CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

Growth and production of a tropical predatory shrimp, Macrobrachium hainanense (Palaemonidae), in two Hong Kong streams

1. Macrobrachium hainanense is a predatory palaemonid shrimp (total length >7 cm) that can be abundant [density 3-5 m-2; biomass 484-606 mg ash-free dry mass (AFDM) m-2] in forest streams in Hong Kong, China. This study investigated the growth and production of M. hainanense during 2001 and 2002 in pools of two forested streams (one third- and one fourth-order). 2. The growth of tagged individuals was recorded in situ and compared with that of tagged and untagged shrimps in laboratory tanks. Field and laboratory estimates yielded similar growth rates of 0.7 mm carapace length (CL) per month, and instantaneous growth rate was 0.004 g AFDM g-1 day-1. Tagging did not affect growth in the laboratory. Cohort analysis of field populations produced similar estimates of growth to that of tagged individuals, and the growth of M. hainanense was generally slower than has been reported for other Macrobrachium species. Mass-specific growth rate of M. hainanense in the field varied with size and was two to five times higher in small individuals (<10 mm CL). In addition, growth rate varied with season and was 40% lower in the dry season when temperature was at the annual minimum. 3. Males grew bigger than females (36 versus 25 mm CL). The minimum lifespan of M. hainanense in the field, calculated from size-specific growth rates, ranged from 29.3 months (females) to 47.6 months (males). Male lifespan derived from cohort analysis was estimated as 48 and 46 months in the two streams. Females reached maturity in 17-18 months (at 15-17 mm CL) while males matured at 24-26 months (at 18-22 mm CL). Females bred twice (at 2 and 3 years of age) while males probably bred three times (at 2, 3 and 4 years) in both streams. 4. Macrobrachium hainanense production in the fourth-order stream, calculated by the size-frequency method, was 900 and 1096 mg AFDM m-2 year-1 (for 2001 and 2002, respectively) with a production/biomass (P/B) of 2.1-2.3 year-1. In the third-order stream, production was 987 and 1304 mg AFDM m-2 year-1 (for 2001 and 2002, respectively) with a P/B of 1.7-2.1 year-1. Production estimates based on the instantaneous growth method were half of those obtained by the size-frequency method. 5. Although M. hainanense production at the third-order stream exceeded that in the fourth-order, growth rates showed the opposite pattern and were 0.31-0.43 mm CL month-1 and 0.56-0.65 mm CL month-1 in the third- and fourth-order streams, respectively. Greater mortality in the latter may account for low production at a site where growth rate was high. 6. Production of M. hainanense in both streams was lower during 2001 when rainfall was higher. This may reflect the influence of spates associated with monsoonal rains, which could have reduced M. hainanense production through spate-induced mortality or by reducing the abundance of prey. This study provides the first in situ estimate of secondary production by a non-commercial Macrobrachium species in Asia or elsewhere. It involved a whole-pool approach to sampling that allowed the estimation of production and population parameters on a realistic scale.link_to_subscribed_fulltex

Measuring Psychological Mechanisms in Meditation Practice: Using a Phenomenologically Grounded Classification System to Develop Theory-Based Composite Scores

Objectives: Deepening our understanding of the mechanisms by which meditation practices impact well-being and human flourishing is essential for advancing the science of meditation. A recent phenomenologically grounded classification system distinguishes attentional, constructive, and deconstructive forms of meditation based on the psychological mechanisms these practices primarily target or necessitate. Our main aim was to understand whether this theory-based taxonomy could be used as a guiding principle for combining established psychological self-report measures of meditation-related mechanisms into psychometrically adequate composite scores. Methods: We used cross-sectional data to compute meditation composite scores in three independent samples, namely meditation-naïve healthy older adults from the Age-Well trial (n = 135), meditation-naïve older adults with subjective cognitive decline from the SCD-Well trial (n = 147), and healthy long-term meditators (≥ 10,000 h of practice including one 3-year meditation retreat) from the Brain & Mindfulness project (n = 29). The psychometric properties of the composite scores were assessed via floor and ceiling effects, composite intercorrelations, interpretability, and convergent validity in relation to well-being, anxiety, and depression. Results: Three theoretically derived meditation composite scores, reflecting mechanisms involved in attentional, constructive, and deconstructive practices, displayed adequate psychometric properties. Separate secondary confirmatory factor analyses empirically corroborated the theoretically predicted three-factor structure of this classification system. Conclusions: Complementing data-driven approaches, this study offers preliminary support for using a theoretical model of meditation-related mechanisms to create empirically meaningful and psychometrically sound composite scores. We conclude by suggesting conceptual and methodological considerations for future research in this area

Latitude dictates plant diversity effects on instream decomposition

Abstract Running waters contribute substantially to global carbon fluxes through decomposition of terrestrial plant litter by aquatic microorganisms and detritivores. Diversity of this litter may influence instream decomposition globally in ways that are not yet understood. We investigated latitudinal differences in decomposition of litter mixtures of low and high functional diversity in 40 streams on 6 continents and spanning 113° of latitude. Despite important variability in our dataset, we found latitudinal differences in the effect of litter functional diversity on decomposition, which we explained as evolutionary adaptations of litter-consuming detritivores to resource availability. Specifically, a balanced diet effect appears to operate at lower latitudes versus a resource concentration effect at higher latitudes. The latitudinal pattern indicates that loss of plant functional diversity will have different consequences on carbon fluxes across the globe, with greater repercussions likely at low latitudes