155 research outputs found
Code for: Testing emotional response coherence assumptions: Comparing emotional vs. non-emotional states
No full textThese two files contain code written to a) create within-person cross-correlations and b) run multilevel models, as presented in the following paper: Constantinou, E., Vlemincx, E., & Panayiotou, G. (2023). Testing emotional response coherence assumptions: Comparing emotional versus non-emotional states. Psychophysiology, 00, e14359. https://doi.org/10.1111/psyp.1435
The possible role of Ziziphus lotus as an ecosystem engineer in semiarid landscapes
No full textPositive interactions between nurse plants and their facilitated species are most notable in dry/high-elevation habitats. Plants that modify limiting resources or constraining variables creating an even stronger positive impact on the community are considered ecosystem engineers. Ziziphus lotus, a dominant deep-rooted shrub of arid/semi-arid Mediterranean habitats, can create fertile islets; most likely acting as a nurse plant. To further investigate its role as an ecosystem engineer, we assessed for Thymbra capitata the density of 1377 individuals and the night time-dehydration of 66 individuals, growing around 11 Z.lotus plants for three successive zones (0–5m, 5–10m and 10–15m) and for wetter and drier habitats created by topography in Cyprus. We discovered that T. capitata significantly increases in density (by c. 2.5 times) and can improve its night-time rehydration in mid-summer (by c. 60 times) when growing up to 5m around Z.lotus compared to thymes growing 10–15m away. Density and stem moisture for thymes growing near Z.lotus do not seem to be significantly affected by topography. Hence, Z.lotus may have properties to be classified as an ecosystem engineer and the potential to boost semiarid ecosystem productivity in the battle against desertification under global climatic change
How can ecosystem engineer plants boost productivity in east Mediterranean drylands
No full textAbstract Background Water availability is the key limiting factor for plant productivity in drylands covering ca. 40% of Earth’s land surface. For such ecosystems to retain productivity and biodiversity under climatic change, it would be valuable to identify/promote keystone plant species that (i) have developed strategies to more efficiently utilize moisture resources not easily accessible and (ii) improve moisture conditions for neighboring plants. The very deep-rooted Ziziphus lotus, considered an ecosystem engineer, is one such example. However, it is not known which biotic traits: (a) canopy interception of moisture/rainfall, (b) hydraulic redistribution of deep ground moisture by roots, or non-biotic factors: (c) soil’s volume, and (d) organic matter content, Z. lotus activates/modulates to play such a role. We, thus, selected dryland ecosystems where the plant dominates and measured for potential effects on the less deep-rooted Thymbra capitata. For assessing impacts on ecosystem productivity, we measured the spatial aggregation of ca. 3600 T. capitata plants. As a proxy for soil moisture availability and its spatial variability, we conducted a 7-year-long study using thymes’ nighttime rehydration. Sampling extended up to 15 m away from Z. lotus. Results The density of T. capitata plants growing up to 5 m around Z. lotus vs. thymes growing 10–15 m away was found significantly increased (2.5–4.5 times), while their stem/leaf moisture was ca. 10% higher at predawn compared to nightfall during the dry season. This suggests that ecosystem productivity is driven by a greater soil moisture availability around Z. lotus permitting more thyme daytime transpiration, in contrast to thymes growing further away. The phenomenon appeared only under dry topsoil (during the dry season; becoming stronger during dry years). Morning dew/rainfall interception from the canopy or soil depth/organic matter did not show significant effects, leaving only the hydraulic lift properties of Z. lotus as the most likely driver for soil moisture availability. Conclusions The deep-rooting properties and hydraulic lift potential of Z. lotus may be the key in permitting it to boost ecosystem productivity. Such hydraulic plant traits require more attention as they may prove valuable in combating desertification and restoring ecosystems in arid/semiarid regions threatened by climate change
Facilitation network in phryganic plant communities: evidence from a Mediterranean island
No full textPlant to plant interactions are key drivers of community structure and assembly. We investigate the effect of facilitation on phryganic plant community structure, focusing on plant crown size, and whether the identified facilitative interactions related to community architecture are common in arid environments. We analysed the spatial patterns of 11 species in an arid area in Cyprus. A matrix was created to illustrate the associations between recruited and canopy species, which were found to be more positive than expected by chance, based on the Chi-square test. The corresponding indices of nestedness and connectance were calculated. The associations between recruited and canopy species were found to be positive, exhibiting a high nested structure (p < 0.001) with a 26% connectance in a non-random nested pattern. The presence of facilitative interactions was confirmed by the almost double number of recruits under the canopies of facilitators versus open ground. Ziziphus lotus, demonstrated the highest facilitation capacity (ca. 1.4 times higher than expected; covering ca. 57% of the area occupied by the nurses). Thymbra capitata and Noaea mucronata followed. The high degree of regularity in the assembly of plants within the community suggests that a facilitator’s network is fundamental for maintaining plant diversity in phryganic communities
