Change Of Coordinates Research Articles

Singlet Oxygen Photocatalytic Generation by Silanized TiO2 Nanoparticles

AbstractA commercial TiO2 sample, used as received or hydrothermally treated to increase surface hydroxylation, has been functionalized by surface modification with hexadecyltrimethoxysilane. The anchoring of the silane has been characterized by means of FTIR and solid‐state NMR spectroscopies, and the grafting density was determined by thermogravimetric and N2 physisorption analyses. The silane moieties induce a partial decrease of the shielding of the valence electrons of the Ti ions at the surface, and a local modification of their crystal field, as demonstrated by XPS and UV/Vis spectroscopy, respectively. The changes in coordination and the produced oxygen vacancies result in the formation of Ti3+ defects localized in the sub‐surface region, as revealed by EPR spectroscopy. These paramagnetic centers are stabilized in the silanized samples, as the electron transfer to O2 is efficiently inhibited even under UV irradiation. However, the amount of Ti3+ centers appears to be correlated with the singlet oxygen (1O2) formation rate. Accordingly, epoxidation of limonene under UV light, chosen as a model photocatalytic reaction triggered by 1O2, occurred with higher selectivity when TiO2 was silanized and upon simultaneous NIR irradiation. These evidences suggest that in the silanized sample 1O2 may be generated through Förster‐type energy transfer from excited sub‐surface Ti3+ centers.

Mechanisms for the Spin-State Switching of Strapped Ni-Porphyrin Complexes Deposited on Metal Surfaces: Insights from Quantum Chemical Calculations.

The incorporation of molecular switches on nanodevices requires both the intactness of the molecule once deposited on a substrate and the persistence of the reversible switching feature. Recently, the reversible spin-switching of strapped Ni(II)-porphyrin complexes deposited on Ag(111) surface is demonstrated with low-temperature scanning tunneling microscopy (STM). The spin transition is accompanied by the coordination change of the metal center, a phenomenon denominated in coordination-induced spin-state switching (CISSS). In this contribution, the spin switching of the deposited strapped Ni-porphyrin molecules using different quantum chemistry approaches is explored. This calculations inform about the geometry and electronic structure of the adsorbed molecules and the origin of the voltage-dependent switching promoted by the STM tip. Two different mechanisms are inspected to elucidate the key role of the tip, mainly the electron injection between the tip and the molecule and the differential stabilization of the two spin states by the applied electric field between the tip and the silver surface. This study puts in evidence the relevance of the pyridine ligand contained in the strap in the transport properties as in the CISSS process itself.

Classifying Abelian Groups Through Acyclic Matchings

AbstractThe inquiry into identifying sets of monomials that can be eliminated from a generic homogeneous polynomial via a linear change of coordinates was initiated by E. K. Wakeford. This linear algebra problem prompted C. K. Fan and J. Losonczy to introduce the notion of acyclic matchings in the additive group $$\mathbb {Z}^n$$ Z n , subsequently extended to abelian groups by the latter author. Alon, Fan, Kleitman, and Losonczy established the acyclic matching property for $$\mathbb {Z}^n$$ Z n . This note aims to classify all abelian groups with respect to the acyclic matching property.

Identifying Levers for Change in Healthcare Coordination Between the Emergency Youth Shelter and Health Systems in Toronto, Canada Through Stakeholder Engagement: A Qualitative Study

