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Uncovering plant root traits and mechanisms that enable penetration, exploration, and exploitation of soil parent materials: a systematic review
No full textBackground and Aims: Certain plant species, including some trees, have been observed growing not only in soil but also in soil parent materials. However, the root traits and mechanisms enabling these species to penetrate soil parent materials are not yet thoroughly understood. This systematic review aims to identify and discuss the root traits and mechanisms that allow plant roots to grow into soil parent materials. It will also draw insights from the characteristics and mechanisms that plants employ to overcome the challenges posed by compacted soils.
Methods: We adhered to the 'Preferred Reporting Items for Systematic Reviews and Meta-Analyses' (PRISMA) guidelines for our methodology.
Results: We identified increased root radial pressure, investment in root biomass, fine root development, root trematotropism, mycorrhizal associations, root hairs, and root exudates as key traits aiding plants in soil penetration. The mentioned root traits and mechanisms have also been shown to help plants overcome compacted soil, except for mycorrhizal associations.
Conclusion: The key root traits and mechanisms identified in this review lay the groundwork for a deeper understanding of root-soil parent material interactions and plant adaptations in changing physical environments. This enhances our ability to select the next generation of robust and resilient crops capable of thriving in complex root-soil parent material interactions. Future research on root-parent material interactions in food crops holds promise for improving our understanding of how crops can grow beyond traditional soil limitations (such as soil depth)
Saprotrophic-ectomycorrhizal fungal interactions affect poplar performance
No full textMycorrhizal and saprotrophic fungi are key players in plant nutrition in forest ecosystems, affecting nutrient availability and plant nutrient acquisition, but the impact of their interaction on plant performance remains largely understudied. Their interaction is particularly important under nutrient-limited conditions (e.g., nitrogen limitation) as they may compete for resources or engage in facilitative interactions that ultimately affect plant nutrient uptake and growth. Here, we used a simplified, plant-centric experimental design to investigate the effects of fungal interactions on plant performance. Poplar (Populus × canescens) plantlets were grown under nutrient-poor conditions for 23 weeks with a single nutrient source: a mixture of 15 N-labelled poplar (labile) and beech (recalcitrant) leaf litter. Plants were inoculated with Pholiota squarrosa (saprotrophic), Laccaria bicolor (ectomycorrhizal), both, or neither. We analysed growth, nitrogen uptake, and photosynthetic performance. Ectomycorrhizal-inoculated plants showed greater growth, root development, and nitrogen accumulation than non-inoculated controls or those inoculated with saprotrophic fungi alone. Photosynthetic performance, particularly at 16 weeks, was also enhanced. In contrast, saprotrophic fungi increased nitrogen concentration in roots but did not improve plant biomass. Plant biomass and root architecture did not differ between EMF-only and dual-inoculated plants, suggesting that the addition of saprotrophic fungi did not further enhance or impair these traits. However, for nitrogen-related traits, dual-inoculated plants showed intermediate values between EMF-only and STF-only treatments. Despite these trends, statistical analysis did not detect a significant interaction between fungal guilds. These findings indicate that ectomycorrhizal fungi play a stronger role in promoting plant performance under nitrogen-limited conditions, likely through enhanced nutrient uptake and photosynthetic efficiency. Saprotrophic fungi alone did not promote plant growth under the experimental conditions, nor did their presence alter the benefits conferred by ectomycorrhizal fungi
Early internationalization: a meta-analysis of antecedents, dimensions, and performance
No full textMore than three decades after Oviatt and McDougall’s pioneering 1994 paper “Towards a theory of international new ventures,” the study of early internationalizing firms continues to captivate international business scholars. The research questions we address involve the antecedents of early internationalization, the dimensions of this phenomenon and its performance outcomes. In the present study we include all three issues in a comprehensive meta-analysis, thereby gaining a more complete understanding of the early internationalization process, while building upon the various, partial pathways identified in extant research. We use meta-analytic structural equation modeling (MASEM) and build upon 426 samples from 378 empirical studies. We distinguish between the effects of individual-level and firm-level antecedents on the main dimensions of early internationalization—speed, scope, and intensity—and we assess the impact thereof on post-entry performance. Our results provide a comprehensive overview of the constructs used in prior research, thereby laying the foundation for future empirical studies on early internationalization
On the nature of mistakes in nature
No full textSome things happen of necessity, others merely happen to occur – but are there things that happen to occur, but should not have? The latter constitute mistakes and, prima facie, they are everywhere – from our setting the wrong cutlery at the dinner table to young turtles crawling in the wrong direction to the safety of the sea. As obvious and ubiquitous as they may seem, the question of whether mistakes are real is not an unfounded one. For inherent in the nature of mistakes is the core concept of normativity, as mistakes imply the existence of states of affairs that are supposed to occur, but which unfortunately do not. Whether normativity is a feature of the ontological fabric of our world, rather than an epistemological by-product of the heuristic framework we use to comprehend its denizens and their activities, is a question at the centre of a long-standing debate in the philosophy of science. In this paper, we will ask: what must the world be like if mistakes are really out there? In answering that question, we will highlight some central aspects of the nature of mistakes that any ontological foundation which purports to include them must somehow accommodate. After showing that even the most promising ontological framework that might do so – namely, a powers ontology – is seemingly not up to the task, we will propose a novel refocusing of the analysis of the nature of mistakes, one centred on the metaphysics of causal feedback and the concept of organismal flourishing
