Navigating Complex Environments with Finite-State Controllers

Organisms relying on chemical cues for navigation face significant challenges due to complexity in the environment. For instance, atmospheric turbulence dilutes and mixes odor signals with other scents and clean air, providing only weak, intermittent cues for insects like moths to navigate. Despite these challenges, many species develop effective strategies to locate distant targets in complex environments. This raises a key question: how are the sporadic chemical signals utilized to implement efficient source-localization strategies? The searcher’s memory of previously detected signals plays a vital role in this process. Current algorithms typically require continuous memory spaces with high dimensionality, which may impede optimization and complicate interpretation. In this research, we demonstrate through a computational modeling of the source localization problem that finite-state controllers, simple algorithmic devices with minimal memory requirements, are rich enough to explain various behavioral patterns observed in nature, first in the context of olfactory search. The controller’s memory states emerged to encode dual information streams: temporal data functioning as a clock, and spatial data serving as a map. In the microscale level, we developed a finite-state controller for E. coli chemotaxis that achieves precise adaptation and exhibits positive responses to increasing stimuli. Lastly, we extend the olfactory search problem to analyze sourcetracking in an alternative context: a porous medium characterized by chaotic flow patterns, where agents must simultaneously learn to circumvent obstacles while localizing a chemical signal source. Our findings demonstrate that finite-state controllers are simple yet powerful tools for understanding behavioral patterns in diverse navigation scenarios

Skin biocompatibility of hexagonal boron nitride: An in vitro study on HaCaT keratinocytes and 3D reconstructed human epidermis

Hexagonal boron nitride (hBN) is a promising two-dimensional (2D) material of interest to the scientific community and industry due to its revolutionary physico-chemical features. Skin contact is one of the most feasible exposure routes both for workers, producing hBN, and consumers, using hBN-enabled nanotechnologies. Hence, the toxic potential of hBN at the cutaneous level was evaluated following an in vitro approach with different degree of complexity, using a simplified cell model (HaCaT keratinocytes), and a more predictive and complete skin tissue (a 3D model of human epidermis). Despite its significant uptake by keratinocytes, hBN exerted only weak adverse effects, such as slight alterations of cells parameters indices of cytotoxicity (cell viability, cell mass and plasma membrane integrity) and mitochondrial-related dysfunctions (mitochondrial depolarization, ATP depletion and reactive oxygen species production), detectable only at high concentrations (>25 μg/mL) and mainly after a long exposure (72 h). In addition, adoption of the OECD TG 431 and 439 on the 3D reconstructed human epidermis model demonstrated hBN as a non-corrosive and non-irritant material, with an extremely low pro-inflammatory potential. These results denote a good biocompatibility of hBN at the skin level

Coffee in Health and Disease Prevention - 23. Diterpenes in coffee

Lipids represent one of the most abundant classes of compounds found in green and roasted coffee beans. The biological role of diterpenes is not fully clarified, but they are probably involved in the plant defense (defense compounds) and in the plant interaction with other organisms. During the roasting process, diterpenes in green coffee, especially cafestol and kahweol, turn into degradation products, while in storage conditions, there is an increase of free diterpenes due to the activity of endogenous lipase. Diterpene content depends on several parameters and their amounts are usually expressed in a range varying from a minimum to a maximum. In literature we found quantification on green coffee, roasted coffee, and beverages. Diterpenes are a powerful tool to discriminate coffee species and varieties both from a chemical and taxonomic point of view. In recent years, new diterpenes have been identified both in Arabica and Robusta coffee (green and roasted). Diterpenes have several physiological effects on human health, thereby it is important to quantify them in coffee beverages

Prognostic impact of juxtarenal inner vessel diameter and vertical distance in renal artery outcomes after fenestrated endovascular repair

Objective: The aim of this retrospective multicenter study is to evaluate the impact of juxtarenal inner vessel diameter (JR-IVD) and vertical distance between renal arteries (RA-VerDi) on RA instability (RAI) and associated complications in patients undergoing fenestrated endovascular aortic repair for complex aortic pathology. Methods: Patients undergoing fenestrated endovascular aortic repair with custom-made stent grafts at six referral hospitals between 2017 and 2023 were included. Data on patient demographics, anatomical characteristics, stent configurations, and outcomes were collected. Patients were divided into tertiles and categorized into three groups: JR-IVD 24 mm. RA-VerDi was determined by measuring the distance between the center of the lowest RA and the highest RA, based on the planning specifications for each custom-made graft. The primary outcome was freedom from RAI, with secondary outcomes including RA stenosis/occlusion, endoleak, and reintervention. Statistical analyses were performed using MedCalc software, with logistic regression and Kaplan-Meier survival curves used to assess outcomes. Results: In total, 520 RAs among 260 patients were analyzed. The technical success rate was 98.7%, with a 30-day mortality rate of 2.3%. After a mean follow-up of 26.9 ± 28.1 months (range, 1-154 months), RAI was observed in 5.6% of cases, including stenosis/occlusion (3.2%) and endoleak (2.2%). Freedom from RAI at 12, 24, and 48 months was 95.8% (standard error [SE], 0.01), 93.5% (SE, 0.01), and 90.7% (SE, 0.01), respectively. JR-IVD of <20 mm was identified as a significant risk factor for RA stenosis/occlusion (P = .01), although it did not increase the risk of RAI or reintervention compared with larger JR-IVDs. A correlation was found between RA-VerDi and RAI, with smaller vertical distances associated with higher RAI risk (odds ratio, 0.89; 95% confidence interval, 0.82-0.99; P = .05), but no significant cutoff was determined. Severe RA stenosis was an independent predictor of RAI (odds ratio, 13.28; 95% confidence interval, 3.1-55.86; P = .004). Conclusions: The use of fenestrated custom-made grafts in patients with a JR-IVD of <20 mm may increase the risk of RA complications, particularly stenosis/occlusion. Although a correlation between RA-VerDi and RAI was observed, a definitive predictive cutoff could not be established. Attention should be given to patients with severe RA stenosis, because this condition seems to be an independent predictor of RAI

