Fine Analysis Research Articles

Risk stratification for ventricular tachyarrhythmia in patients with nonischemic cardiomyopathy.

The implantable cardioverter defibrillator reduces mortality among patients with heart failure (HF) due to ischemic heart disease. Clinical trial data have called into question the benefit of an ICD in patients with HF due to nonischemic cardiomyopathy (NICM). We developed a risk stratification score for ventricular tachyarrhythmia (VTA) among patients with NICM receiving a primary prevention ICD. The study population comprised 1515 patients with NICM who were enrolled in the landmark MADIT trials. Fine and Gray analysis was used to develop a model to predict the occurrence of VTAs and ICD therapies while accounting for the competing risk of non-arrhythmic mortality. External validation was carried out in the RAID Trial population. Four risk factors associated with increased risk for VTA were identified: male sex, left ventricular ejection fraction ≤25%, no indication for cardiac resynchronization therapy with a defibrillator (CRT-D), and Black race. A score was generated based on this model, and patients were stratified into low (N = 390), intermediate (N = 728), and high-risk (N = 387) groups. The 5-year cumulative incidences of VTA were 15%, 24%, and 42%, respectively. Application of score groups for the secondary endpoints of Fast VT or VF and Appropriate ICD Shock revealed similar findings. Recurrent event analysis yielded consistent results. The AUC in the validation cohort for the endpoint of Appropriate ICD Shock was 69.3. Our study shows that patients with NICM can be risk stratified using demographic and clinical variables and may be used when evaluating such patients for a primary prevention ICD.

CCDC28A deficiency causes head-tail coupling defects and immotility in murine spermatozoa

Male infertility presents a substantial challenge in reproductive medicine, often attributed to impaired sperm motility. The present study investigates the role of CCDC28A, a protein expressed specifically in male germ cells, whose paralog CCDC28B has been implicated in ciliogenesis. We identify unique expression patterns for CCDC28A and CCDC28B within the mouse testes, where CCDC28A is expressed in germ cells, whereas CCDC28B is expressed in supporting somatic cells. Through knockout mouse models and histological analyses, we reveal that CCDC28A deficiency results in diminished sperm motility and structural aberrations in sperm tails, notably affecting the head-tail coupling apparatus (HTCA), thereby causing male infertility. Fine structural analyses by transmission electron microscopy reveal disruptions at the capitulum-basal plate junction of the HTCA in the CCDC28A mutants. This results in the bending of the head within the neck region, often accompanied by thickening of the tail midpiece. Our discovery demonstrates that CCDC28A plays an essential role in male fertility and sperm tail morphogenesis through the formation of HTCA.

Multiplicity of solutions for a nonhomogeneous quasilinear elliptic equation with concave-convex nonlinearities

Abstract We investigate the multiplicity of solutions for a quasilinear scalar field equation with a nonhomogeneous differential operator defined by S u ≔ − div ϕ u 2 + ∣ ∇ u ∣ 2 2 ∇ u + ϕ u 2 + ∣ ∇ u ∣ 2 2 u , Su:= -\hspace{0.1em}\text{div}\hspace{0.1em}\left\{\phi \left(\frac{{u}^{2}+{| \nabla u| }^{2}}{2}\right)\nabla u\right\}+\phi \left(\frac{{u}^{2}+{| \nabla u| }^{2}}{2}\right)u, where ϕ : [ 0 , + ∞ ) → R \phi :\left[0,+\infty )\to {\mathbb{R}} is a positive continuous function. This operator is introduced by Stuart [Two positive solutions of a quasilinear elliptic Dirichlet problem, Milan J. Math. 79 (2011), 327–341] and depends on not only ∇ u \nabla u but also u u . This particular quasilinear term generally appears in the study of nonlinear optics model, which describes the propagation of self-trapped beam in a cylindrical optical fiber made from a self-focusing dielectric material. When the reaction term is concave-convex nonlinearities, by using the Nehari manifold and doing a fine analysis associated on the fibering map, we obtain that the equation admits at least one positive energy solution and negative energy solution, which is also the ground state solution of the equation. We overcome two main difficulties which are caused by the nonhomogeneity of the differential operator S S : (i) the almost everywhere convergence of the gradient for the minimizing sequence { u n } \left\{{u}_{n}\right\} ; (ii) seeking the reasonable restrictions about S S .

