"Some of the boys ..." The Civil War letters of Isaac Jackson, 1862-1865.

Mode of access: Internet.

Dr. Jackson

Professor Jackson at his desk.

El espíritu curricular y el cuerpo escolar : a propósito del 'Handbook' de investigación curricular de Jackson.

Revisión crítica de 'Handbook of Research on Curriculum: A project of the AERA' de Philip W. Jackson, que ha promovido la Asociación Americana de Investigación Educativa (AERA) y en el que se revisa el estado de los estudios curriculares y de sus principales campos de investigación. Editado en forma de enciclopedia, y no de manual, por acuerdo de su editor y del comité consultivo, está dividido en cuatro partes; cada una, con diversos capítulos: Perspectivas conceptuales y metodológicas; Cómo se configura el curriculum; El curriculum como una fuerza configuradora y; Tópicos y aspectos de las áreas o las materias curriculares.

Elements of conic sections. /

Mode of access: Internet.

An elementary treatise on optics.

Mode of access: Internet.

An elementary treatise on mechanics.

Mode of access: Internet.

Location and ages of terrestrial peatlands located on continental shelves and in coastal sediments

This synthesis dataset contains records of freshwater peat and lake sediments from continental shelves and coastal areas. Information included is site location (when available), thickness and description of terrestrial sediments as well as underlying and overlying sediments, dates (when available), and references.

Nombres 11-12 et la question d'une rédaction deutéronomique dans le Pentateuque

(Résumé de l'ouvrage) The volume is presented to Professor C.H.W. Brekelmans in celebration of his 75th birthday. The editors were of the opinion that there could be no better way to honour Chris Brekelmans than with a collection of articles treating the "Deuteronomic" traditions found in the Book of Deuteronomy as well as in the so-called Tertrateuch, and Deuteronomistic History. In the past years, a renewed impetus has been given to the development of Deuteronomic Studies. The present Festschrift aims at contributing to the current debate which has a special interest in methodological questions regarding the identification and characterization of "Deuteronomistic" texts in the aforementioned complexes of Old Testament writings. The volume is divided into four sections. The first section offers a collection of articles which focus on the Book of Deuteronomy itself. The second section contains contributions dealing with Deuteronomic History. The third section is devoted to the relationship between the Deuteronomic - in the largest sense of the word - traditions and the Tetrateuch. The fourth and final section presents a collection of articles on a number of important issues, each of which offers its own direct or indirect contribution to the study of the Deuteronomi(sti)c literature and its relationship to the remaining texts of the Old Testament.

Creatividad y escuela.

Poner al servicio de la escuela instrumentos válidos para el desarrollo de la creatividad, fijando objetivos a conseguir por medio de la educación. Construir una batería que puede evaluar la actividad en el aula 'elaborar cuestiones efectivas para discernir el grado de creatividad de una actividad'; evaluando a través de la misma las aptitudes creativas y sus factores intervinientes. La creatividad centrada en la relación creatividad-educación. A partir de los datos teóricos y siguiendo el enfoque concreto 'morfológico' se elaboró la batería teniendo en cuenta y como variables, las ocho actitudes básicas de la creatividad: sensibilidad ante los problemas, fluidez, flexibilidad, originalidad, elaboración, análisis y sintaxis, redefinición, evaluación. Revisión teórica de los estudios sobre la producción creativa a partir de 1950 y tomando como base las investigaciones de S.P. Guilford, así como los estudios y aportaciones realizadas por E.P. Torrance, J.N. Getzels, P.N. Jackson, C.W. Taylor, D.W. Mackinon, F. Barron y A.F. Osbom, S.J. Parnes. Las técnicas de análisis se basan en el modelo teórico de la 'estructura de la inteligencia' de Guilford. Modelo de análisis factorial. Creación de una batería 'ad hoc' para evaluar la potencialidad creativa de cualquier actividad educativa. Es una forma de contribuir al 'desarrollo de la creatividad' como potencial humano ampliamente reconocido, diseñando distintas maneras de reconocer en qué medida un individuo es creativo, qué aspectos creativos tiene más o menos desarrollados, qué lagunas dificultan el que una persona pueda tener una vida creativa plena.

