bluuebunny/crossref_metadata_2025 huggingface dataset:
Juvenile Ossifying Fibroma in a Juvenile Diabetic: A Case Report with Surgical Management
Authors: Hosmani Jagadish , Byahatti Sujata M , Nayak Ranganath , Nayak Ramakant , Jayade Bhushan
Published: December 2010

Juvenile ossifying fibroma (JOF) is a highly aggressive uncommon fibro-osseous lesion occurring in the facial bones. Two histological variants of JOF, i.e. trabecular and psammomatoid have been reported. Here we present a case of a 20-year-old juvenile diabetic patient with massive growth on her left side of the jaw which was diagnosed as juvenile ossifying fibroma. This huge aggressive mass in the left side of the mandible had lead to complete lingual tilting of molars and premolars. After clinical and radiological examination, a biopsy led to the histopathological diagnosis of mixed variant of juvenile ossifying fibroma. The required surgical treatment (hemimandibulectomy) was undertaken under GA. The aggressive local behavior and high recurrence rate of JOF emphasizes the need for an early diagnosis, and appropriate radical treatment with long-term follow-up. One such case is reviewed and discussed in detail in the following article.
Multiple Odontogenic Keratocysts
Authors: Charantimath Shivayogi , LNU Zameera , Bagewadi Anjana , Keluskar Vaishali
Published: December 2010

Odontogenic keratocyst is a cyst of odontogenic origin that exhibits a keratinized epithelial lining. Odontogenic keratocyst has been the topic of numerous investigators and is known for its potentially aggressive behavior and significant rate of recurrences.1

OKC cyst often occurs as a solitary lesion at the angle of the mandible, however in some instances, multiple such cysts may occur in association with a syndrome called “Nevoid basal cell syndrome”.1

These patients have propensity to develop multiple neoplasm including basal cell carcinoma and medulloblastoma. Hence early diagnosis and treatment is of utmost importance in reducing the severity of long-term sequelae of this syndrome. Here we present a case of multiple odontogenic keratocysts with nevi and narrowed ribs which has profound relevance to specialist in Oral Medicine and Radiology and Oral and Maxillofacial Surgery.
DNA Extraction from Pulp Tissue for its Application in PCR. A Study to Extract DNA with High Purity as Quantified by Gel Electrophoresis
Authors: Vaseemuddin Syed
Published: December 2010

The isolation of human genomic DNA is an important step involved in genetic identity analysis. Also getting optimal quantity and quality of DNA is important as this can alter the results. This consideration is especially important in the field of forensic analysis and genetic identity, where DNA is extracted from extremely small amounts of starting material often recovered from suboptimal storage conditions. Odontological examinations have always been a critical determinant in the search of human identity. Teeth form a natural barrier to exogenous DNA contamination. DNA extraction from dental tissues both hard tissues and dental pulp, has been reported the use of dental pulp, as a source of DNA offers a new paradigm in the process of DNA extraction and its use in forensic analysis.11 The following procedures elucidate a novel method of extraction of DNA using dental pulp, which offers a cost-effective and attractive procedure, which can be replicated and applied in DNA amplification (PCR).
Predictably Restoring Natural Beauty: A Clinically Proven Direct Approach
Authors: Bachmann Marc
Published: December 2010

A clinically proven restorative approach is presented to achieve natural esthetics using an utmost conservative freehand bonding technique respecting the patient's wish for immediate esthetic and functional rehabilitation to affordable costs.
Pediatric Basic Resuscitation in Dental Office
Authors: Ahmed Bijle Mohammed Nadeem , Chunawalla Yussuf K , Mansukhani Kavina , Musale Prasad K
Published: December 2010

Medical emergencies are little understood by most of the dentists. Thus, there is a significant need for increased awareness by dental professionals in the area of emergency medicine. Medical emergencies can and do occur in pediatric patients. Therefore, pediatric dentists should develop skills to handle various pediatric emergencies that have the potential to develop life-threatening conditions. We must be aware of the various protocols for initial stabilization of pediatric victims at risk in dental setup. Every patient expects his/her dentist to be familiar with emergency interventions that include atleast basic life support requirements and, if necessary, advanced methods including administration of specific medication. This review article will brief us with basic protocols required to manage pediatric emergencies in case of life-threatening conditions.
Ultrasonography and Color Doppler as a Diagnostic Aid in Differentiation of Periapical Lesions of Endodontic Origin: Report of Two Cases
Authors: Boruah Lalit Chandra , Bhuyan AC
Published: December 2010

Ultrasound with color Doppler is a proven, useful and noninvasive diagnostic tool in endodontics. It can give an idea about the nature and dimension of periapical lesion, which helps in preoperative assessment and treatment planning. This report discusses two cases of periapical lesions of endodontic origin diagnosed with the help of ultrasound and color Doppler and treated surgically.
Esthetic and Functional Rehabilitation of Mesiodens Associated with Dens Invaginatus
Authors: Nanjannawar Girish , Hegde Reshma S
Published: December 2010

Anomalous and supernumerary teeth, when present in the oral cavity may affect the facial harmony and esthetics. Managing patients with anomalous and supernumerary teeth poses a challenge for dentists especially, when smile esthetics is affected. We report management of a case of mesiodens associated with dens invaginatus, a rare presentation wherein the patient required immediate esthetic restoration.