Experimental and numerical investigation of in-plane cyclic response of a point-fixed glass façade system for seismic performance assessment

This study investigates the seismic performance of point-fixed glass façade systems (PFGFS) through a full-scale experimental campaign conducted at the University of Coimbra. Two façade systems were tested, accounting for two fixing configurations: fully drilled countersunk bolts and partially through (embedded) bolts. Each system consisted of nine glass panels arranged in a 3 × 3 configuration, with individual panel dimensions of 1490 mm × 1490 mm. The façade systems were subjected to quasi-static cyclic loading to assess their in-plane drift response and post-fracture behaviour. Results indicate that failure initiated in the middle row, yet the façade system remained functional, sustaining additional loading cycles without complete failure. Maximum lateral drift ratios were 2.12 % for partially through bolts and 2.28 % for fully drilled bolts. Deformations were accommodated through rigid body motion, bolt rotation, and sealant relaxation, with washer yielding acting as a sacrificial mechanism to absorb deformation. The lamination foil played a crucial role in retaining shattered glass, ensuring post-failure integrity, and preventing the release of hazardous debris. A finite element model (FEM), validated against experimental results, successfully captured the façade's force-displacement response, confirming progressive failure behaviour. These findings highlight the ductility of point-fixed glass façade systems and demonstrate their capacity to sustain lateral displacement while maintaining structural stability. The results provide valuable insights into the deformation capacity of glass façades, enhancing the understanding of their safety and resilience in seismic regions

Decoding Late Quaternary faulting through marine terraces and MIS 5.5 tilted tidal notches: Insights from central Mediterranean Sea (NW Sicily, Italy)

This study investigates the recent tectonic evolution of coastal landscapes, focusing on integrating fossil tidal notches and fossil marine terraces as tools for coastal tectonic studies in the Capo Rama promontory (central Mediterranean, southern Italy, NW Sicily). These geomorphological features are crucial for understanding the tectonic forcings that shape coastal landscapes (e.g. active faulting or regional uplift), especially in the context of the high resolution topographic and morphometric data available today. This research addresses a significant gap in the current understanding of the combined use of these markers to study the evolution of the coastal landscape and its tectonic drivers. The aim is to elucidate the interplay between coastal geomorphology and tectonics in areas with elusive tectonic activity (i.e., regions deforming at a rate lesser than 1 mm/yr), hosting previously undetected seismogenic sources and, for that reason, assumed as having low seismic hazard. Employing a multidisciplinary approach, the study integrates surveys conducted along the emerged and submerged coastline with analytic/statistical morphometric analyses and fault modelling. This methodology offers a comprehensive view of the elevation and distribution of MIS 5.5 littoral deposits and coastal geomorphological markers such as marine terrace inner edges and tidal notches. Key findings reveal substantial elevation differences in these markers, varying between +34 and +1.9 m above sea level along a north-south transect, highlighting an active seaward tilting in the study area. Such tilting is related to the Quaternary deformation of a previously unknown buried fault crossing the study area. Achieved outcomes allowed exploring the integration of tidal notches and marine terraces’ inner edges as geomorphological markers for coastal tectonic analyses. Moreover, this study lays foundations for future research, enabling a more detailed understanding of the hypothesized buried fault, and its contributions to the understanding of the active faulting processes in the southern Tyrrhenian region

Molecular clustering on ctDNA improves the prognostic stratification of patients with DLBCL compared with ctDNA levels

