Chemical basis of pupal cannibalism in a caterpillar (Utetheisa ornatrix)

The mothUtetheisa ornatrix derives protection against predation from systemic pyrrolizidine alkaloids (PAs) that it sequesters as a larva from its foodplants (Leguminosae,Crotalaria spp.). We here show, in laboratory tests, thatUtetheisa deficient in body PA can make up for the chemical shortfall by cannibalizing pupae. We present evidence indicating that cannibalism in larvae is elicited not by hunger, but possibly by PA deficiency itself, and that in making cannibalistic choices larvae prefer PA-containing over PA-free pupae. PAs themselves, either in crystalline form or as additives to food items, proved phagostimulatory to larvae. In natureUtetheisa tend to pupate away from their foodplant, essentially out of reach of larval attack. The threat of cannibalism may have contributed to the evolution of this pupation behavior.Paper No. 102 of the series Defense Mechanisms of Arthropods; No. 101 is Eisner et al., Chemoecology (in press).     

Forecasting with unbalanced panel data

This paper derives the best linear unbiased prediction (BLUP) for an unbalanced panel data model. Starting with a simple error component regression model with unbalanced panel data and random effects, it generalizes the BLUP derived by Taub (Journal of Econometrics, 1979, 10, 103–108) to unbalanced panels. Next it derives the BLUP for an unequally spaced panel data model with serial correlation of the AR(1) type in the remainder disturbances considered by Baltagi and Wu (Econometric Theory, 1999, 15, 814–823). This in turn extends the BLUP for a panel data model with AR(1) type remainder disturbances derived by Baltagi and Li (Journal of Forecasting, 1992, 11, 561–567) from the balanced to the unequally spaced panel data case. The derivations are easily implemented and reduce to tractable expressions using an extension of the Fuller and Battese (Journal of Econometrics, 1974, 2, 67–78) transformation from the balanced to the unbalanced panel data case.     

Variance intervention

Variance intervention is a simple state-space approach to handling sharp discontinuities of level or slope in the states or parameters of models for non-stationary time-series. It derives from earlier procedures used in the 1960s for the design of self-adaptive, state variable feedback control systems. In the alternative state-space forecasting context considered in the present paper, it is particularly useful when applied to structural time series models. The paper compares the variance intervention procedure with the related ‘subjective intervention’ approach proposed by West and Harrison in a recent issue of the Journal of Forecasting, and demonstrates it efficacy by application to various time-series data, including those used by West and Harrison.     

From centripetal forces to conic orbits: a path through the early sections of Newton’s Principia

In this study, we test the security of a crucial plank in the Principia’s mathematical foundation, namely Newton’s path leading to his solution of the famous Inverse Kepler Problem: a body attracted toward an immovable center by a centripetal force inversely proportional to the square of the distance from the center must move on a conic having a focus in that center. This path begins with his definitions of centripetal and motive force, moves through the second law of motion, then traverses Propositions I, II, and VI, before coming to an end with Propositions XI, XII, XIII and this trio’s first corollary. To test the security of this path, we answer the following questions. How far is Newton’s path from being truly rigorous? What would it take to clarify his ambiguous definitions and laws, supply missing details, and close logical gaps? In short, what would it take to make Newton’s route to the Inverse Kepler Problem completely convincing? The answer is very surprising: it takes far less than one might have expected, given that Newton carved this path in 1687.     

Newton's Easy Quadratures ``Omitted for the Sake of Brevity'