Key Message

Immediate esthetic management of mesiodens.
Tecnologias e sistemas de informação: uma área científica orientada às necessidades de conhecimento dos profissionais envolvidos na contínua transformação das organizações através das tecnologias da informação
Authors: Carvalho João Álvaro
Published: December 2010

Tecnologias e sistemas de informação é a área científica de enquadramento para aqueles que se interessam, académica ou profissionalmente, pela adopção e exploração de tecnologias da informação no contexto das organizações ou da sociedade. É uma área que emergiu como consequência da importância que as TI tem vindo a assumir nas actividades humanas que envolvem alguma forma de processamento de informação. Dada a sua forte interligação com outras áreas, as suas fronteiras são de difícil delimitação. As actividades dos profissionais de TSI e as suas necessidades de conhecimento são usadas neste artigo como critério para definir o âmbito da área científica. Assim, após uma caracterização das actividades profissionais de TSI, são apresentados os grandes grupos que constituem o corpo de conhecimento da área e são apresentados os principais métodos de I&D usados na produção de novo conhecimento cientificamente válido.
Coordenadores de comunidades de repositórios institucionais: o caso do repositórium
Authors: Rosa Flávia Garcia , Gomes Maria João
Published: December 2010

O Movimento do Acesso Livre – Open Access Movement (OAM) – foi estimulado por dois eventos importantes: a evolução das TIC, processo facilitador da disseminação e acessibilidade à informação, e os elevados custos das publicações científicas impressas, face a contextos de maiores constrangimentos financeiros da instituições de ensino superior e de investigação. Os Repositórios Institucionais (RI) são um dos elementos fundamentais do OAM e encontram-se em processo de expansão. Este texto reporta-se a um estudo focado nos coordenadores de comunidades do repositório institucional da Universidade do Minho tendo por objectivos a identificação do perfil dos coordenadores e a identificação de práticas de estímulo ao depósito ao nível das diferentes comunidades. A metodologia de investigação adoptada consistiu num levantamento (survey) através de um questionário online. Os dados recolhidos apontam para o reconhecimento, por parte dos coordenadores, das vantagens associadas ao depósito em RI, mas identificam também casos de desconhecimento do OAM e de baixo nível de auto-arquivamento por parte de alguns coordenadores de comunidades. São identificadas como principais iniciativas ao nível das políticas de estímulo ao depósito, por parte das várias comunidades, a “obrigatoriedade do depósito” e práticas de “apoio mediado”. A análise dos dados recolhidos conduziu-nos a um conjunto de reflexões que entendemos poderem ser aplicadas ao caso do RepositóriUM, mas também constituir uma orientação para outros RI em desenvolvimento.
Bibliotecas universitárias portuguesas no universo da web 2.0
Authors: Santos Alexandra , Andrade António
Published: December 2010

A agregação das designadas tecnologias da Web 2.0 aos serviços materializados nos Websites e nos portais das grandes instituições tem provocado um forte impacto, em particular, no plano da concepção dos serviços, do marketing e da aprendizagem social. O presente artigo analisa um sector tradicional como sãos as bibliotecas, mas no seio de um ambiente inovador e exigente como as universidades, no sentido de identificar como estará este conceito e recurso a ser adoptado nas bibliotecas das universidades portuguesas. Adoptando a metodologia de estudo de caso e recorrendo à revisão bibliográfica para identificar plataformas e produtos Web 2.0 foi construída uma grelha de análise dos Websites das bibliotecas das universidades portuguesas, onde são contempladas algumas plataformas de publicação, discussão, partilha, relacionamento, agregação e colaboração, analisáveis no plano do seu acesso, participação e edição de conteúdos, sejam eles feitos exclusivamente pela instituição, ou pelos próprios utilizadores. Com base nesta análise foi possível concluir que as bibliotecas das universidades portuguesas ainda não adoptaram uma cultura organizacional que incorpore plenamente este tipo de plataformas, apesar de todas as potencialidades que delas podem advir no plano do desenvolvimento da inteligência colectiva.
Investigação em sistemas de informação organizacionais em Portugal: caracterização do período de 2004 a 2007
Authors: Grilo Ricardo , Varajão João , Basto-Fernandes Vitor , Pereira António
Published: December 2010

As tecnologias e sistemas de informação são um elemento central do desenvolvimento da Sociedade da Informação, encontrando-se actualmente múltiplas e variadas aplicações nas mais variadas áreas. Dada a sua importância, verifica-se uma grande diversidade de projectos de investigação neste campo, variando na sua natureza, objectivos, foco, e em muitos outros aspectos. Para acomodar as diferentes finalidades e características intrínsecas aos estudos nesta área, têm sido utilizados diferentes instrumentos de investigação, comummente organizados em epistemologias, abordagens, metodologias e técnicas. Procurando caracterizar a realidade da investigação em sistemas de informação organizacionais em Portugal no período de 2004 a 2007, realizou-se um trabalho de pesquisa e análise de teses e dissertações disponíveis em bibliotecas de universidades públicas portuguesas. Concretamente, identificaram-se os trabalhos de investigação realizados neste período e efectuou-se a respectiva análise, tendo em consideração a epistemologia subjacente, as abordagens adoptadas, as metodologias seguidas e as técnicas aplicadas. Neste artigo, após um enquadramento conceptual, são apresentados os principais resultados obtidos.
Estudo comparativo das plataformas de ensino-aprendizagem
Authors: Gabardo Patricia , De Quevedo Silvia R. P. , Ulbricht Vânia Ribas
Published: December 2010

