Universidad Nacional de San Agustin de Arequipa

Understanding the reproductive biology of microendemic species is crucial for developing effective conservation strategies since they frequently have small, restricted and threatened populations. Nolana chapiensis (Solanaceae: Nolanoideae) is a desert microendemic species found in southern Peru that was studied in the Arequipa department at an altitude of 2280 m, from March to April 2023–2024. This study documents floral features, breeding system, pollination process and fruiting success. The breeding system was assessed by isolating plants from pollinators (bagging). Pollination processes were observed in the field using photo and video documentation. Flowers exhibited a short lifespan (3–5 days) with opening and closing events correlated with fluctuations in temperature. Nolana chapiensis is pollinator‐dependent and self‐incompatible (unable to set fruit without cross‐pollination mediated by pollinators). All five identified pollinator species are solitary bees, with Andrenidae species accounting for 83.91% of visits. Most pollinators are female bees that pollinate during pollen‐collecting activities. However, Andrenidae males also contribute to pollination while waiting for females inside the floral tube. Natural fruiting success per individual was high, ranging from 35.15% to 74.77%. While high fruiting success might be unexpected in desert environments and in self‐compatible species, in this case, it could be attributed to the diversity and behaviour of pollinator species. This study represents the first detailed study of reproductive biology within the genus, coupling breeding system experiments with detailed pollinator observations.

This study aims to evaluate the behavior of concrete reinforced with treated bamboo fiber (TBF) under sulfate exposure, determining its optimal dosage (0.5–2% by cement weight) to enhance mechanical properties and durability without altering the water/cement ratio. The methodology integrates advanced statistical analyses (ANOVA/Tukey) and a cost–benefit assessment. The fibers were cut to a length of 20 mm with an approximate diameter of 2 mm. Results showed that workability and density decreased as TBF content increased, while air content rose. After 28 days of curing, the optimal dosage of 1.5% TBF significantly improved mechanical properties, with increases of: 20.61% in compressive strength, 9.81% in modulus of elasticity, 34.51% in flexural strength, and 31.20% in tensile strength. However, higher dosages (2% TBF) reduced mechanical performance—though not below control concrete levels. Regarding durability at 56 days, mass loss due to sodium sulfate (Na2SO4) exposure increased by up to 72.71% with 2% TBF, yet all values remained within acceptable limits (< 12%). This suggests that in high-salt or severe weathering environments, excessive TBF may compromise durability. Statistical analysis (ANOVA and Tukey tests, p < 0.05) confirmed significant differences in all properties. The cost–benefit analysis revealed that 1.5% TBF is economically viable, costing S/400.42 Peruvian soles per m3 while delivering a 31.20% tensile strength improvement. These findings demonstrate TBF’s potential as a sustainable reinforcement for structural and non-structural concrete, provided dosages are optimized and environmental conditions are accounted for.

The construction sector plays a key role in climate change due to its high energy consumption and greenhouse gas emissions. Developing environmentally friendly building materials with low environmental impact is essential to improving energy efficiency. Insulation derived from agricultural waste is particularly promising due to its low ecological footprint, responsible resources use, and potential for integration into various construction systems. This study evaluates the potential of rice husk fiber as a thermal insulating material applied through the blowing technique in the Skylark 250 modular system. Rice husk fiber was morphologically and thermally characterized using scanning electron microscopy (SEM), while its thermal behavior was analyzed by thermogravimetric analysis (TGA) alongside a fire behavior assessment. Additionally, energy simulations were conducted to compare the thermal performance of rice husk fiber with other insulating materials when integrated into a building’s thermal envelope. The results showed an average thermal conductivity of 0.040 W/mK, a U-value of 0.17 W/m²K, and a heating demand of 9.56 kWh/m²-year when applied to the modular system. The material also exhibited good fire resistance, with a smoldering velocity of 3.40 mm/min. These findings highlight rice husk fiber’s potential as a sustainable insulation material for modular construction, contributing to energy efficiency and climate change mitigation.

