Puzzling Results Research Articles

Origin and Potentialities of the Selective Host‐Matrix Effect in Hydrogenated III‐V‐N Alloys.

AbstractIn a previous study, puzzling experimental results regarding the neutralization of N effects on the bandgap energy in the hydrogenated In0.21Ga0.79As0.975N0.025 alloy were explained by theoretical investigations revealing the occurrence of a novel phenomenon: thermal annealing changes the InGaAs host‐matrix by making it able to exert a selection of the N–H complexes responsible of the N neutralization. In view of technological applications of this effect, the underlying selective host‐matrix model was carefully checked here by theoretically investigating InGaAsN alloys of different compositions ranging from Ga‐rich to In‐rich. As a most important result, such an extensive investigation inspired a comprehensive explanation of the origin of the host‐matrix effect which clarifies how the effect works, firmly establishes its occurrence, gives indications for a bandgap tuning based on a matrix design, sets conditions for its extension to other III‐V‐N alloys and suggests ways to induce fine changes of the alloy mechanical behavior.

Effects of zonal fields on energetic-particle excitations of reversed shear Alfvén eigenmode: Simulation and theory

Abstract Employing both nonlinear gyrokinetic simulation and analytical theory, we have investigated the effects of zonal (electromagnetic) fields on the energetic particle's drive of reversed shear Alfv'en eigenmodes in tokamak plasmas. Contrary to the conventional expectation, simulations with zonal fields turned on and off in the energetic particle dynamics while keeping the full nonlinear dynamics
of the thermal plasma indicate that zonal fields further enhance the instability drive and lead, thus, to a higher saturation level. These puzzling simulation results can be understood analytically in terms of the general fishbone-like dispersion relation with the correspondingly different energetic-particle phase-space structures induced by the zonal fields. Analytical expressions for the zonal fields beat driven by the reversed shear Alfv'en eigenmodes are also derived, and shown to be in good agreement with the simulation results.

Paclitaxel - a Product of Fungal Secondary Metabolism or an Artefact?

Taxol (common name: paclitaxel) is an extremely important component of drugs for the treatment of various cancers. Thirty years after the discovery of its effectiveness, a metabolic precursor of Taxol (10-deacetylbaccatin III) is still primarily extracted from needles of European yew trees. In order to meet the considerable demand, hopes were pinned on the possibilities of biotechnological production from the very beginning. In 1993, as if by chance, Taxol was supposedly discovered in fungi that grow endobiotically in yew trees. This finding aroused hopes of biotechnological use to produce fungal Taxol in large quantities in fermenters. It never came to that. Instead, a confusing flood of publications emerged that claimed to have detected Taxol in more and more eukaryotic and even prokaryotic species. However, researchers never reproduced these rather puzzling results, and they could certainly not be applied on an industrial scale. This paper will show that some of the misguided approaches were apparently based on a seemingly careless handling of sparse evidence and on at least questionable publications. Apparently, the desired gold rush of commercial exploitation was seductive. Scientific skepticism as an indispensable core of good scientific practice was often neglected, and the peer review process has not exerted its corrective effect. Self-critical reflection and more healthy skepticism could help to reduce the risk of such aberrations in drug development. This article uses this case study as a striking example to show what can be learned from the Taxol case in terms of research ethics and the avoidance of questionable research practices.

The finance and growth nexus revisited: a truly Schumpeterian perspective

Abstract The nexus between the financial system and economic development is an issue that is as important for economic theory as it is for economic policy. This article provides a theoretical and empirical analysis of the standard literature that uses Joseph A. Schumpeter as an academic patron. The starting point of our study is the theoretical finding that Schumpeter is misinterpreted in the finance and growth literature. We show that this leads to puzzling empirical results and difficulties in explaining even fundamental relationships. After a critical analysis of the literature, we provide our own empirical analysis using a panel of 43 countries to explore the relationships between finance and growth variables based on a truly Schumpeterian and thus monetary growth model. Our empirical analysis shows that (i) dynamic credit variables are better at describing the finance and growth nexus than static credit variables, (ii) as saving is not a prerequisite for credit, we do not find a statistically significant relationship between household saving and gross domestic product (GDP) growth, and (iii) in line with the empirical literature, we find a bi-directional relationship between credit and GDP growth.

