Researchers considering children's traditional ecological knowledge (TEK) highlighted the importance of examining children's daily activities as empirical contexts for its acquisition. Many of them ...evaluated children's TEK acquisition linearly as gain or loss, and paid less attention to the adaptive nature of this knowledge system and the social relationships arising from its acquisition processes. This study approaches children's TEK acquisition considering these abovementioned aspects. I utilize pastoral Maasai girls' firewood collection as a case study, and analyze the personal, interpersonal and cultural institutional aspects of girls' Ethnobotanical knowledge (EK) acquisition within this chore.
Participant observation and unstructured interviews were used for data collection. I joined 12 girls (6 to 15 years old) on day trips for firewood collection, and documented their participation and performance during this chore. I observed interactions among girls and between girls and women concerning this activity, and investigated girls' perceptions of local wood species via their descriptions. I also informally interviewed 15 women, between 20 and 80 years old on their evaluation of the wood species to be used as firewood.
Current diet change and gender-age roles in chore participation in Maasai society require females to continually participate in firewood collection. Within this social context, girls intensively participated in day trips of firewood collection during the long-term vacation in the dry season. They collected a sizable amount from 24 plant species, and generated EK through personal sensual experiences, such as fragrance, hardness, and heaviness of different wood species. They acquired local taxonomy and terminology of different wood species, and learned others preferences for wood species used as fuel through interpersonal communication. These personal and interpersonal aspects, together with current diet change and division of labor within gender-age roles in Maasai society, provide EK with multi-dimensional meanings in current subsistence strategies.
Results of this study show that girls acquired EK with multi-dimensional meanings through daily firewood collection, which cannot be only evaluated in a linear manner. Future studies focused on children's TEK acquisition should consider the personal, interpersonal, and cultural institutional aspects of this adaptive knowledge system and children's roles within it.
Pastoralists in East Africa are well known for their abilities in effective livestock and natural resource management in the dynamic arid and semi-arid ecosystem in which they live. Their ...ethnobiological knowledge, manifest in their skills of managing livestock and natural resources, is generated from the daily experiences of individuals in different landscapes. Since the early twentieth century, the pastoralist Maasai have gradually experienced land fragmentation and lifestyle changes. However, how Maasai children learn ethnobiological knowledge and how their learning processes are related to the local accessibility of their land remain largely unknown. Focusing on eleven children's daily activities during long school vacations in a Maasai village, where lands are still communally owned, this paper aims to understand the children's ethnobiological knowledge learning and its relation to access to land in current social contexts. The children independently undertake work, such as livestock herding and food preparation, as well as engaging in various play activities. With access to the land, they continue generating ethnobiological knowledge in different spatial and temporal contexts during work and play. The results of this study illustrate that access to the land plays important roles in current Maasai societies in terms of children's ethnobiological knowledge learning. The study also suggests the necessity for further investigation of the relationship between land use changes and the ethnobiological knowledge learning of children in different small-scale societies.
Main conclusion
OsWRKY24 functions redundantly with OsWRKY53, while OsWRKY70 functions differently from OsWRKY53 in regulating grain size
.
Grain size is a key agronomic trait that affects grain ...yield and quality in rice (
Oryza sativa
L.). The transcription factor
OsWRKY53
positively regulates grain size through brassinosteroid (BR) signaling and Mitogen-Activated Protein Kinase (MAPK) cascades. However, whether the
OsWRKY53
homologs
OsWRKY24
and
OsWRKY70
also contribute to grain size which remains unknown. Here, we report that grain size in
OsWRKY24
overexpression lines and
oswrky24
mutants is similar to that of the wild type. However, the
oswrky24 oswrky53
double mutant produced smaller grains than the
oswrky53
single mutant, indicating functional redundancy between
OsWRKY24
and
OsWRKY53
. In addition,
OsWRKY70
overexpression lines displayed an enlarged leaf angle, reduced plant height, longer grains, and higher BR sensitivity, phenotypes similar to those of
OsWRKY53
overexpression lines. Importantly, a systematic characterization of seed length in the
oswrky70
single, the
oswrky53 oswrky70
double and the
oswrky24 oswrky53 oswrky70
triple mutant indicated that loss of
OsWRKY70
also leads to increased seed length, suggesting that
OsWRKY70
might play a role distinct from that of
OsWRKY53
in regulating grain size. Taken together, these findings suggest that
OsWRKY24
and
OsWRKY70
regulate rice grain size redundantly and independently from
OsWRKY53
.