Circulating tumor DNA (ctDNA) levels can help predict outcomes in diffuse large B-cell lymphoma (DLBCL), but its integration with DLBCL molecular clusters remains unexplored. Using the LymphGen tool in 77 DLBCL cases with both ctDNA and tissue biopsy, a 95.8% concordance rate in molecular cluster assignment was observed, showing the reproducibility of molecular clustering on ctDNA. A multicenter, prospective cohort of 166 patients with newly diagnosed DLBCL was analyzed for ctDNA levels and molecular clusters using cancer personalized profiling by deep sequencing. Patients with ctDNA levels of <2.5 log10 haploid genome equivalents (hGE)/mL had a 4-year progression-free survival (PFS) and overall survival (OS) of 71.7% and 85.7%, respectively, compared with 50.3% and 61.0% for those with higher ctDNA levels (P = .0018 and P = .0017). Recursive partitioning showed that patients with ctDNA levels of ≥2.5 log10 hGE/mL were further stratified by clusters ST2/BN2. In this group, ST2/BN2 patients associated with a favorable outcome with a 4-year PFS and OS of 87.5% and 100%, respectively, compared to 38.0% and 47.1% for other clusters (P = .003 and P = .001). Combining ctDNA levels and ST2/BN2 clusters improved outcome prediction. Low-risk patients (n = 51), characterized by ctDNA levels of <2.5 log10 hGE/mL and/or BN2/ST2 cluster, had a 4-year PFS and OS of 75.3% and 87.8%, respectively. High-risk patients (n = 115), with ctDNA levels of ≥2.5 log10 hGE/mL and no BN2/ST2 cluster, had a 4-year PFS and OS of 38.0% and 47.1%, respectively. Adding cluster assignment to ctDNA levels improved the model’s C statistics (0.63 vs 0.59 for PFS; 0.68 vs 0.63 for OS). Liquid biopsy thus provides a multilayered approach for outcome prediction in DLBCL

On the Tracks to “Smart” Single-Atom Catalysts

Despite their enormous impact in modern heterogeneous catalysis, single-atom catalysts (SACs) continue to puzzle the catalysis community, which often struggles to draw correct conclusions in SAC-catalyzed experiments. In many cases, the reasons for such an uncertainty originate from the lack of knowledge of the exact single-atom evolution under operative conditions and the fundamental factors controlling the fate of the single atom in relation to the catalytic mechanism. This has led to confusion also about correct definition and terminology, where the coined term single-site catalysts reflects the difficulty in defining the true active species as well as in obtaining long-range ordered homogeneous supports [Chi, S.; et al. J. Catal. 2023, 419, 49-57. DOI: 10.1016/j.jcat.2023.02.003]. Most recent studies have attempted to clarify several of the key aspects that are in play during SAC catalysis. However, one largely overlooked opportunity is to take advantage of all the dynamic phenomena occurring at the single metal site to turn the conventional catalytic sequences into a smart, stimulus-responsive, and controllable evolution of the single atom under operative conditions. Such “smartness” could potentially unleash pathways that mitigate some of the typical drawbacks of SACs, such as selectivity and stability. Here we present our vision on these yet-unexplored opportunities for exploiting the dynamicity of SACs, and we discuss various examples that could be the cornerstones for the advent of a next generation of SACs, that we term here “smart” single-atom catalysts (SSACs). Despite smart-behaving SACs still being far from realization, the clues provided here suggest pathways to achieve this goal

Follow-up of non-palpable testicular incidentalomas under 1 cm: does growth rate differentiate malignant and non-malignant lesions?

Objective: To determine whether small, incidentally detected testicular lesions can be safely followed up, by assessing growth rate and volume threshold for benign vs. malignant lesions. Methods: This retrospective observational study includes a consecutive series of 130 testicular incidentalomas 10 × 10-3 mm/day, and > 5 × 10-3 mm/day for SGR, DT, ∆Dmax, ∆Dav, respectively. Conclusions: Malignant and non-malignant small incidentalomas can be effectively differentiated based on growing parameters, even though overlap exists. An increase of the maximum diameter of about 1 mm and 2 mm in three months and in six months, respectively, suggests malignancy. Clinical relevance statement: Growing parameters allow an educated assessment of benign and malignant small testicular incidentalomas. Non-aggressive management is justified and safe when follow-up includes self-examination and tumour marker assessment to reduce the risk of interval tumour growth. Key points: Small, non-palpable and asymptomatic testicular nodules < 1 cm are unexpectedly discovered during scrotal ultrasound. Growth indicators estimate the potential malignancy, even though overlap with non-malignant lesions exists. Non-growing incidentalomas can be safely followed up

Thermally Cured Gelatin-Methacryloyl Hydrogels Form Mechanically Modulating Platforms for Cell Studies

Gelatin methacryloyl (GelMA) is a polypeptide derived from the methacryloylation of gelatin and retains the thermoresponsive behavior of gelatin. When cooled, GelMA undergoes a sol–gel transition. By photo-cross-linking GelMA in a heated (“Hot”) or cooled (“Cold”) state, it results in a set of hydrogels with distinct properties. To date, the mechanical properties of these resulting hydrogels have not been fully elucidated. Here, we show that “Cold” hydrogels are viscoelastic, while “Hot” hydrogels are almost completely elastic. These features have remarkable implications for cell–substrate interactions in vitro: here, we show that fibroblasts, when cultured on these different substrates, adhere preferentially to Cold hydrogels. These results suggest that efficient cell adhesion requires specific mechanical properties of the substrate. This novel platform enables the precise control of different mechanical properties of GelMA by simply adjusting the cross-linking temperature, providing a flexible approach for the design of biologically inspired microenvironments in vitro