Is bismuth(III) able to inhibit the activity of urease? Puzzling results in the quest for soluble urease complexes for agrochemical and medicinal applications.

Bismuth(III) complexes have been reported to act as inhibitors of the enzyme urease, ubiquitously present in soils and implicated in the pathogenesis of several microorganisms. The general insolubility of Bi(III) complexes in water at neutral pH, however, is an obstacle to their utilization. In our quest to improve the solubility of Bi(III) complexes, we selected a compound reported to inhibit urease, namely [Bi(HEDTA)]·2H2O, and co-crystallized it with (i) racemic DL-histidine to obtain the conglomerate [Bi2(HEDTA)2(μ-D-His)2]·6H2O + [Bi2(HEDTA)2(μ-L-His)2]·6H2O, (ii) enantiopure L-histidine to yield [Bi2(HEDTA)2(μ-L-His)2]·6H2O, and (iii) cytosine to obtain [Bi(HEDTA)]·Cyt·2H2O. All compounds, synthesised by mechanochemical methods and by slurry, were characterized in the solid state by calorimetric (DSC and TGA) and spectroscopic (IR) methods, and their structures were determined using powder X-ray diffraction (PXRD) data. All compounds show an appreciable solubility in water, with values ranging from 6.8 mg mL-1 for the starting compound [Bi(HEDTA)]·2H2O to 36 mg mL-1 for [Bi2(HEDTA)2(μ-L-His)2]·6H2O. The three synthesized compounds as well as [Bi(HEDTA)]·2H2O were then tested for inhibition activity against urease. Surprisingly, no enzymatic inhibition was observed during in vitro assays using Canavalia ensiformis urease and in vivo assays using cultures of Helicobacter pylori, raising questions on the efficacy of Bi(III) compounds to counteract the negative effects of urease activity in the agro-environment and in human health.

Spin model for the honeycomb NiPS3

In the Van der Waals material NiPS3, Ni atoms have spin S = 1 and realize a honeycomb lattice. Six sulfur atoms surround each Ni and split their d manifold into three filled and two unfilled bands. Aimed to determine the spin Hamiltonian of NiPS3, we study its exchange mechanisms using a two-band half-filled Hubbard model. Hopping between d-orbitals is mediated by p orbitals of sulfur and gives rise to bilinear and biquadratic spin couplings in the limit of strong electronic correlations. The microscopic model exposed a ferromagnetic biquadratic spin interaction K1, allowing the completion of a minimal J1−J3−K1 spin Hamiltonian for NiPS3. In bulk, a ferromagnetic first nearest neighbor J1 and a more significant antiferromagnetic third nearest neighbor spin coupling J3 agreed with the literature, while in monolayer, J1 is positive and very small in comparison. Using a variational scheme, we found that a zig–zag antiferromagnetic order is the ground state of bulk samples. The zig–zag pattern is adjacent to commensurate and incommensurate spin spirals, which could hint at the puzzling results reported in NiPS3 monolayers.

Incommensurability Explained in the Terms of Presuppositions. A Comment to Kuhn’s Thesis on Radical Meaning Variance

