1,934 research outputs found

    Flexible signalling strategies by victims mediate post-conflict interactions in bonobos

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    Compared to other animals, humans supposedly excel at voluntarily controlling and strategically displaying emotional signals. Yet, new data shows that nonhuman great apes' emotion expressions may also be subject to voluntary control. A key context to further explore this is during post-conflict (PC) periods, where signalling by distressed victims may influence bystander responses, including the offering of consolation. To address this, our study investigates the signalling behaviour of sanctuary-living bonobo victims following aggression and its relation to audience composition and PC interactions. Results show that the production of paedomorphic signals by victims (regardless of age) increased their chances of receiving consolation. In adults, the production of such signals additionally reduced the risk of renewed aggression from opponents. Signal production also increased with audience size, yet strategies differed by age: while immatures reduced signalling in proximity of close-social partners, adults did so especially after receiving consolation. These results suggest that bonobos can flexibly adjust their emotion signalling to influence the outcome of PC events, and that this tendency has a developmental trajectory. Overall, these findings highlight the potential role that flexible emotion communication played in the sociality of our last common ancestor with Pan

    What drives young children to over-imitate? Investigating the effects of age, context, action type, and transitivity

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    Imitation underlies many traits thought to characterize our species, which includes the transmission and acquisition of language, material culture, norms, rituals, and conventions. From early childhood, humans show an intriguing willingness to imitate behaviors, even those that have no obvious function. This phenomenon, known as “over-imitation,” is thought to explain some of the key differences between human cultures as compared with those of nonhuman animals. Here, we used a single integrative paradigm to simultaneously investigate several key factors proposed to shape children’s over-imitation: age, context, transitivity, and action type. We compared typically developing children aged 4–6 years in a task involving actions verbally framed as being instrumental, normative, or communicative in function. Within these contexts, we explored whether children were more likely to over-imitate transitive versus intransitive actions and manual versus body part actions. Results showed an interaction between age and context; as children got older, they were more likely to imitate within a normative context, whereas younger children were more likely to imitate in instrumental contexts. Younger children were more likely to imitate transitive actions (actions on objects) than intransitive actions compared with older children. Our results show that children are highly sensitive to even minimal cues to perceived context and flexibly adapt their imitation accordingly. As they get older, children’s imitation appears to become less object bound, less focused on instrumental outcomes, and more sensitive to normative cues. This shift is consistent with the proposal that over-imitation becomes increasingly social in its function as children move through childhood and beyond

    Biological control of Canada thistle (Cirsium arvense) in South Dakota

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    Canada thistle, Cirsium arvense L., is an aggressive invasive species that is found in the northern United States and not easily controlled by chemical and mechanical methods. Integrating biological control agents with other methods may improve control. This study investigated the effects of Canada thistle gall fly (Urophora cardui Diptera: Tephritidae); Canada thistle stem or crown weevil (Ceutorhynchus litura Coleoptera: Curculionidae); Canada thistle bud weevil (Larinus planus Coleoptera: Curculionidae); and Canada thistle tortoise beetle (Cassida rubiginosa Coleoptera: Chysomelidae) on Canada thistle at three SD sites 1997 and 1998, about three years after initial release. Active stem weevil larvae were found in all release sites early in the season (May, June). Bud weevils were found in a limited number of plants in July. Galls and gall fly larvae were found late in the season. Defoliation from the tortoise beetle was not noted at the one site of release. Total nonstructural carbohydrate (TNC) contents of roots were 50% lower in roots from release sites compared to TNC levels in roots from control sites at two locations in 1998. Since Canada thistle infestations rely on roots for survival, reduction of root TNC may be an important mechanism to reduce patch vigor, and ultimately, Canada thistle’s importance in the SD landscape

    Atrazine and Alachlor Adsorption Characteristics to Benchmark Soil Series in Eastern South Dakota