The global production of sugarcane ethanol generates vast amounts of vinasse, a liquid waste by-product requiring treatment to mitigate environmental impacts. Using vinasse as a feedstock for microalgae cultivation offers a sustainable alternative. This study evaluates the performance of the native strain Chlorella sp. MC18 in internal-loop airlift flat-panel photobioreactors (PBR) for treating industrial raw sugarcane vinasse (SCV) while producing biomass. Cultures were grown in diluted, centrifugation-pretreated SCV (5–25% v/v) as the sole nutrient source, with CO2 supplied by aeration. The best results were obtained with 10% SCV. Nutrient removal efficiencies reached up to 99% for nitrates and 90% for phosphates, with reduction in chemical oxygen demand (COD) exceeding 75% at 5–10% SCV. The highest specific growth rate (0.711 day–1) and biomass productivity (116 mg L–1 day–1) occurred at 10% SCV, maintaining stable pH control (8.2–8.5). The PBR design enabled scalable, reproducible growth kinetics while minimising biofouling. Biomass from 10% SCV holds significant potential for energy recovery (20.24 kJ g–1) and production of high-value product pools (lipids, carbohydrates, proteins, and carotenoids). These results demonstrate the feasibility of scaling up the PBR design for integrated vinasse treatment with Chlorella and biomass valorisation, reinforcing the concept of an agro-industrial sector biorefinery.

Task delegation in multi-agent systems (MASs) is crucial for ensuring efficient collaboration among agents with different capabilities and skills. Traditional delegation models rely on social mechanisms such as trust and reputation to evaluate potential partners. While these approaches are effective in selecting competent agents, they often lack transparency, making it difficult for users to understand and trust the decision-making process. To address this limitation, we propose a novel task delegation model that integrates explainability through argumentation-based reasoning. Our approach employs the quantitative argumentation with votes framework (QuAD-V), a voting-based argumentation system that enables agents to justify their partner selection. We evaluate our model in a scenario involving the distribution of petroleum products via pipelines, where agents represent bases capable of temporarily storing a quantity of product. The connections between agents represent transportation routes, allowing the product to be sent from an origin to a destination base. The results demonstrate the effectiveness of our model in optimizing delegation decisions while maintaining clear, understandable explanations for agents’ decisions.

Thestability of a control system is essential for its effective operation. Stability implies that small changes in input, initial conditions, or parameters do not lead to significant fluctuations in output. Various stability properties, such as inner stability, asymptotic stability, and BIBO (Bounded Input, Bounded Output) stability, are well understood for classical linear control systems in Euclidean spaces. This paper aims to thoroughly address the stability problem for a class of linear control systems defined on matrix Lie groups. This approach generalizes classical models corresponding to the latter when the group is Abelian and non-compact. It is important to note that this generalization leads to a very difficult control system, due to the complexity of the state space and the special dynamics resulting from the drift and control vectors. Several mathematical concepts help us understand and characterize stability in the classical case. We first show how to extend these algebraic, topological, and dynamical concepts from Euclidean space to a connected Lie group of matrices. Building on classical results, we identify a pathway that enables us to formulate conjectures about stability in this broader context. This problem is closely linked to the controllability and observability properties of the system. Fortunately, these properties are well established for both classes of linear systems, whether in Euclidean spaces or on Lie groups. We are confident that these conjectures can be proved in future work, initially for the class of nilpotent and solvable groups, and later for semi-simple groups. This will provide valuable insights that will facilitate, through Jouan’s Equivalence Theorem, the analysis of an important class of nonlinear control systems on manifolds beyond Lie groups. We provide an example involving a three-dimensional solvable Lie group of rigid motions in a plane to illustrate these conjectures.

Protected areas are crucial sanctuaries for biodiversity, strictly prohibiting the direct exploitation of natural resources and helping to maintain viable populations and communities. However, even species within these areas face challenges from climate changes. This study compared the present distribution of five woody species (Aspidosperma tomentosum, Kielmeyera coriacea, Peixotoa tomentosa, Qualea multiflora, and Senna velutina) with their projected distribution (in 2080–2100) in 30 protected Brazilian national parks. Our objectives were to evaluate ecological niche models; determine which bioclimatic variables best explain the geographic distribution of species; assess the current distribution of these species; predict changes under distinct future climatic scenarios; and analyze the potential species richness within Brazilian national parks. We overlayed binarized maps of each species and extracted statistical metrics—mean potential, standard deviation, minimum, and maximum potential—using the ‘extract’ function (raster package, v.3.5-2) in the R platform. The results revealed the dynamic nature of species distribution, each one of them being affected by a specific group of factors. All species exhibited changes in their ecological niche or distribution areas in future projections, be it losing areas (A. tomentosum: 26.27–100%; K. coriacea: 38.39–100%; P. tomentosa: 40.46–96.66%; Q. multiflora: 7.34–100%; Senna velutina: 4.52–99.99%) or gaining areas (Q. multiflora: up to 92.21%, and S. velutina: up to 22.07%). We conclude that the potential species richness within Brazilian national parks will be lower in the future. This information is crucial for biodiversity conservation efforts, offering insights into species habitat dynamics and emphasizing the need for adaptive conservation strategies. This study reinforces the urgency of preserving natural ecosystems to ensure a sustainable future for their flora and fauna.

