bluuebunny/crossref_metadata_2025 huggingface dataset:
Le problème du mal dans le Guide des Perplexes et son arrière-plan talmudique
Authors: Costa José
Published: January 2011

A primera vista, el problema del mal es abordado en la Guía de Perplejos de manera paradójica. Para Maimónides, las nociones de bien y mal son subjetivas y no resultan ni rigorosas ni exactas, a la inversa de las nociones de verdad y falsedad (Guía I, 2). Sin embargo, el problema del mal es muy importante en la Guía, como lo demostraran varios autores. Maimónides es el heredero de la tradición rabínica y existe en la Guía una interacción entre la filosofia de Maimónides y los textos talmúdicos y midrásicos. Es particularmente el caso de las treinta y nueve citas rabínicas de la Guía II, 8-24, que tratan del origen del mal, del significado del sufrimiento y de la inclinación al mal. Maimónides cita los midrašim que concuerdan con sus posiciones racionalistas y evoca también algunas tradiciones rabínicas próximas al mu ͑tazilismo, ciertamente consciente de la profunda semejanza entre las doctrinas rabínicas y mu ͑tazilíes del mal y de la retribución.
La polémica sobre el judeoespañol en la prensa sefardí del Imperio otomano: más materiales para su estudio
Authors: Romero Elena
Published: January 2011

En el presente artículo se publican y estudian doce textos aljamiados tomados de la prensa sefardí que ilustran sobre la polémica acerca de la supervivencia del judeoespañol, entablada entre los sefardíes del Imperio otomano desde finales del siglo xix en adelante. Los textos proceden de los periódicos El Tiempo de Constantinopla, La Época y El Avenir de Salónica y El Meseret de Esmirna, y vieron la luz en los años 1883, 1893, 1900, 1904 y 1906. Los temas a tratar se distribuyen en los siguientes apartados: 1) Los españoles ante el judeoespañol y el problema de los caracteres rašíes; 2) El rechazo de los sefardíes a España y a su herencia lingüistica versus la campaña de Ángel Pulido; y 3) El turco como solución. Para ilustrar tales temas se aduce algún otro texto de fuente española, así como la versión aljamiada de un conocido artículo de Leon Lamouche, el cual sirve de un a modo de resumen de todo lo expuesto.
Una capitulación relativa a una compañía crediticia de judíos de Huesca y Jaca
Authors: Gracia Eugenio Benedicto
Published: January 2011

Estudio de la capitulación acordada en 1428 entre Abram Ambivag de Huesca y Judas Avingoyós de Jaca, para la resolución de los problemas suscitados por el cobro de ciertas deudas de la compañía crediticia que tienen formada. La lectura del documento pone de manifiesto algunas de las limitaciones de las fuentes notariales para el estudio del crédito judío debido a los pactos tácitos entre prestador y deudor que no siempre eran recogidos por escrito, y subraya la necesidad de reconsiderar determinados aspectos de su historia.
Noticias en torno a Yom Tob Atías, alias Jerónimo de Vargas
Authors: Salomon Herman P.
Published: January 2011

El equipo de editores de Ferrara fue dirigido por dos antiguos cristianos nuevos, uno financiero, originario de España, y el otro, un latinista portugués. En las distintas introducciones a edición bíblica los dos se autodenominan alternativamente por sus nombres cristianos –Jerónimo de Vargas y Duarte Pinel– y por sus nombres judíos, Yom Tob Atías y Abraham Usque. Esta «esquizofrenia editorial» ha dejado huella en los archivos italianos. Mientras que las investigaciones de Renata Segre han documentado que Pinel y Usque eran la misma persona, no consiguió una prueba archivística para identificar a Vargas y Atías. El investigador Aron Leoni descubrió en los archivos de Ferrara un documento notarial en latín, en el que «Juantu Athias» es denominado «ptrem ac legitimum administratorum Hieronimi Vargas» y también «patre et legitimo administrador» de este último. Leoni conjeturaba que «patrem» era una abreviatura de «procuratorem» y que «patre» significaba padre, concluyendo que Atías sería padre de Jerónimo de Vargas. Un reexamen del documento y su comparación con otros dos que han salido a la luz revelan que Yom Tob Atías y Jerónimo de Vargas eran la misma persona: estamos en presencia de un caso típico de identidad doble entre antiguos cristianos nuevos que habían adoptado el judaísmo fuera de la península Ibérica, manteniendo su identidad onomástica cristiana, pero separada de la judía.
La sinagoga medieval de Molina de Aragón: evidencia documental y epigráfica
Authors: Arenas Esteban Jesús A. , Castaño Javier
Published: January 2011

Noticias acerca de la sinagoga de Molina de Aragón (Guadalajara) y análisis de los fragmentos epigráficos hebreos aparecidos durante las excavaciones realizadas en el yacimiento arqueológico de «Castil de Judíos» de dicha localidad y cuyos restos hallados corresponderían al siglo XIV.
Methyl transferase, a polyketide biosynthetic enzyme from Dreschlera monceras: purification and properties
Authors: Weerasooriya MKB , Crosby J
Published: January 2011