In the 1687 Principia, Newton gave a solution to the direct problem (given the orbit and center of force, find the central force) for a conic-section with a focal center of force (answer: a reciprocal square force) and for a spiral orbit with a polar center of force (answer: a reciprocal cube force). He did not, however, give solutions for the two corresponding inverse problems (given the force and center of force, find the orbit). He gave a cryptic solution to the inverse problem of a reciprocal cube force, but offered no solution for the reciprocal square force. Some take this omission as an indication that Newton could not solve the reciprocal square, for, they ask, why else would he not select this important problem? Others claim that ``it is child's play' for him, as evidenced by his 1671 catalogue of quadratures (tables of integrals). The answer to that question is obscured for all who attempt to work through Newton's published solution of the reciprocal cube force because it is done in the synthetic geometric style of the 1687 Principia rather than in the analytic algebraic style that Newton employed until 1671. In response to a request from David Gregory in 1694, however, Newton produced an analytic version of the body of the proof, but one which still had a geometric conclusion. Newton's charge is to find both ``the orbit' and ``the time in orbit.' In the determination of the dependence of the time on orbital position, t(r), Newton evaluated an integral of the form ∫dx/x <sup>n</sup> to calculate a finite algebraic equation for the area swept out as a function of the radius, but he did not write out the analytic expression for time t = t(r), even though he knew that the time t is proportional to that area. In the determination of the orbit, θ (r), Newton obtained an integral of the form ∫dx/√(1−x<sup>2</sup>) for the area that is proportional to the angle θ, an integral he had shown in his 1669 On Analysis by Infinite Equations to be equal to the arcsin(x). Since the solution must therefore contain a transcendental function, he knew that a finite algebraic solution for θ=θ(r) did not exist for ``the orbit' as it had for ``the time in orbit.' In contrast to these two solutions for the inverse cube force, however, it is not possible in the inverse square solution to generate a finite algebraic expression for either ``the orbit' or ``the time in orbit.' In fact, in Lemma 28, Newton offers a demonstration that the area of an ellipse cannot be given by a finite equation. I claim that the limitation of Lemma 28 forces Newton to reject the inverse square force as an example and to choose instead the reciprocal cube force as his example in Proposition 41. (Received August 14, 2002) Published online March 26, 2003 Communicated by G. Smith     

Prediction in a Generalized Spatial Panel Data Model with Serial Correlation

This paper considers the generalized spatial panel data model with serial correlation proposed by Lee and Yu (Spatial panels: random components versus fixed effects. International Economic Review 2012; 53 : 1369–1412.), which encompasses many of the spatial panel data models considered in the literature, and derives the best linear unbiased predictor (BLUP) for that model. This in turn provides valuable BLUP for several spatial panel models as Special Cases. Copyright © 2016 John Wiley & Sons, Ltd.     

Memory

Our understanding of the cellular and molecular mechanisms underlying learning and memory formation derives from studies of species as diverse as worms, mollusks, insects, birds and mammals. Despite the quite different brain structures and neuronal networks, the studies support the current notion that neuronal activity leads to changes in synaptic connections as the neural substrate of behavioral plasticity. The analysis of the mechanisms underlying learning and memory formation reveals a surprisingly high conservation between invertebrates and mammals, both at the behavioral as well as the molecular level. This special issue provides an overview of the current knowledge on cellular and molecular processes underlying memory formation. The contributing reviews summarize the findings in different organisms, such as Aplysia, Drosophila, honeybees and mammals, and discuss new approaches, developments and hypotheses all aimed at understanding how the nervous system acquires, stores and retrieves information.     

Avantages et inconvénients de la fixation par perfusion du tissu nerveux à la lumière d'une donnée de cytochimie

Summary It has been extensively demonstrated that perfusion is the best fixation procedure for providing good morphological evidence ofstructures, especially in the case of nervous tissue. But it might be questioned if it should also be preferred whencytochemical data have to be obtained or compared.As a preliminary attempt to answer this question, lipoproteic inclusions in nerve cells of vegetative ganglia of adult cat have been considered. These occur in about 25% of cells after immersion in fixative, whereas if perfusion is used, a relation appears between the amount of saline perfused before the fixative fluid and the percentage of cells containing inclusions: this falls to 10% after 300 ml saline, to 1% after 800 ml. In conclusion, though structural artefacts have been avoided and fixation appears excellent, perfusion is significantly responsible for a definite cytochemical alteration.     

Application of the linear partial information model to forecasting the Swiss timber market

Most often, statistical analyses only provide partial information about the appropriateness of different models, structures and parameters which may underlie the dynamic process that has generated a time series. Linear partial information (LPI), in particular, consists of linear restrictions such as LPI: p_a> p_b, p_a> p_c where p_a denotes the probability that structure a holds. Fuzzy information of this type can be put to use for decision-making by LPI analysis. In this paper, LPI analysis is applied to answer the question of whether subsidizing price, given an abnormal disturbance on the timber market, would contribute to continuous forest management, a stated goal of Swiss environmental policy.     

La nature de la substance minérale de l'os

Summary In answer to objections put forward byBrandenberger andSchintz against their theory concerning the chemical nature of bone salts, the authors afford supplementary evidence about the real crystalline and chemical entity of hydrated tricalcium phosphate. According to the conditions, the precipitate contains either dicalcium phosphate or lime and this affects the nature of the product obtained by calcination.The mineral bone substance is not a hydroxylapatite because it turns either to carbonato-apatite or oxyapatite according to carbon dioxide being kept or not in the crystal lattice. The X-ray patterns of those two apatites are undoubtedly different.

