bluuebunny/crossref_metadata_2025 huggingface dataset:
Bio-Inspired Micro-Fluidic Angular-Rate Sensor for Vestibular Prostheses
Authors: Andreou Charalambos , Pahitas Yiannis , Georgiou Julius
Published: July 2014

This paper presents an alternative approach for angular-rate sensing based on the way that the natural vestibular semicircular canals operate, whereby the inertial mass of a fluid is used to deform a sensing structure upon rotation. The presented gyro has been fabricated in a commercially available MEMS process, which allows for microfluidic channels to be implemented in etched glass layers, which sandwich a bulk-micromachined silicon substrate, containing the sensing structures. Measured results obtained from a proof-of-concept device indicate an angular rate sensitivity of less than 1 °/s, which is similar to that of the natural vestibular system. By avoiding the use of a continually-excited vibrating mass, as is practiced in today’s state-of-the-art gyroscopes, an ultra-low power consumption of 300 μW is obtained, thus making it suitable for implantation.
A Large Response Range Reflectometric Urea Biosensor Made from Silica-Gel Nanoparticles
Authors: Alqasaimeh Muawia , Heng Lee , Ahmad Musa , Raj A.S. , Ling Tan
Published: July 2014

A new silica-gel nanospheres (SiO2NPs) composition was formulated, followed by biochemical surface functionalization to examine its potential in urea biosensor development. The SiO2NPs were basically synthesized based on sol–gel chemistry using a modified Stober method. The SiO2NPs surfaces were modified with amine (-NH2) functional groups for urease immobilization in the presence of glutaric acid (GA) cross-linker. The chromoionophore pH-sensitive dye ETH 5294 was physically adsorbed on the functionalized SiO2NPs as pH transducer. The immobilized urease determined urea concentration reflectometrically based on the colour change of the immobilized chromoionophore as a result of the enzymatic hydrolysis of urea. The pH changes on the biosensor due to the catalytic enzyme reaction of immobilized urease were found to correlate with the urea concentrations over a linear response range of 50–500 mM (R2 = 0.96) with a detection limit of 10 mM urea. The biosensor response time was 9 min with reproducibility of less than 10% relative standard deviation (RSD). This optical urea biosensor did not show interferences by Na+, K+, Mg2+ and NH4+ ions. The biosensor performance has been validated using urine samples in comparison with a non-enzymatic method based on the use of p-dimethylaminobenzaldehyde (DMAB) reagent and demonstrated a good correlation between the two different methods (R2 = 0.996 and regression slope of 1.0307). The SiO2NPs-based reflectometric urea biosensor showed improved dynamic linear response range when compared to other nanoparticle-based optical urea biosensors.
Waterfront Areas as Hotspots of Sustainable and Creative Development of Cities
Authors: Girard Luigi , Kourtit Karima , Nijkamp Peter
Published: July 2014

This special issue of Sustainability is devoted to a very important sustainability topic, viz. cities and waterfront infrastructure. The presence of—and access to—water has been a critical factor in the long history of settlement patterns of humankind. Water is not only a necessary consumption good for survival, but has also an important production potential in an economic sense. [...]
The Effects of Biofuel Feedstock Production on Farmers’ Livelihoods in Ghana: The Case of Jatropha curcas
Authors: Acheampong Emmanuel , Campion Benjamin
Published: July 2014

The widespread acquisition of land for large-scale/commercial production of biofuel crops in Ghana has raised concerns from civil society organizations, local communities and other parties, regarding the impact of these investments on local livelihoods. This paper assessed the effect of large-scale acquisition of land for production of Jatropha curcas on farmers’ livelihoods in Ghana. The study was conducted in 11 communities spanning the major agro-ecological zones and political divisions across Ghana. Methods of data collection included questionnaire survey, interviews and focus group discussions. Results show that several households have lost their land to Jatropha plantations leading, in some cases, to violent conflicts between biofuel investors, traditional authorities and the local communities. Most people reported that, contrary to the belief that Jatropha does well on marginal lands, the lands acquired by the Jatropha Companies were productive lands. Loss of rights over land has affected households’ food production and security, as many households have resorted to reducing the area they have under cultivation, leading to shortening fallow periods and declining crop yields. In addition, although the cultivation of Jatropha led to the creation of jobs in the communities where they were started, such jobs were merely transient. The paper contends that, even though the impact of Jatropha feedstock production on local livelihoods in Ghana is largely negative, the burgeoning industry could be developed in ways that could support local livelihoods.
The Combined Repetitive Oligopeptides of Clostridium difficile Toxin A Counteract Premature Cleavage of the Glucosyl-Transferase Domain by Stabilizing Protein Conformation
Authors: Olling Alexandra , Hüls Corinna , Goy Sebastian , Müller Mirco , Krooss Simon , Rudolf Isa , Tatge Helma , Gerhard Ralf
Published: July 2014

Toxin A (TcdA) and B (TcdB) from Clostridium difficile enter host cells by receptor-mediated endocytosis. A prerequisite for proper toxin action is the intracellular release of the glucosyltransferase domain by an inherent cysteine protease, which is allosterically activated by inositol hexaphosphate (IP6). We found that in in vitro assays, the C-terminally-truncated TcdA1–1065 was more efficient at IP6-induced cleavage compared with full-length TcdA. We hypothesized that the C-terminally-located combined repetitive oligopeptides (CROPs) interact with the N-terminal part of the toxin, thereby preventing autoproteolysis. Glutathione-S-transferase (GST) pull-down assays and microscale thermophoresis confirmed binding between the CROPs and the glucosyltransferase (TcdA1–542) or intermediate (TcdA1102–1847) domain of TcdA, respectively. This interaction between the N- and C-terminus was not found for TcdB. Functional assays revealed that TcdB was more susceptible to inactivation by extracellular IP6-induced cleavage. In vitro autoprocessing and inactivation of TcdA, however, significantly increased, either by acidification of the surrounding milieu or following exchange of its CROP domain by the homologous CROP domain of TcdB. Thus, TcdA CROPs contribute to the stabilization and protection of toxin conformation in addition to function as the main receptor binding domain.
L'amélioration du vanillier à Madagascar
Authors: Dequaire Jean
Published: July 2014