Background To estimate the socioeconomic burden of people with secondary progressive multiple sclerosis (pwSPMS), considering direct health care, direct non-health care, and indirect costs, and to evaluate the relationship between costs and patients’ functional outcomes. Methods Observational, cross-sectional, multicenter study with retrospective real-life clinical practice data collection from pwSPMS visiting the neurology services of 34 hospitals during 2019–2020. Clinical data included Expanded Disability Status Scale scores, number of relapses, magnetic resonance imaging, disease-modifying treatment (DMT), symptoms, and comorbidities from 24 months before the study visit. Resource use and allied costs were collected 12 months before the study visit. Patient-reported outcomes, functional and cognitive scales were also collected. Results 70% of pwSPMS used primary care services, and nearly 50% needed assistance in a daycare or rehabilitation center. Almost 60% of the participants were receiving DMT at the study visit, and 80% needed support for domestic/housekeeping tasks. More than 90% were inactive at work, with nearly 80% taking early retirement. The estimated total annual cost per pwSPMS in Spain was almost €41,500, of which more than 50% (€21,400) were indirect costs, followed by direct health care costs (30%, €11,300), and, finally, direct non-health care costs (about 20%, €8,800). Older patients with severe disabilities and worse functional outcomes incurred higher costs. Conclusions SPMS is a major burden on health care systems, patients, and society as a whole. Health care and societal policies should be aimed at improving the SPMS care pathway and minimizing patients’ funding of direct non-health care costs. Trial registration The trial is a non-interventional study. The NCC code is CBAF312AES01/NOV-EMS-2019–01.

A novel bacterium, designated as strain M3T, was isolated from a hyperalkaline spring in the Philippines and identified as a new species within the genus Lysinibacillus through 16 S rRNA gene sequence and genomic analyses. Although strain M3T shared a high 16 S rRNA gene sequence similarity (> 98.7%) with many Lysinibacillus species, the digital DNA-DNA hybridization and orthologous average nucleotide identity values between strain M3T and its closet relative, Lysinibacillus xylanilyticus DSM 23,493T, were 41.2% and 90.6%, respectively—both below the established threshold for prokaryotic species delineation. Genome mining of the 5.3 Mbp-draft genome of strain M3T revealed eight biosynthetic gene clusters, which shared little sequence similarity with characterized clusters, suggesting the potential for encoding novel specialized metabolites. The cells of strain M3T were Gram-stain-positive, aerobic, rod-shaped, non-motile, and capable of endospore formation. Optimum growth was observed at 30 °C, pH 8.0, and 0.5% (w/v) NaCl. The major respiratory quinone was menaquinone-7, and the predominant polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, and two unknown phospholipids. Its fatty acid profile showed an elevated level of iso-C15:0, and the peptidoglycan type was determined to be A4α (L-Lys–D-Asp). This study contributes to the growing database and understanding of the genus and aims to help drive future research on the bioactive potential of the genus. Lysinibacillus zambalensis sp. nov. is proposed with strain M3T as the type strain (= TISTR 10640T = BIOTECH 10973T).

Andean crops are highlighted for their bioactive compounds with diverse functional properties. These properties can be exploited to produce functional coatings that conserve fresh fruits. This study aimed to evaluate the purple corn flour coating by adding muña essential oil and montmorillonite to the shelf life of strawberries. The components of muña essential oil were characterized. The treatments evaluated were T1-control, without coating, T2 (2.5% w/v), T3 (3% w/v), and T4 (4% w/v) of purple corn flour, 0.2% w/v montmorillonite, and 0.2% v/v muña essential oil. The strawberries were stored at 4 °C ± 1ºC for 12 days. Weight loss, total soluble solids, pH, acidity, color, firmness, and microbial activity were evaluated. The results show that the main compounds of muña essential oil were pulegone (49.4%), iso-menthone (18.5%), and menthone (17.7%). The coated strawberries showed less weight loss than the control, and their acidity decreased slightly. The coating conserved the color and appearance of the strawberries. The concentration of purple corn flour did not significantly influence the color of coated strawberries. T3 and T4 maintain the firmness of strawberries during storage. The mold and yeast count of the coated treatments was 1.24 log CFU g⁻¹ smaller than the control. In conclusion, the antimicrobial activity of the coating reduced the development of molds and yeasts and helped preserve the physicochemical characteristics of strawberries during 12 days of refrigeration.

