122,236 research outputs found
Sensory analysis of juices from apples of different varieties
No full textDotsenko Y. I. Sensory analysis of juices from apples of different varieties / Y.I. Dotsenko, N. V. Dotsenko, T. A. Manoli // Збірник наукових праць молодих учених, аспірантів та студентів / Одес. нац. технол. ун-т; гол. ред. Л. В. Іванченкова. – Одеса, 2023. – С. 55-57: рис. – Бібліогр.: 3 назв
Platform-mediated local power in tourism
No full textThis research note develops a conceptual framework for analysing how digital platforms reconfigure place-based power in tourism. Rather than treating the “local turn” as a bounded community or an ontological essence, the note approaches locality as a relational and contested claim, historically produced through political economy, mobilities and uneven social hierarchies, which is increasingly validated through platform infrastructures. Drawing on critical tourism political economy and platform studies, the note introduces platform-mediated local power to describe how platforms shape who can credibly claim local legitimacy, how such claims circulate across publics, and how they are converted into economic participation under ranking, review and recommendation regimes. Through the interrelated dimensions of visibility, credibility and convertibility, the framework shows how algorithmic mediation reorganises long-standing asymmetries in land, capital, labour, and representation by layering informational control onto material relations. The note concludes by arguing that decolonising tourism knowledge must be pursued alongside efforts to contest platform infrastructures through regulation, transparency and alternative forms of data governance
Strigolactones involvement in maize root response to nitrate availability
No full textStrigolactones (SLs) are a new class of carotenoid-derived phytohormones. They act as stimulants for both germination of parasitic weeds in the Orobanchaceae family and for arbuscular mycorrhization initiation, but they also play multiple roles in regulating plant development. In addition, soil nutrient deficiencies, mainly due to low Pi and low nitrate, trigger enhanced SL biosynthesis and exudation, which seems to influence root architecture. In our previous study (Manoli et al., 2016, Frontiers in Plant Science), we showed how a 2 h-nitrate treatment is sufficient to repress the transcription of genes involved in SLs biosynthesis and transport. In the present study, we demonstrated that 24 h of nitrate deficiency are necessary to induce the transcription of the same genes. Moreover, SLs involvement in maize root response to nitrate was investigated by determining their influence on the frequency of sites of lateral root (LR) emergence in maize seedlings. After 24h in a nitrate-depleted solution, an hematoxylin staining assay was carried out to detect the number of LR primordia (LRP) within three treatments groups: 24h in a nitrate-deficient solution, 24h in a nitrate-1mM-supplied solution or 24h in a nitrate-deficient solution with the presence of a SLs biosynthesis inhibitor (TIS108, 2μM). The results from LR density analysis suggest a putative involvement of SLs in the inhibition of LR emergence in nitrate-depleted roots, while nitrate seems to be involved in LR development through inhibition of some SLs pathway. To deepen the SLs involvement in maize root response to nitrate fluctuations, a germination bioassay on Phelipanche ramosa seeds was then performed. P. ramosa belongs to the Orobanchaceae family, namely obligate root-parasitic plants whose seeds can be used to indirectly detect the SLs exudation. A modified bioassay and a neutral red staining were developed to evaluate the germination rate in P. ramosa seeds. Root exudates of maize seedlings grew in nitrate-1mM-supplied solution, or nitrate-deficient solution (-N), or nitrate-deficient solution supplied with TIS108 were tested. On a quality level, a clear induction of germination was shown in those seeds treated with –N root exudates, whereas a very reduced germination was detected in the seeds treated with +NO3-root exudates or with –N+TIS108-root exudates. In conclusion, our preliminary results are consistent with the involvement of strigolactones in the repression of lateral root development in nitrate-deficient media, while the inhibition of SLs action by nitrate supply seems to participate in the complex mechanism leading to regulation of lateral root development by this anion
Building team brand equity through perceived CSR: the mediating role of dual identification