O impulso registrado pela Educação a Distância (EAD) com o desenvolvimento das novas Tecnologias de Informação e Comunicação (TIC) nos últimos anos, demonstra o aperfeiçoamento tecnológico dos ambientes virtuais de aprendizagem. O fato requereu a necessidade de aperfeiçoar-se o uso de novas ferramentas, potencializando seu uso e propondo uma nova visão pedagógica à modalidade, que é o de contribuir para o aprendizado autônomo do aluno, porém de forma mais colaborativa. Nesse aspecto, as plataformas utilizadas pelas Instituições de Ensino Superior para EAD estariam de acordo com esta nova visão? Estudo de caso relativo às plataformas para ensino e aprendizagem utilizadas no Brasil demonstra o largo caminho que há para ser percorrido na potencialização das novas tecnologias.
Investigação em sistemas de informação
Authors: Pinto Carlos Sousa , Baptista Ana Alice
Published: December 2010

INVESTIGAÇÃO EM SISTEMAS DE INFORMAÇÃOCarlos Sousa Pinto - csp@dsi.uminho.ptAna Alice Baptista - analice@dsi.uminho.ptDepartamento de Sistemas de Informação, Universidade do Minho, PT
DEVELOPING A MODEL OF COOPERATING TEACHER EFFECTIVENESS
Authors: Roberts T. Grady
Published: December 2010

A trend in agricultural education has been a shortage of graduates from preservice agricultural education programs who choose to enter the teaching profession, thus causing a deficit in the number of qualified teachers to fill vacancies. When examining preservice agricultural education programs, student teaching is often the capstone experience, during which, the student teacher works closely with the cooperating teacher. Given that the student teaching experience is often the final semester of preservice agricultural education programs, it is reasonable to assume that satisfaction with that experience contributed to a student teacher’s decision to enter the teaching profession. Because the decision to enter teaching is made by the student teacher, insight into their perceptions of the student teaching experience, particularly the cooperating teacher, is invaluable. The purpose of this study was to develop a model of cooperating teacher effectiveness by replicating the work of Roberts and Dyer (2004). The Delphi method was utilized with an expert panel (N = 13) of all the student teachers from the University of Florida. Thirty characteristics were identified and grouped into the categories of Teaching/Instruction, Professionalism, Student Teacher/Cooperating Teacher Relationship, and Personal Characteristics.
THE RELATIONSHIP BETWEEN LEARNING STYLES, LEARNING ENVIRONMENTS, AND STUDENT SUCCESS
Authors: McCann Brian M.
Published: December 2010

The purpose of this study was to investigate the relationship between Extension employees' learning styles and their performance in three different types of learning environments: traditional face-to-face instruction, minimally interactive online instruction, and highly interactive, multimedia-rich online instruction. Keith Golay's Learning Pattern Assessment and a ten-question post-test were used to gather data for this study. A 4 x 3 factorial ANOVA was used to test the data at the .10 level of significance. Results indicate that participants in the traditional face-to-face and the multimedia-rich, highly interactive online environment had statistically higher post-test scores than those participants in a minimally interactive online environment. Further, it was discovered that a participant's learning style had no statistically significant effect on their final post-test scores in any of the three instructional methods; and no significant interaction was found between the learning style and instructional method.
MEASURING LEARNING IN THE AFFECTIVE DOMAIN USING REFLECTIVE WRITING ABOUT A VIRTUAL INTERNATIONAL AGRICULTURE EXPERIENCE
Authors: Boyd Barry L. , Dooley Kim E. , Felton Summer
Published: December 2010

Agricultural educators are familiar with the three domains of learning: 1) cognitive, 2) affective, and 3) psychomotor. When teaching agricultural content, the instructional and assessment strategies are typically focused on the cognitive domain of learning because of the difficulty in measuring gains in the affective domain. The purpose of this study was to measure affective learning after viewing an asynchronously delivered simulation, reflecting (metacognition), and writing about the experience. Research in agricultural education is devoid of writing as an assessment tool to measure learning in the affective domain. Content analysis of 83 reflective writing samples was used to analyze affective learning at the levels of receiving, responding, valuing, organization, and characterization. It was evident in the reflective writing that all students participated at the receiving and responding levels. It is much more difficult to assess students at the higher levels of the affective domain (valuing, organizing, and characterizing). From the analysis of reflective writing, the researchers recognized and determined that some students expressed affective learning at higher levels of the affective taxonomy and increased their level of reflective writing in the process.
TEACHING LEADERSHIP IN AGRICULTURAL SCIENCE: BEHAVIORAL FACTORS THAT INFLUENCE SECONDARY AGRICULTURAL SCIENCE LEADERSHIP INSTRUCTION
Authors: Morgan A. Christian , Rudd Rick D.
Published: December 2010

