Social decision-making: insights from game theory and neuroscience

By combining the models and tasks of Game Theory with modern psychological and neuroscientific methods, the neuroeconomic approach to the study of social decision-making has the potential to extend our knowledge of brain mechanisms involved in social decisions and to advance theoretical models of how we make decisions in a rich, interactive environment. Research has already begun to illustrate how social exchange can act directly on the brain's reward system, how affective factors play an important role in bargaining and competitive games, and how the ability to assess another's intentions is related to strategic play. These findings provide a fruitful starting point for improved models of social decision-making, informed by the formal mathematical approach of economics and constrained by known neural mechanisms.     

Predictability and preparedness in influenza control

The threat of pandemic human influenza looms as we survey the ongoing avian influenza pandemic and wonder if and when it will jump species. What are the risks and how can we plan? The nub of the problem lies in the inherent variability of the virus, which makes prediction difficult. However, it is not impossible; mathematical models can help determine and quantify critical parameters and thresholds in the relationships of those parameters, even if the relationships are nonlinear and obscure to simple reasoning. Mathematical models can derive estimates for the levels of drug stockpiles needed to buy time, how and when to modify vaccines, whom to target with vaccines and drugs, and when to enforce quarantine measures. Regardless, the models used for pandemic planning must be tested, and for this we must continue to gather data, not just for exceptional scenarios but also for seasonal influenza.     

Planetary biology--paleontological, geological, and molecular histories of life

The history of life on Earth is chronicled in the geological strata, the fossil record, and the genomes of contemporary organisms. When examined together, these records help identify metabolic and regulatory pathways, annotate protein sequences, and identify animal models to develop new drugs, among other features of scientific and biomedical interest. Together, planetary analysis of genome and proteome databases is providing an enhanced understanding of how life interacts with the biosphere and adapts to global change.     

Cell polarity: quantitative modeling as a tool in cell biology

Among a number of innovative approaches that have modernized cell biology, modeling has a prominent yet unusual place. One popular view is that we progress linearly, from conceptual to ever more detailed models. We review recent discoveries of cell polarity mechanisms, in which modeling played an important role, to demonstrate that the experiment-theory feedback loop requires diverse models characterized by varying levels of biological detail and mathematical complexity. We argue that a quantitative model is a tool that has to fit an experimental study, and the model's value should be judged not by how complex and detailed it is, but by what could be learned from it.     

Motion integration and postdiction in visual awareness

In the flash-lag illusion, a flash and a moving object in the same location appear to be offset. A series of psychophysical experiments yields data inconsistent with two previously proposed explanations: motion extrapolation (a predictive model) and latency difference (an online model). We propose an alternative in which visual awareness is neither predictive nor online but is postdictive, so that the percept attributed to the time of the flash is a function of events that happen in the approximately 80 milliseconds after the flash. The results here show how interpolation of the past is the only framework of the three models that provides a unified explanation for the flash-lag phenomenon.     

The effect of electrical coupling on the frequency of model neuronal oscillators

Neurons with oscillatory properties are a common feature of the nervous system, but little is known about how neural oscillators shape the behavior of neuronal networks or how network interactions influence the properties of neural oscillators. Mathematical models are used to examine the effect of electrically coupling an oscillatory neuron to a second neuron that is either silent or tonically firing. Models of oscillatory neurons with varying degrees of complexity show that this coupling can either increase or decrease the frequency of an oscillator, depending on its membrane potential wave form, the state of the neuron to which it is coupled, and the strength of the coupling. Thus, electrical coupling provides a flexible mechanism for modifying the behavior of an oscillatory neural network.     

