bluuebunny/crossref_metadata_2025 huggingface dataset:
Tatouages et marques d'attention
Authors: Pailler Jean-Jacques
Published: December 2010

Résumé Un chemin mène d’un sauteur à skis, d’alpinistes, filmés par W. Herzog, à un taggeur et finalement au tatouage. Celui-ci permet par la fonction d’attention de faire parvenir au moi de petites quantités d’excitations qui s’ajoutent à la libido sexuelle provenant de la coexcitation et du rapport à l’objet tatoueur afin de lutter contre un affaissement du moi. Comme une transfusion traitant l’hémorragie narcissique.
L'arbre qui cache la peau
Authors: Aloupis Panos
Published: December 2010

Résumé À partir du suivi d’un homme qui s’est fait tatouer sur une cicatrice, conséquence d’une intervention chirurgicale cardiaque, l’auteur parle des effets sur l’appareil psychique qu’entraîne un corps marqué par l’excitation et la maladie. Il met ainsi en relation la fonction d’inhibition et la place de l’idéal, inscrites psychiquement dans le commerce entre la pulsion et l’altérité.
Corps scarifié, adolescence marquée
Authors: Dargent Fanny
Published: December 2010

Résumé À partir d’une clinique hospitalière, l’auteur s’attache à montrer le caractère polymorphe de la pratique des scarifications. Non réductible à une pure décharge, celle-ci se situe au carrefour des différents modèles qui ont cherché à préciser l’articulation psyché-soma en jeu dans l’investissement morbide du corps propre. Si la force et le sens sont engagés, c’est à une tentative de maintien du système défensif préexistant qu’elle semble répondre.
Translocal Communities in Urban Settlements of Port Moresby. Notions of Space in the Formation of Ethnic Identities
Authors: Repič Jaka
Published: December 2010

Avtor v prispevku predstavlja urbano skupnost priseljencev iz Okape v Vzhodnem višavju, ki živijo v barakarskem naselju Two Mile v Port Moresbyju, glavnem mestu Papue Nove Gvineje. Obravnavano je razmerje med pojmovanjem prostora in nastankom translokalnih urbanih etničnih skupnosti.V kontekstu (post)kolonialne urbanizacije in migracij v mesta se priseljenci v urbane skupnosti povezujejo na podlagi predstav o skupnem izvirnem okolju ter ustvarjajo in rekonceptualizirajo svoje socialne mreže. Skupno izvirno okolje namreč v mestih postane tista kategorija, zaradi katere se posamezniki združujejo s sorodniki in rojaki, se naselijo v majhne zaselke in se povezujejo v širše urbane skupnosti. Njihove razpršene lokacije v urbanih naseljih Port Moresbyja so povezane v širšo socialno mrežo ali translokalno etnično skupnost.
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This paper presents an urban community of migrants from Okapa in Eastern Highlands that settled in an urban settlement (shantytown) Two Mile in Port Moresby, the capital of Papua New Guinea. The author explores a connection between conceptualisation of space and creation of translocal urban ethnic communities. In the context of (post)colonial urbanization and rural-urban migration, city immigrants create and reconceptualize their social networks and identifications on the basis of their common origin. Common origin that also implies a possession of a common culture is a category, which in an urban context, allows a formation of a wantok sistem, a network of migrants, settled in various urban settlements. Although they live in small settlements at various locations, dispersed all over the city, Okapians are organized into a wider social network or translocal urban ethnic community.
A Motif of a Fish Called Faronika in Slovenian Literature and Fine Arts of the 20th Century
Authors: Tucovič Vladka
Published: December 2010

Prispevek analizira medbesedilno in intermedialno razmerje motiva svet noseče ribe Faronike v slovenski ljudski pesmi iz Podmelca v Baški grapi in njegovega prenosa v književnost in likovno umetnost 20. stoletja. Transformacija v šibkem besedilnem nizu je opazovana v proznih delih Ivana Preglja Plebanus Joannes, Saše Vuge Na rožnatem hrbtu faronike, Gustava Strniše Riba Feronika in v intermedialnem razmerju likovnih del Marija Preglja, Franceta Miheliča, Marka Pogačnika in Boštjana Kavčiča.
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The article analyses intertextual and intermedial relation between a motif of a pregnant fish called Faronika, from a Slovene folk song from the settlement of Podmelec in Baška grapa, and its transfer to literature and fine arts of the 20th century. The transformation in a weak text train is observed in prose works Plebanus Joannes by Ivan Pregelj, Na rožnatem hrbtu faronike by Saša Vuga, Riba Feronika by Gustav Strniša and in intremedial relation in art works by Marij Pregelj, France Mihelič, Marko Pogačnik and Boštjan Kavčič.
La reproducción de la población en las provincias españolas (1975-2005). Análisis a través del reemplazo de nacimientos
Authors: Del Rey Poveda A. , Ortega Osona J. A.
Published: December 2010

