There has been considerable recent interest in the consequences of closed timelike curves (CTCs) for the dynamics of quantum mechanical systems. A vast majority of research into this area makes use of the dynamical equations developed by Deutsch, which were developed from a consistency condition that assumes that mixed quantum states uniquely describe the physical state of a system. We criticize this choice of consistency condition from an epistemic perspective, i.e., a perspective in which the quantum state represents a state (...) of knowledge about a system. We demonstrate that directly applying Deutsch’s condition when mixed states are treated as representing an observer’s knowledge of a system can conceal time travel paradoxes from the observer, rather than resolving them. To shed further light on the appropriate dynamics for quantum systems traversing CTCs, we make use of a toy epistemic theory with a strictly classical ontology due to Spekkens and show that, in contrast to the results of Deutsch, many of the traditional paradoxical effects of time travel are present. (shrink)

The comparison of growth, whether it is between different strains or under different growth conditions, is a classic microbiological technique that can provide genetic, epigenetic, cell biological, and chemical biological information depending on how the assay is used. When employing solid growth media, this technique is limited by being largely qualitative and low throughput. Collecting data in the form of growth curves, especially automated data collection in multi‐well plates, circumvents these issues. However, the growth curves themselves are subject to stochastic (...) variation in several variables, most notably the length of the lag phase, the doubling rate, and the maximum expansion of the culture. Thus, growth curves are indicative of trends but cannot always be conveniently averaged and statistically compared. Here, we summarize a simple method to compile growth curve data into a quantitative format that is amenable to statistical comparisons and easy to graph and display. (shrink)

Many people argue that uncertain science—or controversial policies based on science—can be clarified primarily by greater attention to social/political values influencing the science and by greater attention to the vested interests involved. This paper argues that while such clarification is necessary, it is not a sufficient condition for achieving better science and policy; indeed its importance may be overemphasized. Using a case study involving the current, highly politicized controversy over the shape of dose‐response curves for biological effects of ionizing radiation, (...) the paper argues that the conflict could be significantly resolved through specific methodological improvements in the areas of metascience and philosophy of science. These improvements focus on taking account, respectively, of scale, data trimming, aggregation, measurability, and simplicity. (shrink)

Many people argue that uncertain science -- or controversial policies based on science -- can be clarified primarily by greater attention to the social and ethical values influencing the science and the policy and by greater attention to the vested, economic interests involved. This paper argues that while such clarification is necessary, it is neither a sufficient condition, nor even the primary means, by which to achieve better science and better policy. Using a case study involving the current, highly politicized (...) controversy over the shape of dose-response curves for biological effects of ionizing radiation in both the protective action levels (PALS) and the International Commission on Radiological Protection (ICRP) environmental proposals, the paper argues that the conflict could be resolved largely through five specific methodological improvements in the areas of metascience and philosophy of science. (shrink)

The ‘Kantian ideal’ is often misunderstood as invoking individual autonomy rather than rational self-legislation. Le Morvan and Stock’s otherwise insightful discussion of ‘Medical learning curves and the Kantian ideal’, for example, draws the mistaken inference that that ideal is inconsistent with the realities of medical practice. But it is not. Rationally to be a patient entails accepting its necessary conditions, one of which is the ineliminable existence of medical learning curves. Their rational necessity, therefore, offers no grounds against a Kantian (...) understanding of how morality might function in the practgice of medicine. (shrink)

Ainslie advances Freud's and Skinner's theories of homunculi by basing their emergent complexity on the interaction of simple algorithms. The rules of competition and cooperation of these interests are underspecified, but they provide a new way of thinking about the basic elements of conditioning, particularly conditioned stimuli (CSs).

The D-CTC condition, introduced by David Deutsch as a condition to be fulfilled by analogues for processes of quantum systems in the presence of closed timelike curves, is investigated for classical statistical bi-partite systems. It is shown that the D-CTC condition can generically be fulfilled in classical statistical systems, under very general, model-independent conditions. The central property used is the convexity and completeness of the state space that allows it to generalize Deutsch’s original proof for q-bit systems to more general (...) classes of statistically described systems. The results demonstrate that the D-CTC condition, or the conditions under which it can be fulfilled, is not characteristic of, or dependent on, the quantum nature of a bi-partite system. (shrink)

Confidence can dissociate from perceptual accuracy, suggesting distinct computational and neural processes underlie these psychological functions. Recent investigations have therefore sought to experimentally isolate metacognitive processes by creating conditions where perceptual sensitivity is matched but confidence differs (“matched-performance / different-confidence”; MPDC). Despite these endeavors’ success, much remains unknown about MPDC effects and how to best harness them in experimental settings. Here we developed a principled approach to comprehensively characterizing MPDC effects through analyzing metaperceptual (i.e., type 2 psychometric) functions relating objective (...) performance to subjective confidence across widely varying performance levels and experimental manipulations. We found that MPDC effect magnitude depends on stimulus properties, observers’ sensitivity level, and critically on trial type order (blocked or interleaved across stimulus property variations). Our findings provide the first comprehensive exploration of MPDC effects, offer a prescriptive guide to metaperceptual analysis, and suggest optimal experimental paradigms for experimentally isolating metacognition and awareness in future studies. (shrink)

Priority setting of scarce resources in healthcare is high on the agenda of most healthcare systems implying a need to develop robust foundations for making fair allocation decisions. One central factor for such decisions in needs-based systems, following both empirical studies and theoretical analyses, is severity. However, it has been noted that severity is an under-theorized concept. One such aspect is how severity should relate to temporality. There is a rich discussion on temporality and distributive justice, however, this discussion needs (...) to be adapted to the practical and ethical requirements of healthcare priority setting principles at mid-level. In this article, we analyze how temporal aspects should be taken into account when assessing severity as a modifier for cost-effectiveness. We argue that when assessing the severity of a condition, we have reason to look at complete conditions from a time-neutral perspective, meaning that we take the full affectable stretch of the condition into account without modifying severity as patients move through the temporal stretch and without discounting the future. We do not find support for taking the ‘shape’ of a condition into account per se, e.g. whether the severity has a declining or inclining curve, or that severity is intermittent rather than continuous. In order to take severity seriously, we argue that we have reason to apply a quantified approach where every difference in severity should impact on priority setting. In conclusion, we find that this approach is practically useful in actual priority setting. (shrink)