This is a review of the works done at the Vanilla Research Station of Antalaha Madagascar until 1974. Vanilla vines are attacked by several diseases, and chiefly vanilla root-rot, which as soil borne disease is quite difficult to fight. A study of diseases causes and implications is developed. The methods used, and the results reached in breeding vanilla plant for resistance and improvement are exposed.
Le palmier à sucre, Borassus flabellifer L., ses différents produits et la technologie associée en Birmanie
Authors: Lubeigt Guy
Published: July 2014

Les palmiers à sucre (Borassus flabellifer L.), probablement originaire de l'Inde du Sud, sont répandus dans toute l'Asie du Sud-Est. Dans la zone sèche de Birmanie centrale, ils humanisent un paysage qui évolue entre le désert et la savane à épineux. Les palmiers Borassus jouent un rôle important dans l'économie du pays, en fournissant environ la moitié du sucre consommé par la population. Les techniques mises en œuvre pour exploiter ces palmiers sont particulièrement élaborées et témoignent de très anciennes traditions. Les conditions de vie des paysans-grimpeurs qui cultivent des Borassus sont de plus en plus précaires dans une région où le milieu naturel est fortement menacé par l'explosion démographique. L'équilibre séculaire entre l'homme et la nature est ainsi en voie de rupture.
Domestication of American wild rice (Zizania aquatica L., Gramineae)
Authors: de Wet J.M.J. , Oelke Ervin A.
Published: July 2014

Largement distribué dans le Nord et l'Est de l'Amérique du Nord tempérée, l'espèce Zizania aquatica L. comprend quatre variétés dont les caractéristiques et la distribution sont données. La variété angustifolia est la plus communément récoltée dans le Nord (New Brunswick, Manitoba et parties proches des États Unis). Une race améliorée est cultivée et la perte de grains à maturité est bien moindre que celle des «races sauvages». Le semis est cependant naturellement assuré par les grains tombés lors du passage de la moissonneuse.
Vocabulaire des maladies du bétail en langue Fulfuldé chez les Mbororo de l'Empire Centrafricain
Authors: Morvan Hervé , Vercruysse Joseph
Published: July 2014

This is a survey of the vocabulary used by the Mbororo of the Central African Empire to designate animal diseases. Data on how these Africans breeders perceive disease is also provided.
The polyploidy revolution then…and now: Stebbins revisited
Authors: Soltis Douglas E. , Visger Clayton J. , Soltis Pamela S.
Published: July 2014

Polyploidy has long been considered a major force in plant evolution. G. Ledyard Stebbins, Jr., an architect of the Modern Synthesis, elegantly addressed a broad range of topics, from genes to chromosomes to deep phylogeny, but some of his most lasting insights came in the study of polyploidy. Here, we review the immense impact of his work on polyploidy over more than 60 years, from his entrance into this fledgling field in the 1920s until the end of his career. Stebbins and his contemporaries developed a model of polyploid evolution that persisted for nearly half a century. As new perspectives emerged in the 1980s and new genetic tools for addressing key aspects of polyploidy have become available, a new paradigm of polyploidy has replaced much of the Stebbinsian framework. We review that paradigm shift and emphasize those areas in which the ideas of Stebbins continue to propel the field forward, as well as those areas in which the field was held back; we also note new directions that plant geneticists and evolutionists are now exploring in polyploidy research. Perhaps the most important conclusion from recent and ongoing studies of polyploidy is that, following Levin and others, polyploidy may propel a population into a new adaptive sphere given the myriad changes that accompany genome doubling.
Organic and inorganic–organic thin film structures by molecular layer deposition: A review
Authors: Sundberg Pia , Karppinen Maarit
Published: July 2014

The possibility to deposit purely organic and hybrid inorganic–organic materials in a way parallel to the state-of-the-art gas-phase deposition method of inorganic thin films, i.e., atomic layer deposition (ALD), is currently experiencing a strongly growing interest. Like ALD in case of the inorganics, the emerging molecular layer deposition (MLD) technique for organic constituents can be employed to fabricate high-quality thin films and coatings with thickness and composition control on the molecular scale, even on complex three-dimensional structures. Moreover, by combining the two techniques, ALD and MLD, fundamentally new types of inorganic–organic hybrid materials can be produced. In this review article, we first describe the basic concepts regarding the MLD and ALD/MLD processes, followed by a comprehensive review of the various precursors and precursor pairs so far employed in these processes. Finally, we discuss the first proof-of-concept experiments in which the newly developed MLD and ALD/MLD processes are exploited to fabricate novel multilayer and nanostructure architectures by combining different inorganic, organic and hybrid material layers into on-demand designed mixtures, superlattices and nanolaminates, and employing new innovative nanotemplates or post-deposition treatments to, e.g., selectively decompose parts of the structure. Such layer-engineered and/or nanostructured hybrid materials with exciting combinations of functional properties hold great promise for high-end technological applications.
The chemoenzymatic synthesis of clofarabine and related 2′-deoxyfluoroarabinosyl nucleosides: the electronic and stereochemical factors determining substrate recognition by E. coli nucleoside phosphorylases
Authors: Fateev Ilja V , Antonov Konstantin V , Konstantinova Irina D , Muravyova Tatyana I , Seela Frank , Esipov Roman S , Miroshnikov Anatoly I , Mikhailopulo Igor A
Published: July 2014

