1,812 research outputs found
Nucleic acid sequence and oncogenic properties of the HZ2 feline sarcoma virus v-abl insert.
No full textHardy-Zuckerman 2 feline sarcoma virus (HZ2-FeSV), isolated from a multicentric feline fibrosarcoma is a replication-defective acute transforming feline retrovirus which originated by transduction of feline c-abl sequences with feline leukemia virus (FeLV) and is known to encode a 110-kilodalton gag-abl fusion protein with tyrosine-specific protein kinase activity (P. Besmer, W. D. Hardy, E. E. Zuckerman, P. J. Bergold, L. Lederman, and H. W. Snyder, Nature (London) 303:825-828, 1983). The nucleotide sequence of the abl segment in the HZ2-FeSV genome was determined and compared with the murine and human v-abl and c-abl sequences. The predicted transforming protein consists of 344 amino acids (aa) of FeLV gag origin, 439 aa of abl origin, and at least 200 aa of FeLV pol origin (p110gag-abl-pol). The 1,317-base-pair HZ2-FeSV v-abl segment (fv-abl) corresponds to 5' abl sequences which include the region known to specify the protein kinase domain. The 5' 189 base pairs of fv-abl correspond to 5' c-abl sequences not contained in Abelson murine leukemia virus (MuLV) v-abl. The mouse c-abl exon which contains these segments was identified, and its nucleotide sequence was determined. Comparison of the predicted amino acid sequence of fv-abl with those of Abelson MuLV v-abl and c-abl revealed five aa differences. The 5' junction between FeLV and abl was found to involve a preferred region in FeLV gag p30 (P. Besmer, J. E. Murphy, P. C. George, F. H. Qiu, P. J. Bergold, L. Lederman, H. W. Snyder, D. Brodeur, E. E. Zuckerman, and W. D. Hardy, Nature (London) 320:415-421, 1986). A six-base homology exists at the recombination site between the parental FeLV and the c-abl sequences. The 3' junction between fv-abl and FeLV pol predicts an in-frame fusion of fv-abl and FeLV pol. A transformed cell line containing a truncated gag-abl-pol protein, p85, that lacks most of the FeLV pol sequences was obtained by transfection of NIH 3T3 mouse cells. This result implies that the pol sequences of the p110gag-abl-pol protein are dispensable for fibroblast transformation. To assess whether the fv-abl segment specifies the unique biological properties of HZ2-FeSV, we constructed a Moloney MuLV-based version of HZ2-FeSV, Mo-MuLV(fv-abl), in which the fv-abl sequences were contained in a genetic context similar to that in HZ2-FeSV.(ABSTRACT TRUNCATED AT 400 WORDS
Stop the Century--We’re Not Ready!
No full textThe distinguished Nobel Laureate and contributing author of the newly released Science Literacy for the Twenty-first Century and author of The God Particle will explore how science and technology serve as the drivers for 21st Century changes in our social, political and economic lives. Profits and conveniences made by deployment of new knowledge force the issue of whether such deployment is in society’s best long-term interest. The need grows exponentially for the voting public in our democratic society to play a significant role in making decisions. Lederman discusses whether we can devise a feasible educational system that will produce high school graduates with a sense of how science works, as well as whether voter-citizens can employ a “science way of thinking” in order to participate in issues affecting their lives and those of their children.
The lecture will be followed by a proclamation from Mike McCoy, Chairman of the Kane County Board: The Kane County “Dr. Leon Lederman Day” and a book launch, refreshments and signing of Science Literacy for the Twenty-first Century
WHAT DO PRIMARY STUDENTS KNOW ABOUT SCIENCE, SCIENTISTS AND HOW THEY DO THEIR WORK?
