Alemania desde el ángulo de la educación.

Se analiza la organización de la educación en Alemania desde la Primera Guerra Mundial, en los centros que se crearon en torno a la enseñanza primaria: liceo de lenguas antiguas, liceo de lenguas modernas, escuela práctica superior y escuela superior alemana. El método de enseñanza que se seguía era el método activo, que perfeccionaba el método directo y que consistía en limitar el uso de la memoria, utilizar el método inductivo a través de la observación, supresión de la enseñanza dogmática y participación del alumno en clase, designando el profesor y orientando las iniciativas y discusión de los alumnos. Se perseguía de este modo el ideal de 'formación de alemanes'. Introdujeron en su programa de estudios una nueva asignatura llamada 'kulturkunde', que estudiaba el cuadro del estado moral, estético e intelectual de las grandes naciones modernas. En la enseñanza secundaria se establecieron las siguientes asignaturas: gimnasio latino, gimnasio clásico, inglés y francés. Al terminar el décimo grado de instituto el alumno tenía que superar un examen de 'madurez intermedia'. La superación de ese examen suponía poder seguir estudiando enseñanza superior y después, la universidad. En el caso de las mujeres, no todas podían optar a la enseñanza superior. Según sus aptitudes se las direccionaba al bachillerato de labor, que tras su término, podían ejercer las carreras propiamente femeninas.

Los problemas pedagógicos bajo el ángulo de la innovación.

Conferencia pronunciada por el autor en el Simposio sobre el lema Continuidad y Articulación entre la Enseñanza Obligatoria y las Enseñanza Medias, celebrado en La Manga, Murcia, del 22 al 27 de abril de 1974. El Simposio fue organizado por el Gobierno español bajo los auspicios del Consejo de Cooperación Cultural del Consejo de Europa. La información concerniente al Simposio esta contenida en CCC/EGT (74)23

Pol??mica en torno al problema de la trisecci??n del ??ngulo en la prensa de Badajoz en 1900

Hasta la aparici??n de centros educativos superiores en Badajoz se cont?? con dos Escuelas Normales, un Instituto de Segunda Ense??anza, el Seminario Diocesano San At??n y la Real Sociedad Econ??mica de Amigos del Pa??s como centros de estudio cient??fico. Estos centros utilizaban la prensa para la transmisi??n de saberes. En el art??culo se estudia la pol??mica surgida en el primer semestre de 1900 en diversos peri??dicos de Badajoz, protagonizada por profesores de la Escuela Normal de Maestros, sobre la trisecci??n del ??ngulo.

Contribución al estudio del proceso de doblado al aire de chapa. Modelo de predicción del ángulo de recuperación y del radio de doblado final

Modelo de predicción de la geometría final de una pieza de chapa, radio y ángulo de doblado final, producida mediante un proceso de doblado al aire.

Ressonância magnética espectroscópica de rotação do ângulo mágico (HRMAS) como instrumento de caracterização de doentes obesos

A Obesidade é um problema em franco crescimento por todo o globo, com muitas relações com outras comorbilidades. Novos desenvolvimentos tecnológicos como a Ressonância Magmética Espectroscópica de Rotação do Ângulo Mágico (HRMAS) podem ajudar a acelaerar o nosso conhecimento deste complexo e principal tecido - a pele obesa. No presente trabalho os autores aplicaram a técnica de ressonância designada por 1H HRMAS NMR para estudar a pele de doentes obesos e assim contribuir para definir o seu perfil metabólico. Foram obtidas amostras de pele das regiões mamárias e abdominal de 5 doentes obesos e comparadas com idênticas amostras obtidas de 5 paciente normais. Os resultados, embora preliminares, sugerem a existência de diferenças entre os perfis lipídicos dos doentes obesos e dos pacientes normais, a nível da insaturação, especialmente reduzida nas amostras de abdómen da pele obesa. Assim a 1H HRMAS parece proporcionar um interessante meio adicional para melhor caracterizar esta patologia.