Background: Healthcare coordination involves supporting youth experiencing homelessness (YEH) with accessing appropriate healthcare; synchronizing delivery of their healthcare across multiple systems; sharing healthcare and discharge plans with youth and providers who fall under their ‘circle of care;’ and coordinating post-care follow-up as necessary. Challenges with coordinating healthcare within and between the emergency youth shelter (EYS) and health systems include poor accountability for healthcare coordination across systems; information-sharing and privacy policies inhibiting communication between sectoral staff; inconsistencies in system-based and organizational norms, operations, and funding; and each system’s historically fragmented structure. Methods: We used a system thinking framework to identify levers for change in healthcare coordination within and between the EYS and health systems in Toronto, Canada. Six stakeholders who work at various levels of each system participated in online breakout room discussions as part of a two-hour forum facilitated by our research team. A series of four questions were asked to identify levers for change in system parts and system patterns in healthcare coordination within and between the EYS and health systems. Breakout room discussions were recorded, transcribed, and co-analyzed by the research team using reflexive thematic analysis for each question. Results: Organizational and system-wide goals discussed to strengthen healthcare coordination include clarifying accountability in staff roles, revisiting discharge policies to improve continuity of care, prioritizing funding for programs evaluated to be effective, establishing more opportunities for system cross over, enhancing accessibility for YEH, integrating social medicine into healthcare approaches, and streamlining health communication across both systems. When asked about what is realistically possible, stakeholders were optimistic about enhancing information-sharing through digital health platforms, adapting organizational policies to consider the holistic needs of YEH, and dispersing funds more intentionally to support coordination initiatives. Furthermore, poor staff-youth relations, harmful discharge policies and the Toronto housing crisis were noted as patterns impeding meaningful change in coordinating healthcare. Finally, stakeholders identified systems integration and alignment of well-defined healthcare coordination processes across systems to harmonize efforts in achieving healthcare coordination goals. Conclusions: Stakeholder forum participants discussed promising levers for change that are recommended to strengthen parts of the EYS and health systems along with patterns that influence healthcare coordination between them.

High-Fat Diet-Induced Blood-Brain Barrier Dysfunction: Impact on Allodynia and Motor Coordination in Rats.

The associations among increased pain sensitivity, obesity, and systemic inflammation have not been described as related to BBB dysfunctions. To analyze the metabolic, behavioral, and inflammatory effects of a high-fat diet (HFD) and ultrastructural modifications in brain regions, we used an in vivo experimental model. Adult male Wistar rats were randomly assigned to one of two conditions, an ad libitum control group or an HFD (60%)-fed group, for eight weeks. At the end of the protocol, glucose and insulin tolerance tests were performed. Additionally, we analyzed the response to a normally innocuous mechanical stimulus and changes in motor coordination. At the end of the protocol, HFD-fed rats presented increased HOMA-IR and metabolic syndrome (MetS) prevalence. HFD-fed rats also developed an increased nociceptive response to mechanical stimuli and neurological injury, resulting in impaired motor function. Hypothalamus and cerebellum neurons from HFD-fed rats presented with nuclear swelling, an absence of nucleoli, and karyolysis. These results reveal that HFD consumption affects vital brain structures such as the cerebellum, hippocampus, and hypothalamus. This, in turn, could be producing neuronal damage, impairing cellular communication, and consequently altering motricity and pain sensitivity. Although direct evidence of a causal link between BBB dysfunction and sensory-motor changes was not observed, understanding the association uncovered in this study could lead to targeted therapeutic strategies.

Mapping the influence: Institutional blockholder coordination and climate change risk disclosure

This study investigates the relationship between institutional blockholder coordination, proxied by geographic proximity, and climate change risk disclosure. Using a sample of 2,887 firm-year observations for S&P 500 companies from 2010 to 2022, we reveal that a firm's climate change risk disclosure decreases when its institutional blockholders are more coordinated. In addition, we find that the negative relationship between institutional blockholder coordination and climate change risk disclosure manifests more in firms with less diversified institutional blockholders, a smaller number of institutional blockholders, a prominent position to their blockholders, and more dedicated institutional blockholder ownership. Moreover, we find that the negative association between institutional blockholder coordination and climate change risk disclosure is more pronounced in firms with corporate general counsels, a non-concentrated customer base, higher asset tangibility, and those that are environmentally sensitive. Our main conclusion still holds after using an alternative measure for climate change risk disclosure as well as a battery of endogeneity tests. Finally, we propose that institutional blockholder coordination lessens climate change risk disclosure through the channel of increased performance-induced CEO dismissal. Collectively, this study provides insightful implications for academics, financial statement users, regulators, and policymakers.