La dinámica demográfica de España en los últimos 30 años ha estado marcada por una pronunciada caída de la fecundidad y la mortalidad y por una fuerte transformación de la movilidad. A nivel provincial se observa una misma tendencia en la fecundidad y la mortalidad. Sin embargo, la evolución de los nacimientos y conse cuentemente de la reproducción ha sido muy dispar. Esta situación pone de manifiesto el desigual impacto de la migración sobre la reproducción. En este trabajo analizamos la reproducción de las provincias españolas desde la perspectiva de la evolución de sus nacimientos utilizando un nuevo indicador, la Razón de Reemplazo de Nacimientos. El primer objetivo es analizar si los nacimientos anuales suponen la renovación de la generación de sus padres. El segundo objetivo es analizar el impacto de la migración en las trayectorias de reemplazo y en la composición del efectivo de mujeres en edades reproductivas.
A TCR Targeting the HLA-A*0201–Restricted Epitope of MAGE-A3 Recognizes Multiple Epitopes of the MAGE-A Antigen Superfamily in Several Types of Cancer
Authors: Chinnasamy Nachimuthu , Wargo Jennifer A. , Yu Zhiya , Rao Mahadev , Frankel Timothy L. , Riley John P. , Hong Jenny J. , Parkhurst Maria R. , Feldman Steven A. , Schrump David S. , Restifo Nicholas P. , Robbins Paul F. , Rosenberg Steven A. , Morgan Richard A.
Published: December 2010

Adoptive immunotherapy using TCR-engineered PBLs against melanocyte differentiation Ags mediates objective tumor regression but is associated with on-target toxicity. To avoid toxicity to normal tissues, we targeted cancer testis Ag (CTA) MAGE-A3, which is widely expressed in a range of epithelial malignancies but is not expressed in most normal tissues. To generate high-avidity TCRs against MAGE-A3, we employed a transgenic mouse model that expresses the human HLA-A*0201 molecule. Mice were immunized with two HLA-A*0201–restricted peptides of MAGE-A3: 112–120 (KVAELVHFL) or MAGE-A3: 271–279 (FLWGPRALV), and T cell clones were generated. MAGE-A3–specific TCR α- and β-chains were isolated and cloned into a retroviral vector. Expression of both TCRs in human PBLs demonstrated Ag-specific reactivity against a range of melanoma and nonmelanoma tumor cells. The TCR against MAGE-A3: 112–120 was selected for further development based on superior reactivity against tumor target cells. Interestingly, peptide epitopes from MAGE-A3 and MAGE-A12 (and to a lesser extent, peptides from MAGE-A2 and MAGE-A6) were recognized by PBLs engineered to express this TCR. To further improve TCR function, single amino acid variants of the CDR3 α-chain were generated. Substitution of alanine to threonine at position 118 of the α-chain in the CDR3 region of the TCR improved its functional avidity in CD4 and CD8 cells. On the basis of these results, a clinical trial is planned in which patients bearing a variety of tumor histologies will receive autologous PBLs that have been transduced with this optimized anti–MAGE-A3 TCR.
Dicer Insufficiency and MicroRNA-155 Overexpression in Lupus Regulatory T Cells: An Apparent Paradox in the Setting of an Inflammatory Milieu
Authors: Divekar Anagha A. , Dubey Shweta , Gangalum Pallavi R. , Singh Ram Raj
Published: December 2010

Systemic lupus erythematosus is a chronic autoimmune disease characterized by loss of tolerance to self-Ags and activation of autoreactive T cells. Regulatory T (Treg) cells play a critical role in controlling the activation of autoreactive T cells. In this study, we investigated mechanisms of potential Treg cell defects in systemic lupus erythematosus using MRL-Faslpr/lpr (MRL/lpr) and MRL-Fas+/+ mouse models. We found a significant increase in CD4+CD25+Foxp3+ Treg cells, albeit with an altered phenotype (CD62L−CD69+) and with a reduced suppressive capacity, in the lymphoid organs of MRL strains compared with non-autoimmune C3H/HeOuj mice. A search for mechanisms underlying the altered Treg cell phenotype in MRL/lpr mice led us to find a profound reduction in Dicer expression and an altered microRNA (miRNA, miR) profile in MRL/lpr Treg cells. Despite having a reduced level of Dicer, MRL/lpr Treg cells exhibited a significant overexpression of several miRNAs, including let-7a, let-7f, miR-16, miR-23a, miR-23b, miR-27a, and miR-155. Using computational approaches, we identified one of the upregulated miRNAs, miR-155, that can target CD62L and may thus confer the altered Treg cell phenotype in MRL/lpr mice. In fact, the induced overexpression of miR-155 in otherwise normal (C3H/HeOuj) Treg cells reduced their CD62L expression, which mimics the altered Treg cell phenotype in MRL/lpr mice. These data suggest a role of Dicer and miR-155 in regulating Treg cell phenotype. Furthermore, simultaneous appearance of Dicer insufficiency and miR-155 overexpression in diseased mice suggests a Dicer-independent alternative mechanism of miRNA regulation under inflammatory conditions.
TLR-2–Activated B Cells Suppress Helicobacter-Induced Preneoplastic Gastric Immunopathology by Inducing T Regulatory-1 Cells
Authors: Sayi Ayca , Kohler Esther , Toller Isabella M. , Flavell Richard A. , Müller Werner , Roers Axel , Müller Anne
Published: December 2010