Two approaches to the synthesis of 2-chloro-9-(2-deoxy-2-fluoro-β-D-arabinofuranosyl)adenine (1, clofarabine) were studied. The first approach consists in the chemical synthesis of 2-deoxy-2-fluoro-α-D-arabinofuranose-1-phosphate (12a, 2FAra-1P) via three step conversion of 1,3,5-tri-O-benzoyl-2-deoxy-2-fluoro-α-D-arabinofuranose (9) into the phosphate 12a without isolation of intermediary products. Condensation of 12a with 2-chloroadenine catalyzed by the recombinant E. coli purine nucleoside phosphorylase (PNP) resulted in the formation of clofarabine in 67% yield. The reaction was also studied with a number of purine bases (2-aminoadenine and hypoxanthine), their analogues (5-aza-7-deazaguanine and 8-aza-7-deazahypoxanthine) and thymine. The results were compared with those of a similar reaction with α-D-arabinofuranose-1-phosphate (13a, Ara-1P). Differences of the reactivity of various substrates were analyzed by ab initio calculations in terms of the electronic structure (natural purines vs analogues) and stereochemical features (2FAra-1P vs Ara-1P) of the studied compounds to determine the substrate recognition by E. coli nucleoside phosphorylases. The second approach starts with the cascade one-pot enzymatic transformation of 2-deoxy-2-fluoro-D-arabinose into the phosphate 12a, followed by its condensation with 2-chloroadenine thereby affording clofarabine in ca. 48% yield in 24 h. The following recombinant E. coli enzymes catalyze the sequential conversion of 2-deoxy-2-fluoro-D-arabinose into the phosphate 12a: ribokinase (2-deoxy-2-fluoro-D-arabinofuranose-5-phosphate), phosphopentomutase (PPN; no 1,6-diphosphates of D-hexoses as co-factors required) (12a), and finally PNP. The substrate activities of D-arabinose, D-ribose and D-xylose in the similar cascade syntheses of the relevant 2-chloroadenine nucleosides were studied and compared with the activities of 2-deoxy-2-fluoro-D-arabinose. As expected, D-ribose exhibited the best substrate activity [90% yield of 2-chloroadenosine (8) in 30 min], D-arabinose reached an equilibrium at a concentration of ca. 1:1 of a starting base and the formed 2-chloro-9-(β-D-arabinofuranosyl)adenine (6) in 45 min, the formation of 2-chloro-9-(β-D-xylofuranosyl)adenine (7) proceeded very slowly attaining ca. 8% yield in 48 h.
New records of Paraleptophlebia werneri Ulmer, 1920 and P. strandii (Eaton, 1901) from Finland (Ephemeroptera, Leptophlebiidae)
Authors: Salmela Jukka , Savolainen Eino
Published: July 2014

The mayfly species Paraleptophlebia werneri has been rediscovered from Finland. The species was classified as RE (regionally extinct) in the most recent national red-list assessment. The new locality is close to the Russian border in NE Lapland, Savukoski. Adult males were collected with a sweep net around a pond. Paraleptophlebia strandii is a rather poorly known but widespread Finnish species. The adults of this species occurred in great numbers in aapamires of central Lapland (Sodankylä). We hypothesize that these leptophlebid species are not dependent on running water but may instead thrive in small lentic water bodies.
Agir pour construire des savoirs
Authors: Rousselet Jeanne
Published: July 2014

À partir de son expérience de professeur, l’auteur tente de décrire les évolutions de la pédagogie dans l’enseignement, et de montrer comment, depuis la toute petite enfance jusqu’à l’entrée au collège, les enfants puis les élèves bâtissent leurs apprentissages en agissant ; comment l’enseignement fonctionne mieux, quel que soit le profil des élèves, si le pédagogue tient compte des particularités de ses élèves pour proposer une démarche pédagogique active, où l’élève opère sur son propre savoir, tous âge, handicap, précocité confondus, dans un même souci éducatif de différencier ses propositions d’actions.
Du passage à l'acte au passage par l'acte. Le soin dans un hébergement thérapeutique pour adolescent
Authors: Boussion Raphaël
Published: July 2014

L’accueil d’adolescents dans un service de soins pédopsychiatriques confronte inévitablement les soignants aux passages à l’acte, à l’expression de violences agies et au traitement des questions qu’ils soulèvent. L’institution malmenée, objet des mouvements destructeurs, doit pouvoir survivre. Si le deuil d’une institution réparatrice peut être traversé, si un vécu d’impuissance relative peut être toléré par l’équipe, le « vivre ensemble » peut offrir la possibilité d’accueillir les violences qui accompagnent les nouveaux liens. Le travail institutionnel d’élaboration collective permet l’établissement de relations nouvelles et tempérées, propices à l’investissement de la pensée et de la parole.
La violence des adolescentes. Déviances et genre
Authors: Le Goaziou Véronique
Published: July 2014

