Online dynamical learning and sequence memory with neuromorphic nanowire networks

Nanowire Networks (NWNs) belong to an emerging class of neuromorphic systems that exploit the unique physical properties of nanostructured materials. In addition to their neural network-like physical structure, NWNs also exhibit resistive memory switching in response to electrical inputs due to synapse-like changes in conductance at nanowire-nanowire cross-point junctions. Previous studies have demonstrated how the neuromorphic dynamics generated by NWNs can be harnessed for temporal learning tasks. This study extends these findings further by demonstrating online learning from spatiotemporal dynamical features using image classification and sequence memory recall tasks implemented on an NWN device. Applied to the MNIST handwritten digit classification task, online dynamical learning with the NWN device achieves an overall accuracy of 93.4%. Additionally, we find a correlation between the classification accuracy of individual digit classes and mutual information. The sequence memory task reveals how memory patterns embedded in the dynamical features enable online learning and recall of a spatiotemporal sequence pattern. Overall, these results provide proof-of-concept of online learning from spatiotemporal dynamics using NWNs and further elucidate how memory can enhance learning.

A herbaceous species provides insights into drought-driven plant adaptation

This article comments on: Thonglim A, Bortolami G, Delzon S, Larter M, Offringa R, Keurentjes JJB, Smets E, Balazadeh S, Lens F. 2023. Drought response in Arabidopsis displays synergistic coordination between stems and leaves. Journal of Experimental Botany 74, 1004–1021

A framework to quantify flow through coral reefs of varying coral cover and morphology

Flow velocities within coral reefs are greatly reduced relative to those at the water surface. The in-reef flow controls key processes that flush heat, cycle nutrients and transport sediment from the reef to adjacent beaches, all key considerations in assessments of reef resilience and restoration interventions. An analytical framework is proposed and tested with a suite of high-resolution numerical experiments. We demonstrate a single parameter that describes the total coral frontal area explains variation of horizontally averaged velocity within a reef canopy across morphologies, densities, and flow depths. With the integration of existing data of coral cover and geometry, this framework is a practical step towards the prediction of near-bed flows in diverse reef environments.

Hearing Parents' Voices: Parental Refusal of Cochlear Implants and the Zone of Parental Discretion

It has been forty years since the first multi-channel cochlear implant was used in Australia. While heralded in the hearing world as one of the greatest inventions in modern medicine, not everyone reflects on this achievement with enthusiasm. For many people in the Deaf community, they see the cochlear implant as a tool that reinforces a social construct that pathologizes deafness and removes Deaf identity. In this paper, I set out the main arguments for and against cochlear implantation. While I conclude that, on balance, cochlear implants improve the well-being and broaden the open futures of deaf children, this does not justify mandating implants in circumstances where parents refuse them because this may compound unintended harms when society interferes in the parent-child relationship. For this reason, I argue that parental refusal of cochlear implantation falls within Gillam's concept of the zone of parental discretion.

Be Happy: Navigating Normative Issues in Behavioral and Well-Being Public Policy

Psychological science is increasingly influencing public policy. Behavioral public policy (BPP) was a milestone in this regard because it influenced many areas of policy in a general way. Well-being public policy (WPP) is emerging as a second domain of psychological science with general applicability. However, advocacy for WPP is criticized on ethical and political grounds. These criticisms are reminiscent of those directed at BPP over the past decade. This déjà vu suggests the need for interdisciplinary work that establishes normative principles for applying psychological science in public policy. We try to distill such principles for WPP from the normative debates over BPP. We argue that the uptake of BPP by governments was a function of its relatively strong normative and epistemic foundations in libertarian paternalism, or nudging, for short. We explain why the nudge framework is inappropriate for WPP. We then analyze how boosts offer a strict but feasible alternative framework for substantiating the legitimacy of well-being and behavioral policies. We illuminate how some WPPs could be fruitfully promoted as boosts and how they might fall short of the associated criteria.

A return-on-investment approach for prioritization of rigorous taxonomic research needed to inform responses to the biodiversity crisis

Global biodiversity loss is a profound consequence of human activity. Disturbingly, biodiversity loss is greater than realized because of the unknown number of undocumented species. Conservation fundamentally relies on taxonomic recognition of species, but only a fraction of biodiversity is described. Here, we provide a new quantitative approach for prioritizing rigorous taxonomic research for conservation. We implement this approach in a highly diverse vertebrate group-Australian lizards and snakes. Of 870 species assessed, we identified 282 (32.4%) with taxonomic uncertainty, of which 17.6% likely comprise undescribed species of conservation concern. We identify 24 species in need of immediate taxonomic attention to facilitate conservation. Using a broadly applicable return-on-investment framework, we demonstrate the importance of prioritizing the fundamental work of identifying species before they are lost.

