Wireless microphone for studies of animal vocalizations.

A microphone collar for obtaining good quality recordings of animal vocalizations is described. An inexpensive, commercially available wireless microphone was modified and mounted on a collar with a hearing-aidbattery pack. The complete assembly weighs 25 g, and is readily accepted by domestic cats.     

Source of the tentacular hormone in terrestrial pulmonates

Summary Collar cells around the optic tentacles of pulmonate gastropods were shown to have a stimulating effect on spermatogenesis in vivo and in vitro. No hormonal action was found in the tentacles other than in collar cells. Therefore, collar cells are considered to be the source of the so-called tentacular hormone in stylommatophoran pulmonates. We propose to name the collar cell group optic gland.     

Localization of sound producing animals using the arrival time differences of their signals at an array of microphones

Summary This method provides a reliable means to determine distance between vocalizing individuals and their locations through a prolonged period of time without disturbance to the communication process by the presence of an observer. The accuracy of this method was tested by varying the arrival time differences on the microphone grid for known locations in a random fashion. This test shows that a vocalizing animal within an area of 4 ha surrounding the microphone array can be localized with an accuracy of ±1 m. The accuracy decreases with the distance from the central area and as a function of the geometry of the array. The location of an individual can be determined based on 5 vocalizations given in sequence.Acknowledgment. This research was supported by funds granted to Irene Magyar from the Chapman Fund, The American Museum of Natural History and Sigma Xi, Grants in Aid of Research.     

Instrumentalizing Failure: Edison's Invention of the Carbon Microphone

For Thomas Edison, experiencing a failure did not mean that he had failed. Through an examination of the process that led to his invention of the carbon microphone, I argue that his positive approach to failure contributed both to his success as an inventor and to the functional success of his inventions. Edison's laboratory notebooks and legal testimony reveal that his seemingly erratic approach and reliance on trial and error methods in fact had a consistent direction and a rational basis, well suited to the under-determined problems he faced. The outcome of this process, the carbon microphone, contributed significantly to the commercial success of the telephone and remains in use today. Thomas Hughes has observed that nineteenth century inventors made use of the unexpected behaviour of their inventions as sources of novel phenomena to exploit in new inventions. This paper identifies other ways in which Edison made use of failure and proposes that, paradoxically, the success of technological artefacts can be determined by the thoroughness with which failure is pursued in their creation. It also notes a parallel between Edison's instrumentalizing of failure and the way in which recent philosophers of science have proposed that scientists should make use of error.     

Eine bisher unbekannte endokrine Drüse im Kopf vonScutigera coleoptrata L. (Chilopoda,Notostigmophora)

Summary A hitherto unknown endocrine gland in the head ofScutigera coleoptrata is described. It is attached to a small blood vessel. Its cells are typical podocytes. Between the pedicells and along the lateral cell membranes, there are many intercellulary spaces. The fine structure of the gland is very similar to that of the collar gland in the diplopodPolyxenus lagurus.     

一种基于谱相减法的声信号时延估计

利用信号增强算法,结合广义互相关时延估计原理,提出一种声信号时延估计算法。在噪声背景下先采用谱相减法从带噪信号中估计出原始声信号,提高信噪比,利用四元立体传声器阵列和广义互相关算法原理,对相关数据进行加权处理得到较高精度的时廷估计值。该算法可以有效抑制空间加性噪声,得到有效声信号准确的时延估计。实验仿真结果表明了该算法的可行性,在信噪比较低的情况下,与单一使用广义互相关函数相比,极大地提高了时延估计算法的准确程度。     

The occurrence of peripherical molluscan neurons (Cryptomphallus aspersa)

Resumen Se describen en la membrana y collar del manto próximos al poro respiratorio del moluscoCryptomphallus aspersa (Gasteropoda, Pulmonata) la presencia de varios tipos de neuronas y plexos. Estas observaciones morfológicas se discuten en relación a hallazgos previos con técnicas electrofisiólogicas obtenidos por otros autores.     

The morphology of the lateral line system in 3 species of Pacific cottoid fishes occupying disparate habitats

Summary The superficial neuromasts inLeptocottus armatus (Pacific staghorn sculpin) andOligocottus maculosus (tidepool sculpin) are depressed below the rim of an epidermal collar, whereas the superficial neuromasts inPsychrolutes paradoxus (tadpole sculpin) are surrounded by a pair of hillocks. The lateral line canal system appears identical across these species, whereas the system of superficial neuromasts shows some intraspecific variation. The sand-livingLeptocottus has a more highly developed system of superficial neuromasts thanOligocottus, which lives in a rocky habitat. The present results support the correlation between lateral line system morphology and habitat features previously postulated by Dijkgraaf.     