The Interoceptive Sensitivity and Attention Questionnaire (ISAQ): Evaluating aspects of self-reported interoception in patients with persistent somatic symptoms, stress-related syndromes and healthy controls
No full textOBJECTIVE: This study aimed to validate the Interoceptive Sensitivity and Attention Questionnaire (ISAQ), a 17-item self-report measure assessing sensitivity and attention to interoceptive signals. METHODS: In study 1, exploratory and confirmatory factor analysis was performed in a student convenience sample (n = 1868). In study 2, ISAQ data of a healthy sample (n = 144) and various patient groups experiencing stress-related syndromes (overstrain, n = 63; burnout, n = 37; panic disorder [PD]. n = 60) and/or persistent somatic symptoms in daily life (irritable bowel syndrome, n = 38; fibromyalgia and/or chronic fatigue syndrome, n = 151; medically unexplained dyspnea [MUD], n = 29) were compared. RESULTS: Three subscales were revealed: (F1) sensitivity to neutral bodily sensations, (F2) attention to unpleasant bodily sensations, and (F3) difficulty disengaging from unpleasant bodily sensations. Overall, patients with fibromyalgia and/or chronic fatigue syndrome and patients with MUD scored significantly higher on F1 (p = .009 and p = .027, respectively) and F2 (p = .002 and p < .001, respectively) than healthy controls. Patients with PD had higher scores on subscales F2 (p < .001) and F3 (p < .001) compared with healthy controls, as well as higher scores on F2 compared with all other patient groups (pPD versus MUD = .008; all other p values < .001). CONCLUSIONS: Interoceptive sensibility-the self-reported aspect of interoception-is not a homogeneous or unitary construct. The subscales of the ISAQ differentiate healthy controls from patients with persistent somatic and/or stress-related complaints in daily life and distinguish different patient groups. The ISAQ can be used as a concise, reliable, and clinically relevant research tool to further disentangle adaptive and maladaptive aspects of interoceptive ability.status: Published onlin
Comprehensive Review on Two-Step Thermochemical Water Splitting for Hydrogen Production in a Redox Cycle
No full textThe interest in and need for carbon-free fuels that do not rely on fossil fuels are constantly growing from both environmental and energetic perspectives. Green hydrogen production is at the core of the transition away from conventional fuels. Along with popularly investigated pathways for hydrogen production, thermochemical water splitting using redox materials is an interesting option for utilizing thermal energy, as this approach makes use of temperature looping over the material to produce hydrogen from water. Herein, two-step thermochemical water splitting processes are discussed and the key aspects are analyzed using the most relevant information present in the literature. Redox materials and their compositions, which have been proven to be efficient for this reaction, are reported. Attention is focused on non-volatile redox oxides, as the quenching step required for volatile redox materials is unnecessary. Reactors that could be used to conduct the reduction and oxidation reaction are discussed. The most promising materials are compared to each other using a multi-criteria analysis, providing a direction for future research. As evident, ferrite supported on yttrium-stabilized zirconia, ceria doped with zirconia or samarium and ferrite doped with nickel as the core and an yttrium (III) oxide shell are promising choices. Isothermal cycling and lowering of the reduction temperature are outlined as future directions towards increasing hydrogen yields and improving the cyclability.ChemE/Catalysis Engineerin
Computational Investigation of Microreactor Configurations for Hydrogen Production from Formic Acid Decomposition Using a Pd/C Catalyst
No full textThe need to replace fossil fuels with sustainable alternatives has been a critical issue in recent years. Hydrogen fuel is a promising alternative to fossil fuels because of its wide availability and high energy density. For the very first time, novel microreactor configurations for the formic acid decomposition have been studied using computational modeling methodologies. The decomposition of formic acid using a commercial 5 wt % Pd/C catalyst, under mild conditions, has been assessed in packed bed, coated wall, and membrane microreactors. Computational fluid dynamics (CFD) was utilized to develop the comprehensive heterogeneous microreactor models. The CFD modeling study begins with the development of a packed bed microreactor to validate the experimental work, subsequently followed by the theoretical development of novel microreactor configurations to perform further studies. Previous work using CFD modeling had predicted