B cells regulate autoimmune pathologies and chronic inflammatory conditions such as autoimmune encephalomyelitis and inflammatory bowel disease. The potential counterregulatory role of B cells in balancing pathogen-specific immune responses and the associated immunopathology is less well understood owing to the lack of appropriate persistent infection models. In this paper, we show that B cells have the ability to negatively regulate adaptive immune responses to bacterial pathogens. Using mouse models of infection with Helicobacter felis, a close relative of the human gastrointestinal pathogen H. pylori, we found that B cells activated by Helicobacter TLR-2 ligands induce IL-10–producing CD4+CD25+ T regulatory-1 (Tr-1)–like cells in vitro and in vivo. Tr-1 conversion depends on TCR signaling and a direct T-/B-interaction through CD40/CD40L and CD80/CD28. B cell-induced Tr-1 cells acquire suppressive activity in vitro and suppress excessive gastric Helicobacter-associated immunopathology in vivo. Adoptive cotransfer of MyD88-proficient B cells and Tr-1 cells restores a normal gastric mucosal architecture in MyD88−/− and IL-10−/− mice in a manner that depends on T cellular, but not B cellular, IL-10 production. Our findings describe a novel mechanism of B cell-dependent Tr-1 cell generation and function in a clinically relevant disease model. In conclusion, we demonstrate that the B cell/Tr-1 cell axis is essential for balancing the control of Helicobacter infection with the prevention of excessive Th1-driven gastric immunopathology, promoting gastric mucosal homeostasis on the one hand and facilitating Helicobacter persistence on the other.
The C5a Receptor Impairs IL-12–Dependent Clearance of Porphyromonas gingivalis and Is Required for Induction of Periodontal Bone Loss
Authors: Liang Shuang , Krauss Jennifer L. , Domon Hisanori , McIntosh Megan L. , Hosur Kavita B. , Qu Hongchang , Li Fenge , Tzekou Apostolia , Lambris John D. , Hajishengallis George
Published: December 2010

The C5a anaphylatoxin receptor (C5aR; CD88) is activated as part of the complement cascade and exerts important inflammatory, antimicrobial, and regulatory functions, at least in part, via crosstalk with TLRs. However, the periodontal pathogen Porphyromonas gingivalis can control C5aR activation by generating C5a through its own C5 convertase-like enzymatic activity. In this paper, we show that P. gingivalis uses this mechanism to proactively and selectively inhibit TLR2-induced IL-12p70, whereas the same pathogen-instigated C5aR-TLR2 crosstalk upregulates other inflammatory and bone-resorptive cytokines (IL-1β, IL-6, and TNF-α). In vivo, the ability of P. gingivalis to manipulate TLR2 activation via the C5a-C5aR axis allowed it to escape IL-12p70–dependent immune clearance and to cause inflammatory bone loss in a murine model of experimental periodontitis. In the latter regard, C5aR-deficient or TLR2-deficient mice were both resistant to periodontal bone loss, in stark contrast with wild-type control mice, which is consistent with the interdependent interactions of C5aR and TLR2 in P. gingivalis immune evasion and induction of bone-resorptive cytokines. In conclusion, P. gingivalis targets C5aR to promote its adaptive fitness and cause periodontal disease. Given the current availability of safe and effective C5aR antagonists, pharmacological blockade of C5aR could act therapeutically in human periodontitis and reduce associated systemic risks.
Double Transseptal Puncture for Catheter Ablation of Atrial Fibrillation: Safety of the Technique and Its Use in the Outpatient Setting
Authors: Haegeli Laurent M. , Wolber Thomas , Ercin Ercüment , Altwegg Lukas , Krasniqi Nazmi , Novak Paul G. , Sterns Laurence D. , Brunckhorst Corinna B. , Lüscher Thomas F. , Leather Richard A. , Duru Firat
Published: December 2010

Introduction. For pulmonary vein isolation in patients with atrial fibrillation (AF), some centers use the double transseptal puncture technique for catheter access in order to facilitate catheter manipulation within the left atrium. However, no safety data has so far been published using this approach.Method. 269 ablation procedures were performed in 243 patients (mean age years, 75% men) using the double transseptal puncture for catheter access in all cases. Patients were considered for ablation of paroxysmal (80%), persistent (19%), and permanent (1%) AF. 230 procedures were performed on an outpatient basis (85.5%), and 26 were repeat procedures (9.7%).Results. The double transseptal puncture catheter access was successfully achieved in all patients. The procedural success with the endpoint of pulmonary vein isolation was reached in 255 procedures (95%). A total of 1048 out of 1062 pulmonary veins (99%) were successfully isolated. Major complications occurred in eight patients (3.0%). Of these, seven patients (2.6%) had pericardial effusion requiring percutaneous drainage, and one patient (0.4%) suffered a minor reversible stroke. One patient (0.4%) had a minor air embolism with transient symptoms.Conclusion. The double transseptal puncture catheterization technique allows easy catheter manipulation within the left atrium to reach the goal of acute procedural success in AF ablation. Procedure-related complications are rare, and the technique can be used safely for AF ablation in the outpatient setting.
Differences in the Form of Presentation between Papillary Microcarcinomas and Papillary Carcinomas of Larger Size
Authors: Zafon Carles , Baena Juan Antonio , Castellví Josep , Obiols Gabriel , Monroy Gabriela , Mesa Jordi
Published: December 2010

Papillary thyroid carcinomas (PTCs) with a diameter ≤1 cm are referred to as papillary microcarcinomas (PTMCs). The prognostic factors for PTMCs have not been defined. Different clinical and histopathologic variables were studied in 152 PTCs, including 74 PTMCs and 78 PTCs of larger size. We found that PTMCs are associated with less multifocality () and bilaterality (), fewer lymphadenectomies (), and a higher rate of incidental tumours (). Moreover, patients with a low aggressive profile were significantly older than the remaining patients ( years versus years; ). In conclusion PTMCs show significant differences compared to PTCs of larger size in the form of presentation. Furthermore, it is possible that the classic risk factors, which are well validated in PTCs, such as age, must be cautiously interpreted in the current increasing subgroup of PTMCs.
Die verhouding tussen Christologie en etiek in Kolossense � praxis vir die postmoderne gelowige en kerk
Authors: Pienaar Johannes P. , Van Eck Ernest
Published: December 2010