Spoonful of honey or a gallon of vinegar? A conditional COVID-19 vaccination policy for front-line healthcare workers

Seven COVID-19 vaccines are now being distributed and administered around the world (figure correct at the time of submission), with more on the horizon. It is widely accepted that healthcare workers should have high priority. However, questions have been raised about what we ought to do if members of priority groups refuse vaccination. Using the case of influenza vaccination as a comparison, we know that coercive approaches to vaccination uptake effectively increase vaccination rates among healthcare workers and reduce patient morbidity if properly implemented. Using the principle of least restrictive alternative, we have developed an intervention ladder for COVID-19 vaccination policies among healthcare workers. We argue that healthcare workers refusing vaccination without a medical reason should be temporarily redeployed and, if their refusal persists after the redeployment period, eventually suspended, in order to reduce the risk to their colleagues and patients. This 'conditional' policy is a compromise between entirely voluntary or entirely mandatory policies for healthcare workers, and is consistent with healthcare workers' established professional, legal and ethical obligations to their patients and to society at large.

Early public adherence with and support for stay-at-home COVID-19 mitigation strategies despite adverse life impact: a transnational cross-sectional survey study in the United States and Australia

BACKGROUND

Governments worldwide recommended unprecedented measures to contain the coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As pressure mounted to scale back measures, understanding public priorities was critical. We assessed initial public adherence with and support for stay-at-home orders in nations and cities with different SARS-CoV-2 infection and COVID-19 death rates.

METHODS

Cross-sectional surveys were administered to representative samples of adults aged ≥18 years from regions with different SARS-CoV-2 prevalences from April 2-8, 2020. Regions included two nations [the United States (US-high prevalence) and Australia (AU-low prevalence)] and two US cities [New York City (NY-high prevalence) and Los Angeles (LA-low prevalence)]. Regional SARS-CoV-2 and COVID-19 prevalence (cumulative SARS-CoV-2 infections, COVID-19 deaths) as of April 8, 2020: US (363,321, 10,845), AU (5956, 45), NY (81,803, 4571), LA (7530, 198). Of 8718 eligible potential respondents, 5573 (response rate, 63.9%) completed surveys. Median age was 47 years (range, 18-89); 3039 (54.5%) were female.

RESULTS

Of 5573 total respondents, 4560 (81.8%) reported adherence with recommended quarantine or stay-at-home policies (range of samples, 75.5-88.2%). Additionally, 29.1% of respondents screened positive for anxiety or depression symptoms (range of samples, 28.6-32.0%), with higher prevalences among those of younger age, female gender, and those in quarantine or staying at home most of the time versus those who did not report these behaviours. Despite elevated prevalences of adverse mental health symptoms and significant life disruptions, 5022 respondents (90.1%) supported government-imposed stay-at-home orders (range of samples, 88.9-93.1%). Of these, 90.8% believed orders should last at least three more weeks or until public health or government officials recommended, with support spanning the political spectrum.

CONCLUSIONS

Public adherence with COVID-19 mitigation policies was highly prevalent, in both highly-affected (US, NY) and minimally-affected regions (AU, LA). Despite disruption of respondents' lives, the vast majority supported continuation of extended stay-at-home orders. Despite common support, these two countries diverged in stringent mitigation implementation, which may have contributed to subsequent outcomes. These results reveal the importance of surveillance of public support for and adherence with such policies during the COVID-19 pandemic and for future infectious disease outbreaks.

Deep profiling of apoptotic pathways with mass cytometry identifies a synergistic drug combination for killing myeloma cells

Multiple myeloma is an incurable and fatal cancer of immunoglobulin-secreting plasma cells. Most conventional therapies aim to induce apoptosis in myeloma cells but resistance to these drugs often arises and drives relapse. In this study, we sought to identify the best adjunct targets to kill myeloma cells resistant to conventional therapies using deep profiling by mass cytometry (CyTOF). We validated probes to simultaneously detect 26 regulators of cell death, mitosis, cell signaling, and cancer-related pathways at the single-cell level following treatment of myeloma cells with dexamethasone or bortezomib. Time-resolved visualization algorithms and machine learning random forest models (RFMs) delineated putative cell death trajectories and a hierarchy of parameters that specified myeloma cell survival versus apoptosis following treatment. Among these parameters, increased amounts of phosphorylated cAMP response element-binding protein (CREB) and the pro-survival protein, MCL-1, were defining features of cells surviving drug treatment. Importantly, the RFM prediction that the combination of an MCL-1 inhibitor with dexamethasone would elicit potent, synergistic killing of myeloma cells was validated in other cell lines, in vivo preclinical models and primary myeloma samples from patients. Furthermore, CyTOF analysis of patient bone marrow cells clearly identified myeloma cells and their key cell survival features. This study demonstrates the utility of CyTOF profiling at the single-cell level to identify clinically relevant drug combinations and tracking of patient responses for future clinical trials.