that the deactivation of the Pd/C catalyst was due to the production of the poisoning species CO during the reaction. The novel membrane microreactor facilitates the continuous removal of CO during the reaction, therefore prolonging the lifetime of the catalyst and enhancing the formic acid conversion by approximately 40% when compared to the other microreactor configurations. For all microreactors studied, the formic acid conversion increases as the temperature increases, and the liquid flow rate decreases. Further studies revealed that all microreactor configurations had negligible internal and external pore diffusion resistances. The detailed models developed in this work have provided an interesting insight into the intensification of the formic acid decomposition reaction over a Pd/C catalyst
School change and leadership: an insider perspective of how school change can be achieved within a centralised education system
No full textAffective processing of interoceptive information in persons with Medically Unexplained Symptoms
No full textSelf-reported physical symptoms not explained by an identifiable organic dysfunction (Medically Unexplained Symptoms; MUS) are highly prevalent. Several sources of evidence suggest that misperception of bodily signals stems from dysfunctions at various stages of processing of interoceptive information. One source of dysfunction not adequately investigated is affective processes involved in interoception. Prior research has repeatedly shown that affect can influence symptom perception, with negative affect resulting in augmented symptom reports. Such symptom over-reporting, though, seems to be constrained by various factors, namely: a) state negative affect, b) ambiguity of bodily signals and c) trait characteristics (trait Negative Affectivity and habitual symptom reporting).The current doctoral project aimed to delineate the mechanisms by which negative affect influences symptom reporting, and specifically to test a mood-congruent schema activation hypothesis as an explanatory mechanism for the observed affective influences on symptom reporting. Mood-congruency theories pose that affective influences reflect either a priming process, with state affect activating affectively-congruent memory representations or an inferential process, where state affect is used to infer the affective value of a stimulus. Based on elements from these two basic models that are also relevant for symptom reporting, we hypothesized that: a) affective influences are more pronounced when stimuli are ambiguous, b) intensified under conditions of high emotional arousal, c) reduced when people regulate their affective reactions and d) may alternatively be explained by shifts in the processing style of information (analytical/schematic). This doctoral study investigates these four hypotheses in the context of symptom reporting, as well as their relation to individual differences in the experience of MUS.The first study (Chapter 3) tested the role of ambiguity using an interoceptive challenge under varied affective contexts and attentional focus conditions (ambiguity manipulation). Contrary to initial hypotheses, we found that affective influences were intensified under conditions of internal focus (low ambiguity), but this process was not moderated by trait characteristics. The second study (Chapter 4), used an affective picture viewing paradigm to examine the effects of emotional arousal, and showed that unpleasant pictures amplified symptom reports, especially when they were highly arousing and more so for people high in MUS.The next two studies examined the role of emotion regulation by incorporating an emotion regulation task (affect labeling) in the picture viewing paradigm. Results from a student study and a study with patients (Irritable Bowel Syndrome) and healthy controls (Chapters 5 and 6) showed that the effect of unpleasant cues was stronger for both non-clinical high symptom reporters and IBS patients. They also showed more reduction in symptom reports when they regulated their negative affect. Finally, the last study (Chapter 7) examined processing styles shifts using a semantic priming task after positive or negative mood induction. We found that negative mood resulted in more schematic processing for high symptom reporters and less for low symptom reporters when the stimuli to be processed were body-related.Overall, this series of studies suggests that factors theoretically linked to mood-congruency also moderate the affective influences observed in symptom reporting. This confirms the hypothesis that negative affect induces symptom over-reporting via an affect-congruent schema activation process. Symptom schemata are by default linked to unpleasantness, thus they are triggered by negative affect, a process that is pronounced when people possess extended symptom schemata, and are less able to regulate their affect, leading to phenomena like unexplained symptom reports. Chapter 8 discusses these tentative conclusions, as well as limitations of the presented studies, and suggestions for future research.<w:latentstyles deflockedstate="false" defunhidewhenused="true" <w:lsdexception="" locked="false" priority="0" semihidden="false" <w:lsdexceptionlocked="false" status: Publishe
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