Effective conditioning requires a correlation between the experimenter's definition of a response and an organism's, but an animal's perception of its behavior differs from ours. These experiments explore various definitions of the response, using the slopes of learning curves to infer which comes closest to the organism's definition. The resulting exponentially weighted moving average provides a model of memory that is used to ground a quantitative theory of reinforcement. The theory assumes that: incentives excite behavior and focus the excitement (...) on responses that are contemporaneous in memory. The correlation between the organism's memory and the behavior measured by the experimenter is given by coupling coefficients, which are derived for various schedules of reinforcement. The coupling coefficients for simple schedules may be concatenated to predict the effects of complex schedules. The coefficients are inserted into a generic model of arousal and temporal constraint to predict response rates under any scheduling arrangement. The theory posits a response-indexed decay of memory, not a time-indexed one. It requires that incentives displace memory for the responses that occur before them, and may truncate the representation of the response that brings them about. As a contiguity-weighted correlation model, it bridges opposing views of the reinforcement process. By placing the short-term memory of behavior in so central a role, it provides a behavioral account of a key cognitive process. (shrink)

Context can determine whether a given gene acts as an oncogene or a tumor suppressor. Deubiquitinating enzymes (DUBs) regulate the stability of many components of the pathways dictating cell fate so it would be expected that alterations in the levels or activity of these enzymes may have oncogenic or tumor suppressive consequences. In the current review we survey publications reporting that genes encoding DUBs are oncogenes or tumor suppressors. For many DUBs both claims have been made. For such “double agents,” (...) the effects of gain or loss of function will depend on the overall status of a complex of molecular signaling networks subject to extensive crosstalk. As the TGF‐β paradox makes clear context is critical in cell fate decisions, and the disconnect between experimental findings and patient survival outcomes can in part be attributed to disparities between culture conditions and the microenvironment in vivo. Convincing claims for oncogene or tumor suppressor roles require the documentation of gene alterations in patient samples; survival curves are alone inadequate. (shrink)

This article studies the impact of a credit expansion monetary policy on output and unemployment rate. In the introduction the history of the Phillips curve and its interpretation are presented to understand why New Consensus Macroeconomics argues that monetary policy is neutral in long-run i. e. has no effect on economic activity and natural unemployment rate. This New Consensus Macroeconomics supports the independence of the Central Bank, inflation-targeting and the strategy of constrained discretion model and influences strongly the monetary (...) policy of central bank today. The second section critics these three principles of the new consensus. It opposes free-banking to central banking system, and takes the defense of deflation to critic the inflation-targeting. Then the third section deals with long-run neutrality of monetary policy. In an Austrian Business Cycle perspective, there is neutrality of monetary only if the production structure must always return exactly to its level of before the boom. It is improbable, because the monetary policy via tax inflation and artificial variation of real interest rate has a long-run effects on the conditions of financing of entrepreneurial project and in fine all the market process dynamic. (shrink)

Corruption involves greed, money, and risky decision-making. We explore the love of money, pay satisfaction, probability of risk, and dishonesty across cultures. Avaricious monetary aspiration breeds unethicality. Prospect theory frames decisions in the gains-losses domain and high-low probability. Pay dissatisfaction (in the losses domain) incites dishonesty in the name of justice at the individual level. The Corruption Perceptions Index, CPI, signals a high-low probability of getting caught for dishonesty at the country level. We theorize that decision-makers adopt avaricious love-of-money aspiration (...) as a lens and frame dishonesty in the gains-losses domain (pay satisfaction-dissatisfaction, Level 1) and high-low probability (CPI, Level 2) to maximize expected utility and ultimate serenity. We challenge the myth: Pay satisfaction mitigates dishonesty across nations consistently. Based on 6500 managers in 32 countries, our cross-level three-dimensional visualization offers the following discoveries. Under high aspiration conditions, pay dissatisfaction excites the highest- (third-highest) avaricious justice-seeking dishonesty in high (medium) CPI nations, supporting the certainty effect. However, pay satisfaction provokes the second-highest avaricious opportunity-seizing dishonesty in low CPI entities, sustaining the possibility effect—maximizing expected utility. Under low aspiration conditions, high pay satisfaction consistently leads to low dishonesty, demonstrating risk aversion—achieving ultimate serenity. We expand prospect theory from a micro and individual-level theory to a cross-level theory of monetary wisdom across 32 nations. We enhance the S-shaped Curve to three 3-D corruption surfaces across three levels of the global economic pyramid, providing novel insights into behavioral economics, business ethics, the environment, and responsibility. (shrink)

Curved multi-dimensional space-times (5D and higher) are constructed by embedding them in one higher-dimensional flat space. The condition that the embedding coordinates have a separable form, plus the demand of an orthogonal resulting space-time, implies that the curved multi-dimensional space-time has 4D de-Sitter subspaces (for constant extra-dimensions) in which the 3D subspace has an accelerated expansion. A complete determination of the curved multi-dimensional spacetime geometry is obtained provided we impose a new type of “equivalence principle”, meaning that there is a (...) geodesic which from the embedding space has a rectliniar motion. According to this new equivalence principle, we can find the extra-dimensions metric components, each curved multi-dimensional spacetime surface’s equation, the energy-momentum tensors and the extra-dimensions as functions of a scalar field. The generic geodesic in each 5D spacetime are studied: they include solutions where particle’s motion along the extra-dimension is periodic and the 3D expansion factor is inflationary (accelerated expansion). Thus, the 3D subspace has an accelerated expansion. (shrink)