A scientometric analysis investigating melatonin and cortisol in the context of sleep in autism
No full textSleep disturbances are extensively reported in Autism Spectrum Disorder (ASD) but the nature of this association is, to date, unclear. This study uses a scientometric methodology to explore the role of two key biological factors, namely melatonin and cortisol, including its precursor adrenocorticotropic hormone on sleep. Six hundred and thirty-four papers were retrieved from Scopus. A co-citation analysis was carried out, from which ten thematic clusters were identified and discussed chronologically, these were: “Epilepsy” (average year of publication = 1998), “Biology of sleep” (average year of publication = 2001), “Paediatric sleep” (average year of publication = 2001), “Sleep in ASD” (average year of publication = 2003), “Co-occurring conditions” (average year of publication = 2007), “Psychopharmacology, ASD and sleep” (average year of publication = 2007), “HPA-axis dysregulation” (average year of publication = 2009), “Use of melatonin for sleep disturbances in ASD” (average year of publication = 2013), “Safety of melatonin medications for sleep in ASD” (average year of publication = 2015), “Disturbed sleep in children, a symptom in a bigger picture” (average year of publication = 2016). Detailed analysis of each cluster indicated that the association between ASD and sleep is complex and multifactorial. As such, two main areas for future research were identified: (a) the need for larger studies that allow stratification of the population to uncouple confounding factors (e.g. concomitant use of medications) and (b) the need for longer, longitudinal studies assessing melatonin and cortisol in ASD across development
The efficacy of a combined speech modification and mindfulness therapy approach for adults who stutter
No full textIntroduction: This study investigates the efficacy of integrating Speech Modification (SM) and
Mindfulness-Based Cognitive Therapy (MBCT) for managing adult stuttering in Saudi Arabia.
SM, a well-established approach to stuttering, seeks to enhance speech fluency and reduce
stuttering occurrences by modifying speaking behaviours and addressing underlying emotional
factors. In contrast, MBCT introduces a cognitive dimension, focusing on emotional regulation
and acceptance, crucial elements for managing the psychological impacts of stuttering. The
integration of these approaches referred to as the Speech Modification and Mindfulness
Therapy (SMMT) approach, is designed to provide a comprehensive intervention that targets
both the behavioural and cognitive-affective components of stuttering. The ultimate goal is to
enhance the quality of life for adults who stutter by addressing the disorder holistically.
Methodology: This study employed a single-arm efficacy design with a mixed-methods
approach, involving 30 adult participants. The intervention was delivered via telepractice over
eight consecutive weeks, with weekly two-hour group therapy sessions. Quantitative
assessments included the Five Facet Mindfulness Questionnaire (measuring key facets of
mindfulness), the Overall Assessment of the Speaker’s Experience of Stuttering (evaluating the
psychological and quality-of-life impact of stuttering), and the Stuttering Severity Instrument
(assessing the frequency and severity of stuttering). Data were collected at three time points:
immediately post-therapy, as well as at 3- and 6-month follow-ups, to evaluate sustained
effects. In addition to the quantitative measures, qualitative data were gathered through open-ended questions and semi-structured interviews to capture participants' experiences,
perceptions of the intervention, and overall satisfaction with the therapy and its delivery.
Results: The study observed statistically significant improvements in all quantitative measures,
including self-reported speech naturalness, with these benefits persisting through the 6-month
follow-up. Qualitative data identified four key emerging themes: 1) Readiness for Therapy, 2)
Therapeutic Intervention Components, 3) Service Delivery Format, and 4) Perceived
Challenges and Constraints.
Discussion and Conclusion: The findings from this study underscore the efficacy of the SMMT
approach as a comprehensive treatment strategy for adult stuttering. By merging traditional
speech therapy techniques with mindfulness practices, the intervention not only led to
improvements in speech fluency but also significantly bolstered emotional regulation,
communication skills, and social engagement among participants. These advancements
contributed to an overall enhancement in participants' well-being and quality of life. The group
therapy format emerged as a critical factor in the success of the intervention, fostering a
supportive community that facilitated skill acquisition and encouraged self-acceptance. This
sense of community was instrumental in maintaining participant motivation and engagement
throughout the treatment process. Despite some logistical challenges, such as telepractice
technological and environmental difficulties, the high satisfaction rates and the sustained
treatment outcomes strongly support the effectiveness of the telepractice model. This model
not only expanded access to treatment for individuals who might have otherwise encountered
barriers to participation but also proved to be a viable method for delivering comprehensive
stuttering therapy. The SMMT approach, therefore, holds promise as a valuable framework for
future stuttering interventions, particularly in contexts where access to traditional in-person
therapy is limited. Further research is recommended to explore the validity and applicability of
this model across various demographic and cultural groups, ensuring it can be broadly
implemented and sustained over time
Inter-instrument variability of Vaisala CL61 lidar-ceilometer's attenuated backscatter, cloud properties and mixed-layer height
No full textCharacterising inter-instrument variability of sensors is crucial to assessing uncertainties in observational campaigns, networks, and for
data assimilation. Here, we co-locate six high signal-to-noise ratio Vaisala CL61 lidar-ceilometers for a period of ten days to quantify
instrument-related differences in several observed variables: profiles of attenuated backscatter, its components (parallel- and crosspolarised backscatter) and the volume linear depolarisation ratio (δ), as well as derived cloud variables and mixed-layer height.