This study sought to explain why agricultural science instructors teach leadership in their classrooms. The variables measured were instructor leadership teaching behavior, instructor attitude towards teaching leadership, instructor demographics, instructor leadership knowledge, and instructor expectations of students after the teaching of leadership. In this national study 400 participants were contacted and 167 responded to the questionnaire. This study revealed that instructor attitude towards teaching leadership, selected instructor demographics, and instructor expectations were significant predictors of instructor leadership teaching behavior. Instructor leadership knowledge had no significant contribution to instructor leadership teaching behavior. It was recommended that pre-service instructors be encouraged to take a leadership course so they will be better prepared to teach leadership concepts as an instructor; leadership professional development programs should be offered to current instructors to increase instructor leadership knowledge; and teacher preparation institutions should provide pre-service instructors with LifeKnowledge curriculum training so new agriculture instructors will be prepared to teach leadership in agricultural science classrooms.
A COMPARISON OF STUDENT TEACHERS’ PERCEPTIONS OF IMPORTANT ELEMENTS OF THE STUDENT TEACHING EXPERIENCE BEFORE AND AFTER A 12-WEEK FIELD EXPERIENCE
Authors: Young R. Brent , Edwards M. Craig
Published: December 2010

This study describes student teachers’ perceptions of important elements of the student teaching experience. Selected characteristics of student teachers and their cooperating centers are also identified. The purposive sample (N = 25) included all student teachers who completed a 12- week field experience during the spring 2004 semester. Student teachers rated 34 elements of student teaching before and after the experience using a summated rating scale: “5” = “High Importance”, “1” = “No Importance.” Questionnaire items also identified selected characteristics of participants. Cronbach’s coefficient alpha reliability estimates for five core areas of the experience ranged from .60 to .84; the overall importance scale yielded an estimate of .91. The overall pretest and posttest means were 4.30 and 4.58, respectively, or about midway between “much” and “high importance.” Results from both observations revealed student teachers perceived that the relationship with their cooperating teacher was the most important aspect of the student teaching experience. Perceptions related to students’ SAEs held the lowest importance before and after student teaching. Findings provide some support for what other researchers posit about the role of concrete experience and modification of one’s perceptions, especially viewpoints that may have been abstracted originally.
COMPARISON OF TEACHER EFFICACY AMONG TRADITIONALLY AND ALTERNATIVELY CERTIFIED AGRICULTURE TEACHERS
Authors: Rocca Steven J. , Washburn Shannon G.
Published: December 2010

The shortage of qualified teachers in agricultural education has led to the hiring of uncertified teachers to fill vacancies. Many states have resorted to alternative certification routes to fill the need for teachers. In Florida, alternatively certified teachers represent over half of all new teachers in agricultural education. This situation has created uncertainty about the status of agricultural education in Florida and provided the motivation for this study. The purpose of this study was to describe traditionally and alternatively certified Florida agriculture teachers, compare their perceptions of teacher efficacy, and examine the relationship between teaching experience and teacher efficacy. Data analysis found that traditionally and alternatively certified teachers differed in age, education level, agricultural occupational experience, and gender and ethnic proportions. Comparison of teachers’ self-efficacy found no notable difference between the two groups. Results also showed a low positive association existed between agriculture teaching experience and teacher efficacy. Suggestions for future research include the need for replication of the study with other beginning teachers, increased recruitment of underrepresented populations into teacher preparation programs, and investigation of the curriculum and teaching practices of traditionally and alternatively certified teachers as they may impact teachers’ perceptions of efficacy and student achievement.
EFFECTS OF A MATH-ENHANCED CURRICULUM AND INSTRUCTIONAL APPROACH ON THE MATHEMATICS ACHIEVEMENT OF AGRICULTURAL POWER AND TECHNOLOGY STUDENTS: AN EXPERIMENTAL STUDY
Authors: Parr Brian A. , Edwards M. Craig , Leising James G.
Published: December 2010

The purpose of this study was to empirically test the hypothesis that students who participated in a contextualized, mathematics-enhanced high school agricultural power and technology curriculum and aligned instructional approach would develop a deeper and more sustained understanding of selected mathematical concepts than those students who participated in the traditional curriculum and instruction. This study included teachers and students from 38 high schools in the state of Oklahoma (18 experimental classrooms; 20 control classrooms). Students were enrolled in an agricultural power and technology course in the spring of 2004. The total number of students participating was 447 (206 experimental; 241 control). The experimental design employed was a posttest only control group design. One-way analysis of variance (ANOVA) was used to test the study’s null hypothesis. The math-enhanced agricultural power and technology curriculum and aligned instructional approach did significantly affect (p < .05) a student’s need for postsecondary mathematics remediation as measured by a mathematics placement test used to determine a student’s need for remediation at the postsecondary level. A one-year replication of the study is recommended.
CHALLENGES OF SERVICE-LEARNING IN TENNESSEE 4-H YOUTH DEVELOPMENT: A DELPHI STUDY
Authors: Mantooth Lori Jean , Fritz Carrie Ann
Published: December 2010

