Pollinating fig wasps’ simple solutions to complex sex ratio problems: a review

Local mate competition (LMC) favours female biased clutch sex ratios because it reduces competition between brothers and provides extra mating opportunities for sons. Fig wasps seem to fit LMC model assumptions and lay female-biased sex ratios as predicted. These female biased sex ratios increase fitness greatly. In line with predictions, their sex ratios become less female-biased as the number of mothers laying in the same fig increases. However, this variation results in comparatively small fitness benefits compared to just biased ratios and data suggest substantial mismatches with LMC theory. The mismatches are due to several factors. (1) Multiple foundresses typically lay too many daughters. (2) Single foundress sex ratios are explained by sequential oviposition and ladies-last models. (3) Mortality that typically exceeds 10% may decouple the link between primary sex ratios, the focus of model predictions, and secondary sex ratios of adult wasps that are counted by researchers. (4) Model assumptions are frequently violated: (a) clutch sizes are unequal, (b) oviposition may not be simultaneous (c) cryptic/multiple wasp species inhabit the same host, (d) foundress numbers are systematically undercounted, (e) inbreeding coefficient calculations are inaccurate, and (f) male wasps sometimes disperse. These data and calculations suggest that alternative explanations must be considered seriously. Substantial data show that wasps typically lay most of their male eggs first followed by mostly female eggs require a new approach. These “slope” strategies result in more accurate sex ratios that are automatically adjusted to foundress number, own and relative clutch sizes and to sequential clutches. This effect will alter sex ratios in all species once the egg capacity of a fig is crossed or when interference reduces clutch sizes. In addition to this passive response, the females of about half the studied species have a conditional response that reduces female bias under higher foundress numbers by laying more sons. Therefore, wasps seem to use a very simple strategy that increases their fitness. Natural selection could have optimized parameters of the slope strategy and possibly the existence of the slope strategy itself. Variation in the slope strategy that is the result of natural selection is adaptive. Research should therefore focus on quantifying variables of this slope strategy. Currently, it is unclear how much of the variation is adaptive as opposed to being coincidental by-products. Graphical Abstract

Evaluation and Construction of College Students’ Growth and Development Index System Based on Data Association Mining and Deep Learning Model

The rise of big data in the field of education provides an opportunity to solve college students’ growth and development. The establishment of a personalized student management mode based on big data in universities will promote the change of personalized student management from the empirical mode to the scientific mode, from passive response to active warning, from reliance on point data to holistic data, and thus improve the efficiency and quality of personalized student management. In this paper, using the latest ideas and techniques in deep learning such as self-supervised learning and multitask learning, we propose an open-source educational big data pretrained language model F-BERT based on the BERT model architecture. Based on the BERT architecture, F-BERT can effectively and automatically extract knowledge from educational big data and memorize it in the model without modifying the model structure specific to educational big data tasks so that it can be directly applied to various educational big data domain tasks downstream. The experiment demonstrates that Vanilla F-BERT outperformed the two Vanilla BERT-based models, Vanilla BERT and BERT tasks, by 0.0.6 and 0.03 percent, respectively, in terms of accuracy.

Nanocrystalline Composite Smart Coating Deposition for Corrosion Self-Healing of Mild Steel

This work examine the potential of ZrB2 in the presence of Ni-P-Zn sulphate rich bath coating on mild steel under change in time from 10-25 min. The coating pH of 5, current density of 1 A/cm2, and stirring rate of 250 rpm was considered in the fabrication process. The microstructure evolution and properties of the deposited coating was analysed using a scanning electron microscope enhanced with energy dispersive spectroscopy (SEM/EDS). All deposited composite coating was investigated in 0.5 M H2SO4 and 3.5% NaCl with the help of linear polarization and open circuit potential. From the result, a solid crystal formation containing zirconium boride was seen from the SEM study. At 25 min a remarkable dispersed and even thin film was noticeable at the interface. From all indication, coating produced with Ni-P-Zn-10ZrB2 at 25 min provides a passive response against corrosion damage. Keywords: Electrodeposition, interface, nanocrystalline, structure, coating