Analysing intervals between 5-60 min, median absolute differences between sensors (AD50) and percentiles (e.g. AD75) are used to
quantify instrument related uncertainties. For backscatter and δ, we differentiate between conditions with rain, clear sky, and clouds.
Here we address instrument precision rather than accuracy, with instrument accuracy assumed. The detected agreement between
instruments suggests a distributed measurement network should be capable of providing context for interpretation of spatial differences.
If instruments measure accurately, it is possible to resolve spatial differences (e.g. urban-rural) for attenuated backscatter, derived cloud
variables and layer heights. However, differences exist and vary with signal-to-noise ratio and atmospheric conditions. The AD50 intersensor results for 15 min intervals for total cloud-cover fraction (excluding clear sky and fully overcast conditions) is 1.9 %, and for
cloud base height 7.3 m. Agreement of all cloud variables is better for boundary layer clouds (when first cloud layer < 4 km agl) than for
all five cloud layers recorded by the sensor firmware. The 15 min mixed-layer height AD50 is 0 m and the AD75 21.5 m. We show that
instrument precipitation flags are in good agreement, but do not link closely with ground-level rainfall observations, hence an alternative
algorithm is proposed. We provide quality control recommendations for data processing to improve inter-instrument agreement of cloud
variables and mixed-layer height
Localised land-use and maize agriculture by the pre-Columbian Casarabe Culture in Lowland Bolivia
Get PDFMultiple pre-Columbian (pre- 1492 CE) archaeological sites now challenge the traditional portrayal of Amazonia as a ‘pristine wilderness’. This is especially true within the forest-savanna mosaic landscapes of lowland Bolivia, where the pre-Columbian Casarabe Culture constructed hundreds of settlement mounds, integrated with a dense causeway-canal network—one of the most complex, stratified societies yet discovered in Amazonia. Excavations at previous sites indicate that this culture sustained itself by practicing large-scale, maize-based agriculture. However, the Casarabe Culture’s mounds have also been found within the riparian forests abutting major river systems, where their inhabitants could have benefitted from greater access to forest resources and local fish species. To determine whether these differences influenced how the Casarabe Culture utilised the landscape, we conducted palaeoecological analysis on the sediments collected from Laguna Loma Suarez (LLS), an oxbow lake situated adjacent to a monumental habitation mound within these riparian forests. Our analysis reveals that, despite significant differences in natural resource availability, the Casarabe Culture continued to cultivate maize locally around LLS for over a millennium, between 280 BCE and 1130 CE, with anthropogenic fires largely restricted to the open savannas. Our record also suggests that the Casarabe Culture possibly delayed either forest recovery or natural forest encroachment until after the nearby settlement mound was abandoned. These findings, when compared with those of other sites in the region, show that maize was an important crop in pre-Columbian times, irrespective of major differences in natural resource availability across the complex forest-savanna mosaic settings of Amazonian Bolivia
A systematic review of marketing interventions in reducing consumer plate waste
Get PDFPurpose – This study provides a systematic literature review to explore the factors contributing to effective plate waste reduction intervention in catering outlets. This paper aims to understand which factors effectively facilitate consumers to reduce food waste when eating out of home, particularly from the perspective of how marketing plays a role in influencing consumers’ sustainable behaviour to reduce plate waste.
Design/methodology/approach – This systematic literature review, which follows PRISMA guidelines, identified 27 peer-reviewed studies that examined plate waste reduction programs published in peer-reviewed scholarly literature over the past decade.
Findings – This study presents a systematic literature review to synthesise extant knowledge in peer-reviewed journals of the barriers, motivations, utilization and effectiveness of marketing in plate waste reduction, and the extent of theory used in plate waste reduction program conducted over the past decade. Literature on plate waste reduction is fragmented and findings are inconclusive.
Practical implications - This review contributes to understanding effective plate waste reduction interventions that have previously been applied in universities, hotels, and commercial settings. Such interventions could enhance sustainable out-of-home food consumption practices, thereby contributing to the attainment of SDG 12.3.
Originality – This paper extends our understanding of plate waste reduction. Although all 27 included studies heavily relied on informational elements, adjusting product and place is found to be more influential than pricing strategies in reducing consumer plate waste