Fine analysis and size optimization of spherical hinge in swivel construction

Contact stress and friction torque are the two primary mechanical responses of a spherical hinge. In general engineering practice, the calculation methods for contact stress and friction in spherical hinges often involve simplifying the spherical hinge into a planar hinge. To accurately analyze the stress state of the spherical hinge, it is essential to establish a detailed model. In this study, 17 groups of spherical hinge models were developed. The support radius, curvature radius, and thickness of the spherical hinge are considered influencing factors, while the maximum contact stress, friction torque, and amount of steel used are treated as responses. A three-factor, three-level, and three-response design is implemented. Using the response surface method, optimization design is conducted, resulting in two proposed optimization schemes. The maximum contact stress is reduced by 40.10% and 10.91%, respectively, while the friction torque is decreased by 0.82% and 26.50%, respectively. The maximum error between the predicted and calculated values is 7.04%. This indicates that the model presented in this study possesses sufficient predictive accuracy and can effectively guide the selection of spherical hinge dimensions.

Balancing Layered Ordering and Lattice Oxygen Stability for Electrochemically Stable High-Nickel Layered Cathode for Lithium-ion Batteries

Despite the high-capacity nature of high-nickel cathode materials, achieving their practical implementation is challenging due to the susceptibility of atomic arrangement to calcining conditions. Extensive studies have enlightened the correlation between layered ordering and calcining conditions; nevertheless, the alterations in the electronic structure of lattice oxygen remain obscure. In this study, by comparing cathode materials with varying degrees of layered ordering, achieved through adjustments in calcination temperature and lithium equivalent, it is shown that although layered ordering increases, it compromises the electronic structure, creating a labile lattice oxygen environment. Fine structural analysis reveals that a higher local Li/O ratio in highly ordered cathode subsequently alters the band structure by narrowing the band gap between Ni 3d and O 2p, which enhances transition metal–oxygen covalency, and reduces the oxygen vacancy formation energy, adversely affecting cyclability. In highly ordered cathode, the tendency of lattice oxygen to reside within a Li-enriched environment arises from the changes in the favorability of non-paired antisite defects contingent upon the calcination temperature and lithium equivalent. This research underscores the need to balance layered ordering and lattice oxygen stability, offering important insights for the future design of high-nickel cathodes.

Prognostic implications and alterations in left atrial deformation following transcatheter aortic valve implantation for severe aortic stenosis

Abstract Background Left atrial reservoir strain (LARS) as a single parameter estimate of left ventricular (LV) diastolic dysfunction (DD), may provide important prognostic insights into patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI). Purpose To evaluate the prognostic implications of pre- and post TAVI LARS-defined DD (LARS-DD) grade in patients undergoing TAVI for severe AS and its association with new-onset atrial fibrillation. Methods Pre-TAVI LARS-DD was evaluated by speckle-tracking echocardiography and was assigned as grade 0 to 1 (LARS ≥24%), grade 2 (LARS ≥19 to <24%) and grade 3 (LARS <19%). Patients were followed-up for the primary endpoint of all-cause mortality from the date of TAVI. For the secondary endpoint, patients with pre- and post-TAVI LARS measurements, no history of atrial fibrillation and with clinical/ECG follow-up following the post-TAVI follow-up echocardiogram were evaluated for the occurrence of new-onset atrial fibrillation. Results A total of 601 patients (median age 81 [76-85] years, 53% male) undergoing TAVI for severe AS were included. Overall, 169 patients (28%) were LARS-DD grade 0/1, 96 patients (16%) were LARS-DD grade 2 and 336 (56%) were LARS-DD grade 3. Over a median follow-up of 40 (IQR 26 to 58) months, a total of 258 (43%) patients died (Figure 1). In a comprehensive multivariable Cox regression model adjusted for age, sex, EuroSCORE II, New York Heart Association class III to IV symptoms, LV ejection fraction, atrial fibrillation, LA volume index and LV stroke volume index, LARS-DD grade was independently associated with all-cause mortality (adjusted HR 1.28 per one grade increase above LARS-DD grade 0/1, 95% CI 1.07 to 1.53, P=0.007). For the secondary endpoint of new-onset atrial fibrillation, a total of 285 patients were evaluated (Figure 2). On multivariable Fine and Gray regression analyses adjusting for age and LA volume index, post-TAVI LARS (SDHR 1.14 per 1% <20%, 95% CI 1.05 to 1.23, P=0.0009), rather than pre-TAVI LARS (SDHR 1.00 per 1% <20%, 95% CI 0.91 to 1.11, P=0.93) was associated with the occurrence of new-onset atrial fibrillation. Conclusions Increasing LARS-DD grade was independently associated with long-term post-TAVI survival in patients with severe AS and may enhance risk stratification. In addition, post-TAVI LARS, but not pre-TAVI LARS, was closely related to the occurrence of new-onset atrial fibrillation, likely better reflecting intrinsic LA dysfunction.Figure 1:All-Cause MortalityFigure 2:New-Onset Atrial Fibrillation

