953 resultados para Cal


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Housepits have a remarkably short research history as compared to Fennoscandian archaeological research on the Stone Age in general. The current understanding of the numbers and the distribution of Stone Age housepits in the Nordic countries has, for the most part, been shaped by archaeological studies carried out over the last twenty to thirty years. The main subjects of this research are Neolithic housepits, which are archaeological remains of semi-subterranean pithouses. This dissertation consists of five peer-reviewed articles and a synthesis paper. The articles deal with the development of housepits as seen in the data gathered from Finland (the Lake Saimaa area and south-eastern Finland) and Russia (the Karelian Isthmus). This synthesis expands the discussion of the changes observed in the Papers to include Fennoscandian housepit research as a whole. Certain changes in the size, shape, environmental location, and clustering of housepits extended into various cultures and ecological zones in northern Fennoscandia. Previously, the evolution of housepits has been interpreted to have been caused by the adaptation of Neolithic societies to prevailing environmental circumstances or to re-organization following contacts with the agrarian Corded Ware/Battle Axe Cultures spreading to North. This dissertation argues for two waves of change in the pithouse building tradition. Both waves brought with them certain changes in the pithouses themselves and in the practices of locating the dwellings in the environment/landscape. The changes in housepits do not go hand in hand with other changes in material culture, nor are the changes restricted to certain ecological environments. Based on current information, it appears that the changes relate primarily to the spread of new concepts of housing and possibly to new technology, as opposed to representing merely a local response to environmental factors. This development commenced already before the birth of the Corded Ware/Battle Axe Cultures. Therefore, the changes are argued to have resulted from the spreading of new ideas through the same networks that actively distributed commodities, exotic goods, and raw materials over vast areas between the southern Baltic Sea, the north-west Russian forest zone, and Fennoscandia.

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Con el objetivo de determinar el efecto de cal, urea y la combinación de ambos en la sobrevivencia del moko bacteriano en plantaciones de Musáceas, se desarrolló en la finca TICOMO en el Km 9 carretera Managua-El Crucero en el período de Octubre del 95 a Julio del 96 el presente estudio de investigación, el cual se dividió en dos etapas: una etapa de campo que incluyó metodología para la realización de los tratamientos, formas de muestreo de suelo y período para muestrear. La otra etapa se realizó en Laboratorio y consistió en la realización de pruebas bioquímicas para la identificación de la bacteria, métodos de siembra y conteos de colonias. Dentro del mismo período se realizó una encuesta a los productores del departamento de Rivas. Se realizaron análisis económicos de los tratamientos y se compararon con el producto químico Glifosato. Como resultado final de la Evaluación se obtuvo que la urea reduce en un 93.89% las colonias de bacterias iniciales, en segundo termino la cal disminuyó las colonias de bacterias en un 88.29%, la combinación de ambos tratamientos aminoró en un 86.5% el número de colonias de bacterias y el testigo redujo el 71.86% de la población. En general la Urea P.S el tratamiento más eficaz para bajar las poblaciones de bacterias en menor tiempo comparado con los otros tratamientos; cabe señalar que con sólo el saneamiento en la plantación la bacteria sin ningún tipo de tratamiento puede disminuir sus poblaciones, pero significará esperar mayor tiempo para que la bacteria descienda sus poblaciones y se atrasaría la época de resiembra, quedando a criterio del productor el utilizar o no sólo el saneamiento. Los resultados de las encuestas reflejan que los productores reconocen la enfermedad en sus distinto síntomas, la mayoría sabe como se transmite y como se puede prevenir pero no cómo controlar. Sin la debida Asistencia Técnica y la falta de información acerca de las enfermedades e indicarles la importancia de las medidas fitosanitarias, los productores tendrán siempre los mismos problemas de enfermedades en sus plantaciones