Biomechanical characterization of the passive response of the thoracic aorta in chronic hypoxic newborn lambs using an evolutionary strategy

The present study involves experiments and modelling aimed at characterizing the passive structural mechanical behavior of the chronic hypoxic lamb thoracic aorta, whose gestation, birth and postnatal period were carried at high altitude (3600 masl). To this end, the mechanical response was studied via tensile and pressurization tests. The tensile and pressurization tests measurements were used simultaneously to calibrate the material parameters of the Gasser–Holzapfel–Ogden (GHO) hyperelasctic anisotropic constitutive model through an analytical-numerical optimization procedure solved with an evolutionary strategy that guarantees a stable response of the model. The model and procedure of calibration adequately adjust to the material behavior in a wide deformation range with an appropriate physical description. The results of this study predict the mechanical response of the lamb thoracic aorta under generalized loading states like those that can occur in physiological conditions and/or in systemic arterial hypertension. Finally, the novel use of the evolutionary strategy, together with the set of experiments and tools used in this study, provide a robust alternative to validate biomechanical characterizations.

Ontological (In)visibility and Cyber Conflict: The Problem of Sight and Vision in Establishing Threat

This paper builds on the work of scholars working on ontological security, cyber security, and computer science to understand the problem of threat assessment and vision before, during, and after cyber-attacks. The previous use of ontological security theory (OST) has been limited because it has relied upon an overly simplistic vision of threat assessment at the international, state, and individual level. While previous scholars have examined the background, latent, or assumed visions of security threats as interpreted by agents and how their conditions do or do not effectively capture the anxieties of populations and practitioners this piece seeks to put these issues in conversation. In conceiving of ‘the state’ and ‘threat’ this piece examines the notion of vision, because as states conceive of threats in terms of terrorism (overt and theatrical) and cyber (covert and private) a mismatch of responses is noted. This piece reads the current cyber security landscape (2009-2019) in the United States through a lens of repeated and rambunctious cyber-threats and attacks and a largely passive response by the US citizenry through OST alongside: (1) the literature on computer science dealing with the concept of ontology, (2) the traditional threat framework found in the terrorism literature around response to threat with a comparison to the cyber-conflict literature, an (3) examination of the interplay between the public and government around the visibility and salience of cyberthreats.

Flexibility Effects of a Flapping Mechanism Inspired by Insect Musculoskeletal System on Flight Performance

Flying animals such as insects display great flight performances with high stability and maneuverability even under unpredictable disturbances in natural and man-made environments. Unlike man-made mechanical systems like a drone, insects can achieve various flapping motions through their flexible musculoskeletal systems. However, it remains poorly understood whether flexibility affects flight performances or not. Here, we conducted an experimental study on the effects of the flexibility associated with the flapping mechanisms on aerodynamic performance with a flexible flapping mechanism (FFM) inspired by the flexible musculoskeletal system of insects. Based on wing kinematic and force measurements, we found an appropriate combination of the flexible components could improve the aerodynamic efficiency by increasing the wingbeat amplitude. Results of the wind tunnel experiments suggested that, through some passive adjustment of the wing kinematics in concert with the flexible mechanism, the disturbance-induced effects could be suppressed. Therefore, the flight stability under the disturbances is improved. While the FFM with the most rigid spring was least efficient in the static experiments, the model was most robust against the wind within the range of the study. Our results, particularly regarding the trade-off between the efficiency and the robustness, point out the importance of the passive response of the flapping mechanisms, which may provide a functional biomimetic design for the flapping micro air vehicles (MAVs) capable of achieving high efficiency and stability.

