12 resultados para 42495


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Sustainability has been a major factor and determinant of commercial property design, construction, retro-fitting and landlord and tenant requirements over the last decade, supported by the introduction of rating tools such as NABERS and GreenStar and the recently mandated Building Energy Efficiency Certificate (BEEC). However, the movement to sustainable and energy efficient housing has not been established for the same period, and although mandatory building regulations have been in place for new residential housing construction since 2004, the requirement to improve the sustainability and energy efficiency of housing constructed prior to 2004 has not been mandatory. Residential dwelling energy efficiency and rating schemes introduced in Australia over the past decade have included rating schemes such as BASIX, NatHERS, First rate, ACTHERS, and Building Code of Australia and these have applied to new dwelling construction. At both National and State level the use of energy efficiency schemes for existing residential dwellings has been voluntary and despite significant cash incentives have not always been successful or achieved widespread take-up. In 2010, the Queensland Government regulated that all homes offered for sale, whether a new or existing dwellings require the seller to provide a ―sustainability declaration‖ that provides details of the sustainability measures associated with the dwelling being sold. The purpose of this declaration being to inform buyers and increase community awareness of home sustainability features. This paper uses an extensive review of real estate marketing material, together with a comprehensive survey of real estate agents to analyse the current market compliance, awareness and acceptance of existing green housing regulations and the importance that residential property owners and purchasers place on energy efficient and sustainable housing. The findings indicate that there is still little community awareness or concern of sustainable housing features when making home purchase decisions.

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he thermodynamic properties of the spinel Mg2SnO4 have been determined by emf measurements on the solid oxide galvanic cell,View the MathML source in the temperature range 600 to 1000°C. The Gibbs' free energy of formation of Mg2SnO4 from the component oxides can be expressed as View the MathML source,View the MathML source These values are in good agreement with the information obtained by Jackson et al. [Earth Planet. Sci. Lett.24, 203 (1974)] on the high pressure decomposition of magnesium stannate into component oxides at different temperatures. The thermodynamic data suggest that the spinel phase is entropy stabilized, and would be unstable below 207 (±25)°C at atmospheric pressure. Based on the information obtained in this study and trends in the stability of aluminate and chromite spinels, it can be deduced that the stannates of nickel and copper(II) are unstable.

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光合作用是地球上最重要的化学反应,它主要发生在叶绿体的类囊体膜上。光能是整个光合作用反应的驱动力,因此光能的捕获和传递过程将会直接影响整个生物体的光合作用表现。在高等植物中,光系统II(PSII)的大量捕光色素蛋白复合体(LHCIIb)作为最主要的、含量最多的光能捕获和传递器官,在光合作用过程中发挥着极其重要的作用。经过数十年的研究,认为LHCIIb主要的功能有以下四个方面:捕获和传递光能、光保护和过剩能量耗散、调节光能在两个光系统中分配和维持类囊体膜的结构。同时对其空间结构也在2.72Å的水平上进行了解析,发现每个单体含有14个叶绿素分子(Chl),其中8个叶绿素 a(Chl a)和6个叶绿素 b(Chl b),2个黄体素(Lut),一个新黄质(Neo)和一个紫黄质(Vio),3个跨膜α-螺旋和2个双亲α-螺旋。尽管目前对其空间结构和基本功能有了初步的了解,但以往研究均是对LHCIIb的三个色素蛋白复合体(Lhcb1、Lhcb2和Lhcb3)的混合研究,而关于Lhcb1、Lhcb2和Lhcb3各自的氨基酸组成、色素组成、各种光谱性质和稳定性研究还处于起步阶段。对Lhcb1、Lhcb2和Lhcb3各自的特性研究可以使我们更加深刻地理解LHCIIb的结构和功能。 本论文首先利用RT-PCR技术从豌豆(Pisum sativum L.)中提取了编码大量捕光色素蛋白复合体的三个脱辅基蛋白基因,分析了它们编码蛋白的氨基酸序列,并系统地研究了三个蛋白与其他物种中的三个蛋白之间的亲缘关系;然后在体外进行了成功的表达和与色素重组,进而对重组LHCIIb的色素组成及光谱特征进行了系统地对比和研究。实验结果表明,Lhcb1和Lhcb3的保守性高于Lhcb2,且Lhcb3最高,Lhcb1和Lhcb2的蛋白序列相似程度高于Lhcb3;Lhcb1同质三聚体的Neo含量和α-螺旋含量高于Lhcb1单体,Lhcb2单体和Lhcb3单体的α-螺旋含量高于Lhcb1单体;与Lhcb1单体和Lhcb2单体相比,Lhcb1同质三聚体和Lhcb3单体的荧光发射光谱明显红移,与核心复合物的光谱特征更加接近,这一区别可能更加有利于能量向核心传递;吸收光谱中表明,Lhcb1和Lhcb2存在两个Chl a吸收峰,根据分析超快吸收得到的模型(Amerongen & Grondelle,2001),这两个吸收峰可能代表Chl a的两个吸收中心。 在对LHCIIb各种基本特性研究的基础之上,本论文使用三氟乙酸(TFA)、离液剂尿素、离子性去污剂SDS、非离子型去污剂Triton X-100对Lhcb1单体进行了处理,使用不同温度对Lhcb1单体和同质三聚体、Lhcb2单体和Lhcb3单体进行处理。研究了它们在不同条件下的稳定性,主要结果如下: 1) 低浓度的尿素不能使Lhcb1变性,但可以影响色素之间的能量传递效率和相互作用。尽管SDS可以使Lhcb1解体,但解体后的蛋白仍旧保留了部分α-螺旋结构。TFA和非离子型去污剂Triton X-100可以使Lhcb1完全解体,并且可以完全破坏蛋白α-螺旋结构,TFA主要是通过影响色素结构和增加蛋白内部的分子间排斥力来破坏Lhcb1,而Triton X-100主要是通过破坏疏水作用力来破坏Lhcb1。高温可以使LHCIIb解体,但不能使蛋白二级结构完全消失。 2) 尿素、温度和Triton X-100均不引起色素本身的破坏,SDS和三氟乙酸使氢置换叶绿素卟啉环所螯合的镁离子,产生去镁叶绿素,造成色素本身结构的严重破坏。 3) 随着温度的升高,色素蛋白复合体的结构和功能会遭到破坏。在Lhcb1和Lhcb2中首先被破坏的是长波长吸收的Chl a。 4) .就功能而言,Lhcb1同质三聚体最为稳定,其次为:Lhcb1单体 > Lhcb3单体 > Lhcb2单体;.就结构而言,Lhcb1单体和Lhcb1同质三聚体相似,稍微较Lhcb2和Lhcb3稳定。 5) 不同处理方式均发现色素蛋白复合体的变性过程依次为:以Chl a为主的相互作用消失,其后依次为以Chl b为主的相互作用消失,以类胡萝卜素为主的相互作用,最后消失的是蛋白的二级结构。在结构受到破坏的同时,能量传递最先受到影响。 6) 解体过程并不是折叠过程的逆过程。