LRP1 Repression by SNAIL Results in ECM Remodeling in Genetic Risk for Vascular Diseases.

Genome-wide association studies implicate common genetic variations in the LRP1 (low-density lipoprotein receptor-related protein 1) locus at risk for multiple vascular diseases and traits. However, the underlying biological mechanisms are unknown. Fine mapping analyses included Bayesian colocalization to identify the most likely causal variant. Human induced pluripotent stem cells were genome-edited using CRISPR-Cas9 to delete or modify candidate enhancer regions and generate LRP1 knockout cell lines. Cells were differentiated into smooth muscle cells through a mesodermal lineage. Transcription regulation was assessed using luciferase reporter assay, transcription factor knockdown, and chromatin immunoprecipitation. Phenotype changes in cells were conducted using cellular assays, bulk RNA sequencing, and mass spectrometry. Multitrait colocalization analyses pointed at rs11172113 as the most likely causal variant in LRP1 for fibromuscular dysplasia, migraine, pulse pressure, and pulmonary function trait. We found the rs11172113-T allele to associate with higher LRP1 expression. Genomic deletion in induced pluripotent stem cell-derived smooth muscle cells supported rs11172113 to locate in an enhancer region regulating LRP1 expression. We found transcription factors MECP2 (methyl CpG binding protein 2) and SNAIL to repress LRP1 expression through an allele-specific mechanism, involving SNAIL interaction with disease risk allele. LRP1 knockout decreased induced pluripotent stem cell-derived smooth muscle cell proliferation and migration. Differentially expressed genes were enriched for collagen-containing extracellular matrix, connective tissue development, and lung development. LRP1 knockout and deletion of rs11172113 enhancer showed potentiated canonical TGF-β (transforming growth factor beta) signaling through enhanced phosphorylation of SMAD2/3. Analyses of the protein content of decellularized extracts indicated partial extracellular matrix remodeling involving enhanced secretion of CYR61, a known LRP1 ligand involved in vascular integrity and TIMP3, implicated in extracellular matrix maintenance and also known to interact with LRP1. Our findings support allele-specific LRP1 gene repression by the endothelial-to-mesenchymal transition regulator SNAIL. We propose decreased LRP1 expression in smooth muscle cells to remodel the extracellular matrix enhanced by TGF-β as a potential mechanism of this pleiotropic locus for vascular diseases.

A Janus Platinum/Tin Oxide Heterostructure for Durable Oxygen Reduction Reaction.

Designing efficient and durable electrocatalysts for oxygen reduction reaction (ORR) is essential for proton exchange membrane fuel cells (PEMFCs). Platinum-based catalysts are considered efficient ORR catalysts due to their high activity. However, the degradation of Pt species leads to poor durability of catalysts, limiting their applications in PEMFCs. Herein, a Janus heterostructure is designed for high durability ORR in acidic media. The Janus heterostructure composes of crystalline platinum and cassiterite tin oxide nanoparticles with carbon support (J-Pt@SnO2/C). Based on the synchrotron fine structure analysis and electrochemical investigation, the crystalline reconstruction and charge redistribution at the interface of Janus structure are revealed. The tightly coupled interface could optimize the valance states of Pt and the adsorption/desorption of oxygenated intermediates. As a result, the J-Pt@SnO2/C catalyst possesses distinguishing long-term stability during the accelerated durability test without obvious degradation after 40000 cycles and keeps the majority of activity after 70000 cycles. Meanwhile, the catalyst exhibits outstanding activity with half-wave potential at 0.905V and a mass activity of 0.355AmgPt -1 (2.7 times higher than Pt/C). The approach of the Janus catalyst paves an avenue for designing highly efficient and stable Pt-based ORR catalyst in the future implementation.