Methyl transferase, a polyketide biosynthetic enzyme in monocerin biosynthesis was isolated and purified from Dreschlera monoceras. The enzyme was purified to near homogeneity with 11.1% recovery, using ammonium sulphate fractionation followed by ultra filtration, SP Sepharose chromatography and gel filtration chromatography.  The molecular mass of the purified enzyme as determined by elution through Superdex TM gel filtration chromatography was found to ~ 165kDa. SDS-PAGE of the purified enzyme showed a single band at ~55kDa indicating that possibly enzyme could be a trimer of 3 subunits. The enzyme showed optimum pH at  7.5-7.7,  whereas optimum assay temperature was 35-37°C. Enzyme was stable up to 45°C and above this temperature enzyme activity slowly declined and inactivated around 70°C. Apparent Km of the enzyme was found to be ~ 0.083mM.Keywords: methyl transferase;  monocerin biosynthesis; polyketides;  D. monoceras.DOI: 10.4038/josuk.v3i0.2734J. Sci. Univ. Kelaniya 3 (2007) : 1-16
Evaluation of immune responses in an Indian carp, Labeo rohita (Hamilton) fed with levamisole incorprated diet
Authors: Wijendra GDNP , Pathinratne A
Published: January 2011

Effects of oral administration of  levamisole on the selected components of the immune system of an Indian carp,  Labeo rohita, were evaluated with a view in assessing the potential of using this compound as an immunostimulant in culturing this fish. Sub-adults of L. rohita were fed with levamisole incorporated diet (5 mg kg-1 body weight),  on the first day and every third day for 16 days (6 doses) and effects on haematocrit, total and differential leucocyte counts, phagocytic activity, production of oxygen radicals from phagocytes in the blood, lysozyme activity in the serum, total protein and immunoglobulin levels in the blood plasma were assessed at different time points in comparison to the levels of controls. Results showed that the populations of total leucocytes, neutrophils, monocytes and lymphocytes were elevated significantly on 14 and 21 days post levamisole treatment. In addition, total phagocytic activity, phagocytic index and lysozyme activity of the fish blood were enhanced significantly on 21 days post treatment.  Results support the potential use of levamisole as an immunostimulant in culturing this fish. Keywords: Labeo rohita; levamisole; immunostimulant; Indian carp DOI: 10.4038/josuk.v3i0.2735J. Sci. Univ. Kelaniya 3 (2007) : 17-28
Study on approaches to integrated control of Meloidogyne graminicola in rice
Authors: Amarasinghe LD , Kariyapperuma KADPS , Pathirana HNI
Published: January 2011

This study presents the results obtained from the studies carried out to find out the response of Meloidogyne graminicola to different rice varieties and to different soil amendments when applied with and without NPK fertilizer in young rice plants. The use of soil amendments such as poultry manure and cow dung significantly reduced the nematode population, the total percentage of yellow leaves and dead leaves and significantly increased the plant growth.  Two varieties namely, Bg 300 and Bg 352 were found to be immune for M. graminicola not allowing the nematodes to penetrate the roots. The varieties Bg 350, Bg 356, Bg 357 and Bg 360 were categorized as resistant. These varieties allowed the nematodes to penetrate the roots, but the development and the reproduction of the nematodes were not permitted. The varieties Bg 11, Bg 351, and Bg 358 were found to be susceptible for the nematode, M. graminicola of which Bg 351 is highly susceptible host with high rate of reproduction while Bg 358 and Bg 11 are less susceptible with low rate of reproduction of the nematode. This study also revealed that the young plants of susceptible varieties were unable to compensate the nematode damage under unfertilized conditions. Keywords: root-knot nematode; Meloidogyne graminicola; Oryza sativa; management DOI: 10.4038/josuk.v3i0.2736J. Sci. Univ. Kelaniya 3 (2007) : 29-46
Determination of protonation constants for 2-hydroxy-1-(2-hydroxy-4-sulpho-1-naphthylazo)-3-napthoic acid
Authors: Liyanage JA , Janaratne TK
Published: January 2011

Chemical speciation modelling in combination with potentiometric titration method was used to determine the protonation constants for 2-hydroxy-1-(2-hydroxy-4-sulpho-1-naphthylazo)-3-naphthoic acid, the Patton and Reeder's reagent, at 25° C in three ionic strengths of 0.1 mol dm-3, 0.01 mol dm-3 and 0.001 mol dm-3 NaNO3. Potentiometric titrations were performed and pH, titrant volume, temperature and free and total proton concentrations at each titration point were measured. Constants were determined for three of the four protonated sites and the forth one being a very low value as this site is always in the ionic form and is readily ionized in aqueous solutions.Keywords: Patton and Reeder; Protonation constants; Potentiometric titrations; Chemical speciation modelling DOI: 10.4038/josuk.v3i0.2737J. Sci. Univ. Kelaniya 3 (2007) : 47-52
Automatic segmentation of given set of Sinhala text into syllables for Speech Synthesis
Authors: Kumara KH , Dias NGJ , Sirisena H
Published: January 2011

