 2006 and 2009. The predominant CH2O source (92 ± 4% of total) is secondary production formed during the atmospheric oxidation of highly reactive volatile organic compounds (HRVOCs) emitted from the petrochemical facilities. Smaller contributions are primary emissions from these facilities (4 ± 2%), and secondary production (~3%) and primary emissions (~1%) from vehicles. The primary emissions from both sectors are well quantified by current emission inventories. Since secondary production dominates, control efforts directed at primary CH2O emissions cannot address the large majority of CH2O sources in the Houston area, although there may still be a role for such efforts. Ongoing efforts to control alkene emissions from the petrochemical facilities, as well as volatile organic compound emissions from the motor vehicle fleet, will effectively reduce the CH2O concentrations in the Houston region. We have not addressed other emission sectors, such as off-road mobile sources or secondary formation from biogenic hydrocarbons. Previous analyses based on correlations between ambient concentrations of CH2O and various marker species have suggested much larger primary emissions of CH2O, but those results neglect confounding effects of dilution and loss processes, and do not demonstrate the causes of the observed correlations. Similar problems must be suspected in any source apportionment analysis of secondary species based upon correlations of ambient concentrations of pollutants.
Linguistic Landscapes as Public Communication: A Study of Public Signage in Gaborone Botswana
Authors: Akindele Dele Olufemi
Published: December 2011

The study of public signage is termed linguistic landscape (LL). Landry & Bourhis (1997) define the notion as “the language of public road signs, advertising billboards, street names, place names, commercial shop signs, and public signs on government buildings combines to form the linguistic landscape of a given territory, region, or urban agglomeration” (p.25). The present study intends to contribute to this development in Gaborone the capital city of Botswana. The aim of this study is to show that LL can provide valuable insight into the linguistic situation of Gaborone Botswana, including common patterns of language usage, official language policies, prevalent language attitudes, and the long-term consequences of language contact, among others. This was be done by analyzing the data collected from specific public domains such as street signs, advertising signs, building names, warning notices and prohibitions, billboards, shop signs, informative signs (directions, hours of opening), etc. in Gaborone.
Effectiveness of Information from Vehicles beyond Nearest Vehicle Ahead for Traffic Flow
Authors: Shimizu Hikaru , Nishiyama Sho , Wakita Yukiko , Kita Eisuke
Published: December 2011

A driver usually controls the vehicle according to only the information from the nearest leader vehicle. If the information from the other leader vehicles is also available, the driver can control the vehicle more adequately. The aim of this study is to discuss the effectiveness of the information from the other leader vehicles than the nearest one for the traffic flow. For this purpose, the traffic flow is modeled by using the Chandler-type multi-vehicle-following model. This model changes the vehicle acceleration rate according to the velocity differences between the vehicle
and its multileader vehicles. After the model stability analysis, the traffic flow simulation is performed. The results reveal that the stable region of the model parameters expands according to the increase of the number of the leader vehicles.
A Study of the Hazardous Glare Potential to Aviators from Utility-Scale Flat-Plate Photovoltaic Systems
Authors: Riley Evan , Olson Scott
Published: December 2011

The potential flash glare a pilot could experience from a proposed 25-degree fixed-tilt flat-plate polycrystalline PV system located outside of Las Vegas, Nevada, was modeled for the purpose of hazard quantification. Hourly insolation data measured via satellite for the years 1998 to 2004 was used to perform the modeling. The theoretical glare was estimated using published ocular safety metrics which quantify the potential for a postflash glare after-image. This was then compared to the postflash glare after-image potential caused by smooth water. The results show that the potential for hazardous glare from flat-plate PV systems is similar to that of smooth water and not expected to be a hazard to air navigation.
Reduction of Adherence of E. coli O157:H7 to HEp-2 Cells and to Bovine Large Intestinal Mucosal Explants by Colicinogenic E. coli
Authors: Etcheverría A. I. , Arroyo G. H. , Alzola R. , Parma A. E.
Published: December 2011

Enterohemorrhagic E. coli strains (EHEC) had emerged as foodborne pathogens and cause in human diarrhea and hemolytic-uremic syndrome. Because of the widespread distribution of EHEC serotypes and O157 and non-O157 in cattle population, its control will require interventions at the farm level such as the administration of probiotics that produce inhibitory metabolites. E. coli O157:H7 shows tissue tropisms for the gastrointestinal tract (GIT) of cattle. The aim of this study was to test the ability of a colicinogenic E. coli (isolated from bovine) to reduce the adherence of E. coli O157:H7 to HEp-2 cells and to GIT of cattle. We inoculated HEp-2 cells and bovine colon explants with both kinds of strains. Colicinogenic E. coli was able to reduce the adherence of E. coli O157:H7 to HEp-2 cells and to bovine tissues.
Patient Compliance during 24-Hour Dual pH Probe Monitoring for Extraesophageal Reflux
Authors: Musser Joy , Kelchner Lisa , Neils-Strunjas Jean , Montrose Marshall
Published: December 2011