Sediment source-to-sink patterns along the southeast China coast during the late Quaternary: New insights from sediment geochemistry and OSL ages in Ningde Bay

The geomorphology and environmental conditions of the southeast China coast are significantly influenced by sediment discharge from the Yangtze River, a major river located to the north. Nonetheless, the extent to which the Yangtze River affects sediment transport processes from source to sink along the southeast coast remains unclear. Our recent findings in coastal/marine deposits from the late Quaternary period (MIS5e, MIS3, and MIS1) in Ningde Bay offer new perspectives on this issue. Provenance discrimination of the late Quaternary boreholes was carried out using sediment geochemical analysis and OSL dating of fine- and medium-grained quartz. The results indicate varying provenances during sea-level fluctuation, with distal Yangtze River origins during MIS5e, MIS3, and MIS1, and a local source during MIS4. The findings also suggest that the southward transport of Yangtze sediments along the southeast China coast has occurred since MIS5e. However, OSL ages of the fine-grained quartz in the MIS3 deposit range from approximately 90 to 140 kyr, notably older than those of medium-grained quartz (40–80 kyr). This remarkable age discrepancy indicates that Yangtze-derived sediments previously deposited on the shelf of the East China Sea during MIS5 were reworked and transported southward in MIS3. This phenomenon can be elucidated by the insufficient supply of Yangtze sediments during MIS3, which could be linked to the weakened East Asian monsoon. This new source-to-sink pattern for the southeast China coast is characterized by a compensating mechanism of inner shelf old sediment in response to the inadequate supply of Yangtze sediments. This study contributes to a better understanding of the significant impacts of reduced Yangtze sediment input on its distal sedimentary systems over time.

High Price Impact Trade Identification and Its Implication for Volatility and Price Efficiency

We include limit order book (LOB) matchedness as a new trade attribute to identify high price impact trades (HPITs). HPITs are trades associated with large price changes relative to their volume proportion. We show that the inclusion of matchedness provides a finer analysis of the relationship between price contribution and trade categories. We further verify that a stronger presence of HPITs leads to a decline in volatility and improves price efficiency, which suggests a link between HPITs and informed trades.

Association of HRS-AKI with Mortality in Patients with Cirrhosis Requiring Renal Replacement Therapy: Results from the HRS-HARMONY Consortium.

While AKI requiring renal replacement therapy (AKI-RRT) is associated with increased mortality in heterogeneous inpatient populations, the epidemiology of AKI-RRT in hospitalized patients with cirrhosis is not fully known. Herein, we evaluated the association of etiology of AKI with mortality in hospitalized patients with cirrhosis and AKI-RRT in a multicentric contemporary cohort. This is a multicenter retrospective cohort study using data from the HRS-HARMONY consortium, which included 11 U.S. hospital network systems. Consecutive adult patients admitted in 2019 with cirrhosis and AKI-RRT were included. The primary outcome was 90-day mortality, and the main independent variable was AKI etiology, classified as hepatorenal syndrome (HRS-AKI) vs. other (non-HRS-AKI). AKI etiology was determined by at least two independent adjudicators. We performed Fine and Gray sub-distribution hazard analyses adjusting for relevant clinical variables. Of 2,063 hospitalized patients with cirrhosis and AKI, 374 (18.1%) had AKI-RRT. Among these, 65 (17.4%) had HRS-AKI and 309 (82.6%) non-HRS-AKI, which included ATN in most cases (62.6%). Continuous RRT (CRRT) was used as the initial modality in 264 (71%) of patients, while intermittent hemodialysis (IHD) was utilized in 108 (29%). The HRS-AKI (vs. non-HRS-AKI) group received more vasoconstrictors for HRS management (81.5% vs. 67.9%), while the non-HRS-AKI group received more mechanical ventilation (64.3% vs. 50.8%) and more CRRT (vs. IHD) as the initial RRT modality (73.9% vs. 56.9%). In the adjusted model, HRS-AKI (vs. non-HRS-AKI) was not independently associated with increased 90-day mortality (sHR=1.36, 95% CI: 0.95-1.94). In this multicenter contemporary cohort of hospitalized adult patients with cirrhosis and AKI-RRT, HRS-AKI was not independently associated with an increased risk of 90-day mortality when compared to other AKI etiologies. The etiology of AKI appears less relevant than previously considered when evaluating the prognosis of hospitalized adult patients with cirrhosis and AKI requiring RRT.