Metamorphic records of multiple seismic cycles during subduction

Large earthquakes occur in rocks undergoing high-pressure/low-temperature metamorphism during subduction. Rhythmic major-element zoning in garnet is a common product of such metamorphism, and one that must record a fundamental subduction process. We argue that rhythmic major-element zoning in subduction zone garnets from the Franciscan Complex, California, developed in response to growth-dissolution cycles driven by pressure pulses. Using electron probe microanalysis and novel techniques in Raman and synchrotron Fourier transform infrared microspectroscopy, we demonstrate that at least four such pressure pulses, of magnitude 100-350 MPa, occurred over less than 300,000 years. These pressure magnitude and time scale constraints are most consistent with the garnet zoning having resulted from periodic overpressure development-dissipation cycles, related to pore-fluid pressure fluctuations linked to earthquake cycles. This study demonstrates that some metamorphic reactions can track individual earthquake cycles and thereby opens new avenues to the study of seismicity.

Abundance and local-scale processes contribute to multi-phyla gradients in global marine diversity

Among the most enduring ecological challenges is an integrated theory explaining the latitudinal biodiversity gradient, including discrepancies observed at different spatial scales. Analysis of Reef Life Survey data for 4127 marine species at 2406 coral and rocky sites worldwide confirms that the total ecoregion richness peaks in low latitudes, near +15°N and -15°S. However, although richness at survey sites is maximal near the equator for vertebrates, it peaks at high latitudes for large mobile invertebrates. Site richness for different groups is dependent on abundance, which is in turn correlated with temperature for fishes and nutrients for macroinvertebrates. We suggest that temperature-mediated fish predation and herbivory have constrained mobile macroinvertebrate diversity at the site scale across the tropics. Conversely, at the ecoregion scale, richness responds positively to coral reef area, highlighting potentially huge global biodiversity losses with coral decline. Improved conservation outcomes require management frameworks, informed by hierarchical monitoring, that cover differing site- and regional-scale processes across diverse taxa, including attention to invertebrate species, which appear disproportionately threatened by warming seas.

The impact of indigenous cultural identity and cultural engagement on violent offending

BACKGROUND

Possessing a strong cultural identity has been shown to protect against mental health symptoms and buffer distress prompted by discrimination. However, no research to date has explored the protective influences of cultural identity and cultural engagement on violent offending. This paper investigates the relationships between cultural identity/engagement and violent recidivism for a cohort of Australian Indigenous people in custody.

METHODS

A total of 122 adults from 11 prisons in the state of Victoria completed a semi-structured interview comprising cultural identification and cultural engagement material in custody. All official police charges for violent offences were obtained for participants who were released from custody into the community over a period of 2 years.

RESULTS

No meaningful relationship between cultural identity and violent recidivism was identified. However a significant association between cultural engagement and violent recidivism was obtained. Further analyses demonstrated that this relationship was significant only for participants with a strong Indigenous cultural identity. Participants with higher levels of cultural engagement took longer to violently re-offend although this association did not reach significance.

CONCLUSIONS

For Australian Indigenous people in custody, 'cultural engagement' was significantly associated with non-recidivism. The observed protective impact of cultural engagement is a novel finding in a correctional context. Whereas identity alone did not buffer recidivism directly, it may have had an indirect influence given its relationship with cultural engagement. The findings of the study emphasize the importance of culture for Indigenous people in custody and a greater need for correctional institutions to accommodate Indigenous cultural considerations.

Processing political misinformation: comprehending the Trump phenomenon

This study investigated the cognitive processing of true and false political information. Specifically, it examined the impact of source credibility on the assessment of veracity when information comes from a polarizing source (Experiment 1), and effectiveness of explanations when they come from one's own political party or an opposition party (Experiment 2). These experiments were conducted prior to the 2016 Presidential election. Participants rated their belief in factual and incorrect statements that President Trump made on the campaign trail; facts were subsequently affirmed and misinformation retracted. Participants then re-rated their belief immediately or after a delay. Experiment 1 found that (i) if information was attributed to Trump, Republican supporters of Trump believed it more than if it was presented without attribution, whereas the opposite was true for Democrats and (ii) although Trump supporters reduced their belief in misinformation items following a correction, they did not change their voting preferences. Experiment 2 revealed that the explanation's source had relatively little impact, and belief updating was more influenced by perceived credibility of the individual initially purporting the information. These findings suggest that people use political figures as a heuristic to guide evaluation of what is true or false, yet do not necessarily insist on veracity as a prerequisite for supporting political candidates.