Condorcet admissibility: Indeterminacy and path-dependence under majority voting on interconnected decisions

Judgement aggregation is a model of social choice where the space of social alternatives is the set of consistent evaluations (`views') on a family of logically interconnected propositions, or yes/no-issues. Unfortunately, simply complying with the majority opinion in each issue often yields a logically inconsistent collection of judgements. Thus, we consider the Condorcet set: the set of logically consistent views which agree with the majority in as many issues as possible. Any element of this set can be obtained through a process of diachronic judgement aggregation, where the evaluations of the individual issues are decided through a sequence of majority votes unfolding over time, with earlier decisions possibly imposing logical constraints on later decisions. Thus, for a fixed profile of votes, the ultimate social choice can depend on the order in which the issues are decided; this is called path dependence. We investigate the size and structure of the Condorcet set ---and hence the scope and severity of path-dependence ---for several important classes of judgement aggregation problems.judgement aggregation; diachronic; path-dependence; indeterminacy; Condorcet; median rule; majoritarian

Ice-melt period dominates annual carbon dioxide evasion from clear-water Arctic lakes

Current estimates of carbon dioxide (CO2) evasion from Arctic lakes are highly uncertain because few studies integrate seasonal variability, specifically evasion during spring ice-melt. We quantified annual CO2 evasion for 14 clear-water Arctic lakes in Northern Sweden through mass balance (ice-melt period) and high-frequency loggers (open-water period). On average, 80% (SD: +/- 18) of annual CO2 evasion occurred within 10 d following ice-melt. The contribution of the ice-melt period to annual CO2 evasion was high compared to earlier studies of Arctic lakes (47% +/- 32%). Across all lakes, the proportion of ice-melt : annual CO2 evasion was negatively related to the dissolved organic carbon concentration and positively related to the mean depth of the lakes. The results emphasize the need for measurements of CO2 exchange at ice-melt to accurately quantify CO2 evasion from Arctic lakes

Escalating Carbon Export from High-Elevation Rivers in a Warming Climate

High-elevation mountains have experienced disproportionately rapid warming, yet the effect of warming on the lateral export of terrestrial carbon to rivers remains poorly explored and understood in these regions. Here, we present a long-term data set of dissolved inorganic carbon (DIC) and a more detailed, short-term data set of DIC, delta C-13(DIC), and organic carbon from two major rivers of the Qinghai-Tibetan Plateau, the Jinsha River (JSR) and the Yalong River (YLR). In the higher-elevation JSR with similar to 51% continuous permafrost coverage, warming (>3 degrees C) and increasing precipitation coincided with substantially increased DIC concentrations by 35% and fluxes by 110%. In the lower-elevation YLR with similar to 14% continuous permafrost, such increases did not occur despite a comparable extent of warming. Riverine concentrations of dissolved and particulate organic carbon increased with discharge (mobilization) in both rivers. In the JSR, DIC concentrations transitioned from dilution (decreasing concentration with discharge) in earlier, colder years to chemostasis (relatively constant concentration) in later, warmer years. This changing pattern, together with lighter delta C-13(DIC) under high discharge, suggests that permafrost thawing boosts DIC production and export via enhancing soil respiration and weathering. These findings reveal the predominant role of warming in altering carbon lateral export by escalating concentrations and fluxes and modifying export patterns

Decadal increase in groundwater inorganic carbon concentrations across Sweden

Groundwater concentrations of dissolved inorganic carbon and carbon dioxide have increased by 28% and 49%, respectively, across Sweden between 1980 and 2020 due to partial recovery from historic anthropogenic acid deposition and increased soil respiration, suggest geochemical model calculations.Groundwater is one of the largest continental carbon reservoirs and tightly linked to globally important carbon fluxes such as uptake on land, degassing from inland waters and delivery to oceans. Despite emerging evidence that these fluxes are sensitive to environmental changes, long-term carbon dynamics in groundwater remain widely unknown. Here I show that dissolved inorganic carbon and carbon dioxide concentrations in groundwater, calculated from environmental monitoring data (e.g. alkalinity, pH), have increased on average by 28% and 49%, respectively, across Sweden during 1980-2020. I attribute the observed changes mainly to a partial recovery from atmospheric sulfate deposition and associated shifts in weathering pathways, but also to enhanced soil respiration. The results highlight previously neglected long-term and large-scale dynamics in groundwater carbon cycling. These dynamics should be included in carbon cycle models for accurate evaluations and predictions of the effects of environmental changes on landscape and global carbon stocks and fluxes