Over the turn of the 21st century, the use of data from large electronic corpora has changed research on Spanish historical syntax, spurring interest in long-range evolutions and the shape of the correspondent diachronic curves. However, general reflections on diffusion and the factors that drive and influence it are still pretty much lacking. In this paper, I reflect on the research possibilities laid open by the availability of such large masses of data, focusing particularly on new knowledge on syntactic change (...) brought about by the study of low-frequency phenomena and of recessive changes, as well as on the exploration of changes conditioned by dialect contact and textual traditions. I conclude with some remarks on the general typology of diffusion in syntactic change. (shrink)

The Schrödinger equation for a particle of rest mass $m$ and electrical charge $ne$ interacting with a four-vector potential $A_i$ can be derived as the non-relativistic limit of the Klein–Gordon equation $\left( \Box '+m^2\right) \varPsi =0$ for the wave function $\varPsi $ , where $\Box '=\eta ^{jk}\partial '_j\partial '_k$ and $\partial '_j=\partial _j -\mathrm {i}n e A_j$ , or equivalently from the one-dimensional action $S_1=-\int m ds +\int neA_i dx^i$ for the corresponding point particle in the semi-classical approximation $\varPsi \sim (...) \exp {(\mathrm {i}S_1)}$ , both methods yielding the equation $\mathrm {i}\partial _0\varPsi \approx \left( \frac{1}{2m}\eta ^{\alpha \beta }\partial '_{\alpha }\partial '_{\beta } + m + n e\phi \right) \varPsi $ in Minkowski space–time , where $\alpha ,\beta =1,2,3$ and $\phi =-A_0$ . We show that these two methods generally yield equations that differ in a curved background space–time $g_{ij}$ , although they coincide when $g_{0\alpha }=0$ if $m$ is replaced by the effective mass $\mathcal{M}\equiv \sqrt{m^2-\xi R}$ in both the Klein–Gordon action $S$ and $S_1$ , allowing for non-minimal coupling to the gravitational field, where $R$ is the Ricci scalar and $\xi $ is a constant. In this case $\mathrm {i}\partial _0\varPsi \approx \left( \frac{1}{2\mathcal{M}'} g^{\alpha \beta }\partial '_{\alpha }\partial '_{\beta } + \mathcal{M}\phi ^{(\mathrm g)} + n e\phi \right) \varPsi $ , where $\phi ^{(\mathrm g)} =\sqrt{g_{00}}$ and $\mathcal{M}'=\mathcal{M}/\phi ^{(\mathrm g)} $ , the correctness of the gravitational contribution to the potential having been verified to linear order $m\phi ^{(\mathrm g)} $ in the thermal-neutron beam interferometry experiment due to Colella et al. Setting $n=2$ and regarding $\varPsi $ as the quasi-particle wave function, or order parameter, we obtain the generalization of the fundamental macroscopic Ginzburg-Landau equation of superconductivity to curved space–time. Conservation of probability and electrical current requires both electromagnetic gauge and space–time coordinate conditions to be imposed, which exemplifies the gravito-electromagnetic analogy, particularly in the stationary case, when div ${{\varvec{A}}}=\hbox {div}{{\varvec{A}}}^{(\mathrm g)}=0$ , where ${{\varvec{A}}}^{\alpha }=-A^{\alpha }$ and ${{\varvec{A}}}^{(\mathrm g)\alpha }=-\phi ^{(\mathrm g)}g^{0\alpha }$ . The quantum-cosmological Schrödinger (Wheeler–DeWitt) equation is also discussed in the $\mathcal{D}$ -dimensional mini-superspace idealization, with particular regard to the vacuum potential $\mathcal V$ and the characteristics of the ground state, assuming a gravitational Lagrangian $L_\mathcal{D}$ which contains higher-derivative terms up to order $\mathcal{R}^4$ . For the heterotic superstring theory , $L_\mathcal{D}$ consists of an infinite series in $\alpha '\mathcal{R}$ , where $\alpha '$ is the Regge slope parameter, and in the perturbative approximation $\alpha '|\mathcal{R}| \ll 1$ , $\mathcal V$ is positive semi-definite for $\mathcal{D} \ge 4$ . The maximally symmetric ground state satisfying the field equations is Minkowski space for $3\le {\mathcal {D}}\le 7$ and anti-de Sitter space for $8 \le \mathcal {D} \le 10$. (shrink)

Behavioral science has long been puzzled by the experience of temptation, the resulting impulsiveness, and the variably successful control of this impulsiveness. In conventional theories, a governing faculty like the ego evaluates future choices consistently over time, discounting their value for delay exponentially, that is, by a constant rate; impulses arise when this ego is confronted by a conditioned appetite. Breakdown of Will presents evidence that contradicts this model. Both people and nonhuman animals spontaneously discount the value of expected events (...) in a curve where value is divided approximately by expected delay, a hyperbolic form that is more bowed than the rational, exponential curve. With hyperbolic discounting, options that pay off quickly will be temporarily preferred to richer but slower-paying alternatives, a phenomenon that, over periods from minutes to days, can account for impulsive behaviors, and over periods of fractional seconds can account for involuntary behaviors. Contradictory reward-getting processes can in effect bargain with each other, and stable preferences can be established by the perception of recurrent choices as test cases in recurrent intertemporal prisoner's dilemmas. The resulting motivational pattern resembles traditional descriptions of the will, as well as of compulsive phenomena that can now be seen as side-effects of will: over-concern with precedent, intractable but circumscribed failures of self-control, a motivated unconscious, and an inability to exploit emotional rewards. Hyperbolic curves also suggest a means of reducing classical conditioning to motivated choice, the last necessary step for modeling many involuntary processes like emotion and appetite as reward-seeking behaviors; such modeling, in turn, provides a rationale for empathic reward and the “construction” of reality. Key Words: altruism ; appetite; behavioral economics; classical conditioning; compulsions; dynamic inconsistency; emotions; empathy; freedom of will; hyperbolic discounting; impulsiveness; intertemporal bargaining; self-control; social construction; volition; weakness of will. (shrink)