Objective. During ambulatory 24-hour dual pH probe monitoring for suspected extraesophageal reflux (EER), patients are responsible for indicating relevant study events. Study interpretation relies on patient accuracy and compliance to test instructions. This study sought to explore patient compliance during pH probe monitoring and evaluated the utility of a Post-Evaluation Questionnaire as a clinical tool. Participants and Methods. Participants were prospectively studied during 24-hour dual pH probe monitoring. Participants used both a food diary and monitor settings to indicate relevant study events. Following pH testing, participants completed a Post-Evaluation Questionnaire regarding test experiences. Results. Eighty-two participants completed the study. Means and standard deviations were calculated for individual responses on the Post-Evaluation Questionnaire. Means indicate high participant accuracy for study events, and adherence to typical activities and diet over the testing period. Factor analysis was performed on the Post-Evaluation Questionnaire items and identified two factors: “typical experiences” and “times forgot.” Cronbach's alpha demonstrated acceptable reliability levels for questions related to “typical experiences,” but poor reliability for “times forgot” questions. Conclusions. Assessment of participant compliance during pH probe testing can quickly and easily be completed through a Post-Evaluation Questionnaire. Participant compliance can be assessed for improved study interpretation.
Modeling and Optimization of Advanced Single- and Multijunction Solar Cells Based on Thin-Film a-Si:H/SiGe Heterostructure
Authors: Kosarian Abdolnabi , Jelodarian Peyman
Published: December 2011

In amorphous thin-film p-i-n solar cell, a thick absorber layer can absorb more light to generate carriers. On the other hand, a thin i-layer cannot absorb enough light. Thickness of the i-layer is a key parameter that can limit the performance of solar cell. Introducing Ge atoms to the Si lattice in Si-based solar cells is an effective approach in improving their characteristics. Especially, current density of the cell can be enhanced without deteriorating its open circuit voltage, due to the modulation of material band-gap and the formation of a heterostructure. This work presents a novel numerical evaluation and optimization of an amorphous silicon double-junction structure thin-film solar cell (a-SiGe:H/a-Si:H) and focuses on optimization of a-SiGe:H mid-gap single-junction solar cell based on the optimization of the Ge content in the film, thickness of i-layer, p-layer and doping concentration of p-layer in a (p-layer a-Si:H/i-layer a-SiGe:H/n-layer a-Si:H) single-junction thin-film solar cell. Optimization shows that for an appropriate Ge concentration, the efficiency of a-Si:H/a-SiGe solar cell is improved by about 6.5% compared with the traditional a-Si:H solar cells.
Detection ofTrichomonas vaginalisin Vaginal Swab Clinical Samples from Palestinian Women by Culture
Authors: Houso Yasmeen , Farraj Mohammad A. , Ramlawi As'ad , Essawi Tamer
Published: December 2011

Background. Trichomoniasis is a common sexually transmitted disease caused byTrichomonas vaginalis. It is a major health problem worldwide. The World Health Organization (WHO) has estimated that 180 million infections are acquired annually worldwide.Methodology. Vaginal swabs (1207) were cultured forT. vaginalison Trichomonas Medium no. 2 (Oxoid) soon after specimen collection. The cultures were examined daily using a light microscope to detect the presence ofT. vaginalis.Results. The prevalence ofT. vaginaliswas 13.6% (164/1207). The infection rate was the highest during pregnancy, 28.1%, and the lowest among women whose spouses use condoms, 8.6%.Conclusions. The culture method was used in this study to accurately determine the prevalence of this parasite in the West Bank, Palestine. The results of the study will eliminate ambiguities concerning trichomoniasis in this country and will contribute to better management and proper treatment.
Paramagnetic Resonance as a Probe of the Spin Gap in Normal State of Superconductor
Authors: Owens Frank J.
Published: December 2011

It is shown that electron paramagnetic resonance (EPR) can be used to observe the spin gap in copper oxide superconductors. The electron paramagnetic resonance spectra of the Cu2+ ion in underdoped show a pronounced decrease in intensity in the normal state as the temperature is lowered to 133 K, the superconducting transition temperature of the material. The decrease is attributed to a pairing of the Cu2+   spins to form a spin gap. A spin gap of 0.0533 eV is estimated from the data which is in order of magnitude agreement with values obtained from NMR measurements.
Boron: Metallacarbaboranes
Authors: Housecroft Catherine E.
Published: December 2011

Metallacarbaboranes comprise carbon, boron, and metal‐atom‐containing clusters. The classes of compounds and their syntheses are described, as well as skeletal isomerism, electrochemistry, and reactivity. The applications of metallacarbaboranes in biosciences, medicinal chemistry, and materials science are gradually becoming more significant.