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Réponse à une note deE. Brandenberger etH. R. Schinz, Exper.4, 59 (1948).     

Can We Predict Exchange Rate Movements at Short Horizons?

This paper explains the unpredictability of exchange rate movements at short horizons and provides a plausible answer on the exchange rate disconnect puzzle. By generalizing Chaboud and Wright's (Journal of International Economics 2005; 66 : 349–362) work, it is shown that exchange rates follow a martingale process at short horizons but over long horizons may contain some predictable structure. The empirical results applied to several major currencies of the US dollar support our hypothesis. This evidence is not coincided with the explanation of the inefficient market hypothesis under which exchange rate movements can be predictable in both short and long horizons. Copyright © 2011 John Wiley & Sons, Ltd.     

Decision theory and information propagation in quantum physics

In recent papers, Zurek [(2005). Probabilities from entanglement, Born's rule p_k=|ψ_k|² from entanglement. Physical Review A, 71, 052105] has objected to the decision-theoretic approach of Deutsch [(1999) Quantum theory of probability and decisions. Proceedings of the Royal Society of London A, 455, 3129–3137] and Wallace [(2003). Everettian rationality: defending Deutsch's approach to probability in the Everett interpretation. Studies in History and Philosophy of Modern Physics, 34, 415–438] to deriving the Born rule for quantum probabilities on the grounds that it courts circularity. Deutsch and Wallace assume that the many worlds theory is true and that decoherence gives rise to a preferred basis. However, decoherence arguments use the reduced density matrix, which relies upon the partial trace and hence upon the Born rule for its validity. Using the Heisenberg picture and quantum Darwinism—the notion that classical information is quantum information that can proliferate in the environment pioneered in Ollivier et al. [(2004). Objective properties from subjective quantum states: Environment as a witness. Physical Review Letters, 93, 220401 and (2005). Environment as a witness: Selective proliferation of information and emergence of objectivity in a quantum universe. Physical Review A, 72, 042113]—I show that measurement interactions between two systems only create correlations between a specific set of commuting observables of system 1 and a specific set of commuting observables of system 2. This argument picks out a unique basis in which information flows in the correlations between those sets of commuting observables. I then derive the Born rule for both pure and mixed states and answer some other criticisms of the decision theoretic approach to quantum probability.     

Nonseparable processes and causal explanation

If physical reality is nonseparable, as quantum mechanics suggests, then it may contain processes of a quite novel kind. Such nonseparable processes could connect spacelike separated events without violating relativity theory or any defensible locality condition. Appeal to nonseparable processes could ground theoretical explanations of such otherwise puzzling phenomena as the two-slit experiment, and EPR-type correlations. We find such phenomena puzzling because they threaten cherished conceptions of how causes operate to produce their effects. But nonseparable processes offer us an alternative deal of natural order, conformity to which makes such phenomena seem quite normal and not at all unexpected. Attempts to answer the further question, as to whether an appeal to a nonseparable process provides a genuine causal explanation, have something to teach us about our concept of causation, but do not threaten to undermine the value of the explanation itself.     

Henry Dresser and Victorian Ornithology: Birds,Books and Business

The metaphysical commitment to the circle as the essential element in the analysis of celestial motion has long been recognized as the hallmark of classical astronomy. Part I of this paper contains a discussion of how, for Kepler, the circle also functions in geometry to select the basic polygons, in music to select the basic harmonies, and in astrology to select the basic aspects. In Part II, the discussion centres on the question of how the replacement of circular planetary orbits by elliptical orbits in the Astronomia Nova of 1609 affected Kepler's metaphysical commitment to celestial circularity that was made manifest in the derivation of planetary radii in the Mysterium Cosmographicum of 1596. The answer is found in the new and much more accurate derivation of both the planetary radii and their eccentricities in the Harmonice Mundi of 1619. It is the relationship of the diurnal movements of single planets at aphelion and perihelion to specific musical consonances that provides the first step. Then, in the second step, these ratios are ‘tempered’ so that all six planets can provide a heavenly choir. The third and final step employs the ‘mean period’, which is obtained directly from the tempered ratios given by musical theory and diurnal (not annual) motion, in the 3/2 power law to calculate the planetary radii and eccentricities with amazing accuracy. Thus the ellipse is necessary to supply the variation in angular velocities that contain the Creator's archetypal celestial circularity.     