FTIR traced modification of defect-engineered UiO-66 for enhanced accessibility of zirconium sites

This research focuses on identifying the accessibility of active sites within the defect-engineered UiO-66 framework. The task is particularly challenging due to reversible changes in the framework during dehydroxylation: the loss of μ3-OH groups with simultaneous reduction of the Zr coordination number and the possible creation of Zr4+ Lewis acid sites in defect MOFs. We used in-situ FTIR and XANES analyses, as well as interaction with probe molecules, to monitor the changes in Zr coordination and the host-guest interaction. The defects were introduced using benzoic acid as a modulator, which coordinated to Zr4+ in defective pores. Our results showed that the UiO-66 sample synthesized with benzoic acid contained defects, but these were concealed under benzoate residues and thus inaccessible. Standard washing and heating did not remove benzoate anions. Dehydroxylation of the sample leads to the development of “hidden” Lewis acidity: some Zr4+ sites were not able to form complexes with the weak base CO, but they interact with the stronger bases acetonitrile. Additionally, in-situ XANES analysis revealed that the effect of acetonitrile adsorption is similar to that of water rehydration. Treatment of the sample with HCl and DMF led to the replacement of benzoates with formate ions, exposing the bare Zr4+ sites within the defective pores. These cationic sites acted as true Lewis acids and were able to coordinate both CO and acetonitrile. Our findings emphasize that the active sites in UiO-66 highly depend on synthesis conditions and post-synthetic treatments. Comprehensive site-specific methods are crucial for accurately predicting and identifying these active sites.

Rapid monitoring of structural deformation based on unsupervised segmentation model

This paper presents a novel approach for rapid structural deformation monitoring using an enhanced segmentation model, SAM-DM (Segment Anything Model-Deformation Monitoring). The method enhances the SAM model by integrating an innovative point prompt generation technique, image fusion, and connected domain analysis, enabling structural deformation monitoring with just a single manual click on the target area in the initial video frame. Specifically, this manual click generates coordinate information for the target area, serving as a point prompt for the SAM-DM model. This process results in the creation of a high-quality binary mask, which is then fused with the original image to isolate only the target area. Subsequently, connected domain analysis is employed to automatically process the mask, extracting the pixel centroid coordinates of the target area, which are then used as prompts for segmenting subsequent frames. This approach allows continuous tracking of changes in the target area's coordinates, thereby facilitating rapid structural deformation monitoring. Experimental results demonstrate that this method can accurately monitor deformation across all target points and adapt to varying lighting conditions and noise levels. Applied to monitor the bending deformation of reinforced concrete beams and the in-plane deformation of concrete slabs, the method achieves results closely aligned with actual measurements, yielding relative errors of 0.95 % and 0.48 %, respectively. Additionally, in monitoring the vibrational deformation of steel frames, the primary frequency of the curve precisely matches measured values, confirming that the SAM-DM-based method delivers both high accuracy and strong robustness.

Singlet Oxygen Photocatalytic Generation by Silanized TiO2 Nanoparticles.

A commercial TiO2 sample, used as received or hydrothermally treated to increase surface hydroxylation, has been functionalized by surface modification with hexadecyltrimethoxysilane. The anchoring of thesilane has been characterized byFTIR and solid-state NMR spectroscopies, and the grafting density was determined by thermogravimetric and N2 physisorption analyses. The silane moieties induce a partial decrease of the shielding of the valence electrons of the Ti ions at the surface, and a local modification of their crystal field, as demonstrated by XPS and UV-vis spectroscopy, respectively. The changes in coordination and the produced oxygen vacancies result in the formation of Ti3+ defects localized in the sub-surface region, as revealed by EPR spectroscopy. These paramagnetic centers are stabilized in the silanized samples, as the electron transfer to O2 is efficiently inhibited even under UV irradiation. However, the amount of Ti3+ centers appears to be correlated with the singlet oxygen (1O2) formation rate. Accordingly, epoxidation of limonene under UV light, chosen as a model photocatalytic reaction triggered by 1O2, occurred with higher selectivity when TiO2 was silanized and upon simultaneous NIR irradiation. These evidences suggest that in the silanized sample 1O2 may be generated through Förster-type energy transfer from excited sub-surface Ti3+ centers.