A dictionary based automatic syllabification tool has been given for Speech Synthesis in Sinhala language. This tool is also capable of providing frequency distributions of Vowels, Consonants and Syllables for a given set of Sinhala text.A method of determining syllable boundaries has also been shown. Detection of Syllable boundaries for a given Sinhala sentence is achieved by four main phases and those phases have been described with examples. Rules for the automatic segmentation of words into syllables have been derived based on a dictionary.  An algorithm has been produced for the implementation of these rules which utilizes the dictionary together with an accurate mark up of the syllable boundaries.Keywords: Speech Synthesis; Text to Speech (TTS); Phonetic; Vowels; Consonants; Syllables; algorithm; transcription. DOI: 10.4038/josuk.v3i0.2738J. Sci. Univ. Kelaniya 3 (2007) : 53-62
Distribution of Genes Encoding Nucleoid-Associated Protein Homologs in Plasmids
Authors: Takeda Toshiharu , Yun Choong-Soo , Shintani Masaki , Yamane Hisakazu , Nojiri Hideaki
Published: January 2011

Bacterial nucleoid-associated proteins (NAPs) form nucleoprotein complexes and influence the expression of genes. Recent studies have shown that some plasmids carry genes encoding NAP homologs, which play important roles in transcriptional regulation networks between plasmids and host chromosomes. In this study, we determined the distributions of the well-known NAPs Fis, H-NS, HU, IHF, and Lrp and the newly found NAPs MvaT and NdpA among the whole-sequenced 1382 plasmids found in Gram-negative bacteria. Comparisons between NAP distributions and plasmid features (size, G+C content, and putative transferability) were also performed. We found that larger plasmids frequently have NAP gene homologs. Plasmids with H-NS gene homologs had less G+C content. It should be noted that plasmids with the NAP gene homolog also carried the relaxase gene involved in the conjugative transfer of plasmids more frequently than did those without the NAP gene homolog, implying that plasmid-encoded NAP homologs positively contribute to transmissible plasmids.
Development and Validation of Stability-Indicating HPTLC Determination of Tamsulosin in Bulk and Pharmaceutical Dosage Form
Authors: Bari S. B. , Bakhshi A. R. , Jain P. S. , Surana S. J.
Published: January 2011

A simple, economic, selective, precise, and stability-indicating high-performance thin-layer chromatographic method for analysis of tamsulosin hydrochloride, both as a bulk drug and in formulations, was developed and validated according to ICH guidelines. The method employed HPTLC aluminium plates precoated with silica gel 60F-254 as the stationary phase while the solvent system consisted of toluene  :  methanol  :  triethylamine (3.5  :  1.2  :  0.2 v/v). The system was found to give compact spot for drug ( value of ). Densitometric analysis of tamsulosin was carried out in the absorbance mode at 280 nm. The linear regression analysis data for the calibration plots showed good linear relationship, with respect to peak area in the concentration range 400–2400 ng per spot. The mean value ± SD of slope and intercept were and with respect to peak area. The method was validated for precision, recovery, and robustness. The limits of detection and quantitation were 20.49 and 62.10 ng per spot, respectively. Tamsulosin was subjected to hydrolysis, oxidation, and thermal degradation which indicate the drug is susceptible to hydrolysis, oxidation, and heat. Statistical analysis proves that the method is repeatable, selective, and accurate for the estimation of tamsulosin.
Waist Circumference, Body Mass Index, and Other Measures of Adiposity in Predicting Cardiovascular Disease Risk Factors among Peruvian Adults
Authors: Knowles K. M. , Paiva L. L. , Sanchez S. E. , Revilla L. , Lopez T. , Yasuda M. B. , Yanez N. D. , Gelaye B. , Williams M. A.
Published: January 2011

Objectives. To examine the extent to which measures of adiposity can be used to predict selected components of metabolic syndrome (MetS) and elevated C-reactive protein (CRP).Methods. A total of 1,518 Peruvian adults were included in this study. Waist circumference (WC), body mass index (BMI), waist-hip ratio (WHR), waist-height ratio (WHtR), and visceral adiposity index (VAI) were examined. The prevalence of each MetS component was determined according to tertiles of each anthropometric measure. ROC curves were used to evaluate the extent to which measures of adiposity can predict cardiovascular risk.Results. All measures of adiposity had the strongest correlation with triglyceride concentrations (TG). For both genders, as adiposity increased, the prevalence of Mets components increased. Compared to individuals with low-BMI and low-WC, men and women with high-BMI and high- WC had higher odds of elevated fasting glucose, blood pressure, TG, and reduced HDL, while only men in this category had higher odds of elevated CRP. Overall, the ROCs showed VAI, WC, and WHtR to be the best predictors for individual MetS components.Conclusions. The results of our study showed that measures of adiposity are correlated with cardiovascular risk although no single adiposity measure was identified as the best predictor for MetS.
Myocardial Infarction due to Endocarditis
Authors: Bathina Jaya D. , Yusuf Syed Wamique
Published: January 2011

We present a case of a 43-year-old man who sustained a myocardial infarction due to infective endocarditis.
Floatation-Spectrophotometric Determination of Thorium, Using Complex Formation with Eriochrome Cyanine R
Authors: Shiri Sabah , Delpisheh Ali , Haeri Ali , Poornajaf Abdolhossein , Khezeli Tahereh , Badkiu Nadie
Published: January 2011