No full textWhile involvement in CSR activities is common practice in today's sporting world, there is a need to go beyond the activities themselves to explore how fans' perceptions of CSR can affect customer-based brand equity and what role online community and team identification can play in this relationship, which this study aims to explore. Data collected through an online survey of South Korean Samsung Lions baseball club fans (N = 331), analysed through structural equation modelling, support the positive influence of perceived CSR on dual identification (team and online community), and the impact of team identification on brand equity. Interestingly, CSR perception is shown to be an insignificant predictor of brand equity, influenced fully by team identification. This study suggests that promoting a sport team's socially responsible image is important in terms of building both team and online community identification while developing team identification can be vital in increasing the value of the sport brand
NITRATE SENSING BY MAIZE ROOTS: A KEY ROLE FOR NITRIC OXIDE SIGNALING IN THE TRANSITION ZONE
No full textOver the past five decades, intensive agriculture has been able to increase the rate of food production more rapidly than that of human population growth but, at the same time, has also given rise to a series of negative environmental consequences, at both local and global level. Most of them are directly due to the large use in agriculture of synthetic ammonia fertilizers industrially produced by the Haber-Bosch process. Over 50% of the applied nitrogen in fact, is lost from the plant-soil system, leading to severe environmental damages and to negative impacts on human health. Maize (Zea mays L.) is one of the world’s major crops and is also expected to give an important contribution to human nutrition in the next few decades, when world population should exceed 8 billion people and rise to 9.2/11 billion by 2050. To ensure future global food security, increasing crop yields are dramatically needed, however, sustainable ways of crop production are far from being achieved, considering also that further nitrogen accumulation in the environment is expected to be increased in the future without an adequate enhancement of Nitrogen Use Efficiency (NUE) in the main crops. For this reason, the understanding of the molecular events underlying root adaptation to nitrogen fluctuations is a primary goal to develop tools for sustainable agriculture.
Crop plant development in fact, is not only strongly dependent on nitrogen availability in the soil but also on the efficiency of its recruitment by roots. Plants take up and assimilate both nitrate and ammonium, but nitrate is the main source of inorganic nitrogen for plants in aerobic soil conditions typical of most cultivated soils. In addition to its role as a nutrient, nitrate acts as a signaling molecule regulating the expression of the genes involved in growth and developmental processes. However, the mechanisms governing the sensing of nitrate by roots and of the signaling leading to an altered development of roots are still only partially characterized. Nitric oxide (NO) has been recently proposed to be implicated in plant responses to environmental stresses, but its exact role in the response of plants to nutritional stress is still under evaluation. In this work, the role of NO production by maize roots after nitrate perception was investigated by focusing on the regulation of transcription of genes involved in NO homeostasis and by measuring NO production in roots. Moreover, its involvement in the root growth response to nitrate was also investigated.
To better discriminate nitrate-specific effects from those more generally N-dependent, the expression of a number of genes previously identified as being nitrogen-responsive, was evaluated in response to nitrate/ammonium supply and deprivation. The transcriptional response of five genes encoding (i) the cytosolic nitrate reductase NR1, (ii) two different non-symbiotic hemoglobins (nsHbs) isoforms, (iii) a gene encoding nitrite reductase together with (iv) a gene encoding the high-affinity root nitrate transporter (NRT2.1), evidenced a very strong and exclusive nitrate responsiveness in roots. Conversely, no effects were observed when ammonium was supplied as the sole nitrogen source. This first screening allowed the current work to focus later only on genes whose expression seems to depend exclusively on nitrate and to be specifically involved in the control of NO biosynthesis and scavenging. Our results highlight the importance of the coordinate spatio-temporal expression of nitrate reductase and non-symbiotic hemoglobins in controlling the NO homeostasis in the maize root after nitrate provision.
In addition, data obtained by analysing root morphological parameters by the WinRhizo software underlined the same specificity of nitrate, which significantly affected root growth when supplied to N-deprived roots.
