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• In native highlanders, S P O 2 was greater in the upright-seated than in the flat posture. • Changes in oxyhemoglobin saturation were greatest in older subjects. • Flat posture may be a significant contributor to hypoxemia during sleep. • Postural maneuvers may mitigate nocturnal hypoxemia and its sequelae in highlanders. At high altitude, hypoxia amplifies oxyhemoglobin saturation (S P O 2) swings with changes in respiratory mechanics. Our objective was to examine the effects of posture on S P O 2 and determine predictors of postural S P O 2 changes in highlanders. 50 native highlanders from Puno, Peru (3825 m) assumed supine and upright-seated postures, in rotating sequence, while undergoing continuous pulse-oximetry. We compared mean S p O 2 in each posture with a paired t -test. We examined associations of BMI, age, sex and spirometry with postural S p O 2 changes with mixed-effects linear regression. In highlanders, S p O 2 was 84% in the supine posture and was 1.0% ± 1.1 (p < 0.0001) greater in the upright-seated posture. Greater postural changes in S p O 2 were associated with older age (p = 0.01 for interaction) but not with sex, BMI, FVC or FEV 1. In highlanders, S p O 2 is higher in the upright-seated compared to supine posture, especially with older age. Because we generally sleep flat, posture may contribute significantly to highlanders' hypoxemic burden during sleep. Postural intervention during sleep may mitigate nocturnal hypoxemia. [ABSTRACT FROM AUTHOR]

Tropical forests are shifting in species and trait composition, but the main underlying causes remain unclear because of the short temporal scales of most studies. Here, we develop a novel approach by linking functional trait data with 7000 years of forest dynamics from a fossil pollen record of Lake Sauce in the Peruvian Amazon. We evaluate how climate and human disturbances affect community trait composition. We found weak relationships between environmental conditions and traits at the taxon level, but strong effects for community‐mean traits. Overall, community‐mean traits were more responsive to human disturbances than to climate change; human‐induced erosion increased the dominance of dense‐wooded, non‐zoochorous species with compound leaves, and human‐induced fire increased the dominance of tall, zoochorous taxa with large seeds and simple leaves. This information can help to enhance our understanding of forest responses to past environmental changes, and improve predictions of future changes in tropical forest composition. [ABSTRACT FROM AUTHOR]

Background: The development of gross motor coordination (GMC) is governed by biological and environmental factors whose effect sizes are still unclear. Aim: To investigate sibling resemblance in GMC, as well as biological and environmental correlates of GMC among Peruvian children. Materials and methods: The sample comprised 1256 biological siblings (6–15 years old), from three geographical areas of Peru. GMC was assessed using the Korperkoordinationtest für Kinder (KTK) test battery. Anthropometry, biological maturation and physical fitness (PF) were also measured. Multilevel modelling was performed using Stata 14 software. Results: In general, sister–sister pairs (SS) showed the highest resemblance in GMC (ρ = 0.24) compared to brother–sister (BS) (ρ = 0.10) and brother–brother (BB) pairs (ρ = 0.07). On average, BB pairs had higher GMC than SS pairs and older siblings had higher GMC than younger siblings. Further, those with lower body mass index (BMI) and higher PF had higher GMC. There was also a significant interaction between age and PF with GMC. Siblings from the rainforest region demonstrated higher GMC than those from sea level and high-altitude siblings demonstrated lower GMC than their sea-level peers. Conclusion: These results demonstrate statistically significant sibling resemblance in GMC. Age, BMI, PF and geographical area were significant correlates of GMC. [ABSTRACT FROM AUTHOR]

The Black-goggled Tanager (Trichothraupis melanops) is a South American forest species that comprises two disjunct populations in the Atlantic Forest and in the Andes. During visits to natural history museums, we noticed morphological differences between these populations, which led to a taxonomic revision of the species based on plumage patterns and morphometry. Our analyses revealed that both populations are fully diagnosable, and that the Andean population represents an undescribed taxon, which we name Trichothraupis griseonota sp. nov. The new taxon differs from T. melanops by the extension of black in the faces of the males, covering the auricular region, and a greyer shade on the back (instead of olive). A previous mtDNA study with Trichothraupis is consistent with our conclusions that a new taxon requires recognition. The new species is found from 400 m up to 1,700 m on the eastern slopes of the Andes in Peru, Bolivia, and northwestern Argentina, inhabiting Tucumano-Boliviano and Yungas Forests as opposed to the Atlantic Forests where T. melanops is found. The biogeographical disjunction of the two species is similar to what has been observed for other bird species and subspecies, whereby avian lineages are allopatrically distributed and separated by the Chaco-Cerrado vegetation. The description of this taxon reinforces the importance of continued studies and analyses of museum specimens, which may yet reveal little-known patterns and undescribed taxa.

Non-structural carbohydrates (NSC) are major substrates for plant metabolism and have been implicated in mediating drought-induced tree mortality. Despite their significance, NSC dynamics in tropical forests remain little studied. We present leaf and branch NSC data for 82 Amazon canopy tree species in six sites spanning a broad precipitation gradient. During the wet season, total NSC (NSC T ) concentrations in both organs were remarkably similar across communities. However, NSC T and its soluble sugar (SS) and starch components varied much more across sites during the dry season. Notably, the proportion of leaf NSC T in the form of SS (SS:NSC T ) increased greatly in the dry season in almost all species in the driest sites, implying an important role of SS in mediating water stress in these sites. This adjustment of leaf NSC balance was not observed in tree species less-adapted to water deficit, even under exceptionally dry conditions. Thus, leaf carbon metabolism may help to explain floristic sorting across water availability gradients in Amazonia and enable better prediction of forest responses to future climate change.