The appearance of the time derivative of the acceleration in the equation of motion (EOM) of an electric charge is studied. It is shown that when an electric charge is accelerated, a stress force exists in the curved electric field of the accelerated charge, and in the case of a constant linear acceleration, this force is proportional to the acceleration. This stress force acts as a reaction force which is responsible for the creation of the radiation (instead of the “radiation (...) reaction force” that actually does not exist at low velocities). Thus the initial acceleration should be supplied as an initial condition for the solution of the EOM of an electric charge. (shrink)

The Kripke/Wittgenstein paradox and Goodman’s riddle of induction can be construed as problems of multiple redescription, where the relevant sceptical challenge is to provide factual grounds justifying the description we favour. A choice of description or predicate, in turn, is tantamount to the choice of a curve over a set of data, a choice apparently governed by implicitly operating constraints on the relevant space of possibilities. Armed with this analysis of the two paradoxes, several realist solutions of Kripke’s paradox (...) are examined that appeal to dispositions or other non-occurrent properties. It is found that all neglect crucial epistemological issues: the entities typically appealed to are not observational and must be inferred on the basis of observed entities or events; yet, the relevant sceptical challenge concerns precisely the factual basis on which this inference is made and the constraints operating on it. All disposition ascriptions, the thesis goes on to argue, contain elements of idealization. To ward off the danger of vacuity resulting from the fact that any disposition ascription is true under just the right ideal conditions, dispositional theories need to specify limits on legitimate forms of idealization. This is best done by construing disposition ascriptions as forms of (implicit) curve-fitting, I argue, where the “data” is not necessarily numeric, and the “curve” fitted not necessarily graphic. This brings us full circle: Goodman’s and Kripke’s problems are problems concerning curve-fitting, and the solutions for it appeal to entities the postulation of which is the result of curve-fitting. The way to break the circle must come from a methodology governing the idealizations, or inferences to the best idealization, that are a part of curve-fitting. The thesis closes with an argument for why natural science cannot be expected to be of much help in this domain, given the ubiquity of idealization. (shrink)

Operating universities under pandemic conditions is a complex undertaking. The Artificial University responds to this need. TAU is a configurable, open-source computer simulation of a university using a contact network based on publicly available information about university classes, residences, and activities. This study evaluates health outcomes for an array of interventions and testing protocols in an artificial university of 6,500 students, faculty, and staff. Findings suggest that physical distancing and centralized contact tracing are most effective at reducing infections, but there (...) is a tipping point for compliance below which physical distancing is less effective. If student compliance is anything short of high, it helps to have separate buildings for quarantining infected students, thereby gracefully increasing compliance. Hybrid in-person and online classes and closing fitness centers do not significantly change cumulative infections but do significantly decrease the number of the infected at any given time, indicating strategies for “flattening the curve” to protect limited resources. Supplementing physical distancing with centralized contact tracing decreases infected individuals by an additional 14%; boosting frequency of testing for student-facing staff yields a further 7% decrease. A trade-off exists between increasing the sheer number of infection tests and targeting testing for key nodes in the contact network. There are significant advantages to getting and acting on test results quickly. The costs and benefits to universities of these findings are discussed. Artificial universities can be an important decision support tool for universities, generating useful policy insights into the challenges of operating universities under pandemic conditions. (shrink)

COVID-19 is a highly contagious infection with no proven treatment. Approximately 2.5% of patients need mechanical ventilation while their body fights the infection.1 Once COVID-19 patients reach the point of critical illness where ventilation is necessary, they tend to deteriorate quickly. During the pandemic, patients with other conditions may also present at the hospital needing emergency ventilation. But ventilation of a COVID-19 patient can last for 2–3 weeks. Accordingly, if all ventilators are in use, there will not be time for (...) patients to ‘queue up’ to wait for those who arrived earlier to recover. Those who need a ventilator will die if they do not receive access to one quickly. Many nations now face the prospect that they failed to prepare appropriately for this foreseen risk of pandemic (another issue worthy of legal analysis) and that their populations will need far more ventilators than the health service can supply. For many weeks, the UK has been anticipating a surge of COVID-19 infections that could leave patients queuing in hospitals for ICU care. Luckily, social distancing has ‘flattened the curve’ and this problem might not arise. There is still a degree of risk, however, and other countries will not be so lucky. At some point, during this pandemic or the next, all countries will need to answer hard questions about whether and when scarce ICU resources (such as ventilators, beds and staff) should be either withheld or withdrawn from certain groups of patients solely for the purpose of providing them to others. Attempts to answer these questions can be found in a wide range of ICU triage protocols and ethical guidance documents, many of which embrace the foundational principle of ‘save the most lives’. Unfortunately, this worthwhile goal has generated many suggestions that could violate the law. This article identifies …. (shrink)

The Anderson-Friedman absolute objects program has been a favorite analysis of the substantive general covariance that supposedly characterizes Einstein's General Theory of Relativity (GTR). Absolute objects are the same locally in all models (modulo gauge freedom). Substantive general covariance is the lack of absolute objects. Several counterexamples have been proposed, however, including the Jones-Geroch dust and Torretti constant curvature spaces counterexamples. The Jones-Geroch dust case, ostensibly a false positive, is resolved by noting that holes in the dust in some models (...) ensure that no physically relevant nonvanishing timelike vector field exists there, so no absolute object exists. The Torretti constant curvature spaces case, allegedly a false negative, is resolved by testing an irreducible piece of the metric, the conformal metric density of weight -2/3, for absoluteness; this geometric object is absolute. A new counterexample is proposed involving the orthonormal tetrad said to be necessary to couple spinors to a curved metric. The threat of finding an absolute object in GTR + spinors is overcome by the use of an alternative spinor formalism that takes a symmetric square root of the metric (with the help of the matrix diag(-1,1,1,1)), eliminating 6 of the 16 tetrad components as irrelevant. The importance of eliminating irrelevant structures, as Anderson emphasized, is clear. The importance of the choice of physical fields is also evident. A new counterexample due to Robert Geroch and Domenico Giulini, however, finds an absolute object in vacuum GTR itself, namely the scalar density $g$ given by the metric components' determinant. Thus either the definition of absoluteness or its use to analyze GTR's substantive general covariance is flawed. Anderson's belief that all absolute objects are nonvariational (that is, not varied in a suitable action principle) and vice versa is also falsified by the Geroch-Giulini counterexample. However, it remains plausible that all nonvariational fields are absolute, so adding nonvariationality as a necessary condition for absoluteness, as Hiskes once suggested, would likely leave no useful work to the Anderson-Friedman condition of sameness in all models. Simply having only variational fields in an action principle (suitably free of irrelevant fields) might be a satisfactory analysis of substantive general covariance, if one exists. This proposal also resembles the suggestion that GTR is "already parameterized," if one decides to parameterize theories by defining the nonvariational fields in terms of preferred coordinates called clock fields. More questions need to be addressed. Which fields should be tested for absoluteness: only primitive fields (which ones?), or all or some (which?) of their concomitants also? Geroch observes that some kinds of geometric objects, such as tangent vectors, scalar densities, and tangent vector densities of non-unit weight, satisfy the condition of sameness in all models if they merely fail to vanish. If these "susceptible" geometric objects can hardly help being absolute, to what degree are they, or the theories harboring them, responsible for this absoluteness? The answer to this question helps to determine the significance of the Geroch-Giulini counterexample. (shrink)