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    Corn, grain sorghum, and soybean are grown on about six million acres in eastern South Dakota each year. Two herbicides used routinely for weed control are atrazine(6-chloro-N-ethyl-N’-(1-methylethyl)-1,3,5-triazine-2,4-diamine) in corn and grain sorghum and alachlor (2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide) in all three crops. Six benchmark soil series that include a majority of the cropped acres treated with these herbicides are the Egan, Moody, Nora, and Brandt silty clay loams, and Clarno and Enet loams. Batch adsorption studies determined atrazine and alachlor binding characteristics to these soils and aids in assessing the amount of herbicide available for movement. These data also provide a basis for future use and management decisions for these and other related herbicides in similar soils. Soils from three horizons (A, B, and C) for each soil type were treated with atrazine or alachlor at four herbicide concentrations. Atrazine and alachlor sorption partition coefficients differed most in A horizon soils and ranged from 2.16 to 5.35 ”mol1-1/n L1/nKg-1 for atrazine and 1.95 to 5.78 ”mol1-1/n L1/nKg-1 for alachlor. Atrazine binding to A horizon soils ranked as Brandt \u3eEgan = Moody \u3e Enet = Clarno \u3e Nora. Alachlor binding to A horizon soils ranked as Brandt \u3eMoody \u3e Nora \u3e Enet \u3e Clarno. B and C horizon soils had lower binding for both herbicides; the sorption partition coefficient for atrazine ranged from 0.12 to 1.9 ”mol1-1/n L1/nKg-1 while alachlor ranged from 0.43 to 1.64 ”mol1-1/n L1/nKg-1. These data indicate that some soil types would be more susceptible to herbicide leaching than others. Once the herbicide moves through the A horizon, it may move rapidly through the lower soil profile (because of the decrease in binding capacity), and therefore, increase the vulnerability of the aquifer to contamination. Best management practices for these herbicides are being investigated to limit their movement through soil

    The Association Between the Bared-Teeth Display and Social Dominance in Captive Chimpanzees (Pan troglodytes)

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    Humans use smiles — widely observed emotional expressions — in a variety of social situations, of which the meaning varies depending on social relationship and the context in which it is displayed. The homologue of the human smile in non-human primates — both due to morphological and functional similarities — is the bared-teeth display (BT). According to the power asymmetry hypothesis (PAH), species with strict linear dominance hierarchies are predicted to produce distinct communicative signals to avoid escalations of social conflicts. Hence, while the BT in a despotic species is predicted to be expressed from low- to high-ranking individuals, signaling submission, the BT in a tolerant species is predicted to be expressed in multiple contexts, regardless of rank. We tested this hypothesis in a group of 8 captive chimpanzees (Pan troglodytes), a species commonly characterized as rather despotic. An investigation of 11,774 dyadic social interactions revealed this chimpanzee group to have a linear dominance hierarchy, with moderate steepness. A Bayesian GLMM — used to test the effects of social contexts and rank relationships of dyads on the use of the BT display — indicated multi-contextual use of the BT which is contingent on the rank relationship. We also found that slight morphological and/or acoustic variants (i.e., silent bared-teeth and vocalized bared-teeth) of the BT display may have different communicative meanings. Our findings are in line with the prediction derived from the PAH for a moderately despotic species, and the view that the human smile originated from the primate BT display

    Theoretical Derivation of Stable and Nonisotopic Approaches for Assessing Soil Organic Carbon Turnover

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    Techniques for measuring soil organic C (SOC) turnover in production fields are needed. The objectives of this study were to propose and test nonisotopic and 13 C stable isotopic techniques for assessing SOC turnover. Based on SOC equilibrium and mass balance relationships, an equation was derived: NHC/SOC initial=[1/(SOC× k NHC)](dSOC/dt)+ k SOC/k NHC, where dSOC/dt is the annual change in SOC, NHC is nonharvested C returned to soil, k SOC is the annual mineralization rate of SOC, and k NHC is the annual mineralization rate of NHC. This equation was used to calculate maintenance rates. An isotopic approach based on simultaneously solving the equations was developed to determine C budgets:(i) SOC retained=[SOC final (Δ soil final− Δ PCR)/(Δ SOCretained− Δ PCR)];(ii) Δ SOC retained= Δ soc initial−[Δ ln (SOC retained/SOC initial)],(iii) Δ PCR= Δ NHC−[Δ ln (PCR/NHC)]; and (iv) SOC fina

    Jet aircraft engine exhaust emissions database development: Year 1990 and 2015 scenarios

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    Studies relating to environmental emissions associated with the High Speed Civil Transport (HSCT) military jet and charter jet aircraft were conducted by McDonnell Douglas Aerospace Transport Aircraft. The report includes engine emission results for baseline 1990 charter and military scenario and the projected jet engine emissions results for a 2015 scenario for a Mach 1.6 HSCT charter and military fleet. Discussions of the methodology used in formulating these databases are provided

    Older, vulnerable patient view: a pilot and feasibility study of the patient measure of safety (PMOS) with patients in Australia