To deepen the hypothesis that nitric oxide may be produced by roots as an early signal of nitrate perception, NO in vivo detection was carried out. Results obtained using the DAF-2DA probe and stereo- and confocal microscopy evidenced a clear induction of fluorescence after nitrate provision. Very interestingly, the main zone of NO production seemed to be located immediately above the meristematic apex and more precisely to coincide with the root transition zone. The fluorescence detected after nitrate supply was not revealed in the presence of the specific nitrate reductase inhibitor tungstate, giving support to the role of NR in nitric oxide production. Moreover, the addition of the nitric oxide scavengers cPTIO together with nitrate, similarly suppressed the development of fluorescence, confirming the specificity of NO detection by the probe. These results suggest that a NR-dependent NO burst occurred immediately after nitrate supply to roots. The NR-dependent NO production observed after nitrate supply was then further confirmed by the strong induction of NR1, NiR, and nsHbs transcription in the early phases of nitrate perception. In this case also, the transcription was significantly inhibited in response to tungstate and cPTIO addition, endorsing the cooperation between nitrate reductase and haemoglobin activities in the finely tuned control of NO homeostasis.
To deepen the spatial regulation of NO homeostasis balance, the expression of NR1, NiR and nsHbs genes was also analysed in four different root zones (i.e. meristem, transition zone, elongation zone, maturation zone) both in nitrate-depleted and in nitrate-treated seedlings. In N-starved roots, all transcripts evidenced their maximum accumulation at the meristem level. This pattern radically changed when nitrate was furnished to roots with a very significant increase of transcript abundance in the transition zone. As a result, we suggest that nitrate supply could activate its own sensing by stimulating NO production by the transition zone cells, thus initiating a signalling pathway contributing to the physiological adaptation (e.g. root growth) to nitrate fluctuations.
Based on the preliminary results showing the preferential localization of NO production at the level of the transition zone, the attention was then focused on nitrate effects on root elongation, which takes place in the zone immediately above and neighbouring the transition zone. Our finding evidenced a strong and specific induction of root elongation of young maize seedlings supplied with 1 mM nitrate and a drastic inhibition in the presence of ammonium, cPTIO, and tungstate. On the contrary, when the negative control (-NO3-) was supplied with a NO donor (SNP) the root length increased significantly. These results strongly suggest that the NO generated through NR should significantly contribute to the root lengthening noticed after nitrate provision.
To summarize, it would seem that the NO-mediated pathway here described represents an early alert system for external nitrate sensing by root cells, which seem to individually possess the competence to activate this pathway when external nitrate is perceived. Additional experiments are necessary to better understand the functioning of this NO-mediated pathway and to identify the downstream events that link the NO burst with the physiological redirection of root growth. In this regard, it has been reported that NO signaling can alter cell polarity and cytoskeleton-mediated vesicle trafficking processes, thus affecting cell growth and root morphogenesis. This suggests that there should be more downstream effectors of NO action, acting either in parallel or in series with cytoskeletal constituents. Furthermore, since NO and phytohormones auxin act synergically to control diverse aspects of root biology and also considering that lateral root development in response to nitrate is strongly auxin dependent, a role of NO as a coordinator of nitrate and auxin signaling to control the overall root response to the anion cannot be excluded.