A novel and sensitive floatation-spectrophotometric method is presented for determination of trace amounts of thorium in water samples. The method is based on the ion-associated formation between thorium, Eriochrome cyanine R and Brij-35 at pH = 4 media. The complex was floated in the interface of the aqueous phase and n-hexane by vigorous shaking. After removing the aqueous phase the floated particles were dissolved in methanol and the absorbance was measured at 607 nm. The influence of different important parameters such as Eriochrome cyanine R and surfactants concentration, pH, volume of n-hexane, standing time and interfering ions were evaluated. Under optimized conditions the calibration graph was linear in the range of 6-230 ng mL-1 of thorium with a correlation coefficient of 0.9985. The limit of detections (LOD), based on signal to noise ratio (S/N) of 3 was 1.7 ng mL-1. The relative standard deviations for determination of 150 and 30 ng ml-1 of thorium were 3.26 and 4.41%, respectively (n = 10). The method showed a good linearity, recoveries, as well as some advantages such as sensitivity, simplicity, affordability and a high feasibility. The method was successfully applied to determine thorium in different water and urine samples.
Skin Cancer Recognition by Using a Neuro-Fuzzy System
Authors: Salah Bareqa , Alshraideh Mohammad , Beidas Rasha , Hayajneh Ferial
Published: January 2011

Skin cancer is the most prevalent cancer in the light-skinned population and it is generally caused by exposure to ultraviolet light. Early detection of skin cancer has the potential to reduce mortality and morbidity. There are many diagnostic technologies and tests to diagnose skin cancer. However many of these tests are extremely complex and subjective and depend heavily on the experience of the clinician. To obviate these problems, image processing techniques, a neural network system (NN) and a fuzzy inference system were used in this study as promising modalities for detection of different types of skin cancer. The accuracy rate of the diagnosis of skin cancer by using the hierarchal neural network was 90.67% while using neuro-fuzzy system yielded a slightly higher rate of accuracy of 91.26% in diagnosis skin cancer type. The sensitivity of NN in diagnosing skin cancer was 95%, while the specificity was 88%. Skin cancer diagnosis by neuro-fuzzy system achieved sensitivity of 98% and a specificity of 89%.
The Effectiveness of Women’s Agricultural Education Programs: A Survey from Annie’s Project
Authors: Heins Lynn Hambleton , Beaulieu Jeff , Altman Ira
Published: January 2011

This study determined the effectiveness of ‘Annie’s Project—Education for Farm Women’ in improving women’s skill sets. Illinois farm women who participated in Annie’s Project were given a pre–test or baseline survey which measured farming practices in the five areas of risk (production, marketing, financial, legal and human resource). The women were later resurveyed. The main methodology to measure improvement in skill is calculated by the difference in the percentage of ‘yes’ responses from the baseline to the post–test. Results suggest an overall increase of 10.92 percent with the largest improvement occurring in the financial area of risk. In general, the differences in ‘yes’ responses were found to be significantly different from zero. Regression analysis was also performed to determine whether socio–economic variables, such as marital status and farm size, play a role in the difference in the percentages of ‘yes’ responses.
Agriscience Student Engagement in Scientific Inquiry: Representations of Scientific Processes and Nature of Science
Authors: Grady Julie R. , Dolan Erin L. , Glasson George E.
Published: January 2011

Students’ experiences with science integrated into agriscience courses contribute to their developing epistemologies of science. The purpose of this case study was to gain insight into the implementation of scientific inquiry in an agriscience classroom. Also of interest was how the tenets of the nature of science were reflected in the students’ experiments. Participants included an agriscience teacher and her fifteen students who were conducting plant experiments to gain insight into the role of a gene disabled by scientists. Data sources included classroom observations, conversations with students, face–to–face interviews with the teacher, and students’ work. Analysis of the data indicated that the teacher viewed scientific inquiry as a mechanical process with little emphasis on the reasoning that typifies scientific inquiry. Students’ participation in their experiments also centered on the procedural aspects of inquiry with little attention to scientific reasoning. There was no explicit attention to the nature of science during the experiments, but the practice implied correct, incorrect, and underdeveloped conceptions of the nature of science. Evidence from the study suggests a need for collaboration between agriscience and science teacher educators to design and conduct professional development focused on scientific inquiry and nature of science for preservice and practicing teachers.
Eugene Davenport’s Education for Efficiency
Authors: Martin Michael J.
Published: January 2011

Philosophical research into the Smith–Hughes Vocational Education Act of 1917 has primarily centered on the arguments of Social Efficiency and Democracy and Education. Yet, there was a philosopher that stood for a middle ground of this debate, Eugene Davenport (1856–1941). He fought against legislation that betrayed his Education for Efficiency philosophy. Davenport wrote books and pamphlets about a national system of vocational education. Davenport and his Education for Efficiency philosophy was significant in the legislative battles for vocational education and represented an agricultural voice in the educational debates of the day.
Likelihood of Students in the Formal Education System in Trinidad to Pursue Agriculture as a Profession and the Implications for Development
Authors: Ramdwar Marcus N. A. , Ganpat Wayne G.
Published: January 2011