The infratribe Neosatyriti is a section of the entirely Neotropical subtribe Pronophilina, accounting for 57 species distributed from southern Patagonia to the Andes of northern Peru, and along the Atlantic coast, with the highest diversity in central Chile. They are found in two main types of habitats, i.e. puna, pampas and subantarctic grasslands, and Valdivian forests and Chilean matorral, from sea level to nearly 5000 m above sea level. We propose a phylogenetic hypothesis of the infratribe based on molecular data obtained by target enrichment (TE) of 621 nuclear loci, totalling 248,373 base pairs, from 53 species of this infratribe and 12 outgroups. Our analysis confirms that Neosatyriti is monophyletic with full support. Based on these results, we propose eight new combinations and two status reinstatements. Molecular data are congruent with morphological characters except for Homoeonympha which appears to be paraphyletic, thus almost all the genera described originally by L. Herrera, K. Hayward and W. Heimlich in the Twentieth century based only on morphological characters are confirmed as valid, except for Haywardella that is synonymised with Pampasatyrus. Neosatyriti diverged from other Pronophilina some 23 Ma and split into two major lineages some 20 Ma. Our reconstructions do not indicate a single area of origin, rather a multisource origin, but they suggest the Neosatyriti originated in the lowlands, and that their ancestral plants were non-bambusoid grasses. Major divergence of the infratribe started some 12–11 Ma when it split into the ‘Neomaenas clade’ (9 genera), the ‘Pampasatyrus clade’ (4 genera) and the ‘Neosatyrus clade’ (5 genera). The next main radiation took place some 7–5 Ma with the switch to bamboo host plants and the colonisation of Valdivian forests. The final dispersal of the tribe was associated with the colonisation of Mata Atlantica some 6–5 Ma, and high Andean puna in Peru in the Early Pleistocene. ZooBank: urn:lsid:zoobank.org:pub:29A961D1-99EF-465C-87E7-FB5B3570E3AE

This study aims to synthesize sustainable zeolite catalysts by taking advantage of the great abundance of natural precursors, such as pozzolana, ignimbrite, and pumice, found in the southern zone of Peru. Different methodologies were selected. On the one hand, an alkaline fusion/hydrothermal reaction with NaOH processes was utilized and, on the other hand, the hydrothermal method was employed. The characteristics of these catalysts and their application in the catalytic pyrolysis of polypropylene were evaluated. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were employed to investigate the structure and properties of the obtained catalysts. Catalytic pyrolysis experiments of polypropylene were carried out at 450 °C for 30 min with a 6% w/w zeolite catalyst. It was possible to synthesize zeolites similar to commercial zeolites such as ZSM-5 and zeolite X, with a BET surface area of up to 451.3 m²/g⁻¹, offering the possibility of obtaining commercial products from natural materials. According to the results obtained in the pyrolytic process, method 1 (alkaline fusion/hydrothermal reaction with NaOH) presents the best results, with 94% in liquid and gaseous products. The zeolite synthesized with the pozzolan precursor was the most successful, followed by pumice.

This study presents a sustainable and scalable biosynthesis method for zinc oxide (ZnO) nanoparticles using Bacillus subtilis, focusing on their application in photocatalytic cyanide degradation in aqueous solutions. The bacterial strain was molecularly identified through 16S rRNA gene sequencing and phylogenetic analysis. The optimized biosynthesis process yielded crystalline ZnO nanoparticles in the zincite phase with an average size of 21.87 ± 5.84 nm and a specific surface area of 27.02 ± 0.13 m²/g. Comprehensive characterization confirmed the formation of high-purity hexagonal ZnO (space group P63mc) with a bandgap of 3.20 eV. Photocatalytic tests under UV irradiation demonstrated efficient concentration-dependent cyanide degradation, achieving 75.5% removal at 100 ppm and 65.8% at 500 ppm within 180 min using 1.0 g/L ZnO loading. The degradation kinetics followed a pseudo-first-order model with rate constants ranging from 6.64 × 10⁻³ to 3.98 × 10⁻³ min⁻¹. The enhanced photocatalytic performance is attributed to the optimal crystallite size, high surface area, and surface defects identified through a microscopic analysis. These results establish biosynthesized ZnO nanoparticles as promising eco-friendly photocatalysts for industrial wastewater treatment.