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Encontrar las dificultades que impiden a los sujetos resolver con éxito tareas formales. Diseñar estrategias de aprendizaje para comprobar si mediante ellas los adolescentes superan tales dificultades. Muestra I: 30 estudiantes de ambos sexos de octavo de EGB. Edad entre 13,2 y 15,2 años. Nivel socioeconómico: clase media. Muestra II: 20 estudiantes de la muestra I subdivididos en dos grupos. Método muestreo: puntuación similar en el pre-test. Muestra III: 40 sujetos, estudiantes de primero de Formación Profesional. Edad 14,9 y 17,3 años. Clase media baja. Tipo muestreo: puntuación media similar en el pre-test. Experimento I: diseño intrasujetos con dos variaciones de la variable independiente: dependencia-independencia del campo perceptivo. Variable dependiente: resultados de la resolución de las tareas (se utilizan tres esquemas de control de variables). Experimento II: diseño pretest-postest con grupo de control. Variable independiente: sesiones de aprendizaje de proporcionalidad sin contenido probabilístico. Variable dependiente: resultados en la prueba que emplea el esquema formal de proporcionalidad. Experimento III: diseño con tres grupos experimentales y un grupo de control. Variable independiente: sesiones aprendizaje del razonamiento proporcional y del funcionamiento de la balanza. Variable dependiente: resultados de las tareas: razonamiento proporcional con contenido probabilístico, combinaciones, equilibrio de la balanza. Variable controlada: nivel formal. Cuando un sujeto se enfrenta a un problema que le rebase cognitivamente experimenta una regresión a una estrategia anterior en la que se encuentra más seguro. Para construir un esquema lógico formal de un modo completo, es condición necesaria pero no suficiente, que el sujeto compruebe que la utilización de un esquema más primitivo no le garantiza el éxito en todas las ocasiones. El pensamiento formal tiene un fuerte componente jerárquico y secuencial. Cuando se quiere estudiar el comportamiento lógico-formal ante tareas formales, hay que definir de antemano el universo de contenido de la tarea y su estructura subyacente. No es suficiente considerar la sola corrección de la respuesta sino el método seguido por el sujeto para llegar a ella. El estudio del pensamiento formal es un campo que permanece abierto los dos paradigmas básicos que se interesan por el tema: el anglosajón y el europeo continental no han conseguido integrarse en un nivel superior que sintetice estos dos enfoques, a esta tarea deben encaminarse futuros estudios. Hasta ahora se ha considerado el estilo cognitivo de un modo lineal: un continuo entre dos polos opuestos. Un enfoque dialectivo del problema podría abrir nuevas perspectivas. Destaca implicaciones educativas de los resultados de la investigación.

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Changes in the geological interpretation of the history of the ancient Solent river basin have focused attention on the handaxes discovered in the Corfe Mullen area during quarrying before the Second World War. Recent geological research suggests that the fluvial terrace the handaxes are associated with may pre-date the Anglian glaciation. This is important because it contributes to the question of just when the Solent basin was first occupied by hominins, and how this relates to other areas of possible contemporary pre-Anglian occupation such as the Boxgrove Marine embayment. However, the artefacts were believed to come from the bluff of the river terrace and were thus not in situ. This paper explores that question and re-examines the context from which the handaxes at Corfe Mullen were discovered.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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We examined whether pintado catfish (Pseudoplatystoma corruscans) can discriminate between scents of non-injured conspecifics stressed by a predator or by confinement and how fish use this information in the trade-off between feeding and predator avoidance. In the confinement stress condition, fish ingested the food, whereas in the predator stress condition, fish did not eat. This finding and comparisons of the latency to food ingestion and the time spent swimming between the confinement and predator-stress conditions indicated that pintado catfish can discriminate between conspecifics stressed by a predator or confinement using chemical cues, and use this information for adjusting the trade-off between food intake and predator avoidance.

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