Vocal-tract resonances as indexical cues in rhesus monkeys

Vocal-tract resonances (or formants) are acoustic signatures in the voice and are related to the shape and length of the vocal tract. Formants play an important role in human communication, helping us not only to distinguish several different speech sounds [1], but also to extract important information related to the physical characteristics of the speaker, so-called indexical cues. How did formants come to play such an important role in human vocal communication? One hypothesis suggests that the ancestral role of formant perception--a role that might be present in extant nonhuman primates--was to provide indexical cues [2-5]. Although formants are present in the acoustic structure of vowel-like calls of monkeys [3-8] and implicated in the discrimination of call types [8-10], it is not known whether they use this feature to extract indexical cues. Here, we investigate whether rhesus monkeys can use the formant structure in their "coo" calls to assess the age-related body size of conspecifics. Using a preferential-looking paradigm [11, 12] and synthetic coo calls in which formant structure simulated an adult/large- or juvenile/small-sounding individual, we demonstrate that untrained monkeys attend to formant cues and link large-sounding coos to large faces and small-sounding coos to small faces-in essence, they can, like humans [13], use formants as indicators of age-related body size.     

The Metabolic Syndrome and ECG Detected Left Ventricular Hypertrophy – Influences from IGF-1 and IGF-Binding Protein-1

Background and Aims

The metabolic syndrome (MetS) is associated with an increased risk for left ventricular hypertrophy (LVH) and cardiovascular mortality. The aim of this study was to investigate potential influences from insulin-like growth factor-1 (IGF-1) and IGF binding protein-1 (IGFBP-1) on the relationship between the MetS and LVH, also taking into account the role of physical activity (PA), use of oestrogen and gender.

Methods and Results

In a population-based cross-sectional study of 60-year-old men (n = 1822) and women (n = 2049) participants underwent physical examination and laboratory tests, including electrocardiography (ECG), and completed an extensive questionnaire. Women showed higher levels of IGFBP-1 than men (37.0 vs. 28.0 µg/l, p<0.001), and women with LVH had lower levels of IGFBP-1 than women without LVH (31.0 µg/l vs. 37.0 µg/l, p<0.001). Furthermore, women with low levels of IGFBP-1 had a significantly increased risk of having LVH (crude OR≈2.5). When stratifying for PA and oestrogen, respectively, a weaker association between IGFBP-1 and LVH was demonstrated in physically active men and women, compared to inactive individuals, as well as in women using oestrogen, compared to non-users.

Conclusion

In a representative sample of 60-year-old Swedish men and women, the main findings were higher levels of IGFBP-1 in women than in men; lower levels of IGFBP-1 in women with LVH, compared to women without LVH; and an increased risk of having LVH in women with low levels of IGFBP-1. The association between IGFBP-1 and LVH was diminished in physically active men and women, as well as in women using oestrogen.     

Effect of iTRAQ Labeling on the Relative Abundance of Peptide Fragment Ions Produced by MALDI-MS/MS

The identification of proteins in proteomics experiments is usually based on mass information derived from tandem mass spectrometry data. To improve the performance of the identification algorithms, additional information available in the fragment peak intensity patterns has been shown to be useful. In this study, we consider the effect of iTRAQ labeling on the fragment peak intensity patterns of singly charged peptides from MALDI tandem MS data. The presence of an iTRAQ-modified basic group on the N-terminus leads to a more pronounced set of b-ion peaks and distinct changes in the abundance of specific peptide types. We performed a simple intensity prediction by using a decision-tree machine learning approach and were able to show that the relative ion abundance in a spectrum can be correctly predicted and distinguished from closely related sequences. This information will be useful for the development of improved method-specific intensity-based protein identification algorithms.     

Soil frost enhances stream dissolved organic carbon concentrations during episodic spring snow melt from boreal mires

Changes in winter time conditions at high‐latitude ecosystems could severely affect the carbon exchange processes. Using a 15 year stream record combined with winter field measurements and laboratory experiment, we studied the regulation of dissolved organic carbon (DOC) concentration in stream water draining boreal mire during snow melt. The most unanticipated finding was that cold soils with deep soil frost resulted in increased snow melt DOC concentrations in the stream runoff. Wintertime field measurements of DOC concentrations below the mire soil frost showed that this phenomenon could be explained by freeze‐out of DOC giving higher levels of DOC in the soil water below the ice as the soil frost developed downwards in the mire. Experimental freezing of water with a certain DOC concentration in the laboratory further corroborated the freeze‐out of DOC. In this experiment, as much as 96% of the DOC was excluded from the ice, whereas the freeze‐out in the mire was less effective (60%). The difference between the proportion of DOC retained in pure water relative to the proportion retained in peat water during freezing is probably due to trapped DOC in the solid peat soil matrix. A simple mass‐balance model showed that to explain the higher stream DOC concentrations during a winter with deep soil frost, approximately 0.5% of the mire area needed to be hydrologically connected to the stream discharge. In the stream records, we also found that the DOC concentrations during snow melt episodic runoff were negatively related to increasing intensity of the snow melt episodes (dilution by low DOC snow melt water) and higher previous export of DOC.     

Aquatic export of young dissolved and gaseous carbon from a pristine boreal fen: Implications for peat carbon stock stability

The stability of northern peatland's carbon (C) store under changing climate is of major concern for the global C cycle. The aquatic export of C from boreal peatlands is recognized as both a critical pathway for the remobilization of peat C stocks as well as a major component of the net ecosystem C balance (NECB). Here, we present a full year characterization of radiocarbon content (¹⁴C) of dissolved organic carbon (DOC), carbon dioxide (CO₂), and methane (CH₄) exported from a boreal peatland catchment coupled with ¹⁴C characterization of the catchment's peat profile of the same C species. The age of aquatic C in runoff varied little throughout the year and appeared to be sustained by recently fixed C from the atmosphere (<60 years), despite stream DOC, CO₂, and CH₄ primarily being sourced from deep peat horizons (2–4 m) near the mire's outlet. In fact, the ¹⁴C content of DOC, CO₂, and CH₄ across the entire peat profile was considerably enriched with postbomb C compared with the solid peat material. Overall, our results demonstrate little to no mobilization of ancient C stocks from this boreal peatland and a relatively large resilience of the source of aquatic C export to forecasted hydroclimatic changes.     

Biogenic Sediment Compounds in Relation to Marine Meiofaunal Abundances

Correlations between a series of biogenic sediment compounds, commonly used in ecological studies, and a major component of the benthic infauna, the meiofauna, were studied on the continental margin off Southwest Africa (Angola) and in a central oceanic region of the Atlantic Ocean (Mid Oceanic Ridge). Biogenic sediment compounds chosen for this investigation (electron-transport-system activity, total adenylates and energy charge, particulate proteins, chloroplastic pigments) are obviously not suitable for a quick and rough estimation of meiofaunal abundances. Nevertheless, biogenic sediment compounds might reflect quite well the activity and biomass of the total benthic infauna, including all size classes (from bacteria to macrofaunal organisms) and/or the total particulate organic matter within the sediments. Furthermore, analyzing biogenic sediment compounds leads to a better understanding of environmental conditions and biological activities of benthic organisms. Consequently, despite their limitations, biochemical sediment parameters may be very useful in benthic ecological studies to obtain rapid information on the eco-status of the benthic system.