Depuis plus d’un siècle, l’un des constats majeurs en histoire et en sociologie de la déviance est que la délinquance et la criminalité sont un phénomène principalement masculin. En dépit de la médiatisation d’une supposée augmentation de la violence des filles, les femmes, et plus particulièrement les adolescentes, demeurent largement minoritaires dans les passages à l’acte réprouvés par la loi. Cet article revient sur cette différence et tente d’en comprendre et d’en discuter les raisons.
Application of mycotoxin adsorbent to cattle feed contaminated with zearalenone: urinary zearalenone excretion and association with anti-Müllerian hormone
Authors: Fushimi Y. , Takagi M. , Hasunuma H. , Uno S. , Kokushi E. , Watanabe U. , Liu J. , Marey M.A. , Miyamoto A. , Otoi T. , Deguchi E. , Fink-Gremmels J.
Published: July 2014

This study investigated (1) protective effects of a commercially available mycotoxin adsorbent (MA) and (2) endocrine effects ofin vivo exposure to zearalenone (ZEA) in cattle. The sample included a Japanese Black female cattle herd (MYT herd) that displayed persistently high urinary ZEA concentrations. A second herd (NM herd) was used as a control. Three groups from each herd were assessed: MX (n=6; MA mixed with concentrate), TD (n=6; MA applied as topdressing with the concentrate), and a positive control (n=6; no MA application). Urine and blood samples were collected at the start of MA supplementation (day 0), on the final day of supplementation (day 16), and on the final day of the sampling period (day 58 for MYT herd and day 50 for NM herd). Urinary ZEA concentrations (pg/mg of creatinine) were measured by ELISA and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Haematological and serum biochemical analyses were performed to monitor hepatic, renal, nutritional, and mineral intake statuses. Ovulation status was assessed by progesterone (P4) and antral follicle population by anti-Müllerian hormone (AMH) levels. The urinary concentrations of ZEA and its metabolites in the MX and TD groups were significantly lower (P<0.05) at day 16 compared with the control group, as measured by LC-MS/MS. The valid ratio of AMH-positive (≯0.08 ng/ml) cattle was significantly higher in the NM herd than in the MYT herd without affecting the P4-positive (≯3 ng/ml) ratio, suggesting different populations of antral follicles. Significant differences were also observed between the MX and the control in aspartate aminotransferase and γ-glutamyltransferase at day 58, suggesting preventive effects of MA supplementation. Our field trial indicated that MA supplementation of a ZEA-contaminated diet has beneficial effects in reducing ZEA absorption from the intestine of cattle, maintaining endocrine homeostasis and reversing hepatic effects.
Systematic Review of Clinical Judgment and Reasoning in Nursing
Authors: Cappelletti Adriana , Engel Joyce K. , Prentice Dawn
Published: July 2014

A systematic review was conducted to examine the findings on clinical judgment and reasoning in nursing that have emerged since Tanner's review in 2006. Electronic databases were searched to locate primary research studies about clinical judgment and reasoning in nursing. Fifteen studies were extracted and analyzed using the five main conclusions outlined by Tanner. The findings of the systematic review generally support Tanner's original model, although the role of experience in clinical reasoning and judgment is still not well understood or fully established. In recent literature, researchers have furthered their knowledge by using tools for improving these skills in both nursing students and practicing nurses, although no one strategy has been identified as being more effective. This is reflected in the consideration of a sixth conclusion on clinical judgment and reasoning in nursing—education strategies to improve clinical judgment may influence what a nurse brings to the situation. [
J Nurs Educ.
2014;53(8):453–458.]
Clinical Research Education: Perspectives of Nurses, Employers, and Educators
Authors: Galassi Annette L. , Grady Meredith A. , O'Mara Ann M. , Ness Elizabeth A. , Parreco Linda K. , Belcher Anne E. , Hastings Clare E.
Published: July 2014

The aim of this study was to understand the current environment around clinical research relating to nursing education and practice. This descriptive study analyzed data from 33 in-depth interviews with faculty members, nurse executives, staff development directors, and practicing nurses, as well as an online interactive brainstorming session with 28 deans of schools of nursing (or their designee). Patterns and themes that emerged within each group were identified and analyzed in relation to study objectives. Central themes emerged around participants' knowledge and attitudes about clinical research education for baccalaureate nursing students, factors enhancing or inhibiting inclusion of clinical research content in baccalaureate nursing programs, and professional roles nursing students could expect to assume after graduation. Although the participants agreed that mastery of clinical research knowledge and related skills is important, there was no agreement whether nurses should receive this education and training in baccalaureate programs or in staff development. [
J Nurs Educ.
2014;53(8):466–472.]
Profecía congelada: El Manifiesto Comunista hoy
Authors: Toscano Alberto
Published: July 2014

Este pequeño ensayo pretende ir más allá de las celebraciones hagiográficas que hacen del Manifiesto Comunista un monumento para reflexionar sobre las lecciones que se pueden extraer de las formas específicas de su fallida realización. Contra el cliché de que el Manifiesto es un texto profético, deberíamos explorar la disyunción entre el pronóstico incisivo de la “prosa” del capitalismo y la anticipación frustrada de la “poesía” de la revolución. Este ensayo argumenta que las limitaciones analíticas y políticas del Manifiesto deben ser localizadas en la excesiva linealidad y homogeneidad con que enmarca los poderes de abstracción del capital. En la medida en que el capital procede mediante una dialéctica de la homogeneización y la diferenciación, de la expansión y la división espacial, la erosión de la tradición y su refuncionamiento cínico con el objeto de apuntalar la dominación, las tareas de la unidad de la clase obrera y la internacionalización planteadas por el Manifiesto devienen aún más apremiantes políticamente, y cualquier cosa excepto inevitables.
Comunismo y reflexión sobre la historia en la obra de K. Marx
Authors: Martínez Francisco José
Published: July 2014