Self-similar solution for laminar bubbly flow evolving from a vertical plate

The development of a bubble plume from a vertical gas-evolving electrode is driven by buoyancy and hydrodynamic bubble dispersion. This canonical fluid mechanics problem is relevant for both thermal and electrochemical processes. We adopt a mixture model formulation for the two-phase flow, considering variable density (beyond Boussinesq), viscosity and hydrodynamic bubble dispersion. Introducing a new change of coordinates, inspired by the Lees–Dorodnitsyn transformation, we obtain a new self-similar solution for the laminar boundary layer equations. The results predict a wall gas fraction and gas plume thickness that increase with height to the power of 1/5 before asymptotically reaching unity and scaling with height to the power 2/5, respectively. The vertical velocity scales with height to the power of 3/5. Our analysis shows that self-similarity is only possible if gas conservation is entirely formulated in terms of the gas specific volume instead of the gas fraction.

Technology availability, sector policies and behavioral change are complementary strategies for achieving net-zero emissions

In this study, we analyze the effects of technology availability, political coordination, and behavioral change on transformation pathways toward net-zero greenhouse gas emissions in the European Union by 2050. We implemented an iterative stakeholder dialogue to co-design the scenarios that were calculated using a global multi-regional energy-economy-land-climate model. We find that in scenarios without behavioral change and with restriction of technologies, the target of greenhouse gas neutrality in the European Union cannot be reached. Already a target of 200 Mt CO2eq/yr requires CO2 prices above 100 €/tCO2 in 2030 across all sectors in all scenarios. The required CO2 price can increase to up to 450 €/tCO2 by 2030 if technologies are constrained, if no complementary regulatory measures are implemented, and if changes in consumer behavior towards a more sustainable lifestyle do not materialize.

Kinetic theory of tilted Dirac cone materials

We formulate the Boltzmann kinetic equations for interacting electrons with tilted Dirac cones in two space dimensions characterized by a tilt parameter 0≤ζ<1. By solving the linearized Boltzmann equation, we find that the broadening of the Drude pole is enhanced by κ(ζ)×(1−ζ2)−1/2, where the κ is interaction-induced enhancement factor. The intensity of the Drude pole is also anisotropically enhanced by (1−ζ2)−1. The ubiquitous “redshift” factors (1−ζ2)1/2 can be regarded as a manifestation of an underlying spacetime structure in such solids. The additional broadening κ that arises from the interactions cannot be obtained from a simple coordinate change and are more pronounced for electrons in a ζ-deformed Minkowski spacetime of tilted Dirac fermions.

General Trends in the Compression of Glasses and Liquids

The present work relates the isothermal volumes of silicate glasses and melts to the combined ionic volumes of their chemical constituents. The relation is an extension of a relation that has already been established for crystalline oxides, silicates, alumosilicates, and other materials that have O2− as a constituent anion. The relation provides constraints on bond coordination, indicates pressure-induced changes in coordination in melts and glasses and interatomic distances, and quantifies the extent of transitory regions in pressure-induced coordination changes.

One-year developmental changes in motor coordination and tennis skills in 10–12-year-old male and female tennis players