The relationship between Christology and ethics in Colossians praxis for the postmodern believer and church In Colossians, there is a close relationship between Christology and ethics. This relationship provides answers to the many questions that face the postmodern believer and the church in the current secular world. Believers constantly battle to apply their faith in a practical way. The reason for this is that believers do not have a reference point from which to apply their faith in practice. The relationship between Christology and ethics in the letter to the Colossians presents such a reference point, namely the believer�s identity in Jesus Christ. This identity in Christ, and not nomalism, should determine all ethical decisions of the believer.
Mathematics and Algorithms in Tomography
Authors: Burger Martin , Louis Alfred K. , Quinto Eric Todd
Published: December 2010

This is the eighth Oberwolfach conference on the mathematics of tomography. Modalities represented at the workshop included X-ray tomography, sonar, radar, seismic imaging, ultrasound, electron microscopy, impedance imaging, photoacoustic tomography, elastography, vector tomography, and texture analysis.
Algebraic Groups
Authors: Brion Michel , Jantzen Jens Carsten
Published: December 2010

The workshop dealt with a broad range of topics from the structure theory and the representation theory of algebraic groups (in the widest sense). There was emphasis on the following areas:• classical and quantum cohomology of homogeneous varieties,• representation theory and its connections to orbits and flag varieties.
Interactions between Algebraic Geometry and Noncommutative Algebra
Authors: Happel Dieter , Small Lance W. , Stafford J. Toby , Van den Bergh Michel
Published: December 2010

The aim of this workshop was to communicate the most current developments in the field of noncommutative algebra and its interactions with algebraic geometry and representation theory.
Phase Transitions
Authors: Bhattacharya Kaushik , Ioffe Dmitry , Luckhaus Stephan , Otto Felix
Published: December 2010

Phase transitions are common phenomena which occur in many fields of material sciences. Models of phase transitions in diverse physical systems often lead to ill-posed mathematical problems whose solutions are characterized by oscillations, bifurcations and singularities. Random fluctuations and stochastic events also play an important role in determining the nature of the solutions.
Geometry, Quantum Fields, and Strings: Categorial Aspects
Authors: Bouwknegt Peter G. , Freed Daniel S. , Schweigert Christoph
Published: December 2010

Currently, in the interaction between string theory, quantum field theory and topology, there is an increased use of category-theoretic methods. Independent developments (e.g. the categorificiation of knot invariants, bundle gerbes and topological field theories on extended cobordism categories) have put higher categories in the focus.The workshop has brought together researchers working on diverse problems in which categorical ideas play a significant role.
Geometrie
Authors: Lott John , Taimanov Iskander A. , Wilking Burkhard
Published: December 2010

The program of this meeting covered a wide range of recent developements in geometry such as geometric flows and connections to transport problems, metric and Alexandrov geometry, positively curved manifolds and the positive energy theorem.
A HISTORICAL ANALYSIS OF H. M. HAMLIN AND THE COMMUNITY SCHOOL CONCEPT
Authors: Martin Michael J. , Ball Anna L. , Connors James J.
Published: December 2010

The purpose of this historical study was to gain a deeper understanding of the community school and its developer, Herbert M. Hamlin. Primary sources including texts, magazines, monographs, and an oral interview and secondary sources including books, journals, and magazines were analyzed. The researchers found Hamlin’s community school philosophy revolved around practical applications of a community-based program of education. His philosophy was grounded in the ideals of the American democratic process and rural communities. Community schools represented a logical way for today’s teachers to intertwine the community and program’s needs and wants.
SCIENCE ACHIEVEMENT OF HIGH SCHOOL STUDENTS IN COMPLETE PROGRAMS OF AGRISCIENCE EDUCATION
Authors: Ricketts John C. , Duncan Dennis W. , Peake Jason B.
Published: December 2010

The purpose of this descriptive and correlational study was to describe the science achievement of participants in complete programs of agriscience in Georgia. A secondary purpose was to compare science achievement of agriscience students to the science achievement of college prep, dual track, and technology/career prep students. The findings indicate that agriscience students enrolled in an average of four agriscience education courses, have a high level of engagement in SAE, and a moderate level of engagement with FFA. The mean score for agriscience students on the science portion of the Georgia High School Graduation Test (GHSGT) was 511.24, approximately three points lower than college prep students (M = 514.85). Nearly 78% of the agriscience students passed the test on their first attempt in comparison to 68% for the state average, and only 38% for technology/career prep students. Further findings indicate a low but positive correlation between science achievement among agriscience students and the number of agriscience courses taken. There was also a low but positive correlation between the level of FFA and SAE engagement for both student achievement in science and the first time passing rate for the science portion of the GHSGT.
A LONGITUDINAL EXAMINATION OF TEACHING EFFICACY OF AGRICULTURAL SCIENCE STUDENT TEACHERS
Authors: Roberts T. Grady , Harlin Julie F. , Ricketts John C.
Published: December 2010

The purpose of this study was to longitudinally examine the teaching efficacy of agricultural science student teachers throughout the student teaching experience. The population of interest for this study was all agricultural science student teachers at Texas A&M University. The accessible sample of the population was all student teachers during the Fall 2004 semester (n = 33). Using the Teachers’ Sense of Efficacy Scale instrument (Tschannen-Moran & Woolfolk Hoy, 2001), efficacy in student engagement, instructional strategies, and classroom management were measured: 1) the first day of the 4-week on-campus portion of the student teaching semester; 2) the last day of the 4-week on-campus block; 3) the middle of the 11-week student teaching experience; and 4) the final day of the student teaching experience. It was concluded that efficacy in student engagement and instructional strategies changed, while efficacy in classroom management did not. Overall teaching efficacy also changed. Student teachers had “Quite a Bit” of teaching efficacy at the beginning of the semester, which slightly increased four weeks later, then decreased to its lowest level at the middle of the 11-week student teaching experience, and then rebounded by the end of the experience.
CHALLENGES EXPERIENCED BY NEW MEXICO AGRICULTURAL EDUCATION TEACHERS IN INCLUDING SPECIAL NEEDS STUDENTS
Authors: Dormody Thomas J. , Seevers Brenda S. , Andreasen Randall J. , VanLeeuwen Dawn
Published: December 2010