As part of Caribbean–wide initiatives to modernize agriculture, the formal education system for agriculture in Trinidad is coming under scrutiny. This paper investigates the perceptions students have about agriculture, the likelihood of those in the secondary school system (n=300) to pursue a formal education in agriculture, and the likelihood of those in the tertiary system (n=100) to continue in a career in agriculture. Likert–type scales were used to assess perceptions, and the likelihood of students in the formal education system in Trinidad to pursue agriculture as a profession was measured on a rating scale. Relationships were examined between school location (North, South, and Central), students’ residential area (Rural, Urban), gender, and the likelihood to pursue a career in agriculture. Data were presented as descriptives and correlations. Results show that in schools where agriculture is not taught, while students firmly believed that agriculture is very important, very few would make it a career–choice. In secondary schools where agriculture is taught, students were generally favorable in their overall attitudes to agriculture, but there was only moderate indication that they would pursue the field further as a career. There were significant relationships between gender, school’s location, and students’ residential area and the likelihood to pursue agriculture. At the tertiary level, there was very strong indication that these students would continue in a career in agriculture. However, they were most likely to seek higher education and research in the field or seek out salaried positions in the public service. Female students were more likely to continue a career in agriculture than males. Recommendations included policy actions to introduce agriculture as a science to all students in the formal education system, a re–engineered curriculum based on modern technology use and specially developed career days, exhibitions and field visits to attract young people to the discipline.
Implementation of Supervised Agricultural Experience Programs: The agriculture teachers’ perspective
Authors: Retallick Michael S.
Published: January 2011

The purpose of this qualitative exploratory study was to examine how agriculture teachers implement supervised agricultural experience (SAE). A combination of focus groups and individual telephone interviews were conducted. Iowa agriculture teachers offered SAE because it is (a) a means of developing life skills, (b) a component of the FFA award system, and (c) theoretically, one–third of the agricultural education model. Although agriculture teachers were able to talk conceptually and theoretically about the benefits and value of SAE, they did not necessarily practice SAE in that manner. The method in which teachers implemented SAE programs varied considerably as did the means by which they conducted their SAE programs. Five factors were identified that limited SAE: (a) changing demographics and societal attitudes, (b) mechanics and structure of schools, (c) resource availability, (d) image, and (e) the agricultural education system. These findings would indicate that there is dissonance between (a) theory and practice, and (b) experience and learning of SAE. It is recommended that the purpose of SAE be further refined, communication regarding the value of SAE be increased among the stakeholders, creative and innovated approaches to SAE be explored, and the complete experiential learning model be incorporated into SAE programming.
Economic Impact of Supervised Agricultural Experiences: Returns from SAE Investment Costs in Texas, 2007–2008
Authors: Hanagriff Roger D. , Murphy Tim H. , Roberts T. Grady , Briers Gary E. , Lindner James R.
Published: January 2011

Experiential learning, commonly called supervised agricultural experience (SAE), is a well documented, valuable, and integral part of agricultural education (Bryant, 2003; Cheek, Arrington, Carter, & Randall, 1994; Deyoe, 1953; Dyer & Osborne, 1996; Moore, 1988; Roberts & Harlin, 2007). Measuring the cost and economic benefits of SAEs would provide valuable information in communicating additional benefits of SAE programs (Cole and Connell, 1993). Results from the study presented here found that Texas entrepreneurship SAEs contributed $103 million in direct spending to the Texas economy during the 2007–2008 school year. A common measure of economic impacts is the IMPLAN Model, which provides estimates of additional economic benefits from direct spending. When the IMPLAN Model was applied to direct spending of $103 million, results indicated $189 million in total economic value from SAE related spending. The 189 million dollar economic impact is an important value and should be communicated to school stakeholders. Methods of assessment should be improved to provide more accurate estimates of value.
Food Safety Inservice Educational Needs of Agriculture Teachers
Authors: Koundinya Vikram , Martin Robert A.
Published: January 2011

The purpose of this census study was to determine the food safety inservice educational needs of agriculture teachers in Iowa. The population for this study was all of the 211 agriculture teachers in the state out of which 161 were accessible. The response rate was 54.03% of the accessible population and 41.23% of the total population. Eleven food safety topics were identified with input from experts in agricultural education, food science and human nutrition, and animal science, as well as some input from the agriculture teachers themselves. The teachers were asked to rate the extent of their perceived need for inservice education on each topic on a six–point Likert–type scale. The findings indicated that these teachers needed more inservice education on all of these topics. Teachers indicated a greater need for inservice education focusing on foodborne illnesses, food safety, bacterial contamination, food irradiation, food processing, and pesticide pollution. Hence, these topics were identified as the critical professional development areas in food safety. It was recommended that all of the topics be included in the food safety inservice programs for agriculture teachers, with priority given to the identified critical professional development areas.
Early Career Agriculture Teachers’ Efficacy Toward Teaching Students with Special Needs
Authors: Aschenbrener Mollie S. , Garton Bryan L. , Ross Amanda L.
Published: January 2011

This study sought to assess the perceptions of early career agriculture teachers’ ability to teach students with special needs. Agriculture teachers in the first five years of their careers indicated that administrative support contributed the most to their success in working with students with special needs, while in–service activities that focused on students with special needs contributed little. Self–efficacy was the strongest predictor of self–perceived success of teaching students with special needs. Self–efficacy, combined with administrator support, in–service and teacher preparation, accounted for 27% of the variance in early career agriculture teachers’ self–perceived success of teaching students with special needs.
An Investigation of Missouri Secondary Agriculture Teachers’ Perceptions of Interorganizational Cooperative Behavior
Authors: McKim Billy R. , Torres Robert M. , Smith Amy R.
Published: January 2011