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Em Cal, livro do escritor português José Luís Peixoto, a morte mostra-se sob diversas perspectivas. Esta dissertação objetiva, primeiramente, reconhecer as singularidades dessas perspectivas, bem como o movimento de identificação entre elas. Considerando que o livro não apenas desvela possibilidades de morte, mas, principalmente, as interseções entre as noções de morte e de vida, buscaremos responder às seguintes questões: é possível saber se, de fato, estamos vivos? A morte é definitiva? Morte e vida são condições excludentes? A temática da memória e dos afetos, inseparável das reflexões acerca da finitude e das noções de presença e ausência, perpassará, inevitavelmente, toda a progressão deste trabalho. Para pensarmos esses temas, assim como seus temas transversais, tomamos como referência conceitos de teóricos da literatura, da filosofia e da psicanálise, como G. Deleuze, J. Derrida, M. Blanchot, F. Nietzsche, S. Freud, B. Spinoza, G. Bataille. O diálogo com e entre pensadores de contextos distintos contribui para dar a esta dissertação seu aspecto fragmentário, na qual as reflexões surgem e resurgem em progressão labiríntica, de limites deslocáveis

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Homenaje a Ignacio Barandiarán Maestu / coord. por Javier Fernández Eraso, Juan Santos Yanguas

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东海陆架是世界上最宽阔的陆架之一,面积达770 000 km2左右。在末次冰盛期(LGM),东海海平面下降120~130 m左右,绝大部分陆架暴露出海面。而冲绳海槽是第四纪以来一直保持海洋环境的东海深海区。本文以冲绳海槽北部PC-1岩芯为材料,通过分析该孔的孢粉,加上详细的AMS 14C测年,恢复了周边地区24 cal.kaBP以来的古植被,并推测古环境和古气候变化,重点讨论了LGM时期出露大陆架上发育的植被。 PC-1孔(31°27.5′N,128°24.8′E)位于黑潮支流对马暖流东侧,水深590 m,柱长812 cm。孢粉分析按间隔8 cm取样,个别为4~6 cm,共分析了103个孢粉样品。利用9个AMS 14C数据建立年龄标尺,用Calib5.1.0软件进行年龄校正。通过相邻样品深度的线性内插获得每个样品的年龄,采用外延法得到顶部和底部的校正年龄分别为351cal aBP、24 280 cal aBP,孢粉样品的时间分辨率平均为230 a。 根据孢粉百分比和沉积率的变化,可划分出四个带:Ⅰ带(812~715 cm,24.2~21.1 cal. kaBP)、Ⅱ带(715~451 cm,21.1~15.2 cal. kaBP)、Ⅲ带(451~251 cm,15.2~10.8 cal. kaBP)、Ⅳ带(251~0 cm,10.8~0.3 cal. kaBP),分别对应MIS 3末期、末次冰盛期、冰消期和全新世。末次冰盛期草本植物花粉占优势,孢粉沉积率较高,此时草本花粉主要来源于出露的大陆架,其上发育了以蒿属为主的草地植被,气候比较寒冷干燥;冰消期海平面开始回升,松属花粉含量升高,草本植物花粉含量下降;全新世以木本植物花粉占绝对优势,栗属-栲属花粉迅速增加,蕨类孢子含量升高,草本植物花粉含量锐减,孢粉沉积率降低,由于海平面回升,大陆架被淹没,此时孢粉主要来源于日本岛,九州地区生长了以栲属、栎属为主的常绿阔叶与落叶阔叶林,气候温暖湿润。 叶枝杉属花粉在整个岩芯中零星出现。叶枝杉属植物分布于菲律宾吕宋北部至塔斯马尼亚和新西兰气候潮湿的山地林中,该属花粉在岩芯中的出现,可能暗示了黑潮的影响或者是较强的夏季风。 草本植物与松属花粉百分比变化很好的反映了海平面的升降,松属花粉含量较高指示海平面较高。对岩芯中主要类型的花粉百分比进行了频谱分析,显示存在千年尺度的准周期变化,有明显的6.8,3.8,2.2,1.6 ka的周期。 孢粉样品中的炭屑统计表明,末次冰消期炭屑含量最高,可能因为末次冰消期降雨量增加,炭屑可被降水带到沉积地点沉积下来;全新世的炭屑浓度较高,尤其在晚全新世,出现了一个峰值,究其原因可能与气候变化和人类活动有关。