Kuhn’s radical meaning variance thesis implies that scientists, who work in different paradigms cannot understand each other. This, however, seems incredible. The air of paradox can be dispersed once the role of presuppositions in constituting a paradigm is acknowledged. Presuppositions function in the way of the Wittgensteinian ungrounded hinges and often are only implicitly assumed. In the face of recalcitrant puzzles some presuppositions can be made explicit and revised. The mechanism of possible revisions of presuppositions can be accounted for in terms of Hintikka’s interrogative model of scientific inquiry with some amendments. The model includes three possible reactions to an anomaly: (i) a conservative offer of an auxiliary hypothesis within the current paradigm, (ii) a reinterpretation of puzzling experimental results and non-revolutionary enrichment of the current paradigm with a novel hypothesis, and (iii) a revision of presuppositions that amounts to a full-fledged scientific revolution. The choice depends on the success or failure of more conservative alternatives and the scope of application of the theory under investigation. In the proposed approach, incommensurability does not hinder communication between the proponents of different paradigms. In addition, some other controversial points in Kuhn’s views are explained, like Kuhn’s losses, reproaching conservative attitudes towards anomalies, or the admissibility or inadmissibility of the coexistence of rival paradigms. Last but not least, a link between a paradigm shift and the strive for truth is established.

Troubles and Puzzles: The 2022 General Elections in Papua New Guinea

ABSTRACT This paper focuses on the 2022 general elections in Papua New Guinea, covering both electoral quality and election outcomes. Overall, the 2022 elections were very troubled. In parts of the country, serious violence and electoral fraud were major issues. In other parts of the country, polling was less fraught. However, some problems, such as the roll, were serious almost everywhere. In terms of election outcomes, one outcome – only two women won seats – was predictable. However, the election brought puzzling results too: in particular, incumbents were re-elected at the highest rate ever. And the largest party won a larger share of seats than has been the case in any election since 1982. Neither of the latter two results appear to have been a direct product of electoral fraud. Rather, the party outcome stems from a turn-of-the-millennium rule change. High incumbent re-election rates remain a genuine puzzle.

Why Volume and Dynamics Decouple in Nanocomposite Matrices: Space that Cannot Be Accessed is Not Free.

Polymer nanocomposites have important material applications and are an ongoing focus of many molecular level investigations, however, puzzling experimental results exist. For example, specific volumes for some polymer nanocomposite matrices are 2% to 4% higher than for the neat polymer; in a pure polymer melt this would correspond to a pressure change of 40 to 100MPa, and a decrease in isothermal segmental relaxation times of 3 to 5 orders of magnitude. However, the nanocomposite segmental dynamics do not show any speed up. We can explain this apparent uncoupling of dynamics from specific volume, and the key is to consider the system expansivity, i.e., the temperature dependence of the volumetric data, together with the concept of limiting volume at close liquid packing. Using pressure, volume, temperature data as a path to both, we are able to predict the effect of nanoadditives on the accessible, i.e., free, space in the material, which is critical for facilitating molecular rearrangements in dense systems. Our analysis explains why an increase in specific volume in a material may not always lead to faster segmental dynamics.

Two sorts of biological kind terms: The cases of ‘rice’ and ‘Rio de Janeiro Myrtle’

AbstractExperiments have led some philosophers to conclude that the reference determination of natural kind terms is neither simply descriptive nor simply causal‐historical. Various theories have been aired to account for this, including ambiguity, hybrid, and different‐idiolects theories. Devitt and Porter (2021) hypothesized that some terms are covered by one theory, some another, with a place for all the proposed theories. The present paper tests hypotheses that the term ‘Rio de Janeiro Myrtle’ is simply causal‐historical but the term ‘rice’ is hybrid. For, whereas the former term is of scientific but little practical interest, the latter is not: rice is a significant part of the human diet. So, we predicted there would be two factors to the reference determination of ‘rice’: a superficial‐descriptive one and a deep‐causal one. Our experiments confirmed these hypotheses using the methods of elicited production and truth value judgments. We take our results to support the hybrid Theory of ‘rice’ rather than the ambiguity or different‐idiolects theory. We were not testing ‘myrtle’ but, surprisingly, our results implied that ‘myrtle’ was partly descriptive and so like ‘rice’ but not ‘Rio de Janeiro Myrtle’. A follow‐up experiment confirmed these puzzling results. More investigation is needed.

