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Mei-yu front assessment in CMIP6 earth system models during the East Asian summer monsoon
Get PDFThe East Asian Summer Monsoon (EASM) plays a pivotal role in redistributing water across East Asia, including a considerable flood risk due to the potential of localized extreme precipitation. To gain insights into future EASM changes, it is crucial to explore the dynamics of a core driver of extreme precipitation during the EASM, the Mei-yu front. While prior studies have examined various EASM aspects in climate models, the comprehensive assessment of the dynamically important Mei-yu front, remains largely unexplored.
In this study, we evaluate the Mei-yu front representation in 38 CMIP6 models from May to August with ECMWF Reanalysis version 5 (ERA5) as reference. Our findings reveal that several CMIP6 models struggle to accurately reproduce the MYF climatology, with performance varying by month. By categorizing models based on the east-west bias of MYF position in May, we identify distinct monthly evolutions in these biases during the monsoon season. Our study shows that a significant association between the misrepresentation of MYF climatology in CMIP6 models and the misrepresentation of the Western North Pacific High,
particularly its western edge. Other potential sources of biases based on misrepresentation of the other large-scale circulation pattern, such as South Asian High, are also discussed
Exploring climate-driven phenological mismatches in pears, pests and natural enemies: a multi-model approach
Get PDFPear psyllid (Cacopsylla pyri) is the dominant pest of UK pear orchards, with an estimated cost of £5 million per annum. Insecticide withdrawal and increased pesticide resistance of C. pyri have led many growers to depend more on natural enemies for pest management, including earwigs. However, there is concern how phenological events may shift with future climate change, which may result in phenological mismatches. This study aimed to determine shifts in timing of phenological events within an agroecosystem and predict phenological mismatches or synchronies between trophic levels. We evaluated three models: the C. pyri phenology model, the earwig degree day model and the PhenoFlex model (flowering time). Phenological events predicted by models included: first, full and last flowering time for Pyrus communis; peak psyllid abundance date for first-generation (G1) C. pyri nymphs and second-generation (G2) eggs, nymphs and adults; and peak abundance date for stage 4 Forficula auricularia and adults. Findings indicated that the timing of phenological events was advancing for all trophic levels, becoming significantly earlier under the current time period. Furthermore, predictions indicated that timing events would continue to advance under the RCP8.5 scenario. However, not all phenological events advanced at the same rate; the date of peak C. pyri G1 nymph abundance advanced at a higher rate than full flowering time, which could result in a phenological mismatch by 2071. Conversely, C. pyri and F. auricularia showed phenological synchrony, with peak abundance dates advancing at a similar rate, which could be beneficial for future biological control
Mistakes in action: on clarifying the phenomenon of goal-directedness
Get PDFCommon sense tells us that biological systems are goal-directed, and yet the concept remains philosophically problematic. We propose a novel characterization of goal-directed activities as a basis for hypothesising about and investigating explanatory mechanisms. We focus on survival goals such as providing adequate nutrition to body tissues, highlighting two key features – normativity and action. These are closely linked inasmuch as goal-directed actions must meet normative requirements such as that they occur when required and not at other times. We illustrate how goal-directed actions are initiated and terminated not by environmental features and goals themselves, but by markers for them. For example, timely blood clotting is the essential response to injury, but platelet activation, required for clotting, is initiated not by the injury itself but by a short sequence of amino acids (GPO) that provides a reliable marker for it. We then make the case that the operation of markers is a prerequisite for common biological phenomena such as mistake-proneness and mimicry. We go on to identify properties of markers in general, including those that are genetically determined, and those which can be acquired through associative learning. Both provide the basis for matching actions to changing environments and hence adaptive goal-directedness. We describe how goal-directed activities such as bird nest construction and birdsong learning, completed in anticipation of actions in the environment, have to be evaluated and practised against a standard of correctness. This characterization of goal-directedness is sufficiently detailed to provide a basis for the scientific study of mechanisms
Statistical analysis of comet disconnection events using STEREO HI and a data-assimilative solar wind model
Get PDFComets tails can reveal information about the local solar wind conditions. They can exhibit various signatures of interactions with the solar wind including bending, developing kinks and sometimes a undergoing tail disconnections.
In this study, we investigate comet tail disconnection events observed in the STEREO HI data during the period of 2007 to 2023. Using the Heliospheric Upwind eXtrapolation model with a time-dependency (HUXt) solar wind model alongside novel solar wind data assimilation (DA) techniques, each disconnection event was investigated to determine its cause. The resulting statistical analysis led to three main conclusions; 1) For every Heliospheric Current Sheet (HCS) crossing predicted by HUXt that occurs when the comet is within the region of influence of DA, a tail disconnection follows, 2) For HCS crossings that occur outside the region where DA can be applied, 54.5% are followed by a tail disconnection, 3) There is an approximately linear relationship between the speed of the solar wind at the HCS crossing and the time delay to the onset of a disconnection given by the equation V_rel (km s^-1) = (2.23 +/- 0.35)Delta_t (hours) + (400 +/- 10) (km s^-1)
Parents’ and teachers’ roles in supporting the development of digital citizenship among Saudi children in early childhood schools
Get PDFIn recent decades, there has been a substantial increase in research into children’s online
technology use worldwide. Digital technology is introduced to children early, exposing them
to online opportunities and threats. Providing children with appropriate online knowledge and
abilities is therefore vital to ensure their safe and responsible digital growth. Nevertheless,
although Saudi Arabia has seen a dramatic increase in living standards and development in
online technology-based services since implementing the national transformation plan (2016-
2020) to achieve the ‘2030 Vision’ (NTP, 2018), research on childhood and constructing digital
citizenship remains limited.