Service-learning is growing in popularity as a methodology for teaching youth life skills and 4-H project knowledge. Through a modified Delphi technique, a panel comprised of 4-H’ers, volunteers, and agents in Tennessee identified challenges of utilizing service-learning to fulfill the mission of the state’s 4-H Youth Development program. The subpanels of 4-H youth, volunteers, and Extension agents found that primary challenges of conducting service-learning projects through 4-H Youth Development include coordination, working around everyone’s schedule, and funding. There were some differences among the subpanels’ lists and prioritization of the challenges. The study has implications for 4-H leaders, both youth and adult, who employ service-learning as a teaching tool.
EVALUATION OF A LIVESTOCK ETHICS CURRICULUM FOR HIGH SCHOOL YOUTH
Authors: Rusk Clinton P. , Brubaker Keli M. , Balschweid Mark A. , Pajor Edmond A.
Published: December 2010

The purpose of this study was to evaluate the effectiveness of a livestock ethics curriculum developed for high school students in Agricultural Education classes. The three hour curriculum was taught by Keli Brubaker to 305 students enrolled in eight Indiana High School Agriculture programs. Data were collected using a pre-test/post-test experimental design and both tests were administered by the researcher to ensure consistent and detailed instructions were given to students. The McNemar test in SPSS was used to evaluate pre-test/post-test responses. Participants increased their awareness and knowledge of the overall principles involved in making ethical choices when faced with decisions in youth livestock programs. Students improved their understanding of the consequences associated with making unethical choices when faced with decisions in the youth livestock program. Participants were better informed and thus, more likely to make an ethical choice when faced with a decision in the youth livestock program as a result of the case study analysis. The researchers concluded that a livestock ethics curriculum is beneficial for students in high school Agricultural Education classes. Additional research should be done to determine if students will make an ethical choice when faced with a decision in a real life situation.
TEACHER ATTRITION AMONG WOMEN IN SECONDARY AGRICULTURAL EDUCATION
Authors: Kelsey Kathleen D.
Published: December 2010

Although women have enjoyed majority status as teachers in most disciplines, they are underrepresented in secondary agricultural education (AGED). To better understand female underrepresentation within agricultural education, this study used Grissmer and Kirby’s (1987) theory of teacher attrition to investigate the career-related experiences of female preservice students in the agriculture education department at Oklahoma State University and AGED teachers within Oklahoma using a mixed-method case study design. It was found that, although the women were well prepared to teach and had contextually rich experiences in AGED, only a fraction of the women who entered the preservice program successfully gained employment as AGED teachers. Reasons for attrition included a lack of commitment to teaching AGED, being place-bound, and gender bias from school administrators. To reduce attrition, women desiring to teach AGED and those already in the field need support from university faculty, state staff, and school administrators in regard to challenges they face in nontraditional careers to increase specific human capital and a commitment to the profession.
Long-term record of aerosol optical properties and chemical composition from a high-altitude site (Manora Peak) in Central Himalaya
Authors: Ram K. , Sarin M. M. , Hegde P.
Published: December 2010

Abstract. A long-term study, conducted from February 2005 to July 2008, involving chemical composition and optical properties of ambient aerosols from a high-altitude site (Manora Peak: 29.4° N, 79.5° E, ~1950 m a.s.l.) in the central Himalaya is reported here. The total suspended particulate (TSP) mass concentration varied from 13 to 272 μg m−3 over a span of 42 months. Aerosol optical depth (AOD) and TSP increase significantly during the summer (April–June) due to increase in the concentration of mineral dust associated with the long-range transport from desert regions (from the middle-East and Thar Desert in western India). The seasonal variability in the carbonaceous species (EC, OC) is also significantly pronounced, with lower concentrations during the summer and monsoon (July–August) and relatively high during the post-monsoon (September–November) and winter (December–March). On average, total carbonaceous aerosols (TCA) and water-soluble inorganic species (WSIS) contribute nearly 25 and 10% of the TSP mass, respectively. The WSOC/OC ratios range from 0.36 to 0.83 (average: 0.55 ± 0.15), compared to lower ratios in the Indo-Gangetic Plain (range: 0.35–0.40), and provide evidence for the enhanced contribution from secondary organic aerosols. The mass fraction of absorbing EC ranged from less than a percent (during the summer) to as high as 7.6% (during the winter) and absorption coefficient (babs, at 678 nm) varied between 0.9 to 33.9 Mm−1 (1 Mm−1=10−6 m−1). A significant linear relationship between babs and EC (μgC m−3) yields a slope of 12.2 (± 2.3) m2 g−1, which is used as a measure of the mass absorption efficiency (σabs) of EC.
Decadal regional air quality simulations over Europe in present climate: near surface ozone sensitivity to external meteorological forcing
Authors: Katragkou E. , Zanis P. , Tegoulias I. , Melas D. , Kioutsioukis I. , Krüger B. C. , Huszar P. , Halenka T. , Rauscher S.
Published: December 2010