Approximately 19% of the students enrolled in agricultural education in New Mexico are classified as special education students. The purpose of this descriptive-correlational study was to describe the challenges experienced by agricultural education teachers in New Mexico when including special needs students in their programs. A census of New Mexico secondary school agricultural education teachers received a mail questionnaire during spring and summer 2003. Most programs in the state offered instruction in a combination classroom and shop/laboratory format (85%) and a classroom-only (59%) format. Among disabilities/special needs, students with mental retardation and limited English proficiency were the most challenging to include in courses with the classroom-only format. In the laboratory/shop-only format, students with mental retardation, physical disabilities and emotional/behavioral disorders were most challenging. Mentally retarded students were the most challenging in the combination format. Older teachers and teachers on a regular schedule had lower perceptions of the degree of challenge in including students with special needs than younger teachers and teachers on a block schedule.
Retrieval of atmospheric parameters from GOMOS data
Authors: Kyrölä E. , Tamminen J. , Sofieva V. , Bertaux J. L. , Hauchecorne A. , Dalaudier F. , Fussen D. , Vanhellemont F. , Fanton d'Andon O. , Barrot G. , Guirlet M. , Mangin A. , Blanot L. , Fehr T. , Saavedra de Miguel L. , Fraisse R.
Published: December 2010

Abstract. The Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument on board the European Space Agency's ENVISAT satellite measures attenuation of stellar light in occultation geometry. Daytime measurements also record scattered solar light from the atmosphere. The wavelength regions are the ultraviolet-visible band 248–690 nm and two infrared bands at 755–774 nm and at 926–954 nm. From UV-Visible and IR spectra the vertical profiles of O3, NO2, NO3, H2O, O2 and aerosols can be retrieved. In addition there are two 1 kHz photometers at blue 473–527 nm and red 646–698 nm. Photometer data are used to correct spectrometer measurements for scintillations and to retrieve high resolution temperature profiles as well as gravity wave and turbulence parameters. Measurements cover altitude region 5–150 km. Atmospherically valid data are obtained in 15–100 km. In this paper we present an overview of the GOMOS retrieval algorithms for stellar occultation measurements. The low signal-to-noise ratio and the refractive effects due to the point source nature of stars have been important drivers in the development of GOMOS retrieval algorithms. We present first the Level 1b algorithms that are used to correct instrument related disturbances in the spectrometer and photometer measurements The Level 2 algorithms deal with the retrieval of vertical profiles of atmospheric gaseous constituents, aerosols and high resolution temperature. We divide the presentation into correction for refractive effects, high resolution temperature retrieval and spectral/vertical inversion. The paper also includes discussion about the GOMOS algorithm development, expected improvements, access to GOMOS data and alternative retrieval approaches.
Simulation of the diurnal variations of the oxygen isotope anomaly (Δ17O) of reactive atmospheric species
Authors: Morin S. , Sander R. , Savarino J.
Published: December 2010

Abstract. The isotope anomaly (Δ17O) of secondary atmospheric species such as nitrate (NO3−) or hydrogen peroxyde (H2O2) has potential to provide useful constrains on their formation pathways. Indeed, the Δ17O of their precursors (NOx, HOx etc.) differs and depends on their interactions with ozone, which is the main source of non-zero Δ17O in the atmosphere. Interpreting variations of Δ17O in secondary species requires an in-depth understanding of the Δ17O of their precursors taking into account non-linear chemical regimes operating under various environmental settings. We present results from numerical simulations carried out using the atmospheric chemistry box model (CAABA/MECCA) to explicitly compute the diurnal variations of the isotope anomaly of short-lived species such as NOx and HOx. Δ17O was propagated from ozone to other species (NO, NO2, OH, HO2, RO2, NO3, N2O5, HONO, HNO3, HNO4, H2O2) according to the classical mass-balance equation, through the implementation of various sets of hypotheses pertaining to the transfer of Δ17O during chemical reactions. The model confirms that diurnal variations in Δ17O of NOx are well predicted by the photochemical steady-state relationship during the day, but that at night a different approach must be employed (i.e. "fossilization" of the Δ17O of NOx as soon as the photolytical lifetime of NOx drops below ca. 5 min). We quantify the diurnally-integrated isotopic signature (DIIS) of sources of atmospheric nitrate and H2O2 under the various environmental conditions analyzed, which is of particular relevance to larger-scale implementations of Δ17O where high computational costs cannot be afforded.
Water droplet calibration of the Cloud Droplet Probe (CDP) and in-flight performance in liquid, ice and mixed-phase clouds during ARCPAC
Authors: Lance S. , Brock C. A. , Rogers D. , Gordon J. A.
Published: December 2010

