存在一般性的生物多样性垂直格局理论吗？

　是否存在一般性的生物多样性垂直格局理论，是人们普遍关心的问题。为了解决这一疑问。本文设计了三个方面的问题作为研究的内容。一、标准化系统取样能够满足山地生物多样性研究的需要吗？二、山地植物群落中不同植物类群的物种丰富度沿海拔梯度有相同的格局变化吗？三、山地植物群落中，不同植物类群的群落水平多样性，包括物种丰富度、均匀度和群落多样性沿海拔梯度有怎样的变化？不同植物类群内，及不同植物类群间物种丰富度、物种均匀度和群落多样性之间的空间相互关系？ 为了解决上述问题，我们采用了模拟和试验两类数据（来自北京东灵山地区7条垂直样带），研究中着重考虑了数据的空间相关性或尺度依赖性，应用地统计学和多元地统计学的方法对数据进行分析，得出如下结论： 一、标准化系统取样是不能满足山地物种多样性研究的需要的，它忽略了取样单元面积效应。理论上，文献所列的四种典型的生物多样性格局类型都可以随取样单元而相互转换;评价生物多样性垂直格局时，不存在唯一合适的取样单元尺度。通常在一定尺度范围内，多样性显现某一格局类型，超过了尺度阀值，格局类型会发生转换，但是存在一个最小取样单元尺度，小于这一尺度生物多样性的空间结构将不能正确显现;山地生物多样性分布具各向异性，垂直方向物种替代速率远大于水平方向，因此，不但取样面积，而且取样单元的形状也对多样性格局有重要影响。山地生物多样性格局研究中，以垂直方向作长边的长方形较为合适;本研究没有对物种多样性格局随取样单元发生转换的决定因素得出明确的结论，但 多样性的空间分布可能是一主要因素。 二、乔、灌、草和群落总的物种丰富度格局，大多数大尺度上呈现梯度格局，小尺度上呈斑块的聚集。物种丰富度垂直格局的尺度依赖性与坡向有密切关系，同一坡向的格局的特征表现出很强的一致性;乔、灌、草及总的植物物种丰富度垂直梯度格局与取样单元尺度的关系也表现出与坡向的密切关系，同一坡向合适的取样面积基本一致;总的来说，不同植物类群的物种丰富度垂直格局都表现出其独特的特点，不同坡向同一植物类群又表现出明显不同的特点。将我们的研究结果与其它山地物种丰富度的垂直格局研究进行比较，得出这样的推论：在山地植物多样性研究中，同一群落层次在相同的生物地理区（或气候带）内，物种丰富度具有一致的垂直格局类型，而在不同的生物地理区内具有不同的特点。分别研究不同群落层次物种丰富度在同一生物地理区不同地点，以及在不同生物地理区的垂直格局，有利于区别历史、进化因素和现时生态因素对生物多样性形成和维持的作用，形成一般的生物多样性理论。 三、乔、灌、草三层的群落多样性Simpson指数和物种丰富的垂直格局类型基本一致，多样性和丰富度格局的相似性不但表现在格局的类型上，而且表现在对空间的尺度依赖上，如自相关范围、大尺度上梯度效应等都表现出了一致性;均匀度格局变化比较复杂，在乔木层、阴坡灌木层与物种丰富度有相似的格局特征，阳坡灌木层均匀度则基本不随海拔变化;草本层均匀度很高，表现出与物种丰富度、多样性相反的格局。我们认为物种丰富度、多样性、均匀度沿着环境梯度变化以及它们之间的关系还不能确定是否有一般性特征，它们可能不但与生物类群而且与垂直样带所处的环境有关。理论研究认为在大尺度上群落多样性的变化主要反映在物种丰富度水平上的变化，主要由均匀度引起的多样性的变化可能只存在小范围的环境梯度中，本文的研究为这一理论提供了佐证。理论模拟表明物种丰富度、均匀度和多样性之间是简单的强正相关性，丰富度和均匀度相互独立存在，我们证明了它们之间并非简单的正相关，丰富度和均匀度也非简单独立存在，它们的关系与尺度、坡向（环境条件）、植物类群密切相关，不同的生态过程或因素在不同尺度上的作用决定了它们的关系类型。乔、灌层间各多样性测度间总体呈正相关关系，并随尺度增加而降低;乔、草层间多样性测度间的关系与乔、灌层间明显不同，乔木层各多样性测度与草本层丰富度、多样性指数间显著负相关，与草本层均匀度间弱正相关，并随尺度增大渐弱;灌、草层间与乔、草层间情形相似，特别是阴坡。不同层次间多样性测度的相互关系还与坡向和尺度密切相关。 通过本研究，虽然不能肯定回答是否存在一般性的生物多样性垂直格局理论，但是我们认为在同一生物地理区域内，对同一生物类群（具有相同或相似的生物、生态学特性，具有对外界环境相同或相似的适应方式），并匹配于适宜的尺度揭示生物多样性垂直格局，并比较不同生物地理区、不同生物类群的生物多样性垂直格局，可能会找出一般性的生物多样性垂直格局理论。