Se trata de realizar dos calas en los escritos marxianos: los artículos y trabajo de 1843 y 1844 centrados en torno a los Anales Franco Alemanes y los análisis de la guerra civil en Francia y la Comuna de París. A partir de dichas calas se sostiene el carácter antidealista y antiutópico del pensamiento marxiano, y especialmente de su idea de comunismo, las relaciones entre la superación de la filosofía y la abolición del proletariado, su ajuste a la realidad contemporánea como punto de partida esencial para su comprensión y transformación, y su clarividencia sobre la centralidad de la ciencia en el proceso productivo así como sobre el carácter colectivo de dicho proceso de la producción capitalista desarrollada.
Eric Hobsbawm y su lectura marxista de la historia
Authors: Pilatowsky Mauricio
Published: July 2014

En este ensayo se presenta un breve estudio de las aportaciones del historiador Eric Hobsbawm en el campo de la historia y de sus posturas marxistas; tanto en su trabajo académico como en su práctica política. El análisis incluye una revisión de su biografía ya que según el autor los investigadores y su manera de investigar responden a las circunstancias que les toca vivir. Desde esta perspectiva se aborda su interpretación de Marx
y del marxismo, su forma de entender la historia, su militancia en el Partido Comunista, su identidad judía y el tratamiento del nacionalismo en su relación con el estudio del capitalismo.
El marxismo político, excéntrico, heterodoxo, radical y sin ismos de un epistemólogo comunista que amaba “La flauta mágica”
Authors: López Arnal Salvador
Published: July 2014

Manuel Sacristán Luzón (1925-1985), un lógico, epistemólogo y filósofo heterodoxo, militante del PSUC-PCE durante largos años, que tuvo un papel esencial en la reintroducción de la tradición marxista-comunista en nuestro país a finales de los años cincuenta, sugirió en sus últimos años una fuerte revisión del ideario comunista tras el Mayo del 68, la aniquilación de la Primavera de Praga y, destacadamete, la irrupción de las problemáticas ecológicas. Sus propuestas para una política de la ciencia de orientación socialista, próxima a la tradición tecnocientífica no cegada y crítica a un tiempo de las concepciones neorrománticas inspiradas en la obra de Heidegger (sobre cuya gnoseología escribió su tesis doctoral), siguen siendo muestra de la lucidez y penetración de un pensamiento nunca servil ni agotado que apostó siempre por una pasión (emancipatoria) razonada anclada en la informacióncientífica contrastada, en el compromiso con los desfavorecidos de la tierra y en la práctica de un filosofar creativo y humanista.
La especificidad del discurso moral en Kant
Authors: Mumbrú Mora Àlex
Published: July 2014

El objetivo del presente artículo es mostrar cómo la especificidad del discurso moral obliga a introducir un modo de exposición de nuestros conceptos que no acaba de ajustarse plenamente a ninguno de los dos modelos presentados por Kant en el parágrafo 59 de la Crítica de la facultad de juzgar. Situándose a medio camino de esquema y símbolo, la noción de «tipo» (Typus) actúa como elemento mediador entre la ley moral y cada una de sus posibles concreciones.
Prostaglandin E2 Negatively Regulates the Production of Inflammatory Cytokines/Chemokines and IL-17 in Visceral Leishmaniasis
Authors: Saha Amrita , Biswas Arunima , Srivastav Supriya , Mukherjee Madhuchhanda , Das Pijush K. , Ukil Anindita
Published: July 2014

Persistence of intracellular infection depends on the exploitation of factors that negatively regulate the host immune response. In this study, we elucidated the role of macrophage PGE2, an immunoregulatory lipid, in successful survival of Leishmania donovani, causative agent of the fatal visceral leishmaniasis. PGE2 production was induced during infection and resulted in increased cAMP level in peritoneal macrophages through G protein–coupled E-series prostanoid (EP) receptors. Among four different EPs (EP1–4), infection upregulated the expression of only EP2, and individual administration of either EP2-specific agonist, butaprost, or 8-Br–cAMP, a cell-permeable cAMP analog, promoted parasite survival. Inhibition of cAMP also induced generation of reactive oxygen species, an antileishmanial effector molecule. Negative modulation of PGE2 signaling reduced infection-induced anti-inflammatory cytokine polarization and enhanced inflammatory chemokines, CCL3 and CCL5. Effect of PGE2 on cytokine and chemokine production was found to be differentially modulated by cAMP-dependent protein kinase A (PKA) and exchange protein directly activated by cAMP (EPAC). PGE2-induced decreases in TNF-α and CCL5 were mediated specifically by PKA, whereas administration of brefeldin A, an EPAC inhibitor, could reverse decreased production of CCL3. Apart from modulating inflammatory/anti-inflammatory balance, PGE2 inhibited antileishmanial IL-17 cytokine production in splenocyte culture. Augmented PGE2 production was also found in splenocytes of infected mice, and administration of EP2 antagonist in mice resulted in reduced liver and spleen parasite burden along with host-favorable T cell response. These results suggest that Leishmania facilitates an immunosuppressive environment in macrophages by PGE2-driven, EP2-mediated cAMP signaling that is differentially regulated by PKA and EPAC.
PTX3 Binds MD-2 and Promotes TRIF-Dependent Immune Protection in Aspergillosis
Authors: Bozza Silvia , Campo Silvia , Arseni Brunilde , Inforzato Antonio , Ragnar Lindstedt , Bottazzi Barbara , Mantovani Alberto , Moretti Silvia , Oikonomous Vasileios , De Santis Rita , Carvalho Agostinho , Salvatori Giovanni , Romani Luigina
Published: July 2014