A note on the admissibility of complex BTZ metrics

We perform a nontrivial check of Witten’s recently proposed admissibility criterion for complex metrics. We consider the ‘quasi-Euclidean’ metrics obtained from continuing the BTZ class of metrics to imaginary time. Of special interest are the overspinning metrics, which are smooth in this three-dimensional context. Their inclusion as saddle points in the gravitational path integral would lead to puzzling results in conflict with those obtained using other methods. It is therefore encouraging that the admissibility criterion discards them. For completeness, we perform an analysis of smoothness and admissibility for the family of quasi-Euclidean BTZ metrics at all values of the mass and angular momentum.

Revisiting the New Keynesian policy paradoxes under QE

Standard New Keynesian models deliver puzzling results at the effective lower bound of short-term interest rates: greater price flexibility amplifies the fall in the output gap in response to adverse demand shocks; labour tax cuts are contractionary; the multiplier of wasteful government spending is large. These outcomes stem from a failure to characterise monetary policy correctly. Both analytically and numerically, we show that allowing the central bank to respond to inflation with quantitative easing can resolve all these paradoxes. In quantitative terms, mild adjustments to the central bank’s balance sheet are sufficient to obtain results more in line with conventional wisdom.

An Alternative Explanation for the “Fed Information Effect”

Regressions of private-sector macroeconomic forecast revisions on monetary policy surprises often produce coefficients with signs opposite to standard macroeconomic models. The “Fed information effect” argues these puzzling results are due to monetary policy surprises revealing Fed private information. We show they are also consistent with a “Fed response to news” channel, where both the Fed and professional forecasters respond to incoming economic news. We present new evidence challenging the Fed information effect and supporting the Fed response to news channel, including: regressions that control for economic news, our own survey of professional forecasters, and financial market responses to FOMC announcements. (JEL D82, E23, E27, E43, E44, E52, E58)

Monetary policy transmission in Sri Lanka

ABSTRACT Sri Lanka’s monetary policy has evolved differently during and after a three-decade-long ethnic conflict. This paper empirically investigates effects of monetary policy shocks on Sri Lankan economy with particular focus on the strength of credit and exchange rate channels using a VAR model for 2003–2019 period. We find that: (i) monetary policy shocks have a significant and persistent impact on key macroeconomic variables even though several puzzling results emerge; (ii) the effects of monetary policy shocks are significant and more persistent in the post-conflict period than in the conflict period; (iii) a tight monetary policy effectively contains inflation in the post-conflict period; and (iv) interest rate and exchange rate channels play a dominant role while the credit channel responds with some lags in the post-conflict period.

Learning from Our Study Organisms about Sexual Selection: Lessons from the Ocellated Wrasse.

AbstractSexual selection is a powerful force shaping not only the details but also the breadth of what we see in nature. Yet so much unexplained variation remains. Organisms often solve the "problem" of how to pass on their genes in ways that do not fit our current expectations. I argue here that integrating empirical surprises will push our understanding of sexual selection forward. Such "nonmodel" organisms (i.e., species that do not do what we think they should do) challenge us to think deeply, integrate puzzling results, question our assumptions, and consider the new (and arguably better) questions these unexpected patterns pose. In this article, I share how puzzling observations from my long-term research on the ocellated wrasse (Symphodus ocellatus) have shaped my understanding of sexual selection and suggested new questions about the interplay among sexual selection, plasticity, and social interactions. My general premise, however, is not that others should study these questions. Instead, I argue for a change in the culture of our field-to consider unexpected results a welcome opportunity to generate new questions and learn new things about sexual selection. Those of us in positions of power (e.g., as editors, reviewers, and authors) need to lead the way.