No full textThe teaching of scientific literacy is the primary goal of elementary science education. Scientific literacy is composed of the overall understanding of what science is and how scientific knowledge is developed. The purpose of this study was to see if elementary students’ understandings of science, scientists and how scientists do their work changes from grade one to grade five of elementary school. Furthermore, the study attempts to determine whether there is a difference in scientific literacy between students taught using a textbook curriculum versus a kit-based curriculum. The study draws on a sample of 338 students from 18 different classrooms situated in six different schools in both urban and suburban areas of a large Midwestern city. Students’ understandings of science, scientists and how they do their work was measured through a valid and reliable oral protocol entitled Young Children’s Views of Science (YCVS) (Lederman, J., Bartels, Lederman, & Ganankkan, 2014). The YCVS assesses students’ understandings of the aspects of scientific inquiry (SI) and the nature of science (NOS) that young elementary students are able to understand. These aspects are; science, scientists, multiple methods, observation/inference, begins with a question, empirical, subjectivity, tentativeness and creativity. The YCVS was administered orally for grade one students, and a paper-and-pencil version was given to grades three and five. Twenty percent of the students in grade three and five were interviewed to ensure the proper interpretation of their YCVS responses. Responses to the YCVS were analyzed and students were given a rating of no answer, inadequate, mixed or informed for each aspect assessed on the YCVS. Frequency data was totaled for each grade level of each school. In order to determine if significant gains were made between the grade levels a Fisher’s exact test was run between each grade (one and three, three and five and one and five); significance of < 0.05 was selected. Fisher’s exact test was selected because the data were categorical with low frequencies for some categories. Additionally, a comparison between the kit-based curriculum schools and the textbook-based curriculum schools was made for each of the aspects of NOS and SI assessed in this study. Results indicated that there are very few gains in NOS and SI understandings between grades one and five in the schools included in this study. None of the schools in this study made significant gains for all of the nine aspects measured in this study. Only two schools made significant (p< 0.05) gains in five or more aspects of NOS/SI. The other four schools in this study made gains in fewer than four aspects. Two schools had a significant (p<0.05) decrease in understandings for more than one aspect. Examining curriculum’s affect on NOS and SI understandings, understanding of only one aspect was significantly impacted by curriculum differences. Subjectivity understanding was impacted by kit-based instruction. Overall, students’ understandings of science, scientists and how they do their work did not significantly change from grade one to grade five regardless of what type of curriculum they followed. This study shows that students’ scientific literacy is not being developed throughout elementary school. Therefore, the teaching of scientific literacy in an explicit and reflective manner should be the focus of preservice elementary school education.Ph.D. in Science Education, December 201
La construcción del imaginario nacional brasileño en el "diálogo" entre Veja y Primera Plana en torno a la rivalidad Brasil-Argentina (1968-1973)
No full textLa dictadura de Brasil (1964-1985) fue una dictadura institucional de las Fuerzas Armadas. La Doctrina de Seguridad Nacional (DSN) fue su sustento ideológico, apelando a la defensa de la nación a través de la "lucha antisubversiva" y de la identificación de un potencial ?enemigo externo? (siempre bajo la idea de "guerra generalizada"). La construcción del imaginario nacional se sostuvo tanto en la dimensiones interna y externa de la DSN. En las revistas Veja de Brasil y Primera Plana de Argentina circularon referencias y noticias sobre las respectivas situaciones nacionales y sobre las hipótesis de conflicto geopolítico entre los países. Presentamos una primera aproximación a la construcción del imaginario nacional brasileño a partir del "diálogo" entre estas dos revistas de circulación masiva, entendiéndolas como actores políticos relevantes. En sendos artículos, publicados en 1971, Veja responde a las "acusaciones" sobre la supuesta amenaza de Brasil sobre el resto de América Latina. Estas acusaciones fueron realizadas por Primera Plana en un artículo divulgado en junio de ese año. De esta manera, daremos cuenta de las representaciones de la nación, a través de los elementos fundantes ?guerra? y ?desarrollo? que conformaron el imaginario nacional basado en la DSN y cómo estas contribuyeron a la legitimación de la dictadura de Brasil.Fil: Lederman, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Estudios de América Latina y el Caribe; Argentin
Acerola "Sertaneja BRS" (Malpighia emarginata (L.) DC.).