Fine Structural Analysis of Degummed Fibroin Fibers Reveals Its Superior Mechanical Capabilities.

Bombyx mori silk fibroin fibers constitute a class of protein building blocks capable of functionalization and reprocessing into various material formats. The properties of these fibers are typically affected by the intense thermal treatments needed to remove the sericin gum coating layer. Additionally, their mechanical characteristics are often misinterpreted by assuming the asymmetrical cross-sectional area (CSA) as a perfect circle. The thermal treatments impact not only the mechanics of the degummed fibroin fibers, but also the structural configuration of the resolubilized protein, thereby limiting the performance of the resulting silk-based materials. To mitigate these limitations, we explored varying alkali conditions at low temperatures for surface treatment, effectively removing the sericin gum layer while preserving the molecular structure of the fibroin protein, thus, maintaining the hierarchical integrity of the exposed fibroin microfiber core. The precise determination of the initial CSA of the asymmetrical silk fibers led to a comprehensive analysis of their mechanical properties. Our findings indicate that the alkali surface treatment raised the Young's modulus and tensile strength, by increasing the extent of the fibers' crystallinity, by approximately 40 % and 50 %, respectively, without compromising their strain. Furthermore, we have shown that this treatment facilitated further production of high-purity soluble silk protein with rheological and self-assembly characteristics comparable to those of native silk feedstock, initially stored in the animal's silk gland. The developed approaches benefits both the development of silk-based materials with tailored properties and the proper mechanical characterization of asymmetrical fibrous biological materials made of natural building blocks.

Fine root dynamics analyses in a tropical rain forest—A case study and challenges on root scanner method—

Fine root dynamics analyses in a tropical rain forest—A case study and challenges on root scanner method—

Wolff potential estimates and Wiener criterion for nonlocal equations with Orlicz growth

We prove the Wolff potential estimates for nonlocal equations with Orlicz growth. As an application, we obtain the Wiener criterion in this framework, which provides a necessary and sufficient condition for boundary points to be regular. Our approach relies on the fine analysis of superharmonic functions in view of nonlocal nonlinear potential theory.

Fine mapping-based multi-omics analysis interprets the gut-lung axis function of SGLT2 inhibitors.

Currently, Sodium-glucose cotransporter 2 (SGLT2) inhibitors demonstrate additional effects beyond glucose control on the gut microbiota and circulating metabolites. The gut microbiota and metabolites have been found to be useful in elucidating potential biological mechanisms of pulmonary diseases. Therefore, our study aims to investigate the effects of gut microbiota and metabolites mediating SGLT2 inhibition in 10 pulmonary diseases through Mendelian randomization (MR) research. We conducted a two-sample, two-step MR study to assess the association between SGLT2 inhibition and 10 pulmonary diseases and to investigate the mediating effects of gut microbiota and metabolite. Gene-fine mapping and annotation of mediators by FUMA and Magma analyses were performed, and causal associations of mapped genes with diseases were assessed by muti-omics MR analyses. Possible side effects of SGLT2 inhibition were assessed by PheWAS analysis. SGLT2 inhibition was linked to a reduced risk of T2DM, Interstitial lung disease (ILD), Pneumoconiosis, Pulmonary tuberculosis, and Asthma(OR=0.457, 0.054, 0.002, 0.280, 0.706). The family Enterobacteriaceae and order Enterobacteriales were associated with SGLT2 inhibition and ILD(95% CI:0.079-0.138). The family Alcaligenaceae and X-12719 were linked to pneumoconiosis (95% CI: 0.042-0.120, 0.050-0.099). The genus Phascolarctobacterium was connected to pulmonary tuberculosis (95% CI: 0.236-0.703).The degree of unsaturation (Fatty Acids), ratio of docosahexaenoic acid to total fatty acids, and 4-androsten-3beta,17beta-diol disulfate 2, were associated with asthma(95% CI: 0.042-0.119, 0.039-0.101, 0.181-0.473). Furthermore, Fuma and Magma analyses identified target genes for the four diseases, and proteomic MR analysis revealed six overlapping target genes in asthma. PheWAS analysis also highlighted potential side effects of SGLT2 inhibition. This comprehensive study strongly supports a multi-omics association between SGLT2 inhibition and reduced risk of interstitial lung disease, tuberculosis, pneumoconiosis, and asthma. Four identified gut microbiota, four metabolites, sixteen metabolic pathways, and six target genes appear to play a potential role in this association. The results of the comprehensive phenome-wide association analysis also identified the full effect of SGLT2 inhibitors.