Cuticular wax plays crucial roles in protecting plants from environmental stresses, particularly drought stress. Many enzymeencoding genes and transcription factors involved in wax biosynthesis have ...been identified, but the underlying posttranslational regulatory mechanisms are poorly understood. Here, we demonstrate that DROUGHT HYPERSENSITIVE (DHS), encoding a Really Interesting New Gene (RING)-type protein, is a critical regulator of wax biosynthesis in rice (Oryza sativa). The cuticular wax contents were significantly reduced in DHS overexpression plants but increased in dhs mutants compared with the wild type, which resulted in a response opposite that of drought stress. DHS exhibited E3 ubiquitin ligase activity and interacted with the homeodomain-leucine zipper IV protein ROC4. Analysis of ROC4 overexpression plants and roc4 mutants indicated that ROC4 positively regulates cuticular wax biosynthesis and the drought stress response. ROC4 is ubiquitinated in vivo and subjected to ubiquitin/26S proteasome-mediated degradation. ROC4 degradation was promoted by DHS but delayed in dhs mutants. ROC4 acts downstream of DHS, and Os-BDG is a direct downstream target of the DHS-ROC4 cascade. These results suggest a mechanism whereby DHS negatively regulates wax biosynthesis by promoting the degradation of ROC4, and they suggest that DHS and ROC4 are valuable targets for the engineering of drought-tolerant rice cultivars.
Studies focused on jumping performance in humans have so far investigated either its biological or sociocultural significance, with very little attentions paid to the inseparable relations of these ...two aspects in daily life of people. Integrating both ethnographic and biomechanical methods, this research investigated the biosocial features of the jump performance of Maasai youth in its most well observed context, the wedding ceremony. Ethnographic data were used to explain the social status of participants, the physical movements and singing tempo of performers, and their interactions. Biomechanical methods were applied to assess the heights and frequencies of identified repetitive double-legged vertical jumps (n = 160, from 15 male youths). All youth performers followed a certain posture pattern, paying specific attention to their final landing. Large variations exist in their jumping heights coefficient of variation (CV) = 0.237; however, the frequency in jump repetitions were maintained with the least variations (CV = 0.084). Cheering interactions were confirmed, but with no significant difference in height between the cheered and non-cheered groups. These results indicate that the Maasai youths did not compete for jump height during local ceremonies. Rather, they emphasized the rhythmical retention of jumps, corresponding to other youth mates who were singing alongside. In the broader context of human behaviors, the analysis addresses the diverse meanings of motor performances in different daily contexts that reject the generalized sports regime of “higher/faster-the-better”.
Studies focused on jumping performance in humans have so far investigated either its biological or sociocultural significance, with very little attentions paid to the inseparable relations of these ...two aspects in daily life of people. Integrating both ethnographic and biomechanical methods, this research investigated the biosocial features of the jump performance of Maasai youth in its most well observed context, the wedding ceremony. Ethnographic data were used to explain the social status of participants, the physical movements and singing tempo of performers, and their interactions. Biomechanical methods were applied to assess the heights and frequencies of identified repetitive double-legged vertical jumps (n = 160, from 15 male youths). All youth performers followed a certain posture pattern, paying specific attention to their final landing. Large variations exist in their jumping heights coefficient of variation (CV) = 0.237; however, the frequency in jump repetitions were maintained with the least variations (CV = 0.084). Cheering interactions were confirmed, but with no significant difference in height between the cheered and non-cheered groups. These results indicate that the Maasai youths did not compete for jump height during local ceremonies. Rather, they emphasized the rhythmical retention of jumps, corresponding to other youth mates who were singing alongside. In the broader context of human behaviors, the analysis addresses the diverse meanings of motor performances in different daily contexts that reject the generalized sports regime of "higher/faster-the-better".