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    Objectives The UK-developed patient measure of safety (PMOS) is a validated tool which captures patient perceptions of safety in hospitals. We aimed (1) to investigate the extent to which the PMOS is appropriate for use with stroke, acute myocardial infarction (AMI) and hip fracture patients in Australian hospitals and (2) to pilot the PMOS for use in a large-scale, national study ‘Deepening our Understanding of Quality in Australia’ (DUQuA). Participants Stroke, AMI and hip fracture patients (n=34) receiving care in 3 wards in 1 large hospital. Methods 2 phases were conducted. First, a ‘think aloud’ study was used to determine the validity of PMOS with this population in an international setting, and to make amendments based on patient feedback. The second phase tested the revised measure to establish the internal consistency reliability of the revised subscales, and piloted the recruitment and administration processes to ensure feasibility of the PMOS for use in DUQuA. Results Of the 43 questions in the PMOS, 13 (30%) were amended based on issues patients highlighted for improvement in phase 1. In phase 2, a total of 34 patients were approached and 29 included, with a mean age of 71.3 years (SD=16.39). Internal consistency reliability was established using interitem correlation and Cronbach's α for all but 1 subscale. The most and least favourably rated aspects of safety differed between the 3 wards. A study log was categorised into 10 key feasibility factors, including liaising with wards to understand operational procedures and identify patterns of patient discharge. Conclusions Capturing patient perceptions of care is crucial in improving patient safety. The revised PMOS is appropriate for use with vulnerable older adult groups. The findings from this study have informed key decisions made for the deployment of this measure as part of the DUQuA study

    Higher fundamental frequency in bonobos is explained by larynx morphology

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    Acoustic signals, shaped by natural and sexual selection, reveal ecological and social selection pressures [1]. Examining acoustic signals together with morphology can be particularly revealing. But this approach has rarely been applied to primates, where clues to the evolutionary trajectory of human communication may be found. Across vertebrate species, there is a close relationship between body size and acoustic parameters, such as formant dispersion and fundamental frequency (f0). Deviations from this acoustic allometry usually produce calls with a lower f0 than expected for a given body size, often due to morphological adaptations in the larynx or vocal tract [2]. An unusual example of an obvious mismatch between fundamental frequency and body size is found in the two closest living relatives of humans, bonobos (Pan paniscus) and chimpanzees (Pan troglodytes). Although these two ape species overlap in body size [3], bonobo calls have a strikingly higher f0 than corresponding calls from chimpanzees [4]. Here, we compare acoustic structures of calls from bonobos and chimpanzees in relation to their larynx morphology. We found that shorter vocal fold length in bonobos compared to chimpanzees accounted for species differences in f0, showing a rare case of positive selection for signal diminution in both bonobo sexes

    Blunt trauma induced splenic blushes are not created equal

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    <p>Abstract</p> <p>Background</p> <p>Currently, evidence of contrast extravasation on computed tomography (CT) scan is regarded as an indication for intervention in splenic injuries. In our experience, patients transferred from other institutions for angioembolization have often resolved the blush upon repeat imaging at our hospital. We <it>hypothesized </it>that not all splenic blushes require intervention.</p> <p>Methods</p> <p>During a 10-year period, we reviewed all patients transferred with blunt splenic injuries and contrast extravasation on initial postinjury CT scan.</p> <p>Results</p> <p>During the study period, 241 patients were referred for splenic injuries, of whom 16 had a contrast blush on initial CT imaging (88% men, mean age 35 ± 5, mean ISS 26 ± 3). Eight (50%) patients were managed without angioembolization or operation. Comparing patients with and without intervention, there was a significant difference in admission heart rate (106 ± 9 <it>vs </it>83 ± 6) and decline in hematocrit following transfer (5.3 ± 2.0 <it>vs </it>1.0 ± 0.3), but not in injury grade (3.9 ± 0.2 <it>vs </it>3.5 ± 0.3), systolic blood pressure (125 ± 10 <it>vs </it>115 ± 6), or age (38.5 ± 8.2 <it>vs </it>30.9 ± 4.7). Of the 8 observed patients, 3 underwent repeat imaging immediately upon arrival with resolution of the blush. In the intervention group, 4 patients had ongoing extravasation on repeat imaging, 2 patients underwent empiric embolization, and 2 patients underwent splenectomy for physiologic indications.</p> <p>Conclusions</p> <p>For blunt splenic trauma, evidence of contrast extravasation on initial CT imaging is not an absolute indication for intervention. A period of observation with repeat imaging could avoid costly, invasive interventions and their associated sequelae.</p
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