Abstract. Regional climate-air quality decadal simulations over Europe were carried out with the RegCM3/CAMx modeling system for the time slice 1991–2000, in order to study the impact of different meteorological forcing on surface ozone. The RegCM3 regional climate model was firstly constrained by the ERA40 reanalysis dataset which is considered as an experiment with perfect meteorological boundary conditions and then it was constrained by the global circulation model ECHAM5. A number of meteorological parameters were examined including the 500 mb geopotential height, solar radiation, temperature, cloud liquid water path, planetary boundary layer height and surface wind. The different RegCM meteorological forcing resulted in changes of near surface ozone over Europe ranging between ± 4 ppb for winter and summer. The area showing the greatest sensitivity in O3 during winter is central and southern Europe while in summer central north continental Europe. The different meteorological forcing impacts on the atmospheric circulation, which in turn affects cloudiness and solar radiation, temperature, wind patterns and the meteorology depended biogenic emissions. For comparison reasons, the impact of chemical boundary conditions on surface ozone was additionally examined with a series of sensitivity studies, indicating that surface ozone changes are comparable to those caused by the different meteorological forcing. These findings suggest that, when it comes to regional climate-air quality simulations, the selection of external meteorological forcing can be as important as the selection of adequate chemical lateral boundary conditions.
Measurements and modelling of molecular iodine emissions, transport and photodestruction in the coastal region around Roscoff
Authors: Leigh R. J. , Ball S. M. , Whitehead J. , Leblanc C. , Shillings A. J. L. , Mahajan A. S. , Oetjen H. , Lee J. D. , Jones C. E. , Dorsey J. R. , Gallagher M. , Jones R. L. , Plane J. M. C. , Potin P. , McFiggans G.
Published: December 2010

Abstract. Iodine emissions from the dominant six macroalgal species in the coastal regions around Roscoff, France, have been modelled to support the Reactive Halogens in the Marine Boundary Layer Experiment (RHaMBLe) undertaken in September 2006. A two-dimensional model is used to explore the relationship between geographically resolved regional emissions (based on maps of seaweed beds in the area and seaweed I2 emission rates previously measured in the laboratory) and in situ point and line measurements of I2 performed respectively by a broadband cavity ringdown spectroscopy (BBCRDS) instrument sited on the shoreline and a long-path differential optical absorption spectroscopy (LP-DOAS) instrument sampling over an extended light path to an off-shore island. The modelled point and line I2 concentrations compare quantitatively with BBCRDS and LP-DOAS measurements, and provide a link between emission fields and the different measurement geometries used to quantify atmospheric I2 concentrations during RHaMBLe. Total I2 emissions over the 100 km2 region around Roscoff are calculated to be 1.7×1019 molecules per second during the lowest tides. During the night, the model replicates I2 concentrations up to 50 pptv measured along the LP-DOAS instrument's line of sight, and predicts spikes of several hundred pptv in certain conditions. Point I2 concentrations up to 50 pptv are also calculated at the measurement site, in broad agreement with the BBCRDS observations. Daytime measured concentrations of I2 at the site correlate with modelled production and transport processes. However substantial recycling of the photodissociated I2 is required for the model to quantitatively match measured concentrations. This result corroborates previous modelling of iodine and NOx chemistry in the semi-polluted marine boundary layer which proposed a mechanism for recycling I2 via the formation, transport and subsequent reactions of the IONO2 reservoir compound. The methodology presented in this paper provides a tool for linking spatially distinct measurements to inhomogeneous and temporally varying emission fields.
Mid-latitude ozone monitoring with the GOMOS-ENVISAT experiment version 5: the noise issue
Authors: Keckhut P. , Hauchecorne A. , Blanot L. , Hocke K. , Godin-Beekmann S. , Bertaux J.-L. , Barrot G. , Kyrölä E. , van Gijsel J. A. E. , Pazmino A.
Published: December 2010

Abstract. The GOMOS ozone profiles have been analysed to evaluate the GOMOS ability to capture the long-term ozone evolution at mid-latitudes during the expected recovery phase of the ozone layer. Version 5 of the operational GOMOS ozone data has been compared with data from two of the longest ground-based instruments based on different techniques and already involved with many other previous space instrument validations. Comparisons between ground-based and GOMOS data confirm the occurrence of spurious retrievals mainly occurring since 2006. Using a selected set of data it is shown that some bad retrievals are induced by the increasing dark charge of the detectors combined with an inadequate method for its correction. This effect does not only induce a continuous bias, but is rather exhibiting a bimodal distribution including the correct profiles and the bad retrievals. For long-term analyses it is recommended filtering the data according to background light conditions and star temperature (spectrum shape). The new method of the dark charge estimate proposed to be implemented in the version 6 of the ESA algorithm seems to significantly reduce the occurrence of such effects and should allow to monitor stratospheric ozone using GOMOS data with greater confidence.
Cloud thermodynamic phase inferred from merged POLDER and MODIS data
Authors: Riedi J. , Marchant B. , Platnick S. , Baum B. A. , Thieuleux F. , Oudard C. , Parol F. , Nicolas J.-M. , Dubuisson P.
Published: December 2010