Stability of Resistance of Maize to Ear Rots (Fusarium graminearum, F. verticillioides and Aspergillus flavus) and Their Resistance to Toxin Contamination and Conclusions for Variety Registration.

All major ear rots (F. graminearum, F. verticillioides, and Aspergillus flavus) and their toxins are present in maize of preharvest origin in Hungary. Resistance can be an important tool in reducing the infection and toxin contamination from these rots in maize. Previous results identified resistance differences in maize hybrids that were suitable for use in evaluating their risk from toxigenic fungi and their toxins. During the tests, two methodical improvements were achieved: the use of three isolates of the fungus secured and a more precise estimation of resistance to ear rots and their resistance to toxin accumulation or overproduction. The improvement in sampling and the tests of subsamples made the evaluation for the statistics much more exact. This way, we were able to reduce the Within value, providing a statistically more reliable method of evaluation. Earlier data had confirmed that toxin contamination could not be predicted well from visual ear rot severity data. Contradictory results for hybrid ranking were often identified between isolates. The resistance to disease and toxin contamination is not generally valid. The new suggested methodology compares the performance of hybrids in a large number of epidemic situations to identify adaptable hybrids that can respond to diverse conditions; therefore, the stability of resistance and toxin response is decisive information to evaluate risk analyses. The increased number of disease toxin data allowed for lower LSD 5% values for toxins, a much finer analysis of toxin overproduction and underproduction, and a wider database for stability analyses. This way, we obtained important additional separated information about resistance to accumulation of toxins and about maize resistance to these pathogens that is suitable to provide much more reliable testing than was possible until now. Globally, about 50-100 million metric tons can be saved by excluding susceptible hybrids from commercial production.

Association between the visceral leishmaniasis vector Lutzomyia longipalpis and tree families in a Brazilian tropical urban area

BackgroundVisceral leishmaniasis (VL) is a neglected disease endemic to many tropical and subtropical countries. In Brazil, VL is caused by the protozoan parasite Leishmania infantum and is transmitted by the sand fly Lutzomyia longipalpis. The geographical variation in the incidence of the disease in certain urban areas of Brazil suggests a possible association with features of the urban landscape. The objective of this study was to verify the association of urban tree families with the presence of the vector Lu. longipalpis.MethodsThe study area of the municipality of Teresina, capital of the State of Piauí. The sand flies were captured using CDC light traps—one placed close to the houses, on a tree in the backyard, less than 5 m from the house, and another in the living room. The traps remained three consecutive nights, or, at the most, alternating days, working 12 h a night (from 6 p.m. to 6 a.m.), during 2016 and 2017.ResultsTree species were identified in an area of 100 m radius around CDC-type traps for capturing Lu. longipalpis installed in household backyards. Association between tree families and the occurrence of Lu. longipalpis was evaluated using the Fisher exact test and multiple correspondence analysis. Both Anacardiaceae (represented by mango and cashew trees) and Meliaceae (neem) families were more commonly found around sand fly traps capturing fewer Lu. longipalpis. Conversely, Fabaceae (several species of legumes) and Myrtaceae (guava) trees were associated with traps capturing higher number of VL vectors. In multiple correspondence analysis, the presence of trees from the Myrtaceae, Combretaceae (Almond), Fabaceae and Arecaceae (different species of palm trees) families were grouped with traps capturing high number of insects.ConclusionsThe findings suggest that trees from the Fabaceae, Myrtaceae, Combretaceae, and Arecaceae families might potentially attract sand flies, and Anacardiaceae and Meliaceae families may have a repellent effect. Finer analyses to distinguish the specific effects from the different species of the Anacardiaceae (mango and cashew), Arecaceae and Fabaceae families are still needed. The manipulation of urban landscaping might be a useful and clean alternative to help in the control of urban VL.