In order to try to answer to these last questions, in the final part of my Ph. D. thesis, we focused the attention on studying both cytoskeleton-mediated xyloglucans (a major primary cell wall component) modifications and polar auxin transport in the maize root transition zone cells in response to nitrate. Preliminary data achieved so far by using immunofluorescence labelling indicate that nitrate is able to modify cell wall recycling in the transition zone. Xyloglucans in fact, were very abundant especially in the sample subjected to nitrate treatment, when compared to the negative control, suggesting a higher rate of XGs synthesis /or recycling, in response to the anion in the maize root transition zone. Additionally, Brefeldin A (a chemical which prevents vesicle formation in the exocytosis pathway while allowing endocytosis, resulting in the cytoplasmic accumulation of all recycling molecules) treatment partially failed in removing all XGs from cell walls in +N samples, since a marked immunofluorescence was still visible at cross walls, despite the strong effect of the drug that resulted in the abundance of BFA-compartments also within these cells. These latter data could suggest that nitrate promotes a higher rate of XGs recycling in order to maintain a loosened cell wall structure, thus allowing an extensive and fast cell elongation in response to the anion. Taken together, these data open a fascinating scenario in which nitrate might act in promoting rapid cell elongation of root apex by regulating, in a mechanism as yet unknown, the synthesis or the turn-over (or both) of xyloglucans within root transition cells. Also PIN1-mediated auxin accumulation seems to be interfered in response to nitrate. IAA signal in fact, was strongly localized at the cross wall (end-poles) of transition zone cells only in nitrate-supplied roots, thus suggesting that IAA end-poles labelling was probably due to increased IAA fluxes triggered specifically by nitrate. In support to this hypothesis we also observed that IAA and its transporter PIN1 protein co-localize in NO3--treated roots at the cross walls (end-poles), thus providing further, although preliminary, evidences that nitrate in the maize root transition zone is able to increase IAA-fluxes, in a mechanism as yet unknown, that involved also PIN1 proteins. Further immunolabeling data, by also using NO donors and scavengers, will be needed to better understand the coordinated actions of nitric oxide, auxin and cytoskeleton adjustments in tightly regulating root motoric response to nitrate
From horizontal to vertical relationships: how online community identification fosters sport fans’ team identification and behavioural intentions
No full textPurpose With the remarkable advancements in information and communication technologies, comprehending online sport fan communities is being pushed further up in the agenda of sport teams worldwide. Based on social identity theory, the main purpose of this research paper is to test the mechanism of how horizontal relationships developed through online communities lead to vertical relationships such as team identification and behavioural intentions. Design/methodology/approach Using a sample of online baseball fan community members in South Korea (N = 400) and employing structural equations modelling, the current research examined the structural relations among online community identification, team identification, behavioural intention and WOM intention while testing moderating effect of perceived authenticity. Findings This study finds that online community identification has a significant positive impact on team-level consumer outcomes: team identification, behavioural intention and WOM intention. Team identification is verified as a significant determinant of both behavioural intention and WOM intention. Moreover, the partial mediating role of team identification in the relationships between online community identification and behavioural intentions are corroborated. Originality/value The present study furnishes essential information for identifying the underlying mechanism of how fan-to-fan horizontal relationships cultivate team-to-fan vertical relationships in the context of the virtual fan community
Does relationship quality matter in policy-making? The impact of government-public relationships and residents’ perceptions on their support towards a mega-sport event
No full textGuided by the increase in social and political challenges faced by local governments in their efforts to host mega-sport events, this study attempts to shed light on the under-researched relationship quality between a local government and its residents. Enhancing the relationship quality and mutual understanding through two-way communication between the government and its residents has become more important than ever, with the host community considered a key stakeholder in the policy decision-making process, due to the development of online communication technologies. This research aims to identify the major determinants of residents’ support, using government public relationships and social exchange theory. Data collected through a survey of Tokyo residents (N = 406), where the Tokyo 2020 Olympic and Paralympic Games were hosted, are analysed using structural equation modelling. Results show that satisfaction with the government can considerably influence the perceived impacts of a mega-sport event and trust, while trust in the government is shown to be a robust predictor of residents’ support and a mediator to social exchange theory. Also, the importance of a mega-sport event’s perceived impacts on residents’ support is shown, further supporting social exchange theory. Through the findings and the integration of the two theories, this study illustrates the need for the government to focus on producing policies aiming to increase its public satisfaction and thus their trust in government using balanced symmetric communication, which in turn can raise residents’ support for a mega-sport event and help establish a mutually beneficial relationship between the government and its public. 