Response of lake metabolism to catchment inputs inferred using high-frequency lake and stream data from across the northern hemisphere

In lakes, the rates of gross primary production (GPP), ecosystem respiration (R), and net ecosystem production (NEP) are often controlled by resource availability. Herein, we explore how catchment vs. within lake predictors of metabolism compare using data from 16 lakes spanning 39 degrees N to 64 degrees N, a range of inflowing streams, and trophic status. For each lake, we combined stream loads of dissolved organic carbon (DOC), total nitrogen (TN), and total phosphorus (TP) with lake DOC, TN, and TP concentrations and high frequency in situ monitoring of dissolved oxygen. We found that stream load stoichiometry indicated lake stoichiometry for C : N and C : P (r2 = 0.74 and r2 = 0.84, respectively), but not for N : P (r2 = 0.04). As we found a strong positive correlation between TN and TP, we only used TP in our statistical models. For the catchment model, GPP and R were best predicted by DOC load, TP load, and load N : P (R2 = 0.85 and R2 = 0.82, respectively). For the lake model, GPP and R were best predicted by TP concentrations (R2 = 0.86 and R2 = 0.67, respectively). The inclusion of N : P in the catchment model, but not the lake model, suggests that both N and P regulate metabolism and that organisms may be responding more strongly to catchment inputs than lake resources. Our models predicted NEP poorly, though it is unclear why. Overall, our work stresses the importance of characterizing lake catchment loads to predict metabolic rates, a result that may be particularly important in catchments experiencing changing hydrologic regimes related to global environmental change

Editorial

The journal focuses on current debates and research on justice, morality, responsibility, dignity, rights, and self-determination in relation to socially relevant issues like globalisation, markets, climate change, welfare, migration, and digitalisation. It mainly publishes articles, essays, term papers etc. on pertinent topics written by young scholars and advanced students. In the first issue Democracy in Times of Unstable Conditions we give students the voice, on the one hand addressing important aspects of internal threats to democracy and on the other presenting political instruments to counteract the climate catastrophe

Editorial

editor's not

Magnetic buoyancy in simulated galactic discs with a realistic circum galactic medium

We present simulations of isolated disc galaxies in a realistic environment performed with the Tree-SPMHD-Code Gadget-3. Our simulations include a spherical circum-galactic medium (CGM) surrounding the galactic disc, motivated by observations and the results of cosmological simulations. We present three galactic models with different halo masses between 10e10 Msol and 10e12 Msol, and for each we use two different approaches to seed the magnetic field, as well as a control simulation without a magnetic field. We find that the amplification of the magnetic field in the centre of the disc leads to a biconical magnetic outflow of gas that magnetizes the CGM. This biconical magnetic outflow reduces the star formation rate (SFR) of the galaxy by roughly 40 percent compared to the simulations without magnetic fields. As the key aspect of our simulations, we find that small scale turbulent motion of the gas in the disc leads to the amplification of the magnetic field up to tens of 10e-6 G, as long as the magnetic field strength is low. For stronger magnetic fields turbulent motion does not lead to significant amplification but is replaced by an alpha-omega dynamo. The occurance of a small scale turbulent dynamo becomes apparent through the magnetic power spectrum and analysis of the field lines' curvature. In accordance with recent observations we find an anti-correlation between the spiral structure in the gas density and in the magnetic field due to a diffusion term added to the induction equation.Comment: 22 pages, 16 figures, submitted to MNRA

Early goal-directed hemostatic therapy for severe acute bleeding management in the intensive care unit: a narrative review.