Looking for structure in all the wrong places: Ramsey sentences, multiple realisability, and structure

‘Epistemic structural realism’ (ESR) insists that all that we know of the world is its structure, and that the ‘nature’ of the underlying elements remains hidden. With structure represented via Ramsey sentences, the question arises as to how ‘hidden natures’ might also be represented. If the Ramsey sentence describes a class of realisers for the relevant theory, one way of answering this question is through the notion of multiple realisability. We explore this answer in the context of the work of Carnap, Hintikka and Lewis. Both Carnap and Hintikka offer clear structuralist perspectives which, crucially, accommodate the openness inherent in theory change. Unfortunately there is little purchase for a viable form of realism in either case. Lewis’s approach, on the other hand, offers more scope for realism but, as we shall see, concerns arise as to whether a relevant form of structuralism can be maintained. In particular his thesis of Ramseyan humility undermines certain conceptions of scientific laws that the structural realist might naturally cleave to. Our overall conclusion is that the representational device of Ramsey sentence plus multiple realisability can accommodate either the structuralist or realist aspects of ESR but has difficulties capturing both.     

Eine Produktdarstellung für das Deckungskapital

Summary The author derives from the differential equation for the annuity and from the difference equation for the value of the policy several relations, which allow to represent approximately the value of composed forms of insurances by the value of simple forms of insurances; likewise, it is easy to render formally the influence of a variation of the rate of interest.     

Lockean superaddition and Lockean humility

This paper offers a new approach to an old debate about superaddition in Locke. Did Locke claim that some objects have powers that are unrelated to their natures or real essences? The question has split commentators. Some (Wilson, Stuart, Langton) claim the answer is yes and others (Ayers, Downing, Ott) claim the answer is no. This paper argues that both of these positions may be mistaken. I show that Locke embraced a robust epistemic humility. This epistemic humility includes ignorance of the real essences of bodies, of the causal processes underlying the production of natural phenomena, and of God's method of creation. I show how this epistemic humility offers strong support for an agnostic response to the question of superaddition. Locke did not intend to claim that bodies either do or do not have properties unrelated to their real essences. Instead, his primary goal in discussing the topic was to emphasize the strict limits to human knowledge.     

Prediction in an Unbalanced Nested Error Components Panel Data Model

This paper derives the best linear unbiased predictor for an unbalanced nested error components panel data model. This predictor is useful in many econometric applications that are usually based on unbalanced panel data and have a nested (hierarchical) structure. Examples include predicting student performance in a class in a school, or house prices in a neighborhood in a county or a state. Using Monte Carlo simulations, we show that this predictor is better in root mean square error performance than the usual fixed‐ or random‐effects predictors ignoring the nested structure of the data. This is applied to forecasting the productivity of public capital in the private sector using nested panel data of 48 contiguous American states. Copyright © 2013 John Wiley & Sons, Ltd.     

Chemical basis of pupal cannibalism in a caterpillar (Utetheisa ornatrix).

The moth Utetheisa ornatrix derives protection against predation from systemic pyrrolizidine alkaloids (PAs) that it sequesters as a larva from its foodplants (Leguminosae, Crotalaria spp.). We here show, in laboratory tests, that Utetheisa deficient in body PA can make up for the chemical shortfall by cannibalizing pupae. We present evidence indicating that cannibalism in larvae is elicited not by hunger, but possibly by PA deficiency itself, and that in making cannibalistic choices larvae prefer PA-containing over PA-free pupae. PAs themselves, either in crystalline form or as additives to food items, proved phagostimulatory to larvae. In nature Utetheisa tend to pupate away from their foodplant, essentially out of reach of larval attack. The threat of cannibalism may have contributed to the evolution of this pupation behavior.     

A frame-theoretic analysis of two rival conceptions of heat

Under what circumstances, if any, are we warranted to assert that a theory is true or at least has some truth content? Scientific realists answer that such assertions are warranted only for those theories or theory-parts that enjoy explanatory and predictive success. A number of challenges to this answer have emerged, chief among them those arising from scientific theory change. For example, if, as scientific realists suggest, successive theories are to increasingly get closer to the truth, any theory changes must not undermine (i) the accumulation of explanatory and predictive success and (ii) the theoretical content responsible for that success. In this paper we employ frame theory to test to what extent certain theoretical claims made by the outdated caloric theory of heat and that, prima facie at least, were used to produce some of that theory’s success have survived into the theory that superseded it, i.e. the kinetic theory of heat. Our findings lend credence to structural realism, the view that scientific theories at best reveal only structural features of the unobservable world.