We discuss the possibility to build and operate a time machine, a device that produces closed timelike curves. We specify the spacetime structure needed to implement a time machine and assess attempted no-go results against time machines in classical general relativity, semi-classical quantum gravity, quantum field theory on curved spacetime, and in Euclidean quantum gravity. Such no-go theorems for time machines would show that, under physically reasonable conditions, CTCs cannot develop in spacetimes initially free of these pathologies. Our review indicates (...) that an investigation of the prospects of achieving no-go results has not been entirely successful in establishing such generality. At the same time, the pursuit of chronology protection results has proved to be a fruitful way to probe the foundations of classical GTR and the interface between general relativity and quantum field theory. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Good and Bad Ways to Think about Religion and Politics by Robert Benne, and: The Way of Peace: Christian Life in the Face of Discord by James M. Childs Jr.Bruce P. RittenhouseGood and Bad Ways to Think about Religion and Politics Robert Benne Grand Rapids, Mich.: Eerdmans, 2010. 127 pp. $14.00The Way of Peace: Christian Life in the Face of Discord James M. Childs Jr. Minneapolis: Fortress Press, (...) 2008. 149 pp. $19.00A comparison of Robert Benne’s Good and Bad Ways to Think about Religion and Politics and James Childs’s The Way of Peace illustrates the current divisions in political theology in the US Lutheran tradition. Benne’s book is a polemic aimed at the leadership of the mainline Protestant denominations and their mode of engagement with the American political process. In Benne’s account, these denominations draw too direct and exclusive a line between Christian faith and liberal political commitments; conversely, he sees greater agreement between core Christian norms and conservative political concerns. By contrast, Childs’s book provides an exegetical development of Christian norms of peace and peacemaking, followed by direct applications of Christian norms to public issues of economic justice and war that parallel the positions of secular liberals.Benne seeks to explore anew the issue of how Christians should interact with the political process. Unlike H. Richard Niebuhr, who undertook a similar project in Christ and Culture, Benne engages contemporary secular interpretations and critiques of religious engagement in politics. Benne rejects the strict separationist positions of the new atheists such as Richard Dawkins and the fusionist positions he attributes to Paul Tillich and the leadership of the contemporary mainline denominations in favor of a critical engagement model based on the Lutheran two kingdoms doctrine. Benne’s passion is not matched by the strength of his arguments. There is a straw man quality to his characterization of his antagonists. For example, Benne describes Tillich as seeing no difference between the demands of the Christian faith and democratic socialism. But Tillich explicitly recognizes the limitations of democratic [End Page 195] socialism in expressing Christian ideals and makes clear that his preference for this form of government is conditioned on a historical situation in which the alternatives are laissez-faire capitalism, fascism, and communism. Benne displays epistemological hubris when he questions mainstream scientific judgments. For example, he mocks the “alleged global warming consensus” (35) without offering any evidence that he possesses the necessary evidence or expertise to judge that consensus. He adds questionable historical claims, exaggerating Nazi persecution of Christians and minimizing the religious motivation of the European wars following the Reformation.Childs’s treatment of the question of how Christians are to engage in the US political process is even more problematic than Benne’s. His political prescriptions are written as if the problem did not exist, as if there existed a unified Christian polity fully faithful to its ideals that could express those ideals directly in the nation’s public policies. In this, there is a lack of the moral realism that Lutherans traditionally express through the doctrine that Christians are simul justus et peccator (at the same time justified and sinner). It is telling that the only sins that Childs acknowledges in the church are those that correspond to secular liberal norms: “racism, sexism, classism, and other forms of discrimination” (110). Childs’s representations of the church as holy, a community of peacemakers, and a sign of peace are normative not descriptive, effacing the traditional Lutheran distinction between the visible and invisible church. Childs also demonstrates a lack of political realism with respect to the influence of Christians in the American political process. In proposing that public policy be directed by Christian ideals, Childs either presupposes a significant conversion of our pluralistic society or he imagines that those not presently acting in the political process according to Christian moral principles can be persuaded to selflessness without conversion. The former position is not an empirical reality, and the latter contradicts the traditional Lutheran understanding of original sin, which holds that in the absence of faith human beings are curvatus in se, curved in upon themselves.Benne makes a... (shrink)

Philosophy and its descendents in the behavioral sciences have traditionally divided incentives into those that are sought and those that are avoided. Positive incentives are held to be both attractive and memorable because of the direct effects of pleasure. Negative incentives are held to be unattractive but still memorable (the problem of pain) because they force unpleasant emotions on an individual by an unmotivated process, either a hardwired response (unconditioned response) or one substituted by association (conditioned response). Negative incentives are (...) divided into those that are always avoided and those that are avoided only by higher mental processes—archetypically the passions, which are also thought of as hardwired or conditioned. Newer dichotomies within the negative have been proposed, hinging on whether a negative incentive is nevertheless sought (“wanted but not liked”) or on an incentive's being negative only because it is confining (the product of “rule worship”). The newer dichotomies have lacked motivational explanations, and there is reason to question conditioning in the motivational mechanism for the older ones.