The cultural ecology of development: Ten precepts for survival

This paper uses a cultural ecology of development approach to critique existing models of development. The critique identifies existing models as running counter to ecological and biological imperatives, placing an over-emphasis on growth as the solution to development, and resulting in considerable cultural wastage. An argument is made that many of the attempts to construct an alternative development paradigm can be grouped within the cultural ecology of development approach. Ten precepts that will enhance the long-term survivability of the earth are proposed. The final portion of the paper looks at how compatible current trends in thinking about development are with these ten precepts and assesses the prospects for adoption of these precepts in an alternative development paradigm.     

The occurrence and mass distribution of close-in super-Earths, Neptunes, and Jupiters

The questions of how planets form and how common Earth-like planets are can be addressed by measuring the distribution of exoplanet masses and orbital periods. We report the occurrence rate of close-in planets (with orbital periods less than 50 days), based on precise Doppler measurements of 166 Sun-like stars. We measured increasing planet occurrence with decreasing planet mass (M). Extrapolation of a power-law mass distribution fitted to our measurements, df/dlogM = 0.39 M(-0.48), predicts that 23% of stars harbor a close-in Earth-mass planet (ranging from 0.5 to 2.0 Earth masses). Theoretical models of planet formation predict a deficit of planets in the domain from 5 to 30 Earth masses and with orbital periods less than 50 days. This region of parameter space is in fact well populated, implying that such models need substantial revision.     

森林林种调整技术方法的研究

本文提出了以森林的三大效益为目标,用线性规划结合Fuzzy线性规划的方法进行森林林种结构的最优设计。并阐述其数学模型和具体的调整方法。对闽北森林林种进行实际设计运用,收到了良好的效果。     

用模糊数学综合评判建筑观感质量等级

观感质量的评定得分率,是组成单位工程质量“合格”、“优良”等级的内容之一。该文主要试论用模糊数学的方法分析处理观感质量综合评价当中存在的一些模糊问题,并针对观感质量及其检评特点,建立相应的评价模型与等级评判准则,用以进行等级判定。     

Earth's core and the geodynamo

Earth's magnetic field is generated by fluid motion in the liquid iron core. Details of how this occurs are now emerging from numerical simulations that achieve a self-sustaining magnetic field. Early results predict a dominant dipole field outside the core, and some models even reproduce magnetic reversals. The simulations also show how different patterns of flow can produce similar external fields. Efforts to distinguish between the various possibilities appeal to observations of the time-dependent behavior of the field. Important constraints will come from geological records of the magnetic field in the past.     

2019-12ml 目录

林业遥感经历了航片判读、卫片目视解译、蓄积量定量估测阶段后,已经进入参数定量反演阶段。在林业对遥感业务化监测和精度提升的强烈需求下,定量遥感逐步与林业遥感交叉融合,林业遥感定量化研究的人才队伍、理论模型、数据源和应用方法逐渐成熟。本文提出了林业定量遥感的概念和框架,指出了其中关键的科学问题:（1）如何使遥感解译、建模和反演适应复杂的森林状况;（2）如何提高参数反演的准确度;（3）如何丰富林业遥感数据源;（3）如何发展更为智能化的遥感数据自动化算法。在介绍适合林业的定量遥感模型和通用反演方法的基础上,阐述了高光谱、热红外、激光雷达和微波遥感数据源的林业应用方法。未来林业定量遥感将在全波段数据统一建模和信息融合机制、机理模型反演、大数据融合等方面进行突破。      

基于可拓工程方法的土地整理规划设计探讨

可拓工程是以开拓创新规律与方法为研究对象的一门学科.根据我国土地整理产业的特点,运用物元理论,在分析土地资源可拓性的基础上,初步构建了土地整理的物元模型.并以浙江省余姚市马渚镇土地整理规划设计为例,探讨了如何通过物元变换,来生成符合规划要求的方案.研究结果为土地整理规划设计提供了新的手段和思路.     

