Dissolved inorganic carbon accumulating complexes from autotrophic bacteria from extreme environments

In nature, concentrations of dissolved inorganic carbon (DIC; = CO 2 + HCO 3 - + CO 3 2- ) can be low, and autotrophic organisms adapt with a variety of mechanisms to elevate intracellular DIC concentrations to enhance CO 2 fixation. Such mechanisms have been well-studied in Cyanobacteria , but much remains to be learned about their activity in other phyla. Novel multi-subunit membrane-spanning complexes capable of elevating intracellular DIC were recently described in three species of bacteria. Homologs of these complexes are distributed among 17 phyla in Bacteria and Archaea, and are predicted to consist of one, two, or three subunits. To determine whether DIC accumulation is a shared feature of these diverse complexes, seven of them, representative of organisms from four phyla, from a variety of habitats, and with three different subunit configurations were chosen for study. A high-CO 2 requiring, carbonic anhydrase-deficient ( yadF - cynT - ) strain of E. coli Lemo21(DE3), which could be rescued via elevated intracellular DIC concentrations, was created for heterologous expression and characterization of the complexes. Expression of all seven complexes rescued the ability of E. coli Lemo21(DE3) yadF - cynT - to grow under low CO 2 conditions, and six of the seven generated measurably elevated intracellular DIC concentrations when their expression was induced. For complexes consisting of two or three subunits, all subunits were necessary for DIC accumulation. Isotopic disequilibrium experiments clarified that CO 2 was the substrate for these complexes. In addition, the presence of an ionophore prevented the accumulation of intracellular DIC, suggesting that these complexes may couple proton potential to DIC accumulation. IMPORTANCE To facilitate the synthesis of biomass from CO 2 , autotrophic organisms use a variety of mechanisms to increase intracellular DIC concentrations. A novel type of multi-subunit complex has recently been described, which has been shown to generate measurably elevated intracellular DIC concentrations in three species of bacteria, begging the question of whether these complexes share this capability across the 17 phyla of Bacteria and Archaea where they are found. This study shows that DIC accumulation is a trait shared by complexes with varied subunit structures, from organisms with diverse physiologies and taxonomies, suggesting that this trait is universal among them. Successful expression in E. coli suggests the possibility of their expression in engineered organisms synthesizing compounds of industrial importance from CO 2 .

Conceptualizing Consciousness

One of the most promising theories of consciousness currently available is higher-order thought (“HOT”) theory, according to which consciousness consists in having suitable HOTs regarding one’s mental life. But critiques of HOT theory abound. We explore here three recent objections to the theory, which we argue at bottom founder for the same reason. While many theorists today assume that consciousness is a feature of the actually existing mental states in virtue of which one has experiences, this assumption is in tension with the underlying motivations for HOT theory and arguably false. We urge that these objections, though sophisticated, trade on this questionable conception of consciousness, thereby begging the question against HOT theory. We then explain how HOT theory might instead understand consciousness.

“Begging the Question”—Does Toxocara Infection/Exposure Associate with Multiple Sclerosis-Risk?

Although the cause of multiple sclerosis (MS) is unclear, infectious agents, including some parasitic roundworms (nematodes), have been proposed as possible risk factors or contributors. Here, we conducted a systematic review and meta-analysis of published observational studies to evaluate whether there is a possible association between infection with, or exposure to, one or more members of the genus Toxocara (phylum Nematoda; superfamily Ascaridoidea) and MS. We undertook a search of public literature databases to identify relevant studies and then used a random-effects meta-analysis model to generate the pooled odds ratio (OR) and 95% confidence intervals (CIs). This search identified six of a total of 1371 articles that were relevant to the topic; these published studies involved totals of 473 MS patients and 647 control subjects. Anti-Toxocara IgG serum antibodies were detected in 62 MS patients and 37 controls, resulting in respective seroprevalences of 13.1% (95% CI: 8.2–20.3) and 4.8% (95% CI: 2.5–9.2), indicating an association (pooled OR, 3.01; 95% CI: 1.46–6.21). Because of the publication bias identified (six eligible studies), well-designed and -controlled studies are required in the future to rigorously test the hypothesis that Toxocara infection/exposure has an association with MS.