BackgroundTo date, no longitudinal studies of quarterly changes have been conducted on the differences in the development of motor coordination between boys and girls in relation to changes in their tennis skills level. Therefore, the aim of the study was to assess the development of motor coordination of 10–12-year-old tennis players over the course of 1 year, in the light of changes in tennis skills preparation.MethodsOne-hundred eighty male and female tennis players aged 10, 11, or 12 years old participated in the study. Each age group comprised 30 boys and 30 girls. To investigate their motor coordination development, a battery of general tests (simple reaction, complex reaction, Spalding test, spider test, hexagon jumping, Starosta’s test, hand–eye test, balance, plate tapping, jump rope) and specific tennis skills tests (wall game and 100-tennis ball tests) were performed 4 times quarterly over 1 year. Differences between sexes and the time points were assessed. The rate of development evaluation was based on beta coefficient of linear regression.ResultsBoys generally performed better in tennis skills tests than girls. The boys performed better also in one motor coordination test (Spalding test) among 10-year-olds, in two additional tests (spider and plate tapping tests) among 11-year-olds, and another three more tests (simple reaction, complex reaction and Starosta’s tests) among 12-year-olds. Jump rope test among 10-year-olds and hexagon jump test among 12-year-olds were the only tests where girls performed better than boys. On the other hand, girls showed higher rate of development in balance and complex reaction tests than boys.ConclusionsWe conclude that motor coordination and tennis skills development over 1 year is age-, sex-, and task-dependent, with the 10–12-year-old male tennis players performing better in tennis skills and overall motor coordination than females.

Ventral tegmental area dopamine neural activity switches simultaneously with rule representations in the prefrontal cortex and hippocampus.

This study examines neural activity in mammalian brain networks that support the ability to respond flexibly to changing contexts. We use a rule-switching spatial task to examine whether the key reward-responsive and predictive dopamine (DA) activity changes in coordination with changes in rule representations in key cognitive regions, the prefrontal cortex (PFC) and hippocampus. We first established distinct rule representations in PFC and hippocampus, and predictive coding of reward outcomes by DA neuronal activity. We show that the rule-specific DA reward prediction after a rule switch develops in temporal coordination with changes in rule representations especially in PFC, eventually leading to behavioral changes. These results thus provide an integrated understanding of reward prediction, cognitive representations of rules and behavioral adaptation.

CsPb(Br/Cl)3-Sm3+ codoped glasses for optical temperature sensing in FIR and chromatic coordinate modes

We have fabricated Sm3+ doped glasses, CsPb(Br/Cl)3 quantum dots (QDs) glasses and CsPb(Br/Cl)3-Sm3+ codoped glasses by melt-quenching and subsequent heat treatment for optical temperature sensing. Photoluminescence (PL), photoluminescence excitation (PLE) spectra and PL decay have been measured. Two CsPb(Br/Cl)3-Sm3+ samples with different PL peaks of QDs at 486 nm and 503 nm have been studied for fluorescence intensity ratio (FIR) and chromatic coordinate sensing. The CsPb(Br/Cl)3 QDs and Sm3+ ions exhibit distinguished spectral components and they are dynamically independent. PL intensity of QDs rapidly decreases with temperature, whereas PL intensity of Sm3+ slowly decreases with temperature. PL intensity of Sm3+ ions and CsPb(Cl/Br)3 QDs have been independently fitted. Then, FIR sensing has been studied. The different variation in PL intensity with temperature for Sm3+ and CsPb(Cl/Br)3 leads to the change of luminescent color and chromatic coordinate. The chromatic coordinate sensing has also been studied. Absolute sensitivity (Sa) and relative sensitivity (Sr) have been analyzed for both FIR and chromatic coordinate sensing. Compared with the chromatic coordinate mode, FIR mode has the larger Sa and Sr. But the chromatic coordinate method is more convenient for application, which does not require separating two spectral components. Both FIR and chromatic coordinate sensing modes show outstanding temperature cycling characteristics.

First person – Daniel Lenthall

ABSTRACT First Person is a series of interviews with the first authors of a selection of papers published in Biology Open, helping researchers promote themselves alongside their papers. Daniel Lenthall is first author on ‘ Lower-limb coordination changes following a 6-week training intervention that elicited enhancements to maximum velocity sprint performance’, published in BiO. Daniel is a Master's in Research student at Leeds Beckett University, and strength and conditioning coach in the lab of Mr Andreas Wallbaum at the University of Bath, Bath, UK, investigating research that bridges the gap between theory and practice, making a meaningful impact beyond academia.