Rashba electron transport in one-dimensional quantum waveguides

The properties of Rashba wave function in the planar one-dimensional waveguide are studied, and the following results are obtained. Due to the Rashba effect, the plane waves of electron with the energy E divide into two kinds of waves with the wave vectors k(1)=k(0)+k(delta) and k(2)=k(0)-k(delta), where k(delta) is proportional to the Rashba coefficient, and their spin orientations are +pi/2 (spin up) and -pi/2 (spin down) with respect to the circuit, respectively. If there is gate or ferromagnetic contact in the circuit, the Rashba wave function becomes standing wave form exp(+/- ik(delta)l)sin[k(0)(l-L)], where L is the position coordinate of the gate or contact. Unlike the electron without considering the spin, the phase of the Rashba plane or standing wave function depends on the direction angle theta of the circuit. The travel velocity of the Rashba waves with the wave vector k(1) or k(2) are the same hk(0)/m*. The boundary conditions of the Rashba wave functions at the intersection of circuits are given from the continuity of wave functions and the conservation of current density. Using the boundary conditions of Rashba wave functions we study the transmission and reflection probabilities of Rashba electron moving in several structures, and find the interference effects of the two Rashba waves with different wave vectors caused by ferromagnetic contact or the gate. Lastly we derive the general theory of multiple branches structure. The theory can be used to design various spin polarized devices.

X(3915) and X(4350) as New Members in the P-Wave Charmonium Family

The analysis of the mass spectrum and the calculation of the strong decay of P-wave charmonium states strongly purport to explain the newly observed X(3915) and X(4350) as new members in the P-wave charmonium family, i.e., chi'(c0) for X(3915) and chi ''(c2) for X(4350). Under the P-wave charmonium assignment to X(3915) and X(4350), the J(PC) quantum numbers of X(3915) and X(4350) must be 0(++) and 2(++) respectively, which provide important criteria to test the P-wave charmonium explanation for X(3915) and X(4350) proposed by this Letter. The decay behavior of the remaining two P-wave charmonium states with the second radial excitation is predicted, and an experimental search for them is suggested.

Automatic Recognition of Tractability in Inference Relations

A procedure is given for recognizing sets of inference rules that generate polynomial time decidable inference relations. The procedure can automatically recognize the tractability of the inference rules underlying congruence closure. The recognition of tractability for that particular rule set constitutes mechanical verification of a theorem originally proved independently by Kozen and Shostak. The procedure is algorithmic, rather than heuristic, and the class of automatically recognizable tractable rule sets can be precisely characterized. A series of examples of rule sets whose tractability is non-trivial, yet machine recognizable, is also given. The technical framework developed here is viewed as a first step toward a general theory of tractable inference relations.