Abstract. The global spatial and diurnal distribution of cloud properties is a key issue for understanding the hydrological cycle, and critical for advancing efforts to improve numerical weather models and general circulation models. Satellite data provides the best way of gaining insight into global cloud properties. In particular, the determination of cloud thermodynamic phase is a critical first step in the process of inferring cloud optical and microphysical properties from satellite measurements. It is important that cloud phase be derived together with an estimate of the confidence of this determination, so that this information can be included with subsequent retrievals (optical thickness, effective particle radius, and ice/liquid water content). In this study, we combine three different and well documented approaches for inferring cloud phase into a single algorithm. The algorithm is applied to data obtained by the MODIS (MODerate resolution Imaging Spectroradiometer) and POLDER3 (Polarization and Directionality of the Earth Reflectance) instruments. It is shown that this synergistic algorithm can be used routinely to derive cloud phase along with an index that helps to discriminate ambiguous phase from confident phase cases. The resulting product provides a semi-continuous index ranging from confident liquid to confident ice instead of the usual discrete classification of liquid phase, ice phase, mixed phase (potential combination of ice and liquid particles), or simply unknown phase clouds. The index value provides simultaneously information on the phase and the associated confidence. This approach is expected to be useful for cloud assimilation and modeling efforts while providing more insight into the global cloud properties derived from satellite data.
Comparison of UV irradiances from Aura/Ozone Monitoring Instrument (OMI) with Brewer measurements at El Arenosillo (Spain) – Part 2: Analysis of site aerosol influence
Authors: Cachorro V. E. , Toledano C. , Antón M. , Berjón A. , de Frutos A. , Vilaplana J. M. , Arola A. , Krotkov N. A.
Published: December 2010

Abstract. Several validation studies have shown a notable overestimation of the clear sky ultraviolet (UV) irradiance at the Earth's surface derived from satellite sensors such as the Total Ozone Mapping Spectrometer (TOMS) and the Ozone Monitoring Instrument (OMI) with respect to ground-based UV data at many locations. Most of this positive bias is attributed to boundary layer aerosol absorption that is not accounted for in the TOMS/OMI operational UV algorithm. Therefore, the main objective of this study is to analyse the aerosol effect on the bias between OMI erythemal UV irradiance (UVER) and spectral UV (305 nm, 310 nm and 324 nm) surface irradiances and ground-based Brewer spectroradiometer measurements from October 2004 to December 2008 at El Arenosillo station (37.1° N, 6.7° W, 20 m a.s.l.), with meteorological conditions representative of the South-West of Spain. The effects of other factors as clouds, ozone and the solar elevation over this intercomparison were analysed in detail in a companion paper (Antón et al., 2010). In that paper the aerosol effects were studied making only a rough evaluation based on aerosol optical depth (AOD) information at 440 nm wavelength (visible range) without applying any correction. We have used the precise information given by single scattering albedo (SSA) from AERONET for the determination of absorbing aerosols which has allowed the correction of the OMI UV data. An aerosol correction expression was applied to the OMI operational UV data using two approaches to estimate the UV absorption aerosol optical depth, AAOD. The first approach was based on an assumption of constant SSA value of 0.91. This approach reduces the OMI UVER bias against the reference Brewer data from 13.4% to 8.4%. Second approach uses daily AERONET SSA values reducing the bias only to 11.6%. Therefore we have obtained a 37% and 12% of improvement respectively. For the spectral irradiance at 324 nm, the OMI bias is reduced from 10.5% to 6.98% for constant SSA and to 9.03% for variable SSA. Similar results were obtained for spectral irradiances at 305 nm, and 310 nm. Contrary to what was expected, the constant SSA approach has a greater bias reduction than variable SSA, but this is a reasonable result according to the discussion about the reliability of SSA values. Our results reflect the level of accuracy that may be reached at the present time in this type of comparison, which may be considered as satisfactory taking into account the remaining dependence on other factors. Nevertheless, improvements must be accomplished to determine reliable absorbing aerosol properties, which appear as a limiting factor for improving OMI retrievals.
A minimum bulk microphysics
Authors: Yano J.-I. , Bouniol D.
Published: December 2010

Abstract. Cloud microphysics present extreme complexities, and even under bulk approaches, the formulation tends to be involved. A minimum microphysics is proposed, aimed at applications for geophysical fluid dynamics, by a maximum simplification of a standard bulk formulation. The proposed formulation is also independently derived by a simple phenomenological argument. The formulational structure of the bulk microphysics is also discussed. The autoconversion process formulation is discussed separately in a phenomenological manner, because a formal application of the bulk approach becomes involved. Four major possible formulations for autoconversion are identified. The proposed formulation is tested with a nonhydrostatic anelastic model under segmentally-constant approximation (NAM-SCA).
Ionization effect of solar particle GLE events in low and middle atmosphere
Authors: Usoskin I. G. , Kovaltsov G. A. , Mironova I. A. , Tylka A. J. , Dietrich W. F.
Published: December 2010

Abstract. Using a new reconstruction of the solar proton energy spectra for Ground Level Enhancement (GLE) events, based on fits to measurements from ground-based and satellite-borne instruments covering a wide energy range, we quantitatively evaluate the possible ionization effects in the low and middle atmosphere for 58 out of the 66 GLE events recorded by the world-wide neutron monitor network since 1956. The ionization computations are based on the numerical 3-D CRAC:CRII model. A table of the ionization effect caused by the GLE events at different atmospheric heights is provided. It is shown that the direct ionization effect is negligible or even negative, due to the accompanying Forbush decreases, in all low- and mid-latitude regions. The ionization effect is important only in the polar atmosphere, where it can be dramatic in the middle and upper atmosphere (above 30 km) during major GLE events.
Why hydrological predictions should be evaluated using information theory
Authors: Weijs S. V. , Schoups G. , van de Giesen N.
Published: December 2010