Interorganizational teams have the potential to accomplish more than the sum of individual efforts of members working independently, provided that members share similar goals and tasks. Thus, an interorganizational team consisting of organizations that share similar roots and educational and outreach objectives would seem logical. Subjects of this study were randomly selected secondary agriculture teachers (n = 140) in Missouri. Factors that teachers perceived as important to cooperation and the perceived affect the factors had on relationships with 4–H youth development personnel were investigated guided by the modified team performance and training framework (Cannon–Bowers, Tannenbaum, Salas, & Volpe, 1995). Mean weighted discrepancy scores were calculated to determine deficiencies between the perceived and desired levels of cooperative activities, as perceived by secondary agriculture teachers. Results indicated that interorganizational behavior was indeed desirable to secondary agriculture teachers. However, despite their desire to cooperate, the perceived level of cooperation was considerably lower than the desired level of cooperation.
Program Needs of Middle School Agricultural Education Teachers: A Delphi Study
Authors: Rayfield John , Croom Barry
Published: January 2011

This study examined program needs of middle school agricultural education teachers in North Carolina. A three–round Delphi technique used two open–ended questions to collect information from an expert panel of middle school agricultural education teachers. Each panel member was asked to respond to: Question one: “What can be done on the local, state and national levels to improve middle school agricultural education programs?” Question two: “When looking at the three circle model for agricultural education, what improvements can be made for middle school agricultural education related to FFA, Supervised Agricultural Experience (SAE), and classroom instruction?” Panel members identified 29 areas of concern on the local, state, and national level and 19 areas related to FFA, SAE, and classroom instruction. Middle school agricultural education teachers in [State] believe that the curriculum for their students should contain more hands–on activities and should have a stronger agricultural focus. This panel of teachers also revealed that there are many more concerns with FFA activities for middle school students than there are for SAE and classroom instruction.
Using Case–Scenarios to Determine the Perceptions of Secondary Agriculture Teachers and 4-H Youth Development Personnel Regarding Interorganizational Cooperation
Authors: McKim Billy R. , Torres Robert M.
Published: January 2011

The Prisoners Dilemma (Axelrod, 1984) served as a basis for determining the levels of cooperative behavior secondary agriculture teachers and 4-H youth development Extension personnel exhibited in response to two case–scenarios. Additionally, the study sought to determine if the interorganizational cooperation was positively or negatively interdependent. A simple random sample (n = 210) was taken from secondary agriculture teachers (N = 414) in Missouri and a census of 4-H youth development personnel (N = 91) employed by the University of Missouri Extension was taken at the time of this study. A mixed–mode design was implemented for data collection, which was accomplished using mailed and electronic questionnaires. Responses to the two case–scenarios indicated levels of cooperation varied depending on the context of the situation. The existence or absence of competition also appeared to shift the level of cooperation to or from pure cooperation. In addition, the cooperative behaviors of secondary agriculture teachers and 4-H youth development personnel differed regarding the level of cooperation desired, thereby affecting whether interdependence was positive or negative.
Evaluation of stratospheric chlorine chemistry for the Arctic spring 2005 using modelled and measured OClO column densities
Authors: Oetjen H. , Wittrock F. , Richter A. , Chipperfield M. P. , Medeke T. , Sheode N. , Sinnhuber B.-M. , Sinnhuber M. , Burrows J. P.
Published: January 2011

Abstract. Chlorine dioxide, OClO, column amounts retrieved from measurements of the SCIAMACHY satellite instrument are presented and validated by comparison with simultaneous ground-based DOAS observations. In addition, the measurements are compared to model calculations taking into account the photochemical change along the light path. Although OClO does not participate directly in the destruction of ozone, its accurate measurement as well as modelling is crucial to understand the highly perturbed chlorine chemistry in the polar vortices. SCIAMACHY OClO slant columns retrieved during spring 2005 have been quantitatively validated by comparison with slant columns retrieved from measurements made in Ny-Ålesund (79° N, 12° E) and Summit (73° N, 38° W) as well qualitatively for Bremen (53° N, 9° E). Fair to good agreement is found depending on location as well as time of year. OClO slant column densities modelled with a set of stacked box models and considering the light path through the atmosphere are also included in this comparison. The model predictions differ significantly from the measured quantities. OClO amounts are underestimated for conditions of strong chlorine activation and at large solar zenith angles. Sensitivity studies for several parameters in the stacked box model have been performed and it is inferred that using the chemistry known to date, the observed OClO cannot be adequately reproduced within the range of uncertainties given for the various model parameters.
Estimating the influence of the secondary organic aerosols on present climate using ECHAM5-HAM
Authors: O'Donnell D. , Tsigaridis K. , Feichter J.
Published: January 2011

