Annals of the New York Academy of Sciences最新文献

This study explores the impact of feathers on the hydrodynamic drag experienced by diving birds, which is critical to their foraging efficiency and survival. Employing a novel experimental approach, we analyzed the kinematics of both feathered and nonfeathered projectiles during their transition from air to water using high-speed imaging and an onboard accelerometer. The drag coefficients were determined through two methods: a direct calculation from the acceleration data and a theoretical approach fitted to the observed velocity profiles. Our results indicate that feathers significantly increase the drag force during water entry, with feathered projectiles exhibiting approximately double the drag coefficient of their smooth counterparts. These findings provide new insights into the role of avian feather morphology in diving mechanics and have potential implications for the design of bioinspired aquatic vehicles in engineering. The study also discusses the biological implications of increased drag due to feathers and suggests that factors such as body shape might play a more critical role in the diving capabilities of birds than previously understood.

One difference among writing systems is how orthographic cues are used to demarcate words; although most alphabetic scripts use inter-word spaces, some Asian scripts do not explicitly mark word boundaries (e.g., Chinese). It is unclear whether these differences are arbitrary or whether they are designed to maximize reading efficiency. Here, we show that spaces inserted between words in non-demarcated scripts provide less information about word boundaries than spaces in demarcated scripts. Furthermore, despite the fact that less information is contained by inter-word spaces than characters/letters of the same size, the information content of inter-word spaces in demarcated scripts is closer to that of characters/letters compared to the information content of inter-word spaces that are inserted in non-demarcated scripts. These results suggest that the conventions used to demarcate word boundaries are sufficient to support efficient reading. Our findings provide new insights into the universals and variation across writing systems and shed light on the mental processes that support skilled reading.

Considerable debate exists about the interplay between auditory and motor speech systems. Some argue for common neural mechanisms, whereas others assert that there are few shared resources. In four experiments, we tested the hypothesis that priming the speech motor system by repeating syllable pairs aloud improves subsequent syllable discrimination in noise compared with a priming discrimination task involving same-different judgments via button presses. Our results consistently showed that participants who engaged in syllable repetition performed better in syllable discrimination in noise than those who engaged in the priming discrimination task. This gain in accuracy was observed for primed and new syllable pairs, highlighting increased sensitivity to phonological details. The benefits were comparable whether the priming tasks involved auditory or visual presentation. Inserting a 1-h delay between the priming tasks and the syllable-in-noise task, the benefits persisted but were confined to primed syllable pairs. Finally, we demonstrated the effectiveness of this approach in older adults. Our findings substantiate the existence of a speech production-perception relationship. They also have clinical relevance as they raise the possibility of production-based interventions to improve speech perception ability. This would be particularly relevant for older adults who often encounter difficulties in perceiving speech in noise.

Micronutrient interventions can reduce child mortality. By applying Micronutrient Intervention Modeling methods in Senegal, Burkina Faso, and Nigeria, we estimated the impacts of bouillon fortification on apparent dietary adequacy of vitamin A and zinc among children and folate among women. We then used the Lives Saved Tool to predict the impacts of bouillon fortification with ranges of vitamin A, zinc, and folic acid concentrations on lives saved among children 6-59 months of age. Fortification at 250 µg vitamin A/g and 120 µg folic acid/g was predicted to substantially reduce vitamin A- and folate-attributable deaths: 65% for vitamin A and 92% for folate (Senegal), 36% for vitamin A and 74% for folate (Burkina Faso), and >95% for both (Nigeria). Zinc fortification at 5 mg/g would avert 48% (Senegal), 31% (Burkina Faso), and 63% (Nigeria) of zinc-attributable deaths. The addition of all three nutrients at 30% of Codex nutrient reference values in 2.5 g bouillon was predicted to save an annual average of 293 child lives in Senegal (3.5% of deaths from all causes among children 6-59 months of age), 933 (2.1%) in Burkina Faso, and 18,362 (3.7%) in Nigeria. These results, along with evidence on program feasibility and costs, can help inform fortification program design discussions.