Executive control and emotional processing in ADHD and anxiety. Evidence from eye-tracking experiments
No full textAttention-deficit/hyperactivity disorder (ADHD) and anxiety co-occur at above chance levels in both clinical and sub-clinical cases. However, little is known about the underlying neuropsychological basis of this overlap. In this thesis, we addressed this question by exploring a pattern of dysfunctional cognitive control linked to these conditions. Our hypothesis was that ADHD would be associated with core deficits in cognitive control in both non-emotional and emotional contexts. In addition, we anticipated cognitive control deficits in anxiety to manifest in situations involving processing of emotional stimuli and particularly in threat contexts. Furthermore, we predicted that the combination of these cognitive control challenges would be exacerbated in the case of co-occurring ADHD and anxiety. We investigated these hypotheses using eye-movement measurements in a Go/NoGo paradigm to examine inhibitory control (i.e., suppression of reflexive saccades) and sustained attention (i.e., saccadic execution) in emotional and non-emotional contexts. We also designed an eye-movement version of the Spatial Cueing paradigm to examine attentional orienting in the presence of emotional cue distractors using representations of another person’s eye-gaze. The current thesis contains four empirical chapters discussing the relationship between ADHD and anxiety symptom dimensions (and their interaction) on task performance. We examined the Go/No-Go task using symptoms of ADHD and anxiety in typically developing (TD) children/adolescents (n= 27) and healthy adults (n=27) (Chapter 3), and symptoms of ADHD and Generalised Anxiety Disorder (GAD) in a larger sample of children and adolescents (n=68), that included both TD children/adolescents and clinical cases of ADHD and anxiety (Chapter 4). We then examined the Spatial Cueing task in the same samples across Chapters 5 and 6. High levels of ADHD were associated with impaired inhibitory control and disrupted processing, in the context of threat (such as angry faces) (Chapter 3) with reduced sustained attention regardless of the emotional valence of the stimuli used (Chapter 4). Individuals with ADHD did not effectively use social cues (i.e., poorer attentional orienting), especially in the presence of negative emotional expressions (such as angry and fearful faces) relative to other emotional expressions (Chapters 5 and 6). Anxiety symptoms were associated with faster processing of negative facial expressions (Chapter 3) and improved attentional orienting following social cues of negative emotional expressions, relative to other facial expressions (Chapter 5). Anxiety was also associated with better attentional orienting following social cues of angry faces relative to fearful faces (Chapter 6). In terms of the interactions between anxiety and ADHD, elevated anxiety symptoms were associated with attenuation of disrupted attentional processes found in ADHD including faster processing of negative emotional expressions relative to positive ones (Chapter 3 and 4), improved sustained attention (Chapter 4) and better attentional orienting processes (Chapters 5 and 6). Overall, our results showed that ADHD was associated with deficits in cognitive control, particularly in emotionally charged contexts. However, anxiety was associated with improved attentional processes in response to negative emotional stimuli. Contrary to our predictions, we found that co-occurring ADHD and anxiety were associated with improved attentional control and emotional processing. Overall, the synergistic effects between ADHD and anxiety provide evidence towards a potentially distinct cognitive phenotype
Insights from the inside: marketing agency practitioners’ perspectives on developing athlete brands
No full textPurpose: Building on existing research that has analysed the components of athlete brands externally, this study examines how athlete brands are being developed internally by marketing agency practitioners (MAPs), who are oftentimes the individuals leading the process. Design/methodology/approach: Qualitative data generated through interviews with MAPs (N = 28) from 16 different marketing and public relations UK agencies are utilised in this study, offering insights from the key individuals involved in the process. Findings: The findings revealed a three-step co-creational approach to athlete brand development, consisting of (1) brand brainstorming, (2) brand pillaring and (3) brand training, led by clearly defined strategic goals. Originality/value: Capturing this three-step process has not only theoretical implications by shedding light on a previously undisclosed process but also practical implications, forwarding a roadmap to guide the athlete brand development process
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
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