Determinants of frequency of wine consumption in Croatia

Purpose: In the last 10 years, wine consumption in Croatia has increased and consumer habits and expectations have changed. Understanding consumer behavior in relation to wine consumption is important for wine-producing countries where wine is an important component of economy. The aim of this study is to identify the factors that influence the frequency of wine consumption in Croatia, where wine production is an important agricultural activity in terms of the number of people employed in the sector and an important factor in the development of tourism.Methodology: Empirical research was conducted by means of a questionnaire filled out by 169 wine consumers who visited a wine fair in the Croatian Adriatic region. Based on the collected data, we developed and estimated a multinomial logit model. Results: The results indicate that wine is consumed more frequently by men, married people, people in long-term relationships, and older people. In addition, people with high levels of education tend to drink wine less frequently. The paper explains the reasons for somewhat puzzling results and suggests future avenues of research.Conclusion: Behavioral differences were confirmed in this study between subsample groups in accordance with four demographic characteristics, i.e., gender, age, marital status, and education criteria. Our analysis showed that males are more likely to consume wine than women, older than younger and less educated than more educated participants. Our results help wine marketers to segment and target wine consumers.

The Intelligence of Spiritual Intelligence: Making the Case

Spiritual Intelligence (SI) is the ability to draw on and embody spiritual qualities and resources to enhance daily functioning and wellbeing. Despite Gardner’s rejection of SI, the proliferation of SI models and research supporting the advantages of SI across a wide field of endeavors, and correlation with neurological structures and genetic indicators strongly support its validity as an intelligence. This article reviewed key models of SI, and studies supporting its adaptability and biological correlates. Puzzling results in some areas warrant exploration, especially the degree to which various models converge and the extent to which a single SI model may be truly universal.

Self-Supervised Language Learning From Raw Audio: Lessons From the Zero Resource Speech Challenge

Recent progress in self-supervised or unsupervised machine learning has opened the possibility of building a full speech processing system from raw audio without using any textual representations or expert labels such as phonemes, dictionaries or parse trees. The contribution of the Zero Resource Speech Challenge series since 2015 has been to break down this long-term objective into four well-defined tasks -- Acoustic Unit Discovery, Spoken Term Discovery, Discrete Resynthesis, and Spoken Language Modeling -- and introduce associated metrics and benchmarks enabling model comparison and cumulative progress. We present an overview of the six editions of this challenge series since 2015, discuss the lessons learned, and outline the areas which need more work or give puzzling results.

Microparticle Brownian motion near an air-water interface governed by direction-dependent boundary conditions

HypothesisAlthough the dynamics of colloids in the vicinity of a solid interface has been widely characterized in the past, experimental studies of Brownian diffusion close to an air–water interface are rare and limited to particle-interface gap distances larger than the particle size. At the still unexplored lower distances, the dynamics is expected to be extremely sensitive to boundary conditions at the air–water interface. There, ad hoc experiments would provide a quantitative validation of predictions. ExperimentsUsing a specially designed dual wave interferometric setup, the 3D dynamics of 9 μm diameter particles at a few hundreds of nanometers from an air–water interface is here measured in thermal equilibrium. FindingsIntriguingly, while the measured dynamics parallel to the interface approaches expected predictions for slip boundary conditions, the Brownian motion normal to the interface is very close to the predictions for no-slip boundary conditions. These puzzling results are rationalized considering current models of incompressible interfacial flow and deepened developing an ad hoc model which considers the contribution of tiny concentrations of surface active particles at the interface. We argue that such condition governs the particle dynamics in a large spectrum of systems ranging from biofilm formation to flotation process.

A Delayed-Choice Quantum Eraser with Photon-Counting MKIDs (Experimental Design)

An extension to the delayed-choice quantum eraser (DCQE) photonic experiment is described in this paper. It is proposed to employ an array of superconducting detectors on the measurement plane, and use their high sensitivity, low-noise, and fast response time to provide significantly better control of the system in a real-time, photon-counting format. We present an experimental design that would allow a pulse-triggered feedback loop to be added to be system, in an attempt to test an apparent information paradox. We show how new light might be shed on the interpretations and conclusions made from the somewhat puzzling results of the DCQE. While we focus on using an array of microwave kinetic induction detectors for this experiment, other, potentially better-suited superconducting devices are also considered.