Saturday, August 13, 2022

Female teams lower their contribution to the public good in the event of low likeability among members, while male teams achieve high levels of co-operation irrespective of the level of mutual likeability

I (Don’t) Like You! But Who Cares? Gender Differences in Same-Sex and Mixed-Sex Teams. Leonie Gerhards, Michael Kosfeld. The Economic Journal, Volume 130, Issue 627, April 2020, Pages 716–739, https://doi.org/10.1093/ej/uez067

Abstract: We study the effect of likeability on women’s and men’s team behaviour in a lab experiment. Extending a two-player public goods game and a minimum effort game by an additional pre-play stage that informs team members about their mutual likeability, we find that female teams lower their contribution to the public good in the event of low likeability, while male teams achieve high levels of co-operation irrespective of the level of mutual likeability. In mixed-sex teams, both women’s and men’s contributions depend on mutual likeability. Similar results are found in the minimum effort game. Our results offer a new perspective on gender differences in labour market outcomes: mutual dislikeability impedes team behaviour, except in all-male teams.


About half of the cobalt ends up being lost during production; indium sees losses hit 70 pct; and many metals have production losses of 95 pct or higher: arsenic, gallium, germanium, hafnium, scandium, selenium, & tellurium

Losses and lifetimes of metals in the economy. Alexandre Charpentier Poncelet, Christoph Helbig, Philippe Loubet, Antoine Beylot, St├ęphanie Muller, Jacques Villeneuve, Bertrand Laratte, Andrea Thorenz, Axel Tuma & Guido Sonnemann. Nature Sustainability, corr. May 31 2022. https://www.nature.com/articles/s41893-022-00895-8


Abstract: The consumption of most metals continues to rise following ever-increasing population growth, affluence and technological development. Sustainability considerations urge greater resource efficiency and retention of metals in the economy. We model the fate of a yearly cohort of 61 extracted metals over time and identify where losses are expected to occur through a life-cycle lens. We find that ferrous metals have the longest lifetimes, with 150 years on average, followed by precious, non-ferrous and specialty metals with 61, 50 and 12 years on average, respectively. Production losses are the largest for 15 of the studied metals whereas use losses are the largest for barium, mercury and strontium. Losses to waste management and recycling are the largest for 43 metals, suggesting the need to improve design for better sorting and recycling and to ensure longer-lasting products, in combination with improving waste-management practices. Compared with the United Nations Environmental Programme’s recycling statistics, our results show the importance of taking a life-cycle perspective to estimate losses of metals to develop effective circular economy strategies. We provide the dataset and model used in a machine-readable format to allow further research on metal cycles.


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Popular version: New study estimates how long mined metals circulate before being lost https://arstechnica.com/science/2022/05/new-study-estimates-how-long-mined-metals-circulate-before-being-lost/

Losses at different stages of a metal's life cycle also varied widely. We're very good at extracting most metals from ores so that most of the losses are incidental—that is, some of the metal happens to be present in an ore we use for other materials. For example, iron ore may contain something like manganese at low concentrations, but the amount of ore we process means that a lot of manganese will end up being thrown away. Overall, these losses tended to be in the area of 15 percent, with the exception of specialty metals, which averaged about 25 percent.


Both those averages obscure some fairly horrifying losses. About half of the cobalt, which is highly desired for many types of batteries, ends up being lost during production. Indium, used in many semiconductor products, sees losses hit 70 percent. And many metals have production losses of 95 percent or higher: arsenic, gallium, germanium, hafnium, scandium, selenium, and tellurium.


Losses in manufacturing are much less scary; they're generally a rounding error compared to the losses in extraction. Manufacturing produces the smallest losses for over half the metals analyzed, and there's none for which it's the highest. Even the worst rate of loss (among non-ferrous metals) only reaches 6 percent. It's clear that manufacturing has been very good at avoiding waste.


Once in use, most metals suffer minimal losses, with averages of about 5 percent or less for everything but specialty metals. But those specialty metals see losses that average over 30 percent during use. Some of them, notably strontium and barium, primarily end up in single-use products that are permanently lost to the environment (they're part of the mud injected into wells during gas and oil drilling). Those two, along with mercury, are the only three for which use is the largest source of loss.

Meta-analysis: Afternoon naps sharpen the mind; effects are small to medium

Systematic review and meta-analyses on the effects of afternoon napping on cognition. Ruth L.F. Leong, June C. Lo, Michael W.L. Chee. Sleep Medicine Reviews, August 13 2022, 101666. https://doi.org/10.1016/j.smrv.2022.101666

Abstract: Naps are increasingly considered a means to boost cognitive performance. We quantified the cognitive effects of napping in 60 samples from 54 studies. 52 samples evaluated memory. We first evaluated effect sizes for all tests together, before separately assessing their effects on memory, vigilance, speed of processing and executive function. We next examined whether nap effects were moderated by study features of age, nap length, nap start time, habituality and prior sleep restriction. Naps showed significant benefits for the total aggregate of cognitive tests (Cohen's d = 0.379, CI95 = 0.296–0.462). Significant domain specific effects were present for declarative (Cohen's d = 0.376, CI95 = 0.269–0.482) and procedural memory (Cohen's d = 0.494, CI95 = 0.301–0.686), vigilance (Cohen's d = 0.610, CI95 = 0.291–0.929) and speed of processing (Cohen's d = 0.211, CI95 = 0.052–0.369). There were no significant moderation effects of any of the study features. Nap effects were of comparable magnitude across subgroups of each of the 5 moderators (Q values = 0.009 to 8.572, p values > 0.116). Afternoon naps have a small to medium benefit over multiple cognitive tests. These effects transcend age, nap duration and tentatively, habituality and prior nocturnal sleep.

Keywords: NapCognitionVigilanceMemoryAge effects