This study investigated parents’ and teachers’ practices and views on nine dimensions of
digital citizenship (Ribble, 2015), particularly in relation to the key principles of ‘Respect,
Educate and Protect’ (REP) when dealing with the online technology use of children enrolled
in early childhood schools. It also examined the similarities and differences in how parents and
teachers interact with their children’s online usage to develop digital citizenship. This
exploratory study used a mixed-methods research approach, employing both quantitative and
qualitative measures online. Scales of parents’ and teachers’ practice of digital citizenship were
developed to gather data from 357 parents and 156 teachers. Semi-structured interviews were
conducted with ten parents, five teachers and five early childhood specialists. The study’s key
findings indicate that the teachers demonstrated high digital citizenship practices of all three
REP principles, whereas the parents were found to have high practices of Respect and Protect
but only a modest practice in the principle of Educate. The findings also showed that the
parents’ practices regarding the dimension of digital literacy differed according to their
children’s age. Furthermore, although the parents and teachers discussed various relevant
issues, the data showed their limited understanding of digital citizenship. Using Vygotsky’s
(1978) concepts of mediation and Bronfenbrenner’s (1994) macrosystem lens, the findings
showed that the parents and teachers perceived digital citizenship as composed of mediation
strategies and socio-cultural constructs. They also demonstrated that the socio-cultural context,
online media and home and school relationships affected children’s formation of digital
citizenship. This study is a valuable contribution to the Saudi education context in regard to the
development of digital citizenship among children, and it provides the basis for future studies
to extend the educational literature
Exploring the relationships between extraction conditions and anti-browning functionality of Codium sp. aqueous extract
Get PDFThe extract of Codium tomentosum, a green edible seaweed, has shown promise as a coating agent to inhibit browning in fresh-cut apples—a common issue that limits the shelf-life of these products due to oxidative processes. This study aimed to optimize the extraction conditions for C. tomentosum to maximize its anti-browning functionality and further understand the mechanisms behind its effects. Using a Box-Behnken Design, extracts were produced under varying conditions of time (0–180 min), temperature (20–90 °C), and pH (3–10), and were subsequently characterized. Response Surface Methodology was employed to analyse the impact of these variables, with extraction yield significantly increased at longer extraction times (over 120 min) and in a pH range of 6–10. The extract’s ability to inhibit browning was primarily influenced by temperature, with extractions conducted at temperatures above 60 °C producing more effective anti-browning agents. NMR analysis revealed the presence of galactans, which are likely contributing to the anti-browning effect through their barrier properties and potential interactions with browning-related enzymes. Overall, this study demonstrates that C. tomentosum extracts, even when subjected to relatively intense extraction conditions, can effectively inhibit browning in fresh-cut apples, offering a natural solution for extending their shelf-life
Avatars' phygital social presence in the metaverse: an engaged theory perspective
Get PDFWhile prior authors have explored the notions of human and/or automated social presence, these concepts have been predominantly assessed either individually or as mutually exclusive theoretical entities. However, we draw on engaged theory to develop the hybrid concept of phygital social presence that comprises aspects of both the human and automated social presence of metaverse avatars. We define phygital social presence as the degree to which a metaverse avatar instils the feeling in other users that they are in the company of a social entity, as elicited by the avatar’s (a) human social presence (i.e., the actions taken by its human user, in line with engaged theory’s ways of acting), and (b) automated social presence (i.e., the avatar’s embodiment or its appearance, look, design, and the character that these emit, in line with engaged theory’s ways of being). We next propose a conceptual framework and a set of propositions, which suggest that metaverse avatars’ (a) human social presence primarily impacts metaverse users’ positive or negative behavioral engagement in the metaverse, and (b) automated social presence chiefly influences users’ positive or negative cognitive and emotional engagement. Moreover, an avatar’s ways of relating, as also informed by engaged theory, primarily impact users’ positive or negative social engagement
Transnational families
No full textTransnational families are defined as familial groups where one or more family members spend all or most of their time geographically separated from each other across borders, but nevertheless share a collective sense of connection as a ‘family’. Care of older people and transnational motherhood have been investigated, with considerable policy concern about children ‘left behind’. Care has been conceptualised as both ‘proximate’ and ‘at a distance’, circulating among family members through time and space. Migration regimes and other institutional contexts provide parameters for caring arrangements, which are also shaped by migrants’ agency in negotiating caring arrangements. Children’s caring roles, including language brokering, may be significant; they are not just ‘dependents’ receiving care, but provide care and support for older and younger generations and their peers, in ‘proximate’ and ‘at a distance’ relationships. Such caring arrangements may have positive and negative impacts on family members’ wellbeing and opportunities
A Faraday cup for charge measurements in biophysical and environmental fieldwork
Get PDFA novel miniature (28mm × 38mm) shielded Faraday cup is described for quantifying picocoulomb charges on millimetre environmental objects, such as small insects or plants, droplets, dust particles or powders. The electrometer electronics is contained within the device, avoiding any transfer of low level signals to an external electrometer. It is calibrated using a voltage ramp – capacitor method, generating defined charge pulses without a reference electrometer. The device can fit within an acoustic levitator to provide non-contact, zero leakage suspension of small objects, measuring charge on their release. Convenience and simplicity of use open new environmental charge measurement opportunities