Encroachment and Reaction of Civil Society in Non-liberal Democracies: The Case of Israel and the New Israel Fund

Recent decades have seen a major political shift in many nations, manifested in democratic regression, rise of populist non-liberal democracies, resurgence of extreme right, infractions against democratic watchdogs, and increasing nationalism and unilateralism. A central manifestation of this process is the active encroachment by governments on civil society, and particularly on its liberal elements. These manifestations allegedly emanate from resistance to the liberal world order and to threats from pressures imported by national NGOs, and are made possible by changing political opportunity structures. We explore the case of Israel, through an analysis of the New Israel Fund (NIF), as a particular yet demonstrative example of these dynamics. The manifestations of civil society encroachment in Israel include concerted and coordinated actions meant to weaken and delegitimize left-wing civil society actors and their supporters and donors, by Israel’s right-wing governments and their NGO allies, through legislation and rhetorical assaults; attempts to curb international funding of human rights organizations; and differential treatment of civil society organizations according to political stance. Interviews with former and current leaders of the NIF show that the attacks have galvanized liberal civil society actors to counteract, and drove them from passive response to active and strategic engagement, professionalization of media work and program evaluation, adjustment of public relations and legal strategies, and even adjustment of programmatic choice, shifting focus to supporting the infrastructure of civil society and democracy. The discussion stresses pressures by international illiberal forces, alongside the backlash to liberal world society, as causes for encroachment, and highlights the less explored reactions of civil society actors to such encroachment.

Communal Authority, Counsel and Resistance in the Reign of James I: A Conceptual Approach

This article examines the relationship between counsel and resistance, as well as the interplay between royal and communal authority, in the kingdom of the Scots during the reign of James I. It does so through an analysis of the language and ideas used in political tracts and literary texts—particularly ‘The Dethe of the Kynge of Scotis’—and also in the records of parliaments and councils. The aim of this article is to suggest that counsel is usefully viewed not simply as a tool which contemporaries might deploy as a passive response to the exercise of royal (or quasi-regal) authority, but as a means by which medieval actors could proactively shape the governance they experienced in late medieval Scotland.

Slow phase-locked endogenous modulations support selective attention to sound

To make sense of complex soundscapes, listeners must select and attend to task-relevant streams while ignoring uninformative sounds. One possible neural mechanism underlying this process is alignment of endogenous oscillations with the temporal structure of the target sound stream. Such a mechanism has been suggested to mediate attentional modulation of neural phase-locking to the rhythms of attended sounds. However, such modulations are compatible with an alternate framework, where attention acts as a filter that enhances exogenously-driven neural auditory responses. Here we attempted to adjudicate between theoretical accounts by playing two tone steams varying across condition in tone duration and presentation rate; participants attended to one stream or listened passively. Attentional modulation of the evoked waveform was roughly sinusoidal and scaled with rate, while the passive response did not. This suggests that auditory attentional selection is carried out via phase-locking of slow endogenous neural rhythms.

Ciona embryonic tail bending is driven by asymmetrical notochord contractility and coordinated by epithelial proliferation

ABSTRACTVentral bending of the embryonic tail within the chorion is an evolutionarily conserved morphogenetic event in both invertebrates and vertebrates. However, the complexity of the anatomical structure of vertebrate embryos makes it difficult to experimentally identify the mechanisms underlying embryonic folding. This study investigated the mechanisms underlying embryonic tail bending in chordates. To further understand the mechanical role of each tissue, we also developed a physical model with experimentally measured parameters to simulate embryonic tail bending. Actomyosin asymmetrically accumulated at the ventral side of the notochord, and cell proliferation of the dorsal tail epidermis was faster than that in the ventral counterpart during embryonic tail bending. Genetic disruption of actomyosin activity and inhibition of cell proliferation dorsally caused abnormal tail bending, indicating that both asymmetrical actomyosin contractility in the notochord and the discrepancy of epidermis cell proliferation are required for tail bending. In addition, asymmetrical notochord contractility was sufficient to drive embryonic tail bending, whereas differential epidermis proliferation was a passive response to mechanical forces. These findings showed that asymmetrical notochord contractility coordinates with differential epidermis proliferation mechanisms to drive embryonic tail bending.This article has an associated ‘The people behind the papers’ interview.