Both experimental findings and the examination of common experience indicate that even the most aversive experiences, such as pain and panic, do not prevail in reflex fashion, but because of an urge to attend to them. The well-established hyperbolic curve in which prospective rewards are discounted implies a mechanism for such an urge, as well as for the “lower” incentives in the other dichotomies. The properties of these lower incentives are predicted by particular durations of temporary preferences on a continuum that stretches from fractions of a second to years. (shrink)

In a much-discussed article on fair grading, Daryl Close said that impartial and consistent grading of students forbids practices like grading on a curve and dropping the lowest grade. I show—negatively—that impartiality and consistency don’t forbid these practices. I also show—positively—that some other conditions on fair and reasonable grading do rule out grading on a curve and dropping the lowest grade.

This paper discusses the role of Multi-User Virtual Environments (MUVEs) in the development of epistemic learner identity. MUVEs might help educators create the types of tasks and intellectual open spaces helping students with learner identity development in the information age. MUVEs can create new possibilities for dissemination and sharing of critical information (e.g. nonhierarchical, non-linear), opening up spaces of (safe) rebellion against top-down, teacher directed educational processes, helping students become more autonomous thinkers, ready to question information, and search for multiple (...) sources in problem-solving. The experiment reported here follow two General Education classes for pre-service teachers (58 students) that integrated the MUVE Second Life as a major part of their curriculum. The experimental MUVE condition was compared to two classes (59 students) using the same curricula approach and the same instructor but without using a MUVE. Individual student blog posts (weekly assignments) were extracted for both groups (experimental, active control) from three different time points over the semester. The posts were coded for levels of complexity/uncertainty, critical perspective and source of information. It was expected that students in the experimental (MUVE integrated) group would show increases over the semester as compared to the active control group. Growth curve analyses suggests students in the experimental (MUVE-integrated) condition did indeed increase in modes of thinking that question authority through increased complexity/uncertainty and critical thinking in their assigned academic/intellectual tasks, suggesting possibilities for epistemological shifts. (shrink)

This study aims at identifying the tools necessary for COVID-19 health emergency management, with particular reference to the period following the first lockdown, a crucial phase in which it was important to favor the maintenance of protective behaviors. It also aims at identifying the messages and sources that were most effective in managing communication correctly in such a crucial phase that is likely characterized by a fall in perceived health risk (due to the flattening of the epidemic curve) and (...) a simultaneous rise in perceived economic and social risks (due to the enduring calamity). Knowing what source will be most effective to convey a specific message is fundamental in enabling individuals to focus on and comply with the rules. At the same time, it is necessary to understand how the message should be presented, and the relationships between messages, sources and targets. To meet these goals, data were collected through a self-administered online questionnaire submitted to a sample of undergraduate students from a University in Lombardy–the region most affected by the pandemic in the first wave- (Study 1), and to a national sample composed of Italian citizens (Study 2). Through our first manipulation which explored the effectiveness of social norms in relation to different sources, we found that, in the national sample, the injunctive norm conveyed by the government was the most effective in promoting behavioral intentions. By contrast, among the students, results showed that for the critical group with a lower risk perception (less inclined to adopt prevention behavior) descriptive norms, which implicitly convey the risk perception of peers, were as effective as the government injunctive norm. Our second manipulation, identical in Study 1 and 2, compared four types of communication (emotional, exponential growth, both of them, or neutral). The neutral condition was the most memorable, but no condition was more effective than the others. Across all message types there was a high intention to adopt protective behaviors. The results indicate possible applicative implications of the adopted communicative tools. (shrink)

The Schaechter–Maaløe–Kjeldgaard papers, which have their 50th anniversary this year, have major implications for understanding the cell cycle, control of cell growth, control of cell size, metabolic control, the basic bacterial growth curve, and myriad other bacterial and eukaryotic growth phenomena. These ideas have broad applications that should be considered in current studies of the cell cycle. In particular, the emphasis on steady‐state growth conditions, and clear and sharp changes in growth conditions were fundamental to their experiments and have (...) been codified in the principles of the Copenhagen School of Microbiology. BioEssays 30:1019–1024, 2008. © 2008 Wiley Periodicals, Inc. (shrink)

While issues of efficacy and specificity are crucial for the future of neurofeedback training, there may be alternative designs and control analyses to circumvent the methodological and ethical problems associated with double-blind placebo studies. Surprisingly, most NF studies do not report the most immediate result of their NF training, i.e. whether or not children with ADHD gain control over their brain activity during the training sessions. For the investigation of specificity, however, it seems essential to analyze the learning and adaptation (...) processes that take place in the course of the training and to relate improvements in self-regulated brain activity across training sessions to behavioral, neuropsychological and electrophysiological outcomes. To this aim, a review of studies on neurofeedback training with ADHD patients, which include the analysis of learning across training sessions or relate training performance to outcome, is presented. Methods on how to evaluate and quantify learning of EEG regulation over time are discussed. “Non-learning” has been reported in a small number of ADHD-studies, but has not been a focus of general methodological discussion so far. For this reason, selected results from the brain-computer interface (BCI) research on the so-called “brain-computer illiteracy”, the inability to gain control over one’s brain activity, are also included. It is concluded that in the discussion on specificity, more attention should be devoted to the analysis of EEG regulation performance in the course of the training and its impact on clinical outcome. It is necessary to improve the knowledge on characteristic cross-session and within-session learning trajectories in ADHD and to provide the best conditions for learning. (shrink)