La pensée Sensible

Tese apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Doutor em Ciências Sociais, especialidade em Psicologia

Resonant and Secular Orbital Interations

In stable solar systems, planets remain in nearly elliptical orbits around their stars. Over longer timescales, however, their orbital shapes and sizes change due to mutual gravitational perturbations. Orbits of satellites around a planet vary for the same reason. Because of their interactions, the orbits of planets and satellites today are different from what they were earlier. In order to determine their original orbits, which are critical constraints on formation theories, it is crucial to understand how orbits evolve over the age of the Solar System. Depending on their timescale, we classify orbital interactions as either short-term (orbital resonances) or long-term (secular evolution). My work involves examples of both interaction types. Resonant history of the small Neptunian satellites In satellite systems, tidal migration brings satellite orbits in and out of resonances. During a resonance passage, satellite orbits change dramatically in a very short period of time. We investigate the resonant history of the six small Neptunian moons. In this unique system, the exotic orbit of the large captured Triton (with a circular, retrograde, and highly tilted orbit) influences the resonances among the small satellites very strongly. We derive an analytical framework which can be applied to Neptune's satellites and to similar systems. Our numerical simulations explain the current orbital tilts of the small satellites as well as constrain key physical parameters of both Neptune and its moons. Secular orbital interactions during eccentricity damping Long-term periodic changes of orbital shape and orientation occur when two or more planets orbit the same star. The variations of orbital elements are superpositions of the same number of fundamental modes as the number of planets in the system. We investigate how this effect interacts with other perturbations imposed by external disturbances, such as the tides and relativistic effects. Through analytical studies of a system consisting of two planets, we find that an external perturbation exerted on one planet affects the other indirectly. We formulate a general theory for how both orbits evolve in response to an arbitrary externally-imposed slow change in eccentricity.

Crafting analytical tools to study institutional change

Most powerful analytical tools used in the social sciences are well suited for studying static situations. Static and mechanistic analysis, however, is not adequate to understand the changing world in which we live. In order to adequately address the most pressing social and environmental challenges looming ahead, we need to develop analytical tools for analyzing dynamic situations -particularly institutional change. In this paper, we develop an analytical tool to study institutional change, more specifically, the evolution of rules and norms. We believe that in order for such an analytical tool to be useful to develop a general theory of institutional change, it needs to enable the analyst to concisely record the processes of change in multiple specific settings so that lessons from such settings can eventually be integrated into a more general predictive theory of change. Copyright © The JOIE Foundation 2010.

CBE-conveyor: a case-based reasoning system to assist engineers in designing conveyor systems

In this paper, we address the use of CBR in collaboration with numerical engineering models. This collaborative combination has a particular application in engineering domains where numerical models are used. We term this domain “Case Based Engineering” (CBE), and present the general architecture of a CBE system. We define and discuss the general characteristics of CBE and the special problems which arise. These are: the handling of engineering constraints of both continuous and nominal kind; interpolation over both continuous and nominal variables, and conformability for interpolation. In order to illustrate the utility of the method proposed, and to provide practical examples of the general theory, the paper describes a practical application of the CBE architecture, known as CBE-CONVEYOR, which has been implemented by the authors.Pneumatic conveying is an important transportation technology in the solid bulks conveying industry. One of the major industry concerns is the attrition of powders and granules during pneumatic conveying. To minimize the fraction of particles during pneumatic conveying, engineers want to know what design parameters they should use in building a conveyor system. To do this, engineers often run simulations in a repetitive manner to find appropriate input parameters. CBE-Conveyor is shown to speed up conventional methods for searching for solutions, and to solve problems directly that would otherwise require considerable intervention from the engineer.

Hormesis - The Stimulation Of Growth By Low-Levels Of Inhibitors

Hormesis is the name given to the stimulatory effects caused by low levels of potentially toxic agents. When this phenomenon was first identified it was called the Arndt-Schulz Law or Hueppe's Rule, because it was thought to occur generally. Although this generalisation is not accepted today, there has never been more evidence in its support, justifying a re-examination of the phenomenon. Evidence from the literature shows that not only has growth hormesis been observed in a range of taxa after exposure to a variety of agents, but also that the dose-response data have a consistent form. While there are a number of separate hypotheses to explain specific instances of hormesis, the evidence presented here suggests that different examples might have a common explanation, and the possibility of a general theory is considered.

