Effects of Calcium Pyruvate Supplementation During Training On Body Composition, Exercise Capacity, and Metabolic Responses To Exercise

Objective: We evaluated the effects of calcium pyruvate supplementation during training on body composition and metabolic responses to exercise. Method: Twenty-three untrained females were matched and assigned to ingest in a double blind and randomized manner either 5 g of calcium pyruvate (PYR) or a placebo (PL) twice daily for 30 d while participating in a supervised exercise program. Prior to and following supplementation, subjects had body composition determined via hydrodensiometry; performed a maximal cardiopulmonary exercise test; and performed a 45-min walk test at 70% of pre-training VO2 max in which fasting pre- and post exercise blood samples determined. Results: No significant differences were observed between groups in energy intake or training volume. Univariate repeated measures ANOVA revealed that subjects in the PYR group gained less weight (PL 1.2 ± 0.3, PYR 0.3 ± 0.3 kg, P = 0.04), lost more fat (PL 1.1 ± 0.5; PYR −0.4 ± 0.5 kg, P = 0.03), and tended to lose a greater percentage of body fat (PL 1.0 ± 0.7; PYR −0.65 ± 0.6%, P = 0.07), with no differences observed in fat-free mass (PL 0.1 ± 0.5; PYR 0.7 ± 0.3 kg, P = 0.29). However, these changes were not significant when body composition data were analyzed by MANOVA (P = 0.16). There was some evidence that PYR may negate some of the beneficial effects of exercise on HDL values. No significant differences were observed between groups in maximal exercise responses or metabolic responses to submaximal walking. Conclusions: Results indicate that PYR supplementation during training does not significantly affect body composition or exercise performance and may negatively affect some blood lipid levels

Surface and Temporal Biosignatures

Recent discoveries of potentially habitable exoplanets have ignited the prospect of spectroscopic investigations of exoplanet surfaces and atmospheres for signs of life. This chapter provides an overview of potential surface and temporal exoplanet biosignatures, reviewing Earth analogues and proposed applications based on observations and models. The vegetation red-edge (VRE) remains the most well-studied surface biosignature. Extensions of the VRE, spectral "edges" produced in part by photosynthetic or nonphotosynthetic pigments, may likewise present potential evidence of life. Polarization signatures have the capacity to discriminate between biotic and abiotic "edge" features in the face of false positives from band-gap generating material. Temporal biosignatures -- modulations in measurable quantities such as gas abundances (e.g., CO2), surface features, or emission of light (e.g., fluorescence, bioluminescence) that can be directly linked to the actions of a biosphere -- are in general less well studied than surface or gaseous biosignatures. However, remote observations of Earth's biosphere nonetheless provide proofs of concept for these techniques and are reviewed here. Surface and temporal biosignatures provide complementary information to gaseous biosignatures, and while likely more challenging to observe, would contribute information inaccessible from study of the time-averaged atmospheric composition alone.Comment: 26 pages, 9 figures, review to appear in Handbook of Exoplanets. Fixed figure conversion error

Tools shape paradigms of plant-environment interactions

The direction of science is often driven by contemporary theory, and theory emerges from consolidated empirical knowledge. What we know emerges from what we explore, and we explore what we have technical tools for. I feel that technical opportunities contributed strongly towards what is held as a contemporary, widely accepted theory. However, the presumed causality may become reverted, if one accounts for those less explored questions, for which tools are missing. Here, I will reflect on decades of research experience in empirical plant sciences, mainly plant water relations, plant carbon relations and biogeography, during which some mainstream paradigms became challenged. Scientific theory passes through waves and cycles and is even linked to fashion. Insight that seemed established at one time may become outdated by novel concepts facilitated by novel methods, and as time progresses, old concepts may find a revival. In the following chapter, I will illustrate such shifts in awareness and misleading paradigms that were driven by the contemporary availability of methods rather than stringent logics. Examples include plant responses to drought stress; the drivers of plant growth in general, as well as in the context of rising atmospheric CO2 concentrations; and how physiological plant ecology can contribute to resolving biogeographical questions such as range limits of plant species and plant life forms. My résumé is that explanations of plant responses to the environment are predominantly below ground and require an understanding of developmental and meristematic processes, whereas available tools often lead to attempts at above-ground answers based on primary metabolism (e.g. photosynthesis). Further, well-understood processes at the organ (leaf) level are losing relevance at the community or ecosystem level, where much less understood mechanisms come into action (e.g. stand density control). While the availability of certain convenient methods can open new research arenas, it may also narrow the scope and may direct theory development towards easily measurable parameters and processes

Correction: The 5th edition of The World Health Organization Classification of Haematolymphoid Tumours: Lymphoid Neoplasms (vol 36, pg 1720, 2022)

10.1038/s41375-023-01962-5LEUKEMIA3791944-195