In order to study drag reduction mechanism in mud parts’ operation of surface machine tools for paddy field, this paper takes floating plate, the main working part of laminating mechanism, as the research object and systematically analyzes the mechanism of action of elevation angle, curved angle, penetrating angle, and local microstructure of floating plate on working resistance and local fluid flow characteristics of the laminating structure based on VOF model in Fluent. Using ship mechanics theory and fluid lubrication theory, the (...) drag reduction mechanism under different structural parameters of the floating plate is analyzed. The results show that, compared with the ordinary floating plate, the pressure difference resistance can be reduced by increasing the elevation angle by 60°, curved angle by 20°, and mud separation angle by 20°. The increase of the concave nonsmooth bottom surface structure can reduce viscous frictional resistance, and the total working resistance after structural optimization is comparatively reduced by 48.3%, with lowered hilling height in the forward direction and improved lubrication condition of the bottom surface, forming liquid lubrication effect. This study can provide theoretical references for the optimization design of muddy soil mud parts, mud-machine interaction research, and the development of paddy field laminating mechanism. (shrink)

In this paper, we give a thorough account of Brianchon and Poncelet’s joint memoir on equilateral hyperbolas subject to four given conditions, focusing on the most significant theorems expounded therein, and the determination of the “nine-point circle”. We also discuss about the origin of this very rare example of collaborative work for the time, and the general challenge of finding the nature of the loci described by the centres of the conic sections required to pass through m points and to (...) be tangent to n straight lines given in position, m + n = 4, which was posed at the end of their work. In the case m = 4, i.e. when the conic sections have to pass through the vertices of a quadrilateral, the locus of centres is another conic section passing through the intersection points of the opposite sides and the two diagonals of the quadrilateral, respectively, and, as Gergonne showed analytically shortly after, through other significant points connected with the quadrilateral; this curve was later given the name of the “nine-point conic”, being a natural generalization of the above mentioned circle. (shrink)

Currently, the coronavirus disease 2019 pandemic experienced by the international community has increased the usage frequency of borderless, highly personalized social media platforms of all age groups. Analyzing and modeling texts sent through social media online can reveal the characteristics of the psychological dynamic state and living conditions of social media users during the pandemic more extensively and comprehensively. This study selects the Sina Weibo platform, which is highly popular in China and analyzes the subjective well-being of Weibo users during (...) the COVID-19 pandemic in combination with the machine learning classification algorithm. The study first invokes the SWB classification model to classify the SWB level of original texts released by 1,322 Weibo active users during the COVID-19 pandemic and then combines the latent growth curve model and the latent growth mixture model to investigate the developmental trend and heterogeneity characteristics of the SWB of Weibo users after the COVID-19 outbreak. The results present a downward trend and then an upward trend of the SWB of Weibo users during the pandemic as a whole. There was a significant correlation between the initial state and the development rate of the SWB after the COVID-19 outbreak. LGMM results show that there were two heterogeneous classes of the SWB after the COVID-19 outbreak, and the development rate of the SWB of the two classes was significantly different. The larger class showed a slow growth, while the smaller class showed a rapid growth. Furthermore, the slope means across the two classes were significantly different. Therefore, the individuals with a higher growth rate of SWB exhibited stronger adaptability to the changes in their living environments. These results could help to formulate effective interventions on the mental health level of the public after the public health emergency outbreak. (shrink)

There is no question that nowadays the phenomenon of prices is central to the media and political agenda and is the object of heated debates in the Argentine public arena. However, it is striking that these discussions forget to mention the social conditions in which market actors significantly set and shape prices. Debates focus on price increase and the spontaneous movements of the supply and demand curves supported by the neoclassical economic perspective, while the market agents that specifically cause such (...) increase fade into the background and the subjective aspects of the phenomenon of price formation are underestimated as a mere manifestation of states of mind or individual preferences. This article argues that it is possible to criticize the neoclassical paradigm presuppositions based on the work of Alfred Schutz. His phenomenologically oriented sociology takes a critical stand facing the approaches that only consider the movements of the supply and demand curves in price formation, and that put aside the subjective values of the actors in the market. It is held that in line with the sociology of valuation, Schutz’s perspective resumes the inquiry around the intersubjective structures of meaning showing the importance of his thought to help us think about present-day problems. (shrink)

Different types of tasks exist, including tasks for research purposes or exams assessing knowledge. According to expectation-value theory, tests are related to different levels of effort and importance within a test taker. Test-taking effort and importance in students decreased over the course of high-stakes tests or low-stakes-tests in research on test-taking motivation. However, whether test-order changes affect effort, importance, and response processes of education students have seldomly been experimentally examined. We aimed to examine changes in effort and importance resulting from (...) variations in test battery order and their relations to response processes. We employed an experimental design assessing N = 320 education students’ test-taking effort and importance three times as well as their performance on cognitive ability tasks and a mock exam. Further relevant covariates were assessed once such as expectancies, test anxiety, and concentration. We randomly varied the order of the cognitive ability test and mock exam. The assumption of intraindividual changes in education students’ effort and importance over the course of test taking was tested by one latent growth curve that separated data for each condition. In contrast to previous studies, responses and test response times were included in diffusion models for examining education students’ response processes within the test-taking context. The results indicated intraindividual changes in education students’ effort or importance depending on test order but similar mock-exam response processes. In particular effort did not decrease, when the cognitive ability test came first and the mock exam subsequently but significantly decreased, when the mock exam came first and the cognitive ability test subsequently. Diffusion modeling suggested differences in response processes on cognitive ability tasks suggesting higher motivational levels when the cognitive ability test came first than vice versa. The response processes on the mock exam tasks did not relate to condition. (shrink)