Structure of PTB bound to RNA: specific binding and implications for splicing regulation

The polypyrimidine tract binding protein (PTB) is a 58-kilodalton RNA binding protein involved in multiple aspects of messenger RNA metabolism, including the repression of alternative exons. We have determined the solution structures of the four RNA binding domains (RBDs) of PTB, each bound to a CUCUCU oligonucleotide. Each RBD binds RNA with a different binding specificity. RBD3 and RBD4 interact, resulting in an antiparallel orientation of their bound RNAs. Thus, PTB will induce RNA looping when bound to two separated pyrimidine tracts within the same RNA. This leads to structural models for how PTB functions as an alternative-splicing repressor.     

输出立场与美学立场在高校英美文学课程中的应用

本论文以罗森布莱特的读者反应理论为参照,通过在实际教学中的调查数据,探究以下问题:教师在课堂上使用美学式教学和输出式教学分别对学生的学习动力以及学生对文学作品的理解会产生什么样的影响;在高校英美文学的教学中,教师应如何有效地利用美学式教学和输出式教学。     

Extinction and ecosystem function in the marine benthos

Rapid changes in biodiversity are occurring globally, yet the ecological impacts of diversity loss are poorly understood. Here we use data from marine invertebrate communities to parameterize models that predict how extinctions will affect sediment bioturbation, a process vital to the persistence of aquatic communities. We show that species extinction is generally expected to reduce bioturbation, but the magnitude of reduction depends on how the functional traits of individual species covary with their risk of extinction. As a result, the particular cause of extinction and the order in which species are lost ultimately govern the ecosystem-level consequences of biodiversity loss.     

Frames, biases, and rational decision-making in the human brain

Human choices are remarkably susceptible to the manner in which options are presented. This so-called "framing effect" represents a striking violation of standard economic accounts of human rationality, although its underlying neurobiology is not understood. We found that the framing effect was specifically associated with amygdala activity, suggesting a key role for an emotional system in mediating decision biases. Moreover, across individuals, orbital and medial prefrontal cortex activity predicted a reduced susceptibility to the framing effect. This finding highlights the importance of incorporating emotional processes within models of human choice and suggests how the brain may modulate the effect of these biasing influences to approximate rationality.     

农业可持续发展的若干问题(Ⅱ)——农业可持续发展的主要模式和关键技术

农业可持续发展问题已引起世界各国的广泛关注和高度重视。我国是一个拥有 13亿人口的发展中农业大国 ,入世后 ,农业如何实现和保持快速、持续、健康发展 ,这是新世纪全国上下亟待研究回答的问题。对农业可持续发展的主要模式及其关键技术进行了分析和讨论 ,旨在为新世纪促进我国农业的可持续发展提供新的思路、方法和途径     

Dissociable roles of ventral and dorsal striatum in instrumental conditioning

Instrumental conditioning studies how animals and humans choose actions appropriate to the affective structure of an environment. According to recent reinforcement learning models, two distinct components are involved: a "critic," which learns to predict future reward, and an "actor," which maintains information about the rewarding outcomes of actions to enable better ones to be chosen more frequently. We scanned human participants with functional magnetic resonance imaging while they engaged in instrumental conditioning. Our results suggest partly dissociable contributions of the ventral and dorsal striatum, with the former corresponding to the critic and the latter corresponding to the actor.     

基于模型和WebGIS数字农作支持系统的设计与实现

基于系统用户需求及现有农作模型特点,研究GIS技术与农作模型集成的机制与方法,提出了"XML技术+自定义地图引擎"的技术思路,设计了合理的系统体系结构.运用软构件技术,基于B/S(Browser/Server) 的分布式网络技术,以WebGIS为空间信息管理平台,建立了基于模型和WebGIS的数字农作支持系统(MGDFSS) .该系统实现了基本地图操作、农作空间信息管理、作物生态区划、种植制度设计、栽培方案设计、生长模拟预测、管理策略分析、生长监测与调控、精准农作处方、生产力分析、专家咨询以及系统维护等综合功能.该系统的建立和应用可显著提升农作生产过程的数字化表达与信息化管理,促进数字农作技术的发展.