基于光学衍射的纳米尺度深度重建

传统的离焦深度恢复方法（depth from defocus,DFD）在计算离焦图像的模糊程度时,均是基于几何光学成像原理,并没有考虑光波衍射对图像模糊的影响.然而,衍射现象是波的基本特性,以针孔成像为基础的光学成像系统中必然存在光波衍射.本文基于光学衍射和图像模糊机理,提出了一种精确的单目视觉全局景物3D深度信息获取方法.首先,详细分析了光学成像系统中的菲涅耳衍射机理,建立了衍射模糊与景物深度之间的关系曲线;然后,采用曲线拟合的方式建立了衍射模糊的模糊程度（点扩散函数扩散程度）与景物深度的数学关系模型,结合热辐射和图像相对模糊原理,构建了衍射模糊热辐射方程组,并把衍射模糊深度获取问题转换成一个深度信息动态优化问题.最后,使用标准的纳米栅格模板验证了衍射模糊深度重建算法在纳米尺度相对深度和绝对深度重建中的有效性和精确性.     

The theory theory thrice over: the child as scientist, Superscientist or social institution?

Alison Gopnik and Andrew Meltzoff have argued for a view they call the ‘theory theory’: theory change in science and children are similar. While their version of the theory theory has been criticized for depending on a number of disputed claims, we argue that there is a fundamental problem which is much more basic: the theory theory is multiply ambiguous. We show that it might be claiming that a similarity holds between theory change in children and (i) individual scientists, (ii) a rational reconstruction of a Superscientist, or (iii) the scientific community. We argue that (i) is false, (ii) is non-empirical (which is problematic since the theory theory is supposed to be a bold empirical hypothesis), and (iii) is either false or doesn't make enough sense to have a truth-value. We conclude that the theory theory is an interesting failure. Its failure points the way to a full, empirical picture of scientific development, one that marries a concern with the social dynamics of science to a psychological theory of scientific cognition.     

基于分支限界搜索框架的测试用例自动生成

作为软件测试领域的一个基本问题和热点问题,面向路径的测试用例自动生成有着特殊的重要意义.面向路径的测试用例生成本质上是一个约束满足问题,并通过搜索算法求解.着眼于提升搜索算法的效率,本文提出了一种新的智能算法,将分支限界和爬山法进行了有机的整合,分支限界作为全局搜索算法,而爬山法作为局部搜索算法,发挥各自的优势来对测试用例的解空间进行搜索.     

Ergodic Theory, Interpretations of Probability and the Foundations of Statistical Mechanics

The traditional use of ergodic theory in the foundations of equilibrium statistical mechanics is that it provides a link between thermodynamic observables and microcanonical probabilities. First of all, the ergodic theorem demonstrates the equality of microcanonical phase averages and infinite time averages (albeit for a special class of systems, and up to a measure zero set of exceptions). Secondly, one argues that actual measurements of thermodynamic quantities yield time averaged quantities, since measurements take a long time. The combination of these two points is held to be an explanation why calculating microcanonical phase averages is a successful algorithm for predicting the values of thermodynamic observables. It is also well known that this account is problematic.This survey intends to show that ergodic theory nevertheless may have important roles to play, and it explores three other uses of ergodic theory. Particular attention is paid, firstly, to the relevance of specific interpretations of probability, and secondly, to the way in which the concern with systems in thermal equilibrium is translated into probabilistic language. With respect to the latter point, it is argued that equilibrium should not be represented as a stationary probability distribution as is standardly done; instead, a weaker definition is presented.     

基因组学:生命科学的系统化研究和生物世纪的科学革命

DNA(脱氧核糖核酸)是基因的“文字”，基因是生命的“语言”，生命的“剧本”用基因来编写。基因组学则是生命剧本的“导演”。DNA序列因此就成了舞台剧本。基因组学是一门大规模地、系统地研究物种全部基因和它们生物学意义和运动的学问。如今，我们正站在一个革命性的转折点上，也就是基因组学正处于生命科学的领导前沿。我们不该为此恐慌、怀疑甚或因而改变方向。获得一个物种的基本的基因组信息，比如基因的图谱及其在细胞中的产物，是我们了解该物种生物学意义的第一步。我们应该根据基础研究、经济效益和社会的需要来考虑测序日程上物种的先后次序。     

The regulation of trehalose metabolism in insects

Trehalose is a non-reducing disaccharide comprising two glucose molecules. It is present in high concentration as the main haemolymph (blood) sugar in insects. The synthesis of trehalose in the fat body (an organ analogous in function to a combination of liver and adipose tissue in vertebrates) is stimulated by neuropeptides (hypertrehalosaemic hormones), released from the corpora cardiaca, a neurohaemal organ associated with the brain. The peptides cause a decrease in the content of fructose 2,6-bisphosphate in fat body cells. Fructose 2,6-bisphosphate, acting synergistically with AMP, is a potent activator of the glycolytic enzyme 6-phosphofructokinase-1 and a strong inhibitor of the gluconeogenic enzyme fructose 1,6-bisphosphatase. This indicates that fructose 2,6-bisphosphate is a key metabolic signal in the regulation of trehalose synthesis in insects. Trehalose is hydrolysed by trehalase (E.C. 3.2.1.28). The activity of this enzyme is regulated in flight muscle, but the mechanism by which this is achieved is unknown. Trehalase from locust, flight muscle is a glycoprotein bound to membranes of the microsomal fraction. The enzyme can be activated by detergents in vitro and by short flight intervals in vivo, which indicates that changes in the membrane environment modulate trehalase activity under physiological conditions.     