Increasing student involvement in classes has always been a challenge for teachers and school managers. In online learning, some interactivity mechanisms like quizzes are increasingly used to engage students during classes and tasks. However, there is a high demand for tools that evaluate the efficiency of these mechanisms. In order to distinguish between high and low levels of engagement in tasks, it is possible to monitor brain activity through functional near-infrared spectroscopy. The main advantages of this technique are portability, low (...) cost, and a comfortable way for students to concentrate and perform their tasks. This setup provides more natural conditions for the experiments if compared to the other acquisition tools. In this study, we investigated levels of task involvement through the identification of correct and wrong answers of typical quizzes used in virtual environments. We collected data from the prefrontal cortex region of 18 students while watching a video lecture. This data was modeled with supervised learning algorithms. We used random forests and penalized logistic regression to classify correct answers as a function of oxyhemoglobin and deoxyhemoglobin concentration. These models identify which regions best predict student performance. The random forest and penalized logistic regression obtained, respectively, 0.67 and 0.65 area of the ROC curve. Both models indicate that channels F4-F6 and AF3-AFz are the most relevant for the prediction. The statistical significance of these models was confirmed through cross-validation and a permutation test. This methodology can be useful to better understand the teaching and learning processes in a video lecture and also provide improvements in the methodologies used in order to better adapt the presentation content. (shrink)

All physical theories, from classical Newtonian mechanics to relativistic quantum field theory, entail propositions concerning the geometric structure of spacetime. To give an example, the general theory of relativity entails that spacetime is curved, smooth, and four-dimensional. In this dissertation, I take the structural commitments of our theories seriously and ask: how is such structure instantiated in the physical world? Mathematically, a property like 'being curved' is perfectly well-defined insofar as we know what it means for a mathematical space to (...) be curved. But what could it mean to say that the physical world is curved? Call this the problem of physical geometry. The problem of physical geometry is a plea for foundations--a request for fundamental truth conditions for physical-geometric propositions. My chief claim is that only a substantival theory of spacetime--a theory according to which spacetime is an entity in its own right, existing over and above the material content of the world--can supply the necessary truth conditions. (shrink)

Hydromechanical continuously variable transmission is capable of bearing large torque and has wide transmission range, which is suitable for high-power tractors. Dynamic characteristics could influence the tractor life, especially in a high-power tractor. Wet clutch is the crucial component in the HMCVT, which could smooth and soft power transmission. Therefore, it is important to study the dynamic characteristics and implement the wet clutch test of HMCVT. In this paper, AMESim is used to establish virtual models of gearbox, pump-controlled hydraulic motor (...) system, and shifting hydraulic system. Then, a simulation study of tractor operation under working condition is carried out. The internal and external meshing forces of the planetary row are analyzed. Finally, the wet clutch engagement process of HMCVT in the high-power tractor is tested to verify the oil pressure. The simulation results show that the values of internal and external meshing force become larger as the throttle opening increases. At the moment of shifting change, the meshing forces of the planetary gear have great impact. The clutch test shows that the trend of the oil filling curve obtained from the bench test is similar to that obtained from the theoretical curve, which verifies the simulation results. (shrink)

Hirschi and Gottfredson (1983) claim that the relationship between age and crime is similar in all social and cultural conditions and that no current sociological or criminological theory can account for this similarity. We introduce the new field of evolutionary psychology and extend Daly and Wilson's (1988) work on homicide to construct a general theory of male criminality, which explains why men commit violent and property crimes. The theory can also explain the age-crime curve. It might also account for (...) some empirical anomalies such as why physically smaller boys are more delinquent, and why violent criminals desist more slowly. (shrink)

Must space be a unity? This question, which exercised Aristotle, Descartes and Kant, is a specific instance of a more general one; namely, can the topology of physical space change with time? In this paper we show how the discussion of the unity of space has been altered but survives in contemporary research in theoretical physics. With a pedagogical review of the role played by the Euler characteristic in the mathematics of relativistic spacetimes, we explain how classical general relativity (modulo (...) considerations about energy conditions) allows virtually unrestrained spatial topology change in four dimensions. We also survey the situation in many other dimensions of interest. However, topology change comes with a cost: a famous theorem by Robert Geroch shows that, for many interesting types of such change, transitions of spatial topology imply the existence of closed timelike curves or temporal non-orientability. Ways of living with this theorem and of evading it are discussed. (shrink)

We investigate the evolution of linear density contrasts obtained with respect to a homogeneous spatially flat Friedman-Lemaître–Robertson–Walker background by solving the density contrast equations governed by Newtonian and MONDian force laws using symmetry-based approach. We find eight-parameter Lie group symmetries for the linear order density perturbation equation for the Newtonian case whereas the density contrast equation follows only one parameter Lie group symmetry in MONDian case. We use Lie symmetries to find the group invariant solutions from invariant curve condition. (...) The physical features of the evolution for various mode of density contrast with respect to the global cosmic background density in homogeneous isotropic cosmological models have been investigated using analytical group invariant solutions along with their numerical solutions. An account for cosmological density contrast and mass fluctuation also have been provided. We also have shown that the MONDian force law generates higher amplitudes in the density fluctuation, results in a more rapid structure formation that cannot be possible under the Newtonian force law. (shrink)

This study investigated the relative role of sub-syllabic components in spoken word recognition of Mandarin Chinese using an eye-tracking experiment with a visual world paradigm. Native Mandarin speakers were presented with four pictures and an auditory stimulus. They were required to click the picture according to the sound stimulus they heard, and their eye movements were tracked during this process. For a target word, nine conditions of competitors were constructed in terms of the amount of their phonological overlap with the (...) target: consonant competitor, rime competitor, tone competitor, consonant plus rime competitor, consonant plus tone competitor, rime plus tone competitor, cohort competitor, cohort plus tone competitor, and baseline competitor. A growth curve analysis was conducted with the fixation to competitors, targets, and distractors, and the results showed that competitors with consonant or rime overlap can be adequately activated, while tone overlap plays a weaker role since additional tonal information can strengthen the competitive effect only when it was added to a candidate that already bears much phonological similarity with the target. Mandarin words are processed in an incremental way in the time course of word recognition since different partially overlapping competitors could be activated immediately; like the pattern found in English, both cohort and rime competitors were activated to compete for lexical activation, but these two competitors were not temporally distinctive and mainly differed in the size of their competitive effects. Generally, the gradation of activation based on the phonological similarity between target and candidates found in this study was in line with the continuous mapping models and may reflect a strategy of native speakers shaped by the informative characteristics of the interaction among different sub-syllabic components. (shrink)