On the Nodal Set of Solutions to a Class of Nonlocal Parabolic Equations

We investigate the local properties, including the nodal set and the nodal properties of solutions to the following parabolic problem of Muckenhoupt-Neumann type: { ∂ t u ¯ − y − a ∇ ⋅ ( y a ∇ u ¯ ) = 0 a m p ; in B 1 + × ( − 1 , 0 ) − ∂ y a u ¯ = q ( x , t ) u a m p ; on B 1 × { 0 } × ( − 1 , 0 ) , \begin{equation*} \begin {cases} \partial _t \overline {u} - y^{-a} \nabla \cdot (y^a \nabla \overline {u}) = 0 \quad &\text { in } \mathbb {B}_1^+ \times (-1,0) \\ -\partial _y^a \overline {u} = q(x,t)u \quad &\text { on } B_1 \times \{0\} \times (-1,0), \end{cases} \end{equation*} where a ∈ ( − 1 , 1 ) a\in (-1,1) is a fixed parameter, B 1 + ⊂ R N + 1 \mathbb {B}_1^+\subset \mathbb {R}^{N+1} is the upper unit half ball and B 1 B_1 is the unit ball in R N \mathbb {R}^N . Our main motivation comes from its relation with a class of nonlocal parabolic equations involving the fractional power of the heat operator H s u ( x , t ) = 1 | Γ ( − s ) | ∫ − ∞ t ∫ R N [ u ( x , t ) − u ( z , τ ) ] G N ( x − z , t − τ ) ( t − τ ) 1 + s d z d τ . \begin{equation*} H^su(x,t) = \frac {1}{|\Gamma (-s)|} \int _{-\infty }^t \int _{\mathbb {R}^N} \left [u(x,t) - u(z,\tau )\right ] \frac {G_N(x-z,t-\tau )}{(t-\tau )^{1+s}} dzd\tau . \end{equation*} We characterise the possible blow-ups and we examine the structure of the nodal set of solutions vanishing with a finite order. More precisely, we prove that the nodal set has at least parabolic Hausdorff codimension one in R N × R \mathbb {R}^N\times \mathbb {R} , and can be written as the union of a locally smooth part and a singular part, which turns out to possess remarkable stratification properties. Moreover, the asymptotic behaviour of general solutions near their nodal points is classified in terms of a class of explicit polynomials of Hermite and Laguerre type, obtained as eigenfunctions to an Ornstein-Uhlenbeck type operator. Our main results are obtained through a fine blow-up analysis which relies on the monotonicity of an Almgren-Poon type quotient and some new Liouville type results for parabolic equations, combined with more classical results including Federer’s reduction principle and the parabolic Whitney’s extension.

A synthetic vulnerable population dataset for fine scale geographical equity analysis and urban planning

Assessing the social and economic vulnerability of populations within a given area is essential for conducting environmental equity evaluations and devising effective public policies to mitigate disparities. However, prevailing indicators used to measure socio-economic vulnerability exhibit several shortcomings. Primarily relying on factor analysis, these indicators face challenges in terms of comparability over time, lack of standardized scales, and inherent limitations associated with composite indicators. To address these shortcomings, we propose a novel approach that estimates the number of potentially vulnerable individuals by constructing a synthetic population. Our methodology, developed using open tools and datasets, offers a scalable solution applicable to the entire Canadian context. The resulting percentage of potentially vulnerable populations demonstrates strong correlations with traditional vulnerability indicators commonly used in Canada, while overcoming their inherent limitations. The generated dataset holds significant potential and serves as a valuable resource for both researchers and governmental organizations. It provides a robust foundation for conducting equity analyses, assessments, and policy evaluations, thereby facilitating evidence-based decision-making processes aimed at promoting social and economic inclusivity.

Neurofibroma in Unusual Localisation: Rare Case

Neurofibroma is a rare entity, with only few cases reported in the literature so far. Magnetic resonance imaging (MRI) is the key to the diagnosis. We report a 23 year-old women with an antero medial thigh mass diagnosed as neurofibroma on the basis of the imaging findings on US and MRI examinations. The differential diagnosis can be excluded by the fine imaging analysis always associated with the clinical context.