Abstract. Laboratory calibrations of the Cloud Droplet Probe (CDP) sample area and droplet sizing are performed using water droplets of known size, generated at a known rate. Although calibrations with PSL and glass beads were consistent with theoretical instrument response, liquid water droplet calibrations were not, and necessitated a 2 μm shift in the manufacturer's calibration. We show that much of this response shift may be attributable to a misalignment of the optics relative to the axis of the laser beam. Comparison with an independent measure of liquid water content (LWC) during in-flight operation suggests much greater biases in the droplet size and/or droplet concentration measured by the CDP than would be expected based on the laboratory calibrations. Since the bias in CDP-LWC is strongly concentration dependent, we hypothesize that this discrepancy is a result of coincidence, when two or more droplets pass through the CDP laser beam within a very short time. The coincidence error, most frequently resulting from the passage of one droplet outside and one inside the instrument sample area at the same time, is evaluated in terms of an "extended sample area" (SAE), the area in which individual droplets can affect the sizing detector without necessarily registering on the qualifier. SAE is calibrated with standardized water droplets, and used in a Monte-Carlo simulation to estimate the effect of coincidence on the measured droplet size distributions. The simulations show that extended coincidence errors are important for the CDP at droplet concentrations even as low as 200 cm−3, and these errors are necessary to explain the trend between calculated and measured LWC observed in liquid and mixed-phase clouds during the Aerosol, Radiation and Cloud Processes Affecting Arctic Climate (ARCPAC) study. We estimate from the simulations that 60% oversizing error and 50% undercounting error can occur at droplet concentrations exceeding 400 cm−3. Modification of the optical design of the CDP is currently being explored in an effort to reduce this coincidence bias.
Bayesian analysis of rapid climate change during the last glacial using Greenland δ18O data
Authors: Peavoy D. , Franzke C.
Published: December 2010

Abstract. We present statistical methods to determine climate regimes for the last glacial period using three temperature proxy records from Greenland: measurements of δ18O from the Greenland Ice Sheet Project 2 (GISP2), the Greenland Ice Core Project (GRIP) and the North Greenland Ice Core Project (NGRIP) using different timescales. A Markov Chain Monte Carlo method is presented to infer the number of states in a latent variable model along with their associated parameters. By using Bayesian model comparison methods we find that a model with 3 states is sufficient. These states correspond to a gradual cooling during the Greenland Interstadials, more rapid temperature decrease into Greenland Stadial and to the sudden rebound temperature increase at the onset of Greenland Interstadials. We investigate the recurrence properties of the onset of Greenland Interstadials and find no evidence to reject the null hypothesis of randomly timed events.
Modeling geologically abrupt climate changes in the Miocene
Authors: Haupt B. J. , Seidov D.
Published: December 2010

Abstract. The gradual cooling of the Cenozoic, including the Miocene epoch, was punctuated by many geologically abrupt warming and cooling episodes – strong deviations from the cooling trend with time span of ten to hundred thousands of years. Our working hypothesis is that some of those warming episodes at least partially might have been caused by dynamics of the emerging Antarctic Ice Sheet, which, in turn, might have caused strong changes of sea surface salinity in the Miocene Southern Ocean. Feasibility of this hypothesis is explored in a series of coupled ocean-atmosphere computer experiments. The results suggest that relatively small and geologically short-lived changes in freshwater balance in the Southern Ocean could have significantly contributed to at least two prominent warming episodes in the Miocene. Importantly, the experiments also suggest that the Southern Ocean was more sensitive to the salinity changes in the Miocene than today, which can attributed to the opening of the Central American Isthmus as a major difference between the Miocene and the present-day ocean-sea geometry.
A multiple threshold method for fitting the generalized Pareto distribution to rainfall time series
Authors: Deidda R.
Published: December 2010

Abstract. Previous studies indicate the generalized Pareto distribution (GPD) as a suitable distribution function to reliably describe the exceedances of daily rainfall records above a proper optimum threshold, which should be selected as small as possible to retain the largest sample while assuring an acceptable fitting. Such an optimum threshold may differ from site to site, affecting consequently not only the GPD scale parameter, but also the probability of threshold exceedance. Thus a first objective of this paper is to derive some expressions to parameterize a simple threshold-invariant three-parameter distribution function which assures a perfect overlapping with the GPD fitted on the exceedances over any threshold larger than the optimum one. Since the proposed distribution does not depend on the local thresholds adopted for fitting the GPD, it is expected to reflect the on-site climatic signature and thus appears particularly suitable for hydrological applications and regional analyses. A second objective is to develop and test the Multiple Threshold Method (MTM) to infer the parameters of interest by using exceedances over a wide range of thresholds applying again the concept of parameters threshold-invariance. We show the ability of the MTM in fitting historical daily rainfall time series recorded with different resolutions and with a significative percentage of heavily quantized data. Finally, we prove the supremacy of the MTM fit against the standard single threshold fit, often adopted for partial duration series, by evaluating and comparing the performances on Monte Carlo samples drawn by GPDs with different shape and scale parameters and different discretizations.
Infrared Spectral Emissivity Dynamics of Surfaces Under Water Condensation
Authors: Lavielle Nicolas , Othman Ahmed M. , Hervé Armande , Hamaoui Georges , Fei Jipeng , Tan Jun Yan , Marty Frédéric , Li Hong , Mongruel Anne , Beysens Daniel , Nefzaoui Elyes , Bourouina Tarik
Published: May 2024