Photoacoustic (PA) imaging, by integrating optical and ultrasound (US) modalities, combines high spatial resolution with deep tissue penetration, making it a transformative tool in biomedical research. This review presents a comprehensive analysis of the current status of dual PA/US imaging technologies, emphasising their applications in preclinical research. It details advancements in light excitation strategies, including tomographic and microscopic modalities, innovations in pulsed laser and alternative light sources, and US instrumentation. The review further explores preclinical methodologies, encompassing dedicated instrumentation, signal processing, and data analysis techniques essential for PA/US systems. Key applications discussed include the visualisation of blood vessels, micro-circulation, and tissue perfusion; diagnosis and monitoring of inflammation; evaluation of infections, atherosclerosis, burn injuries, healing, and scar formation; assessment of liver and renal diseases; monitoring of epilepsy and neurodegenerative conditions; studies on brain disorders and preeclampsia; cell therapy monitoring; and tumour detection, staging, and recurrence monitoring. Challenges related to imaging depth, resolution, cost, and the translation of contrast agents to clinical practice are analysed, alongside advancements in high-speed acquisition, artificial intelligence-driven reconstruction, and innovative light-delivery methods. While clinical translation remains complex, this review underscores the crucial role of preclinical studies in unravelling fundamental biomedical questions and assessing novel imaging strategies. Ultimately, this review delves into the future trends of dual PA/US imaging, highlighting its potential to bridge preclinical discoveries with clinical applications and drive advances in diagnostics, therapeutic monitoring, and personalised medicine.

Severe air pollution plagues Arequipa, Peru, due to anthropogenic and natural emissions. Persistent volcano emission in the vicinity of Arequipa makes it among the largest SO2 sources in the world. Because volcano plumes mostly exist in the free troposphere and stratosphere where horizontal transport acts rather quickly, previous studies mostly focused on their global‐scale impacts. Whether these plumes can affect near‐surface air quality has not attracted much research attention. This study uses WRF‐Chem simulations to reveal that in the presence of northerly/northwesterly winds and favorable mountain meteorology, the plume from volcano Sabancaya (elevation 5,960 m, ∼80 km north of Arequipa) can be brought down to near the surface of Arequipa through two steps of transport and dispersion processes: (a) With northerly/northwesterly winds, the free troposphere plume from Sabancaya is transported southward and intercepted by Mountain Chachani located between Sabancaya and Arequipa and subsequently transported downward to Arequipa by nighttime downslope winds linked to large‐amplitude lee‐side mountain gravity waves. Often the plume reaches down to be close to the boundary layer over Arequipa. (b) In the following day, convective boundary layer growth brings the above boundary‐layer plume to near the surface through vertical mixing processes, thus exacerbating ambient air pollution in Arequipa. A mechanism on how volcano plumes above 6‐km height cause air pollution over the lower‐lying Arequipa city is therefore revealed for the first time. The mountain dynamic effect in inducing the large‐amplitude mountain lee waves is further illustrated by an idealized simulation excluding mountain's thermal effect.

Quinoa (Chenopodium quinoa) is recognized for its tolerance to abiotic stress, including salinity, and its recent genome sequencing has facilitated the study of the mechanisms underlying this adaptation. This study focused on characterizing the ZAT genes of the C2H2 subfamily in quinoa, evaluating their expression under saline stress. Eight ZAT genes were identified and analyzed in silico using genomic databases and bioinformatics tools, assessing their conserved domains, cis-regulatory motifs, and physicochemical characteristics. Additionally, germination assays, hydroponic cultivation, and gene expression analyses via qPCR were performed on halotolerant (UNSA_VP033) and halosensitive (UNSA_VP021) accessions exposed to different NaCl concentrations. The genes CqZAT4 and CqZAT6 showed high expression in the halotolerant accession under saline stress, correlating with increased dry matter, root length, and water retention. In contrast, the halosensitive accession exhibited lower tolerance, with significant reductions in these metrics. Promoter analysis revealed cis-elements associated with hormonal and stress responses. ZAT genes play a key role in quinoa’s response to saline stress, with CqZAT4 and CqZAT6 standing out in the halotolerant accession. These findings could drive the development of more resilient varieties, contributing to agricultural sustainability in saline soils.