University community partnerships for climate change adaptation in Malawi: Exploring contributions, potential opportunities and challenges

Partnerships with local communities have emerged as a prominent educational strategy within university functions, aligning with the ethos of an institution dedicated to community engagement. These partnerships serve not only to empower communities with essential skills to address societal challenges, notably climate change, but also reflect a broader shift in academia towards fostering collaborative relationships with local stakeholders. For students, partnerships offer invaluable hands-on experience by immersing them in direct engagement with community members, bridging the gap between theoretical knowledge and practical application to enrich their educational learning outcomes. This article explores the multifaceted benefits and contributions of partnerships to sustainable community well-being while addressing the inherent complexities that arise when universities engage with communities in promoting human development. Drawing upon qualitative data obtained from interviews with lecturers, students, and community focus groups involved in climate adaptation initiatives, the study investigates the contributions and potential opportunities presented by partnerships and examines challenges encountered by stakeholders in advancing partnerships interventions. Despite the positive impact of partnerships on community skills and empowerment, I argue that while partnerships are contributing towards sustainable community well-being, coordination, funding, and mindset change remain key issues to be addressed. Further, educational practices and pedagogical approaches should prioritize addressing the multidimensionality of climate change and fostering agency and empowerment among community leaders to actively engage in partnership activities. This includes giving them a voice in the choice of adaptation interventions and inclusion of communities' voices in the monitoring and assessment of partnership interventions. By doing so, partnerships can be more effective in promoting sustainable community well-being and improving students' learning outcomes.

Investigation of red-emitting CaMoO4: Eu3+ phosphor by partitioning of substitutional PO4 3- ions via solid-state reaction method.

To investigate the impact of PO4 3- anionic groups, the trivalent europium ion-doped calcium molybdate (CaMoO3-PO4:xEu3+, where x = 0.5, 1.0, 1.5, 2.0, and 2.5mol%) phosphors were synthesized using the solid-state reaction method. The detailed study of the phosphor materials was carried out by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), optical diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The XRD results indicate that the substitution of PO4 3- anion and Eu3+ dopant ion did not affect the crystal structures of the CaMoO4 phosphors. Ultraviolet-visible (UV-vis) absorption analysis revealed the change of absorption edge of both un-doped and Eu3+-doped CaMoO4-PO4 phosphors. Under the 394 nm UV-excitation, the recorded PL spectra showed an intense peak at 615 nm corresponding to the Eu3+: 5D0 → 7F2 transition. The results of the Commission Internationale de l'Eclairage (CIE) diagram reported that the color of the emissions lies in the red color zone and there is no change in the CIE coordinates of the overall emission for Eu3+-doped CaMoO4-PO4 as Eu concentration changes. Thus, these observations led to finding the best red components for white light-emitting diode applications.

Lower-limb coordination changes following a 6-week training intervention that elicited enhancements to maximum velocity sprint performance.

Alterations to intra- and inter-limb coordination with improved maximal velocity performance remain largely unexplored. This study quantified within-day variability in lower-limb segmental coordination profiles during maximal velocity sprinting and investigated the modifications to coordination strategies in 15 recreationally active males following a 6-week period comprised of a multimodal training programme [intervention group (INT); n=7] or continued participation in sports (control group; n=8). The INT demonstrated a large decrease (effect size=-1.54) in within-day coordination profile variability, suggesting potential skill development. Thigh-thigh coordination modifications for the INT were characterised by an earlier onset of trail thigh reversal in early swing (26 versus 28% stride) and lead thigh reversal in late swing (76 versus 79% stride), rather than increases in overall time spent in anti-phase. Moreover, an increase in backward rotation of thigh relative to shank (effect size, 95% CIs: 0.75, 0.17 to 1.33) and shank relative to foot (0.76, -0.17 to 1.68) during late swing likely facilitated more aggressive acceleration of the limb, contributing to reduced touchdown distance and more favourable lower-limb configuration at initial ground contact. These novel findings provide empirical support for the role of longitudinal coordination modifications in improving maximal velocity performance.