Ein interpoliertes Textstück im neunten Kapitel der Aristotelischen Hermeneutik

The section 18b16–⁠25 of the famous chapter 9 of Aristotle’s De interpretatione presents two objections against the assumption that both members of a contradictory pair of future singular statements might be false. This section is unlikely to be genuine, because (1) the first objection is either directly begging the question or misusing a previous argument in a question-begging way, (2) the second objection includes irrelevant observations, and (3) the rebuttal of the said assumption interrupts the intimate connection between the immediately preceding and following sections.

Mouse higher visual areas provide both distributed and discrete contributions to visually guided behaviors

SummaryCortical parallel processing streams segregate many diverse features of a sensory scene. However, some features are distributed across streams, begging the question of whether and how such distributed representations contribute to perception. We determined the necessity of primary visual cortex (V1) and three key higher visual areas (LM, AL and PM) for perception of orientation and contrast, two features that are robustly encoded across all four areas. Suppressing V1, LM or AL decreased sensitivity for both orientation discrimination and contrast detection, consistent with a role for these areas in sensory perception. In comparison, suppressing PM selectively increased false alarm rates during contrast detection, without any effect on orientation discrimination. This effect was not retinotopically-specific, suggesting a distinct role for PM in the regulation of noise during decision-making. Thus, we find that distributed representations in the visual system can nonetheless support specialized perceptual roles for higher visual cortical areas.

Romans 2:13 and Future Justification

Given that Paul’s letter to the Romans is a touchstone for the distinctively Protestant confessional teaching concerning justification by faith alone, Romans 2:13 poses a challenge. Following the pattern of Philip Melanchthon, Protestant expositors have typically met this challenge by interpreting it as a ‘legal’ justification that no sinner can attain. This article illustrates the dominant ‘Melanchthonian’ trajectory in early modern Protestant exegesis, while also drawing attention to a minority alternative that reads it as a future justification of Christians according to works (the ‘Bucerian’ alternative). Many modern Protestant exegetes now prefer something like the Bucerian alternative, begging the question as to how this squares coherently with any confessional commitment to a once-for-all justification that is by faith alone. Noting this, this article sets forth an early modern Protestant model of cogent dogmatic harmonization on this score. The chosen case study is Petrus van Mastricht and his magisterial Theoretico-Practica Theologia.

Systems and Functions

Descartes’ reliance on functional analyses to understand automata has struck many critics as deeply problematic, particularly in light of his rejection of the necessity of ends or final causes in physics. This chapter examines how important answering this question was to Descartes to avoid falling into the trap of vitalism, on the one side, and a materialist reduction of human nature, on the other. It advances a non-teleological analysis of “function” that steers a middle course between teleological/normative accounts and naïvely causal accounts that identify functions in terms of what they contribute to the complex causal capacities of a system. Causal functional analyses are accused of begging the question on the identity of the system to whose capacities they contribute. Drawing on an examination of how Descartes uses the notion of “function” in biological contexts and how it relates to a concept of work, implicit in his physics, it is argued that his notion of “function” is neither teleological nor causal in the standard sense, although it represents an extension of the causal approach. Descartes thus makes a unique and lasting contribution to debates about the notion of function and its place in a mechanical physics.

S (for Syllogism) Revisited

In 1978, the authors began a paper, “S (for Syllogism),” henceforth [S4S], intended as a philosophical companion piece to the technical solution [SPW] of the Anderson-Belnap P–W problem. [S4S] has gone through a number of drafts, which have been circulated among close friends. Meanwhile other authors have failed to see the point of the semantics which we introduced in [SPW]. It will accordingly be our purpose here to revisit that semantics, while giving our present views on syllogistic matters past, present and future, especially as they relate to not begging the question via such dubious theses as A → A. We shall investigate in particular a paraconsistent attitude toward such theses.

Hierarchy and the Value of Outcomes

Acceptable versions of distributive principles will take status into account, so that an animal at a given level of well-being will, by virtue of its lower status, have a correspondingly weaker distributive claim than would a person at the same level of well-being. This chapter sketches some promising ways of modifying the various distributive principles, making them sensitive to differences in status. The details remain uncertain, however, as the author illustrates by pointing out some problems for the modified version of the priority view. Turning to the question of whether the very value of well-being itself (that is, the contribution it makes to the overall goodness of an outcome) should also depend on status, the author answers in the affirmative. Surprisingly, an appeal to the principle of equal consideration of interests cannot be used to reject this view, on pain of begging the question.