The long pentraxin 3 (PTX3) modulates different effector pathways involved in innate resistance to Aspergillus fumigatus, including complement activation or promotion of phagocytosis by interacting with FcγRs. However, whether and how TLRs modulate PTX3 mediates antifungal resistance is not known. In this study, we demonstrate that PTX3 binds myeloid differentiation protein 2 (MD-2) in vitro and exerts its protective antifungal activity in vivo through TLR4/MD-2–mediated signaling. Similar to Tlr4−/− mice, Md2−/− mice displayed high susceptibility to pulmonary aspergillosis, a phenotype associated with a proinflammatory cytokine profile and impaired antifungal activity of polymorphonuclear neutrophils. Treating Md2−/− mice with PTX3 failed to confer immune protection against the fungus, whereas adoptive transfer of MD-2–competent polymorphonuclear neutrophils restored it. Mechanistically, engagement of MD-2 by PTX3-opsonized Aspergillus conidia activated the TLR4/Toll/IL-1R domain-containing adapter inducing IFN-β–dependent signaling pathway converging on IL-10. Thus, we have identified a novel receptor mechanism, involving the TLR4/MD-2/Toll/IL-1R domain-containing adapter inducing IFN-β–mediated signaling, whereby PTX3 elicits antifungal resistance with limited immunopathology in A. fumigatus infection.
The matrix model for dessins d'enfants
Authors: Ambjørn Jan , Chekhov Leonid
Published: July 2014

We present the matrix models that are the generating functions for branched covers of the complex projective line ramified over 0, 1, and

\infty

(Grotendieck’s dessins d’enfants) of fixed genus, degree, and the ramification profile at infinity. For general ramifications at other points, the model is the two-logarithm matrix model with the external field studied previously by one of the authors (L.Ch.) and K.Palamarchuk. It lies in the class of the generalised Kontsevich models (GKM) thus being the Kadomtsev–Petviashvili (KP) hierarchy tau function and, upon the shift of times, this model is equivalent to a Hermitian one-matrix model with a general potential whose coefficients are related to the KP times by a Miwa-type transformation. The original model therefore enjoys a topological recursion and can be solved in terms of shifted moments of the standard Hermitian one-matrix model at all genera of the topological expansion. We also derive the matrix model for clean Belyi morphisms, which turns out to be the Kontsevich–Penner model introduced by the authors and Yu. Makeenko. Its partition function is also a KP hierarchy tau function, and this model is in turn equivalent to a Hermitian one-matrix model with a general potential. Finally we prove that the generating function for general two-profile Belyi morphisms is a GKM thus proving that it is also a KP hierarchy tau function in proper times.
On the two-point function of general planar maps and hypermaps
Authors: Bouttier Jérémie , Fusy Éric , Guitter Emmanuel
Published: July 2014

We consider the problem of computing the distance-dependent two-point function of general planar maps and hypermaps, i.e. the problem of counting such maps with two marked points at a prescribed distance. The maps considered here may have faces of arbitrarily large degree, which requires new bijections to be tackled. We obtain exact expressions for the following cases: general and bipartite maps counted by their number of edges, 3-hypermaps and 3-constellations counted by their number of dark faces, and finally general and bipartite maps counted by both their number of edges and their number of faces.
The Bialgebra of specified graphs and external structures
Authors: Manchon Dominique , Belhaj Mohamed Mohamed
Published: July 2014

We construct a Hopf algebra structure on the space of specified Feynman graphs of a quantumfield theory. We introduce a convolution product and a semigroup of characters of this Hopf algebra with values in some suitable commutative algebra taking momenta into account. We then implement the renormalization described by A. Connes and D. Kreimer in [2] and the Birkhoff decomposition for two renormalization schemes: the minimal subtraction scheme and the Taylor expansion scheme.
Identifying Etiological Agents Causing Diarrhea in Low Income Ecuadorian Communities
Authors: Vasco Gabriela , Trueba Gabriel , Atherton Richard , Calvopiña Manuel , Cevallos William , Andrade Thamara , Eguiguren Martha , Eisenberg Joseph N. S.
Published: July 2014

Continued success in decreasing diarrheal disease burden requires targeted interventions. To develop such interventions, it is crucial to understand which pathogens cause diarrhea. Using a case-control design we tested stool samples, collected in both rural and urban Ecuador, for 15 pathogenic microorganisms. Pathogens were present in 51% of case and 27% of control samples from the urban community, and 62% of case and 18% of control samples collected from the rural community. Rotavirus and Shigellae were associated with diarrhea in the urban community; co-infections were more pathogenic than single infection; Campylobacter and Entamoeba histolytica were found in large numbers in cases and controls; and non-typhi Salmonella and enteropathogenic Escherichia coli were not found in any samples. Consistent with the Global Enteric Multicenter Study, focused in south Asia and sub-Saharan Africa, we found that in Ecuador a small group of pathogens accounted for a significant amount of the diarrheal disease burden.
Polymorphisms in Plasmodium falciparum Chloroquine Resistance Transporter and Multidrug Resistance 1 Genes: Parasite Risk Factors That Affect Treatment Outcomes for P. falciparum Malaria After Artemether-Lumefantrine and Artesunate-Amodiaquine
Authors: Venkatesan Meera , Gadalla Nahla B. , Stepniewska Kasia , Dahal Prabin , Nsanzabana Christian , Moriera Clarissa , Price Ric N. , Mårtensson Andreas , Rosenthal Philip J. , Dorsey Grant , Sutherland Colin J. , Guérin Philippe , Davis Timothy M. E. , Ménard Didier , Adam Ishag , Ademowo George , Arze Cesar , Baliraine Frederick N. , Berens-Riha Nicole , Björkman Anders , Borrmann Steffen , Checchi Francesco , Desai Meghna , Dhorda Mehul , Djimdé Abdoulaye A. , El-Sayed Badria B. , Eshetu Teferi , Eyase Frederick , Falade Catherine , Faucher Jean-François , Fröberg Gabrielle , Grivoyannis Anastasia , Hamour Sally , Houzé Sandrine , Johnson Jacob , Kamugisha Erasmus , Kariuki Simon , Kiechel Jean-René , Kironde Fred , Kofoed Poul-Erik , LeBras Jacques , Malmberg Maja , Mwai Leah , Ngasala Billy , Nosten Francois , Nsobya Samuel L. , Nzila Alexis , Oguike Mary , Otienoburu Sabina Dahlström , Ogutu Bernhards , Ouédraogo Jean-Bosco , Piola Patrice , Rombo Lars , Schramm Birgit , Somé A. Fabrice , Thwing Julie , Ursing Johan , Wong Rina P. M. , Zeynudin Ahmed , Zongo Issaka , Plowe Christopher V. , Sibley Carol Hopkins , _ _
Published: July 2014