Water condensation on a surface strongly affects its effective emissivity, especially in the atmospheric window, a wavelength range essential for outdoor applications related to energetically passive cooling and heating. The evolution of emissivity of a silicon surface during dropwise and filmwise water deposition is studied. The evolution of the spectral radiative properties shows that the increase in effective emissivity due to the growth of a droplet pattern is steeper than for a growing water film of equivalent thickness. The change of surface emissivity takes place in the first moments of condensation where droplets as small as 10 µm drastically impact the reflectance of the pristine surface. The upper limit of effective emissivity is reached for a droplet radius or film thickness of 50 µm. During dropwise condensation, effective emissivity is weighted by the drop surface coverage and then remains within an asymptotic maximum value of 0.8, while in case of filmwise condensation, it is shown to reach 0.9 corresponding to water emissivity. Micrometer‐scale spatially‐resolved infrared spectral images enable to correlate the spatial variation of spectral properties to the droplet size and localization. Such findings are of interest to the implementation of moisture‐controlled emissivity tuning and radiative sky‐coolers for dew harvesting.
Hot Exciton Carbon Dots‐Based Deep Blue Electroluminescent Light‐Emitting Diodes Exceeding 7% External Quantum Efficiency
Authors: Wang Boyang , Wang Hongwei , Zhang Baowei , Hu Yongsheng , Lu Siyu
Published: May 2024

Carbon dots (CDs) have emerged as an exceptional material for the emission layer in the new generation of electroluminescent light‐emitting diodes (ELEDs) owing to their low cost, high stability, and high luminous efficiency. Although blue CDs‐based ELEDs have a wide bandgap and a low exciton utilization efficiency (EUE), it is still challenging to increase their external quantum efficiency (EQE). Although thermally activated delayed fluorescence and triplet‐triplet annihilation may improve EUE, the design of blue ELEDs is complicated by the significant charge transfer characteristics introduced by the low energy spitting of T1 and S1. This research effectively produced blue‐emitting CDs using a heated exciton process by carefully selecting precursors to overcome the aforementioned challenges. Deep blue and blue ELEDs based on CDs are developed by manipulating the electron‐hole mobility and the energy level structure of the device. The EQEs of these ELEDs exceeded those of previously reported CDs‐based blue ELEDs by over 7%. This study presents design concepts for new CDs and introduces a novel approach to develop cost‐effective, environmentally friendly, and highly efficient metal‐free blue ELEDs.
A Database of Electrochemical Stability Windows Containing over 1500 Solid‐State Inorganic Compounds
Authors: Wang Xianyue , He Bing , Liu Bo , Avdeev Maxim , Shi Siqi
Published: May 2024

Electrochemical stability window (ESW) of an inorganic compound (solid‐state electrolyte (SSE) or coating) is an indispensable parameter to evaluate the interface compatibility between the electrode and electrolyte in ion batteries. The discovery of novel coatings and SSEs, driven by extensive ESW data, is expected to accelerate the design of high‐performance batteries. However, only a very small fraction of the ESW of inorganic compounds has been experimentally measured at present, which limits technological progress. Benefiting from the high‐accuracy ESW prediction with dynamically determined direct or indirect decomposition pathway proposed in the previous work, both the oxidation and reduction potentials align to the experimental data reasonably. Here, a database containing phase diagrams and electrochemical stability information is established for more than 1500 solid‐state inorganic compounds with Li+, Na+, K+, Mg2+, Ca2+, and Al3+ as the migrating ions, and this number is still growing. The database is reproducible and provides a unified picture of the structure–activity relationships associated with electrochemical stability of inorganic compounds. This study demonstrates the validity of the improved ESW prediction method and paves the way for accelerated screening of superior SSEs or coatings based on machine learning.
Single Dispersion of Fe(H2O)2‐Based Polyoxometalate on Polymeric Carbon Nitride for Biomimetic CH4 Photooxidation
Authors: Ren Jing , Wang Baifan , Yin Hua‐Qing , Zhang Peng , Wang Xin‐Hui , Quan Yangjian , Yao Shuang , Lu Tong‐Bu , Zhang Zhi‐Ming
Published: May 2024

Direct methane conversion to value‐added oxygenates under mild conditions with in‐depth mechanism investigation has attracted wide interest. Inspired by methane monooxygenase, the K9Na2Fe(H2O)2{[γ‐SiW9O34Fe(H2O)]}2·25H2O polyoxometalate (Fe‐POM) with well‐defined Fe(H2O)2 sites is synthesized to clarify the key role of Fe species and their microenvironment toward CH4 photooxidation. The Fe‐POM can efficiently drive the conversion of CH4 to HCOOH with a yield of 1570.0 µmol gPOM−1 and 95.8% selectivity at ambient conditions, much superior to that of [Fe(H2O)SiW11O39]5− with Fe(H2O) active site, [Fe2SiW10O38(OH)]214− and [P8W48O184Fe16(OH)28(H2O)4]20− with multinuclear Fe−OH−Fe active sites. Single‐dispersion of Fe‐POM on polymeric carbon nitride (PCN) is facilely achieved to provide single‐cluster functionalized PCN with well‐defined Fe(H2O)2 site, the HCOOH yield can be improved to 5981.3 µmol gPOM−1. Systemic investigations demonstrate that the (WO)4−Fe(H2O)2 can supply Fe═O active center for C−H activation via forming (WO)4−Fea−Ot···CH4 intermediate, similar to that for CH4 oxidation in the monooxygenase. This work highlights a promising and facile strategy for single dispersion of ≈1–2 Å metal center with precise coordination microenvironment by uniformly anchoring nanoscale molecular clusters, which provides a well‐defined model for in‐depth mechanism research.
Highly Efficient Luminescent Solar Concentrators Based on BODIPY Derivatives
Authors: Arrigo Antonino , Gangemi Chiara Maria Antonietta , Barattucci Anna , Bonaccorsi Paola Maria , Greco Valentina , Giuffrida Alessandro , Genovese Salvatore , Campagna Sebastiano , Nastasi Francesco , Puntoriero Fausto
Published: May 2024