Ecological specificity of arbuscular mycorrhizae: evidence from foliar- and seed-feeding insects

Arbuscular mycorrhizal (AM) fungi have a variety of effects on foliar-feeding insects, with the majority of these being positive, although reports of negative and null effects also exist. Virtually all previous experiments have used mobile insects confined in cages and have studied the effects of one, or at most two, species of mycorrhizae on one species of insect. The purpose of this study was to introduce a greater level of realism into insect-mycorrhizal experiments, by studying the responses of different insect feeding guilds to a variety of AM fungi. We conducted two experiments involving three species of relatively immobile insects (a leaf-mining and two seed-feeding flies) reared in natural conditions on a host (Leucanthemum vulgare). In a field study, natural levels of AM colonization were reduced, while in a phytometer trial, we experimentally colonized host plants with all possible combinations of three known mycorrhizal associates of L. vulgare. In general, AM fungi increased the stature (height and leaf number) and nitrogen content of plants. However, these effects changed through the season and were,dependent on the identity of the fungi in the root system. AM fungi increased host acceptance of all three insects and larval performance of the leaf miner, but these effects were also season- and AM species-dependent. We suggest that the mycorrhizal effect on the performance of the leaf miner is due to fungal-induced changes in host-plant nitrogen content, detected by the adult fly. However, variability in the effect was apparent, because not all AM species increased plant N content. Meanwhile, positive effects of mycorrhizae were found on flower number and flower size, and these appeared to result in enhanced infestation levels by the seed-feeding insects. The results show that AM fungi exhibit ecological specificity, in that different. species have different effects on host-plant growth and chemistry and the performance of foliar-feeding insects. Future studies need to conduct experiments that use ecologically realistic combinations of plants and fungi and allow insects to be reared in natural conditions.

Influence of foliar diseases and their control by fungicides on grain yield and quality in wheat

Twenty-eight field experiments on sandy-loam soils in the UK (1982-2003) are reviewed by relating the extension of the green area duration of the flag leaf (GLADF) by fungicides to effects on yield and quality of winter wheat. Over all experiments mean grain yield = 8.85t ha(-1) at 85% DM. With regards quality, mean values were: thousand grain weight (TGW) = 44.5 g; specific weight (SWT) = 76.9 kg hl(-1); crude protein concentration (CP (N x 5.7)) = 12.5 % DM; Hagberg falling number (HFN) = 285 s; and sodium dodecyl sulphate (SDS)-sedimentation volume = 69ml. For each day (d) that fungicides increased GLADF there were associated average increases in yield (0.144 1 ha(-1) d(-1), se 0.0049, df = 333), TGW (0.56 gd(-1), se = 0.017) and SWT (0.22 kg hl(-1) d(-1), se 0.011). Some curvature was evident in all these relationships. When GLADF was delayed beyond 700 degrees Cd after anthesis, as was possible in cool wet seasons, responses were curtailed, or less reliable. Despite this apparent terminal sink limitation, fungicide effects on sink size, eg endosperm cell numbers or maximum water mass per grain, were not prerequisites for large effects on grain yield, TGW or SWT. Fungicide effects on CP were variable. Although the average response of CP was negative (-0.029%DM/d; se = 0.00338), this depended on cultivar and disease controlled. Controlling biotrophs such as rusts, (Puccinia spp.) tended to increase CP, whereas controlling a more necrotrophic pathogen (Septoria tritici) usually reducedCP. Irrespective of pathogen controlled, delaying senescence of the flag leaf was associated with increased nitrogen yields in the grain (averaging 2.24 kg N ha-1 d(-1), se = 0.0848) due to both increased N uptake into the above ground crop, and also more efficient remobilisation of N from leaf laminas. When sulphur availability appeared to be adequate, fungicide x cultivar interactions were similar on S as for CP, although N:S ratios tended to decline (i.e. improve for bread making) when S. tritici was controlled. On average, SDS-sedimentation volume declined (-0. 18 ml/d, se = 0.027) with increased GLADF, broadly commensurate with the average effect on CP. Hagberg falling number decreased as fungicide increased GLADF (-2.73 s/d, se = 0.178), indicating an increase in alpha-amylase activity.

Differential susceptibilities of peach-potato aphid, Myzus persicae (Homoptera: Aphididae) and its parasitoid, Aphidius matricariae (Hymenoptera: Aphidiidae) to foliar insecticides on partially resistant and susceptible potato cultivars