Adequate clinical and parasitologic cure by artemisinin combination therapies relies on the artemisinin component and the partner drug. Polymorphisms in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multidrug resistance 1 (pfmdr1) genes are associated with decreased sensitivity to amodiaquine and lumefantrine, but effects of these polymorphisms on therapeutic responses to artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) have not been clearly defined. Individual patient data from 31 clinical trials were harmonized and pooled by using standardized methods from the WorldWide Antimalarial Resistance Network. Data for more than 7,000 patients were analyzed to assess relationships between parasite polymorphisms in pfcrt and pfmdr1 and clinically relevant outcomes after treatment with AL or ASAQ. Presence of the pfmdr1 gene N86 (adjusted hazards ratio = 4.74, 95% confidence interval = 2.29 – 9.78, P < 0.001) and increased pfmdr1 copy number (adjusted hazards ratio = 6.52, 95% confidence interval = 2.36–17.97, P < 0.001) were significant independent risk factors for recrudescence in patients treated with AL. AL and ASAQ exerted opposing selective effects on single-nucleotide polymorphisms in pfcrt and pfmdr1. Monitoring selection and responding to emerging signs of drug resistance are critical tools for preserving efficacy of artemisinin combination therapies; determination of the prevalence of at least pfcrt K76T and pfmdr1 N86Y should now be routine.
Trends in Peroxyacetyl Nitrate (PAN) in the upper troposphere and lower stratosphere over Southern Asia during the summer monsoon season: regional impacts
Authors: Fadnavis S. , Schultz M. G. , Semeniuk K. , Mahajan A. S. , Pozzoli L. , Sonbawane S. , Ghude S. D. , Kiefer M. , Eckert E.
Published: July 2014

Abstract. We analyze temporal trends of Peroxyacetyl Nitrate (PAN) retrievals from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) during 2002–2011 in the altitude range 8–23 km over the Asian summer monsoon (ASM) region. The greatest enhancements of PAN mixing ratios in the upper troposphere and lower stratosphere (UTLS) are seen during the summer monsoon season from June to September. During the monsoon season, the mole fractions of PAN show statistically significant (at 2 sigma level) positive trends from 0.2 ± 0.05 to 4.6 ± 3.1 ppt year−1 (except between 12–14 km) which is higher than the annual mean trends of 0.1 ± 0.05 to 2.7 ± 0.8 ppt year−1. These rising concentrations point to increasing NOx (=NO+NO2) and volatile organic compound (VOC) emissions from developing nations in Asia, notably India and China. We analyze the influence of monsoon convection on the distribution of PAN in UTLS with simulations using the global chemistry-climate model ECHAM5-HAMMOZ. During the monsoon, transport into the UTLS over the Asian region primarily occurs from two convective zones, one extending from the Bay of Bengal to the South China Sea and the other over the southern flank of the Himalayas. India and China are NOx limited regions, and thus we use the model to evaluate the contributions from enhanced NOx emissions to the changes in PAN, HNO3 and O3 concentrations in the UTLS. From a set of sensitivity experiments with emission changes in particular regions it can be concluded that Chinese emissions have a greater impact on the concentrations of these species than Indian emissions. NOx emissions increases over India are about half of those over China.
Future biogeochemical forcing in Eastern Siberia: cooling or warming?
Authors: Arneth A. , Olin S. , Makkonen R. , Paasonen P. , Holst T. , Kajos M. , Kulmala M. , Maximov T. , Miller P. A. , Schurgers G.
Published: July 2014

Abstract. Over-proportional warming in the northern high latitudes, and large carbon stocks in boreal and (sub)arctic ecosystems have raised concerns as to whether substantial positive climate feedbacks from biogeochemical process responses should be expected. Such feedbacks occur if increasing temperatures lead to e.g., a net release of CO2 or CH4. However, temperature-enhanced emissions of biogenic volatile organic compounds (BVOC) have been shown to contribute to a cooling feedback via growth of secondary organic aerosol (SOA), and related aerosol forcings. Combining measurements in Eastern Siberia with model-based estimates of vegetation and permafrost dynamics, BVOC emissions and aerosol growth, we show here that the additional climate forcing from changes in ecosystem CO2 balance and BVOC-SOA interactions nearly cancel on a regional scale. The interactions between emissions and vegetation dynamics that underlie individual forcing estimates are complex and highlight the importance of addressing ecosystem-climate feedbacks in consistent, process-based model frameworks that account for a multitude of system processes.
Mobile air monitoring data-processing strategies and effects on spatial air pollution trends
Authors: Brantley H. L. , Hagler G. S. W. , Kimbrough E. S. , Williams R. W. , Mukerjee S. , Neas L. M.
Published: July 2014