Three new chromophores based on difluoroborondipyrromethene dyes (Bodipy‐1, Bodipy‐2, and Bodipy‐3) are used as precursors to prepare luminescent solar concentrators (LSC) based on poly‐acrylate, following a thermally activated polymerization involving lauryl methacrylate as monomer, ethyl glycol dimethacrylate as cross‐linking agent, and lauroyl peroxide as initiator. The new dyes exhibit typical BODIPY absorption and emission properties in dichloromethane fluid solution, assigned to the lower‐lying singlet π–π∗ level, which in the case of Bodipy‐2 and Bodipy‐3, both containing diamino‐substituted styryl subunits in their structure, has a strong charge transfer contribution. The LSCs obtained starting from each of the three Bodipys are interfaced to silicon photovoltaic (PV) cells, and the PV light‐to‐energy conversion efficiencies ηopt for the three systems are calculated. The results yield ηopt of 4.53% for LSC‐Bodipy‐1, 5.26% for LSC‐Bodipy‐2, and 8.23% for LSC‐Bodipy‐3. The optical efficiency for LSC‐Bodipy‐3 is a remarkable value among the LSC based on organic dyes.
Uniaxial‐Stress Driven Performance Enhancement of Multi‐Beam Spark Plasma Sintered BiSbTe/Epoxy Flexible Films
Authors: Ai Xiaoling , Ke Shaoqiu , Nie Xiaolei , Chen Tiantian , Liang Dong , Fu Kai , Zhu Wanting , Wei Ping , Zhao Wenyu , Zhang Qingjie
Published: May 2024

The multi‐beam discharge plasma sintering (MB‐SPS) method is successfully applied to the preparation of Bi2Te3‐based thermoelectric (TE) films with insulating substrates. Herein, the impact of uniaxial stress on the microstructure evolution and TE performance are explored systematically. The results indicate that the increase of uniaxial stress promotes the preferential growth of Bi0.5Sb1.5Te3 (BST) grains along the (000l) crystal plane, leading to the remarkable increase in carrier mobility. The maximum (000l) preferential orientation factor reaches 80% for the BST/epoxy (EP) film sintered under 25 MPa, which is 3.08 times higher than that of BST/EP film sintered at 10 MPa. While the highest power factor reaches 2.36 mW m−1 K−2 at 300 K for the BST/EP film sintered under 20 MPa, increased by 97% as compared with that of the film sintered under 10 MPa. This work once again confirms that the MB‐SPS technology is an effective approach to prepare high‐performance Bi2Te3‐based films with insulating substrates and demonstrates that the (000l) preferential orientation and TE performance of the films can be further enhanced by an appropriate uniaxial stress.
Highly Efficient Broadband Near‐Infrared Emission in Cr3+‐Activated Organic Hafnium Chlorine for Multi‐Optoelectronic Applications
Authors: Lai Jun'an , Wang Zixian , Wang Yijia , Cao Sijun , Wu Daofu , Zhou Yongqiang , An Kang , Du Juan , He Peng , Tang Xiaosheng
Published: May 2024

Cr3+ ions doped broadband emission near‐infrared (NIR) phosphors are pertinent to widespread emerging applications and get rapid developed. However, it remains a challenge to simultaneously achieve highly efficient and broadband near‐infrared emission in Cr3+ ions doped phosphors. Herein, the Cr3+ ions firstly doped into organic–inorganic hafnium chlorine TEA2HfCl6 (TEA = Tetraethylammonium, C8H20N), which show broadband emission at a range of 700–1300 nm, a full width at half maximum (FWHM) of 164 nm, and a high photoluminescence quantum yield (PLQY) of 60%. The organic–inorganic metal halides show huge advantages than traditional inorganic phosphors, like high luminescence efficiency, low temperature solution synthesis progress, and low cost, which provide an efficiency strategy for lighting industry. Based on these advantages, a high power NIR light emitting diode (LED) is fabricated by TEA2HfCl6:Cr3+ with a high‐power 530 nm chip, which is used in food analysis, night vision, and biomedical imaging as a demonstration. This work indicates the feasibility of organic–inorganic metal halides as host materials for developing Cr3+ ions emitting phosphor toward multi‐optoelectronic applications.
High‐Performance Self‐Filtering Organic Photodetectors with Photomultiplication Narrowing
Authors: Suthar Gajendra , Chu Chih‐Wei , Chen Fang‐Chung
Published: May 2024

Narrowband organic photodetectors (OPDs) conventionally necessitate high applied biases to accommodate a sufficiently thick active layer for self‐filtering functions. Herein, a concept leveraging the photomultiplication (PM) process is proposed to achieve spectral narrowing in OPDs which can operate at low external biases. This PM narrowing mechanism integrates two distinct functions through a pseudo bilayer structure comprising a photon‐filtering (PF) layer and a PM layer, respectively. The initial PF layer absorbs short‐wavelength photons and selectively permits light within a narrow bandwidth at the band edge of the PF material to enter the subsequent PM layer, thereby initiating the PM effect. The combined action of these two layers synergistically empowers the OPDs to exhibit a pronounced PM effect, resulting in a notably high external quantum efficiency of 5840% at a narrowband peak of 680 nm under a low bias of −5.0 V. Furthermore, the OPDs achieve a substantial −3 dB bandwidth of 5.2 kHz, alongside a maximum detectivity of 2.60 × 1013 Jones. These findings position the OPDs among the top‐performing self‐filtering narrowband detectors, particularly for those capable of functioning at low external biases.