No full textOrigem; Características; Áreas recomendadas para cultivo; Pragas e doenças; Recomendações técnicas
The business of product innovation : international empirical evidence
No full textIt is so widely recognized that innovation is a key driver of economic growth that it is cliché to say so. This article studies product innovation by firms with data from 68 countries, covering more than 25,000 firms in eight manufacturing sectors. The author assesses the predictions of inter-disciplinary research on innovation by firms. The econometric evidence suggests that globalization and local knowledge increase the likelihood that firms will introduce new products. By contrast, domestic regulatory impediments to competition are not robustly correlated with product innovation.E-Business,Innovation,Microfinance,Education for Development (superceded),Statistical&Mathematical Sciences
Trade structure and growth
No full textLederman and Maloney examine the empirical relationships between trade structure and economic growth, particularly the influence of natural resource abundance, export concentration, and intra-industry trade. They test the robustness of these relationships across proxies, control variables, and estimation techniques. The authors find trade variables to be important determinants of growth, especially natural resource abundance and export concentration. In contrast with much of the recent literature, natural resource abundance appears to have a positive effect on growth, whereas export concentration hampers growth, even after controlling for physical and human capital accumulation, among other factors.Economic Conditions and Volatility,Environmental Economics&Policies,Health Monitoring&Evaluation,Economic Theory&Research,Public Health Promotion,Economic Theory&Research,Achieving Shared Growth,Environmental Economics&Policies,Economic Growth,Inequality
Haptic Integration of Object Properties: Texture, Hardness, and Planar Contour
No full textPlanar objects varying in shape, texture, and hardness were classified under haptic exploration. Classes were defined by values on one dimension, or redundantly, by two or three dimensions. Response times and exploratory procedures (Lederman & Klatzky, 1987) were recorded. Experiment 1 showed that a second dimension speeded responses for all combinations (redundancy gain), but a third dimension produced no further effect. In Experiments 2 and 3, classification trials began with two redundant dimensions, and subsequently one was withdrawn (held constant). When texture and hardness varied redundantly, withdrawal of either increased response time—even when subjects were initially instructed to focus on one dimension. Joint exploration for texture and hardness dominated whenever the two varied redundantly and persisted despite withdrawal. Redundancy gains (Experiment 1), but not substantial withdrawal effects (Experiments 2 and 3), were observed for combinations of texture or hardness with planar contour, indicating less integration than between substance dimensions. Compatibility of exploratory procedures appears to constrain dimensional integration
Panel IV: Interrogating Terrorists: Probing the Limits
No full textPanel presentations on interrogation and national security.
Appearing: Robert M. Chesney (Wake Forest University), moderator ; Marty Lederman (Georgetown Law Center), Robert A. Fein, Laura Dickinson (University of Connecticut), and James A. Candelmo (U.S. Department of Justice)
Efeito da cianamida hidrogenada associada à desfolha química e manual na indução floral de pinheiras (Annona squamosa L.).
No full textAs técnicas de poda, desfolha e indução floral na pinheira (Annona squamosa L.) merecem uma especial atenção na região do Nordeste do Brasil, vista a possibilidade de se obter duas colheitas anuais. Visando avaliar a influência da cianamida hidrogenada (CH), associada à desfolha química e manual, na indução floral de pinheiras irrigadas por gotejo, foi realizado experimento com os seguintes tratamentos: testemunha absoluta; duas dosagens para desfolha química com ethephon a 1.000 ppm e 2.000 ppm e poda os ponteiros; dois tipos de desfolha (toda parte aérea da planta e 50% da parte aérea) e poda dos ponteiros; duas dosagens de CH a 1,5% e 2,0% e poda dos ponteiros; desfolha da planta e poda dos ponteiros. O delineamento experimental foi o de blocos ao acaso, com dez tratamentos, três repetições e três plantas por parcela. As desfolhas manual e química, associadas a indutores de brotação constituem uma boa alternativa para regular e aumentar a brotação de gemas e promover a frutificação. A desfolha manual em 50% da parte aérea da planta (DM2CH) e a desfolha química com ethephon a 1.000 ppm (DQICH), poda e pulverização com CH a 1,5%, apresentaram os melhores resultados. A colheita não foi antecipada nem retardada pela ação dos tratamentos utilizados.Número especial
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