Abstract. The collection of real-time air quality measurements while in motion (i.e., mobile monitoring) is currently conducted worldwide to evaluate in situ emissions, local air quality trends, and air pollutant exposure. This measurement strategy pushes the limits of traditional data analysis with complex second-by-second multipollutant data varying as a function of time and location. Data reduction and filtering techniques are often applied to deduce trends, such as pollutant spatial gradients downwind of a highway. However, rarely do mobile monitoring studies report the sensitivity of their results to the chosen data-processing approaches. The study being reported here utilized 40 h (> 140 000 observations) of mobile monitoring data collected on a roadway network in central North Carolina to explore common data-processing strategies including local emission plume detection, background estimation, and averaging techniques for spatial trend analyses. One-second time resolution measurements of ultrafine particles (UFPs), black carbon (BC), particulate matter (PM), carbon monoxide (CO), and nitrogen dioxide (NO2) were collected on 12 unique driving routes that were each sampled repeatedly. The route with the highest number of repetitions was used to compare local exhaust plume detection and averaging methods. Analyses demonstrate that the multiple local exhaust plume detection strategies reported produce generally similar results and that utilizing a median of measurements taken within a specified route segment (as opposed to a mean) may be sufficient to avoid bias in near-source spatial trends. A time-series-based method of estimating background concentrations was shown to produce similar but slightly lower estimates than a location-based method. For the complete data set the estimated contributions of the background to the mean pollutant concentrations were as follows: BC (15%), UFPs (26%), CO (41%), PM2.5-10 (45%), NO2 (57%), PM10 (60%), PM2.5 (68%). Lastly, while temporal smoothing (e.g., 5 s averages) results in weak pair-wise correlation and the blurring of spatial trends, spatial averaging (e.g., 10 m) is demonstrated to increase correlation and refine spatial trends.
Evidence for benthic–pelagic food web coupling and carbon export from California margin bamboo coral archives
Authors: Hill T. M. , Myrvold C. R. , Spero H. J. , Guilderson T. P.
Published: July 2014

Abstract. Deep-sea bamboo corals (order Gorgonacea, family Isididae) are known to record changes in water mass chemistry over decades to centuries. These corals are composed of a two-part skeleton of calcite internodes segmented by gorgonin organic nodes. We examine the spatial variability of bamboo coral organic node 13C/12C and 15N/14N from 13 bamboo coral specimens sampled along the California margin (37–32° N, 792–2136 m depth). Radiocarbon analyses of the organic nodes show the presence of the anthropogenic bomb spike, indicating the corals utilize a surface-derived food source (pre-bomb D14C values of ∼−100‰, post-bomb values up to 82‰). Carbon and nitrogen isotope data from the organic nodes (δ13C = −15.9‰ to −19.2‰; δ15N = 13.8‰ to 19.4‰) suggest selective feeding on surface-derived organic matter or zooplankton. A strong relationship between coral δ15N and habitat depth indicates a potential archive of changing carbon export, with decreased δ15N values reflecting reduced microbial degradation (increased carbon flux) at shallower depths. Using four multi-centennial-length coral records, we interpret long-term δ15N stability in the California Current. Organic node δ15C values record differences in carbon isotope fractionation dictated by nearshore vs. offshore primary production. These findings imply strong coupling between primary production, pelagic food webs, and deep-sea benthic communities.
Constraining Holocene hydrological changes in the Carpathian–Balkan region using speleothem δ18O and pollen-based temperature reconstructions
Authors: Drăguşin V. , Staubwasser M. , Hoffmann D. L. , Ersek V. , Onac B. P. , Veres D.
Published: July 2014

Abstract. Here we present a speleothem isotope record (POM2) from Ascunsă Cave (Romania) that provides new data on past climate changes in the Carpathian–Balkan region from 8.2 ka until the present. This paper describes an approach to constrain the effect of temperature changes on calcite δ18O values in stalagmite POM2 over the course of the middle Holocene (6–4 ka), and across the 8.2 and 3.2 ka rapid climate change events. Independent pollen temperature reconstructions are used to this purpose. The approach combines the temperature-dependent isotope fractionation of rain water during condensation and fractionation resulting from calcite precipitation at the given cave temperature. The only prior assumptions are that pollen-derived average annual temperature reflects average cave temperature, and that pollen-derived coldest and warmest month temperatures reflect the range of condensation temperatures of rain above the cave site. This approach constrains a range of values between which speleothem δ18O changes should be found if controlled only by surface temperature variations at the cave site. Deviations of the change in δ18Ocspel values from the calculated temperature-constrained range of change are interpreted towards large-scale variability of climate–hydrology. Following this approach, we show that an additional ∼0.6‰ enrichment of δ18Oc in the POM2 stalagmite was caused by changing hydrological patterns in SW Romania across the middle Holocene, most likely comprising local evaporation from the soil and an increase in Mediterranean moisture δ18O. Further, by extending the calculations to other speleothem records from around the entire Mediterranean basin, it appears that all eastern Mediterranean speleothems recorded a similar isotopic enrichment due to changing hydrology, whereas all changes recorded in speleothems from the western Mediterranean are fully explained by temperature variation alone. This highlights a different hydrological evolution between the two sides of the Mediterranean. Our results also demonstrate that during the 8.2 ka event, POM2 stable isotope data essentially fit the temperature-constrained isotopic variability. In the case of the 3.2 ka event, an additional climate-related hydrological factor is more evident. This implies a different rainfall pattern in the Southern Carpathian region during this event at the end of the Bronze Age.