A Proof-Producing Compiler for Blockchain Applications

Cairo is a programming language for running decentralized applications (dapps) at scale. Programs written in the Cairo language are compiled to machine code for the Cairo CPU architecture, and cryptographic protocols are used to verify the results of the execution traces efficiently on blockchain. We explain how we have extended the Cairo compiler with tooling that enables users to prove, in the Lean 3 proof assistant, that compiled code satisfies high-level functional specifications. We demonstrate the success of our approach by verifying primitives for computations with an elliptic curve over a large finite field, as well as their use in the validation of cryptographic signatures

Effects of airgun discharges used in seismic surveys on development and mortality in nauplii of the copepod Acartia tonsa

Seismic surveys are conducted worldwide to explore for oil and gas deposits and to map subsea formations. The airguns used in these surveys emit low-frequency sound waves. Studies on zooplankton responses to airguns report a range of effects, from none to substantial mortality. A field experiment was conducted to assess mortality and naupliar body length of the calanoid copepod Acartia tonsa when exposed to the discharge of two 40-inch airguns. Nauplii were placed in plastic bags and attached to a line at a depth of 6 m. For each treatment, three bags of nauplii were exposed to one of three treatments for 2.5 h: Airgun array discharge, a boat control, or a silent control. After exposure, nauplii were kept in filtered seawater in the laboratory without food. Immediate mortality in the nauplii was approximately 14% compared to less than 4% in the silent and boat control. Similarly, there was higher mortality in the airgun exposed nauplii up to six days after exposure compared to the control treatments. Nearly all of the airgun exposed nauplii were dead after four days, while >50% of the nauplii in the control treatments were alive at six days post-exposure. There was an interaction between treatment and time on naupliar body length, indicating lower growth in the nauplii exposed to the airgun discharge (growth rates after 4 days: 1.7, 5.4, and 6.1 μm d−1 in the airgun exposed, silent control, and boat control, respectively). These experiments indicate that the output of two small airguns affected mortality and growth of the naupliar stages of Acartia tonsa in close vicinity to the array.publishedVersio

Jellyfish Modulate Bacterial Dynamic and Community Structure

Jellyfish blooms have increased in coastal areas around the world and the outbreaks have become longer and more frequent over the past few decades. The Mediterranean Sea is among the heavily affected regions and the common bloom - forming taxa are scyphozoans Aurelia aurita s.l., Pelagia noctiluca, and Rhizostoma pulmo. Jellyfish have few natural predators, therefore their carcasses at the termination of a bloom represent an organic-rich substrate that supports rapid bacterial growth, and may have a large impact on the surrounding environment. The focus of this study was to explore whether jellyfish substrate have an impact on bacterial community phylotype selection. We conducted in situ jellyfish - enrichment experiment with three different jellyfish species. Bacterial dynamic together with nutrients were monitored to assess decaying jellyfish-bacteria dynamics. Our results show that jellyfish biomass is characterized by protein rich organic matter, which is highly bioavailable to ‘jellyfish - associated’ and ‘free - living’ bacteria, and triggers rapid shifts in bacterial population dynamics and composition. Based on 16S rRNA clone libraries and denaturing gradient gel electrophoresis (DGGE) analysis, we observed a rapid shift in community composition from unculturable Alphaproteobacteria to culturable species of Gammaproteobacteria and Flavobacteria. The results of sequence analyses of bacterial isolates and of total bacterial community determined by culture independent genetic analysis showed the dominance of the Pseudoalteromonadaceae and the Vibrionaceae families. Elevated levels of dissolved proteins, dissolved organic and inorganic nutrient release, bacterial abundance and carbon production as well as ammonium concentrations characterized the degradation process. The biochemical composition of jellyfish species may influence changes in the amount of accumulated dissolved organic and inorganic nutrients. Our results can contribute insights into possible changes in bacterial population dynamics and nutrient pathways following jellyfish blooms which have important implications for ecology of coastal waters

Depression, anxiety, and psychological defense in attempted suicide: A pilot study using PORT