Abstract. In recent years, several field measurement campaigns have highlighted the importance of the organic fraction of aerosol mass, and with such spatial diversity that one may assert that these aerosols are ubiquitous in the troposphere, with particular importance in continental areas. Investigation of the chemical composition of organic aerosol remains a work in progress, but it is now clear that a significant portion of the total organic mass is composed of secondary organic material, that is, aerosol chemically formed from gaseous volatile organic carbon (VOC) precursors. A number of such precursors, of both biogenic and anthropogenic origin, have been identified. Experimental, inventory building and modelling studies have followed. Laboratory studies have yielded information on the chemical pathways that lead to secondary organic aerosol (SOA) formation, and provided the means to estimate the aerosol yields from a given precursor-oxidant reaction. Global inventories of anthropogenic VOC emissions, and of biogenic VOC emitter species distribution and their emission potential have been constructed. Models have been developed that provide global estimates of precursor VOC emissions, SOA formation and atmospheric burdens of these species. This paper estimates the direct and indirect effects of these aerosols using the global climate-aerosol model ECHAM5-HAM. For year 2000 conditions, we estimate a global annual mean shortwave (SW) aerosol direct effect due to SOA of −0.3 W m−2. The model predicts a positive SW indirect effect due to SOA amounting to +0.23 W m−2, arising from enlargement of particles due to condensation of SOA, together with an enhanced coagulation sink for small particles. Longwave effects are small. Finally, we indicate of areas of research into SOA that are required in order to better constrain our estimates of the influence of aerosols on the climate system.
Better constraints on sources of carbonaceous aerosols using a combined 14C – macro tracer analysis in a European rural background site
Authors: Gilardoni S. , Vignati E. , Cavalli F. , Putaud J. P. , Larsen B. R. , Karl M. , Stenström K. , Genberg J. , Henne S. , Dentener F.
Published: January 2011

Abstract. The source contributions to carbonaceous PM2.5 aerosol were investigated at a European background site at the edge of the Po Valley, in Northern Italy, during the period January–December 2007. Carbonaceous aerosol was described as the sum of eight source components: primary (1) and secondary (2) biomass burning organic carbon, biomass burning elemental carbon (3), primary (4) and secondary (5) fossil fuel burning organic carbon, fossil fuel burning elemental carbon (6), primary (7) and secondary (8) biogenic organic carbon. The concentration of each component was quantified using a set of macro tracers (organic carbon OC, elemental carbon EC, and levoglucosan), micro tracers (arabitol and mannitol), and 14C measurements. This was the first time that 14C measurements were performed on a long time series of data able to represent the entire annual cycle. This set of 6 tracers, together with assumed uncertainty ranges of the ratios of OC-to-EC, and the fraction of modern carbon in the 8 source categories, provides strong constraints to the source contributions to carbonaceous aerosol. The uncertainty of contributions was assessed with a Quasi-Monte Carlo (QMC) method accounting for the variability of OC and EC emission factors, and the uncertainty of reference fractions of modern carbon. During winter biomass burning composed 50% of the total carbon (TC) concentration, while in summer secondary biogenic OC accounted for 45% of TC. The contribution of primary biogenic aerosol particles was negligible during the entire year. Moreover, aerosol associated with fossil fuel burning represented 26% and 43% of TC in winter and summer, respectively. The comparison of source apportionment results in different urban and rural areas showed that the sampling site was mainly affected by local aerosol sources during winter and regional air masses from the nearby Po Valley in summer. This observation was further confirmed by back-trajectory analysis applying the Potential Source Contribution Function method to identify potential source regions. The contribution of secondary organic aerosol (SOA) to the organic mass (OM) was significant during the entire year. SOA accounted for 23% and 83% of OM during winter and summer, respectively. While the summer SOA was dominated by biogenic sources, winter SOA was mainly due to biomass and fossil fuel burning. This indicates that the oxidation of intermediate volatility organic compounds co-emitted with primary organics is a significant source of SOA, as suggested by recent model results and Aerosol Mass Spectrometer measurements in urban regions. Comparison with previous global model simulations, indicates a strong underestimate of wintertime primary aerosol emissions in this region.
Observation of atmospheric aerosols at Mt. Hua and Mt. Tai in central and east China during spring 2009 – Part 1: EC, OC and inorganic ions
Authors: Wang G. , Li J. , Chen C. , Hu S. , Xie M. , Gao S. , Zhou B. , Dai W. , Cao J. , An Z.
Published: January 2011