Abstract. Probabilistic predictions are becoming increasingly popular in hydrology. Equally important are methods to test such predictions, given the topical debate on uncertainty analysis in hydrology. Also in the special case of hydrological forecasting, there is still discussion about which scores to use for their evaluation. In this paper, we propose to use information theory as the central framework to evaluate predictions. From this perspective, we hope to shed some light on what verification scores measure and should measure. We start from the ''divergence score'', a relative entropy measure that was recently found to be an appropriate measure for forecast quality. An interpretation of a decomposition of this measure provides insight in additive relations between climatological uncertainty, correct information, wrong information and remaining uncertainty. When the score is applied to deterministic forecasts, it follows that these increase uncertainty to infinity. In practice, however, deterministic forecasts tend to be judged far more mildly and are widely used. We resolve this paradoxical result by proposing that deterministic forecasts either are implicitly probabilistic or are implicitly evaluated with an underlying decision problem or utility in mind. We further propose that calibration of models representing a hydrological system should be the based on information-theoretical scores, because this allows extracting all information from the observations and avoids learning from information that is not there. Calibration based on maximizing utility for society trains an implicit decision model rather than the forecasting system itself. This inevitably results in a loss or distortion of information in the data and more risk of overfitting, possibly leading to less valuable and informative forecasts. We also show this in an example. The final conclusion is that models should preferably be explicitly probabilistic and calibrated to maximize the information they provide.
Stability and forcing of the Iceland-Faroe inflow of water, heat, and salt to the Arctic
Authors: Hansen B. , Hátún H. , Kristiansen R. , Olsen S. M. , Østerhus S.
Published: December 2010

Abstract. The flow of Atlantic water across the Greenland-Scotland Ridge (Atlantic inflow) is critical for conditions in the Nordic Seas and Arctic Ocean by importing heat and salt. Here, we present a decade-long series of measurements from the Iceland-Faroe inflow branch (IF-inflow), which carries almost half the total Atlantic inflow. The observations show no significant trend in volume transport of Atlantic water, but temperature and salinity increased during the observational period. On shorter time scales, the observations show considerable variations but no statistically significant seasonal variation is observed and even weekly averaged transport values were consistently uni-directional from the Atlantic into the Nordic Seas. Combining transport time-series with sea level height from satellite altimetry and wind stress reveals that the force driving the IF-inflow across the topographic barrier of the Ridge is mainly generated by a pressure gradient that is due to a continuously maintained low sea level in the Southern Nordic Seas. This implies that the relative stability of the IF-inflow derives from the processes that lower the sea level by generating outflow from the Nordic Seas, especially the thermohaline processes that generate overflow. The IF-inflow is an important component of the system coupling the Arctic region to the North Atlantic through the thermohaline circulation, which has been predicted to weaken in the 21st century. Our observations show no indication of weakening.
Retroflection from a double-slanted coastline: a model for the Agulhas leakage variability
Authors: Zharkov V. , Nof D. , Weijer W.
Published: December 2010

Abstract. The Agulhas leakage to the South Atlantic exhibits a strong anti-correlation with the mass flux of the Agulhas Current. When the Agulhas retroflection is in its normal position near Cape Agulhas, leakage is relatively high and the nearby South African coastal slant (angle of derivation from zonal) is very small and relatively invariant alongshore. During periods of strong incoming flux (low leakage), the retroflection shifts upstream to Port Elizabeth or East London, where the coastline shape has a "kink", i.e., the slant changes abruptly from small on the west side, to large (about 55°) on the east side. Here, we show that the variability of rings shedding and anti-correlation between Agulhas mass flux and leakage to the South Atlantic may be attributed to this kink. To do so, we develop a nonlinear analytical model for retroflection near a coastline that consists of two sections, a zonal western section and a strongly slanted eastern section. The principal difference between this and the model of a straight slanted coast (discussed in our earlier papers) is that, here, free purely westward propagation of eddies along the zonal coastline section is allowed. This introduces an interesting situation in which strong slant of the coast east of the kink prohibits the formation and shedding of rings, while the almost zonal coastal orientation west of the kink encourages shedding. Therefore, the kink "locks" the position of the retroflection, forcing it to occur just downstream of the kink. Rings are necessarily shed from the retroflection area in our kinked model, regardless of the degree of eastern coast slant. In contrast, a no-kink model with a coastline of intermediate slant indicates that shedding is almost completely arrested by that slant. We suggest that the observed difference in ring-shedding intensity during times of normal retroflection position and times when the retroflection is shifted eastward is due to the change in the retroflection location with respect to the kink. When the incoming flux detaches from the coast north of the kink, ring transport is small; when the flux detaches south of the kink, transport is large. Simple process-oriented numerical simulations are in fair agreement with our analytical results.