This is a narrative review of the published evidence for bleeding management in critically ill patients in different clinical settings in the intensive care unit (ICU). We aimed to describe “The Ten Steps” approach to early goal-directed hemostatic therapy (EGDHT) using point-of-care testing (POCT), coagulation factor concentrates, and hemostatic drugs, according to the individual needs of each patient. We searched National Library of Medicine, MEDLINE for publications relevant to management of critical ill bleeding patients in different settings in the ICU. Bibliographies of included articles were also searched to identify additional relevant studies. English-language systematic reviews, meta-analyses, randomized trials, observational studies, and case reports were reviewed. Data related to study methodology, patient population, bleeding management strategy, and clinical outcomes were qualitatively evaluated. According to systematic reviews and meta-analyses, EGDHT guided by viscoelastic testing (VET) has been associated with a reduction in transfusion utilization, improved morbidity and outcome in patients with active bleeding. Furthermore, literature data showed an increased risk of severe adverse events and poor clinical outcomes with inappropriate prophylactic uses of blood components to correct altered conventional coagulation tests (CCTs). Finally, prospective, randomized, controlled trials point to the role of goal-directed fibrinogen substitution to reduce bleeding and the amount of red blood cell (RBC) transfusion with the potential to decrease mortality. In conclusion, severe acute bleeding management in the ICU is still a major challenge for intensive care physicians. The organized and sequential approach to the bleeding patient, guided by POCT allows for rapid and effective bleeding control, through the rational use of blood components and hemostatic drugs, since VET can identify specific coagulation disorders in real time, guiding hemostatic therapy with coagulation factor concentrates and hemostatic drugs with individual goals

Early goal-directed hemostatic therapy for severe acute bleeding management in the Intensive Care Unit: A narrative review

This is a narrative review of the published evidence for bleeding management in critically ill patients in different clinical settings in the intensive care unit (ICU). We aimed to describe “The Ten Steps” approach to early goal-directed hemostatic therapy (EGDHT) using point-of-care testing (POCT), coagulation factor concentrates, and hemostatic drugs, according to the individual needs of each patient. We searched National Library of Medicine, MEDLINE for publications relevant to management of critical ill bleeding patients in different settings in the ICU. Bibliographies of included articles were also searched to identify additional relevant studies. English-language systematic reviews, meta-analyses, randomized trials, observational studies, and case reports were reviewed. Data related to study methodology, patient population, bleeding management strategy, and clinical outcomes were qualitatively evaluated. According to systematic reviews and meta-analyses, EGDHT guided by viscoelastic testing (VET) has been associated with a reduction in transfusion utilization, improved morbidity and outcome in patients with active bleeding. Furthermore, literature data showed an increased risk of severe adverse events and poor clinical outcomes with inappropriate prophylactic uses of blood components to correct altered conventional coagulation tests (CCTs). Finally, prospective, randomized, controlled trials point to the role of goal-directed fibrinogen substitution to reduce bleeding and the amount of red blood cell (RBC) transfusion with the potential to decrease mortality. In conclusion, severe acute bleeding management in the ICU is still a major challenge for intensive care physicians. The organized and sequential approach to the bleeding patient, guided by POCT allows for rapid and effective bleeding control, through the rational use of blood components and hemostatic drugs, since VET can identify specific coagulation disorders in real time, guiding hemostatic therapy with coagulation factor concentrates and hemostatic drugs with individual goals. Hemorrhage and thrombosis are frequent complications in the intensive care unit (ICU), compromising the clinical outcome of patients.1 Among them, the main cause of death in the world is thrombosis. However, there is concern about the risk of bleeding in patients who have pathological results from conventional coagulation tests (CCTs).2 For this reason, prophylactic transfusion of allogeneic blood components is still very frequent, even in the absence of bleeding. However, transfusion is associated with life-threatening adverse events.3 In this literature review, we aimed to describe critical aspects of the approach to patients with severe acute bleeding in the ICU, focusing on the importance of point-of-care testing (POCT) for early identification of coagulopathy to guide early goal-directed hemostatic therapy (EGDHT) using coagulation factor concentrates and hemostatic drugs