Abstract. PM10 samples were simultaneously collected at Mt. Hua (2060 m a.s.l.) and Mt. Tai (1545 m a.s.l.) in central and east coastal China during spring, 2009 including an intensive dust storm event occurring on 24 April, and determined for EC, OC and inorganic ions. During the non-dust storm period particles, EC, OC and major ions except for SO42− were 2–10 times more abundant at Mt. Tai than at Mt. Hua. SO42− (13 ± 7.1 μg m−3) at Mt. Hua was the dominant ion, followed by NO3− (5.0 ± 3.9 μg m−3), NH4+ (2.5 ± 1.3 μg m−3) and Ca2+ (1.6 ± 0.8 μg m−3). In contrast, at Mt. Tai NO3− was most abundant (20 ± 14 μg m−3), followed by SO42− (16 ± 13 μg m−3), NH4+ (12 ± 8.9 μg m−3) and Ca2+ (3.9 ± 2.1 μg m−3). The fact of NO3− exceeding over SO42− suggests a significant change in chemical composition of the atmosphere over east China due to sharply increasing vehicle emission. pH values of the water-extracts of PM10 samples indicate that at the two mountain sites aerosols transported from the south regions are more acidic than those from the north and more acidic at Mt. Tai than at Mt. Hua during the non-dust storm period. During the dust storm event particle mass, OC, Na+, K+, Mg2+ and Ca2+ at both sites increased by a factor of 1–9, while EC, NO3− and NH4+ decreased by 20–80%. However, SO42− concentrations (13 ± 7.7 μg m−3 at Mt. Hua and 15 ± 5.6 μg m−3 at Mt. Tai, respectively) at the two sites during the episode were comparable and did not change significantly compared to those in the non-dust storm period, probably due to a similar level of free tropospheric SO2 in central and east China. Compared with those at Mt. Hua the coarse modes of K+ and SO42− at Mt. Tai during the non-event period were more abundant and the coarse mode of NO3− was less abundant. When the dust storm was present all ions significantly moved toward coarse particles, except for NH4+, with a disappeared peak in fine mode for NO3−. Linear regression for ion equivalents in fine particles indicates that ammonium exists in the forms of NH4NO3 and NH4HSO4 at Mt. Hua and NH4NO3 and (NH4) 2SO4 at Mt. Tai during both the nonevent and the event periods. While the regression for coarse mode of Ca2+ suggests a close coupling of dust with nitrate during the nonevent time and with sulfate during the dust-storm period. pH values of the size-resolved samples further suggest that during the nonevent period most acidic particles at Mt. Hua are in the range of 0.7–1.1 μm, while those at Mt. Tai are in the range of 1.1–2.1 μm. Aerosols at both sites became alkaline during the event, but the Mt. Tai particles still showed a lower pH value.
Organic functional groups in aerosol particles from burning and non-burning forest emissions at a high-elevation mountain site
Authors: Takahama S. , Schwartz R. E. , Russell L. M. , Macdonald A. M. , Sharma S. , Leaitch W. R.
Published: January 2011

Abstract. Ambient particles collected on teflon filters at the Peak of Whistler Mountain, British Columbia (2182 m a.s.l.) during spring and summer 2009 were measured by Fourier transform infrared (FTIR) spectroscopy for organic functional groups (OFG). The project mean and standard deviation of organic aerosol mass concentrations (OM) for all samples was 3.2±3.3 (μg m−3). The OM was dominated by regional forest sources, burning, and non-burning that occurred mostly during June–September. On average, organic hydroxyl, alkane, carboxylic acid, ketone, and amine, groups represented 31%±11%, 34%±9%, 23%±6%, 6%±7%, and 6%±3% of OM, respectively. Ketone groups were associated with the forest aerosols and represented up to 27% of the OM in these aerosols. Additional measurements of aerosol mass fragments, size, and number concentrations were used to separate fossil-fuel combustion and burning and non-burning forest sources of the measured organic aerosol. The OM concentrations observed at Whistler Peak during this campaign were higher than those measured during a shorter period in the spring of 2008 at a site in Whistler valley, over one km lower than the peak location. The 2009 campaign was largely influenced by the wildfire emissions that were absent during the 2008 campaign.
Atmospheric ice nuclei in the Eyjafjallajökull volcanic ash plume
Authors: Bingemer H. , Klein H. , Ebert M. , Haunold W. , Bundke U. , Herrmann T. , Kandler K. , Müller-Ebert D. , Weinbruch S. , Judt A. , Ardon-Dryer K. , Levin Z. , Curtius J.
Published: January 2011

Abstract. Explosive volcanism affects weather and climate. Primary volcanic ash particles which act as ice nuclei (IN) can modify the phase and properties of cold tropospheric clouds. During the Eyjafjallajökull volcanic eruption we have measured the highest ice nucleus number concentrations (>600 L) in our record of 2 years of daily IN measurements in central Germany. Even in Israel, located about 5000 km away from Iceland, IN were as high as otherwise only during desert dust storms. These measurements are the only ones available on the properties of IN in the Eyjafjallajökull plume. The measured high concentrations and high activation temperature (−8 °C) point to an important impact of volcanic ash on microphysical and radiative properties of clouds through enhanced glaciation.
Quantification of the carbonaceous matter origin in submicron marine aerosol particles by dual carbon isotope analysis
Authors: Ceburnis D. , Garbaras A. , Szidat S. , Rinaldi M. , Fahrni S. , Perron N. , Wacker L. , Leinert S. , Remeikis V. , Facchini M. C. , Prevot A. S. H. , Jennings S. G. , O'Dowd C. D.
Published: January 2011

Abstract. Dual carbon isotope analysis has been performed for the first time demonstrating a potential in organic matter apportionment between three principal sources: marine, terrestrial (non-fossil) and fossil fuel due to unique isotopic signatures. The results presented here, utilising combinations of dual carbon isotope analysis, provides a conclusive evidence of a dominant biogenic organic fraction to organic aerosol over biologically active oceans. In particular, the NE Atlantic, which is also subjected to notable anthropogenic influences via pollution transport processes, was found to contain 80% organic aerosol matter of biogenic origin directly linked to plankton emissions. The remaining carbonaceous aerosol was of fossil-fuel origin. By contrast, for polluted air advecting out from Europe into the NE Atlantic, the source apportionment is 30% marine biogenic, 40% fossil fuel, and 30% continental non-fossil fuel. The dominant marine organic aerosol source in the atmosphere has significant implications for climate change feedback processes.