Microbe-associated molecular pattern (MAMP) signatures, synergy, size and charge: influences on perception or mobility and host defence responses

Triggering of defences by microbes has mainly been investigated using single elicitors or microbe-associated molecular patterns (MAMPs), but MAMPs are released in planta as complex mixtures together with endogenous oligogalacturonan (OGA) elicitor. We investigated the early responses in Arabidopsis of calcium influx and oxidative burst induced by non-saturating concentrations of bacterial MAMPs, used singly and in combination: flagellin peptide (flg22), elongation factor peptide (elf18), peptidoglycan (PGN) and component muropeptides, lipo-oligosaccharide (LOS) and core oligosaccharides. This revealed that some MAMPs have additive (e.g. flg22 with elf18) and even synergistic (flg22 and LOS) effects, whereas others mutually interfere (flg22 with OGA). OGA suppression of flg22-induced defences was not a result of the interference with the binding of flg22 to its receptor flagellin-sensitive 2 (FLS2). MAMPs induce different calcium influx signatures, but these are concentration dependent and unlikely to explain the differential induction of defence genes [pathogenesis-related gene 1 (PR1), plant defensin gene 1.2 (PDF1.2) and phenylalanine ammonia lyase gene 1 (PAL1)] by flg22, elf18 and OGA. The peptide MAMPs are potent elicitors at subnanomolar levels, whereas PGN and LOS at high concentrations induce low and late host responses. This difference might be a result of the restricted access by plant cell walls of MAMPs to their putative cellular receptors. flg22 is restricted by ionic effects, yet rapidly permeates a cell wall matrix, whereas LOS, which forms supramolecular aggregates, is severely constrained, presumably by molecular sieving. Thus, MAMPs can interact with each other, whether directly or indirectly, and with the host wall matrix. These phenomena, which have not been considered in detail previously, are likely to influence the speed, magnitude, versatility and composition of plant defences.

Bacterial evolution by genomic island transfer occurs via DNA transformation in planta

Our understanding of the evolution of microbial pathogens has been advanced by the discovery of "islands" of DNA that differ from core genomes and contain determinants of virulence [1, 2]. The acquisition of genomic islands (GIs) by horizontal gene transfer (HGT) is thought to have played a major role in microbial evolution. There are, however, few practical demonstrations of the acquisition of genes that control virulence, and, significantly, all have been achieved outside the animal or plant host. Loss of a GI from the bean pathogen Pseudomonas syringae pv. phaseolicola (Pph) is driven by exposure to the stress imposed by the plant's resistance response [3]. Here, we show that the complete episomal island, which carries pathogenicity genes including the effector avrPphB, transfers between strains of Pph by transformation in planta and inserts at a specific att site in the genome of the recipient. Our results show that the evolution of bacterial pathogens by HGT may be achieved via transformation, the simplest mechanism of DNA exchange. This process is activated by exposure to plant defenses, when the pathogen is in greatest need of acquiring new genetic traits to alleviate the antimicrobial stress imposed by plant innate immunity [4].

Plant pathogens as suppressors of host defense

This chapter reviews our current knowledge about mechanisms of suppression developed by pathogens to avoid host defense responses. In general, plants perceive pathogens by diverse pathogen- or microbe- or even damage-associated molecular patterns (PAMPs, MAMPs, DAMPs) and induce a variety of defense mechanisms referred to as horizontal or basal resistance, nowadays designated PAMP-triggered immunity (PTI). In addition, plants can also recognize specific pathogen-derived effectors and have derived a highly specific defense response termed effector-triggered immunity (ETI), classically called R gene-mediated, specific or vertical resistance. Both PTI and ETI are responses to potential dangers and have common components. Fungal, oomycete, and bacterial pathogens have evolved various effector-based mechanisms of suppression that interfere with such components. Plants strongly depend on RNA gene silencing to interfere with viral pathogens. Plant viruses counteract this response by encoding suppressor proteins of RNA silencing.

Genomic and genetic analyses of diversity and plant interactions of Pseudomonas fluorescens

Background: Pseudomonas fluorescens are common soil bacteria that can improve plant health through nutrient cycling, pathogen antagonism and induction of plant defenses. The genome sequences of strains SBW25 and Pf0-1 were determined and compared to each other and with P. fluorescens Pf-5. A functional genomic in vivo expression technology (IVET) screen provided insight into genes used by P. fluorescens in its natural environment and an improved understanding of the ecological significance of diversity within this species. Results: Comparisons of three P. fluorescens genomes (SBW25, Pf0-1, Pf-5) revealed considerable divergence: 61% of genes are shared, the majority located near the replication origin. Phylogenetic and average amino acid identity analyses showed a low overall relationship. A functional screen of SBW25 defined 125 plant-induced genes including a range of functions specific to the plant environment. Orthologues of 83 of these exist in Pf0-1 and Pf-5, with 73 shared by both strains. The P. fluorescens genomes carry numerous complex repetitive DNA sequences, some resembling Miniature Inverted-repeat Transposable Elements (MITEs). In SBW25, repeat density and distribution revealed 'repeat deserts' lacking repeats, covering approximately 40% of the genome. Conclusions: P. fluorescens genomes are highly diverse. Strain-specific regions around the replication terminus suggest genome compartmentalization. The genomic heterogeneity among the three strains is reminiscent of a species complex rather than a single species. That 42% of plant-inducible genes were not shared by all strains reinforces this conclusion and shows that ecological success requires specialized and core functions. The diversity also indicates the significant size of genetic information within the Pseudomonas pan genome.