Scaling laws of ambush predator 'waiting' behaviour are tuned to a common ecology

The decisions animals make about how long to wait between activities can determine the success of diverse behaviours such as foraging, group formation or risk avoidance. Remarkably, for diverse animal species, including humans, spontaneous patterns of waiting times show random ‘burstiness’ that appears scale-invariant across a broad set of scales. However, a general theory linking this phenomenon across the animal kingdom currently lacks an ecological basis. Here, we demonstrate from tracking the activities of 15 sympatric predator species (cephalopods, sharks, skates and teleosts) under natural and controlled conditions that bursty waiting times are an intrinsic spontaneous behaviour well approximated by heavy-tailed (power-law) models over data ranges up to four orders of magnitude. Scaling exponents quantifying ratios of frequent short to rare very long waits are species-specific, being determined by traits such as foraging mode (active versus ambush predation), body size and prey preference. A stochastic–deterministic decision model reproduced the empirical waiting time scaling and species-specific exponents, indicating that apparently complex scaling can emerge from simple decisions. Results indicate temporal power-law scaling is a behavioural ‘rule of thumb’ that is tuned to species’ ecological traits, implying a common pattern may have naturally evolved that optimizes move–wait decisions in less predictable natural environments.

Narrative change in psychotherapy

This thesis focuses on the processes of narrative change in psychotherapy. Previous reviews of the processes of narrative change in psychotherapy concluded that a general theory that details narrative concepts appropriate to understand psychotherapy processes, explains the dynamic processes between narratives, and how they relate to positive outcomes is needed. This thesis addresses this issue by suggesting a multi-layered model that accounts for transformations in different layers of narrative organization. Accordingly, a model was specified that considers three layers of narrative organization: a micro-layer of narrative innovations that disrupt the clients’ usual way of construct meaning from life situations (innovative moments), a meso-layer of narrative scripts that integrate these narrative innovations in narrative scripts that consolidate its transformative potential (protonarratives), and, finally, a macro-layer of clients’ life story (self-narrative). Globally, the empirical studies provided support for the conceptual plausibility of this model and to the specific hypothesis that were formulated on its basis. Our observations complement previous research that had underlined the integrative processes either by emphasizing thematic coherence or integration, by emphasizing the role of dynamicity and differentiation of narrative contents and processes. Additionally, they also contribute to expand previous accounts of narrative innovation through insights on the processes that characterize narrative innovation development across psychotherapy. These studies also emphasize the role of quantitative procedures in the study of narrative processes of change as they allow us to accommodate the complexity and dynamic properties of narrative processes.

Espaço e perspectivas na representação visual

Relatório da prática de ensino supervisionada, Mestrado em Ensino de Artes Visuais, Universidade de Lisboa, 2011

Transformation in teaching : listening to every voice

Action research is a methodology that supports practitioner research. This study is an exploration of one researcher's practice using the living-theory approach to action research. Initially, my focus was to improve my practice by asking how I can facilitate transformative learning experiences with the teachers with whom I work. As part of this search, I examined the contradictions between my espoused and implicit values. In keeping with the evolving nature of my inquiry, I unveiled the telos that constituted the impetus for my search, which began as a tension about the quality of my interactions and ended as a quest to find my voice among the others'. I used personal narratives, journal entries, a videotaping session, interactions with critical friends and interviews with colleagues and administrators to engage in a process of continuing self- and interactive reflection. Throughout my study, I explored how theoretical concepts intertwine with personal experiences. In the final chapter, I share the possible connections between my living educational theory and a more general theory of transformative learning. I conclude my study with a look at the transformation process I underwent as a result of the study and the new questions I formulated as I began the action research spiral again.

'To do justice and judgement' : the place of passion in public life

Please consult the paper edition of this thesis to read. It is available on the 5th Floor of the Library at Call Number: Z 9999 P65 F47 2003

L'intervention du juge canadien avant et durant un arbitrage commercial international

"Thèse présentée à la Faculté des études supérieures de l'Université de Montréal en vue de l'obtention du grade de Docteur en droit (LL.D.) et à l'Université Panthéon-Assas (Paris II) Droit-économie-Sciences Sociales en vue de l'obtention du grade de Docteur en droit (Arrêté du 30 mars 1992 modifié par l'arrêté du 25 avril 2002)"