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目的研究异丙酚对大鼠海马CA1区神经元兴奋性突触后电流(EPSC)和自发性兴奋性突触后电流(sEPSC)的影响。方法 Wistar大鼠断头后分离海马脑组织,制成400μm厚度的海马脑片,脑片随机分为5组(n=10)。脂肪乳剂Ⅰ组、异丙酚Ⅰ组、SR95531+异丙酚组:记录EPSC 10 min (基础值)后分别加入10%脂肪乳剂90μl、1%异丙酚90μl(相当于100μmol/L)、10μmol/L SR95531+100 μmol/L异丙酚,继续记录EPSC 40 min,分析EPSC幅值的变化。脂肪乳剂Ⅱ组、异丙酚Ⅱ组:细胞破膜后稳定10-15 min,分别加入10%脂肪乳剂90μl和1%异丙酚90μl,记录sEPSC 40 min,分析sEPSC频率、幅值和半衰期的变化。膜钳制电压均为-70 mV。结果与基础值比较,给药后脂肪乳剂Ⅰ组和 SR95531+异丙酚组EPSC幅值差异无统计学意义,异丙酚Ⅰ组EPSC幅值降低;给药后异丙酚Ⅰ组 EPSC幅值比脂肪乳剂Ⅰ组降低(P<0.05)。与脂肪乳剂Ⅱ组比较,异丙酚Ⅱ组sEPSC的频率、幅值降低、半衰期缩短(P<0.05)。结论异丙酚主要通过增强大鼠海马CA...

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观褰戊四氮对大鼠海马CAl区动作电位(action potential,AP)、兴奋性突触后电流(excitatory poBtsynapfic cu膈I吐,皿sc)的影响以厦眯唑安定的拮抗作用。方法断头法分离Wistar大鼠海马半脑,切片机切出 400脚厚度的海马脑片,奎细胞电流钳记录CAl区锥体神经元动作电位发放情况,全细胞电压钳记录电刺激 Sch踮如r侧支/联合鲆维诱发的CAl区锥体神经元EPSC的变化。结果戊四氮健动作电位发放频率增加.脚值降低;咪唑安定拮抗戊四氪的作用,使动作电值发放减少甚至消失,EPSC值上升互加八咪唑安定前的2.5倍左右。结论眯唑安定可以部分恢复大鼠海马cAl区戌四氮谤发的动作电位发放和E巧c的改变,从而产生抗癫痫作用。

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This paper investigates evidence for palaeoclimatic changes during the period ca. 1500-500 cal. yr BC through peat humification studies on seven Irish ombrotrophic bogs. The sites are well-correlated by the identification of three mid-first millennium BC tephras, which enable the humification records at specific points in time to be directly compared. Phases of temporarily increased wetness are suggested at ca. 1300-1250 cal. yr BC, ca. 1150-1050 cal. yr BC, ca. 940 cal. yr BC and ca. 740 cal. yr BC. The last of these is confirmed to be synchronous at five sites, suggesting external forcing on a regional scale. The timing of this wet-shift is constrained by two closely dated tephras and is demonstrated to be distinct from the widely reported changes to cooler/wetter conditions associated with a solar minimum at 850-760 cal. yr BC, at which time the Irish sites appear instead to experience drier conditions. The results suggest the possibility of either non-uniform responses to solar forcing in northwest Europe at this time, or the existence of unrelated climate events in the early first millennium BC. The findings caution against the correlation of loosely dated palaeoclimate data if the effects of forcing mechanisms are to be understood.