We used resting-state functional magnetic resonance imaging to measure the amplitude of low-frequency fluctuations (ALFF) of intrinsic brain activity in 23 patients with moderate Alzheimer's disease ...(AD) and 27 age- and gender-matched healthy controls. Two different frequency bands were analyzed (slow-5:0.01-0.027 Hz; slow-4:0.027-0.073 Hz). In many brain regions, widespread ALFF differences between the two frequency bands were observed, including predominantly the posterior cingulate cortex/precuneus (PCC/PCu), hippocampus/parahippocampal gyrus (Hip/PHG), insula, thalamus, and basal ganglia. Compared to controls, AD patients showed decreased ALFF values in the bilateral PCC/PCu, inferior parietal lobe, and several temporal regions, and increased ALFF values mainly in the bilateral Hip/PHG, and middle and inferior temporal gyri. Intriguingly, the ALFF abnormalities in the left PCu, left supramarginal gyrus, and several temporal regions were greater in the slow-5 band compared to the slow-4 band. Moreover, correcting for gray matter volume loss significantly affected the functional analytical results, suggesting that gray matter loss can partially account for the functional imaging analytical results obtained in AD. Finally, we showed that regions with changes in ALFF demonstrated a significant correlation with patient cognitive performance as measured using Mini-Mental State Examination scores. The results also demonstrated a significant correlation between hippocampal volume and the ALFF in slow-5 band in the AD group. This study demonstrated widespread ALFF abnormalities of intrinsic brain activity in AD and revealed that the ALFF abnormalities in severe specific regions were frequency-dependent. Taken together, our findings provided novel insights into the pathophysiological mechanism of AD and may be helpful in the development of imaging biomarkers for disease diagnosis.
This article proposes a methodology for the application of Bayesian networks in conducting quantitative risk assessment of operations in offshore oil and gas industry. The method involves translating ...a flow chart of operations into the Bayesian network directly. The proposed methodology consists of five steps. First, the flow chart is translated into a Bayesian network. Second, the influencing factors of the network nodes are classified. Third, the Bayesian network for each factor is established. Fourth, the entire Bayesian network model is established. Lastly, the Bayesian network model is analyzed. Subsequently, five categories of influencing factors, namely, human, hardware, software, mechanical, and hydraulic, are modeled and then added to the main Bayesian network. The methodology is demonstrated through the evaluation of a case study that shows the probability of failure on demand in closing subsea ram blowout preventer operations. The results show that mechanical and hydraulic factors have the most important effects on operation safety. Software and hardware factors have almost no influence, whereas human factors are in between. The results of the sensitivity analysis agree with the findings of the quantitative analysis. The three‐axiom‐based analysis partially validates the correctness and rationality of the proposed Bayesian network model.
The Bayesian network models of redundant systems including parallel system and voting system, taking account of common cause failure and imperfect coverage, are proposed. The Triple Modular ...Redundancy (TMR) and Double Dual Modular Redundancy (DDMR) control systems for subsea Blowout Preventer (BOP) are presented. By applying the proposed Bayesian network models, the reliability of subsea BOP control systems are evaluated at any given time, and the difference between posterior and prior probabilities of each single component given the system failure is obtained. The effects of coverage factor of redundant subsystem and failure rate of single component on reliability of systems are also researched. The results show that the DDMR control system has a little higher reliability than TMR system. To improve the reliability of subsea BOP control systems, the component failure rates of Ethernet switch (ES), programmable logic controller (PLC) and personal computer (PC) should be reduced for TMR system, whereas the failure rates of ES and PC should be reduced for DDMR system. The recovery mechanism of PLC, PC and ES subsystems, and PC and ES subsystems should be paid more attention for TMR and DDMR control systems, respectively.
► The common cause failure and imperfect coverage are modeled by Bayesian networks. ► The reliabilities of subsea BOP control systems are studied by Bayesian networks. ► The ES, PLC and PC have great effects on TMR control system. ► The ES and PC have great effects on DDMR control system.
Place recognition is an essential part of simultaneous localization and mapping (SLAM). LiDAR-based place recognition relies almost exclusively on geometric information. However, geometric ...information may become unreliable when faced with environments dominated by unstructured objects. In this paper, we explore the role of segmentation for extracting key structured information. We propose STV-SC, a novel segmentation and temporal verification enhanced place recognition method for unstructured environments. It contains a range image-based 3D point segmentation algorithm and a three-stage process to detect a loop. The three-stage method consists of a two-stage candidate loop search process and a one-stage segmentation and temporal verification (STV) process. Our STV process utilizes the time-continuous feature of SLAM to determine whether there is an occasional mismatch. We quantitatively demonstrate that the STV process can trigger false detections caused by unstructured objects and effectively extract structured objects to avoid outliers. Comparison with state-of-art algorithms on public datasets shows that STV-SC can run online and achieve improved performance in unstructured environments (Under the same precision, the recall rate is 1.4∼16% higher than Scan context). Therefore, our algorithm can effectively avoid the mismatching caused by the original algorithm in unstructured environment and improve the environmental adaptability of mobile agents.
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