In a field experiment the effects of Sumicidin (super) 5EC (fenitrothion), Metasystox EC25 (oxydemeton-methyl) and Tamaron SL600 (methamidophos), applied at different dosages, were evaluated against peach-potato aphid, Myzus persicae (Sulzer) and its parasitoid Aphidius matricariae Haliday on Cardinal and Desiree (respectively partially resistant and susceptible potato cultivars to M. persicae). Sumicidin (super) 5EC was found about 30% more effective in reducing aphid populations than the other insecticides tested. The highest doses of each insecticide caused maximum aphid mortality; in general aphid mortality appeared dose dependent. Almost all the higher and lower doses of the tested insecticides were about 19% more effective on Cardinal than on Desiree. The most significant result was the synergistic interaction at the lower doses with plant resistance, so that the same level of control was recorded with second highest dose on Cardinal as with the highest dose on Desiree. Also the same control level was achieved at the lowest dosage rate on Cardinal compared with the next higher dose on the Desiree. Sumicidin (super) 5EC was found least toxic to the parasitoid, A. matricariae in terms of percent parasitism, emergence of parasitoids and number of mature eggs in the emerging female parasitoids; increase of about 22, 67 and 47% respectively were found in parasitoid performance with Tamaron SL600 which was found comparatively highly toxic. The highest doses of all insecticides were found clearly toxic to the parasitoid. In general, effects on the parasitoid were dose dependent. Maximum yield was obtained from the second highest dose of Sumicidin (super) 5EC.

Summer drought alters plant-mediated competition between foliar- and root-feeding insects

Summer droughts are predicted to increase in severity and frequency in the United Kingdom, due to climate change. Few studies have addressed the impacts of drought on interactions between species, and the majority have focussed on increases in CO2 concentration and changes in temperature. Here, the effect of experimental summer drought on the strength of the plant-mediated interaction between leaf-mining Stephensia brunnichella larvae and root-chewing Agriotes larvae was investigated. Agriotes larvae reduced the abundance and performance of S. brunnichella feeding on a mutual host plant, Clinopodium vulgare, as well as the rate of parasitism of the leaf-miner. The interaction did not, however, occur on plants subjected to a severe drought treatment, which were reduced in size. Changes to summer rainfall, due to climate change, may therefore reduce the occurrence of plant-mediated interactions between insect herbivores.

Effects of straw and silicon soil amendments on some foliar and stem-base diseases in pot-grown winter wheat

Four foliar and two stem-base pathogens were inoculated onto wheat plants grown in different substrates in pot experiments. Soils from four different UK locations were each treated in three ways: (i) straw incorporated in the field at 10 t ha−1 several months previously; (ii) silicon fertilization at 100 mg L−1 during the experiment; and (iii) no amendments. A sand and vermiculite mix was used with and without silicon amendment. The silicon treatment increased plant silica concentrations in all experiments, but incorporating straw was not associated with raised plant silica concentrations. Blumeria graminis and Puccinia recondita were inoculated by shaking infected plants over the test plants, followed by suitable humid periods. The silicon treatment reduced powdery mildew (B. graminis) substantially in sand and vermiculite and in two of the soils, but there were no effects on the slight infection by brown rust (P. recondita). Phaeosphaeria nodorum and Mycosphaerella graminicola were inoculated as conidial suspensions. Leaf spot caused by P. nodorum was reduced in silicon-amended sand and vermiculite; soil was not tested. Symptoms of septoria leaf blotch caused by M. graminicola were reduced by silicon amendment in a severely infected sand and vermiculite experiment but not in soil or a slightly infected sand and vermiculite experiment. Oculimacula yallundae (eyespot) and Fusarium culmorum (brown foot rot) were inoculated as agar plugs on the stem base. Severity of O. yallundae was reduced by silicon amendment of two of the soils but not sand and vermiculite; brown foot rot symptoms caused by F. culmorum were unaffected by silicon amendment. The straw treatment reduced severity of powdery mildew but did not detectably affect the other pathogens. Both straw and silicon treatments appeared to increase plant resistance to all diseases only under high disease pressure.

Foliar salt tolerance of Acer genotypes using chlorophyll fluorescence

The effect of increasing salinity on a range of chlorophyll fluorescence parameters in foliar tissue of 30 Acer genotypes was examined. The magnitude of the fluorescence responses differed among genotypes ranging from minor effects to substantial leaf tissue damage. Interpretation of the fluorescence expressions provided an insight into mechanisms of salt damage and resilience among genotypes. Based on reductions in a performance index (PIp) following salinity, genotypes were ranked in order from tolerant to sensitive. Based on this ranking criterion, marked differences in salt tolerance among genotypes were distinguished. It is concluded that chlorophyll fluorescence offers a rapid screening technique for assessing the foliar salinity tolerance of urban trees.