Depressive affect, anxiety, and psychological defenses were studied in the presented research with PORT, a projective test that exploits subliminal perception of object-relation images. Protocols of 20 hospitalized suicide attempters were compared to those of 20 matched controls, 34 previously studied non-suicidal depressed patients, 18 patients with panic attac, and 32 patients with borderline and psychotic disorders. The suicide attempters were anxious; their defenses resembled those seen in borderline pathology; depressive reactions were limited in symbolic content; reality testing was poor. The closeness between depression and anxiety in suicidality is further discussed throughout this article. A con¬stella¬tion of signs using the PORT was hypothesized to be a marker for suicidality. The test is deemed useful for future research on suicide

The Hidden Dimension: Context‐Dependent Expression of Repeatable Behavior in Copepods

In ecotoxicology and aquatic ecology, we often ignore responses of individuals and focus on average responses. However, both terrestrial and aquatic animals display consistent behavioral differences between individuals. The distribution of behavioral differences within a population contains vital information for predicting population responses to novel environmental challenges. Currently, individual data for behavioral and physiological traits of small marine invertebrates are few, partly because such variation is lost within published group means and assumed normality. We tested the combined effects of an inorganic contaminant (copper) and a biological stressor (i.e., chemical cues of a fish predator) on activity in a marine copepod. Although direct stress effects were weak, individuals behaved consistently differently, depending on the context. Individual differences in behavior were only expressed under the influence of kairomones, but not by copper exposure alone. This finding indicates that copepods express repeatable and context‐dependent behavior. We also demonstrate how large variations in behavioral data can hide consistent differences between individuals. Environ Toxicol Chem 2020;39:1017–1026. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC

Rational suicide? : Interviews with Swedish psychiatrists

Semi-structured interviews were performed with 12 psychiatrists regarding their perceptions of the Swedish Vision Zero for Suicide. Focusing on the topic of rational suicide, we re-analyzed these interviews using descriptive content analysis. The informants generally acknowledged the existence of rational suicide and its occurrence also among severely ill psychiatric patients, but expressed varying perceptions of the relevance of the concept in clinical practice. The difficulty of identifying rational suicide was considered to be a major problem. Another experience was a potential conflict between promoting a patient’s rationality and preventing suicide. While the normative aspects of rational suicide have been addressed in the literature, our results highlight a need for further attention to the epistemological and practical aspects of rational suicid

Suicide-nearness assessed with PORT, the Percept-genetic Object-Relation Test: A replication and a reliability study

To determine the reliability and validity of a previously identified "suicide cluster" in the Percept-genetic Object-Relation Test (PORT), which test documents subliminal perception of object-relation pictures, 20 suicide attempters and 70 controls were investigated. The correspondence between scores assigned by two judges was 95%-100%. The suicide-cluster signs in PORT, notably "lack of attachment relationships" and "Motor activity," were significant. Differences between the results of this and the previous study are discussed as is the role of psychiatric disorder in suicide. (Bulletin of the Menninger Clinic, 75[4], 295-314

Skepticism towards the Swedish vision zero for suicide: interviews with 12 psychiatrists

Abstract Background The main causes of suicide and how suicide could and should be prevented are ongoing controversies in the scientific literature as well as in public media. In the bill on public health from 2008 (Prop 2007/08:110), the Swedish Parliament adopted an overarching “Vision Zero for Suicide” (VZ) and nine strategies for suicide prevention. However, how the VZ should be interpreted in healthcare is unclear. The VZ has been criticized both from a philosophical perspective and against the background of clinical experience and alleged empirical claims regarding the consequences of regulating suicide prevention. This study is part of a larger research project in medical ethics with the overarching aim to explore whether the VZ is ethically justifiable. The aim is to enrich the normative discussion by investigating empirically how the VZ is perceived in healthcare. Methods Interviews based on a semi-structured interview guide were performed with 12 Swedish psychiatrists. The interviews were analysed with descriptive qualitative content analysis aiming for identifying perceptions of the Vision Zero for Suicide as well as arguments for and against it. Results Though most of the participants mentioned at least some potential benefit of the Vision Zero for Suicide, the overall impression was a predominant skepticism. Some participants focused on why they consider the VZ to be unachievable, while others focused more on its potential consequences and normative implications. Conclusions The VZ was perceived to be impossible to realize, nonconstructive or potentially counterproductive, and undesirable because of potential conflicts with other values and interests of patients as well as the general public. There were also important notions of the VZ having negative consequences for the working conditions of psychiatrists in Sweden, in increasing their work-related anxiety and thwarting the patient-physician relationship