Cold thermopeaking-induced drift of nase Chondrostoma nasus larvae.

Research on how intermittent water releases from hydropower plants affect the early life stages of fish has advanced in the last years, focusing not only on the direct impacts of rapid flow changes (hydropeaking), but also on the short-term fluctuations in water temperature (thermopeaking). Flow and thermal fluctuations caused by hydropeaking may affect fish movement patterns and migration at critical stages of a species' life cycle, e.g., by inducing passive downstream drift. Using two experimental outdoor channels, we investigated how nase (Chondrostoma nasus, Cypriniformes) larvae respond to a rapid drop in water temperature during hydropeaking (simulating a cold thermopeaking event), reaching on average 5.5 °C under peak flow (maximum discharge) conditions, in comparison with a hydropeaking treatment with a constant water temperature regime. Responses of fish larvae were analyzed during acclimation, up-ramping (increase in discharge), peak flow and down-ramping (decrease in discharge) phases. Fish drift increased during peak flow in the cold thermopeaking treatment compared to hydropeaking. Higher drift rates were also negatively associated with pronounced water temperature drops during peak flow conditions. In addition, the starting temperature of the experiment influenced drift during up-ramping. Overall, the results suggest that cold thermopeaking may increase drift in the early life stages of cypriniform fish compared with hydropeaking with stable water temperature. Hence, monitoring and active water temperature adjustments following hydropower releases should be adopted as strategies to mitigate power plant-related impacts on aquatic organisms. Supplementary Information: The online version contains supplementary material available at 10.1007/s00027-023-00955-x.

Assessing the faecal source sensitivity and specificity of ruminant and human genetic microbial source tracking markers in the central Ethiopian highlands.

This study tested genetic microbial source tracking (MST) methods for identifying ruminant- (BacR) and human-associated (HF183/BacR287, BacHum) bacterial faecal contaminants in Ethiopia in a newly created regional faecal sample bank (n = 173). BacR performed well, and its marker abundance was high (100% sensitivity (Sens), 95% specificity (Spec), median log10 8·1 marker equivalents (ME) g-1 ruminant faeces). Human-associated markers tested were less abundant in individual human samples (median: log10 5·4 and 4·2 (ME + 1) g-1 ) and were not continuously detected (81% Sens, 91% Spec for BacHum; 77% Sens, 91% Spec for HF183/BacR287). Furthermore, the pig-associated Pig2Bac assay was included and performed excellent (100% Sens, 100% Spec). To evaluate the presence of MST targets in the soil microbiome, representative soil samples were tested during a whole seasonal cycle (n = 60). Only BacR could be detected, but was limited to the dry season and to sites of higher anthropogenic influence (log10 3·0 to 4·9 (ME + 1) g-1 soil). In conclusion, the large differences in marker abundances between target and non-target faecal samples (median distances between distributions ≥log10 3 to ≥log10 7) and their absence in pristine soil indicate that all tested assays are suitable candidates for diverse MST applications in the Ethiopian area.

Young children's phonological sensitivity after exposure to a rhyming or nonrhyming story.

This study examined the ability of preschool children to make phonological discriminations after hearing rhyming or nonrhyming versions of the same story. Participants first listened to either a rhyming or nonrhyming version of a story, Rainy Day Kate (Blegvad, 1987), then attempted a phonological deletion and a rhyme/alliteration detection task. In accordance with prior theoretical notions that listening to rhyme sensitizes young children to phonological properties of words, children who heard the rhyming version of the story showed significantly higher performance on the rhyme/alliteration task than did participants who heard the nonrhyming narrative. Children in the rhyme condition also offered more rhyming and clang (nonword but phonologically similar) associates in completing the phonological deletion task.

Enmity in males at four developmental levels: cognitive bases for disliking peers.

The goal of this study was to determine whether, at different age levels, males cite different bases as reasons for disliking peers. Male preschoolers, primary graders, preadolescents, and young adults were asked to name and give reasons for disliking an actual same-sex peer. Participants from preschool through preadolescence frequently cited aggression and aberrant behavior as reasons for disliking, a finding that suggests that both dimensions serve as major sources of enmity across childhood. Although aggression was not cited frequently by the young adults, aberrant behavior persisted as a significant basis for disliking across all four developmental levels. Lack of general play and rule violation constituted reliable bases for disliking only at the preschool level, whereas lack of help was cited frequently by both the primary-grade and preadolescent participants. The preadolescents and the young adults also specified negative evaluation as a major basis of enmity, whereas lack of genuineness was cited at above-chance levels only by the young adults.

Young children and television: the retention of emotional reactions.

In 6 experiments, we examined preschoolers' ability to interpret or remember the affective reactions of television characters. In 2 studies, children viewed a "Sesame Street" or "Cosby Show" segment, and then retold the story. In both, mention of the protagonists' affective states was low, with less than 1% of the reactions recalled. In 3 experiments (using muppet, cartoon, or human portrayals), we examined whether this low retention was due to an inability to interpret reactions, identify their emotional labels, or remember them across a short period. For muppet and cartoon shows, children accurately recognized labels for reactions immediately after portrayal, but showed significant reductions in recognition memory by the end of the show. For human portrayals, subjects showed accurate recognition immediately after presentation, as well as after the show. In a final experiment, free descriptions of the reactions were assessed. Correct description was significantly higher for basic emotions than complex emotions.