The growth of mathematical knowledge—Introduction of convex bodies

The article addresses the topic of the growth of mathematical knowledge with a special focus on the question: How are mathematical objects introduced to mathematical practice? It takes as starting point a proposal made in a previous paper which is based on a case study on the introduction of Riemann surfaces. The claim is that (i) a new object first refers to previously accepted objects, and that (ii) reasoning is possible via a correspondence to the objects with reference to which it is introduced. In addition Riemann surfaces are geometrical objects, i.e., they are placed in a geometrical context, which makes new definitions possible. This proposal is tested on a case study on Minkowski’s introduction of convex bodies. The conclusion is that the proposal holds also for this example. In both cases we notice that in a first stage is a close connection between the new object and the objects it is introduced with reference to, and that in a later stage, the new object is given an independent definition. Even though the two cases display similarity in these respects, we also point to certain differences between the cases in the process of the first stage. Overall we notice the fruitfulness of representing problems in different contexts.     

Eine Dressurmethode für wahrnehmungsphysiologische Untersuchungen und ihre Anwendung in Orientierungsversuchen mit Vögeln

Summary A conditioning method for the investigation of bird orientation is described: A duck (Anas platyrhynchos) is attached to a slowly rotating turntable, and its heart rate is recorded (Figure 1). When facing a certain direction, the animal gets a weak electrical shock. If the bird is able to determine this direction, its heart rate increases in anticipation of the shock, and there is a maximum at this angle even if no shock at all is applied (Figure 2). By this means it is possible to show whether a certain stimulus situation is appropriate to establish a conditioned reaction of this kind (Figure 3). It is assumed that this method can easily be adapted to investigate other problems of perception and learning.

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Mit Unterstützung der Stiftung Volkswagenwerk.     

Is electromagnetic field momentum due to the flow of field energy?

Momentum and energy conservation require electromagnetic field momentum and energy to be treated as physically real, even in static fields. This motivates the conjecture that field momentum might be due to the flow of a relativistic mass density (defined as energy density divided by the square of the speed of light).This article investigates the velocity of such a mass flow and finds a conflict between two different definitions of it, both of which originally seem plausible if the flow is to be taken as real. This investigation is careful to respect the transformation rules of special relativity throughout.The paper demonstrates that the consensus definition of the flow velocity of electromagnetic energy is inconsistent with the transformation rules of special relativity, and hence is incorrect. A replacement flow velocity is derived which is completely consistent with those transformation rules.The conclusion is that these conflicting definitions of flow velocity cannot be resolved in a way that is consistent with special relativity and also allows electromagnetic field momentum density to be the result of relativistic mass flow. Though real, field momentum density cannot be explained as the flow of a relativistic mass density.As a byproduct of the study, it is also shown that there is a comoving system in which the electromagnetic energy-momentum tensor is reduced to a simple diagonal form, with two of its diagonal elements equal to the energy density and the other two diagonal elements equal to plus and minus a single parameter derived from the electromagnetic field values, a result that places constraints on possible fluid models of electromagnetism.     

Objective probability and the mind-body relation

Objectiveprobability in quantum mechanics is often thought to involve a stochastic process whereby an actual future is selected from a range of possibilities. Everett's seminal idea is that all possible definite futures on the pointer basis exist as components of a macroscopic linear superposition. I demonstrate that these two conceptions of what is involved in quantum processes are linked via two alternative interpretations of the mind-body relation. This leads to a fission, rather than divergence, interpretation of Everettian theory and to a novel explanation of why a principle of indifference does not apply to self-location uncertainty for a post-measurement, pre-observation subject, just as Sebens and Carroll claim. Their Epistemic Separability Principle is shown to arise out of this explanation and the derivation of the Born rule for Everettian theory is thereby put on a firmer footing.     

De-synthesizing the relative a priori

This paper considers the question whether the notion of the relative apriori, central to Michael Friedman’s transcendentalist programme for philosophy of science, is available also to philosophers who reject appeals to a synthetic a priori. After tracing the rediscovery of the relative a priori and delineating its potential, the question is considered whether Friedman’s arguments against Quinean naturalism and Carnap’s attenuated logicism tell against a conception of philosophy as scientific metatheory that combines logical and empirical inquiries. Finding an opening here it is argued that this conception can also help itself to the notion of a relative a priori which, it is agreed, is central to historically informed theorising about science.     

Demonstration and characterization of mannosyl phosphoryl dolichol synthesized in the outer membrane of liver mitochondria]

There is in mitochondrial outer membrane a mannosyl-transferase which is able to catalyse the mannose transfer on a polyprenic acceptor, to give a mannosyl-phosphoryl-dolichol. This enzyme is stimulated by Mn2+, Mg2+ and dithiothreitol. It is inhibited by GDP, mersalyl and EGTA.